Proposed Rules Title 30

TITLE 30. ENVIRONMENTAL QUALITY

Part 1. TEXAS COMMISSION ON ENVIRONMENTAL QUALITY

Chapter 50. ACTION ON APPLICATIONS AND OTHER AUTHORIZATIONS

Subchapter F. ACTION BY THE COMMISSION

30 TAC §50.113

The Texas Commission on Environmental Quality (commission) proposes to amend §50.113.

BACKGROUND AND SUMMARY OF THE FACTUAL BASIS FOR THE PROPOSED RULE

This rulemaking implements House Bill (HB) 2654, 80th Legislature, 2007. HB 2654 amended Texas Water Code (TWC), §27.021 and added new TWC, §27.023 to allow the commission to issue a general permit authorizing the use of a Class I injection well to inject nonhazardous brine from desalination operations or nonhazardous drinking water treatment residuals. These legislative changes are intended to promote desalination technology and address the need for public water supply systems to dispose of drinking water treatment residuals. To implement HB 2654, this rulemaking amends §50.113(d).

The amended rule adds two new types of applications and actions to a listing of applications that the commission may act on without holding a contested case hearing. This listing is in §50.113(d). There are two paragraphs under §50.113(d) that are affected by the proposed amendment.

First, the proposed amendment to §50.113(d)(5) will update the list of applications that are not subject to a contested case hearing by adding an application for a Class I injection well used only for the disposal of nonhazardous drinking water treatment residuals. This exception is in addition to the exception for applications for disposal of desalination brine which was added by a previous rulemaking in the September 10, 2004, issue of the Texas Register (29 TexReg 8814). Amendment of §50.113(d)(5) also includes updates to reflect use of the term "nonhazardous brine from a desalination operation" instead of "desalination brine," and inserts the word "injection" into the phrase "Class I injection wells," to achieve consistency with the title of TWC, §27.021 as amended by HB 2654.

Second, a new paragraph has been inserted as §50.113(d)(6) with renumbering of subsequent paragraphs. The new paragraph implements part of TWC, §27.023 in HB 2654 that allows the commission to issue a general permit authorizing a Class I injection well to inject nonhazardous brine from desalination operations or nonhazardous drinking water treatment residuals, without providing the opportunity for a contested case hearing, as long as all requirements for a Class I injection well permit are met. Public notice of, and the opportunity to comment on, a permit application will not be affected by this rulemaking. Removing the opportunity for a contested case hearing may expedite the approval of Class I injection well permits for the disposal of nonhazardous desalination brine and nonhazardous drinking water treatment residuals. The commission's ability to hold a discretionary hearing under the provisions of TWC, §5.102(b) was not amended by HB 2654.

Changes to 30 TAC Chapters 55, 305 and 331 are also proposed in this issue of the Texas Register to implement HB 2654 and to incorporate other changes to facilitate disposal of nonhazardous desalination brine and nonhazardous drinking water treatment residuals.

SECTION DISCUSSION

§50.113. Applicability and Action on Application.

The proposal would amend §50.113(d)(5) by adding a permit application for a Class I injection well used only for the disposal of nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals to the list of applications upon which the commission may act without holding a contested case hearing. The proposal would add §50.113(d)(6) to include the issuance, amendment, renewal, suspension, revocation or cancellation of a general permit, or the authorization for the use of an injection well under a general permit in the list of items upon which the commission may act without holding a contested case hearing. Section 50.113(d)(6) - (8) will be renumbered as (d)(7) - (9), respectively.

FISCAL NOTE: COSTS TO STATE AND LOCAL GOVERNMENT

Nina Chamness, Analyst, Strategic Planning and Assessment, has determined that, for the first five-year period the proposed amendment is in effect, no significant fiscal implications are anticipated for the agency or other units of state or local governments as a result of administration or enforcement of the proposed rule. The agency will utilize existing resources to develop rules and guidelines for a general permit to authorize the use of Class I injection wells for disposal of nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals.

HB 2654, 80th Legislature, Regular Session allows the commission to issue a general permit to authorize the use of a Class I injection well for disposal of nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals and allows the Railroad Commission of Texas to authorize the use of these wastes as appropriate injection fluids for enhanced recovery purposes without the necessity of obtaining a permit from the commission. HB 2654 requires agency rules governing the issuance of the general permit including the requirement for the submission of a notice of intent by the prospective permittee. In addition, HB 2654 specifies that the general permit is not subject to the requirements of a contested case hearing. The proposed rulemaking is part of the agency's effort to establish a general permit program authorizing the use of Class I injection wells as specified by the legislation. In addition to this rulemaking, amendments are also proposed for appropriate sections of Chapters 55, 305, and 331. This fiscal note addresses only the fiscal implication of proposed changes to Chapter 50. The fiscal implications for needed amendments to other chapters are addressed in separate fiscal notes.

The proposed rule would comply with the contested case hearing requirements of HB 2654. These administrative changes allow the agency to authorize disposal of nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals under a general permit without holding a contested case hearing if all permit requirements are met.

Local governments and state agencies that are suppliers of public drinking water are not expected to experience significant fiscal implications because of the proposed rule. Governmental entities supplying public drinking water are expected to choose the most economical method of disposal of nonhazardous desalination and drinking water residual wastes, and disposal of these wastes in these injection wells is one option among various options available to suppliers of public drinking water regarding waste disposal.

If a local government or state agency chooses to own or operate a Class I injection well qualifying for authorization under the proposed general permit, the proposed rule could streamline the process for the governmental entity by deleting the requirement for contested case hearings, public notice, and public meetings. Savings generated by not holding contested case hearings could be as much as $500,000 although a contested case hearing would likely cost less. Not being required to publish public notices required by individual permits could save as much as $1,000 to $3,000 depending on the circulation size of the newspapers used. Savings generated by not being required to hold a public meeting, if an application had generated sufficient public interest for the agency to require one for an individual permit, could range from $1,700 to $4,700 depending on the cost of notices and the price for renting a meeting place.

PUBLIC BENEFITS AND COSTS

Nina Chamness also determined that for each year of the first five years the proposed amendment is in effect, the public benefit anticipated from the changes seen in the proposed rule will be to allow desalination projects to come on line in a shorter time frame thus providing an increased supply of public drinking water while continuing to safeguard public health and the environment.

Individuals and business entities that are suppliers of public drinking water are not expected to experience significant fiscal implications because of the proposed rule. Suppliers of public drinking water are expected to choose the most economic method of disposal of nonhazardous desalination concentrate and drinking water treatment residuals, and disposal of these wastes in these injection wells is one option among various options available to suppliers of public drinking water regarding waste disposal.

Large businesses that own or operate these types of injection wells could possibly save both time and money since the proposed rule does not subject them to contested case hearings, requirements of public notice, and requirements for public meetings that would be required under an individual permit. Savings generated by not holding contested case hearings could be as much as $500,000 although a contested case hearing would likely cost less. Public notices required for individual permits could cost as much as $1,000 to $3,000 depending on the circulation size of the newspapers used. If applying for authorization under a general permit, applicants could be expected to save this expense. Applicants for authorization under this general permit could also save on the public meeting costs incurred for individual notices if an application would have had a public meeting under the requirements for an individual permit. These costs could range from $1,700 to $4,700 depending on the number of notices of public meeting that would have been required and the price of rentals for meeting places in the area.

Oil and gas businesses that might utilize enhanced recovery methods by injecting nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals are expected to experience the same cost savings regarding contested case hearings, public notice and public meetings as those experienced by suppliers of public drinking water.

SMALL BUSINESS AND MICRO-BUSINESS ASSESSMENT

No adverse fiscal implications are anticipated for small or micro-businesses as a result of the proposed rule. Staff knows of no small or micro-businesses that are owners of Class I wells. The proposed rule establishes that wells authorized under the general permit for Class I injection wells disposing of nonhazardous desalination and drinking water treatment residual wastes are not subject to the requirements of a contested case hearing, requirements of public notice, and requirements of public meetings as are those required by individual permits. If a small or micro-business decides to request authorization under a general permit to own or operate a Class I injection well for nonhazardous desalination concentrate or drinking water treatment residual waste disposal, it should experience the same cost savings associated with contested case hearings, public notices, and public meetings as those experienced by large businesses.

SMALL BUSINESS REGULATORY FLEXIBILITY ANALYSIS

The commission has reviewed this proposed rulemaking and determined that a small business regulatory flexibility analysis is not required because the proposed rule is needed to comply with state law and does not adversely affect a small or micro-business in a material way for the first five years that the proposed rule is in effect.

LOCAL EMPLOYMENT IMPACT STATEMENT

The commission has reviewed this proposed rulemaking and determined that a local employment impact statement is not required because the proposed rule does not adversely affect a local economy in a material way for the first five years that the proposed rule is in effect.

DRAFT REGULATORY IMPACT ANALYSIS DETERMINATION

The commission reviewed the proposed rulemaking in light of the regulatory analysis requirements of Texas Government Code, §2001.0225, and determined that the rulemaking does not meet the definition of a "major environmental rule" as defined by that statute. A "major environmental rule" means a rule the specific intent of which is to protect the environment or reduce risks to human health from environmental exposure and that may adversely affect in a material way the economy, a sector of the economy, productivity, competition, jobs, the environment, or the public health and safety of the state or a sector of the state. This rulemaking does not meet the statutory definition of a "major environmental rule" because it is not intended to reduce risks to human health from environmental exposure, nor does it adversely affect in a material way the economy, a sector of the economy, productivity, competition, jobs, the environment, or the public health and safety of the state or a sector of the state.

The intent of the proposed rulemaking is to implement HB 2654, passed during the 80th Legislature, 2007, and to revise criteria for authorizing Class I nonhazardous wells injecting desalination concentrate and other water treatment residuals from public water systems so that the state's rules are no more stringent than federal Class I nonhazardous injection well regulations. The specific intent of the proposed amendment to Chapter 50 is to address the authority of the commission to take actions regarding the proposed general permit and authorizations under the proposed general permit. The rule substantially advances this purpose by adding notices of intent submitted under §331.203 to the applicability of Chapter 50, Subchapter F. Further, applications for a Class I injection well permit used only for the disposal of drinking water treatment residuals and the issuance, amendment, renewal, suspension, revocation or cancellation of a general permit or authorization under a general permit for a Class I injection well used only for the disposal of nonhazardous brine from desalination operations or drinking water treatment residuals are added to the list of items upon which the commission may act without holding a contested case hearing.

This rulemaking does not meet the statutory definition of a "major environmental rule" because the proposed amendment would not adversely affect in a material way the economy, a sector of the economy, productivity, competition, jobs, the environment, or public health and safety of the state or a sector of the state. It is not anticipated that the cost of complying with the proposed amendment will be significant with respect to the economy; therefore, the proposed amendment will not adversely affect in a material way the economy, a sector of the economy, competition, or jobs.

Additionally, this rulemaking does not meet any of the four applicability requirements listed in Texas Government Code, §2001.0225(a). Texas Government Code, §2001.0225 only applies to a major environmental rule, the result of which is to: 1) exceed a standard set by federal law, unless the rule is specifically required by state law; 2) exceed an express requirement of state law, unless the rule is specifically required by federal law; 3) exceed a requirement of a delegation agreement or contract between the state and an agency or representative of the federal government to implement a state and federal program; or 4) adopt a rule solely under the general powers of the agency instead of under a specific state law. This rulemaking does not meet any of these four applicability requirements because this rulemaking does not exceed any standard set by federal law but rather amends the rules so that they are no more stringent or restrictive than the federal regulations. The proposed rule does not exceed the requirements of state law under the TWC, Chapter 27. Further, the proposed rule does not exceed a requirement of a delegation agreement or contract between the state and an agency or representative of the federal government to implement any state and federal program. Finally, the rule is not proposed solely under the general powers of the agency, but rather specifically under TWC, §27.023(m), which allows the commission to adopt rules to implement the general permit authorizing use of a Class I injection well to inject nonhazardous brine from desalination operations or nonhazardous drinking water treatment residuals and TWC, §27.109, which authorizes the commission to adopt rules to implement TWC, Chapter 27 (regarding Injection Wells), as well as the other general powers of the agency.

The commission invites public comment regarding this draft regulatory impact analysis determination. Written comments on the draft regulatory impact analysis determination may be submitted to the contact person at the address listed under the SUBMITTAL OF COMMENTS section of this preamble.

TAKING IMPACT ASSESSMENT

The commission evaluated the proposed amendment to Chapter 50 and performed a preliminary assessment of whether the proposed amendment would constitute a taking under Texas Government Code, Chapter 2007. The primary purpose of the proposed amendment is to implement HB 2654, authorizing use of a general permit for Class I injection wells injecting only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals. The proposed amendment would substantially advance this purpose by amending §50.113 to add to the list of actions upon which the commission may act without first holding a contested case hearing applications for a Class I injection well permit used only for the disposal of drinking water treatment residuals and the issuance, amendment, renewal, suspension, revocation or cancellation of a general permit or authorization under a general permit for a Class I injection well permit used only for the disposal of nonhazardous brine from desalination operations or drinking water treatment residuals.

Promulgation and enforcement of the proposed amendment would constitute neither a statutory nor a constitutional taking of private real property. There are no burdens imposed on private real property under this rule because the proposed amendments neither relate to, nor have any impact on the use or enjoyment of private real property, and there would be no reduction in property value as a result of this rule. Therefore, the proposed rule would not constitute a taking under Texas Government Code, Chapter 2007.

The commission has no reasonable alternative that could accomplish the specific purpose of addressing the commission's authority to act other than by amending Chapter 50.

CONSISTENCY WITH THE COASTAL MANAGEMENT PROGRAM

The commission reviewed the proposed rule and found that it is are neither identified in Coastal Coordination Act Implementation Rules, 31 TAC §505.11(b)(2) or (4), nor will it affect any action/authorization identified in Coastal Coordination Act Implementation Rules, 31 TAC §505.11(a)(6). Therefore, the proposed rule is not subject to the Texas Coastal Management Program.

ANNOUNCEMENT OF HEARING

The commission will hold a public hearing on this proposal in Austin on April 8, 2008 at 10:00 a.m. in Building E Room 201S, at the commission's central office located at 12100 Park 35 Circle. The hearing is structured for the receipt of oral or written comments by interested persons. Individuals may present oral statements when called upon in order of registration. Open discussion will not be permitted during the hearing; however, commission staff members will be available to discuss the proposal 30 minutes prior to the hearing.

Persons who have special communication or other accommodation needs who are planning to attend the hearing should contact Ms. Kristin Smith, Office of Legal Services at (512) 239-0177. Requests should be made as far in advance as possible.

SUBMITTAL OF COMMENTS

Written comments may be submitted to Ms. Kristin Smith, MC 205, Office of Legal Services, Texas Commission on Environmental Quality, P.O. Box 13087, Austin, Texas 78711-3087, or faxed to (512) 239-4808. Electronic comments may be submitted at: http://www5.tceq.state.tx.us/rules/ecomments/ . File size restrictions may apply to comments being submitted via the eComments system. All comments should reference Rule Project Number 2007-030-331-PR. The comment period closes April 14, 2008. Copies of the proposed rulemaking can be obtained from the commission's Web site at http://www.tceq.state.tx.us/nav/rules/propose_adopt.html . For further information, please contact Ms. Kathryn Hoffman, Waste Permits Division, (512) 239-6890.

STATUTORY AUTHORITY

The amendment is proposed under Texas Water Code (TWC), §5.103, which provides the commission with the authority to adopt any rules necessary to carry out its powers and duties under this code and other laws of this state and to adopt rules repealing any statement of general applicability that interprets law or policy; §5.105, which authorizes the commission to establish and approve all general policy of the commission by rule; §27.019, which requires the commission to adopt rules reasonably required for the regulation of injection wells; and §27.023, which allows the commission to adopt rules as necessary to implement and administer a general permit authorizing the use of Class I injection wells to inject nonhazardous brine from desalination operations or nonhazardous drinking water treatment residuals.

The proposed amendment implements TWC, §27.023, relating to General Permit Authorizing Use of Class I Injection Wells to Inject Nonhazardous Brine from Desalination Operations or Nonhazardous Drinking Water Treatment Residuals, and TWC, Chapter 27.

§50.113.Applicability and Action on Application.

(a) Applicability. This subchapter applies to applications that are declared administratively complete on or after September 1, 1999. Applications that are declared administratively complete before September 1, 1999, are subject to Subchapter B of this chapter (relating to Action by the Commission).

(b) This chapter does not create a right to a contested case hearing where the opportunity for a contested case hearing does not exist under other law.

(c) After the deadline for filing a request for reconsideration or contested case hearing under §55.201 of this title (relating to Requests for Reconsideration or Contested Case Hearing), the commission may act on an application without holding a contested case hearing or acting on a request for reconsideration, if:

(1) no timely request for reconsideration or hearing has been received;

(2) all timely requests for reconsideration or hearing have been withdrawn, or have been denied by the commission;

(3) a judge has remanded the application because of settlement; or

(4) for applications under Texas Water Code, Chapters 26 and 27 and Texas Health and Safety Code, Chapters 361 and 382, the commission finds that there are no issues that:

(A) involve a disputed question of fact;

(B) were raised during the public comment period; and

(d) Without holding a contested case hearing, the commission may act on:

(1) an application for any air permit amendment, modification, or renewal application that would not result in an increase in allowable emissions and would not result in the emission of an air contaminant not previously emitted;

(2) an application for any initial issuance of an air permit for a voluntary emission reduction or electric generating facility;

(3) an application for a hazardous waste permit renewal under §305.631(a)(8) of this title (relating to Renewal);

(4) an application for a wastewater discharge permit renewal or amendment under Texas Water Code, §26.028(d), unless the commission determines that an applicant's compliance history as determined under Chapter 60 of this title (relating to Compliance History) raises issues regarding the applicant's ability to comply with a material term of its permit;

(5) an application for a Class I injection well permit used only for the disposal of nonhazardous [ ~~desalination~~ ] brine produced by a desalination operation or nonhazardous drinking water treatment residuals under Texas Water Code, §27.021, concerning Permit for Disposal of Brine From Desalination Operations or of Drinking Water Treatment Residuals in Class I Injection Wells;

(6) the issuance, amendment, renewal, suspension, revocation, or cancellation of a general permit, or the authorization for the use of an injection well under a general permit under Texas Water Code, §27.023, concerning General Permit Authorizing Use of Class I Injection Well to Inject Nonhazardous Brine from Desalination Operations or Nonhazardous Drinking Water Treatment Residuals;

(7) [ ~~(6)~~ ] an application for pre-injection unit registration under §331.17 of this title (relating to Pre-Injection Units Registration);

(8) [ ~~(7)~~ ] an application for a permit, registration, license, or other type of authorization required to construct, operate, or authorize a component of the FutureGen project as defined in §91.30 of this title (relating to Definitions), if the application was submitted on or before January 1, 2018; and

(9) [ ~~(8)~~ ] other types of applications where a contested case hearing request has been filed but no opportunity for hearing is provided by law.

This agency hereby certifies that the proposal has been reviewed by legal counsel and found to be within the agency's legal authority to adopt.

Filed with the Office of the Secretary of State on February 29, 2008.

TRD-200801189

Robert Martinez

Director, Environmental Law Division

Texas Commission on Environmental Quality

Earliest possible date of adoption: April 13, 2008

For further information, please call: (512) 239-0177

Chapter 55. REQUESTS FOR RECONSIDERATION AND CONTESTED CASE HEARINGS; PUBLIC COMMENT

The Texas Commission on Environmental Quality (commission) proposes amendments to §55.101 and §55.201.

BACKGROUND AND SUMMARY OF THE FACTUAL BASIS FOR THE PROPOSED RULES

The amended rules add two new types of applications and actions to a listing of applications that the commission may act on without holding a contested case hearing. This listing is in §55.101(f). There are two paragraphs under §55.101(f) that are affected by the proposed amendments. First, the proposed amendment to §55.101(f)(4) will update the list of applications that are not subject to a contested case hearing by adding an application for a Class I injection well used only for the disposal of nonhazardous drinking water treatment residuals. This exception is in addition to the exception for applications for disposal of desalination brine which was added by a previous rulemaking in the September 10, 2004, issue of the Texas Register (29 TexReg 8817). Amendment of §55.101(f)(4) also includes updates to reflect use of the term "nonhazardous brine from a desalination operation" instead of "desalination brine," and inserts the word "injection" into the phrase "Class I injection wells," to achieve consistency with the title of TWC, §27.021 as amended by HB 2654.

Second, a new paragraph has been inserted as §55.101(f)(5) with renumbering of the subsequent paragraph. The new paragraph implements part of TWC, §27.023 in HB 2654 that allows the commission to issue a general permit authorizing a Class I injection well to inject nonhazardous brine from desalination operations or nonhazardous drinking water treatment residuals, without providing the opportunity for a contested case hearing, as long as all requirements for a Class I injection well permit are met. Public notice of, and the opportunity to comment on, a permit application will not be affected by this rulemaking. Removing the opportunity for a contested case hearing may expedite the approval of Class I injection well permits for the disposal of nonhazardous desalination brine and nonhazardous drinking water treatment residuals. The commission's ability to hold a discretionary hearing under the provisions of TWC, §5.102(b) was not amended by HB 2654.

Changes to 30 TAC Chapters 50, 305 and 331 are also proposed in this issue of the Texas Register to implement HB 2654 and to incorporate other changes to facilitate disposal of nonhazardous desalination brine and nonhazardous drinking water treatment residuals.

SECTION BY SECTION DISCUSSION

§55.101. Applicability.

The proposal would amend §55.101(f)(4) by adding a permit application for a Class I injection well used only for the disposal of nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals to the list of applications upon which the commission may act without holding a contested case hearing. The proposal would add §55.101(f)(5) to include the issuance, amendment, renewal, suspension, revocation or cancellation of a general permit, or the authorization for the use of an injection well under a general permit in the list of items upon which the commission may act without holding a contested case hearing. Current paragraph §55.101(f)(5) will be renumbered as paragraph (6). Proposed §55.101(f)(5) implements part of TWC, §27.023 in HB 2654 that allows the commission to issue a general permit authorizing a Class I injection well to inject nonhazardous brine from desalination operations or nonhazardous drinking water treatment residuals, without providing the opportunity for a contested case hearing.

§55.201. Subchapter F, Requests for Reconsideration or Contested Case Hearing.

The proposal would amend §55.201(i)(6) by adding a permit application for a Class I injection well used only for the disposal of nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals to the list of applications for which there is no right to a contested case hearing. The proposal would add §55.201(i)(7) to include the issuance, amendment, renewal, suspension, revocation or cancellation of a general permit, or the authorization for the use of an injection well under a general permit in the list of items for which there is no right to a contested case hearing. Current paragraphs (7) - (9) will be renumbered as paragraphs (8) - (10), respectively.

FISCAL NOTE: COSTS TO STATE AND LOCAL GOVERNMENT

Nina Chamness, Analyst, Strategic Planning and Assessment, has determined that, for the first five-year period the proposed rules are in effect, no significant fiscal implications are anticipated for the agency or other units of state or local governments as a result of administration or enforcement of the proposed rules. The agency will utilize existing resources to develop rules and guidelines for a general permit to authorize the use of Class I injection wells for disposal of nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals.

HB 2654, 80th Legislature, Regular Session allows the commission to issue a general permit to authorize the use of a Class I injection well for disposal of nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals and authorizes the use of these wastes as appropriate injection fluids for enhanced oil and gas recovery purposes without obtaining a permit. HB 2654 requires the agency to issue rules governing the issuance of the general permit and establish the requirement for a notice of intent covered by the general permit. In addition, HB 2654 specifies that the general permit is not subject to the requirements of a contested case hearing. The proposed rulemaking is part of the agency's effort to establish a general permit program authorizing the use of Class I injection wells as specified by the legislation. In addition to this rulemaking, amendments are also proposed for appropriate sections of Chapters 50, 305, and 331. This fiscal note addresses only the fiscal implication of proposed changes to Chapter 55. The fiscal implications for needed amendments to other chapters are addressed in separate fiscal notes.

The proposed rules would comply with the notice of intent and contested case hearing requirements of HB 2654. These administrative changes allow the agency to authorize disposal of nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals under a general permit without holding a contested case hearing if all permit requirements are met.

Local governments and state agencies that are suppliers of public drinking water are not expected to experience significant fiscal implications because of the proposed rules. Governmental entities supplying public drinking water are expected to choose the most economical method of disposal of nonhazardous desalination and drinking water residual wastes, and disposal of these wastes in these injection wells is one option among various options available to suppliers of public drinking water regarding waste disposal.

If a local government or state agency chooses to own or operate a Class I injection well qualifying for authorization under the proposed general permit, the proposed rules could streamline the process for the governmental entity by not subjecting it to a requirement for contested case hearings, public notice, and public meetings. Savings generated by not holding contested case hearings could be as much as $500,000 although a contested case hearing would likely cost less. Not being required to publish public notices required by individual permits could save as much as $1,000 to $3,000 depending on the circulation size of the newspapers used. Savings generated by not being required to hold a public meeting, if an application had generated sufficient public interest for the agency to require one for an individual permit, could range from $1,700 to $4,700 depending on the cost of notices and the price for renting a meeting place.

PUBLIC BENEFITS AND COSTS

Nina Chamness also determined that for each year of the first five years the proposed rules are in effect, the public benefit anticipated from the changes seen in the proposed rules will be to allow desalination projects and operations requiring the disposal of nohazardous drinking water treatment residuals to come on line in a shorter time frame thus providing an increased supply of public drinking water while continuing to safeguard public health and the environment.

Individuals and business entities that are suppliers of public drinking water are not expected to experience significant fiscal implications because of the proposed rules. Suppliers of public drinking water are expected to choose the most economic method of disposal of nonhazardous desalination concentrate and drinking water treatment residuals, and disposal of these wastes in these injection wells is one option among various options available to suppliers of public drinking water regarding waste disposal.

Large businesses that own or operate these types of injection wells could possibly save both time and money since the proposed rules do not subject them to contested case hearings, requirements of public notice, and requirements for public meetings that would be required under an individual permit. Savings generated by not holding contested case hearings could be as much as $500,000 although a contested case hearing would likely cost less. Public notices required for individual permits could cost as much as $1,000 to $3,000 depending on the circulation size of the newspapers used. If applying for authorization under a general permit, applicants could be expected to save this expense. Applicants for authorization under this general permit could also save on the public meeting costs incurred for individual notices if an application would have had a public meeting under the requirements for an individual permit. These costs could range from $1,700 to $4,700 depending on the number of notices of public meeting that would have been required and the price of rentals for meeting places in the area.

Oil and gas businesses that might utilize enhanced recovery methods by injecting nonhazardous desalination concentrate or drinking water treatment residuals are expected to experience the same cost savings regarding contested case hearings, public notice and public meetings as those experienced by suppliers of public drinking water.

SMALL BUSINESS AND MICRO-BUSINESS ASSESSMENT

No adverse fiscal implications are anticipated for small or micro-businesses as a result of the proposed rules. Staff knows of no small or micro-businesses that are owners of Class I wells. The proposed rules establish that wells authorized under the general permit for Class I injection wells disposing of nonhazardous desalination and drinking water treatment residual wastes are not subject to the requirements of a contested case hearing, requirements of public notice, and requirements of public meetings as are those required by individual permits. If a small or micro-business decides to request authorization under a general permit to own or operate a Class I injection well for nonhazardous desalination concentrate or drinking water treatment residual waste disposal, it should experience the same cost savings associated with contested case hearings, public notices, and public meetings as those experienced by large businesses.

SMALL BUSINESS REGULATORY FLEXIBILITY ANALYSIS

The commission has reviewed this proposed rulemaking and determined that a small business regulatory flexibility analysis is not required because the proposed rules are needed to comply with state law and do not adversely affect a small or micro-business in a material way for the first five years that the proposed rules are in effect.

LOCAL EMPLOYMENT IMPACT STATEMENT

The commission has reviewed this proposed rulemaking and determined that a local employment impact statement is not required because the proposed rules do not adversely affect a local economy in a material way for the first five years that the proposed rules are in effect.

DRAFT REGULATORY IMPACT ANALYSIS DETERMINATION

The intent of the proposed rulemaking is to implement HB 2654, passed during the 80th Legislature, 2007, and to revise criteria for authorizing Class I nonhazardous wells injecting desalination concentrate and other water treatment residuals from public water systems so that the state's rules are no more stringent than federal Class I nonhazardous injection well regulations. The specific intent of the proposed amendments to Chapter 55 is to address certain procedural rights regarding applications for Class I injection well permits used only for the disposal of drinking water treatment residuals and the issuance, amendment, renewal, suspension, revocation or cancellation of a general permit or authorization under a general permit for a Class I injection well authorized to inject nonhazardous brine from desalination operations or nonhazardous drinking water treatment residuals. The rule substantially advances this purpose by adding notices of intent submitted under §331.203 to the applicability of Chapter 55, Subchapters D - G and by adding to the list of actions for which there is no right to a contested case hearing applications for a Class I injection well permit used only for the disposal of drinking water treatment residuals and the issuance, amendment, renewal, suspension, revocation or cancellation of a general permit or authorization under a general permit for a Class I injection well used only for the disposal of nonhazardous brine from desalination operations or drinking water treatment residuals.

This rulemaking does not meet the statutory definition of a "major environmental rule" because the proposed amendments would not adversely affect in a material way the economy, a sector of the economy, productivity, competition, jobs, the environment, or public health and safety of the state or a sector of the state. It is not anticipated that the cost of complying with the proposed amendment will be significant with respect to the economy; therefore, the proposed amendments will not adversely affect in a material way the economy, a sector of the economy, competition, or jobs.

Additionally, this rulemaking does not meet any of the four applicability requirements listed in Texas Government Code, §2001.0225(a). Texas Government Code, §2001.0225 only applies to a major environmental rule, the result of which is to: 1) exceed a standard set by federal law, unless the rule is specifically required by state law; 2) exceed an express requirement of state law, unless the rule is specifically required by federal law; 3) exceed a requirement of a delegation agreement or contract between the state and an agency or representative of the federal government to implement a state and federal program; or 4) adopt a rule solely under the general powers of the agency instead of under a specific state law. This rulemaking does not meet any of these four applicability requirements because this rulemaking does not exceed any standard set by federal law but rather amends the rules so that they are no more stringent or restrictive than the federal regulations. The rules proposed do not exceed the requirements of state law under TWC, Chapter 27. Further, the rules proposed do not exceed a requirement of a delegation agreement or contract between the state and an agency or representative of the federal government to implement any state and federal program. Finally, the rule is not proposed solely under the general powers of the agency, but rather specifically under TWC, §27.023(m), which allows the commission to adopt rules to implement the general permit authorizing use of a Class I injection well to inject nonhazardous brine from desalination operations or nonhazardous drinking water treatment residuals and TWC, §27.109, which authorizes the commission to adopt rules to implement TWC, Chapter 27, as well as the other general powers of the agency.

TAKING IMPACT ASSESSMENT

The commission evaluated the proposed amendments to Chapter 55 and performed a preliminary assessment of whether the amendments would constitute a taking under Texas Government Code, Chapter 2007. The primary purpose of the proposed amendments is to implement HB 2654, authorizing use of a general permit for Class I injection wells injecting only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals. The proposed amendments would substantially advance this purpose by amending §55.201 to add to the list of actions for which there is no right to a contested case hearing applications for a Class I injection well permit used only for the disposal of drinking water treatment residuals and the issuance, amendment, renewal, suspension, revocation or cancellation of a general permit or authorization under a general permit for a Class I injection well used only for the disposal of nonhazardous brine from desalination operations or drinking water treatment residuals.

Promulgation and enforcement of the proposed amendments would constitute neither a statutory nor a constitutional taking of private real property. There are no burdens imposed on private real property under this rulemaking because the proposed amendments neither relate to, nor have any impact on the use or enjoyment of private real property, and there would be no reduction in property value as a result of this rulemaking. Therefore, the proposed rules would not constitute a taking under Texas Government Code, Chapter 2007.

The commission has no reasonable alternative that could accomplish the specific purpose of addressing certain procedural rights regarding applications for Class I injection well permits used only for the disposal of nonhazardous desalination concentrate or drinking water treatment residuals and the issuance, amendment, renewal, suspension, revocation or cancellation of a general permit or authorization under a general permit for a Class I injection well authorized to inject nonhazardous brine from desalination operations or nonhazardous drinking water treatment residuals. These procedural issues regarding permit applications and notices of intent can only be affected through amendments to the commission's rules.

CONSISTENCY WITH THE COASTAL MANAGEMENT PROGRAM

The commission reviewed the proposed rules and found that they are neither identified in Coastal Coordination Act Implementation Rules, 31 TAC §505.11(b)(2) or (4), nor will they affect any action/authorization identified in Coastal Coordination Act Implementation Rules, 31 TAC §505.11(a)(6). Therefore, the proposed rules are not subject to the Texas Coastal Management Program.

ANNOUNCEMENT OF HEARING

SUBMITTAL OF COMMENTS

Subchapter D. APPLICABILITY AND DEFINITIONS

30 TAC §55.101

STATUTORY AUTHORITY

§55.101.Applicability.

(a) - (e) (No change.)

(f) Subchapters D - G of this chapter do not apply to hearing requests related to:

(1) - (3) (No change.)

(4) applications for Class I injection well permits used only for the disposal of nonhazardous [ ~~desalination~~ ] brine produced by a desalination operation or nonhazardous drinking water treatment residuals under Texas Water Code, §27.021, concerning Permit for Disposal of Brine From Desalination Operations or of Drinking Water Treatment Residuals in Class I Injection Wells; [ ~~and~~ ]

(5) the issuance, amendment, renewal, suspension, revocation, or cancellation of a general permit, or the authorization for the use of an injection well under a general permit under Texas Water Code, §27.023, concerning General Permit Authorizing Use of Class I Injection Well to Inject Nonhazardous Brine from Desalination Operations or Nonhazardous Drinking Water Treatment Residuals; and

(6) [ ~~(5)~~ ] applications where the opportunity for a contested case hearing does not exist under other laws.

(g) (No change.)

This agency hereby certifies that the proposal has been reviewed by legal counsel and found to be within the agency's legal authority to adopt.

Filed with the Office of the Secretary of State on February 29, 2008.

TRD-200801190

Robert Martinez

Director, Environmental Law Division

Texas Commission on Environmental Quality

Earliest possible date of adoption: April 13, 2008

For further information, please call: (512) 239-0177

Subchapter F. REQUESTS FOR RECONSIDERATION OR CONTESTED CASE HEARING

30 TAC §55.201

STATUTORY AUTHORITY

§55.201.Requests for Reconsideration or Contested Case Hearing.

(a) - (h) (No change.)

(i) Applications for which there is no right to a contested case hearing include:

(1) - (5) (No change.)

(6) an application for a Class I injection well permit used only for the disposal of nonhazardous [ ~~desalination~~ ] brine produced by a desalination operation or nonhazardous drinking water treatment residuals under Texas Water Code, §27.021, concerning Permit for Disposal of Brine From Desalination Operations or of Drinking Water Treatment Residuals in Class I Injection Wells;

(7) the issuance, amendment, renewal, suspension, revocation, or cancellation of a general permit, or the authorization for the use of an injection well under a general permit under Texas Water Code, §27.023, concerning General Permit Authorizing Use of Class I Injection Well to Inject Nonhazardous Brine from Desalination Operations or Nonhazardous Drinking Water Treatment Residuals;

(8) [ ~~(7)~~ ] an application for a pre-injection unit registration under §331.17 of this title (relating to Pre-Injection Units Registration);

(9) [ ~~(8)~~ ] an application for a permit, registration, license, or other type of authorization required to construct, operate, or authorize a component of the FutureGen project as defined in §91.30 of this title (relating to Definitions), if the application was submitted on or before January 1, 2018; and

(10) [ ~~(9)~~ ] other types of applications where a contested case hearing request has been filed, but no opportunity for hearing is provided by law.

This agency hereby certifies that the proposal has been reviewed by legal counsel and found to be within the agency's legal authority to adopt.

Filed with the Office of the Secretary of State on February 29, 2008.

TRD-200801191

Robert Martinez

Director, Environmental Law Division

Texas Commission on Environmental Quality

Earliest possible date of adoption: April 13, 2008

For further information, please call: (512) 239-0177

Chapter 217. DESIGN CRITERIA FOR DOMESTIC WASTEWATER SYSTEMS

The Texas Commission on Environmental Quality (commission) proposes new §§217.1 - 217.17, 217.31 - 217.39, 217.51 - 217.70, 217.91 - 217.100, 217.121 - 217.129, 217.151 - 217.164, 217.181 - 217.193, 217.201 - 217.213, 217.241 - 217.252, 217.271 - 217.283, 217.291 - 217.300, and 217.321 - 217.333.

BACKGROUND AND SUMMARY OF THE FACTUAL BASIS FOR THE PROPOSED RULES

Proposed new Chapter 217, Design Criteria for Domestic Wastewater Systems, has three major goals: implementing the commission's goal of having all water related rules in the Chapter 200 series by repealing 30 TAC Chapter 317 and proposing a new chapter; bringing the standards and criteria for wastewater collection systems and treatment facilities up-to-date with current engineering practices and technology; and updating the rules to reflect the current permitting practices of the commission.

The commission last comprehensively revised Chapter 317 in 1986. Since then, minor revisions in 1988, 1990, and 1994, have addressed specific concerns, but did not seek to bring the whole chapter in line with advances in wastewater technologies. These proposed rules incorporate those advances. Additionally, revisions are needed to address requirements in current wastewater treatment facility discharge permits that are not addressed by Chapter 317 requirements.

These new rules will ease the administrative burden on the commission by providing additional specific criteria for building or modifying wastewater collection systems and treatment facilities. The proposed rules provide minimum design standards for wastewater collection and treatment. The criteria require a licensed professional engineer to design the systems and facilities.

The proposed rules also allow the executive director to approve variances for innovative technology on a case-by-case basis. Approval may include requirements for pilot studies, demonstration projects, and/or performance bonds. If the executive director grants conditional approval and recognizes after a reasonable time that the technology meets the design standards, a performance bond would no longer be required. The objectives of these rules are to ensure that wastewater collection systems and treatment facilities designed using innovative technology will be protective of human health and environment, as well as cost effective.

The proposed rules also provide flexibility for the approval of nonconforming technology, which is defined in this rulemaking as technology that is not addressed in or does not conform to the design criteria in this chapter, but produces effluent that protects human health and environment. The rule also establishes criteria for a treatment facility's use of reclaimed water and establishes design criteria for reclaimed water use, as authorized by 30 TAC Chapter 210, Use of Reclaimed Water.

Proposed new Chapter 217 eliminates the use of appendices. The information that was in Chapter 317 appendices has been incorporated into the body of the rule. This format groups all like requirements together and improves readability.

For 180 days after the effective date of this rulemaking, the executive director will grant variance requests that meet the design criteria of Chapter 317 for any project that was in its design phase when these rules are adopted. Projects that are in the design phase will not have to be re-engineered. To be granted, variances must be protective of human health and the environment.

A corresponding rulemaking is published in this issue of the Texas Register and includes the repeal of Chapter 317, Design Criteria for Sewage Systems.

SECTION BY SECTION DISCUSSION

The commission proposes to repeal Chapter 317. However, the commission will retain some of the existing Chapter 317 requirements and move these requirements to proposed new Chapter 217. For clarity and readability, the commission proposes to reorganize, reformat, and revise Chapter 317 provisions to bring them up-to-date with current agency rule standards regarding style, formatting, and structure. The commission also proposes to amend some of the Chapter 317 requirements and add new requirements that would bring the design criteria up-to-date with current technology and engineering practice.

Many of the modifications to the provisions being moved to Chapter 217 allow increased flexibility in designing wastewater collection systems and treatment facilities. By providing more flexibility in design, a system or facility will be better able to meet the current and future needs of the community for which the system or facility is designed. Owners need more flexibility to meet changing and more site-specific effluent limitations. Increased flexibility will also allow designs to incorporate evolving technology.

Unless common industry standard uses a specific term, the commission proposes to change the following terms throughout the rule: "pond" to "lagoon;" "plant" to "facility;" "lines" to "pipe;" "sewage system" or "sewerage system" to "collection system;" and "permittee" to "owner." The commission proposes these changes for consistency with other rules and readability.

Additionally, the commission proposes to change the word "commission" to "executive director" where appropriate in the proposed rule to conform to current agency rule standards. The term "executive director," as defined in 30 TAC Chapter 3, means the executive director of the commission or any authorized individual designated to act for the executive director. The agency uses the term "executive director" in rules to denote any actions carried out by the executive director's staff.

SUBCHAPTER A. ADMINISTRATIVE REQUIREMENTS

Subchapter A consolidates and streamlines the administrative requirements relating to collection systems and treatment facilities.

Proposed new §217.1, Applicability, establishes that Chapter 217 applies to any person who proposes to construct facilities that will collect, transport, treat, or dispose of domestic wastewater. This section contains the specific requirements for the administrative processes that govern the implementation of this chapter. For 180 days after the effective date of this rule, the executive director will grant variance requests that meet the design criteria of Chapter 317 for any project that is in its design phase when this rule is adopted. This section also states that Chapter 217 does not apply to facilities constructed to comply with non-domestic wastewater permits or constructed under 30 TAC Chapter 285, On-Site Sewage Facilities.

Proposed new §217.2, Definitions, defines terms as used in this chapter. The definitions for these words are consistent with wastewater industry standards.

Proposed new §217.3, Purpose, explains that these design criteria are minimum requirements necessary for domestic wastewater collection, treatment, and disposal systems to meet state water quality standards. In order for the executive director to evaluate a project, the plans, specifications, and reports for a proposed project must meet the requirements of this chapter. The executive director may require more stringent criteria than those in this chapter, if necessary to meet public health and water quality goals.

Proposed new §217.4, Variances, states the requirements for applying for and reviewing variances. The rule clarifies and expands the former Chapter 317 variance requirements.

Proposed new §217.4(a) requires that the report include all requested variances from the requirements of this chapter.

Proposed new §217.4(b) requires that a technical justification be included for any request for a variance.

Proposed new §217.4(c) authorizes the executive director to deny a variance or require additional protective measures if the executive director determines that the variance would result in a potential compromise of public health or environment.

Proposed new §217.4(d) states that the executive director may not grant or approve a variance from any expressed prohibition within this chapter. The executive director determined that the prohibitions in proposed Chapter 217 are necessary to protect public health and environment. The commission proposes this provision to provide notice to the regulated community.

Proposed new §217.4(e) provides that a variance is conditionally approved if the executive director does not notify the owner in writing within 30 days that further information is requested or that the variance is denied. The commission proposes 30 days instead of the 10 days allowed in Chapter 317 to allow sufficient time for the executive director to complete a thorough review of a variance request.

Proposed new §217.4(f) provides that any plans and specifications that do not meet the conditions in subsections (c) and (d) are not eligible for the automatic approval process in subsection (e).

Proposed new §217.4(g) provides that any plans and specifications that include design elements that require an affirmative approval are not eligible for the automatic approval process in subsection (e).

Proposed new §217.5, Plans and Specifications General Requirements , explains how plans and specifications approval relates to wastewater permits.

Proposed new §217.5(a) requires that the effluent limits used as the basis of the plans and specifications for a facility be at least as stringent as the effluent limits in the associated wastewater permit. This requirement ensures that a treatment facility will meet the effluent limits in the current wastewater permit, but allows the owner the flexibility to design to a higher standard to meet future needs, such as population growth, industrial development, more stringent effluent limits, or other contingencies.

Proposed new §217.5(b) expressly states that an owner is not required to submit plans and specifications for a proposed facility prior to the commission issuing a wastewater permit. Under the Chapter 317 rules, the question regarding when plans and specifications must be submitted arose in contested case hearings. This requirement specifically states that an owner has no obligation to submit plans and specifications prior to receiving an issued permit. Because the preparation of plans and specification is costly, the commission will not require an owner to submit them prior to knowing that the facility is authorized and what effluent limits and other conditions the issued permit will ultimately require.

Proposed new §217.5(c) explains that approval of plans and specifications under this chapter does not relieve the owner of the responsibility to obtain a wastewater permit or any other authorization required by Texas Water Code, Chapter 26. The commission has made this provision more specific than the requirement in Chapter 317 so that an owner knows additional authorizations may be needed.

Proposed new §217.5(d) specifies that the executive director's approval of a wastewater permit does not relieve an owner of the responsibility to obtain plans and specifications approval of a facility before commencing construction.

Proposed new §217.5(e) requires that a facility's design meet all the design requirements in the associated wastewater permit. Design requirements are sometimes added to wastewater permits to ensure compliance with specific effluent limitations.

Proposed new §217.6, Submittal Requirements and Review Process , outlines the procedure an owner must follow to submit a project for the executive director's review and the process that the review will take.

Proposed new §217.6(a) enumerates the elements required in the transmittal letter and names the recipients as the executive director and the appropriate regional office. This list is similar to the requirements of Chapter 317 with the exception of an additional requirement to add all requested variances to the transmittal letter.

Proposed new §217.6(b) states that the executive director may review any facility's plans and specifications. This requirement states that although the executive director may not review all plans and specifications, all are subject to review. The commission proposes to remove the list of factors that were listed in Chapter 317, because it is not an exhaustive list.

Proposed new §217.6(c) states that an owner is not required to submit plans and specifications unless the owner receives a written request from the executive director within 30 days after submitting a transmittal letter. The commission proposes to change the 10-day approval to 30 days to allow staff adequate time to review a transmittal letter and determine if a full plans and specifications review is warranted.

Proposed new §217.6(d) is a requirement that an owner must respond to a request for additional information or plans and specifications within 30 days after receiving the executive director's request. The 30-day deadline for submittal of plans and specifications or additional information is intended to make the review process more efficient.

Proposed new §217.7, Types of Plans and Specifications Approvals , lists the ways the executive director may approve plans and specifications.

Proposed new §217.7(a) states that a plans and specifications approval does not relieve an owner of the responsibility for designing, constructing, and operating a facility in accordance with commission rules and the associated wastewater permit.

Proposed new §217.7(b) explains that there are three types of plans and specifications approval that may be granted by the executive director: standard approval for plans and specifications with no requested variances; approval of innovative or nonconforming technologies; and conditional approval based on specific parameters.

Proposed new §217.7(b)(1) requires the executive director grant a standard approval for plans and specifications that comply with all applicable parts of the design criteria listed in these rules.

Proposed new §217.7(b)(2) authorizes the executive director to grant approval for innovative or nonconforming technology after the executive director evaluates the supporting documentation and determines that the innovative or nonconforming technology will be as protective of public health and environment as the design criteria in this chapter.

Proposed new §217.7(b)(2)(A)(iv) authorizes the executive director to require evidence of an acceptable two-year performance bond that insures the performance of the innovative or nonconforming technology. This provision ensures that a wastewater facility will have funds available to replace a failed unit or facility if an innovative or nonconforming technology fails. The provision allows owners the flexibility to use innovative and nonconforming technology without threatening public health or environment.

Proposed new §217.7(b)(3) contains the provisions regarding conditional approvals. A conditional approval grants approval for a set of plans and specifications that the executive director determined may work only in certain circumstances. A conditional approval will contain conditions, stipulations, or restrictions that are necessary to ensure compliance with this chapter and protect human health and environment. The commission proposes to remove the following language from the Chapter 217 requirements, "Any conditional approval granted may be issued for a specific set of flow situations, wastewater characteristics, and/or required effluent quality." Because these items are examples, they are more appropriately included in this preamble rather than the rule.

Proposed new §217.8, Municipality Reviews , allows certain municipalities to apply for authorization to perform technical reviews of wastewater treatment collection systems within their boundaries, and incorporates requirements of Texas Water Code, §26.034(d) and (e).

Proposed new §217.8(g)(8), requires a municipality whose review authority is revoked to inform all applicants for new projects in its jurisdiction of the requirement to contact the executive director for review and approval. The commission proposes this section to ensure that owners are aware of the proper review authority.

Proposed new §217.9, Texas Water Development Board Reviews , provides that if the Texas Water Development Board reviews and approves plans and specifications, in accordance with Texas Water Code, §17.276(d), the owner must send a copy of the approval to the executive director. This section ensures that the agency is aware of facilities approved by the Texas Water Development Board.

Proposed new §217.10, Final Engineering Design Report , contains the requirements for the final engineering design report (report). The rule provides that the report contain the necessary information for a staff engineer to evaluate a project.

Proposed new §217.10(a) requires that an owner submit a report for each facility or system that is proposed for new construction, expansion, re-rating, or major modification.

Proposed new §217.10(b) requires that the report be signed, sealed, and dated by the engineer that prepared the report.

Proposed new §217.10(c) requires the report to include information and data used to comply with this chapter or to justify variances.

Proposed new §217.10(d) requires that an owner submit any additional requested information within 30 days after the request. This added requirement makes the plans and specification review process more efficient.

The commission proposes not to include the requirements for a preliminary engineering report from Chapter 317 in proposed new Chapter 217. Staff has found that a preliminary engineering report adds cost and time to the review process, but adds little value. Discussions between staff engineers and design engineers resolve most issues.

In proposed new §217.10(e) the commission specifies a list of what is required in the report for wastewater collection systems. These requirements ensure the executive director has sufficient information to evaluate the proposed plans and specifications. For clarity, the new rule proposes separate lists of required elements in the reports for wastewater collection systems and treatment facilities.

In proposed new §217.10(f) the commission specifies a list of what is required in the report for wastewater treatment facilities. These requirements ensure the executive director has sufficient information to evaluate the proposed plans and specifications. For clarity, the new rule proposes separate lists of required elements in the reports for wastewater collection systems and treatment facilities.

Proposed new §217.11, Construction of an Approved Facility , states that approval of plans and specifications alone do not imply that construction of the facility may begin.

Proposed new §217.11(a) states that construction must not begin on a facility with approved plans and specifications until the executive director issues a wastewater permit, unless the commission authorized the applicant to construct before permit issuance, under Texas Water Code, §26.027. In most instances, the wastewater permit will be issued before the plans and specifications review, but this requirement covers the contingency that the review may precede the issuance of the permit. This requirement will not affect collection system construction since there is no corresponding permit for collection systems.

Proposed new §217.11(b) requires an owner to obtain plans and specifications approval before the facility may begin constructing or operating at the next permit phase. This requirement ensures consistency between phases included in the wastewater permit, plans and specifications review, and construction. This requirement will not affect collection system construction since there is no corresponding permit for collection systems.

Proposed new §217.11(c) requires that phased construction of a facility correspond to phases included in the associated wastewater permit. If an owner desires to phase construction differently, the owner must request a variance through the procedure outlined in §217.4. This requirement provides notice that the executive director's approval will be based on the phases approved in the issued wastewater permit. This requirement will not affect collection system construction since there is no corresponding permit for collection systems.

Proposed new §217.11(d) prohibits a collection system or treatment facility from creating a bypass that discharges untreated or partially treated wastewater during construction without a commission order. This requirement provides that construction does not justify a discharge of untreated or partially treated wastewater. This requirement applies equally to treatment facilities and collection systems.

Proposed new §217.11(e) states that an owner must meet the design criteria in effect at the time that the plans and specifications for a new or modified system or facility are submitted to the executive director. This requirement eliminates any ambiguity regarding what design criteria apply to a facility or collection system's plans and specifications. This requirement applies equally to treatment facilities and collection systems.

Proposed new §217.11(f) states that an owner is subject to the design criteria in place at the time a new permit application is submitted or when plans and specifications are submitted for approval if the owner's wastewater permit was allowed to lapse or the owner failed to get a plans and specifications approval when the facility was built.

Proposed new §217.11(g) requires the owner of a collection system to meet the collection system design criteria in effect when it is discovered that the plans and specifications of the system have not been approved. Subsections (f) and (g) prevent an owner from claiming to comply with rules that have been superseded.

Proposed new §217.12, Substantial Design Changes , specifies how to address changes to approved plans and specifications.

Proposed new §217.12(a) defines substantial design change. Minor changes dictated by things such as material substitutions, (e.g., cast aluminum walkways instead of steel) unforeseen site anomalies (i.e., an underground boulder in the path of the collection system), and minor design changes (e.g., installing a board fence instead of a chain link fence) will not be submitted to staff engineers for review. Staff engineers plan to review only those design changes that may affect the way a collection system or a treatment facility operates. Some examples of substantial design changes are adding a treatment unit, switching from chlorine disinfection to ultraviolet disinfection, or including fifty extra connections in a collection system.

Proposed new §217.12(b) requires that the request for approval of a substantial design change include the dated signature and seal of an engineer.

Proposed new §217.12(c) authorizes the executive director to deny the substantial design change or require more stringent criteria as necessary to ensure protection of public health or environment.

Proposed new §217.12(d) notifies the regulated community that the executive director may not approve a design change that violates an expressed prohibition in this chapter.

Proposed new §217.12(e) states that a substantial design change is approved unless the executive director notifies the owner in writing within 30 days that further information is requested or that the substantial design change is denied. The commission proposes 30 days to allow sufficient time for the executive director to review a substantial design change request.

Proposed new §217.13, Final Construction Drawings and Technical Specifications, divides construction drawings for collection systems and treatment facilities into two different paragraphs for clarity.

Proposed new §217.13(a) states that an owner must submit final construction drawings and technical specifications only if requested by the executive director. The executive director will request final construction drawings or technical specifications if there is a question about the treatment facility or collection system's ability to protect human health or environment.

Proposed new §217.13(b) requires that any final construction drawings or technical specifications submitted must include the dated signature and seal of an engineer.

Proposed new §217.13(c) lists the items that must be submitted with the final construction drawings and technical specifications. Because the lists are different for collection systems and treatment facilities and for new and modified projects, the lists are divided. Section 217.13(c)(1) lists the items for a new collection system; §217.13(c)(2) lists the items for a new treatment facility; §217.13(c)(3) lists the items for a modified collection system; and §217.13(c)(4) lists the items for a modified treatment facility.

Proposed new §217.14, Completion Notice , requires an owner to provide notice to the executive director when construction of a collection system or treatment facility is complete.

Proposed new §217.14(a) lists the elements that must be included in a completion notice.

Proposed new §217.14(b) requires the completion notice to include all deviations from the approved plans and specifications and substantial design changes. The completion notice must also certify that any change not submitted for approval does not qualify as substantial design change.

Proposed new §217.15, Inspection, notifies the regulated community that the executive director may inspect a project at any point during construction to determine compliance with the project's plans and specifications, report, approval letters, or other requirements of this chapter.

Proposed new §217.16, Treatment Facility Operation and Maintenance Manual, states that the requirements for an operations and maintenance manual, including emergency procedures. The rule expands the requirements from Chapter 317 to outline more specifically what is required to ensure enough detail for operators to manage the day-to-day and emergency operation of a facility.

Proposed new §217.17, Collection System Records , requires that a collection system owner keep a specific set of records necessary to facilitate operation during the expected life of the system.

SUBCHAPTER B. TREATMENT FACILITY DESIGN REQUIREMENTS

Subchapter B updates the Chapter 317 treatment facility design requirements. A significant amount of flexibility has been incorporated into the design requirements while maintaining the standard of protecting human health and environment.

Proposed new §217.31, Applicability, contains the design values that must be used to determine the size of any wastewater treatment component. Additionally, this section specifically applies Subchapter B to designs for new treatment facilities, upgrades of existing facilities, and re-ratings of existing facilities.

Proposed new §217.32, Organic Loadings and Flows, states the organic loading and flow values that must be used to design a wastewater treatment facility. This section updates past commission practices and procedures, incorporates new procedures requested by the regulated community, and adds new requirements from Chapter 319, General Regulations Incorporated into Permits.

Proposed new §217.32(a) prescribes the method to determine design requirements if there are no pre-existing loading and flow data on which to base calculations. Table B.1 is included to simplify selection of the correct parameters.

Proposed §217.32(b) authorizes an owner to use data from an existing facility in accordance with §217.33, Flow Measurement, when constructing a new facility to serve the same area as an existing facility with sufficient historical data. This requirement allows the design of a wastewater treatment facility to be based on actual data.

Proposed new §217.33, Flow Measurement, outlines the requirements for flow measurement in a treatment facility. Accurate flow measurement is necessary for both reporting and efficient operations.

Proposed new §217.33(a) requires that each facility have a method to accurately measure effluent flow.

Proposed new §217.33(b) requires that the flow-measuring device be located for easy inspection and maintenance.

Proposed new §217.33(c) lists the requirements for primary and secondary flow-measuring devices.

Proposed new §217.34, Re-Rating, Upgrading, or Modifying an Existing Facility , authorizes existing facilities that are being modified or re-rated to meet new permit conditions to justify the size of existing or proposed treatment components by using historical data as the design basis. This section updates past commission practices and procedures and adds new requirements from Chapter 319.

Proposed new §217.34(1) lists the requirements that flow data must meet before being used as the basis for design criteria.

Proposed new §217.34(2) lists the requirements that loading data must meet before being used as the basis for design criteria.

Proposed new §217.35, One Hundred-Year Flood Plain Requirements , lists the requirements related to a treatment facility located in or near a flood plain.

Proposed new §217.35(a) requires that the site plan for a proposed wastewater facility include the 100-year flood plain if there is a 100-year flood plain within 1,000 feet of the proposed site. The subsection further outlines the requirements for the 100-year flood plain determination. The subsection also states that FEMA maps are prima facie evidence of flood plain locations. The owner must determine the elevation and design to prevent flood damage to the facility or allow unanticipated discharges of untreated or partially treated wastewater.

Proposed new §217.35(b) requires that the hydraulic profile of the wastewater facility show the 100-year water surface elevation. This requirement is to enable the commission to confirm the protection of all units and the ability of the facility to operate during a 100-year flood event.

Proposed new §217.35(c) prohibits the executive director from approving a proposed treatment unit within the 100-year flood plain unless satisfactory measures to protect all open process tanks and electric units are provided as part of the proposed design. This requirement provides notice to the regulated community that protection from a 100-year flood event is required.

Proposed new §217.36, Emergency Power Requirements , outlines the requirements for emergency power supply for treatment facility components.

Proposed new §217.36(a) requires that an owner obtain the power outage records from the appropriate power company(s) showing the reliability of the power service for the facility. Chapter 317 required the commission to collect the data. The owner has the responsibility to provide the records regarding the power service reliability to the executive director.

Proposed new §217.36(b) requires the power reliability documentation to be included in the report. The executive director will then review the documentation and determine the power service's reliability.

Proposed new §217.36(c) lists the required procedure when the executive director determines that the power supply is unreliable. The commission requires the facility to incorporate an on-site, automatically-starting generator, capable of ensuring continuous operation of all critical facility components for a period equal to the longest power outage in the power records if the executive director determines the power supply is unreliable.

Proposed new §217.36(c)(4) contains the exceptions to the auxiliary power generator requirements for wastewater treatment facilities and off-site lift stations. Included in this paragraph are the requirements for qualifying for an exemption to the requirement for an automatically-starting generator. These requirements were not in Chapter 317. The new requirements are to ensure the disinfection units can operate during a power outage, a minimum air supply is maintained, and pumping requirements are met to prevent an unauthorized discharge into or adjacent to water in the state.

Proposed new §217.37, Disinfection System Power Reliability, contains additional requirements for power reliability and emergency power for disinfection units because their operation is vital even under emergency conditions.

Proposed new §217.38, Buffer Zones and Odor Abatement , lists the requirements for buffer zones and other abatement requirements to manage odor.

Proposed new §217.38(a) states that the buffer zone restrictions in §309.13 apply to all construction of wastewater treatment facilities.

Proposed new §217.38(b) requires the report include any design for odor abatement facilities intended to attain compliance with permit buffer zone requirements. This provision ensures that this information is included in the report and available for staff review.

Proposed new §217.38(c) requires that the executive director consider all odor abatement measures as nonconforming or innovative technologies and review them on a case-by-case basis under §217.7(b)(2), because of the site-specific nature of potential odor issues for a wastewater treatment facility.

Proposed new §217.39, Facility Use of Reclaimed Water , requires the use of reclaimed water for equipment washing and irrigating the treatment facility grounds. It also offers the option to use reclaimed water for any other suitable purpose.

Proposed new §217.39(a) specifies that all facilities designed after the effective date of these rules must use reclaimed water in place of potable water for wash down water and for irrigating the facility grounds. The commission proposes this requirement as a measure to conserve potable water and to be consistent with Chapter 210.

Proposed new §217.39(b) requires that reclaimed water be metered. This requirement is included so that accurate effluent flows for the facility can be determined, since reclaimed water is considered part of the total effluent flow.

Proposed new §217.39(c) requires that water be disinfected before it can be reclaimed for use at the facility. This requirement is included to protect the health of the facility staff and to prevent degradation of any adjacent surface water or groundwater.

Proposed new §217.39(d) authorizes an owner to use water that meets the requirements of either Type I or Type II reclaimed water for any appropriate use. This subsection allows an owner the flexibility to design a reclaimed water system that fits the needs of a particular treatment facility.

Proposed new §217.39(e) reiterates that no further authorization is necessary to use reclaimed water at a treatment facility, provided the requirements in this section are met.

SUBCHAPTER C. CONVENTIONAL COLLECTION SYSTEMS

Subchapter C expands and updates the design requirements for collection systems. This subchapter also adds flexibility, while protecting human health and environment. Alternative collection systems have been separated from convention collection systems and given their own subchapter.

Proposed new §217.51, Applicability, states that this subchapter covers the design, construction, and testing standards for conventional gravity wastewater collection systems, conventional wastewater lift stations, force mains, and reclaimed water conveyance systems.

Proposed new §217.52, Edwards Aquifer, notifies the regulated community that all wastewater collection systems located over the recharge zone of the Edwards Aquifer must be designed and installed following the requirements of Chapter 213, Edwards Aquifer, in addition to the requirements in these rules.

Proposed new §217.53, Pipe Design, establishes the requirements for all collection system designs, including but not limited to flow design and pipe material. This section specifies requirements for separation distances between wastewater pipes and drinking water pipes, laterals and traps, odor and corrosion control, and structural analysis of flexible and rigid pipe.

Proposed new §217.53(a) specifies the flow design basis for collection systems and the required calculations. This subsection formalizes the existing staff review procedures by specifying the computations involved in determining the flow design basis for collection systems.

Proposed new §217.53(b) specifies that the report must identify the proposed collection system pipes with their appropriate standard numbers for both quality control and installation. This subsection also specifies that quality control includes dimensions and tolerances and that installation includes bedding and backfill. This subsection also lists the considerations for choosing collection system pipes.

Proposed new §217.53(c) lists the requirements for pipe joints. The technical specifications must include the materials and methods used in making joints. The subsection also requires that the technical specifications include an appropriate national reference standard for the joints. This requirement ensures that the executive director has sufficient information to review the joint construction.

Proposed new §217.53(d) requires that the wastewater pipes and manholes maintain certain separation distances from potable water pipes to protect potable water from cross contamination from wastewater.

Proposed new §217.53(e) requires that laterals and taps on a new collection system include manufactured fittings that limit infiltration, prevent protruding service pipes, and protect the mechanical and structural integrity of the collection system. This requirement ensures the mechanical and structural integrity of the collection system. An unprotected pipe may have a higher incidence of infiltration, which could lead to sanitary sewer overflows or hydraulic overload of the treatment facility.

Proposed new §217.53(f) requires that the spacing of supports for carrier pipe through casings ensure and maintain grade, slope, and structural integrity as required by §217.53(k) and (l). This requirement ensures that the carrier pipe has the same slope as the collection system pipe.

Proposed new §217.53(g) specifies that if a pipe deteriorates when subjected to corrosive internal conditions, the collection system must incorporate a corrosion-resistant liner installed by the pipe manufacturer, unless the report demonstrates that the design and operational characteristics of the facility will maintain the structural integrity for at least 50 years.

Proposed new §217.53(h) contains requirements for odor control. If wastewater does not always flow at a constant rate through the pipes, there is a potential for odors. This requirement ensures that potential odors are controlled throughout the life of the collection system.

Proposed new §217.53(i) contains the requirements for laying a collection system near active geologic faults. This subsection requires an owner to locate any active faults within the area of the collection system and minimize the number of pipes crossing faults. The requirement states that the design must use joints that provide maximum deflection and manholes on both sides of a fault so that a portable pump may be used in the event of a collection system failure. Section 217.53(i)(2) states that no collection system service connection may be installed within 50 feet of an active fault. In Chapter 317, both of these provisions were optional. The executive director determined that these requirements are needed to ensure the protection of human health and the environment.

Proposed new §217.53(j) requires that a collection system have the capacity for the service area during the expected life of the system. For example, if there are 100 houses currently in the subdivision with another 100 to be added during the next 10 years, the collection system must be designed to handle 200 houses. The subsection lists the considerations necessary to successfully size a collection system. The considerations are population; institutional, industrial, and commercial flows; peak flows; surcharges; minimum pipe diameters; and storm water drains. The prohibition against allowing storm water in a wastewater collection system is added to be consistent with §281.25 and 40 Code of Federal Regulations (CFR) §122.26.

Proposed new §217.53(k) states the structural analysis requirements for collection systems. Their design must provide a minimum structural life expectancy of 50 years. The subsection also requires an owner to provide inspection during the construction and testing phases of the project. This subsection includes definitions and design analysis requirements for both flexible and rigid pipes.

Proposed new §217.53(l) states the requirements for minimum and maximum slopes to ensure that gravity collection systems flow correctly.

Proposed new §217.53(m) states the alignment requirements for collection systems. The commission proposes to prohibit variances from uniform grade, grade breaks, and vertical curves, without manholes with open cut construction and prohibit construction methods that use flexure of a pipe joint. The prohibitions are necessary to protect human health and environment.

The rule authorizes horizontal pipe curvature if supporting calculations are included in the report and the plans. The executive director receives frequent requests for this type of variance. The rule allows this type of construction with proper safeguards, because it is not always possible to construct straight pipes due to topographic features. The rule sets 300 feet as the maximum allowable manhole spacing for sewers with horizontal curvature and requires that a manhole must be at the point of curvature and point of termination of each curve. These manhole spacing requirements are consistent with §217.55(a)(1).

Proposed new §217.53(n) enumerates the requirements for inverted siphons and sag pipes, including sizing, cleaning, velocity, odors, and testing.

Proposed new §217.53(o) contains requirements for bridged sections. These requirements give the regulated community criteria to design bridged pipelines and allow the executive director to perform consistent reviews of bridged sections.

Proposed new §217.54, Criteria for Laying Pipe , establishes the requirements for pipe embedment material, embedment compaction, envelope size, and excavated trench width. Proper pipe construction is necessary for proper operation and life expectancy of a collection system. This provision will protect human health and the environment.

Proposed new §217.55, Manholes and Related Structures , explains manhole placement, size, structure, types, spacing, and the size increase of a manhole opening. This section requires that manholes be placed at all points of change in alignment, grade, or size of the collection system and lists specific design requirements for manholes. The rule specifies spacing for straight alignment and uniform grade, with modifications in areas subject to flooding. The inside diameter of manhole openings is specified, as well as size of manhole covers and design requirements for manholes in the 100-year floodplain. This section also provides the design specifications for manhole inverts, connections, vents, and cleanouts.

In proposed new §217.55(k) the rule changes the minimum clear opening from 24 inches required in Chapter 317 to 30 inches in diameter for a manhole where personnel entry is anticipated. This diameter requirement will ease the entry of personnel and equipment and provide additional safety when necessary for sewer maintenance and repairs. Additionally, the rule specifies that the opening must be free of any obstructions.

Proposed new §217.55(l)(1)(D) requires that a manhole cover located in a public or private roadway meet the American Association of State Highways and Transportation Officials (AASHTO) standard M-306 in relation to load bearing. The commission proposes this new standard to ensure that manhole covers are strong enough to support vehicle traffic. This standard protects vehicles and the integrity of the manholes.

Proposed new §217.55(m) prohibits steps in a manhole. The environment inside a manhole may be corrosive and cause the steps to deteriorate.

Proposed new §217.55(n) contains the requirements for connections made within and to a manhole.

Proposed new §217.55(o) requires vents be located above the 100-year flood elevation to prevent flooding, and that tunnel venting requirements are consistent with manhole venting requirements.

Proposed new §217.55(p) requires that cleanouts are equal in size to the collection main to allow the cleaning equipment to fit into the cleanouts.

Proposed new §217.56, Trenchless Pipe Installation , describes the trenchless technologies that may be approved through the standard approval process. Trenchless methods other than those listed in this section are subject to the nonconforming technology approval process.

Proposed new §217.57, Testing Requirements for Installed Gravity Collection System Pipes, requires that the design specify an infiltration, exfiltration, or low-pressure air test and that test results are submitted to the executive director upon request. This section also contains the testing requirements. The section requires that a pipe be retested following any remediation action to clarify that a test must ensure that the remediation action was successful.

Proposed new §217.58, Testing Requirements for Manholes , requires that all manholes must pass a leak test and outlines the requirements for leak-testing a manhole. The commission modified these requirements from Chapter 317 by requiring the test to be run after assembly and backfilling the manholes. These requirements conform to the wastewater industry standards for manhole testing and allow an owner to select an appropriate testing method.

Proposed new §217.59, Lift Station Site Requirements , establishes the criteria for lift station sites. They ensure accessibility by authorized personnel only, protection from 100-year flood events, and minimization of odors.

Proposed new §217.60, Lift Station, Wet Well, and Dry Well Designs , establishes criteria for pump controls, flood protection, wet wells, lift station ventilation (including passive ventilation for wet wells and mechanical ventilation in lift stations), wet well slope, hoisting equipment, dry well/vault valve drains, and dry well sump pumps. These requirements ensure proper operations, prevent sanitary sewer overflows, and protect the safety of the surrounding community.

Proposed new §217.61, Lift Station Pumps , establishes general requirements for the pumps that may be used in lift stations. This section incorporates current engineering practices.

Proposed new §217.61(a) requires that all raw wastewater pumps must be capable of passing a sphere equal to or greater than 2.5 inches in diameter.

Proposed new §217.61(b) states that pump design must accommodate easy removal of the rotation elements.

Proposed new §217.61(c), (d), and (e) add requirements to ensure that a lift station does not pump more water into a treatment facility than it can process, unless flow splitting or equalization is provided.

Proposed new §217.61(f) specifies how a self-priming pump must be designed for a collection system.

Proposed new §217.61(g) specifies the provisions for vacuum priming pumps that allow flexibility in selecting pumps for lift stations.

Proposed new §217.61(h) specifies the requirements for vertical positioning of pumps. Because the commission added vacuum-primed pumps in §217.61(g), the rule includes them as exempted pumps for consistency with the requirements for self-priming pumps.

Proposed new §217.61(i) states that a grinder pump that is privately owned, maintained, and operated and serves only one structure is not subject to this chapter because it is considered part of the plumbing of the structure and not part of the collection system.

Proposed new §217.61(j) sets the standards for a pump for a low-flow lift station so that odors do not collect.

Proposed new §217.62, Lift Station Pipes , establishes requirements for pump suctions, valves, and pipes that must be used in the design of lift stations. The rule allows flexibility in the design of lift station piping.

Proposed new §217.63, Emergency Provisions for Lift Stations , establishes provisions for handling a lift station failure. This section incorporates current engineering practices and requires lift station designs to prevent water pollution in the event of an overflow or discharge of raw wastewater.

Proposed new §217.63(e) prohibits the use of spill containment structures to provide service reliability, but authorizes a spill containment structure if service reliability is provided by another approved method.

Proposed new §217.64, Materials for Force Main Pipes , establishes the requirements for materials used for force main pipe. The rule requires that the force main pipes material must withstand the pressure generated by instantaneous pump stoppage due to power failure under maximum pumping conditions.

Proposed new §217.65, Force Main Pipe Joints , incorporates current engineering practices for joints of force mains in buried service. This section requires that joints have either push-on rubber gaskets or be mechanical joints with a pressure rating equal to or greater than the pipe material. Additionally, this section requires that exposed joints be flanged or flexible and adequately secured to prevent movement due to surges. National reference standards for the joints must be included in the project specifications. These requirements specify force main pipe joint requirements for the regulated community.

Proposed new §217.66, Identification of Force Main Pipes , requires a detector metal tape in the same trench above and parallel to the force main. The words "pressurized wastewater" must be repeated continuously on the tape in letters at least 1.5 inch high. The commission proposes this requirement to ensure that the pipe can be located by conventional equipment and by sight.

Proposed new §217.67, Force Main Design , specifies the requirements for velocities, detention time, water hammer from surges, gravity main connections, pipe separation distances, odor control, and air release valves in force main design to reflect current engineering practices and standards.

Proposed new §217.68, Force Main Testing , explains the required pressure testing procedures for force mains. To simplify the calculation for the minimum test pressure, the design pressure was set at 50 pounds per square inch (psi) above the normal operating pressure of the force main.

Proposed new §217.69, Reclaimed Water Facilities , states the requirements for the design of distribution systems that will convey reclaimed water to a user. These requirements are written for consistency with Chapter 210, Use of Reclaimed Water.

Proposed new §217.70, Storage Tanks for Reclaimed Water , is the design requirements for both elevated and ground-level storage tanks. These requirements are written for consistency with the storage requirements in Chapter 210, Use of Reclaimed Water, and Chapter 331, Underground Injection Control.

SUBCHAPTER D. ALTERNATIVE COLLECTION SYSTEMS

Subchapter D expands the requirements for alternative collection systems so that more of these systems can be given a standard review and approval. Under Chapter 317, many of these systems required review and approval under the variance, nonconforming, or innovative technology sections. These rules expand the criteria to provide the owner of an alternative collection system more options for design, management, and oversight of the system.

Proposed new §217.91, Edwards Aquifer, notifies the regulated community that the design of alternative collection systems must comply with Chapter 213, Edwards Aquifer, in addition to the requirements in this chapter.

Proposed new §217.92, Component Sizing, uses current engineering practices to establish that component size must be based on existing flow data from similar systems and service areas whenever such data is available. It contains the formulas for sizing components if there is no comparable data. This section also prohibits roof, street, or other types of drains that permit entrance of storm water runoff into the wastewater collection system because combined collection systems are prohibited by §281.25 and 40 CFR §122.26.

Proposed new §217.93, General Requirements , subsection (a) states that, except where specifically stated in this subchapter, designs for alternative wastewater collection systems must comply with the applicable requirements of Subchapter C, in addition to the requirements of Subchapter D.

Proposed new §217.93(b) requires the owner to prepare a manual that specifies the operating procedures and maintenance practices for each alternative wastewater collection system.

Proposed new §217.93(c) ensures compliance with subsection (b).

Proposed new §217.94, Management, states the requirements for management of an alternative collection system by making them specific. This provision will allow the owner of an alternative collection system to know more precisely what is required for managing these types of systems.

Proposed new §217.94(a) requires that an alternative wastewater collection system discharge to wastewater facility permitted by the commission.

Proposed new §217.94(b) authorizes the owner of an alternative wastewater collection system to operate the system or to contract for management and operation services with a public or private service provider. The owner may terminate the contract if the provider's services are in conflict with the contract requirements, the wastewater permit, the requirements of this chapter, or other commission rules. These requirements provide owner flexibility in the management of an alternative collection system.

Proposed new §217.94(c) exempts grinder pumps and septic tank effluent pumps discharging directly into a conventional wastewater collection system because these items are considered part of a service lateral pipe and not part of the alternative collection system.

Proposed new §217.95, Service Agreements , specifies the requirements for alternative collection system service agreements and establishes that a service agreement must be executed between the system owner and the service provider. These requirements eliminate inconsistencies regarding how the rule is interpreted. In the past, the executive director has received questions and reviewed submissions regarding the interpretation of these provisions on a case-by-case basis.

Proposed new §217.96, Small Diameter Effluent Sewers , establishes the criteria for the components of a small diameter effluent sewers (SDES), including interceptor tank design, pre-treatment units, tank monitoring, service pipe design, and collection system design, including hydraulic design and vertical alignment.

Proposed new §217.96(a) contains the requirements for interceptor tank design. These requirements were added to ensure consistency with Chapter 285, On-Site Sewage Facilities.

Proposed new §217.96(b) adds requirements for pretreatment units to prevent fats, oils, grease, and sludge from entering the collection system.

Proposed new §217.96(c) contains requirements to ensure that service pipe design conforms to standard engineering practices.

Proposed new §217.96(d) contains requirements for an acceptable SDES design, including hydraulic and vertical design, and to ensure that the executive director can determine compliance with these requirements.

Proposed new §217.97, Pressure Sewers, contains requirements that establish the design criteria for pressure sewers, including pumps service pipes, on-site mechanical equipment, discharge pipes and the collection system. These requirements are included because of questions from the regulated community regarding pressure sewer requirements. These requirements conform to standard engineering practices.

Proposed new §217.98, Vacuum Sewer Systems , brings the provisions for vacuum sewer systems up-to-date with current technology and industry standards. The requirements in this section clarify that a vacuum sewer system is nonconforming technology and may be reviewed by the executive director in accordance with §217.7(b)(2). Historically, the design criteria rules have not contained specific provisions regarding vacuum sewers and the staff has answered questions on a case-by-case basis or reviewed requests for variances for vacuum sewers. These requirements standardize the requirements for vacuum sewers and eliminate the need for many variances.

Proposed new §217.99, Testing Requirements , requires testing all components of an alternative collection system for leaks. These provisions set the minimum testing requirements that conform to standard engineering practices.

Proposed new §217.100, Termination, requires that an alternative collection system terminate at a treatment facility or into a conventional collection system. It also outlines the parameters of the connection between an alternative collection system and a treatment facility or conventional collection system.

SUBCHAPTER E. PRELIMINARY TREATMENT UNITS

Subchapter E creates a separate place for the requirements relating to the first units in a treatment facility. Chapter 317 combined all treatment facility design requirements into one section. This subchapter allows for better, clearer organization and explanation of the requirements for these units.

Proposed new §217.121, Coarse Screening Devices , specifies that all wastewater treatment facilities must use a coarse screening device, unless otherwise provided in this chapter. This section also incorporates new safety and design requirements for coarse screening devices, including location, screen openings, hydraulics, and corrosion resistance of screens and related structure. These requirements protect the process units in the facility because coarse screening devices prevent large debris from entering the treatment units.

Proposed new §217.122, Fine Screening Devices , provides a definition for a fine screen that conforms to industry standards and explains that, although not required, fine screens may be used in lieu of coarse screens, because of improved technology. This section also provides the circumstances under which it is acceptable to use a fine screen in lieu of a primary sedimentation unit. These requirements incorporate improved technology and ensure consistency with new design parameters.

Proposed new §217.123, Screenings and Debris Handling , specifies that all screenings and debris collected must be managed and disposed of in accordance with 30 TAC Chapter 330, Municipal Solid Waste.

Proposed new §217.124, Grit Removal Systems , requires that all treatment facilities using anaerobic digesters must have grit removal systems, because grit can damage anaerobic digesters. Grit removal must occur prior to an anaerobic digester to ensure that as little inert material as possible enters the anaerobic digester. The rule also defines what constitutes grit removal and makes grit removal optional for other facilities.

