Adopted Sections 
 An agency may take final action on a section 30 days after a proposal has been 
published in the Texas Register. The section becomes effective 20 days after the 
agency files the correct document with the Texas Register, unless a later date 
is specified or unless a federal statute or regulation requires implementation 
of the action on shorter notice. 
 If an agency adopts the section without any changes to the proposed text, only 
the preamble of the notice and statement of legal authority will be published. 
If an agency adopts the section with changes to the proposed text, the proposal 
will be republished with the changes. 
 
   
  TITLE 1. ADMINISTRATION 
 Part IV. Office of the Secretary of State 
  Chapter 78. Athlete Agents 
  
  Administrative Penalties 
 
  1 TAC sec.78.60 
 
  The Office of the Secretary of State adopts new sec.78.60 concerning the 
assessment of administrative penalties, without changes to the proposed text as 
publish in the April 30, 1993, issue of the Texas Register (18 TexReg 2841). 
 Adoption of the new rule will provide individuals and companies with a 
clarification of the procedure for determining the amount of an administrative 
penalty that is assessed under the Athlete Agents Act, sec.9, Texas Civil 
Statutes, Article 8871 (Vernon Supplement 1993). 
 No comments were received regarding adoption of the new rule. 
 The new rule is adopted under Texas Civil Statutes, Article 8871, sec.11, which 
provide the secretary of state with the authority to prescribe and adopt rules 
necessary to carry out the administration and enforcement of the Athlete Agents 
Act. 
 
  This agency hereby certifies that the rule as adopted has been reviewed by 
legal counsel and found to be a valid exercise of the agency's legal authority. 
 Issued in Austin, Texas, on June 9, 1993. 
 TRD-9324069 
  Audrey Selden 
 Assistant Secretary of State 
 Office of the Secretary of State 
    Effective date: June 30, 1993 
 Proposal publication date: April 30, 1993 
 For further information, please call: (512) 463-5570 
         
               
  TITLE 28. INSURANCE 
 Part II. Texas Workers' Compensation Commission 
  Chapter 126. Benefits-General Provisions Applicable to All Benefits 
  
  28 TAC sec.126.7 
 
  The Texas Workers' Compensation Commission adopts the repeal of sec.126.7, 
concerning Injured Employee's Choice of Doctor without changes to the proposed 
text as published in the January 26, 1993, issue of the Texas Register  (18 
TexReg 459). 
 Repeal of this section is required by the expiration of Texas Civil Statutes, 
Article 8308-4.62 on December 31, 1992. 
 No public comments were received regarding adoption of the repeal. 
 The repeal is adopted under Texas Civil Statutes, Article 8308-2.09(a), which 
authorize the commission to adopt rules necessary to administer the Act. 
 
  This agency hereby certifies that the proposal has been reviewed by legal 
counsel and found to be within the agency's authority to adopt. 
 Issued in Austin, Texas, on June 8, 1993. 
 TRD-9324006 
  Susan Cory 
 General Counsel 
 Texas Workers' Compensation Commission 
    Effective date: July 1, 1993 
 For further information, please call: (512) 440-3592 
         
             
  
  Chapter 126. General Provisions Applicable to All Benefits 
  
  28 TAC sec.126.8, sec.126.9 
 
  The Texas Workers' Compensation Commission adopts new sec.126.8 and sec.126. 
9, concerning Commission-Approved Doctor List and Choice of Treating Doctor and 
Liability for Payment, with changes to the text as published in the January 26, 
1993, issue of the Texas Register(18 TexReg 460). Section 126.8 establishes 
criteria, in addition to the criteria specified in Texas Civil Statutes, Article 
8308-4.63, for the addition of doctors to the list of commission-approved 
doctors and for the removal of doctors from the list. Section 126.9 establishes 
how the employee selects a treating doctor and what the doctor and injured 
employee must do to be in compliance with the requirements of the Act and 
commission rules. 
 These sections are required by Texas Civil Statutes, Article 8308-4.63. 
 Changes to the text of sec.126.8 involve the addition of the phrase "or 
commission orders" to the end of subsection (d)(1) and (6). While the commission 
did not receive any public comment on sec.126.8, these changes were made based 
on comments received on the companion rule, sec.126.9, and the commission 
responses to those comments. 
 Changes to the text of sec.126.9 made in response to public comments include: 
 deletion of the words "an interlocutory" and "supersedes this order" from 
subsection (f) and insertion of the words "superseded by a subsequent" in front 
of "order"; 
 adding "within ten days after receiving the order" to the end of the first 
sentence of subsection (g); 
 adding the phrase "or health care provider at the doctor's direction" to 
subsection (h) prior to the word "if:"; 
 deleting "as provided in subsection (h) of this section," "treatment provided 
after the date the commission relieves the carrier of liability," and "doctor" 
from subsection (i) while adding the phrases "medical treatments or services" 
after "may be billed for," "health care provider" in place of the deleted word 
"doctor," and "medical treatments or" in front of "services" in the last line of 
subsection (i); and 
 adding subsection (j) to describe how the health care provider and the injured 
employee will know who is liable for payment. 
 Comments opposing the sections were received from the Alliance of American 
Insurers and from an attorney who represents injured employees. Those comments 
and responses follow. 
 Recommend alternative language in sec.126.9(d), "on a form prescribed by the 
commission or another writing containing the same information as the form 
prescribed by the commission." 
 The commissioners disagree. The form prescribed by the commission will be 
handled in the manner that most forms are handled, with commission approval of 
alternate forms on a case-by-case basis. 
 Recommend allowing an agreement for change of doctors to occur between the 
carrier and injured employee without commission intervention. 
 Recommend allowing an informal change of treating doctor process with 
notification through the TWCC-64. 
 The commissioners disagree with both of these comments for the same reason. The 
intent of the Act was to establish and maintain control of medical treatment by 
the treating doctor. To accomplish that intent, the Act specifies a formal 
process where the commission will grant authority to select an alternate doctor. 
The Act, sec.4.63(d) specifies, "The commission will prescribe criteria by which 
the commission will grant the employee authority to select an alternate doctor." 
 Recommend adding the following reasons for approving a change in doctors to the 
list in sec.126.9(e): (a) the employee's condition is not improving with 
continued treatment from the doctor; (b) the doctor does not schedule frequent 
appointments with the employee; or (c) the doctor believes that the employee may 
be more appropriately treated by another doctor. 
 The commissioners disagree. The rule is not a complete laundry list of reasons 
for allowing a change in treating doctor which is why sec.126.9(e) states that 
the reasons for approving a change "include, but are not limited to," those 
reasons listed. Each injured employee is different and will require case-by-case 
consideration for changing treating doctors. 
 Specifically: reason (a) may not be a valid reason to change doctors because it 
appears to describe an employee who has reached maximum medical improvement; 
reason (b) may not be a valid reason to change doctors because many conditions 
do not require frequent appointments to improve the employee's condition; and 
reason (c) may not be a valid reason to change doctors because it describes the 
process contemplated in the Act where the treating doctor may have other doctors 
treat the injured employee while maintaining oversight of the treatment by all 
doctors. 
 Recommend clarification of sec.126.9(f) by adding, "if a change is approved, 
shall include an order to pay for reasonable and necessary treatment provided by 
the approved doctor unless and a later order of the commission supersedes this 
order." 
 The commissioners agree in part. Using the more generic reference to a later 
order of the commission in place of interlocutory order allows more flexibility 
in addressing possible errors. The words "reasonable and necessary" do not need 
to be inserted because the Act establishes that all payment for health care must 
be for reasonable and necessary care. The phrase "an interlocutory order" is 
deleted and the text changed to provide for superseding by a subsequent order. 
 This comment also leads to the need to change subsection (g) to establish a 
time frame within which either the employee or carrier may dispute the 
commission decision regarding a request to change doctors. 
 Recommend changing sec.126.9(i) to read, "If the carrier is relieved of 
liability for the costs of health care, by a final order of the commission, a 
doctor or other health care provider acting under orders of the doctor can bill 
the employee for treatment or supplies provided after the date the commission 
finally relieves the carrier of liability; provided that the doctor or other 
health care provider had no knowledge of the violation by the employee at the 
time the services or supplies were rendered." 
 The commissioners disagree with the recommendation that the employee only be 
subject to direct billing after an order of the commission becomes final. Once 
the carrier is relieved of liability, the health care provider must either be 
allowed to bill the employee or, if the health care provider was aware of the 
employee's violation, told that treatment provided after the date of the hearing 
decision may not be billed to either the carrier or the employee. To further 
clarify this point, a new subsection (j) is added to specify that the commission 
shall tell the carrier, doctor, and employee when a carrier is relieved of 
liability, the time period it applies to and whether the health care provider 
can bill the employee. This clarifies the procedure the commission will use to 
allow a health care provider to bill someone other than the carrier. 
 The commissioners agree to substitute "health care provider" for the word 
"doctor". While the reference to "health care furnished by the doctor" 
implicitly includes health care providers, as described in sec.4.65 and sec.8.42 
of the Act, this change will remove the confusion which the public comment 
reflects regarding the commission's intent. 
 The commissioners agree that the rule should address more than medical 
treatments. To be consistent with the Act, the commission will use the phrase 
"medical treatments or services" in this subsection. 
 Recommend alternative language in sec.126.9(h), "the commission shall" to 
ensure fairness. The use of the more liberal "may" still subjects carriers to 
potential payments to physicians even though the employee may have clearly 
violated paragraphs (1) or (2). If a judge at the Benefit Contested Case Hearing 
finds an employee violated subsection (h)(1) and/or (2), there should be no 
discretion for the judge to order payment by the carrier. 
 The commissioners disagree. Using "may" allows the commission to exercise 
discretion in relieving the carrier of liability. An inadvertent violation by an 
employee should not necessarily relieve the carrier of liability. The facts of 
each case must be examined to determine whether the carrier should be relieved 
of liability and using "may" requires a conscious decision to be made. 
 The new sections are adopted under Texas Civil Statutes, Article 8308-2. 09(a), 
which authorize the commission to adopt rules necessary to administer the Act, 
and Article 8308-4.63, which require the commission to develop a program to add 
and remove doctors from the list of approved doctors and further requires the 
commission to establish a process for injured employees to change doctors. 
 
 
  sec.126.8. Commission-Approved Doctor List. 
 
  (a) On or after January 1, 1993, except in emergency situations, injured 
employees must receive medical treatment from a doctor on the commission-
approved doctor list (the list). This list initially includes all doctors 
licensed in Texas on or after January 1, 1993, and doctors licensed in other 
jurisdictions who have been added to the list by the commission. 
   
  (b) Doctors licensed in other jurisdictions may ask to be added to the list by 
submitting a written request containing information prescribed by the 
commission. Unless the doctor has been deleted from the list by the commission, 
a carrier shall not withhold reimbursement to doctors licensed in other 
jurisdictions when the only reason for nonpayment is that the doctor is not 
presently on the list. 
   
  (c)  Each month, the division of medical review (the division) will provide 
insurance carriers, through designated Austin representatives, with the names 
of: 
 
  (1) doctors deleted from the list; 
   
  (2) doctors reinstated to the list; and 
   
  (3) doctors added to the list from other jurisdictions. 
     
  (d) Doctors may be deleted from the list for the following: 
 
  (1) sanctions imposed by the commission against the doctor for violations of 
the Act, commission rules, or commission orders; 
   
  (2)  sanctions by Medicare or Medicaid for substandard medical care, 
overcharging, or overutilization of medical services; 
   
  (3) substantial differences between the doctor's charges, fees, diagnoses, or 
treatments and those the commission finds to be fair and reasonable; 
   
  (4) revocation or suspension of a doctor's license by the appropriate 
licensing authority; 
   
  (5) limitations or restrictions on the professional license or disciplinary 
actions taken by the appropriate licensing authority; 
   
  (6)  criminal conviction which indicates an unwillingness or inability to 
provide quality treatment or to abide by the Act, commission rules, or 
commission orders; or 
   
  (7) other activities which warrant deletion. 
     
  (e) The division shall notify a doctor by certified mail, return receipt 
requested, of the division's intent to recommend to the commissioners that the 
doctor be deleted from the list. Within 20 days after receiving the notice, a 
doctor may request a hearing as provided by Texas Civil Statutes, Article 8308-
4.63 and Article 6252-13a (the Administrative Procedure and Texas Register Act), 
and sec.145.3 of this title (relating to Requesting a Hearing). If a request for 
hearing is received, the commission shall hold a hearing as provided in Chapter 
145 of this title (related to Dispute Resolution-Hearings Under the 
Administrative Procedure and Texas Register Act). If no request for hearing is 
filed within the time allowed, the division's recommendation will be reviewed by 
the commissioners at a public meeting and a decision made to either delete or 
maintain the doctor on the list. 
   
  (f)  As described in Article 8308-2.09(f) and sec.145.24 of this title 
(relating to Special Provisions for Imposing Sanctions Pursuant to the Act, 
sec.2.09(f)), only the commissioners may delete a doctor from the list. The 
commission shall notify the doctor by issuing an order of deletion which 
describes the effects of the deletion on the doctor and the doctor's patients 
subject to workers' compensation. This order shall be delivered to the doctor by 
certified mail, return receipt requested, with a copy to the licensing authority 
and copies to those injured employees the commission is aware are being treated 
by that doctor. After receipt, the doctor shall also inform any injured 
employees, seeking treatment under the Act, of the doctor's deletion from the 
list and that the injured employee may not, except in an emergency, receive 
care. Failure to inform the injured employees in the form and format prescribed 
by the commission may subject the doctor to administrative penalties of up to 
$10,000 and other sanctions as provided by the Act. 
   
  (g) To be reinstated, a doctor deleted from the list must apply for 
reinstatement in the form and manner prescribed by the commission through the 
Medical Review Division in Austin. If, in the division's opinion, the doctor has 
all the appropriate unrestricted licenses to practice at the time of 
reinstatement, has overcome the conditions which resulted in deletion, and 
should be reinstated, the division shall recommend that the commissioners 
reinstate the doctor to the list. 
   
  (h) If, in the division's opinion, the doctor has not met the requirements for 
reinstatement, or for other reasons should not be reinstated, the division shall 
notify the doctor by certified mail, return receipt requested, of the division's 
intent to recommend to the commissioners that the doctor not be reinstated to 
the list. Within 20 days after receiving the notice, a doctor may request a 
hearing as provided in subsection (e) of this section. 
 
     
  sec.126.9. Choice of Treating Doctor and Liability for Payment. 
 
  (a) The injured employee is entitled to the employee's initial choice of 
treating doctor from the list of doctors approved by the Texas Workers' 
Compensation Commission. As of January 1, 1993, any change in treating doctor 
after the initial choice requires approval from the commission. The term 
"doctor," as used in this section, has the meaning defined in Article 8308-1. 
03(17). 
   
  (b) The commission shall include, with the information mailed to the employee 
as required by  5.09 of the Act, the requirements related to the selection of a 
treating doctor from the commission-approved doctor list and to changing 
treating doctors as described in this section. 
   
  (c)  The first doctor who provides health care to an injured employee shall be 
known as the injured employee's initial choice of treating doctor. The following 
do not constitute an initial choice of treating doctor: 
 
  (1)  a doctor salaried by the employer; 
   
  (2) a doctor recommended by the carrier or employer, unless the injured 
employee continues, without good cause as determined by the commission, to 
receive treatment from the doctor for a period of more than 60 days; or 
   
  (3) any doctor providing emergency care unless the injured employee receives 
treatment from the doctor for other than follow-up care related to the emergency 
treatment. 
     
  (d)  If an injured employee wants to change treating doctors, other than 
exceptions as described in Article 8308-4.64 or removal of the doctor from the 
list, the employee shall submit to the field office handling the claim, reasons 
why the current treating doctor is unacceptable. Unless medical necessity exists 
for an immediate change, the submission shall be in writing on a form prescribed 
by the commission. If the need for an immediate change exists, then the injured 
employee may notify the field office by telephone. Injured employees who change 
doctors because the doctor is removed from the list or for one of the exceptions 
listed in Article 8308-4.64 shall immediately notify the commission of the 
change in the form and format prescribed by the commission. 
   
  (e) Reasons for approving a change in treating doctor include but are not 
limited to: 
 
  (1) the reasons listed in Article 8308-4.63(d); and 
   
  (2) the selected doctor chooses not to be responsible for coordinating injured 
employee's health care as described in sec.133.3 of this title (relating to 
Responsibilities of Treating Doctor). 
     
  (f) The commission shall issue an order approving or denying a change of 
doctor request. This order shall be issued within ten days after receiving the 
request and, if a change is approved, shall include an order for the insurance 
carrier to pay for treatment provided by the approved doctor unless superseded 
by a subsequent order. 
   
  (g) With good cause, the injured employee or carrier may dispute the order 
regarding a change to an alternate treating doctor within ten days after 
receiving the order. That dispute will be handled through the dispute resolution 
process described in Chapters 140-143 of this title (relating to Dispute 
Resolution/General Provisions, Benefit Review Conference, Benefit Contested Case 
Hearing, and Review by the Appeals Panel). 
   
  (h) The commission may, after holding a benefit contested case hearing as 
provided by Chapter 142 of this title (relating to Benefit Contested Case 
Hearing), relieve the carrier of liability for health care furnished by a doctor 
or health care provider at the doctor's direction if: 
 
  (1) the doctor chosen by the employee is not on the list at the time the 
medical treatments or services are rendered; or 
   
  (2) the employee failed to comply with commission rules regarding a change in 
treating doctor. 
     
  (i)  If the carrier is relieved of liability for the costs of health care, the 
employee may be billed for medical treatments or services provided the health 
care provider billing the employee had no knowledge of the violation by the 
employee at the time the medical treatments or services were rendered. 
   
  (j) The commission shall relieve the carrier of liability by an order which 
identifies the health care provider(s) and expressly states the time period for 
which the carrier is relieved of liability and whether the health care provider 
may submit the bill to the employee for those treatments or services. Provided, 
however, that a doctor removed from the list may not seek reimbursement under 
workers' compensation for treatments or services rendered. 
 
  This agency hereby certifies that the rule as adopted has been reviewed by 
legal counsel and found to be a valid exercise of the agency's legal authority. 
 Issued in Austin, Texas, on June 8, 1993. 
 TRD-9324004 
  Susan Cory 
 General Counsel 
 Texas Workers' Compensation Commission 
    Effective date: July 1, 1993 
 Proposal publication date: January 26, 1993 
 For further information, please call: (512) 440-3592 
         
                 
  TITLE 31. NATURAL RESOURCES AND CONSERVATION 
 Part IX. Texas Water Commission 
  Chapter 293. Water Districts 
  
  The Texas Water Commission (Commission) adopts the repeal of sec.sec.293.41, 
293.61, 293.62, 293.82, and 293.95, concerning bond-related document filings, 
and changes in construction work plans; amendments to sec.sec.293.6, 293.14, 
293. 18, 293.32-293.34, 293.43-48, 293.50, 293.51, 293.56, 293.57, 293.59, 
293.70, 293.81, 293.83-293.87, 293.91, 293.92, 293.94-293.96 and 293.131, 
concerning district creations, director qualifications, review and approval of 
engineering projects, issuance of bonds, change orders, use of surplus funds and 
escrowed funds, changes in approved bond interest rate, financial and other 
reporting requirements, and district dissolutions, and new sec.sec.293.41, 
293.61, 293.62, 293.82, 293.88, 293.95, 293.97 and 293.171-293.177, concerning 
bond related document filings, construction related document filings, changes in 
project scope or plans, extensions of time to sell bonds and the processing of 
impact fee applications. 
 Sections 293.18, 293.33, 293.44, 293.46, 293.48, 293.50, 293.51, 293.56, 
293.59, 293.82, 293.91, 293.96, 293.97, and 293.176 were adopted with changes to 
the proposed text as published in the March 26, 1993, issue of the Texas 
Register  at (18 TexReg 1896). Sections 293.6, 293.14, 293.32, 293. 34, 293.41, 
293.43, 293.45-293.48, 293.57, 293.61, 293.62, 293.70, 293.81, 293. 83-293.86, 
293.92, 293.94, 293.95, 293.131, 293.171-293.175, and 293.177 are adopted 
without changes and will not be republished. An amendment to sec.293.88 and new 
sec.293.87 were published in the March 30, 1993, issue of the Texas Register (18 
TexReg 2126) and were adopted without changes and will not be republished. 
 The Commission received comments concerning sec.293.44 and sec.293.176 and has 
clarified cross-references and corrected minor errors and sentence structure 
deficiencies in the proposal. 
 The notice form in sec.293.18 contains a grammatical clarification to the 
justiciable interest language. 
 The reference to "Appendix A" in sec.293.33 is deleted to match the 
corresponding title of the form listed in sec.293.34. 
 A commenter submitted alternative language to sec.293.44(a)(14)-(18) which, as 
a whole, expands the obligations of districts regarding developer 
reimbursements. The language expands the use of bond proceeds to repairs and 
other non-capital uses and in some instances affords no time limitations for 
this expanded use of bond proceeds. The commission disagrees with the 
appropriateness of this language. The proposed rules offer a fair mechanism for 
developer reimbursements. The commission has modified sec.293.44(a)(16) to allow 
those developers who made advances to districts in good faith prior to the 
adoption of these rules to seek reimbursement under the existing policy. 
 After further consideration the commission has elected to retain the permissive 
verb currently found in sec.293.46(1)(5). The flexibility allowed by this term 
is preferred. 
 The forms addressed in sec.293.48 were misreferenced. The references have been 
corrected to correspond to their respective provisions found in sec.293.56 and 
sec.293.57. 
 Punctuation marks have been added to sec.293.50(b) to improve sentence 
structure. 
 Typographical errors have been corrected in sec.293.51. A typographical error 
in the letter of credit form set forth in sec.293.56 has been corrected. 
 A connecting word inadvertently omitted from sec.293.59 has been inserted. 
 The certification requirement found in sec.293.82 has been clarified. The 
commission proposed replacement language for the phrase "an increase" in 
sec.293.82(b). The proposed language "a change" was published correctly; 
however, the brackets for the terms proposed for deletion were not published. 
The inclusion of all the subject language renders the subsection confusing. 
Therefore, the commission adopts sec.293.82(b) as it should have been published. 
 Section 293.91 contains corrections to citation form and a connecting word 
needed to correct the sentence structure. 
 A typographical error in sec.293.96 has been corrected. 
 Section 293.97 was proposed as a new section. The published version of this 
section reflects a partial sentence in brackets denoting deletion. Since the 
section is new, the bracketed language was unnecessary and the commission has 
deleted the subject partial sentence. 
 A commenter suggested the addition of language which clarifies the overlapping 
fees provisions found in sec.293.176. The commission generally agrees with this 
comment and has included most of the suggested and other clarifying language. 
Another comment was received concerning the impact fees sections 
(sec.sec.293.171-293.177) generally. The commenter requested language requiring 
local governments (municipalities) located within a district to agree, by 
resolution, to accept a district's land use plan, or in the alternative, for the 
local government to develop a land use plan encompassing the city and provide a 
copy to the district for inclusion in the district wide impact fee calculation. 
This type of requirement is inappropriate since it is beyond the commission's 
jurisdiction and has not been added to these rules. 
 Comments were received from the following groups/companies: Vinson & Elkins, 
Brushy Creek Municipal Utility District, Reed-Stowe & Company, and the Law 
Offices of Ronald J. Freeman. 
   
  General Provisions 
 
  31 TAC sec.293.6 
 The amendment is adopted under the Texas Water Code sec. sec.5.103, 5.105, and 
5. 235, which provides the Texas Water Commission with the authority to adopt 
any rules necessary to carry out the powers and duties under the provisions of 
the Texas Water Code and other laws of this state, to establish and approve all 
general policy of the commission, and to collect statutory fees from persons 
filing various applications with the commission. 
 
  This agency hereby certifies that the rule as adopted has been reviewed by 
legal counsel and found to be a valid exercise of the agency's legal authority. 
 Issued in Austin, Texas, on June 9, 1993. 
 TRD-9324027 
  Mary Ruth Holder 
 Director, Legal Division 
 Texas Water Commission 
    Effective date: June 30, 1993 
 Proposal publication date: March 26, 1993 
 For further information, please call: (512) 463-8069 
         
       
  Creation of Water Districts 
 
  31 TAC sec.293.14, sec.293.18 
 
  The amendments are adopted under the Texas Water Code,  sec.sec.5.103, 5.105, 
and 5.235, which provides the Texas Water Commission with the authority to adopt 
any rules necessary to carry out the powers and duties under the provisions of 
the Texas Water Code and other laws of this state, to establish and approve all 
general policy of the commission, and to collect statutory fees from persons 
filing various applications with the commission. 
 
 
  sec.293.18. Form of Notice of a Public Hearing on the Creation of a Water 
District. The following form should be used to provide notice of the public 
hearing on the creation of a water district. 
   
  TO: ALL PERSONS INTERESTED IN THE PETITION FOR CREATION OF 
_________________________ DISTRICT, OF ________________ COUNTY, TEXAS 
   
  Notice is hereby given that a public hearing will be held at _______ o'clock, 
____.m., on ____________________, 19__, before the Texas Water Commission (the 
"Commission"), in room _______ of the Stephen F. Austin State Office Building, 
1700 North Congress Avenue, Austin, Travis County, Texas, upon a Petition for 
the Organization of ____________________ District (the "Petition") relating to 
the proposed ____________________ District of ____________________ County, Texas 
(the "District"). The Petition is filed and the hearing is held under the 
authority of Chapter _______, Subchapter _______, Texas Water Code, 31 Texas 
Administrative Code  sec.sec.293.11-293.14 and under the Rules of Procedure of 
the Commission. The Petition reflects that it has been signed by landowners 
within the proposed District who collectively represent a majority in value of 
the owners of land therein, as required by sec.________, Texas Water Code. 
   
  The nature and purpose of the Petition is for the organization, creation and 
establishment of the District as a _________________ district under the 
provisions of Article XVI, Section 59, Texas Constitution, and Chapter _______, 
Texas Water Code, as amended, which District shall have the purposes provided 
for in Section _______, Texas Water Code, and the powers provided for in Section 
_______, Texas Water Code. The general nature of the work to be done is the 
purchase, construction, acquisition, ownership, operation, repair, improvement 
and extension of a waterworks and sanitary sewer system for domestic and 
commercial purposes, and a drainage system to control, abate and amend harmful 
excesses of waters and to reclaim and drain overflowed lands within said 
District, all as more particularly described in an engineer's report filed 
simultaneously with the filing of the Petition, to which report reference is 
hereby made for a more detailed description of the District's proposed 
facilities. Such report estimates that the cost of all such improvements will be 
$_________. 
   
  The territory to be included within the proposed District is set forth in the 
following metes and bounds description designated as Exhibit "A" hereto, and is 
depicted in the following vicinity map designated as Exhibit "B" hereto. 
   
  Any affected person may request an evidentiary hearing. Affected persons 
appearing at the hearing may request to be granted party status and thereby have 
the opportunity to present evidence and cross-examine witnesses of the other 
parties concerning the petition, the necessity and feasibility of the proposed 
District's project, and the benefits to accrue. All parties will be given an 
opportunity to negotiate a settlement prior to the hearing on the merits. No 
person or entity will be admitted as a party to the proceeding unless the person 
or entity complies with the Commission's Rules of Procedure which require a 
showing of a justiciable interest and attendance at the hearing either in person 
or by a qualified representative. 
 
  This agency hereby certifies that the rule as adopted has been reviewed by 
legal counsel and found to be a valid exercise of the agency's legal authority. 
 Issued in Austin, Texas, on June 9, 1993. 
 TRD-9324028 
  Mary Ruth Holder 
 Director, Legal Division 
 Texas Water Commission 
    Effective date: June 30, 1993 
 Proposal publication date: March 26, 1993 
 For further information, please call: (512) 463-8069 
         
           
  Appointment of Directors 
 
  31 TAC sec.sec.293.32-293.34 
 
  The amendments are adopted under the Texas Water Code,  sec.sec.5.103, 5.105, 
and 5.235, which provides the Texas Water Commission with the authority to adopt 
any rules necessary to carry out the powers and duties under the provisions of 
the Texas Water Code and other laws of this state, to establish and approve all 
general policy of the commission, and to collect statutory fees from persons 
filing various applications with the commission. 
 
 
  of Directors. Requests accompanied by the following: 
 
  (1) a petition signed by a landowner within the district requesting 
appointment of temporary directors or directors to fill one or more vacancies on 
the board; 
   
  (2)  evidence of each former director's failure or refusal to qualify or serve 
for each vacancy on the board to be filled; 
   
  (3) requests for consideration of appointment as director in the form shown in 
sec.293.34 of this title (relating to Form of Affidavit for Appointment as 
Director) for those persons desiring consideration as director for vacant 
positions; 
   
  (4) a filing fee of $100; and 
   
  (5) any other information as the executive director may require. 
 
  This agency hereby certifies that the rule as adopted has been reviewed by 
legal counsel and found to be a valid exercise of the agency's legal authority. 
 Issued in Austin, Texas, on June 9, 1993. 
 TRD-9324029 
  Mary Ruth Holder 
 Director, Legal Division 
 Texas Water Commission 
    Effective date: June 30, 1993 
 Proposal publication date: March 26, 1993 
 For further information, please call: (512) 463-8069 
         
             
  Issuance of Bonds 
 
  31 TAC sec.293.41 
 
  The repeal is adopted under the Texas Water Code, sec. sec.5.103, 5.105, and 
5. 235, which provides the Texas Water Commission with the authority to adopt 
any rules necessary to carry out its powers and duties under the provisions of 
the Texas Water Code and other laws of this state, to establish and approve all 
general policy of the commission, and to collect statutory fees from persons 
filing various applications with the commission. 
 
  This agency hereby certifies that the rule as adopted has been reviewed by 
legal counsel and found to be a valid exercise of the agency's legal authority. 
 Issued in Austin, Texas, on June 9, 1993. 
 TRD-9324036 
  Mary Ruth Holder 
 Director, Legal Division 
 Texas Water Commission 
    Effective date: June 30, 1993 
 Proposal publication date: March 26, 1993 
 For further information, please call: (512) 463-8069 
         
         
  Issuance of Bonds 
 
  31 TAC sec.sec.293.41, 293.43-293.48, 293.50, 293.51, 293.56, 293. 57, 293.59 
 
  The new and amended sections are adopted under the Texas Water Code (Vernon 
1992), sec.sec.5.103, 5.105, and 5.235 which provide the Texas Water Commission 
with the authority to adopt any rules necessary to carry out the powers and 
duties under the provisions of the Texas Water Code and other laws of this 
state, to establish and approve all general policy of the commission, and to 
collect statutory fees from persons filing various applications with the 
commission. 
 
 
  sec.293.44. Special Considerations. 
 
  (a) Developer projects. The following provisions shall apply unless the 
commission, in its discretion, determines that application to a particular 
situation renders an inequitable result. 
 
  (1) A developer project is a district engineering project which provides 
water, sewer or drainage service for property owned by a developer, as defined 
by the Texas Water Code,  sec.50.026(d). 
   
  (2)  Except as permitted pursuant to subsection (a)(8) of this section, the 
costs of joint facilities that benefit the district and others should be shared 
on the basis of benefits received. Generally, the benefits are the design 
capacities in the joint facilities for each participant. Proposed cost sharing 
for conveyance facilities should account for both flow and inflow locations. 
   
  (3) The cost of clearing and grubbing of district facilities easements that 
will also be used for other facilities that are not eligible for district 
expenditures, such as roads, gas lines, telephone lines, etc., should be shared 
equally by the district and the developer, except where unusually wide road or 
street rights-of-way or other unusual circumstances are present, as determined 
by the commission. The district's share of such costs is further subject to any 
required developer contribution pursuant to sec.293. 47 of this title (relating 
to Thirty Percent of District Construction Costs to be Paid by Developer). The 
applicability of the competitive bidding statutes and/or regulations shall be 
determined by the amount of the estimated district share, including any required 
developer contribution; provided, however, that in instances where such clearing 
and grubbing construction contracts are let and awarded in the developer's name 
and the developer's aggregate reimbursable share of such costs, including any 
required developer contribution, exceeds 50% of the total construction contract 
costs, the competitive bidding statutes and/or regulations are not considered to 
be applicable. 
   
  (4) A district may finance the cost of spreading and compacting of fill in 
areas that require the fill for development purposes, such as in abandoned 
ditches or floodplain areas, only to the extent necessary to dispose of the 
spoil material (fill) generated by other projects of the district. 
   
  (5) The cost of any clearing and grubbing in areas where fill is to be placed 
should not be paid by the district unless the district can demonstrate a net 
savings in the costs of disposal of excavated materials when compared to the 
estimated costs of disposal off site. 
   
  (6) When a developer changes the plan of development requiring the abandonment 
or relocation of existing facilities, the district may pay the cost of either 
the abandoned facilities or the cost of replacement facilities, but not both. 
   
  (7) When a developer changes the plan of development requiring the redesign of 
facilities that have been designed, but not constructed, the district may pay 
the cost of the original design or the cost of the redesign, but not both. 
   
  (8) A district shall not finance the pro rata share of oversized water, sewer 
or drainage facilities to serve areas outside the district unless: 
 
  (A) such oversizing: 
 
  (i) is required by or represents the minimum approvable design sizes 
prescribed by local governments or other regulatory agencies for such 
applications; 
   
  (ii) does not benefit out-of-district land owned by the developer; 
   
  (iii) does not benefit out-of-district land currently being developed by 
others; and 
   
  (iv) the district agrees to use its best efforts to recover such costs if a 
future user outside the district desires to use such capacity; or 
     
  (B) the district has entered into an agreement with the party being served by 
such oversized capacity which provides adequate payment to the district to pay 
the cost of financing, operating and maintaining such oversized capacity; or 
   
  (C) the district has entered into an agreement with the party to be served or 
benefitted in the future by such oversized capacity, which provides for 
contemporaneous payment by such future user of the incremental increase in 
construction and engineering costs attributable to such oversizing and which, 
until the costs of financing, construction, operation, and maintenance of such 
oversized facilities are prorated according to paragraph (2) of this subsection, 
provides that: 
 
  (i) the capacity or usage rights of such future user shall be restricted to 
the design flow or capacity of such oversized facilities multiplied by the 
fractional engineering and construction costs contemporaneously paid by such 
future user; and 
   
  (ii) such future user shall pay directly allocable operation and maintenance 
costs proportionate to such restricted capacity or usage rights. 
       
  (9) Railroad, pipeline, or underground utility relocations that are needed 
because of road crossings should not be financed by the district; however, if 
such relocations result from a simultaneous district project and road crossing 
project, then such relocation costs should be shared equally. 
   
  (10) Engineering studies, such as topographic surveys, soil studies, fault 
studies, boundary surveys, etc., that contain information that will be used both 
for district purposes and for other purposes, such as roadway design, foundation 
design, land purchases, etc., should be shared equally by the district and the 
developer, unless unusual circumstances are present as determined by the 
commission. 
   
  (11) Land planning, zoning, and development planning costs should not be paid 
by the district, except for conceptual land use plans required to be filed with 
a city as a condition for city consent to creation of the district. 
   
  (12) The cost of constructing lakes or other facilities that are part of the 
developer's amenities package should not be paid by the district. The cost of 
combined lake and detention facilities should be shared with the developer on 
the basis of the volume attributable to each use, and land costs should be 
shared on the same basis, unless the district can demonstrate a net savings in 
the cost of securing fill and construction materials from such lake or detention 
facilities, when compared to the costs of securing such fill or construction 
materials off-site. 
   
  (13) Bridge and Culvert Crossings shall be financed in accordance with the 
following provisions. 
 
  (A) The costs of bridge and culvert crossings needed to accommodate the 
development's road system shall not be financed by a district unless such 
crossing consists of a single culvert with a cross sectional area of not more 
than nine square feet. The districts share shall be subject to the developer's 
30% contribution as may be required by sec.293.47 of this title. 
   
  (B) Drainage Districts and Levee Improvement Districts which were confirmed 
and operating pursuant to the Water Code, Chapters 56 and 57, respectively, 
prior to September 1, 1989, may fund the costs of bridge and culvert crossings 
larger than those specified in subparagraph (A) of this paragraph which are 
necessary as a result of required channel improvements subject to the following 
limitations: 
 
  (i)  the crossing must be located entirely or partially within the district's 
boundaries; 
   
  (ii) the drainage channel construction or renovation must benefit property 
within the district's boundaries; 
   
  (iii)  the costs shall not exceed a pro rata share based on the percent of 
total drainage area of the channel crossed, of crossing, calculated by taking 
the total cost of such bridge or culvert crossing multiplied by a fraction, the 
numerator of which is the total drainage area located within the district 
upstream of the crossing, and the denominator of which is the total drainage 
area upstream of the crossing; 
   
  (iv)  the district shall be responsible for not more than 50% of the cost as 
calculated under this subsection, subject to the developer's 30% contribution as 
may be required by sec.293.47 of this title. 
     
  (C) The cost of replacement of existing bridges and culverts not constructed 
or installed by the developer, or the cost of new bridges and culverts across 
existing roads not financed or constructed by the developer, may be financed by 
the district, except that any costs of increasing the traffic carrying capacity 
of bridges or culverts shall not be financed by the district. 
     
  (14) In evaluating district construction projects, including those described 
in paragraphs (1) -(12) of this subsection, primary consideration shall be given 
to engineering feasibility and whether the project has been designed in 
accordance with good engineering practices, notwithstanding that other 
acceptable or less costly engineering alternatives may exist. 
   
  (15) Bond issue proceeds will not be used to pay or reimburse consultant fees 
for the following: 
 
  (A)  special or investigative reports for projects which, for any reason, have 
not been constructed and, in all probability, will not be constructed; 
   
  (B) fees for bond issue reports for bond issues consisting primarily of 
developer reimbursable and approved by the commission but which are no longer 
proposed to be issued; or 
   
  (C) fees for completed projects which are not and will not be of benefit to 
the district; provided, however, that the foregoing limitations shall not apply 
to regional projects or special or investigative reports necessary to properly 
evaluate the feasibility of alternative district projects. 
     
  (16) The district shall not program bond funds to finance operation and 
administrative costs except for: 
 
  (A)  deficits incurred during the period of construction prior to the issuance 
of the subject bonds or the net expenses expected to accrue during the period of 
construction after the issuance of the subject bonds but in no event shall the 
total period exceed three years; 
   
  (B) deficits incurred for the district's share of operation and administration 
costs resulting from the district entering into an agreement for the 
construction of a Water Plant or Waste Water Treatment Plant serving or 
programmed to serve three thousand equivalent single family connections or more. 
For purposes of this paragraph, deficits shall be calculated by taking the total 
operating and administrative cost of the district for the period and 
subtracting: 
 
  (i) revenue received which shall include but not be limited to interest 
earnings, rates, charges and other fees assessed by the district; and 
   
  (ii) revenue which would be received from the assessment of a $0.25 per/$100 
assessed valuation maintenance tax during the period assuming a 100% collection 
rate. 
     
  (C) Advances made to a district for operation and administrative cost prior to 
June 1, 1993, if all of the following are true: 
 
  (i) a reimbursement agreement was executed with the district in good faith at 
the time the advance was made; and 
   
  (ii) the total reimbursed does not exceed three years of actual operating and 
administration expenses incurred by the district. 
     
  (D) Lease payments associated with lease/purchase agreements for central plant 
capacity. 
     
  (17) In instances where creation costs to be paid from bond proceeds are 
determined to be excessive, the executive director may request that the 
developer submit invoices and cancelled checks to determine whether such 
creation costs were reasonable and customary and necessary for district creation 
purposes. Such creation costs shall not include planning, platting, zoning, 
other costs prohibited by paragraphs (10) and (14) of this subsection and other 
matters not directly related to the district's water, sewage and drainage 
system, even if required for city consent. 
   
  (18) The district shall not purchase, pay for or reimburse the cost of 
facilities, either completed or incomplete, from which it has not and will not 
receive benefit, even though such facilities may have been at one time required 
by a city or other entity having jurisdiction. 
   
  (19) The district shall not enter into any binding contracts with a developer 
which compel the district to become liable for costs above those approved by the 
Commission. 
   
  (20) A district shall not purchase more water supply or wastewater treatment 
capacity than is needed to meet the foreseeable capacity demands of the 
District, except in circumstances where: 
 
  (A) lease payments or capital contributions are required to be made to 
entities owning or constructing regional water supply or wastewater treatment 
facilities to serve the district and others; 
   
  (B) such purchases or leases are necessary to meet minimum regulatory 
standards; or 
   
  (C) such purchases or leases are justified by considerations of economic or 
engineering feasibility. 
       
  (b) All projects. 
 
  (1) The purchase price for existing facilities not covered by a 
preconstruction agreement or otherwise not constructed by a developer in 
contemplation of resale to the district should be established by an independent 
appraisal by a registered professional engineer hired by the district. The 
appraised value should reflect the current condition of the facilities and 
estimated cost of repair, as evidenced by an on-site inspection. 
   
  (2) (No change.) 
   
  (3) Contract revenue bonds proposed to be issued by districts for facilities 
providing water, sewer or drainage, pursuant to contracts authorized under Local 
Government Code, sec.402.014, or other similar statutory authorization, will be 
approved by the commission only when the city's pro rata share of debt service 
on such bonds is sufficient to pay for the cost of the water, sewer or drainage 
facilities proposed to serve areas located outside the boundaries of the service 
area of the issuing district. 
   
  (4) (No change.) 
 
       
  sec.293.50. Developer Interest Reimbursement. 
 
  (a) A developer may be reimbursed by a district for interest accrued for a 
period of up to two years after the final payment by the developer on approved 
construction pay estimates, professional fees and attendant nonconstruction 
costs paid by a developer for providing facilities in anticipation of sale to 
such district. If final payment on a construction contract is 95% complete, the 
initiation of the two year interest accrual period will be six months from the 
date the contract is 95% complete, unless the developer can demonstrate a 
genuine contractual dispute with the contractor, or other extenuating reasons, 
as determined by the commission. The interest rate shall not exceed the net 
effective interest rate on the bonds sold, or the interest rate actually paid by 
the developer for loans obtained for this purpose, whichever is less. If a 
developer uses its own funds rather than borrowed funds, the net effective 
interest rate on the bonds sold shall be applied. 
   
  (b) If reimbursement for accrued interest for a period of more than two years 
after the completion date allowed in (a) of this subsection is requested by a 
district, and if no interest reimbursement has occurred, additional accrued 
interest up to five years from the completion date of the construction contracts 
including related professional fees and nonconstruction costs may be allowed if 
deemed feasible by the commission, and if: 
 
  (1)-(2) (No change.) 
     
  (c) (No change.) 
   
  (d) If otherwise determined to be feasible by the commission, time limitations 
on accrued developer interest shall not apply to: 
 
  (1) wastewater treatment facilities serving or projected to serve 2,000 acres 
or more; 
   
  (2)-(4) (No change.) 
   
  (5)  drainage channels, levees and other flood control facilities and 
stormwater detention facilities meeting the requirements of sec.293.52 of this 
title (relating to Storm Water Detention Facilities) and sec.293.53 of this 
title (relating to District Participation in Regional Drainage Systems) which 
are serving or are programmed to serve 2,000 acres or more. 
     
  (e) These time limitations on accrued developer interest also apply to 
advances made for organizational costs, repair costs and lease payments for 
central plant capacity associated with lease/purchase agreements. 
 
     
  sec.293.51. Land and Easement Acquisition. 
 
  (a) Water, Sanitary Sewer, Storm Sewer, and Drainage Facilities Easements. All 
easements required within a district's boundaries for water lines, sanitary 
sewer lines, storm sewer lines, drainage channels, sanitary control at water 
plants, and noise and odor control at wastewater treatment plants shall be 
dedicated to the public by the developer without reimbursement from the 
district. If any easements are required for such facilities on land not owned by 
a developer in the district, the district may acquire such land at its appraised 
market value, and may also pay legal, engineering, surveying or court fees and 
expenses incurred in acquiring such land, and sec.293.47 of this title (relating 
to 30% of District Construction Costs To be Paid by Developer) shall not apply 
to such acquisition. 
   
  (b) Plants, Lift, or Pump Stations, Detention Ponds and Levee Sites. All land 
needed by a district for plants, lift or pump stations, detention/retention 
ponds, or levees may be acquired in fee simple or by easement from any person, 
including the developer, in accordance with this section, and sec.293.47 of this 
title (relating to 30% of District Construction Costs To be Paid by Developer) 
shall not apply to such acquisition. If a district acquires such a site from a 
developer within the district or subsequent owner of developer reimbursables, 
the price shall be determined by adding to the price paid by the developer for 
such land or easement in a bona fide transaction between unrelated parties the 
developer's actual carrying charges (taxes and interest paid to the date of 
acquisition by the district); provided, however, if the executive director 
determines that such price appears to exceed the fair market value of such land 
or easement, he may require an appraisal to be obtained by the district from a 
qualified independent appraiser and payment to the seller may be limited to the 
fair market value of such land as shown by the appraisal; if the seller acquired 
the land after the improvements to be financed by the district were constructed, 
the price shall be limited to the fair market value of such land or easement 
established without the improvements being constructed; or if the seller 
acquired the land more than five years before the creation of the district and 
the records relating to the actual price paid and the actual carrying charges 
are impossible or difficult to obtain, the district, upon executive director 
approval, may purchase such site at fair market value based on an appraisal 
prepared by a qualified, independent appraiser. If the land or easement needed 
by the district is being acquired based on the appraised value, the application 
to the commission for approval to purchase such site must contain a request by 
the district to acquire the site in such manner and must explain the reason the 
seller is unable to provide price and carrying cost records. If the land or 
easement needed by the district is being acquired from an entity other than a 
developer or subsequent owner of developer reimbursables in the district, the 
district may pay the fair market value established by a qualified, independent 
appraiser, and may also pay legal, engineering, surveying, or court fees and 
expenses incurred in acquiring such land or easement. 
   
  (c) Joint Stormwater Detention/Water Amenity Facilities. If a detention or 
retention pond is also being used as an amenity by the developer, payment to the 
developer shall be limited to that cost that is associated only with the 
drainage function of the facility. The land costs of combined water amenity and 
detention facilities should be shared with the developer on the basis of the 
volume of water storage attributable to each use. 
   
  (d) Land or Easements Outside the District's Boundaries. Land or easements 
needed for any district facilities outside the district's boundaries may be 
purchased by the district as part of the district project at a price not to 
exceed the fair market value thereof. The district may also pay legal, 
engineering, surveying or court fees and expenses spent in acquiring such land. 
If the land or easements are purchased from a developer who owns land within the 
district, the price paid by the district shall be determined in accordance with 
subsection (b) of this section and such purchase price shall be subject to the 
provisions of sec.293.47 of this title unless the facilities constructed in, on, 
or over such land, easements or rights-of-way are, exempt from such contribution 
or the district is exempt from such contribution under the terms of sec.293.47 
of this title. 
   
  (e) When one or more upstream districts need land or easements through one or 
more downstream district(s) each upstream district may pay its pro rata share 
for its needs if none of the acquisitions is or will be required for partial or 
full development of the downstream district(s). If the out-of-district land or 
easement is required for a drainage channel downstream of the district and a 
portion of such land or easement is or will be needed by another district(s), 
whether upstream or downstream, for development, the district shall only pay for 
its proportionate share of the land costs based upon the acreage of the drainage 
area contributing drainage to such drainage channel at full development. 
However, in the event there is no developer in another district(s) to dedicate 
the district's pro rata share of the required land, the district may pay the 
entire cost to acquire such land, but the commission shall order the other 
district(s) to reimburse the district at such time as development occurs in the 
other district that requires such drainage right-of-way. 
   
  (f) Regional Facilities. A district may use bond proceeds to acquire the 
entire site for any regional plant, lift or pump station, detention pond, 
drainage channel, or levee if the commission determines that regionalization 
will be promoted and the district will recover the appropriate pro rata share of 
the site costs, carrying costs and bond issuance costs from future participants. 
The district may pay the fair market value based on an appraisal for such 
regional site and also may pay legal, engineering, surveying, or court fees and 
expenses incurred in acquiring such land. The commission shall, by separate 
order, order other districts participating in such regional facility to 
reimburse the acquiring district a proportionate share of such site costs, 
carrying costs and bond issuance costs at such time as development occurs in 
such other districts requiring such regional site. 
   
  (g) Prior to the district purchasing or obligating district funds for hte 
purchase of sites for water plants, wastewater plants or lift or pump stations, 
the district must have a registered professional engineer certify that the site 
is suitable for the purposes for which it intended and identify what areas will 
need to be designated as buffer zones to satisfy all entities with 
jurisdictional authority. 
 
     
  sec.293.56. Requirements for Letters of Credit (LOC). 
 
  (a) Any LOC submitted as a financial guarantee for combined amounts greater 
than $10, 000 and less than $250,000 pursuant to these rules must be from 
financial institutions which meet the following qualifications: 
 
  (1)  Qualifications for Banks: 
 
  (A) must be federally insured; 
   
  (B)  Sheshunoff rating must be ten or better; and 
   
  (C) total assets must be at least 50 million dollars. 
     
  (2) Qualifications for Savings and Loan Associations: 
 
  (A) must be federally insured; and 
   
  (B)  tangible capital must be at least: 
 
  (i) 1.5% of total assets if total assets are fifty million dollars or more; or 
   
  (ii)  tangible capital must be at least 3.0% of total assets if total assets 
are less than 50 million dollars; and 
     
  (C) Sheshunoff rating must be 30 or better. 
       
  (b) any LOC submitted as a financial guarantee for combined amounts greater 
than $250,000 pursuant to these rules must be from financial institutions which 
meet the following qualifications. 
 
  (1)  Qualifications for Banks: 
 
  (A) must be federally insured; 
   
  (B)  Sheshunoff rating must be 30 or better; and 
   
  (C) total assets must be at least 75 million dollars. 
     
  (2) Qualifications for Savings and Loan Associations. 
 
  (A) must be federally insured; 
   
  (B)  tangible capital must be at least: 
 
  (i) 3.0% of total assets and total assets must be 75 million dollars or more; 
or 
   
  (ii)  tangible capital must be at least 5.0% of total assets if total assets 
are less than 75 million dollars; and 
     
  (C) Sheshunoff rating must be thirty or better. 
       
  (c) All LOC's must be valid for a minimum of one year from the date of 
issuance and should provide that if the letter of credit is: 
 
  (1) not renewed for an additional year at least 30 days prior to its date of 
expiration; 
   
  (2) not called upon in its entirety at least 30 days prior to is date of 
expiration; 
   
  (3) not found to be unnecessary by the commission at least 30 days prior to 
its date of expiration; or 
   
  (4) unless the construction project has been completed as certified by the 
district's engineer at least 30 days prior to its date of expiration; the 
financial institution shall deposit in a special account in the name of the 
district, the face amount of the letter of credit. The District shall not commit 
or expend such funds until the commission has held a hearing authorizing the use 
of said funds. 
     
  (d) All LOC's required pursuant to these rules must be approved by the 
commission staff. 
   
  (e)  Form of Letter of Credit. The following form shall be used as a letter of 
credit for the financial guarantee for utilities construction and/or 
construction and paving of streets. 
 
  [graphic] 
       
  
  GENTLEMEN: 
 You are hereby authorized to value on ROCK OF GIBRALTAR BANK for account of ALL 
AMERICAN HOMES, INC. up to an aggregate amount of ------ TWO HUNDRED FIFTY 
THOUSAND AND NO/100 DOLLARS ------ available by your drafts at ------ SITE -----
- to be accompanied by the original of this letter of credit and the following 
documents: 
 
  (1) Written statement signed by the President or Vice President of the Board 
of Directors of Green Acres Municipal Utility District that All American Homes 
Inc. has failed to construct streets in Knot Holes West Subdivision in 
accordance with the terms of the Utility/Street And Road Construction Agreement 
dated December 1, 1980. (Required only for draft Number One), and a written 
certification(s) by the engineer for Green Acres Municipal Utility District that 
payment is due to the contractor for construction of streets in Knot Holes West 
Subdivision in the amount shown on the draft(s); or 
   
  (2) Written statement signed by the President or Vice President of the Board 
of Directors of Green Acres Municipal Utility District that All American Homes, 
Inc. has failed to renew or replace this letter of credit within 45 days prior 
to its expiration date; or 
   
  (3) Written statement signed by the President or Vice president of the Board 
of Directors of Green Acres Municipal Utility District that All American Homes, 
Inc. has commenced any proceeding, voluntary or involuntary, or that any 
proceeding has been commenced against All American Homes, Inc. involving 
bnkruptcy, insolvency, reorganization, liquidation or dissolution of All 
American Homes, Inc., that any receiver has been appointed by All American 
Homes, Inc., or that All American Homes, Inc. has made a general assignment for 
the benefit of creditors. 
     
  Multiple drafts may be presented. 
 Drafts must be presented to drawee bank not later than May 31, 1983, all drafts 
must state on their face "DRAWN UNDER ROCK OF GIBRALTAR BANK IRREVOCABLE CREDIT 
NUMBER ONE". 
 We hereby engage with you, that all drafts drawn under and in compliance with 
the terms of this credit will be duly honored, if drawn and presented for 
payment at our office in Megalopolis, Texas, on or before the expiration date of 
this credit. 
 We further engage with you that without further notice, we shall deposit in a 
special account in the name of the district, the remaining face amount of the 
letter of credit if the letter of credit is: 
 
  (1) not renewed for an additional year at least 30 days prior to its date of 
expiration; 
   
  (2)  not called upon in its entirety at least 30 days prior to its date of 
expiration; 
   
  (3) not found to be unnecessary by the Executive Director of the Texas Water 
Commission at least 30 days prior to its date of expiration; or 
   
  (4) unless the construction project has been completed as certified by the 
district's engineer at least 30 days prior to its date of expiration. 
     
  Very truly yours, 
   
  Authorized Signature 
 
   
  sec.293.59. Economic Feasibility of project. 
 
  (a) In addition to determining the engineering feasibility of a project, the 
commission shall also determine the economic feasibility of each proposed bond 
issue, bond amendment, and extension of time application for a bond issue. The 
staff of the commission shall use the following sections in making economic 
feasibility analysis. In its written recommendations to the commission which 
analyzes the particular application, the staff shall always address the economic 
feasibility. 
   
  (b)-(j) (No change.) 
   
  (k) For a district's first bond issue, the following paragraphs apply except 
that paragraphs (5), (6), (7) , (8), and (10) of this subsection are only 
applicable to a district that has a developer as defined by Texas Water Code, 
sec.50.026(d). 
 
  (1)-(7) (No change.) 
   
  (8) For bonds supported by taxes, a written agreement must be executed between 
the district and the developer and any other landowner and their respective 
lenders receiving proceeds of the bonds which permanently waives the right to 
claim agricultural, open-space, timberland or inventory valuation for any land, 
homes or buildings which they own in the district with respect to taxation by 
the district. The agreement shall be binding for 30 years on such developer, 
other landowners, their respective lenders, any related or affiliated entities 
and their successors and assignees, unless such exemptions were in effect at the 
time of the commission's approval of the bond issue and such exemptions were 
shown in the projected tax rate calculations. Such developer, landowners, and 
lenders shall record covenants running with the land to such effect, which shall 
not be modified or released without written authorization of the commission, and 
shall provide recorded copies to the commission prior to the approval of the 
bond issue. 
   
  (9)-(10) (No change.) 
   
  (11) Requirements of subsection (k)(6)(A)(C) and (E), and the requirements of 
subsection (k)(7) of this section shall not apply in the following cases where: 
 
  (A) the no-growth debt service tax rate for a district containing 2,000 acres 
or more providing only drainage facilities does not exceed $1.30; the no-growth 
debt service tax rate of a district providing major water and sewage facilities 
which it finances by the issuance of its bonds to an area containing 2,000 acres 
or more does not exceed $1.30, and the combined no-growth debt service tax rate 
does not exceed $2.00; and, the developer has completed a substantial amount of 
major thoroughfare or other infrastructure to serve the district; or 
   
  (B)-(C) (No change.) 
   
  (D) for the immediately preceding exceptions in paragraph (11)(A) or (C) of 
this subsection, the developer shall provide a guarantee for its 30% share, if 
required pursuant to sec.293.47 of this title (relating to 30% of District 
Construction Costs To Be Paid by Developer), in the form and manner required by 
subsection (g) thereof. For the immediately preceding exceptions in paragraph 
(11)(B) or (C) of this subsection, the developer shall provide a paving 
guarantee pursuant to sec.293.48 of this title (relating to Street and Road 
Construction by Developer). 
       
  (l) (No change.) 
   
  (m) Except for districts whose primary purpose is to provide service for 
agricultural uses, the economic feasibility of bond issues supported by benefit 
assessments shall be analyzed by converting the assessment to an equivalent tax 
rate per unit of assessment. The calculated equivalent tax rate shall be added 
into the combined no-growth tax rate defined in subsection (e) and the combined 
projected tax rate defined in subsection (f) of this section. The commission may 
compare these equivalent tax rates to those listed in subsection (k)(3) and (4) 
of this section. 
   
  (n) Bond issues supported only by revenue from a defined area shall be 
analyzed to assure that the defined area meets the requirements of this section 
independently of the remainder of the issuing district. 
   
  (o) A district may request a variance if it does not meet the guidelines 
contained in subsection (k) and (l) of this section, and a majority of the 
district's board of directors finds by resolution that the district would be 
justified in requesting a variance. The district will be responsible for 
providing sufficient documentation to justify any request for a variance. The 
commission will only grant variances in exceptional cases and may deny any 
request for a variance. The Commission shall not grant a variance to the maximum 
combined projected debt service tax rate or the maximum combined no-growth debt 
service tax rate specified in subsection (k) of this section for Districts that 
have a developer and the district is financing 100% of construction costs 
pursuant to criteria set out in sec.293.47(a) of this title which would 
otherwise require 30% developer participation. In determining whether to grant a 
variance, the following factors shall be considered; 
 
  (1)-(7) (No change.) 
 
  This agency hereby certifies that the rule as adopted has been reviewed by 
legal counsel and found to be a valid exercise of the agency's legal authority. 
 Issued in Austin, Texas, on June 9, 1993. 
 TRD-9324030 
  Mary Ruth Holder 
 Director, Legal Division 
 Texas Water Commission 
    Effective date: July 1, 1993 
 Proposal publication date: March 26, 1993 
 For further information, please call: (512) 463-8069 
         
               
  District Actions if the Commission Approves the Engineering Project and 
Issuance of Bonds 
 
  31 TAC sec.293.61, sec.291.62 
 
  The repeals are adopted under the Texas Water Code, sec. sec.5.103, 5.105, and 
5.235, which provides the Texas Water Commission with the authority to adopt any 
rules necessary to carry out its powers and duties under the provisions of the 
Texas Water Code and other laws of this state, to establish and approve all 
general policy of the commission, and to collect statutory fees from persons 
filing various applications with the commission. 
 
  This agency hereby certifies that the rule as adopted has been reviewed by 
legal counsel and found to be a valid exercise of the agency's legal authority. 
 Issued in Austin, Texas, on June 9, 1993. 
 TRD-9324038 
  Mary Ruth Holder 
 Director, Legal Division 
 Texas Water Commission 
    Effective date: June 30, 1993 
 Proposal publication date: March 26, 1993 
 For further information, please call: (512) 463-8069 
         
         
  District Actions if the Commission Approves the Engineering Project and 
Issuance of Bonds 
 
  31 TAC sec.sec.293.61, 293.62, 293.70 
 
  The amendment and new sections are adopted under the Texas Water Code (Vernon 
1992), sec.sec.5.103, 5.105, and 5.235, which provides the Texas Water 
Commission with the authority to adopt any rules necessary to carry out the 
powers and duties under the provisions of the Texas Water Code and other laws of 
this state, to establish and approve all general policy of the commission, and 
to collect statutory fees from persons filing various applications with the 
commission. 
 
  This agency hereby certifies that the rule as adopted has been reviewed by 
legal counsel and found to be a valid exercise of the agency's legal authority. 
 Issued in Austin, Texas, on June 9, 1993. 
 TRD-9324031 
  Mary Ruth Holder 
 Director, Legal Division 
 Texas Water Commission 
    Effective date: June 30, 1993 
 Proposal publication date: March 26, 1993 
 For further information, please call: (512) 463-8069 
         
         
  Other Actions Requiring Commission Consideration of Approval 
 
  31 TAC sec.sec.293.81-293.88 
 
  The amendments and new sections are adopted under the Texas Water Code, 
sec.sec.5.103, 5.105, and 5.235, which provides the Texas Water Commission with 
the authority to adopt any rules necessary to carry out the powers and duties 
under the provisions of the Texas Water Code and other laws of this state, to 
establish and approve all general policy of the commission, and to collect 
statutory fees from persons filing various applications with the commission. 
 
 
  sec.293.82. Change in Project Scope or Plans. 
 
  (a) A change in project scope is a change in projects funded or a change in 
the land use plan used to support the feasibility of a commission-approved bond 
issue which affects the central water or wastewater needs of the district or the 
amount of financial guarantees required pursuant to commission rules and that 
does not require an increase in the commission-approved bond amount. All 
applications for a change in the project scope shall include: 
 
  (1) a copy of a resolution or letter signed by a majority of the governing 
board, indicating concurrence in the proposed change; 
   
  (2) revised land use plan; 
   
  (3) revised build-out projections used to support the feasibility of the bond 
issue, if changed; 
   
  (4) revised cash-flow analysis, if revised build-out projections have caused a 
reduction in projected assessed valuations; 
   
  (5) a complete justification for the change; 
   
  (6)  the number of equivalent utility connections added or deleted by the 
change; 
   
  (7) an engineer's certification as to the availability and sufficiency of 
water supply and wastewater treatment capacities to serve such additional 
connections; 
   
  (8) a draft of the revised financial guarantee and an agreement between the 
district and developer, along with an engineer's cost-estimate to complete the 
required projects if a change in the amount of financial guarantees is necessary 
to comply with commission rules; 
   
  (9) a Market Study Update if one was required at the time of the bond approval 
and bonds have not been issued and there has been a change in type of 
development; 
   
  (10) plans and specifications approved by all entities having jurisdictional 
responsibilities; and 
   
  (11) other information as the executive director or commission may require. 
     
  (b) A change in plans is a change in commission-approved plans and 
specifications for construction work that is not under contract and that does 
not require a change in the commission-approved bond amount. 
 
  (1) No commission approval is required if the change in plans is $25,000 or 
less. 
   
  (2) If the change in plans is $25,000 or less, a copy of the change order 
signed by the contractor and an authorized representative of the district shall 
be filed with the executive director within 10 days of the execution date of the 
change order, together with any revised construction plans and specifications 
approved by all agencies and entities having jurisdictional responsibilities, 
i.e., city, county, state, or other, if required. 
   
  (3) All applications for change in plans shall include: 
 
  (A) a copy of a resolution or letter signed by the governing board, indicating 
concurrence in the proposed change (and for drainage districts, an advertisement 
affidavit indicating the proposed change in plans was published as required by 
the Texas Water Code, sec.56.123); 
   
  (B) a revised construction plans and specifications approved by all agencies 
and entities having jurisdictional responsibilities, i.e., city, county, state, 
and other, if required; 
   
  (C)  a revised land use plan, if changed; 
   
  (D) a detailed explanation for the change; 
   
  (E) a detailed cost summary showing additions and/or deletions to the approved 
plans and specifications and new cost estimate; 
   
  (F) a statement indicating amount and source of funding for the change in 
plans, including how the available funds were generated; 
   
  (G) the number of utility connections added or deleted by the change; 
   
  (H) an engineer's certification as to the availability and sufficiency of 
water supply and wastewater treatment capacities to serve such additional 
connections; 
   
  (I) a filing fee in the amount of $100; and 
   
  (J)  other information as the executive director or the commission may 
require. 
     
  (4) For purposes of this section, if either the total additions or total 
deletions contained in the change order exceed $25,000, even though the net 
change in the contract price will be $25,000 or less, approval by the executive 
director is required. 
     
  (c) Copies of all changes in plans, specifications, and supporting documents 
for all water district projects will be sent directly to the appropriate 
commission field office, simultaneously with the submittal of the documents to 
the executive director. 
 
  This agency hereby certifies that the rule as adopted has been reviewed by 
legal counsel and found to be a valid exercise of the agency's legal authority. 
 Issued in Austin, Texas, on June 9, 1993. 
 TRD-9324033 
  Mary Ruth Holder 
 Director, Legal Division 
 Texas Water Commission 
    Effective date: June 30, 1993 
 Proposal publication date: March 26, 1993 
 For further information, please call: (512) 463-8069 
         
             
  Other Actions Requiring Commission Consideration for Approval 
 
  31 TAC sec.293.82 
 
  The repeal is adopted under the Texas Water Code, sec. sec.5.103, 5.105, and 
5. 235, which provides the Texas Water Commission with the authority to adopt 
any rules necessary to carry out its powers and duties under the provisions of 
the Texas Water Code and other laws of this state, to establish and approve all 
general policy of the commission, and to collect statutory fees from persons 
filing various applications with the commission 
 
  This agency hereby certifies that the rule as adopted has been reviewed by 
legal counsel and found to be a valid exercise of the agency's legal authority. 
 Issued in Austin, Texas, on June 9, 1993. 
 TRD-9324039 
  Mary Ruth Holder 
 Director, Legal Division 
 Texas Water Commission 
    Effective date: June 30, 1993 
 Proposal publication date: March 26, 1993 
 For further information, please call: (512) 463-8069 
         
         
  Reports 
 
  31 TAC sec.sec.293.91, 293.92, 293.94-293.97 
 
  The amendments and new sections are adopted under the Texas Water Code, 
sec.sec.5.103, 5.105, and 5.235, which provides the Texas Water Commission with 
the authority to adopt any rules necessary to carry out its powers and duties 
under the Water Code and other laws of the State of Texas, to establish and 
approve all general policy of the commission, and to collect statutory fees from 
persons filing various applications with the commission. 
 
 
  sec.293.91. Reporting by Districts. 
 
  (a) All districts are required to file certain documents and reports with the 
executive director by the Texas Water Code, Chapter 50, as follows: 
 
  (1)-(5) (No change.) 
   
  (6) an annual audit report, financial report, or financial dormancy affidavit, 
as required by subsections (c), (e), and (f) of sec.293.94 of this title 
(relating to Annual financial Reporting Requirements); and 
   
  (7)  an annual filing affidavit, as required by subsection (g) of sec.293.94 
of this title (relating to Annual financial Reporting Requirements), and the 
Texas Water Code, sec.50.374(d), certifying that all filings of copies of the 
annual audit report, an annual financial dormancy affidavit, or annual financial 
report, as applicable, have been completed. 
     
  (b) (No change.) 
 
     
  sec.293.96. Miscellaneous Reports To Be Filed with the Executive Director. 
 
  (a) Certified copy of order canvassing results of any maintenance tax 
elections shall be filed within 30 days after adoption. 
   
  (b) Certified copy of water and sewer rate order adopted by the board and any 
amendments thereto, shall be filed within 30 days of adoption. 
 
     
  sec.293.97. Adoption of Fiscal Year and Operating Budget. 
 
  (a)  Fiscal year. Within 30 days after a district becomes financially active, 
the governing board of that district shall adopt a fiscal year by a formal board 
resolution and so note it in the district's minutes. The president or chairman 
of the governing board, a member of the board designated by the presiding 
officer, or the attorney representing the district shall notify the executive 
director of the adopted fiscal year within 30 days after adoption. 
   
  (b) Operating Budget. Prior to the start of a fiscal year, or as soon 
thereafter as possible, the governing board of each active district shall adopt 
an operating budget for the upcoming fiscal year. The adopted budget and any 
subsequent amendments shall be passed and approved by a resolution of the 
governing board and shall be made a part of the governing board minutes. Budget 
amendments may be made from time to time in the discretion of the governing 
board. The adopted budget is not a spending limitation imposed by the 
commission. However, the governing board may adopt rules to limit the spending 
authority of the district officers in relation to the budget. A comparison of 
the actual operating results to the adopted budget, as amended, shall be 
presented in the annual report of each district. The budgetary comparison 
statement shall be included either within the audited financial statements or 
within a supplementary section. 
 
  This agency hereby certifies that the rule as adopted has been reviewed by 
legal counsel and found to be a valid exercise of the agency's legal authority. 
 Issued in Austin, Texas, on June 9, 1993. 
 TRD-9324032 
  Mary Ruth Holder 
 Director, Legal Division 
 Texas Water Commission 
    Effective date: June 30, 1993 
 Proposal publication date: March 26, 1993 
 For further information, please call: (512) 463-8069 
         
             
  Reports 
 
  31 TAC sec.293.95 
 
  The repeal is adopted under the Texas Water Code, sec. sec.5.103, 5.105, and 
5. 235, which provides the Texas Water Commission with the authority to adopt 
any rules necessary to carry out its powers and duties under the provisions of 
the Texas Water Code and other laws of this state, to establish and approve all 
general policy of the commission, and to collect statutory fees from persons 
filing various applications with the commission 
 
  This agency hereby certifies that the rule as adopted has been reviewed by 
legal counsel and found to be a valid exercise of the agency's legal authority. 
 Issued in Austin, Texas, on June 9, 1993. 
 TRD-9324040 
  Mary Ruth Holder 
 Director, Legal Division 
 Texas Water Commission 
    Effective date: June 30, 1993 
 Proposal publication date: March 26, 1993 
 For further information, please call: (512) 463-8069 
         
         
  Dissolution of Districts 
 
  31 TAC sec.293.131 
 
  The amendment is adopted under the Texas Water Code, sec. sec.5.103, 5.105, 
and 5.235, which provides the Texas Water Commission with the authority to adopt 
any rules necessary to carry out its powers and duties under the provisions of 
the Texas Water Code and other laws of this state, to establish and approve all 
general policy of the commission, and to collect statutory fees from persons 
filing various applications with the commission. 
 
  This agency hereby certifies that the rule as adopted has been reviewed by 
legal counsel and found to be a valid exercise of the agency's legal authority. 
 Issued in Austin, Texas, on June 9, 1993. 
 TRD-9324034 
  Mary Ruth Holder 
 Director, Legal Division 
 Texas Water Commission 
    Effective date: June 30, 1993 
 Proposal publication date: March 26, 1993 
 For further information, please call: (512) 463-8069 
         
         
  Petition for Approval of Impact Fees 
 
  31 TAC sec.sec.293.171-293.177 
 
  The new sections are adopted under the Texas Water Code,  sec.sec.5.103, 
5.105, and 5.235, which provides the Texas Water Commission with the authority 
to adopt any rules necessary to carry out its powers and duties under the 
provisions of the Texas Water Code and other laws of this state, to establish 
and approve all general policy of the commission, and to collect statutory fees 
from persons filing various applications with the commission. 
 
 
  sec.293.176. Prior Approval of Overlapping Impact Fees.  If a district is 
required to collect an impact fee for another political subdivision which has 
complied with the procedures set out in Texas Civil Statutes, Local Government 
Code, Chapter 395, then the district is not required to seek further approval 
from the commission of the same fee. A test for applying this section shall be 
that the district does not retain any portion of said impact fee for its own 
use, but that it passes all such fees through to the political subdivision which 
has adopted said impact fee. 
 