Proposed new §217.125, Grit Chambers, updates the Chapter 317 requirements and adds new requirements for horizontal flow grit chambers, aerated grit chambers, mechanical grit chambers, cyclonic degritters, and vortex chambers. These requirements are based on manufacturer's recommendations and standard engineering practices.

Proposed new §217.126, Grit Handling, explains the requirements for grit washing, storage, and disposal.

Proposed new §217.127, Pre-Aeration Units , authorizes pre-aeration to be used for odor control, flocculation of solids, reducing septicity, grease separation, and promoting uniform distribution of solids to clarifiers. It also requires the report to include the basis for pre-aeration system designs. These requirements clarify when a facility requires a pre-aeration unit.

Proposed new §217.128, Flow Equalization Basins , explains design requirements for determining when a flow equalization basin must be used, and the mixing, aeration, volume and pumped flow requirements of equalization basins. These requirements ensure that facilities can handle periodic high flows.

Proposed new §217.129, Primary Clarifiers , establishes the design criteria for primary clarifiers, including the requirements for inlets, scum removal, effluent weirs, basin sizing, including the maximum surface loading at peak flow, maximum surface loading at design flow, minimum effective detention time at peak flow, and minimum effective detention time at design flow. The requirements for final clarifiers are in Subchapter F for better organization of the requirements. This section also includes the requirements for sidewater depth, freeboard, drains, accessibility, 5-day biochemical oxygen demand (BOD₅) removal, sludge pumping, and sludge pipes.

SUBCHAPTER F. ACTIVATED SLUDGE SYSTEMS

Subchapter F explains the requirements for activated sludge systems, which comprise the majority of treatment facilities. Rule provisions are included to address new technologies, such as sequencing batch reactors and membrane bioreactor systems and other rule provisions are included to allow for flexibility in design methods, such as the volume flux method.

Proposed new §217.151, Requirements for an Aeration Basin , provides the requirements for minimum dissolved oxygen concentration in aeration basins and alternate aeration basin volumes. The requirements ensure that the contents of the basin are thoroughly mixed, allow flexibility in the design of aeration basins, and prohibit the use of contact stabilization for nitrification. These requirements meet current engineering standards for aeration basins.

Proposed new §217.152, Requirements for Clarifiers , provides the requirements for activated sludge clarifier components such as inlets, scum removal, effluent weirs, sludge pipes, sludge collection equipment, pumped inflow, side water depth, and redundancy. This section also provides restrictions on hopper bottom clarifiers, prohibits designs that allow short-circuiting of influent or effluent weirs, and specifies the calculations that are required to determine return sludge pumping capacity. Additionally, the language notes that the sludge digester or disposal methods must comply with 30 TAC Chapter 312, Sludge Use, Transportation, and Disposal.

Proposed new §217.153, Requirements for Both Aeration Basins and Clarifiers , lists the requirements related to construction material, freeboard, redundancy, and flow control that are common to both aeration basins and clarifiers.

Proposed new §217.154, Aeration Basin and Clarifier Sizing--Traditional Design , subsection (a) provides the standard design values to be used to size aeration basins and clarifiers when using the traditional design approach.

Proposed new §217.154(b) contains the requirements for aeration basin sizing. The size of an aeration basin must be based on the organic loading of the influent and the permitted effluent limits. The aeration basin volume must be calculated to ensure that the organic loading on the aeration basins does not exceed a rate that might cause a violation of permitted effluent limits. This requirement also authorizes loading rates to vary from the requirements of this section, if justified in the report.

Proposed new §217.154(c) contains the requirements for clarifier sizing. It establishes the maximum surface loading rates and the minimum detention times used to determine the size of an activated sludge clarifier.

Proposed new §217.155, Aeration Equipment Sizing , updates, explains, and adds flexibility to the methods for achieving the proper oxygenation of the wastewater by mechanical or diffused aeration systems. It includes processes formerly considered nonconforming or innovative technologies that have become industry standards. This will streamline the review process and allow the executive director to grant a standard approval to facilities that would have needed a variance under Chapter 317.

Proposed new §217.156, Sequencing Batch Reactors , explains the design criteria for Sequencing Batch Reactors (SBRs), including the number of basins and tanks, aeration requirements, utilization of duplicate controllers, measures for flow variation, and decanting devices. These requirements allow greater flexibility in SBR design options. Staff has identified a trend of increased use of these designs in Texas. SBRs have a significant appeal for small communities because a properly designed SBR can achieve a high degree of treatment at a reduced cost. In order to ensure protection of human health and environment, the rules codify the standards for SBRs that the executive director currently uses to review these designs.

Proposed new §217.157, Membrane Bioreactor Systems , outlines the requirements for Membrane Bioreactor Systems (MBRs) that were considered innovative technology in Chapter 317. MBRs have gained wide acceptance in the wastewater industry. Including standards for these systems informs the regulated community of the standards the executive director will use to review these systems. It also authorizes the executive director to grant a standard approval for MBRs that meet these requirements instead of reviewing each facility for a variance on a case-by-case basis. Standards for these requirements were based on information gathered from other states' rules and numerous engineers, consultants, and vendors experienced in MBR design and operation.

Proposed new §217.157(a) is the applicability statement. It includes the notice that an MBR that does not meet the requirements of this section is innovative technology and is subject to approval under §217.7(b)(2).

Proposed new §217.157(b) contains the acceptable performance standards for MBRs. Any design based on performance standards greater than the ones in this subsection must be justified by supporting data.

Proposed new §217.157(c) contains the design standards for both flat plate and hollow tube MBRs, including parameters for pretreatment, biological treatment, aeration, recycle rates, nutrient removal, use of membranes, membrane design, supporting data, redundancy, other equipment, and disinfection.

Proposed new §217.157(d) contains the standards for operating an MBR including membrane cleaning, operational parameters, and control instrumentation.

Proposed new §217.157(e) outlines the requirements for the use and disposal of chemicals associated with an MBR.

Proposed new §217.157(f) ensures that operators assigned to an MBR are trained and familiar with its operation.

Proposed new §217.157(g) requires an MBR to be covered by a warranty and authorizes the executive director to require a performance bond if there is a question about the MBR's ability to perform to the standards of this chapter.

Proposed new §217.158, Solids Management , specifies the requirements for properly handling sludge within the treatment facility, including recycling, monitoring, wasting, solids blanket, return activated sludge pump design, waste activated sludge pump design, and piping.

Proposed new §217.158(a) requires that the return sludge system operate satisfactorily at all anticipated flow conditions in order to protect human health and environment.

Proposed new §217.158(b) requires adequate equipment to store and/or process the waste activated sludge under all flow conditions. Staff experience has shown that some small facilities did not have adequate sludge wasting equipment, causing unauthorized discharges into waters in the state. This provision prevents this shortcoming to protect human health and the environment.

Proposed new §217.158(c) and (d) contains the sludge pump requirements. This requirement ensures that the facility will be able to pump sludge under all conditions with the largest pump out of service and is consistent with other redundancy requirements in this chapter.

Proposed new §217.158(e) includes the standards for the design of the sludge pipe system that include provisions to address cleaning, flushing, solids settling, and scouring.

Proposed new §217.159, Process Control, provides the criteria for implementing solids retention time (SRT) control and aeration system control.

Proposed new §217.159(a) requires that an activated sludge facility be designed with the necessary equipment for an operator to control the SRT in the aeration tanks by wasting a measured volume of surplus activated sludge regularly. The report and the operating manual must provide the formulas for determining the SRT. This requirement was added because an operator must manage for an activated sludge facility to operate properly.

Proposed new §217.159(b) lists the requirements for aeration control. A facility may be designed to adjust the airflow in proportion to the biological loading of the influent. If this type of control is installed, the aeration equipment must be easily adjustable and must maintain solids in suspension. This requirement allows flexibility in designing aeration controls and conserves energy.

Proposed new §217.160, Operability and Maintenance Requirements , explains the requirements of having equipment that is designed to operate at the temperature extremes of the facility location, being accessible to staff for operation and maintenance, and being housed in facilities with adequate room for removal, repair, and installation. This section was added in response to problems encountered.

Proposed new §217.161, Electrical and Instrumentation Systems , establishes power supply requirements for facility equipment, safety requirements for electrical equipment, and design standards for alarm systems for malfunctioning equipment. These requirements ensure that a facility is monitored and protected from vandalism, natural disasters, power interruptions, and equipment failures.

Proposed new §217.162, Internal Process Flow Measurement , requires facilities with design flows greater than 400,000 gallons per day to include process flow measurement. An operator must be able to determine the return rates and flow rates to properly operate the facility. This requirement addresses this operational need.

Proposed new §217.163, Advanced Nutrient Removal , provides the requirements for including processing units that removed nutrients other than the standard effluent set (total suspended solids, biochemical oxygen demand, ammonia-nitrogen). Chapter 317 considered advanced nutrient removal innovative technology, but technology has improved and advanced nutrient removal is required at many facilities. It authorizes the executive director to grant a standard approval for advanced nutrient removal designs that meet these requirements instead of reviewing each facility on a case-by-case basis. Standards for these requirements were based on information gathered from other states' rules and numerous engineers and consultants.

Proposed new §217.164, Aeration Basin and Clarifier Sizing--Volume-Flux Design Method , provides an alternative method to determine the size of aeration basins and clarifiers. This requirement was added to allow flexibility in designing a treatment facility and is needed to ensure that the volume-flux design methods are consistent with sound engineer practice. The volume-flux design approach is as protective of human health and the environment as the traditional design method.

SUBCHAPTER G. FIXED FILM AND FILTRATION UNITS

Proposed new §217.181, Applicability, states that this subchapter applies to trickling filters, rotating biological contactors, submerged biological contactors, and filtration systems.

Proposed new §217.182, Trickling Filters--General Requirements , states the general requirements for the use of trickling filters, which are secondary aerobic biological processes used for treatment of wastewater. This section defines biofilters or biotowers as trickling filters that use random or stackable modular synthetic media. This section also provides requirements for determining process applicability and pretreatment requirements.

Proposed new §217.182(a) contains the requirements for process applicability and explains that trickling filters are classified according to applied influent hydraulic and organic loadings.

Proposed new §217.182(b) contains the requirements for trickling filter classification and classifies trickling filters based loading rates. In Chapter 317, trickling filters were distinguished based on their role in treatment. These requirements specify the different types of trickling filters according to their capacity.

Proposed new §217.182(c) contains Table G.1, which contains the hydraulic and organic loadings for different classes of trickling filters. The values in the table update the standards for consistency with current technology.

Proposed new §217.182(d) contain the requirements for pretreatment. All trickling filters must have upstream preliminary treatment units that remove grit, debris, suspended solids, oil, grease, and large particles, as well as control the release of hydrogen sulfide.

Proposed new §217.182(e) contains the requirements for materials and placement of rock filter media. These requirements ensure that the rock media filter material will function properly.

Proposed new §217.182(f) contains the requirements for synthetic (manufactured or prefabricated) media materials. The executive director may consider synthetic media materials to be innovative or nonconforming technology subject to review under §217.7(b)(2). Additionally, the provisions for structural integrity state that the structural design must support the synthetic media, water flowing through or trapped in voids, the maximum anticipated thickness of wetted biofilm. The synthetic media must also support the weight of a person while the trickling filter is in operation, unless separate provisions are made for maintenance access.

Proposed new §217.182(g) contains the requirements for filter dosing and requires that the design include suitable flow characteristics for the application of wastewater to the filters by siphons, pumps, or gravity discharge from preceding treatment units. The commission requires design provisions to control instantaneous dosing rates under both normal operating conditions and filter-flushing conditions. Table G.2 provides design ranges of dosing intensity for normal usage and flushing periods. This requirement is included for consistency with current industry standards and to provide more specific information regarding filter dosing.

Proposed new §217.182(h) includes the requirements for distribution equipment. A trickling filter must include electrically driven, variable speed filter distributors to allow operation at optimum dosing intensity independent of recirculation pumping. This requirement prevents failures from unequal distribution and drying of the media and conforms to standard engineering practices. Additionally, the rule specifies that if existing rectangular trickling filters are retrofitted with rotary distributors, any media that will not be fully wetted must not be considered as part the effective treatment area of the process.

Proposed new §217.182(h)(11) requires that rotary distributors operate at speeds of at least one revolution per 30 minutes to prevent unequal distribution and drying of the media.

Proposed new §217.182(h)(12) requires that trickling filters with a height or diameter that does not allow removal and replacement of distributors by a crane must provide jacking columns and pads at the distributor column. Some trickling filters have been designed without a way to remove the distributors once they are in place. This situation has caused problems when the distributors need to be repaired or replaced and this requirement is included to address the problem.

Proposed new §217.182(i) contains the requirements for recirculation. In paragraph (1), it requires the minimum flow rate be sufficient to keep the rotary distributors turning by requiring designs using hydraulically driven distributors to keep rotary distributors turning at the minimum design rotational velocity. This requirement applies to any facility that treats at least 400,000 gallons per day to remain consistent with the other requirements in this chapter.

Proposed new §217.182(i)(2) contains the requirements to provide recirculation that supplements influent flow if design and flushing dose intensities are not achieved solely by control of distributor operation. Controls for the distributor speed and recycle pumping rate must provide optimum dosing intensity under all anticipated influent flow conditions. This provision is included because recirculation helps to optimize removal efficiencies.

Proposed new §217.182(i)(3) contains the requirements for process calculations. The benefits of recirculation are primarily related to dosing intensity, and may often be achieved by control of the distributor speed only. The report must describe a design that propose recirculation for removal of remaining organic matter in the wastewater, identify the effect of dilution of the influent on the rate of diffusion of dissolved organic substrates into the biofilm, the effect of reduced influent concentrations on reaction rates in sections of the filter having first order kinetics. This requirement is included because it is consistent with current industry standards and provides more specific direction regarding process calculations.

Proposed new §217.182(i)(4) contains the requirement that recirculation rates may not exceed four times design flow, unless the report provides calculations to justify the higher rate. This requirement was added for consistency with industry standards.

Proposed new §217.182(i)(5) states that if influent organic loadings are constant, a facility must use direct recirculation of unsettled trickling filter effluent and that the distributor nozzles handle the sloughed biofilm. These provisions ensure that distributor nozzles do not become clogged. If influent organic loadings are variable, a facility must recirculate effluent from the final clarifier to either the primary clarifier or to the trickling filter to equalize organic loading. The input point of recirculated influent depends on the content of the influent.

Proposed new §217.182(j) contains the requirements for average hydraulic surface loading. Section 217.182(j)(2) includes "except in roughing applications" to the requirement because roughing applications can exceed the average hydraulic surface loadings of filters with crushed rock, slag, or similar media. Roughing applications by definition are systems that only partially filter the wastewater.

Proposed new §217.182(k) contains the requirements for underdrain system design. The requirement follows the manufacturer's recommendation to ensure that the media will be properly installed and used.

Proposed new §217.182(l) requires the floors of underdrain systems to be sloped. Trickling filters using stackable modular synthetic media must slope toward the drainage channel based upon filter size and hydraulic loading. Staff has identified an increased use of stackable modular synthetic media and the provision set requirements for stackable modular synthetic media in order to protect human health and the environment.

Proposed new §217.182(m) contains the requirements for passive ventilation that are included to conform to standard industry practice and to protect human health and the environment.

Proposed new §217.182(n) contains the requirements for forced ventilation. Equation G.2 and the values in Table G.3 set minimum airflow rates. These requirements provide an option for nitrification. They establish the minimum criteria for forced air ventilation for trickling systems based on standard engineering practices.

Proposed new §217.182(o) contains the requirements for cleaning, sloughing, controlling nuisance organisms, and corrosion control. Proper maintenance is necessary for proper operation of the equipment.

Proposed new §217.182(p) requires that a trickling filter system include a means to measure flows to the filter and recirculation flows.

Proposed new §217.182(q) contains the requirement for odor control. Paragraph (1) requires that a trickling filter system use ventilation capable of controlling odors at design flow and during periodic flushing. The paragraph also states that the executive director may require a facility with a history of odor complaints to cover its trickling filter. Covers trap odors and the scrubbers or adsorption columns remove the odors from the air before it is vented from the system.

Proposed new §217.182(q)(2) requires that a trickling filter with high influent organic loadings have forced ventilation to minimize odors and lists the options for handling odorous off-gases. These requirements are included to allow design options for odor control.

Proposed new §217.182(r) requires that the final clarifiers be sized to handle the additional total suspended solids due to the biomass.

Proposed new §217.182(s) lists elements that must be included in the report related to fixed film and filtration.

Proposed new §217.183, Nitrifying Trickling Filters--Additional Requirements, provides requirements in addition to §217.182 for using trickling filters to provide nitrification sufficient to meet the requirements of a wastewater permit. This section includes requirements for ventilation, temperature, pH, predation, hydraulic application rates, media, tertiary nitrification filter, combined BOD/nitrification filters, and to update the rules to comply with engineering design advances. Currently, many wastewater permits require nitrification based on modeling of the receiving water for a wastewater discharge. This requirement was added to reduce toxicity and maintain the dissolved oxygen level in receiving waters. To assist facilities in meeting the new nitrification requirements, new engineering standards were developed and these provisions are consistent with current industry standards.

Proposed new §217.184, Dual Treatment Using Trickling Filters , explains the requirements and processes for use of trickling filters or other attached growth units in series with suspended growth processes. This section includes classification of dual treatment processes, design criteria for attached and suspended growth processes, and treatment unit design criteria. Each combination option in this section is protective of human health and the environment.

Proposed new §217.184(c)(1) - (4) require that the design of suspended and attached growth systems include all of the features and operational capabilities required for the same treatment units when used for single-process treatment, as well as pretreatment, snail control, return sludge, and aeration. Additionally, an aeration system for a second-stage treatment unit in a facility designed for nitrification must transfer sufficient oxygen for biomass growth; respiration for both carbonaceous material oxidation and nitrification; and oxygen demand due to biomass sloughing events from the first stage.

Proposed new §217.184(c)(5) requires that a second-stage suspended growth process operate in a way that varies the age of the sludge and that a nitrifying dual system control the total combined mean cell residence time. This provision ensures adequate time for nitrification to occur.

Proposed new §217.184(c)(6) requires a minimum hydraulic residence time for consistency with standard engineering practices.

Proposed new §217.184(c)(7) requires nitrification using a dual treatment process including a sludge re-aeration basin if the second process is an aerated solids contact basin or an intermediate clarifier if the second process is an activated sludge aeration basin. This provision is consistent with standard engineering practices.

Proposed new §217.185, Rotating Biological Contactors , provides the requirements and provisions for the use of improved Rotating Biological Contractors (RBC) units, including pretreatment, enclosures and ventilation, media design, design flexibility, tank configuration, control of unwanted growth in the initial stages, downtime maintenance provisions, bearing maintenance, organic loading design requirements, hydraulic loading design requirements, stages of RBC units, drive systems, and dissolved oxygen.

Proposed new §217.185(a) requires pretreatment of wastewater entering an RBC so that the RBC will operate properly and provide the expected treatment results.

Proposed new §217.185(b) requires that the RBC unit be covered and have adequate ventilation, and to include access doors and observation ports to allow access and a visual inspection of the RBC without having to open the unit.

Proposed new §217.185(c) and (d) contain the required and optional design criteria for RBCs and requires that these items be included in the report.

Proposed new §217.185(e) requires that an RBC tank minimize the zones in which solids will settle out and contains a requirement that an RBC tank must include tank drains to facilitate removal of any accumulated solids. This requirement is included to ensure that the tanks maintain adequate treatment capacity.

Proposed new §217.185(f) authorizes the use of chlorine upstream of an RBC system to control the growth of beggiatoa, which is an unwanted microorganism that may inhibit the initial stage of an RBC system. This requirement was added because chlorine may control the growth of beggiatoa without harming the operation of the RBC.

Proposed new §217.185(g) and (h) contains the provisions for maintenance. An RBC system designed for a facility with a permitted flow of at least 1.0 mgd must have three or more stages in series. A stage must be capable of being taken off-line for maintenance or cleaning. RBC bearings must be easily accessible for inspection and lubrication. These requirements ensure that maintenance can be performed without interrupting operation of the facility.

Proposed new §217.185(i) contains the requirements to base the organic loading for an RBC system on total BOD_5, to adjust the required RBC media area to compensate for the ratio of soluble BOD₅ to total BOD₅ , and to set the allowable organic loading for the entire RBC system. In Chapter 317, these requirements were in a table. This provision incorporates them into the proposed rule language to make them more readable.

Proposed new §217.185(j) contains the requirements for an RBC system to include flow equalization when the peak-to-design flow ratio is higher than 2.5 to 1.0 to prevent loss of fixed growth from the media. The first stage of the RBC system must include a means of spreading the influent evenly across the media to ensure that the fixed growth is not scoured. This provision is consistent with industry standards.

Proposed new §217.185(k) contains the requirements for stages. A stage includes one or more RBC unit divided by a vertical baffle or wall. An RBC system designed for BOD₅ removal must have at least three stages in series, unless the report justifies a lesser number.

Proposed new §217.185(l) requires that an RBC drive system handle the maximum anticipated media load and allows a variable speed drive system and the RBC units to be mechanically or air driven.

Proposed new §217.185(m) contains the requirements for dissolved oxygen in an RBC and states that the executive director may require supplemental aeration.

Proposed new §217.186, Nitrifying Rotating Biological Contactors , provides additional requirements for RBCs used for BOD₅ removal and nitrification.

Proposed new §217.186(a) requires that an RBC system designed for BOD₅ removal and nitrification in a single system include four stages. This subsection also sets the maximum overall organic loading rate to be consistent with industry standards.

Proposed new §217.186(b) requires that a nitrifying RBC system include capabilities for chemical addition if the influent pH is below 7.0. This requirement ensures that the pH can be raised to a neutral level if the pH is too acidic. The fixed growth media does not function efficiently if the pH is below 7.

Proposed new §217.186(c) requires that the report justify the nitrification rate of the system to ensure that the executive director can efficiently review the design of the nitrification rate of the system.

Proposed new §217.186(d) states that a nitrifying RBC system may be subject to the requirements of §217.7(b)(2).

Proposed new §217.187, Dual Treatment Systems Utilizing Rotating Biological Contactors, explains the requirements for allowing RBC units to be used in conjunction with other units and to conform to engineering design advances. These combined systems may be subject to the requirements of §217.7(b)(2). This provision allows an owner the flexibility to use RBC units in conjunction with existing treatment units.

Proposed new §217.188, Submerged Biological Contactor , proscribes the process for designing SBCs using criteria similar to RBC criteria except that two air headers are required for each SBC unit and any submerged bearings must be sealed. These changes comply with current engineering standards.

Proposed new §217.188(a) states that an air driven SBC system does not require a cover, since 60% of a unit is submerged and the possibility of the media drying out is low.

Proposed new §217.188(b) requires an SBC system to use the same pretreatment as an RBC and must meet the criteria §217.184 with two exceptions, headers and bearings.

Proposed new §217.189, Dual Treatment Systems Using Submerged Biological Contactor, authorizes an SBC unit to be used in conjunction with other systems. This provision allows an SBC system to be used as a roughing unit in series with activated sludge and to be installed in existing activated sludge basins to create a combination fixed and suspended growth process. The rule requires that the report include supporting data, calculations, process descriptions, and vendor information to describe how the proposed system will provide the required treatment levels; and specifies that these designs may be subject to the requirements of §217.7(b)(2). These provisions allow flexibility to use existing systems when expanding an existing facility and are consistent with standard engineering practices.

Proposed new §217.190, Filtration, states the general requirements for filtration systems such as permit water quality requirements, redundancy, source of backwash water, disposition of backwash water, sequence of treatment units, overload conditions, and control of slime growth.

Proposed new §217.190(a)(1) requires that a treatment facility with tertiary effluent limitations (e.g., total suspended solids effluent limit less than 15 milligrams per liter) use filtration to supplement suspended solids removal.

Proposed new §217.190(a)(2) authorizes a treatment facility with secondary or advanced secondary effluent limitations to use filtration to supplement operation if filters are not necessary to meet permitted effluent limitations. Filtration reduces oxygen-demanding substances by removing the non-soluble fraction of the clarifier effluent and normally provides effective removal for suspended biological floc and residual materials that remain after secondary clarification.

Proposed new §217.190(b) requires that a treatment facility using filtration to provide tertiary treatment for have a minimum of two filter units, and must provide adequate filtration with the largest filter unit out of service. If a filter is not required to meet permit requirements, only one filter is required. This may save the owner of the facility the expense of installing two filters.

Proposed new §217.190(c) requires a filtration system to use filtered effluent as the source of backwash water to ensure that the backwash sufficiently cleans the filter.

Proposed new §217.190(d) requires that a filtration system to return backwash water containing material cleaned from the filter to the head of the treatment facility for processing. Chapter 317 required that the wastewater be returned to an upstream treatment unit. This provision defines "upstream treatment unit."

Proposed new §217.190(e) requires that a final clarifier designed in accordance with Subchapter F precede a filter unit. A filter system may be used in conjunction with disinfection tanks to provide additional detention time. These provisions will allow by rule a practice that the executive director has allowed by variance. This process is protective of human health and the environment.

Proposed new §217.190(f) requires a facility design include a method to prevent effluent from overflowing from the wastewater treatment units. If not properly designed, during peak flows or excessive carryover of suspended solids from the final clarifier for an extended period of time, the filter units may overload and overflow.

Proposed new §217.190(g) requires that a filtration system provide periodic disinfection of the filters to control slime growth in the filter and backwash storage tank.

Proposed new §217.191, Additional Requirements for Deep Bed, Intermittently Backwashed, Granular Media Filters, includes the design criteria required in addition to the requirements in §217.190 for deep bed, intermittently backwashed, granular media filters, including application rates, media design, backwash system, underdrain system, tank design and controls.

Proposed new §217.191(a) sets application rates for single, dual, and mixed media filters. This subsection also requires that filters be able to treat the peak flow with one filter out of service.

Proposed new §217.191(b) contains the requirements for media design, including uniformity coefficient, particle size, depth of media, and underdrain systems.

Proposed new §217.191(c) contains the requirements for backwash systems. Backwash systems are critical to the operation of filters. These requirements ensure that the backwash systems function properly and adequately clean the filters.

Proposed new §217.191(d) requires that the underdrain system provide a uniform distribution for filter backwash without excessive head loss or plugging.

Proposed new §217.191(f) lists the requirement regarding tank design in relation to backwashing filters. These requirements are in place to ensure that filter media is not lost during backwashing.

Proposed new §217.191(g) sets the requirements for the backwash system control mechanism. These requirements ensure that the controls are adequate to allow proper monitoring and operation of the backwash process.

Proposed new §217.192, Additional Design Requirements for Multi-Compartmented, Low Head, Automatically Backwashed Filters, updates and explains that in addition to meeting the requirements in §217.191, additional design criteria for multi-compartmented, low head, automatic backwash filters including application rates, media design, backwash system, and traveling bridge apply.

Proposed new §217.192(a) sets the application rate for single, dual, and multi media filters. This option allows short-term overloading of the unit because it will not impair its function.

Proposed new §217.192(b) specifies media sizes and depths consistent with standard engineering practices.

Proposed new §217.192(c) contains the requirements for automatic backwash systems. This requirement changes the Chapter 317 requirement of 10 gallons per minute to 20 gallons per minute to reduce the backwash duration. The provision reduces the requirement of "30 to 60 seconds" in the Chapter 317 rules to "at least 20 seconds" to correspond to the increased gallons per minute. This change allows the filters to return to service more quickly.

Proposed new §217.192(d) provides that a traveling bridge that provides support and access to the backwash pumps and equipment must be constructed of corrosion-resistant materials, have adequate bridge tracking, safe support of the power cords, and automatic initiation of the backwash cycle. The requirement responds to questions from the regulated community regarding what is required for a traveling bridge and is consistent with current industry standards.

Proposed new §217.192(e) provides for automatic and regular removal of any floating material. Floating materials that are too large to pass through the filter system must be returned to the head of the facility to pass through a bar screen. This requirement ensures that floating material is properly processed.

Proposed new §217.193, Alternative Designs for Effluent Polishing , explains that the use of other processes for tertiary suspended solids removal, such as microscreens or countercurrent, continuous filtrate and backwash flow filters, will subject to the nonconforming technology requirements of §217.7(b)(2).

SUBCHAPTER H. NATURAL TREATMENT FACILITIES

Subchapter H addresses natural treatment systems separately from mechanical treatment facilities. This separation lets the commission address the different criteria and requirements needed to construct and operate treatment lagoons.

Proposed new §217.201, Applicability, states that this subchapter applies to Imhoff tanks, constructed wetlands, facultative lagoons, aerated and partially aerated lagoons, stabilization lagoons, treated effluent storage lagoons, evaporative lagoon systems, and overland flow processes.

Proposed new §217.202, Primary and Secondary Treatment Units , is the requirements for primary and secondary treatment units in natural treatment systems.

Proposed new §217.203, Design Criteria for Natural Treatment Facilities , updates and groups the requirements that apply to one or more of the natural treatment facilities or units. Natural treatment include flow distribution, windbreaks and screening, maximum liner permeability, embankment design and construction, disinfection, sampling point significance, and storm water drainage. These criteria provide more flexibility by allowing options that combine treatment methods. These options allow better use of the surrounding land features and better long range planning.

Proposed new §217.203(a) requires the shape and size of these treatment facilities to ensure even distribution of the wastewater.

Proposed new §217.203(b) requires that all natural treatment units include windbreaks if spray irrigation is used in a location where drift presents a risk of contact with the general public and allows the use of vegetative screening. The use, the type, and the extent of windbreaks or vegetative screening are subject to approval by the executive director.

Proposed new §217.203(c) contains the requirements for maximum liner permeability. These rules provide greater flexibility than the Chapter 317 rules and may allow a cost savings for the owner of the facility. Section 217.208 and §217.209 establish liner and permeability requirements for evaporative lagoon facilities or overland flow facilities systems.

Proposed new §217.203(d) contains the requirements for testing and compliance with the liner permeability requirements and requires that the report include the results of any tests required in this subsection. This testing protocol is consistent with the commission's current permit requirements and is more cost effective. This subsection establishes protocols to eliminate the need for a variance for using amended in-situ soils because amended in-situ soil protocol is as protective as using in-situ soils. The provision also requires a synthetic liner to have a thickness of 40 millimeters to protect groundwater from contamination.

Proposed new §217.203(e) contains the requirements for embankment design and construction. It will allow access for vehicles and maintenance equipment. It also prohibits steep embankments because these slopes have a greater potential to fail and make it difficult to maintain a vegetative cover. All embankments must be protected against erosion by planting grass, paving, riprapping, or other approved methods.

Proposed new §217.203(f) specifies that chemical or ultraviolet disinfection is not required if a detention time of at least 21 days is provided in a entire, free-water surface, natural treatment unit. This requirement is consistent with 30 TAC Chapter 309.

Proposed new §217.203(g) requires that holding time in a storage lagoon cannot be used to meet the permit 21-day detention time requirement for disinfection. Treated effluent storage lagoons may be used for municipal permit storage requirements or for reclaimed water projects and must comply with other requirements of Chapter 210.

Proposed new §217.203(h) requires that a natural treatment facility prevent storm water drainage into the treatment units.

Proposed new §217.204, Imhoff Tanks, provides updated design criteria for constructing Imhoff tanks that address settling compartments, surface loading, scum baffles, gas vents, digestion compartment loading, Imhoff tank dimensions, sludge removal, odor management, treatment efficiency, material, and construction. The design criteria regulating Imhoff tanks were repealed by the commission in 1990. These requirements are standard engineering designs for Imhoff tanks and are consistent with other commission rules.

Proposed new §217.205, Facultative Lagoons , provides the design criteria for facultative lagoons, including configuration of inlets and outlets, depth, organic loading, odor control, and removal efficiency. This provision allows flexibility in the design of lagoons protecting human health and the environment.

Proposed new §217.206, Aerated Lagoons, provides updated requirements for completely and partially mixed aerated lagoons. The requirements address redundancy, piping, monitoring, location temperature, sizing, and scouring. The requirements offer flexibility as well as protection of human health and the environment.

Proposed new §217.207, Stabilization Lagoons , requires lagoons that are designed as secondary units to treat suspended and dissolved organic matter in wastewater. It addresses primary treatment, odor management, the number of lagoons, dimensions of the lagoons, water level considerations, hydraulic and pipe considerations, maximum organic loading, and inlet and outlet structures.

Proposed new §217.207(a) requires primary treatment to remove the settleable and floatable solids in the influent wastewater prior to the stabilization lagoons, which treat suspended and dissolved organic matter in wastewater.

Proposed new §217.207(b) requires an owner to include measures to manage odors from stabilization lagoons.

Proposed new §217.207(b)(1) requires that a stabilization lagoon be located so that prevailing winds will be toward less populated areas to minimize nuisance odors.

Proposed new §217.207(b)(2) requires that the lagoons must be pre-filled to the two-foot level at start-up, if uncontaminated water is available. This requirement is included to encourage the rapid start-up of the biological process and to discourage odor.

Proposed new §217.207(b)(3) requires that a lagoon system must include a pipe arrangement that allows the recirculation of effluent. Surface spray may be used to assist in maintaining aerobic conditions at the lagoon surface and reduce potential odors. These requirements are included because recirculation provides active algal cells to the upstream feed area, which provides photosynthetic oxygen for organic digestion. Recirculation also provides a more completely-mixed environment within the lagoon system.

Proposed new §217.207(c) requires that a facility must have at least two stabilization lagoons if they are used to meet effluent limits. The stabilization lagoons must be in series with each other following the primary treatment unit.

Proposed new §217.207(d) contains the design requirements for stabilization lagoons.

Proposed new §217.207(d)(1) requires a minimum length-to-width ratio of a stabilization lagoon to ensure that the wastewater is properly treated.

Proposed new §217.207(d)(2) avoids dead zones and ensures proper treatment by prohibiting islands, peninsulas, or coves within the lagoon boundaries.

Proposed new §217.207(d)(3), specifies the normal water depth for stabilization lagoons to ensure the proper stratification of water treatment.

Proposed new §217.207(d)(4) specifies that inlet and outlet structures must allow for adjusting water levels to assist in controlling weeds and other vegetative growth to ensure proper operation and maintenance of the facility.

Proposed new §217.207(d)(5) requires that a stabilization lagoon have a 2.0 foot minimum freeboard if less than 20 acres and a 3.0 foot minimum freeboard if 20 acres or more. The potential for white-capping on a larger lagoon surface may encourage erosion. A deeper freeboard compensates for the erosion potential in lagoons with larger surface areas.

Proposed new §217.207(e) contains the requirements for hydraulic and pipe considerations. These requirements are included to ensure that an operator has flexibility to manage the lagoons properly in normal and worst-case conditions.

Proposed new §217.207(f) contains the requirements for the maximum surface organic loading rate for stabilization lagoons. The provision is included to specify that the loading rates are based on the BOD₅ influent load after the preliminary treatment units.

Proposed new §217.207(g) contains the requirements for inlet and outlet structures.

Proposed new §217.207(g)(1) requires that an outlet must include removable baffles to prevent floating material from being discharged and be constructed to operate varying surface levels under normal operating conditions.

Proposed new §217.207(g)(2) specifies that the discharge must be submerged. If a lagoon does not have submerged outlets, the lagoons may have a discharge that contains algae and high fecal coliform.

Proposed new §217.207(g)(3) specifies that multipurpose control structures may be used to facilitate normal operational functions to and allow the operator to properly operate and maintain the facility.

Proposed new §217.207(g)(4) specifies that all pipe embankment penetrations must have seep water-stop collars to prevent wastewater from leaking through or eroding an embankment.

Proposed new §217.207(g)(5) specifies that a stabilization lagoon must have a drainage system to allow scheduled maintenance or emergency repair on the lagoon.

Proposed new §217.208, Evaporative Lagoons , establishes the requirements for evaporative lagoons, including size and number, odor management, liners, and configuration of depth and loading, embankment, and inlet and outlet structures of the lagoon. These requirements are included in response to questions from the regulated community regarding minimum design criteria for evaporative lagoons.

Proposed new §217.208(a) is the minimum design criteria necessary for using evaporative lagoons in a treatment facility.

Proposed new §217.208(a)(1) requires that an evaporative lagoon process must have a minimum of two lagoons. Redundancy is necessary to keep the treatment process operating during repairs and maintenance.

Proposed new §217.207(a)(2) specifies that the primary evaporative lagoon must provide at least 60% of the total surface area. These provisions are consistent with standard engineering practices.

Proposed new §217.208(a)(3) requires the minimum number and size of evaporative lagoons provide adequate evaporation of the design flow during periods of low evaporation. During low evaporation or wet weather periods, secondary lagoons may be required to provide adequate evaporative surface area to accommodate influent flows and precipitation.

Proposed new §217.208(b) specifies that evaporative lagoons be located so that the local prevailing winds will be toward less populated areas to minimize nuisance odors.

Proposed new §217.208(c) contains the requirements for evaporative lagoon liners.

Proposed new §217.208(c)(1) requires that evaporative lagoons be constructed with synthetic membrane liners with a minimum thickness of 40 millimeters. The provision requires synthetic membrane liners because they are less likely to crack than clay liners.

Proposed new §217.208(c)(2) requires that the liners have an underdrain leak detection system consisting of at least a leachate collection and a detection system to ensure that the liner is intact and groundwater is not threatened.

Proposed new §217.208(c)(3) specifies that the liner construction requires proper compaction of soils beneath the liner so that the liner is not compromised by settling or shifting.

Proposed new §217.208(c)(4) specifies that the liner material must be capable of receiving constant sunlight without degrading to lengthen the functional life expectancy of the liner.

Proposed new §217.208(d) contains the requirements for configuration, depth, and loading.

Proposed new §217.208(d)(1) authorizes an evaporative lagoon to be constructed in round, square or rectangular style shapes to ensure that an evaporative lagoon can be designed to fit the topography of the location.

Proposed new §217.208(d)(2) specifies that the depth of an evaporative lagoon is dependent on its location within the lagoon system. These requirements are included for consistency with standard engineering practices.

Proposed new §217.208(d)(3) contains the evaporation and organic loading requirements.

Proposed new §217.208(e) specifies that the owner must construct embankments for evaporative lagoons in accordance with §217.203(e). This requirement is included to maintain consistency throughout the design criteria rules.

Proposed new §217.208(f) contains the requirements for inlet and outlet structures to be consistent with standard engineering practices.

Proposed new §217.209, Constructed Wetlands , includes general requirements for artificially constructed wetlands designed to simulate natural wetland ecologic conditions based on advances in engineering design.

Proposed new §217.209(a) authorizes the construction of wetlands at wastewater treatment facilities that are either free surface water systems (FWS) or subsurface flow systems (SFS).

Proposed new §217.209(b) prohibits the use of natural wetlands in order to protect them and clarify that constructed wetlands may not use any water in the state, as defined by Texas Water Code, §26.001(5).

Proposed new §217.209(c) established the general design criteria for constructed wetlands. Later sections address the two different types of constructed wetlands.

Proposed new §217.209(d) specifies that a constructed wetland must have a diverse vegetative community. This subparagraph also specifies that a constructed wetland may have both emergent and floating aquatic vegetation to maintain a diverse vegetative community suitable to local growing conditions. An acclimated and diverse vegetative community helps minimize adverse impacts from potential disease, insect pests, or species-specific toxicity.

Proposed new §217.209(d)(4) requires that the plans for harvesting aquatic plants from waters of the state must be reviewed with the United States Corp of Engineers to determine if regulatory coordination is required. This requirement is consistent with 40 CFR §122.2 and the Clean Water Act, §404. The use of indigenous plants is recommended, if the species have demonstrated they are effective for use in a constructed wetlands wastewater environment.

Proposed new §217.209(d)(5) requires that procurement of seed plants from natural wetlands must assure minimum impact on the harvested plant community. The use of indigenous plants is recommended, if these species have demonstrated they are effective for use in a constructed wetlands wastewater environment.

Proposed new §217.209(d)(6) specifies that the Texas Parks and Wildlife Department must approve use of all harmful or potentially harmful wetlands plants and organisms, as described in 31 TAC §§57.111 - 57.118 and 31 TAC §§57.251 - 57.258. This rule requires that the report identify the wetlands plants and organisms that will be used so that the executive director can ensure compliance with this requirement.

Proposed new §217.209(e) sets the maintenance requirements for constructed wetlands.

Proposed new §217.209(e)(1) prohibits the use of herbicides, insecticides, and fertilizers. Without an individual review of each chemical being discharged, a chemical could cause a water quality violation in the receiving stream.

Proposed new §217.209(e)(2) contains the requirements for floating material removal. For proper functioning, constructed wetlands systems must remove the primary treated effluent algal mat or other floating materials prior to entering the wetlands. The use of covered primary treatment systems may eliminate the need for algal mat removal. The rule also requires the removed floating material be stored and disposed of in a way to minimize nuisance odors. The disposal practices must conform to the requirements in Chapter 330.

Proposed new §217.209(e)(3) requires that the facility operations and maintenance manual include the maintenance of emergent and aquatic vegetation in constructed wetlands. Periodic removal of dead plant matter and detritus must prevent damage to living plants, liners, and system hydraulics. Constructed wetlands maintenance may include promoting active growth, controlling of mosquitoes, maintaining hydraulic capacity, and must not result in a deterioration of water quality. This provision is included to ensure that the manual contains the information necessary to operate the facility and so that the executive director can ensure compliance during the executive director's review.

Proposed new §217.209(f) requires that a properly functioning wetlands system be allowed to mature before wastewater effluent is processed. This requirement is included to ensure that constructed wetlands have adequate time for flow ecosystems to mature since mature ecosystems are required for effective wastewater treatment. It also requires the report to include the plan for establishing the constructed wetland before wastewater is introduced

Proposed new §217.209(g) specifies that the liners for wetlands systems must comply with the requirements of §217.203(3) and (4) and prohibits synthetic liners in wetland systems. A minimum 6 inch layer of productive topsoil must be placed above the liner to encourage subgrade root penetration. This requirement is included to protect against contamination of groundwater and to conform to standard engineering practices.

Proposed new §217.209(h) contains the requirements for berms. These requirements are included to prevent erosion of the side slopes and to conform to standard engineering practices and to allow synthetic side slopes to provide flexibility in designing berms.

Proposed new §217.209(i) requires that a constructed wetland must be protected from a 100-year flood event in accordance with the requirements of §217.35.

Proposed new §217.209(j) specifies that all constructed wetlands intended to provide nitrification are innovative and nonconforming technology, subject to §217.7(b)(2). The provision authorizes the executive director to consider these facilities on a case-by-case basis because of the inherent site-specific nature of nitrification at an individual treatment facility.

Proposed new §217.209(k) authorizes constructed wetlands to be used as secondary treatment units, advanced secondary treatment units, or as a means of polishing wastewater effluent. This provision specifies how the engineer may use FWS wetlands and SFS wetlands.

Proposed new §217.210, Constructed Wetlands--Free Water System (FWS) Design, contains the design criteria for FWS wetlands, which are shallow open water bodies and populated principally by emergent plants. Wastewater flows through the wetland, primarily in a horizontal direction, and is treated by a variety of physical, biological, and chemical processes.

Proposed new §217.210(a) requires a FWS wetlands design to be based on a maximum water depth of no more than 24 inches in emergent vegetation areas at design flow. Chapter 317 set the maximum depth at 18 inches, but 24 inches allows greater flexibility in design and plant selection.

Proposed new §217.210(b) sets the standards for plants in an FWS. Plant spacing must allow for growth of the wetlands flora ecosystem under normal conditions. The rule prohibits floating plants because flowing water would continually displace them.

Proposed new §217.210(c) requires the FWS to meet permitted effluent limits with any single cell removed from service. This requirement ensures that the design will be able to meet a wastewater facility's permit requirement during routine maintenance or emergency repair of an FWS cell.

Proposed new §217.210(d) requires that an FWS wetland cell have adequate bottom slope to facilitate drainage for maintenance and to maintain appropriate wetlands water depth range along the entire wetlands length under all anticipated operational flow conditions. This allows flexibility to meet local conditions in the design of the cell.

Proposed new §217.210(e) requires parallel treatment trains to increase operational flexibility and to allow routine maintenance without compromising the system.

Proposed new §217.210(f) requires that an FWS wetland cell be oriented to avoid cross winds perpendicular to the process flow direction or use elevated berms or vegetative windbreaks to prevent cross winds. The provision allows the use of elevated berms or vegetative windbreaks, which were not allowed in Chapter 317, to provide more flexibility to meet the needs of the topographical area of the constructed wetland.

Proposed new §217.210(g) contains the requirements relating to FWS inlets and outlets.

Proposed new §217.210(g)(1) requires that the FWS inlets and outlets of a wetland assure uniform flow across the cell. This requirement is included to prevent localized overloading on the treatment system.

Proposed new §217.210(g)(2) requires inlets and outlets to minimize erosion of wetlands substrate by controlling locally high flow velocities.

Proposed new §217.210(g)(3) requires inlet and outlets to allow variations in operational water level to ensure that the cell can treat a fluctuating flow volume.

Proposed new §217.210(g)(4) requires that the inlets be submerged under normal operational conditions to reduce the potential for odors.

Proposed new §217.210(g)(5) specifies that the design allow inspecting and cleaning of inlet and outlet devices for routine maintenance.

Proposed new §217.210(i) contains the design requirements for organic loading and treatment efficiencies of an FWS.

Proposed new §217.210(i)(1) authorizes a constructed wetlands design to be based on organic loading of the facility's primary or secondary effluent. This requirement is included because suspended solids removal efficiency normally does not require separate design consideration, being equally efficient or more efficient than organic removal efficiency.

Proposed new §217.210(i)(2) requires the organic removal treatment efficiency for FWS wetlands be based on the areal loading rate equation (Equation H.3), unless the report justifies an alternate method, the source of the method, and all supporting calculations. This provision is included to allow more site-specific calculations for each FWS wetland.

Proposed new §217.210(j) contains the requirements for vector control.

Proposed new §217.210(j)(1) requires mosquito control using mosquito fish, (Gambusia) other natural predators, aerobic conditions, and other biological controls.

Proposed new §217.210(j)(2) requires design controls to minimize the potential damage to wetlands caused by mammals such as nutria and muskrats, which can damage FWS wetland systems by burrowing into the berms.

Proposed new §217.211, Constructed Wetlands--Subsurface Flow System (SFS) General Design, contains the design criteria for SFS constructed wetlands, which are shallow water bodies populated by various floating and emergent plants. Wastewater flow in SFS wetlands is maintained below the surface of a porous media, such as gravel, where the emergent plants are rooted. Wastewater flows primarily in a horizontal direction and is treated by a variety of physical, biological, and chemical processes.

Proposed new §217.211(a) specifies that SFS media must allow root penetration. Treatment efficiency generally improves with effective root penetration through the entire wetted media depth. The provision requires the report to identify the wetted subsurface media so that the executive director can ensure compliance.

Proposed new §217.211(b) requires that the operational water depth of an SFS wetland not exceed the lesser of 18 inches at design flow or the maximum anticipated root penetration for the emergent plant species.

Proposed new §217.211(c) requires seasonal draw down of the water level to encourage deeper root penetration into the wetted media. This requirement ensures plants have adequate root penetration to grow to maturity and encourages new plant growth.

Proposed new §217.211(d) requires that plant spacing must not exceed 36 inches and be based on the size of the mature plant. The vegetation in an SFS wetland system will take at least one full growing season to mature and that adequate spacing allows for growth of the plants. The requirements for plant spacing are included to ensure that the wetland system will reach maturity in an efficient time frame.

Proposed new §217.211(e) contains the configuration requirements for SFS.

Proposed new §217.211(e)(1) requires multiple cells that may be operated independently, allowing individual cells to be removed from service while maintaining system operations. This provision allows the number of cells that are in service to match the amount of flow that the facility is receiving.

Proposed new §217.211(e)(2) requires that the size of the cells continue to meet permit effluent limits with any single cell out of service. This provision allows the operator to perform routine maintenance without compromising the treatment system.

Proposed new §217.211(e)(3) contains the hydraulic design requirements. An SFS wetland must maintain a minimum media cover to ensure that the cell does not dry out.

Proposed new §217.211(e)(4) specifies that the maximum wetted media depth of an SFS wetland is the lesser of 24 inches at design flow, or the maximum anticipated root penetration for the planned primary population of emergent plant species. Additionally, an SFS wetland must have a dry media cover depth of 6 to 9 inches above the design flow hydraulic gradient. These requirements are included because the hydraulic profile of SFS wetlands may be significantly steeper than FWS systems.

Proposed new §217.211(e)(6) specifies that an SFS wetland must provide parallel treatment trains must be provided to increase operational flexibility. This rule ensures consistency with the free water surface system requirements in this section.

Proposed new §217.211(f) requires the design to include minimum flow distribution, submergence, maintenance, and staged influent feed standards for an SFS system. Constructed wetlands treatment efficiency depends on effective flow distribution, loading, maintenance, and depth of the water. These requirements are included to ensure that the design meets certain minimum standards.

Proposed new §217.211(g) contains the requirements for SFS organic loading and treatment efficiency. This provision is included to allow more site-specific calculations to determine the total suspended solids (TSS) and biochemical oxygen demand (BOD) information for each SFS wetland.

Proposed new §217.211(h) requires that temperature the design of the SFS be adequate to provide treatment at the temperatures expected.

Proposed new §217.211(i) specifies that the vegetation maintenance practices be part of an SFS design. This requirement is included to reduce mosquito breeding opportunities.

Proposed new §217.211(j) requires that the media must be hard rock, slag, or other clean, comparable media material. Synthetic media is nonconforming technology and subject to §217.7(b)(2). These requirements ensure that the proper media is included in the design of an SFS.

Proposed new §217.212, Overland Flow Process , requires that an overland flow process be reviewed as a nonconforming technology. This system does not have a successful track record in Texas.

Proposed new §217.213, Integrated Facultative Lagoons , sets the requirements for new engineering design of integrated facultative lagoons, which the executive director will consider nonconforming technology. The section provides design criteria for integrated facultative lagoons including configuration of inlets and outlets, depth, organic loading, odor control, and removal efficiency.

All the requirements in this section are based on research conducted by Texas Tech University. Research using small-scale facilities has shown that a deeper pit in a facultative lagoon located in the center of the lagoon allows the lagoon to produce a higher quality of effluent using a smaller amount of land. The commission is incorporating the research into this section to provide another option for designing integrated facultative lagoons. This technology can help to reduce the cost and natural resources required for a lagoon system. To ensure that lagoons designed using this research are appropriate for full-scale facilities, the executive director will review all integrated facultative lagoons as nonconforming technology.

SUBCHAPTER J. SLUDGE TREATMENT UNITS

Subchapter J contains more detailed requirements than were contained in Chapter 317. Sludge management and sludge handling technology has advanced as disposal has become more expensive and more of a public issue. Today, there are more environmentally compatible ways to manage sludge, many, such as beneficial land application, enhance the environment rather than taxing it like landfilling sludge.

Proposed new §217.241, General Requirements , sets the minimum design requirements for sewage sludge treatment processes and treatment units; defines the sludge process to include thickening, stabilization, and dewatering; and requires the engineer to base the selection and operation of the sludge unit processes on the final sludge product. Additionally, this section requires that all municipal wastewater treatment facilities that dispose of sludge under Chapter 312 must stabilize the sludge and that all municipal wastewater treatment facilities that dispose of sludge under Chapter 330 must comply with the requirements of that chapter.

Proposed new §217.242, Control of Sludge and Supernatant Volumes, contains the requirements for controlling sludge supernatant volumes. This section ensures that the facility will transfer waste sludge to the sludge digester in a manner that minimizes the volume of digester supernatant. The supernatant from thickeners and digesters must be returned to the head of the treatment works or to the aeration system.

Proposed new §217.243, Sludge Pipes, provides the requirements for pipes used in the treatment of sludge. The piping design must be an adequate size, allow for cleaning, and prevent blockages and corrosion.

Proposed new §217.244, Sludge Pumps, contains the design standards for sludge transfer pumps, based on the quantity and character of the anticipated solids load and adequate redundancy.

Proposed new §217.245, Exclusion of Grit and Grease from Sludge Treatment Units, incorporates provisions of Chapter 312 into the design criteria for wastewater treatment facilities. These provisions are included to ensure that the design criteria rules are consistent with Chapter 312 requirements.

Proposed new §217.246, Ventilation and Odor Control , provides the ventilation requirements for wastewater treatment facilities to eliminate the presence of fumes or gases. This requirement is included to ensure that the design of the ventilation system eliminates the danger to human health and the environment in areas where the presence of fumes or gases rise to a level that might constitute a public health hazard or a threat to air quality. It also requires the sludge treatment design to minimize potential nuisance odors.

Proposed new §217.247, Chemical Pretreatment of Sludge , establishes criteria incorporating new state and federal requirements from 40 CFR Part 503 and Texas Health and Safety Code, Chapter 361, for the use and handling of chemicals used to enhance solids removal, necessary for many sludge treatment or processing units.

Proposed new §217.247(a) requires that chemical used in the pretreatment of sludge be compatible with the treatment process and not affect water quality.

Proposed new §217.247(b) requires that the choice and amount chemicals be based on pilot or field data.

Proposed new §217.247(c) requires chemicals to be stored safely.

Proposed new §217.247(d) states the requirements for a liquid storage tank.

Proposed new §217.247(e) requires activated carbon properly stored due to its combustible properties.

Proposed new §217.247(f) requires explosion-proof electrical devices in areas where volatile or explosive chemicals are used.

Proposed new §217.247(g) prohibits the discharge of volatile chemicals.

Proposed new §217.247(h) requires the facility to maintain a 30-day supply of needed chemical to ensure uninterrupted operations, unless an alternate method of ensuring uninterrupted service is included in the report.

Proposed new §217.247(i) requires chemical tanks to be an adequate size to operate at design flow.

Proposed new §217.247(j) requires written procedures for measuring chemical mixed into solutions to ensure that solutions contain the appropriate amount of each chemical required for treating sludge.

Proposed new §217.247(k) requires tank and pipe material to be appropriate to the chemicals being used. The material should be resistant to any reaction caused by the chemicals in use.

Proposed new §217.247(l) prohibits mixing chemicals prior to preparing the feed solution to prevent unintended chemical reactions.

Proposed new §217.247(m) prohibits storing a concentrated liquid acid in an open vessel and requires it be transferred directly to the point of use. This requirement is included to prevent the chemical reactions that can concentrated acids can undergo when exposed to air or moisture.

Proposed new §217.247(n) requires concentrated liquid acid storage containers be able to prevent discharge or unintended chemical reactions.

Proposed new §217.247(o) requires a toxic material to be transferred by a device that is engaged by the action of a person or automatic controller upon demand. This requirement is included to protect facility staff, human health, and the environment.

Proposed new §217.247(p) requires that a facility have a method for dust control during the transfer of dry chemicals. This requirement is included to protect facility staff, human health, and the environment.

Proposed new §217.247(q) requires disposal of chemicals and chemical containers be done in compliance with the waste disposal requirements in Chapter 335.

Proposed new §217.247(r) contains the requirements chemical feed equipment, including structures, redundancy, design, capacity, spill containment, controls, scales, protection, water supply, solution tanks, and application. These requirements are included to ensure that the sludge pretreatment process is designed for adequate and safe operation.

Proposed new §217.248, Sludge Thickening , establishes minimum criteria for sludge thickening for use in volume reduction and conditioning as an aid to processing and managing the sludge waste stream. Sludge thickening is optional. If sludge thickeners are used, the criteria outlined in this section must be used.

Proposed new §217.248(a) contains general requirements for thickeners. Section 217.248(a)(1) requires that the thickeners be capable of operating during the two-hour peak flow. The commission proposes this requirement to be consistent with clarifier design requirements and disinfection design requirements. Section 217.248(a)(2) requires that the sludge thickening system have a bypass. All facilities with a design flow greater than 1.0 mgd must have dual units, an alternate means of thickening, or an alternate disposal method. This requirement ensures that the facility is designed to manage its sludge if the sludge thickening system is out of service.

Proposed new §217.248(b) contains the requirements for mechanical gravity thickeners that ensure these thickeners will meet engineering standards and properly thicken the sludge by allowing the solids to settle and the liquid to be scraped away. The requirements also ensure that the executive director has sufficient information to review the design of the thickeners.

Proposed new §217.248(c) contains the design criteria for dissolved air flotation thickeners, which includes equipment feature requirements and design requirements.

Proposed new §217.248(d) contains the design criteria for centrifugal thickeners. The executive director may require pilot or field data for the review of any centrifugal thickener design.

Proposed new §217.248(e) contains the design criteria for gravity belt thickeners, which includes equipment feature requirements and design requirements.

Proposed new §217.249, Sludge Stabilization , contains the requirements for sludge stabilization based on requirements in 40 CFR Part 503 and Chapter 312. This provision addresses the stabilization processes including anaerobic digestion, aerobic sludge digestion, heat stabilization, and alkaline addition. In addition, the section states the requirements for anaerobic digesters. Additionally, the design requirements for the stabilization processes in this section are based on the assumption that the process is the sole stabilization process employed at the facility. If a facility employs series of two or more stabilization processes or methods, the report must justify a variance for reducing these requirements.

Proposed new §217.249(c) contains the requirements for anaerobic digestion. Section 217.249(c)(1) requires that a facility with a design flow exceeding 0.4 mgd have a minimum of two anaerobic digesters, so each digester may be used as a first stage or primary reactor for treating primary and secondary sludge flows. Each digester must have the means for transferring a portion of its contents to other digesters. A facility without multiple digesters must have an emergency storage basin, so the digester may be taken out of service. This provision allows the operator to perform routine maintenance without compromising the treatment system.

Proposed new §217.249(d) specifies that the anaerobic digester must provide a minimum of six feet of storage depth for supernatant liquor. This requirement is included to be consistent with standard engineering practice.

Proposed new §217.249(e) requires that the design allow access to all units that require maintenance. This provision allows the operator to perform routine maintenance without compromising the treatment system.

Proposed new §217.249(f) requires that a digester bottom slope towards the withdrawal drain pipe. The rule prohibits a flat-bottomed digestion chamber. The requirement is included to ensure the effective removal of the digester contents.

Proposed new §217.249(g) requires that the top of the digester have at least two access manholes and a gas dome. One manhole must have sufficient diameter to permit the use of mechanical equipment to remove grit and sand. A digester system must have a separate side wall manhole at ground level. This requirement is included to ensure that the digester is accessible for maintenance without compromising the system.

Proposed new §217.249(h) requires that the operation and maintenance manual require the use of non-sparking tools, rubber-soled shoes, safety harness, gas detectors for flammable and toxic gases, and at least one self-contained breathing apparatus. These requirements are included to ensure that unsafe working conditions for facility staff do not interrupt or stop the functions of the facility. An interruption of the treatment processes at a facility could compromise the protection of human health and the environment.

Proposed new §217.249(i) requires that a digester have multiple sludge inlets, outlets, and at least three recirculation sections and discharge points to facilitate effective mixing of the digester contents. One inlet must discharge above the liquid level and be located at the center of the digester. Raw sludge inlet discharge points must be located to minimize short circuiting to the supernatant draw-off. This requirement is included to ensure consistency with standard engineering practices.

Proposed new §217.249(j) contains the requirements for digester capacity. The digester capacity must be designed to process the expected volume and character of the sludge. The report must include the calculations to justify the basis of design. These requirements are included to ensure that the executive director has sufficient information to review the design for digester capacity and to be consistent with requirements in Chapter 312 and 40 CFR Part 503.

Proposed new §217.249(k) contains the requirements for gas collection pipes, storage, and appurtenances. This rule is included to be consistent with standard engineering practices and to allow routine maintenance without compromising the treatment system.

Proposed new §217.249(l) requires that the waste gas burners be accessible and must be located at least 50 feet away from any structure if placed at ground level. The waste gas burners may be located on the roof of the control building. The waste gas burners must not be located on top of the digester. The discharge of less than 100 cubic feet per hour (CFH) of digester gas through a return bend screened vent with a flame trap terminating at least 10 feet above the walking surface is allowed. These requirements are included to ensure that unsafe working conditions for facility staff do not interrupt the functions of the facility. An interruption of the treatment processes at a facility could compromise the protection of human health and the environment.

Proposed new §217.249(m) requires that all underground enclosures connected to anaerobic digesters tanks, gas pipes, or sludge equipment have forced ventilation in accordance §217.246. All underground enclosures must include tightly fitting, self-closing doors to minimize the spread of gas. This requirement is included to prevent the accumulation of explosive gases in underground enclosures.

Proposed new §217.249(n) requires that the system have a gas meter with a bypass to measure total gas production, which is an indicator of the activity in the digester. This requirement is included to authorize the operator to monitor the activity in the digester.

Proposed new §217.249(o) requires that the gas manometers have shut-off vents and vent cocks. The vent pipes must extend outside the buildings. The vent pipe openings must have screens and be arranged to prevent the entrance of rainwater, which can cause fouling of the manometers. The safety devices are required for the manometer pipe system.

Proposed new §217.249(p) requires the gas pipes for anaerobic digesters be equipped with pressure gauges. These requirements are included to ensure that unsafe working conditions do not interrupt the functions of the facility. An interruption of the treatment processes at a facility could compromise the protection of human health and the environment.

Proposed new §217.249(q) contains the requirements for digestion temperature control. These requirements are included to be consistent with standard engineering practices.

Proposed new §217.249(r) contains the requirements for supernatant withdrawal. This requirement is included to ensure the proper operation of the digester, to prevent damage to the unit, and to ensure that the executive director has sufficient information to review the report.

Proposed new §217.249(s) contains the requirements for digester covers. It prohibits uncovered anaerobic digesters; requires pipes be arranged to minimize air in the gas chamber; requires a digester cover to include a gas chamber, be gas tight, be tested, and be equipped with an air vent with a flame trap, a vacuum breaker, and a pressure relief valve.

Proposed new §217.249(t) contains the requirements for aerobic sludge digestion and applies to the stabilization of waste sludge to Class B biosolid by aerobic digestion. Class B biosolid is defined in Chapter 312. This requirement is included to be consistent with Chapter 312 and to ensure that the executive director has sufficient information to review the report. Proposed new §217.249(t)(5) - (7) is included to ensure the efficient operation of the system and to be consistent with Chapter 312 and 40 CFR Part 503.

Proposed new §217.249(u) contains the requirements for heat stabilization. The system must operate continuously to minimize additional heat input required to start up the system. This requirement is included to be consistent with standard engineering practices Chapter 312 and 40 CFR Part 503.

Proposed new §217.249(v) requires that the report must identify the method of treatment for recycle streams from heat treatment. The recycle streams must not impact effluent quality or the facility's treatment processes. This requirement is included to ensure that the executive director has sufficient information to review the report and to be consistent with standard engineering practices.

Proposed new §217.249(w) contains the requirements for alkaline stabilization. The design must include provisions for maintenance and repair based on data from comparable facilities and adequate storage for process, feed, and downtime. This requirement is included to be consistent with standard engineering practices Chapter 312 and 40 CFR Part 503, for vector and pathogen reduction. It also ensures the executive director has sufficient information to review the report.

Proposed new §217.250, Sludge Dewatering , contains the minimum design criteria for comprehensive consideration of sewage sludge dewatering unit processes, including general requirements, sludge conditioning, sludge drying beds, modified drying beds, rotary vacuum filtration, centrifugal dewatering, plate and frame presses, and belt presses.

Proposed new §217.250(a) requires the report to include justification for the sludge dewatering design.

Proposed new §217.250(b) requires the sludge dewatering design be based on mass balance principles.

Proposed new §217.250(c) contains general dewatering requirements. Section 217.250(c)(1) requires the drainage from beds and centrate or filtrate from dewatering units to be returned to the head of the facility for treatment. The organic loading from the centrate or filtrate must be included in the design of the facility's treatment units.

Proposed new §217.250(c)(2) requires that the dewatering system not allow the release of constituents that threatens water quality or wastewater permit compliance.

Proposed new §217.250(c)(3) contains the requirements for redundancy. This provision is included to allow operations during breakdowns and routine maintenance without compromising the treatment system and to be consistent with standard engineering practices.

Proposed new §217.250(c)(4) contains storage requirements. These requirements are included to prevent nuisance odor conditions, to be consistent with standard engineering practice, and to ensure the protection of human health and the environment.

Proposed new §217.250(c)(5) requires that the dewatering system have sampling stations before and after each dewatering unit or any other segment of the unit identified in the report and allow periodic evaluation of the dewatering process. This requirement is included to ensure efficient operation of the facility.

Proposed new §217.250(c)(6) requires that all dewatering system units must have bypass capabilities to allow maintenance. This provision is included to authorize the operator to perform routine maintenance without compromising the treatment system.

Proposed new §217.250(d) contains the requirements for sludge conditioning. These requirements are included to be consistent with standard engineering practices and to ensure that the executive director has sufficient information to review the report.

Proposed new §217.250(e) contains the requirements for sludge drying beds. The sludge drying beds size must be based on data from similar facilities in the same geographical area with the same influent sludge characteristics. If such data is unavailable, or if the executive director determines that the data is not appropriate for the proposed facility, the sludge drying bed design must be based on the requirements in §217.250(e)(2) - (5). These requirements are included to authorize a sludge drying bed to be designed for the geographic region, consistent with current engineering practices, and protective human health and the environment.

Proposed new §217.251, Sludge Storage, contains specific criteria for the storage of residuals after processing and prior to final disposal or removal from the site, including general criteria, solids storage, dewatered solids storage, and dried solids storage to protect the environment. Staff experience has shown that some facility designs have failed to include sludge storage.

Proposed new §217.251(a) specifies that this section applies to sludge after processing and before disposition or disposal.

Proposed new §217.251(b) states that sludge may be stored in liquid, dewatered, or dry forms, if properly processed.

Proposed new §217.251(c) contains general requirements. These requirements are included to ensure that the sludge storage minimize nuisance conditions. Additionally, the requirement that the report include a solids management plan is to ensure that the executive director has sufficient information to ensure compliance with these rules.

Proposed new §217.251(d) contains the requirements for non-dewatered solids storage that are consistent with standard engineering practices. Section 217.251(d)(2) authorizes a storage facility to store anaerobically digested solids in covered basins that control odor. The executive director determined that this option is protective of human health and the environment.

Proposed new §217.251(e) contains the requirements for dewatered solids storage. The commission proposes these requirements to be consistent with standard engineering practices.

Proposed new §217.251(f) contains the requirements for open stockpiles, including an impervious pad and the ability to collect rainfall runoff and return it to the head of the treatment facility. Because rainfall runoff from stockpiles will not meet the discharge limits for storm water, the water must be treated.

Proposed new §217.251(g) contains the requirements for dried solids storage. This requirement is included to be consistent with standard engineering practices.

Proposed new §217.252, Final Use or Disposal of Sludge , contains the criteria for the final use or disposal of sewage sludge, including quantities of solids, pollutants, pathogens, vector attraction, emergency provisions and weather factors.

Proposed new §217.252(b) requires the quantity of solids generated by the treatment process must be based on similar full scale facilities or pilot facilities and a mass balance. This requirement is included to be consistent with Chapter 305.

Proposed new §217.252(c) requires the sludge use or disposal option be based on the character of the sludge. The pollutant levels must be less than the levels specified in §312.82 and determined by Standard Method's laboratory test procedures.

Proposed new §217.252(d) requires that metals, pathogens, and vector attraction meet the requirements of Chapter 312 concerning the ultimate use or disposal method.

Proposed new §217.252(e) requires that the design include a backup plan in the event of equipment failure or conditions that prevent the facility's primary use or disposal method. The requirement to include the secondary plan in the report ensures that the executive director has sufficient information to review the design.

Proposed new §217.252(f) requires the design to include contingencies for weather factors such as rainfall, wind conditions, and humidity in the selection of the use or disposal of sewage sludge. This requirement is included to account for site-specific conditions.

SUBCHAPTER K. CHEMICAL DISINFECTION

The requirements in this subchapter are related to disinfecting treated effluent with chlorine and the subsequent dechlorination of the effluent. Chlorine and sulfur dioxide are toxic, oxidizing chemicals, which makes them very effective for disinfection and dechlorination. But, both are harmful or fatal if inhaled. These required specifications represent commonly accepted best practices for the safe handling of these hazardous chemicals and should be considered minimum requirements to protect facility staff, the public, and the environment.

The requirements also ensure consistency with permitting requirements for facilities that use chlorination disinfection and have a Texas Pollutant Discharge Elimination System (TPDES) permit that are required to conduct biomonitoring. Dechlorination is a requirement of these permits.

Proposed new §217.271, Chlorine (Cl₂ ) Disinfection and Sulfur Dioxide (SO₂ ) Dechlorination System Redundancy Requirements , contains the redundancy requirements to ensure continuing operation of the disinfection system.

Proposed new §217.271(a) requires each chlorine disinfection system to have at least two banks of chemical cylinders.

Proposed new §217.271(b) requires that a bank of cylinders automatically switch from an empty bank to a full bank of cylinders in a manner that ensures continuous disinfection.

Proposed new §217.271(c) requires that the facility to have sufficient space to store empty cylinders.

Proposed new §217.271(d) requires that the chemical delivery system so that the pound per day requirements in §217.272 are met with the largest chlorinator, sulfonator, or evaporator out of service.

Proposed new §217.271(e) requires that a chemical delivery system include backup pumps for any injector water supply systems requiring booster pumps. These requirements are included to ensure that this subsection is consistent with the other redundancy requirements in this rule.

Proposed new §217.272, Capacity and Sizing of Chlorine (Cl₂) Disinfection and Sulfur Dioxide (SO₂) Dechlorination Systems , contains the requirements for determining capacity and size of the system.

Proposed new §217.272 (a) requires the capacity of the chlorine and sulfur dioxide gas withdrawal systems be based on the two-hour peak flow in accordance with organic and hydraulic loading requirements in §217.32(1), Equation K.1 (a standard engineering equation), and Table K.1 (minimum concentration needed for disinfection). This requirement is included to ensure consistency in the design criteria rules.

Proposed new §217.272(b) establishes the minimum chlorine dosage necessary for disinfection in Table K.1.

Proposed new §217.272(c) requires the dechlorination system design to include at least an equal amount of sulfur dioxide as chlorine.

Proposed new §217.273, Cylinder Requirements for Chlorine (Cl₂ ) Disinfection and Sulfur Dioxide (SO₂) Dechlorination Systems , contains the general requirements for using chemicals stored in cylinders for disinfection and dechlorination.

Proposed new §217.273(a) requires gas withdrawal rates to be based on Equation K.2, using the variables in Table K.2 and sets maximum withdrawal rates for liquid chemicals. It also prohibits the use of heating blankets on chlorine gas cylinders.

Proposed new §217.273(b) sets the number of cylinders required based on Equation K.3.

Proposed New §217.274, Dosage Control for Chlorine (Cl₂ ) Disinfection and Sulfur Dioxide (SO₂) Dechlorination Systems , requires systems to have automatic controls that adjust chemical levels to meet effluent flow levels.

Proposed New §217.275, Requirements for Chlorine (Cl₂ ) Disinfection and Sulfur Dioxide (SO₂) Dechlorination Systems Using 150 pound (lb) Cylinders , contains the requirements for the smaller of the two cylinder sizes that facilities can use. Chemicals are always withdrawn from this size cylinder in a gaseous state.

Proposed new §217.275(a) states the requirements for storing cylinders in heated rooms.

Proposed new §217.275(b) states the requirements for using heating blankets on cylinders. Heating blankets are prohibited on chlorine cylinders because of the inherent dangers of chlorine. Heating blankets may be used on sulfur dioxide cylinders, but only if it does not heat the cylinder above 100 degrees and has the required safety features.

Proposed new §217.275(c) requires that chlorine and sulfur dioxide cylinders are stored separately and are handled so that they never come into close proximity to each other.

Proposed new §217.276, Requirements for Chlorine (Cl₂) Disinfection and Sulfur Dioxide (SO₂ ) Dechlorination Systems Using Gas Withdrawal from One-Ton Cylinders , contains the requirements for using the larger cylinder size and drawing the chemicals from them in the gaseous state.

Proposed new §217.276(a) requires the equipment that injects the chemicals into the effluent to be in a temperature controlled room because temperature affects gas pressure and therefore the chemical dosing levels.

Proposed new §217.276(b) states the requirements for storing cylinders outdoors, including the requirements for sizing, storage facilities, and piping.

Proposed new §217.276(c) prohibits the use of heating blankets on chlorine cylinders and proscribes the requirements for using heating blankets on sulfur dioxide cylinders.

Proposed new §217.276(d) states the requirements for maintaining the separation between chlorine cylinders and sulfur dioxide cylinders.

Proposed new §217.277, Requirements for Chlorine (Cl₂ ) Disinfection and Sulfur Dioxide (SO₂ ) Disinfection Systems Using Liquid Withdrawal from One-Ton Cylinders , contains the requirements related to withdrawing chemicals from large cylinders in a liquid state.

Proposed new §217.277(a) requires the equipment that injects the chemicals into the effluent to be in a temperature controlled room because temperature affects gas pressure and therefore the chemical dosing levels. Even with liquid withdrawal, chemicals are in a gaseous state when injected into the effluent stream.

Proposed new §217.277(b) requires withdrawal at the limits set in §217.273(a)(2).

Proposed new §217.277(c) states the requirements for maintaining the separation between chlorine cylinders and sulfur dioxide cylinders.

Proposed new §217.278, Housing Requirements for Chlorine (Cl₂) Disinfection and Sulfur Dioxide (SO₂) and Dechlorination Systems, contains the requirements for housing facilities for chemicals, including drainage, door and windows, ventilation, and gas detectors and protection.

Proposed new §217.278(a) requires that the drainage system for a room that contains either chlorine or sulfur dioxide be separate from every other drain system to ensure that chlorine or sulfur dioxide does not migrate into other areas and does not mix with any other substances.

Proposed new §217.278(b) contains the requirements for openings into a room that contains chlorine or sulfur dioxide equipment or cylinders. These requirements ensure the safety of facility staff and the safe operation of the disinfection system.

Proposed new §217.278(c) requires that any room that contains chlorine or sulfur dioxide equipment or cylinders have ventilation sufficient to prevent a buildup of chemical fumes. These requirements ensure the safety of facility staff and the safe operation of the disinfection system.

Proposed new §217.278(d) requires that any room that contains pressurized chlorine or sulfur dioxide equipment or cylinders have detection and protection devices. These requirements ensure the safety of facility staff and the safe operation of the disinfection system.

Proposed new §217.279, Equipment and Material Requirements for Chlorine (Cl₂) Disinfection and Sulfur Dioxide (SO₂) Dechlorination Systems , includes the specification necessary to ensure that equipment and material used in chlorine/sulfur dioxide systems are appropriate for that use.

Proposed new §217.279(a) ensures that equipment and materials used in these systems were designed and manufactured to be compatible with these chemicals.

Proposed new §217.279(b) ensures that cylinders are stored appropriately.

Proposed new §217.279(c) contains the requirements for gas piping for chlorine/sulfur dioxide systems. These requirements ensure the safe transfer of chemicals in a gaseous state.

Proposed new §217.279(d) contains the requirements for piping for liquid chlorine/sulfur dioxide. These requirements ensure the safe transfer of chemicals in a liquid state.

Proposed new §217.280, Design of Sodium Hypochlorite (NaClO) Disinfection and Sodium Bisulfite (NaHSO₃ ) Dechlorination Systems , contains the requirement for systems that use alternate chemicals to achieve chlorination and dechlorination.

Proposed new §217.280(a) contains the requirements to ensure that the system can operate during times that a pump is out of service.

Proposed new §217.280(b) contains the capacity sizing requirements for a sodium hypochlorite/sodium bisulfite system. These requirements ensure that the designed size of the system is appropriate for the amount and properties of the facility's effluent.

Proposed new §217.280(c) contains the requirement for automatic control of positive-pressure chemical dosing.

Proposed new §217.280(d) contains the requirements for proper chemical handling, including storage and temperature considerations. These requirements ensure the safe storage and transfer of sodium hypochlorite and sodium bisulfite.

Proposed new §217.280(e) requires that the equipment and materials used in a sodium hypochlorite/sodium bisulfite system be designed and manufactured to be compatible with these chemicals.

Proposed new §217.280(f) contains the safety requirement for a hypochlorite/sodium bisulfite system, including ventilation, tank indicator, spill containment, and emergency and protective equipment for facility staff. These chemicals are liquid and are therefore not as great a safety risk as chlorine and sulfur dioxide.

Proposed new §217.281, Application of Chlorination and Dechlorination Chemicals, contains the requirements to ensure that chemicals are added to effluent in an effective manner.

Proposed new §217.281(a) requires that chlorine is thoroughly mixed with effluent before the calculation of the chlorine contact time begins.

Proposed new §217.281(b) ensures that chlorine contact basins are properly sized to allow the necessary chlorine contact time.

Proposed new §217.281(c) ensures that the effluent is dechlorinated sufficiently to meet the limits of the facility's permit.

Proposed new §217.282, Other Chemical Disinfection or Dechlorination Processes, requires that any chemical process not covered by Subchapter K must be approved through the variance process in §217.7(b)(2).

Proposed new §217.283, Post-Disinfection Requirements , contains the design requirements necessary for the treatment train after the disinfection units.

Proposed new §217.283(a) requires the design include a sufficient number access points from which effluent samples may be taken so that the system may be monitored and adjust to keep the disinfection/dechlorination process within the limits of the wastewater permit.

Proposed new §217.283(b) requires that the disinfection/dechlorination system be designed to be capable of maintaining the permitted dissolved oxygen levels in the effluent. For facilities with high dissolved oxygen minimum limits, the report must justify the design.

SUBCHAPTER L. ULTRAVIOLET LIGHT DISINFECTION

This subchapter regulates the use of ultraviolet light to disinfect wastewater. Ultraviolet (UV) is a growing segment of the disinfection technology. An advantage of UV disinfection is that it does not require the addition of chemicals and thereby avoids the environmental impact of production, transport, and disposal of disinfection chemicals.

Proposed new §217.291, Ultraviolet Light Disinfection Systems Definitions, contains definitions specific to this subchapter.

Proposed new §217.292, Ultraviolet Light Disinfection Systems Effluent Limitations, requires UV systems to be designed with the capability of meeting the permit limits regarding disinfection in the facility's wastewater permit.

Proposed new §217.293, Ultraviolet Light Disinfection System Redundancy Requirements, requires UV systems to have sufficient backup equipment to be able to provide disinfection during equipment outages for maintenance or repairs.

Proposed new §217.294, Ultraviolet Light Disinfection System Monitoring and Alarms, contains the monitoring and alarm requirements that allow an operator to monitor and adjust the UV system and alert an operator of a problem. This requirement is included to ensure proper operations during normal operating and emergency situations.

Proposed new §217.295, Ultraviolet Light Disinfection Dosage and System Sizing, contains the requirement for designing the amount of UV required and the size of the UV system. This requirement is included to ensure that a UV system is capable of delivering adequate disinfection to meet permitted effluent limits.

Proposed new §217.296, Ultraviolet Light Disinfection Bioassay Test Procedure, contains the requirement for the bioassay test used as the basis for UV dosing and system sizing. This requirement is included to ensure the reliability of the bioassay.

Proposed new §217.297, Ultraviolet Light Disinfection Reactor Design, contains the specifications for a UV reactor. This requirement is included to ensure the UV reactor meets engineering standards.

Proposed new §217.298, Ultraviolet Light Disinfection System Cleaning and Maintenance, contains the requirement that the design of a UV system must allow adequate cleaning and maintenance. This requirement is included because cleaning and maintenance are essential for proper operation of a UV system.

Proposed new §217.299, Ultraviolet Light Disinfection System Safety, contains the requirement that personal safety equipment must be worn by any person entering the UV area. This requirement is included to protect operators, contractors, investigators and any other person who might be exposed to UV light by the UV disinfection system.

Proposed new §217.300, Post-Disinfection Requirements , contains the design requirements necessary for the treatment train after the disinfection units.

Proposed new §217.300(a) requires the design include a sufficient number of access points from which effluent samples may be taken so that the system may be monitored and adjust to keep the disinfection process within the limits of the wastewater permit.

Proposed new §217.300(b) requires that the disinfection system be designed to be capable of maintaining the permitted dissolved oxygen levels in the effluent. For facilities with high dissolved oxygen minimum limits, the report must justify the design.

SUBCHAPTER M. SAFETY

Subchapter M is included to ensure that wastewater collection systems and treatment facilities provide safe working conditions. Safety-related incidents often result in an environmental threat or incident. To protect public health and the environment, a system or facility must be designed to be safe for the workers who operate it.

Proposed new §217.321, Safety Design, specifies the general safety guidelines for designing collection systems and treatment facilities.

Proposed new §217.321(a) requires a facility design to be based on a widely accepted safety design standard. This requirement is included to ensure that unsafe working conditions for staff do not interrupt the facility's functions.

Proposed new §217.321(b) requires collection system and treatment facility designs to address workplace safety and the safety of the public located near the system or facility.

Proposed new §217.321(c) requires the design specifies treatment processes that use non-hazardous, non-toxic, less hazardous, less toxic, dilute chemicals, and a minimum inventory of chemicals. This requirement is included to ensure that only the minimum amount of chemicals needed to produce a quality effluent are used. This will limit the likelihood of human exposure, spills, and contamination of groundwater or surface water.

Proposed new §217.321(d) requires that the applicable standards in 29 CFR Part 1910, Occupational Safety and Health Administration (OSHA), be the basis for the safety elements in the design of a collection system or treatment facility.

Proposed new §217.321(e) requires the owner to demonstrate compliance with this section by implementing §217.322 and §217.323. This requirement is included to ensure that the safety aspects of the design are verifiable.

Proposed new §217.322, Safety and Security Audits , requires a collection system or treatment facility owner to conduct both a safety audit of the working conditions and a security audit. The commission envisions these audits being conducted by the owner, the design engineer, and facility staff. The intent of this requirement is to ensure that safety and security are an integral part of any design.

Proposed new §217.322(a) requires that the owner of an existing facility being modified or expanded review the safety related injuries and incidents from the prior three years, identify problem locations and tasks, report any corrective action taken, and address any outstanding problems in the design of the facility upgrade.

Proposed new §217.322(b) authorizes an owner to evaluate the security of a collection system or treatment facility based on Asset Based Vulnerability Checklist for Wastewater Utilities by the Association of Metropolitan Sewerage Agencies (AMSA) or its equivalent. This section is included to be consistent with the National Homeland Security Act. At this time, the United States Department of Homeland Security is recommending, but not requiring, a security audit.

Proposed new §217.323, Hazardous Operation and Maintenance , requires an owner to perform an analysis of hazardous operation and maintenance activities for new, expanded, or modified facilities. From that analysis, the owner must develop an inventory of necessary equipment, tools, and supplies needed for each task. The tools supplied must be sufficient to allow workers to safely and properly operate equipment, to perform required preventive maintenance, and to make repairs according to manufacturers' recommendations.

Proposed new §217.324, Chemical Handling, requires that the necessary equipment is available for personnel to handle chemicals safely and to address any accident that may happen.

Proposed new §217.325, Railings, Ladders, Walkways, and Stairways, specifies criteria for the use of railings, ladders, walkways, and stairways contained in safety requirements from the Occupational Safety and Health Act, §1910.23.

Proposed new §217.326, Electrical Code , requires that electrical design must conform to local electrical codes or if none, to the National Electrical Code.

Proposed new §217.327, Non-Potable Water , explains that when non-potable water is made available to any part of the plant, all yard hydrants and outlets must be properly marked.

Proposed new §217.328, Facility Access Control , requires that the facility area be completely fenced, have lockable gates at all access points, and have a means of access during 100-year flood conditions. This requirement is included to allow flexibility in the access control design of a treatment facility.

Proposed new §217.329, Color Coding of Pipes , specifies the color coding for pipes used in a wastewater facility. Standardization of color coding makes it safer for staff who change facilities and commission investigators who visit many facilities. These colors were chosen because they correspond with national standards provided by the American Water Works Association (AWWA) and the Water Environment Federation (WEF). The colors for the wastewater and related pipes are from the WEF and the colors for water and related pipes are from the AWWA.

Proposed new §217.330, Public Drinking Water Supply Connections , requires a facility with a potable water connection to have double check backflow preventers at the water main and atmospheric vacuum breakers for all potable water wash down hoses. These requirements protect the potable water supply from cross contamination.

Proposed new §217.331, Freeze Protection , requires the facility design to prevent ice formation on equipment that might be damaged by ice and to prevent personnel from walking on icy surfaces.

Proposed new §217.332, Noise Levels, requires that the noise levels in all working areas must remain below standards established by the Occupational Safety and Health Act, and prohibits removable noise attenuations.

Proposed new §217.333, Confined Spaces, requires that the design of collection systems and treatment facilities minimize the use of confined spaces as defined in 29 CFR §1910.146. Confined spaces present an inherent danger to personnel required to work in them.

FISCAL NOTE: COSTS TO STATE AND LOCAL GOVERNMENT

Jeff Horvath, Analyst, Strategic Planning and Assessment, has determined that for the first five-year period the proposed rules are in effect, no significant fiscal implications are anticipated for the agency or other units of state or local government as a result of the administration or enforcement of the proposed rules.

The proposed rules provide new minimum requirements for domestic wastewater treatment facilities and domestic wastewater collection systems. The rules are proposed in order to bring the standards and criteria for wastewater collection systems and treatment facilities up-to-date with current engineering practices and technology, and to better reflect the current permitting practices of the commission.

Any governmental entity that plans to modify or build a new wastewater collection system or treatment facility will be affected by this rule. Municipalities, municipal utility districts, and school districts are most frequently the types of entities that build wastewater collection systems and treatment facilities. The proposed rules would also apply to state agencies such as the Department of Criminal Justice, Parks and Wildlife Department, Texas Department of Transportation, Texas Youth Commission, as well as institutions of higher education.

At this time, there are approximately 2,521 domestic wastewater treatment facilities permitted in the state. Of those, 1,746 facilities are publicly owned. There are governmental entities that own collection systems that empty into privately owned treatment facilities. Since collection systems are not permitted, no data exists for governmental entities that own collection systems.

The following items are the more significant aspects of the proposed rules and would impact domestic wastewater treatment facilities.

Larger manhole openings

The proposed rule requires manhole openings with a minimum diameter of 30 inches. Larger manhole openings require a larger ring and cover. None of the other manhole structures are affected by the new requirement. The cost for a larger ring and cover is $50 to $60. The cost for a typical manhole is $30,000 to $50,000, depending on equipment and location. Therefore the added cost of the larger ring and cover is not expected to be significant. All major cities in the state, with the exception of San Antonio, are already requiring the new larger manhole openings.

Emergency power

The proposed rules will require all lift stations to be wired with generator connections. It is estimated that for a typical lift station, the additional wiring will cost approximately $500 to $1,000. Only essential wastewater treatment equipment must be wired for emergency power. Each owner is given the latitude to determine which treatment units are essential for a particular treatment facility. Additional cost for wiring a treatment unit should be similar to the costs for a lift station. This expense is necessary to ensure the operation of a collection system and essential treatment units in the event of a wide-spread power outage.

Color coding of pipe

The proposed rules will require the color coding of pipe. Most wastewater treatment facilities currently color-code facility pipes. The proposed rule would standardize the colors across the state. There would be less likelihood of an environmental incident when engineers and operators change treatment facilities if the pipe coding is standardized.

Safety audit

The proposed rules will require a safety audit in order to address safety issues in the facility or system design. Agency staff does not anticipate an owner having to hire a safety specialist to perform the audit. The design engineer, with the cooperation of the owner and the operational staff, would be able to perform the safety audit to the level required by the proposed rule and without significant additional cost.

In general, the proposed rules are not expected to result in significant fiscal implications for local governments. For each more stringent requirement in the proposed rule, there are options and the opportunity for approval of variances that would eliminate any extra cost. In addition, the proposed rules are anticipated to result in clearer, more up-to-date criteria to use in developing wastewater collection system and wastewater treatment facility projects. Plans and specification approval process time should be shortened, which could translate into cost savings. The proposed rules are expected to provide more flexibility and more choice in design options. With more flexibility in the requirements, collection system and treatment facility owners can tailor the system or facility design to meet the needs of their community and geographic location. While more flexibility in design options may or may not result in initial savings, a collection system or treatment facility that is a better fit for the community and location it serves should save money over the life of the system. These savings would result from easier operations, less maintenance, and a longer life span of the system or facility.

Finally, the proposed rules provide a procedure for requesting a variance from rule requirements. Formerly, there was an informal procedure, but the new criteria will standardize the procedures and applies timeframes for the executive director's response and the owner's reply for more information.

PUBLIC BENEFITS AND COSTS

Mr. Horvath also determined that for each year of the first five years the proposed new rules are in effect, the public benefit anticipated from the changes seen in the proposed rules will be updated design criteria which reflect current engineering practices and technology, while providing more options for the design of wastewater treatment facilities and collection systems.

No significant fiscal implications are anticipated for businesses or individuals as a result of the proposed rules for the first five years the rules are in effect.

At this time, there are an estimated 775 municipal permits for wastewater treatment facilities held by private entities in the state. There is no data for the number of collection systems owned by private entities. Any private entity that proposes to modify or build a new collection system or treatment facility would be affected by this proposed rule.

The effect on businesses will be the same as it is on governmental entities. Privately owned municipal wastewater treatment facilities would be affected by the proposed requirements for larger manhole covers, requirements for lift stations to be wired with generator connections for emergency power, the standardization of color coding for pipes, and the safety audit requirements. The costs associated with designing and building wastewater treatment facilities are dependent upon the design options chosen. With the increased number of options for wastewater treatment allowed in the proposed requirements, projects could be more or less expensive than those designed under the current regulations.

Costs for wastewater service to individuals are not expected to increase due to this proposed rule. The rulemaking will bring the regulations into line with current technology and offer wastewater service providers greater latitude in the design of their collection systems and treatment facilities. Although there may be some cost increases due to more stringent requirements, such as larger manhole openings and emergency power availability, those increases may be offset with newer, less expensive alternatives elsewhere in the design. In many instances, higher initial costs related to construction and equipment result in long-term savings in operational and maintenance costs and life expectancy of the system or facility.

SMALL BUSINESS AND MICRO-BUSINESS ASSESSMENT

In general, no adverse fiscal implications are expected for small or micro-businesses as a result of the proposed rules. At this time, there are approximately 140 small investor owned sewer utilities in Texas. Any of these utilities that plan to modify or to build a new collection system or treatment facility would be affected by the proposed rule. Existing systems and facilities that are not modified will not be affected by the proposed rule.

Small treatment facilities may see a greater impact from the new design criteria than larger facilities. Because of advancing technology and engineering practices, larger facilities have long been designed with standards higher than current rules require. Smaller facilities, especially those known as package plants (wastewater treatment equipment that is assembled off-site and delivered as a complete "package"), will have to alter the designs for aeration basins and clarifiers.

Aeration basins and clarifiers are required to be deeper in the new rules, but aeration basins are designed on the volume of wastewater they are required to process. A deeper sidewall depth will reduce the other dimensions (width and/or length) proportionately. Although there will be an initial cost for package plant manufacturers to retool their designs for aeration basins, the material and construction costs are not expected to change appreciably.

Clarifiers are designed on a surface loading basis; therefore, an increased sidewall depth requirement would increase the cost of a clarifier. More material (either concrete or steel) would be required to build a deeper clarifier. There would also be an increase in the cost of excavation due to the deeper hole required. The capital cost increase should be off-set, at least partially, by avoiding non-compliance with permitted effluent limitations, more efficient settling of solids, and less operator time spent dealing with an improperly operating unit. The initial cost of the clarifier is estimated to increase an average ten percent. Operational cost will not change. Most small facility designs include a clarifier, but there are plans that use other treatment units such as membrane bioreactor systems.

Entities that purchase package plants may see a temporary spike in overall costs due to the manufacturers' need to retool their manufacturing facilities. The spike should diminish as package plant manufacturers adjust their production equipment to meet the new regulations. The price will still include the increased cost of the deeper clarifier if a clarifier is included in the design.

SMALL BUSINESS REGULATORY FLEXIBILITY ANALYSIS

The commission has reviewed this proposed rulemaking and determined that a small business regulatory flexibility analysis is not required because the proposed rules do not adversely affect a small or micro-business in a material way for the first five years that the proposed rules are in effect.

At this time, there are approximately 140 small investor owned sewer utilities in Texas. The rules are proposed in order to bring the standards and criteria for wastewater collection systems and treatment facilities up-to-date with current engineering practices and technology, and to better reflect the current permitting practices of the commission. An exemption from all or part of the rules would potentially violate the Texas Water Code. Any applicant, including small and micro-businesses, may ask for variances from specific design criteria in the rule if they can demonstrate that the requested change will be at least as protective of human health and the environment as the rule requirement.

LOCAL EMPLOYMENT IMPACT STATEMENT

DRAFT REGULATORY IMPACT ANALYSIS DETERMINATION

The commission reviewed this rulemaking in light of the regulatory analysis requirements of Texas Government Code, §2001.0225, and determined that the rulemaking is not subject to §2001.0225, because it does not meet the criteria for a "major environmental rule" as identified in that statute. Major environmental rule is defined as a rule, the specific intent of which, is to protect the environment or reduce risks to human health from environmental exposure and that may adversely affect in a material way the economy, a sector of the economy, productivity, competition, jobs, the environment, or the public health and safety of the state or a sector of the state. This proposal does not adversely affect, in a material way, the economy, a section of the economy, productivity, competition, jobs, the environment, or the public health and safety of the state or a sector of the state. The intent of this proposal is to update the design standards and criteria for wastewater treatment systems to current engineering practices and include recent advances in wastewater treatment technologies. Additionally, the proposed rules will allow increased flexibility to attain the design standards and criteria; update the standards and criteria reflect the commission's related permitting practices; and amend and specify the commission's review and approval process for proposed wastewater treatment facility projects. Furthermore, the rulemaking does not meet any of the four applicability requirements listed in Texas Government Code, §2001.0225(a). Specifically, the proposed rule does not exceed a federal standard because no applicable federal standards exist. The proposed rule does not exceed an express requirement of state law nor exceed a requirement of a delegation agreement. The proposed rule was not developed solely under the general powers of the agency; but also under the specific authority of Texas Water Code, §26.034. The commission invites public comment regarding this draft regulatory impact analysis determination.

TAKINGS IMPACT ASSESSMENT

The commission performed an assessment of these rules in accordance with Texas Government Code, §2007.043. The specific purpose of the rulemaking is to update the design standards and criteria for wastewater treatment systems to current engineering practices and include recent advances in wastewater treatment technologies. Additionally the proposed rules will allow increased flexibility to attain the design standards and criteria; update the standards and criteria reflect the commission's related permitting practices; and amend and specify the commission's review and approval process for proposed wastewater treatment facility projects. Promulgation and enforcement of these rules will constitute neither a statutory nor a constitutional taking of private real property. This rulemaking will impose no burdens on private real property because the proposed rule neither relates to, nor has any impact on the use or enjoyment of private real property, and there is no reduction in value of the property as a result of this rulemaking. The commission invites public comment regarding this draft takings impact analysis determination.

CONSISTENCY WITH THE COASTAL MANAGEMENT PROGRAM

The commission reviewed the proposed rulemaking and found that the proposal is subject to the Coastal Management Program (CMP) in accordance with the Coastal Coordination Act, Texas Natural Resources Code, §33.201 et.seq, and therefore must be consistent with all applicable CMP goals and policies. The commission conducted a preliminary consistency determination for the proposed rules in accordance with Coastal Coordination Act Implementation Rules, 31 TAC §505.22 and found the proposed rulemaking is consistent with the applicable CMP goals and policies.

CMP goals applicable to the proposed rule are: to protect; preserve; restore; and enhance the diversity, quality, quantity, functions, and values of coastal natural resource areas (CNRAs); to ensure sound management of all coastal resources by allowing for compatible economic development and multiple human uses of the coastal zone; and, to balance the benefits from economic development and multiple human uses of the coastal zone, the benefits from protecting, preserving, restoring, and enhancing CNRAs, the benefits from minimizing loss of human life and property, and the benefits from public access to and enjoyment of the coastal zone.

CMP policies applicable to the proposed rule include the standards for the discharge of municipal and industrial wastewater to coastal waters in 31 TAC §501.14(f) and standards for development in critical areas in 31 TAC §501.14(h).

The rules are consistent with the goals and policies of the Coastal Management Program because, even though these rules do not directly govern wastewater discharge permits but rather set the minimum criteria for designing wastewater treatment facilities, the rules are written to support the commission's rules that do govern wastewater discharge permits. Additionally, these rules are as stringent as the existing design criteria; therefore, there will be no reduction in the quality of the effluent reaching the receiving waters.

Promulgation and enforcement of these rules will not violate or exceed any standards identified in the applicable CMP goals and policies. The proposed rules are consistent with these CMP goals and policies, because these rules do not create or have a direct or significant adverse effect on any Coastal Natural Resource Areas, and because the proposed rules do not reduce the quality of the effluent reaching the receiving waters.

Written comments on the consistency of this rulemaking may be submitted to the contact person at the address listed under the SUBMITTAL OF COMMENTS section of this preamble.

ANNOUNCEMENT OF HEARING

The commission will hold a public hearing on this proposal in Austin April 10, 2008 at 10:00 a.m. at the Texas Commission on Environmental Quality Complex located at 12100 Park 35 Circle in Building B, Room 201A. The hearing will be structured for the receipt of oral or written comments by interested persons. Registration will begin 30 minutes prior to the hearing. Individuals may present oral statements when called upon in order of registration. There will be no open discussion during the hearing; however, commission staff members will be available to informally discuss the proposal 30 minutes before the hearing.

Persons who have special communication or other accommodation needs who are planning to attend the hearing should contact Kristin Smith, Office of Legal Services at (512) 239-0177. Requests should be made as far in advance as possible.

SUBMITTAL OF COMMENTS

Written comments may be submitted to Kristin Smith, Texas Register Team, MC 205, Office of Legal Services, Texas Commission on Environmental Quality, P.O. Box 13087, Austin, Texas 78711-3087, or faxed to (512) 239-4808. Electronic comments may be submitted at: http://www5.tceq.state.tx.us/rules/ecomments/ . File size restrictions may apply to comments being submitted via the eComments system. All comments should reference Rule Project Number 2006-044-217-PR. The comment period closes April 14, 2008. Copies of the proposed rulemaking can be obtained from the commission's Web site at http://www.tceq.state.tx.us/nav/rules/propose_adopt.html . For further information, please contact Sherry Smith, Rule Project Manager, Water Quality Division, (512) 239-0571 or Louis C. Herrin, III, P.E., Rule Technical Manager, Water Quality Division, (512) 239-4552.

Subchapter A. ADMINISTRATIVE REQUIREMENTS

30 TAC §§217.1 - 217.17

STATUTORY AUTHORITY

The new rules are proposed under the authority of Texas Water Code (TWC), §5.013, which provides the commission's general jurisdiction; §5.103, which provides the commission's authority to adopt any rules necessary to carry out its powers and duties under the laws of Texas; §5.105, which provides the commission's authority to, by rule, establish and approve general policy of the commission; §5.120, which provides the commission's authority to administer the law to promote conservation and protection of the quality of the environment; §26.027, which authorizes the commission to issue permits; §26.034, which provides the commission's authority to adopt rules for the approval of disposal system plans; and §26.121, which provides the commission's authority to prohibit unauthorized discharges.

The proposed rules implement TWC, §§5.013, 5.103, 5.105, 5.120, 26.027, 26.034, and 26.121.

§217.1.Applicability.

(a) This chapter applies to any person who proposes to construct, renovate, or re-rate a wastewater collection system or commission permitted wastewater treatment facility that will collect, transport, treat, or dispose of wastewater that retains the characteristics of domestic wastewater although it may contain industrial wastewater, except those systems regulated by Chapter 285 of this title (relating to On-Site Sewage Facilities).

(b) This chapter does not apply to a person who proposes to construct a collection system or commission permitted treatment facility that will collect, transport, treat, or dispose of wastewater that does not have the characteristics of domestic wastewater although it may contain domestic wastewater.

(c) The executive director will grant variances from the requirements of this chapter to a person who proposes to construct, modify, upgrade, or re-rate a collection system or treatment facility, if the plans and specifications for the project meet the design criteria, are protective of human health and the environment, and are submitted within 180 days after the effective date of this chapter.

§217.2.Definitions.

The following words and terms, when used in this chapter, have the following meanings unless the context clearly indicates otherwise.

(1) Advanced nutrient removal--A process to remove phosphorus and/or nitrogen and produce effluent of higher quality than normally achieved by secondary treatment processes.

(2) Alternative collection system--A system or combination of systems that collects wastewater and incorporates any of the following: pressure sewer, small diameter gravity sewer, or vacuum sewer that is not a conventional gravity collection system. An alternative collection system is comprised of both on-site and off-site components.

(3) Annual average flow--The arithmetic average of all daily flow determinations taken within a period of 12 consecutive months.

(4) Biotower--A biological filtration system that involves biological film on a plastic media that reduces the biological oxygen demand of the effluent.

(5) Building lateral--A pipe that conveys raw wastewater and connects the plumbing of a structure to an on-site component. A building lateral is not a part of an alternative wastewater collection system.

(6) Bypass--The intentional diversion of a waste stream from any portion of a treatment facility.

(7) Collection system--Pipes, conduits, lift stations, force mains, and all other constructions, devices, and appurtenant appliances used to transport wastewater.

(8) Constructed Wetland--A water treatment facility built to duplicate the processes occurring in natural wetlands, which are complex, integrated systems in which water, plants, animals, microorganisms and the environment (sun, soil, and air) interact to improve water quality.

(9) Design flow--The average daily flow rate for a treatment facility permitted by the commission.

(10) Diurnal Flow--The daily cycle of high and low influent flows to a wastewater treatment system.

(11) Domestic Wastewater--Sewage that is characterized as residential wastewater, not produced by commercial or industrial activity, and which originates primarily from kitchen, bathroom, and laundry sources, including waste from food preparation, dishwashing, garbage grinding, toilets, baths, showers, and sinks of a residential dwelling.

(12) Effective size--If a sample of filter media is examined and the grain size plotted as a semi-log grain size curve with the ordinates representing the percent (P), by weight, of grains is smaller than the size denoted by the abscissa, then the effective size of the sample is the diameter, D10, that corresponds to P = 10%. In other words, 10% of the sample particles are finer and 90% are larger than the effective size.

(13) Engineer--A professional engineer with expertise in wastewater design and construction licensed by the Texas Board of Professional Engineers.

(14) Equivalent dwelling unit--Any building or section of a building that produces wastewater of a composition and quantity comparable to that discharged by a single, private residence.

(15) Facility--All land, structures, operational units, or appurtenances used jointly to process, treat, and dispose of wastewater.

(16) Filter media--The material placed in a filter containment structure to perform the filtering action.

(17) Firm pumping capacity--The maximum flowrate under design conditions with the largest pumping unit out of service.

(18) Flat plate system--A membrane bioreactor that arranges membranes into rectangular cartridges with a porous backing material sandwiched between two membranes for structural support.

(19) Force main--A pressure-rated conduit that conveys wastewater from a pump station to a discharge point.

(20) Free water system--A constructed wetlands designed to have the water surface above the wetland bed or substrate.

(21) Grinder pump--A component that receives raw wastewater through a building lateral, grinds the solids in the wastewater into a slurry, and provides the motive force for transporting the raw wastewater to a lift station or the terminus of a collection system.

(22) Gross flux rate--The volume of water that passes through a membrane measured in gallons per day per square-foot of membrane area at a standard temperature of 20 degrees Centigrade.

(23) Headworks--The location where wastewater enters a facility and the first chance to treat the flow, typically by removing large solids and grit.

(24) Hollow fiber system--A membrane bioreactor composed of bundles of very fine membrane fibers, approximately 0.5 - 2 millimeter diameter, held in place at the ends with hardened plastic potting material, and supported on stainless steel frames or rack assemblies. The outer surface of each fiber is exposed to the mixed liquor with filtrate flow from outside to inside through membrane pores.

(25) Innovative technology--A process not addressed in this chapter or a process specifically identified as innovative by this chapter.

(26) Interceptor tank--A component that receives raw wastewater from a building lateral, removes floatable and settleable solids, stores the removed solids, and provides flow attenuation.

(27) Lift station--A belowground structure that collects wastewater and utilizes pumps to raise it to a higher elevation. The term lift station applies to a structure in which the static head exceeds the frictional headlosses.

(28) Membrane bioreactor system--An activated sludge biological treatment system that uses membrane filtration rather than secondary clarification for solids separation and conventional filtration.

(29) Minimum grade effluent sewer--A wastewater collection pipeline with a constant downward slope.

(30) Multiple equivalent dwelling unit is:

(A) a group of residences served by a common service connection; or

(B) a commercial, industrial, institutional, or other non-residential establishment that produces wastewater:

(i) in excess of 1,500 gallons per day; or

(ii) not comparable in composition to that discharged by a single private residence.

(31) Net flux rate--The gross flux rate adjusted for production lost during backwash, relaxation, and cleaning.

(32) Nonconforming technology--Technology or a process that does not conform to the design criteria of this chapter or a technology or process specifically identified as nonconforming by this chapter.

(33) Off-site component--A wastewater collection system component that includes collection system pipes, force mains, pump stations, lift stations, vacuum stations, and related appurtenances located outside a wastewater treatment facility's site boundary.

(34) On-site component--Equipment, structure, or pipe located within a wastewater treatment facility's site boundary.

(35) Overflow--A flow over the weir of a treatment unit.

(36) Owner--A person who owns a collection system or a treatment facility or part of a system or facility.

(37) Peak flow--The highest two-hour flow expected under any operational conditions, including times of high rainfall based on a two-year 24-hour storm or a prolonged period of wet weather.

(38) Pressure sewer--A wastewater collection system that is pressurized by pumps at each service connection.

(39) Project--A TCEQ permitted wastewater treatment facility on which construction has begun but that is not yet complete.

(40) Proposed facility--A TCEQ permitted wastewater treatment facility on which construction has not begun.

(41) Pump--A device that raises, transfers, or compresses fluids by suction, pressure, or both.

(42) Report--The final engineering design report prepared, signed, sealed by the design engineer that contains calculations and written descriptions of processes, equipment, and structures that demonstrate compliance with this chapter, as described in §217.10 of this title (relating to Final Engineering Design and Report).

(43) Sequencing Batch Reactor (SBR)--A fill and draw activated sludge treatment system that is identical to conventional activated sludge systems, except the processes are carried out sequentially in the same tank. An SBR system has the following five steps that are carried out in the following sequence:

(A) Fill--The basin is filled with the influent;

(B) React--The influent in the basin is aerated;

(D) Draw--The basin is decanted; and

(E) Idle--The sludge is removed from the basin.

(44) Small diameter effluent sewer--A collection system that receives effluent from an interceptor tank, transports the flow by gravity, and may include minimum grade effluent sewers and variable grade effluent sewers.

(45) Transmembrane pressure--The difference between the average pressure on the feed side of a membrane and the average pressure on the permeate side of a membrane or the driving force associated with any given flux rate.

(46) Tubular system--A system in which sludge is pumped from an aeration basin to a pressure driven membrane system outside of a bioreactor where the suspended solids are retained and recycled back into the bioreactor while the effluent passes through a membrane.

(47) Variable grade effluent sewer--A small diameter gravity wastewater collection system that does not require a uniform gradient, but will allow inflective gradients where sections of the collection system are below the hydraulic grade line. May be used with septic tank effluent pumps.

(48) Variance--A deviation from a specific requirement of this chapter.

(49) Wastewater--A waterborne industrial waste, recreational waste, domestic waste, or combination of these wastes.

(50) Wasting--The practice of removing excess or old sludge from a wastewater treatment process.

§217.3.Purpose.

(a) The purpose of this chapter is to establish the minimum design criteria for the comprehensive design of domestic sewage collection, treatment, and disposal systems. The minimum design criteria are not sufficient for all situations. A design must protect the public health and meet water quality standards established by the commission.

(b) The executive director may require more stringent design criteria of a facility if the executive director determines it to be necessary to protect public health or to meet water quality standards established by the commission.

§217.4.Variances.

(a) The report must include all requested variances from the requirements of this chapter.

(b) The report must include a technical justification for each variance requested.

(c) If the executive director determines that a variance may potentially endanger public health or the environment, the executive director may deny the variance or require compensatory measures be taken.

(d) The executive director shall not grant or approve a variance that would violate any expressed prohibition in this chapter.

(e) If the executive director does not notify an owner by facsimile or letter that additional information is requested or that a variance is denied within thirty days after receiving a signed and dated variance request that has been sealed by an engineer, the variance is approved.

(f) A variance request from any rule in this chapter that requires affirmative executive director approval is not eligible for the approval process in subsection (e) of this section.

§217.5.Plans and Specifications General Requirements.

(a) An owner is required to build a wastewater collection system or treatment facility according to the plans and specifications approved by the executive director.

(b) The executive director's approval of plans and specifications does not relieve an owner of the responsibility to obtain a wastewater permit or other authorization in accordance with Texas Water Code, Chapter 26.

(c) The executive director's approval of a wastewater permit does not relieve an owner of the responsibility to obtain a plans and specifications approval in accordance with this chapter.

(d) An owner must ensure that its facility plans and specifications meet all design requirements in the associated wastewater permit.

§217.6.Submittal Requirements and Review Process.

(a) An owner is not required to submit plans and specifications for approval prior to the commission issuing the facility's wastewater permit.

(b) The facility's plans and specifications must be based on a design that will produce effluent that will at least meet the requirements and effluent limits in the associated wastewater permit.

(c) An owner shall submit to the executive director and the appropriate regional office a summary transmittal letter that includes the following requirements, except as provided by §217.8 of this title (relating to Municipality Reviews):

(1) the name and address of the design firm;

(2) the name, phone number, and facsimile number of the design engineer;

(3) the county(s) where the project will be located;

(4) an identifying name for the project;

(5) the name(s) of the person(s) that proposes to operate the facility;

(6) the owner's name, permit number, and facility name;

(7) a statement certifying that the plans and specifications are in substantial compliance with all requirements of this chapter, with the exception of any listed variance requests;

(8) a statement certifying that any variances from the requirements will not threaten public health or environment, based on the best professional judgment of the engineer who prepared the report and the project plans and specifications;

(9) a brief description of the project scope that includes:

(A) a brief engineering summary of the facility;

(B) a description of variances from the requirements of this chapter, including the use of nonconforming or innovative technology; and

(C) an explanation of the reasons for such variances in accordance with §217.4 of this title (relating to Variances); and

(10) the signature and seal of the engineer responsible for the design of the facility.

(d) The executive director may review the plans and specifications for any facility.

(e) If the executive director does not notify an owner within 30 days after the receipt of a summary transmittal letter that a review will occur, the project is approved. However, such approval is conditional subject to an executive director determination under §217.4(c) or (d) of this title. Additionally, if this provision conflicts with any other rule in this chapter that requires affirmative executive director approval, then this provision does not apply.

(f) If the executive director notifies an owner of the intent to review a facility's design, the owner shall submit the following within 30 days:

(1) a complete set of plans and specifications;

(2) a complete report;

(3) any requested variances; and

(4) sufficient information to satisfy the executive director that a project is in substantial compliance with this chapter.

§217.7.Types of Plans and Specifications Approvals.

(a) Approval given by the executive director or other authorized review authority does not relieve an owner of any liability or responsibility with respect to designing, constructing, or operating a system or facility in accordance with applicable commission rules and the associated wastewater permit.

(b) The executive director or other authorized review authority may grant the following types of approvals:

(1) Standard approval. The executive director may grant a standard approval for plans and specifications that do not include any requested variances and comply with all applicable parts of this chapter.

(2) Approval of innovative and nonconforming technologies.

(A) An owner who requests approval for an innovative or nonconforming technology must submit a summary transmittal letter in accordance with §217.6(a) of this title (relating to Submittal Requirements and Review Process) and must describe the technology and give the reason(s) for selecting the engineering proposal for a process, equipment, and construction material.

(B) An owner must receive written approval from the executive director before constructing, installing, or operating any innovative or nonconforming technology.

(C) The executive director may require a request to use a nonconforming or innovative technology to be supported by a pilot or demonstration study. Performance data from a similarly designed full-scale process that has operated for a reasonable period under conditions similar to those of a proposed design may be submitted in addition to or in lieu of pilot or demonstration study.

(D) The executive director may require an owner to submit evidence that the owner, the manufacturer, or the supplier of the nonconforming equipment has provided a performance bond that:

(i) is acceptable to the executive director;

(ii) is from a surety company listed on the United States Treasury Department's current Listing of Certified Companies; and

(iii) insures the performance of the innovative or nonconforming equipment or process.

(E) The performance bond must cover:

(i) the full cost of removing equipment and closing the facility;

(ii) the replacement of all failing processes and equipment with corresponding processes and equipment that conforms to these rules;

(iii) all associated engineering costs necessary for the removal and replacement of any failing process or equipment; and

(iv) at least two years from the date the facility or equipment is put into service.

(F) The executive director may require an owner to submit a separate report on the performance of a nonconforming or innovative technology after a facility is built and operating.

(3) Conditional approval.

(A) The executive director may grant conditional approval for a specific set operating conditions.

(B) If a conditional approval is granted, an owner is responsible for ensuring that the conditions, stipulations, and restrictions outlined by the executive director are met. Operating outside the conditions, stipulations, or restrictions in a conditional approval is a violation of this section.

§217.8.Municipality Reviews.

(a) The executive may grant approval authority to a municipality that request approval authority and meets the requirements in Texas Water Code, §26.034(d).

(b) The executive director may not require plans and specifications for a wastewater collection system that transports primarily domestic waste to be submitted for approval from:

(1) a municipality, if the plans and specifications subject to review are prepared by a private engineering consultant and a review is conducted by an engineer who is an employee of or consultant to the municipality separate from the private engineering consultant charged with the design of the plans and specifications under review; or

(2) an entity that is required by local ordinance to submit the plans and specifications to a municipality for review and approval.

(c) If a municipality seeks to perform technical reviews of wastewater collection systems, the municipality shall submit a map or maps to the executive director delineating the municipality's jurisdictional boundaries for the area it is seeking responsibility for review of plans and specifications at least 30 days before commencing to review plans and specifications in accordance with subsection (b) of this section.

(d) The municipality shall submit a revised map or maps to the executive director identifying jurisdictional boundary changes at least 30 days prior to any proposed change.

(e) If a municipality ends its review authority, the municipality shall provide written notice to the executive director at least 30 days prior to ending municipal reviews.

(f) A municipality's review program must incorporate the following requirements:

(1) The municipality's review and approval process shall ensure compliance with all the applicable rules of this chapter.

(2) A municipality may review and approve engineering reports and plans and specifications only for projects that transport primarily domestic waste within the boundaries of jurisdiction of that municipality.

(3) The municipality shall issue a document that approves and details each project approved for construction.

(4) The municipality shall maintain complete files of all review and approval activities.

(g) The executive director may perform periodic audits of the review and approval process of a municipality with review authority to ensure that the review process and approved projects comply with this chapter.

(1) The executive director shall provide a municipality with written notice of a pending audit a minimum of five working days prior to beginning review of municipal files related to an audit.

(2) The municipality shall provide to the executive director an opportunity to review any existing project files relating to its review and approval activities under this chapter.

(3) The municipality shall provide to the executive director an opportunity to review documentation of all agreements between a private consultant or consultants and the municipality that relate to its review and approval activities under this chapter.

(h) If the executive director finds through review of specific projects or through audit of a municipality's review and approval process that a municipality's review and approval process does not provide for compliance with the minimum design and installation requirements detailed in this chapter, the municipality must achieve compliance within a time frame established by the executive director.

(i) If the municipality does not achieve the required compliance within the timeframe established by the executive director, the commission may revoke the review authority of a municipality and require that all plans and specifications reviewed by the municipality under these rules be submitted to the executive director for review and approval.

(j) The executive director shall notify a municipality in writing of the intention to revoke the municipality's authority and shall include a justification for revoking the authority.

(k) If the authority of a municipality is revoked, all new projects proposed to be constructed within that municipality's jurisdiction must be submitted to the executive director in accordance with §217.6(a) of this title (relating to Submittal Requirements and Review Process).

(l) If the authority of a municipality is revoked, the municipality shall return all subsequently submitted plans and specification projects in its jurisdiction and notify any applicants of the requirement to seek approval from the commission.

§217.9.Texas Water Development Board Reviews.

If the Texas Water Development Board reviews plans and specifications for a wastewater collection, treatment, or disposal system in accordance with Texas Water Code, §17.276(d), the owner shall send a copy of the approval to the executive director.

§217.10.Final Engineering Design Report.

(a) An owner shall submit the report for any proposed facility or proposed modification or expansion to an existing facility.

(b) The report must include the signed and dated seal of the engineer responsible for the report.

(c) The report must demonstrate compliance with this chapter or justify variances from this chapter in accordance with §217.4 of this title (relating to Variances) by including all pertinent calculations, analyses, graphs, formulas, constants, tables, geologic information, hydraulic and hydrological information, historical data, and technical assumptions.

(d) If the executive director requests additional information for the report, an owner shall submit the requested information prepared, signed, and sealed by an engineer, within 30 days after receiving a request.

(e) The report for a wastewater collection system must include the following:

(1) a map showing the current service area, the proposed service area, and any area proposed for future expansion;

(2) the topographical features of the current, the proposed, and any future service areas;

(3) a description of how the design flow was determined;

(4) the minimum and maximum grades for each size and type of pipe;

(5) calculations of expected minimum and maximum velocities in the system for each size and type of pipe;

(6) the proposed system's effect on an associated existing system's capacity;

(7) the existing and anticipated inflow and infiltration, the hydraulic effect of the inflow and infiltration on the proposed and existing systems, any inflow and infiltration flow rate monitoring, and any inflow and infiltration abatement measures;

(8) a description of the ability of the existing and proposed trunk and interceptor wastewater collection systems and lift stations to handle the peak flow;

(9) the capability of the receiving treatment facility to receive and adequately treat the anticipated peak flow;

(10) an engineering analysis showing compliance with structural design, minimization of odor-causing conditions, and the pipe design requirements of §217.55 of this title (relating to Manholes and Related Structures);

(11) a description of the areas not initially served by a project, and the projected means of providing service to these areas, including special provisions incorporated in the present plans for future expansion;

(12) the calculations and curves showing the operating characteristics of all system lift stations at minimum, maximum, and design flows during both present and future conditions; and

(13) the safety considerations incorporated into a project design, including ventilation, entrances, working areas, and explosion prevention.

(f) The report for a wastewater treatment facility must include the following:

(1) The quantity and characteristics of any existing wastewater influent, any proposed changes, and any anticipated changes.

(2) If adequate records are not available, analyses must be made of the existing conditions, and the results included in the report, including:

(A) a map of the proposed facility and the area surrounding the facility, the area included in the facility site, the area that makes up the buffer zone, any 100-year flood event floodway or floodplain, and the discharge route or land application unit;

(B) a description of the surrounding area that includes prevailing winds, water treatment facilities, water supply wells, surface water intakes, present and proposed housing developments, present and proposed industrial sites, present and proposed highways and streets, present and proposed parks, present and proposed schools, present and proposed recreational areas, and present and proposed shopping centers;

(C) documentation of compliance with the buffer zone criteria and the 100-year floodplain restrictions specified in §309.13 of this title (relating to Unsuitable Site Characteristics);

(D) a sludge management plan, including:

(i) the estimated quantity and quality of sludge that will be generated, including future sludge loads based on flow projections;

(ii) the sludge treatment requirements for ultimate disposal, and the sludge storage requirements for each alternative;

(iii) a method of sludge transport, use, storage, and disposal; and

(iv) the alternatives, contingencies, and mitigation plans that ensure reliable capacity and operational flexibility.

(E) The methods to control bypassing, including:

(i) information and data describing features to prevent bypassing such as auxiliary power, standby and duplicate units, holding tanks, storm water clarifiers, or flow equalization basins; and

(ii) operational arrangements such as flexibility of pipes and valves to control flow through the treatment units and reliability of power sources to prevent unauthorized discharges of untreated or partially treated wastewater.

(F) information and calculations demonstrating the facility's compliance with the design requirements of this chapter, including:

(i) the types of units proposed and their capacities;

(ii) the detention times, surface loadings, and weir loadings pertinent to each wastewater treatment unit; and

(iii) hydraulic profiles for wastewater and sewage sludge that include:

(I) a plot of the hydraulic gradient at peak flow conditions for all gravity lines;

(II) the anticipated operation mode of the facility;

(III) organic and volumetric loadings pertinent to each unit; and

(IV) aeration demands and how those demands will be supplied.

§217.11.Construction of an Approved Facility.

(a) An owner may not begin construction of a facility with approved plans and specifications until the executive director issues a wastewater permit for the facility, unless the commission issues the owner an authorization to construct under Texas Water Code, §26.027(c).

(b) An owner must obtain a plans and specifications approval of a particular permit phase before beginning to construct or operate under that permit phase.

(c) An owner must phase the construction of a facility as required by the associated wastewater permit, unless a variance is granted under §217.4 of this title (relating to Variances).

(d) A person is prohibited from allowing a bypass of untreated or partially treated wastewater during construction without a commission order for such discharge.

(e) An owner that substantially modifies an existing facility or builds a new facility must comply with the requirements of this chapter that are in effect on the date the plans and specifications are submitted for approval.

(f) A facility owner that must apply for a new permit or that never received a plans and specifications approval for an existing facility must comply with the requirements of this chapter that are in effect at the time the new permit application is submitted or the lack of plans and specifications approval is discovered.

(g) A collection system owner that never received a plans and specifications approval for an existing collection system must meet the design criteria in effect at the time the lack of the plans and specifications approval is discovered.

§217.12.Substantial Design Changes.

(a) A substantial design change is a change to the approved plans and specifications or an approved variance of a process, equipment, or design that has the potential to alter the way a wastewater facility or system functions.

(b) A substantial design change request must include the signed and dated seal of an engineer.

(c) If the executive director determines that a substantial design change may potentially endanger public health or environment, the executive director may deny the design change or require compensatory measures to be taken.

(d) The executive director shall not grant or approve a substantial design change that would violate any expressed prohibition in this chapter.

(e) If the executive director does not notify an owner by fax or letter that additional information is requested or that a substantial design change is denied within thirty days after receiving a signed and dated substantial design change request that has been sealed by an engineer, the substantial design change is approved. However, such approval is conditional subject to an executive director determination under subsection (c) or (d) of this section. Additionally, if this provision conflicts with any other rule in this chapter that requires affirmative executive director approval, then this provision does not apply.

(f) A substantial design change must be approved by the executive director before it can be built, installed, or put into service.

§217.13.Final Construction Drawings and Technical Specifications.

(a) If requested by the executive director, an owner shall submit construction drawings and technical specifications for a constructed system or facility within 30 days after receiving the request.

(b) The signed and dated seal of the engineer who is responsible for the facility design must be on each sheet of the construction drawings and on the title page of the bound technical specifications.

(c) The final construction drawings and technical specifications must include all items in the following paragraphs that are applicable to a project.

(1) Construction drawings for a wastewater collection system.

(A) The drawings for a wastewater collection system must include plan and profile drawings for both gravity pipes and pressure pipes, and the drawings must specify the size, grade, and type of pipe materials.

(B) The drawings must also specify the location of any structural features of a collection system, including manholes, waterway crossings, bridge crossings, siphons, lift stations, and air release valves.

(C) The drawings must locate all potable water distribution lines that are 9.0 feet or closer to any portion of a wastewater collection system and indicate the actual separation distances.

(D) The drawings must include dimensional section details of manholes, manhole covers, and any other collection pipe appurtenances.

(E) The drawings for a lift station must show the location of the following:

(i) all pumps, valves, pumping control equipment, safety equipment, and ventilation equipment;

(ii) points that may be accessed by operational staff, such as manholes and cleanout ports;

(iii) hatches and hoisting equipment for installing and removing equipment;

(iv) slope and location of any wet well, floor grouting, valve vaults, valve vault pipes, and gas migration prevention measures used between a wet well and a valve vault;

(v) pipe entrances and exits;

(vi) sump pumps;

(vii) elevations of level control switches; and

(viii) any other lift station-related appurtenances.

(2) Construction Drawings for a Wastewater Treatment Facility.

(A) The drawings for a wastewater treatment facility show a vertical and horizontal scale and must include:

(i) plan drawings of all pipes;

(ii) plan and profile drawings of each treatment unit;

(iii) the dimensions of each wastewater treatment unit;

(iv) all mechanical, electrical, and construction details; and

(v) a hydraulic profile of a treatment facility at both design and peak flows.

(B) The construction drawings may include plans for future expansion of a facility.

(C) The construction drawings may include a clarification of any complex details of pipe systems by including an isometric flow diagram.

(3) The specifications for a modification of an existing collection system or treatment facility must include technical descriptions of all equipment including:

(A) the quantity and sizes of any equipment;

(B) any applicable materials specifications;

(D) national standards citations.

(4) If requested by the executive director, an owner must submit additional information relating to the plans and specifications within 30 days after the date of a request.

§217.14.Completion Notice.

(a) Upon completion of the construction of a collection system or treatment facility, an owner shall provide a completion notice to the executive director that:

(1) is signed, sealed, and dated by an engineer;

(2) certifies that the completed work substantially complies with this chapter, the approved plans and specifications, any approved variances, any approved substantial design changes, and the associated wastewater permit; and

(3) states that an operation and maintenance manual, as required in §217.16 of this title (relating to Treatment Facility Operation and Maintenance Manual), has been prepared and a copy is located at the facility.

(b) An owner shall disclose in a completion notice any deviation from the approved plans and specifications that is incorporated into a project after construction began or from an approved substantial design change. An owner shall certify that, based on the best professional judgment of an engineer, the change that was not submitted for approval will not result in substantial design change, as defined in §217.12(a) of this title (relating to Substantial Design Changes).

§217.15.Inspection.

The executive director may inspect a project at any time during any phase of the project to determine compliance with the project plans and specifications, the report, any variance approval, any substantial change approval, an associated permit, or the requirements of this chapter.

§217.16.Treatment Facility Operation and Maintenance Manual.

(a) An owner is responsible for developing an operation and maintenance manual with the assistance of an engineer.

(b) An owner must ensure that the operation and maintenance manual includes all information specific to the facility that is necessary to ensure efficient and safe operation, maintenance, monitoring, and reporting by a facility operator. The operation and maintenance manual must include the following items:

(1) administrative and recordkeeping items, including:

(A) a table of contents;

(B) a copy of the wastewater permit;

(D) a sample of each type of Discharge Monitoring Report or Monthly Effluent Report an owner is required to submit for the facility;

(E) a sample daily activity report for documenting internal monitoring done in association with internal process control, including flow rates from various units, dissolved oxygen levels, pH, solids concentrations, sludge settling, clarifier sludge blanket depths, sludge age or retention time, and disinfection residuals; and

(F) a description of the quality assurance and quality control recordkeeping requirements for all laboratory analyses performed.

(2) operation and maintenance items, including:

(A) expected flow patterns, size, and capacity of all units within the facility;

(B) start-up procedures, routine operational procedures, emergency operations procedures, and shut down procedures for all units;

(D) expected solids concentrations in each unit;

(E) expected clarifier overflow rates;

(F) expected disinfectant and dechlorination usage and dosage amounts during normal and emergency operating conditions;

(G) descriptions and frequencies of routine in-situ and laboratory analyses to be performed and a list of references to standard testing procedures literature;

(H) description and schedule of routine maintenance activities to be performed, including lubrication and inspection of all pumps, motors, and other equipment; and

(I) a recommended spare parts inventory with source information.

(3) safety requirements, including:

(A) all known potential or actual safety hazards within a facility;

(B) the location and method of use for all personal safety equipment;

(D) the names and phone numbers of entities and individuals to be contacted during emergencies;

(E) emergency operation plans for power outages, flooding, and other site specific emergency situations that may develop; and

(F) annual safety training curriculum and schedule for all facility staff.

(d) An owner shall submit a copy of the operation and maintenance manual to the executive director within 30 days after receiving a request.

§217.17.Collection System Records.

An owner of a collection system shall maintain and make available to the executive director upon request the following:

(1) a complete set of the final plans and specifications with engineer's certification;

(2) a copy of the complete report;

(3) all change orders and test results;

(4) a copy of the summary transmittal letter submitted to the executive director; and

(5) any approvals for variances or substantial changes.

This agency hereby certifies that the proposal has been reviewed by legal counsel and found to be within the agency's legal authority to adopt.

Filed with the Office of the Secretary of State on February 29, 2008.

TRD-200801200

Robert Martinez

Director, Environmental Law Division

Texas Commission on Environmental Quality

Earliest possible date of adoption: April 13, 2008

For further information, please call: (512) 239-0177

Subchapter B. TREATMENT FACILITY DESIGN REQUIREMENTS

30 TAC §§217.31 - 217.39

STATUTORY AUTHORITY

The proposed new rules implement TWC, §§5.013, 5.103, 5.105, 5.120, 26.027, 26.034, and 26.121.

§217.31.Applicability.

This subchapter details the design values that an owner shall use when determining the size of any wastewater treatment facility component. This subchapter applies to the treatment design for a new facility, up-grade of an existing facility, and the re-rating of an existing facility.

§217.32.Organic Loadings and Flows.

(a) The design of a new facility must be based on the flows and loadings in paragraphs (1) - (3) of this subsection, unless subsection (b) of this section applies.

(1) Design flow.

(A) For a facility equal to or greater than 1.0 million gallons per day (mgd), the permitted flow is the average annual flow value determined by multiplying the per capita flow in Table B.1 in paragraph (3) of this subsection by the number of people in the service area.

(B) For a facility less than 1.0 mgd, the permitted flow is the maximum 30-day average flow estimated by multiplying the average annual flow by a factor of at least 1.5.

(2) Peak flow. When site-specific data is unavailable, the instantaneous two-hour peak flow must be estimated by multiplying the permitted flow by a factor of 4.0.

(A) If a facility experiences unusual diurnal or seasonal flow variations, a higher multiplier may be used to calculate the peak flow.

(B) In a facility with flow equalization, the facility may be designed for a lower estimated peak flow, if supporting data included in the report supports the estimate.

(C) A treatment unit, pipe, weir, flume, disinfection unit, or any other treatment unit that is flow limited must be sized to transport or treat the estimated peak flow.

(D) A facility must use a totalizing flow meter for flow measurement.

(3) Design organic loading. If available, actual organic loading data must be used as the basis for design. If actual data is not available, the design organic load must be used as the basis for design. The design organic load is determined by multiplying the projected uses by annual average flow determined from the following table and by using the appropriate influent concentration from the following table:

Figure: 30 TAC §217.32(a)(3)

(b) For an owner constructing a new system to serve the same service area as an existing facility with sufficient historical data, the data from §217.34 of this title (relating to Re-Rating, Upgrading, or Modifying an Existing Facility), may be used to design a wastewater treatment facility if justified in the report.

§217.33.Flow Measurement.

(a) A facility must include a means of accurate effluent flow measurement.

(b) An effluent flow-measuring device must have an open channel to allow for easy inspection, calibration, and cleaning.

(1) Primary measuring devices.

(A) A primary measuring device must include a weir or a flume.

(B) A primary measuring device must have a non-corrosive ruler (staff gauge) that is graduated in no greater than 1/4 inch increments that are clearly visible.

(C) A primary measuring device must be installed upstream of a secondary measuring device to permit the manual measurement of water depth.

(2) Weirs.

(A) A channel approach section to a weir must be straight for at least 20 times the maximum expected head on a weir.

(B) The minimum height between a channel bottom and a weir crest must be the greater of twice the maximum expected head on the weir or a minimum of 1.0 foot.

(D) The crest of a weir must be exactly level to ensure a uniform depth of flow.

(E) The upstream face of a weir must be smooth and perpendicular to the axis of the channel in both the horizontal and vertical directions.

(F) Upstream of a weir, there must be a secondary measuring device located a minimum distance of the greater of:

(i) three times the maximum expected head on a weir; or

(ii) the distance recommended by the equipment manufacturer.

(3) Flumes.

(A) A flume must be located in a straight section of an open channel.

(B) A flume must be installed in accordance with the manufacturer's recommendations.

(4) Secondary measuring devices.

(A) A secondary measuring device must measure the liquid level in the primary measuring device, and must convert this liquid level into a flow rate that is integrated to a totalized flow.

(B) A secondary measuring device must be installed in accordance with the manufacturer's recommendations and in a manner that reduces turbulence and promotes laminar flow.

(C) A secondary measuring device must include a display of the instantaneous flow rate and a means of reading the totalized flow.

§217.34.Re-Rating, Upgrading, or Modifying an Existing Facility.

An owner who proposes to modify, upgrade, or re-rate an existing facility in order to meet an amended permit condition is required to use the facility's current operating data as the design basis for sizing the proposed wastewater treatment equipment and processes. The compiled data must meet the criteria outlined in paragraphs (1) and (2) of this section.

(1) Flows.

(A) The volume of existing flow shall be determined when an existing treatment facility is to be re-rated, expanded, or upgraded.

(B) An existing facility's data for the latest five years must be used to determine the annual average flow, the maximum monthly average flow, the peak flow, the ratio of maximum monthly average flow to annual average flow, and the ratio of the peak flow to the annual average flow. If the facility is less than five years old, all data must be used. All calculations and assumptions must be included in the report.

(D) An analysis of the peak flow must be based on a frequency distribution analysis using flow charts for each individual day to determine the maximum sustained flow rate over any two-hour period.

(E) The projected peak flow must be the result of collection system monitoring or modeling based on a two-year, 24-hour storm event for the service area.

(2) Organic loadings.

(A) When an owner seeks to have an existing facility re-rated or to expand or upgrade an existing facility, the design organic loading must be calculated based on the average daily organic load that the facility is required to treat during the design life. A calculation of the average daily organic loading must use the facility's actual data plus one standard deviation. The data must conform at a minimum to the following:

(i) The data must document a minimum of one year, consisting of three samples per week taken during weekdays. If a sampling program is for a frequency of less than three times per week or less than a three-part grab sample, an owner shall document how the proposed sampling program is representative of actual conditions at the facility.

(ii) The samples must be representative of the peak loading.

(iii) Sampling data must include a minimum of five-day carbonaceous biochemical oxygen demand or five-day biochemical oxygen demand, total suspended solids, and ammonia-nitrogen, unless justified because of specific treatment requirements.

(iv) An engineering analysis for the minimum sampling period must include:

(I) a summary of the monthly data;

(II) annual-average monthly load; and

(III) the standard deviation of the monthly data.

(v) An analysis may use a linear regression or other appropriate statistical method for predicting the design organic load when significant data exists.

(B) A design must be based future loading and future flow calculated from the anticipated changes from the existing loading and flow.

(i) A design organic loading must account for both dry weather and wet weather conditions.

(ii) An owner shall use the design organic loading to determine the size of any treatment unit that provides treatment of organic waste.

§217.35.One Hundred-Year Flood Plain Requirements.

(a) If within 1,000 feet of the site of a proposed facility, the owner must show the 100-year flood plain on the site plan. A flood plain determination must be based on a superimposition of the 100-year flood elevation on the most accurate available topography and elevation of a proposed site.

(1) A 100-year flood plain must be based on the Federal Emergency Management Agency (FEMA) Flood Insurance Study (FIS) in effect at the time the plans and specifications are submitted to the executive director. FEMA maps are prima facie evidence of flood plain locations.

(2) An appropriate flood insurance rate map or FIS profile adjusted to the project's vertical data determines flood elevations.

(3) If a site is adjacent to a FEMA 100-year flood delineation but has no flood elevation published, a 100-year flood elevation may be determined by overlaying the effective FEMA delineation over a United States Geological Survey Quadrangle Map and interpolating a flood elevation.

(4) If FEMA flood plain information is not available, the report shall include a 100-year flood elevation based on the best information available.

(b) One hundred-year flood plain must be shown on profile.

(1) The FEMA 100-year water surface elevation must be marked on a hydraulic profile of a facility in accordance with the vertical scale of the drawing.

(2) If a proposed facility will occupy less than 1,000 feet of shoreline along a flood plain, the profile must show a single line coincident with the elevation of the centerline of any outfall pipe.

(3) When a proposed facility will occupy 1,000 feet or more of shoreline along a flood plain, the profile must show the water surface elevation at both the upstream and downstream limits of any protective structure for the proposed facility.

(c) The executive director will not approve a design of a proposed treatment unit within a 100-year flood plain, unless the design provides protection for all open process tanks and electric units from inundation during a 100-year flood event.

§217.36.Emergency Power Requirements.

(a) Reliability of existing commercial power service.

(1) An owner shall determine the reliability of the existing commercial power service for a facility from the power outage records obtained from the appropriate power company.

(2) The records must:

(A) be in writing;

(B) be on the utility's letterhead and bear a signature of a utility employee;

(D) list the total number of outages that have occurred during the past 24 months; and

(E) indicate the date and duration of each recorded outage.

(b) An owner shall submit an power reliability determination and all backup documentation in the report for the approval of the executive director.

(1) the owner will be notified in writing;

(2) the facility shall incorporate an on-site, automatically starting generator, capable of ensuring continuous operation of all critical wastewater treatment system units for a duration equal to the longest power outage in the power records; and

(3) any off-site lift station must incorporate an on-site, automatically-starting generator capable of ensuring continuous operation of the lift station for a duration equivalent to the longest power outage on record for the past 24 months.

(d) Exceptions to the auxiliary power generator requirements for wastewater treatment facilities are:

(1) The requirements for on-site, automatically starting generators for wastewater treatment facilities may be reduced as follows:

(A) Facilities may use lift stations and collection systems to store wastewater in lieu of on-site generators when the report calculations show that sufficient storage volume exists in the lift stations, upstream gravity wastewater collection system lines, and manholes to store the volume of wastewater during a peak diurnal event equal to the longest outage in the power records.

(B) If storage is used in lieu of backup power generators, the report must show that the hydraulic grade line of a collection system is such that in no case will wastewater be allowed to bypass the treatment facility during a peak flow event equal to the longest outage in the power records.

(C) When upstream storage is used as a means of ensuring complete treatment of the influent wastewater, a design must include the following:

(i) Storage is prohibited as a substitute for on-site generators if any of the flow to the treatment facility is gravity flow.

(ii) If the influent storage is less than two hours and power outage records indicate a maximum outage of less than two hours, the on-site, automatically starting generators need only provide sufficient power to operate all components of the disinfection system.

(iii) If the influent storage is at least two hours but not more than four hours and the power outage records indicate an outage of at least two hours but not more than four hours, a generator need only supply sufficient power to operate all or components of the disinfection system. Auxiliary generators are also required to supply power for return activated sludge pumps if the report does not show sufficient volume in the clarifiers for storage of sludge.

(2) Off-Site Lift Stations. Off-site lift stations may substitute portable generators or pumps in combination with collection system storage for on-site generators if the following criteria exist:

(A) the firm pumping capacity of a lift station is less than 100 gallons per minute;

(B) a station includes an auto-dialer or telemetry system with battery backup;

(D) a station is accessible during a 25-year flood event;

(E) reasonable assurances exist as to the timely availability and accessibility of the proper portable equipment; and

(F) a station is equipped with properly designed and tested quick connections.

§217.37.Disinfection System Power Reliability.

(a) A disinfection system must include a backup power system capable of providing sufficient power to operate during any power outage.

(b) A backup power system must automatically restart the disinfection system during a power outage.

(c) A backup power system must meet the requirements of §217.36 of this title (relating to Emergency Power Requirements).

§217.38.Buffer Zones and Odor Abatement.

(a) The buffer zone requirements in §309.13 of this title (relating to Unsuitable Site Characteristics), apply to all areas of a facility.

(b) The report must include the design of any odor abatement measures intended to comply with §309.13(e) - (g) of this title.

(c) An odor abatement measure that is used in lieu of buffer zone requirements is subject to review in accordance with §217.7(b)(2) of this title (relating to Types of Plans and Specifications Approvals).

§217.39.Facility Use of Reclaimed Water.

(a) A facility that is designed after the effective date of this chapter must use reclaimed water in place of potable water used for wash down water, irrigating the grounds, and any other appropriate use.

(b) A facility that is designed after the effective date of this chapter must include a meter to measure reclaimed water use at the facility.

(c) An owner must reclaim water after it has been disinfected. A reclaimed water system must provide for screening or filtration, pumping backup with controls, and a pressure-sustaining device such as a hydro-pneumatic tank.

(d) An owner may use only reclaimed water that meets the requirements for Type I or Type II water, in accordance with §210.33 of this title (relating to Quality Standards for Using Reclaimed Water) for wash down water, disinfection system operation, chemical mixing, irrigating the grounds, and any other appropriate use.

(e) An owner may use reclaimed water on a facility site with no further authorization from the executive director.

This agency hereby certifies that the proposal has been reviewed by legal counsel and found to be within the agency's legal authority to adopt.

Filed with the Office of the Secretary of State on February 29, 2008.

TRD-200801201

Robert Martinez

Director, Environmental Law Division

Texas Commission on Environmental Quality

Earliest possible date of adoption: April 13, 2008

For further information, please call: (512) 239-0177

Subchapter C. CONVENTIONAL COLLECTION SYSTEMS

30 TAC §§217.51 - 217.70

STATUTORY AUTHORITY

The proposed new rules implement TWC, §§5.013, 5.103, 5.105, 5.120, 26.027, 26.034, and 26.121.

§217.51.Applicability.

This subchapter applies to the design, construction, operation, and testing standards for conventional gravity wastewater collection systems, conventional wastewater lift stations, force mains for wastewater transport, and reclaimed water conveyance systems.

§217.52.Edwards Aquifer.

An owner who plans to install a wastewater collection system located over the Edwards Aquifer recharge zone must design and install the system in accordance with Chapter 213 of this title (relating to Edwards Aquifer), in addition to these rules.

§217.53.Pipe Design.

(a) Flow Design Basis. An owner must use the requirements of this section to design a gravity collection system.

(1) An owner must design a wastewater collection system to handle the transport of the peak dry weather flow from the service area, plus infiltration and inflow.

(2) The flow calculations must include the details of the average dry weather flow, the dry weather flow peaking factor, and the infiltration and inflow.

(3) The flow calculations must include the flow expected in the facility immediately upon completion of construction and at the end of its 50-year life.

(b) Gravity Pipe Materials.

(1) An owner must identify in the report the proposed gravity collection system pipe with its appropriate American Society for Testing and Materials (ASTM), American National Standards Institute (ANSI), or American Water Works Association (AWWA) standard numbers for both quality control (dimensions, tolerances, etc.) and installation (bedding, backfill, etc.).

(2) The selection of gravity collection system pipe must be based on:

(A) the characteristics of the wastewater conveyed;

(B) the character of industrial wastes;

(D) the exclusion of inflow and infiltration;

(E) any external forces;

(F) any groundwater;

(G) the internal pressures; and

(H) the abrasion and corrosion resistance of the pipe material.

(1) The technical specifications for joints for gravity pipe must include the materials and methods used in making joints.

(2) Materials used for gravity pipe joints must prevent infiltration and root entrance. A joint must:

(A) include rubber gaskets,

(B) include polyvinyl chloride (PVC) compression joints,

(D) be welded,

(E) be heat fused, or

(F) include other types of factory made joints.

(3) The technical specifications must include ASTM, AWWA, ANSI, or other appropriate national reference standards for the joints.

(d) Separation distances between public water supply pipes and wastewater collection system pipes or manholes.

(1) Collection system pipes must be installed in trenches separate from public water supply trenches.

(2) Collection system pipes must be no closer than nine feet in any direction to a public water supply line.

(3) If a nine-foot separation distance cannot be achieved, the following guidelines will apply.

(A) If a collection system parallels a public water supply pipe the following requirements apply.

(i) A collection system pipe must be constructed of cast iron, ductile iron, or PVC meeting ASTM specifications with at least a 150 pounds per square inch (psi) pressure rating for both the pipe and joints.

(ii) A vertical separation must be at least two feet between the outside diameters of the pipes.

(iii) A horizontal separation must be at least four feet between outside diameters of the pipes.

(iv) A collection system pipe must be below a public water supply pipe.

(B) If a collection system pipe crosses a public water supply pipe, the following requirements apply:

(i) If a collection system is constructed of cast iron, ductile iron, or PVC with a minimum pressure rating of 150 psi, the following requirements apply:

(I) A minimum separation distance is six inches between outside diameters of the pipes.

(II) A collection system pipe must be below a public water supply pipe.

(III) Collection system pipe joints must be located as far as possible from an intersection with a public water supply line.

(ii) If a collection system pipe crosses under a public water supply pipe and the collection system pipe is constructed of acrylonitrile butadiene styrene (ABS) truss pipe, similar semi-rigid plastic composite pipe, clay pipe, or concrete pipe with gasketed joints, the following requirements apply:

(I) A minimum separation distance is two feet.

(II) If a collection system pipe is within nine feet of a public water supply pipe, the initial backfill around the collection system pipe must be:

(-a-) sand stabilized with two or more 80 pound bags of cement per cubic yard of sand for any section of collection system pipe within nine feet of a public water supply pipe.

(-b-) installed from one quarter of the diameter of the collection system pipe below the centerline of the collection system pipe to one pipe diameter (but not less than 12 inches) above the top of the collection system pipe.

(iii) If a collection system crosses over a public water supply pipe, one of the following procedures must be followed:

(I) Each portion of a collection system pipe within nine feet of a public water supply pipe must be constructed of cast iron, ductile iron, or PVC pipe with at least a 150 psi pressure rating using appropriate adapters.

(II) A collection system pipe must be encased in a joint of at least 150 psi pressure class pipe that is:

(-a-) centered on the crossing;

(-b-) sealed at both ends with cement grout or manufactured seal;

(-c-) at least 18 feet long;

(-d-) at least two nominal sizes larger than the wastewater collection pipe; and

(-e-) supported by spacers between the collection system pipe and the encasing pipe at a maximum of five-foot intervals.

(4) Public water supply pipe and collection system manhole separation.

(A) Unless collection system manholes and the connecting collection system pipe are watertight, as supported by leakage tests showing no leakage, they must be installed a minimum of nine feet of horizontal clearance from an existing or proposed public water supply pipe.

(B) If a nine-foot separation distance cannot be achieved, the requirements in paragraph (3) of this subsection apply.

(e) Laterals and taps. Laterals and taps on an installation must:

(1) include a manufactured fitting that limits infiltration;

(2) prevent protruding service lines; and

(3) protect the mechanical and structural integrity of a wastewater collection system.

(f) Bore or tunnel for crossings. The spacing of supports for carrier pipe through casings must maintain the grade, slope, and structural integrity of a pipe as required by subsection (k) of this section.

(g) Corrosion potential.

(1) If a pipe or an integral structural component of a pipe will deteriorate when subjected to corrosive internal conditions or if a pipe or component does not have a corrosive resistant liner installed by the pipe manufacturer, the report must demonstrate the structural integrity of a pipe during the minimum 50-year design life cycle.

(2) A pipe must have an appropriate lining if the corrosion analysis indicates that corrosion will reduce the functional life of the pipe to less than 50 years.

(h) Odor Control.

(1) An owner shall determine if odor control measures are necessary to prevent a wastewater collection system from becoming a nuisance, based upon the potential of the wastewater collection system to generate hydrogen sulfide.

(2) A potential odor determination must include the estimated flows immediately following construction and throughout a system's 50-year expected life cycle.

(i) Active Geologic Faults.

(1) An owner shall identify any active faults within the area of a collection system and minimize the number of collection system lines crossing faults.

(A) Where an active fault crossing is unavoidable, the report must specify design features that protect the integrity of a wastewater collection system in the event of movement of the fault.

(B) If a collection system line cross an active fault line, the design must specify:

(i) joints that provide maximum deflection, as required in subsection (m) of this section; and

(ii) manholes on each side of the fault so that a portable pump may be used in the event of a wastewater collection system failure.

(2) An owner shall not install a collection system service connection within 50 feet of an active fault.

(j) Capacity Analysis.

(1) An owner must ensure that a wastewater collection system's capacity is sufficient to serve the estimated future population, including institutional, industrial, and commercial flows.

(2) An owner must include in the report the calculations that demonstrate that the hydraulic capacity of a collection system includes the peak flow of domestic sewage, peak flow of waste from industrial sites, and maximum infiltration rates.

(3) A collection system must be designed to prevent a surcharge in any pipe at the expected peak flow.

(4) The minimum diameter allowed for a gravity pipe is 6.0 inches.

(5) Connecting storm water drains to a collection system is prohibited.

(6) An owner may use the data from an existing collection system. In the absence of existing data, a design must use data from a similar system or as described in paragraph (7) of this subsection.

(7) New collection systems.

(A) The sizing of pipe for a new collection system must be based on an engineering analysis of initial and future flows.

(B) A new collection system design must be based on the estimated daily sewage flow contribution as shown in Figure: 30 TAC §217.32(a)(3), Table B.1 of this title (relating to Organic Loadings and Flows).

(k) Structural Analysis.

(1) An owner must ensure that a collection system is designed to have a minimum structural life of 50 years.

(2) For flexible pipe, which is pipe that will deflect at least 2% without structural distress, used in a collection system, the report must include:

(A) live load calculations;

(B) allowable buckling pressure determinations;

(D) wall crushing determinations;

(E) strain prediction calculations;

(F) calculations that quantify long term pipe deflection; and

(G) all information pertinent to a determination of an adequate design including, but not limited to:

(i) the method of determining the modulus of soil reaction for bedding material and in-situ material;

(ii) pipe diameter and material with reference to appropriate standards;

(iii) modulus of elasticity,

(iv) tensile strength,

(v) pipe stiffness or ring stiffness constant converted to pipe stiffness;

(vi) Leonhardt's zeta factor;

(vii) trench width;

(viii) depth of cover;

(ix) water table elevation; and

(x) unit weight of soil.

(3) The design procedure dictates a minimum pipe stiffness. For trench installations, the design must specify a minimum stiffness requirement to ensure ease of handling, transportation, and construction. Pipe stiffness must be related to ring stiffness constant by the following equation:

Figure: 30 TAC §217.53(k)(3)

(4) Pipe that meet all the requirements in this paragraph are not required to perform the structural calculations in paragraph (3) of this subsection, provided that a pipe is installed and tested in accordance with all other requirements of this subchapter:

(A) open trench design;

(B) flexible pipe with a pipe stiffness of 46 psi or greater;

(D) diameter of 12 inches or less;

(E) modulus of soil reaction for the in-situ soil of 200 psi or greater;

(F) no effects on a pipe due to live loads;

(G) a unit weight of soil of 120 pounds per cubic foot or less; or

(H) a pipe trench width of 36 inches or greater.

(5) A design analysis for rigid pipe installations must be included in the report, including a structural analysis and any details necessary to verify that the structural strength is sufficient to withstand the expected stresses. For rigid conduits, the minimum strength for each class of pipe material and the appropriate standard must be included.

(l) Minimum and Maximum Slopes.

(1) All wastewater collection systems must contain slopes sufficient to allow a velocity when flowing full of not less than 2.0 feet per second.

(2) Absent site-specific data, a collection system must be designed in accordance with the minimum and maximum slopes specified in this paragraph.

(A) The grades shown in the following table are based on Manning's formula with an assumed "n factor" of 0.013 and are the minimum acceptable slopes.

Figure: 30 TAC §217.53(l)(2)(A)

(i) The minimum acceptable "n" value for design and construction is 0.013.

(ii) The "n" value must take into consideration the slime, grit, and grease layers that will affect hydraulics or hinder flow as a pipe ages.

(B) If a velocity greater than 10 feet per second will occur when a pipe flows full, based on Manning's formula, shown in the following figure, and an "n" value of 0.013, special provisions must protect against pipe and bedding displacement.

Figure: 30 TAC §217.53(l)(2)(B)

(m) Alignment.

(1) A gravity collection system must be laid with a uniform grade between manholes.

(2) The report must justify any deviation from straight alignment by complying with the requirements of this section.

(3) Deviation from uniform grade (e.g., grade breaks or vertical curves) without manholes and with open cut construction is prohibited.

(4) The calculations for horizontal pipe curvature and the detail of the proposed curvature on the plans must be included in the report.

(5) A construction method that flexes a pipe joint is prohibited, unless a joint deflection meets the least of the following:

(A) equal to 5 degrees;

(B) less than or equal to 80% of the manufacturer's recommended maximum deflection; or

(6) The maximum allowable manhole spacing for collection systems with horizontal curvature is 300 feet. A manhole must be at the point of curvature and the point of termination of a curve.

(n) Inverted Siphons and Sag Pipes.

(1) A sag pipe must include:

(A) two or more barrels;

(B) a minimum pipe diameter of 6.0 inches; and

(2) A manhole must include adequate clearance for rodding and cleaning.

(3) Sag pipes must be sized and designed with sufficient head to achieve a velocity of at least 3.0 feet per second at initial and design flows.

(4) The arrangement of inlet and outlet details must divert the normal flow to one barrel.

(5) A system must allow any barrel to be taken out of service for cleaning.

(6) Provisions must be made to allow cleaning across each bend with equipment available to the entity operating the collection system.

(7) Sag pipe must be designed to minimize nuisance odors.

(8) Inverted siphons and sag pipes must be pressure tested according to the requirement of §217.57 of this title (relating to Testing Requirements for Installation of Gravity Collection System Pipes).

(o) Bridged Sections.

(1) Pipe with restrained joints or monolithic pipe across a bridged section requires a manhole on each end.

(2) A bridged section must withstand the hydraulic forces applied by the occurrence of a 100-year flood event for a collection system site, including buoyancy.

(3) A bridged section must be capable of withstanding impacts from debris.

(4) Bank sections must be stabilized to prevent erosion.

(5) Bridge supports must be designed to ensure that a pipe has adequate grade, slope, and structural integrity.

§217.54.Criteria for Laying Pipe.

(a) Pipe Embedment.

(1) A rigid pipe must be laid with the adequate bedding, haunching, and initial backfill to support the anticipated load. The bedding classes that are allowed are A, B, or C, as described in American Society for Testing and Materials (ASTM) C 12, American National Standards Institute (ANSI) A 106.2, Water Environment Federation Manual of Practice No. 9 or American Society of Civil Engineers (ASCE) MOP 37.

(2) A flexible pipe must be laid with the adequate bedding, haunching, and initial backfill to support the anticipated load. The bedding classes that are allowed are IA, IB, II, or III, as described in ASTM D-2321 or ANSI K65.171.

(3) Debris, large clods, or stones that are greater than six inches in diameter, organic matter, or other unstable materials are prohibited as bedding, haunching, or initial backfill.

(4) Backfill must not disturb the alignment of a collection system pipe.

(5) If trenching encounters significant fracture, fault zones, caves, or solutional modification to the rock strata, an owner must halt construction until an engineer prepares a written report detailing how construction will accommodate these site conditions.

(b) Compaction.

(1) Compaction of an embedment envelope must meet the manufacturer's recommendations for the collection system pipe used in a project.

(2) Compaction of an embedment envelope must provide the modulus of soil reaction for the bedding material necessary to ensure a wastewater collection system pipe's structural integrity as required by §217.53 of this title (relating to Pipe Design).

(3) The placement of the backfill above a pipe must not affect the structural integrity of a pipe.

(1) A minimum clearance of 6.0 inches below and on each side of the bell of all pipes to the trench walls and floor is required.

(2) The embedment material used for haunching and initial backfill must be installed to a minimum depth of 12 inches above the crown of a pipe.

(d) Trench Width.

(1) The width of a trench must allow a pipe to be laid and jointed properly and must allow the backfill to be placed and compacted as needed.

(2) The maximum and minimum trench width needed for safety and a pipe's structural integrity must be included in the report.

(3) The width of a trench must be sufficient to properly and safely place and compact haunching materials.

(4) The space between a pipe and a trench wall must be wider than the compaction equipment used in the pipe zone.

Figure: 30 TAC §217.54(d)(4)

§217.55.Manholes and Related Structures.

(a) An owner must include manholes in a wastewater collection system at:

(1) all points of change in alignment, grade, or size;

(2) at the intersection of all pipes; and

(3) at the end of all pipes that may be extended at a future date.

(b) Manholes placed at the end of a wastewater collection system pipe that may be extended in the future must include pipe stub outs with plugs.

(c) A clean-out with watertight plugs may be installed in lieu of a manhole at the end of a wastewater collection system pipe if no extensions are anticipated.

(d) Cleanout installations must pass all applicable testing requirements outlined for gravity collection pipes in §217.57 of this title (relating to Testing Requirements for Installation of Gravity Collection System Pipes).

(e) A manhole must be made of monolithic, cast-in-place concrete, fiberglass, pre-cast concrete, high-density polyethylene, or equivalent material that provides adequate structural integrity.

(f) The use of bricks to adjust a manhole cover to grade or construct a manhole is prohibited.

(g) Manholes may be spaced no further apart than the distances specified in the following table for a wastewater collection system with straight alignment and uniform grades, unless a variance based on the availability of cleaning equipment that is capable of servicing greater distances is granted by the executive director.

Figure: 30 TAC §217.55(g)

(h) Tunnels are exempt from manhole spacing requirements because of construction constraints.

(i) An intersection of three or more collection pipes must have a manhole.

(j) A manhole must not be located in the flow path of a watercourse, or in an area where ponding of surface water is probable.

(k) The inside diameter of a manhole must be no less than 48 inches. A manhole diameter must be sufficient to allow personnel and equipment to enter, exit, and work in the manhole and to allow proper joining of the collection system pipes in the manhole wall.

(l) Manholes must meet the following requirements for covers, inlets, and bases.

(1) Manhole Covers.

(A) A manhole where personnel entry is anticipated requires at least a 30 inch diameter clear opening.

(B) A manhole located within a 100-year flood plain must have a means of preventing inflow.

(D) A manhole cover that is located in a roadway must meet or exceed the American Association of State Highways and Transportation Officials standard M-306 for load bearing.

(2) Manhole Inverts.

(A) The bottom of a manhole must contain a U-shaped channel that is a smooth continuation of the inlet and outlet pipes.