  This agency hereby certifies that the rule as adopted has been reviewed by 
legal counsel and found to be a valid exercise of the agency's legal authority. 
 Issued in Austin, Texas, on June 9, 1993. 
 TRD-9324035 
  Mary Ruth Holder 
 Director, Legal Division 
 Texas Water Commission 
    Effective date: June 30, 1993 
 Proposal publication date: March 26, 1993 
 For further information, please call: (512) 463-8069 
         
             Chapter 334. Underground and Aboveground Storage Tanks 
  
  Subchapter M. Reimbursable Cost Guidelines for the Petroleum Storage Tank 
Reimbursement Program 
 
  31 TAC sec.334.560 
 
  The Texas Water Commission (Commission) adopts new sec.334.560, concerning 
Reimbursable Cost Guidelines for the Commission's Petroleum Storage Tank 
Reimbursement Program, with changes to the proposed text as published in the 
March 12, 1993, issue of the Texas Register (18 TexReg 1625). This section is 
adopted to implement by rule necessary guidelines for determining amounts that 
may be paid from the petroleum storage tank remediation fund to make the most 
efficient use possible of the money and to provide the most effective protection 
to the environment and public health and safety. 
 Section 334.560 contains the Reimbursable Cost Guidelines for the Petroleum 
Storage Tank Reimbursement Program. The adopted section also provides that the 
cost guidelines will be used to evaluate and process all claims for costs 
incurred in the performance of corrective action activities associated with 
leaking petroleum storage tank (LPST) sites. 
 Public comment on the proposed section was received in writing during the 30-
day comment period and at the seven public meetings from the following groups: 
Chambers Pump Service, Inc., CURA, East Texas Testing Labs, ERM-Southwest, Inc., 
Environmental Fuel Systems, G.L. "Hoot" Gibson Construction, Industry Council on 
the Environment, Landmark Environmental, Marshall and Son Construction, 
Methodist Hospital, Miller Tank Testing, National Convenience Stores, Parkhill 
Smith & Cooper, Inc., Petroleum Services, Petroleum Solutions, Inc., Post 
Economic Development Corporation, Rauhut & Associates, Susser Environmental 
Services, Texas Association of Storage Tank Professionals, Texas Automobile 
Dealers Association, Texas Mid-Continent Oil & Gas Association, Texas Oil 
Marketers Association, TU Services, Inc., and White's Pump Service. 
 The commission received comments regarding unit rates, hours allowed for 
personnel, costs for corrective action activities, equipment prices, and 
disposal. The commenters stated that the proposed costs are low compared to 
market rates and some are below actual costs. The commission responds that it 
believes that the proposed costs, which were determined through a market survey 
of the petroleum industry composed of owners and operators, contractors, 
consultants, oil marketers, and PST Task Force members, reasonably reflect the 
fair market value of costs associated with the cleanup of LPST sites. 
 A commenter stated that the costs incurred by some owners and operators are 
lower than for others due to differing levels of consulting that are needed, and 
that large companies with trained staff may show less cost because they use in-
house consultants but do not include those costs in their reimbursement 
applications. The commission responds that when determining the reimbursable 
costs, only the fair market value for cleaning up LPST sites was evaluated 
without regard to involvement by the owner or operator. 
 A commenter stated that the markup of subcontractor's charges should be treated 
the same as purchasing parts and supplies for inventory. Another commenter 
stated there needs to be a more realistic markup of third party goods and 
services based on market conditions and business economics. The commission 
believes that the guidelines for markup rates fairly reflect the costs to 
contractors of hiring subcontractors for various remediation activities. 
 A commenter stated that the hours allowed for professionals are unreasonable 
because of the restrictions placed on certain professionals with regard to 
negotiating hours. Another commenter objected to the TWC specifying personnel 
classifications for businesses. The commission responds that the hours allowed 
were based on a market survey of certain corrective action activities. The 
commission has the statutory authority to implement by rule necessary guidelines 
for determining amounts that may be paid from the petroleum storage tank 
remediation fund. The commission also responds that the cost guidelines are not 
intended to impact the business arrangements that a professional engages in, 
rather, it is providing an owner or operator a range of costs within which the 
commission will reimburse for certain activities. In addition, the titles 
designated for individuals performing certain corrective action activities were 
developed to standardize these functions and to provide consistency in the 
technical and financial review of reimbursement applications. 
 A commenter stated that the cost guidelines need to be clarified since it is 
unclear what specific costs are included in the general categories. The 
commission responds that it believes that the guidelines provide sufficient 
detail to enable owners, operators, contractors, and consultants to carry out 
corrective action activities. The commission believes that some flexibility and 
independent decision making should be left up to the parties involved. 
 A commenter stated the Reimbursable Cost Guidelines may reduce competition 
since they leave no room for justification of expenses on the more severe LPST 
sites. Another commenter stated the guidelines do not appear to allow owners and 
operators to exceed the guidelines due to variable site conditions. Another 
commenter stated that the Reimbursable Cost Guidelines is meant to establish 
guidelines, not ceilings on costs and that if costs fall above the established 
guideline, benefit of the doubt should be given to the responsible party, 
assuming that the actions were taken in good faith. The commission responds that 
a justification for those costs that exceed the reimbursable cost guidelines 
should be submitted to the executive director for a determination as to whether 
those costs are allowable for reimbursement. The guidelines are not intended to 
set pricing for certain activities or to remove an element of competition for 
the petroleum storage tank industry; rather, the guidelines are intended to 
allow for a range of costs that will not be static, but which can be as dynamic 
as necessary to support and enhance competition. 
 Some commenters suggested that the commission formalize the statement in the 
preamble to this proposal which states that upon executive director approval, 
costs associated with tank removals can be applied toward the deductible. This 
commenter wanted a clarification that this applies when corrective action is 
required. Another commenter expressed a concern that if costs of tank pulls are 
used to offset the deductible, this would only benefit owners of multiple tanks, 
and not the smaller tank owners. The commission responds that since sec.334.308 
of this chapter provides for reimbursement of a portion of costs associated with 
tank removals, the remaining costs incurred shall not be applied to reduce the 
owner/operator contribution. 
 A commenter stated that the proposed regulations and limits on reimbursable 
costs appear not to have been coordinated internally within the commission. The 
commission responds that the cost guidelines were developed by the commission's 
technical, fiscal, and legal staff, along with members of the PST Task Force, 
which is composed of representatives of the commission, petroleum industry, 
Texas Oil Marketers Association, Industry Council On The Environment, Texas 
Association of Storage Tank Professionals, contractors, and consultants. 
 A number of commenters said that the Reimbursable Cost Guidelines should be 
updated on at least an annual basis through the review of the same criteria that 
went into formulating the current guidelines, i.e., market surveys, review of 
protested amounts, and history of payments made from the Fund. In addition, a 
mechanism should be included for reimbursable costs to increase with inflation, 
rising labor and material costs. Another commenter stated that there needs to be 
a method by which those total costs that are too low could be raised to market 
level through arbitration or negotiation. The commission responds that the 
Reimbursable Cost Guidelines will be updated on a regular basis, as necessary, 
to reflect current market values. The guidelines will be updated based upon 
actual costs as reflected in reimbursement applications which will be tracked on 
a data base for specific activities relating to the cleanup of LPST sites. 
 A commenter stated that the reimbursement rules should provide an option to bid 
by lump-sum corrective action activities, and that the lump-sum bid option be 
operated with a reimbursable cost cap. The commission responds that the current 
cost guidelines do not allow for lump-sum bidding; however, this option is 
currently being reviewed by the commission. 
 Numerous commenters stated that it is unfair to apply the Reimbursable Cost 
Guidelines retroactively and that the guidelines should become effective upon 
the effective date of this rule. The commission responds that the cost 
guidelines will be used to evaluate and process all claims for corrective action 
activities associated with LPST sites, unless otherwise provided by commission 
policy or rules in effect at the time the activities were performed. 
 A commenter stated that if significant revisions to the Reimbursable Cost 
Guidelines are proposed, those revisions should be re-proposed to allow the 
regulated industry to comment on the intended final version as a whole. The 
commission responds that since no significant revisions to the proposal have 
been made, re-proposal is not warranted at this time; however, the revisions 
which are being contemplated for the near future will be made available for 
review by the PST Task Force prior to publication and will be proposed for 
comment by the public. 
 A commenter stated that an attempt to cap reimbursable costs for tank owners 
and operators by promulgating Subchapter M is setting up those owners for 
financial hardship, and that persons who do not initiate compliance with 
regulations will benefit over those who attempt to maintain compliance with 
applicable regulations. The commission responds that the guidelines are simply 
to provide owners, operators, consultants, and contractors with information 
regarding how their reimbursement application will be evaluated and what the 
reimbursable cost ranges are for various cleanup activities. 
 A commenter stated the remediation industry is a for-profit business and too 
many disincentives to LPST owners and to the remediation industry will cause 
some firms to remove themselves from the market, that the remediation industry 
is not an altruistic, "save the earth" endeavor, that it is a business, and that 
recent directives issued by the commission have put some firms on the brink of 
bankruptcy. The commission responds that the reimbursable cost guidelines 
document has been established to reduce the number of disputes regarding 
reimbursable costs in an effort to streamline the reimbursement process and to 
make the most efficient use of the limited money in the PSTR Fund. 
 A commenter stated that if allowable costs are too strictly regimented or 
overly detailed costs reviews become the "norm", the TWC staff will spend most 
of its efforts bogged down in cost protests and explanations, and that efforts 
would be better spent with less detailed cost review and more efforts on 
cleaning up sites, enforcing regulations on those who do not comply, and 
pursuing the remaining contractors and consultants preying on the unaware. The 
commission responds that although upfront approval will require significant 
staff time initially, a focusing of effort early on in the process will reduce 
the resources required once the activities and associated costs have been 
reviewed and approved. 
 A commenter stated TWC has begun to act like an overly-cost conscious "owner" 
with regard to prices, that TWC's role is to administer the fund that the owners 
and operators have paid into. The commenter also stated that the Fund belongs to 
the owners and operators, not TWC, and that TWC should only look at technical 
merit and whether the costs are in the range of the cost guidelines. The 
commission responds that the Texas Water Code, sec.26.3573(g) mandates that the 
commission make the most efficient use possible of money in the PSTR Fund. 
Section 26.3573(h) authorizes the commission to implement by rule any necessary 
guidelines for determining amounts that may be paid from the PSTR Fund. The 
commission also responds that it does in fact consider the technical merit of 
all performed corrective action activities that are submitted for reimbursement, 
in addition to determining whether those costs are in the range of the cost 
guidelines. 
 A commenter stated that the Reimbursable Cost Guidelines, the pre-approval 
process, and Subchapter J have reduced the speed and efficiencies with which 
sites are addressed and closed while increasing costs due to more administrative 
paperwork and subsequent delays. The commission responds that guidelines are 
intended to increase rate at which applicants are reimbursed, contingent upon 
availability of funds. Furthermore, the changes adopted in subchapters H and J 
will enable the PST program to more effectively and efficiently oversee the 
remediation of contaminated sites and administer the PSTR Fund. 
 The new section is adopted under the Texas Water Code,  sec.5.103 and sec.5. 
105, which provides the Texas Water Commission with the authority to adopt any 
sections necessary to carry out its powers and duties under the Texas Water Code 
and other laws of the State of Texas, and to establish and approve all general 
policy of the commission. 
 
 
  sec.334.560. Reimbursable Cost Guidelines. The Texas Water Commission hereby 
adopts the following Reimbursable Cost Guidelines for the Petroleum Storage Tank 
Reimbursement Program which are in effect as of June 9, 1993. 
 
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
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  This agency hereby certifies that the rule as adopted has been reviewed by 
legal counsel and found to be a valid exercise of the agency's legal authority. 
 Issued in Austin, Texas, on June 8, 1993. 
 TRD-9323989 
  Mary Ruth Holder 
 Director, Legal Division 
 Texas Water Commission 
    Effective date: June 29, 1993 
 Proposal publication date: March 12, 1993 
 For further information, please call: (512) 463-8069 
         