(B) A manhole connected to a pipe less than 15 inches in diameter must have a channel depth equal to at least half the largest pipe's diameter.

(C) A manhole connected to a pipe at least 15 inches in diameter but not more than 24 inches in diameter must have a channel depth equal to at least three-fourths of the largest pipe's diameter.

(D) A manhole connected to a pipe greater than 24 inches in diameter must have a channel depth equal to at least the largest pipe's diameter.

(E) A manhole with pipes of different sizes must have the tops of the pipes at the same elevation and flow channels in the invert sloped on an even slope from pipe to pipe.

(F) A bench provided above a channel must slope at a minimum of 0.5 inch per foot.

(G) An invert must be filleted to prevent solids from being deposited if a wastewater collection system pipe enters a manhole higher than 24 inches above a manhole invert.

(H) A wastewater collection system pipe entering a manhole more than 24 inches above an invert must have a drop pipe.

(m) The inclusion of steps in a manhole is prohibited.

(n) Connections. A manhole-pipe connection must use watertight, size-on-size resilient connectors that allow for differential settlement and must conform to American Society for Testing and Materials C-923.

(o) Venting. An owner must use an alternate means of venting if manholes are at more than 1,500 foot intervals and gasketed manhole covers are required for more than three manholes in sequence. Vents must meet the following requirements:

(1) Vent design must minimize inflow;

(2) Vents must be located above a 100-year flood event elevation; and

(3) Tunnels must be vented in compliance with this subsection.

(p) Cleanouts. The size of a cleanout must be equal to the size of the wastewater collection system main.

§217.56.Trenchless Pipe Installation.

(a) The following trenchless technologies may be used for installation of new wastewater collection system pipe:

(1) impact moling, which is technique that launches a percussive soil displacement hammer (mole) from an excavation to displace soil and form a bore. The new pipe is drawn behind the mole or pulled into the bore using the hammer's reverse action. A pneumatically driven mole displaces the soil by the action of a percussive piston;

(2) pipe ramming, which is a simple technique using a pneumatic hammer to drive steel casings through the ground from one pit to another; or

(3) microtunneling, which is a remotely controlled mechanical tunneling system where the spoil is removed from the cutting head within the new pipeline, which is advanced by pipe jacking. The cutting head must have the appropriate cutting tools and crushing devices for the range of gravels, sands, silts, and clays that may be found at the collection system site.

(b) The following trenchless technologies may be used for replacement of wastewater collection system pipe:

(1) pipe bursting, which is a method of on-line replacement of fracturable pipe. An expanding device, either pneumatic or hydraulic, is introduced into the defective pipeline, shattering the pipe and drawing in the new pipe behind it. Insertion of short lengths may be made from pits but this involves jointing of the pipeline within the pit;

(2) pipe splitting, which is similar in technique to pipe bursting but is used on non-fragmental pipes such as steel, ductile iron or polyethylene. The system uses specialized splitting heads designed to cut through the pipe wall and joints and expand the existing pipe into the surrounding ground; or

(3) pipe eating, which is an on-line microtunneled replacement technique. The existing defective pipeline is crushed (or eaten), by the tunneling machine and removed through the new pipeline. It is used predominantly on concrete sewer installations. This system allows for size replacement and upsizing.

(c) The following trenchless technologies may be used for lining of existing wastewater collection system pipe, which reduces the inside diameter of the pipe:

(1) cement mortar lining, which is the application of a cement mortar (typically about four millimeters thick) to the inside of a pipe to protect against corrosion;

(2) epoxy spray lining, which is a method of lining pipes with a thin lining of resin (typically about one millimeter thick) that is sprayed onto the interior surface of a cleaned collection system pipe to isolate the pipe from the wastewater and possibly reinforce the structural capabilities of the pipe;

(3) cure in place pipe, which is method of lining existing pipe with a flexible tube impregnated with a resin that produces a pipe after the resin cures. The resin may be set by the use of heat or ultraviolet light; or

(4) sliplining, by which continuous or discreet pipes are inserted within existing pipes.

(d) Any other trenchless method of installing, replacing, or repairing collection system pipe is nonconforming technology and subject to the requirements of §217.7(b) of this title (relating to Types of Plans and Specifications Approvals).

(e) A wastewater collection system using a trenchless technology must be designed, installed, and constructed in accordance with American Society for Testing and Materials (ASTM) or American Water Works Association (AWWA) standards with reference to materials used and construction procedures. In the absence of ASTM or AWWA standards, executive director review may be based upon other recognized standards utilized by industry engineers.

(f) The report must include the following;

(1) the trenchless method;

(2) the type of pipe;

(3) the type(s) of soil;

(4) the pipe length and diameter;

(5) pipe slope;

(6) the method for disconnecting and reconnecting lateral and service connections;

(7) the provisions for flow bypass for existing system; and

(8) the pipe standard.

(g) Lateral and service connections must be disconnected prior to repair or replacement of existing collection system pipe.

(h) Pipe installed by a trenchless technology is subject to the testing requirements in §217.57 of this title (relating to Testing Requirements for Installation of Gravity Collection System Pipes) and §217.68 of this title (relating to Force Main Testing).

§217.57.Testing Requirements for Installation of Gravity Collection System Pipes.

(a) For a collection system pipe that will transport wastewater by gravity flow, the design must specify an infiltration and exfiltration test or a low-pressure air test. A test must conform to the following requirements:

(1) Low Pressure Air Test.

(A) A low pressure air test must follow the procedures described in American Society For Testing And Materials (ASTM) C-828, ASTM C-924, or ASTM F-1417 or other procedure approved by the executive director, except as to testing times as required in Table C.3 in subparagraph (B)(ii) of this paragraph or Equation 3.c in subparagraph (C) of this paragraph.

(B) For sections of collection system pipe less than 36 inch average inside diameter, the following procedure must apply, unless a pipe is to be tested as required by paragraph (2) of this subsection.

(i) A pipe must be pressurized to 3.5 pounds per square inch (psi) greater than the pressure exerted by groundwater above the pipe.

(ii) Once the pressure is stabilized, the minimum time allowable for the pressure to drop from 3.5 psi gauge to 2.5 psi gauge is computed from the following equation:

Figure: 30 TAC§217.57(a)(1)(B)(ii)

(C) Since a K value of less than 1.0 may not be used, the minimum testing time for each pipe diameter is shown in the following table:

Figure: 30 TAC §217.57(a)(1)(C)

(D) An owner may stop a test if no pressure loss has occurred during the first 25% of the calculated testing time.

(E) If any pressure loss or leakage has occurred during the first 25% of a testing period, then the test must continue for the entire test duration as outlined above or until failure.

(F) Wastewater collection system pipes with a 27 inch or larger average inside diameter may be air tested at each joint instead of following the procedure outlined in this section.

(G) A testing procedure for pipe with an inside diameter greater than 33 inches must be approved by the executive director.

(2) Infiltration/Exfiltration Test.

(A) The total exfiltration, as determined by a hydrostatic head test, must not exceed 50 gallons per inch of diameter per mile of pipe per 24 hours at a minimum test head of 2.0 feet above the crown of a pipe at an upstream manhole.

(B) An owner shall use an infiltration test in lieu of an exfiltration test when pipes are installed below the groundwater level.

(C) The total infiltration, as determined by a hydrostatic head test, must not exceed 50 gallons per inch diameter per mile of pipe per 24 hours at a minimum test head of two feet above the crown of a pipe at an upstream manhole, or at least two feet above existing groundwater level, whichever is greater.

(D) For construction within a 25-year flood plain, the infiltration or exfiltration must not exceed 10 gallons per inch diameter per mile of pipe per 24 hours at the same minimum test head as in subparagraph (C) of this paragraph.

(E) If the quantity of infiltration or exfiltration exceeds the maximum quantity specified, an owner shall undertake remedial action in order to reduce the infiltration or exfiltration to an amount within the limits specified. An owner shall retest a pipe following a remediation action.

(b) If a gravity collection pipe is composed of flexible pipe, deflection testing is also required. The following procedures must be followed:

(1) For a collection pipe with inside diameter less than 27 inches, deflection measurement requires a rigid mandrel.

(A) Mandrel Sizing.

(i) A rigid mandrel must have an outside diameter (OD) not less than 95% of the base inside diameter (ID) or average ID of a pipe, as specified in the appropriate standard by the ASTMs, American Water Works Association, UNI-BELL, or American National Standards Institute, or any related appendix.

(ii) If a mandrel sizing diameter is not specified in the appropriate standard, the mandrel must have an OD equal to 95% of the ID of a pipe. In this case, the ID of the pipe, for the purpose of determining the OD of the mandrel, must equal be the average outside diameter minus two minimum wall thicknesses for OD controlled pipe and the average inside diameter for ID controlled pipe.

(iii) All dimensions must meet the appropriate standard.

(B) Mandrel Design.

(i) A rigid mandrel must be constructed of a metal or a rigid plastic material that can withstand 200 psi without being deformed.

(ii) A mandrel must have nine or more odd number of runners or legs.

(iii) A barrel section length must equal at least 75% of the inside diameter of a pipe.

(iv) Each size mandrel must use a separate proving ring.

(i) An adjustable or flexible mandrel is prohibited.

(ii) A test may not use television inspection as a substitute for a deflection test.

(iii) If requested, the executive director may approve the use of a deflectometer or a mandrel with removable legs or runners on a case-by-case basis.

(2) For a gravity collection system pipe with an inside diameter 27 inches and greater, other test methods may be used to determine vertical deflection.

(3) A deflection test method must be accurate to within plus or minus 0.2% deflection.

(4) An owner shall not conduct a deflection test until at least 30 days after the final backfill.

(5) Gravity collection system pipe deflection must not exceed five percent (5%).

(6) If a pipe section fails a deflection test, an owner shall correct the problem and conduct a second test after the final backfill has been in place at least 30 days.

(7) An owner shall not use any mechanical pulling devices during testing.

(8) An owner shall include a certification in the construction report or the notice of completion required in §217.14 of this title (relating to Completion Notice), that the wastewater collection system passed the deflection tests.

(c) An owner of a collection system must inspect the structural analysis of collection system under the direction of an engineer during the construction and testing phases of the project.

§217.58.Testing Requirements for Manholes.

(a) All manholes must pass a leakage test.

(b) An owner shall test each manhole (after assembly and backfilling) for leakage, separate and independent of the collection system pipes, by hydrostatic exfiltration testing, vacuum testing, or other method approved by the executive director.

(1) Hydrostatic Testing.

(A) The maximum leakage for hydrostatic testing or any alternative test methods is 0.025 gallons per foot diameter per foot of manhole depth per hour.

(B) To perform a hydrostatic exfiltration test, an owner shall seal all wastewater pipes coming into a manhole with an internal pipe plug, fill the manhole with water, and maintain the test for at least one hour.

(2) Vacuum Testing.

(A) To perform a vacuum test, an owner shall plug all lift holes and exterior joints with a non-shrink grout and plug all pipes entering a manhole.

(B) No grout must be placed in horizontal joints before testing.

(D) An owner shall use a minimum 60 inch/lb torque wrench to tighten the external clamps that secure a test cover to the top of a manhole.

(E) A test head must be placed at the inside of the top of a cone section, and the seal inflated in accordance with the manufacturer's recommendations.

(F) There must be a vacuum of 10 inches of mercury inside a manhole to perform a valid test.

(G) A test does not begin until after the vacuum pump is off.

(H) A manhole passes the test if after 2.0 minutes and with all valves closed, the vacuum is at least 9.0 inches of mercury.

§217.59.Lift Station Site Requirements.

(a) Site access.

(1) A lift station design must include an access road located in a dedicated right-of-way or a permanent easement.

(2) A road surface must have a minimum width of 12 feet and must be constructed for use in all weather conditions.

(3) A road surface must be above the water level caused by a 25-year rainfall event.

(b) Security.

(1) The design of a lift station, including all mechanical and electrical equipment, must restrict access by an unauthorized person.

(2) A lift station must include an intruder-resistant fence, enclosure, or a lockable structure.

(3) An intruder-resistant fence must use a minimum of a 6.0 feet high chain link, masonry, or board fence with at least a 1.0 foot section of three strands of barbed wire.

(c) Flood Protection. The design of a lift station, including all electrical and mechanical equipment, must be designed to withstand and operate during a 100-year flood event, including wave action.

(d) Odor Control. The design of a lift station must minimize potential odor. An owner shall include any design for odor control in the report.

§217.60.Lift Station, Wet Well, and Dry Well Designs.

(a) Pump Controls.

(1) A lift station pump must operate automatically, based on the water level in a wet well.

(2) The location of a wet well level mechanism must ensure that the mechanism is unaffected by currents, rags, grease, or other floating materials.

(3) A level mechanism must be accessible without entering the wet well.

(4) Wet well controls with a bubbler system require dual air supply and dual controls.

(5) Motor control centers must be mounted on a 4.0 inch tall housekeeping pad.

(6) Electrical equipment and electrical connections in a wet well or a dry well must be meet National Electric Code explosion prevention requirements, unless continuous ventilation is provided.

(b) Wet Wells.

(1) A wet well must be enclosed by watertight and gas tight walls.

(2) A penetration through a wall of a wet well must be gas tight.

(3) A wet well must not contain equipment requiring regular or routine inspection or maintenance, unless inspection and maintenance can be done without staff entering the wet well.

(4) A gravity pipe discharging to a wet well must be located so that the invert elevation is above the liquid level of a pump's "on" setting.

(5) Gate valves and check valves are prohibited in a wet well.

(6) Gate valves and check valves may be located in a valve vault next to a wet well or in a dry well.

(7) Pump cycle time, based on peak flow, must equal or exceed those in the following table:

Figure: 30 TAC §217.60(b)(7)

(8) An evaluation of minimum wet well volume requires the following formula:

Figure: 30 TAC §217.60(b)(8)

(1) An underground dry well must be accessible.

(2) A stairway in a dry well must use non-slip steps and conform to Occupational Safety and Health Administration regulations with respect to rise and run.

(3) A ladder in a dry well must made of non-conductive material and rated for the load necessary for staff and equipment to descend and ascend.

(d) Lift Station Ventilation.

(1) Passive Ventilation for Wet Wells.

(A) Passive ventilation structures must include screening to prevent the entry of birds and insects to a wet well.

(B) All mechanical and electrical equipment in a wet well with passive ventilation must be constructed in compliance with explosion requirement in the National Electric Code.

(C) A passive ventilation system must be sized to vent at a rate equal to the maximum pumping rate of a lift station, but not to exceed 600 feet per minute through a vent pipe.

(D) The minimum acceptable diameter for an air vent is 4.0 inches.

(E) A vent outlet must be at least 1.0 foot above a 100-year flood plain elevation.

(2) Mechanical Ventilation in Lift Stations.

(A) Dry Wells.

(i) A dry well must use mechanical ventilation.

(ii) Ventilation equipment under continuous operation must have a minimum capacity of six air exchanges per hour.

(iii) Ventilation equipment under intermittent operations must have a minimum capacity of 30 air exchanges per hour and be connected to a lift station's lighting system.

(B) Wet Wells.

(i) A wet well must use continuous mechanical ventilation.

(ii) The ventilation equipment must have a minimum capacity of 12 air exchanges per hour and be constructed of corrosion resistant material.

(iii) The design of a wet well must reduce odor potential in a populated area.

(e) Wet Well Slopes.

(1) A wet well floor must have a smooth finish and minimum slope of 10% to a pump intake.

(2) A wet well design must prevent deposition of solids under normal operating conditions.

(3) A lift station with greater than 5.0 million gallons per day firm pumping capacity must have anti-vortex baffling.

(f) Hoisting Equipment. A lift station must have permanent hoisting equipment or be accessible to portable hoisting equipment for removal of pumps, motors, valves, pipes, and other similar equipment.

(g) Valve Vault Drains. A floor drain from a valve vault to a wet well must prevent gas from entering a valve vault by including flap valves, "P" traps, submerged outlets, or a combination of these devices.

(h) Dry Well Sump Pumps.

(1) Pumps.

(A) A dry well must use dual sump pumps, each with a minimum capacity of 1,000 gallons per hour and capable of handling the volume of liquid generated during peak operations.

(B) A pump must have a submersible motor and watertight wiring.

(D) The minimum sump depth is 6.0 inches and must prevent standing water on a dry well floor under normal operation.

(E) A sump pump must operate automatically by use of a float switch or other level-detecting device.

(2) Pipes.

(A) A sump pump must use separate pipes capable of discharging more than the maximum liquid level of an associated wet well.

(B) A sump pump outlet pipe must be at least 1.5 inches in diameter and have at least two check valves in series.

§217.61.Lift Station Pumps.

(a) General Requirements. A raw wastewater pump, with the exception of a grinder pump, must:

(1) be designed to prevent clogging;

(2) be capable of passing a sphere of 2.5 inches in diameter or greater; and

(3) have greater than 3.0 inch diameter suction and discharge openings.

(b) Submersible and Non-submersible Pumps.

(1) A non-submersible pump must have inspection and cleanout plates on both the suction and discharge sides of each pumping unit that facilitate locating and removing blockage-causing materials, unless the pump design accommodates easy removal of the rotation elements.

(2) A pump support must prevent movement and vibration during operation.

(3) A submersible pump must use a rail-type pump support system with manufacturer-approved mechanisms designed to allow personnel to remove and replace any single pump without entering or dewatering the wet well.

(4) Submersible pump rails and lifting chains must be constructed of a material that performs to at least the standard of Series 300 stainless steel.

(d) Pump Head Calculations.

(1) An owner shall select a pump based upon analysis of the system head and pump capacity curves that determine the pumping capacities alone and with other pumps as the total dynamic-head increases due to additional flows pumped through a force main.

(2) The pipe head loss calculations, using the Hydraulic Institute Standards, pertaining to head losses through pipes, valves, and fittings, must be included in the report.

(3) The selected friction coefficient (Hazen-Williams "C" value) used in friction head loss calculations must be based on the pipe material selected.

(4) For a lift station with more than two pumps, a force main in excess of one-half mile, or firm pumping capacity of 100 gallons per minute or greater, system curves must be provided for both the normal and peak operating conditions at C values for proposed and existing pipe.

(e) Flow Control.

(1) A lift station or a transfer pumping station located at or discharging directly to a wastewater treatment system must have a peak pump capacity equal to or less than the peak design flow, unless equalization is provided.

(2) A wastewater treatment system with a peak flow that is greater than 300,000 gallon per day must use three or more pumps, unless duplex, automatically controlled, variable capacity pumps are provided.

(f) Self-Priming Pumps.

(1) A self-priming pump must be capable of priming without reliance upon a separate priming system, an internal flap valve, or any external means for priming.

(2) A self-priming pump must use a suction pipe velocity at least 3.0 feet per second but not more than 7.0 feet per second, and must incorporate its own suction pipe.

(3) A self-priming pump must vent air back into the wet well during priming.

(g) Vacuum-Priming Pumps.

(1) A vacuum-primed pump must be capable of priming by using a separate positive priming system with a dedicated vacuum pump for each main wastewater pump.

(2) A vacuum-priming pump must use a suction pipe velocity at least 3.0 feet per second but less than 7.0 feet per second and must have its own suction pipe.

(h) Vertical Positioning of Pumps. A raw wastewater pump must have positive static suction head during normal on-off cycling, except a submersible pump with "no suction" pipes, a vacuum-primed pump, or a self-priming unit capable of satisfactory operation under any negative suction head anticipated for the lift station.

(i) Individual Grinder Pumps. A grinder pump serving only one residential or commercial structure that is privately owned, maintained, and operated is not subject to the rules of this chapter.

(j) Pump for Low-Flow Lift Station. A pump used for a lift station with a peak flow of less than 120 gallons per minute must be submersible and include a grinder.

§217.62.Lift Station Pipes.

(a) Horizontal Pump Suctions.

(1) Each pump must have a separate suction pipe that uses an eccentric reducer.

(2) Pipes in a wet well must have a turndown type flared intake.

(b) Valves.

(1) The discharge side of each pump followed by a full-closing isolation valve must also have a check valve.

(A) A check valve must be a swing type valve with an external lever.

(B) A valve must include a position indicator to show its open and closed positions, unless a full-closing valve is a rising-stem gate valve.

(2) A grinder pump installation may use a rubber-ball check valve or a swing-type check valve.

(3) A butterfly valve, tilting-disc check valve, or any other valve using a tilting-disc in a flow pipe is prohibited.

(1) A lift station pipe must have flanged or flexible connections to allow for removal of pumps and valves without interruption of the lift station operations.

(2) Wall penetrations must allow for pipe flexure while excluding exfiltration or infiltration.

(3) Pipe suction velocities must be at least 3.0 feet per second but not more than 7.0 feet per second.

§217.63.Emergency Provisions for Lift Stations.

(a) A collection system lift station must be equipped with a tested quick-connect mechanism or a transfer switch properly sized to connect to a portable generator, if not equipped with an onsite generator.

(b) Lift stations must include an audiovisual alarm system and the system must transmit all alarm conditions through use of an auto-dialer system, Supervisory Control and Data Acquisition system, or telemetering system connected to a continuously monitored location.

(d) A lift station constructed to pump raw wastewater must have service reliability based on:

(1) Retention Capacity.

(A) The retention capacity in a lift station's wet well and incoming gravity pipes must prevent discharges of untreated wastewater at the lift station or any point upstream for a period of time equal to the longest electrical outage recorded during the past 24 months, but not less than 20 minutes.

(B) For calculation purposes, the outage period begins when a lift station pump finished its last normal cycle, excluding a standby pump.

(2) On-Site Generators. A lift station may be provided emergency power by on-site, automatic electrical generators sized to operate the lift station at its firm pumping capacity or at the average daily flow, if the peak flow can be stored in the collection system.

(3) Portable Generators and Pumps.

(A) A lift station may use portable generators and pumps to guarantee service if the report includes:

(i) the storage location of each generator and pump;

(ii) the amount of time that will be needed to transport each generator or pump to a lift station;

(iii) the number of lift stations for which each generator or pump is dedicated as a backup; and

(iv) the type of routine maintenance and upkeep planned for each portable generator and pump to ensure that they will be operational when needed.

(B) An operator that is knowledgeable in operation of the portable generators and pumps shall be on call 24 hours per day every day.

(e) Spill Containment Structures.

(1) The use of a spill containment structure as a means of providing service reliability is prohibited.

(2) A lift station may use a spill containment structure in addition to one of the service reliability options detailed in this in subsection (a) of this section.

(3) The report must include a detailed management plan for cleaning and maintaining each spill containment structure.

(4) A spill containment structure must have a locked gate and be surrounded by a 6.0 foot high chain link or board fence that is topped with a minimum of three strands of barbed wire.

(f) A lift station must be fully accessible during a 25-year 24-hour rainfall event.

§217.64.Materials for Force Main Pipes.

(a) Force main pipe material must withstand the pressure generated by instantaneous pump stoppage due to power failure under maximum pumping conditions.

(b) The use of pipe or fittings rated at a working pressure of less than 150 pounds per square inch is prohibited.

(c) Pipe must be identified in the technical specifications with the appropriate specification number for both quality control and installation from the American Society For Testing And Materials, American National Standards Institute, or American Water Works Association.

(d) Pipe material specified for a force main must have an expected life equal to or longer than that of the lift station and must be suitable for the material being pumped.

§217.65.Force Main Pipe Joints.

(a) An underground force main pipe joint must include either push-on rubber gaskets or mechanical joints with a pressure rating equal or greater than the force main pipe material.

(b) Exposed force main pipe joints must be flanged or flexible and adequately secured to prevent movement due to surges.

(c) American Society for Testing and Materials, American Water Works Association, or other widely accepted national reference standard for the joints must be included in the project specifications.

§217.66.Identification of Force Main Pipes.

(a) A detector tape must be laid in the same trench as a force main pipe. The detector tape must be located above and parallel to the force main.

(b) The detector tape must bear the label "PRESSURIZED WASTEWATER" continuously repeated in at least 1.5 inch letters.

§217.67.Force Main Design.

(a) Velocities.

(1) A force main must be a minimum of 4.0 inches in diameter, unless it is used in conjunction with a grinder pump station.

(2) For a duplex pump station, the minimum velocity is 3.0 feet per second with one pump in operation.

(3) For a pump station with three or more pumps:

(A) the minimum velocity in a force main is 2.0 feet per second with only the smallest pump in operation; and

(B) a minimum flushing velocity of 5.0 feet per second or greater must occur in a force main at least once daily.

(4) The report must certify that a pipeline with a velocity greater than 6.0 feet per second can withstand high and low negative surge pressures in event of sudden pump failure.

(b) Detention Time.

(1) A force main detention time calculations must be included in the report.

(2) The force main detention time calculations must be performed using a range of flow rates that represent the flows expected to be delivered to a force main by an upstream pump station during any 24-hour period.

(c) Water Hammer. A force main design must include surge control measures to manage pressure due to water hammer that may exceed the working strength of a force main pipe.

(d) Connection to Gravity Main.

(1) A force main must terminate in an appropriate structure and either at a manhole on the wastewater collection system or at a wastewater treatment facility.

(2) The discharge end of a force main inside a manhole must remain steady and produce non-turbulent flow.

(3) A receiving wastewater collection system must accept the maximum pump discharge without surcharging.

(e) Pipe Separation. A separation distance between a force main and any water supply water pipe must meet the minimum separation requirements established in §217.53(d) of this title (relating to Pipe Design).

(f) Odor Control.

(1) A force main must terminate below a manhole invert with the top of the pipe matching the water level in the manhole at design flow.

(2) A force main must be designed to abate any anticipated odor.

(g) Air Release Valves in Force Mains.

(1) Any high point along the vertical force main alignment must include an air release valve or a combination of air release and air vacuum valves.

(2) An air release valve must have an isolation valve between the air release valve and the force main.

(3) An air release valve must be inside of a vault that is at least 48 inches in diameter and has a vented access opening at least 30 inches in diameter.

(h) Valves. A force main must have valves spaced at no more than 2,000 foot intervals to facilitate initial testing and subsequent maintenance and repairs.

§217.68.Force Main Testing.

(a) The final plans and specifications must include the pressure testing procedures.

(b) A pressure test must use 50 pounds per square inch above the normal operating pressure of a force main.

(c) A temporary valve for pressure testing may be installed near the discharge point of a force main and removed after a test is successfully completed.

(d) A pump isolation valve may be used as an opposite termination point.

(e) A test must involve filling a force main with water.

(f) A pipe must hold the designated test pressure for a minimum of 4.0 hours.

(g) The leakage rate must not exceed 10.0 gallons per inch diameter per mile of pipe per day.

§217.69.Reclaimed Water Facilities.

(a) In accordance with §217.6 of this title (relating to Submittal Requirements and Review Process), the design of a distribution system that will convey reclaimed water to a user must be submitted, reviewed, and approved by the executive director before the distribution system may be used.

(b) A municipality may be the review authority in accordance with §217.8 of this title (relating to Municipality Reviews), and may approve a reclaimed water distribution system.

(c) A distribution system designed to transport Type II reclaimed water, as defined by §210.33(2) of this title (relating to Quality Standards for Using Reclaimed Water), must comply with Subchapter C of this chapter (relating to Conventional Collection Systems), as applicable to the project.

(d) A distribution system designed to transport Type I reclaimed water, as defined by §210.33 of this title must meet the following requirements:

(1) Type I reclaimed water gravity pipes must comply with §§217.53 - 217.55, 217.58, and 217.59 of this title (relating to Pipe Design; Criteria for Laying Pipe; Manholes and Related Structures; Testing Requirements for Manholes; and Lift Station Site Requirements).

(2) A design must prevent pipe and bedding displacement.

(3) The design of a pipe must prevent the deposition of solids in a gravity pipe.

(e) Each appurtenance designed to handle reclaimed water must be identified.

(1) An above-ground hose bib, spigot, or other hand-operated connection is prohibited, excepted in secured areas of a facility that only trained staff has access to.

(2) An underground hose bib must be:

(A) located in locked, below-grade vaults, and clearly labeled "NON-POTABLE WATER"; or

(B) operated only by a special tool in non-lockable, underground service boxes clearly labeled as non-potable water;

(D) designed to prevent a connection to a standard water hose.

(3) Storage areas, hose bibs, and faucets must include signs in both English and Spanish reading "NON-POTABLE WATER, DO NOT DRINK" and "El AGUA NO-POTABLE, NO BEBE."

(f) Cross Connection Control and Separation Distances.

(1) A type I reclaimed water pipe must be at least 4.0 feet from a potable water pipe, as measured from the outside surface of each of the respective pipes.

(2) A physical connection between a potable water pipe and a reclaimed water pipe is prohibited.

(3) An appurtenance must prevent any possibility of reclaimed water entering a drinking water system.

(4) Where a 4.0 foot separation distance cannot be achieved, a reclaimed water pipe must meet the following requirements:

(A) If a new Type I reclaimed water pipe is installed parallel to an existing potable water pipe, the reclaimed water pipe must:

(i) maintain a horizontal separation distance of no less than 3.0 feet with a potable water pipe at the same level or above a reclaimed water pipe;

(ii) have a minimum pipe stiffness of 115 pounds per square inch (psi) with compatible joints, or a pressure rating of 150 psi for both pipe and joints;

(iii) is embedded in cement stabilized sand, if parallel to a potable water pipe, is placed in the same benched trench as a reclaimed water pipe; and

(iv) if cement-stabilized sand is used, the sand must:

(I) have a minimum of 10% cement, based on loose dry weight volume;

(II) be a minimum of 6.0 inches above and one quarter of the pipe diameter on either side and below a reclaimed water pipe.

(B) New Type I Reclaimed Water Pipe - Crossing Pipes.

(i) If a new Type I reclaimed water pipe is installed crossing an existing potable water pipe, one segment of a Type I reclaimed water pipe must be centered on a potable water pipe such that the joints of the reclaimed water pipe are equidistant from the center point of the potable water pipe.

(ii) A crossing of the two pipes must be centered between the joints of the potable water pipe.

(C) A Type I reclaimed water pipe must have either a pressure rating of 150 psi for both pipe and joints or a pipe stiffness of at least 115 psi with compatible joints for a minimum distance of 4.0 feet in each direction, as measured perpendicularly from any point on the potable water pipe to the Type I reclaimed water pipe.

(D) The minimum distance between a reclaimed water pipe and any potable water pipe is 6.0 inches.

(E) Any portions of reclaimed water pipe within 4.0 feet of a potable water pipe must be embedded in cement stabilized sand.

(F) The cement stabilized sand must comply with the requirements listed in subparagraph (A) of this paragraph.

(g) Site Selection of Type I Reclaimed Water Pump Stations. A design must comply with §217.59(a) - (c) of this title.

(h) Design of Type I Reclaimed Water Pump Stations. A design must comply with §§217.60(d) and (g), 217.61(d), and 217.62(a) and (c) of this title (relating to Lift Station, Wet Well, and Dry Well Designs; Lift Station Pumps; and Lift Station Pipes), and paragraphs (1) - (3) of this subsection.

(1) Pump Controls.

(A) All electrical equipment must be operable during a 100-year flood event and be protected from potential flooding from a wet well.

(B) Motor control centers must be mounted on a 4.0 inch tall housekeeping pad.

(2) Pumps.

(A) A pump support must prevent movement or vibration during operation.

(B) A submersible pump must use a rail-type pump support incorporating manufacturer-approved mechanisms designed to allow an operator to remove and replace any single pump without first entering or dewatering the wet well.

(C) Submersible pump rails and lifting chains must be made of a material that is equivalent to Series 300 stainless steel at minimum.

(3) Pump Station Valves.

(A) The discharge side of each pump must include a check valve followed by a full-closing isolation valve.

(B) Check valves must be swing type with an external lever.

(C) All valve types other than rising stem gate valves must include a position indicator to show their open or closed position.

(i) Force Main Pipe for Type I Reclaimed Water. A force main pipe for Type I reclaimed water must comply with sections §§217.54, 217.64, 217.65, 217.67(a) - (c) and (e), and 217.68 of this title (relating to Materials for Force Main Pipes; Force Main Joints; Force Main Design; and Force Main Testing) and the following:

(1) A valve casing for an underground isolation valve must include "REUSE" or "NPW" cast into its lid.

(2) A force main pipe must be purple in color or contained in an 8.0 millimeter purple polyethylene sleeve conforming to American Water Works Association C105, Class C and in-line isolation valves for reuse pipes must open clockwise to distinguish them from potable water isolation valves.

§217.70.Storage Tanks for Reclaimed Water.

Ground level storage tanks and elevated storage tanks for reclaimed water must be designed, installed, and constructed in accordance with the American Water Works Association standards with reference to materials and construction practices, except for health-based standards strictly related to potable water storage and contact practices.

This agency hereby certifies that the proposal has been reviewed by legal counsel and found to be within the agency's legal authority to adopt.

Filed with the Office of the Secretary of State on February 29, 2008.

TRD-200801202

Robert Martinez

Director, Environmental Law Division

Texas Commission on Environmental Quality

Earliest possible date of adoption: April 13, 2008

For further information, please call: (512) 239-0177

Subchapter D. ALTERNATIVE COLLECTION SYSTEMS

30 TAC §§217.91 - 217.100

STATUTORY AUTHORITY

The proposed new rules implement TWC, §§5.013, 5.103, 5.105, 5.120, 26.027, 26.034, and 26.121.

§217.91.Edwards Aquifer.

An owner who plans to install an alternative wastewater collection system located over the recharge zone of the Edwards Aquifer must design and install the system in accordance with Chapter 213 of this title (relating to Edwards Aquifer) in addition to these rules.

§217.92.Component Sizing.

(a) The components of an alternative collection system must be sized based on existing flow data from a similar system and service area, if such data is available.

(b) If flow data from a similar service area with a conventional wastewater collection system is used, the report must include the expected effects of inflow and infiltration on the peak flow of the system.

(c) Design and construction of an alternative wastewater collection system must minimize excess flows from inflow and infiltration.

(d) Roof, street, or other type of drain that permit entrance of storm water into a wastewater collection system is prohibited.

(e) In the absence of existing data, the sizing of on-site components in an alternative wastewater collection system must use Figure: 30 TAC §217.32(a)(3), Table B.1 of this title (relating to Organic Loadings and Flows), in conjunction with the following equation:

Figure: 30 TAC §217.92(e)

(f) Design of the off-site components must be based on the maximum flow rate expected, calculated using the following equation:

Figure: 30 TAC §217.92(f)

(1) An equivalent dwelling unit (EDU) is assumed to have an occupancy of 3.5 people. For EDU population greater than 3.5, the following equation must be used:

Figure: 30 TAC §217.92(f)(1)

(2) The safety factor, "B", may be adjusted if higher wastewater flows are anticipated. A discharge from commercial or institutional dischargers must be measured directly or calculated under this subsection.

§217.93.General Requirements.

(a) Except where specifically stated in this subchapter, the design of an alternative wastewater collection system must comply with the applicable requirements of Subchapter C of this chapter (relating to Conventional Collection Systems).

(b) An owner shall obtain from an engineer:

(1) an operation and maintenance manual covering the recommended operating procedures and maintenance practices for the alternative collection system; and

(2) as-built drawings indicating the location of all on-site components of the alternative wastewater collection system.

(c) An owner shall certify by letter to the executive director that the requirements in subsection (b) of this section have been met. The letter must include the permit number and name(s) of the owner(s) of the associated wastewater treatment facility.

(d) An intersection of three or more collection pipes must have a manhole.

(e) A manhole must not be located in the flow path of a watercourse, or in an area where ponding of surface water is probable.

§217.94.Management.

(a) An alternative collection system must discharge to a wastewater facility permitted by the commission.

(b) An owner of an alternative collection system shall comply with one of the following:

(1) An owner of an alternative wastewater collection system may operate the collection system and contract with another entity permitted by the commission for wastewater treatment; or

(2) An owner of an alternative collection system may contract for management and operation of the collection system with a public or private service provider and a permitted entity for treatment.

(A) A contract must address the responsibility for management and operation of the alternative collection system.

(B) An owner may terminate a contract at any time if the service provider's services are in conflict with the owner's requirements, the wastewater permit, the requirements of this chapter, or other commission requirements.

(c) This section does not apply to grinder pumps or septic tank effluent pumps discharging directly into a conventional collection system.

§217.95.Service Agreements.

(a) An alternative collection system service agreement must be executed between a collection system owner and a property owner that allows for the placement and maintenance of system components located on private property.

(b) The on-site components may be owned by the property owner or the collection system owner. An alternative collection system service agreement must specify which entity is responsible for the proper construction and competent maintenance of the on-site components.

(c) A collection system owner shall submit an alternative collection system service agreement to the executive director with the summary transmittal letter required in §217.6(a) of this title (relating to Submittal Requirements and Review Process).

(d) An alternative collection system service agreement must include the following provisions.

(1) Any existing alternative collection system component or building lateral that is to be incorporated into a new or modified system must be cleaned, inspected, tested, repaired, modified, or replaced, as necessary, to the satisfaction of a collection system owner before connection of the component to the collection system.

(2) A collection system owner shall approve all materials and equipment before incorporating the materials and equipment into any construction or repair of an alternative collection system component.

(3) A collection system owner shall have an engineer inspect and approve the installation of all alternative collection system components before placing the system into service.

(4) A collection system owner shall have access at all reasonable times to inspect on-site alternative collection system components.

(5) A collection system owner has the right to make an emergency repair and perform emergency maintenance to any alternative collection system component, including building laterals and utility-owned on-site collection system components. The cost of any such repair or maintenance may be charged to the owner of the property, as determined in the service agreement.

(6) For an alternative collection system design with any component that uses power, the service agreement must state which entity, the property owner or the collection system owner, is responsibility for power costs.

(7) The ownership and responsibility for the operation and maintenance of an alternative collection system must be agreed to by the collection system owner and the property owner.

(A) An agreement must provide:

(i) to whom the cost of any repair or maintenance will be charged;

(ii) a means to determine the cost of any repair or maintenance;

(iii) a schedule of payment; and

(iv) a methodology to recover costs.

(B) An agreement must grant the collection system owner:

(i) a right to inspect and approve the installation of any pre-treatment unit;

(ii) access for inspection and maintenance; and

(iii) a right to make an emergency repair or perform emergency maintenance when required to protect the integrity or operation of the alternative collection system.

(8) Any on-site component owned by the collection system owner must have an upstream isolation valve.

(9) Any on-site component owned by the owner of the property serviced by a collection system must have a service isolation valve located on a service pipe from an on-site component to the collection system.

(10) A service isolation valve must be accessible at all times through an easement granted by the property owner to the collection system owner.

(11) A collection system owner shall have the ability to collect, transport, and dispose of any residual material.

§217.96.Small Diameter Effluent Sewers.

(a) Interceptor tank design. Septic tanks used as interceptor tanks must be designed and constructed in accordance with §285.32(b)(1) of this title (relating to Septic Tanks).

(1) An outlet of an interceptor tank must have a commercially available effluent filter designed to remove particles larger than 1/16 inch.

(2) The volume of an equivalent dwelling unit (EDU) interceptor tank must be based the criteria in Chapter 285 of this title (relating to On-site Sewage Facilities).

(3) Multiple equivalent dwelling unit (MEDU) interceptor tanks size must be calculated using the following equations:

Figure: 30 TAC §217.96(a)(3)

(b) Pre-treatment units.

(1) An MEDU must provide a method for trapping and removing fats, oils, and grease (FOG) from the wastewater before the wastewater enters an interceptor tank.

(2) A pretreatment unit must have at least two compartments.

(3) The primary compartment volume must equal at least 60% of the total tank volume.

(4) Construction of a grease trap must meet the same requirements as an interceptor tank with regard to water tightness, materials of construction, and access to contents.

(5) FOG retention capacity in pounds must be equal to at least twice the pretreatment unit's flow capacity in gallons per minute. The FOG retention capacity of a trap is the amount of FOG that it can hold before its efficiency drops below 90%.

(6) Plumbing for a pretreatment unit must be designed to prevent wastes other than FOG from entering the pretreatment unit.

(7) A pretreatment unit must be capable of monitoring the sludge and FOG levels.

(1) Pipe materials used for service pipe must meet or exceed the performance characteristics of American Society for Testing and Materials (ASTM) D 2241 Class 200 polyvinyl chloride (PVC) pipe.

(2) An interceptor tank must include a pumping unit if its outlet elevation is below the main pipe elevation or the hydraulic grade line in a depressed section of a main pipe.

(3) A service pipe for an EDU or MEDU must be sized to meet the hydraulic requirements of the building, but must be at least 2.0 inches in diameter.

(4) The diameter of a service pipe must be no greater than the collection pipe it is connected to.

(5) A service pipe of an interceptor tank that is subject to periodic backflow must include a check valve that:

(A) is located immediately adjacent to the collection pipe;

(B) is made from a corrosion resistant material; and

(6) A collection pipe must have in-line odor control devices that are accessible for maintenance.

(d) Collection system design.

(1) Hydraulic design.

(A) A small diameter effluent sewer (SDES) system with open channel flow must use a design depth of flow of 100% of pipe diameter.

(B) The minimum low velocity in a collection pipe must be at least 1.0 foot per second (fps).

(C) The maximum flow velocity in any portion of an SDES system is 8.0 fps without velocity protection and 13.0 fps with velocity protection.

(D) The report must include velocity calculations for each pipe segment.

(E) The elevation of the hydraulic grade-line at peak flow must be lower than an outlet invert of any upstream interceptor tank, unless the interceptor tank has on-site conveyance equipment.

(F) The report must include an analysis for each pipe showing the hydraulic grade line, energy grade line, and ground elevation in relationship to the outlet elevation of each interceptor tank being served by a collection pipe.

(G) The report must include an engineer's analysis of each segment of a variable grade effluent sewer.

(H) Open pipe flow design must use a Manning's "n" value of 0.013.

(I) Pressure flow design must use a Hazen-Williams "C" value of 120.

(J) No pipe in a SDES may be smaller than 2.0 inches in diameter.

(2) Vertical Alignment.

(A) The vertical alignment of an SDES may be variable; however, the overall downhill gradient must allow the pipe to transport the expected peak flow.

(B) Venting must be provided upstream and downstream of pipe segments that are below the hydraulic grade line.

(D) Collection pipe must have a cleanout that extends to ground level and terminates in a watertight valve box at:

(i) an upstream terminus;

(ii) a minor junction;

(iii) a change in pipe diameter; and

(iv) intervals of no more than 1,000 feet.

(E) Venting at a collection pipe summit must use a wastewater service air release valve or a combination air release and vacuum valve. The valve must be constructed of corrosion resistant material and located in a vault.

(F) Pipe material used in a collection system must meet the performance requirements of ASTM D 3034 SDR 26 PVC pipe, except for any segment under pressure flow conditions. Under pressure flow conditions, pipe material must meet the performance requirements of ASTM D 2241 Class 200 PVC pipe.

§217.97.Pressure Sewers.

(a) Pumps. A pressure sewer system must include a grinder pump or a septic tank effluent pump (STEP).

(b) Exceptions. Except where this section specifically states otherwise, the requirements of this section apply to both grinder pumps and STEPs.

(1) A pressure sewer service pipe buried less than 30 inches must incorporate a check valve and a fully closing gate or ball valve at the junction of a collection pipe and a service pipe to allow isolation of the service pipe.

(2) A check valve must allow an unencumbered flow when fully open.

(3) A valve must be made of corrosion resistant material and must have a position indicator to show its open and closed position.

(4) The minimum size service pipe for an equivalent dwelling unit (EDU) is 1.25 inches.

(5) The minimum size service pipe for a multiple equivalent dwelling unit (MEDU) is 1.5 inches.

(6) A junction to collection pipes must be made with a tee or service saddle and may use solvent weld fittings.

(7) The diameter of a service pipe must be no greater than the diameter of the collection pipe it connects to.

(8) Material used in service pipe must at least be equivalent to the performance characteristics of American Society for Testing and Materials (ASTM) D 2241 Class 200 polyvinyl chloride (PVC) pipe.

(d) On-Site Mechanical Equipment Requirements.

(1) Pump discharge rates must allow the capacity of the pump and the volume of the wet-well dedicated for flow attenuation and storage to accommodate the expected peak flow.

(2) A single pumping unit may be used for an EDU. The report must include an analysis that justifies the selected pump(s).

(3) An MEDU must be served by at least two pumps capable of pumping the peak flow with the largest pump out of service. The report must include an analysis that justifies the selected pumps.

(4) The calculations in the report must show that lift stations and pump chambers are protected against buoyancy forces.

(5) Control panels for all pumps must be at least 2.0 feet above the ground floor elevation of the structure being served by the equipment.

(6) All pipes and appurtenances within a wet well must be corrosion resistant.

(7) An EDU wet well must have a reserve volume of at least 100 gallons after the activation of a high water alarm level.

(8) The reserve volume of an MEDU wet well must equal the volume accumulated during an average two-hour period or 100 gallons, whichever is greater.

(9) A pump located in a STEP chamber that is integral with an interceptor tank may use the reserve volume of the interceptor tank for the required reserve volume.

(10) A housing that contains mechanical equipment or controls must be watertight if immersion would cause failure.

(11) A wet well must include a visual and audio alarm.

(A) An alarm for an EDU must activate at a specified high water level.

(B) An alarm for an MEDU must activate in the event of unit failure or a high water level.

(12) A control panel or other electrical enclosure must:

(A) be constructed of corrosion resistant materials;

(B) be watertight;

(D) prevent the migration and venting of corrosive or explosive gases to the panel or enclosure; and

(E) bear the seal of the Underwriter Laboratory, Inc. or comply with the National Electric Code.

(13) STEP system equipment.

(A) On-site mechanical equipment used in a STEP system may be housed either in an interceptor tank or in a separate stand-alone unit.

(B) A pump used in a STEP system must be located in a hydraulically independent chamber.

(C) A STEP system pump chamber must be hydraulically connected to an interceptor tank to allow the liquid elevation in the pumping chamber to be independent of the liquid elevation in the interceptor tank.

(D) A design that allows a variable liquid elevation in an interceptor tank is prohibited.

(14) Housing for on-site mechanical equipment and any associated control mechanisms must be:

(A) lockable or tamper-resistant;

(B) constructed of corrosion resistant material; and

(15) A vault, chamber, wet-well, or other structure used to contain wastewater must be:

(A) watertight;

(B) able to withstand any expected structural loading;

(D) designed to last at least 50 years.

(e) Discharge Pipe Requirements.

(1) A discharge pipe and connections used to join on-site mechanical equipment to a service pipe must be pressure rated at a minimum of 2.5 times the maximum system design pressure.

(2) Pipe material and valves must be corrosion resistant.

(3) A discharge pipe for a pressure system must include a check valve, a pipe union, and a full closing gate valve or ball valve. A check valve must precede a full closing gate valve.

(4) A ball or gate valve must have a position indicator to show its open and closed positions.

(5) A valve used in an MEDU must be located in a valve box separate from the on-site mechanical equipment.

(f) Collection System Design.

(1) The velocity of wastewater in a grinder pump pressure system main pipe must reach at least 3.0 feet per second at least once per day.

(2) Velocity in a grinder pump main pipe must not be less than 2.0 feet per second or exceed 8.0 feet per second.

(3) The velocity in a STEP system main pipe must reach at least 1.0 foot per second at least once per day.

(4) A collection system head loss calculation must use a Hazen-Williams "C" factor appropriate to the pipe material, but a "C" factor of greater than 140 is prohibited.

(5) The size of the pipe used in a pressure collection system must be at least 1.5 inches in diameter.

(6) Pipe material must have the performance characteristics at least equivalent to ASTM D 2241 Class 200 PVC pipe.

(7) A pipe equal to or greater than 3.0 inches in diameter requires elastomeric pipe joints.

(8) A location where air may accumulate due to a difference in flow conditions requires an air release.

(9) A pumping unit affected by less than full flow conditions must incorporate an anti-siphon device.

(10) An isolation valve must be located at:

(A) each intersection of a collection system main pipe;

(B) both sides of a stream crossing;

(D) maximum intervals of 2,500 feet.

(11) An isolation valve must be:

(A) a resilient seated gate valve or ball valve with a position indicator;

(B) constructed from corrosion resistant materials; and

(12) Each peak in elevation requires a wastewater air release valve.

(A) A valve orifice must not be less than 0.25 inches in diameter.

(B) An air release valve within 50 feet of a residence or public building must control odor released by its operation.

(13) When intermediate pumping of wastewater is required, the design of a collection system lift station must meet the requirements of Subchapter C of this chapter (relating to Conventional Collection Systems).

§217.98.Vacuum Sewer Systems.

(a) A vacuum sewer system is nonconforming technology. The executive director may review a vacuum sewer in accordance with §217.7(b)(2) of this title (relating to Types of Plans and Specifications Approvals) and the criteria described in this section.

(b) On-Site Component Design.

(1) A building lateral must be pipe material that is at least equivalent in performance to American Society for Testing and Materials (ASTM) D 2241 Class 160 polyvinyl chloride (PVC) pipe.

(2) A building lateral must use a screened auxiliary vent no less than 4.0 inches in diameter and located no closer than 10.0 feet to a vacuum valve.

(3) A vacuum valve control must be in a tamper-resistant, watertight, and corrosion-resistant structure.

(4) A vacuum valve pit must be watertight to prevent surface and groundwater inflow.

(5) A control mechanism that uses a pressure differential must use atmospheric air supplied by a screened breather vented externally to the equipment housing.

(6) A vacuum valve must have a minimum capacity of 30 gallons per minute.

(7) A service pipe must be a minimum of 3.0 inches in diameter.

(8) A service pipe must have performance characteristics at least equivalent to ASTM D 2241 Class 200 PVC pipe.

(9) A service pipe joint must be made by either vacuum-rated elastomeric gasket or by solvent welding.

(10) At least 5.0 feet of service pipe must be between a vacuum valve and a main pipe.

(11) When there is a vertical profile change in a service pipe, the system must incorporate a minimum of 5.0 feet between the vacuum valve and first profile change and between the last profile change and the main pipe.

(12) A service pipe must have a minimum slope between the vacuum valve and main collection pipe or between vertical profile change that is equal to or greater than:

(A) a 2.0 inch drop; or

(B) a 0.2% slope.

(13) The connection of a service pipe to a main pipe must use a wye and a long radius elbow, oriented so that the invert of the service pipe is higher than the crown of the collection pipe, and must not be made within 6.0 feet of a collection pipe vertical profile change.

(1) A pipe in a vacuum sewer must be at least equivalent to the performance characteristics of ASTM D 2241 Class 200 PVC pipe.

(2) A pipe joint must have a vacuum-rated rubber gasket or be solvent welded.

(3) The minimum pipe size in a vacuum sewer must be 4.0 inches in diameter, except for a service pipe that may be 3.0 inches in diameter.

(A) The length of a 4.0 inch diameter vacuum pipe must not exceed 2,000 feet.

(B) The length of a pipe larger than 4.0 inches in diameter must be determined by friction and lift headloss.

(4) The total available head loss from the farthest input point in a system is 18 feet; five feet to operate the vacuum valve and 13 feet available for wastewater transport.

(5) A vacuum sewer system must be laid out in a branched pattern. A pipe must have a saw-tooth profile that slopes toward a vacuum station.

(6) The design of an upgrade mainline transport pipe must reduce the risk of blocking a pipe with trapped sewage.

(7) A collection pipe depressed in order to avoid an obstruction must have a minimum 20 foot segment centered on the obstruction.

(8) An intersection of collection pipes must include a division valve at both sides of a watercourse crossing and both sides of an area of unstable soil, and at intervals of no more than 1,500 feet.

(A) A plug valve or a resilient-seated gate valve, capable of sustaining a vacuum of 24 inches of mercury may be used.

(B) A gauge tap must be provided downstream of a division valve.

(d) Vacuum station design. The vacuum pump capacity must be the greater of the capacities calculated using the following equations, but not less than 150 gallons per minute:

Figure: 30 TAC §217.98(d)

(e) Vacuum Pumps.

(1) A vacuum pump must evacuate the system in less than 180 seconds.

(2) The design must include duplicate pumps, each capable of delivering 100% of required airflow and capable of continuous duty.

(3) A vacuum pump may be either liquid-ring or sliding-vane type. Liquid-ring pumps must be sized at least 15% larger than the necessary vacuum pump capacity.

(4) The transfer pipe must have an electrically or pneumatically controlled plug valve between the collection tank and reservoir to prevent carry over of liquid into the pump.

(f) Duplicate discharge pumps.

(1) Duplicate discharge pumps are required and must have the capacity to deliver the peak flow with one pump out of service.

(2) A discharge pump must be:

(A) designed for vacuum sewage duty;

(B) have equalizing pipes;

(D) constructed from corrosion resistant material.

(3) A discharge pump must use double mechanical shaft seals and have shut-off valves on both the suction and discharge pipes.

(4) The total dynamic head calculation must include the head attributed to overcoming the vacuum in the collection tank.

(5) The available net positive suction head must be greater than required net positive suction head for the expected vacuum operating range.

(6) The pump suction pipe must be sized 2.0 inches larger than the discharge pipe to prevent wastewater from forming a vortex in the collection tank.

(7) The pump design calculations and pump curves must be included in the report.

(g) Vacuum Reservoir.

(1) A vacuum system that requires a collection tank of 1,600 gallons or more must also include a vacuum reservoir tank with a capacity of at least 400 gallons.

(2) A vacuum pump must be piped to the top of the vacuum reservoir tank.

(3) A vacuum reservoir tank must include internal access for periodic cleaning and inspection.

(4) All main pipes must connect to the collection tank.

(5) The wastewater pump suction pipe must lie at the lowest point on the collection tank and away from the main pipe inlet.

(6) The main pipe must enter at the top of the collection tank with the inlet elbows inside the tank turned at an angle from the pump suction opening.

(7) The collection tank must include probes for liquid level sensing for operation of the discharge pumps.

(8) A vacuum pump must include vacuum switch controls located in the reservoir tank.

(9) The collection tank and low system vacuum must include an alarm for high liquid level.

(h) An owner shall include a description of the alternative collection system's anti-corrosive protection in the report.

§217.99.Testing Requirements.

(a) Components of an alternative wastewater collection system must be tested for water tightness by one of the methods shown in the following table:

Figure: 30 TAC §217.99(a)

(b) Hydrostatic Head Test for Pipe. The total infiltration or exfiltration, as determined by the hydrostatic head test, must not exceed 10 gallons per inch diameter per mile of pipe per 24 hours at a minimum head of 2.0 feet. If the quantity of infiltration or exfiltration exceeds the maximum quantity specified, the owner shall take remedial action to reduce the infiltration or exfiltration to an amount within the specified limits.

(c) Hydrostatic Head Test for Tanks. The test consists of filling the tank to the top and holding the water for 24-hours with no leakage.

(1) The hydrostatic heat test is required before the placement of backfill around a rigid tank.

(2) The test for a tank constructed from flexible or semi-rigid material is required after placement and backfilling according to the manufacturer's recommendations.

(d) Low-Pressure Air Test. The low-pressure air test must conform to the requirements of §217.57 of this title (relating to Testing Requirements for Installation of Gravity Collection System Pipes).

(e) Pressure Pipe Test.

(1) The test pressure must be a minimum of 25 pound per square inch or 1.5 times the maximum pipe design pressure, whichever is larger. The calculations for the maximum allowable leakage must use the following equation:

Figure: 30 TAC §217.99(e)(1)

(2) If the leakage exceeds the maximum amount calculated, the owner shall take remedial action to reduce the leakage to an amount within the allowable limit.

(f) Vacuum Test for a Tank.

(1) The test may begin only after establishing an initial stable vacuum of 4.0 inches of mercury.

(2) The total vacuum loss during a vacuum test must not exceed 1.0 inch loss of mercury vacuum after 5 minutes.

(3) A tank constructed of flexible or semi-rigid material must not exceed the 3% change in tank dimensions in any direction.

(4) If the quantity of vacuum loss or if tank deformation equals or exceeds the maximum quantity specified, then the owner shall take remedial action to reduce the amount of vacuum loss or amount of deformation to comply with this subsection.

§217.100.Termination.

(a) An alternative collection system must terminate at a treatment facility or into a manhole that is part of a conventional collection system.

(b) Release of gases must be controlled by minimizing turbulence in the discharge into a manhole.

(c) A discharge into a manhole that is made up of flows from an alternative collection system and a conventional collection system must have the majority of the flow from the conventional collection system.

(d) An alternative wastewater collection system that discharges at a facility must discharge below the liquid level at the headworks.

This agency hereby certifies that the proposal has been reviewed by legal counsel and found to be within the agency's legal authority to adopt.

Filed with the Office of the Secretary of State on February 29, 2008.

TRD-200801203

Robert Martinez

Director, Environmental Law Division

Texas Commission on Environmental Quality

Earliest possible date of adoption: April 13, 2008

For further information, please call: (512) 239-0177

Subchapter E. PRELIMINARY TREATMENT UNITS

30 TAC §§217.121 - 217.129

STATUTORY AUTHORITY

The proposed new rules implement TWC, §§5.013, 5.103, 5.105, 5.120, 26.027, 26.034, and 26.121.

§217.121.Coarse Screening Devices.

(a) A facility must use a coarse screening device, unless stated otherwise in this subchapter.

(b) A coarse screening device must include a bypass channel sized to handle the peak flow of the facility.

(d) If the primary channel uses a mechanically cleaned coarse screening device, the bypass channel must have a coarse screening device, either manually or mechanically cleaned.

(e) Location Requirements.

(1) Any enclosed structure that houses a coarse screening device and contains other equipment or an office must have a separate entrance that is separated from the other areas by a gas tight partition.

(2) Each coarse screening device enclosure must have a vent fan capable of providing at least 30 air exchanges per hour if staff entry is allowed.

(3) Each coarse screening device must be readily accessible for maintenance and screenings removal.

(4) Any coarse screening device located 4.0 or more feet below ground level must include equipment capable of lifting the screenings to ground level.

(f) Screen Openings.

(1) For a manually cleaned coarse screen, the bar openings must be at least 0.5 inch but not more than 1.75 inches.

(2) For a mechanically cleaned coarse screen, the bar openings must be at least 0.25 inch but not more than 1.75 inches.

(3) A manually cleaned coarse screen must use a bar rack sloped at least 30 degrees but not more than 60 degrees from horizontal.

(4) A manually cleaned coarse screen must be attached to a horizontal platform that has provisions to drain and temporarily store the screenings.

(g) Hydraulics.

(1) The velocity through the coarse screen bar racks must be at least 1.0 foot per second but not more than 3.0 feet per second at design flow.

(2) The inlet channel for a screening device must minimize deposition of solids.

(3) The flow line of the inlet channel must not exceed 6.0 inches below the invert elevation of the incoming influent.

(h) Corrosion Resistance. A coarse screening device and any related structure must resist the effects of a corrosive environment, including long-term exposure to hydrogen sulfide.

§217.122.Fine Screening Devices.

(a) A fine screen may be used in lieu of a coarse screening device.

(b) A fine screen is any screen with a clear opening less than 0.25 inch.

(c) The use of a fine screen in lieu of a primary sedimentation unit is acceptable only if the design of any downstream treatment unit is based on the amount of five-day biochemical oxygen demand (BOD₅ ) reduction expected by the fine screen. The BOD₅ reduction percentage must be developed through a study conducted on actual full-scale operation of the proposed fine screen unit.

(d) The report must include the justification for any reduction the size of any treatment unit based on removal of BOD₅ by the use of a fine screen.

(e) An owner who claims a BOD₅ reduction credit must include a sufficient number of fine screen units so that any BOD₅ reduction claimed may occur with the largest fine screen unit out of service.

(f) A design may include a single fine screen unit if the design includes a bypass channel with a coarse screening device to accept flow when the fine screen is out of service. No BOD₅ removal credit is allowed with a single fine screen design.

(g) A fine screen must follow a coarse screening device, unless the manufacturer's recommendations include installation of the unit without a preliminary screening device or evidence of successful use of fine screens in a similar installation is provided.

(h) A facility must be designed to remove fats, oils, and grease from the wastewater before the wastewater reaches the fine screen.

(i) A moving or rotating fine screen must use a continuous cleaning device, such as water jets or wiper blades.

(j) A fine screen unit must automatically convey the screenings to a storage area or processing unit that complies with §217.123 of this title (relating to Screenings and Debris Handling).

(k) A fine screen must meet its manufacturer's recommendation with respect to velocity and head loss through the fine screen.

(l) A fine screen may use a bar rack or perforated plate.

§217.123.Screenings and Debris Handling.

(a) A screening device must have a minimum storage capacity of one-day of screenings and debris.

(b) A container for screenings and debris must have a tight-fitting cover.

(d) Any screenings and debris collected must be managed and disposed of in accordance with Chapter 330 of this title (relating to Municipal Solid Waste).

§217.124.Grit Removal Systems.

(a) A wastewater treatment system using anaerobic digestion must have a grit removal system. A grit removal system is optional for all other facilities.

(b) A grit removal system includes those units and processes capable of removing inert, non-biodegradable particles.

(d) Each grit removal unit must include:

(1) a bypass channel to accept flow when a grit removal unit is off-line; and

(2) a means of diverting flow to a bypass channel.

§217.125.Grit Chambers.

(a) Horizontal Flow Grit Chambers.

(1) Velocity through a grit chamber must range at least 0.8 feet per second but not more than 1.3 feet per second.

(2) A grit chamber channel must minimize turbulence and provide uniform velocity across the channel.

(3) The channel size must accommodate the grit removal equipment capacity and grit storage.

(b) Aerated Grit Chambers.

(1) An air diffuser and baffle arrangement design must separate the size of grit planned for removal.

(2) The aeration equipment must vary air feed rates along the length of a grit chamber from 3.0 seconds per cubic foot per meter (scfm) per linear foot but not more than 8.0 scfm per linear foot.

(3) A grit chamber must have a hydraulic detention time of at least 3.0 minutes.

(4) A grit chamber must include a grit hopper located under an air diffuser.

(1) The velocity through mechanical grit chambers must be no greater than 1.0 foot per second at the design flow.

(2) A channel must include a grit hopper at the side of a tank contiguous to a grit removal mechanism.

(3) An inlet must include baffles to prevent short-circuiting.

(4) Grit removal must be provided by one of the following:

(A) Reciprocating rake;

(B) Screw conveyor; or

(d) Cyclonic Degritters.

(1) A cyclonic degritter must prevent entry-to-overflow short circuit.

(2) A cyclonic degritter must include an adjustable apex with a quick disconnect assembly to remove any oversized object.

(3) Detention time in a cyclonic degritter must be at least 1.0 minute at the design flow.

(4) The flow velocity must be at least 1.0 foot per second but not more than 2.0 feet per second at the design flow.

(5) A screening unit must be installed upstream of a cyclonic degritter.

(e) Vortex Grit Chamber.

(1) An inlet channel must include a straight length in order to deliver smooth flow into the vortex grit chamber.

(2) Minimum initial inlet velocity at the peak flow must be at least 2.0 feet per second.

(3) A vortex system must include rotating paddles in the center of a grit chamber and must rotate at a maximum 21 revolutions per minute.

(4) An outlet channel must maintain a constant elevation.

(5) Grit removal from a grit storage chamber must be by pumps specifically designed to handle grit.

§217.126.Grit Handling.

(a) The recycle water and the drainage from a grit washing unit or a grit storage area must return to the head of the facility.

(b) A grit chamber located below ground level must include mechanical grit handling equipment.

(c) Grit must be stored in a container with a tight-fitting cover and must be managed and disposed of in accordance with §217.123 of this title (relating to Screenings and Debris Handling).

§217.127.Pre-Aeration Units.

(a) Pre-aeration may be used for odor control, flocculation of solids, reducing septicity, grease separation, and promoting uniform distribution of solids to clarifiers.

(b) The report must include the basis for any pre-aeration system design.

§217.128.Flow Equalization Basins.

(a) A facility must use a flow equalization basin if:

(1) A facility's total daily influent flow volume occurs during a period of time less than or equal to ten hours of a day for any day of any week;

(2) A facility experiences periods of time when it receives an influent flow of less than 10% of its design capacity for a period of time equal to or greater than 48 hours in any one week; or

(3) At any time that flow equalization is necessary to minimize random or cyclic peaking of organic or hydraulic loadings.

(b) A flow equalization basin must have an upstream screening device.

(c) A flow equalization basin must include an aeration system sized to maintain a dissolved oxygen level of at least 1.0 milligram per liter (mg/l) in the flow equalization basin.

(d) A flow equalization basin must include a mixing system sufficient to prevent solids from settling.

(e) The size of a flow equalization basin must be based on diurnal flow variations and the size and capability downstream process units. The report must include the calculations justifying the size of a flow equalization basin.

(f) For pumped flow to an equalization basin, the effluent from a basin must be controlled by a flow-regulating device capable of maintaining a flow rate that allows downstream process units to operate properly.

(g) For pumped flow from an equalization basin, a variable-speed pump or multiple pumps are required to deliver a constant flow to downstream processing units.

§217.129.Primary Clarifiers.

(a) Inlets.

(1) A primary clarifier inlet must provide uniform flow and stilling.

(2) Vertical flow velocity through an inlet stilling well must not exceed 0.15 feet per second at peak flow.

(3) An inlet distribution channel must not have a dead-end corner and must prevent the settling of solids in the channel.

(4) An inlet structure must allow floating material to enter the clarifier.

(b) Scum removal.

(1) A primary clarifier must have scum baffles and a means of collecting and disposing of scum.

(2) A primary clarifier must discharge scum to a sludge digester or another method of disposal approved by the executive director.

(3) The discharge of scum to any open drying area is prohibited.

(4) A primary clarifier with a design flow equal to or greater than 25,000 gallons per day (gpd) must include a mechanical skimmer.

(5) A primary clarifier with a design flow less than 25,000 gpd may use hydraulic differential skimming, only if the scum pickup is capable of removing scum from the entire operating surface of the clarifier.

(6) A scum pump must be specifically designed for this purpose.

(1) An effluent weir must prevent turbulence or localized high vertical flow velocity in the primary clarifier.

(2) A weir must be located to prevent short circuiting flow through a primary clarifier.

(3) A weir must be adjustable for leveling.

(4) Weir loading, for a facility with a design flow of 1.0 million gallons per day (mgd) or less, must not exceed 20,000 gpd per linear foot of weir length.

(5) Weir loading for a facility with a design flow in excess of 1.0 mgd must not exceed 30,000 gpd peak flow per linear foot of weir length.

(d) Basin sizing.

(1) The surface area of a facility's clarifier(s) determines the proper overflow rates.

(2) The actual clarifier size is based on the larger of the two surface area calculations: peak flow rate or design flow surface loading rate.

(3) The design criteria for primary a clarifier in subparagraphs (A) and (B) of this paragraph are based upon a minimum side water depth of 10.0 feet.

(A) Maximum surface loading:

(i) must not exceed 1800 gpd per square foot at peak flow;

(ii) must not exceed 1,000 gpd per square foot at design flow; and

(iii) does not include recirculation flow.

(B) Detention Time.

(i) Detention time at peak flow must be no less than 54 minutes (0.9 hour).

(ii) Detention time at design flow must at least 108 minutes (1.8 hours).

(iii) Overflow rate and side water depth (SWD) may be adjusted from a minimum of 10 feet a maximum of 18 feet, as long as the detention time remains unchanged.

(iv) The detention time must be based on the effective volume and the overflow rate of a circular or rectangular clarifier.

(I) The effective volume includes all liquid above the sludge blanket.

(II) For a cone bottom tank, the top of the sludge blanket is considered to be at the top of the cone.

(III) For a flat bottom tank, a sludge blanket of 3.0 feet must be allowed for development of maximum return sludge concentration.

(e) SWD. The minimum SWD for primary clarifiers is 10.0 feet.

(f) Freeboard. The walls of a primary clarifier must extend at least 6.0 inches above the surrounding ground surface and must provide a minimum freeboard of 12.0 inches at peak flow.

(g) Drains.

(1) A primary clarifier must have the capability of draining completely to an appropriate point in the facility.

(2) A portable dewatering pump is acceptable for complete dewatering.

(h) Accessibility. A primary clarifier must be accessible to facilitate routine operation and maintenance.

(i) Five-day biochemical oxygen demand (BOD₅ ) Removal. A design shall be based on no greater than 35% BOD₅ reduction, unless a higher efficiency is justified by a pilot study or data from a similar full-scale operation.

(j) Sludge Transfer.

(1) A primary clarifier unit must include mechanical sludge collection equipment designed to rapidly remove sludge and transfer it for subsequent processing.

(2) A gravity sludge transfer pipe must be at least 8.0 inches in diameter.

This agency hereby certifies that the proposal has been reviewed by legal counsel and found to be within the agency's legal authority to adopt.

Filed with the Office of the Secretary of State on February 29, 2008.

TRD-200801204

Robert Martinez

Director, Environmental Law Division

Texas Commission on Environmental Quality

Earliest possible date of adoption: April 13, 2008

For further information, please call: (512) 239-0177

Subchapter F. ACTIVATED SLUDGE SYSTEMS

30 TAC §§217.151 - 217.164

STATUTORY AUTHORITY.

The proposed new rules implement TWC, §§5.013, 5.103, 5.105, 5.120, 26.027, 26.034, and 26.121.

§217.151.Requirements for an Aeration Basin.

(a) Unless designed for advanced nutrient removal, an aeration basin must be designed maintain a minimum dissolved oxygen concentration of 2.0 milligrams per liter (mg/l) throughout the basin at the maximum diurnal organic loading rate determined in §217.32(a)(3) and Figure: 30 TAC §217.32(a)(3) of this title (relating to Organic Loading and Flows).

(b) An activated sludge system may use the volume in aerated influent wastewater channels and aerated mixed liquor transfer channels to meet aeration basin volume requirements, provided the system uses aeration by diffused air and the diffuser depth conforms to the requirements of §217.155(b)(5)(A) of this title (relating to Aeration Equipment Sizing).

§217.152.Requirements for Clarifiers.

(a) Inlets.

(1) A clarifier must have an inlet valve or gate.

(2) A clarifier inlet must provide uniform flow and stilling.

(3) A transfer pipe must not trap or entrain air.

(4) Vertical flow velocity through an inlet stilling well must not exceed 0.15 feet per second at peak flow.

(5) An inlet distribution channel must prevent the settling of solids in the channel.

(b) Scum removal.

(1) A clarifier must include scum baffles and a means for the collection and disposal of scum.

(2) Scum collected from a clarifier in a facility using an activated sludge process and an aerated lagoon may be discharged to an aeration basin or digester, or may use another disposal method that complies with Chapter 312 of this title (relating to Sludge Use, Disposal, and Transportation).

(3) Scum from a clarifier in a facility not using an activated sludge process and an aerated lagoon must be discharged to a sludge digester or may use another disposal method that complies with Chapter 312 of this title.

(4) Discharge of scum to an open drying area is prohibited.

(5) A system with a design flow equal to or greater than 10,000 gallons per day (gpd) must use a mechanical skimmer.

(6) A system with a design flow less than 10,000 gpd may use hydraulic differential skimming if the scum pickup is capable of removing scum from the entire operating surface.

(7) A scum pump must be specifically designed to pump scum.

(1) An effluent weir must prevent turbulence or a localized high vertical flow velocity in a clarifier.

(2) A weir must be located a minimum of 6.0 inches from an outer wall or baffle and must prevent the short-circuiting of flow through a clarifier.

(3) A weir must be adjustable to allow leveling of the weir and to provide for minor changes to the water surface elevation in a clarifier.

(4) For a facility with a design flow of less than 1.0 million gallons per day (mgd), the weir loading must not exceed 20,000 gpd at the peak flow per linear foot of weir length.

(5) For a facility with a design flow equal to or greater than 1.0 mgd, the weir loading must not exceed 30,000 gpd at the peak flow per linear foot of weir length.

(6) A circular clarifier must have overflow weirs around the entire perimeter of the clarifier.

(7) A circular clarifier is not limited to the weir overflow rate listed in this subsection.

(d) Sludge Pipes.

(1) Sludge transfer from a clarifier to a subsequent processing unit must not negatively affect treatment efficiency.

(2) A sludge pipe must be a minimum of 4.0 inches in diameter.

(3) The flow velocity in a sludge pipe must be greater than 2.0 feet per second.

(4) Each sludge pipe should have a means to remove any blockage.

(e) Sludge Collection Equipment. A clarifier must include mechanical sludge collecting equipment if it is part of a wastewater treatment facility with a design flow of 10,000 gpd or greater.

(f) Pumped Inflow.

(1) For a facility with pumped inflow, a clarifier must be able to accommodate all anticipated flow without overflow.

(2) A facility must hydraulically accommodate peak flows without adversely affecting the treatment processes.

(g) Side Water Depth (SWD).

(1) The SWD is defined as:

(A) the water depth from the top of the cone in a cone bottom tank to the water surface; or

(B) the water depth from 2.0 feet above the bottom of a flat bottom tank with a hydraulic sludge removal mechanism.

(2) A clarifier with a mechanical sludge collector and a surface area:

(A) equal to or greater than 300 square feet (sf) must have a minimum SWD of 10.0 feet.

(B) less than 300 sf must have a minimum SWD of 8.0 feet.

(3) A clarifier with a hopper bottom must determine the SWD using the following equation:

Figure: 30 TAC §217.152(g)(3)

(4) An SWD computed using Equation F.1 in paragraph (3) of this subsection excludes the hopper portion of a clarifier. The upper third of the hopper portion of a hopper bottom clarifier may be counted as part of the SWD only if the surface area of the hopper bottom clarifier is increased by 15% over the surface area determined from the design surface loading calculated using Table F.2 in Figure: 30 TAC §217.154(c)(1) of this title (relating to Aeration Basin and Clarifier Sizing--Traditional Design), and if an activated sludge facility includes a flow equalization basin. The SWD of a hopper bottom clarifier must never be less than 5.0 feet.

(h) Restrictions on Hopper Bottom Clarifiers.

(1) A hopper bottom clarifier without mechanical sludge collection equipment is prohibited for use in a facility with a maximum flow equal to or greater than 10,000 gpd.

(2) Each hopper cell of a hopper bottom clarifier must have individually controlled sludge removal equipment.

(3) A hopper bottom clarifier must have a smooth wall finish.

(4) A hopper bottom clarifier must have an upper hopper slope of not less than 60 degrees from horizontal.

(i) Restrictions on Short Circuiting. The influent stilling baffle and effluent weir must prevent short circuiting.

(j) Return Sludge Pumping Capacity.

(1) The capacity of a return sludge-pumping unit must be calculated based on the area of an activated sludge clarifier(s), including the stilling well area.

(2) The return sludge pumping capacity is the clarifier underflow rate in gallons per day per square foot (gpd/sf).

(3) A return sludge pumping system must be capable of pumping least 200 gpd/sf but not more than 400 gpd/sf.

(4) The pumping capacity may be controlled via throttling, variable speed drives, or multiple pump operation.

§217.153.Requirements for Both Aeration Basins and Clarifiers.

(a) Construction. Construction material for an aeration basin and a clarifier must resist the effects of a corrosive wastewater environment.

(b) Freeboard.

(1) An aeration basin must have a minimum freeboard of 18 inches at the peak flow.

(2) A clarifier must have a minimum freeboard of 12 inches at the peak flow.

(1) A facility with a design flow of equal to or greater than 0.4 million gallons per day (mgd) must have a minimum of two aeration basins and two clarifiers, unless the aeration equipment is removable without taking the aeration basin out of service.

(2) Internal and interconnecting pipes must be capable of hydraulically passing the peak flow without overflow and with either the largest clarifier or the largest aeration basin out of service.

(3) Each aeration basin and clarifier must have gates or valves to allow it to be hydraulically isolated.

(4) Each aeration basin and clarifier must have a dedicated means for dewatering.

§217.154.Aeration Basin and Clarifier Sizing--Traditional Design.

(a) This section applies to the traditional approach for sizing an aeration basin and clarifier based on values that have been used historically as standard engineering practice.

(b) Aeration Basin Sizing.

(1) A aeration reactor must be sized using the organic load calculated in §217.32 of this title (relating to Organic Loading and Flows).

(2) Based on this organic load, the aeration basin volume must ensure that the organic loading on the aeration basin does not exceed the rates in the following table:

Figure: 30 TAC §217.154(b)(2)

(3) When identifying the reactor temperature for the process design in Table F.1 in paragraph (2) of this subsection, the average of the lowest consecutive seven-day mean reactor temperature from a similar wastewater treatment facility located within 50 miles of the proposed site must be used.

(1) The following table establishes the maximum surface loading rates and the minimum detention times used to determine the size of an activated sludge clarifier:

Figure: 30 TAC §217.154(c)(1)

(2) A clarifier must meet both the detention time and overflow rate criteria.

(A) When calculating overflow rates for a proposed clarifier, sludge recycle flow must not be used in the calculation of the maximum overflow rate, in compliance with Table F.2 in paragraph (1) of this subsection.

(B) When calculating the overflow rate for a proposed clarifier, the surface area of the stilling well may be included as part of the clarifier surface area.

§217.155.Aeration Equipment Sizing.

(a) Oxygen Requirements (O₂R) of wastewater.

(1) An aeration system must be designed to provide a minimum dissolved oxygen concentration in the aeration basin of 2.0 milligrams per liter (mg/l).

(2) Mechanical and diffused aeration systems must supply the O₂ R calculated by Equation F.2 located in paragraph (3) of this subsection or use the recommended values presented in Table F.3 in paragraph (3) of this subsection.

(3) The O₂ R values in Table F.3 in the following figure use concentrations of 200 mg/l five-day biochemical oxygen demand (BOD₅) and 45 mg/l ammonia-nitrogen (NH₃-N) in Equation F.2 in the following figure:

Figure: 30 TAC §217.155(a)(3)

(b) Diffused Aeration System. An airflow design must be based either paragraph (1) or (2) of this subsection.

(1) Design Airflow Requirements - Default Values. A diffused air system may use the following table to determine the airflow for sizing:

Figure: 30 TAC §217.155(b)(1)

(2) Design Airflow Requirements - Equipment and Site Specific Values. A diffused air system may base calculations of the airflow requirements for the diffused air equipment in accordance with subparagraphs (A) - (D) of this paragraph.

(A) Determine Clean Water Oxygen Transfer Efficiency.

(i) A diffused air system may have a clean water oxygen transfer efficiency greater than 4% only if the full scale diffuser performance data from a certified testing laboratory or sealed by an independent licensed professional engineer demonstrates the diffuser's transfer efficiency.

(ii) A testing laboratory or licensed engineer shall use the oxygen transfer testing methodology described in the most current version of the American Society of Civil Engineers (ASCE) publication, A Standard for the Measurement of Oxygen Transfer in Clean Water.

(iii) A diffused air system with a clean water transfer efficiency greater than 18% for a coarse bubble system and greater than 26% for a fine bubble system is considered an innovative technology and is subject to §217.7(b)(2) of this title (relating to Types of Plans and Specifications Approvals).

(iv) A design for clean water transfer efficiencies obtained at temperatures other than 20 degrees Celcius must be adjusted for a diffused air system to reflect the approximate transfer efficiencies and air requirements under field conditions by using the following equation:

Figure: 30 TAC §217.155(b)(2)(A)(iv)

(B) Determining Wastewater Oxygen Transfer Efficiency (WOTE).