         Chapter 335. Industrial Solid Waste and Municipal Hazardous Waste In 
General 
  
  Subchapter A. Risk Reduction Standards 
 
  The Texas Water Commission adopts amendments to sec.sec.335.1, 335.5, 335.6, 
and 335.8 concerning industrial solid waste and municipal hazardous waste 
management in general, and adopts new sec.sec.335.551-335.569 concerning risk 
reduction standards. Sections 335.1, 335.8, 335.551-335.560, 335.563, and 335. 
566-335.569 are adopted with changes to the proposed text as published in the 
December 18, 1992, issue of the Texas Register  (17 TexReg 8881). Sections 
335.5, 335.6, 335.561, 335.562, 335.564, and 335.565 are adopted without changes 
and will not be republished. 
 The Texas Water Commission (TWC) is promulgating these risk reduction rules to 
achieve a number of broad implementation and policy improvements for closures 
and remediations regulated under the hazardous/industrial solid waste, 
superfund, and spill programs. These goals are discussed in this section and 
were also thoroughly described in the preamble for the proposed rule published 
in the December 18, 1992, issue of the Texas Register. 
 These final rules represent an important and large step toward the adoption of 
a risk-based approach for determining the extent and type of closures or 
remediations which are necessary to protect human health and the environment. 
This approach represents a major departure from the commission's past practice 
of either requiring a responsible person to remove all waste or other 
contaminants to background levels or to contain these materials and perform 
appropriate post-closure care. Through the use of quantitative health-based risk 
assessment procedures, these rules recognize for the first time that limited 
quantities of contaminants may remain in soil or groundwater at a site and not 
present an unacceptable threat to human health or the environment. 
 Most persons who submitted comments during the public comment period expressed 
their general agreement with the goals and structure of the proposed rules but 
requested that the commission modify or allow variance to one or more aspects of 
the proposed rules. Upon review of these letters, the commission is issuing 
these final rules with only those minor changes which are necessary to improve 
their function, clarity, or implementation and are maintaining all essential 
requirements and procedures from the proposed rules. In adopting these rules, 
the commission realizes that they are more conservative and prescriptive and 
allow less site-specific analysis than was endorsed by a number of the 
respondents. The commission considers these rules to be a prudent first step for 
the formal incorporation of risk assessment practices into its waste management 
programs. This analysis is based both upon the desire to be cautious when 
embarking upon a fundamentally different regulatory approach and the need to 
minimize adjustment problems that commission staff and regulated persons will 
have becoming acquainted with and using these new and rather complicated rules. 
While we are not adopting many of the proposals espoused by the respondents in 
this rulemaking, the commission remains open to exploring new approaches. Based 
upon the familiarity and experience that we gain over time, the commission will 
be in a better position to judge whether the flexibility or modified procedures 
requested by the respondents are warranted and should be incorporated into 
future rulemakings. 
 The commission is adopting these regulations to specify a consistent risk 
management policy which will be uniformly applied across hazardous/industrial 
solid waste, Superfund and spill programs to define what cleanup actions are 
necessary to protect human health and the environment. While the nature of the 
various programs requires certain administrative and procedural differences, the 
same substantive cleanup requirements need to apply across programs in order to 
avoid a fragmented system without an underlying consistent approach for managing 
public health and environmental risks. The coherent program described in these 
rules should assist the TWC in effectively pursuing the cleanup of 
industrial/hazardous solid waste units, superfund sites, and spills of hazardous 
substances and other contaminants. 
 The commission is promulgating these rules to require closures, corrective 
actions, and remediations to provide risk reduction to levels that are 
protective of human health and the environment through the use of remedies that 
are permanent or have a high degree of long-term effectiveness. Long-term 
effectiveness refers to a remedy's ability to maintain the required level of 
protection over time. A remedy is permanent when it will endure indefinitely 
without posing the threat of any future release that would increase the risk 
above levels established for the facility or area. 
 The TWC is establishing three closure/remediation performance standards which 
persons may use to satisfy their cleanup responsibilities at contaminated 
facilities and areas. Each of the three closure/remediation performance 
standards are designed to be protective of human health and the environment when 
combined with the post-closure care and deed recordation requirements for that 
performance standard. While conformance with any of these standards would result 
in a high level of risk reduction with an appreciable degree of long-term 
effectiveness, the residual threat of possible future endangerment of human 
health or the environment would vary depending upon the performance standard 
achieved. As a result, varying degrees of post-closure care and deed recordation 
requirements are coupled with each closure/remediation standard so that the 
combined requirements will provide long-term protection for human health and the 
environment. 
 The commission is also adopting these regulations to establish an incentive-
based program which encourages responsible persons to perform remedies with a 
high degree of long-term effectiveness. These rules require responsible persons 
to close/remediate a facility or area to meet one or more of the risk reduction 
performance standards. Unless another regulation, order, or permit of the 
commission specifies a different approach, the actual performance standard 
selected for a specific site will be left to the discretion of the person 
responsible for taking the action. These rules, however, provide significant 
incentives for a responsible person to achieve permanence or a high degree of 
long-term effectiveness so as to avoid the more burdensome post-closure care and 
deed recordation responsibilities that are to be imposed on remedies with a 
lesser degree of long-term effectiveness. 
 These risk reduction rules have also been designed with the goal of increasing 
the efficiency and timeliness of environmental cleanup activities by 
streamlining the process for review and approval of closure and remediation 
plans. These rules reduce, where appropriate, the paperwork burden on both 
regulated parties and the commission. We have crafted these rules to require 
responsible persons to prepare and submit information and reports which are 
commensurate with the degree of risk posed by an area and the type of remedy to 
be performed. We have also sought in these rules to remove impediments which 
preclude the voluntary and timely implementation of remedial measures in those 
instances where prior approval of the commission is not warranted. At the same 
time, the commission recognizes its responsibility to provide a sufficient 
degree of review and oversight to ensure that these rules will be implemented in 
a manner which will be protective of human health and the environment. We have 
sought in these rules to achieve an appropriate balance between these two 
objectives. 
 In this same vein, under the present circumstances there are few promulgated 
standards that are available for use as cleanup levels. This is a significant 
hindrance to the prompt remediation of contaminated sites. In the absence of 
readily available, previously agreed upon cleanup standards, the remediation 
levels for each site must be independently determined using quantitative risk 
assessment procedures. Without carefully prescribed procedures, this process can 
be fraught with disagreements, time delays, and unjustifiable differences among 
sites. These regulations establish generic cleanup levels that can be used 
immediately unless special circumstances apply at a site, as well as 
standardized risk assessment procedures that can be used for the development of 
site-specific cleanup levels. The speed and defensibility of the cleanup process 
should be enhanced by this standardization of the procedures used. 
 The next section of this preamble presents a brief summary of the requirements 
for each of the three risk reduction standards. This is followed by a section 
which discusses the persons to whom and the facilities to which these rules are 
applicable. Next comes a section which discusses the relationship of these risk 
reduction rules to the hazardous waste closure and remediation program. That 
section is followed by a discussion of the summary statements of support, or 
lack thereof, made by respondents who submitted letters during the public 
comment period for these rules. The following portion of this preamble presents 
a sequential, section-by-section analysis of the final rule. That portion of the 
preamble briefly describes the effect that a section will have, the comments 
that we received pertaining to that section, any modifications we are making to 
the text of that section, and our rationale for not making any other changes 
that were suggested. And finally, we are republishing a small section of the 
preamble for the proposed rules in which numbers expressed in scientific 
notation were not accurately represented. 
 Risk Reduction Standard 1 as promulgated at sec.335.8(b) requires a responsible 
person to remove and/or decontaminate all waste, waste residues, leachate, and 
contaminated media to background levels unaffected by waste management or 
industrial activities. The requirements for conforming to this standard are 
specified in sec.335.553(a) (relating to Required Information) and sec.335.554 
(relating to Attainment of Risk Reduction Standard Number 1: Closure/Remediation 
to Background). 
 The fundamental requirement for compliance with the first standard is that 
wastes and contaminated media must be removed and/or decontaminated to 
background levels. Through removal, the waste materials and contaminated media 
would be transported from the facility for off-site treatment and/or disposal. 
Through decontamination, the contaminated materials would be treated to destroy 
or eliminate its hazardous properties. Both removal and decontamination are 
irreversible processes that result in permanent risk reduction at a site. 
 Closure or remediation to achieve the first standard is highly desirable since 
it represents a permanent remedy with a great degree of risk reduction. 
Conformance to this standard would result in a property being restored to 
background conditions via processes that will remain protective over time. These 
rules encourage responsible persons to pursue closure/remediation in accordance 
with this highly protective standard by removing any requirement for post-
closure care or deed recordation. 
 Risk Reduction Standard 2 as promulgated at sec.335.8(b) requires a responsible 
person to remove and/or decontaminate all waste, waste residues, leachate, and 
contaminated media to standards and criteria such that any substantial present 
or future threat to human health or the environment is eliminated. The 
requirements for conforming to this standard are specified in sec.335.553 
(relating to Required Information) and sec. sec.335.555-335.560. 
 Closure/remediation to achieve Risk Reduction Standard 2 provides a permanent 
remedy with a high degree of risk reduction, although somewhat less than the 
first standard, and is therefore also favored. This standard requires the use of 
the irreversible processes of removal and decontamination to restore a site to 
highly protective levels. These protective levels are derived either by 
conservative quantitative health-based risk assessment procedures or by directly 
using other appropriate promulgated standards. This standard establishes 
separate levels for residential and nonresidential use of contaminated 
properties. 
 To encourage closures/remediations under this standard, these rules release the 
responsible person from all post-closure care responsibilities, such as 
groundwater monitoring. These rules, however, impose a deed certification 
requirement on the responsible person so that future prospective owners would be 
informed of any residual levels of contaminants remaining on the property. For a 
site which has been restored to nonresidential or residential levels, the 
responsible person or any future owner has a continuing obligation to perform 
any additional closure or remediation actions required by the rules of the 
commission if a substantial change in circumstances occurs at the facility such 
that it is no longer protective of human health and the environment. 
 Risk Reduction Standard 3 as promulgated at sec.335.8(b) requires a responsible 
person to remove, decontaminate, and/or control all waste, waste residues, 
leachate, and contaminated media to levels and in a manner such that any 
substantial present or future threat to human health or the environment is 
eliminated or reduced to the maximum extent practicable. The requirements for 
conforming to this standard are specified in sec.335.553 (relating to Required 
Information) and sec.sec.335.561-335.566. 
 The third performance standard provides flexibility in those instances where 
closure or remediation strictly by removal or decontamination would not be 
feasible. The third performance standard allows the use of measures to control 
the contaminated materials or the property where the contaminated materials are 
located. Such measures may consist of engineering controls such as construction 
of a fence, placement of a cap, installation of a slurry wall, or 
stabilization/solidification/fixation of the waste or waste residues. These 
measures may also involve institutional controls such as voluntary deed 
restrictions. 
 Under the third standard, the responsible person would use removal and 
decontamination processes where feasible to remove the principal threats at a 
site. Where decontamination or removal is not appropriate, then treatment 
methods that significantly reduce the mobility, toxicity, and/or volume of the 
waste and waste residues would be used to address the principal threats at a 
site. Treatment that does not achieve the standard of eliminating substantial 
present or future threats is considered to be a control measure rather than 
decontamination. Treatment could be used in combination with other control 
measures such as capping to reduce present and future threats from the site. 
 Among other requirements, sec.335.561 requires remedies conforming to the third 
standard to be permanent or, if that is not practicable, achieve the highest 
degree of long-term effectiveness possible. Thus, the responsible person would 
have the burden of being able to demonstrate that the particular mix of removal, 
decontamination, and/or control that he wishes to use is the optimal blend to 
eliminate or abate present and future threats to human health and the 
environment to the maximum extent practicable. The responsible person would also 
need to demonstrate that he has selected the control measure(s) which most 
effectively abates present and future threats from the site. Institutional 
controls are most effective as a supplement to engineering controls. 
Institutional controls should not substitute for active response measures (i.e., 
removal, decontamination, and/or engineering controls) as a sole remedy unless 
such active measures are determined to not be practicable. 
 Due to the more reversible nature of control measures, these rules require 
post-closure care for those closures or remediations under the third standard 
which involve either engineering or institutional controls. The type, extent, 
and duration of these measures would be determined during the remedy evaluation 
process and would be dependent upon the permanence or degree of long-term 
effectiveness afforded by the selected remedy. The responsible person would also 
be required to file a deed recordation which states that continued post-closure 
care or institutional control measures are required to protect human health and 
the environment. 
 In addition to this discussion of the general aspects of Risk Reduction 
Standards Numbers 1, 2, and 3, a more thorough explanation of the requirements 
for each of the standards was included in the preamble for the proposed rule. In 
addition, subsequent sections of this preamble expand upon and in some areas 
will replace the previous preamble through presentation of a section-by-section 
response to comments and a description of changes made to the text of the rule. 
 This section provides an overview of the applicability of these final rules. A 
substantial number of comments were submitted by respondents regarding the 
applicability of these rules. These comments, our response to the comments, and 
changes we are making to these rules are discussed more thoroughly in the 
section-by-section analysis for sec.335.8. 
 These final rules will become effective 20 days after they are filed with the 
Texas Register  for publication. These rules seek to provide greater consistency 
in both the extent and types of closures and remediation that are performed in 
response to the various contaminant cleanup programs managed by this agency. 
Accordingly, these rules will have broad applicability. Revised  sec.335.8(a) 
(pertaining to Applicability) describes the activities to which and the persons 
to whom these rules apply. 
 These rules supplement but do not replace any requirements for closure or 
remediation that are present in the regulations for the various programs subject 
to these rules. These rules set consistent standards for the level of cleanup 
and types of analyses that will be required by the various programs subject to 
these rules. In instances where the regulations for a specific program have 
other more stringent or supplemental requirements pertaining to closure or 
remediation, persons shall comply with those more stringent requirements in 
addition to the requirements of these regulations. 
 The amendments to sec.335.8 and the requirements of new Subchapter S apply to 
persons who undertake the closure of facilities used for the storage, 
processing, or disposal of industrial solid waste or municipal hazardous waste. 
These regulations also apply to persons who undertake the remediation of 
contaminated media resulting from unauthorized spills from such facilities, 
either as a part of closure or at any time before or after closure. 
 Permitted facilities used for the storage, processing, or disposal of 
industrial solid waste (including industrial hazardous waste) or municipal 
hazardous waste must be closed in accordance with the closing provisions of the 
permit unless specifically modified by other order of the commission. The TWC 
will use these rules along with program-specific requirements to develop the 
closure provisions to be placed into new and amended permits for industrial 
solid waste and municipal hazardous waste facilities. The TWC will also use 
these regulations to determine appropriate remediations pursuant to the 
corrective action program for solid waste management units (SWMUs) at permitted 
hazardous waste management facilities. 
 These rules also apply to persons conducting closures or remediations at 
nonhazardous industrial solid waste units. Additionally, these regulations apply 
to owners and operators of hazardous waste storage, processing or disposal 
facilities who are exempt from a permit, or are operating under interim status, 
and are conducting closure or remediation activities. 
 Even though these closure/remediation performance standards are contained in 
Subchapter A of this title (relating to Industrial Solid Waste and Municipal 
Hazardous Waste Management in General), the requirements of sec.335.8 (relating 
to Closure and Remediation) and of Subchapter S (relating to Risk Reduction 
Standards) apply to a substantially broader array of materials than just 
industrial solid waste and municipal hazardous waste. 
 The regulations of sec.335.8 along with other rules, permits, or orders issued 
by the commission establish the obligation for persons to perform closures or 
remediations for facilities or areas containing industrial solid and municipal 
hazardous waste and further specify the mechanism to evaluate such closures or 
remediations. The obligation to perform remediations for unauthorized discharges 
of contaminants under the state superfund and spill response programs occurs 
through the application of the commission's rules and statutes pertaining to 
those programs. However, once such obligation has occurred the regulations of 
this rulemaking for Subchapters A and S of this chapter will be used to specify 
the mechanism to evaluate remediation of unauthorized discharges of contaminants 
subject to these programs. 
 A definition of the term "contaminant" is added to sec.335.1 to include not 
only solid waste materials but also pollutants and hazardous substances as 
defined by the commission as well as other substances that are subject to the 
Texas Hazardous Substances Spill Prevention and Control Act. As a result, these 
regulations apply not only to industrial solid waste and municipal hazardous 
waste facilities and to discharges from those facilities, but also to areas of 
unauthorized discharge of other contaminants where response is required by 
application of regulations pertaining to another of the commission's program 
areas. However, discharges or spills from storage tanks that are already 
regulated under Chapter 334 of this title (relating to Underground and 
Aboveground Storage Tanks) are specifically excluded from coverage by these 
rules. 
 The remediation of spills and requirements for immediate response actions will 
continue to be regulated pursuant to the Texas Water Code, sec.26.039 and 
sec.26.261 and the administrative and procedural requirements of the commission 
to carry out the Texas Hazardous Substance Spill Prevention and Control Act. As 
a separate but related action to these risk reduction rules, the commission has 
been working on and expects to propose spill response rules in the next several 
months to provide further definition of a person's responsibility to respond to 
both current and historic unauthorized discharges of contaminants. These two 
sets of rules will define a consistent, sequential program for response to 
spills. When initially discovered, spills are not subject to these risk 
reduction rules. Spills become subject to these risk reduction rules when the 
responsible person's actions do not achieve remediation to the levels and within 
the timeframe specified by the commission's spill response program. The spill 
response program has normally required that spills be removed to levels 
representative of background conditions. Once these risk reduction rules become 
applicable to a spill, they will be used to define the level of remediation and 
appropriate additional controls such as post-closure care and deed recordation. 
 The State Superfund Program will continue to be performed in accordance with 
Chapter 335, Subchapter K (relating to Hazardous Substance Facilities Assessment 
and Remediation) of the TWC's rules. However, in order to develop a uniform and 
consistent approach for contaminated sites, the portions of these rules which 
describe the calculation of cleanup levels and the required level of remediation 
will also apply to state superfund sites. As a result, remedial actions at state 
superfund sites could be performed to be consistent with the substantive 
requirements of any of the three risk reduction standards established in new 
Subchapter S. Specific sections of this rulemaking such as  sec.335.8(c) 
(relating to Closure and Remediation Notification and Initiation Requirements), 
sec.335.8(d) (relating to Demonstration of Conformance with Risk Reduction 
Standards), sec.335.553 (relating to Required Information), and sec.335.562 
(relating to Remedy Evaluation Factors), which describe administrative, 
procedural, or informational requirements will not apply to the State Superfund 
Program. Potentially responsible parties will be required to submit information 
and to evaluate remedies in accordance with the administrative requirements of 
Subchapter K even if Subchapter S would require less information or allow 
abbreviated procedures. In particular, multiple candidate remedies will be 
evaluated in the feasibility study and a baseline risk assessment will be 
performed for a state superfund site regardless of which risk reduction standard 
is pursued. Only the substantive requirements of these rules which describe the 
required level of remediation or cleanup will apply to the State Superfund 
Program. The remedy selection criteria for Risk Reduction Standard 3 specified 
in sec.335.561 are substantive requirements and will apply to the State 
Superfund Program. 
 The risk reduction standards of Subchapter S may be used as applicable or 
relevant and appropriate requirements (ARARs) under the Federal Superfund 
Program to the extent that they represent more stringent state standards. The 
medium specific concentrations (MSCs) developed for Risk Reduction Standard 2 
will not by themselves serve as ARARs since their use is not mandatory and a 
person may use the more site-specific analysis procedure provided by Risk 
Reduction Standard 3. While the individual parts of this rule will not serve as 
ARARs, the rules in their entirety do constitute a State ARAR for the Federal 
Superfund Program in Texas. 
 The TWC has incorporated closure performance standards for hazardous waste 
landfills, surface impoundments, and waste piles as provided by federal 
regulations contained in 40 CFR Parts 264 and 265 into sec.sec.335.112(a)(5) and 
335.152(a)(5). The TWC has followed the closure interpretation set forth in the 
preamble to the July 26, 1982 RCRA codification rule, published at (47 FedReg 
32274). This interpretation requires that when an owner/operator cannot 
demonstrate that all hazardous waste and waste constituents have been removed or 
decontaminated to background conditions, the unit must be closed in-place as a 
hazardous waste landfill, capped, and must be monitored for 30 years under a 
post-closure care plan and/or permit. 
 The commission is adopting these rules to be consistent with the modified 
closure-by-removal approach discussed by EPA in the March 19, 1987 preamble to a 
final rule on interim status closure requirements for owners and operators of 
hazardous waste treatment, storage, and disposal facilities published in 52 
Fed.Reg. 8704 et seq. That preamble described the amount of removal or 
decontamination that obviates the need for post-closure care for both permitted 
and interim status facilities. EPA recognized that at certain sites limited 
quantities of hazardous waste constituents might remain in the subsoil and yet 
present only insignificant risks to human health and the environment. Thus, EPA 
states that owners and operators would be required to remove all waste and 
contaminated liners and may demonstrate that any hazardous waste constituents 
left in the subsoils will not cause "unacceptable risks to human health or the 
environment" (52 FedReg 8706) (March 19, 1987). 
 The TWC incorporated the EPA rule by reference in the  Texas Register (16 
TexReg 6937) on November 29, 1991 with an effective date of December 13, 1991 
but has delayed implementation of that approach pending final promulgation of 
today's rules. These risk reduction rules are consistent with EPA's approach for 
hazardous waste closures. For Risk Reduction Standards Numbers 1 and 2, all 
hazardous waste and contaminated design and operating system components such as 
liners or leachate collection systems must be removed. Unless lower levels are 
necessary to be in conformance with current hazardous waste regulations, the 
cleanup levels determined by the processes for Risk Reduction Standards Numbers 
1 and 2, as applicable, will be used to determine when media (e.g., soil and 
groundwater) do not "contain" hazardous waste and do not require post-closure 
care. These requirements are also discussed in the section-by-section analyses 
later in this preamble for sec.335. 554(b) and sec.335.555(b). 
 The TWC received a total of 42 letters from respondents during the public 
comment period for the proposed risk reduction rules. Most of these letters were 
supportive, and sometimes highly supportive, of the general direction, 
structure, and requirements of the proposed rules. While expressing general 
support for the proposed rules, most respondents did make a number of specific 
comments which they felt the commission should consider prior to making the 
rules final. This section of the preamble presents a representative sampling of 
the summary statements made by the respondents. 
 The Texas Chemical Council's (TCC's) letter stated that: "Texas Chemical 
Council members support the proposed risk reduction rules and commend the TWC on 
regulatory actions to speed environmental cleanup. . .TCC strongly supports the 
concept of voluntary implementation to meet Risk Reduction Standards 1 and 2. 
This is probably one of the most important features of the proposed regulation 
since it will both speed cleanup efforts and reduce paperwork delays and costs 
for both the TWC staff and the regulated community." 
 Individual companies such as Texas Eastman (Kodak), Merichem Company, Exxon 
Chemical Americas, and Shell Oil Company expressed their concurrence with the 
comments submitted by the TCC. 
 The Texas Mid-Continent Oil and Gas Association (TMOGA) expressed concerns 
about the proposed rules in four general areas: the economic impact and cost-
effectiveness of the rules; the overly broad extension of the rules to spills 
and discharges; the administrative burden of the rules; and the overly broad 
definition of background. In spite of these areas of concern, TMOGA's letter 
stated that: "TMOGA members endorse the concept of risk reduction rules and 
support the Texas Water Commission (TWC) on all of their work to streamline 
environmental cleanup which benefits all citizens of Texas. Regulations which 
allow industry to initiate quicker, more efficient methods to protect and 
enhance the environment will result in a better Texas for all of us. We believe 
that these proposed regulations would have that goal." 
 Exxon Company USA, Shell Oil Company, Koch Refining Company, Valero Refining 
Company, Star Enterprise, Amoco Oil Company, and Fina Oil and Chemical Company 
stated their agreement with the comments provided by TMOGA. 
 The American Industrial Health Council (AIHC) which is a diverse coalition of 
companies and trade associations whose mission is to promote the sound use of 
scientific principles in the assessment and regulation of chronic human health 
effects and directly related public policy issues was supportive of the rules 
when it stated: AIHC applauds several aspects of the Proposed Standards and 
supports the Texas Water Commission's (TWC's) general reliance on health-based 
risk assessments to establish these types of cleanup standards. In particular, 
AIHC commends TWC's reliance on good science and science policy in the 
development of the proposed risk reduction standards. 
 However, AIHC also expressed a degree of concern by stating: AIHC applauds 
TWC's recognition of the need to consider site-specific circumstances when 
setting cleanup levels under Risk Reduction Standards 2 and 3. AIHC feels, 
however, that even greater consideration of site-specific considerations and the 
opportunity for substitution of different non-site-specific default values 
should be incorporated into the proposed standards. 
 While expressing several major concerns, Exxon Chemical Americas strongly 
endorsed the goals and structure of the rules by stating: Exxon Chemical 
Americas (Exxon) supports the proposed amendments concerning solid waste 
management in general and the new risk reduction standards as they would apply 
to closure and remediation performance requirements. For the first time, these 
risk reduction standards have the potential to provide a clear path for the 
development of reasonable and scientifically based remedies that could be 
appropriately applied to various circumstances in a cost-effective manner. We 
are also encouraged by the Texas Water Commission's attempt to develop a 
consistent risk management policy which would be uniformly applied across the 
hazardous/industrial solid waste and Superfund programs. 
 Some of the same sentiments are echoed in this summary statement from the 
letter submitted by Groundwater Services, Inc.: We feel that the Texas Water 
Commission (TWC) is to be commended for development of the proposed Risk 
Reduction Rules package, which, for the first time, establishes comprehensive, 
risk-based standards for remediation of soil, groundwater, and surface water 
contamination problems. The optional risk reduction standards provide a workable 
system for determination of cleanup standards that are appropriate to the level 
of environmental risk associated with each site. By providing clear guidelines 
regarding the issue of "how clean is clean", these rules should greatly enhance 
both the efficiency and economy of future corrective action projects. In 
addition, under Risk Reduction Standards Numbers 1 and 2, the rules pre-
authorize commencement of cleanup activities for relatively straightforward 
problems, which should serve to reduce the current administrative burden on the 
TWC and allow government resources to be focused on significant environmental 
hazards. 
 Other respondents recognized and agreed with the approach developed in the 
proposed rules to encourage the timely completion of remediations. The following 
comments from the letters submitted by ENSR Consulting and Engineering, Cooper 
Industries, and Shell Oil Company, respectively, highlight this aspect of the 
rules: ENSR recognizes the hard work that went into developing the TWC Risk 
Reduction Rules and commends the Commission staff involved. The rules provide a 
workable program to expedite the voluntary closures of contaminated sites in the 
State. 
 In summary, we applaud the TWC's proposal to define a set of standards to 
govern cleanup and closure at active, inactive, onsite, and offsite source 
areas. We believe that the TWC's concept of establishing standards such as Risk 
Reduction Standard Number 1 and Risk Reduction Standard Number 2, which require 
the responsible party to make proper notification to the director and then 
proceed directly to implementation of the requirements under the first and 
second risk reduction standards will go a long way toward encouraging proactive 
cleanup of contaminated sites throughout the state. 
 The proposed three-tiered approach appears to provide the needed flexibility, 
has a self-implementation feature for Standards 1 and 2, and provides options to 
deal with a wide variety of remediation situations that would be subject to 
these rules. 
 Also, while sometimes expressing a number of concerns, Amoco Oil Company; Texas 
Eastman (Kodak); TransAmerican Waste Industries, Inc.; ERM-Southwest, Inc.; IT 
Corporation; Porter & Clements; and Brooks Air Force Base did include positive 
summary statements in their letters, which are repeated here in the same order: 
Amoco supports the commission's efforts to expedite the cleanup of waste 
management units while allowing industry to direct limited resources 
productively. 
 "The TWC is to be commended for the foresight to develop and propose these 
rules. With the proposal of these "risk" regulations, the TWC has made 
significant progress in optimizing the management of wastes in Texas." 
 TransAmerican Waste Industries, Inc. is generally supportive of the proposed 
rules and hopes that the enclosed comments will be considered as constructive 
suggestions to further improve these rules. 
 "We believe that the rules as published are scientifically sound and reasonable 
in scope and that they offer a flexible range of fair and balanced remedial 
options. 
 As a risk assessor, I am pleased to see continued movement toward risk-based 
decision making in the regulatory arena. The approaches outlined in the proposed 
amendments are, on the whole, reasonable and if properly applied can expedite 
site remediation and closure. 
 Our review of the proposed rules discloses that the Texas Water Commission has 
performed a very thorough job in preparation of the rules. It is evident that 
the TWC staff expended considerable effort and diligence in studying both the 
scientific and practical aspects of risk reduction. 
 I would like to applaud the Texas Water Commission for taking a reasonable 
approach to a problem with which many other states are struggling. The dilemma 
is whether to promulgate "generic" cleanup standards for chemical contaminants 
in the environment which can be applied to any hazardous waste site or to 
require compliance to site-specific risk-based cleanup standards." 
 While the majority of the letters submitted by respondents contained positive 
summary statements regarding the proposed rules, a few letters expressed a high 
degree of concern. For example, Fina Oil and Chemical Company's letter stated: 
"While the Texas Water Commission (TWC) is to be commended for proposing Risk 
Reduction Standards in addition to background cleanup levels, the proposed 
regulations have severe shortcomings that require substantial revisions." 
 Shell Pipeline Corporation stated that while the proposed rules seem to provide 
industry with greater flexibility in the cleanup aspects of spill response, they 
found "the proposed cleanup levels for Risk Reduction Standard Number 2 for 
soils to be overly conservative." And finally a respondent from the Department 
of Soil & Crop Sciences of Texas A&M University challenged the technical 
adequacy of the rules by stating: "I realize that you seem to be in a hurry to 
promulgate a set of standards, but the discrepancies I have seen indicate to me 
that you need to withdraw your proposed cleanup levels at once and start over 
again with a systematic comprehensive evaluation of the data base and the 
calculational procedure for each of the contaminants for which you wish to set 
standards." 
 The following portion of this preamble proceeds sequentially through each 
section of these rules and discusses the effect that a section will have, the 
comments that we received pertaining to the section, any modification we are 
making to the text of the section, and our rationale for not making any other 
changes which were suggested. 
 Section 335.1 contains the definitions which are necessary to describe the 
requirements of Subchapter A. Upon review of the comments from the respondents, 
we are amending several definitions previously proposed to describe the planned 
modifications to Subchapter A. 
 Respondents regarding sec.335.1 included: Exxon Company, USA; Texas Mid-
Continent Oil and Gas Association (TMOGA); Texas Chemical Council (TCC); Baker & 
Botts/Beazer; Amoco Oil Company; Fina Oil and Chemical Company; Valero Refining 
Company; Exxon Chemical Americas; Porter & Clements; Texas Eastman; Union 
Carbide Chemical and Plastics Company; and Kelly Air Force Base. 
 The proposed definition for "contaminant" received a significant amount of 
attention from the respondents. The thrust of their statements was that the 
proposed definition was overly broad and that the term should be restricted to 
those chemicals which have proven toxic properties. Commenters recommended that 
the phrase "and any other substance, chemical component of a substance or 
mixture of substances which, when discharged, released or spilled can create a 
present or future threat to human health and the environment" be removed from 
the definition. Two commenters also stated that the previously included lists of 
constituents (i.e., pollutants as in the Texas Water Code and hazardous 
substances as in the Texas Health and Safety Code) would provide an adequate 
definition of "contaminant" and that if the commission wished to regulate other 
constituents as contaminants, they should be added to these source lists. In 
response to these comments, the commission has modified the definition to remove 
the problematic language regarding a present or future threat to human health 
and the environment. We have, however, added additional language to make it 
clear that the risk reduction rules do extend to any "other substances that are 
subject to the Texas Hazardous Substances Spill Prevention and Control Act, 
Texas Water Code, sec. sec.26.261-26.268." 
 Several commenters pointed out that the proposed definition for "contaminated 
medium/media" did not have a consideration of threshold concentrations so that 
any detectable level of a contaminant would make a medium, such as soil or 
groundwater, "contaminated". This was contrary to our intent so we have modified 
this definition to clarify that the mere presence of a contaminant would not 
necessarily make a medium contaminated. The definition now states that a 
contaminated medium contains contaminants "at levels that pose a substantial 
present or future threat to human health and the environment." This definition 
was also amended to remove the language "as well as man-made features, such as 
but not limited to dikes, liners, or other containment or waste handling 
structures or components." This change was necessary since the new requirements 
for attainment of Risk Reduction Standards Numbers 1 and 2 in sec.335.554 and 
sec.335.555, respectively, distinguish between "contaminated media" and 
contaminated design and operating system components and set different 
requirements for these materials in certain instances. In response to one 
commenter, we have also augmented the definition to clarify that the media that 
may be contaminated include "soil, sediment, surface water, groundwater, or 
air". A broad theme running through a number of the respondents' letters was 
that conditions "that pose a substantial present or future threat to human 
health or the environment" had not been clearly defined in the proposed rules 
and that the phrase was too subjective. The commission believes that use of a 
broad environmental performance standard which distinguishes those materials and 
situations which pose "a substantial present or future threat to human health or 
the environment" is a necessary component of these rules and is not subjective 
or vague when viewed in the entire context of these rules. This analysis is 
explained further in the next paragraph. To minimize confusion, however, we have 
removed this performance standard from those definitions and sections of this 
final rule where it is not needed to distinguish those materials or conditions 
which are subject to these rules. As previously discussed, the definition of 
"contaminant" has been amended to remove this phrase. Likewise, as discussed 
later, the definitions for the action verbs "remove" and "control" have been 
amended to remove this phrase. Also, as discussed previously, this performance 
standard has been added to the definition for "contaminated medium/media" to 
distinguish which media will be considered contaminated. We have also maintained 
this phrase in the definition for "decontaminate" to help distinguish those 
treatment processes which qualify as decontamination. 
 The text for Risk Reduction Standards Numbers 2 and 3 in  sec.335.8(b)(2)(B) 
and (C) both contain this environmental performance language and conclude with 
the following words, respectively: "as further specified in sec.335.555 of this 
title (relating to Attainment of Risk Reduction Standard Number 2)" and "as 
further specified in sec.335.561 of this title (relating to Attainment of Risk 
Reduction Standard Number 3)". Thus, the commission will use the risk-based 
procedures for the risk reduction standards that are described in Subchapter S 
to distinguish those materials and conditions that pose "a substantial present 
or future threat to human health or the environment" and therefore require 
action under these rules. Of course, a responsible person could also use the 
background approach incorporated into Risk Reduction Standard Number 1 to 
fulfill their responsibilities under these rules. In essence, the entire 
Subchapter S rules (relating to Risk Reduction Standards) define the conditions 
that "pose a substantial present or future threat to human health or the 
environment". Given the nature of the subject being addressed we agree that 
these rules may appear to be somewhat complex; however, we also believe that 
they are neither subjective nor vague and that they do constitute an 
understandable and supportable method to make these judgments. This analysis 
also supports our decision not to add a definition for the term "threats" as was 
suggested by one commenter. 
 In this same general subject area, several respondents felt that this 
environmental performance language should be removed because it does not provide 
a clear definition of what conditions trigger a responsible person's obligation 
to investigate, notify, and perform remediation as needed. These respondents are 
correct that this environmental performance standard does not adequately perform 
this function; however, it was never intended to be used as the trigger to 
determine when investigation of a facility or area is needed. Section 335.8(a) 
has been amended to state more clearly the persons to whom and the conditions 
under which these risk reduction rules apply. Section 335. 8(a) and other 
applicable solid waste rules, permits, or orders establish the obligation (i.e., 
trigger the requirement) for persons to perform closures or remediations for 
facilities or areas containing industrial solid waste and municipal hazardous 
waste. However, the obligation to perform remediations for unauthorized 
discharges of contaminants being addressed through the state superfund and spill 
response programs occurs (i.e., is triggered) through application of the 
commission's rules and statutes for those program areas. In other words, for 
those programs these risk reduction rules become applicable only after the 
requirement to respond is triggered through application of the commission's 
rules for these programs. Thus, the procedures described in Subchapter S for 
interpreting the risk reduction standards are not intended to be used to trigger 
an investigation. Subchapter S is to be used to determine what response action, 
if any, is needed, once the obligation to perform such an evaluation has been 
triggered by other rules, permits, or orders issued by the commission. 
 Several respondents recommended that the definition for "control" be revised to 
be clearer and less open-ended. As stated previously, we have removed the phrase 
regarding the "elimination of all substantial present or future threats" from 
this definition since it is not needed to distinguish which actions constitute 
"control" of a facility or area. We have also rearranged the wording for the 
definition to more clearly state its intent; have removed the word "sites" and 
inserted "facilities or areas" to be consistent with the wording in the rest of 
the rule; and have added language to make clear that "reversible treatment 
methods" constitute a control measure. 
 We made this last change regarding "reversible treatment methods" in partial 
response to several respondents who requested that we make clearer the 
definitional differences among "decontaminate", "control", and "remediation". In 
addition, language moved to sec.335.553(c) (relating to Required Information) 
and made applicable to all three standards clearly establishes what a treatment 
process must achieve in order to be considered "decontamination" rather than a 
"control" measure. In addition, we have added words to the definition for 
"decontaminate" to clarify that not only contaminated media but also wastes may 
be decontaminated. Also, the definition for "remediation" has been revised to 
make more clear the distinction between that term and "closure". As defined, 
"closure" refers to the act of permanently taking a waste management unit or 
facility out of service while "remediation" means the act of eliminating or 
reducing the concentration of contaminants in contaminated media. 
 One of the most commented upon areas in the proposed rule was the requirement 
that in order to achieve either Risk Reduction Standard Number 1 or Number 2 
"all waste and waste residues must be removed from the unit." We are modifying 
this requirement in these final rules and this is discussed more fully in the 
following sections pertaining to sec.335.554 and sec.335.555. What is pertinent 
here, however, is that several commenters supported their argument that the 
proposed rules were inconsistent in this regard by noting that the definition 
for "remove" contained the environmental performance language regarding "a 
substantial present or future threat to human health and the environment." They 
reasoned that since the proposed rules required waste and waste residues to be 
"removed" that this could be read to mean that the waste and waste residues are 
considered removed when they no longer pose a substantial present or future 
threat to human health or the environment. We are clearing up this ambiguity by 
amending the definition of "remove" to delete the environmental performance 
language. "Remove" now refers to the physical process of taking materials away 
from a facility or area and does not define residual levels that may remain. 
"Remove" is used as an action verb in the risk reduction standards of Subchapter 
S and the standards define the amount of removal necessary to achieve protection 
of human health and the environment. The definition for "remove" has also been 
revised to state more clearly the materials that are to be taken away, where 
they are to be taken from, and where they are to be taken to. 
 Two respondents also suggested that the term "environmental media" should not 
be used in the rule since it has not been defined and is overly broad. We have 
revised the text of the rule in response to this comment and either use the word 
"media" or list the particular media that we are addressing (e.g., soil, 
sediment, surface water, groundwater, or air). And finally, we have added 
additional language to sec.335.559(e) which makes it unnecessary to add a 
definition for the term "volatile organics" to either Subchapter A or Subchapter 
S. 
 Section 335.5 describes the requirements that apply to deed recordation of 
disposal of industrial solid waste or municipal hazardous waste in a landfill. 
Union Carbide Chemical and Plastics Company, Inc. was the only commenter on this 
section and recommended that the words "in a landfill" be deleted. This 
suggestion was made as part of a recommended solution to the question whether 
all wastes must be removed in order to comply with Risk Reduction Standards 
Numbers 1 and 2. As explained later, we are addressing this question by amending 
the language of sec.335.554 and  sec.335.555. As a result, we are making no 
changes to the text of this section previously published. 
 Section 335.6 describes the notification requirements which apply to persons 
who intend to perform any activity of industrial solid waste or municipal 
hazardous waste facility expansion not authorized by a permit. The Barton 
Springs/Edwards Aquifer Conservation District submitted the only comment 
regarding this section and suggested that notification of the pertinent 
groundwater district of closure or remediations would also be appropriate. 
Having heard from only one groundwater district, the commission is not at this 
time incorporating this requirement into these rules but does remain open to 
discussing this idea further. We are making no changes to the text of this 
section previously published. 
 Section 335.8 is amended to establish three closure/remediation performance 
standards which are referred to as "Risk Reduction Standards 1, 2, and 3". This 
section sequentially defines the persons to whom these rules apply, their 
closure and remediation obligations, their notification and initiation 
requirements, and what they must do to demonstrate conformance with the risk 
reduction standards. A significant number of comments were received on these 
subjects and this section is discussed extensively below. 
 Respondents on sec.335.8 included: Vinson & Elkins; Exxon Company, USA; Texas 
Chemical Council; Baker & Botts/Beazer; Porter & Clements; Texas Eastman; Kelly 
Air Force Base; Thompson & Knight; Geraghty & Miller, Inc.; Phillips Petroleum 
Company; EXIDE Corporation; Texas Mid-Continent Oil and Gas Association; Valero 
Refining Company; Industrial Service Company; Koch Refining Company; Exxon 
Chemical Americas; Amoco Oil Company; Colonial Pipeline Company; Fina Oil and 
Chemical Company; Crain, Caton & James; and TransAmerican Waste Industries, Inc. 
 These respondents submitted a large number of comments and suggestions 
regarding what should be the proper purpose, scope, and applicability of 
sec.335.8 (relating to Closure and Remediation). These comments relate for the 
most part to the following questions, which will serve as an introduction to and 
be used to guide the discussion of this section: What is the effective date for 
these rules? What is the appropriate applicability of these rules to spills and 
discharges? Are these rules intended to be applied to permitted discharges as 
well as unauthorized discharges? What actions or conditions at a facility or 
area trigger the closure or remediation obligations specified in sec.335.8(b)? 
Do these rules establish an independent basis for requiring closures or 
remediations or, on the other hand, do they only provide a mechanism to evaluate 
closures/remediations once the obligation to perform such actions has occurred 
through the application of other commission rules, permits, or orders? How, if 
at all, should these rules apply to contaminants other than industrial solid 
waste and municipal hazardous waste? What is the appropriate relationship 
between these risk reduction rules and the spill response rules under 
development by the commission? What is the applicability of these rules to the 
State Superfund program? How will these rules effect closures or remediations 
that are already in progress or have been approved and not implemented? How will 
these rules apply to closure or remediation plans contained in previously issued 
permits? Under what conditions should a person who has initiated or completed a 
response action in accordance with one of the three risk reduction standards be 
required to take additional actions? And, finally, what is the rationale for not 
covering releases from underground storage tanks under these rules? 
 We start this discussion by noting that one respondent stated that the rules 
should provide some statement of effective date so that the circumstances where 
these rules apply could be more clearly defined. The commission agrees with this 
comment and has inserted an effective date in the first sentence of subsection 
(a) of this section (relating to Applicability) which will be 20 days after the 
date that these rules are filed with the  Texas Register for publication. 
 We have made a minor change to the second sentence of subsection (a) so that it 
addresses the "storage, processing, or disposal" of wastes rather than the 
"storage, treatment, or disposal" of waste. Also, we have amended the third 
sentence of subsection (a) to speak of the remediation "of contaminated media" 
in order to be consistent with the revised definition for "remediation" placed 
in sec.335.1. 
 At least five of the respondents recommended that the following sentence be 
removed from subsection (a) of this section: "The regulations in this section 
also apply to persons who undertake remediation of areas that are not otherwise 
designated as a facility but that contain discharges of industrial solid waste, 
municipal hazardous waste, or other contaminant. . . " Note that discussion of 
how these rules apply to "other contaminants" is examined later in the 
discussion for this section. Several of the commenters stated that the proposed 
rule had been well thought out as it pertains to waste management units, but 
questioned why spills and discharges, from other than waste management units, 
were to be regulated under Chapter 335, Subchapter A, of the commission's rules, 
which is titled Industrial Solid Waste and Municipal Hazardous Waste in General. 
Another commenter suggested that by including facilities that would not 
otherwise be subject to permitting requirements under these closure/remediation 
rules that the commission would "in effect be increasing the number of regulated 
facilities by orders of magnitude". This commenter felt that such an extension 
would act "as a severe regulatory disincentive to cleanup voluntarily initiated 
by private parties", particularly with regard to releases of "products", and 
that this would clearly be detrimental to the environment. In short, the 
commenters expressed the view that these rules should only apply to spills and 
discharges from facilities used for the storage, processing, or disposal of 
industrial solid waste or municipal hazardous waste and should not extend to 
persons who undertake remediation of areas that are not otherwise designated as 
a facility but that contain discharges of these same waste materials. 
 In response to these comments, we note that Subchapter A applies to Industrial 
Solid Waste and Municipal Hazardous Waste in General and that the commission's 
jurisdiction over such wastes is not restricted to their management in or 
discharge from facilities. The commission considers it fully appropriate for 
these rules to address areas of discharge of industrial solid waste or municipal 
hazardous waste whether or not such discharge resulted from a solid waste 
facility. As a result, the fourth sentence of subsection (a) in this final rule 
retains the statement regarding the applicability of these regulations to areas 
not designated as a facility. As discussed later in the preamble for this 
section, we have, however, amended this sentence to remove the reference to 
"other contaminant" and the language regarding an exception from these rules for 
substances discharged from underground storage tanks has been moved to new 
paragraph (6) of this subsection. We have also made necessary conforming changes 
to other parts of  sec.335.8 to note that these rules apply not only to 
facilities but also "areas". 
 Also, as will be amplified in the following discussion of this section, the 
commission is not extending these risk reduction rules to additional facilities, 
areas, situations, or materials that are not presently subject to regulation 
under one of the commission's program areas. These rules merely specify a 
consistent risk management approach to evaluate closures or remediations once 
the obligation to perform such action has occurred through a statutory 
requirement or rule, order, or permit issued by the commission. The commission 
has decided to place these risk reduction regulations in a single place (i.e., 
Chapter 335, Subchapters A and S) in order to achieve uniformity among the 
programs subject to these rules and to avoid the needless repetition of the 
lengthy and complex text in several areas of this agency's rules. 
 Several respondents noted that the commission had not been clear in the 
proposed rule regarding whether we intended to regulate permitted discharges 
under these closure and remediation regulations. It was never the commission's 
intention to regulate permitted discharges under these rules, such as from a 
wastewater treatment plant with an NPDES permit. As a result, we have inserted 
language throughout sec.335.8 which makes clear that these rules apply to 
"unauthorized discharges". 
 Several commenters stated that, in contrast to waste management units, the 
"trigger" which would activate these rules for spills and discharge events was 
not clear. Additionally, another commenter argued that subsection (b) of this 
section should not be construed to provide an independent basis for requiring 
that closures/remediations be conducted in accordance with the provisions of 
these risk reduction rules. The commenter stated that the proposed language for 
subsection (b) inappropriately created a new and independent basis for requiring 
remedial activities and that this subsection should be modified to make it clear 
that sec.335.8 "only provides a mechanism by which facilities will be closed 
once  the obligation to close or commence remediation has occurred through the 
implementation of other commission rules." The language in question from 
subsection (b) as proposed reads: "Any person who has stored, processed, or 
disposed of industrial solid waste. . .has a continuing obligation to: . . .(3) 
perform closure or remediation activities at the facility or area of discharge. 
. ." 
 In response to these comments, the commission has amended sec.335.8 by 
inserting language into subsection (a) and removing language from subsection 
(b). These revisions make clear what actions or conditions at a facility or area 
of discharge activate or trigger the closure or remediation obligations 
specified in these rules. 