(i) The WOTE must be determined from clean water test data by multiplying the clean water transfer efficiency by 0.65 for a coarse bubble diffuser and by multiplying the clean water transfer efficiency by 0.45 for a fine bubble diffuser.

(ii) The executive director may require additional testing and data to justify actual WOTE for a facility treating wastewater containing greater than 10% industrial wastes.

(C) Determining Required Airflow (RAF). The RAF must be calculated using the following equation to determine the size needed for a diffuser submergence of 12.0 feet. If the diffuser submergence is other than 12.0 feet, a diffused air system must correct the RAF detailed in subparagraph (D) of this paragraph.

Figure: 30 TAC §217.155(b)(2)(C)

(D) Corrections to RAF based on varying diffuser submergence depths. If the diffuser submergence is not 12.0 feet, the design must specify the adjustment of the minimum airflow rate as calculated in subparagraph (C) of this paragraph by multiplying the calculated values by the factors in the following table:

Figure: 30 TAC §217.155(b)(2)(D)

(3) Mixing Requirements for Diffused Air. The air requirements for mixing must be calculated using:

(A) Design of Municipal Wastewater Treatment Plants , Chapter 11, a joint publication of the ASCE and the Water Environment Federation, for mixing requirements; or

(B) provide mixing air at a rate greater than or equal to 20 scfm/1000 cf for a coarse bubble diffuser and greater than or equal to 0.12 scfm /square foot (sf) for a fine bubble diffuser.

(4) Blowers and Air Compressors.

(A) A blower and a compressor must have sufficient capacity to provide the required aeration rate for biological treatment and the air requirements of any supplemental unit.

(B) The report must include blower or compressor calculations that show the actual air requirements for the expected temperature range, including both summer and winter conditions, and the impact of the actual site elevation on the air supply.

(C) A diffused air system must have multiple compressors arranged to provide an adjustable air supply to meet the variable organic load on the facility.

(D) The compressors must be capable of handling the maximum design air requirements with the largest single unit out of service.

(E) A blower unit and a compressor unit must restart automatically after a power outage, or a telemetry system or an auto-dialer with battery backup must notify an operator of any outage.

(F) A design must specify blowers or air compressors with sufficient capacity to handle air intake temperatures that may exceed 100 degrees Fahrenheit (38 degrees Celsius), and pressures that may be less than standard (14.7 pounds per square inch absolute).

(G) A design must specify the capacity of a motor drive necessary to handle air intake temperatures that may be 20 degrees Fahrenheit (-7 degrees Celsius) or less in a location that experiences temperatures below 20 degrees Fahrenheit (-7 degrees Celsius).

(5) Diffuser Systems - Additional Requirements.

(A) Diffuser Submergence.

(i) A submergence depth for any diffuser must meet the minimum depths in the following table, for a new facility:

Figure: 30 TAC §217.155(b)(5)(A)(i)

(ii) A diffuser submergence depth for any modification or expansion of an existing facility may vary from the values in Table F.6 in clause (i) of this subparagraph to match existing air pressure, delivery rate, and hydraulic requirements.

(iii) A submerged depth for a diffuser of less than 7.0 feet is prohibited.

(B) Grit Removal. A facility that uses diffusers and has wastewater with high concentrations of grit must include a grit removal unit upstream of an aeration process or must include multiple trains that may be taken out of service to allow for grit removal.

(i) Each diffuser header must include an open/close or throttling type control valve that can withstand the heat of compressed air.

(ii) An air header must be able to withstand temperatures up to 250 degrees F.

(iii) The capacity of an air diffuser system, including pipes and diffusers, must equal 150% of design air requirements.

(iv) The design of an aeration system must minimize head loss. The report must include a hydraulic analysis of the entire air pipe system that quantifies head loss through the pipe system and details the distribution of air from the blowers to the diffusers.

(v) An aeration system may use non-metallic pipes only in the aeration basin, but the pipes must be a minimum of 4.0 feet below the average water surface elevation in the aeration basin.

(1) Required Airflow - Equipment and Site Specific Values. The airflow requirements for a mechanical aeration system must be calculated in accordance with subparagraphs (A) and (B) of this paragraph.

(A) Determine Clean Water Oxygen Transfer Efficiency.

(i) The report must include the oxygen transfer efficiency rate for the mechanical equipment.

(ii) Clean water oxygen transfer rate must not exceed 2.0 pounds of oxygen per horsepower-hour, unless justified by full scale performance data conducted by a certified testing laboratory or sealed by an independent, licensed professional engineer using the oxygen transfer testing methodology described in the most current version of the ASCE publication, A Standard for the Measurement of Oxygen Transfer in Clean Water.

(iii) A proposed clean water transfer efficiency in excess of 2.0 pounds of oxygen per horsepower-hour is innovative technology and subject to the requirements of §217.7(b)(2) of this title (relating to Types of Plans and Specifications Approvals).

(B) Determine Wastewater Oxygen Transfer Efficiency.

(i) The report must include data to justify actual wastewater transfer efficiency.

(ii) A design must include an estimate of the wastewater transfer efficiency from the clean water transfer efficiency by multiplying the clean water transfer efficiency by 0.65 for all mechanical aeration equipment for a facility treating greater than 10% industrial wastes.

(2) Mixing Requirements.

(A) A mechanical aeration device must provide sufficient mixing to prevent deposition of mixed liquor suspended solids (MLSS) under any flow condition.

(B) A mechanical aeration device must be capable of re-suspending the MLSS after a shutdown period.

(C) Mechanical aeration devices with channel or basin layout must have a minimum of 100 horsepower per million gallons of aeration basin volume or 0.75 horsepower per thousand cubic feet of aeration basin volume.

(3) Mechanical Components.

(A) Process reliability.

(i) Each basin must include a minimum of two mechanical aeration devices.

(ii) A mechanical aeration device must meet the maximum design requirements for oxygen transfer with the largest single unit out of service.

(iii) A mechanical aeration device must automatically restart after a power outage, or a telemetry system with battery backup or an auto-dialer with battery backup must notify a facility operator or owner.

(B) Operation and maintenance.

(i) A mechanical aeration device must have two speed or variable speed drive units, unless another means of varying the output is provided.

(ii) A mechanical aeration device may use single-speed drive units with timer-controlled operation, if the device also includes an independent means of mixing.

(iii) A facility operator must be able to perform routine maintenance on the aeration equipment without the potential of coming into contact with raw or partially treated wastewater.

(iv) Any bearing, drive motor, or gear reducer must be accessible and be equipped with a splash prevention device.

(v) Any gear reducer must have a drainage system to prevent operator contact with mixed liquor.

§217.156.Sequencing Batch Reactors.

(a) System Sizing and Reliability.

(1) A sequencing batch reactor (SBR) must meet the reliability requirements in §217.155(b) and (c)(3) of this title (relating to Aeration Equipment Sizing), and power source reliability requirements in §217.36 of this title (relating to Emergency Power Requirements).

(2) A SBR must have a minimum decantable volume that is sufficient to pass the design flow without changing cycle times with the largest basin out of service.

(3) A two-basin treatment facility without removable aeration devices is required to have aerated storage of mixed liquor separate from the SBR tank(s).

(4) An SBR with a fixed level decanter must have more than two basins and additional decantable storage volume because of the added settling time before a discharge may occur.

(5) An SBR with fixed decant equipment and decant volumes that do not accommodate the design flow requires an equalization basin.

(6) Organic space loadings must conform to the values in Figure: 30 TAC §217.154(b)(2), Table F.1 of this title (relating to Aeration Basin and Clarifier Sizing--Traditional Design). Maximum space loadings must be below 35 pounds of five-day biochemical oxygen demand (CBOD₅) per 1,000 cubic feet of tank volume.

(7) The reactor mixed liquor suspended solids (MLSS) level at the normal operating level must range be at least 3,000 milligrams per liter (mg/l) but not more than 5,000 mg/l.

(8) The minimum depth MLSS during a react phase is 9.0 feet.

(9) The minimum side water depth of a tank is 12 feet.

(10) An SBR must include sludge digestion pursuant to the requirements in Subchapter J of this chapter (relating to Sludge Treatment Units).

(b) Decanter Design.

(1) A decanter design must control the velocity at an inlet port or at the edge of submerged weirs to prevent vortexing, disturbance of the settled sludge, and entry of floating materials.

(2) The entrance velocity to a decanter must not exceed 1.0 foot per second.

(3) A decanter must draw effluent from below the water surface and include a device that excludes scum.

(4) A decanter must maintain a zone of separation between the settled sludge and the decanter of no less than 12 inches.

(5) A decanter must prevent solids from entering the decanter during a react cycle by one the following methods:

(A) Recycle treated effluent to wash out solids trapped in a decanter;

(B) Mechanically close a decanter when it is not in use; or

(6) The design of a decanter and related pipes and valves must include freeze protection, if located in a location subject to freezing.

(7) A fixed decanter is prohibited in a basin where simultaneous fill and decant may occur.

(8) For any system of tanks that is fed sequentially, the size of the decant system must accommodate the design flow with a constant cycle time with the largest tank out of service.

(9) An SBR system utilizing more than two basins must allow the decanting of at least two tanks simultaneously.

(10) If units downstream of an SBR are not capable of accepting the peak flowrate of the decanting cycle, flow equalization must be provided between the decanter and the downstream units.

(1) An SBR requires multiple tanks.

(2) An SBR with two tanks or an SBR system operating with a continuous feed during settling and decanting phases must include influent baffling and physical separation from the decanter.

(3) An elongated tank must be used for an SBR system if influent baffling is required.

(4) An SBR tank must have a minimum freeboard of 18 inches at the maximum liquid level.

(5) An SBR tank must resist buoyant uplift when empty.

(6) Structures using a common wall must be designed to accommodate the stresses generated when one basin is full and an adjacent basin is empty.

(7) Each SBR wall must be watertight.

(8) A sump must be provided in any basin with a flat bottom.

(9) An SBR system must have a dedicated means of transferring sludge between aeration basins.

(10) An SBR system must include a means of scum removal in each aeration basin.

(11) Each SBR tank must include a dewatering system and an overflow to another aeration tank(s) or a storage tank.

(12) At a facility that is not staffed 24-hours each day, a manually operated SBR tank must include a high-level alarm that notifies facility staff, in accordance with §217.161 of this title (relating to Electrical and Instrumentation Systems).

(13) A design must specify the means and frequency for removal of grit and other debris from the basins.

(14) All equipment must be accessible for inspection, maintenance, and operation.

(15) An SBR may use fine screens pursuant to §217.122 of this title (relating to Fine Screening Devices).

(16) An SBR preceded by a primary clarifier may use a comminutor.

(17) An SBR must have a sufficient number of tanks to operate at design flow with one tank out of service.

(d) Aeration and Mixing Equipment.

(1) In addition to the requirements of §217.155 of this title aeration equipment must handle the cyclical operation in an SBR.

(2) The aeration and mixing equipment must not interfere with settling.

(3) The oxygen transfer rate for the aerators at average water depth during a fill cycle must provide a residual of 2.0 mg/l dissolved oxygen in the basin.

(4) A design must specify the blower discharge pressure at the maximum water depth.

(5) A SBR used for biological nutrient removal or reduction must meet the design requirements of §217.163 of this title (relating to Advanced Nutrient Removal).

(6) The design of an SBR must allow for the removal of air diffusers or mechanical aeration devices without dewatering the tank.

(e) Control Systems.

(1) The motor control center must include programmable logic controllers (PLC) with able to operate with limited operator adjustment and be programmed to meet the required effluent limitations for the design loadings.

(2) A hard-wired backup means of operating the SBR is required.

(3) The PLC must include battery backup. A duplicate set of all circuit boards must be kept at the facility.

(4) Adequate controls for the separate operation of each reactor tank must be provided.

(5) A tank level system must include floats or pressure transducers.

(A) A float system must be protected from prevailing winds and freezing.

(B) A bubbler system in a tank level system is prohibited.

(6) The control panel switches must include at least:

(A) Pumps - hand/off/automatic;

(B) Valves - open/closed/automatic;

(D) Selector switch for tank(s) - in operation/standby.

(7) The control panel visual displays must include:

(A) Mimic diagram of the process that shows the status and position of any pumps, valves, blowers or aerators, and mixers;

(B) Process cycle and time remaining;

(D) Tank level gauges or levels;

(E) Sludge pumping rate and duration; and

(F) Airflow rate and totalizer.

(8) The required alarm condition indicators for an annunciator panel must include:

(A) High and low water levels in each tank;

(B) Failure of all automatically operated valves;

(D) Blowers, if used - low pressure, high temperature, and failure;

(E) Mechanical aerator, if used - high temperature and failure;

(F) Pump - high pressure and failure; and

(G) Mixers, if used - failure.

§217.157.Membrane Bioreactor Systems.

(a) Applicability.

(1) This section contains criteria for low-pressure, vacuum, and gravity ultrafiltration or microfiltration membrane bioreactors.

(2) Other types of membrane bioreactors (MBRs) are considered innovative technology and are subject to the requirements of §217.7(b)(2) of this title (relating to Types of Plans and Specifications Approvals).

(b) Performance Standards.

(1) MBR performance standards for conventional pollutants and nutrients are shown in the following table:

Figure: 30 TAC §217.157(b)(1)

(2) An owner may be required to submit a pilot study report or data from a similar facility if a proposed facility is designed to achieve higher quality effluent than the performance standards listed in the table in paragraph (1) of this subsection.

(1) Pretreatment.

(A) Each MBR system must have fine screening to prevent damage from abrasive particles or fibrous, stringy material.

(i) Fine screens must be rotary drum or traveling band screen with either perforated plate or wire mesh with an opening size of 0.5 - 2.0 millimeter (mm) for hollow fiber systems and tubular systems and 2.0 - 3.0 mm for flat plate systems.

(ii) Bypass of a fine screen must be prevented with either a duplicate fine screen, overflow to a wet well, or an alternative that has been approved by the executive director.

(iii) A fine screen must be designed to prevent overflow at the peak flow.

(iv) Coarse screens followed by fine screens may be used in larger facilities to minimize the complications of fine screening.

(B) The economic feasibility of primary clarification must be evaluated for facilities designed for an average daily flow of 5.0 million gallons per day (mgd) or more. The evaluation must be included in the report.

(C) Oil and grease removal is required if the oil and grease levels in the influent may cause damage to the membranes. The specific detrimental concentration must be determined by the equipment manufacturer. However, influent concentrations of oil and grease equal to or more than 100 milligram per liter (mg/l) must have oil and grease removal.

(D) The necessity of grit removal must be evaluated for a facility that has a collection system with excessive inflow and infiltration. An evaluation must be included in the report.

(2) Biological treatment.

(A) The reactor volume for any biological treatment zone must be determined using rate equations for substrate utilization and biomass growth in a manner similar to determining basin sizes for conventional activated sludge processes.

(B) The design sludge retention time (SRT) for an MBR must be at least 10 days but no more than 25 days.

(i) at least 4,000 mg/l but not more than 10,000 mg/l in the bioreactor; and

(ii) at least 4,000 mg/l but not more than 14,000 mg/l in the membrane tank.

(D) A system designed for an SRT or MLSS outside theses ranges requires a pilot study in compliance with paragraph (8) of this subsection, or data from a similar facility that demonstrates that the design parameters are sustainable and can achieve the expected performance.

(3) Aeration.

(A) An aeration system in a bioreactor must be capable of maintaining dissolved oxygen levels as listed in subparagraph (C) of this paragraph.

(B) A bioreactor aeration system must compensate for a low oxygen transfer efficiency due to the higher MLSS concentrations with a justified alpha value of 0.5 or lower.

(i) Anoxic: not more than 0.5 mg/l;

(ii) Aerobic: at least 1.5 mg/l but not more than 3.0 mg/l; and

(iii) Membranes: at least 2.0 mg/l but not more than 8.0 mg/l.

(D) A design must include oxygen monitoring and an alarm to notify an operator of potential or actual oxygen depravation.

(4) Recycle Rates. Facilities without advanced treatment must be designed with recycle rates sufficient to sustain the design mixed liquor concentrations; typically from 200% to 400% of the facility's influent flow.

(5) Nutrient removal.

(A) A system designed for enhanced nutrient removal must include an isolated tank or baffled zone for anoxic treatment, anaerobic treatment, or both.

(B) Calculations for sizing the reactor volumes must be based on one of these models for nutrient removal:

(i) Bardenpho;

(ii) modified Ludzak-Etinger;

(iii) University of Capetown; or

(iv) an alternative approved by the executive director.

(C) A facility designed for nitrogen or biological nutrient removal must contain a deoxygenation basin, a larger anoxic basin, or another method approved by the executive director of decreasing dissolved oxygen concentration, if the recycled activated sludge is returned to an anoxic or anaerobic basin.

(D) An advanced nutrient removal system must be designed with recycle rates sufficient to sustain the designed mixed liquor concentrations in both the aeration and anoxic basins; typically totaling 600% or more of the influent flow.

(6) Use of Membranes.

(A) Use of a membrane system other than a hollow fiber system, tubular system, or a flat plate system must be considered innovative treatment technology and is subject to §217.7(b)(2) of this title.

(B) Use of a membrane material other than one of the following must be justified in the report:

(i) polyethersulfone (PES);

(ii) polyvinylidene fluoride (PVDF);

(iii) polypropylene (PP);

(iv) polyethylene (PE);

(v) polyvinylpyrrolidone (PVP); or

(vi) chlorinated polyethylene (CPE).

(C) The nominal pore size used in an MBR for microfiltration membranes must be at least 0.10 micrometers (microns) but not more than 0.4 microns.

(D) The nominal pore size used in an MBR for ultrafiltration must be at least 0.02 microns but not more than 0.10 microns.

(E) Any chemical used for cleaning must not adversely affect the membrane material.

(7) Membrane design parameters.

(A) MBRs must be designed for:

(i) An average daily net flux rate of not more than 15 gallons per day per square-foot of membrane area (gfd);

(ii) A peak daily net flux rate equal to or less than 1.25 times the average daily net flux rate; and

(iii) A two-hour peak net flux rate equal to or less than 1.5 times the average daily net flux rate.

(B) The executive director may approve larger net flux rates if the rates are substantiated with a pilot study or data from a similar facility that substantiate the proposed duration, frequency, and recovery time from peak flow.

(C) A system with a peak flow rate that is greater than 2.5 times the average daily flow must use equalization volume, off-line storage, or reserve membrane capacity to accommodate the higher peak flow.

(D) Hollow fiber transmembrane pressure (TMP).

(i) The operational pressure range must be at least 2.0 pounds per square inch (psi) but not more than 10.0 psi.

(ii) The maximum pressure must not exceed 12.0 psi.

(E) Flat plate TMP.

(i) The operational pressure range must be at least 0.3 psi but not more than 3.0 psi.

(ii) The maximum pressure must not exceed 4.5 psi.

(F) Tubular, Out of Basin TMP.

(i) The operational pressure range must be at least 0.5 psi but not more than 5.0 psi.

(ii) The maximum pressure must not exceed 10.0 psi.

(8) Supporting Data. Pilot study reports or data from similar facilities must be provided if a facility is designed to achieve better than the performance standards in Table F.7 in subsection (b)(1) of this section, or outside normal operating parameters defined within this section.

(A) A pilot study must be operated at least 30 days after the initial start-up and acclimation period.

(B) A pilot study must be designed to evaluate the membrane performance during actual operational conditions including flow variations and influent wastewater characteristics.

(C) The treatment and pretreatment processes in a pilot study or similar facility must be equivalent to the proposed facility.

(D) The results of the pilot study must include the following recommendations:

(i) average, peak day, and peak two-hour design net flux rates;

(ii) average and maximum TMP;

(iii) cleaning and backwash intervals;

(iv) expected percent recovery after chemical cleaning;

(v) dissolved oxygen concentrations for reactors and membrane basins;

(vi) MLSS concentrations for reactors and membrane basins;

(vii) SRTs for reactors and membrane basins; and

(viii) expected effluent concentrations of conventional pollutants and nutrients, including the pollutants and nutrients that will be limited or monitored in the facility's wastewater permit.

(9) Redundancy.

(A) A facility must be able to operate at normal operating parameters and conditions for daily average flow with one MBR unit or train out of service.

(B) Acceptable methods of providing redundancy are additional treatment trains, additional treatment units, or storage. Calculations must be included in the report to demonstrate adequate redundancy.

(10) Other components.

(A) Mixers.

(i) Unaerated (deoxygenation, pre/post anoxic, and anaerobic) zones must have submersible mixers or an alternative mixer that has been approved by the executive director.

(ii) Coarse bubble air diffusers may be used for mixing in a pre-anoxic tank.

(B) Scum and Foam Handling.

(i) Scum and foam must not interfere with treatment or overflow a treatment unit.

(ii) Surface wasting of excess mixed liquor or skimmers may be used to control scum and foam.

(iii) Surface wasting may be performed in a aerated basin, a membrane basin, or both.

(C) Cranes and Hoists. A crane, hoist or some other process or mechanism must be provided for periodic cleaning and maintenance.

(11) Disinfection.

(A) An owner may request and the executive director may grant decreased ultraviolet light or chlorine dosing requirements for MBR effluent.

(B) Design for ultraviolet light disinfection for MBR effluent that is based on greater than 75% transmissivity must be justified in the report.

(d) MBR operation.

(1) Membrane cleaning. The following methods may be used:

(A) Air scouring of at least 0.01 standard cubic feet per minute of air per square foot of membrane area but not more than 0.04 standard cubic feet per minute of air per square foot of membrane area;

(B) A mixture of air scouring with mixed liquor jet feed;

(D) Relaxation, which is short periods of air scouring without filtration; or

(E) Chemical cleaning.

(2) Operational control parameters.

(A) In-line continuous turbidity monitoring of filtrate from each membrane train or cassette or an equivalent must be provided for operational control and indirect membrane integrity monitoring. If turbidity is used for indirect integrity monitoring, the value that indicates problems must be less than or equal to 1.0 nephelometric turbidity units (NTU).

(B) An owner must follow the manufacturer's recommended frequency for MBR component inspection, testing, and maintenance. The inspection, testing, and maintenance procedures and frequencies must be included in the facility's operation and maintenance manual.

(C) An owner must provide a facility operator access to any specialized tool necessary for the operation or maintenance of an MBR system. A description of all specialized tools and instructions for their use must be included in a operation and maintenance manual for the facility.

(3) Control instrumentation.

(A) A facility must have the ability to run in full manual mode in case of an automatic control failure; or

(B) An operational backup programmable logic control center (PLC) is required if manual control is not possible.

(e) Chemical Use and Disposal.

(1) The chemicals used in treatment and maintenance must not harm the MBR system or interfere with treatment.

(2) The chemicals, including concentrations and disposal methods, must be identified in the report.

(f) Training.

(1) Key staff must be trained to operate the particular MBR at a facility. They must be familiar with the sequencing and set points of all operations and actions typically controlled by automated systems in order to identify and respond to irregularities.

(2) Proposals for staff training must be included in the report.

(g) Warranty and Bonds.

(1) The membranes must have a warranty of at least five years.

(2) The executive director may require a performance bond that meets the requirements of §217.7(b)(2)(E) of this title.

§217.158.Solids Management.

(a) Solids Recycling and Monitoring.

(1) A return sludge system must operate satisfactorily in all flow conditions.

(2) A monitoring and control system must provide a means to control return and waste sludge flows from each clarifier, to control return sludge flows into each aeration basin, to meter return sludge flows, and to measure waste sludge flows.

(b) Solids Wasting. A design must be adequate to store and process the waste activated sludge under all flow conditions.

(1) A centrifugal sludge pump must have a positive suction head, unless the pump is self-priming.

(2) An airlift pump must allow for cleaning without removal from a basin.

(3) A RAS system must have sufficient pumping units to maintain the maximum design return pumping rate with the largest single pumping unit out of service.

(d) Waste Activated Sludge Pump Design. A waste activated sludge pumping system requires at least two pumping units and must be sized to prevent excessive solids accumulation in the clarifiers.

(e) Sludge Piping System.

(1) The design of a sludge piping system must accommodate cleaning and flushing.

(2) A sludge piping system must be sized for a minimum velocity of 3.0 feet per second at the maximum waste or return rate to prevent solids from settling and must prevent scouring at anticipated normal operating conditions.

(3) A sludge pipe must have a minimum diameter of 4.0 inches.

§217.159.Process Control.

(a) Solids Retention Time Control.

(1) A facility design must include the necessary equipment for a facility operator to control the solids retention time (SRT) in the aeration tanks by wasting a measured volume of surplus activated sludge from either a mixed liquor tank, a sludge re-aeration tank, or the return sludge.

(2) The report and the operating manual must provide the formulas for determining the SRT.

(3) The SRT required for nitrification applies to the aerobic portion of the facility.

(b) Aeration System Control. Aeration control must include the total air supplied and the distribution of air to the aeration tanks.

(1) In order to conserve energy, a facility design may include the ability to adjust the airflow in proportion to the oxygen demand of the facility.

(2) If this adjustable type of airflow control is installed, the aeration equipment must be field adjustable over the entire range of oxygen demands and must maintain solids in suspension.

§217.160.Operability and Maintenance Requirements.

(a) All equipment must operate at the temperature extremes of the facility location and may require enclosures to allow operation of the equipment at all times.

(b) All equipment must be accessible for inspection, maintenance, and operation.

(c) A building that houses equipment must be designed with sufficient clearance and working room to remove and reinstall equipment. The building must be accessible to portable lifting devices or must be equipped with overhead lifting eyes, hoists, trolleys, or cranes to facilitate the safe removal of equipment.

§217.161.Electrical and Instrumentation Systems.

(a) All three-phase motors must have phase failure protection.

(b) Instrumentation and monitoring equipment must have power surge protection.

(c) A facility must conduct fault monitoring and reporting on high wet well, power interruption, disinfection failure, blower failure, and return sludge pumping failure.

(d) For a facility not staffed 24 hours a day, a telemetry with battery back-up or supervisory control and data acquisition system with battery backup must be able to notify an operator of a malfunction at any time.

§217.162.Internal Process Flow Measurement.

A facility with a design flow greater than 0.4 million gallons per day must provide flow measurement of the return sludge and waste sludge discharges for process control.

§217.163.Advanced Nutrient Removal.

(a) A facility designed to provide advanced nutrient removal must specify the process units needed to achieve the permit's effluent limits.

(b) Biological nutrient removal, membrane filtration, sand filtration, or a combination of these processes may be used for advanced nutrient removal without applying for the executive director's approval under the innovative or nonconforming technology criteria in §217.7(b)(2) of this title (relating to Types of Plans and Specifications Approvals).

(1) The anticipated food to microorganism ratio in both the anoxic and anaerobic zones;

(2) The volatile fatty acid recycle ratio; and

(3) The design of a foaming control system.

(d) If a chemical addition unit is proposed, it must comply with the requirements in Subchapter K of this chapter (relating to Chemical Disinfection).

(e) A fixed film and filtration process must comply with the requirements of Subchapter G of this chapter (relating to Fixed Film and Filtration Units).

§217.164.Aeration Basin and Clarifier Sizing--Volume-Flux Design Method.

(a) A volume-flux design must size an aeration basin and clarifier on the relationship between the volume flux of solids in the secondary clarifier, the sludge volume index (SVI), and the sludge blanket depth. The following design approach may be used as an alternative to the traditional design approach.

(1) A design may base the aeration tank volume and the clarifier volume on a mixed liquor suspended solids (MLSS) and floc volume (at SVI of 100) for the required minimum solids retention time.

(2) Larger values of MLSS require less aeration tank volume and greater clarifier volume.

(3) By examining a range of values of the MLSS and the floc volume, the most favorable arrangement for a wastewater treatment facility may be selected.

(4) When using the volume-flux design method, the size of an aeration basin and a clarifier must be in accordance with the requirements of this section.

(b) Design approach.

(1) Determine the solids retention time (SRT) needed to meet the permit requirement for five-day carbonaceous biochemical oxygen demand (CBOD₅) and ammonia-nitrogen (NH₃ -N) effluent limitations.

(2) Select a trial value mixed liquor floc volume, (for example, MLSS at an SVI of 100).

(3) Using the design organic loading rate, the required SRT and yield, and the trial MLSS, determine the aeration tank volume.

(4) Using the trial value of mixed liquor flow volume, determine the clarifier area.

(5) For clarifiers overloaded in thickening at the peak flow, determine the final MLSS during storm flow and the resulting sludge blanket depth.

(6) Observing effluent limitations, determine the side water depth (SWD) and volume of the clarifier.

(7) Repeat the steps in paragraphs (2) - (6) of this subsection at different mixed liquor floc volumes and select the most favorable conditions for the facility design.

(1) For a facility that does not require nitrification, the minimum SRT is as follows:

(A) For a facility with an effluent CBOD₅ monthly average limitation of 20 milligrams per liter (mg/l), the minimum SRT is three days;

(B) For an extended aeration facility with an effluent CBOD₅ monthly average limitation of 20 mg/l, the minimum SRT is 22 days;

(D) For an extended aeration facility with an effluent CBOD₅ monthly average limitation of less than 20 mg/l, the minimum SRT is 25 days.

(2) For a facility that requires nitrification, the minimum SRT is based on the winter reactor temperature as set forth in §217.154(a) of this title (relating to Aeration Basin and Clarifier Sizing--Traditional Design) and the values of SRT and net solids production (Y), as listed in Table F.8 in paragraph (3) of this subsection. The maximum CBOD₅ monthly average loading limitation for a single-step facility is 50 pounds (lb) CBOD₅ per 1,000 cubic feet (cf) and for the first step of two-step facilities is 100 lb CBOD/1,000 cf.

(3) An above-ground steel or fiberglass tank requires 2 degrees Celcius lower minimum operating temperature than a facility utilizing a reinforced concrete tank. A facility must be designed for an MLSS concentration of at least 2,000 mg/l but less than 5,000 mg/l. The net solids production (Y), in the following table includes both coefficients for yield and endogenous respiration:

Figure: 30 TAC §217.164(c)(3)

(4) To calculate the SRT, divide the safety factor by the maximum growth rate as shown in the following equation. The safety factor includes the design factor for the ratio of average to maximum diurnal ammonia loading. A value of 3.0, as recommended in the United States Environmental Protection Agency manual, Nitrogen Control, is used in calculating the values in Table F.8 in paragraph (3) of this subsection.

Figure: 30 TAC §217.164(c)(4)

(5) To determine the aeration basin volume, select a trial value of MLSS. The aeration basin volume is calculated as the maximum value from the following equations:

Figure: 30 TAC §217.164(c)(5)

(d) Clarifier Sizing.

(1) A clarifier basin size is based on volume flux from the floc volume of solids entering the clarifier.

(2) Biological solids may occupy different volumes for the same mass of solids as indicated by the SVI.

(3) For purposes of determining overflow rates for clarifier sizing, the design flow and the peak flow must include any return flows from units downstream of the clarifier, including flow from skimmer, thickeners, and filter backwash.

(4) A clarifier must be sized to prevent overloading under any design condition.

(5) The settling velocity of the mixed liquor solids must equal or exceed the two-hour peak overflow rate.

(6) A clarifier must be sized to prevent overloading in the thickening process at the design flow.

(7) The facility's operation and maintenance manual must state the design maximum mixed liquor floc volume.

(8) Dimensions for clarifiers not designed for solids storage (i.e., not overloaded in thickening at the peak flow).

(e) Determine Overflow Rate and Area. The values in Table F.9 in paragraph (2)(I) of this subsection determine the maximum surface loading rates. The MLSS concentration must include the same concentration used for sizing an aeration basin. The design must be based the underflow rate. The design must include calculations for maximum overflow rate for the clarifier at the peak flow (Figure 1: 30 TAC §217.164(e)(2)(I), Table F.9), the aeration basin MLSS concentration, and a selected underflow rate. The area of the clarifier is determined by the following equation:

Figure: 30 TAC §217.164(e)

(1) Determine Volume of a Clarifier. The volume of a clarifier must exceed the values determined from the minimum side wall depth (SWD) in Equation F.9 located in the following figure or the minimum detention time in Equation F.10 located in the following figure:

Figure: 30 TAC §217.164(e)(1)

(2) Dimensions for clarifiers designed for solids storage capabilities. The design of a clarifier that may be overloaded in thickening at the design flow must include the ability to store solids during peak flow events. The design must be based on the values in Figure 1: 30 TAC §217.164(e)(2)(I), Table F.9, Figure 2: 30 TAC §217.164(e)(2)(I), Table F.10, and Figure 3: 30 TAC §217.164(e)(2)(I), Table F.11. The process for designing a clarifier based on this concept is as follows:

(A) Determine the area of a clarifier. The area calculations must be based on the trial MLSS value selected for the sizing of the aeration basin in paragraph (1) of this subsection. The area of a clarifier must exceed the greater of the areas determined by Equation F.11 or Equation F.12 located in the following figure:

Figure: 30 TAC §217.164(e)(2)(A)

(B) The final MLSS value must be the result of the transfer of solids from an aeration tank to a clarifier at the peak flow. A clarifier design must allow for rates of flow that will transfer solids from an aeration tank to a clarifier if the clarifier becomes overloaded in thickening until the mixed liquor solids are reduced to the concentration that no longer causes the overload.

(C) Using Figure 3: 30 TAC §217.164(e)(2)(I), Table F.11 and the selected underflow rate, the MLSS concentration at peak flow is determined using the following equation:

Figure: 30 TAC §217.164(e)(2)(C)

(D) Determine depth of sludge blanket at peak flow. The depth of a sludge blanket is determined by the aeration basin volume, the change in MLSS, the area of the clarifier and the concentration of the blanket solids at the selected underflow rate as shown in the following equation:

Figure: 30 TAC §217.164(e)(2)(D)

(E) Determine the SWD. The SWD of a clarifier is the maximum value resulting from the following conditions:

(i) 10 ft, unless a lower depth is allowed by §217.152(g) of this title (relating to Requirements for Clarifiers);

(ii) 3.0 times the sludge blanket depth; and

(iii) minimum detention time per the following equation:

Figure: 30 TAC §217.164(e)(2)(E)(iii)

(F) Determine clarifier volume. The volume of a clarifier is the area multiplied by the SWD determined in subparagraph (E) of this paragraph.

Figure: 30 TAC §217.164(e)(2)(F)

(G) The formulas for Figure: 30 TAC §217.164(e)(2)(G)(i), Equation F.17; Figure: 30 TAC §217.164(e)(2)(G)(ii), Equation F.18; and Figure 2: 30 TAC §217.164(e)(2)(I), Table F.10; calculate the rates that are equal to the settling velocity of activated sludge at various floc volume concentrations. For values less than 30%, the floc volume is the 30-minute settled volume in an unstirred one-liter graduated cylinder. For values greater than 30%, the sample is diluted so that the settled volume is at least 15% but not more than 30%, and the result multiplied by the dilution factor.

(i) For floc volume less than 40% use the following equation; or

Figure: 30 TAC §217.164(e)(2)(G)(i)

(ii) For floc volume greater than 40%, use the following equation:

Figure: 30 TAC §217.164(e)(2)(G)(ii)

(H) Figure 1: 30 TAC §217.164(e)(2)(I), Table F.9 and Figure 3: 30 TAC §217.164(e)(2)(I), Table F.11 are based on an analysis of the floc volume flux, i.e. floc volume times settling velocity, calculated from Figure: 30 TAC §217.164(e)(2)(G)(i), Equation F.17 and Figure: 30 TAC §217.164(e)(2)(G)(ii), Equation F.18. Figure 3: 30 TAC §217.164(e)(2)(I), Table F.11 is a tabulation of the maximum concentration of the underflow at different underflow rates. The equation for Figure 3: 30 TAC §217.164(e)(2)(I), Table F.11 is as follows:

Figure: 30 TAC §217.164(e)(2)(H)

(I) The following table determines the overflow rate that, along with the underflow rate and MLSS, determines the same floc volume flux as shown in Figure 3: 30 TAC §217.164(e)(2)(I), Table F.11:

Figure 1: 30 TAC §217.164(e)(2)(I)

Figure 2: 30 TAC §217.164(e)(2)(I)

Figure 3: 30 TAC §217.164(e)(2)(I)

This agency hereby certifies that the proposal has been reviewed by legal counsel and found to be within the agency's legal authority to adopt.

Filed with the Office of the Secretary of State on February 29, 2008.

TRD-200801205

Robert Martinez

Director, Environmental Law Division

Texas Commission on Environmental Quality

Earliest possible date of adoption: April 13, 2008

For further information, please call: (512) 239-0177

Subchapter G. FIXED FILM AND FILTRATION UNITS

30 TAC §§217.181 - 217.193

STATUTORY AUTHORITY

The proposed new rules implement TWC §§5.013, 5.103, 5.105, 5.120, 26.027, 26.034, and 26.121.

§217.181.Applicability.

This subchapter establishes the requirements for trickling filters, rotating biological contactors, submerged biological contactors, and filtration systems.

§217.182.Trickling Filters--General Requirements.

(a) Trickling filters are classified according to applied hydraulic loading, including recirculation, in million gallons per day (mgd) per acre of filter media surface area and influent organic loadings in pounds of five-day biochemical oxygen demand (BOD₅ ) per day per 1,000 cubic feet of filter media, The following factors must be the basis for the selection of the design hydraulic and organic loadings:

(1) strength of the influent wastewater;

(2) effectiveness of pretreatment;

(3) type of filter media; and

(4) treatment efficiency required.

(b) A trickling filter is classified as:

(1) a roughing filter, which provides at least 50% but not more than 75% removal of soluble BOD₅;

(2) a secondary treatment filter, which provides the required settled effluent BOD₅ and total suspended solids (TSS);

(3) a combined BOD₅ and nitrifying filter, which provides the required settled effluent BOD₅ , ammonia-nitrogen (NH₄-N), and TSS; or

(4) a tertiary nitrifying filter, which provides the required settled effluent NH₄-N, if the influent to a trickling filter is a clarified secondary effluent.

Figure: 30 TAC §217.182(c)

(d) Pretreatment.

(1) A trickling filter must have upstream preliminary treatment units that:

(A) remove grit, debris, suspended solids, oil, and grease;

(B) particles with a diameter greater than three millimeters; and

(2) A primary clarifier equipped with scum and grease removal devices must precede a rock media trickling filter.

(e) Rock Filter Media.

(1) Materials.

(A) Rock media using crushed rock, slag, or similar material containing more than 5% by weight of pieces with their longest dimension three times greater than the least dimension is prohibited.

(B) Rock media must conform to the following size distribution and grading. Mechanical grading over a vibrating screen with square openings must meet the following:

(i) passing 5.0 inch sieve - 100% by weight;

(ii) retained on 3.0 inch sieve - 95-100% by weight;

(iii) passing 2.0 inch sieve - 0.2% by weight;

(iv) passing 1.0 inch sieve - 0.1% by weight; and

(v) the loss of weight by a 20-cycle sodium test, as described in American Society of Civil Engineers' Manual of Engineering and Engineering Practice No. 13 , must be less than 10%.

(2) Placement.

(A) Rock media must be at least 4.0 feet deep at the shallowest point.

(B) Dumping rock media directly on a filter is prohibited. Rock media must be placed by hand to a depth of 12 inches above the underdrains. The remainder may be placed by belt conveyor or an equivalent mechanical method.

(C) Crushed rock, slag, and other similar media must be washed and screened or forked to remove clay, organic material, and fines prior to placement.

(D) The placement of any material must not damage the underdrains.

(E) Vehicles and equipment are prohibited from driving over the filter media.

(f) Synthetic (Manufactured or Prefabricated) Media Materials.

(1) Any synthetic media material must be used in accordance with all manufacturer's recommendations.

(2) Synthetic media material may be considered innovative or nonconforming technology and may be subject to §217.7(b)(2) of this title (relating to Types of Plans and Specifications Approvals).

(A) Suitability. The suitability of synthetic media material must be evaluated based on experience with an installation treating wastewater under similar hydraulic and organic loading conditions. The report must include a relevant case history involving the use of the synthetic media.

(B) Durability. A synthetic media must be insoluble in wastewater and resistant to flaking, spalling, ultraviolet degradation, disintegration, erosion, aging, common acids and alkalis, organic compounds, and biological attack.

(i) A structural design must support the synthetic media, water flowing through or trapped in voids, and the maximum anticipated thickness of the wetted biofilm.

(ii) The synthetic media must support the weight of a person, unless a separate provision is made for maintenance access to the entire top of the trickling filter media and to the distributor.

(D) Placing of Synthetic Media. Modular synthetic media must be installed with the edges matched as nearly as possible to provide consistent hydraulic conditions within the trickling filter.

(g) Filter Dosing.

(1) Suitable flow characteristics must be used for the application of wastewater to a filter by siphon, pump, or gravity discharge from preceding treatment unit.

(2) A filter must be designed to control instantaneous dosing rates under both normal operating conditions and filter-flushing conditions.

(3) The distributor speed and the recirculation rate must be adjusted for the dosing intensity as a compensatory measure under low-flow conditions. The following table provides design ranges of dosing intensity for normal usage periods and for flushing periods:

Figure: 30 TAC §217.182(g)(3)

(4) A design may be based on instantaneous dosing intensity for rotary distributors using the equation in the following figure:

Figure: 30 TAC §217.182(g)(4)

(h) Distribution Equipment.

(1) A design must include a rotary, horizontal, or traveling wastewater distribution system that distributes wastewater uniformly over the entire surface of a filter at the design and flushing dosing intensities.

(2) A design must include filter distributors that operate properly at all anticipated flow rates.

(3) A design must not deviate from the design dosing intensity by more than 10%.

(4) A new trickling filter or upgrade of an existing trickling filter must include electrically driven, variable speed a filter distributor to allow operation at optimum dosing intensity independent of recirculation pumping.

(5) If an existing rectangular trickling filter is retrofitted with rotary distributors, any media that will not be fully wetted must not be considered part of the required effective treatment area.

(6) The center column of a rotary filter distributor must have adequately sized overflow ports to prevent water from reaching the bearings in the center column.

(7) A filter distributor must include cleanout gates on the ends of the arms and an end spray nozzle to wet the edge of the media.

(8) The filter walls must extend at least 12.0 inches above the top of the ends of the distributor arms.

(9) The use of a mercury seal in a distributor of a trickling filter is prohibited in a new facility. If an existing treatment facility is modified, any mercury seal in a trickling filter must be replaced with an oil or mechanical seal.

(10) The minimum clearance between the top of the filter media and the distributing nozzles is 6.0 inches.

(11) Rotary distributors must capable of operating at speeds as low as one revolution per 30 minutes.

(12) A trickling filter with a height or diameter that does not allow distributors to be removed and replaced by a crane must provide jacking columns and pads at the distributor column.

(i) Recirculation.

(1) Low Flow Conditions.

(A) A design must include minimum recirculation during periods of low flow in order to ensure that the biological growth on the filter media remains active at all times.

(B) A design must include the minimum recirculation in the evaluation of the efficiency of a filter, if it is part of a proposed specified continuous recirculation rate.

(C) Minimum flow to the filters must equal to or greater than 1.0 mgd per acre of filter aerial surface and must keep the distribution nozzles properly operating.

(D) The minimum flow rate for a design using hydraulically driven distributors must keep rotary distributors turning at the minimum design rotational velocity.

(E) For a facility designed with a capacity equal to or greater than 0.4 mgd and recirculation for BOD₅ removal, the recirculation system must include variable speed pumps and a method of conveniently measuring the recycle flow rate.

(2) Compensatory Recirculation.

(A) A design must provide recirculation to supplement influent flow if design and flushing dosing intensities are not achieved solely by the control of distributor operation.

(B) Controls for the distributor speed and recycle pumping rate must provide optimum dosing intensity under all anticipated influent flow conditions.

(3) Process Calculations. The report must:

(A) describe a design that propose removal of the remaining organic matter by recirculation;

(B) identify the effect of dilution of the influent on the rate of diffusion of dissolved organic substrates into the biofilm; and

(C) identify the effect of reduced influent concentrations on reaction rates in each section of a filter having first order kinetics.

(4) Maximum Recirculation Rate. A recirculation rate may exceed four times design flow if calculations to justify the higher rate are included in the report.

(5) Configuration.

(A) In a facility with influent that has constant organic loadings, a system must use direct recirculation of unsettled trickling filter effluent.

(B) A design must ensure that the distributor nozzles can handle the recirculated sloughed biofilm.

(C) In a facility with variable influent organic loadings, effluent must recirculate from a final clarifier to either a primary clarifier or a trickling filter to equalize organic loading.

(j) Average Hydraulic Surface Loading.

(1) The report must include calculations of the maximum, design, and minimum area cross-section surface loadings on the filters in terms of million gallons per acre of filter area per day for the initial year and the design year.

(2) The average hydraulic surface loadings of a filter with crushed rock, slag, or similar media must not:

(A) exceed 40 mgd per acre based on design flow, except in roughing applications;

(B) be less than 1.0 mgd per acre; and

(k) Underdrain System Design.

(1) A trickling filter must include an underdrain with semicircular inverts that cover the entire floor.

(2) An underdrain must be vitrified clay or pre-cast reinforced concrete.

(3) An underdrain constructed of half tile is prohibited.

(4) Underdrain inlet openings must have a gross cross-sectional area greater than 15% of a filter's surface area.

(5) A modular synthetic media design must be supported above a filter floor by beams and grating with support and clearances in accordance with the media manufacturer's recommendations.

(l) Underdrain Slopes.

(1) An underdrain and filter effluent channel floor must have a minimum slope of 1%.

(2) An effluent channel must produce a minimum velocity of 2.0 feet per second at design flow rate to a trickling filter.

(3) The floor of a new trickling filter using stackable modular or synthetic media must slope toward a drainage channel on slope of at least 1% and not more than 5%, based on filter size and hydraulic loading.

(m) Passive Ventilation.

(1) The effluent channel and effluent pipe of an underdrain system or a synthetic media support structure must permit free passage of air.

(2) Any drain, channel, or effluent pipe must have a cross-sectional area with not more than 50% of the area submerged at peak flow plus recirculation.

(3) The effluent channels must accommodate the specified flushing hydraulic dosing intensity and allow the possibility of increased hydraulic loading.

(4) A ventilation system may include an extension of an underdrain through a filter sidewall, a ventilation opening through a sidewall, and an effluent discharge conduit designed as a partially full flow pipe or an open channel.

(5) A vent opening through a trickling filter walls must include hydraulic closure to allow flooding of a filter for nuisance organism control.

(6) A passive ventilation design must provide at least 2.5 square feet (sf) of ventilating area per 1,000 lbs of primary effluent BOD₅ per day.

(7) An underdrain system for a rock media filter must provide at least 1.0 sf of ventilating area for every 250 sf of plan area.

(8) The minimum required ventilating area for a synthetic media underdrain is the area recommended by the manufacturer.

(9) The ventilating area must be the greater of 1.0 sf per 175 sf of synthetic media area or 2.6 sf per 1,000 cf of media volume.

(n) Forced Ventilation.

(1) Forced ventilation is required for a trickling filter designed for nitrification, for a trickling filter design with a media depth in excess of 6.0 feet, or for any location where seasonal or diurnal temperatures do not provide sufficient difference between the ambient air and wastewater temperatures to sustain passive ventilation.

(2) A design must specify the minimum airflow for forced ventilation and optimized process performance, and the report must include any calculation associated with this determination.

(3) A down-flow forced ventilation system must include a provision for:

(A) the removal of entrained droplets: or

(B) the return of air containing entrained moisture to the top of a trickling filter; and

(C) a reversible fan or other mechanism to reverse the airflow when a wide temperature difference between the ambient air and wastewater create strong updrafts.

(4) A ventilation fan and the associated controls must withstand flooding of a filter without sustaining damage.

(5) The following equation and the values in Table G.3 determine the minimum airflow rate:

Figure: 30 TAC §217.182(n)(5)

(o) Maintenance.

(1) Cleaning and Sloughing.

(A) A flow distribution device, an underdrain, a channel, and a pipe must allow maintenance, flushing, and drainage.

(B) A trickling system must hydraulically accommodate the specified flushing hydraulic dosing intensity and must facilitate cleaning and rodding of the distributor arms.

(C) A trickling filter system must prevent recirculation of sloughed biomass in pieces larger than the distributor nozzle opening or the filter media voids.

(2) Nuisance Organism Control. A trickling filter system must control nuisance organisms by operation of trickling filters at proper design dosing intensities, with periodic flushing at higher dosing intensities.

(A) Filter Flies.

(i) The structural and hydraulic design of a new trickling filter must enable flooding of the trickling filter for fly control.

(ii) The executive director may approve an alternate method of fly control for a filter that exceeds 6.0 feet in height if the effectiveness of the alternate method is verified at a full-scale installation and documented in the report.

(B) Snails. A trickling filter system must minimize areas where sludge may accumulate. The system must include a low-velocity, open channel between a trickling filter and final clarifier for manual removal of snails.

(3) Corrosion Protection. A design must minimize corrosion and use corrosion-resistant materials for all equipment and construction of a trickling filter, including ventilation equipment and covers.

(p) Flow Measurements. A trickling filter system must include a means to measure the flow to a filter and the recirculation flow.

(q) Odor Control. A trickling filter system must use ventilation with periodic flushing at a higher dosing intensity to minimize potential odor.

(1) Covers.

(A) The executive director may require an owner of a facility with a history of odor complaints to install a cover over a new or modified trickling filter.

(B) A cover must allow access to the entire top of the filter media and to the distributor for maintenance and removal.

(C) A covered trickling filter must have a forced ventilation system with a scrubber or an adsorption column for odor control.

(2) Stripping. A trickling filter with high influent organic loading must have forced ventilation in a down-flow mode to minimize odor. Odorous off-gases may be:

(A) recycled through a trickling filter;

(B) used to ventilate a tertiary nitrifying trickling filter in an up-flow mode;

(D) treated separately for odor control using a scrubber or an adsorption column.

(r) Final Clarifiers. The size of the final clarifiers for a facility with a trickling filter must allow for the required effluent total suspended solids removal at the maximum influent flow and the maximum recirculation with all pumps in operation.

(s) Report Requirements.

(1) The report must specify the filter efficiency formula used in the design calculations.

(2) The report must include the operating data from any existing trickling filter of similar construction and operation at the facility to justify the projected treatment efficiency, kinetic coefficients, and other design parameters.

(3) The report may include more than one set of applicable design equations to allow crosschecking of predicted treatment efficiency.

§217.183.Nitrifying Trickling Filters--Additional Requirements.

(a) Ventilation. A nitrifying trickling filter must include forced ventilation to distribute airflow throughout the underdrain area. Minimum design airflow rate must provide the greater of:

(1) 50 pounds of oxygen provided per pound of oxygen required at average organic loading, based on stoichiometry; or

(2) 30 pounds of oxygen provided per pound of oxygen required at peak organic loading, based on stoichiometry.

(b) Temperature. The report must justify the temperature used in the design equations. A design may include deep towers or other means to minimize recirculation while providing a design hydraulic dosing intensity that lessens the effects of temperature on removal efficiency.

(d) Predation. A nitrifying trickling filter must include a means for effective control of biomass predators, such as snails.

(e) Hydraulic Application Rates. A nitrifying trickling filter must operate at a design dosing intensity of at least 1.47 gallons per minute per square foot and provide operational control of dosing intensity.

(f) Media. Cross-flow synthetic media is required for a new tertiary nitrification filter or for the nitrifying section of a new combined nitrification filter.

(g) Tertiary Nitrification Filters. A trickling filter treating influent that has a five-day biochemical oxygen demand (BOD₅ ) to total Kjeldahl nitrogen (TKN) ratio of equal to or greater than (≥) 1.0 and soluble BOD₅ of less than or equal to (≤) 12 milligrams per liter (mg/l) is a tertiary nitrification filter.

(1) Design Justification. The report must include process design calculations and selection criteria of kinetic coefficients for a tertiary nitrifying filter and must be justified by operating data from any existing trickling filter of similar construction and operation.

(2) Media biotowers. A tertiary nitrifying filter design must minimize pH depression due to recirculation and by control of influent instantaneous application rates, by means other than compensatory recirculation. A tertiary nitrifying filter must use either:

(A) tower ≥20 feet; or

(B) a series of towers less than 20 feet operating in series if the design includes provisions to readily switch the operating sequence of the filters.

(h) Combined BOD₅ and Nitrification Filters. A trickling filter intended to perform nitrification and treating influent having a BOD₅ to TKN ratio of ( 1.0 or soluble BOD₅ of ( 12 mg/l is a combined BOD₅/nitrification filter.

(1) Design Justification. The report must justify the projected treatment efficiency and other design parameters by including operating data from any existing trickling filter of similar construction and operation.

(2) BOD₅ Removal Requirements. A combined BOD₅ and nitrification filter must achieve effluent total BOD₅ of ≤15 mg/l. The design must not take credit for nitrification in sections of the filter having soluble BOD₅ of ≤20 mg/l.

(3) Recirculation. A combined nitrification filter design must enable a high recirculation rate with turndown capability.

§217.184.Dual Treatment Using Trickling Filters.

(a) Classification. A trickling filter or other attached-growth treatment unit in series with a suspended-growth process is considered a dual treatment process that is classified as one of the following:

(1) Activated Biological Filter (ABF) System. An ABF consists of a tricking filter and a final clarifier. An ABF system recirculates settled solids from the final clarifier through the trickling filter with no separate aeration basin or solids contact basin.

(2) Trickling Filter/Solids Contact (TF/SC) System. A TF/SC system consists of a trickling filter sized to remove the majority of the soluble five-day biochemical oxygen demand (BOD₅ ), followed by an aerated solids contact basin sized to provide polishing and improved sludge settleability, followed by a final clarifier. A TF/SC system recirculates activated sludge to a solids contact basin. The design may include a sludge re-aeration basin.

(3) Roughing Filter/Activated Sludge (RF/AS) System. A RF/AS system consists of a trickling filter sized to perform primary treatment, followed by an aeration basin sized to remove the majority of the soluble BOD₅, followed by a final clarifier. A RF/AS system circulates activated sludge to the aeration basin.

(4) Activated Biological Filter/Activated Sludge (ABF/AS) System. An ABF/AS system consists of a trickling filter sized to perform primary treatment, followed by an aeration basin sized to remove the majority of the soluble BOD₅, followed by a final clarifier. An ABF/AS system recirculates activated sludge to the trickling filter.

(5) Trickling Filter/Activated Sludge (TF/AS) System. A TF/AS system consists of a trickling filter sized to perform roughing and concentration dampening, followed by an intermediate clarifier, followed by an aeration basin sized to remove the majority of the soluble BOD₅, followed by a final clarifier. A TF/AS system circulates activated sludge to the aeration basin.

(b) Process Design.

(1) Attached and suspended growth sub-processes in a dual system must be designed in an integrated process that includes the effluent quality from the first stage in determining the design basis of the second stage.

(2) A design must include an estimate of the performance of the second stage of a dual system using data from existing similar installations or applicable pilot studies.

(3) For a treatment process design in which activated sludge is recycled to first-stage trickling filters, the design must not include the reduction of oxygen demand to the second-stage aeration basin because of sludge recirculation to the trickling filters.

(4) A design may include estimates of the applicable design equations and methodology used for a single stage process.

(c) Treatment Unit Design. The detailed design of a suspended and attached growth system must include all of the features and operational capabilities required for the same treatment unit used for single-process treatment, as well as the following items:

(1) Pretreatment. Pretreatment of a dual system must conform to requirements for a first-stage process.

(2) Snail Control. A dual system must include a low-velocity channel between the first stage and second stage treatment units for control of snails.

(3) Return sludge.

(A) A dual system that includes recirculation of activated sludge or sloughing to trickling filters must prevent recirculation of pieces larger than will pass through the distributor nozzles or the filter media voids.

(B) The trickling filters in a dual system that recirculates sludge to the trickling filters must be high-rate, vertical flow, and fully corrugated media.

(C) Sludge must be incorporated into influent prior to application to trickling filters, and must be incorporated into the effluent from first-stage processes prior to being introduced into second-stage aeration basins.

(4) Aeration. An aeration system for second-stage treatment units in a dual system not designed for nitrification must transfer at least 1.2 pounds of oxygen per pound of first stage effluent BOD₅ per day. An aeration system for second-stage treatment units in systems designed for nitrification must transfer sufficient oxygen to meet stoichiometric requirements for:

(A) biomass growth;

(B) respiration for both carbonaceous material oxidation and nitrification; and

(5) Sludge Age.

(A) A design of second-stage suspended growth processes must operate in a way that varies the age of the sludge.

(B) The mean cell residence time must be:

(i) at least 1.5 days for the suspended growth process for TF/SC systems; or

(ii) at least 3.0 days if the second process is an activated sludge aeration basin.

(C) A nitrifying dual system must maintain a total combined mean cell residence time in the attached and suspended growth systems of at least 10.0 days with capability to provide at least 6.0 days mean cell residence time in the suspended growth process alone.

(6) Hydraulic Residence Time. A design of second-stage processes must have a minimum hydraulic residence time of:

(A) 0.5 hour if the second process is an aerated solids contact basin; or

(B) 3.0 hours if the second process is an activated sludge aeration basin.

(7) Nitrification Design. A design for nitrification using dual treatment processes must include:

(A) a sludge re-aeration basin if the second process is an aerated solids contact basin; or

(B) an intermediate clarifier if the second process is an activated sludge aeration basin.

§217.185.Rotating Biological Contactors.

(a) Pretreatment.

(1) Pretreatment to remove grit, debris, and excess oil and grease must precede an rotating biological contractor (RBC) unit.

(2) A design may require primary clarifiers, fine screens, or grit removal chambers to control high levels of grease, oil, grit, or other debris in the influent waste stream.

(3) A RBC unit must include pre-aeration if influent has a high hydrogen sulfide concentration.

(b) Enclosures and Ventilation.

(1) An RBC unit must be covered and provide appropriate levels of ventilation.

(2) A cover must have working clearance of at least 30 inches above an RBC unit, unless the cover can be removed with on-site equipment.

(3) Enclosures must be constructed of a corrosion resistant material.

(4) An RBC unit must include:

(A) access doors on each end, and

(B) observation ports with covers at 3.0 foot intervals along the RBC unit.

(1) An RBC unit must provide self-cleaning action for the media.

(2) RBC media must be compatible with the wastewater to be treated.

(3) An RBC design using multiple stages must use low-density media for the first stage.

(d) Design Flexibility. If included in the design of an RBC, the report must include descriptions of the following:

(1) controlled flow to multiple first stages;

(2) alternate flow and staging arrangements;

(3) removable baffles between stages; and

(4) provision for step feed and supplemental aeration.

(e) Tank Configuration. A design must ensure that an RBC tank:

(1) minimizes the zones in which solids will settle out; and

(2) includes tank drains to facilitate removal of any accumulated solids.

(f) Control of Unwanted Growth in the Initial Stages. Chlorine may be added upstream of an RBC system to control the growth of beggiatoa.

(g) Maintenance Provisions.

(1) An RBC system designed for 1.0 million gallons per day (mgd) or greater must have two or more process trains consisting of three or more stages in series in each process train.

(2) Each process train must be capable of being removed from service when maintenance or cleaning is required.

(h) Bearing Maintenance. An RBC system's bearings must be easily accessible for inspection and lubrication.

(i) Organic Loading Design Requirements.

(1) A design must be based on the organic loading for an RBC system on total five-day biochemical oxygen demand (BOD₅ ) in the waste.

(2) The maximum loading rate must not exceed 8.0 pounds of BOD₅ per day per 1,000 square feet (sf) of media in any stage.

(3) A design must require the RBC media area be adjusted to compensate for the effects of the ratio of soluble BOD₅ to total BOD₅.

(4) Allowable organic loading for the entire RBC system must not exceed:

(A) 3.0 lbs of BOD₅ per day per 1,000 sf of media area for facilities required to meet secondary treatment; or

(B) 2.0 lbs of BOD₅ per day per 1,000 sf for a facility required to meet advanced secondary treatment.

(j) Hydraulic Loading Design Requirements. An RBC system must include flow equalization when the peak-to-design flow ratio is higher than 2.5 to 1.0 to prevent loss of fixed growth from the media.

(k) Stages.

(1) An RBC system designed for a BOD₅ removal unit must have at least three stages in series, unless the report justifies a lesser number using operational data from either a full-scale operating facility or pilot unit with an appropriate scale-up factor.

(2) The first stage of an RBC system must include a means of spreading the influent flow evenly across the media.

(l) Drive Systems. An RBC drive system must handle the maximum anticipated media load and may be a variable speed system. An RBC unit may be mechanically driven or air driven.

(1) Mechanical Drive.

(A) A mechanical drive must have a motor and speed control unit capable of maintaining the required revolutions per minute.

(B) A fully assembled spare for each size mechanical drive unit must be on-site.

(2) Air Drive.

(A) Each RBC unit must have air diffusers mounted below the media and off-center from the vertical axis of the RBC unit and must have air cups mounted on the outside of the media to collect the air.

(B) The blowers must provide the capacity to supply adequate airflow for:

(i) each RBC unit;

(ii) double the airflow rate to any one unit while the others are running normally; and

(iii) the required airflow with the largest blower out of service.

(i) be mounted so that the air diffuser pipe may be removed without draining the tank or without moving the RBC media; and

(ii) include an air control valve to each RBC unit.

(m) Dissolved Oxygen.

(1) An RBC system must maintain a minimum dissolved oxygen concentration of 1.0 milligram per liter in all stages during the maximum organic loading rate.

(2) The executive director may require supplemental aeration.

§217.186.Nitrifying Rotating Biological Contactors.

(a) A rotating biological contractor (RBC) system designed for five-day biochemical oxygen demand (BOD₅) removal and nitrification of domestic wastewater in a single system must include four stages and have a maximum overall organic loading rate of 1.6 pounds of BOD₅/day/1,000 square feet of media.

(b) A nitrifying RBC must be designed to allow chemical addition if the influent pH is below 7.0.

(d) A nitrifying RBC system may be subject to the requirements of §217.7(b)(2) of this title (relating to Types of Plans and Specifications Approvals).

§217.187.Dual Treatment Utilizing Rotating Biological Contactors.

(a) A rotating biological contactors (RBC) unit may be used in conjunction with other systems.

(b) An RBC system may be used as a "roughing" unit in series with an activated sludge system as described in §217.183 of this title (relating to Nitrifying Trickling Filters--Additional Requirements).

(c) The report must include supporting data, calculations, process descriptions, and vendor information to describe how a proposed system will meet the permitted effluent limitations.

(d) Combined systems may be subject to the requirements of §217.7(b)(2) of this title (relating to Type of Plans and Specifications Approvals).

§217.188.Submerged Biological Contactor.

(a) A submerged biological contactor (SBC) system must be air driven and does not require a cover.

(b) An SBC system requires the same pretreatment as a rotating biological contactor system and must meet the criteria in §217.185 of this title (relating to Rotating Biological Contactors), except as described in paragraphs (1) and (2) of this subsection.

(1) Each SBC unit must include two air headers, one for rotation of the unit and one to provide dissolved oxygen for the biological activity.

(2) The submerged bearings must be sealed to prevent intrusion of the wastewater.

§217.189.Dual Treatment Systems Using Submerged Biological Contactor.

(a) A submerged biological contactor (SBC) unit may be used in conjunction with other systems.

(b) An SBC system may be used as a roughing unit in series with activated sludge as described in §217.183 of this title (relating to Nitrifying Trickling Filters--Additional Requirements).

(c) SBC units may be installed in existing activated sludge basins to create a combination fixed and suspended growth process.

(d) If a dual system employs an SBC unit, the report must include supporting data, calculations, process descriptions, and vendor information to describe how the proposed system will provide the required treatment levels.

(e) These designs may be subject to the requirements of §217.7(b)(2) of this title (relating to Type of Plans and Specifications Approvals).

§217.190.Filtration.

(a) Reasons for Use.

(1) Permit Requirements. A facility with tertiary effluent limitations must use filtration as a unit of operation to supplement suspended solids removal.

(2) Specific Water Quality Requirements. At facility with secondary or advanced secondary effluent limitations may use filtration as a unit of operation to supplement suspended biological floc removal and intermittent filter operation if filters are not necessary to meet permitted effluent limitations.

(b) Redundancy.

(1) A facility using filtration to provide tertiary treatment for a permit requirement must have a minimum of two filter units.

(2) A design must specify the required filter surface area based on peak flow through the filters with the largest filter unit out of service.

(3) If a filter is being provided to polish wastewater for situations where permit compliance does not depend on the use of a filter, such as some cases of reclaimed water usage, one filter is allowed.

(d) Disposition of Backwash Water. A filtration system must return backwash water containing material cleaned from a filter to the head of the facility for processing.

(e) Sequence of Treatment Units.

(1) A final clarifier must precede a filter, in accordance with Subchapter F of this chapter (relating to Activated Sludge Systems).

(2) A filter system may be used in conjunction with a disinfection tank to provide additional detention time, provided a filter is backwashed to the headworks of the facility.

(f) Overload Conditions. A design must prevent effluent or partially treated effluent from overflowing from any filtration unit.

(g) Control of Slime Growth. A filtration system must provide periodic disinfectant in the influent stream to a filter to control slime growth in the filter and backwash storage tank.

§217.191.Additional Requirements for Deep Bed, Intermittently Backwashed, Granular Media Filters.

(a) Application Rates. With one unit out of service, the peak application rate to any deep bed, intermittently backwashed, granular media filtration unit must not exceed twice the design application rate.

(1) Single Media.

(A) The design filtration rate for single media (sand) filters must not exceed three gallons per minute (gpm) per square foot (sf) of media surface.

(B) The maximum filtration run time between backwash periods is 6.0 hours.

(2) Dual Media. The design filtration rate for a dual media (anthracite and sand) filter must not exceed 4.0 gpm/sf of media surface.

(3) Mixed Media. The design filtration rate for mixed media (non-stratified anthracite, sand, garnet, or other materials) must not exceed 5.0 gpm/sf of media surface.

(b) Media Design.

(1) A filter underdrain system must include a graded gravel layer with a minimum depth of 15 inches, or other filter media support material unless a filter media other than gravel is justified in the report.

(2) Uniformity coefficient of media used in a filter must be 1.7 or less.

(3) The particle size distribution for dual and mixed media filters must perform a hydraulic grading of material during backwash that will result in a filter bed with a pore space graded from progressively coarse to fine from the top of the media to the supporting layer.

(4) Media depths for the various filter types must conform to the values in the following table, unless other media depths are justified in the report with an analysis of the backwash rates:

Figure: 30 TAC §217.191(b)(4)

(1) Flowrate and Media Expansion.

(A) A backwash system must allow a media expansion of at least 20%.

(B) A single media filter must provide a minimum backwash flowrate of 6.0 gpm/sf of media area.

(D) Backwash times must be at least 10 minutes but not more than 15 minutes, unless the report justifies a different time.

(2) Surge Control.

(A) A wastewater treatment facility that does have flow equalization or other means of surge control must have a backwash tank.

(B) A surge control device must prevent increases in flow greater than 15% of the design flow of the upstream treatment units if backwash is taken directly to the headworks.

(C) A design must be based on calculations that demonstrate the slug effects of backwash water and that demonstrate treatment capabilities are not diminished with the return of backwash water to the facility headworks.

(D) An enclosed backwash tank must be vented.

(3) Pumps.

(A) Pumps for backwashing filter units must deliver the required rate with the largest pump out of service.

(B) A backup pump must be available on-site.

(D) A backwash system employing automatic controls must include a manual override system.

(4) Supplemental Systems.

(A) A single media filter system must include an air scour system or combination air and water scour system in addition to an up-flow backwash water system.

(B) A dual or mixed media filter system must include either a surface air or water scour system.

(C) Air scour system flowrates must be at least 3.0 standard cubic feet per minute per square foot of media surface area but not more than 5.0 scfm/sf of media surface area.

(D) Water scour system flowrates must be at least 0.5 gpm/sf of media area but not more than 2.0 gpm/sf of media area.

(d) Underdrain System. An underdrain system must provide a uniform distribution for filter backwash without plugging or exceeding the manufacturer's recommendation for maximum headloss.

(e) Tank Design.

(1) The bottom of a wash water collection trough must be a minimum of 6.0 inches above the maximum elevation of the expanded media during backwash.

(2) A wash water trough must have a minimum freeboard of 3.0 inches during the maximum backwash flowrate.

(f) Controls.

(1) The filter operation controls may be manual or automatic.

(2) Control indicators must be visible to a facility operator while adjusting the controls.

(3) An automatically controlled system must include a manual override system.

(4) Each filter unit must have a head loss indicator.

§217.192.Additional Design Requirements for Multi-Compartmented, Low Head, Automatically Backwashed Filters.

(a) Application Rates.

(1) With one unit out of service, the peak application rate to any unit must not exceed twice the design application rate

(2) The report must include manufacturer's recommended filtration rates with test data.

(3) Single Media. A single media filter must have a maximum design filtration rate of 3.0 gallons per minute per square foot of media surface.

(4) Dual Media. A dual media filter must have a maximum design filtration rate of 4.0 gallons per minute per square foot of media surface.

(b) Media Design. Media sizes and depths must correspond to the values in the following figure, unless the report justifies different media sizes and/or depths:

Figure: 30 TAC §217.192(b)

(1) A backwash system must provide a minimum of 20 gallons per minute per square foot of media being backwashed at a given time.

(2) The backwash duration must last at least 20 seconds for each compartment and must expand the media a minimum of 20% unless the report includes the manufacturer's recommended backwash rates with test data.

(3) The surge control and pumping system requirements must be the same as those detailed in §217.191(d)(2) and (3) of this chapter (relating to Additional Design Requirements for Deep Bed, Intermittently Backwashed, Granular Media Filters).

(d) Traveling Bridge. A traveling bridge mechanism must:

(1) provide support and access to the backwash pumps and equipment;

(2) be constructed of corrosion resistant materials;

(3) have provisions for consistent tracking of the bridge and safe support of the power cords; and

(4) initiate a backwash cycle automatically when a preset head loss through the filter media occurs.

(e) Floating Material Control. A filter system must provide for automatic and regular removal of any floating material from the surface of a filter and return the floating material to the head of the facility for further processing.

§217.193.Alternative Designs for Effluent Polishing.

The executive director shall review processes for tertiary suspended solids removal other than filters as nonconforming technologies subject to the requirements of §217.7(b)(2) of this title (relating to Type of Plans and Specifications Approvals).

This agency hereby certifies that the proposal has been reviewed by legal counsel and found to be within the agency's legal authority to adopt.

Filed with the Office of the Secretary of State on February 29, 2008.

TRD-200801206

Robert Martinez

Director, Environmental Law Division

Texas Commission on Environmental Quality

Earliest possible date of adoption: April 13, 2008

For further information, please call: (512) 239-0177

Subchapter H. NATURAL TREATMENT FACILITIES

30 TAC §§217.201 - 217.213

STATUTORY AUTHORITY

The proposed new rules implement TWC §§5.013, 5.103, 5.105, 5.120, 26.027, 26.034, and 26.121.

§217.201.Applicability.

This subchapter establishes the minimum design requirements for Imhoff tanks, constructed wetlands, facultative lagoons, aerated and partially aerated lagoons, stabilization lagoons, treated effluent storage lagoons, evaporative lagoon systems, and overland flow processes.

§217.202.Primary and Secondary Treatment Units.

(a) A primary treatment unit may be an aerated lagoon, a partially aerated lagoon, a facultative lagoon, an evaporative lagoon, or an Imhoff tank.

(b) A secondary treatment unit may be a stabilization lagoon, a constructed wetland, an evaporative lagoon, or an overland flow process. A secondary treatment unit may be used for polishing and tertiary treatment.

(c) A treated effluent storage lagoon downstream of the permit sampling location is not considered a treatment unit for the purposes of this chapter.

(d) A secondary treatment unit must be preceded by a primary unit.

§217.203.Design Criteria for Natural Treatment Facilities.

(a) Flow Distribution. This section applies to a constructed wetland, a facultative lagoon, an aerated lagoon, a partially aerated lagoon, a stabilization lagoon, and an overland flow process.

(1) The shape and size of a treatment unit must ensure even distribution of the wastewater flow.

(2) The distribution system for an overland flow process must ensure uniform sheet flow of the wastewater onto and across the overland flow terraces.

(b) Windbreaks and Screening.

(1) If spray irrigation is used in a location where drift presents a risk of contact with the public, a windbreak or vegetative screening must be used.

(2) The use, the type, and the extent of windbreaks or vegetative screening must be approved by the executive director.

(1) Except as exempted in paragraphs (4) and (5) of this subsection, a constructed wetland, facultative lagoon, earthen aerated lagoon, partially-aerated lagoon, stabilization lagoon, and treated effluent storage lagoon must be constructed with a liner material with a minimum coefficient of permeability of 1x10^-7 centimeters per second (cm/sec) with a thickness of 2.0 feet for water depths less than or equal to 8.0 feet and a thickness of 3.0 feet at water depths greater than 8.0 feet.

(2) A liner must extend from the lowest lagoon elevation or lowest constructed wetland elevation up to an elevation of 2.0 feet above normal water elevation in a lagoon or constructed wetland.

(3) The executive director may grant a variance to the liner requirements, in accordance with §217.4 of this title (relating to Variances).

(4) If a lagoon is constructed to store treated wastewater authorized as reclaimed water under Chapter 210 of this title (relating to Reclaimed Water), the lagoon liner must comply with §210.23 of this title (relating to Storage Requirements for Reclaimed Water).

(5) This subsection does not apply to an evaporative lagoon system or an overland flow system. Liner and permeability requirements for these systems are established in §217.208 of this title (relating to Evaporative Lagoons) and §217.209 of this title (related to Constructed Wetlands).

(d) Compliance with the Liner Permeability Requirements. Paragraph (1)(A) - (E) of this subsection provides the minimum criteria for ensuring that the liner's permeability will not exceed that allowed in paragraph (3) of this subsection. The report must include the results of any test required in this subsection.

(1) Using Unmodified In-Situ Soils. If the soils that naturally exist at a proposed lagoon or constructed wetland site restrict the movement of wastewater to a degree equivalent to a liner placed as described in subsection (c)(1) of this section. A design must meet the requirements in subparagraphs (A) - (E) of this paragraph to certify the permeability of the in-situ soil layer to ensure that groundwater and surface water quality are protected.

(A) A minimum of one core sample is required for each 0.25 acres of bottom area for each lagoon or constructed wetland.

(B) Each core sample must be sampled to determine the coefficient of permeability, the percent passing a 200-mesh sieve, the liquid limit value, and the plasticity index value for the soil that is to serve as a liner.

(C) Each core sample test result must show a coefficient of permeability of less than or equal to 1x10^-7 cm/sec, in compliance with subparagraph (B) of this paragraph.

(D) A liner must be constructed in accordance with one of paragraphs (2), (3), or (4) of this subsection if test results indicate that in-situ soils do not exhibit a hydraulic conductivity of 1x10^-7 cm/sec or less.

(E) An in-situ soil may be used as a lagoon liner or constructed wetland liner if the in-situ soil meets all the requirements in subsection (c)(1) of this section provided that one layer of excavated in-situ material, with the minimum soil characteristic requirements is placed on scarified subgrade in one 8 inch loose lift compacted to no less than 6 inches at 95% standard proctor density in accordance with American Society For Testing And Materials (ASTM) D 698.

(2) Placed Liners. The soil characteristics of the liner material for a placed liner must comply with subparagraphs (A) - (E) of this paragraph. The tests to determine the soil characteristics must conform to standard methods such as ASTM.

(A) At least 30% of the liner material must pass through a 200 mesh sieve;

(B) The liner material must have a liquid limit greater than 30%;

(D) The liner material must be placed in four loose lifts that are each a maximum of 8.0 inches in depth and that are compacted to 95% standard proctor density in accordance with ASTM D 698. Each lift must be no less than 6.0 inches thick after compaction resulting in a total vertical thickness of at least 24 inches for a liner; and

(E) An in-situ subgrade must be scarified prior to placement of the lowest lift.

(3) Using Amended In-Situ Soils.

(A) A liner may be constructed from amended soils or blended soils made of imported soils and soils excavated from the proposed lagoon site.

(B) Each sample of amended soil must sufficiently decrease the coefficient of permeability to 1x10^-7 cm/sec.

(i) three representative samples from each 6,700 cubic feet of amended soil:

(ii) one field permeability test; and

(iii) one laboratory permeability test.

(D) Each of the permeability tests must verify that the coefficient of permeability is equal to or less than 1x10^-7 cm/sec.

(E) When soil permeability is decreased by amending in-situ soil, the liner thickness throughout the lagoon may be decreased to 6.0 inches, if the liner is placed on scarified subgrade in one 8.0 inch loose lift compacted to no less than 6.0 inches at 95% standard proctor density in accordance with ASTM D 698.

(4) Use of a synthetic membrane liner.

(A) A synthetic membrane liner must have a minimum thickness of 40 mils.

(B) A lagoon with a membrane liner must include an underdrain with a leachate detection and collection system.

(D) The use of a synthetic membrane liner for a constructed wetland is prohibited.

(e) Embankment Design and Construction. This section applies to a constructed wetland, a facultative lagoon, an aerated lagoon, a partially aerated lagoon, a stabilization lagoon, a treated effluent storage lagoon, and an evaporative lagoon.

(1) The top width of an embankment must be a minimum of 10.0 feet.

(2) The report must justify all inner and outer embankment slope steeper than 1.0 foot vertical to 4.0 feet horizontal from the top of an embankment.

(3) Inner and outer embankment slopes steeper than 1.0 foot vertical to 3.0 feet horizontal are prohibited.

(4) All embankments must be protected against erosion by planting grass, paving, riprapping, or other method approved by the executive director.

(5) All embankments must have a minimum cover of 6.0 inches of topsoil if vegetated.

(f) Disinfection. Chemical or ultraviolet disinfection is not required if a detention time of at least 21 days is provided in the entire, free-water surface, natural treatment unit, in accordance with §309.3(g) of this title (relating to Disinfection).

(g) Sampling Point Significance.

(1) Sizing or design of any treatment unit upstream of the permitted sampling point must not be based on any unit downstream of the permitted sampling point.

(2) A wastewater lagoon downstream of the permitted sampling point is a treated effluent storage lagoon and must comply with the requirements of §210.23 of this title (relating to Storage Requirements for Reclaimed Water).

(h) Storm Water Drainage. A natural treatment system must be constructed to prevent storm water from draining into the system.

§217.204.Imhoff Tanks.

(a) Settling Compartment.

(1) The minimum length-to-width ratio of a settling compartment is 2.0 to 1.0.

(2) A tank inlet must provide uniform flow distribution across the width of a settling compartment.

(3) The septum walls must slope to the center of a compartment at an angle of at least 50 degrees but not more than 60 degrees from horizontal. The septum walls must create an overlap with a continuous slot at least 8.0 inches wide provided between the walls to allow solids to be dispersed into a digestion compartment.

(4) The maximum depth between the normal water level and the plane of a slot is 9.0 feet.

(5) The minimum freeboard above the normal water level is 18 inches.

(6) One of the septum walls must continue past the slot to create a minimum slot overhang of 8.0 inches.