 Specifically, all of the aforementioned language from subsection (b) of this 
section occurring before and including the phrase "has a continuing obligation 
to" has been deleted from the final rule. This is replaced with the much simpler 
statement that: "Persons identified in subsection (a) of this section have the 
obligation to conduct the activities described in paragraphs (1)-(4) of this 
subsection when performing a closure or remediation." Thus, subsection (a) 
describes who is to respond and subsection (b) describes the actions they must 
perform. With the exception of additional language which has been added to 
subsection (b) pertaining to "a substantial change in circumstances (which) 
results in an unacceptable risk to human health or the environment", and which 
will be addressed later in the discussion for this section, subsection (b) has 
been amended to remove any independent basis for requiring that closure or 
remediation must begin. 
 The same commenter further stated that subsection (a) of this section also does 
not provide an independent basis for imposing closure or remediation 
obligations. The commission disagrees, in part, with this statement and has 
amended subsection (a) accordingly. Specifically, we have added a new fifth 
sentence to subsection (a) which states "the regulations of this subsection, in 
addition to other applicable rules, permits, or orders, establish the obligation 
for persons to perform closures or remediations for facilities or areas 
containing industrial solid waste and municipal hazardous wastes. . ." This 
sentence continues by clarifying that these rules also specify the mechanism to 
evaluate such closures or remediations involving these types of waste materials. 
Thus, the requirements of subsection (a) along with other applicable rules, 
permits, or orders do establish the obligation for persons to perform 
remediations or closures for facilities or areas containing industrial solid or 
municipal hazardous waste. 
 We agree with this commenter; neither subsection (a) nor (b) of this section 
establishes the obligation for persons to perform the remediation of 
unauthorized discharges of contaminants. As a result, we have added a new sixth 
sentence to subsection (b) which states "The obligation to perform remediations 
for unauthorized discharges of contaminants under the state superfund and spill 
response programs occurs through the application of the commission's rules and 
statutes pertaining to those programs;. . ." This sentence continues by 
concluding ". . . however, once such obligation has occurred the regulations in 
this section will be used to specify the mechanism to evaluate remediation of 
unauthorized discharges of contaminants subject to those programs." 
 A significant number of respondents commented upon what they considered to be 
the overly broad and inappropriate nature in which discharges of "other 
contaminants" were proposed to be regulated under these risk reduction rules. 
These final rules address these concerns expressed by the respondents in a 
number of fashions. First, as discussed previously, the definition for 
"contaminant" in sec.335.1 has been amended to remove reference to "any 
substance . . . which , when discharged, . . . can create a present or future 
threat to human health and the environment." This change will provide more 
certainty regarding which substances are considered to be contaminants. Second, 
as mentioned previously, the fourth sentence of subsection (a) of this section 
has been amended to remove reference to "or other contaminant." Third, as 
discussed previously, the sixth sentence of subsection (a) has been crafted so 
that "the obligation to perform remediations for unauthorized discharges of 
contaminants under the state superfund and spill response programs occurs 
through the application of the commission's rules and statutes pertaining to 
those programs." Fourth, as discussed previously, subsection (b) has been 
revised to remove the requirement that "Any person who has . . . allowed . . . 
the discharge of . . . other contaminant . . . has a continuing obligation to: " 
And fifth, as discussed later in the preamble for this section, we have made the 
interrelationship between these rules, on the one hand, and the spill response 
and state superfund programs, on the other hand, clearer by revising paragraphs 
(1) and (2), respectively, of subsection (a). 
 The effect of the second, third, and fourth change is to make clear that only 
the unauthorized discharge of contaminants regulated via the commission's state 
superfund and spill response programs may become subject to these risk reduction 
rules. Contrary to a number of the respondents' letters, the commission is not 
extending its jurisdiction under these rules to cover materials or events that 
are not presently subject to one of the commission's program areas. The effect 
of the third and fifth changes is to make clear that the obligation to perform 
remediation for unauthorized discharges of contaminants occurs (i.e., is 
triggered) through application of the commission's rules and statutes pertaining 
to the state superfund and spill response programs. The rest of the sixth 
sentence of subsection (a) makes clear that the risk reduction standards of 
subsection (b) will be used to specify the mechanism for remediating an 
unauthorized discharge of contaminants only after the obligation to perform such 
a remediation has first occurred through either the commission's state superfund 
or spill response program. 
 Several commenters expressed a substantial level of concern regarding the 
application of these risk reduction rules to spills. The respondents felt that 
the inclusion of spills in these risk reduction rules could: create an 
administrative burden on industry; create a substantial workload increase for 
the TWC; severely inhibit emergency response actions for new spills; and cause 
unnecessary expenditures for historic spills. The overwhelming sentiment 
expressed in these letters was that the risk reduction rules should defer to the 
spill regulations on the issue of spill reporting and response. 
 The commission's intention has always been that these risk reduction rules 
would defer to the commission's spill program with regard to the reporting of 
and responding to spills. The language of paragraph (1) of subsection (a) of 
this section in the proposed rule was intended to clearly state this situation. 
In light of the significant concern expressed by respondents on this issue, we 
have amended paragraph (1) to state "that persons shall complete notification 
and response actions for spills in accordance with the Texas Water Code, 
sec.26.039 and sec.26.261, and the administrative and procedural requirements of 
the commission to carry out the Texas Hazardous Substance Spill Prevention and 
Control Act." Paragraph (1) is further amended to state that sec.335.8 (relating 
to Closure and Remediation) applies to spills at the point in time "when the 
response actions do not result in remediation within the timeframes specified by 
the commission's spill response program." A final sentence has been added to 
paragraph (1) which indicates that a person shall submit a plan in accordance 
with subsection (b) of this section in circumstances where remediation of a 
spill has not occurred within the timeframe specified by the commission's spill 
program. 
 The commission is not making a formal response in this preamble to a number of 
substantive issues raised in the respondents' letters because the commission is 
currently evaluating these same issues for incorporation into proposed spill 
response rules which are under development and since these issues will be more 
appropriately addressed in that process. A common theme running through the 
comments on this subject area was the concern that "minor spills and leaks which 
can be  32>promptly cleaned up should be addressed under the spill reporting and 
cleanup rules rather than the risk reduction rules." Falling out from this 
single sentence are three matters which are deferred to the spill response 
program for consideration. First, what is a minor spill? Several commenters 
stated that a de minimus lower limit or threshold reportable quantity should be 
established for reporting requirements. The commenters further felt that the 
"prompt cleanup of these types of spills should not be burdened by onerous 
reporting, analytical, or deed recordation requirements." Second, what is a 
prompt action? Two commenters suggested that actions completed within 180 days 
of a spill should not be subject to these risk reduction rules. And third, what 
actions constitute satisfactory cleanup or remediation of a spill so that 
application of these risk reduction rules is not warranted? The letters from 
various commenters mentioned restoration to background, the complete removal or 
decontamination of the spill, and the return of the site to pre-spill conditions 
as criteria which could be used. We are also deferring the question concerning 
whether new spills and historic unauthorized discharges subject to the spill 
response program should be subject to these risk reduction rules in the same or 
a different fashion. In the intervening period between the effective date of 
these risk reduction rules and the effective date for the future spill response 
rules, the commission will use existing statutory requirements and current spill 
response program practices to make decisions regarding the aforementioned 
questions. 
 Only one respondent specifically commented on the language of subsection (a) , 
paragraph (2), in the proposed rule which pertained to the manner in which these 
risk reduction rules will be applied at state superfund actions managed under 
Chapter 335, Subchapter K, (relating to Hazardous Facilities Assessment and 
Remediation). This respondent suggested that the relatively streamlined remedy 
evaluation process for Subchapter S (relating to Risk Reduction Standards) 
should be considered for Subchapter K cleanups. The commission has not adopted 
this suggestion due to the special nature of superfund actions and the specific 
remedy evaluation process requirements contained in Subchapter K. We have 
amended the first sentence of paragraph (2) to address "remediations performed 
under the state superfund program" and have removed the reference to "closure", 
since this term is not used in Subchapter K. The commission has also amended the 
first sentence to include the words "including a baseline risk assessment" to 
emphasize that this study shall be performed for all sites in response to 
Subchapter K. And finally, the commission has amended paragraph (2) by adding a 
second sentence which clarifies the manner in which future land use assumptions 
will be made in order to determine media cleanup levels under the state 
superfund program. This section states that future residential land use will be 
assumed unless a person demonstrates to the executive director, using the 
provisions of sec.335.563(e) (relating to Media Cleanup Requirements for Risk 
Reduction Standard Number 3), that an alternative land use is more appropriate. 
 Several respondents expressed concern regarding the proposed language of 
subsection (a), which states that "In instances where other requirements for 
closure or remediation apply, persons shall comply with those requirements in 
addition to the regulations of this section." These respondents were concerned 
that this statement may be read to require "the reevaluation and/or reclosure of 
previously certified units." In partial response to these comments, the 
commission has deleted this sentence and has replaced it with a sentence 
stating: "The regulations in this section supplement but do not replace any 
requirements for closure or remediation specified in the regulations for 
programs subject to these rules and shall apply as specified in paragraphs (1) -
(6) of this subsection." This sentence makes clear that the manner in which 
these risk reduction standards will be applied to various program areas is 
further defined by the supplemental provisions of paragraphs (1)-(6). 
 As introduced previously, a large number of respondents provided comments which 
in some manner stated that these risk reduction standards should apply 
prospectively rather than retroactively. While arguing that these risk reduction 
rules should not apply to previously approved or submitted closure or 
remediation plans, most respondents did acknowledge, even though their 
terminology varied widely, that the commission should be able to reopen the 
evaluation of a facility or area if there is evidence of a significant risk to 
human health or the environment. 
 In additional response to these comments, the commission is adopting a new 
paragraph (5) of subsection (a) which defines the applicability of these risk 
reduction rules to persons who have submitted closure or remediation plans prior 
to the effective date of these rules. This new paragraph is discussed next. The 
commission is also revising paragraph (5) of subsection (b) to define those 
conditions under which a person would be required to take additional actions 
because a facility or area presents an unacceptable risk to human health or the 
environment. This discussion is presented later in the preamble for this 
section. 
 The commission has always viewed the promulgation of these risk reduction rules 
as an opportunity to develop a more flexible and scientifically supportable 
basis for making decisions regarding our current and future workload of closure 
and remediation plans. The commission has never intended that these rules would 
be used to cause a systematic reevaluation of all previously approved closure 
and remediation plans. We have intended, however, that these rules could be used 
in those instances where a previously approved or completed action does pose an 
unacceptable threat to human health or the environment. 
 In accordance with these objectives the first sentence of new paragraph (5) of 
subsection (a) states "Persons who have received approval of closure or 
remediation plans by the executive director prior to the effective date of this 
section and have either completed or not completed the action prior to the 
effective date of this section may either maintain or complete the action, as 
applicable, according to the approved plan and are not subject to the 
requirements of this section, unless a substantial change in circumstances 
develops at the facility or area which results in an unacceptable risk to human 
health or the environment as described in paragraph (5) of subsection (b) ." 
 In addition, respondents stated that closure or remediation plans that were on 
file with the commission prior to the effective date, but which had not been 
approved by the executive director, should also not be subject to these risk 
reduction rules. The second and third sentences of new paragraph (5) of 
subsection (a) address this topic by stating: "Plans or reports submitted but 
not approved prior to the effective date of this section will be reviewed 
according to the regulations in effect at the time of document submittal. If the 
executive director denies approval of the plan or report under those regulations 
for reason of technical inadequacy, the person must then comply with the 
requirements of this section upon written notice from the executive director 
that the plan or report is not approved." Thus, the plans must be technically 
adequate to fulfill the regulations in effect at the time they were submitted in 
order not to be subject to review under the procedures of this section. 
 Several respondents were also concerned about the application of these risk 
reduction rules to facilities with previously issued permits. One respondent 
commented that an "old issue or permit should not be reopened" unless there is 
"evidence of a threat to human health or the environment." The commission has 
addressed this issue by adding a fourth sentence to new paragraph (5) of 
subsection (a) which states "Closure plans approved as part of an industrial 
solid or municipal hazardous waste permit which was issued prior to the 
effective date of this section but not implemented at the time of permit renewal 
are subject to review for compliance with the terms of this section as part of 
the permit renewal process." A fifth and concluding sentence of paragraph (5) 
states "Persons may resubmit such plans or reports that they have revised 
voluntarily to conform with the requirements of this section, unless such 
resubmittal would result in noncompliance with a previously approved or imposed 
schedule of compliance." Thus, persons may choose, on their own, to develop a 
revised plan under these rules for a previously approved closure or remediation 
but may not use this process to postpone any previously approved or imposed 
schedule. 
 Subsection (a) retains the language which states that this section does not 
apply to substances discharged from underground storage tanks. We have, however, 
moved this statement to a new paragraph (6) to aid in the organization of this 
subsection. Three respondents questioned why the commission was planning to 
maintain separate approaches to evaluate the remediation of media contaminated 
by releases of petroleum substances from underground storage tanks and from 
other sources such as pipelines and refineries. We note that the commission's 
Petroleum Storage Tank program is considering the use of a risk-based approach 
for corrective action at leaking storage tank sites. The commission remains open 
to exploring new approaches and may, with the experience gained over time in 
this area, be in a better position to move toward a more unified approach. 
 This completes the discussion of subsection (a) of this section. A number of 
the changes to subsection (b) have already been presented during the explanation 
of the changes for subsection (a). The remainder of the modifications to 
subsection (b) are presented in the following paragraphs. 
 As presented previously, the first sentence of subsection (b) has been amended 
to require the persons identified in subsection (a) to conduct the activities 
described in paragraphs (1)-(4) of this subsection when performing a closure or 
remediation. The second sentence of the revised subsection (b) states that "Upon 
receipt of approval by the executive director of reports demonstrating 
compliance with all applicable requirements, the person has completed these 
obligations unless a substantial change in circumstances results in an 
unacceptable risk to human health or the environment as described in paragraph 
(5) of this subsection." Thus, as long as a person has conducted the activities 
required by paragraphs (1)-(4) that are in effect at the time the report is 
submitted, including any necessary on-going post-closure care, and the facility 
or area does not pose an unacceptable risk to human health or the environment, 
the person has fulfilled his responsibilities under this section. The commission 
has developed this amended language with the goal of providing persons subject 
to this section a greater degree of certainty that they have fulfilled their 
obligations while at the same time providing the commission with a way to 
require additional actions in those instances where, due to changed 
circumstances, it is clearly necessary to protect human health or the 
environment. 
 The proposed language for paragraph (1) of subsection (b) regarding 
"investigate any such discharge" has been deleted in order to be consistent with 
the language of paragraph (1) of subsection (a) which states that notification 
and response actions for spills will occur in accordance with the commission's 
spill response program. 
 Paragraph (3) of subsection (b) of the proposed rule has been renumbered as 
paragraph (2) and two sentences have been added stating that "Unless the 
requirement to close a waste management facility is specified by other rule, 
permit or order, the person will determine the time for initiation of closure. 
The timely remediation of unauthorized discharges resulting from operation of a 
waste management unit does not compel the closure of the unit unless closure is 
a necessary part of the remedy to achieve protection of human health and the 
environment." This language was added to the final rule to clarify the effect 
that these risk reduction rules will have on the time of closure of waste 
management units. 
 Risk Reduction Standards Numbers 1-3 have not been modified from the proposed 
rule and are presented in subparagraphs (A)-(C) of paragraph (2) of subsection 
(b) of this section in the final rule. The respondents submitted a number of 
comments regarding the wording of these standards. Some letters suggested that 
the conditions "that pose a substantial present or future threat to human health 
or the environment" were subjective and had not been adequately defined. This 
issue has been thoroughly discussed earlier in this preamble under the 
presentation for sec.335.1 (relating to Definitions). A large number of 
commenters also pointed out that the "remove and/or decontaminate" language for 
Risk Reduction Standard Numbers 1 and 2 was not consistent with the requirements 
for sec.335.554(b) and sec.335.555(b) that all waste and waste residues must be 
removed from waste management units in order to achieve these standards. In 
response to these comments, the commission has amended sec.335.554 and 
sec.335.555 in a fashion which removes the inconsistency between these two 
portions of these rules. These amendments will be more fully explained later in 
this preamble during the discussion for those sections. The commission believes 
that the environmental performance language of these standards as is further 
specified by the technical requirements for each standard in Subchapter S 
(relating to Risk Reduction Standards) does constitute an understandable and 
supportable approach for making regulatory judgments regarding the adequacy of 
closures and remediations. Thus, the commission has adopted these standards for 
use in this final rule. 
 As noted in the previous discussion, paragraph (5) of subsection (a) and the 
second sentence of subsection (b) relieve persons of the obligation to perform 
any actions, or additional actions, respectively, in accordance with the terms 
of this section unless a substantial change in circumstances results in an 
unacceptable risk to human health or the environment as described in paragraph 
(5) of subsection (b). The first sentence of paragraph (5) of subsection (b) 
requires a person to "respond on a continuing basis pursuant to paragraphs (1)-
(4) of this subsection in the event that a substantial change in circumstances 
at a facility or area results in an unacceptable threat to human health or the 
environment." The second sentence requires the person to respond to these 
substantial changes in circumstances by using the then-prevailing criteria and 
to perform such actions as necessary to protect human health and the 
environment. The third sentence along with subparagraphs (A)-(D) indicates that 
substantial changes in circumstances may include, but are not limited to: a 
failure of institutional or engineering controls to prevent or mitigate exposure 
at the approved performance level; a change in land use from non-residential to 
residential; an actual exposure condition is determined to be occurring at 
levels not protective of human health or the environment; and new information 
indicates that contamination at the facility or area was not sufficiently 
characterized such that an unacceptable threat to human health or the 
environment continues to exist. Subparagraph (C) of paragraph (5) also states 
that ". . . changes made to Subchapter S of this chapter (relating to Risk 
Reduction Standards) in response to periodic reviews of the general procedures 
specified to generate numeric cleanup levels, or in response to annual revisions 
of Appendix II of Subchapter S to reflect new toxicity data, do not constitute a 
substantial change in circumstances, unless these changes are of such magnitude 
to present an unacceptable threat to human health or the environment when 
evaluated for future exposure conditions based on site-specific considerations." 
 The notification and initiation requirements applicable to persons who intend 
to conduct closure or remediation in conformance with subsection (b) of this 
section are contained in subsection (c) and have been modified slightly from the 
proposed rule. The second sentence of paragraph (1) of subsection (c) has been 
modified to specify that the person will provide the required written 
notification not only to the executive director but also to the commission's 
office in the district where the facility is located and that the person shall 
make such notifications at least ten days prior to conducting the activity. This 
modification has been made to the final rule in order to allow time for 
communication between the commission's central office in Austin and its district 
offices throughout the State regarding impending closure and remediation 
activities. 
 One respondent commented on the issue of whether the notification required by 
paragraph (1) to occur prior to conducting any activity of closure or 
remediation would extend to the initial site characterization activities. The 
answer is no. The notification specified under this paragraph is required ten 
days before the person begins actual closure or remediation activities. Site 
characterization activities to determine the risk reduction standard to be 
achieved and the estimated time necessary to complete the action could occur 
prior to this notification. This does not, however, relieve the person of the 
obligation to perform any earlier notification required under other regulations, 
such as the spill response program. 
 And finally, a number of respondents commented that the commission should 
provide more specific guidance regarding the information which must be included 
in the report required by subsection (d) of this section to demonstrate to the 
executive director that the closure or remediation has achieved the intended 
risk reduction standard. A number of respondents also suggested that the 
proposed rules should be amended to include a specific period of time following 
the receipt of a report within which the commission would be required to respond 
regarding the adequacy of the report. These same comments were submitted 
regarding several other sections of the proposed rules and the commission's 
response to these issues is provided in the following section of this preamble 
for sec.335.553 (relating to Required Information). 
 The commission has placed revised authorization language at the beginning of 
Subchapter S to reflect that we are adopting rather than proposing these new 
sections. 
 Section 335.551 describes the purpose, scope, and applicability of Subchapter S 
(relating to Risk Reduction Standards), which is contained in new 
sec.sec.335.551-335.569 of this final rule. 
 Respondents on sec.335.551 included: Texas Mid-Continent Oil and Gas 
Association; Cooper Industries; Geraghty & Miller, Inc.; Porter & Clements; and 
Exxon Company USA. 
 Respondents submitted a few comments specifically with regard to this section 
which suggested that the risk reduction standards of Subchapter S should only 
apply to the closure and remediation of industrial solid and municipal hazardous 
waste facilities and to any associated contaminated media. The commission has 
not adopted this approach in these final rules and an extensive discussion of 
the applicability of these rules is provided in the previous section of this 
preamble pertaining to sec.335.8 (relating to Closure and Remediation). Several 
respondents also commented upon the last sentence in proposed subsection (b) of 
this section which addressed the conditions under which persons would be 
required to take additional actions in response to changes over time to the 
general provisions of these rules. The commission has deleted this sentence from 
subsection (b) and has incorporated consideration of these issues into the 
formulation of the new language previously discussed for sec.335.8(b) and 
sec.335.8(b)(5). 
 In addition, a respondent commented that the proposed rules should be amended 
to provide persons subject to these rules with certain due process rights to 
appeal decisions of the commission's staff to higher authorities. The commission 
has not revised this final rule to reflect this comment since these risk 
reduction standards are technical requirements which will be implemented through 
a number of the commission's various program areas (e.g., solid waste 
permitting, enforcement, and corrective action; state superfund, and spill 
response). The administrative procedures within these various program areas will 
determine the exact manner in which these rules will be used at a particular 
facility or area. The commission remains open to new approaches and if our 
implementation of these rules indicates that the dispute resolution, mediation, 
contested hearing, or petition processes advocated by the commenter may be 
warranted, we will consider such approaches during future revisions to these 
rules. 
 Section 335.552 establishes the meaning of the terms necessary to define the 
requirements of Subchapter S. Upon review of the comments from the respondents 
we are amending several of the definitions previously proposed. 
 Respondents regarding the definitions contained in sec.335.552 included: 
American Industrial Health Council; Exxon Company, USA; Texas Mid-Continent Oil 
and Gas Association; Exxon Chemical Americas; Colonial Pipeline Company; Amoco 
Oil Company; Fina Oil & Chemical Company; Texas Chemical Council; ENSR 
Consulting and Engineering; Texas Eastman; and Kelly Air Force Base. 
 In response to comments from a respondent, the commission is modifying the 
definitions for the terms "carcinogen classification" and "carcinogen". The 
first few words of the definition for "carcinogen classification" are amended to 
read "The basis by which substances are classified" rather than "Carcinogens 
which have been classified". This change was necessary to make clear that not 
all chemicals classified under this system are carcinogens. The commenter also 
pointed out a number of problems with the proposed definition for "carcinogen" 
which included its failure to distinguish between those chemicals which are 
associated with benign tumors and those that are associated with malignant 
tumors. The previous definition for carcinogen has been deleted and is replaced 
with "Substances which have been classified for human carcinogenic risk based on 
the United States Environmental Protection Agency's Weight of Evidence System of 
Carcinogenicity as Group A-Human Carcinogen; Group B-Probable Human Carcinogen; 
or Group C-Possible Human Carcinogen." And finally, the commenter recommended 
that we reconsider the definition for the term "systemic toxicant" since the 
term is most appropriately used to refer to chemicals which are absorbed, 
transported to a site distant from the portal of entry, and then cause injury. 
Other than to change the word "chemicals" to "substances" we have not modified 
this definition since for the purposes of this rule we are using the term 
"systemic toxicant" in a broader sense to also include chemicals, such as 
irritants, which cause injury at the site of contact or portal of entry such as 
the skin, respiratory tract, or gastrointestinal tract. 
 The commission is also amending the definitions for "non-residential property" 
and "residential property" that were presented in the proposed rules. 
Respondents expressed concern that inclusion of the phrase "activities are being 
conducted" in the definition for non-residential property would exclude 
industrial facilities which are inactive due to closure or which operate 
passively. Commenters also expressed concern that the proposed definition for 
"residential property" could make an entire industrial facility be considered 
"residential property" if any portion of it were used for such purposes as: on-
site living quarters for a resident guard or groundskeeper; employee health 
center; or greenbelt. In response to these concerns, the commission is amending 
the definition of "non-residential property" to read "Any real property or 
portion of a property, not currently being used for human habitation or for 
other purposes with a similar potential for human exposure, at which activities 
have been or are being conducted, having the primary Standard Industrial 
Classification (SIC) major group numbers . . . " This language satisfies the 
concern raised by the respondents but would not allow land presently being used 
for human habitation or other similar purposes to be classified as non-
residential merely because it had been used for non-residential purposes in the 
past. In addition, we are amending the definition of "residential property" to 
state "Any property that does not exclusively meet the definition of non-
residential property. Also, a portion of non-residential property that is used 
in part for residential activities, such as a day care center, is defined as 
residential." This revised definition addresses the respondents' concerns 
regarding the potential for residential use of a portion of an industrial 
facility causing the whole facility to be considered residential property. 
 Respondents also submitted a number of comments which stated that the 
prioritization of data sources expressed in the definition for "practical 
quantitation limit/PQL" would cause out-dated information from the preferred 
sources to be used instead of more recent data from other sources. In response 
to these comments the commission has revised the last sentence of this 
definition to read "The PQL may be directly obtained or derived from the 
following sources with preference given to the most recent, scientifically valid 
method: . . . " The commission agrees with the statements from several 
respondents that specific guidance regarding how the PQL should be determined 
would be helpful. This is one of a number of areas where the commission will be 
working toward the development of more specific instructions as we become more 
experienced during the implementation of these rules. 
 Section 335.553 specifies the type of information which must be developed and 
when that information must be submitted to demonstrate conformance with each of 
the three risk reduction standards. A substantial number of comments were 
submitted regarding this section and we are amending certain aspects of these 
requirements. 
 Respondents on sec.335.553 included: Texas Chemical Council; Texas Mid-
Continent Oil and Gas Association; Exxon Company, USA; Groundwater Services, 
Inc.; Department of Air Force (Kelly Air Force Base); Amoco Oil Company; Baker & 
Botts/Beazer; IT Corporation; Shell Oil Company; Exxon Chemical Americas; 
American Industrial Health Council; Harcros Chemical Group/American Chrome & 
Chemicals, Inc.; Cooper Industries; EXIDE Corporation; Geraghty & Miller, Inc.; 
Porter & Clements; and Union Carbide Chemical and Plastics Company. 
 A number of respondents commented that the commission should provide more 
specific guidance regarding the information which must be included in the report 
required by subsection (a) of this section to demonstrate attainment of Risk 
Reduction Standards Numbers 1 or 2 as well as the report required by paragraph 
(4) of subsection (b) of this section to demonstrate attainment of Risk 
Reduction Standard Number 3. These commenters also stated that the proposed 
rules should be amended to include a specific period of time following receipt 
of a report within which the commission would be required to respond regarding 
the adequacy of the report. These same comments were also submitted regarding 
sec.335.8(d) (relating to Demonstration of Conformance with Risk Reduction 
Standards), sec.335.554(e) (changed to subsection (f) in the final rule) 
(relating to Attainment of Risk Reduction Standard Number 1); and sec.335.555(f) 
(relating to Attainment of Risk Reduction Standard Number 2). 
 In response to these comments, the commission notes that subsection (a) of this 
section presents a list of the types of data regarding both the initial site 
investigation and the closure or remediation activity which must be included in 
a report to demonstrate attainment of either Risk Reduction Standards Numbers 1 
or 2. Likewise, paragraphs (1) and (2) of subsection (b) of this section 
identify the types of data to be included in a remedial investigation and 
baseline risk assessment report, respectively, which the person must submit to 
the executive director for approval prior to conducting a closure or remediation 
under Risk Reduction Standard Number 3. The "sufficient documentation" referred 
to in paragraph (4) of subsection (b) of this section which must be submitted to 
demonstrate that the approved remedy has been completed in accordance with Risk 
Reduction Standard Number 3 would include the same type of remedy completion 
information identified in subsection (a) for Risk Reduction Standard Numbers 1 
and 2. Namely, the report must include "descriptions of removal or 
decontamination action procedures performed in closure or remediation" and 
"summaries of sampling methodology and analytical results which demonstrate that 
contaminants have been removed or decontaminated to applicable levels." We also 
note that subsection (d) of this section in this final rule does contain 
specific language to guide the person in collecting and analyzing samples from 
the media of concern in order to demonstrate that cleanup levels have been 
attained. 
 As a result, the commission believes that these rules provide a framework which 
adequately describes the information which a person must submit to demonstrate 
attainment of these standards. The commission agrees, however, that additional 
guidance in such areas as the minimum number and distribution of samples to be 
collected and analyzed during both the investigation phase and the verification 
phase after an action has been completed would serve to expedite the preparation 
of reports by persons subject to these rules and the subsequent review of those 
reports by the commission. The commission plans to develop and refine such 
supplemental guidance in the coming months as we gain experience through the 
implementation of these rules. 
 Also, the commission has not amended this rule to include a specific period of 
time following receipt of a report within which the commission would be required 
to respond regarding the adequacy of the report. The commission has not included 
such a provision in this rule since we have no way to know at this time either 
the quantity or quality of reports which will be submitted in response to this 
rulemaking. Based upon the experience that we gain with the implementation of 
these rules over time, the commission may be in a better position to judge 
whether limits on the length of the review period would be appropriate for 
inclusion into future revisions of this rule. 
 The only change that the commission made to subsection (a) of this section was 
to delete and insert language so that the report described in this subsection 
must now include "a document that the person proposes to use to fulfill" his 
deed certification requirements for Risk Reduction Standard Number 2. This 
change is necessary to conform to a modification of sec.335.560 (relating to 
Post Closure Care and Deed Certification for Risk Reduction Standard Number 2) 
which states that proof of actual deed certification is not due until 90 days 
after the executive director accepts the report required by this subsection. 
 A number of commenters stated in response to subsections (a) and (b) of this 
section that in order to simplify testing requirements persons should be allowed 
to use indicator parameters such as TPH and BTEX during the investigation of the 
extent of contamination when they know via process knowledge that they are 
dealing with a "nonhazardous petroleum product". The commission agrees with the 
comment provided by one of the respondents that while indicator parameters have 
their place in investigating a site "a broader range of analytical tests would 
be appropriate to evaluate the risk." 
 As presented later in this discussion for this section,  sec.335.554(d) 
(relating to Attainment of Risk Reduction Standard Number 1) and sec.335.555(d) 
(2) (relating to Attainment of Risk Reduction Standard Number 2) have been moved 
and consolidated into a new subsection (d) of this section which defines the 
collection and analysis of samples necessary to demonstrate attainment of Risk 
Reduction Standard Numbers 1, 2, and 3. In response to comments, the commission 
has amended subsection (d) of this section to include new language and has 
revised existing language in order to describe the manner in which indicator 
parameters may be used. This portion of the new subsection (d) of this section 
states: "A sufficient number of samples shall be collected and analyzed for 
individual compounds to both accurately assess the risk to human health and the 
environment posed by the facility or area and to demonstrate the attainment of 
cleanup levels. Non compound-specific analytical techniques (e.g., Total 
Petroleum Hydrocarbons, Total Organic Carbon, etc.) may, where appropriate for 
the nature of the wastes or contaminants, be used to aid in the determination of 
the lateral and vertical extent and volume of contaminated media; however, such 
non compound-specific analyses will serve only as indicator measures and must be 
appropriately supported by compound-specific analyses." 
 Thus, the commission is recognizing the valid role that indicator test methods 
may serve to define the conditions at a facility or area. However, since these 
rules are based upon an analysis of the threat posed to human health or the 
environment by individual compounds, the data collected for a site must include 
determination for the presence and concentration of individual chemicals. The 
sampling plan prepared for a facility or area should be appropriate for the 
contaminants present at the site and may be based upon the history of the site 
and process knowledge. There is no requirement under these rules, as was 
suggested by one commenter, that analyses for all of the compounds listed in 
sec.335.568 (relating to Appendix II) would be required at every site. However, 
the person is responsible for the development of a sampling and analysis plan 
which "accurately assesses the risk to human health or the environment posed by 
the facility or area." 
 In this same general subject area, a commenter also suggested that the 
commission should establish TPH and BTEX performance standards under these risk 
reduction rules for spills or releases of petroleum substances in soil and 
groundwater in a manner consistent with that of the commission's Petroleum 
Storage Tank program. The commission has not taken this approach in these final 
rules for the reasons stated previously and also in view of the fact that the 
commission's Petroleum Storage Tank program is evaluating a risk-based approach 
to determine the extent of remediations. The commission realizes that the 
individual compounds in petroleum substances may be difficult to quantify and 
that there may not be available valid toxicological values for many of the 
substances in these materials. 
 As a result, the commission has further responded to comments on this section 
by developing a new subsection (f) of this section which defines the criteria 
that persons must evaluate under the circumstances that no contaminants as 
defined in sec.335.1 (relating to Definitions) are present in the materials at 
the facility or area and non compound-specific techniques are used to 
characterize the site. New subsection (f) states "For Risk Reduction Standards 
Number 2 and 3, persons determining cleanup levels for contaminated media 
characterized by non compound-specific analytical techniques (e.g., Total 
Petroleum Hydrocarbons, Total Organic Carbon, etc.) and for which individual 
compounds such as hazardous constituents are not present as contaminants, must 
at a minimum consider other scientifically valid published numeric criteria to 
address: adverse impacts on environmental quality; adverse impacts on the public 
welfare and safety; conditions that present objectionable characteristics (e.g., 
taste, odor, etc.); or other conditions that make a natural resource unfit for 
use. 
 Thus, in those situation where compounds can be quantified and valid 
toxicological values are available, these rules would require a risk-based 
approach to be used. Where the risk-based approach either leads to high 
concentrations or cannot be performed, an analysis of other potential adverse 
impacts on environmental quality or the public welfare will be used to determine 
cleanup levels. These same criteria are repeated in sec.335.559(h) (relating to 
Medium Specific Requirements and Adjustments for Risk Reduction Standard Number 
2) and sec.335.563(j)(2) (relating to Media Cleanup Requirements for Risk 
Reduction Standard Number 3). 
 One respondent stated that the rules should allow a portion of a property that 
has attained the appropriate cleanup levels to be released prior to the entire 
property having attained the established cleanup criteria. The commission notes 
that subsection (b) of this section provides the person this flexibility for the 
initial report under Risk Reduction Standard Number 3 when it states "The 
results of activities required by paragraphs (1)-(3) of this subsection may be 
combined to address a portion of a facility or one or more facilities of a 
similar nature or close proximity." The commission intends to extend this 
flexibility to closures and remediation under subsection (a) of this section for 
Risk Reduction Standard Numbers 1 and 2 as well as for the final report required 
under paragraph (4) of subsection (b) for closures and remediations under Risk 
Reduction Standard Number 3. 
 The respondents submitted a number of comments regarding the requirement of 
paragraph (2) of subsection (b) that the initial report prepared by a person 
under Risk Reduction Standard Number 3 must include a baseline risk assessment. 
First, several commenters stated that "no specific methods (i.e., equations) for 
determining exposure from contaminated surface/groundwater and soil are 
recommended in sec.335.563(g), (h), and (i)" (relating to Media Cleanup 
Requirements for Risk Reduction Standard Number 3). The commission notes that 
the procedures and approaches described in sec.335.563 describe risk-based 
approaches to determine cleanup levels based upon a target risk level (e.g., one 
in one million) rather than the manner in which the baseline risk assessment 
will be performed. The determination of cleanup levels and the preparation of 
the baseline risk assessment report are performed for different purposes and use 
similar but not identical methodologies. 
 With the exception of specifying the standard exposure factors in Table 1 
located following paragraph (4) of subsection (b) of this section, the 
commission has purposefully not taken a prescriptive approach regarding the 
exact manner in which the baseline risk assessment will be performed. The 
commission intends to use Part A, Volume 1 of EPA's Risk Assessment Guidance for 
Superfund (EPA/540/1-89/002), referred to as RAGS, until such time as we develop 
and make available supplemental guidance in this area. This document is detailed 
and should give the person a clear idea of the type of evaluation that the 
commission expects him to present in the baseline risk assessment report. 
Respondents submitted a large number of comments regarding the standard exposure 
factors presented in Table 1 at the end of this section. We discuss these 
comments and other related comments at the end of the presentation for this 
section in this preamble. 
 Second, this same respondent commented that the proposed regulations did not 
require the degree of uncertainty associated with an exposure assessment to be 
discussed. The commission agrees with the commenter that this is an important 
part of a baseline risk assessment, so in order to be thorough, we have added a 
new sentence to paragraph (2) of subsection (b) of this section which 
specifically requires the person to discuss the degree of uncertainty in the 
baseline risk assessment. 
 Third, several commenters expressed concern with the requirement in paragraph 
(2) of subsection (b) of this section in the proposed rule that residential land 
use with on-site exposure would be used to evaluate the future use condition in 
the baseline risk assessment unless the person demonstrates to the executive 
director that a different land use assumption such as industrial use is more 
appropriate. The commenters argued that a default assumption of residential 
future land use is inappropriate and that persons ought to be able to use the 
definition of "non-residential property" presented in sec.335.552 (relating to 
Definitions) to justify assuming that future use of the property would be non-
residential. The commission did not change the rule in response to these 
comments since we purposefully established different approaches under Risk 
Reduction Standard Numbers 2 and 3 to determine the future land use of a 
property. Under Risk Reduction Standard Number 2, the judgment will be made 
through the use of the standardized definitions for "non-residential property" 
and "residential property". For Risk Reduction Standard Number 3, for both the 
baseline risk assessment and for the calculation of cleanup levels as explained 
at sec.335.563(e) (relating to Media Cleanup Requirements for Risk Reduction 
Standard Number 3) the person shall assume future residential land use unless he 
satisfactorily makes a site-specific demonstration to the executive director 
that a different land use is more appropriate. The commission considers this 
approach to be fully appropriate since Risk Reduction Standard Number 2 operates 
using default, simplifying assumptions, and requires a high degree of permanent 
risk reduction whereas Risk Reduction Standard Number 3 allows more site-
specific analysis and a greater degree of residual risk. 
 Fourth, one respondent commented that EPA's Risk Assessment Guidance for 
Superfund  (EPA/540/1-89/002) (RAGS) is "unduly costly, slow, and overly 
restrictive." One issue the commenter raised is that the RAGS guidance requires 
the evaluation of a hypothetical future residential scenario. This is not a 
pertinent comment since as explained previously, with adequate justification, 
these rules allow a future land use other than residential to be used. This 
respondent also expressed consternation that RAGS calculates risks using the 95% 
upper confidence limit on the arithmetic mean of contaminant concentration 
values rather than mean constituent concentrations. The commission considers the 
95% upper confidence limit on the arithmetic mean for contaminant concentrations 
to be appropriate to assess future potential risks. When making risk management 
decisions, the commission must assure that its actions are protective for 
individuals at the high end of the risk distribution. In short, the commission 
disagrees with the commenter and considers the RAGS document to be an 
appropriate and supportable guidance to use for the implementation of these 
rules. 
 As an important point, several respondents commented that the proposed 
regulations for Risk Reduction Standard Number 3 did not include an analysis of 
a "no action" alternative which is typically one of a range of alternatives 
considered for a superfund site. Another respondent submitted language regarding 
the interrelationship between Risk Reduction Standard Numbers 2 and 3. From 
these comments, we concluded that we had not adequately explained and 
highlighted the importance of sec.335.564 (relating to Post-Closure Care not 
required for Risk Reduction Standard Number 3). This section states that "in 
cases where the executive director determines that neither engineering nor 
institutional control measures are required to protect human health and the 
environment, the person is released from post-closure care responsibilities" but 
must deed record the facility or area. 
 The effect of this language is that a person can arrive at the same end point 
requirements and conditions under sec.335.564 for Risk Reduction Standard Number 
3 as is provided by Risk Reduction Standard Number 2. For both Risk Reduction 
Standard Number 3, under sec.335.564, and Risk Reduction Standard Number 2, 
after the person places a notice in the deed records for the property stating 
the residual contamination and the appropriate future use of the property, he is 
relieved of post-closure care responsibilities. Risk Reduction Standard Number 2 
would allow a person to reach this end point through the use of standardized, 
conservative assumptions and Risk Reduction Standard Number 3 would allow a 
person to reach this end point through a detailed analysis which allows more 
site-specific considerations. Thus, the commission believes that a good part of 
the concerns that were expressed by the respondents regarding the inflexible, 
conservative, and prescriptive methods used to determine cleanup levels under 
Risk Reduction Standard Number 2 are defused by the fact that a person can 
arrive at the same end point through use of the site-specific evaluation 
procedures of Risk Reduction Standard Number 3. Of course, there is a tradeoff, 
since the commission must be provided additional information to assure that 
site-specific decisions under Risk Reduction Standard Number 3 will be 
protective of human health and the environment. 
 As a result, the commission has amended paragraph (3) of subsection (b) of this 
section by deleting a sentence and adding two sentences which more clearly 
describe the circumstances under which a person will be relieved of post closure 
care responsibilities under Risk Reduction Standard Number 3. The first sentence 
states that "Persons may seek to satisfy the requirements of sec.335.564 of this 
title (relating to Post Closure Care not required for Risk Reduction Standard 
Number 3) by demonstrating in the corrective measure study using the procedures 
of sec.335.563 of this title (relating to Media Cleanup Requirements for Risk 
Reduction Standard Number 3) that no remedy needs to be performed since the 
existing conditions of the facility or area conform to the media cleanup 
requirements without the use of removal, decontamination or control measures." 
 The second new sentence states "Persons may also seek to satisfy the 
requirements of sec.335.564 by demonstrating in the corrective measure study 
that following completion of their recommended removal and/or decontamination 
activities the condition of the facility or area will conform to the media 
cleanup requirements of sec.335.563 without the use of control measures." Thus, 
under either of two circumstances, a person may pursue the "no action" 
alternative under Risk Reduction Standard Number 3. Be aware that neither of 
these approaches would reduce a responsible person's duty to propose a high-
quality remedy which best meets the requirements for remedies described in 
sec.335.561 (relating to Attainment of Risk Reduction Standard Number 3). The 
concluding sentence of this paragraph in the rules makes it clear that the 
executive director may upon review of the corrective measure study require the 
person to further evaluate the proposed remedy or to evaluate one or more 
additional remedies. 
 One respondent understood the sentence that we have deleted from paragraph (3) 
of subsection (b) of this section to mean that passive methods including natural 
attenuation of soil and groundwater contamination were being recommended by the 
commission. The replacement language discussed previously explains the 
commission's original intent more clearly. Paragraph (3) pertains to situations 
where: the facility or area presently meets cleanup levels; or the facility or 
area will conform to cleanup levels immediately after the 
removal/decontamination action is completed and no control measures are needed. 
Paragraph (3) does not pertain to the achievement of cleanup levels over time 
through the use of natural processes. Such an approach would have to be 
justified under Risk Reduction Standard Number 3 by using the procedures of 
sec.sec.335.562-335.566. 
 Regarding sec.335.553(b), the commission has added a requirement that conforms 
to changes in the sequence of events for performing the deed recordation for 
Risk Reduction Standard Number 3. Those changes are described fully in the 
discussion on sec.335.560 of this title (relating to Post-closure care and deed 
certification for Risk Reduction Standard Number 2). In response to those 
changes, the person must submit as part of the final report a document that he 
proposes to use to fulfill the deed recordation requirements. This change will 
enable the executive director to review and approve the document prior to its 
filing in the county deed records. 
 The commission has moved the language pertaining to the distinction between 
decontamination and other treatment processes from  sec.335.555(c) (relating to 
Attainment of Risk Reduction Standard Number 2) in the proposed rules to become 
a new subsection (c) of this section. The commission has always intended that 
this language, which explains what a person must demonstrate in order for a 
treatment process to be considered decontamination, would apply to all three 
risk reduction standards. The text of the section has been modified to state 
that it applies to Risk Reduction Standard Numbers 1, 2, and 3 and that the 
determination of whether treatment consists of decontamination for any 
particular standard will be based upon a comparison between test values and 
cleanup levels for that particular risk reduction standard. We have also added 
clarifying language to emphasize that a treatment process under these rules will 
be considered either a control measure or decontamination. 
 A commenter, who stated that this section requires the permanent alteration of 
contaminants, wanted to know whether the dilution of characteristically 
hazardous waste as described at 40 CFR sec.268.3(b) would be prohibited. First, 
subsection (c) of this section does not require all treatment processes to 
"permanently alter all contaminants". This subsection requires a treatment 
process to "permanently alter all contaminants to levels that will not pose a 
substantial present or future threat to human health or the environment" in 
order to be considered decontamination, otherwise it is a control measure. The 
distinction is that a remedy using treatment constituting a control measure must 
be justified and then conducted under Risk Reduction Standard Number 3 and would 
not qualify for consideration under Risk Reduction Standard Number 2. Second, 
nothing in this subsection should be read to disallow any treatment options 
conducted in full accordance with current hazardous waste program regulations. 
 The commission has also moved language pertaining to the collection and 
analysis of samples necessary to demonstrate attainment of the risk reduction 
standards from sec.335.554(d) (relating to Attainment of Risk Reduction Standard 
Number 1) and sec.335.555(d)(2) (relating to Attainment of Risk Reduction 
Standard Number 2) in the proposed rules to a new subsection (d) of this 
section. The proposed rules stated this language twice, once for Risk Reduction 
Standard Number 1 and once for Risk Reduction Standard Number 2, and no similar 
language was stated for Risk Reduction Standard Number 3. The commission 
intended that this language would apply equally to all three standards and has 
therefore changed this final rule accordingly. We have added the phrase "for 
Risk Reduction Standards Number 1, 2, and 3" to clearly state that these 
informational requirements apply to all three standards. 
 The commission received a substantial number of comments regarding the 
statistical procedures specified in the proposed rule to determine whether the 
analytical sampling results for a facility or area verify that the cleanup level 
has been attained. Commenters stated that the proposal to use a 95% tolerance 
limit was overly restrictive and conservative and would require the average of 
the data concentration to be a half to a third of the cleanup value. This 
statistical test would require 95% probability that 95% of the analytical data 
values are less than the cleanup value. Numerous commenters suggested that the 
commission use a test requiring the upper 95% confidence limit for the mean to 
be less than the cleanup value. This procedure would assure that the average 
concentration at the site is less than the cleanup level with a 95% confidence. 
 The commission has accepted these comments as valid and has amended the 
language in paragraph (2) of new subsection (d) of this section to include the 
equation for the upper 95% confidence limit for the mean being less than the 
cleanup level. The commission feels that this is a sufficiently protective 
statistical test given the conservatism built into the cleanup level 
determinations. Commenters also noted that neither the proposed rule nor its 
preamble mentioned how "nondetects" would be handled in the statistical 
procedure. The commission agrees with the respondents that for most sites it is 
appropriate to use one-half of the detection limit for those samples with 
concentration values less than the detection limit in the calculation for the 
mean and standard deviation. 