(b) Surface Loading.

(1) The settling compartment overflow loading rate must not exceed 800 gallons per day per square foot of settling compartment area under design flow conditions.

(2) The longitudinal velocity of wastewater through a settling compartment must not exceed 1.0 foot per second under peak flow conditions.

(c) Scum Baffles. An inlet and an outlet of a tank must include scum baffles with a height that meet the water levels at all flows from minimum flow to peak flow.

(d) Gas Vents.

(1) An Imhoff tank must include gas vents with a total area not less than 20% of the total tank surface area.

(2) The width of at least one vent opening must allow maintenance access into a digestion compartment.

(e) Digestion Compartment Loading. The digestion compartment minimum volume must be the greater of 3.5 cubic feet per capita or 20.5 cubic feet per pound of influent five-day biochemical oxygen demand (BOD₅) per day.

(f) Imhoff Tank Dimensions. The total depth of an Imhoff tank must not be less than 15 feet from the water surface at design flow to the bottom of a digestion compartment, not including the first 18 inches of tank depth below the plane of a slot for design digestion volume.

(g) Sludge Removal.

(1) An Imhoff tank must have a sludge withdrawal pipe in a digestion compartment.

(2) A sludge withdrawal pipe must have a minimum diameter of 8.0 inches and include a provision for regular cleaning.

(3) A digestion compartment design must allow a portable pump to remove accumulated sludge.

(h) Odor Management.

(1) The design of an Imhoff tank must minimize the effect of odor from the gas vents.

(2) The executive director may require a bio-filter, a carbon filter, or other odor control device to minimize odor.

(i) Treatment Efficiency.

(1) An Imhoff tank must be followed by at least one subsequent treatment unit.

(2) A design may assume that an Imhoff tank removes 35% of the influent BOD₅.

(3) A design may assume that subsequent treatment units remove 60% of influent total suspended solids.

(j) Material and Construction.

(1) An Imhoff tank must be constructed of reinforced and sealed concrete.

(2) Each component of an Imhoff tank must be resistant to the corrosive effects of a wastewater environment.

§217.205.Facultative Lagoons.

(a) Configuration, Inlets, and Outlets.

(1) The length-to-width ratio of a facultative lagoon must be 3.0 to 1.0, unless other dimensions more suitable to a site are justified in the report.

(2) The flow in a facultative lagoon must be from an inlet along one end of the lagoon to an outlet at the opposite end.

(3) The length of a facultative lagoon must be oriented in the direction of the prevailing winds with the inlet side located such that debris will be blown toward the inlet.

(4) A facultative lagoon must have inlet baffles to collect floatable material when no pre-screening is provided.

(5) An outlet must be adjustable to allow the water level of a facultative lagoon to vary under normal operating conditions.

(b) Depth.

(1) The deeper portion of a facultative lagoon near the inlets must have a minimum depth of 12 feet to provide sludge storage and anaerobic treatment.

(2) The deeper portion must cover at least 25% of the area of a lagoon bottom.

(3) The remainder of a facultative lagoon must have a minimum depth of 8 feet.

(c) Organic loading. The organic loading must not exceed 150 pounds of five-day biochemical oxygen demand (BOD₅ ) per acre per day based on the surface area of a facultative lagoon.

(d) Odor Control.

(1) A facultative lagoon inlet must be at least 24 inches below the water surface to minimize odor.

(2) An outlet must be at least 12 inches below water surface and not disturb the anaerobic zone.

(3) A facultative lagoon must allow for recirculation from at least 50% to not more than 100% of the design flow.

(4) A facultative lagoon design must prevent siphoning of lagoon contents through a submerged inlet.

(e) Removal efficiency. The design of a facultative lagoon may be based on no more than 50% efficient removal of the influent BOD₅.

§217.206.Aerated Lagoons.

(a) The requirements of this section apply to both completely mixed lagoons and partially mixed lagoons, unless otherwise specified.

(b) An aerated lagoon system must maintain a minimum of 1.6 pounds of oxygen per pound of influent five-day biochemical oxygen demand (BOD₅) with the largest single aeration unit in a lagoon system out of service.

(d) The aeration equipment must have an alarm that will provide sufficient notification to ensure timely repair to prevent a permit violation. If a facility is not staffed 24 hours per day, the alarm system must be connected to a telemetry system with battery backup.

(e) The BOD₅ removal in each lagoon must be calculated using the following equation:

Figure: 30 TAC §217.206(e)

(1) The value of K for a domestic wastewater in a completely mixed lagoon is 0.50 day^-1 at 20 degrees Celsius. The value of K for a partially mixed lagoon is 0.28 day^-1 at 20 degrees Celcius.

(2) The value of K may be adjusted for the minimum monthly water temperature using the following equation:

Figure: 30 TAC §217.206(e)(2)

(3) The value of K may be determined for high-strength or industrial wastewater by either a laboratory study or evaluation of an existing facility treating similar wastewater.

(f) Aeration Equipment.

(1) The size of the aeration equipment in an aerated lagoon must be able to supply the oxygen demand determined in subsection (b) of this section.

(2) For the purpose of sizing aeration equipment, an aerated lagoon must comply with the mechanical and diffused air requirements in §217.155(c) of this title (relating to Aeration Equipment Sizing).

(3) If multiple partially mixed aerated lagoons are used in series, the power input may be reduced as the influent BOD₅ to each lagoon decreases.

(g) Aerated Lagoon Design Requirements. An aerated lagoon system must be designed in accordance with requirements for a wastewater treatment lagoon in §217.203(e) of this title (relating to Design Criteria for Natural Treatment Facilities) and §217.207(d) of this title (relating to Stabilization Lagoons).

(h) Scour Prevention. An earthen-lined aerated lagoon system must include a concrete scour pad in each area of the earthen liner that is subject to a velocity equal to or greater than 1.0 foot per second.

§217.207.Stabilization Lagoons.

(a) Primary treatment must remove the settleable and floatable solids in the influent prior to the wastewater entering a stabilization lagoon.

(b) Odor Management.

(1) A stabilization lagoon must be located so that the local prevailing winds will be toward a less populated area.

(2) If uncontaminated water is available, a stabilization lagoon must be pre-filled to the 2.0 foot level at start-up.

(3) A stabilization lagoon system must include a piping arrangement that allows the recirculation of effluent from a final lagoon to the influent side of an initial stabilization lagoon.

(4) A stabilization lagoon may return recirculation water by surface spray to assist in maintaining aerobic conditions at the lagoon surface and reduce potential odor.

(c) Minimum Number of Wastewater Stabilization Lagoons. A minimum of two stabilization lagoons is required to comply with secondary treatment limits. The stabilization lagoons must be operated in series with each other following the primary treatment unit.

(d) Lagoon Design.

(1) The minimum length-to-width ratio of a stabilization lagoon is 3.0 to 1.0.

(2) Islands, peninsulas, and coves within a stabilization lagoon are prohibited.

(3) A stabilization lagoon must have a depth of at least 3.0 feet but not more than 5.0 feet under design operating conditions.

(4) Inlet and outlet structures must be adjustable to allow for raising and lowering water level a minimum of 6.0 inches to assist in controlling vegetative growth.

(5) A stabilization lagoon must have a minimum of 2.0 feet of freeboard above the normal operating level if the lagoon's normal water surface area is less than 20 acres.

(6) A stabilization lagoon must have a minimum of 3.0 feet of freeboard above the normal operating level if the lagoon's normal water surface area is 20 acres or more.

(e) Pipe and Hydraulic Equipment.

(1) All structures and pipes in a stabilization lagoon must be sized to transport at least 250% of the facility's design flow.

(2) The inlet and outlet structures must be sized to transport the volume of water found in the top 6.0 inches of a lagoon during normal operating depths per day at the available head.

(3) A pipe and recirculation system must allow a stabilization lagoon system to comply with the facility's permitted effluent limitation with any one lagoon of service.

(f) Maximum Surface Organic Loading Rate for Stabilization Lagoons.

(1) The maximum surface organic loading rate on the stabilization lagoon series is 35 pounds (lbs) of five-day biochemical oxygen demand (BOD₅) per acre per day.

(2) The maximum surface organic loading rate on the first lagoon in a stabilization lagoon series is 75 lbs of BOD₅ per acre per day.

(3) The surface organic loading rate applied to the stabilization lagoon series is equal to the total influent organic loading minus any reduction in organic load provided by the primary treatment units.

(g) Inlet and Outlet Structures.

(1) A stabilization lagoon outlet must include removable baffles to prevent floating material from being discharged, and must be constructed to operate correctly as the level of the lagoon surface varies under normal operating conditions.

(2) An outlet must be at least 18 inches but not more than 24 inches below the lagoon surface to control the discharge of algae.

(3) A multipurpose control structure may be used to facilitate a normal operational function such as drawdown, flow distribution, flow depth, measurement, sampling, pump for recirculation and chemical addition; and to minimize the number of construction sites in a lagoon.

(4) A pipe embankment penetration must have a seep water-stop collar.

(5) A stabilization lagoon must have a drainpipe to allow emptying for maintenance and may use a pump as part of a drainage system. If not permanently installed, a temporary pipe suction station must be provided.

§217.208.Evaporative Lagoons.

(a) Design.

(1) If evaporative lagoons are used, a facility must have a minimum of two lagoons.

(2) The primary evaporative lagoon must provide at least 60% of the total surface area of an evaporative lagoon system.

(3) The number and size of evaporative lagoons must provide adequate evaporation for design flow during periods of low evaporation.

(b) Odor Management. An evaporative lagoon must be located so that the local prevailing winds will be toward a less populated area.

(1) A synthetic membrane for an evaporative lagoon must be at least 40 mils thick.

(2) A lagoon with a synthetic membrane liner must have an underdrain leak system consisting of at least a leachate collection system and a detection system.

(3) The liner manufacturer's specifications may require proper compaction of soil beneath the liner.

(4) A liner material must withstand constant sunlight without degrading.

(d) Configuration, Depth, and Loading.

(1) An evaporative lagoon may be constructed in a round, square, or rectangular shape. The corners of a square or rectangular shaped evaporative lagoon must be rounded in order to minimize accumulation of floating materials.

(2) The depth of an evaporative lagoon is dependant on its location within the lagoon system.

(A) The maximum operating depth for a primary lagoon is 5.0 feet, but the area around an inlet must be designed for solids deposition according to the criteria in §217.205 of this title (relating to Facultative Lagoons).

(B) The maximum operating depth for a secondary lagoon is 8.0 feet.

(3) Evaporation and Organic Loading.

(A) An evaporation lagoon system must be sized based on the evaporation rate for the site and a maximum allowable organic loading rate.

(B) The evaporation loss must be calculated by using the Penman-Monteith method or a comparable, established method.

(C) An evaporative lagoon system must be sized to account for the influent flows and precipitation from a 25-year frequency, one-year rainfall event in accordance with §309.20(b)(3)(B) of this title (relating to Land Disposal of Sewage Effluent), unless the report includes an alternate method of disposing of the wastewater and the supporting documentation.

(D) The maximum organic loading rate must be calculated based on an evaporative lagoon system that is sized using the evaporation rate as required by subparagraph (C) of this paragraph.

(E) The five-day biochemical oxygen demand (BOD₅ ) loading on a primary evaporative lagoon must not exceed 150 pounds of BOD₅ per acre of surface area per day.

(e) Embankment. The embankments for an evaporative lagoon must be constructed in accordance with §217.203(e) of this title (relating to Design Criteria for Natural Treatment Facilities).

(f) Inlet and Outlet Structures.

(1) An influent line for an evaporative lagoon must terminate into a manhole located along the embankment edge.

(2) An inlet manhole invert must be a minimum of 6.0 inches above the maximum high water level of a primary evaporative lagoon.

(3) A submerged discharge pipe must extend from a manhole along and anchored to the bottom of an evaporative lagoon.

(4) An inlet discharge pipe must discharge on to concrete apron in a depression near the center of the primary evaporative lagoon to prevent scour.

(A) A concrete apron must be at least 2.0 square feet in surface area, at least 8.0 inches thick, and resistant to the corrosive effects of a wastewater environment.

(B) The report must justify the use of any material other than concrete for a discharge apron.

(5) Inlet and outlet structures for an evaporative lagoon must be constructed in a manner that allows the water surface elevation to be varied during normal operating conditions.

§217.209.Constructed Wetlands.

(a) Types of Constructed Wetlands. A constructed wetland may be a free water surface system or subsurface flow system.

(b) Natural Wetlands. The use of natural wetlands for wastewater treatment is prohibited.

(1) A constructed wetland must be preceded by primary treatment and may be preceded by secondary treatment.

(2) A primary treatment system must be designed to control odor and algae.

(3) A primary treatment system must produce an effluent quality with no more than 150 milligrams per liter of five-day biochemical oxygen demand to minimize anaerobic conditions and stress on vegetative communities in any subsequent wetland treatment unit.

(4) A treatment facility that use a constructed wetland as the means of complying with a permit effluent limit must be sized and designed to ensure that the permit limitations may be met with any one wetland cell out of service. The report must include water balance calculations and the potential effect of evaporation on the predicted effluent concentrations.

(d) Vegetation. A constructed wetland must have a diverse vegetative community of emergent and floating plants to minimize any adverse impact from potential disease, insect pests, or species-specific toxicity. A constructed wetland may have the following flora:

(1) Emergent plants including:

(A) Scirpus spp. (bulrush);

(B) Sagittaria spp. (arrowhead);

(D) Juncus spp. (rushes);

(E) Elecharis spp. (spikerush);

(F) Cyperus spp. (sedges);

(G) Typha spp. (cattails);

(H) Caladium spp. (elephant ear); or

(I) various aquatic grass species (e.g., wild rice).

(2) Floating plants including:

(A) Lemna spp. (duckweed);

(B) Hydrocotyle umbellata spp. (water pennywort);

(D) Nymphaea spp. (water lily);

(E) Wolffia spp. (water meal); or

(F) other appropriate emergent plant species.

(3) The vegetation used in a constructed wetland must be suitable for the local growing conditions. The use of indigenous plants is recommended, if the species have been demonstrated effective in a constructed wetland wastewater environment. The report must identify the plants in the design.

(4) Plans for harvesting aquatic plants from waters in the state must be reviewed with the United States Army Corps of Engineers to determine if regulatory coordination is required.

(5) Gathering seed plants from natural wetlands must minimize any impact on the harvested plant community and the natural wetlands.

(6) The use of any harmful or potentially harmful wetland plant or organism is subject to review by the Texas Parks and Wildlife Department, as required by 31 TAC §§57.111 - 57.118 and §§57.251 - 57.258 (relating to Definitions; General Rules; Exceptions; Health Certification of Harmful or Potentially Harmful Exotic Shellfish; Transportation of Harmful or Potentially Harmful Exotic Species; Exotic Species Transport Invoice; Exotic Species Permit: Application Requirements; Exotic Species Permit Issuance; Definitions; General Provisions; Permit Application; Denial; Renewal; Amendment; Reporting and Recordkeeping; and Prohibited Acts, respectively).

(e) Maintenance activity must not result in a deterioration of water quality.

(1) All herbicides, insecticides, and fertilizers are prohibited in a constructed wetland.

(2) Floating Material Removal.

(A) A constructed wetland must allow the removal of an algal mat or other floating material prior to the effluent entering the wetlands.

(B) A removal mechanism may be a screen, a submerged adjustable inlet, a baffle, or another suitable method. The removal mechanism must be justified in the report.

(C) The removed floating material must be stored and disposed of in a manner that minimizes odor and complies with the requirements of Chapter 330 of this title (relating to Municipal Solid Waste).

(3) A facility operation and maintenance manual for a facility that has a constructed wetland must include detailed description and schedule for maintaining the constructed wetlands.

(f) A wetlands system must be matured and functioning properly before wastewater effluent is processed. The report must include a management and oversight program that specifies construction scheduling, plant species selection, planting practices, and start-up procedures.

(g) Liners.

(1) The liner for a wetland system must comply with the requirements of §217.203(c) of this title (relating to Design Criteria for Natural Treatment Facilities).

(2) A minimum 6.0 inch layer of productive topsoil must be placed above a liner to encourage root penetration.

(h) Berms.

(1) A berm of a constructed wetland must have side slopes no steeper than 3:1.

(2) The interior side slopes must be lined up to 2.0 feet above the normal water level.

(3) The interior side slopes above the normal operational water level and the exterior side slopes must be finished with:

(A) a minimum 6.0 inch productive topsoil layer and vegetated with grass;

(B) a comparable natural erosion control system; or

(i) Flood Hazard Analysis. A constructed wetland must be protected from flooding in accordance with the requirements of §217.35 of this title (relating to One Hundred-Year Flood Plain Requirements).

(j) Nitrification. A constructed wetland that provides nitrification is an innovative and nonconforming technology and subject to §217.7(b)(2) of this title (relating to Types of Plans and Specification Approvals).

(k) Allowed Uses. A constructed wetland may be used as a secondary treatment unit, an advanced secondary treatment unit, or for polishing wastewater effluent, but not for primary treatment.

§217.210.Constructed Wetlands--Free Water System (FWS) Design.

(a) A Free Water System (FWS) wetland must be based on a maximum water depth of not greater than 24 inches in emergent vegetation areas at design flow.

(b) Plants.

(1) Emergent plant spacing must be no more than 66 inches on center.

(2) Floating plants are prohibited in an FWS.

(c) Multiple Cells. An FWS wetland must include multiple cells that may be operated independently, allowing an individual cell to be removed from service while maintaining system operations.

(d) System Size. An FWS wetland must be sized to meet permit effluent limits with any single cell removed from service.

(e) Bottom slope.

(1) A FWS wetland cell must have adequate bottom slope or other means such as strategically placed deep-water zones to facilitate drainage for maintenance.

(2) A design must require that a bottom slope maintain an appropriate range of wetland water depths along the entire cell length under all anticipated operational flow conditions.

(f) Parallel trains. An FWS wetland must have parallel treatment trains to increase operational flexibility.

(g) Wind protection. An FWS wetland cell must be oriented to avoid prevailing winds perpendicular to the process flow direction or use elevated berms or vegetative windbreaks.

(h) Inlets and Outlets.

(1) The inlets and outlets of an FWS wetland cell must assure uniform distribution of influent flow and uniform collection of effluent flow across the entire cell cross section.

(2) Inlet and outlet devices must minimize erosion of wetland substrate from locally high velocity effluent flow.

(3) Each inlet and outlet device must be adjustable to allow variations in operational water level.

(4) Submergence. An inlet must be submerged under normal operational conditions.

(5) Inspection and Cleaning. A design must allow inspection and cleaning of inlet and outlet devices.

(i) Organic Loading and Treatment Efficiency.

(1) Constructed wetland process design may be based on organic loading design for typical municipal wastewater primary or secondary effluent, whichever is the influent for the constructed wetland.

(2) A design must be based on the organic removal treatment efficiency for FWS wetlands on the areal loading rate equation found in the following figure unless the report justifies an alternate method to determine the organic removal treatment efficiency by identifying a method, the sources of the method, and all supporting calculations.

Figure: 30 TAC §217.210(i)(2)

(j) Vector Control.

(1) The design of an FWS wetland must include mosquito control:

(A) using mosquito fish (Gambusia) and other natural predators,

(B) maintaining aerobic conditions, or

(2) A design must minimize the potential damage to wetlands caused by mammals such as nutria and muskrats.

§217.211.Constructed Wetlands--Subsurface Flow System (SFS) General Design.

(a) A wetted subsurface media must allow adequate root penetration and be identified in the report.

(b) The operational water depth of a Subsurface Flow System (SFS) wetland must not exceed the lesser of:

(1) 18 inches at design flow; or

(2) the maximum normal root depth of the emergent plant species used in an SFS wetland.

(d) Plant spacing must be sufficient to allow maturity of a wetlands flora ecosystem, but must not exceed 36 inches on center.

(e) Configuration. An SFS wetland must include the following minimum configuration standards:

(1) Multiple cells. An SFS wetland must include multiple cells that can be operated independently, allowing individual cells to be removed from service while maintaining system operations.

(2) Cell Size. The size of a cell must meet permit effluent limitations with any single cell removed from service.

(3) Hydraulic profile.

(A) An SFS wetland must maintain minimum 6.0 inches of dry media cover at design flow, at least 2.0 inches of upstream media cover during peak flow conditions, and not more than 12.0 inches of upstream media cover during diurnal low flow conditions.

(B) An SFS wetland hydraulic profile must be based on the following figure, unless the report justifies an alternate design method, includes the source of the method, and all supporting calculations and documentation.

Figure 1: 30 TAC §217.211(e)(3)(B)

Figure 2: 30 TAC §217.211(e)(3)(B)

(4) Maximum depth.

(A) The maximum wetted media depth of an SFS wetland is the lesser of:

(i) 24 inches at design flow; or

(ii) the maximum normal root depth for a planned primary population emergent plant species.

(B) An SFS wetland must have a dry media cover depth of at least 6.0 inches and not more than 9.0 inches above the design flow hydraulic gradient.

(5) Minimum slope. An SFS wetland cell must have an adequate bottom slope to facilitate drainage for maintenance and to maintain media water depth over the entire cell length under all anticipated operational flow conditions.

(6) Parallel trains. An SFS wetland must have parallel treatment trains to increase operational flexibility.

(f) Flow Distribution. A constructed wetland must have effective flow distribution and collection to efficiently treat wastewater. An SFS wetland must include the following minimum flow distribution standards:

(1) Flow distribution.

(A) The inlet and outlet system of an SFS wetland cell must assure uniform distribution of influent flow and uniform collection of effluent flow across an entire cell.

(B) The inlet and outlet devices must not cause locally high velocities to avoid the movement of wetland media.

(C) Each inlet and outlet system must be adjustable to allow variation in operational water level and flooding of a cell for weed control.

(2) Submergence. Each inlet and outlet of an SFS wetland must be below the media surface.

(3) Maintenance. The design of an inlet and outlet device must allow inspection and cleaning.

(4) Staged influent feed. If a high influent BOD₅ load is anticipated, the design must allow for staged influent fee to improve process control.

(g) SFS Organic Loading and Treatment Efficiency.

(1) A constructed wetland process may be based on organic loading design for typical municipal wastewater primary or secondary effluent.

(2) A design must be based on the organic removal treatment efficiency for an SFS wetland on the areal loading equation found in the following figure unless the report justifies an alternate method to determine the organic removal treatment efficiency and all supporting calculations.

Figure: 30 TAC §217.211(g)(2)

(h) Temperature. A design must be adequate to treat wastewater in the range of temperatures of the wastewater in the facility.

(i) Vector Control. Vegetation maintenance, including removal of excessive plant litter and detritus, is required to prevent mosquito breeding opportunities.

(j) Media Design. SFS wetland media must meet the following minimum requirements:

(1) The media must be hard rock, slag, or other clean, comparable media material.

(2) The media must contain less than 0.1% by weight of clay, sand, and other fine materials.

(3) The media materials must have a Mohs hardness of at least 5.0.

(4) Media must be resistant to acidic conditions.

(5) Synthetic media is nonconforming or innovative technology and is subject to §217.7(b)(2) of this title (relating to Type of Plans and Specifications Approvals).

(6) Media gradation and uniformity must be used to determine the wetland's hydraulic conductivity.

(7) The media must be placed in an SFS wetland by light equipment to avoid introduction of clay or other undesirable materials, to avoid compaction, and to avoid creating ruts in the subgrade.

(8) If an SFS wetland has gravel media larger than 1.5 inch diameter, the design must specify a top layer of small gravel to encourage healthy plant rooting. The gravel layer must be above the normally saturated media zone. The design must specify a transitional (medium grade) layer between small gravel and coarse gravel to minimize small gravel migration into lower void spaces.

§217.212.Overland Flow Process.

An overland flow process is a nonconforming technology and subject to the requirements of §217.7(b)(2) of this title (relating to Types of Plans and Specifications Approvals).

§217.213.Integrated Facultative Lagoons.

(a) Nonconforming technology. An integrated facultative lagoon is nonconforming technology and is subject to review in accordance with §217.7(b)(2) of this title (relating to Types of Plans and Specifications Approvals).

(b) Integrated Facultative Lagoon Design.

(1) The length-to-width ratio of an integrated facultative lagoon must be 3.0 to 1.0, unless the report justifies other dimensions more suitable to the site.

(2) A pit must not be less than 0.40 acre in total surface area.

(3) The outer lagoon area must not be less than 10 times the surface area of the pit.

(4) A pit must have adequate volume to contain:

(A) 0.1 cubic foot per capita per year sludge storage for a minimum of 20-years; and

(B) a two-day hydraulic retention time above the sludge storage area.

(5) The maximum up-flow velocity in the pit is 2.0 feet per day at design flow.

(6) If an integrated facultative lagoon has more than one pit, each pit must receive an amount of wastewater influent equivalent to the size of a pit.

(7) An inlet must be located in the pit portion of a lagoon.

(8) An outlet must be able to maintain the water level within 1.0 foot of a constant level.

(9) A design must locate an integrated facultative lagoon in a central location with regard to the surrounding secondary lagoons and meet the buffer zone requirements specified in §309.13 of this title (relating to Unsuitable Site Characteristics).

(10) Depth.

(A) The depth of an inlet pit must not be less than 15 feet deep from the water surface elevation during normal operating conditions to the influent inlet point within the pit.

(B) An integrated facultative lagoon must have berms or other deflection devices around the pit.

(D) The minimum distance from the water surface elevation during normal operating conditions to the top of the berm around a pit is 5.0 feet.

(11) Organic Loading. The maximum organic loading into a pit is 300 pounds of ultimate five-day biochemical oxygen demand (BOD₅) per acre of total lagoon area per day.

(12) Odor Control.

(A) An inlet to a pit must be 3.0 feet above the bottom of a lagoon and the flow must be directed downward.

(B) A design must allow water from a lagoon following an integrated facultative lagoon must be recirculated to the surface of the integrated facultative lagoon.

(C) An integrated facultative lagoon must be capable of recirculating at least 50% of the design flow from an outlet of the downstream lagoon.

(D) An integrated facultative lagoon must not siphon lagoon contents through a submerged inlet.

(13) Removal Efficiency.

(A) A design may be based on the removal efficiency of the pit of an integrated facultative lagoon no more than 60% of the influent BOD₅.

(B) A design may be based on subsequent removal efficiency of BOD₅ in the outer portion of the integrated facultative lagoon no more than 50% of the remaining BOD₅ , which is 20% of the original BOD₅.

(14) Detention Time. An integrated facultative lagoon must provide a minimum of 21 days hydraulic retention time.

This agency hereby certifies that the proposal has been reviewed by legal counsel and found to be within the agency's legal authority to adopt.

Filed with the Office of the Secretary of State on February 29, 2008.

TRD-200801207

Robert Martinez

Director, Environmental Law Division

Texas Commission on Environmental Quality

Earliest possible date of adoption: April 13, 2008

For further information, please call: (512) 239-0177

Subchapter J. SLUDGE TREATMENT UNITS

30 TAC §§217.241 - 217.252

STATUTORY AUTHORITY

The new rules are proposed under the authority of Texas Water Code (TWC), §5.013, which provides the commission's general jurisdiction; §5.103, which provides the commission's authority to adopt any rules necessary to carry out its powers and duties under the laws of Texas; §5.105, which provides the commission's authority to, by rule, establish and approve general policy of the commission; §5.120, which provides the commission's authority to administer the law to promote conservation and protection of the quality of the environment; §26.027, which authorizes the commission to issue permits; §26.034, which provides the commission's authority to adopt rules for the approval of disposal system plans; §26.121, which provides the commission's authority to prohibit unauthorized discharges; and Texas Health and Safety Code (THSC), §361.022, which provides the state's public policy concerning municipal solid waste and sludge.

The proposed new rules implement TWC §§5.013, 5.103, 5.105, 5.120, 26.027, 26.034, 26.121 and THSC, §361.022.

§217.241.General Requirements.

(a) For purposes of this section, the sludge process includes thickening, stabilization, and dewatering.

(b) A design must base the selection and operation of the sludge processing units on the desired final sludge product.

(c) A facility that disposes of sludge under Chapter 312 of this title (relating to Sludge Use, Disposal, and Transportation) must stabilize the sludge.

(d) A facility that disposes of sludge under Chapter 330 of this title (relating to Municipal Solid Waste) must comply with the requirements of that chapter.

§217.242.Control of Sludge and Supernatant Volumes.

(a) Supernatant, filtrate, or centrate resulting from sludge processing must be returned to the headworks or at a point preceding an aeration system or secondary treatment unit.

(b) A sludge processing unit must limit digester supernatant liquor volume to the greatest extent practical.

§217.243.Sludge Pipes.

(a) Each pipe associated with a sludge processing unit must have sufficient gradient to ensure the flow of sludge.

(b) A pipe under a stationary structure must allow a blockage to be easily eliminated by rodding or a sewer-cleaning device.

(d) The slope of a gravity discharge pipe must not be less than 3.0%.

(e) The minimum diameter for pipe associated with sludge processing is shown in the following figure:

Figure: 30 TAC §217.243(e)

(f) The available head on a discharge using gravity withdrawal pipe must be at least 4.0 feet.

(g) A gravity pipe used for withdrawal from the primary sludge clarifier pump must allow for removal of digested sludge.

(h) Each sludge pipe must include a means to observe the quality of the supernatant from each of the withdrawal outlets.

(i) Each individual sludge processing and treatment unit must have a dedicated means of dewatering.

(j) Pipe located inside a digestion tank must be designed for use in corrosive environments and must be sufficiently supported to prevent damage to the pipe or adjacent equipment.

§217.244.Sludge Pumps.

(a) A sludge transfer pump size must be based on the quantity and character of the anticipated solids load.

(b) A mechanical pumping system must provide the minimum required firm pumping capacity with the largest sludge pumping unit out of service.

(c) An air lift pump is acceptable for use as a sludge pump. Airlift pumps are not subject to redundancy requirement outlined in subsection (b) of this section.

(d) A centrifugal sludge pump must have a positive suction head, unless the pump includes a priming device.

(e) A positive displacement pump or other type of pump with demonstrated solids handling capability must be used for handling raw sludge.

(f) Centrifugal pumps must be designed with sufficient net positive suction head to operate at the minimum anticipated water level occurring on the suction side.

(g) A positive suction head of 24 inches or more is required for all sludge pumps.

§217.245.Exclusion of Grit and Grease from Sludge Treatment Units.

(a) A facility design must minimize the amount grit, debris, oil, and grease entering a sludge treatment unit.

(b) A sludge treatment unit must be designed for the final use or final disposal of the various solids generated during the treatment of domestic sewage.

(c) If sludge is to be land applied, a sludge treatment unit must remove screenings, grit, and grease, which must be disposed of separately from the sludge.

§217.246.Ventilation and Odor Control.

(a) A design must include sufficient ventilation to eliminate an accumulation of fumes or gases at a level that might be a health hazard or a threaten air quality.

(b) An enclosed area that may be accessed by staff must have automatic mechanical ventilation.

(1) A continuous ventilation system must provide at least six complete air exchanges per hour.

(2) An intermittent ventilation system must provide at least 30 complete air exchanges per hour.

§217.247.Chemical Pretreatment of Sludge.

(a) A chemical used to treat sludge must be compatible with the operation of the treatment unit and must have no detrimental effect upon receiving waters.

(b) The report must justify appropriate chemicals and feed ranges by including a pilot plant study or data from a treatment unit with characteristics such as organic levels, metal concentrations, and hydraulics that are within 25% of the proposed design.

(d) A liquid chemical storage tank must include:

(1) a liquid level indicator; and

(2) an overflow receiving basin or drain capable retaining any spill.

(e) Powdered activated carbon must be stored in an isolated fireproof area.

(f) A storage or handling area where potentially volatile chemicals or conditions may occur must have electrical outlets, lights, and motors that meet National Electric Code, including explosion prevention requirements.

(g) Transport, transfer, storage, and use of any volatile chemical must prevent discharge to the atmosphere.

(h) A facility must have at least a 30-day supply of each chemical in dry storage conditions, unless the report justifies a reduced amount.

(i) A solution storage tank or direct-feed day tank must have sufficient capacity for operation at the design flow of the facility.

(j) The procedures for measuring the quantity of each chemical used to prepare each feed solution must be included in the facility's operation and maintenance manual.

(k) The design of a storage tank, pipe, or other equipment must be compatible with the chemical it is designed to handle.

(l) Intermixing of chemicals prior to preparing a feed solution is prohibited.

(m) Concentrated liquid acid must not be stored in an open vessel, but must be pumped in undiluted form from the original container to a point of treatment, a covered day tank, or a storage tank.

(n) Concentrated liquid acid must be kept in a closed, acid-resistant shipping container or storage unit.

(o) The transfer of a toxic material must be controlled by a positive actuating device.

(p) A facility must be designed with one or more of the following control methods to ensure that a transfer of a dry chemical will minimize dust:

(1) Vacuum pneumatic equipment of a closed conveyor system;

(2) A facility for emptying shipping containers in a special enclosure; or

(3) An exhaust fan and dust filter that put a hopper or bin under negative pressure sufficient to eliminate chemical particles in the air.

(q) Disposing of a chemical or an empty chemical container must be done in a manner that minimizes the potential for harmful exposure and in compliance with Chapter 335 of this title (relating to Industrial Solid Waste and Municipal Hazardous Waste).

(r) Chemical feed equipment must meet the following requirements:

(1) Structures housing equipment.

(A) A floor surface must be smooth, slip resistant, impervious, and must have a minimum slope of 1/8 inch per foot.

(B) An open basin, tank, or conduit must be protected from a chemical spill or accidental drainage.

(C) An area that houses chemical feed equipment must provide access for servicing, repair, and observation of operations.

(2) Redundancy. A feed system must have at least two feeders and must be able to supply the amount of chemicals needed for process reliability throughout the range of feed. Feed equipment must be able to maintain operation at design flow with the largest operational unit out of service.

(3) Design and Capacity.

(A) A feed system must be able to deliver a proportional amount of chemical feed based on the rate of flow.

(B) A feed system must not use positive displacement type solution feed pumps to feed chemical slurries, unless the report justifies such use.

(C) If using potable water, the water must be protected by at least the equivalent of two backflow preventers, including at least one air gap between a supply pipe and a solution tank.

(D) A feed system component must be resistant to the chemical it is designed to apply.

(E) A dry chemical feed system must:

(i) measure the chemical volumetrically or gravimetrically;

(ii) provide effective mixing and solution of the chemical in a solution pot;

(iii) provide gravity feed from a solution pot;

(iv) completely enclose chemicals; and

(v) prevent emission of dust to the operation room.

(4) Spill Containment. The feed equipment must have protective curbing to contain a chemical spill.

(5) Control Systems.

(A) All feed systems must have an automatic control system that is capable of manual control.

(B) A feed system must have manual starting equipment.

(D) If an automatic chemical dosing or residual analyzer is used, the design must require both recording charts and an alarm for any critical value.

(6) Weighing Scales. A volumetric dry chemical feeder or a non-volumetrically calibrated carboy must have weighing scales that measure in increments of no greater than 0.5% of the load.

(7) Feed System Protection. A feed system must have freeze protection and must be accessible for cleaning.

(8) Water Supply.

(A) A water supply for chemical mixing may be potable water or reclaimed water.

(B) A feed system must protect its water supply from contamination.

(D) A water supply must include a means for measuring solution concentrations.

(E) A water supply design must include sufficient duplicate equipment to ensure process reliability.

(F) A design may include a booster pump to maintain water pressure.

(9) Solution Tanks.

(A) A solution tank must be able to maintain uniform strength of solution consistent with the nature of the chemical solution and must provide continuous agitation.

(B) A feed system must have at least two solution tanks.

(D) A solution tank must have a drain and a solution level indicator.

(E) An intake point for potable water must have an air gap.

(F) A chemical solution tank must be covered and have an access opening that is curbed and fitted with a tight cover.

(G) Each subsurface solution tank must:

(i) be impermeable;

(ii) be protected against buoyancy;

(iii) include a means to drain groundwater or other accumulated water away from the tank;

(iv) include leak detection; and

(v) allow for containment and remediation of any chemical spill.

(H) An overflow pipe must:

(i) be turned downward;

(ii) have an unobstructed discharge;

(iii) clearly visible;

(iv) drain to a containment area; and

(v) must not contaminate the wastewater or receiving stream.

(10) Chemical Application.

(A) A chemical application system be efficient and operate safely.

(B) The chemicals application system must prevent backflow or back-siphoning between multiple points of feed through common manifolds.

§217.248.Sludge Thickening.

(a) If a sludge thickener(s) is used, following criteria are required:

(1) Capacity. A sludge thickener must be capable of operating at the peak flow rate.

(2) Flexibility.

(A) A sludge thickening system must have a bypass.

(B) A facility with a design flow greater than 1.0 million gallons per day (mgd) must have:

(i) at least dual sludge thickening units;

(ii) an alternate means of thickening; or

(iii) an alternate disposal method.

(b) Specific Requirements for a Mechanical Gravity Thickener.

(1) Equipment Features.

(A) A mechanical gravity thickener must have:

(i) a low-speed stirring mechanism for continuous mixing and flocculation within the zone of sludge concentration;

(ii) sludge storage, if sufficient storage is unavailable in other external tankage; and

(iii) a means of controlling the rate of sludge withdrawal.

(B) A mechanical thickener may use a chemical addition or dilution water feed system.

(C) A scraper mechanical train must be capable of withstanding any expected torque load. The normal working torque load must not exceed 10% of the manufacturer's recommended torque load.

(2) Design Basis.

(A) A mechanical thickener design must be justified in the report.

(B) The executive director may require data from a pilot study or similar sludge thickening unit operating under similar conditions.

(C) The thickener overflow rate must be at least 400 gallons per day per square foot (gpd/sf) but no more than 800 gpd/sf.

(D) The minimum side water depth for a mechanical thickener is 10 feet.

(E) A circular thickener must have a minimum bottom slope of 1.5 inches per foot.

(F) The peripheral velocity of a scraper must be at least 15 feet per minute but no more than 20 feet per minute.

(G) A mechanical thickener design must minimize the potential for short-circuiting.

(1) Equipment Features.

(A) A DAF basin must have a bottom scraper that function independently of the surface skimmer.

(B) A recycle pressurization system for a DAF basin must use effluent or secondary effluent instead of potable water.

(C) A DAF basin must have a polymer feed system. A feed system must meet the requirements of §217.247(r) of this title (relating to Chemical Pretreatment of Sludge).

(D) A DAF basin must be located in a covered building with positive air ventilation.

(2) Design Basis.

(A) A DAF basin design must be justified in the report.

(B) The executive director may require data from a pilot study or similar DAF operating under similar conditions.

(D) The solids loading rate must be at least 1.0 pound but not more than 4.0 pounds per hour per sf.

(E) The air to solids weight ratio must be at least 0.02 but not more than 0.04.

(F) A retention tank system must have a minimum pressure of 40 pounds per square inch gauge.

(G) A skimmer must have multiple or variable speeds that allow an operational range of at least 1.0 foot per minute (fpm) but not more than 25.0 fpm.

(d) Centrifugal Thickener.

(1) A centrifugal thickener design must be justified in the report.

(2) The executive director may require data from a pilot study or similar centrifugal thickener operating under similar conditions.

(3) A centrifugal thickener must be preceded by pretreatment to prevent plugging of a nozzle or excessive wear in the bowl.

(4) The centrate is subject to §217.242 of this title (relating to Control of Sludge and Supernatant Volumes).

(e) Specific Requirements for Gravity Belt Thickeners.

(1) Equipment Features.

(A) Gravity belt thickeners must include a wash water system (60 pounds per square inch minimum) capable of providing 60 gpm per meter of belt width belt. Booster pumps may be employed to achieve design conditions.

(B) Gravity belt thickeners must include a polymer feed system that meets the requirements of §217.247 of this title.

(C) A filtrate drainage system must be sized to remove the full hydraulic capacity of a gravity belt thickener without accumulation or ponding.

(2) Design Basis. Gravity belt thickener sizing must be based upon the following criteria, unless otherwise justified in the report:

(A) maximum solids loading of 1,250 pounds per meter of belt width; or

(B) maximum hydraulic loading 250 gpm per meter of belt width.

(3) Gravity belt thickener filtrate is subject to the requirement in §217.242 of this title.

§217.249.Sludge Stabilization.

(a) Design Requirements. The design requirements for the stabilization processes in this section are based on the assumption that the process is the sole stabilization process employed at the facility.

(b) Variance. An owner must request a variance in accordance with §217.4 of this title (relating to Variances), if a design employs a series of two or more stabilization processes or methods.

(1) A facility with a design flow exceeding 0.4 million gallons per day must have a at least two anaerobic digesters.

(2) Each digester may be used as a first stage or primary reactor for treating primary and secondary sludge flows.

(3) Each digester must have a means for transferring a portion of its contents to another digester.

(4) A facility that has been granted a variance to operate without multiple digesters must have an emergency storage basin so the digester may be taken out of service.

(d) Depth. An anaerobic digester must provide a minimum of 6.0 feet of storage depth for supernatant liquor.

(e) Maintenance Provisions. A design must allow access to each unit for maintenance.

(f) Digester Configuration.

(1) The bottom of a digester must slope towards a drainpipe.

(2) A flat-bottomed digestion chamber is prohibited.

(g) Access Manholes.

(1) The top of a digester must have at least two access manholes and a gas dome.

(2) One manhole must have a sufficient diameter to permit the use of mechanical equipment to remove grit and sand.

(3) A digester system must have a separate sidewall manhole at ground level.

(h) Safety.

(1) The facility operation and maintenance manual must require the use of non-sparking tools, rubber soled shoes, a safety harness, and gas detectors for flammable and toxic gases when working in a digester.

(2) At least one self-contained breathing apparatus must be maintained in operational condition and kept on site.

(i) Sludge Inlets and Outlets. To facilitate effective mixing of the digester contents a digester must have:

(1) multiple sludge inlets located to minimize short-circuiting and at least one inlet located in the center of a digester above the liquid level at design flow;

(2) at least three recirculation sections; and

(3) at least three outlets.

(j) Digester Capacity.

(1) The digester capacity must be calculated using the expected volume and character of the sludge. The report must include the calculations used to justify the design.

(2) The total digester volume must based upon:

(A) the volume of sludge added;

(B) the percent solids and character of the sludge;

(D) the degree or extent of mixing to be obtained; and

(E) the size of the installation with appropriate allowance for sludge and supernatant storage.

(3) A digester must able maintain a minimum daily average sludge digestion temperature of 35 degrees Celsius (95 degrees Fahrenheit) and maintain the temperature within a 4 degrees Celsius (+/-) range.

(4) The minimum detention time for sludge undergoing digestion for stabilization is 15 days in the primary digester for sludge to be landfilled, or the period required to achieve the necessary level of pathogen control and vector attraction reduction as required by Chapter 312, Subchapter D of this title (relating to Pathogen and Vector Attraction Reduction), if sludge is to be land applied.

(5) An unheated digester must provide a minimum detention time of 60 days and maintain a temperature of at least 20 degrees Celcius (68 degrees Fahrenheit), or the period required to achieve the necessary level of pathogen control and vector attraction reduction as required by Chapter 312, Subchapter D of this title.

(6) A Completely Mixed System.

(A) A digester must have an average feed loading rate of less than 200 pounds (lbs) of volatile solids per 1,000 cubic feet (cf) of volume per day in the active digestion volume.

(B) Complete mixing in 30 minutes or less is required for:

(i) a confined mixing system if gas or sludge flow is directed through a vertical channel;

(ii) a mechanical stirring or pumping system; and

(iii) an unconfined continuously discharging gas mixing system.

(D) The minimum gas flow supplied for complete mixing must be 15 cubic feet per minute (cfm) per 1,000 cf of digestion volume.

(E) A complete mixing system must have a flow-measuring device and a throttling valve.

(F) The minimum power supply for a mechanical stirring or pumping complete mixing system is 0.5 horsepower per 1,000 cf of digestion volume.

(7) Moderately Mixed Systems.

(A) A digestion system where mixing is accomplished only by circulating sludge through an external heat exchanger must be loaded at less than 40 lbs of volatile solids per 1,000 cf of volume per day in the active digestion volume. A design must be based on the volatile solids loading in accordance with the degree of mixing.

(B) The report must include a justification for the loading rates, if mixing is accomplished by another method.

(k) Gas Collection, Pipes, Storage, and Appurtenances.

(1) General Requirements. Each portion of a gas system must maintain positive gas pressure under all normal operating conditions, including sludge withdrawal.

(2) Safety Equipment.

(A) A gas system must include a pressure valve, vacuum relief valve, a flame trap, and an automatic safety shut-off valve.

(B) An installation of water seal equipment on a gas pipe is prohibited.

(3) Gas Pipes and Condensate.

(A) The gas pipe system must be designed for the volume of gas expected.

(B) A gas pipe must be pressure tested for leakage at 1.5 times the design pressure before a digester is placed into service.

(D) The main gas pipe from a digester must have a sediment trap and a drip trap.

(E) A float controlled condensate trap is prohibited.

(F) A condensation trap must be accessible for daily servicing and draining.

(G) A drip trap must be located at each low point in the pipes.

(H) A gas pipe to each gas outlet must have a flame check or a flame trap.

(I) A burner pilot must use natural or bottled gas.

(J) Each main gas pipe must have a flame trap with a fusible shut-off.

(K) A gas pipe to a waste gas burner must have a pressure valve and a vacuum relief valve.

(4) Electrical Fixtures and Equipment. The electrical equipment near sludge digester pipe containing gas must be designed to prevent potentially explosive conditions.

(l) Waste gas.

(1) A waste gas burner must be accessible and must be located at least 50 feet away from any structure, if placed at ground level.

(2) A waste gas burner may be located on the roof of the control building.

(3) A waste gas burner must not be located on top of a digester.

(4) A discharge of less than 100 cubic feet per hour of digester gas through a return bend screened vent with a flame trap terminating at least 10 feet above a walking surface is allowed.

(m) Ventilation.

(1) An underground enclosure connected to an anaerobic digesters tank, gas pipe, or sludge equipment must have forced ventilation in accordance §217.246 of this title (relating to Ventilation and Odor Control).

(2) An underground enclosure must have a tight-fitting, self-closing door to minimize the spread of gas.

(n) Gas Meter.

(1) A system must have a gas meter to measure total gas production.

(2) A meter must have a bypass.

(o) Manometer.

(1) A gas manometer must have a tight shut-off vent and vent cock.

(2) A vent pipe must be extended from a manometer to the outside of the building.

(3) A vent pipe opening must have a screen and be designed to prevent the entrance of rainwater.

(4) A design must specify all safety devices that are needed for a manometer pipe system and must list the safety items in the report.

(p) Gas Piping. The gas piping for an anaerobic digester must be equipped with gauges that measure the following in inches:

(1) the pressure of the main pipe;

(2) the pressure to gas-utilization equipment; and

(3) pressure to waste burners.

(q) Digestion Temperature Control.

(1) Passive Temperature Control.

(A) A digester must be constructed above the shallowest ground water table.

(B) A digester must be insulated to minimize heat loss.

(2) Heating Facilities.

(A) The sludge must be heated by circulating the sludge through an external heater.

(B) A piping system must allow for the preheating of feed sludge before introduction to the digesters, unless effective mixing is provided within a digester.

(D) The size of a heat exchanger sludge pipe must be based on the heat transfer requirements.

(3) Heating Capacity.

(A) A digester system must have the heating capacity to maintain the temperature required for sludge stabilization.

(B) A digester system must be designed to use an alternate source of fuel and have an alternate source of fuel available for emergency use.

(4) Mixing. A digester system must have equipment to mix the sludge.

(5) Location of a Sludge Heating Device. A sludge heating device with an open flame must be located above grade and in an area separate from gas production and any storage area.

(r) Supernatant Withdrawal.

(1) Pipe Size. The minimum diameter for a supernatant pipe is 6.0 inches.

(2) Withdrawal Arrangements.

(A) The supernatant pipes must be arranged to allow withdrawal from three or more levels in a tank.

(B) A supernatant selector must have at least two draw-off levels located in the digester's supernatant zone, in addition to an unvalved emergency supernatant draw-off pipe.

(D) A supernatant withdrawal level design must be based on a fixed cover digester design.

(E) Supernatant withdrawal must be by means of interchangeable extensions at the discharge end of a withdrawal pipe.

(F) A supernatant piping system must have high-pressure backwash equipment.

(3) Sampling.

(A) A supernatant pipe must have sampling points at each supernatant draw-off level.

(B) The minimum diameter for a sampling pipe is 1.5 inches.

(4) Supernatant Handling.

(A) The report must include how the treatment units are designed to handle shock organic loads associated with digester supernatant.

(B) Supernatant liquor from an anaerobic digester may be returned directly to the facility for treatment or chemically treated before being returned to the facility for treatment. Any other method of treating supernatant liquor must be approved by the executive director.

(i) Lime must be applied to obtain a pH of at least 11.5 standard units (su).

(ii) A lime feeder must be capable of feeding 2,000 mg/l of hydrated lime or its equivalent.

(iii) Lime must be mixed with the supernatant liquor by a rapid mixer or by agitation with air in a mixing chamber.

(iv) After adequate mixing, the solids must be allowed to settle.

(D) A supernatant liquor treatment system may be a batch or a continuous process.

(i) A batch process may have the mixing and settling processes in the same tank.

(ii) A sedimentation tank for a batch process must have the capacity to hold at least 36 hours of supernatant liquor at design flow, but not less than 1.5 gallons per capita.

(iii) A sedimentation tank for a continuous process must have a detention time of not less than 8.0 hours.

(E) The solids from the supernatant liquor treatment must be returned to a digester or conveyed to a sludge handling unit.

(F) The clarified supernatant liquor must be returned to the head of the treatment works in accordance with §217.242 of this title (relating to Control of Sludge and Supernatant Volumes).

(s) Anaerobic Digester Covers.

(1) An uncovered anaerobic digester is prohibited.

(2) The sludge and supernatant withdrawal pipes for a single-stage or a first-stage digester with a fixed cover must be arranged to minimize the possibility of air being drawn into a gas chamber above the liquid in a digester.

(3) A digester cover must include a gas chamber.

(4) A digester cover must be gas tight. The specifications must include a test of each digester cover for gas leakage.

(5) A digester cover must be equipped with an air vent with a flame trap, a vacuum breaker, and a pressure relief valve.

(t) Aerobic Sludge Digestion. This subsection applies to the stabilization by aerobic digestion of waste sludge to Class B biosolids as defined in Chapter 312 of this title.

(1) Solids Management. The report must include a solids management plan.

(2) Detention Time. The design temperature of an aerobic digester system must be based the average of the lowest consecutive seven-day low temperature at a similar wastewater treatment facility located within 50 miles of a proposed site must be used.

(3) Mass Balance Requirements. Mass balance calculations must be included in report. The mass balance calculations must take into account design sludge age, wastestream concentration, operational hours, operational volume in tanks, decant or dewatering volumes and characteristics, time needed for decanting or dewatering, and the volume needed for storage and sampling.

(4) Single Stage. Single stage aerobic digestion consists of utilizing one tank operating in continuous-mode-no-supernatant removal, continuous-mode-feeding-batch removal, or other mode detailed in a solids management plan.

(A) The design of the size of an aerobic digester must be based on the minimum total detention time for the water temperature in the table located in subparagraph (B) of this paragraph based on Chapter 312 of this title and 40 Code of Federal Regulations Part 503.

(B) The digester size must be sufficient to provide both the detention time in the following table and to provide for the mass load received by the unit:

Figure: 30 TAC §217.249(t)(4)(B)

(5) Multiple Stage. Multiple stage aerobic digestion consists of two or more completely mixed reactors operating in series.

(6) Field Data.

(A) Any increase in flow or organic loading or change in process requires new testing and verification of time and temperature operating parameters.

(B) An expansion of an existing facility may be designed and operated according to previously established time and temperature operating parameters.

(C) The executive director may re-rate a facility under Subchapter B of this chapter (relating to Treatment Facility Design Requirements), if an owner requests a re-rating and submits sufficient supporting data.

(7) Design Requirements.

(A) The maximum solids concentration used to calculate the total detention time for an aerobic digester that concentrates the waste sludge only in a digester tank must be:

(i) 2.0% solids concentration; unless

(ii) supporting data is submitted in the report to increase the solids concentration to 3.0%; or

(iii) a higher concentration is justified by the use of a sludge thickening unit upstream of a digester.

(B) A diffuser must be designed to minimize clogging.

(C) A diffuser must be designed to permit its removal without dewatering a tank for inspection, maintenance, and replacement.

(D) The volatile solids loading rate must be designed to be at least 100 lb but not more than 200 lb of volatile solids per 1,000 cf per day, unless otherwise justified in the report.

(E) The dissolved oxygen concentration maintained in the liquid must be at least 0.5 mg/l.

(F) The energy input for mixing must be at least 0.5 horsepower per 1,000 cf for mechanical aerators.

(G) The energy input for mixing must be at least 20 standard cf per minute per 1,000 cf per 1,000 cf of aeration tank if diffused air mixing is used.

(H) A unit must be designed for effective separation and withdrawal, or decanting of the supernatant.

(u) Heat Stabilization.

(1) The design of a heat treatment system must be based on the anticipated sludge flow, characteristics, and concentration.

(2) A heat treatment system must operate continuously to minimize the additional heat input necessary to start up the system, unless justified in the report.

(3) A heat treatment system must have multiple units, unless storage or an alternate stabilization method is available.

(4) A single unit heat treatment system must have a standby grinder, fuel pump, air compressor, if applicable, and dual sludge pumps.

(5) The report must identify the expected downtime for maintenance and repair, based on data from a comparable facility.

(6) The report must include a design for adequate storage for process feed and downtime.

(7) A heat treatment system must provide heat stabilization in a reaction vessel:

(A) at a minimum of 175 degrees Celcius (350 degrees Fahrenheit) for 40 minutes but not more than 205 degrees Celcius (400 degrees Fahrenheit) for 20 minutes and at a pressure of not less than 250 lbs per square inch gauge (psig) but not more than 400 lbs/psig; or

(B) provide for pasteurization at temperatures of 30 degrees Celcius (85 degrees Fahrenheit) or more and gage pressure of more than 1.0 standard atmosphere (14.7 pounds per square inch) for a period of at least 25 days.

(8) A heat treatment system must have a sludge grinder to protect a heat exchanger from rag fouling.

(9) A heat treatment system must include an acid wash or high-pressure water wash system to remove scale from heat exchangers and reactors.

(10) A decant tank must have a sludge scraper mechanism and must be covered.

(11) A heat exchanger must be constructed of corrosion resistant material.

(12) A heat treatment system must have a continuous temperature recorder.

(v) Recycle Loads.

(1) The report must identify a method of treatment for the recycle stream from heat treatment.

(2) A recycle stream must not impact effluent quality or the facility's treatment processes.

(w) Alkaline Stabilization.

(1) Design Basis.

(A) Alkaline Dosage. The report must include the calculation of the alkaline dosage required to stabilize sludge based on the type of sludge, chemical composition of sludge, and the solids concentration. Performance data taken from a pilot test program or from a comparable facility must be used to determine the proper dosage.

(B) Temperature, pH, and Contact Time. An alkaline stabilization system must uniformly mix an alkaline additive-sludge mixture to maintain the pH, temperature, and contact time, as specified in §312.82 of this title (relating to Pathogen Reduction) and §312.83 of this title (relating to Vector Attraction Reduction).

(2) Reliability.

(A) An alkaline stabilization system must have multiple units, unless storage or an alternate stabilization method is available to continue operations when a unit is not in service.

(B) A single unit that has adequate storage or an alternate stabilization method must have standby conveyance and mixer, backup heat source, and dual blowers.

(i) the expected downtime for maintenance and repair based on data from a comparable facility; and

(ii) adequate storage for process, feed, and downtime.

(3) Alkaline Stabilization Housing Unit.

(A) A housing unit must meet the requirements in §217.247(u)(1) of this title (relating to Chemical Pretreatment of Sludge).

(B) A housing unit must have mechanical or air agitation to ensure uniform discharge from the storage bins.

(4) Feeding Equipment.

(A) The alkaline additive feeding equipment must meet the requirements of §217.247(u)(1) of this title.

(B) Hydrated lime must be fed as at least 6% calcium hydroxide Ca(OH)₂ slurry by weight but not more than 18% Ca(OH)₂ slurry by weight, unless otherwise justified in the report.

(5) Mixing Equipment.

(A) An additive and sludge blending or mixing vessel must be large enough to hold the mixture for a minimum of 30 minutes at maximum feed rate.

(B) A batch process must maintain a pH greater than 12 su in a mixing tank during the blending period.

(D) A continuous flow process must be designed for a detention time that is the tank volume divided by the volumetric input flow rate.

(E) A slurry mixture may be mixed with either a diffused air mixer or a mechanical mixer.

(F) The mixing equipment must maintain an alkaline slurry mixture in complete suspension.

(G) If using a diffused air mixer, the following requirements apply.

(i) A coarse bubble diffuser must have a minimum air supply of 20 standard cubic feet per minute per 1,000 cf of tank volume.

(ii) A mixing tank must be ventilated and include odor control equipment.

(H) If using a mechanical mixer, the following requirements apply.

(i) A mechanical mixer must provide at least 5.0 horse power per 1,000 cf of tank volume but not more than 10 horse power per 1,000 cf of tank volume.

(ii) The impellers must minimize debris fouling in the sludge.

(6) Detention Time. A pasteurization vessel must provide a minimum detention period of 30 minutes.

(7) External Heat. The report must include any supplemental external heat necessary.

§217.250.Sludge Dewatering.

(a) The report must include a justification for the proposed sludge dewatering units, including design calculations, results from any pilot studies, all assumptions, and appropriate references.

(b) The design of a dewatering unit must be based on mass balance principles.

(1) Centrate or Filtrate Recycle.

(A) The drainage from beds and centrate or filtrate from dewatering units must be returned to the head of the facility for treatment.

(B) The design of a treatment unit downstream from a dewatering unit must be based on the organic load from the centrate or filtrate recycle.

(2) Sludge with Industrial Waste Contributions. A dewatering system must be designed to prevent the release of any constituent (such as a free metal, an organic toxin, or a strong reducing or oxidizing compound) that threatens water quality or compliance with the associated wastewater permit.

(3) Redundancy.

(A) A mechanical dewatering system must have at least two units, unless the report justifies adequate storage or an alternative means of sludge handling.

(B) When performance reliability and sludge management are dependent on production of dewatered sludge, the mechanical dewatering units must be able to dewater the average daily sludge flow with the largest unit out of service.

(4) Storage Requirements.

(A) A mechanical dewatering system must have separate storage if the equipment will not operate on a continuous basis and the treatment system has no digesters with built-in short-term storage.

(B) In-line storage of stabilized or unstabilized sludge must not interfere with any treatment unit.

(5) Sampling Points. A dewatering system must have sampling stations before and after each dewatering unit and must allow periodic evaluation of the dewatering process.

(6) Maintenance. Each dewatering system unit must have a bypass to allow for maintenance, repair, and replacement.

(d) Sludge Conditioning.

(1) An additive addition point must be located in relation to downstream equipment and in relation to the combined effect of other additives.

(2) A dewatering system must provide adequate mixing time for the reaction between an additive and the sludge. Any subsequent handling must eliminate floc shearing.

(3) The report must include a pilot plant or full-size performance data used to determine the characteristics and design dosage of any sludge additive.

(4) The report must justify the in-stream flocculation and coagulation system design by including comparable performance data or pilot plant data.

(5) The report must include whether the mixers require conditioning tanks.

(6) The report must include calculations for a range of detention times.

(7) Solution storage may be smaller than the design volume required for daily dosage if the equipment is not in continuous operation.

(8) A minimum of eight hours storage must be provided, unless the specific chemical or additive selected is adversely affected by storage.

(9) The storage for a batch operation must be adequate for one batch at maximum chemical demand.

(10) The report must justify any storage volume reduction and any other method used to ensure a continuous supply of chemicals through an operating day or batch.

(e) Sludge Drying Beds.

(1) The sludge drying beds size must be based on data from a similar facility in the same geographical area with the same influent sludge characteristics.

(2) If such data is unavailable, or if the executive director determines that the data is not appropriate for a proposed facility, the design of sludge drying beds must be based on the following:

(A) Open Beds.

(i) A sludge drying bed system must have at least two beds.

(ii) The report must include the calculation of the minimum surface area for a sludge drying bed using the values in the following figure for an area of the state with less than 45 inches annual average rainfall or annual average relative humidity of less than 50%, as determined by National Weather Service data.

Figure: 30 TAC §217.250(e)(2)(A)(ii)

(iii) Another method of sludge dewatering is required in lieu of a sludge drying bed in an area of the state that experiences either greater than 45 inches average annual rainfall or annual average relative humidity of 50% or greater, as determined by National Weather Service data.

(iv) A design must:

(I) provide a method of effectively dewatering sludge;

(II) provide a means for accelerated dewatering;

(III) size the sludge drying beds to store accumulated sludge during periods of extended high humidity and rainfall; and

(IV) provide an alternative dewatering method to effectively dewater the sludge during periods of extended high humidity and rainfall.

(v) The report must provide justification for use of modified sludge drying beds in high rainfall, high relative humidity areas of the state.

(B) Gravel Media Beds. A gravel media bed must be laid in two or more layers. The gravel around the underdrains must be properly graded and must be at least 12 inches deep, extending at least 6.0 inches above the top of the underdrains. The top layer of a gravel media bed must be at least three inches thick and must consist of gravel 1/8 inch to 1/4 inch in size.

(C) Sand Media Beds. A sand media bed must consist of at least 12 inches of sand with a uniformity coefficient of less than 4.0 and an effective grain size of at least 0.3 millimeters (mm) but not more than 75 mm above the top of an underdrain.

(D) Underdrains.

(i) The underdrains must be at least 4.0 inches in diameter and sloped not less than 1.0% to drain.

(ii) The underdrains must be spaced not more than 20 feet apart.

(E) Decanting. A sludge drying bed may have a method of decanting supernatant installed on the perimeter of the bed.

(F) Walls.

(i) The interior walls of a sludge drying bed must be watertight and extend 12 to 24 inches above and at least 6 inches below the bed surface.

(ii) The exterior walls of a sludge drying bed must be watertight and extend 12 to 24 inches above the bed surface or ground elevation, whichever is higher.

(G) Sludge Removal.

(i) A sludge drying bed system must be arranged to facilitate sludge removal.

(ii) The sludge drying beds must have concrete pads for vehicle support tracks on 20 foot centers for all percolation type sludge beds.

(H) Sludge Influent.

(i) A sludge pipe to the beds must terminate at least 12 inches above the surface of the media and be arranged so that the pipe drains to a sump to be pumped to the headworks.

(ii) A sludge discharge point must have a concrete splash plate.

(I) Drying Bed Bottom.

(i) The bottom of a sludge drying bed must consist of a minimum of one foot layer of clayey subsoil having a permeability of less than 10^-7 centimeters per second (cm/sec).

(ii) An impermeable concrete pad must be installed over a liner in locations where the groundwater table is within 4.0 feet of the bottom.

(3) Modified Drying Beds. The executive director will review any vacuum assisted or other variations to the gravity drying bed concept as innovative and/or nonconforming technologies subject to §217.7(b)(2) of this title (relating to Types of Plans and Specifications Approvals).

(4) Rotary Vacuum Filtration.

(A) Filtration Rate. The report must justify the actual value calculated for the rates of filtering for various types of sludge with proper conditioning, using the following table:

Figure: 30 TAC §217.250(e)(4)(A)

(B) Duplicate Equipment. Unless dual trains are provided, the following equipment must be provided in duplicate to allow equipment alternation: feed pump, vacuum pump and filtrate pump. Spare filter fabric must be provided except when metal coils are used.

(C) Filter Equipment. Wetted parts must be constructed of corrosion-resistant material. Drum and agitator assemblies must be equipped with variable-speed drives and provisions must be made for adjusting the liquid level.

(D) Pumps.

(i) A vacuum pump with a capacity of at least 1.5 cubic feet per minute per square foot (cfm/sf) must be provided for metal-covered drums.

(ii) A dry-type vacuum pump must have a vacuum receiver.

(iii) A filtrate pump must have adequate capacity to pump the maximum amount of liquid to be removed from the sludge.

(iv) Each filter must be fed by a separate feed pump to ensure a proper feed rate.

(5) Centrifugal Dewatering.

(A) The report must justify the sizing and design of a centrifugation system. A design must be based on performance data from a similar centrifugation system when available. If no performance data is available, the results of a pilot or full-scale test must be used.

(B) Selection of a material for a scroll must be include consideration of the amount of grit expected in the sludge.

(D) Unless dual trains are provided, a centrifugation system must have the following spare equipment, including necessary connecting pipes and electrical controls:

(i) drive motor;

(ii) gear assembly; and

(iii) feed pump.

(E) Each feed pump must have variable speed.

(F) Each centrifuge must have a separate feed system.

(G) Each centrifuge must be equipped for variable scroll speed and pool depth.

(H) Each centrifugation system must have a crane or monorail for equipment removal or maintenance.

(I) Each centrifuge system must have access for adequate and efficient wash down of the interior of the machine.

(6) Plate and Frame Presses.

(A) Sizing.

(i) A design must be based on performance data developed from similar operational characteristics concerning the size of a plate and frame press when available. If no performance data is available, the results of a pilot scale tests or full-scale tests must be used.

(ii) A design may be based on appropriate scale-up factors for full size designs if pilot scale testing is done in lieu of full-scale testing.

(iii) The report must justify the size of a plate and frame press.

(B) Duplicate Equipment and Spare Parts. Unless multiple units are provided, a plate and frame press system must include the following spare equipment:

(i) a duplicate feed pump;

(ii) at least one extra plate for every ten required for startup, but not less than two;

(iii) one complete filter fabric set;

(iv) one closure drive system;

(v) air compressor; and

(vi) one washwater booster pump.

(i) The filter feed pumps must be capable of a combination of initial high flow, low pressure filling, followed by sustained periods of operating at 100 pounds per square inch (psi) to 225 psi.

(ii) A design may specify an integral pressure vessel to produce this initial high volume flow.

(iii) A plate and frame system may use operating pressures less than 225 psi if the report includes actual performance data using similar sludge justifying such a use.

(iv) A design may include provisions for cake breaking to protect or enhance down line processes when necessary.

(D) Maintenance.

(i) A plate and frame system must have a crane or monorail capable of removing the plates.

(ii) A plate and frame system must have a high-pressure water or acid wash system to clean the filter.

(7) Belt Presses.

(A) Sizing.

(i) Actual performance data developed from a facility with similar operational characteristics must be used to size a belt press system. If pilot plant testing is performed in lieu of full-scale testing, appropriate scale-up factors must be used to develop a full-scale design.

(ii) A belt press system must have a duplicate belt press or another method of sludge processing or disposal that has been approved by the executive director if:

(I) a single belt press will be operated 60 hours or more in any consecutive 5 day period; or

(II) the design flow exceeds 4.0 million gallons per day (mgd).

(iii) The report must include all data used to size a belt press system.

(B) Duplicate Equipment and Spare Parts. Unless multiple units are provided, a belt press system must have the following spare equipment:

(i) a duplicate feed pump;

(ii) washwater booster pumps;

(iii) one complete set of belts;

(iv) one set of bearings for each type of press bearing;

(v) duplicate tensioning;

(vi) tracking sensors;

(vii) one set of wash nozzles;

(viii) one doctor blade; and

(ix) duplicate conditioning or flocculation drive equipment.

(C) Conditioning. The report must include the polymer selection methodology, account for sludge variability, and document the anticipated sludge loading to the press.

(D) Sludge Feed.

(i) The sludge feed must be relatively constant to eliminate difficulties in polymer addition and press operation.

(ii) The report must include the range in feed variability.

(iii) A belt press system may include grinders ahead of a flocculation system.

(iv) The sludge feed must provide a method for uniform sludge dispersion on a belt.

(v) A belt press system must use thickening of the feed sludge unless the report justifies separate thickening or dual purpose thickening.

(E) Filter Press Belts.

(i) A belt must have variable speed.

(ii) A belt press system must have belt tracking and tensioning equipment.

(iii) The report must justify the weave, material, width, and thickness of the belts.

(F) Filter Press Rollers.

(i) The rollers must have a protective finish.

(ii) The maximum roller deflection and operating tension of a belt must be included in the report to justify equipment selection.

(iii) The roller bearings must be watertight and rated for a life of 100,000 hours.

(G) Spray Wash System.

(i) A belt press system must use high-pressure wash water for each belt.

(ii) A design must specify the operating pressure at the point of washwater discharge.

(iii) A spray wash system must allow cleaning without interfering with the system operation.

(iv) The report must justify the nozzle and nozzle cleaning system selection.

(v) A belt press system must have replaceable spray nozzles and spray curtains.

(H) Maintenance Requirements.

(i) A belt press system must have drip trays under the press and under the thickener when gravity belt thickening is employed.

(ii) The side and floor of a belt press must have adequate clearance for maintenance and removal of the dewatered sludge.

(iii) An electrical panel or other material subject to corrosion must be weatherproof or located outside of the press area.

(iv) A doctor blade clearance must be adjustable.

§217.251.Sludge Storage.

(a) This section applies to the storage of residuals after processing but before final disposal or removal from the facility site.

(b) A site may store residuals in liquid, dewatered, or dry form if the solids have been stabilized in a treatment process.

(1) The design of a storage facility must minimize odor conditions and vector attraction.

(2) A storage facility must provide storage of waste sludge separate from a biological treatment process.

(3) The design of a storage facility must be based on process design, sludge age, waste stream concentration, operational hours, operational volume in tanks, decant or dewatering volumes and characteristics, time frames needed for decanting or dewatering, and volume needed for storage and sampling.

(4) The report must include a solids management plan that demonstrates a method of managing the waste solids that will maintain the design sludge age for a biological process.

(d) Storage of Solids - Not Dewatered.

(1) Aerobically Digested Solids.

(A) A storage facility may store aerobically digested solids.

(B) A basin must have diffused air or mechanical mixing.

(C) A diffused air-mixing unit must provide a minimum air capacity of 30 standard cubic feet per minute per 1,000 cubic feet (cf) of volume.

(D) A mechanical surface aerator must have a minimum of 1.0 horsepower per 1,000 cf of volume.

(E) An earthen basin must be lined in accordance with §217.203(c) and (d) of this title (relating to Design Criteria for Natural Treatment Facilities).

(2) Anaerobically Digested Solids. Anaerobically digested solids may be stored in a covered basin.

(e) Storage of Dewatered Solids.

(1) A storage facility must store the dewatered solids in a container or in a stockpile that prevents re-wetting by precipitation.

(2) A storage container may store dewatered solids with a solids content of less than 35% for no more than seven days.

(3) A storage facility must store dewatered solids in a steel or concrete container that prevents re-wetting by precipitation.

(4) A storage facility may store dewatered solids with a solids content of at least 35% but not more than 50% for no more than 90 days.

(f) Open Stockpiles.

(1) An open stockpile must have an impervious pad underneath the solids to prevent groundwater contamination.

(2) An open stockpile must have a system for collecting storm water runoff and returning it to the head of the treatment facility.

(g) Dried Solids Storage.

(1) A storage facility may store dewatered solids with a solids content of greater than or equal to 50% in a bin or covered facility.

(2) A enclosed storage structure must be mechanically ventilated with at least 20 air exchanges per hour and must have an odor control system for the exhaust.

§217.252.Final Use or Disposal of Sludge.

(a) The report must identify the final use or final disposal of the sludge. The use, disposal, and transportation of sludge must be conducted in accordance with the requirements contained in Chapter 312 of this title (relating to Sludge Use, Disposal, and Transportation).

(b) Quantities of Sludge.

(1) An estimate of the quantity of solids generated by the treatment process from a similar full-scale facility or pilot study must be included in the report.

(2) A mass balance approach must be used to determine the quantity of sludge produced at a facility.

(d) Sludge Constituents.

(1) Metals and their concentration in sludge must be determined using Standard Method's laboratory test procedures and must be less than the levels specified in §312.63 of this title (relating to Metal Limits (Other Than Domestic Septage)).

(2) A sludge processing system must be designed to reduce pathogens in sludge to levels compliant with Chapter 312 of this title concerning the ultimate use or disposal method.

(3) A sludge processing system must be designed to produce digested sludge that complies with Chapter 312 of this title with regards vector attraction.

(e) Emergency Provisions for Sludge Disposal. A design must include a secondary method of sludge disposal in the event of conditions that prevent the use of a facility's primary use or disposal method. A secondary method must be included in the report.

(f) Weather Factors. Weather factors such as rainfall, wind conditions, and humidity must be included in the determination of the use or disposal of sludge.

This agency hereby certifies that the proposal has been reviewed by legal counsel and found to be within the agency's legal authority to adopt.

Filed with the Office of the Secretary of State on February 29, 2008.

TRD-200801208

Robert Martinez

Director, Environmental Law Division

Texas Commission on Environmental Quality

Earliest possible date of adoption: April 13, 2008

For further information, please call: (512) 239-0177

Subchapter K. CHEMICAL DISINFECTION

30 TAC §§217.271 - 217.283

STATUTORY AUTHORITY

The proposed new rules implement TWC §§5.013, 5.103, 5.105, 5.120, 26.027, 26.034, and 26.121.

§217.271. Chlorine (Cl₂ ) Disinfection and Sulfur Dioxide (SO₂ ) Dechlorination System Redundancy Requirements.

(a) Each Cl₂ disinfection and SO₂ and dechlorination system must include at least two banks of chemical storage cylinders.

(b) A bank of cylinders must include a device that automatically switches from an empty bank of cylinders to a full bank of cylinders in a manner that ensures continuous disinfection.

(d) A chemical delivery system must be designed so that the pound per day requirements in §217.272 of this title (relating to Capacity and Sizing of Chlorine (Cl₂) Disinfection and Sulfur Dioxide (SO₂) Dechlorination) are met with the largest chlorinator, sulfonator, or evaporator out of service.

(e) A chemical delivery system must include a backup pump for any injector water supply system requiring a booster pump.

§217.272.Capacity and Sizing of Chlorine (Cl₂ ) Disinfection and Sulfur Dioxide (SO₂ ) Dechlorination Systems.

(a) The capacity of a Chlorine (Cl₂) or a Sulfur Dioxide (SO₂) gas withdrawal system must be based on the peak flow, in compliance with §217.32(a)(1) of this title (relating to Organic Loadings and Flows) and the equation in the following figure:

Figure: 30 TAC §217.272(a)

(b) The following figure establishes the minimum acceptable design Cl₂ dosage for disinfection:

Figure: 30 TAC §217.272(b)

(c) A dechlorination system design must include at least one unit of SO₂ gas to dechlorinate at least one unit of Cl₂ gas.

§217.273.Cylinder Requirements for Chlorine (Cl₂ ) Disinfection and Sulfur Dioxide (SO₂ ) Dechlorination Systems.

(a) Cylinder Withdrawal Rates.

(1) Gas Withdrawal. The gas withdrawal rate per cylinder must be based on the Equation K.2 located in the following figure and the variables from Table K.2 located in the following figure:

Figure: 30 TAC §217.273(a)(1)

(A) If the cylinders are not stored in a temperature-controlled enclosure, the report must include the ambient temperature based on the lowest seven-day average of the average daily local temperatures over the last ten years, as measured at the nearest National Oceanic and Atmospheric Administration's National Weather Service weather station.

(B) Heating blankets on Chlorine (Cl₂ ) gas cylinders are prohibited.

(2) Liquid Withdrawal. If liquid withdrawal from one-ton cylinders is proposed, the following are the maximum withdrawal rates:

(A) 9,600 pounds (lbs)/day of Cl₂; and

(B) 7,200 lbs/day of Sulfur Dioxide (SO₂).

(b) Cylinders per Bank. The number of cylinders per cylinder bank must be based on the equation in the following figure:

Figure: 30 TAC §217.273(b)

§217.274.Dosage Control for Chlorine (Cl₂ ) Disinfection and Sulfur Dioxide (SO₂) Dechlorination Systems.

A new or modified Chlorine (Cl₂) and Sulfur Dioxide (SO₂) system must include automatic dosage control that adjusts the dosage of Cl₂ or SO₂ relative to the flow of an effluent stream.

§217.275.Requirements for Chlorine (Cl₂ ) Disinfection and Sulfur Dioxide (SO₂ ) Dechlorination Systems Using 150 pound (lb) Cylinders.

(a) Heated Rooms.

(1) A Chlorine (Cl₂) and Sulfur Dioxide (SO₂ ) system that uses 150-pound (lb) cylinders must be located indoors at a minimum temperature of 65 degrees Fahrenheit. This provision applies to all chemical feed equipment, including the cylinders, chlorinators, and/or sulfonators.

(2) An unconnected cylinder may be stored outdoors, but the cylinder must reach at least 65 degrees Fahrenheit before being connected to a system.

(b) Heating Blankets.

(1) Heating blankets on Cl₂ gas cylinders are prohibited.

(2) An SO₂ cylinder may have a heating blanket only in a temperature-controlled room to increase the temperature inside a cylinder above the ambient room temperature.

(A) The report must include a calculation determining the setting for a heating blanket to maintain a cylinder temperature of less than 100 degrees Fahrenheit.

(B) A heating blanket must include a mechanism that ensures that a blanket does not heat a cylinder above 100 degrees Fahrenheit.

(C) A cylinder with a heating blanket that is connected to a disinfection system must have a downstream pressure-reducing valve.

(D) An SO₂ system must be capable of deactivating a heating blanket if high pressure is detected downstream.

(c) Separation. The design of a disinfection system using 150-lb cylinders must ensure that Cl₂ and S ₂ are not in the same room and will never come into contact with each other.

§217.276.Requirements for Chlorine (Cl₂ ) Disinfection and Sulfur Dioxide (SO₂ ) Dechlorination Systems Using Gas Withdrawal from One-Ton Cylinders.

(a) Heated Rooms. The chlorinators and sulfonators for a system using one-ton cylinders must be indoors and at a minimum temperature of 65 degrees Fahrenheit.

(b) Outdoor Storage.

(1) If one-ton cylinders are stored outdoors, the system sizing must be done in accordance with §217.273(a) of this title (relating to Cylinder Requirements for Chlorine (Cl₂ ) Disinfection and Sulfur Dioxide (SO₂) Dechlorination Systems). Calculations supporting system sizing must be included in the report.

(2) If a one-ton cylinder is stored outdoors, a storage structure must:

(A) protect a cylinder from direct sunlight; and

(B) allow safe removal and replacement of a cylinder.

(3) A one-ton cylinder stored outdoors may have heated pipes to prevent gas from liquefying when a chemical enters a heated building or when gas cools in a pressure pipe.

(1) A heating blanket on a one-ton Cl₂ gas cylinder is prohibited.

(2) A one-ton SO cylinder may have a heating blanket to increase the operating temperature of an SO₂ system. A design must specify the temperature a heating blanket may be set to maintain an adequate temperature inside a cylinder, based on the lowest seven-day average of the local daily low temperatures over the last ten years.

(3) The ambient temperature must be used to calculate a cylinder withdrawal rate in §217.273(a) of this title.