 Several other respondents requested that the commission allow the use of more 
than one statistical method since the uniform treatment of all data sets would 
be erroneous and problematic. The commission has addressed this concern by 
adding a new paragraph (3) to subsection (d) of this section which states that 
the person may use "other statistical methods appropriate for the distribution 
of the data" with the approval of the executive director. A revised Table 2 
presenting "t" values for the new statistical procedure has been placed at the 
end of this subsection in the final rule. 
 There are two remaining substantive issues that are discussed in the remainder 
of the preamble for this section. They are the acceptable sources of 
toxicological data and the standard exposure factors presented in Table 1 of 
this section. These are both areas where the commission received a substantial 
number of comments requesting more flexibility to deviate on a site-specific 
basis from the risk assessment methods allowed by the proposed rules. 
 We are issuing these final rules with the same requirements in these areas as 
presented in the proposed rules. As stated in the introduction to this preamble, 
the commission realizes that these risk reduction rules are more conservative 
and prescriptive and allow less site-specific analyses than was suggested by a 
number of respondents. However, these rules represent a big step for the 
commission away from the past practice of either requiring sites to be cleaned 
to background levels or to be deed recorded and monitored during a post closure 
care period. The commission considers these rules to be a prudent and 
appropriately conservative first step toward the incorporation of quantitative 
risk assessment into our waste management programs. 
 While the commission is not adopting many of the risk assessment methods 
suggested by the respondents at this time, we remain open to exploring new 
approaches in the future. Based upon the familiarity and the experience that we 
gain over time, the commission expects to be in a better position to judge 
whether the flexibility or modified procedures recommended by the respondents 
are warranted and should be incorporated into future rulemaking. 
 The commission has amended this section to include a new subsection (e) which 
contains the language from proposed sec.335.558(d) (relating to Medium Specific 
Concentrations for Risk Reduction Standard Number 2) regarding the sources for 
toxicological data such as carcinogenic slope factors and reference doses. The 
commission has intended that these procedures would also apply to Risk Reduction 
Standard Number 3 so we have moved this subsection in this final rule and have 
added language to indicate that the subsection now applies to both Risk 
Reduction Standard Numbers 2 and 3. 
 After serious consideration of all comments regarding this issue, the 
commission has decided to maintain the hierarchy of data sources presented in 
the proposed rules. Four respondents commented directly on this issue and stated 
that the prioritization of toxicity data sources would prevent the use of the 
most recent, scientifically valid data. These commenters recommended that the 
commission allow a weight of evidence approach where all available data is 
considered. One commenter recommended that this section contain a variance 
procedure which would allow the hierarchy to be overruled based upon either the 
quality or currency of additional data. 
 While these comments appear to have technical merit, the adoption of the 
suggested approach would present significant implementation problems for the 
commission at this time. The United States EPA is responsible for the three 
highest priority toxicological data sources that we have listed (i.e., 
Integrated Risk Information System (IRIS); Health Effects Assessment Summary 
Table (HEAST); and United States EPA Criteria Documents). United States EPA has 
significantly greater internal scientific resources than the commission to 
determine the relevance and weight to be place upon the results from new 
studies. For example, EPA updates IRIS on a monthly basis to reflect new data 
and the reanalysis of existing data. The commission expects to build its staff 
capability over time to make difficult judgments regarding such complex toxicity 
related questions as the mechanism for cancer induction and appropriate 
projection methods to determine carcinogenic slope factors. 
 In concert with the theme of proceeding forward with these rules in a cautious 
fashion, the commission has decided to make use of these databases to determine 
toxicological values. As with other areas of these rules the commission may gain 
experience and internal staff resources through the implementation of these 
rules over the coming months which would allow it to consider a revision to this 
procedure. 
 The commission has also added some additional text to the end of the second 
sentence of subsection (e) of this section which would allow a person under Risk 
Reduction Standard Number 2 to use more current data from the listed sources 
than was used to derive the unadjusted MSCs listed in sec.335.568 (relating to 
Appendix II) provided he furnishes substantiating evidence in the final report 
to the executive director. 
 The last substantive issue which remains to be discussed regarding this section 
is the standard exposure factors which are presented on Table 1, which is 
located following paragraph (4) of subsection (b) of this section in the final 
rules. Paragraph (2) of subsection (b) of this section states that the 
residential standard exposure factors from this table shall be used in the 
baseline risk assessment required for Risk Reduction Standard Number 3 unless 
the person demonstrates that site-specific exposure data should be used instead. 
The standard exposure factors are also pertinent to the determination of cleanup 
levels under both Risk Reduction Standard Numbers 2 and 3. The standardized 
equations presented in the rules for Risk Reduction Standard Number 2 were 
derived using these exposure parameters. Also, sec.335.563(e) (relating to Media 
Cleanup Requirements for Risk Reduction Standard Number 3) states that a person 
shall use the standard exposure parameters from this table unless the person 
documents to the satisfaction of the executive director that site-specific data 
warrant a deviation from these standard exposure factors. 
 Table 1 is the first time in these rules that standardized exposure factors are 
presented. We are therefore presenting this discussion of standard exposure 
factors in this section and much of this discussion is also pertinent to the 
determination of cleanup levels under Risk Reduction Standard Numbers 2 and 3. 
 First, a number of commenters stated that the default exposure factors used by 
the commission do not incorporate the more recent data on exposure/activity 
patterns. Rather than proceed through each of these factors individually, the 
commission notes that the standard exposure factors presented in Table 1 were 
developed for the most part to be consistent with EPA's OSWER Directive 9285. 6-
03 entitled Human Health Evaluation Manual, Supplemental Guidance: "Standard 
Default Exposure Factors". EPA developed this guidance in 1991 in order to 
achieve national consistency in evaluating site risks and in setting cleanup 
goals under the Federal Superfund program. The commission has adopted these 
standard exposure factors from that guidance also to reduce unwarranted 
variability in the exposure assumptions and to provide a consistent approach to 
the determination of media cleanup levels. 
 Second, respondents generally applauded the degree of site-specific analysis 
offered by the proposed rules, but also stated that the final rules should allow 
consideration of even more site-specific data. A commenter stated that the rules 
proposed by the commission "err too far on the side of simplicity in striving to 
achieve consistency" and then went on to recommend broader use of site-specific 
exposure assumptions. The commission also appreciates the importance and value 
of site-specific evaluations. The commission has incorporated site-specific 
analyses into this final rule to the extent that they are consistent with the 
effective implementation of this new and complicated set of rules. The 
commission is concerned about the potential for unwarranted differences among 
sites which present similar degrees of risk but which are managed in markedly 
different fashions due solely to widely varying site-specific exposure 
assumptions. 
 Commenters pointed out that the standard equations presented in sec.335.558 and 
sec.335.559 for Risk Reduction Standard Number 2 do not allow any site-specific 
evaluation of exposure factors since the default exposure factors from Table 1 
of the rule are built into the equations. This is true; however, the commenters 
should be mollified by the fact, as explained previously, that persons may reach 
the same end-point in terms of post-closure care and deed recordation via the 
more detailed, site-specific analyses allowed under Risk Reduction Standard 
Number 3 as they can under Risk Reduction Standard Number 2. For Risk Reduction 
Standard Number 3, sec.335. 563(e) allows a person to use different exposure 
factors, for either residential or non-residential use of the facility or area, 
provided he demonstrates to the satisfaction of the executive director that 
site-specific data warrant deviation from the standard exposure factors. 
 Third, following on in this vein, one commenter suggested that the commission 
"should allow the substitution of different non-site-specific default values or 
consideration of additional exposure factors when appropriate". Such an approach 
would not be acceptable for Risk Reduction Standard Number 2. For Risk Reduction 
Standard Number 3, non-site-specific default values for the parameters 
specifically listed on Table 1 of sec.335.563 would also not be acceptable. The 
commission has not promulgated specific exposure algorithms in these rules for 
Risk Reduction Standard Number 3, but persons should use the procedures 
described in EPA OSWER Directive 9285.7-01B which is entitled Human Health 
Evaluation Manual, Part B: "Development of Risk-Based Preliminary Remediation 
Goals" to develop cleanup levels until such time as the commission develops 
alternative guidance. Such supplemental guidance may, if deemed appropriate at 
that time, describe a uniform approach for the use of additional exposure 
factors such as soil adsorption coefficients and gastrointestional absorption 
coefficients. The commission does not anticipate authorizing use of such 
additional exposure factors on a case-by-case basis prior to that time. 
 Fourth, a number of commenters provided similar statements that, "the default 
point estimate exposure factors used for Standards 2 and 3 create a worst-case 
scenario which is more extreme than the "reasonable maximum exposure" intended 
by TWC". As mentioned previously, the standard exposure factors were taken from 
EPA's OSWER Directive 9285.6-03 entitled Human Health Evaluation Manual, 
Supplemental Guidance: Standard Default Exposure Factors". According to that 
guidance, "These standard factors are intended to be used for calculating 
reasonable maximum exposure (RME) estimates for each applicable scenario at a 
site. Readers are reminded that the goal of RME is to combine upper-bound and 
mid-range exposure factors . . . so that the result represents an exposure 
scenario that is both protective and reasonable; not the worst possible case." 
Cleanup levels under these rules are to be based upon an estimate of the 
reasonable maximum exposure, which is the highest exposure that is reasonably 
expected to occur at a site under future land use conditions. The commission has 
not defined quantitatively where on the distribution of potential risk 
"reasonable maximum exposure" is for the purposes of these rules. The commission 
believes that the standard exposure factors are appropriate, at this time, to 
define a conservative, but plausible, estimate of the individual exposure for 
those persons at the upper end of an exposure distribution. 
 Fifth, several respondents recommended that the commission use the available 
scientific data on distributions of exposure factors rather than rely on single 
point estimates as representative of the distributions. The commenters continued 
that the use of single worst-case exposure parameters to derive single point 
cleanup standards is inconsistent with current trends in exposure assessment 
methodologies. The commenters recommended that the commission allow the use of 
quantitative probabilistic risk assessment procedures, such as Monte Carlo 
analysis, to simulate the probable distribution of exposures by substituting 
randomly selected point values from known distributions and repeating this 
process many times. According to the respondents, the resulting distribution 
provides the decision-maker with a more realistic view of probable exposures 
from which to choose the "reasonable maximum". 
 The commission is not prepared, at this time, to embrace the use of Monte Carlo 
analysis for the purpose of quantifying risk and establishing cleanup levels 
under these rules. All risk assessment aspects of these rules are based upon 
detailed and explicit guidance documents published by EPA's Office of Solid 
Waste and Emergency Response. The commission appreciates that Monte Carlo 
analysis is an accepted mathematical technique that has been used by engineers 
and scientists for a long time. However, the application of this mathematical 
technique for the quantitative estimation of risk at hazardous substance sites 
is more recent. EPA has not prepared detailed guidance regarding the use of 
Monte Carlo analysis. The commission does not consider it wise to base these 
rules on quantitative probabilistic risk assessment procedures in the absence of 
guidance which defines the accepted distribution of values and probability of 
occurrence for each individual exposure parameter. 
 And finally, we note that one respondent expressed the view that the "TWC 
should employ the most current accepted risk assessment practices and exposure 
assumptions in these rules and add provisions to ensure that the risk assessment 
practices driven by the rules remain "evergreen" with the changing techniques 
and assumptions incorporated in an ongoing fashion". The commission takes the 
different view that, in the absence of a standardized process to evaluate the 
validity of site-specific exposure assumptions, the somewhat prescriptive 
process embodied in these rules, which has opportunities for deviation, where 
justified, will lead to a more consistent, credible, and defensible approach for 
the initial application of these rules. The commission considers it wise to take 
a cautious approach when embarking upon a fundamentally different way to 
evaluate the need for and extent of remediations. The commission is committed to 
revising these rules periodically and making whatever changes are felt to be 
appropriate in light of our experience gained from the implementation of these 
rules. 
 Section 335.554 describes the criteria which must be attained in order for a 
person to achieve compliance with Risk Reduction Standard Number 1. Respondents 
on sec.335.554 included: American Industrial Health Council; Amoco Oil Company; 
Baker & Botts/Beazer; Chemical Manufacturers Association; Exxon Company, USA; 
Exxon Chemical Americas; FINA Oil and Chemical Company; Industrial Service 
Company; KOCH Refining Company; Shell Oil Company; Texas Chemical Council; Texas 
Mid-Continent Oil and Gas Association; Union Carbide Chemicals and Plastics 
Company; and Valero Refining Company. 
 Some commenters stated that cleanup to background as required by Risk Reduction 
Standard Number 1 was overly conservative and arbitrary in its application and 
suggested that this standard be eliminated. The commission has retained cleanup 
to background as one of the risk reduction standards because it continues to 
offer the greatest degree of protection to human health and the environment and 
upon attainment no continuing regulatory obligations are imposed and no notices 
are required to be placed on the title to the property. These risk reduction 
rules afford a person a range of options in performing closures or remediations; 
Risk Reduction Standard Number 1 is but one option. As stated in  
sec.335.8(c)(1) of this title, the person can choose the risk reduction standard 
to be attained. 
 Regarding sec.335.554(a), some designations of subsections have changed as a 
result of the commission having added an additional subsection to this section. 
This is reflected here by changing "(b)-(f)" to "(b)-(g)". 
 Regarding sec.335.554(b), one commenter noted that the requirement to remove 
all waste and waste residues from the unit would require expensive removal of 
all waste, regardless of whether the waste could meet the standards after 
treatment in place. The commenter recommended allowing decontamination of wastes 
as well as removal. This subsection as well as the parallel language in Risk 
Reduction Standard Number 2 received multiple comments. The commission has 
applied the same changes to this subsection as was done for sec.335.555(b) and 
(c) of this title (relating to Attainment of Risk Reduction Standard Number 2), 
in that a differentiation is made between hazardous waste and non-hazardous 
waste. Subsection (b) addresses hazardous waste and hazardous waste residues by 
requiring removal at closure of a unit or remediation of an area of unauthorized 
discharge. Contaminated design and operating system components must also be 
removed. Contaminated media can be removed or decontaminated to achieve the 
cleanup levels for this standard. This issue is discussed more thoroughly under 
the discussion for sec.sec.335.555(b) and (c) later in this preamble. 
 Regarding sec.335.554(c), this language is being added here as a continuation 
of the commission's response to the comment on subsection (b). All remaining 
subsections of this section have been redesignated. The requirements for closure 
of non-hazardous waste units and for response to non-hazardous waste discharges 
allow both the removal and decontamination of waste, waste residues, 
contaminated design and operating system components, and contaminated media so 
as to achieve the cleanup levels for this standard. 
 Regarding sec.335.554(d), formerly designated as subsection (c) of this 
section, numerous commenters discussed the meaning of "background" and sought 
exclusions for industrial areas or expanded guidance in determining background. 
Several commenters agreed with the definition of background, including certain 
anthropogenic levels (e.g., residues from automobile exhaust, or agricultural 
use of pesticides in accordance with labeling requirements), and they expressed 
the view that some areas of Texas have been heavily industrialized for many 
years and that widely dispersed, low levels of contaminants do not pose a health 
threat, are not related to current industrial activities, or have been added to 
a property as a result of a neighbor's industrial activity. For these scenarios, 
the commenters suggested that the commission not exclude such contamination from 
being considered as a part of background. 
 Other commenters sought expanded guidance on the determination of background 
levels as it pertains to statistical characterization or ranges of naturally 
occurring levels as reported in the scientific literature. The commission 
recognizes the need for some flexibility in establishing background levels and 
agrees with one commenter who suggested that site-specific background be 
developed by applicants at each site. On the other hand, the commission has also 
utilized published tables of ranges of values in soils in setting background 
levels. The commission has some concern for this approach if the high literature 
values represent mineralized zones or other areas that are not representative of 
the location in question. The commission does not intend to specify one method 
over the other at this time so as to retain flexibility, but it does intend to 
expand its existing guidance on this subject. The format of this subsection was 
modified by combining paragraphs (1) and (2) with the text of the subsection in 
order to more closely parallel similar language for Risk Reduction Standard 
Number 2. 
 Regarding sec.335.554(e), formerly designated as subsection (d) of this 
section, the majority of the proposed text, including paragraphs (1) and (2), 
was relocated to sec.335.553(d) of this title (relating to Required Information) 
. Comments regarding the relocated text are discussed in that section. 
 Regarding sec.335.554(f), formerly designated as subsection (e) of this 
section, one commenter requested an outline of the required elements of the 
report that is referenced in this subsection. This information is specified in 
sec.335.553(a) of this title (relating to Required Information). Two commenters 
requested a deadline for commission review of the report so as not to delay 
additional work at a site which would cause an unreasonable cost on industry. 
Suggested timeframes ranged from 30 to 180 days. The commission cannot agree to 
a specific time limit within which it will review these reports. The commission 
agrees that timely reviews are desirable and will work towards this goal. No 
change was made to the language previously proposed. 
 Regarding sec.335.554(g), formerly designated as subsection (f) of this 
section, no comments were provided. The commission added the word "area" for 
clarification and consistency in that it is the "facility or area" for which 
attainment of this risk reduction standard can be demonstrated. 
 Sections 335.555-335.560 describe the criteria which must be attained and the 
conditions which must be satisfied in order for a person to achieve compliance 
with Risk Reduction Standard Number 2. 
 Section 335.555 describes the general criteria which must be attained in order 
to achieve compliance with Risk Reduction Standard Number 2 and these criteria 
are further described in sec.sec.335.556-335.560. 
 Respondents on sec.335.555 included: Amoco Oil Company; Baker & Botts/Beazer; 
Department of the Navy; Exxon Chemical Americas; FINA Oil and Chemical Company; 
Geraghty & Miller, Inc.; Groundwater Services, Inc.; IT Corporation; KOCH 
Refining Company; Texas Eastman; Porter & Clements; Shell Oil Company; Shell 
Pipe Line Company; Texas Mid-Continent Oil and Gas Association; Texas Chemical 
Council; and Union Carbide Chemicals and Plastics Company. 
 Two commenters felt that, in general, Risk Reduction Standard Number 2 cleanup 
requirements are too strict as a result of utilizing compounding conservative 
exposure assumptions that exceed the reasonable maximum exposure (RME) suggested 
by EPA guidance. One of these commenters suggested the use of quantitative 
probabilistic methods, such as Monte Carlo Analysis, as an alternative method to 
determine cleanup levels. The TWC acknowledges that the specified methods to 
determine cleanup levels in this section do represent a conservative estimate of 
what is necessary to protect persons at the upper end of the exposure 
distribution, but this approach is a necessary trade-off to define self-
implementing, easy-to-review procedures. Risk Reduction Standard Number 3 offers 
a more flexible approach, but still within prescribed limits, for assessing 
risks and determining cleanup levels. The TWC has committed to revise these 
rules in response to reviews of new or evolving ways to characterize risk. 
 In regard to sec.335.555(b), numerous commenters questioned the requirement to 
remove all waste and waste residues from the waste management unit (WMU) 
undergoing closure. As noted previously regarding the definition for "remove", 
some changes were necessary to rectify an apparent discrepancy between the 
definition of remove, the language of Risk Reduction Standard Number 2 as stated 
in sec.335.8(b)(2)(B), and the required actions to attain this standard as 
stated in this section. Further, some commenters noted that the proposed 
language in this section would require the removal of large quantities of 
minimally contaminated materials from such units as stormwater ponds and raw 
water clarification basins. Such units tend to accumulate particulate residues 
that are soil-like in composition. According to the respondents, removal of such 
materials seemed to be contrary to the concept of determining appropriate action 
based upon the risk posed by the materials. 
 We have addressed this inconsistency by requiring hazardous waste and hazardous 
waste residues to be removed while allowing media that have become contaminated 
by releases from a hazardous waste management unit to be removed or 
decontaminated to the cleanup levels specified for Risk Reduction Standard 
Number 2. Differentiation of requirements for non-hazardous waste is specified 
in sec.335.555(c), also in response to these comments. Additionally, 
unauthorized discharges of hazardous waste must be removed. In practice, the 
commission envisions removal to apply to the hazardous waste that is physically 
separable from the underlying media, as might occur in spill response 
situations. Where hazardous waste is dispersed within the contaminated media, 
decontamination processes can be applied to attain the cleanup levels specified 
or referenced by this section. These revised requirements further specify that 
contaminated design and operating system components such as liners, leachate 
collection systems and dikes must be removed, in contrast to the proposed 
requirement that such components could be removed or decontaminated. This change 
reflects the deletion of these items from the definition of contaminated media 
and, further, conforms with the intent of EPA's modified closure-by-removal 
approach as described in the March 19, 1987, preamble to a final rule on interim 
status closure requirements (52 FedReg 8704). 
 Regarding sec.335.555(c), the original subsection describing treatment 
processes was moved to sec.335.553(c) (relating to Required Information) so that 
it will apply to all three risk reduction standards. In its place we have 
specified that non-hazardous waste and media that have become contaminated by 
discharges of non-hazardous waste or other contaminants must be removed or 
decontaminated during closures or remediations to the cleanup levels determined 
for Risk Reduction Standard Number 2. 
 Regarding sec.335.555(d), commenters noted, here and in sec.335.559, that Risk 
Reduction Standard Number 2 does not define groundwater, as does Risk Reduction 
Standard Number 3 (sec.335.563(h)), in terms of a current or potential source of 
drinking water. This subsection identifies groundwater as an example of 
contaminated media of concern and is not intended to provide additional 
definitions. This comment will be discussed in more detail regarding 
sec.335.559(h). Paragraph 2 of this subsection was modified in a manner similar 
to Risk Reduction Standard Number 1 in that the requirements for sampling and 
testing of contaminated media and the comparison procedures for demonstrating 
attainment of the cleanup levels were moved to sec.335.553(d) (relating to 
Required Information). Comments concerning these requirements were discussed 
previously. 
 Regarding sec.335.555(e), a commenter questioned the timing of the deed 
certification being filed in county records prior to review and approval by the 
executive director of the report demonstrating attainment of the risk reduction 
standard. Another commenter addressed removal of the deed record if at a later 
time a Risk Reduction Standard Number 1 cleanup could be demonstrated. Another 
commenter raised several issues, including potentially serious consequences on 
the marketability of property and the authority of the commission to require 
deed recordations. The changes made to this subsection and subsection (f) of 
this section were in response to the first comment. Rather than filing a deed 
certification without benefit of commission review and approval and possibly 
having to do a second filing, the person is now instructed to submit a document 
as part of the final report that he intends to use for this purpose. 
 Regarding sec.335.555(f), requests were made to clarify the requirements of the 
report required by this subsection and for the commission to commit to a 
reasonable response time (e.g., 90-180 days) to review the report. The required 
contents of the report are specified in sec.335.553(a) of this title (relating 
to Required Information) so additional clarification is not necessary at this 
time. As noted earlier, the commission cannot agree to a specific time limit 
within which it will review these reports. The commission agrees that timely 
reviews are desirable and will work towards this goal. The change made to this 
subsection is a continuation of our response to comments regarding the timing of 
the deed certification. As noted previously, the report must include the 
document intended to fulfill the deed certification requirements for Risk 
Reduction Standard Number 2. Upon approval of the report by the executive 
director, the person then files the deed certification in the county records. 
The last step in demonstrating attainment of Risk Reduction Standard Number 2, 
as specified in sec.335.560 of this title (relating to Post Closure Care and 
Deed Certification for Risk Reduction Standard Number 2), is to submit proof of 
deed certification. This is accomplished by submitting a notarized copy of the 
deed certification consistent with existing practice of the commission. 
 Section 335.556 describes the procedures to be used to determine cleanup levels 
for Risk Reduction Standard Number 2. 
 Respondents on sec.335.556 included: American Industrial Health Council; Cooper 
Industries; Exxon Chemical Americas; IT Corporation; Merichem Company; and Texas 
Mid-Continent Oil and Gas Association. 
 Regarding sec.335.556(a), a commenter stated that the reliance upon standards, 
particularly the drinking water maximum contaminant level (MCL), is 
inappropriate in that this approach, among other things, does not take into 
consideration the effects of attenuation by soils as contaminants migrate to a 
point of exposure. The commenter opinioned that such cleanup levels cannot 
realistically be viewed as risk-based, but instead are rather arbitrary. The 
commission disagrees with this last point since our approach has been to develop 
cleanup standards using quantitative human health-based risk assessment 
procedures only where we lacked a promulgated standard which was well-suited for 
use as a cleanup level. The commission considers MCLs appropriate as cleanup 
levels in a number of situations. Risk Reduction Standard Number 2 assumes 
uncontrolled future land use such that the point of exposure, such as a drinking 
water well, could be placed in the center of the closed unit or remediated area. 
Under this scenario, there would not be an opportunity for attenuation of 
contaminants in the lateral direction of groundwater movement, hence the 
approaches for defining cleanup levels under Risk Reduction Standard Number 3 
are not appropriate for use and cleanup levels therefore must be protective 
throughout the site. The commission has clarified the language of this 
subsection to reflect that these procedures for determining cleanup levels are 
intended for individual contaminants and that if promulgated standards are not 
available or do not provide appropriate protection for human health or the 
environment, then other numeric criteria must be developed as cleanup levels. 
 The potential for the downward migration of contaminants from soil to 
groundwater is addressed under Risk Reduction Standard Number 2 and several 
options are available for use, as specified more fully in sec.335.559 of this 
title (relating to Medium Specific Requirements and Adjustments for Risk 
Reduction Standard Number 2). Other commenters suggested that alternative 
methods or assumptions be allowed to determine cleanup levels. The commission is 
not prepared at this time to offer additional flexibility for the types of 
information necessary to develop cleanup levels under Risk Reduction Standard 
Number 2 in a self-implemented fashion. Within prescribed limits, use of 
alternative values and methods is currently available under Risk Reduction 
Standard Number 3, subject to review and approval by the commission. As the 
staff of the commission gains experience with these risk reduction standards 
over time, the commission will review the general procedures for establishing 
numeric cleanup levels and propose whatever alternative procedures are warranted 
for incorporation into revised versions of these regulations. 
 Regarding sec.335.556(b), commenters agreed with the need to evaluate other 
exposure pathways in addition to those pathways specified for Risk Reduction 
Standard Number 2, but pointed out that these rules do not provide specific 
guidance as to how this evaluation should be done. The commission recognizes 
this as a need of the regulated community and has added language directing 
persons to available guidance or scientific literature in developing cleanup 
levels. The great range of potential environmental receptors and the site-
specific nature of other human-health based exposure pathways precludes the use 
of standardized procedures as was done for the medium-specific concentrations 
(MSCs). The commission recommends starting with the EPA's Environmental 
Evaluation Manual (EPA/540/1-89/001) and Ecological Assessments of Hazardous 
Waste Sites: A Field and Laboratory Reference Document (EPA/600/3-89/013). 
 Additional language was added to this subsection to add emphasis to the 
requirement to consider environmental receptors. One commenter recommended 
limiting Risk Reduction Standard Number 2 to human health considerations only. 
The commission strongly disagrees with this suggestion. While the commission 
believes that levels protective of human health will in many instances also be 
protective of the environment, evaluations must be made, and additional 
remediation must be performed, in those instances when this is not the case. 
Also, the commission clarified that the exposure pathways are those that are 
defined or referenced in this section (sec.335.556). The proposed language was 
unclear by stating "the following sections" which could be interpreted to mean 
sections for Risk Reduction Standard Number 3. Lastly, the language of 
subsections (c), (d), and (e) was clarified by adding "The person must..." to 
indicate who must perform these functions. 
 Section 335.557 describes the criteria which determine whether non-residential 
soil requirements under Risk Reduction Standard Number 2 may be used for the 
closure/remediation of a facility or area. 
 Respondents on sec.335.557 consisted of Colonial Pipeline Company, which 
suggested that government controlled property, such as wetlands under the 
control of the United States Army Corps of Engineers, should be considered for 
non-residential soil requirements. The commission disagrees with this comment 
because of the specific reference to wetlands. For this type of land, the 
commission would expect cleanup levels to be governed by environmental receptors 
and hence inadequately protected by the non-residential worker exposure 
scenario. The commission has deleted language regarding additional notifications 
as part of the deed certification. This change was necessary to conform with 
changes in the model deed certification language of Appendix III, to be 
discussed in more detail later. 
 Section 335.558 describes the processes and equations which will be used to 
determine medium specific concentrations which are the starting point in the 
establishment of cleanup levels under Risk Reduction Standard Number 2. 
 Respondents on sec.335.558 included: American Industrial Health Council; 
Colonial Pipeline Company; Department of the Air Force (Kelly AFB); Exxon 
Chemical Americas; Geraghty & Miller, Inc.; Harcros Chemical Group; Shell Oil 
Company; and Texas Mid-Continent Oil and Gas Association. 
 Regarding sec.335.558(b), commenters generally did not support the use of the 
strict risk levels of (10E-6 or 0.000001) for Class A and B carcinogens and 
(10E-5 or .00001) for Class C carcinogens. The change generally recommended by 
the commenters was to adopt a risk range as was done in Risk Reduction Standard 
Number 3. Some commenters expressed the view that the use of a rigid 0.000001 
risk level, when combined with the compounding effects of conservative exposure 
assumptions, results in a cleanup level that is overly stringent and might even 
compel cleanups to essentially background levels, resulting in excessive 
expenditures that produce little improvement in environmental protection. 
Commenters also noted that the preamble to the proposed rule did not state the 
risk values. Regrettably, those values, which were expressed in scientific 
notation, were omitted from the text but did appear in the rule section. The 
risk range for Risk Reduction Standard Number 3, 10E-6 (0.000001) to 10E-4 
(0.0001), which is consistent with the National Contingency Plan, is from one 
excess cancer case in a population of 1,000,000 to one excess cancer case in a 
population of 10,000. The commission believes that the strict risk levels 
established for Risk Reduction Standard Number 2 are appropriate given the self-
implementing nature of the standard and that no post-closure care is required. 
 Regarding the specific algorithms (Equations 1, 2, 3, and 4) presented in this 
section, commenters generally took exception with the use of default exposure 
assumptions and requested the use of more site-specific values. For the reasons 
stated previously in this preamble, the commission is not prepared at this time 
to allow modifications to the default exposure assumptions. Some amount of site 
specificity can be introduced into Risk Reduction Standard Number 2 in the next 
section (sec.335.559, relating to Medium Specific Requirements and Adjustments 
for Risk Reduction Standard Number 2). Another alternative is to provide site-
specific information in the manner specified for Risk Reduction Standard Number 
3. Consequently, the commission is not making any additional changes to the text 
previously published for subsections (b) and (c) of this section. The format was 
changed by moving subsection (d) of this section to sec.335.553(e) of this title 
(relating to Required Information) to make it applicable to both Risk Reduction 
Standard Numbers 2 and Number 3. Former subsection (e) has been redesignated as 
subsection (d) of this section without making any additional changes to the text 
previously published. 
 One commenter did suggest that the commission ought to carefully survey the 
range of established and soon to be proposed or promulgated regulatory standards 
in order to ensure that Subchapter S criteria are not in significant conflict 
with criteria and limits established under other regulatory programs. The 
commission anticipates doing this survey as part of the annual revision of 
Appendix II. Comments on individual chemicals will be discussed in sec.335.568 
of this title (relating to Appendix II). 
 Section 335.559 specifies requirements that can define or modify numeric 
cleanup levels such as MSCs and can also require non-health based concerns to be 
addressed. 
 Respondents on sec.335.559 included: American Industrial Health Council; Baker 
& Botts/Beazer; Colonial Pipeline Company; Crain, Caton & James; Department of 
the Air Force (Brooks Air Force Base); Department of the Navy; Department of the 
Air Force (Kelly Air Force Base); ENSR Consulting & Engineering; EXIDE Company; 
Exxon Chemical Americas; FINA Oil and Chemical Company; Geraghty & Miller, Inc.; 
Groundwater Services, Inc.; IT Corporation; Porter & Clements; Shell Oil 
Company; Texas Chemical Council; Texas Mid-Continent Oil and Gas Association; 
and Union Carbide Chemicals and Plastics Company. 
 Regarding sec.335.559(b), several commenters questioned the use of MCLs as a 
criteria for surface water quality, particularly if the surface water was not 
suitable as a human drinking water resource. The commission recognizes that this 
situation is likely to exist and has clarified its intentions by substituting 
the word "appropriate" for "applicable" in relation to MCLs. We believe, 
however, that the respondents have misunderstood the requirements of this 
subsection. The first sentence defines the quality of runoff or of overland 
discharge which determines the necessity for conducting soil or groundwater 
remediation. The second sentence speaks to the effect that any discharge from 
the area to a surrounding surface water body can have on that surface water 
body. Another commenter raised the concern that cleanup levels required by this 
section could be lower than permitted discharge limits for the same substance at 
the same location. As a regulatory matter, this concern bears out the difference 
in handling of authorized versus unauthorized discharges, and, similarly, 
controlled versus uncontrolled situations. The second sentence specifically 
states that a discharge may be subject to the permitting requirements of Chapter 
305 or other authorization from the commission. The discharge limits established 
in any such permit for the facility or area would define authorized levels of 
contaminant discharge. Finally, a commenter sought guidance as to whether the 
commission meant these requirements to apply to total concentrations or 
dissolved concentrations of contaminants in surface water. The commission makes 
no distinction in this case, as contaminant transport could occur in both 
situations and should be evaluated on a contaminant and site-specific basis. 
 Regarding sec.335.559(c), one commenter suggested revisions to this subsection 
to clarify references to federal and state requirements which appeared to be 
confusing and incomplete as originally stated. After conferring with the Texas 
Air Control Board, the commission made the suggested revisions. 
 Regarding sec.335.559(d), the commission will first point out the format change 
in that the groundwater requirements that had been in subsection (g) have been 
relocated to subsection (d) so that the order of presentation of media 
requirements more closely follows the order of Risk Reduction Standard Number 3. 
Placement of the discussion for soil cleanup levels last in this sequence is 
appropriate since soil cleanup levels are established in part upon a 
consideration of what contaminant concentrations can remain in soil and still be 
protective of the other media. The discussion of comments on groundwater 
requirements follows. 
 Several commenters questioned the use of the Maximum Contaminant Level (MCL) as 
the cleanup level, noting that this value is meant to be applied to water drawn 
at the tap and that it does not account for attenuation that could occur in the 
subsurface soils. Another commenter added that MCLs are set for a compound group 
based on the more toxic or soluble properties of one compound and are therefore 
overly protective for that compound group. The commission again points out that 
one of the assumptions of Risk Reduction Standard Number 2 is that direct 
exposure could occur at the facility or area. A water well installed in the 
groundwater zone in question would be delivering this water to the tap and must 
therefore be afforded the same level of protection as regulated supply systems. 
Hence, the commission will retain the MCL as appropriate for use in Risk 
Reduction Standard Number 2. 
 Other commenters requested that the standard be revised to allow the potential 
use of groundwater at a location to be determined in a manner similar to Risk 
Reduction Standard Number 3, and others requested an MSC based on non-
residential exposure rates. In taking these comments into account, the 
commission has developed parallel requirements for residential and non-
residential exposure situations and presents these as new paragraphs (1) and 
(2), respectively. Former paragraphs (1) and (2) are now renumbered (3) and (4), 
respectively. Much of the originally proposed requirements for groundwater are 
retained in paragraph (1). The statement regarding phase-separated non-aqueous 
liquids has been clarified to reflect the need for action to be applied in a 
manner consistent with the removal or decontamination requirements of this 
standard. One commenter questioned whether the requirements apply to dissolved 
or total concentrations of the contaminant. The original language specifies 
dissolved concentrations. 
 New paragraph (2) addresses non-residential exposure situations. Much of this 
language has been moved from proposed subsection (f)(2) (now (g)(2)) of this 
section. One commenter questioned why no adjustment was applied to MCLs when 
MSCs could be adjusted by factors of 3.36 or 2.8 for carcinogens or systemic 
toxicants, respectively. The federal government takes into account the 
effectiveness and cost of treatment as well as health effects when setting MCLs. 
The final value of an MCL often is not at a target risk of 0.000001; some equate 
to a target risk of 0.0001. Thus, an MCL in many cases would be less stringent 
than the corresponding MSC calculated for the same compound. Therefore, the 
commission believes sufficient relief already exists in many MCLs such that no 
additional adjustments are being considered at this time. The commission had 
previously proposed that the groundwater cleanup levels for non-residential 
exposure would be the same as for residential exposure because of the concern of 
migration of contaminants to off-site receptors at levels not protective of 
residential exposure. In allowing this adjustment in this final rule, the 
Commission has added a requirement that persons must demonstrate that the 
quality of groundwater at the facility property boundary will be protective for 
residential exposure. This provision therefore will allow for some consideration 
of contaminant attenuation, as several commenters had suggested. Lastly, the 
requirement addressing phase-separated non-aqueous liquids is modified slightly 
to account for non-residential settings. 
 New paragraph (3) addresses the adjustment allowable for groundwater with 
naturally occurring high salinity. Commenters did not question the adjustment 
per se, rather, they sought resolution of the issue of subsequent adjustments to 
soil concentrations being prohibited by this paragraph. In response to this 
concern, the commission has removed this restriction from this paragraph and 
modified the requirements for soils to address residential and non-residential 
soil-to-groundwater cross-media protection concentrations separately. These 
modifications will be discussed below in the subsections regarding soils. 
 Regarding sec.335.559(e), previously designated as subsection (d) of this 
section, one commenter thought that the requirement for soils remaining in place 
to not exhibit the hazardous waste characteristics of ignitability, corrosivity, 
or reactivity was overly restrictive. The scenario described in the comment 
concerned releases from a landfill. As this type of situation would require 
evaluation under Risk Reduction Standard Number 3 (a hazardous waste landfill 
can not be closed and remain in place under Risk Reduction Standard Number 2), 
the commission will retain this requirement. Numerous comments focused on the 
requirement imposing a limitation of 1000 ppm on total volatile organic 
compounds in soils. Commenters questioned its apparent arbitrary nature and 
whether it had a rational basis and suggested that it be removed entirely or be 
modified. Other comments suggested that the commission identify a specific 
analytical method or approach to be used to determine and analyze total volatile 
organic compounds. Also, if this requirement is maintained, should it apply to 
each volatile compound individually or to the total for all volatile compounds? 
The commission found the suggestions of one commenter to be particularly 
convincing and modified this requirement accordingly. The subsection has been 
revised to reflect that the limiting factor is the sum of the concentrations of 
volatile organic compounds in the vapor phase in soil rather than the sum of the 
total concentrations. Methods of analysis and calculation have been added for 
clarification. 
 Regarding sec.335.559(f), previously designated as subsection (e) of this 
section, commenters questioned whether soils buried at some depth, perhaps 5 or 
10 feet deep, should have to address the same criteria as soils at the surface 
where direct exposure via ingestion and inhalation of vapors and particulates is 
more probable. One commenter argued that exposure to subsurface soils is more 
likely to occur in industrial settings via workers in excavations and that the 
subdivisions of the soil column into surface and subsurface soils should be 
applied to the residential soil criteria instead of the non-residential soil 
criteria. Others suggested the soil columns should be divided for both settings. 
Another commenter suggested stopping the soil requirements at the water table. 
The commission disagrees with some of these interpretations of the intent of 
this paragraph for two main reasons. The first reason is that commenters appear 
to have limited the land use to residential (in the sense of a family residence) 
largely from a literal reading of the term. The commission's intent is for 
residential criteria to be protective of any future uncontrolled land use, not 
just human habitation. Under this broader interpretation, no controls would be 
imposed on any activity, which could include excavations deeper than the two 
feet of surface soil. Secondly, the use of the soil MSC serves as an upper limit 
on soil concentrations when the option to develop the soil-to-groundwater cross-
media protection concentration of paragraph (2) of this subsection is used in 
place of the default method of paragraph (1). For these reasons, the commission 
has retained these requirements for residential soils as previously proposed. 
Clarifications were made to identify subsection (e) as being in this section, 
and to differentiate between the residential and non-residential soil-to-
groundwater cross-media protection concentrations. 
 Paragraphs (1) and (2) of this subsection provide options for determining the 
soil-to-groundwater cross-media protection concentration. The method provided in 
paragraph (1) received numerous comments that questioned whether the selection 
of 100 as the dilution attenuation factor was based on sound science. Commenters 
pointed out that it is a conservative estimate that fails to take into account 
site- and chemical-specific factors. The commission acknowledges the concerns of 
the commenters and recognizes that such an approach sacrifices case-by-case 
specificity for ease of implementation. Some commenters noted that the method of 
paragraph (1) seems to account for dilution and attenuation whereas the method 
stated in paragraph (2) does not. The default value of 100 times the groundwater 
concentration is not used here as a true dilution-attenuation factor, as it is 
merely a multiplier to generate a concentration of the contaminant in soil, not 
in a leachate. Consequently, the suggestion that applying a 100 times multiplier 
to the leachate concentration of paragraph (2) as equal treatment allowable 
under paragraph (1) is not valid. The commission points out that these rules 
provide persons with considerable flexibility in defining this cleanup level 
through use of the alternative method of paragraph (2) or other test method 
subject to prior approval. This flexible approach did receive some favorable 
comments. Therefore, the commission retains the method of paragraph (1) and is 
receptive to alternative testing protocols under the provisions of paragraph 
(2). 
 Note that under paragraph (1) of subsection (f) the Residential Soil-to-
Groundwater Cross-Media Protection Concentration is determined by multiplying 
the residential groundwater cleanup level determined by the procedures of 
paragraph (1) of subsection (d) by 100. These rules for residential soil do not 
allow the increase in groundwater cleanup levels due to high total dissolved 
solids content allowed in paragraph (3) of subsection (d) of this section to be 
taken into account when determining the Residential Soil-to-Groundwater Cross-
Media Protection Concentration. 
 Regarding sec.335.559(g), previously designated as subsection (f) of this 
section, commenters questioned the manner in which the commission applied the 
various criteria to non-residential surface and subsurface soils. One commenter 
felt that non-residential surface soils should not be subject to groundwater 
protection criteria. The commission has revised the non-residential soil-to-
groundwater cross-media protection concentration and adjustments such that this 
value will need to be considered along with the soil MSC in determining cleanup 
levels of surface soils. The same commenter was incorrect in stating that 
subsurface soils must be compared to the non-residential soil MSC. This is 
required of surface soils only. Even so, another commenter felt that the soil 
MSC should not even be applied to soils at two feet in depth, the defined limit 
of surface soils. In contrast, another commenter felt that there should not be 
any subdivision of the soil column, as workers could be exposed in excavations 
deeper than two feet. The commission has retained the language as previously 
proposed and notes that other federal programs address workplace safety and 
short-term exposure situations. However, the commission did revise the first 
sentence of this subsection to clarify a requirement that previously appeared to 
apply only to surface soils. It is the commission's intent that the requirements 
of subsection (e) of this section apply to both surface and subsurface soils. 
 Paragraph (2) received comments similar to paragraphs (1) and (2) of subsection 
(f) regarding use of the 100 times multiplier and leachate or other testing to 
develop the soil-to-groundwater cross-media protection concentration. The 
commission's response to comments on those subjects is the same and will not be 
repeated here. Additional comments on this subject include an observation that 
the default approach could result in values that are below background and that 
additional guidance is needed on the performance of the leach test with regard 
to number of samples, replicate analyses, etc. The commission points out that 
sec.335.555(d)(1) gives instructions on the comparison of cleanup levels and 
background levels to demonstrate attainment of Risk Reduction Standard Number 2, 
and sec.335.553(d) gives limited guidance on sampling requirements. Some 
conforming changes were made to address the revisions to subsection (d) of this 
section regarding groundwater cleanup levels. The language describing 
adjustments to account for differences in exposure rates between residential and 
non-residential settings was relocated and revised as a new paragraph (2) of 
subsection (d). In its place is a reference to subparagraphs (A) or (B) for 
defining the soil-to-groundwater cross-media protection concentrations. 
Subparagraph (A) is clarified by applying the 100 times multiplier to the non-
residential groundwater cleanup values of either paragraph (2) (based on 
industrial exposure rates, except MCLs) or paragraph (3) (the saline water 
adjustment for industrial MSCs and MCLs) of subsection (d) of this section. 
These changes therefore allow adjustments to soil concentrations for non-
residential locations underlain by saline groundwater. Subparagraph (B) remains 
unchanged from the text previously published. One commenter asked if other test 
methods, in regard to the standard leach test, allow for the measurement or 
calculation of such values as fractional organic carbon content of soil, 
octanol-water partition coefficients, fractional organic carbon content of soil 
and inorganic distribution coefficient values. Such an approach is not 
prohibited by this subparagraph but it must be submitted for review and approval 
prior to utilization under Risk Reduction Standard Number 2. 
 Regarding sec.335.559(h), one commenter, writing in general terms concerning 
the entire subchapter, requested that the commission establish a Total Petroleum 
Hydrocarbon (TPH) and Benzene, Toluene, Ethylbenzene and Xylene (BTEX) 
performance standard consistent with that of the commission's Petroleum Storage 
Tank program in those situations when the person can verify, through process 
knowledge, that the closure or remediation of concern is related solely to a 
release or spill of a petroleum substance. This comment has been described 
previously in this preamble under the discussion for the new sec.335. 553(f) 
(relating to Required Information). The only other comment on this subsection 
dealt with the concern that secondary MCLs, which are based on aesthetic 
considerations, would automatically be applied to remediations and thereby have 
a major impact on the cost and feasibility of corrective action programs. The 
commenter suggested that the commission retain the option to exercise discretion 
regarding the application of such additional criteria to individual sites. The 
commission agrees with this comment and revised the language to read "may be 
utilized" instead of "shall be utilized". Additionally, the commission added 
"environmental receptors" to be consistent with the requirements of 
sec.335.556(b) of this title (relating to Determination of Cleanup Levels for 
Risk Reduction Standard Number 2). 
 Section 335.560 establishes the deed recordation and post-closure care 
requirements which a person must perform in order to attain Risk Reduction 
Standard Number 2. 
 Respondents on sec.335.560 included: Department of Air Force (Kelly Air Force 
Base); Exxon Chemicals Americas; Exxon Company USA; FINA Oil and Chemical; 
Groundwater Services, Inc.; Shell Pipeline Company; Texas Chemical Council; and 
Texas Mid-Continent Oil and Gas Association. 
 Commenters questioned many aspects of this section. Will deed recordation have 
serious consequences on the marketability of the property? What is required in 
those instances when the responsible person is not the property owner? What is 
the commission's legislative authority to require such deed recordation, 
particularly with regard to spills and unauthorized discharges? If the 
commission's risk reduction standards are protective of human health, why does 
it want such deed recordation? Can any negative consequences be reduced by 
making changes to the proposed model language? Are there timing problems with 
the requirement to certify closures preceding the review and approval of the 
final report by the commission? Should the model language allow consolidation of 
multiple closures at a site into a single document? Can the deed recordation be 
removed if the contamination degrades over time to background levels? 
 In response to these comments, the commission has made numerous revisions to 
the requirements of this sections as well as to the model deed certification 
language of sec.335.569 of this title (relating to Appendix III). It is the 
commission's intent to have persons provide notice to future land owners so that 
they can have knowledge of the condition of the land. When so advised, they can 
obtain more information based on the instructions in the notice. This will be 
done in a manner similar to the current practice by the commission of requiring 
deed recordation for disposal sites (including storage and processing units and 
areas of unauthorized disposal closed as landfills) in accordance with sec.335.5 
of this title (relating to Deed Recordation of Waste Disposal). We have made 
specific changes in the wording of the document to be placed in the county deed 
records. After consideration of the comments, the commission has also revised 
some of the specific requirements of this section. Changes to the model deed 
certification language of Appendix III will be discussed later. 
 Regarding sec.335.560(b), previously designated as subsection (c) of this 
section, commenters noted that the timing of the deed certification requirements 
and the final report requirements of sec.335.555 of this title (relating to 
Attainment of Risk Reduction Standard Number 2) could cause the certifying 
person to attest to actions and make conclusions without certainty that closures 
or remediations were carried out in accordance with commission regulations. 
Under the proposed rules, it would appear that in many cases, commission 
approval of the final report would still be pending when the deed certification 
was required to be filed in the county records. This sequence of actions would 
be burdensome on both the commission and the facilities. The facilities would be 
at risk of having to perform a second filing if the final report was not 
approved and additional closure or remediation had to be performed. This type of 
situation is of concern to the commission; consequently, the sequence of 
required actions has been revised. Former subsection (c) has been redesignated 
as subsection (b) and the language was modified to reflect that the proof of 
deed certification is required 90 days after acceptance of the final report by 
the executive director. In this manner, if additional actions are required of 
the person, they will be completed before the deed certification is filed and a 
second filing should be avoided. 
 Paragraph (1) of subsection (b) of this section was revised in response to 