(4) A heating blanket must include a mechanism to prevent heating a cylinder to more than 100 degrees F.

(5) A dechlorination system must have a pressure-reducing valve downstream from the cylinders connected to the system and a high-pressure interlock to deactivate any heating blanket.

(d) Separation.

(1) The housing of the SO₂ feed equipment for one-ton cylinders must be in a separate room from the chlorination feed equipment and cylinders.

(2) A system with Cl₂ and SO₂ one-ton cylinders must separate the feed equipment from the cylinders with a gas tight wall, except for the following exceptions:

(A) One-ton SO₂ cylinders and Cl₂ cylinders may be stored in the same area if:

(i) the cylinders are stored outdoors;

(ii) an SO₂ outlet valve and a Cl₂ outlet valve are separated by at least 10 feet; and

(iii) the Cl₂ equipment and storage containers are marked differently than SO₂ equipment and storage containers.

(B) SO₂ and Cl₂ chemical feed equipment may be stored in the same room if:

(i) both systems are remote vacuum type;

(ii) no pressure gas pipes are in the room;

(iii) no cylinders are stored in the room; and

(iv) the design ensures that Cl₂ and SO₂ cannot be mixed.

§217.277.Requirements for Chlorine (Cl₂ ) Disinfection and Sulfur Dioxide (SO₂ ) Dechlorination Systems Using Liquid Withdrawal from One-Ton Cylinders.

(a) Heated Rooms. The chlorinators and sulfonators must be located indoors at a minimum temperature of 65 degrees Fahrenheit.

(b) Outdoor Storage. The Chlorine (Cl₂ ) and Sulfur Dioxide (SO₂) cylinders for systems using liquid withdrawal may be stored outdoors without reducing the withdrawal rates assumed in §217.273(a)(2) of this title (relating to Cylinder Requirements for Chlorine (Cl₂ ) Disinfection and Sulfur Dioxide (SO₂ ) Dechlorination Systems).

(c) Separation. The separation requirements for a one-ton cylinder liquid withdrawal systems are the same as those for a one-ton cylinder gas withdrawal system under §217.276(d) of this title (relating to Requirements for Chlorine (Cl₂) Disinfection and Sulfur Dioxide (SO₂) Dechlorination Systems Using Gas Withdrawal from One-Ton Cylinders).

§217.278.Housing Requirements for Chlorine (Cl₂ ) Disinfection and Sulfur Dioxide (SO₂ ) Dechlorination Systems.

(a) Floor Drains. A floor drain from a Cl₂ or SO₂ feed or storage room must not drain to any pipe system connected to any other room of the facility.

(b) Doors and Windows.

(1) Each door must:

(A) open to the outside of the building; and

(B) include panic hardware.

(2) Each room must have at least one clear, gas-tight window in an exterior door.

(3) A room may have additional windows to ensure the disinfection and dechlorination systems may be viewed without entering an enclosed room.

(1) An enclosed storage and feed room must have forced mechanical ventilation with at least 1.0 air exchange every 3.0 minutes.

(2) Exhaust equipment must have:

(A) external controls; and

(B) leak detection equipment.

(3) A fan must be located at the top of the room to push air across the room and through an exhaust vent located at the bottom of the room on the opposite side.

(4) An exhaust system may use negative pressure ventilation instead of forced mechanical ventilation if the facility has gas containment and treatment as prescribed by the National Fire Protection Association's Uniform Fire Code.

(5) A vent from the SO₂ or Cl₂ gas feed systems must exhaust to a point that is:

(A) not frequented by facility staff;

(B) not near a fresh air intake; and

(d) Gas Detectors and Protection.

(1) An area containing Cl₂ or SO₂ under pressure must have a gas detector and alarm system.

(2) An area used for handling pressurized gases must have respiratory and protective equipment that meets the requirements of the National Institute for Occupational Safety and Health.

(A) The respiratory equipment must be immediately accessible and included in the facility's operation and maintenance manual.

(B) The storage of respiratory equipment in any room where gas under pressure is stored or used is prohibited.

(D) The respiratory equipment must use compressed air and must have at least a 30-minute capacity.

§217.279.Equipment and Material Requirements for Chlorine (Cl₂ ) Disinfection and Sulfur Dioxide (SO₂ ) Dechlorination Systems.

(a) All equipment and material used in a disinfection and dechlorination system must meet the manufacturer's recommendations.

(b) Storage Orientation.

(1) One-ton cylinders must be stored horizontally on trunnions.

(2) A 150-pound cylinder must be stored vertically and secured by a clamp or chain.

(c) Measurements. A Chlorine (Cl₂) and Sulfur Dioxide (SO₂) system must have a scale for determining the amount of chemical used daily and the amount of chemical remaining in a container.

(d) Pressure Pipe Systems for Gas Transport.

(1) Gas transport pressure pipe and fittings must be at least equivalent to Schedule 80 black seamless steel pipe and 2,000 pound forged steel fittings.

(2) The use of polyvinyl chloride (PVC) in a pressure pipe system is prohibited.

(3) A one-ton cylinder system must use a gas filter upstream of a pressure-reducing valve.

(4) A pressure pipe system must have a pressure-reducing valve if:

(A) the system has a length of supply pipes greater than 20 feet;

(B) an SO₂ system has a heating blanket; or,

(5) A pressure pipe at the gas discharge side of an evaporator must have a rupture disk and a high-pressure alarm that warns facility staff of disk rupture.

(6) A gas pipe entering a chlorinator or sulfonator must have a heated leg drop sediment trap.

(7) An SO₂ system must have at least the equivalent of 316 stainless steel seat and stem.

(8) A Cl₂ system must have at least the equivalent of a Monel seat and stem.

(e) Pressure Pipe Systems - Liquid Transport.

(1) The use of PVC in a pressure pipe system is prohibited.

(2) The manifolding of one-ton containers for simultaneous liquid chemical withdrawal is prohibited.

(3) A liquid pipe system must include a rupture disk, a pressure switch to warn facility staff of disk rupture, and an expansion chamber.

(f) Vacuum pipes.

(1) Vacuum pipes and fittings downstream of a vacuum regulator must be the equivalent of PVC or 316 stainless steel.

(2) A vacuum pipe must have socket joints.

(g) Diffusers. The report must include calculations that verify a minimum velocity of 10 feet per second through any Cl₂ or SO₂ system diffuser, unless a diffuser has a mechanical mixer.

§217.280.Design of Sodium Hypochlorite (NaClO) Disinfection and Sodium Bisulfite (NaHSO₃ ) Dechlorination Systems.

(a) Redundancy. A Sodium Hypochlorite (NaClO) and Sodium Bisulfate (NaHSO₃) system must include at least two chemical solution pumps and must ensure that the capacity requirements of §217.272(b) of this title (relating to Capacity and Sizing of Chlorine (Cl₂) Disinfection and Sulfur Dioxide (SO₂) Dechlorination Systems) are met with the largest pump out of service.

(b) Capacity and Sizing. The size of a chemical liquid solution pump and pipe system must be determined as follows:

(1) NaClO.

(A) Determine Pounds Per Day of Chlorine (Cl₂ ) Required. Figure: 30 TAC §217.272(b), Table K.1 and Figure: 30 TAC §217.272(a), Equation K.1 of this title must be used to determine the pounds per day of Cl₂ required.

(B) Cl₂ Determination. The pounds of available Cl₂ per gallon of NaClO solution must be determined using values and appropriate references supplied by chemical manufacturer.

(C) Gallons per Hour Determination. In order to size the chemical metering equipment, the gallons per hour must be calculated using the values found in the following equation:

Figure: 30 TAC §217.280(b)(1)(C)

(2) NaHSO₃.

(A) Figure: 30 TAC §217.280(b)(1)(C), Equation K.4 of this subsection must be the basis to determine the pounds per day of chemical required.

(B) The minimum amount of NaHSO₃ needed to dechlorinate one pound of Cl₂ is 1.465 pounds. The pounds per day of Cl₂ that must be dechlorinated, as determined in subparagraph (A) of this paragraph, multiplied by 1.465 pounds of NaHSO₃ per pound of Cl₂ , determines the pounds of NaHSO₃ needed.

(C) The gallons per hour (R) of NaHSO₃ solution needed from the chemical metering equipment must be calculated using the following equation:

Figure: 30 TAC §217.280(b)(2)(C)

(c) Dosage Control. A dosage control system may be positive pressure or vacuum and must automatically adjust the NaClO or NaHSO₃ feed rate to correspond to the flow of the effluent stream.

(d) Chemical Handling.

(1) Storage Tank Sizing.

(A) A bulk storage facility for NaClO with a solution strength greater than or equal to 10% must not be sized to store more than a 15-day supply, unless a residual analyzer or oxidation-reduction potential (ORP) monitor provides automatic feed control to compensate for solution degradation.

(B) For NaClO with a solution strength less than 10%, and where a residual analyzer or ORP monitor is provided, a bulk storage facility must not be sized to store more than a 30-day supply.

(C) A facility with a design flow equal to or greater than 1.0 million gallons per day must have at least two chemical storage tanks.

(2) Temperature considerations.

(A) If a NaClO tank is not stored indoors, the tank must be opaque or otherwise block sunlight penetration.

(B) An outdoor NaHSO₃ storage facility and pipes must be insulated and heat traced in a location where the ambient temperature is below 40 degrees F, based on the lowest 7-day average of the average daily local temperatures over the last 10-years, as measured at the nearest National Oceanic and Atmospheric Administration's National Weather Service weather station.

(e) Equipment and Materials.

(1) Equipment and materials used for storage, pumping, and transport of NaClO must be used according to the manufacturer's recommendations and suitable for use in a corrosive chemical environment.

(2) Equipment and materials used for storage, pumping, and transport of NaHSO₃ must be used according to the manufacturer's recommendations and suitable for use in an acidic chemical environment.

(f) Safety.

(1) Ventilation. A chemical storage area must be sufficiently ventilated to prevent buildup of fumes.

(2) Liquid-depth indicators. A storage tank must have an external liquid-depth indicator.

(3) Spill containment.

(A) A chemical storage area must have secondary containment equal to 125% of the volume of the largest storage tank.

(B) A manifolded tank must have secondary containment equal to 125% of the cumulative manifolded tank volume, unless the pipe system prevents a combined release.

(i) elevated above the secondary containment maximum liquid level; or

(ii) provided with positive drainage from below the tank.

(D) A containment system for NaClO must be separate from a containment system for NaSO₃.

(4) Emergency and Protective Equipment. A chemical storage area must have at least one emergency eyewash station and adequate personal protective equipment for all facility staff working in the area.

§217.281.Application of Chlorination and Dechlorination Chemicals.

(a) Mixing Requirements.

(1) Chlorination Unit. A chlorination unit must be constructed so that the applied chlorine (Cl₂) is thoroughly mixed with the wastewater prior to entry into a Cl₂ contact chamber.

(2) Mixing Zones. A mixing zone within a Cl₂ contact basin of an existing facility must not be considered as part of the volume needed for disinfection.

(3) Cl₂ and Sodium Hypochlorite (NaClO). A disinfection system must apply the Cl₂ gas or solution in a highly turbulent flow regime created by in-line diffusers, mechanical mixers, or jet mixers. Effective initial mixing for the mean velocity gradient (G value) in the area of turbulent flow must exceed 500 per second^-1.

(4) Sulfur Dioxide (SO₂) and Sodium Bisulfite (NaHSO₃):

(A) The mixing for an SO₂ and NaHSO₃ system must ensure compliance with all relevant permit requirements.

(B) A disinfection system must provide a mean velocity gradient (G value) of at least 250 per second^-1.

(b) Disinfection Contact Basins.

(1) A Cl₂ contact basin must provide a minimum Cl₂ contact time of 20 minutes at the peak flow.

(2) The design of a Cl₂ contact chamber must prevent short-circuiting and that a the wastewater is retained in a contact basin for at least 20 minutes.

(3) The report must include supporting data from a contact basin design model, performance data of a similar design, or a field tracer study.

(1) A disinfection system must have sufficient mixing and contact time between the disinfected wastewater and a dechlorinating agent to ensure continuous compliance with the permitted Cl₂ limits.

(2) A design must prevent short-circuiting and provide a minimum contact time of 20 seconds at the peak flow.

§217.282.Other Chemical Disinfection and Dechlorination Processes.

Any chemical disinfection or dechlorination process not discussed in this subchapter, such as chlorine dioxide, ozone, tablet or powder disinfection and dechlorination processes, and liquid solution disinfection and dechlorination processes are subject to the requirements of §217.7(b)(2) of this title (relating to Types of Plans and Specifications Approvals).

§217.283.Post-Disinfection Requirements.

(a) A design must include a sufficient number of sampling points to allow an operator to monitor the system. Sampling points must be identified in the report.

(b) Dissolved Oxygen (DO) Requirements.

(1) A disinfection system must include post-aeration to ensure compliance with DO requirements in the facility's wastewater permit.

(2) If the wastewater permit requires a minimum DO of 5.0 milligrams per liter or greater, the report must include the calculations that demonstrate how a post-aeration system will maintain the minimum DO level.

This agency hereby certifies that the proposal has been reviewed by legal counsel and found to be within the agency's legal authority to adopt.

Filed with the Office of the Secretary of State on February 29, 2008.

TRD-200801209

Robert Martinez

Director, Environmental Law Division

Texas Commission on Environmental Quality

Earliest possible date of adoption: April 13, 2008

For further information, please call: (512) 239-0177

Subchapter L. ULTRAVIOLET LIGHT DISINFECTION

30 TAC §§217.291 - 217.300

STATUTORY AUTHORITY

The proposed new rules implement TWC §§5.013, 5.103, 5.105, 5.120, 26.027, 26.034, and 26.121.

§217.291.Ultraviolet Light Disinfection System Definitions.

(a) Module--A grouping of ultraviolet lamps electrically and physically connected to each other.

(b) Bank--A grouping of modules that:

(1) can be automatically turned on and off in relation to effluent flow variations;

(2) is electrically or physically connected together or physically adjacent to each other; and

(3) forms a complete unit capable of treating the full channel design width and depth.

§217.292.Ultraviolet Light Disinfection Systems Effluent Limitations.

Ultraviolet light disinfection systems must be designed to comply with at least the effluent limits relating to fecal coliform or e.coli in the facility's wastewater permit.

§217.293.Ultraviolet Light Disinfection Systems Redundancy Requirements.

(a) An ultraviolet (UV) disinfection system must include a least two banks positioned in series in a disinfection channel.

(b) A UV light disinfection system must be designed so that the dosage requirements determined in §217.295 of this title (relating to Ultraviolet Light Disinfection Dosage and System Sizing) are met when a bank of UV lamps in each channel is out of service at peak flow, as defined in §217.32(a) of this title (relating to Organic Loadings and Flows).

§217.294.Ultraviolet Light Disinfection Systems Monitoring and Alarms.

(a) An ultraviolet (UV) system shall continuously monitor and display locally at the system control panel the following:

(1) the flow rate in each disinfection channel;

(2) the relative intensity of a lamp in one bank of a disinfection channel;

(3) the operational status and condition of each bank;

(4) the on/off status of each lamp in the system;

(5) the number of operating hours of each bank in the system; and

(6) the total number of hours of operation for each bank in the system.

(b) Flow pacing shall be accomplished by turning the appropriate number of banks on or off in proportion to effluent flow. Set points used to energize the banks shall be operator adjustable.

(1) A facility that is not supervised 24-hours per day must have telemetry with battery backup as part of the alarm system. A telemetry system must notify a facility operator in the event of a UV alarm.

(2) A UV system must include the following minimum alarm conditions:

(A) A minor alarm must activate if:

(i) the relative UV intensity of the system is less than 45%; or

(ii) there is a lamp outage.

(B) A major alarm must activate if:

(i) the relative UV intensity of the system is less than 25% (after 100 hour burn in);

(ii) more than 10% of the lamps fail;

(iii) there is a loss of flow signal upon failure of a bank to energize; or

(iv) there is an outage of any module or bank in series.

§217.295.Ultraviolet Light Disinfection Dosage and System Sizing.

(a) A system must be sized based upon the results of an independent bioassay. The following are the minimum criteria.

(1) The lamp and ballast in a bioassay test system must have the same characteristics and 254 nanometers (nm) output as the full-scale system.

(2) Spacing of the lamps in a bioassay test unit must be the same as in the full-scale system.

(3) A minimum of 80 lamps must be present in a bioassay test unit, with the arrangement of lamps mirroring the full-scale system.

(b) If a variable output lamp is used, detailed documentation from the lamp manufacturer must be provided to document 254nm ultraviolet output, operational wattage versus lamp input power (voltage and current), along with data demonstrating power requirements to the lamp and ballast to achieve the stated output.

§217.296.Ultraviolet Light Disinfection Bioassay Test Procedure.

(a) A bioassay procedure must conform to the publication, USEPA (1986) Design Manual: Municipal Wastewater Disinfection,i EPA/625/1-86/021. The following minimum standards are required for proper validation:

(1) The test organism must be introduced into buffered distilled water.

(2) The depth of the suspension must be 1.0 centimeter (cm). Mathematical depth correction is prohibited.

(3) The organism density must be at least 10⁵ plaque forming units or colony forming units per milliliter.

(4) The dose response relationship must be based on a range of five to seven exposure times.

(5) Runs must be in triplicate, each from a separate dilution of the stock suspension.

(6) Three dilutions should be plated in triplicate.

(7) A minimum of two controls (unexposed) must be sampled with each dose run.

(8) The diameter of the Petri dish and collimating tube should be the same.

(9) The narrow band detector used for intensity determination must be calibrated for accuracy.

(10) 254 nanometer ultraviolet must be measured and reported as the dose response.

(11) Aggressive or rapid stirring of the suspension is prohibited.

(12) Intensity shall be measured at the exact height of the surface of the suspension. Mathematical intensity correction for a different distance is not acceptable.

(b) Lamp intensity in the flow through test reactor shall be set at 75% of a new 100% lamp after a 100-hour burn in stabilization period conducted at the same power input to the lamp.

(c) Effluent percent transmission during the full scale testing shall be established in accordance with the terms and conditions of the facility's wastewater permit.

§217.297.Ultraviolet Light Disinfection Reactor Design.

(a) An approach channel must be unobstructed and have a minimum length of 4.0 feet before the first ultraviolet (UV) bank.

(b) The downstream channel length must be unobstructed for a minimum length of 4.0 feet following the last bank of UV lamps and before a fluid-level control device.

(d) A downstream discharge point of a reactor must include a level control that ensures that the UV lamps remain submerged at a near-constant depth, regardless of flow.

(e) The upstream and downstream portions of a UV reactor channel between UV banks must be covered to shut out all natural light.

§217.298.Ultraviolet Light Disinfection System Cleaning and Maintenance.

(a) A design must include provisions for draining each ultraviolet (UV) disinfection channel and routine cleaning of the UV lamps and modules.

(b) A UV system must include the following spare parts, as a percentage of the total system equaling at least:

(1) 5% of the lamps;

(2) 2% of the ballasts; and

(3) 5% of the quartz sleeves.

(c) For maintenance purposes, the owner must provide a minimum of one spare module for each bank that is parallel to flow.

§217.299.Ultraviolet Light Disinfection System Safety.

Anyone in a reactor area must wear appropriate personal protection, including at least an ultraviolet (UV) UV-rated face shield and safety glasses or goggles.

§217.300.Post-Disinfection Requirements.

(a) Sampling Points. A design must include a sufficient number of sampling points, including at least one point immediately downstream of an ultraviolet (UV) system, to allow an operator to monitor the system. Sampling points must be identified in the report.

(b) Dissolved Oxygen (DO) Requirement.

(1) A UV disinfection system must include post-aeration to ensure compliance with DO requirements in the facility's wastewater permit.

This agency hereby certifies that the proposal has been reviewed by legal counsel and found to be within the agency's legal authority to adopt.

Filed with the Office of the Secretary of State on February 29, 2008.

TRD-200801210

Robert Martinez

Director, Environmental Law Division

Texas Commission on Environmental Quality

Earliest possible date of adoption: April 13, 2008

For further information, please call: (512) 239-0177

Subchapter M. SAFETY

30 TAC §§217.321 - 217.333

STATUTORY AUTHORITY

The proposed new rules implement TWC §§5.013, 5.103, 5.105, 5.120, 26.027, 26.034, and 26.121.

§217.321.Safety Design.

(a) The safety aspects of a treatment facility design must be based on Design of Municipal Treatment Plants, WEF Manual of Practice No. 8, published by the Water Environment Federation, or other safety design guidelines approved by the executive director.

(b) Occupational safety and health hazards and risks to workers and the public must be addressed in the design of collection system and treatment facility equipment and processes.

(c) A facility design must incorporate processes that use the least hazardous and toxic chemicals and the least amounts of those chemicals that will effectively treat and disinfect the influent so that the effluent and the sludge meet the requirements in the associated wastewater permit and do not degrade the water quality in a receiving stream or cause accumulation in a land application area.

(d) Where applicable, a design must follow the guidelines established under 29 Code of Federal Regulations, Part 1910.

(e) A design must demonstrate compliance with this section by implementing §217.292 of this title (relating to Safety and Security Audits) and §217.293 of this title (relating to and Hazardous Operation and maintenance).

§217.322.Safety and Security Audits.

(a) Safety Audit.

(1) The owner of an existing facility being modified or expanded must conduct a safety audit of the facility that evaluates injuries and incidents at the facility during the prior three-year period in order to determine the locations, causes, types of injuries, and jobs being performed when the injuries or incidents occurred.

(2) A safety audit must identify the locations and jobs associated with injuries or incidents and any subsequent corrective action taken or planned.

(3) A design must include measures that address the needed corrective actions identified in the safety audit as part of any modification or expansion project.

(b) Security Audit. The owner of an existing facility may conduct a security audit. The security audit may be based on the Asset Based Vulnerability Checklist for Wastewater Utilities by the Association of Metropolitan Sewerage Agencies or an equivalent security audit protocol.

§217.323.Hazardous Operation and Maintenance.

(a) An owner shall perform an analysis of operational and maintenance tasks to identify potentially hazardous situations for a new, expanded, or modified facility.

(b) For those identified potentially hazardous tasks, a list must be prepared for each task that identifies the necessary:

(1) tools, equipment, and supplies;

(2) fixed and portable lifting equipment;

(3) fixed and portable monitoring equipment;

(4) personal protective equipment and clothing;

(5) warning signs and guards; and

(6) first-aid supplies.

(1) allow workers to safely and properly operate equipment;

(2) perform required preventive maintenance, in compliance with the manufacturers' minimum requirements;

(3) make repairs; and

(4) maintain processes, pumps, motors, blowers, compressors, laboratory, instrumentation, and other equipment.

§217.324.Chemical Handling.

(a) An owner must make available appropriate protective equipment for breathing, eyes, face, head, and extremities for operating staff who will handle any chemical known to pose a potential health risk and must train the facility staff in the use of the equipment.

(b) A facility that uses any chemical must be designed to provide eye washing and showering systems in all appropriate locations.

§217.325.Railings, Ladders, Walkways, and Stairways.

(a) An opening in a railing must have a removable chain.

(b) A open valve box, pit, tank, or basin that extends less than 4.0 feet above ground must have a railing capable of preventing a person from falling into it.

(d) A ladder must have flat safety tread rungs and extensions at least 1.0 foot out of a vault.

(e) A walkway above an open tank must have a raised edge designed to prevent a person from slipping off the walkway.

(f) Walkways, steps, landings, and ladder rungs must have a non-slip finish.

(g) An overhead pipe must have at least a 7.0 foot clearance, unless the pipe is padded to prevent head injury and has a warning sign.

§217.326.Electrical Code.

The electrical elements of a facility or system design must conform to local electrical codes or to the National Electric Code if the facility is located in an area that does not have a local electrical code.

§217.327.Non-Potable Water.

Each hydrant and outlet for non-potable water must be clearly marked as "NON-POTABLE WATER" or "UNSAFE WATER."

§217.328.Facility Access Control.

(a) A facility must be completely fenced and have a lockable gate at each access point.

(b) A facility containing an open tank must have hazard signs stating "DANGER - OPEN TANKS - NO TRESPASSING" within visible sighting of each other on each gate and levee.

(1) at least an 8.0 foot solid material or chain-link fence topped with at least one strand of barbed-wire;

(2) at least a 6.0 foot high solid material or chain-link fence topped with three strands of barbed-wire that reach at least 6.0 inches above the fence for a total of 78 inches; or

(3) a 5-strand barbed-wire fence may be used in a rural area for fencing lagoons, or overland-flow plots, in lieu of chain-link or board fencing required by paragraphs (1) and (2) of this subsection.

(d) A facility must have at least one all-weather access road with the driving surface situated above the 100-year flood plain.

§217.329.Color Coding of Pipes.

(a) A new facility must have color-coded pipes.

(b) A new facility must have tracer tape for each non-metallic underground pipe.

(c) An existing facility must color-code and install tracer tape for each pipe associated with an up-grade or modification.

(d) A non-potable water pipe must be painted purple and be stenciled "NON-POTABLE WATER" or "UNSAFE WATER."

(e) A design must use the following color-coding for pipes:

(1) Sludge - brown;

(2) Natural gas - red;

(3) Potable water - light blue;

(4) Chlorine - yellow;

(5) Sulfur Dioxide - lime green with yellow bands;

(6) Sewage - grey;

(7) Compressed air - light green;

(8) Heated water - blue with 6 inch red bands spaced 30 inches apart;

(9) Power conduit - in compliance with the National Electric Code;

(10) Reclaimed water - purple;

(11) Instrument air - light green with dark green bands;

(12) Liquid alum - yellow with orange bands;

(13) Alum (solution) - yellow with green bands;

(14) Ferric chloride - brown with red bands;

(15) Ferric sulfate - brown with yellow bands;

(16) Polymers - white with green bands;

(17) Ozone - stainless steel with white bands;

(18) Raw water - tan; and

(19) Effluent after clarification - dark green.

§217.330.Public Drinking Water Supply Connections.

(a) Connection between a public drinking water supply system and a wastewater treatment facility must be made through an air gap or a reduced-pressure principle backflow prevention assembly (RPBA) in accordance with American Water Works Association (AWWA) Standard C511-97 or AWWA Manual M14.

(b) Each RPBA must be tested annually.

§217.331.Freeze Protection.

A horizontal surface subject to freezing temperatures and water accumulation must be sloped to prevent ice formation.

§217.332.Noise Levels.

(a) An area accessed by staff must be designed to comply with 29 Code of Federal Regulations §1910.95.

(b) Removable noise attenuation is prohibited.

§217.333.Confined Spaces.

(a) A design must, to the extent practicable, avoid confined spaces as defined in 29 Federal Code of Regulations §1910.146.

(b) A ventilating manhole must be equipped with a connection for a portable ventilator.

This agency hereby certifies that the proposal has been reviewed by legal counsel and found to be within the agency's legal authority to adopt.

Filed with the Office of the Secretary of State on February 29, 2008.

TRD-200801211

Robert Martinez

Director, Environmental Law Division

Texas Commission on Environmental Quality

Earliest possible date of adoption: April 13, 2008

For further information, please call: (512) 239-0177

Chapter 305. CONSOLIDATED PERMITS

Subchapter D. AMENDMENTS, RENEWALS, TRANSFERS, CORRECTIONS, REVOCATION, AND SUSPENSION OF PERMITS

30 TAC §305.72

The Texas Commission on Environmental Quality (commission) proposes to amend §305.72, regarding Underground Injection Control (UIC) Permit Modifications at the Request of the Permittee.

BACKGROUND AND SUMMARY OF THE FACTUAL BASIS FOR THE PROPOSED RULE

This rulemaking amends §305.72 in order to implement House Bill (HB) 2654, 80th Legislature, 2007, and its amendments to Texas Water Code (TWC), §27.021. House Bill 2654 removed the requirement for a contested case hearing under the provisions of TWC, §27.018, for Class I injection wells that dispose of nonhazardous brine produced by a desalination operation or of nonhazardous drinking water treatment residuals. House Bill 2654 does not exclude Class I injection wells for the disposal of any other waste streams from the requirement to provide an opportunity for a contested case hearing.

The purpose of this rulemaking is to subject permit amendments to the opportunity for a contested case hearing when the amendment is to a Class I injection well permit authorizing only disposal of nonhazardous brine produced by a desalination operation or of nonhazardous drinking water treatment residuals and the amendment requests authority to dispose of other types of wastes. The proposed rulemaking specifies that a permit for a Class I injection well used only for the disposal of nonhazardous brine produced by a desalination operation or of nonhazardous drinking water treatment residuals may not be administratively modified, under §305.72(b)(4), in order to add waste streams disposed in the Class I injection well other than nonhazardous brine produced by a desalination operation or nonhazardous drinking water treatment residuals. A permit change to dispose of other types of wastes will require a major amendment under §305.62(c)(1)(A), which provides an opportunity for a contested case hearing. This rulemaking will ensure that the hearing requirements of TWC, §27.018 for conventional Class I injection well permits will be retained after a permit is issued under the provisions of HB 2654. Amendments to 30 TAC Chapters 50, 55 and 331 to implement HB 2654 are also proposed in this issue of the Texas Register.

SECTION DISCUSSION

§305.72. Underground Injection Control (UIC) Permit Modifications at the Request of the Permittee.

The proposal would amend §305.72(b)(4) to specify that the kind of permit modification allowed to a conventional Class I injection well permit by this paragraph shall not include modifying a Class I injection well permit used only for the disposal of nonhazardous brine produced by a desalination operation or of nonhazardous drinking water treatment residuals to a conventional Class I injection well permit. This amendment effectively precludes a permit holder for this type of Class I injection well (used only for the disposal of nonhazardous brine produced by a desalination operation or of nonhazardous drinking water treatment residuals) from adding other types of waste streams without providing the opportunity for a contested case hearing.

The commission proposes an administrative change in §305.72(b)(4) to correct the spelling of "judgement" to "judgment."

FISCAL NOTE: COSTS TO STATE AND LOCAL GOVERNMENT

Nina Chamness, Analyst, Strategic Planning and Assessment, has determined that, for the first five-year period the proposed rule is in effect, no significant fiscal implications are anticipated for the agency or other units of state or local governments as a result of administration or enforcement of the proposed rule. The agency will utilize existing resources to develop rules and guidelines for a general permit to authorize the use of Class I injection wells for disposal of nonhazardous desalination concentrate or drinking water treatment residuals.

This rulemaking implements HB 2654, 80th Legislature, 2007 and aligns state standards for Class I wells disposing only of nonhazardous desalination concentrate and nonhazardous drinking water treatment residuals with federal Class I injection well standards for nonhazardous wells. House Bill 2654 allows the commission to issue a general permit to authorize the use of a Class I injection well for disposal of nonhazardous desalination concentrate or drinking water treatment residuals and eliminates the necessity of obtaining a permit from the commission when the Railroad Commission of Texas authorizes the use of these wastes as appropriate injection fluids for enhanced recovery purposes. The proposed rule is part of the agency's proposal to establish regulations to govern the general permit, and they amend the appropriate sections of Chapter 305 to ensure that, if wastes, other than those authorized by the proposed general permit, are modified, then the change will constitute a major permit amendment and provide the opportunity for a contested case hearing. This proposed rulemaking is part of amendments proposed for appropriate sections of Chapters 50, 55, and 331 to establish a general permit program for these types of Class I injection wells. This fiscal note addresses only the fiscal implication of proposed changes to Chapter 305, and the fiscal implications for needed amendments to other chapters are addressed in separate fiscal notes.

The proposed amendment to Chapter 305 would ensure that, if the waste stream permitted under the proposed general permit is modified to include waste other than nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals, the owners or operators of the Class I injection well would be subject to the requirements of a major permit amendment. These requirements include the chance that the well owners would become subject to a contested case hearing as well as public notice and meeting requirements.

The proposed rule is not expected to have a significant fiscal impact on local governments that have a general permit to operate a Class I injection well for disposal of nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals unless they decide to dispose of other types of wastes in these injection wells. If a local government decides to modify the waste stream, it will be subject to a contested case hearing and other regulations governing other types of injection wells or disposal methods. A contested case hearing could cost as much as $500,000 although it would likely cost less. Public notices could cost as much as $1,000 to $3,000 per notice depending on the circulation size of the newspaper used. If there is sufficient public interest to warrant a public meeting, meeting expenses for an applicant could range from $1,700 to $4,700 depending on the cost of notices and the price for renting a meeting space. It is unknown how many local governments might choose to modify their waste streams and become subject to the proposed rule.

PUBLIC BENEFITS AND COSTS

Nina Chamness also determined that, for each year of the first five years the proposed rule is in effect, the public benefit anticipated from the changes seen in the proposed rule will be continued protection of public health and the environment by requiring owners of Class I injection wells authorized by general permit to dispose of nonhazardous desalination concentrate or drinking water treatment residuals and who desire to change the waste stream to comply with major permit amendment requirements.

Regulated entities that elect to modify the waste stream to be disposed of in a Class I injection well authorized by the proposed general permit issued for a Class I injection well for disposal of nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals will be subject to a contested case hearing and other regulations governing other types of injection wells or disposal methods. A contested case hearing could cost as much as $500,000 although it would likely cost less. Public notices could cost as much as $1,000 to $3,000 per notice depending on the circulation size of the newspaper used. If there is sufficient public interest to warrant a public meeting, meeting expenses for an applicant could range from $1,700 to $4,700 depending on the cost of notices and the price for renting a meeting space.

SMALL BUSINESS AND MICRO-BUSINESS ASSESSMENT

No adverse fiscal implications are anticipated for small or micro-businesses as a result of the proposed rule. Typically, small or micro-businesses do not own or operate Class I injection wells, and staff does not expect these businesses to request a general permit to operate a well of this type. If a small business does request a general permit to own or operate this type of Class I injection well and it elects to modify the wastes injected into the well, it can expect to incur the same costs for a contested case hearing as those incurred by local governments and large businesses.

SMALL BUSINESS REGULATORY FLEXIBILITY ANALYSIS

The commission has reviewed this proposed rulemaking and determined that a small business regulatory flexibility analysis is not required because the proposed rule is required to protect human health and the environment and does not adversely affect a small or micro-business in a material way for the first five years that the proposed rule is in effect.

LOCAL EMPLOYMENT IMPACT STATEMENT

DRAFT REGULATORY IMPACT ANALYSIS DETERMINATION

Additionally, this rulemaking does not meet any of the four applicability requirements listed in Texas Government Code, §2001.0225(a). Texas Government Code, §2001.0225 only applies to a major environmental rule, the result of which is to: (1) exceed a standard set by federal law, unless the rule is specifically required by state law; (2) exceed an express requirement of state law, unless the rule is specifically required by federal law; (3) exceed a requirement of a delegation agreement or contract between the state and an agency or representative of the federal government to implement a state and federal program; or (4) adopt a rule solely under the general powers of the agency instead of under a specific state law. This rulemaking does not meet any of these four applicability requirements because this rulemaking does not exceed any standard set by federal law but rather amends the rules so that they are no more stringent or restrictive than the federal regulations. The proposed rule does not exceed the requirements of state law under the TWC, Chapter 27. Further, the proposed rule does not exceed a requirement of a delegation agreement or contract between the state and an agency or representative of the federal government to implement any state and federal program. Finally, the rule is not proposed solely under the general powers of the agency, but rather specifically under TWC, §27.023(m), which allows the commission to adopt rules to implement the general permit authorizing use of a Class I injection well to inject nonhazardous brine from desalination operations or nonhazardous drinking water treatment residuals and TWC, §27.109, which authorizes the commission to adopt rules to implement TWC, Chapter 27 (regarding Injection Wells), as well as the other general powers of the agency.

TAKING IMPACT ASSESSMENT

The commission evaluated the proposed amendment to Chapter 305 and performed a preliminary assessment of whether the amendment would constitute a taking under Texas Government Code, Chapter 2007. The primary purposes of the proposed amendment are to implement HB 2654 and correct a misspelling identified during review of the rule language. The proposed amendment would substantially advance these purposes by amending §305.72 to ensure that additional waste streams shall not be added as minor modifications to a Class I injection well permitted in such a manner that no opportunity exists for a contested case hearing, and by changing the spelling of "judgement" to "judgment."

Promulgation and enforcement of the proposed amendment would constitute neither a statutory nor a constitutional taking of private real property. There are no burdens imposed on private real property under this rule because the proposed amendment neither relates to, nor has any impact on the use or enjoyment of private real property, and there would be no reduction in property value as a result of this rule. Therefore, the proposed rule would not constitute a taking under Texas Government Code, Chapter 2007.

The commission has no reasonable alternative that could accomplish the specific purpose of ensuring that additional waste streams are not added as minor modifications to a Class I injection well permitted in such a manner that no opportunity exists for a contested case hearing. Without the proposed amendment, a Class I injection well for disposal of only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals could be permitted under an individual permit or other authorization not requiring a contested case hearing, then add another waste stream as a minor modification without the public ever having an opportunity to contest the additional waste stream through the contested case hearing process.

CONSISTENCY WITH THE COASTAL MANAGEMENT PROGRAM

The commission reviewed the proposed rule and found that it is neither identified in Coastal Coordination Act Implementation Rules, 31 TAC §505.11(b)(2) or (4), nor will it affect any action/authorization identified in Coastal Coordination Act Implementation Rules, 31 TAC §505.11(a)(6). Therefore, the proposed rule is not subject to the Texas Coastal Management Program.

ANNOUNCEMENT OF HEARING

The commission will hold a public hearing on this proposal in Austin on April 8, 2008 at 10:00 a.m. in Building E, Room 201S, at the commission's central office located at 12100 Park 35 Circle. The hearing is structured for the receipt of oral or written comments by interested persons. Individuals may present oral statements when called upon in order of registration. Open discussion will not be permitted during the hearing; however, commission staff members will be available to discuss the proposal 30 minutes prior to the hearing.

SUBMITTAL OF COMMENTS

STATUTORY AUTHORITY

§305.72.Underground Injection Control (UIC) Permit Modifications at the Request of the Permittee.

(a) This section applies only to Underground Injection Control permits.

(b) With the permittee's consent, the executive director may modify administratively a permit to make the corrections or allowances for changes in the permitted activity listed in this section, without following the procedures and notice requirements of this chapter. Any change to the permit not processed as a minor modification under this section must be made for cause and in compliance with appropriate public notice requirements. Minor modifications may only:

(1) correct typographical errors;

(2) require more frequent monitoring or reporting by the permittee;

(3) change an interim compliance date in a schedule of compliance, provided the new date is not more than 120 days after the date specified in the existing permit and does not interfere with attainment of the final compliance date requirement;

(4) change quantities or types of fluids injected which are within the capacity of the facility as permitted and in the judgment [ ~~judgement~~ ] of the executive director, would not interfere with the operation of the facility or its ability to meet conditions described in the permit and would not change its classification, provided however, that this provision shall not be used to add a waste stream other than nonhazardous [ ~~desalination~~ ] brine produced by a desalination operation or nonhazardous drinking water treatment residuals to the permit of a Class I injection well issued without the opportunity for a contested case hearing;

(5) change construction requirements, provided that the alterations comply with the requirements of Chapter 331 of this title (relating to Underground Injection Control); or

(6) amend a plugging and abandonment plan which has been updated under §305.154(7) of this title (relating to Standards).

This agency hereby certifies that the proposal has been reviewed by legal counsel and found to be within the agency's legal authority to adopt.

Filed with the Office of the Secretary of State on February 29, 2008.

TRD-200801192

Robert Martinez

Director, Environmental Law Division

Texas Commission on Environmental Quality

Earliest possible date of adoption: April 13, 2008

For further information, please call: (512) 239-0177

Chapter 317. DESIGN CRITERIA FOR SEWERAGE SYSTEMS

30 TAC §§317.1 - 317.13, 317.15

(Editor's note: The text of the following sections proposed for repeal will not be published. The sections may be examined in the offices of the Texas Commission on Environmental Quality or in the Texas Register office, Room 245, James Earl Rudder Building, 1019 Brazos Street, Austin.)

The Texas Commission on Environmental Quality (commission) proposes the repeal of §§317.1 - 317.13 and §317.15.

BACKGROUND AND SUMMARY OF THE FACTUAL BASIS FOR THE PROPOSED REPEAL

The repeal of Chapter 317, along with the proposal of new Chapter 217, accomplishes three tasks: implementing the commission's goal of having all water related rules under the Chapter 200 series; allowing the design criteria to be updated with current technology and engineering practices; and allowing the rules to be written with current rule language guidelines and be more logically organized.

Chapter 317 is irretrievably out of date. The changes needed to bring the design criteria for domestic wastewater systems into conformity with current rule writing standards, logical organization, and technical advances are better served by repealing Chapter 317 and proposing the updated criteria in Chapter 217. The commission last comprehensively revised Chapter 317 in 1986. Minor revisions in 1988, 1990, and 1994 addressed specific concerns, but did not bring the rules in line with advances in wastewater technologies or current commission rule standards. Additionally, repealing Chapter 317 allows the commission to make needed revisions to address requirements in current wastewater permits in Chapter 217.

SECTION BY SECTION DISCUSSION

The proposal will repeal all sections of Chapter 317, §§317.1 - 317.13 and §317.15. The requirements in these sections will be edited, updated, and proposed in new Chapter 217.

FISCAL NOTE: COSTS TO STATE AND LOCAL GOVERNMENT

Jeff Horvath, Analyst, Strategic Planning and Assessment, has determined that for the first five-year period the proposed repeal is in effect, no fiscal implications are anticipated for the agency or other units of state or local government as a result of the administration or enforcement of the proposed repeal.

The proposed repeal would eliminate rules governing domestic wastewater design criteria that will be replaced by new Chapter 217 design standards authorized under Chapter 26 of the Texas Water Code. No fiscal implications are anticipated for the agency or other units of state or local governments as a result of administration or enforcement of the proposed repeal. However, new design standards are proposed in the new Chapter 217, and the fiscal note for Chapter 217 does take into consideration fiscal implications from the updating of the rules governing design criteria for domestic wastewater systems affecting state or local governments.

PUBLIC BENEFITS AND COSTS

Mr. Horvath also determined that for each year of the first five years the proposed repeal is in effect, the public benefit anticipated from the changes seen in the proposed repeal will be the elimination of outdated design criteria which do not reflect current engineering practices and technology.

No fiscal implications are anticipated for businesses or individuals as a result of the proposed repeal for the first five years the repeal is in effect. However, regulated entities will be required to comply with the proposed requirements in Chapter 217 that will replace the obsolete sections being eliminated in this rulemaking. Any fiscal implications for businesses and individuals relating to the new design criteria proposed in Chapter 217 are discussed in that rule proposal.

SMALL BUSINESS AND MICRO-BUSINESS ASSESSMENT

No adverse fiscal implications are expected for small or micro-businesses as a result of the proposed repeal. However, regulated entities will be required to comply with the proposed requirements in Chapter 217 that will replace the obsolete sections being eliminated in this rulemaking. Any fiscal implications for small or micro-businesses relating to the new design criteria proposed in Chapter 217 are discussed in that rule proposal.

SMALL BUSINESS REGULATORY FLEXIBILITY ANALYSIS

The commission has reviewed this proposed rulemaking and determined that a small business regulatory flexibility analysis is not required because the proposed repeal does not adversely affect a small or micro-business in a material way for the first five years that the proposed repeal is in effect.

LOCAL EMPLOYMENT IMPACT STATEMENT

The commission has reviewed this proposed rulemaking and determined that a local employment impact statement is not required because the proposed repeal does not adversely affect a local economy in a material way for the first five years that the proposed repeal is in effect.

DRAFT REGULATORY IMPACT ANALYSIS DETERMINATION

The commission reviewed this rulemaking in light of the regulatory analysis requirements of Texas Government Code, §2001.0225, and determined that the rulemaking is not subject to §2001.0225, because it does not meet the criteria for a "major environmental rule" as identified in that statute. Major environmental rule is defined as a rule, the specific intent of which, is to protect the environment or reduce risks to human health from environmental exposure and that may adversely affect in a material way the economy, a sector of the economy, productivity, competition, jobs, the environment, or the public health and safety of the state or a sector of the state. Repeal of the Chapter 317 rules will not adversely affect, in a material way, the economy, a section of the economy, productivity, competition, jobs, the environment, or the public health and safety of the state or a sector of the state. The intent of this proposal is to repeal the outdated Chapter 317 design standards and issue new rules in Chapter 217 that update the design standards and criteria for wastewater treatment systems to current engineering practices and include recent advances in wastewater treatment technologies. The repeal of Chapter 317 does not meet any of the four applicability requirements listed in §2001.0225(a). Specifically, repealing the Chapter 317 rules does not exceed a federal standard because no applicable federal standard exists. Repeal of the Chapter 317 rules does not exceed an express requirement of state law nor exceed a requirement of a delegation agreement. Finally, the repeal of the Chapter 317 rules was not developed solely under the general powers of the agency; but in conjunction with the specific authority of Texas Water Code, §26.034 to propose new design standards and criteria in Chapter 217.

Written comments on the draft regulatory impact analysis determination may be submitted to the contact person at the address listed under the SUBMITTAL OF COMMENTS section of this preamble.

TAKINGS IMPACT ASSESSMENT

The commission performed an assessment of the rulemaking in accordance with Texas Government Code, §2007.043. The specific purpose of the rulemaking is to repeal the outdated design standards and criteria for wastewater treatment systems and issue a new set of rules in proposed Chapter 217 that updates those rules to meet current engineering practices and to include recent advances in wastewater treatment technologies. Also, the proposed Chapter 217 rules will allow increased flexibility to attain the design standards and criteria; update the standards and criteria reflecting the commission's domestic wastewater permitting practices; and amend and specify the commission's review and approval processes for proposed wastewater treatment facility projects. The repeal of the Chapter 317 rules will constitute neither a statutory nor a constitutional taking of private real property, impose no burdens on private real property because the repealed rules neither relates to, nor has any impact on the use or enjoyment of private real property, and there is no reduction in value of property as a result of this rulemaking.

CONSISTENCY WITH THE COASTAL MANAGEMENT PROGRAM

The commission reviewed the proposed rulemaking and found the proposal is a rulemaking identified in the Coastal Coordination Act Implementation Rules, 31 TAC §505.11(b)(4), relating to rules subject to the Coastal Management Program, and will, therefore, require that goals and policies of the Texas Coastal Management Program (CMP) be considered during the rulemaking process.

The commission determined that the repeal, which is a procedural mechanism for removing rules which are outdated, is consistent with CMP goals and policies and will not have a direct or significant adverse effect on any coastal natural resource areas; will not have a substantive effect on commission actions subject to the CMP; and promulgation of the repeals will not violate (exceed) any standards identified in the applicable CMP goals and policies.

Written comments on the consistency of this rulemaking may be submitted to the contact person at the address listed under the SUBMITTAL OF COMMENTS section of this preamble.

ANNOUNCEMENT OF HEARING

The commission will hold a public hearing on this proposal in Austin on April 3, 2008 at 2:00 p.m. in E201S, at the commission's central office located at 12100 Park 35 Circle. The hearing is structured for the receipt of oral or written comments by interested persons. Individuals may present oral statements when called upon in order of registration. Open discussion will not be permitted during the hearing; however, commission staff members will be available to discuss the proposal 30 minutes prior to the hearing.

SUBMITTAL OF COMMENTS

Written comments may be submitted to Kristin Smith, Texas Register Team, MC 205, Office of Legal Services, Texas Commission on Environmental Quality, P.O. Box 13087, Austin, Texas 78711-3087, or faxed to (512) 239-4808. Electronic comments may be submitted at: http://www5.tceq.state.tx.us/rules/ecomments/. File size restrictions may apply to comments being submitted via the eComments system. All comments should reference Rule Project Number 2006-044-217-PR. The comment period closes April 14, 2008. Copies of the proposed rulemaking can be obtained from the commission's Web site at http://www.tceq.state.tx.us/nav/rules/propose_adopt.html . For further information, please contact Sherry Smith, Rule Project Manager, Water Quality Division, (512) 239-0571 or Louis C. Herrin, III, P.E., Rule Technical Manager, Water Quality Division, (512) 239-4552.

STATUTORY AUTHORITY

The repeal is proposed under the authority of Texas Water Code, §5.013, which provides the commission's general jurisdiction; §5.103, which provides the commission's authority to adopt any rules necessary to carry out its powers and duties under the laws of Texas; §5.105, which provides the commission's authority to, by rule, establish and approve general policy of the commission; §5.120, which provides the commission's authority to administer the law to promote conservation and protection of the quality of the environment; §12.081, which provides the commission's continuing right of supervision over certain districts and authorities; §12.082, which provides the commission's duty to investigate fresh water supply district projects; §26.027, which authorizes the commission to issue permits; §26.034, which provides the commission's authority to adopt rules for the approval of disposal system plans; and §26.121, which provides the commission's authority to prohibit unauthorized discharges.

The proposed repeal implements Texas Water Code, §§5.013, 5.103, 5.105, 5.120, 12.081, 12.082, 26.027, 26.034, and 26.121.

§317.1.General Provisions.

§317.2.Sewage Collection System.

§317.3.Lift Stations.

§317.4.Wastewater Treatment Facilities.

§317.5.Sludge Processing.

§317.6.Disinfection.

§317.7.Safety.

§317.8.Design and Operation Features.

§317.9.Appendix A.

§317.10.Appendix B--Overland Flow Process.

§317.11.Appendix C--Hyacinth Basins.

§317.12.Appendix D.

§317.13.Appendix E--Separation Distances.

§317.15.Appendix G--General Guidelines for the Design of Constructed Wetlands Units for Use in Municipal Wastewater Treatment.

This agency hereby certifies that the proposal has been reviewed by legal counsel and found to be within the agency's legal authority to adopt.

Filed with the Office of the Secretary of State on February 29, 2008.

TRD-200801199

Robert Martinez

Director, Environmental Law Division

Texas Commission on Environmental Quality

Earliest possible date of adoption: April 13, 2008

For further information, please call: (512) 239-0177

Chapter 331. UNDERGROUND INJECTION CONTROL

The Texas Commission on Environmental Quality (commission) proposes amendments to §§331.2, 331.7, 331.17, 331.42, 331.45, 331.46, 331.62 - 331.66, and 331.121 and new §§331.201 - 331.206.

BACKGROUND AND SUMMARY OF THE FACTUAL BASIS FOR THE PROPOSED RULES

This rulemaking supports the commission's role in promoting desalination projects and is intended to facilitate permitting of Class I wells to be used for disposal of nonhazardous desalination concentrate and other nonhazardous water treatment residuals from public water systems and to reduce operating costs for these wells. This project is in response to initiatives by the Governor's Office and the Texas Water Development Board to promote desalination technology in Texas and to address the need for public water supply systems to dispose of drinking water treatment residuals.

This rulemaking implements House Bill (HB) 2654, 80th Legislature, 2007 and amends technical standards to expand disposal options for the special case of nonhazardous brine from a desalination operation (desalination concentrate) and nonhazardous drinking water treatment residuals. HB 2654 allows the commission to issue a general permit to authorize the use of a Class I injection well to dispose of nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals. A single statewide general permit covering all qualifying Class I injection wells that meet the permit's performance standards for injection of nonhazardous desalination concentrate and other nonhazardous drinking water treatment residuals will expedite the processing of authorizations for wells used for these purposes. The general permit will require safeguards to protect groundwater and surface water.

The use of a general permit to authorize Class I wells for disposal of desalination concentrate and other water treatment residuals from public water systems will reduce commission staff time required to perform detailed administrative and technical reviews of individual permit applications. For projects that do not meet the criteria for the general permit, the commission will be able to conduct streamlined reviews of applications for Class I nonhazardous wells for the disposal of desalination concentrate and other water treatment residuals from public water systems. Under current rules, injection of nonhazardous desalination concentrate and other nonhazardous water treatment residuals from public water systems is limited to individually-permitted Class I wells, Class II wells dually permitted as Class I wells, or under special conditions, rule-authorized Class V wells. Other options for disposal of nonhazardous desalination brine and nonhazardous drinking water treatment residuals include evaporation ponds and surface discharge under a Texas Pollutant Discharge Elimination System permit.

Entities disposing of desalination concentrate and other water treatment residuals from public water systems in Class I nonhazardous waste disposal wells and Class I/Class II dually permitted wells will be the primary beneficiaries of this proposed rulemaking. This rulemaking will benefit the public by facilitating the production of public water supplies via desalination. Public water systems that must treat water to meet standards for constituent levels and dispose of the residuals will also benefit. Residents and property owners adjacent to disposal sites may be affected by this rule. This rulemaking may require submittal of a Underground Injection Control (UIC) Program revision to the United States Environmental Protection Agency in order to explain new processes under the proposed rules and future general permit.

HB 2654 also authorizes the use of nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals as an injection fluid for enhanced recovery purposes without first obtaining a permit from the commission (consistent with federal regulations). Prior to this legislation, enhanced oil recovery wells needed permits from both the commission and the Railroad Commission of Texas (Class II wells).

In addition to implementing HB 2654, this rulemaking amends Chapter 331 to create a set of criteria closely analogous to federal Class I nonhazardous injection well regulations for the special case of wells injecting nonhazardous desalination concentrate and other nonhazardous water treatment residuals from public water systems. Currently in Texas the technical standards for Class I hazardous and nonhazardous wells are substantially the same; however, federal Class I standards for nonhazardous waste wells are less stringent. In conjunction with HB 2654, the revised technical standards will facilitate the use of injection wells for these purposes while meeting federal standards.

To implement HB 2654, this rulemaking amends §§331.2, 331.7 and 331.17 and adds new Subchapter L, General Permit Authorizing Use of a Class I Injection Well to Inject Nonhazardous Desalination Concentrate or Nonhazardous Drinking Water Treatment Residuals. To create a set of criteria closely analogous to federal Class I nonhazardous injection well regulations for the special case of wells injecting nonhazardous desalination concentrate and other nonhazardous water treatment residuals from public water systems, §§331.42, 331.45, 331.46, 331.62 - 331.66 and 331.121 are amended. To allow an injection well authorized by the Railroad Commission of Texas to use nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals as an injection fluid for enhanced recovery purposes without a permit from the commission, §331.7 is amended. The proposed amendment to §331.7 also stipulates that, in this context, radioactive material is subject to the applicable requirements of 30 TAC Chapter 336.

Changes to 30 TAC Chapters 50, 55, and 305 to implement HB 2654 are also proposed in this issue of the Texas Register.

SECTION BY SECTION DISCUSSION

The commission proposes to amend §331.2, Definitions, to add the following eight definitions. These definitions are necessary to characterize new terminology used in HB 2654 that do not currently appear in connection with Class I wells in Chapter 331. Desalination concentrate, is added as new paragraph (30). Drinking water treatment residuals is added as new paragraph (35). Enhanced oil recovery project (EOR), is added as new paragraph (37). General permit, is added as new paragraph (44). Individual permit, is added as new paragraph (49). Notice of change (NOC), and Notice of intent (NOI) are added as new paragraphs (71) and (72), respectively. Public water system, is added as new paragraph (84). The commission is renumbering the definitions in §331.2 as a result of the added definitions. Current paragraph (34) is renumbered as paragraph (36); current paragraphs (35) - (40) are renumbered as paragraphs (38) - (43), respectively; current paragraphs (41) - (44) are renumbered as paragraphs (45) - (48), respectively; current paragraphs (45) - (65) are renumbered as paragraphs (50) - (70), respectively; current paragraphs (66) - (76) are renumbered as paragraphs (73) - (83), respectively; current paragraphs (77) - (104) are renumbered as paragraphs (85) - (112), respectively.

Section 331.7, Permit Required, is amended as follows: subsection (a) is amended to include subsections (e) and (f) as exceptions to the requirement that all injection wells and activities must be authorized by an individual permit. The word "permit" is changed to "individual permit" to clarify that §331.7(a) pertains to an individual permit versus the general permit. Subsection (d) is revised to exclude pre-injection units for Class I wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals from the option to be authorized by registration. HB 2654 does not explicitly mention pre-injection units, and the commission plans to address pre-injection units in the general permit. Consistent with federal requirements, no special authorization for pre-injection units associated with these wells will be required. Pre-injection units may also be authorized under an individual permit, such as a Class I UIC permit, or under 30 TAC Chapter 290. Chapter 290 addresses the construction of facilities associated with water treatment. Proposed subsection (e) is added to authorize the commission to issue a general permit for the use of a Class I injection well to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals. If the commission determines that the general permit will not protect ground and surface fresh water from pollution, the commission may require that an injection well and the injection activities be regulated under an individual permit. Proposed subsection (f) is added to stipulate that an injection well authorized by the Railroad Commission of Texas to use nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals as an injection fluid for enhanced recovery purposes does not require a permit from the commission.

Section 331.17(a), Pre-injection Units Registration, is amended to exclude pre-injection units for Class I wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals from the option to be authorized by registration. HB 2654 does not explicitly mention pre-injection units, and the commission plans to address pre-injection units in the general permit. Consistent with federal requirements, no special authorization for pre-injection units will be required for units associated with these wells. This change is made in conjunction with the amendment of §331.7(d).

The proposed amendment to §331.42, Area of Review, substantively affects subsections (a) - (c). The purpose of these changes is to specify standards for the extent of the area of review that are substantially equivalent to federal standards for Class I wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals.

In §331.42(a), the contents of existing §331.42(b)(1) - (4) are incorporated as new paragraphs (1) and (3) - (5). This reformatting groups the area of review requirements for different types and classes of wells under existing §331.42(a). Existing §331.42(b) is relabeled as §331.42(a)(1) and amended to exclude wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals from the area of review requirement for other types of Class I wells. Proposed §331.42(a)(2) is added to specify that the area of review for wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals is a radius of 1/4 mile from the proposed or existing wellbore, or the area within the cone of influence, whichever is greater. This new paragraph further stipulates that the radius of an area of review determined by the mathematical model stated in §331.42(b) is permissible even if it is less than 1/4 mile. The contents of existing §331.42(b)(2) - (4) are incorporated under §331.42(a) as paragraphs (3) - (5). Existing subsection (c), which contains a mathematical equation, is relabeled as subsection (b), and editorial changes are made at two places in the equation to replace an erroneous paragraph symbol with the Greek letter pi (π). Existing subsection (d) is relabeled as subsection (c) and amended to exclude wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals from the requirement for a minimum radius of 2-1/2 miles for the area of review. Existing subsection (e) is relabeled as subsection (d).

The commission proposes to amend §331.45(1) to exclude wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals from certain standards for construction and completion of the well that exceed federal standards for Class I nonhazardous waste wells. New language has been added to §331.45(2) to stipulate standards substantially equivalent to federal standards for construction and completion of Class I wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals. Paragraphs (2) and (3) have been renumbered as paragraphs (3) and (4).

Section 331.46, Closure Standards, is amended to add new subsection (a), stating which of current subsections (a) - (p) of §331.46 apply to Class I wells, salt cavern disposal wells, and Class I wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals. The purpose of these changes is to specify closure standards that are substantially equivalent to federal standards for Class I wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals. Subsection (a) has been relabeled as subsection (b), and subsequent subsections (b) - (p) have been relabeled as subsections (c) - (q), respectively. In subsection (c), the hyphenated word "non-hazardous" is corrected to "nonhazardous."

The commission proposes to amend §331.62, Construction Standards, by adding proposed subsection (a) to state that those construction standards for Class I nonhazardous waste wells which exceed federal standards for Class I wells do not apply to Class I wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals. Proposed subsection (b) is added to stipulate construction standards substantially equivalent to federal standards for Class I nonhazardous waste wells that are authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals.

Section 331.63, Operating Requirements, is amended to add proposed subsection (a), stating which of current subsections (a) - (l) of §331.63 apply to Class I wells in general and which apply to the special case of Class I wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals. The purpose of these changes is to specify operating requirements that are substantially equivalent to federal standards for Class I wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals. Subsection (a) has been relabeled as subsection (b), and subsequent subsections (b) - (l) have been relabeled as subsection (c) - (m), respectively. In subsection (j), the hyphenated word "non-hazardous" is corrected to "nonhazardous" consistent with editorial standards. Proposed subsection (n) is added to stipulate requirements consistent with federal standards for the fluid and pressure in the annulus between the tubing and long string casing.

Section 331.64, Monitoring and Testing Requirements, is amended to add proposed subsection (a) stating that current subsections (a) - (i) of §331.64 apply to all Class I wells except Class I wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals. Proposed subsection (k) is added to specify monitoring and testing requirements that are substantially equivalent to federal standards for Class I wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals. Subsection (a) has been relabeled as subsection (b), and subsequent subsections (b) - (i) have been relabeled as subsections (c) - (j), respectively.

Subsection 331.65, Reporting Requirements, is amended to add proposed subsection (a), stating that current subsections (a) - (c) of §331.64 apply to all Class I wells except Class I wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals. Proposed subsection (e) is added to specify reporting requirements that are substantially equivalent to federal standards for Class I wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals. Subsection (a) has been relabeled as subsection (b), and subsequent subsections (b) and (c) have been relabeled as subsections (c) and (d), respectively.

Section 331.66, Additional Requirements and Conditions, is amended to state that this section applies to all Class I wells except Class I wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals. The requirements in §331.66 exceed federal requirements for Class I nonhazardous waste wells and will not apply to Class I wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals.

Section 331.121(a)(2), Class I Wells, is amended to state that §331.121(a)(2)(A) - (R) apply to all Class I wells except Class I wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals. Proposed §331.121(a)(3) is added to stipulate the information, consistent with federal requirements for Class I nonhazardous waste wells, to be considered by the commission before issuing a Class I permit for a well authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals. Subsection (c) is amended to state that all paragraphs apply to all Class I wells except wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals. Subsection (c) is also amended to specify that, consistent with federal requirements for Class I nonhazardous waste wells, only §331.121(c)(1) applies to Class I wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals. This change eliminates more stringent siting criteria that are not consistent with federal requirements for nonhazardous waste wells.

Proposed §331.201 is titled, Purpose and Applicability. Subsection (a) authorizes the commission to issue a permit to dispose of nonhazardous brine produced by a desalination operation or of nonhazardous drinking water treatment residuals in a Class I well if the facility meets statutory and regulatory requirements. Subsection (b) states that the commission may issue a general permit authorizing the use of a Class I well to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals. Subsection (c) stipulates that authorization for the use of an injection well under a general permit does not confer a vested right. Subsection (d) refers to the requirements of 30 TAC Chapter 336 for the use or disposal of radioactive material under new Subchapter L of Chapter 331.

Proposed §331.202 is titled, Public Notice, Public Meetings, and Public Comment. Subsection (a) states that the requirements of this section apply to processing a new general permit and amendment, renewal, revocation or cancellation of a general permit. Subsection (b) includes requirements for publishing notice of a draft general permit. Subsection (c) stipulates the contents of a public notice of a draft general permit. Subsection (d) includes requirements for public meetings for the draft general permit. Subsection (e) specifies requirements for the executive director's response to public comments on the general permit.

Proposed §331.203 is entitled, Authorizations and Notices of Intent. Subsection (a) requires submission of a Notice of Intent for a person to obtain authorization to use a Class I injection well to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals. Subsection (b) stipulates that the content of the Notice of Intent shall be specified in the general permit. Subsection (c) states requirements for denial of an authorization or Notice of Intent. Subsection (d) covers suspension of authorization and Notices of Intent under a general permit. The executive director is required to provide written notice to a permittee if he intends to suspend the permittee's authority to inject waste under the general permit. Subsection (e) specifies use of a permittee's compliance history in denying or suspending a permittee's authority to inject waste under the general permit.

Proposed §331.204 is entitled, Permit Duration, Amendment and Renewal. Subsection (a) stipulates a ten-year term for the general permit. Subsection (b) specifies conditions for renewal of the general permit. Subsection (c) states that, upon issuance of a renewed or amended general permit, owners or operators covered under the general permit shall submit a Notice of Intent in accordance with the requirements of the new permit. Subsection (d) requires permittees authorized under the general permit to submit an application for an individual permit before the general permit expires if the commission has not proposed to renew the general permit at least 90 days before its expiration date. Subsection (e) states that, through renewal or amendment, the commission may add or delete requirements or limitations to the general permit. Existing permittees covered by the general permit are to be provided a reasonable time to make changes necessary to comply with substantive additional requirements. Subsection (f) states that the commission must find that the general permit is consistent with the goals and policies of the Texas Coastal Management Plan.

Proposed §331.205 is titled, Fees for Notice of Intent and Notice of Change. New subsections (a) and (b) specify that a person must submit a $100 fee along with each Notice of Intent or Notice of Change, respectively, for each disposal well.

Proposed §331.206, titled Annual Fee Assessments, stipulates that annual facility and waste management fees must be paid by a person authorized by the general permit.

FISCAL NOTE: COSTS TO STATE AND LOCAL GOVERNMENT

Nina Chamness, Analyst, Strategic Planning and Assessment, has determined that, for the first five-year period the proposed rules are in effect, no significant fiscal implications are anticipated for the agency or other units of state or local governments as a result of administration or enforcement of the proposed rules. The agency will use existing resources to develop rules and guidelines for a general permit to authorize the use of Class I injection wells for disposal of nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals.

This rulemaking implements HB 2654, 80th Legislature, 2007 and aligns state standards for Class I wells disposing only of nonhazardous desalination concentrate and nonhazardous drinking water treatment residuals with federal Class I injection well standards for nonhazardous wells. HB 2654 allows the commission to issue a general permit to authorize the use of a Class I injection well for disposal of nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals and authorizes the use of these wastes as injection fluids for enhanced recovery purposes without obtaining a permit from the commission. To implement the legislation and revise technical standards, the proposed rules amend existing sections of Chapter 331 and add new Subchapter L. In conjunction with this rulemaking, amendments are proposed for appropriate sections of Chapters 50, 55, and 305. This fiscal note addresses only the fiscal implication of proposed changes to Chapter 331, and the fiscal implications for needed amendments to other chapters are addressed in separate fiscal notes.

A single statewide general permit covering all qualifying Class I injection wells that meet the permit's performance standards for injection of nonhazardous desalination concentrate and nonhazardous drinking water treatment residuals will expedite the processing of authorizations for wells used for these purposes. The general permit will require safeguards to protect groundwater and surface water when constructing and operating a well of this type.

The proposed rules are not expected to have significant fiscal implications for local governments or state agencies. Local governments and state agencies are expected to dispose of desalination concentrate and drinking water treatment residual waste in the least costly manner, and other methods of waste disposal are available which may be more economical than injection into a well permitted under the proposed general permit. Staff currently knows of two local governments that have expressed interest in the proposed general permit, but the number of local governments that would actually apply for the proposed permit is not known.

If a local government or state agency decides to apply for authorization under the general permit to own or operate a Class I injection well, it could expect to pay the same permit fee ($100 per application), construction, testing, and maintenance costs as those paid by owners or operators of Class I wells permitted under an individual permit for disposal of nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals. These costs can vary widely depending on multiple market and environmental factors, but they may be as much as or more than $1 million per well.

PUBLIC BENEFITS AND COSTS

Nina Chamness also determined that for each year of the first five years the proposed rules are in effect, the public benefit anticipated from the changes seen in the proposed rules will be the facilitation of projects for enhanced oil recovery and the supply of public drinking water by establishing a streamlined permit process that remains protective of human health and the environment for disposal of nonhazardous desalination concentrate and nonhazardous drinking water treatment residuals via Class I injection wells.

No significant fiscal implications are expected for businesses that supply public drinking water as a result of the proposed rules. Other disposal options for nonhazardous desalination concentrate and nonhazardous drinking water treatment residuals will remain available in addition to Class I wells. Suppliers of public drinking water are expected to choose the most economically viable disposal methods for these wastes. The number of businesses or individuals that might actually apply for authorization under the general permit is not known.

If an entity that supplies public drinking water applies for authorization under a general permit for a Class I well for the disposal of nonhazardous desalination concentrate or nonhazardous drinking treatment water residuals, it could expect to pay the same permit fee ($100 per application), construction, testing, and maintenance costs as those paid by owners or operators of Class I wells permitted for this type of waste disposal. With the exception of the permit fee, these costs can vary widely depending on multiple market and environmental factors, but they may be as much as or more than $1 million per well.

Businesses that have enhanced oil recovery wells and wish to inject nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals for recovery purposes will not have to apply for a Class I permit under the proposed rules. Cost savings may result because these businesses will not have to pay a $100 application fee, a $50 notice fee, or an estimated $30,000 consultant fee associated with a Class I permit application.

SMALL BUSINESS AND MICRO-BUSINESS ASSESSMENT

No adverse fiscal implications are anticipated for small or micro-businesses as a result of the proposed rules. Typically, small or micro-businesses do not own or operate Class I injection wells, and staff does not expect these businesses to request authorization under the general permit to operate a well of this type. If a small business does request authorization under the general permit to own or operate this type of Class I injection well, it can expect to incur the same costs to construct, maintain, and permit the well that are paid by a large business.

SMALL BUSINESS REGULATORY FLEXIBILITY ANALYSIS

The commission has reviewed this proposed rulemaking and determined that a small business regulatory flexibility analysis is not required because the proposed rules are required by state law and do not adversely affect a small or micro-business in a material way for the first five years that the proposed rules are in effect.

LOCAL EMPLOYMENT IMPACT STATEMENT

DRAFT REGULATORY IMPACT ANALYSIS DETERMINATION

The intent of the proposed rulemaking is to implement HB 2654, passed during the 80th Legislature, 2007, and to revise technical standards for Class I nonhazardous wells injecting desalination concentrate and other water treatment residuals from public water systems so that the state's rules are no more stringent than federal Class I nonhazardous injection well regulations. The rulemaking substantially advances this purpose by: 1) amending §§331.2, 331.7, and 331.17 and adding new Subchapter L to provide for a new general permit authorizing the use of Class I injection wells to inject nonhazardous desalination concentrate or other nonhazardous drinking water treatment residuals, to implement HB 2654; 2) amending §§331.42, 331.45, 331.46, 331.62 - 331.66 and 331.121 to create a set of criteria no more stringent than the federal regulations regarding Class I nonhazardous injection wells; and 3) amending §331.7 to provide that a permit is not required from the commission for an injection well authorized by the Railroad Commission to use nonhazardous desalination concentrate or drinking water treatment residuals for enhanced recovery purposes.

Additionally, this rulemaking does not meet any of the four applicability requirements listed in Texas Government Code, §2001.0225(a). Texas Government Code, §2001.0225 only applies to a major environmental rule, the result of which is to: 1) exceed a standard set by federal law, unless the rule is specifically required by state law; 2) exceed an express requirement of state law, unless the rule is specifically required by federal law; 3) exceed a requirement of a delegation agreement or contract between the state and an agency or representative of the federal government to implement a state and federal program; or 4) adopt a rule solely under the general powers of the agency instead of under a specific state law. This rulemaking does not meet any of these four applicability requirements because this rulemaking does not exceed any standard set by federal law but rather amends the rules so that they are no more stringent or restrictive than the federal regulations. The proposed rules do not exceed the requirements of state law under the TWC, Chapter 27. Further, the proposed rules do not exceed a requirement of a delegation agreement or contract between the state and an agency or representative of the federal government to implement any state and federal program. Finally, the rulemaking is not proposed solely under the general powers of the agency, but rather specifically under TWC, §27.023(m), which allows the commission to adopt rules to implement the general permit authorizing use of a Class I injection well to inject nonhazardous brine from desalination operations or nonhazardous drinking water treatment residuals and TWC, §27.109, which authorizes the commission to adopt rules to implement TWC, Chapter 27, as well as the other general powers of the agency.

TAKING IMPACT ASSESSMENT

The commission evaluated the proposed rules to Chapter 331 and performed a preliminary assessment of whether the amendments would constitute a taking under Texas Government Code, Chapter 2007. The primary purposes of the proposed rules are to implement HB 2654 and to revise the technical standards for Class I wells injecting nonhazardous desalination concentrate or drinking water treatment residuals to be no more stringent than the federal regulations. The proposed rules would substantially advance these purposes by amending various sections of Chapter 331 to conform technical standards for Class I wells injecting nonhazardous desalination concentrate or drinking water treatment residuals to the federal standards and by amending various sections of Chapter 331 and adding Subchapter L to implement the general permit provided by HB 2654.

Promulgation and enforcement of the proposed rules would constitute neither a statutory nor a constitutional taking of private real property. There are no burdens imposed on private real property under this rule because the proposed rules neither relate to, nor have any impact on the use or enjoyment of private real property, and there would be no reduction in property value as a result of this rulemaking. Therefore, the proposed rules would not constitute a taking under Texas Government Code, Chapter 2007.

The commission has no reasonable alternative to rule adoption that could accomplish the specific purpose of implementing HB 2654 and revising technical standards to conform to federal standards.

CONSISTENCY WITH THE COASTAL MANAGEMENT PROGRAM

ANNOUNCEMENT OF HEARING

SUBMITTAL OF COMMENTS

Subchapter A. GENERAL PROVISIONS

30 TAC §§331.2, 331.7, 331.17

STATUTORY AUTHORITY

The amendments are proposed under Texas Water Code (TWC), §5.103, which provides the commission with the authority to adopt any rules necessary to carry out its powers and duties under this code and other laws of this state and to adopt rules repealing any statement of general applicability that interprets law or policy; §5.105, which authorizes the commission to establish and approve all general policy of the commission by rule; §27.019, which requires the commission to adopt rules reasonably required for the regulation of injection wells; and §27.023, which allows the commission to adopt rules as necessary to implement and administer a general permit authorizing the use of Class I injection wells to inject nonhazardous brine from desalination operations or nonhazardous drinking water treatment residuals.

The proposed amendments implement TWC, §27.023, relating to General Permit Authorizing Use of Class I Injection Wells to Inject Nonhazardous Brine from Desalination Operations or Nonhazardous Drinking Water Treatment Residuals, and TWC, Chapter 27.

§331.2.Definitions.

General definitions can be found in Chapter 3 of this title (relating to Definitions). The following words and terms, when used in this chapter, have the following meanings.

(1) - (29) (No change.)

(30) Desalination concentrate--Same as desalination brine.

(31) [ ~~(30)~~ ] Desalination operation--A process which produces water of usable quality by desalination.

(32) [ ~~(31)~~ ] Disposal well--A well that is used for the disposal of waste into a subsurface stratum.

(33) [ ~~(32)~~ ] Disturbed salt zone--Zone of salt enveloping a salt cavern, typified by increased values of permeability or other induced anomalous conditions relative to undisturbed salt which lies more distant from the salt cavern, and is the result of mining activities during salt cavern development and which may vary in extent through all phases of a cavern including the post-closure phase.

(34) [ ~~(33)~~ ] Drilling mud--A heavy suspension used in drilling an injection well, introduced down the drill pipe and through the drill bit.

(35) Drinking water treatment residuals--Materials generated, concentrated or produced as a result of treating water for human consumption.

(36) [ ~~(34)~~ ] Drywell--A well, other than an improved sinkhole or subsurface fluid distribution system, completed above the water table so that its bottom and sides are typically dry except when receiving fluids.

(37) Enhanced oil recovery project (EOR)--The use of any process for the displacement of oil from the reservoir other than primary recovery and includes the use of an immiscible, miscible, chemical, thermal, or biological process. This term does not include pressure maintenance or water disposal projects.

(38) [ ~~(35)~~ ] Excursion--The movement of mining solutions into a designated monitor well.

(39) [ ~~(36)~~ ] Existing injection well--A Class I well which was authorized by an approved state or United States Environmental Protection Agency-administered program before August 25, 1988, or a well which has become a Class I well as a result of a change in the definition of the injected waste which would render the waste hazardous under §335.1 of this title (relating to Definitions).

(40) [ ~~(37)~~ ] Fluid--Material or substance which flows or moves whether in a semisolid, liquid, sludge, gas, or any other form or state.

(41) [ ~~(38)~~ ] Formation--A body of rock characterized by a degree of lithologic homogeneity which is prevailingly, but not necessarily, tabular and is mappable on the earth's surface or traceable in the subsurface.

(42) [ ~~(39)~~ ] Formation fluid--Fluid present in a formation under natural conditions.

(43) [ ~~(40)~~ ] Fresh water--Water having bacteriological, physical, and chemical properties which make it suitable and feasible for beneficial use for any lawful purpose.

(A) For the purposes of this subchapter, it will be presumed that water is suitable and feasible for beneficial use for any lawful purpose only if:

(i) it is used as drinking water for human consumption; or

(ii) the groundwater contains fewer than 10,000 milligrams per liter (mg/L) total dissolved solids; and

(iii) it is not an exempted aquifer.

(B) This presumption may be rebutted upon a showing by the executive director or an affected person that water containing greater than or equal to 10,000 mg/L total dissolved solids can be put to a beneficial use.

(44) General permit--A permit issued under the provisions of this chapter authorizing the disposal of nonhazardous desalination concentrate and nonhazardous drinking water treatment residuals as provided by Texas Water Code, §27.023.

(45) [ ~~(41)~~ ] Groundwater--Water below the land surface in a zone of saturation.

(46) [ ~~(42)~~ ] Groundwater protection area--A geographic area (delineated by the state under Safe Drinking Water Act, 42 United States Code, §300j-13) near and/or surrounding community and non-transient, non-community water systems that use groundwater as a source of drinking water.

(47) [ ~~(43)~~ ] Hazardous waste--Hazardous waste as defined in §335.1 of this title (relating to Definitions).

(48) [ ~~(44)~~ ] Improved sinkhole--A naturally occurring karst depression or other natural crevice found in carbonate rocks, volcanic terrain, and other geologic settings which has been modified by man for the purpose of directing and emplacing fluids into the subsurface.

(49) Individual permit--A permit, as defined in the Texas Water Code (TWC), §27.011 and §27.021, issued by the commission or the executive director to a specific person or persons in accordance with the procedures prescribed in the TWC, Chapter 27, (other than TWC, §27.023).

(50) [ ~~(45)~~ ] Injection interval--That part of the injection zone in which the well is authorized to be screened, perforated, or in which the waste is otherwise authorized to be directly emplaced.

(51) [ ~~(46)~~ ] Injection operations--The subsurface emplacement of fluids occurring in connection with an injection well or wells, other than that occurring solely for construction or initial testing.

(52) [ ~~(47)~~ ] Injection well--A well into which fluids are being injected. Components of an injection well annulus monitoring system are considered to be a part of the injection well.

(53) [ ~~(48)~~ ] Injection zone--A formation, a group of formations, or part of a formation that receives fluid through a well.

(54) [ ~~(49)~~ ] In service--The operational status when an authorized injection well is capable of injecting fluids, including times when the well is shut-in and on standby status.

(55) [ ~~(50)~~ ] Intermediate casing--A string of casing with diameter intermediate between that of the surface casing and that of the smaller long-string or production casing, and which is set and cemented in a well after installation of the surface casing and prior to installation of the long-string or production casing.

(56) [ ~~(51)~~ ] Large capacity cesspool--A cesspool that is designed for a flow of greater than 5,000 gallons per day.

(57) [ ~~(52)~~ ] Large capacity septic system--A septic system that is designed for a flow of greater than 5,000 gallons per day.

(58) [ ~~(53)~~ ] Licensed professional geoscientist--A geoscientist who maintains a current license through the Texas Board of Professional Geoscientists in accordance with its requirements for professional practice.