comments that the commission appears to have gone beyond what is necessary to 
inform any future buyer of the presence of the past cleanup activities. Rather 
than stating that the closure or remediation was carried out in accordance with 
applicable regulations and appropriate guidance and resulted in a remedy, the 
language now states that the plan designed to meet Risk Reduction Standard 
Number 2 was carried out. Paragraph (3) of subsection (b) of this section was 
also revised to provide new language stating that current and future owners must 
undertake actions as necessary to protect human health and the environment in 
accordance with the rules of the commission. References to specific reporting 
actions in response to a change in land use from non-residential to residential 
have been deleted from this paragraph, the model deed certification language and 
sec.335.557 of this title (relating to Criteria for Selection of Non-Residential 
Soil Requirements for Risk Reduction Standard Number 2), and the parallel 
requirement for deed certification in sec.335.566(c) of this title (relating to 
Deed Recordation for Risk Reduction Standard Number 3). 
 Regarding sec.335.560(c), former subsection (b) has been redesignated as 
subsection (c), and additional language is added to clarify the sequence of 
requirements which were partly addressed in the discussion of changes to 
subsection (b) of this section. As newly stated, the person is released from 
post-closure care responsibilities "upon acceptance by the executive director of 
the proof of deed certification required by subsection (b) of this section. " 
 Several other commenters expressed concerns about applying these deed 
certification requirements to spills. This action was viewed as burdensome when 
responding to small, numerous, and frequent spills, as in a manufacturing area. 
One commenter questioned the commission's legal authority to require deed 
certifications of spill cleanups, particularly if the person certifying does not 
own the land in question. Another commenter asked how the federal government can 
apply the recordation of property under deed restrictions for land on federal 
property. Multiple spills could be handled in a single certification in the same 
manner as multiple units or areas can be combined for purposes or reporting to 
the commission in response to sec.335.8(c)(4) of this title (relating to Closure 
and Remediation). 
 The commission believes that many of the commenters' concerns regarding small 
and multiple spills will be addressed in the forthcoming rulemaking for the 
Spill Response program. However, once a spill becomes subject to these risk 
reduction rules, the requirements for deed certification are applicable to the 
person if he conducts the activity under Risk Reduction Standards Numbers 2 or 
3. Please note that the commission is not forcing the person to deed-certify the 
property since the person always has the option to close/remediate in accordance 
with Risk Reduction Standard Number 1, which does not require deed 
certification. For dealing with the issue of imposing a deed certification on 
the property owned by another person, the commission suggests that the 
responsible person close/remediate in accordance with Risk Reduction Standard 
Number 1, thereby eliminating the need to deed certify. Concerns that imposing a 
deed certification on the person's land or land owned by another will devalue 
the property is also of concern to the commission. It is for this reason that 
the commission proposed this model language to begin with. When one considers 
the historical practice and historical model language that merely describes the 
property as having been used for disposal of waste, one should conclude that the 
proposed deed certification language is an improvement. The new language 
reflects that the property has been cleaned up to some acceptable level. This 
notice should not devalue a property in the same way the historical language 
would by referencing use of the property for waste disposal. 
 With regard to the comment that the proposed language appears to go so far as 
to constitute an affirmative warranty about the condition of the property and 
the suitability of the property for certain purposes, the commission has revised 
the model language of Appendix III to include a statement that the deed 
certification is not a representation or warranty by the commission of the 
suitability of the land for any purpose, nor does it constitute a guarantee that 
the remediation standards have been met. The statements about future land use 
have been retained but modified so as not to be an affirmative warranty by 
adding the qualifying word "considered". Other changes not previously discussed 
here were made to conform to the suggested language provided by one of the 
commenters. 
 Sections 335.561-335.566 describe the criteria which must be attained and the 
conditions which must be satisfied in order to achieve compliance with Risk 
Reduction Standard Number 3. 
 Section 335.561 describes the remedy selection criteria which will be used to 
determine what actions a person must take in order to achieve compliance with 
Risk Reduction Standard Number 3. 
 Respondents on sec.335.561 included: Cooper Industries; Department of the Air 
Force (Kelly Air Force Base); Exxon Chemical Americas; and TransAmerican Waste 
Industries, Inc. 
 One commenter stated strong support for the flexibility provided in the 
proposed rule and recommended that this flexibility should be preserved to allow 
consideration of site-specific exposure and algorithms and data evaluation 
procedures that differ from Risk Reduction Standard Number 2 if they can 
demonstrate more satisfactory methods. Another commenter requested that 
probabilistic techniques be specified for use, such as Monte Carlo simulation 
for ranges of exposure values. This section has not been modified from the 
proposed rule. The degree of flexibility under this standard regarding site-
specific exposure parameters and exposure algorithms has been discussed in the 
previous section regarding sec.335.553 (relating to Required Information). The 
discussion for sec.335.553 also explains the commission's rationale for not 
incorporating Monte Carlo and other quantitative probabilistic risk assessment 
methods into the decision-making process for Risk Reduction Standard Number 3. 
Revisions to the data evaluation procedures, as has been discussed previously in 
sec.335.553 of this title (relating to Required Information), allow persons to 
propose alternative statistical procedures for any of the risk reduction 
standards. 
 Regarding sec.335.561(a), another commenter expressed concern over the broad 
discretion of the commission's staff in deciding whether to approve or 
disapprove a proposed remedy and offered suggestions concerning due-process 
rights to appeal such decisions to higher authority. Another commenter felt the 
phrase "in the evaluation of the executive director" was too elusive and may 
create unnecessary delays or misunderstandings. In response to these concerns, 
the commission points out that due process rights of appeal already exist in the 
various regulatory programs which would apply these rules. This has been 
discussed previously in this preamble. As for the mechanisms by which the staff 
of the commission communicates its evaluations, this is similarly handled by 
existing procedures in the various regulatory programs. It is the commission's 
intent and normal practice that such decisions be communicated in writing. The 
commission has added statements to clarify the sequence of events necessary to 
demonstrate attainment of this standard in addition to what had been previously 
proposed, to include submittal of a final report, initiation of any post-closure 
care, and lastly, completion of deed recordation requirements. This listing of 
requirements makes this section conform more closely with the approach taken in 
sec.335.555 of this title (relating to Attainment of Risk Reduction Standard 
Number 2). 
 Regarding sec.335.561(b), a commenter suggested that the last word of this 
sentence, "possible", be replaced with the phrase "that is feasible at a site", 
noting that the phrase was used in the preamble, that the term "feasible" takes 
more factors into account than the word "possible", and that use of the phrase 
coincides with the analysis in subsection (c) of this section regarding cost-
effectiveness. The commission has retained the language as it was previously 
proposed. This subsection requires the highest degree of long-term effectiveness 
possible, if a permanent remedy is not practicable. We disagree that use of the 
word "possible" in this context will preclude other site-specific 
considerations, because the remedy evaluation process must be viewed in its 
entirety, not just its component requirements. In this regard, readers should 
note that subsection (a) of this section indicates that compliance with this 
standard is attained when ". . . the person recommends the remedy which best 
achieves the requirements of subsection (b)-(d) of this section . . ." Thus, the 
remedies are to be compared to each other to determine which one "best achieves" 
all of the requirements. More specifically, a remedy or remedies considered to 
achieve the highest degree of long-term effectiveness possible for a given 
closure or remediation could be modified or eliminated from further 
consideration when the test of cost-effectiveness of subsection (c) is applied. 
We believe the same end result will be reached that the commenter described, but 
in going through the remedy evaluation process, we do not want persons to 
eliminate potential remedies without first giving due consideration to all of 
the criteria. 
 Regarding sec.335.561(c), several commenters discussed and emphasized the role 
that cost considerations should play in the remedy evaluation process. Another 
commenter questioned why the "regulatory community" would be interested in cost 
considerations and what importance it would place on the cost of a remedial 
effort. The commission has identified the role of cost-effectiveness to be an 
important one in the remedy selection process. The commission believes that the 
language in the rule as explained in the preamble for the proposed rule 
describes the proper relationship between long-term effectiveness and cost-
effectiveness. The language from the preamble is repeated in the following two 
paragraphs and it has been modified to reflect that this is a final rather than 
a proposed rule. 
 The second requirement for a Standard 3 remedy is that it must be cost-
effective. The text of the rule describes a cost-effective remedy as one that 
achieves the best balance between long-term effectiveness and cost for 
alternative remedies which meet the cleanup objectives for a facility. Unless 
the executive director requests additional information, the person would only 
describe in the corrective measure study that remedy which he believes best 
meets the remedy selection criteria. The rule requires the person's selection to 
be based upon an evaluation of the relative abilities and effectiveness of 
potential remedies to achieve the remedy requirements. The consideration of a 
range of alternatives would not need to be included in the corrective measure 
study unless requested by the executive director. The commission does not expect 
to request such information in those instances where the person proposes a high 
quality remedy with a high degree of long-term effectiveness. 
 Section 335.553 states that the executive director may upon review of the 
corrective measure study require the person to further evaluate the proposed 
remedy or to evaluate one or more additional remedies. When necessary, the 
commission may require a more extensive cost-effectiveness evaluation as part of 
this additional information. This evaluation would consist of a range of 
alternatives which vary in degree of long-term effectiveness but which will all 
achieve the site remediation objectives. The alternative which achieves the site 
remediation objectives at the lowest cost would be identified and represents the 
bottom value for the cost-effectiveness evaluation. The cost of the permanent 
remedy would also be determined and would represent the ceiling for the cost-
effectiveness evaluation. The total cost for the other alternatives would be 
determined and all alternatives would be ranked according to the degree of long-
term effectiveness they provide. The remedy that provides the best balance 
between long-term effectiveness and cost would be the most cost-effective. 
 On a closely related subject, a respondent stated in regard to sec.335.562(g) 
(relating to Costs), which describes the types of cost that will be considered 
when evaluating remedies, that the commission should add as an evaluation factor 
the financial condition of the person responsible for conducting the closure or 
remediation and his ability to absorb the expense for the action. The commission 
has not modified this rule in response to the commenters suggestion. The 
commission believes that the procedure previously described establishes the 
proper fashion in which cost-effectiveness and long-term effectiveness should be 
considered. The commission believes that the appropriate way to implement this 
regulation is to determine what actions are necessary to protect human health 
and the environment and that neither more stringent nor less protective measures 
should be applied based upon a person's ability or inability to fund the action. 
 Another commenter suggested that costs associated with the "no action" 
alternative be added as there may be cases where this is the best option for a 
site. Yet another commenter thought that the "no action" alternative had not 
been considered as part of these rules. The "no action" alternative is addressed 
in  sec.335.553(b) of this title (relating to Required Information). Under this 
section (sec.335.561), the "no action" alternative would be evaluated as any 
other type of remedy being considered for inclusion in the corrective measures 
study; therefore, it has not been identified separately in this section. 
 No specific comments were offered regarding sec.335.561(d), although some 
suggestions were made to restructure Risk Reduction Standard Number 3 along 
lines of media cleanup requirements and the post-closure care requirements. The 
"no action" alternative would fit into the category of remediation that does not 
require post-closure care, under the rules being finalized today and according 
to the commenter's recommendation. At this time, however, the commission is not 
considering any further subdivisions of these risk reduction standards but will 
be receptive to suggestions if actual experience during implementation suggests 
that these finalized standards need revision. For this reason, the commission is 
not making any additional changes to the text previously published. 
 Section 335.562 describes the factors which persons must consider when 
evaluating the relative abilities and effectiveness of potential remedies to 
achieve the requirements for remedies under Risk Reduction Standard Number 3, 
which are described in sec.335.561. 
 Respondents on sec.335.562 included: EXIDE Company; Exxon Chemical Americas; 
Geraghty & Miller, Inc.; Texas Mid-Continent Oil and Gas Association; and 
TransAmerican Waste Industries. 
 Regarding sec.335.562(a), one commenter supported the remedy evaluation process 
for its streamlined approach in that costly and burdensome feasibility studies 
are not required. Another commenter suggested that the concept of "remedy" 
include an allowance for several different treatment, control, or natural 
remediation processes to be incorporated into a "remedy" to achieve desired 
cleanup goals. The commission agrees with this interpretation in that any 
combination of removal, decontamination, or control measures can be considered 
by these criteria. It is the best combination of measures satisfying these 
criteria that is proposed as the remedy to attain the requirements of Risk 
Reduction Standard Number 3. 
 Regarding sec.335.562(e), one commenter supported the commission's requirement 
to consider the short-term effects of remedies, particularly in instances where 
implementing a remedy poses more problems for acute exposure to workers or local 
population than it solves for chronic exposure. 
 Regarding sec.335.562(g), a commenter noted in a general way, in addition to 
the previous discussion about costs, that the commission should give equal 
consideration to cost of cleanup as it does to the level of protection being 
provided. The commenter also implied that the State will have to perform some 
cleanups in cases where excessive remediation costs will cause companies to fail 
and that other forced, unnecessary cleanups will result in negative economic 
impacts. The commission disagrees with this comment. We believe these rules 
provide an appropriate balance between the need to provide long-term protection 
for human health and the environment and the need for remedies to be cost-
effective. Also, as noted elsewhere, these rules do not "force" the cleanup, 
rather, they provide the means to define the closure or remediation performance 
standards once a statute or another rule, order, or permit of the commission 
requires the action. 
 No specific comments were provided for subsections (b), (c), (d), and (f) of 
this section; therefore, the commission has not changed the language proposed 
previously. 
 Section 335.563 describes the procedures that persons shall use in preparing 
and proposing media cleanup values to satisfy Risk Reduction Standard Number 3. 
 Commenters on sec.335.563 included: American Industrial Health Council; Cooper 
Industries; Department of the Air Force (Kelly Air Force Base); Exxon Chemical 
Americas; Geraghty & Miller, Inc.; IT Corporation; Shell Oil Company; Texas 
Chemical Council; Texas Mid-Continent Oil and Gas Association; Thompson & 
Knight; and TransAmerican Waste Industries, Inc. 
 Regarding sec.335.563(b), one commenter noted approval for the risk range 
specified for carcinogens but expressed concern that the use of 10E-6 (0. 
000001) target risk as a goal will, in practice, create a strict 10E-6 level of 
risk for Risk Reduction Standard Number 3. Other comments provided on the 10E-6 
"brightline" approach of Risk Reduction Standard Number 2 could be directed at 
this provision as well; however, in the larger context of setting cleanup levels 
under Risk Reduction Standard Number 3 procedures, one should see that the 
development of a "brightline" approach in Risk Reduction Standard Number 3 is 
not our intent. For clarification of this issue, the commission is republishing 
the portion of the proposed rule preamble pertinent to this section. In essence, 
one starts with the goal of 10E-6 for an individual carcinogen but then modifies 
this "preliminary remediation goal" according to the criteria of subsection (d) 
of this section. The final cleanup levels should present a cumulative excess 
risk no greater than 10E-4. 
 Regarding sec.335.563(c), several commenters questioned the approach specified 
in paragraph (2) of this subsection for the hazard index when dealing with 
multiple systemic toxicants. One commenter expressed the view that the EPA 
recommends a hazard index of one for scoping purposes in the development of 
preliminary remediation goals but that in the final analysis a hazard index 
greater than one is not a cause for concern, only that additional investigation 
and evaluation are warranted. Another commenter suggested that the approach as 
specified here does not clarify that hazard indices can be calculated that 
cumulatively equal one for only those substances with the same toxic endpoint. 
Further, the commenter suggested allowing a range of one to ten for the hazard 
index. Several commenters noted that a limitation with the hazard index is that 
the summation of a sufficient number of insignificant hazards (i.e., hazard 
quotient less than 1) can lead to the conclusion that an unacceptable hazard 
exists at the site. For example, ten hazard quotients of 0. 1 each would sum to 
a hazard index of 1. They concluded that this is a conclusion based on 
mathematics and not necessarily on science. The commission disagrees with these 
comments and notes that paragraph (2) clearly indicates that the hazard index 
will be determined by summing the hazard quotients which affect the same target 
organ or act by the same method of toxicity. We feel that this method, when 
combined with the flexibility offered by subsections (d) and (e) of this 
section, is necessary to assure adequate protection of human health. As the 
commission staff gains experience in application of this provision, we will any 
consider revisions to the requirements of this subsection which prove to be 
warranted. 
 Regarding sec.335.563(e), commenters questioned the necessity of starting with 
residential exposure assumptions and then having to demonstrate that other site-
specific conditions support a departure from the default exposure values of 
Table 1. This question and the commission's response in this matter has been 
discussed in the previous section of this preamble for sec.335.553(b) (relating 
to Required Information). As this subsection specifies a requirement and then 
offers an alternative which allows flexibility to address other site-specific 
circumstances, the commission has not changed the language that was previously 
proposed. 
 Regarding sec.335.563(f), the commission made changes to address the comments 
of respondents. Changes similar to those made to sec.335.559(c) of this title 
(relating to Air) for Risk Reduction Standard Number 2 were made here in 
response to the same comment to clarify references to federal and state 
requirements which appeared to be confusing and incomplete as originally stated. 
Other commenters suggested that values protective of worker safety, such as 
threshold limit values or OSHA permissible exposure limits or other criteria 
applicable to an industry setting, should be applicable within the property 
boundary of an industrial facility and that criteria that satisfy subsections 
(b)-(e) of this section for contaminants in air should apply at the property 
boundary. The commission revised this subsection as recommended. New paragraphs 
(2) and (3) were added to distinguish the requirements for residential and non-
residential settings, respectively. Another commenter sought clarification of 
the meaning of "site boundary", as to whether it is limited to the solid waste 
management unit disposal boundary or to the lateral extent of soil 
contaminations. The commission believes the proposed language was clear in 
specifying the property boundary. 
 Regarding sec.335.563(g), the commission has clarified the use of Maximum 
Contaminant Levels (MCLs) in the same manner and in response to the same comment 
for sec.335.559(b) of this title (relating to Surface Water), by substituting 
the word "appropriate" for "applicable". 
 Regarding sec.335.563(h), one commenter noted that this subsection provides 
multiple ways to determine alternatives to MCLs as cleanup values for 
groundwater, but that a key factor missing here is that fate and transport 
models must be allowed to be used to characterize concentration profiles in the 
groundwater. Such models are recognized for the determination of soil 
concentration values in subsection (i)(2)(A) of this section but it is not 
specifically stated that they can be used for groundwater. The commission did 
not intend to imply that the use of fate and transport models is specifically 
limited to determining soil cleanup levels. The use of such models is recognized 
implicitly by referencing the informational requirements of sec.335. 160(b) of 
this title (relating to Alternative Concentration Limits). Additionally, the 
specific reference to fate and transport models in subsection (i) of this 
section applies to groundwater cleanup levels, as well as to surface water and 
air cleanup levels, in that contaminants remaining in soils must not cause the 
cleanup levels for these other media to be exceeded. The commission expressly 
states that "such determinations shall be based on sound scientific principles 
including fate and transport evaluations of contaminant migration." in clause 
(2)(A) of that subsection. 
 Several commenters sought clarification of the term "usable quantities" 
relating to the definition of a current or potential source of drinking water as 
specified in paragraph (1) of this subsection. One commenter offered a pumping 
rate of 3 gallons per minute as a cutoff. Others suggested that low producing 
zones and tight clay soils be added as specific examples of where these 
standards are not applicable. Another commenter sought consideration of the 
heterogeneity of an alluvial aquifer system. The commission recognizes the need 
for quantification of this definition. As such a definition can influence other 
regulatory programs and even the activities of other agencies, the commission 
cannot unilaterally act to address this concern as part of this rule 
promulgation but will commit to work with representatives of other programs and 
agencies on this matter. In the interim, one source of guidance is the EPA 
document Guidelines for Groundwater Classification under the EPA Groundwater 
Protection Strategy, Final Draft, December 1986. 
 Another commenter supported the commission's approach in paragraph (2)(c) of 
this subsection which allows for consideration of natural dilution and 
attenuation of a plume consistent with the approach for alternate concentration 
limits, provided that institutional and legal controls will effectively prevent 
the use of contaminated groundwater. 
 Another commenter, in the commission's opinion, misunderstood the intent of 
paragraph (3)(A) of this subsection, so the commission revised the language for 
clarification. This paragraph is not meant to define cleanup levels for 
groundwater that is not a current or potential source of drinking water; rather, 
it is intended to describe a condition that, if met, can result in a decision 
that lesser amounts of remediation need be performed than specified elsewhere in 
this subsection. The commission believes persons could confuse the paragraph 
with the requirements for alternate concentration limits as described in 
paragraph (2) of this subsection. To eliminate this confusion, this paragraph 
has been revised to clarify the three conditions that must be met. Essentially, 
the person must demonstrate that the contaminated groundwater is isolated from 
surface water or other groundwater that is a current or potential source of 
drinking water. The language regarding concentrations of contaminants impacting 
the other water resources has been deleted. If such groundwater did have the 
potential to impact surface water or other usable groundwater, the person cannot 
successfully make this demonstration and must then consider the cleanup levels 
specified in this subsection, such as the alternate concentration limits of 
paragraph (2). Other commenters requested guidance on determining the technical 
impracticability of restoring groundwater to cleanup levels of this subsection 
and suggested, as for the pumping rate issue, that "low producing zones and 
tight clay soils" be specific examples of where these standards are not 
applicable. Additionally, they suggested that the removal of a very viscous 
immobile material be another example. Yet another commenter differed with this 
approach, favoring instead to show that allowing substances to remain in place 
without threat to human health or the environment should be acceptable. The 
commission intends to rely upon guidance from a variety of sources to address 
the range of possible situations covered by this paragraph, but a suitable 
document to serve as a starting point would be EPA's Alternate Concentration 
Limit Guidance for Hazardous Waste Management Facilities Part I; ACL Policy and 
Information Requirements (Directive 9481.00-6C, December 13, 1987). 
 One commenter suggested that a distinction be made in paragraph (4) of this 
subsection regarding "phase-separated non-aqueous liquids" as to residual 
(trapped and non-mobile) hydrocarbons and mobile liquid hydrocarbons which can 
be removed from an aquifer. The commission believes that this concern is 
addressed implicitly in the existing requirement to remove such liquids "to the 
extent practicable", which recognizes the limitations of remedial technologies, 
aquifer conditions, and characteristics of liquids. 
 Regarding sec.335.563(i), a commenter pointed out that fate and transport 
evaluation is an area in which there is a high level of uncertainty and that 
essentially no guidance is given with regard to the use and acceptability of 
fate and transport models. Another commenter sought clarification that certain 
parameters commonly used to describe soils in terms of fate and transport of 
contaminants would be included in consideration as "sound scientific 
principles". The commission recognizes that fate and transport modeling is an 
integral step in determining cleanup levels and it is also one of rapid 
development. The commission will consider the general guidelines set out by EPA 
in the ACL guidance document referenced in the preceding subsection for 
evaluating the suitability of various fate and transport models. Several 
Commenters were supportive of the commission's approach to allow site-specific 
consideration of other exposure pathways regarding soils, as specified in 
subparagraph (B) of paragraph (2) of this subsection. 
 Regarding sec.335.563(j), commenters were supportive of the site-specific or 
flexible approaches allowed in paragraphs (1) and (2), however, one commenter 
stated that paragraph (3) should be deleted because of the uncertainty 
surrounding this provision and the commenter's perceived lack of available 
guidance. The commission disagrees with this commenter and points out that the 
proposed rule preamble cited two EPA documents (Environmental Evaluation Manual 
(EPA/540/1-89/001) and Ecological Assessments of Hazardous Waste Sites: A Field 
and Laboratory Reference Document (EPA/600/3-89/013)) considered to be 
appropriate guidance for ecological risk assessment at its current stage of 
development. It is widely recognized that the state of the art of ecological 
assessments lags behind human health assessment methodologies. The commission 
therefore can not specify in the same detailed way as was done for human health 
criteria the exact manner in which such an evaluation of environmental receptors 
will be performed, but the cited guidance will serve For these reasons the 
commission will retain this provision in the final rule. 
 A second commenter questioned what other more stringent regulations could the 
commission apply (e.g., "Clean Water and Air Act"). The commission points out 
that the specific language of this paragraph states "more stringent cleanup 
levels may be established..." The commission intends this paragraph to be a 
basis for adjusting the site-specific cleanup levels developed according to the 
procedures specified in subsection (a)-(i) of this section. Regulations, and 
standards, would be evaluated according to the remedy evaluation factors of 
sec.335.562(b) of this title (relating to Compliance With Other Laws and 
Regulations). 
 Section 335.564 describes the conditions under Risk Reduction Standard Number 3 
when post-closure care is not required. 
 Commenters included Baker & Botts/Beazer. The commenter suggested that deed 
recordation and post-closure care should only be required if the cleanup 
involves engineering or institutional controls. For example, a facility that 
cleans up with site-specific levels without use of control measures should only 
have to do the limited deed certification as required by Risk Reduction Standard 
Number 2 and should have no continuing requirement for deed recordation or post-
closure care. The commission points out that changes made to the model deed 
certification language of sec.335.569 of this title (relating to Appendix III) 
in response to other comments should result in a document that serves the same 
purpose. For this reason, there were no changes made to the section proposed 
previously. An extensive discussion of the conditions under which a person may 
pursue not performing post-closure care for a Risk Reduction Standard Number 3 
remedy is provided in a previous section of this preamble pertaining to 
sec.335.553(b)(3) (relating to Required Information). 
 Section 335.565 describes the conditions under Risk Reduction Standard Number 3 
when post closure care is required. 
 Commenters included Exxon Chemical Americas. The commenter suggested changing 
the opening phrase of paragraph (2) from "hazardous waste management facilities" 
to "hazardous waste storage, processing, or disposal facilities". The change was 
made as suggested. 
 Section 335.566 explains the deed recordation requirements that are applicable 
under Risk Reduction Standard Number 3. 
 Commenters on sec.335.566 included: Department of the Air Force (Kelly Air 
Force Base); Exxon Chemical Americas; Exxon Company; FINA Oil and Chemical 
Company; Groundwater Services, Inc.; Shell Pipe Line Company; Texas Chemical 
Council; and Texas Mid-Continent Oil and Gas Association. 
 Many of the same comments that were directed to sec.335.560 of this title 
(relating to Post-Closure Care and Deed Certification for Risk Reduction 
Standard Number 2) were made regarding this section as well. The commission's 
response to those comments is equally applicable here, with changes having been 
made to subsections (a), (b) and (c) of this section to address those comments. 
Additionally, the commission has revised subsection (a) so that the sequence of 
required actions now calls for the proof of deed recordation to be submitted 
within 90 days after the executive director accepts the final report. This 
change conforms to changes in the parallel requirements of Risk Reduction 
Standard Number 2. 
 Section 335.567 explains the manner in which the reduced equations for MSCs 
under Risk Reduction Standard Number 2 were derived. 
 Respondents on sec.335.567 included: Department of the Air Force (Kelly Air 
Force Base); ENSR Consulting & Engineering; Exxon Chemical Americas; Geraghty & 
Miller, Inc.; Shell Oil Company; and Texas Mid-Continent Oil and Gas 
Association. 
 Overall, commenters felt that the default values are too conservative and that 
the commission should allow for use of alternative, more realistic values. As 
stated previously, the commission is not prepared at this time to offer 
additional flexibility for the types of information necessary to develop cleanup 
levels under Risk Reduction Standard Number 2 in a self-implemented fashion. As 
the staff of the commission gains experience with these Risk Reduction 
Standards, the staff will review the general procedures for establishing numeric 
cleanup levels and incorporate additional procedures into these regulations as 
necessary. The commission's commitment to do this is specified in sec.335.551(b) 
of this title (relating to Purpose, Scope and Applicability). 
 Regarding Equation 1 (MSC for Ingestion of Water; Carcinogenic Effects), 
several commenters noted that the parameter A (Absorption factor) was included 
in the denominator of the equation, but that the default value was set at one, 
meaning 100% of the substance is absorbed by the body. Some commenters suggested 
that where the absorption potential of a substance is known, this information 
should be utilized, otherwise the effect of the default value is to add to the 
compounding effect of conservative assumptions. These comments apply to Equation 
3 as well. 
 Regarding Equation 2 (MSC for Ingestion of Soils and Inhalation of Volatiles 
and Particulates; Residential Scenario; Carcinogenic Effects), one commenter 
pointed out that the parameter BW (Body Weight) in units of kilograms in the 
denominator should be changed to ED (Exposure Duration). The commenter is in 
error. The parameter IF soil/adj includes units milligram-year/kilogram-day. The 
kilogram units cancel out (as do another pair of kilogram units elsewhere in the 
equation) to produce the proper units of measurement for the equation. Other 
commenters challenge the applicability of the Volatilization Factor (VF) and the 
Particulate Emission Factor (PEF) to a residential setting where air inhalation 
is assumed to be indoors but all other assumptions are for outdoor exposure. 
Also, the site-specific parameters of these two factors are not subject to 
adjustment to fit the specifics of a given situation. These same concerns can be 
repeated for Equations 4, 5, and 6. 
 Regarding the Volatilization Factor equation, other commenters requested use of 
site-specific information. Another commenter questioned the commission's values 
for the parameter T (Exposure Interval), calculated to be 7.9e+08 seconds for 
industrial settings and 9.5e+08 seconds for residential exposure. The commission 
believes these values to be correct because the underlying assumption is that 
the waste unit or area will be subject to blowing wind for 24 hours per day for 
25 and 30 years, respectively. The commenter had suggested that the exposure 
factors for human air intake be used in calculating VF. This is not correct-
human exposure is not considered in calculating VF, rather, it is considered by 
the factors of IR air (Inhalation Rate (daily, indoor)) for residential or 
worker exposure. In other words, a resident would inhale 15 cubic meters per day 
of air that has been receiving vapors at a rate of 24 hours per day for 30 
years. Likewise, a worker inhales 20 cubic meters per 8 hour work day of air 
that has been receiving vapors at a rate of 24 hours per day for 25 years. 
 Regarding the Table of Parameters, Definitions, and Values, several commenters 
suggested using sub-chronic reference doses where shorter term exposure is 
likely. This would not be an appropriate procedure to calculate MSCs but could 
be performed if other exposure pathways are of concern at the site pursuant to 
sec.335.556(b) of this title (relating to Determination of Cleanup Levels for 
Risk Reduction Standard Number 2). For clarification purposes, the commission 
has added values to reflect the industrial worker exposure rates for ATs 
(Averaging Time for Systemic Toxicants), EF (Exposure Frequency), ED (Exposure 
Duration), IRW (Daily Water Ingestion Rate), and IR air (Daily Indoor Inhalation 
Rate). Other commenters offered examples of default values for several 
parameters. The commission recognizes that their values are based on valid 
demographic studies, but for reasons discussed previously, is not going to 
change the default values at this time. 
 Examples of Medium-Specific Concentrations, Standards, and Criteria for Health-
Based Closure/Remediation. Section 335.568 presents a table of examples of MSCs 
that have been calculated using the reduced equations for Risk Reduction 
Standard Number 2, as well as a number of other standards and criteria. 
 Respondents on sec.335.568 included: Chemical Manufacturers Association; Cohn, 
Simpson, Cowlishaw, Aranza, & Wolfe; Department of the Air Force (Brooks Air 
Force Base); ENSR Consulting & Engineering; EXIDE Company; Groundwater Services, 
Inc.; Harcros Chemical Group; KWBES (K.W. Brown Environmental Services); 
Merichem Company; Shell Oil Company; Texas A&M University; Texas Mid-Continent 
Oil and Gas Association; and Union Carbide Chemicals and Plastics Company. 
 Commenters generally offered information on specific chemicals or chemical 
groups. The commission will consider this information in regard to the toxicity 
information preferences specified in sec.335.553(e) of this title (relating to 
Required Information) in determining which Appendix II values to revise. As 
sec.335.553(e) states, persons may utilize data from these sources (referring to 
paragraphs (1)-(5) of that subsection) that are more current than those used to 
derive the unadjusted MSCs of Appendix II. The commission emphasizes that the 
values listed in Appendix II are examples of  32>unadjusted MSCs and should not 
be viewed as final cleanup values. Only after all of the appropriate 
considerations and adjustments, if any, have been performed as specified in 
Subchapter S does one arrive at a final cleanup value. Although the commission 
has committed to performing annual revisions of Appendix II to incorporate 
current toxicity information (as it becomes known to the commission), persons 
should perform their own calculations using the equations and factors specified 
for Risk Reduction Standard Number 2 to ensure that their cleanup values reflect 
the most current data available. Discrepancies between their values and Appendix 
II values should be brought to the attention of the commission. 
 One commenter provided toxicity data for ten compounds and pointed out that 
this information was being considered by EPA for use in updating the IRIS data 
base. Another commenter referenced recent studies concerning the pesticides 
aldrin, dieldrin, and DDT as examples which show that a weight-of-evidence 
approach does not support their classification as human carcinogens. This 
commenter further stated that current guidance at the federal level supports the 
incorporation of supplemental information regarding the likely non-
carcinogenicity of chemicals into the risk assessment process. As stated earlier 
in this preamble, the commission will consider such information to the extent 
that our limited resources allow but that we must rely primarily upon the 
expertice and judgement of other organizations, principally the EPA, in making 
determinations of this type. 
 In considering other comments on this section, however, the commission was able 
to revise some MSCs which had contained errors in calculation or in use of 
appropriate toxicity information. The SAI-Industrial MSC for bis (2-chloro-
ethyl) ether was changed from 5.39e-01 to 3.77e-01 mg/kg as a correction. Para-
cresol was revised to reflect use of the same reference dose of 0.05 mg/kg/day 
as for ortho- and meta-cresol. The reference dose of 0.005 mg/kg/day for para-
cresol had been withdrawn from IRIS but because the three isomers are so similar 
in chemical and physical properties, the commission agreed with the comment that 
their MSCs should be equal. The compound naphthalene was added to the appendix 
because the commenters provided sufficient information to verify that the 
proposed toxicity data (0.04 mg/kg/day oral RfD) complied with sec.335.553(e). 
Another commenter pointed out that the compound pyrene had undergone a weight-
of-evidence classification change from Class C to Class D. After verifying this 
information with the current IRIS data base, the commission revised the MSCs 
utilizing an oral RfD value of 0.03 mg/kg/day. Lastly in this category of 
changes, the commission corrected the SAI-Residential MSC for the compound 
xylene, which had been proposed as 6.00e+3 mg/kg but is being finalized as 
5.47e+3 mg/kg based on the oral RfD of 2 mg/kg/day and inhalation RfD of 0.2 
mg/kg/day. 
 Other changes to the appendix include a substitution of promulgated soil 
cleanup levels in place of MSCs for polychlorinated byphenyls (PCBs). These 
values of 10 and 25 mg/kg for residential and industrial soils, respectively, 
had been referenced by the footnote but are now stated here for clarity. 
Footnotes 2, 3, 4, 6, and 13 were revised to conform to the various changes in 
the rules that are cited therein. In response to the change in Footnote 3, the 
explanation of the column heading for "GW" was revised to clarify that the 
groundwater MSCs of this column are for the residential exposure conditions. 
Lastly, six compounds now show the symbol "NHHB (16)" in place of the SAI-
Industrial MSC: diethyl phthalate, ethylene glycol, nitrate, phenol, phthalic 
anhydride, and vinyl acetate. As explained in the new footnote 16, this symbol 
means "Not Human Health Based. The SAI-Industrial MSC for this compound exceeds 
10e+6 ppm, which means it is not toxic to humans when exposed to soils under 
these assumptions. Persons must consider other criteria of 31 TAC sec.335.559 to 
develop numeric cleanup values." 
 Model Deed Certification Language. Section 335.569 presents an example format 
for the deed certification required for conformance with Risk Reduction Standard 
Numbers 2 and 3. 
 Respondents on sec.335.569 included: Texas Chemical Council and Texas Mid-
Continent Oil and Gas Association. 
 Numerous issues and comments regarding deed certification have been identified 
and discussed previously in sec.335.560 of this title (relating to Post Closure 
Care and Deed Certification for Risk Reduction Standard Number 2), including 
some changes to the model deed certification language. Items being discussed 
here address the balance of comments and changes. One commenter suggested that 
the commission should replace the statements about complying with regulations 
with "the site has been cleaned up to the Texas Water Commission's approved 
standards for protection of human health." The commission is not clear what 
specific language should be replaced so this suggested change was not made. 
Another commenter provided very specific recommendations for alternate language; 
most of these recommendations have been made. The only exceptions are that the 
commission has retained and modified the statement: "future land use is 
considered suitable for (residential, non-residential (i.e., 
industrial/commercial)) purposes in accordance with Risk Reduction Standards 
applicable at the time of this filing. Future land use is intended to be 
(residential, non-residential)." The commission believes that these 
modifications should remove the concerns of commenters that this document 
implies a guarantee or an affirmative warranty on the suitability of the 
property for certain uses and also limits the assumptions determining 
suitability to a specific point in time. 
 In this final section of the preamble, we are republishing for informational 
purposes a small section of the preamble from the proposed rules, in which 
numbers expressed in scientific notation were not accurately represented. 
However, these numbers were accurately presented in the text of the proposed 
rule itself so that the commission's intent regarding implementation of these 
rules was clearly stated within the proposed rule package. The text of this 
section has been modified to reflect that these are final rather than proposed 
rules. 
 The media cleanup requirements for Standard 3 remedies are defined in 
sec.335.563. Section sec.335.563 requires persons to develop media cleanup 
levels in accordance with the conditions described in the following six sections 
and then to propose them in the corrective measure study. 
 First, sec.335.563 (a)-(e) define the general requirements which apply equally 
to the determination of cleanup levels for all media. Cleanup levels will be 
derived in response to these requirements using quantitative human health-based 
risk assessment procedures whenever the media-specific requirements of 
sec.335.563 (f)-(i) do not identify an applicable standard or rule or specify an 
alternative procedure. In addition, sec.335.563(j), which is more fully 
discussed later, describes adjustments that may need to be made to the cleanup 
levels developed in response to sec.335.563 (a)-(i). Among other requirements, 
this subsection allows the executive director to establish more stringent 
cleanup levels if necessary to protect environmental receptors. 
 Subsection 335.563(b) specifies that cleanup levels for known or suspected 
carcinogens will be established at concentrations which represent an excess 
upperbound lifetime risk of between one in ten thousand and one in one million. 
For carcinogens, risks are estimated as the incremental probability of an 
individual developing cancer over a lifetime as a result of exposure to a 
potential carcinogen (i.e. incremental or excess individual lifetime cancer 
risk). Known or suspected carcinogens are those chemicals that are classified as 
Group A, B, or C pursuant to the United States Environmental Protection Agency's 
Weight of Evidence System for Carcinogenicity. "Upperbound" as used in this 
requirement means that the TWC is reasonably confident that the "true risk" will 
not exceed the estimated risk and is likely to be less than predicted. The risk 
estimate is felt to be an upperbound estimate because the slope factor used to 
report the toxicity for carcinogens is generally an upper 95th percentile 
confidence limit of probability of response, based on experimental animal data 
used in the multistage model. 
 Subsection 335.563(b) further states that the executive director will use one 
in one million as a goal in establishing media cleanup level concentrations. 
This means that a cumulative risk level of one in one million will be used as 
the starting point (or initial protectiveness goal) for determining media 
cleanup levels that remedies will attain. The use of one in one million as the 
starting point for a cumulative risk level expresses the TWC's preference for 
media cleanup levels that result in risks at the more protective end of the risk 
range. This preference, however, does not reflect a rigid requirement when other 
factors, identified in the rules and discussed later, point to a different level 
of protection. Subsection 335.563(b) concludes by specifying that in no case 
shall the cumulative excess risk to exposed populations (including sensitive 
subgroups) be greater than one in ten thousand. 
 The remediation goals (i.e. cleanup levels) for a medium will typically be 
established by means of a two-step approach. A preliminary remediation goal for 
a potential carcinogen will be calculated to correspond to a one in one million 
incremental risk of an individual developing cancer over a lifetime as a result 
of exposure to the potential carcinogen from all significant exposure pathways 
for a given medium. For example, the preliminary cleanup concentration for a 
specific potential carcinogen in soil could be calculated by setting the sum of 
the risk from ingestion of soil, inhalation of volatiles from soil, and 
inhalation of particulates from soil equal to one in one million, provided these 
exposure pathways would all be significant at a given site. The TWC will use the 
procedures outlined in EPA OSWER Directive 9285. 7-01B entitled Human Health 
Evaluation Manual, Part B: "Development of Risk-Based Preliminary Remediation 
Goals", or other guidance to be developed by the Commission, to evaluate the 
initial cleanup levels proposed for carcinogens in the media at a site. 
 The second step in the determination of media cleanup levels involves the 
consideration of the site-specific and technical feasibility issues identified 
in sec.335.563(d). Such factors, which are discussed later, will enter into the 
determination of where within the risk range of one in ten thousand to one in 
one million the cleanup level for a potential carcinogen would be established. 
Consideration of such factors may also indicate the need to establish a risk 
goal for an individual carcinogen that is less than one in one million in order 
to achieve the overall cumulative risk goal (i.e., one in one million). Thus, 
the preliminary remediation goal based upon a one in one million risk level 
represents a "sticky point" from which departure in the direction of increased 
or decreased risk would be allowed, provided that action could be justified 
based upon the issues presented in sec.335.563(d). 
 The general media cleanup requirements for systemic toxicants (i.e. 
noncarcinogens) are presented in sec.335.563(c). Preliminary remediation goals 
for noncarcinogens will be calculated based upon these requirements and, similar 
to the case for carcinogens, these preliminary values may be modified based upon 
the site-specific and technical feasibility issues identified in sec.335.563(d). 
The basic requirement for noncarcinogens is that the media cleanup levels be set 
at concentrations to which the human population (including sensitive subgroups) 
could be exposed on a daily basis without appreciable risk of deleterious effect 
during a lifetime. Two conditions must be satisfied to meet this requirement and 
are described in the following paragraphs. 
 The first condition is that the hazard quotient must not exceed 1. The hazard 
quotient is defined as the ratio of a single systemic toxicant exposure level 
for a specified time period to the reference dose for that systemic toxicant 
derived from that same time period. The noncancer hazard quotient assumes that 
there is a level of exposure (i.e. the reference dose) below which it is 
unlikely for even sensitive populations to experience adverse health effects. If 
the exposure level exceeds this threshold (i.e. the hazard quotient exceeds 
unity) there may be concern for potential noncarcinogenic effects. As a rule, 
the greater the value of the hazard quotient above 1, the greater the level of 
concern. In contrast to the case for carcinogens, hazard quotients must not be 
interpreted as statistical probabilities. The hazard quotient value of 1 is used 
as a protective level to judge when adverse noncarcinogenic effects may begin. 
 The second condition is that the hazard index shall not exceed 1. The hazard 
index is the sum of the hazard quotients for a single or multiple systemic 
toxicants which affect the same target organ or act by the same method of 
toxicity and act through a single or multiple media exposure pathways. This 
approach assumes that simultaneous subthreshold exposure to a toxicant or 
several toxicants acting through a single or several exposure pathways could 
also result in an adverse health effect. It also assumes that the magnitude of 
the adverse effect will be proportional to the sum of the ratios of the 
subthreshold exposure to acceptable exposures. This assumption of dose 
additivity is most properly applied when the compound affects the same target 
organ or acts by the same method of toxicity. 
 The preliminary remediation goal for a particular systemic toxicant will be 
determined by calculating the concentration that corresponds to a hazard index 
of 1, based upon human exposure to the chemical from all significant exposure 
pathways in a given medium. As an example, the preliminary cleanup concentration 
for a particular systemic toxicant in soil could be calculated by setting the 
sum of the hazard quotients for ingestion of soil, inhalation of volatiles from 
soil, and inhalation of particulates from soil equal to 1, provided these 
exposure pathways are all significant at a given site. Similar to the case for 
carcinogens, the TWC will use the procedures described in EPA OSWER Directive 
9285.7-01B, which is entitled Human Health Evaluation Manual, Part B: 
"Development of Risk-based Preliminary Remediation Goals", or other guidance to 
be developed by the Commission, to review the initial cleanup levels proposed 
for noncarcinogens in the media at a site. 
 Section 335.563(d) states that in establishing media cleanup levels pursuant to 
sec.335.563(b) and (c) the executive director may consider and may direct 
persons who submit plans or reports to consider a number of additional factors. 
These factors include: multiple contaminants in a medium, exposure to multiple 
contaminated media, reasonable expected future exposure conditions at the 
facility, and the technical limitations, effectiveness, practicability, or other 
relevant features of available remedies. Based upon a consideration of these 
factors, the preliminary remediation goals may be modified, if warranted, to 
determine the final media cleanup levels to be achieved by the proposed remedy. 
 The first two of these factors, that is, multiple contaminants in a medium and 
exposure to multiple contaminated media, may require the risk goal for an 
individual carcinogen or noncarcinogen to be lower than the overall cumulative 
risk goal of one in one million or hazard index of 1, respectively. At many 
sites, it is likely that the potential human health effects of more than one 
contaminant in a medium must be assessed. Determining remediation levels by 
considering one chemical in a medium at a time might significantly underestimate 
the risks associated with simultaneous exposure to several substances. Likewise, 
at some sites an individual might be exposed to a substance or combination of 
substances through several media. For example, an individual might be exposed to 
substance(s) from a site by both consuming contaminated drinking water and by 
inhaling dust originating from the site. One should not automatically sum risks 
from all exposure pathways evaluated at a site, however. Cleanup levels are to 
be based upon an estimate of the reasonable maximum exposure expected to occur 
under future land use conditions. The reasonable maximum exposure is defined as 
the highest exposure that is reasonably expected to occur at a site and is 
estimated for each pathway. The intent of the reasonable maximum exposure is to 
estimate a conservative exposure case (i.e. well above the average case) that is 
still within the range of possible exposures. Until such time as additional 
guidance is developed, the TWC will use EPA's Human Health Evaluation Manual 
Parts A (EPA/540/1-89/002) and B (OSWER Directive 9285.7-01B) to review the 
manner in which the proposed preliminary remediation goal will be modified to 
reflect these two factors. 
 The third factor of sec.335.563(d) allows the preliminary remediation goal to 
be modified based upon the reasonable expected exposure conditions at the 
facility. This is consistent with sec.335.563(e), which addresses whether the 
standard exposure factors for residential use or some other exposure conditions 
will be used to determine media cleanup levels at a site. 
 And finally, the fourth factor of sec.335.563(d) allows the preliminary cleanup 
levels to be modified based upon technical limitations, effectiveness, 
practicability, or other relevant features of available remedies. In cases where 
the remedy which best achieves the requirements for a standard three remedy 
identified in sec.335.561 cannot achieve the cumulative risk goal of one in one 
million, a greater risk level could be allowed, as necessary. For carcinogens, 
the cumulative risk must be within the risk range from one in ten thousand to 
one in one million. Institutional controls may be required as part of the remedy 
for such a site. 
 Subsection 335.563(e) states that in determining media cleanup levels for 
carcinogens and systemic toxicants pursuant to  sec.335.563(b) and (c), a person 
shall use the standard exposure factors for residential use of the facility as 
set forward in Table 1 of Subchapter S unless the person documents to the 
satisfaction of the executive director that alternative assumptions regarding 
future exposure conditions are warranted. The standard exposure factors 
presented in Table 1 have been developed to be consistent for the most part with 
EPA's OSWER Directive 9285.6-03 entitled Human Health Evaluation Manual, 
Supplemental Guidance: "Standard Default Exposure Factors" . The rule describes 
two exceptions where exposure assumptions other than the standard exposure 
factors for residential use would be allowed. 
 The first exception presented in sec.335.563(e)(1) allows alternative exposure 
factors for a particular land use to be used, provided site-specific data 
warrant deviation from the standard exposure factors. The standard default 
values in Table 1 of Subchapter S are being provided to reduce unwarranted 
variability in the exposure assumptions and to provide a consistent approach to 
the determination of media cleanup levels. Accordingly, the exposure factors 
presented in Table 1 are considered most appropriate and must be used unless 
alternative values based upon site-specific data can be clearly justified. The 
TWC's intent is to base media cleanup levels upon a reasonable maximum exposure. 
The standard exposure values have been selected to combine upperbound and mid-
range exposure factors so that the resulting estimate of intake is highly 
protective and reasonable but does not represent the worst possible (and highly 
unlikely) case. 
 The second exception presented in sec.335.563(e)(2) allows the person to base 
the media cleanup levels on a land use other than residential provided the 
person can demonstrate to the satisfaction of the executive director that such 
land use is a more appropriate assumption. Such demonstration must be based upon 
consideration of the historical, current, and probable future land use as well 
as the effectiveness of institutional or legal controls placed on the future use 
of the land. To adequately support a land use other than residential, the person 
must demonstrate both that future residential use of the property is unlikely 
and that effective institutional or legal controls, that are adequate to 
maintain the alternative land use and prevent residential use, have been or will 
be placed on the property. 
 The new sections are adopted under the Texas Water Code,  sec.5.103 and sec.26. 
011, which provides the commission with authority to adopt any rules necessary 
to carry out its powers, duties, and policies and to protect water quality in 
the state. The sections are also promulgated under sec.361.017 of the Texas 
Solid Waste Disposal Act, Texas Health and Safety Code, Chapter 361, which 
provides the commission the authority to regulate industrial solid wastes and 
hazardous municipal wastes and all other powers necessary or convenient to carry 
out its responsibilities. 
   