(59) [ ~~(54)~~ ] Liner--An additional casing string typically set and cemented inside the long string casing and occasionally used to extend from base of the long string casing to or through the injection zone.

(60) [ ~~(55)~~ ] Long string casing or production casing--A string of casing that is set inside the surface casing and that usually extends to or through the injection zone.

(61) [ ~~(56)~~ ] Lost circulation zone--A term applicable to rotary drilling of wells to indicate a subsurface zone which is penetrated by a wellbore, and which is characterized by rock of high porosity and permeability, into which drilling fluids flow from the wellbore to the degree that the circulation of drilling fluids from the bit back to ground surface is disrupted or "lost."

(62) [ ~~(57)~~ ] Mine area--The area defined by a line through the ring of designated monitor wells installed to monitor the production zone.

(63) [ ~~(58)~~ ] Mine plan--A map of adopted mine areas and an estimated schedule indicating the sequence and timetable for mining and any required aquifer restoration.

(64) [ ~~(59)~~ ] Monitor well--Any well used for the sampling or measurement of any chemical or physical property of subsurface strata or their contained fluids.

(A) Designated monitor wells are those listed in the production area authorization for which routine water quality sampling is required.

(B) Secondary monitor wells are those wells in addition to designated monitor wells, used to delineate the horizontal and vertical extent of mining solutions.

(65) [ ~~(60)~~ ] Motor vehicle waste disposal well--A well used for the disposal of fluids from vehicular repair or maintenance activities including, but not limited to, repair and maintenance facilities for cars, trucks, motorcycles, boats, railroad locomotives, and airplanes.

(66) [ ~~(61)~~ ] New injection well--Any well, or group of wells, not an existing injection well.

(67) [ ~~(62)~~ ] New waste stream--A waste stream not permitted.

(68) [ ~~(63)~~ ] Non-commercial facility--A Class I permitted facility which operates only non-commercial wells.

(69) [ ~~(64)~~ ] Non-commercial underground injection control (UIC) Class I well facility--A UIC Class I permitted facility where only non-commercial wells are operated.

(70) [ ~~(65)~~ ] Non-commercial well--An underground injection control Class I injection well which disposes of wastes that are generated on-site, at a captured facility or from other facilities owned or effectively controlled by the same person.

(71) Notice of change (NOC)--A written submittal to the executive director from a permittee authorized under a general permit providing changes to information previously provided to the agency, or any changes with respect to the nature or operations of the facility, or the characteristics of the waste to be injected.

(72) Notice of intent (NOI)--A written submittal to the executive director requesting coverage under the terms of a general permit.

(73) [ ~~(66)~~ ] Off-site--Property which cannot be characterized as on-site.

(74) [ ~~(67)~~ ] On-site--The same or geographically contiguous property which may be divided by public or private rights-of-way, provided the entrance and exit between the properties is at a cross-roads intersection, and access is by crossing, as opposed to going along, the right-of-way. Noncontiguous properties owned by the same person but connected by a right-of-way which the owner controls and to which the public does not have access, is also considered on-site property.

(75) [ ~~(68)~~ ] Out of service--The operational status when a well is not authorized to inject fluids, or the well itself is incapable of injecting fluids for mechanical reasons, maintenance operations, or well workovers or when injection is prohibited due to the well's inability to comply with the in-service operating standards of this chapter.

(76) [ ~~(69)~~ ] Permit area--The area owned or under lease by the permittee which may include buffer areas, mine areas, and production areas.

(77) [ ~~(70)~~ ] Plugging--The act or process of stopping the flow of water, oil, or gas into or out of a formation through a borehole or well penetrating that formation.

(78) [ ~~(71)~~ ] Point of injection--For a Class V well, the last accessible sampling point prior to fluids being released into the subsurface environment.

(79) [ ~~(72)~~ ] Pollution--The contamination of water or the alteration of the physical, chemical, or biological quality of water:

(A) that makes it harmful, detrimental, or injurious:

(i) to humans, animal life, vegetation, or property; or

(ii) to public health, safety, or welfare; or

(B) that impairs the usefulness or the public enjoyment of the water for any lawful and reasonable purpose.

(80) [ ~~(73)~~ ] Pre-injection units--The on-site above-ground appurtenances, structures, equipment, and other fixtures including the injection pumps, filters, tanks, surface impoundments, and piping for wastewater transmission between any such facilities and the well that are or will be used for storage or processing of waste to be injected, or in conjunction with an injection operation.

(81) [ ~~(74)~~ ] Production area--The area defined by a line generally through the outer perimeter of injection and recovery wells used for mining.

(82) [ ~~(75)~~ ] Production area authorization--A document, issued under the terms of an injection well permit, approving the initiation of mining activities in a specified production area within a permit area.

(83) [ ~~(76)~~ ] Production zone--The stratigraphic interval extending vertically from the shallowest to the deepest stratum into which mining solutions are authorized to be introduced.

(84) Public water system--A system for the provision to the public of water for human consumption through pipes or other constructed conveyances as defined in §290.38(47) of this title (relating to Definitions).

(85) [ ~~(77)~~ ] Radioactive waste--Any waste which contains radioactive material in concentrations which exceed those listed in 10 Code of Federal Regulations Part 20, Appendix B, Table II, Column 2, and as amended.

(86) [ ~~(78)~~ ] Restoration demonstration--A test or tests conducted by a permittee to simulate production and restoration conditions and verify or modify the fluid handling values submitted in the permit application.

(87) [ ~~(79)~~ ] Restored aquifer--An aquifer whose local groundwater quality has, by natural or artificial processes, returned to levels consistent with restoration table values or better as verified by an approved sampling program.

(88) [ ~~(80)~~ ] Salt cavern--A hollowed-out void space that has been purposefully constructed within a salt stock, typically by means of solution mining by circulation of water from a well or wells connected to the surface.

(89) [ ~~(81)~~ ] Salt cavern confining zone--A zone between the salt cavern injection zone and all underground sources of drinking water and freshwater aquifers, that acts as a barrier to movement of waste out of a salt cavern injection zone, and consists of the entirety of the salt stock excluding any portion of the salt stock designated as an underground injection control (UIC) Class I salt cavern injection zone or any portion of the salt stock occupied by a UIC Class II or Class III salt cavern or its disturbed salt zone.

(90) [ ~~(82)~~ ] Salt cavern injection interval--That part of a salt cavern injection zone consisting of the void space of the salt cavern into which waste is stored or disposed of, or which is capable of receiving waste for storage or disposal.

(91) [ ~~(83)~~ ] Salt cavern injection zone--The void space of a salt cavern that receives waste through a well, plus that portion of the salt stock enveloping the salt cavern, and extending from the boundaries of the cavern void outward a sufficient thickness to contain the disturbed salt zone, and an additional thickness of undisturbed salt sufficient to ensure that adequate separation exists between the outer limits of the injection zone and any other activities in the domal area.

(92) [ ~~(84)~~ ] Salt cavern solid waste disposal well or salt cavern disposal well--For the purposes of this chapter, regulations of the commission, and not to underground injection control (UIC) Class II or UIC Class III wells in salt caverns regulated by the Texas Railroad Commission, a salt cavern disposal well is a type of UIC Class I injection well used:

(A) to solution mine a waste storage or disposal cavern in naturally occurring salt; and/or

(B) to inject hazardous, industrial, or municipal waste into a salt cavern for the purpose of storage or disposal of the waste.

(93) [ ~~(85)~~ ] Salt dome--A geologic structure that includes the caprock, salt stock, and deformed strata surrounding the salt stock.

(94) [ ~~(86)~~ ] Salt stock--A geologic formation consisting of a relatively homogeneous mixture of evaporite minerals dominated by halite (NaCl) that has migrated from originally tabular beds into a vertical orientation.

(95) [ ~~(87)~~ ] Sanitary waste--Liquid or solid waste originating solely from humans and human activities, such as wastes collected from toilets, showers, wash basins, sinks used for cleaning domestic areas, sinks used for food preparation, clothes washing operations, and sinks or washing machines where food and beverage serving dishes, glasses, and utensils are cleaned.

(96) [ ~~(88)~~ ] Septic system--A well that is used to emplace sanitary waste below the surface, and is typically composed of a septic tank and subsurface fluid distribution system or disposal system.

(97) [ ~~(89)~~ ] Stratum--A sedimentary bed or layer, regardless of thickness, that consists of generally the same kind of rock or material.

(98) [ ~~(90)~~ ] Subsurface fluid distribution system--An assemblage of perforated pipes, drain tiles, or other similar mechanisms intended to distribute fluids below the surface of the ground. This definition includes subsurface area drip dispersal systems as defined in §222.5 of this title (relating to Definitions).

(99) [ ~~(91)~~ ] Surface casing--The first string of casing (after the conductor casing, if any) that is set in a well.

(100) [ ~~(92)~~ ] Temporary injection point--A method of Class V injection that uses push point technology (injection probes pushed into the ground) for the one-time injection of fluids into or above an underground source of drinking water.

(101) [ ~~(93)~~ ] Total dissolved solids--The total dissolved (filterable) solids as determined by use of the method specified in 40 Code of Federal Regulations Part 136, as amended.

(102) [ ~~(94)~~ ] Transmissive fault or fracture--A fault or fracture that has sufficient permeability and vertical extent to allow fluids to move between formations.

(103) [ ~~(95)~~ ] Underground injection--The subsurface emplacement of fluids through a well.

(104) [ ~~(96)~~ ] Underground injection control--The program under the federal Safe Drinking Water Act, Part C, including the approved Texas state program.

(105) [ ~~(97)~~ ] Underground source of drinking water--An "aquifer" or its portions:

(A) which supplies drinking water for human consumption; or

(B) in which the groundwater contains fewer than l0,000 milligrams per liter total dissolved solids; and

(106) [ ~~(98)~~ ] Upper limit--A parameter value established by the commission in a permit/production area authorization which when exceeded indicates mining solutions may be present in designated monitor wells.

(107) [ ~~(99)~~ ] Verifying analysis--A second sampling and analysis of control parameters for the purpose of confirming a routine sample analysis which indicated an increase in any control parameter to a level exceeding the upper limit. Mining solutions are assumed to be present in a designated monitor well if a verifying analysis confirms that any control parameter in a designated monitor well is present in concentration equal to or greater than the upper limit value.

(108) [ ~~(100)~~ ] Well--A bored, drilled, or driven shaft whose depth is greater than the largest surface dimension, a dug hole whose depth is greater than the largest surface dimension, an improved sinkhole, or a subsurface fluid distribution system but does not include any surface pit, surface excavation, or natural depression.

(109) [ ~~(101)~~ ] Well injection--The subsurface emplacement of fluids through a well.

(110) [ ~~(102)~~ ] Well monitoring--The measurement by on-site instruments or laboratory methods of any chemical, physical, radiological, or biological property of the subsurface strata or their contained fluids penetrated by the wellbore.

(111) [ ~~(103)~~ ] Well stimulation--Several processes used to clean the well bore, enlarge channels, and increase pore space in the interval to be injected thus making it possible for wastewater to move more readily into the formation including, but not limited to, surging, jetting, blasting, acidizing, and hydraulic fracturing.

(112) [ ~~(104)~~ ] Workover--An operation in which a down-hole component of a well is repaired, the engineering design of the well is changed, or the mechanical integrity of the well is compromised. Workovers include operations such as sidetracking, the addition of perforations within the permitted injection interval, and the addition of liners or patches. For the purposes of this chapter, workovers do not include well stimulation operations.

§331.7.Permit Required.

(a) Except as provided in §331.9 of this title (relating to Injection Authorized by Rule) and by subsections [ ~~subsection~~ ] (d) - (f) of this section, all injection wells and activities must be authorized by an individual permit.

(b) - (c) (No change.)

(d) Pre-injection units for Class I nonhazardous, noncommercial injection wells and Class V injection wells permitted for the disposal of nonhazardous waste must be either authorized by a permit issued by the commission or registered in accordance with §331.17 of this title (relating to Pre-Injection Units Registration). The option of registration provided by this subsection shall not apply to pre-injection units for Class I injection wells used for the disposal of byproduct material, as that term is defined in Chapter 336 of this title (relating to Radioactive Substance Rules). Pre-injection units for Class I wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals are not subject to authorization by registration but are subject to authorization by an individual permit or under the general permit issued under Subchapter L of this chapter (relating to General Permit Authorizing Use of a Class I Injection Well to Inject Nonhazardous Desalination Concentrate or Nonhazardous Drinking Water Treatment Residuals).

(e) The commission may issue a general permit under Subchapter L of this chapter. The commission may determine that an injection well and the injection activities are more appropriately regulated under an individual permit than under a general permit based on findings that the general permit will not protect ground and surface fresh water from pollution due to site-specific conditions.

(f) Notwithstanding subsection (a) of this section, an injection well authorized by the Railroad Commission of Texas to use nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals as an injection fluid for enhanced recovery purposes does not require a permit from the commission. The use or disposal of radioactive material under this paragraph is subject to the applicable requirements of Chapter 336 of this title (relating to Radioactive Substance Rules).

§331.17.Pre-injection Units Registration.

(a) Pre-injection units not otherwise authorized under this chapter , except for those pre-injection units used in conjunction with a Class I well authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals, must be registered in accordance with the requirements of this section. Pre-injection units used in conjunction with a Class I well authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals are not subject to authorization by registration but are subject to authorization by an individual permit or under the general permit issued under Subchapter L of this chapter (relating to General Permit Authorizing Use of a Class I Injection Well to Inject Nonhazardous Desalination Concentrate or Nonhazardous Drinking Water Treatment Residuals).

(b) - (d) (No change.)

This agency hereby certifies that the proposal has been reviewed by legal counsel and found to be within the agency's legal authority to adopt.

Filed with the Office of the Secretary of State on February 29, 2008.

TRD-200801193

Robert Martinez

Director, Environmental Law Division

Texas Commission on Environmental Quality

Earliest possible date of adoption: April 13, 2008

For further information, please call: (512) 239-0177

Subchapter C. GENERAL STANDARDS AND METHODS

30 TAC §§331.42, 331.45, 331.46

STATUTORY AUTHORITY

§331.42.Area of Review.

(a) The area of review is the area surrounding an injection well or a group of injection wells, for which the permit application must detail the information required in Subchapter G of this chapter [ ~~title~~ ] (relating to Consideration Prior to Permit Issuance).

(1) The area of review for Class I wells, except those wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals, is an area determined by a radius of 2 1/2 miles from the proposed or existing wellbore, or the area within the cone of influence, whichever is greater.

(2) The area of review for those Class I wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals, is an area determined by a radius of 1/4 mile from the proposed or existing wellbore, or the area within the cone of influence, whichever is greater. Notwithstanding subsection (c) of this section, if the area of review is determined by a mathematical model pursuant to subsection (b) of this section, the permissible radius is the result of such calculation even if it is less than 1/4 mile.

(3) The area of review for salt cavern disposal wells and associated caverns, is the sum of the two following areas:

(A) an area determined by a radius of 2 1/2 miles from the proposed or existing wellbore; and

(B) the greatest horizontal plane cross-sectional area of the salt dome between land surface and a depth of 1,000 feet below the projected floor of the proposed or existing salt cavern.

(4) The area of review for Class III wells, is the project area plus a circumscribing area, a minimum of 1/4 mile, the width of which is the lateral distance from the perimeter of the project area, in which the pressures in the injection zone may cause the migration of the injection and/or formation fluid into a Underground Sources of Drinking Water.

(5) The area of review for Class V wells is an area determined by a radius of at least 1/4 mile from the proposed or existing wellbore.

[ ~~(b)~~ ~~The area of review is:~~ ]

[ ~~(1)~~ ~~for Class I wells, an area determined by a radius of 2 1/2 miles from the proposed or existing wellbore, or the area within the cone of influence, whichever is greater;~~ ]

[ ~~(2)~~ ~~for salt cavern disposal wells and associated caverns, the sum of the two following areas:~~ ]

[ ~~(A)~~ ~~an area determined by a radius of 2 1/2 miles from the proposed or existing wellbore; and~~ ]

[ ~~(B)~~ ~~the greatest horizontal plane cross-sectional area of the salt dome between land surface and a depth of 1,000 feet below the projected floor of the proposed or existing salt cavern;~~ ]

[ ~~(3)~~ for Class III wells, the project area plus a circumscribing area, a minimum of 1/4 mile, the width of which is the lateral distance from the perimeter of the project area, in which the pressures in the injection zone may cause the migration of the injection and/or formation fluid into a USDW; or ]

[ ~~(4)~~ ~~for Class V wells, an area determined by a radius of at least 1/4 mile from the proposed or existing wellbore.~~ ]

(b) [ ~~(c)~~ ] The computation of the cone of influence may be based upon the parameters listed in the figure in this subsection and should be calculated for an injection time period equal to the expected life of the injection well or pattern. The following modified Theis equation illustrates one form which the mathematical model may take:

Figure: 30 TAC §331.42(b)

[ ~~Figure 1: 30 TAC 331.42(c)~~ ]

(c) [ ~~(d)~~ ] After an appropriate review, the commission may modify the area of review. In no event shall the boundary of an area of review be less than 2 1/2 miles for Class I wells , except those wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals, or 1/4 mile for Class I wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals, or 1/4 mile from any other injection well covered by the appropriate authorization. The following factors are to be included in the review:

(1) Chemistry of injection and formation fluids;

(2) Hydrogeology;

(3) Population and its dependence on ground water use; and

(4) Historical practices in the area.

(d) [ ~~(e)~~ ] The executive director may require an owner or operator of an existing injection well to submit any reasonably available information regarding the area of review, if the information would aid a review for the prevention or correction of freshwater pollution.

§331.45.Executive Director Approval of Construction and Completion.

The executive director may approve or disapprove the construction and completion for an injection well or project. In making a determination whether to grant approval, the following shall be reviewed for compliance with the standards of this chapter:

(1) for Class I wells, except for those Class I wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals, and [ ~~other than~~ ] salt cavern disposal wells and associated salt caverns:

(A) actual as-built drilling and completion data on the well;

(B) all logging and testing data on the well;

(D) anticipated maximum pressure and flow rate at which the permittee will operate;

(E) results of the injection zone and confining zone testing program as required in §331.62(7) of this title (relating to Construction Standards) and §331.65(a) of this title (relating to Reporting Requirements [ ~~Pre-operation Reports~~ ]);

(F) the actual injection procedure;

(G) the compatibility of injected wastes with fluids in the injection zone and minerals in both the injection zone and the confining zone and materials used to construct the well;

(H) the calculated area of review and cone of influence based on data obtained during logging and testing of the well and the formation, and where necessary, revisions to the information submitted under §331.121 of this title (relating to Class I Wells);

(I) the status of corrective action required for defective wells in the area of review;

(J) compliance with the casing and cementing performance standard in §331.62(5) of this title [ ~~(relating to Construction Standards)~~ ], and where necessary, changes to the permit to provide for additional testing and/or monitoring of the well to insure the continuous attainment of the performance standard; and

(K) compliance with the cementing requirements in §331.62(6) of this title .

(2) for Class I wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals:

(A) all available logging and testing program data on the well;

(B) a demonstration of mechanical integrity;

(D) the results of the formation testing program;

(E) the actual injection procedure;

(F) the compatibility of injected waste with fluids in the injection zone and minerals in both the injection zone and the confining zone; and

(G) the status of corrective action on defective wells in the area of review.

(3) [ ~~(2)~~ ] for salt cavern disposal wells and associated salt caverns:

(A) actual as-built drilling and completion data on the well;

(B) all logging, coring, and testing program data on the well and salt pilot hole;

(D) the anticipated maximum wellhead and casing seat pressures and flow rates at which the well will operate during cavern development and cavern waste filling;

(E) results of the salt cavern injection zone and salt cavern confining zone testing program as required in §331.163(e)(3) of this title (relating to Well Construction Standards [ ~~Salt Cavern Solid Waste Disposal Wells~~ ]);

(F) the injection and production procedures for cavern development and cavern waste filling;

(G) the compatibility of injected materials with the contents of the salt cavern injection zone and the salt cavern confining zone, and with the materials of well construction;

(H) land subsidence monitoring data and groundwater quality monitoring data, including determinations of baseline conditions for such monitoring throughout the area of review;

(I) the status of corrective action required for defective wells in the area of review;

(J) actual as-built specifications of the well's surface support and monitoring equipment; and

(K) conformity of the constructed well system with the plans and specifications of the permit application;

(4) [ ~~(3)~~ ] for Class III wells:

(A) logging and testing data on the well;

(B) a satisfactory demonstration of mechanical integrity for all new wells, excluding monitor wells;

(D) the results of the formation testing program;

(E) the injection procedures; and

(F) the status of corrective action required for defective wells in the area of review.

§331.46.Closure Standards.

(a) Applicability. Subsections (b) - (n) and (q) of this section apply to Class I wells except for salt cavern disposal wells and those Class I wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals. For salt cavern disposal wells, only subsections (c) and (e) - (q) of this section apply. For Class I wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals, only subsections (e) - (h) and (q) of this section apply.

(b) [ ~~(a)~~ ] For Class I wells, [ ~~other than salt cavern disposal wells,~~ ] prior to closing the well, the owner or operator shall observe and record the pressure decay for a time specified by the executive director. The executive director shall analyze the pressure decay and the transient pressure observations conducted pursuant to §331.64 of this title (relating to Monitoring and Testing Requirements [ ~~Class I Wells~~ ]) and determine whether the injection activity has conformed with predicted values.

(c) [ ~~(b)~~ ] For all Class I wells, [ ~~including salt cavern disposal wells,~~ ] prior to well closure, appropriate mechanical integrity testing shall be conducted to ensure the integrity of that portion of the long string casing and cement that will be left in the ground after closure. Testing methods may include:

(1) pressure tests with liquid or gas;

(2) radioactive tracer surveys for wells other than salt cavern disposal wells;

(3) noise logs, temperature logs, pipe evaluation logs, cement bond logs, or oxygen activation logs; and

(4) any other test required by the executive director.

(d) [ ~~(c)~~ ] For Class I wells, [ ~~other than salt cavern disposal wells,~~ ] prior to well closure the well shall be flushed with a nonhazardous [ ~~non-hazardous~~ ] buffer fluid.

(e) [ ~~(d)~~ ] In closure of all Class I wells, [ ~~including salt cavern disposal wells,~~ ] Class III wells, and permitted Class V wells, a well shall be plugged in a manner which will not allow the movement of fluids through the well, out of the injection zone either into or between underground sources of drinking waters (USDWs) or to the land surface. Well plugs shall consist of cement or other materials approved in writing by the executive director, which provide protection equivalent to or greater than that provided by cement.

(f) [ ~~(e)~~ ] The permittee shall notify the executive director before commencing closure according to an approved plan. For Class I wells this notice shall be given at least 60 days before commencement. At the discretion of the executive director, a shorter notice period may be allowed. The executive director shall review any revised, updated, or additional closure plans.

(g) [ ~~(f)~~ ] Placement of the plugs in the wellbore shall be accomplished by an approved method that may include one of the following:

(1) the balance plug method;

(2) the dump bailer method;

(3) the two-plug method; or

(4) an alternate method, approved by the executive director, that will reliably provide a comparable level of protection.

(h) [ ~~(g)~~ ] Prior to closure, the well shall be in a state of static equilibrium with the mud or nonhazardous fluid weight equalized top to bottom, either by circulating the mud or fluid in the well at least once or by a comparable method prescribed by the executive director.

(i) [ ~~(h)~~ ] Each plug used shall be appropriately tagged and tested for seal and stability before closure is completed.

(j) [ ~~(i)~~ ] The closure plan shall, in the case of a Class III production zone which underlies or is in an exempted aquifer, also demonstrate that no movement of contaminants that will cause pollution from the production zone into a USDW or freshwater aquifer will occur. The commission shall prescribe aquifer cleanup and monitoring where deemed necessary and feasible to ensure that no migration of contaminants that will cause pollution from the production zone into a USDW or freshwater aquifer will occur.

(k) [ ~~(j)~~ ] The following shall be considered in determining the adequacy of a plugging and abandonment plan for Class I and III wells:

(1) the type and number of plugs to be used;

(2) the placement of each plug including the elevation of the top and bottom;

(3) the type, grade, and quantity of plugging material to be used;

(4) the method of placement of the plugs;

(5) the procedure used to plug and abandon the well;

(6) any newly constructed or discovered wells, or information, including existing well data, within the area of review;

(7) geologic or economic conditions;

(8) the amount, size, and location by depth of casings and any other materials left in the well;

(9) the method and location where casing is to be parted if applicable;

(10) the estimated cost of the plugging procedure; and

(11) such other factors that may affect the adequacy of the plan.

(l) [ ~~(k)~~ ] For Class I wells only, a monument or other permanent marker shall be placed at or attached to the plugged well before abandonment. The monument shall state the permit number, date of abandonment, and company name.

(m) [ ~~(l)~~ ] Each owner of a Class I hazardous waste injection well, and the owner of the surface or subsurface property on or in which a Class I hazardous waste injection well is located, must record, within 60 days after approval by the executive director of the closure operations, a notation on the deed to the facility property or on some other instrument which is normally examined during a title search that will, in perpetuity, provide any potential purchaser of the property the following information:

(1) the fact that land has been used to manage hazardous waste;

(2) the name of the state agency or local authority with which the plat was filed, as well as the Austin address of the Underground Injection Control (UIC) staff of the commission, to which it was submitted; and

(3) the type and volume of waste injected, the injection interval or intervals, and for salt cavern wells, the maximum cavern radius into which it was injected, and the period over which injection occurred.

(n) [ ~~(m)~~ ] Within 30 days after completion of closure, the permittee shall file with the executive director a closure report on forms provided by the commission. The report shall be certified as accurate by the owner or operator and by the person who performed the closure operation (if other than the owner or operator). This report shall consist of a statement that the well was closed in accordance with the closure plan previously submitted and approved by the executive director. Where the actual closure differed from the plan previously submitted, a written statement shall be submitted specifying the differences between the previous plan and the actual closure.

(o) [ ~~(n)~~ ] For salt cavern disposal wells, prior to sealing the cavern and plugging the well, the owner or operator shall complete any pre-closure monitoring of the cavern and its contents required by rule or permit.

(p) [ ~~(o)~~ ] For salt cavern disposal wells, the cavern shall be closed according to §331.170 of this title (relating to Cavern Closure).

(q) [ ~~(p)~~ ] The obligation to implement the closure plan survives the termination of a permit or the cessation of injection activities. The requirement to maintain and implement an approved plan is directly enforceable regardless of whether the closure plan requirement is a condition of the permit.

This agency hereby certifies that the proposal has been reviewed by legal counsel and found to be within the agency's legal authority to adopt.

Filed with the Office of the Secretary of State on February 29, 2008.

TRD-200801194

Robert Martinez

Director, Environmental Law Division

Texas Commission on Environmental Quality

Earliest possible date of adoption: April 13, 2008

For further information, please call: (512) 239-0177

Subchapter D. STANDARDS FOR CLASS I WELLS OTHER THAN SALT CAVERN SOLID WASTE DISPOSAL WELLS

30 TAC §§331.62 - 331.66

STATUTORY AUTHORITY

§331.62.Construction Standards.

(a) All Class I wells shall be designed, constructed, and completed to prevent the movement of fluids that could result in the pollution of an underground source of drinking water (USDW). The following standards apply to all Class I wells except those wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals.

(1) Design criteria. Casing and cement used in the construction of each newly drilled well shall be designed for the life expectancy of the well, including the post-closure care period. The well shall be designed and constructed to prevent potential leaks from the well, to prevent the movement of fluids along the wellbore into or between USDWs, to prevent the movement of fluids along the wellbore out of the injection zone, to permit the use of appropriate testing devices and workover tools, and to permit continuous monitoring of injection tubing, long string casing, and annulus, as required by this chapter. All well materials must be compatible with fluids with which the materials may be expected to come into contact. A well shall be deemed to have compatibility as long as the materials used in the construction of the well meet or exceed standards developed for such materials by the American Petroleum Institute, the American Society for Testing Materials, or comparable standards acceptable to the executive director.

(A) Casing design. Surface casing shall be set to a minimum subsurface depth, as determined by the executive director, which extends into the confining bed below the lowest formation containing a USDW or freshwater aquifer. At least one long string casing, using a sufficient number of centralizers, shall extend to the injection interval. In determining and specifying casing and cementing requirements, the following factors shall be considered:

(i) depth of lowermost USDW or freshwater aquifer;

(ii) depth to the injection interval;

(iii) injection pressure, external pressure, internal pressure, and axial loading;

(iv) hole size;

(v) size and grade of all casing strings (wall thickness, diameter, nominal weight, length, joint specification, and construction material);

(vi) the maximum burst and collapse pressures, and tensile stresses which may be experienced at any point along the length of the casings at any time during the construction, operation, and closure of the well;

(vii) corrosive effects of injected fluids, formation fluids, and temperatures;

(viii) lithology of injection and confining intervals;

(ix) presence of lost circulation zones or other subsurface conditions that could affect the casing and cementing program;

(x) types and grades of cement; and

(xi) quantity and chemical composition of the injected fluid.

(B) Tubing and packer design. All Class I injection wells shall inject fluids through tubing with a packer, set at a depth specified by the executive director. Fluid seal systems will not be approved by the commission. The annulus system shall be designed and constructed to prevent the leak of injection fluids into any unauthorized zones. In determining and specifying requirements for tubing and packer, the following factors shall be considered:

(i) depth to the injection zone;

(ii) characteristics of injection fluid (chemical content, corrosiveness, temperature, and density);

(iii) injection pressure;

(iv) annular pressure;

(v) rate (intermittent or continuous), temperature, and volume of injected fluid;

(vi) size of casing; and

(vii) tensile, burst, and collapse strengths of the tubing.

(2) Plans and specifications. Except as specifically required in the terms of the disposal well permit, the drilling and completion of the well shall be done in accordance with the requirements of this chapter and all permit application plans and specifications.

(3) Changes to plans and specifications. Any proposed changes to the plans and specifications must be approved in writing by the executive director that said changes provide protection standards equivalent to or greater than the original design criteria.

(A) If during the drilling and/or completion of the well, the operator proposes to change the cementing of the surface casing, the executive director shall require a written description of the proposed change, including any additional data necessary to evaluate the request. The operator may not execute the change until the executive director gives written approval. The operator may change the setting depth of the surface casing to a depth greater than that specified in the permit, either during drilling and/or completion, without approval from the executive director. Approval for setting depths shallower than specified in the permit will not be authorized.

(B) If the operator proposes to change the injection interval to one not reviewed during the permit application process, the operator shall submit an application to amend the permit. The operator may not inject into any unauthorized zone.

(C) Any other changes, including but not limited to the number of casing strings, changes in the size or material of intermediate and production casings, changes in the completion of the well, changes in the exact setting of screens or injection intervals within the permitted injection zone, and changes in the type of cement used, or method of cementing shall be considered minor changes. If minor changes are requested, the executive director may give immediate oral and subsequent written approval or written approval for those changes. The operator is required to submit a detailed written description of all minor changes, along with the information required in §331.65 of this title (relating to Waste Disposal Operating [ ~~Reporting~~ ] Requirements), before approval for operation of the well may be granted.

(4) Drilling requirements.

(A) The well shall be drilled according to sound engineering practices to minimize problems which may jeopardize completion attempts, such as deviated holes, washouts and stuck pipe.

(B) As much as technically practicable and feasible, the hole should be drilled under laminar flow conditions, with appropriate fluid loss control, to minimize hole washouts.

(C) Immediately prior to running casing, the drilling fluid in the hole is to be circulated and conditioned to establish rheological properties commensurate with proper cementing practices.

(5) Construction performance standard. All Class I wells shall be cased and all casings shall be cemented to prevent the movement of fluids along the borehole into or between USDWs or freshwater aquifers, and to prevent movement of fluids along the borehole out of the injection zone.

(6) Cementing requirements, for all Class I wells constructed after the promulgation of this rule, including wells converting to Class I status.

(A) Cementing shall be by the pump and plug or other method approved by the executive director. Cementing may be accomplished by staging. Cement pumped shall be of a volume equivalent to at least 120% of the volume calculated necessary to fill the annular space between the hole and casing and between casing strings to the surface of the ground. The executive director may require more than 120% when the geology or other circumstances warrant it. A two-dimensional caliper shall be used to measure the hole diameter. If the two-dimensional caliper can not measure the diameter of the hole over an interval, then the minimum amount of cement needed for that interval shall be a volume calculated to be equivalent to or greater than 150% of the space between the casing and the maximum measurable diameter of the caliper.

(B) If lost circulation zones or other subsurface conditions are anticipated and/or encountered, which could result in less than 100% filling of the annular space between the casing and the borehole or the casings, the owner/operator shall implement the approved contingency plan submitted according to §331.121(a)(2)(O) of this title (relating to Class I Wells).

(7) Logs and tests.

(A) Integrity testing. Appropriate logs and other tests shall be conducted during the drilling and construction of Class I wells. All logs and tests shall be interpreted by the service company which processed the logs or conducted the test; or by other qualified persons. A minimum of the following logs and tests shall be conducted:

(i) deviation checks on all holes, conducted at sufficiently frequent intervals to assure that avenues for fluid migration in the form of diverging holes are not created during drilling;

(ii) for surface casing;

(I) spontaneous potential, resistivity, natural gamma, and caliper logs before the casing is installed;

(II) cement bond with variable density log, and temperature logs after casing is set and cemented; and

(III) any other test required by the executive director;

(IV) the executive director may allow the use of an alternate to subclauses (I) and (II) of this clause when an alternative will provide equivalent or better information; and

(iii) for intermediate and long string casing:

(I) spontaneous potential, resistivity, natural gamma, compensated density and/or neutron porosity, dipmeter/fracture finder, and caliper logs, before the casing is installed;

(II) a cement bond with variable density log, casing inspection, and temperature logs after casing is set and cemented, and an inclination survey; and

(III) any other test required by the executive director; and

(iv) a mechanical integrity test consisting of:

(I) a pressure test with liquid or gas;

(II) a radioactive tracer survey;

(III) a temperature or noise log;

(IV) a casing inspection log, if required by the executive director; and

(V) any other test required by the executive director.

(B) Pressure tests. Surface casing shall be pressure tested to 1,000 pounds per square inch, gauge (psig) for at least 30 minutes, and long string casing shall be tested to 1,500 psig for at least 30 minutes, unless otherwise specified by the executive director.

(C) Core samples. Full-hole cores shall be taken from selected intervals of the injection zone and lowermost overlying confining zone; or, if full-hole coring is not feasible or adequate core recovery is not achieved, sidewall cores shall be taken at sufficient intervals to yield representative data for selected parts of the injection zone and lowermost overlying confining zone. Core analysis shall include a determination of permeability, porosity, bulk density, and other necessary tests.

(8) Injectivity tests. After completion of the well, injectivity tests shall be performed to determine the well capacity and reservoir characteristics. Surveys shall be performed to establish preferred injection intervals. Prior to performing injectivity tests, the bottom hole pressure, bottom hole temperature, and static fluid level shall be determined, and a representative sample of formation fluid shall be obtained for chemical analysis. Information concerning the fluid pressure, temperature, fracture pressure and other physical and chemical characteristics of the injection and confining zones shall be determined or calculated.

(9) Construction and workover supervision. All phases of well construction and all phases of any well workover shall be supervised by qualified individuals acting under the responsible charge of a licensed professional engineer or licensed professional geoscientist, as appropriate, with current registration under the Texas Engineering Practice Act or Texas Geoscience Practice Act, who is knowledgeable and experienced in practical drilling engineering and who is familiar with the special conditions and requirements of injection well construction.

(10) The executive director shall have the opportunity to witness all cementing of casing strings, logging and testing. The owner or operator shall submit a schedule of such activities to the executive director at least 30 days prior to commencing drilling of the well. The executive director shall be given at least 24 hour notice before each activity in order that a representative of the executive director may be present.

(b) Class I wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals shall be constructed in compliance with the following standards:

(1) Wells shall be sited in such a fashion that they inject into a formation which is beneath the lowermost formation containing, within one quarter mile of the well bore, an underground source of drinking water.

(2) Wells shall be cased and cemented to prevent the movement of fluids into or between underground sources of drinking water. The casing and cement used in the construction of each newly drilled well shall be designed for the life expectancy of the well. In determining and specifying casing and cementing requirements, the following factors shall be considered:

(A) Depth to the injection zone;

(B) Injection pressure, external pressure, internal pressure, and axial loading;

(D) Size and grade of all casing strings (wall thickness, diameter, nominal weight, length, joint specification, and construction material);

(E) Corrosiveness of injected fluid, formation fluids, and temperatures;

(F) Lithology of injection and confining intervals; and

(G) Type or grade of cement.

(3) Injection wells, except those municipal wells injecting non-corrosive wastes or those using an alternative as provided by subparagraph (A) of this paragraph shall inject fluids through tubing with a packer set immediately above the injection zone, or tubing with an approved fluid seal as an alternative. The tubing, packer, and fluid seal shall be designed for the expected service.

(A) The use of other alternatives to a packer may be allowed with the written approval of the executive director. To obtain approval, the operator shall submit a written request to the executive director, which shall set forth the proposed alternative and all technical data supporting its use. The executive director shall approve the request if the alternative method will reliably provide a comparable level of protection to underground sources of drinking water. The executive director may approve an alternative method solely for an individual well or for general use.

(B) In determining and specifying requirements for tubing, packer, or alternatives the following factors shall be considered:

(i) Depth of setting;

(ii) Characteristics of injection fluid (chemical content, corrosiveness, and density);

(iii) Injection pressure;

(iv) Annular pressure;

(v) Rate, temperature and volume of injected fluid; and

(vi) Size of casing.

(4) Appropriate logs and other tests shall be conducted during the drilling and construction of new Class I wells. A descriptive report interpreting the results of such logs and tests shall be prepared by a knowledgeable log analyst and submitted to the executive director. At a minimum, such logs and tests shall include:

(A) Deviation checks on all holes constructed by first drilling a pilot hole, and then enlarging the pilot hole by reaming or another method. Such checks shall be at sufficiently frequent intervals to assure that vertical avenues for fluid migration in the form of diverging holes are not created during drilling; and

(B) Such other logs and tests as may be needed after taking into account the availability of similar data in the area of the drilling site, the construction plan, and the need for additional information, that may arise from time to time as the construction of the well progresses. In determining which logs and tests shall be required, the following logs shall be considered for use in the following situations:

(i) For surface casing intended to protect underground sources of drinking water:

(I) Resistivity, spontaneous potential, and caliper logs before the casing is installed; and

(II) A cement bond, temperature, or density log after the casing is set and cemented.

(ii) For intermediate and long strings of casing intended to facilitate injection:

(I) Resistivity, spontaneous potential, porosity, and gamma ray logs before the casing is installed;

(II) Fracture finder logs; and

(III) A cement bond, temperature, or density log after the casing is set and cemented.

(5) At a minimum, the following information concerning the injection formation shall be determined or calculated for new Class I wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals:

(A) Fluid pressure;

(B) Temperature;

(D) Other physical and chemical characteristics of the injection matrix; and

(E) Physical and chemical characteristics of the formation fluids.

§331.63.Operating Requirements.

(a) Applicability. Subsections (b) - (m) of this section apply to Class I wells except for those Class I wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals. For Class I wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals only subsections (b) - (d) and (n) of this section apply.

(b) [ ~~(a)~~ ] All Class I wells shall be operated to prevent the movement of fluids that could result in the pollution of an underground source of drinking water (USDW) and to prevent leaks from the well into unauthorized zones.

(c) [ ~~(b)~~ ] Except during well stimulation, injection pressure at the wellhead shall not exceed a maximum which shall be calculated so as to assure that the pressure in the injection zone during injection does not initiate new fractures or propagate existing fractures in the injection zone, initiate new fractures or propagate existing fractures in the confining zone, or cause movement of fluid out of the injection zone that may pollute USDWs or surface water.

(d) [ ~~(c)~~ ] Injection between the outermost casing protecting USDWs and fresh or surface water and the wellbore is prohibited.

(e) [ ~~(d)~~ ] The annulus between the tubing and long string casing shall be filled with a non-corrosive or corrosion-inhibiting fluid approved by the commission. The annulus pressure shall be at least 100 psi greater than the injection tubing pressure to prevent leaks from the well into unauthorized zones and to detect well malfunctions, unless the executive director determines that such a requirement might harm the integrity of the well.

(f) [ ~~(e)~~ ] Monthly average and maximum instantaneous rates of injection, and annual and monthly volumes of injected fluids shall not exceed limits specified by the commission.

(g) [ ~~(f)~~ ] All gauges, pressure sensing, and recording devices shall be tested and calibrated quarterly.

(h) [ ~~(g)~~ ] Any chemical or physical characteristic of the injected fluids shall be maintained within specified permit limits for the protection of the injection well, associated facilities, and injection zone and to ensure proper operation of the facility.

(i) [ ~~(h)~~ ] The permittee shall notify the executive director before commencing any workover operation. The notification shall be in writing and shall include plans for the proposed work. Approval by the executive director shall be obtained before the permittee may begin the workover. The executive director may grant an exception to the prior written notification and permission requirements when immediate action is required to comply with subsection (b) [ ~~(a)~~ ] of this section.

(j) [ ~~(i)~~ ] Pressure control equipment shall be installed and maintained during workovers which involve the removal of tubing.

(k) [ ~~(j)~~ ] For workovers or testing operations on hazardous waste disposal wells, all hazardous fluids shall be flushed from the wellbore with a nonhazardous [ ~~non-hazardous~~ ] fluid before conducting any portion of the operations which would result in the exposure of the hazardous wastes to the environment or the public.

(l) [ ~~(k)~~ ] The owner or operator shall maintain mechanical integrity of the injection well at all times.

(m) [ ~~(l)~~ ] The owner or operator of an injection well that has ceased operations for more than two years and is subject to §305.154(a)(7) of this title (relating to Standards) shall notify the executive director in writing 30 days prior to resuming operation of the well.

(n) For Class I wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals, unless an alternative to a packer has been approved under §331.62(b)(3)(A) of this title (relating to Construction Standards), the annulus between the tubing and the long string of casings shall be filled with a fluid approved by the executive director and a pressure, also approved by the executive director, shall be maintained on the annulus.

§331.64.Monitoring and Testing Requirements.

(a) Applicability. Subsections (b) - (j) of this section apply to all Class I wells except for those Class I wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals.

(b) [ ~~(a)~~ ] Injection fluids shall be sampled and analyzed with a frequency sufficient to yield representative data of their characteristics.

(1) The owner or operator shall develop and follow an approved written waste analysis plan that describes the procedures to be carried out to obtain a detailed chemical and physical analysis of a representative sample of the waste, including the quality assurance procedures used. At a minimum, the plan shall specify:

(A) the parameters for which the waste will be analyzed and the rationale for the selection of these parameters;

(B) the test methods that will be used to test for these parameters; and

(2) The owner or operator shall repeat the analysis of the injected wastes as described in the waste analysis plan and when process or operating changes occur that may significantly alter the characteristics of the waste stream.

(3) The owner or operator shall conduct continuous or periodic monitoring of selected parameters as required by the executive director.

(4) The owner or operator shall assure that the plan remains accurate and the analyses remain representative.

(c) [ ~~(b)~~ ] Pressure gauges shall be installed and maintained, at the wellhead, in proper operating conditions at all times on the injection tubing and on the annulus between the tubing and long-string casing, and/or annulus between the tubing and liner.

(d) [ ~~(c)~~ ] Continuous recording devices shall be installed, used, and maintained in proper operating condition at all times to record injection tubing pressures, injection flow rates, injection fluid temperatures, injection volumes, tubing-long string casing annulus pressure and volume, and any other data specified by the permit. The instruments shall be housed in weatherproof enclosures. The owner or operator shall also install and use:

(1) automatic alarm and automatic shutoff systems, designed to sound and shut-in the well when pressures and flow rates or other parameters approved by the executive director exceed a range and/or gradient specified in the permit; or

(2) automatic alarms designed to sound when the pressures and flow rates or other parameters approved by the executive director exceed a rate and/or gradient specified in the permit, in cases where the owner or operator certifies that a trained operator will be on location and able to immediately respond to alarms at all times when the well is operating.

(3) If an automatic alarm or shutdown is triggered, the owner or operator shall immediately investigate as expeditiously as possible the cause of the alarm or shutoff. If, upon investigation, the well appears to be lacking mechanical integrity, or if monitoring otherwise indicates that the well may be lacking mechanical integrity, the owner or operator shall:

(A) cease injection of waste fluids unless authorized by the executive director to continue or resume injection;

(B) take all necessary steps to determine the presence or absence of a leak; and

(4) If the loss of mechanical integrity is discovered by monitoring or during periodic mechanical integrity testing, the owner or operator shall:

(A) immediately cease injection of waste fluids;

(B) take all steps reasonably necessary to determine whether there may have been a release of hazardous wastes or hazardous waste constituents into any unauthorized zone;

(D) notify the executive director when injection can be expected to resume; and

(E) restore and demonstrate mechanical integrity to the satisfaction of the executive director prior to resuming injection of waste fluids.

(5) Whenever the owner or operator obtains evidence that there may have been a release of injected wastes into an unauthorized zone:

(A) the owner or operator shall immediately cease injection of waste fluids; and

(i) notify the executive director within 24 hours of obtaining such evidence;

(ii) take all necessary steps to identify and characterize the extent of any release;

(iii) propose a remediation plan for executive director review and approval;

(iv) comply with any remediation plan specified by the executive director;

(v) implement any remediation plan approved by the executive director; and

(vi) where such release is into a USDW or freshwater aquifer currently serving as a water supply, within 24 hours, notify the local health authority, place a notice in a newspaper of general circulation, and send notification by mail to adjacent landowners;

(B) the executive director may allow the operator to resume injection prior to completing cleanup action if the owner or operator demonstrates that the injection operation will not endanger USDWs or freshwater aquifers.

(e) [ ~~(d)~~ ] Mechanical integrity testing.

(1) The integrity of the long string casing, injection tube, and annular seal shall be tested annually by means of an approved pressure test with a liquid or gas and whenever there has been a well workover. The integrity of the bottom-hole cement shall be tested annually by means of an approved radioactive tracer survey. A radioactive tracer survey may be required after workovers that have the potential to damage the cement within the injection zone.

(2) A temperature log, noise log, oxygen activation log, or other approved log shall be required by the executive director at least once every five years to test for fluid movement along the borehole.

(3) A casing inspection, casing evaluation, or other approved log shall be run whenever the owner or operator conducts a workover in which the injection string is pulled, unless the executive director waives this requirement due to well construction or other factors which limit the test's reliability, or based upon the satisfactory results of a casing inspection log run within the previous five years. The executive director may require that a casing inspection log be run every five years, if there is sufficient reason to believe the integrity of the long string casing of the well may be adversely affected by naturally occurring or man-made events.

(4) The executive director may allow the use of a test to demonstrate mechanical integrity other than those listed in paragraph (1) of this subsection with the written approval of the administrator of the United States Environmental Protection Agency (EPA) or his authorized representative. To obtain approval, the executive director shall submit a written request to the EPA administrator, which shall set forth the proposed test and all technical data supporting its use. The EPA administrator shall approve the request if it will reliably demonstrate the mechanical integrity of wells for which its use is proposed. Any alternate method approved by the EPA administrator shall be published in the Federal Register and may be used unless its use is restricted at the time of approval by the EPA administrator.

(f) [ ~~(e)~~ ] Any wells within the area of review selected for the observation of water quality, formation pressure, or any other parameter, shall be monitored at a frequency sufficient to protect underground sources of drinking water (USDWs) and fresh or surface water.

(g) [ ~~(f)~~ ] Corrosion monitoring.

(1) Corrosion monitoring of well materials shall be conducted quarterly. Test materials shall be the same as those used in the injection tubing, packer, and long string casing, and shall be continuously exposed to the waste fluids with the exception of when the well is taken out of service. The owner or operator shall demonstrate that the waste stream will be compatible with the well materials with which the waste is expected to come into contact, and to submit to the executive director a description of the methodology used to make that determination. Compatibility for purposes of this requirement is established if contact with injected fluids will not cause the well materials to fail to satisfy any design requirement imposed under §331.62(1) of this title (relating to Construction Standards [ ~~Design Criteria~~ ]). Testing shall be by:

(A) placing coupons of the well construction materials in contact with the waste stream; or

(B) routing the waste stream through a loop constructed with the material used in the well; or

(2) The test shall use materials identical to those used in the construction of the well, and those materials must be continuously exposed to the operating pressures and temperatures (measured at the wellhead) and flow rates of the injection operation; and

(3) The owner or operator shall monitor the materials for loss of mass, thickness, cracking, pitting and other signs of corrosion on a quarterly basis to ensure that the well components meet the minimum standards for material strength and performance set forth in §331.62(1) of this title [ ~~(relating to Construction Standards)~~ ].

(4) Corrosion monitoring may be waived by the executive director if the injection well owner or operator satisfactorily demonstrates, before authorization to conduct injection operations, that the waste streams will not be corrosive to the well materials with which the waste is expected to come into contact throughout the life of the well. The demonstration shall include a description of the methodology used to make that determination.

(h) [ ~~(g)~~ ] Ambient monitoring.

(1) Based on a site-specific assessment of the potential for fluid movement from the well or injection zone and on the potential value of monitoring wells to detect fluid movement, the executive director shall require the owner or operator to develop a monitoring program. When prescribing a monitoring system, the executive director may also require:

(A) Continuous monitoring for pressure changes in the first aquifer overlying the confining zone. When a monitor well is installed, the owner or operator shall, on a quarterly basis, sample the aquifer and analyze for constituents specified by the executive director;

(B) the use of indirect, geophysical techniques to determine the position of the waste front, the water quality in a formation designated by the executive director, or to provide other site specific data;

(D) periodic monitoring of the ground water quality in the lowermost USDW; and

(E) any additional monitoring necessary to determine whether fluids are moving into or between USDWs.

(2) The pressure buildup in the injection zone shall be monitored annually, including at a minimum, a shut down of the well for a time sufficient to conduct a valid observation of the pressure fall-off curve.

(i) [ ~~(h)~~ ] Any other monitoring and testing requirements which the executive director determines to be necessary including, but not limited to, monitoring for seismic activity.

(j) [ ~~(i)~~ ] The owner or operator shall submit information demonstrating to the satisfaction of the executive director that the waste stream and its anticipated reaction products will not alter the permeability, thickness, or other relevant characteristics of the confining or injection zones such that they would no longer meet the requirements specified in §331.121(c) of this title (relating to Class I Wells).

(k) Class I Wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals shall comply with the following monitoring and testing requirements:

(1) Monitoring requirements. Monitoring requirements shall, at a minimum, include:

(A) The analysis of the injected fluids with sufficient frequency to yield representative data of their characteristics;

(B) Installation and use of continuous recording devices to monitor injection pressure, flow rate and volume, and the pressure on the annulus between the tubing and the long string of casing;

(C) Installation and use of monitoring wells within the area of review if required by the executive director, to monitor any migration of fluids into and pressure in the underground sources of drinking water. The type, number and location of the wells, the parameters to be measured, and the frequency of monitoring must be approved by the executive director;

(D) A demonstration of mechanical integrity pursuant to paragraph (4) of this subsection at least once every five years during the life of the well; and

(E) The type, number and location of wells within the area of review to be used to monitor any migration of fluids into and pressure in the underground sources of drinking water, the parameters to be measured and the frequency of monitoring.

(2) When the executive director determines that an injection well lacks mechanical integrity pursuant to paragraph (4) of this subsection, the executive director shall give written notice of his determination to the owner or operator. Unless the executive director requires immediate cessation, the owner or operator shall cease injection into the well within 48 hours of receipt of the executive director's determination. The executive director may allow plugging of the well in accordance with the requirements of §331.46 of this title (relating to Closure Standards) or require the owner or operator to perform such additional construction, operation, monitoring, reporting and corrective action as is necessary to prevent the movement of fluid into or between USDWs caused by the lack of mechanical integrity. The owner or operator may resume injection upon receipt of written notification from the executive director that the owner or operator has demonstrated mechanical integrity under paragraph (4) of this subsection.

(3) The executive director may allow the owner or operator of a well which lacks mechanical integrity under paragraph (4) of this subsection to continue or resume injection if the owner or operator has made a satisfactory demonstration that there is no movement of fluid into or between USDWs.

(4) Mechanical Integrity Testing. An injection well has mechanical integrity if:

(A) There is no significant leak in the casing, tubing or packer; and

(B) There is no significant fluid movement into an underground source of drinking water through vertical channels adjacent to the injection well bore.

(5) One of the following methods shall be used to evaluate the absence of significant leaks under paragraph (4)(A) of this subsection:

(A) Following an initial pressure test, monitoring of the tubing-casing annulus pressure with sufficient frequency to be representative, as determined by the executive director, while maintaining an annulus pressure different from atmospheric pressure measured at the surface; or

(B) Pressure test with liquid or gas.

(6) The results of a temperature or noise log must be used to determine the absence of significant fluid movement under paragraph (4)(B) of this subsection.

(7) The executive director may allow the use of a test to demonstrate mechanical integrity other than those listed in paragraph (5)(A) and (B) of this subsection with the written approval of the executive director. To obtain approval, the permittee shall submit a written request to the executive director, which shall set forth the proposed test and all technical data supporting its use. The executive director shall approve the request if it will reliably demonstrate the mechanical integrity of wells for which its use is proposed.

(8) In conducting and evaluating the tests enumerated in this section or others to be allowed by the executive director, the owner or operator and the executive director shall apply methods and standards generally accepted in the industry. When the owner or operator reports the results of mechanical integrity tests to the executive director, he shall include a description of the test(s) and the method(s) used. In making his evaluation, the executive director shall review monitoring and other test data submitted since the previous evaluation.

(9) The executive director may require additional or alternative tests if the results presented by the owner or operator under §331.64(k)(5) of this title (relating to Monitoring and Testing Requirements) are not satisfactory to the executive director to demonstrate that there is no movement of fluid into or between USDWs resulting from the injection activity.

(10) Ambient monitoring.

(A) Based on a site-specific assessment of the potential for fluid movement from the well or injection zone and on the potential value of monitoring wells to detect such movement, the executive director shall require the owner or operator to develop a monitoring program. At a minimum, the executive director shall require monitoring of the pressure buildup in the injection zone annually, including a shut down of the well for a time sufficient to conduct a valid observation of the pressure fall-off curve.

(B) When prescribing a monitoring system the executive director may also require:

(i) Continuous monitoring for pressure changes in the first aquifer overlying the confining zone. When such a well is installed, the owner or operator shall, on a quarterly basis, sample the aquifer and analyze for constituents specified by the executive director;

(ii) The use of indirect, geophysical techniques to determine the position of the waste front, the water quality in a formation designated by the executive director, or to provide other site specific data;

(iii) Periodic monitoring of the ground water quality in the first aquifer overlying the injection zone;

(iv) Periodic monitoring of the ground water quality in the lowermost USDW; and

(v) Any additional monitoring necessary to determine whether fluids are moving into or between USDWs.

§331.65.Reporting Requirements.

(a) Applicability. Subsections (b) - (d) of this section apply to all Class I wells except for those Class I wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals.

(b) [ ~~(a)~~ ] Pre-operation reports. For new wells, including wells converting to Class I status, the requirements are as follows.

(1) Completion report. Within 90 days after the completion or conversion of the well, the permittee shall submit a Completion Report to the executive director. The report must include a surveyor's plat showing the exact location and giving the latitude and longitude of the well. The report must also include a certification that a notation on the deed to the facility property or on some other instrument which is normally examined during title search has been made stating the surveyed location of the well, the well permit number, and its permitted waste streams. The permittee shall also include in the report the following, prepared and sealed by a licensed professional engineer or licensed professional geoscientist with current registration under the Texas Engineering Practice Act or Texas Geoscience Practice Act:

(A) actual as-built drilling and completion data on the well;

(B) all logging and testing data on the well;

(D) anticipated maximum pressure and flow rate at which the permittee will operate;

(E) results of the injection zone and confining zone testing program as required in §331.62 of this title (relating to Construction Standards) and this subsection;

(F) adjusted formation pressure increase calculations, fluid front calculations and updated cross- sections of the confining and injection zones, based on the data obtained during construction and testing;

(G) the actual injection procedure;

(H) the compatibility of injected wastes with fluids in the injection zone and minerals in both the injection zone and the confining zone and materials used to construct the well;

(I) the calculated area of review and cone of influence based on data obtained during logging and testing of the well and the formation, and where necessary, revisions to the information submitted under §331.121 of this title (relating to Class I Wells);

(J) the status of corrective action required for defective wells in the area of review;

(K) a Well Data Report on forms provided by the executive director;

(L) compliance with the casing and cementing performance standard in §331.62(5) of this title; and

(M) compliance with the cementing requirements in §331.62(6) of this title.

(2) Local authorities. The permittee shall provide written notice to the executive director, in a manner specified by the executive director, that a copy of the permit has been properly filed with the health and pollution control authorities of the county, city, and town where the well is located.

(3) Start-up date and time. The permittee shall notify the executive director in writing of the anticipated well start-up date. Compliance with all pre-operation terms of the permit must occur prior to beginning injection operations. The permittee shall notify the executive director at least 24 hours prior to beginning drilling operations.

(4) Approval of construction and completion. Prior to beginning operations, the permittee must obtain written approval from the executive director, according to §331.45 of this title (relating to Executive Director Approval of Construction and Completion).

(1) Injection operation quarterly report. For non-commercial facilities only, within 20 days after the last day of the months of March, June, September, and December, the permittee shall submit to the executive director a quarterly report of injection operation on forms supplied by the executive director. These forms will comply with the reporting requirements of 40 Code of Federal Regulations (CFR) §146.69(a). The executive director may require more frequent reporting.

(2) Injection operation monthly report. Commercial facilities shall meet the following requirements.

(A) The permittee shall submit within 30 days after the last day of each month a report to the commission including the following information for wastes received and injected during the month:

(i) names and locations of the companies and plants generating the wastes;

(ii) chemical and physical characteristics and volume of waste received from each company including pH;

(iii) names of companies transporting the wastes; and

(iv) a log of injection operations for each injection episode including but not limited to time of injection, injection rate, injection pressures, injection fluid volume, injection fluid pH, and injection fluid density.

(B) The permittee shall submit to the commission within 20 days of the last day of each month a report of injection operations on forms provided by the commission. These forms shall comply with the reporting requirements of 40 CFR §146.69(a). The executive director may require more frequent reporting.

(3) Injection zone annual report. For all facilities, the permittee shall submit annually with the December report of injection operation an updated graphic or other acceptable report of the pressure effects of the well upon its injection zone as required by §331.64(h) of this title (relating to Monitoring and Testing Requirements). To the extent this information is reasonably available, the report must also include:

(A) locations of newly constructed or newly discovered wells that penetrate the confining and/or injection zone within the area of review if those wells were not included in the technical report accompanying the permit application or in later reports;

(B) a tabulation of data as required by §331.121(a)(2)(B) [ ~~§331.121(2)(B)~~ ] of this title for wells within the area of review that penetrate the injection zone or confining zone;

(C) the condition of the wells identified in subparagraph (A) of this paragraph and their effect on the injection activities;

(D) the protocol followed to identify, locate, and ascertain the condition of the wells identified in subparagraph (A) of this paragraph;

(E) a corrective action plan for wells not adequately constructed, completed, or plugged; and

(F) for non-commercial facilities only, a current injection fluid analysis.

(4) Mechanical integrity and other reports. The permittee shall submit within 30 days after test completion, a report including both data and interpretation on the results of:

(A) periodic tests of mechanical integrity; and

(B) any other test of the injection well or injection zone if required by the executive director.

(5) Emergency report of leak or other failure. The permittee shall notify the Underground Injection Control (UIC) Unit of the Austin office of the commission within 24 hours of any significant change in monitoring parameters or of any other observations which could reasonably be attributed to a leak or other failure of the well equipment or injection zone integrity.

(d) [ ~~(c)~~ ] Workover reports. Within 30 days after the completion of the workover, a report shall be filed with the executive director including the reason for well workover and the details of all work performed.

(e) Class I Wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals shall comply with the following reporting requirements:

(1) Completion Reports. A new injection well may not commence injection until construction is complete, and

(A) The permittee has submitted notice of completion of construction to the executive director; and

(B) The executive director has inspected or otherwise reviewed the new injection well and finds it is in compliance with the conditions of the permit; or

(C) The permittee has not received notice from the executive director of his intent to inspect or otherwise review the new injection well within 13 days of the date of the notice in paragraph (1)(A) of this subsection, in which case prior inspection or review is waived and the permittee may commence injection. The executive director shall include in his notice a reasonable time period in which he shall inspect the well.

(2) Operating Reports. The owner or operator shall submit reports to the executive director as follows:

(A) Quarterly reports on:

(i) The physical, chemical, and other relevant characteristics of the injection fluids;

(ii) Monthly average, maximum, and minimum values for injection pressure, flow rate and volume, and annular pressure;

(iii) The results from ground-water monitoring wells prescribed in paragraph §331.64(k)(10) of this title (relating to Monitoring and Testing Requirements);

(iv) The results of any test of the injection well conducted by the owner or operator during the reported quarter if required by the executive director; and

(v) Any well work over performed during the reported quarter.

(B) Annual Reports. An annual report to the executive director summarizing the results of monitoring required under §331.64(k)(1)(B) of this title. This summary shall include monthly records of injected fluids and any major changes in characteristics or sources of injected fluid. Previously submitted information may be included by reference.

§331.66.Additional Requirements and Conditions.

(a) This section applies to all Class I wells except for those Class I wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals.

(b) [ ~~(a)~~ ] A permit for a Class I well shall include expressly or by reference the following conditions.

(1) A sign shall be posted at the well site which shall show the name of the company, company well number, and commission permit number. The sign and identification shall be in the English language, clearly legible and shall be in numbers and letters at least one inch high.

(2) An all-weather road shall be installed and maintained to allow access to the injection well and related facilities.

(3) The wellhead and associated facilities shall be painted, if appropriate, and maintained in good working order without leaks.

(4) The commission may prescribe additional requirements for Class I wells to protect USDWs, and fresh or surface water from pollution.

(c) [ ~~(b)~~ ] Permit requirements for owners or operators of disposal wells which inject wastes which have the potential to react with the injection formation to generate gases shall include:

(1) conditions limiting the temperature, pH, or acidity of the injected wastes; and

(2) procedures necessary to assure that pressure imbalances which might cause a backflow or blowout do not occur.

This agency hereby certifies that the proposal has been reviewed by legal counsel and found to be within the agency's legal authority to adopt.

Filed with the Office of the Secretary of State on February 29, 2008.

TRD-200801195

Robert Martinez

Director, Environmental Law Division

Texas Commission on Environmental Quality

Earliest possible date of adoption: April 13, 2008

For further information, please call: (512) 239-0177

Subchapter G. CONSIDERATION PRIOR TO PERMIT ISSUANCE

30 TAC §331.121

STATUTORY AUTHORITY

§331.121.Class I Wells.

(a) The commission shall consider the following before issuing a Class I Injection Well Permit:

(1) all information in the completed application for permit;

(2) all information in the Technical Report submitted with the application for permit in accordance with §305.45(a)(8) of this title (relating to Contents of Application for Permit) . [ ~~including but not limited to:~~ ] Subparagraphs (A) - (R) of this paragraph apply to all Class I wells except those Class I Wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals. Information to be considered includes, but is not limited to:

(A) - (R) (No change.)

(3) This paragraph applies to those Class I Wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals. Information to be considered includes, but is not limited to:

(A) a map showing the injection well(s) for which a permit is sought and the applicable area of review. Within the area of review, the map must show the number, or name, and location of all producing wells, dry holes, surface bodies of water, springs, mines (surface and subsurface), quarries, water wells and other pertinent surface features including residences and roads. The map should also show faults, if known or suspected. Only information of public record is required to be included on this map;

(B) a tabulation of data on all wells within the area of review that penetrate into the proposed injection zone. Such data shall include a description of each well's type, construction, date drilled, location, depth, record of plugging and/or completion, and any additional information the executive director may require;

(C) a topographic map (or other map if a topographic map is unavailable) extending one mile beyond the property boundaries of the source depicting the facility and each of its intake and discharge structures; each of its hazardous waste treatment, storage, or disposal facilities; each well where fluids from the facility are injected underground; and those wells, springs, and other surface water bodies, and drinking water wells listed in public records or otherwise known to the applicant within a quarter mile of the facility property boundary;

(D) maps and cross sections indicating the general vertical and lateral limits of all underground sources of drinking water within the area of review, their position relative to the injection formation and the direction of water movement, where known, in each underground source of drinking water which may be affected by the proposed injection;

(E) maps and cross sections detailing the geologic structure of the local area;

(F) generalized maps and cross sections illustrating the regional geologic setting;

(G) proposed operating data:

(i) average and maximum daily rate and volume of the fluid to be injected;

(ii) average and maximum injection pressure; and

(iii) source and an analysis of the chemical, physical, radiological and biological characteristics of injection fluids;

(H) proposed formation testing program to obtain an analysis of the chemical, physical and radiological characteristics of and other information on the receiving formation;

(I) proposed stimulation program;

(J) proposed injection procedure;

(K) schematic or other appropriate drawings of the surface and subsurface construction details of the well;

(L) contingency plans to cope with all shut-ins or well failures so as to prevent migration of fluids into any underground source of drinking water;

(M) plans (including maps) for meeting the monitoring requirements in §331.64 of this title (relating to Monitoring and Testing Requirements);

(N) for wells within the area of review which penetrate the injection zone but are not properly completed or plugged, the corrective action proposed to be taken under §331.45(2)(G) of this title (relating to Executive Director Approval of Construction and Completion); and

(O) construction procedures including a cementing and casing program, logging procedures, deviation checks, and a drilling, testing, and coring program; and

(4) [ ~~(3)~~ ] whether the applicant will assure, in accordance with Chapter 37, Subchapter Q of this title (relating to Financial Assurance for Underground Injection Control Wells), the resources necessary to close, plug, abandon, and if applicable, provide post-closure care for the well and/or waste disposal cavern as required;

(5) [ ~~(4)~~ ] the closure plan, corrective action plan, and post-closure plan submitted in the technical report accompanying the permit application; except that a post-closure plan is not required for those Class I Wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals; and

(6) [ ~~(5)~~ ] any additional information required by the executive director for the evaluation of the proposed injection well.

(b) In determining whether the use or installation of an injection well is in the public interest under Texas Water Code, §27.051(a)(1), the commission shall also consider:

(1) the compliance history of the in accordance with Texas Water Code, §27.051(e) and §281.21(d) of this title (relating to Draft Permit, Technical Summary, Fact Sheet, and Compliance History [ ~~Summary~~ ]);

(2) - (4) (No change.)

(c) The commission shall consider the following minimum criteria for siting before issuing a Class I injection well permit for all Class I wells except those Class I Wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals . For Class I Wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals, only paragraph (1) of this subsection applies.

(1) - (4) (No change.)

(d) - (g) (No change.)

This agency hereby certifies that the proposal has been reviewed by legal counsel and found to be within the agency's legal authority to adopt.

Filed with the Office of the Secretary of State on February 29, 2008.

TRD-200801196

Robert Martinez

Director, Environmental Law Division

Texas Commission on Environmental Quality

Earliest possible date of adoption: April 13, 2008

For further information, please call: (512) 239-0177

Subchapter L. GENERAL PERMIT AUTHORIZING USE OF A CLASS I INJECTION WELL TO INJECT NONHAZARDOUS DESALINATION CONCENTRATE OR NONHAZARDOUS DRINKING WATER TREATMENT RESIDUALS

30 TAC §§331.201 - 331.206

STATUTORY AUTHORITY

The new sections are proposed under Texas Water Code (TWC), §5.103, which provides the commission with the authority to adopt any rules necessary to carry out its powers and duties under this code and other laws of this state and to adopt rules repealing any statement of general applicability that interprets law or policy; §5.105, which authorizes the commission to establish and approve all general policy of the commission by rule; §27.019, which requires the commission to adopt rules reasonably required for the regulation of injection wells; and §27.023, which allows the commission to adopt rules as necessary to implement and administer a general permit authorizing the use of Class I injection wells to inject nonhazardous brine from desalination operations or nonhazardous drinking water treatment residuals.

The proposed new sections implement TWC, §27.023, relating to General Permit Authorizing Use of Class I Injection Wells to Inject Nonhazardous Brine from Desalination Operations or Nonhazardous Drinking Water Treatment Residuals, and TWC, Chapter 27.

§331.201.Purpose and Applicability.

(a) The commission may issue a permit to dispose of nonhazardous brine produced by a desalination operation or nonhazardous drinking water treatment residuals in a Class I injection well if the facility meets all the statutory and regulatory requirements for the issuance of a permit for a Class I injection well.

(b) The commission may issue a general permit authorizing the use of a Class I injection well to inject nonhazardous brine from a desalination operation or to inject nonhazardous drinking water treatment residuals if the commission determines that the injection well and injection activities are more appropriately regulated under a general permit than under an individual permit based on findings that:

(1) the general permit has been drafted to ensure that it can be readily enforced and that the commission can adequately monitor compliance with the terms of the general permit; and

(2) the general permit will contain proper safeguards to protect ground and surface fresh water from pollution.

(d) The use or disposal of radioactive material under this subchapter is subject to the applicable requirements of Chapter 336 of this title (relating to Radioactive Substance Rules).

§331.202.Public Notice, Public Meetings, and Public Comment.

(a) Applicability. The requirements of subsections (b) - (e) of this section apply to processing a new general permit, an amendment, renewal, revocation, or cancellation of a general permit.

(b) Notice of a draft general permit shall be published as follows:

(1) Notice shall be published in the Texas Register and in at least one newspaper of statewide or regional circulation; and

(2) The public notice shall be published not later than the 30th day before the commission considers the approval of a general permit.

(1) include the applicable information described in §39.11 of this title (relating to Text of Public Notice);

(2) include an invitation for written comments by the public to the commission regarding the proposed draft general permit; and

(3) specify a comment period of at least 30 days.

(d) Requirements relating to public meetings are as follows:

(1) The agency may hold a public meeting to provide an additional opportunity for public comment and shall hold such a public meeting when the executive director determines, on the basis of requests, that a significant degree of public interest in a draft general permit exists.

(2) Notice of a public meeting shall be by publication in the Texas Register not later than the 30th day before the date of the meeting.

(3) Notice of a public meeting shall be mailed to the following:

(A) the county judge of the county or counties in which permittees under the general permit could be located;

(B) persons who filed public comment or request for a public meeting on or before the deadline for filing public comment or request for a public meeting; and

(4) The contents of a notice of a public meeting shall include the applicable information described in §39.11 of this title. Each notice must include an invitation for written or oral comments by the public regarding the draft general permit.

(5) The public comment period shall automatically be extended to the close of any public meeting held by the agency on the proposed general permit.

(e) If the agency receives public comment during the comment period relating to issuance of a general permit, the executive director shall respond in writing to these comments, and this response shall be made available to the public and filed with the chief clerk at least ten days before the commission considers the approval of the general permit. The response shall address all written comments received during the comment period and oral or written comments received during any public meeting held by the agency. The commission shall consider all public comment in making its decision and shall either adopt the executive director's response to public comment or prepare its own response.

(1) The commission shall issue its written response to comments on the general permit at the same time the commission issues or denies the general permit.

(2) A copy of any issued general permit and response to comments shall be made available to the public for inspection at the agency's Austin office and also in the appropriate regional offices.

(3) A notice of the commission's action on the proposed general permit and a copy of its response to comments shall be mailed to each person who made a comment during the comment period.

(4) A notice of the commission's action on the proposed general permit and the text of its response to comments shall be published in the Texas Register.

§331.203.Authorizations and Notices of Intent.

(a) A person may obtain authorization to use a Class I injection well to inject nonhazardous brine from a desalination operation or to inject nonhazardous drinking water treatment residuals under a general permit by complying with the general permit's conditions. A person shall submit a Notice of Intent to the executive director in a form or format that is specified in the general permit or otherwise set out in commission rules.

(b) The general permit shall describe the content of the Notice of Intent. A Notice of Intent shall be signed in accordance with §305.44 of this title (relating to Signatories to Applications).

(1) The executive director shall provide written notice to a facility if the executive director denies the facility's Notice of Intent or authorization to inject waste under a general permit, including, at a minimum, a brief statement of the basis for this decision.

(2) The executive director shall deny authorization to inject waste under an existing general permit for the following reasons:

(A) the quantity of waste to be injected, the type of waste, the type of operation, the injection well design, or the injection well construction does not comply with the general permit;

(B) the person or facility:

(i) has failed to pay any portion of a delinquent fee or charge assessed by the executive director;

(ii) is not in compliance with all requirements, conditions, and time frames specified in an unexpired commission final enforcement order relating to the activity regulated by the general permit; or

(iii) is subject to an unexpired enforcement order that requires the facility to comply with operating conditions different from or additional to the requirements of the general permit.

(3) The executive director may deny authorization to inject or operate an injection well under an existing general permit for reasons including, but not limited to, the following:

(A) the owner and/or the operator of the facility has not filed a Notice of Intent in accordance with §305.43 of this title (relating to Who Applies);

(B) the facility has been determined by the executive director to have been out of compliance with any rule, order, or permit of the commission, including non-payment of fees assessed by the executive director; or

(C) the facility is the subject of an unresolved agency enforcement action in which the executive director has issued a written notice of enforcement.

(4) If authorization to inject waste is denied under this subsection, the executive director may require the person whose authorization is denied to apply for and obtain an individual permit. If the facility is seeking to replace its individual permit with general permit coverage, but the facility's general permit authorization is denied, the facility shall apply for renewal of the individual permit prior to the expiration date of its current individual permit to maintain authorization to inject waste, in accordance with §305.63 of this title (relating to Renewal).

(d) The following requirements apply to suspensions of authorizations and Notices of Intent:

(1) The general permit shall describe the procedures for suspension of authorization and Notices of Intent under a general permit. The general permit shall require the executive director to provide written notice to a permittee that the executive director intends to suspend the permittee's authority to inject waste under a general permit, including:

(A) a brief statement of the basis for this decision under this subsection;

(B) a statement of whether the permittee shall immediately cease injection of waste;

(D) a statement that the permittee's waste injection authorization under the general permit shall be suspended on the effective date of the commission's action on the individual permit application unless the commission expressly provides otherwise, or unless the executive director has required the permittee to immediately cease injection of waste.

(2) If a permittee's authorization under a general permit is suspended, the permittee shall immediately cease waste injection.

(3) The executive director may require the person whose authorization to inject or operate an injection well is suspended to apply for and obtain an individual permit.

(4) After providing written notice to the permittee, the executive director shall suspend authorization to inject or operate an injection well under an existing general permit for the following reasons:

(A) the quantity of waste, the type of waste, or the type of operation does not comply with the general permit;

(B) the permittee or facility:

(i) has failed to pay any portion of a delinquent fee or charge assessed by the executive director;

(ii) is not in compliance with all requirements, conditions, and timeframes specified in an unexpired commission final enforcement order relating to the activity regulated by the general permit: or

(iii) is subject to an unexpired enforcement order that requires the facility to comply with operating conditions different from or additional to the requirements of the general permit; and

(5) After providing written notice to the permittee, the executive director may suspend authorization to inject waste under an existing general permit for reasons including, but not limited to, the following:

(A) a change has occurred in the availability of demonstrated technology or practices for the prevention, control, or abatement of pollutants applicable to the injection necessary to be implemented to meet applicable federal or state standards;

(B) the owner and/or the operator of the facility has not filed a Notice of Intent in accordance with §305.43 of this title;

(C) circumstances have changed since the time of the Notice of Intent so that injection of waste is no longer appropriately controlled to meet applicable standards under the general permit, or either a temporary or permanent cessation of the authorized waste injection is necessary;

(D) the facility has been determined by the executive director to have been out of compliance with any rule, order, or permit of the commission, including non-payment of fees assessed by the executive director; and

(E) the permittee or facility is the subject of an unresolved agency enforcement action in which the executive director has issued written notice that enforcement has been initiated.

(e) The commission, after hearing, shall deny or suspend a permittee's authority to inject waste under a general permit if the commission determines that the permittee operates any facility for which the permittee's compliance history contains violations constituting a recurring pattern of egregious conduct that demonstrates a consistent disregard for the regulatory process, including a failure to make a timely and substantial attempt to correct the violations. A hearing under this subsection is not subject to Texas Government Code, Chapter 2001.

§331.204.Permit Duration, Amendment, and Renewal.

(a) A general permit may be issued for a term not to exceed ten years. After notice and comment as provided by §331.202 of this title (relating to Public Notice, Public Meetings, and Public Comment), a general permit may be amended, revoked, or canceled by the commission or renewed by the commission for an additional term or terms not to exceed ten years each.

(b) A general permit remains in effect until the commission amends, revokes, cancels or renews the general permit, or until it expires, whichever comes first. If before its expiration, the commission proposes to renew a general permit, the general permit shall remain in effect after the expiration date for those existing permittees covered by the general permit until the date on which the commission takes final action on the proposed permit renewal. No new Notices of Intent will be accepted or new authorizations honored for authorization under the general permit after the expiration date.

(c) Upon issuance of a renewed or amended general permit, all owners or operators, including those covered under the expired general permit, shall submit a Notice of Intent in accordance with the requirements of the new permit.

(d) If the commission has not proposed to renew a general permit at least 90 days before its expiration date, permittees authorized under the general permit shall submit an application for an individual permit before the general permit's expiration. If an application for an individual permit is submitted before the general permit's expiration, authorization under the expired general permit remains in effect until the issuance or denial of an individual permit.

(e) The commission may, through renewal or amendment of a general permit, add or delete requirements or limitations to the permit. The commission may provide in the general permit a reasonable time to allow existing permittees covered by the general permit to make the changes necessary to comply with any additional requirements deemed substantive by the commission.

(f) Before issuing a general permit, the commission shall review the general permit for consistency with the Texas Coastal Management Plan (CMP). The commission must find that the general permit is consistent with the applicable CMP goals and policies and that it will not adversely affect any applicable coastal natural resource areas as identified in the CMP before the commission may issue the general permit.

§331.205.Fees for Notice of Intent and Notice of Change.

(a) A person shall include with the notice of intent requesting coverage under the terms of a general permit issued under this subchapter a fee of $100 for each disposal well.

(b) A permittee authorized under a general permit issued under this subchapter shall include with each notice of change a fee of $100 for each disposal well.

§331.206.Annual Fee Assessments.

A person authorized by a general permit shall pay annual facility and waste management fees according to Chapter 335, Subchapter J of this title (relating to Permits for Land Treatment Demonstrations Using Field Tests or Laboratory Analyses) unless specified in the general permit.

This agency hereby certifies that the proposal has been reviewed by legal counsel and found to be within the agency's legal authority to adopt.

Filed with the Office of the Secretary of State on February 29, 2008.

TRD-200801197

Robert Martinez

Director, Environmental Law Division

Texas Commission on Environmental Quality

Earliest possible date of adoption: April 13, 2008

For further information, please call: (512) 239-0177