  31 TAC sec.sec.335.1, 335.5, 335.6, 335.8 
 
  The amended sections are adopted under the Texas Water Code, sec.5.103 and 
sec.26.011, which provides the commission with authority to adopt any rules 
necessary to carry out its powers, duties, and policies and to protect water 
quality in the state. The sections are also promulgated under sec.361.017 of the 
Texas Solid Waste Disposal Act, the Texas Health and Safety Code, Chapter 361, 
which provides the commission the authority to regulate industrial solid wastes 
and hazardous municipal wastes and all other powers necessary or convenient to 
carry out its responsibilities. 
 
 
  sec.335.1. Definitions.  The following words and terms, when used in this 
chapter, shall have the following meanings, unless the context clearly indicates 
otherwise. 
   
     Closure-The act of permanently taking a waste management unit or facility 
out of service. 
   
     Contaminant-Includes but is not limited to solid waste, hazardous waste, 
and hazardous waste constituent as defined in this subchapter; "pollutant," as 
defined in the Texas Water Code, sec.26.001, and the Texas Health and Safety 
Code, sec.361.431, "hazardous substance," as defined in the Texas Health and 
Safety Code, sec.361.003; and other substances that are subject to the Texas 
Hazardous Substances Spill Prevention and Control Act, the Texas Water Code, 
sec.sec.26.261-26.268. 
   
     Contaminated medium/media -A portion or portions of the physical 
environment to include soil, sediment, surface water, groundwater or air, that 
contain contaminants at levels that pose a substantial present or future threat 
to human health and the environment. 
   
     Control-To apply engineering measures such as capping, reversible treatment 
methods, and/or institutional measures such as deed restrictions to facilities 
or areas with wastes or contaminated media which result in remedies that are 
protective of human health and the environment when combined with appropriate 
maintenance, monitoring, and any necessary further corrective action. 
   
     Decontaminate-To apply a treatment process(es) to wastes or contaminated 
media whereby the substantial present or future threat to human health and the 
environment is eliminated. 
   
     Remediation-The act of eliminating or reducing the concentration of 
contaminants in contaminated media. 
   
     Remove-To take waste, contaminated design or operating system components, 
or contaminated media away from a waste management unit, facility, or area to 
another location for storage, processing, or disposal. 
   
     Treatment-To apply a physical, biological, or chemical process(es) to 
wastes and contaminated media which significantly reduces the toxicity, volume, 
or mobility of contaminants and which, depending on the process(es) used, 
achieves varying degrees of long-term effectiveness. 
 
   
  sec.335.8. Closure and Remediation. 
 
  (a) Applicability. The regulations in this section are effective on June 28, 
1993. The regulations in this section apply to persons who undertake the closure 
of facilities used for the storage, processing, or disposal of industrial solid 
waste or municipal hazardous waste. The regulations in this section also apply 
to persons who undertake the remediation of contaminated media resulting from 
unauthorized discharges from such facilities, either as part of closure or at 
any time before or after closure. The regulations in this section also apply to 
persons who undertake remediation of areas that are not otherwise designated as 
a facility but that contain unauthorized discharges of industrial solid waste or 
municipal hazardous waste. The regulations of this subsection, in addition to 
other applicable rules, permits, or orders, establish the obligation for persons 
to perform closures or remediations for facilities or areas containing 
industrial solid and municipal hazardous waste and further specify the mechanism 
to evaluate such closures or remediations. The obligation to perform 
remediations for unauthorized discharges of contaminants under the state 
superfund and spill response programs occurs through the application of the 
commission's rules and statutes pertaining to those programs; however, once such 
obligation has occurred the regulations in this section will be used to specify 
the mechanism to evaluate remediation of unauthorized discharges of contaminants 
subject to those programs. The regulations in this section supplement but do not 
replace any requirements for closure or remediation specified in the regulations 
for the programs subject to these rules and shall apply as specified in 
paragraphs (1)-(6) of this subsection. 
 
  (1)  Persons shall complete notification and response actions for spills in 
accordance with the Texas Water Code,  sec.26.039 and sec.26.261, and the 
administrative and procedural requirements of the commission to carry out the 
Texas Hazardous Substance Spill Prevention and Control Act. This section applies 
to spills when the response actions do not result in remediation within the 
timeframes specified by the commission's spill response program. In such 
circumstances the person shall submit a plan in accordance with subsection (b) 
of this section. 
   
  (2) This section applies to remediations performed under the state superfund 
program in accordance with Subchapter K of this chapter (relating to Hazardous 
Substance Facilities Assessment and Remediation) with the exception that 
information, including a baseline risk assessment, shall be provided and 
potential remedies shall be evaluated in response to Subchapter K rather than 
the requirements of subsections (c) and (d) of this section, sec.335.553 
(relating to Required Information), and sec.335.562 (relating to Remedy 
Evaluation Factors for Risk Reduction Standard Number 3). Also, under the state 
superfund program, persons shall determine media cleanup levels assuming future 
residential land use unless the person demonstrates to the satisfaction of the 
executive director using the provisions of sec.335.563(e) of this title 
(relating to Media Cleanup Requirements for Risk Reduction Standard Number 3) 
that an alternative land use is more appropriate. 
   
  (3) Any person who stores, processes, or disposes of industrial solid waste or 
municipal hazardous waste at a facility permitted under sec.335.2(a) of this 
title (relating to Permit required), shall, unless specifically modified by 
other order of the commission, close the facility in accordance with the closing 
provisions of the permit. 
   
  (4)  Any person who stores, processes, or disposes of hazardous waste is also 
subject to the applicable provisions relating to closure and post-closure in 
Subchapters E and F of this chapter (relating to Interim Standards for Hazardous 
Waste Storage, Processing, or Disposal Facilities; and Permitting Standards for 
Owners and Operators of Hazardous Waste Storage, Processing, or Disposal 
Facilities, respectively). 
   
  (5) Persons who have received approval of closure or remediation plans by the 
executive director and have either completed or not completed the action prior 
to the effective date of this section may either maintain or complete the 
action, as applicable, according to the approved plan and are not subject to the 
requirements of this section unless a substantial change in circumstances 
develops at the facility or area which results in an unacceptable threat to 
human health or the environment as described in subsection (b)(5) of this 
section. Plans or reports submitted but not approved prior to the effective date 
of this section will be reviewed according to the regulations in effect at the 
time of document submittal. If the executive director denies approval of the 
plan or report under those regulations for reasons of technical inadequacy, the 
person must then comply with the requirements of this section upon receipt of 
written notice from the executive director that the plan or report is not 
approved. Closure plans approved as part of an industrial solid or municipal 
hazardous waste permit which was issued prior to the effective date of this 
section but not implemented at the time of permit renewal are subject to review 
for compliance with this section as part of the permit renewal process. Persons 
may resubmit such plans or reports that they have revised voluntarily to conform 
with the requirements of this section, unless such resubmittal would result in 
noncompliance with a previously approved or imposed schedule of compliance. 
   
  (6) The requirements of this section do not apply to substances discharged or 
spilled from storage tanks regulated by Chapter 334 of this title (relating to 
Underground Storage Tanks). 
     
  (b) Closure and Remediation Obligations. Persons identified in subsection (a) 
of this section have the obligation to conduct the activities described in 
paragraphs (1)-(4) of this subsection when performing a closure or remediation. 
Upon receipt of approval by the executive director of reports demonstrating 
compliance with all applicable requirements, the person has completed these 
obligations unless a substantial change in circumstances results in an 
unacceptable risk to human health or the environment as described in paragraph 
(5) of this subsection. 
 
  (1) Notify the executive director in writing of any closure or remediation 
activities as is further specified in subsection (c) of this section; 
   
  (2) Perform closure or remediation activities at the facility or area of 
unauthorized discharge which meet one or more of the risk reduction standards 
specified in subparagraphs (A)-(C) of this paragraph. Unless the requirement to 
close a waste management facility is specified by other rule, permit, or order, 
the person will determine the time for initiation of closure. The timely 
remediation of unauthorized discharges resulting from operation of a waste 
management unit does not compel the closure of the unit unless closure is a 
necessary part of the remedy to achieve protection of human health and the 
environment. 
 
  (A) Risk Reduction Standard Number 1: Closure/remediation to background-to 
remove and/or decontaminate all waste, waste residues, leachate, and 
contaminated media to background levels unaffected by waste management or 
industrial activities as further specified in sec.335.554 of this title 
(relating to Attainment of Risk Reduction Standard Number 1); or 
   
  (B) Risk Reduction Standard Number 2: Closure/remediation to health-based 
standards and criteria-to remove and/or decontaminate all waste, waste residues, 
leachate, and contaminated media to standards and criteria such that any 
substantial present or future threat to human health or the environment is 
eliminated as further specified in sec.335.555 of this title (relating to 
Attainment of Risk Reduction Standard Number 2); or 
   
  (C) Risk Reduction Standard Number 3: Closure/remediation with controls-to 
remove, decontaminate and/or control all waste, waste residues, leachate, and 
contaminated media to levels and in a manner such that any substantial present 
or future threat to human health or the environment is eliminated or reduced to 
the maximum extent practicable, as further specified in sec.335.561 of this 
title (relating to Attainment of Risk Reduction Standard Number 3). 
     
  (3) Demonstrate in writing to the executive director that closure or 
remediation has been completed as is further specified in subsection (d) of this 
section; 
   
  (4) Perform any necessary post-closure care and deed certification or 
recordation activities as required by Subchapter S (relating to Risk Reduction 
Standards) of this chapter; and 
   
  (5) Respond on a continuing basis pursuant to paragraphs (1)-(4) of this 
subsection in the event that a substantial change in circumstances at the 
facility or area results in an unacceptable threat to human health or the 
environment. In response to these substantial changes in circumstances, the 
person shall comply with this subsection utilizing the then-prevailing criteria 
and perform such actions as necessary to provide protection of human health and 
the environment. A substantial change in circumstance can include but is not 
limited to the situations described in subparagraphs (A)-(D) of this paragraph. 
 
  (A) a failure of institutional or engineering controls to prevent or mitigate 
exposure at the approved performance level; 
   
  (B) a change in land use from non-residential to residential; or 
   
  (C) an actual exposure condition is determined to be occurring at levels not 
protective of human health or the environment. For purposes of this 
subparagraph, changes made to Subchapter S of this chapter (relating to Risk 
Reduction Standards) in response to periodic reviews of the general procedures 
specified to generate numeric cleanup levels, or in response to annual revisions 
of Appendix II of Subchapter S to reflect new toxicity data, do not constitute a 
substantial change in circumstances, unless these changes are of such magnitude 
to present an unacceptable threat to human health or the environment when 
evaluated for future exposure conditions based on site-specific considerations; 
or 
   
  (D) new information indicates that the contamination at the facility or area 
was not sufficiently characterized such that an unacceptable threat to human 
health or the environment continues to exist. 
       
  (c) Notification and Initiation Requirements. 
 
  (1) A person who intends to perform any activity of closure or remediation in 
accordance with subsection (b) of this section shall determine the risk 
reduction standard(s) to be attained. The person shall notify the executive 
director and the commission's office in the district where the facility or area 
is located in writing of the following information at least ten days prior to 
conducting the activity: 
 
  (A) the facility or area to be subject to closure or remediation activities; 
   
  (B) the risk reduction standard(s) to be attained; and 
   
  (C) the estimated time necessary to complete the activity. 
     
  (2) After performing notification in accordance with paragraph (1) of this 
subsection, the person may initiate the actions necessary to attain Risk 
Reduction Standard Numbers 1 or 2 without prior approval by the executive 
director, unless such approval is required by other regulation, order, or permit 
of the commission. Any plan submitted for prior approval by the executive 
director shall contain the information specified in sec.335.553(a) of this title 
(relating to Required Information). 
   
  (3) If the person intends to attain Risk Reduction Standard Number 3, or 
determines that Standard Number 1 or 2 have not been attained in a self-
implemented action, the person shall submit to the executive director the 
information specified in sec.335.553(b) of this title (relating to Required 
Information) for approval prior to beginning, or continuing, as applicable, the 
closure or remediation activities. 
   
  (4) The person may include one or more waste management units or areas in a 
submittal for the purpose of responding to this subsection and subsection (d) of 
this section. 
   
  (5)  Notwithstanding any other requirement, the person shall submit to the 
executive director upon request such information as may reasonably be required 
to enable the executive director to determine whether the closure or remediation 
is compliant with this section. 
     
  (d) Demonstration of Conformance with Risk Reduction Standards. Upon 
completion of a closure or remediation, the person shall demonstrate in a form 
acceptable to the executive director that the activity meets the intended risk 
reduction standards and any applicable closure criteria listed or referenced in 
this chapter. Any submittal to the executive director in response to this 
subsection shall be in the form of a plan or report that contains the 
information specified in sec.335.553 of this title (relating to Required 
Information). 
 
  This agency hereby certifies that the rule as adopted has been reviewed by 
legal counsel and found to be a valid exercise of the agency's legal authority. 
 Issued in Austin, Texas, on June 7, 1993. 
 TRD-9323979 
  Mary Ruth Holder 
 Director, Legal Division 
 Texas Water Commission 
    Effective date: June 28, 1993 
 Proposal publication date: December 18, 1992 
 For further information, please call: (512) 908-2340 
         
               Chapter 335. Industrial Solid Waste and Municipal Hazardous Waste 
  
  Subchapter S. Risk Reduction Standards 
 
  31 TAC sec.sec.335.551-335.569 
 
  The mew sections are adopted under the Texas Water Code,  sec.5.103 and 
sec.26.011, which provides the commission with authority to adopt any rules 
necessary to carry out its powers, duties, and policies and to protect water 
quality in the state. The sections are also promulgated under the Texas Solid 
Waste Disposal Act, sec.361.017, Texas Health and Safety Code, Chapter 361 
(Vernon Pamphlet 1992), which provides the commission the authority to regulate 
industrial solid wastes and hazardous municipal wastes and all other powers 
necessary or convenient to carry out its responsibilities. 
 
 
  sec.335.551. Purpose, Scope, and Applicability. 
 
  (a) Purpose. This subchapter specifies the information and procedures 
necessary to demonstrate compliance with the three risk reduction standards of 
sec.335.8 of this title (relating to Closure and Remediation). 
   
  (b) Scope. The requirements of this subchapter will, when adequately carried 
out, assure adequate protection of human health and the environment from 
potential exposure to contaminants associated with releases from solid waste 
management facilities or other areas. Cleanup levels are specified for different 
types of contaminated media such as air, surface water, ground water, and soil, 
and for cross-media contamination pathways such as soil to ground water and soil 
to air. General procedures based on scientific principles are provided or 
referenced by these regulations so that specific numeric cleanup levels can be 
generated. The commission will periodically review the general procedures and 
revise these regulations as necessary. 
   
  (c) Applicability. The requirements of this subchapter apply to persons who 
undertake a closure or remediation in accordance with sec.335.8 of this title. 
 
     
  sec.335.552. Definitions.  The following words and terms, when used in this 
subchapter, shall have the following meanings, unless the context clearly 
indicates otherwise. 
   
     Carcinogen-Substances which have been classified for human carcinogenic 
risk based on the United States Environmental Protection Agency's Weight of 
Evidence System of Carcinogenicity as Group A-Human Carcinogen; Group B-Probable 
Human Carcinogen; or Group C-Possible Human Carcinogen. 
   
     Carcinogen Classification -The basis by which substances are classified for 
human carcinogenic risk based on the United States Environmental Protection 
Agency's Weight of Evidence System for Carcinogenicity: Group A-Human 
Carcinogen; Group B-Probable Human Carcinogen; Group C-Possible Human 
Carcinogen; Group D-Not Classifiable as to Human Carcinogenicity; and Group E-
Evidence of Non-Carcinogenicity for Humans. 
   
     Long-term effectiveness -The ability of a remediation or corrective action 
to maintain over time the required level of protection of human health and the 
environment. 
   
     Non-residential property -Any real property or portion of a property not 
currently being used for human habitation or for other purposes with a similar 
potential for human exposure, at which activities have been or are being 
conducted, having the primary Standard Industrial Classification (SIC) major 
group numbers 01-48 inclusive, 49 except 4941, 50-67 inclusive, 72-79 inclusive, 
80 except 8051, 8059, 8062, 8063, 8069, 81 and 82 except 8211, 8221, 8222, 83 
except 8351, 8361, 84-86 except 8661, 87-91 inclusive, 92 except 9223, and 93-97 
inclusive. Non-residential property includes all of the block(s) and lot(s) 
controlled by the same owner or operator that are vacant land, or that are used 
in conjunction with such business. For leased properties, non-residential 
property includes the leasehold and any external tank, surface impoundment, 
septic system, or any other structure, vessel, contrivance, or unit that 
provides, or are utilized, for the management of contaminants to or from the 
leasehold. 
   
     Permanence/permanent/permanently -The property of achieving the maximum 
degree of long-term effectiveness and of enduring indefinitely without posing 
the threat of any future release that would increase the risk above levels 
established for the facility or area. 
   
     Point of exposure -A location where human or environmental receptors can 
come into contact with contaminants; also, a location which can be arbitrarily 
determined for purposes of estimating or measuring the concentration of 
contaminants available for exposure. 
   
     Practical quantitation limit/PQL-The lowest concentration of an analyte 
which can be reliably quantified within specified limits of precision and 
accuracy during routine laboratory operating conditions. The PQL minimizes to 
the extent possible the effects of instrument and operator variability and the 
influences of the sample matrix and other contaminants or substances upon the 
quantitation of the analyte. "Specified limits of precision and accuracy" are 
the criteria which have been included in applicable regulations or which are 
listed in the quality control sections of the analytical method. The PQL may be 
directly obtained or derived from the following sources with preference given to 
the most recent, scientifically valid method: federal regulations; EPA guidance 
documents; calculation from interlaboratory studies; and experimentally 
determined analytical methods not available from other existing sources. 
   
     Residential property -Any property that does not exclusively meet the 
definition of non-residential property. Also, a portion of non-residential 
property that is used in part for residential activities, such as a day care 
center, is defined as residential. 
   
     Systemic toxicant -Substances shown either through epidemiological studies 
or through laboratory studies to cause adverse health effects other than cancer. 
 
   
  sec.335.553. Required Information. 
 
  (a) For risk reduction standard Number 1 or 2. The person shall provide a 
final report that documents attainment of the risk reduction standard in 
accordance with sec.335.554 or  sec.335.555 of this title (relating to 
Attainment of Risk Reduction Standard Number 1 and Attainment of Risk Reduction 
Standard Number 2). The report shall include, but is not limited to, 
descriptions of procedures and conclusions of the investigation to characterize 
the nature, extent, direction, rate of movement, volume, composition and 
concentration of contaminants in environmental media; basis for selecting 
environmental media of concern; documentation supporting selection of exposure 
factors; descriptions of removal or decontamination procedures performed in 
closure or remediation; summaries of sampling methodology and analytical results 
which demonstrate that contaminants have been removed or decontaminated to 
applicable levels; and a document that the person proposes to use to fulfill the 
requirements of sec.335.560(b) of this title (relating to Post Closure Care and 
Deed Certification), as applicable. 
   
  (b) Risk reduction standard Number 3, the person shall conduct the activities 
set forth in paragraphs (1)-(4) of this subsection. The results of activities 
required by paragraphs (1)-(3) of this subsection may be combined to address a 
portion of a facility or one or more facilities of a similar nature or close 
proximity. The submittal shall be subject to review and approval by the 
executive director prior to carrying out the closure or remediation. Upon 
completion of the approved activity, the person shall submit the final report 
required by paragraph (4) of this subsection. 
 
  (1) The person shall prepare a remedial investigation report which contains 
sufficient documentation such as, but not limited to, descriptions of procedures 
and conclusions of the investigation to characterize the nature, extent, 
direction, rate of movement, volume, composition, and concentration of 
contaminants in environmental media of concern, including summaries of sampling 
methodology and analytical results. Information obtained from attempts to attain 
Risk Reduction Standard Numbers 1 or 2 may be submitted for this purpose. 
   
  (2) The person shall prepare a baseline risk assessment report which describes 
the potential adverse effects under both current and future conditions caused by 
the release of contaminants in the absence of any actions to control or mitigate 
the release. The report shall also discuss the degree of uncertainty associated 
with the baseline risk assessment. Residential land use with on-site exposure 
shall be assumed to evaluate the future use condition unless the person 
demonstrates to the satisfaction of the executive director that a different land 
use assumption such as industrial use is more appropriate. The standard exposure 
factors set forth in Table 1 (located in paragraph (4) of this subsection) shall 
be used unless the person documents to the executive director's satisfaction 
that site-specific exposure data should be used instead. 
   
  (3)  The person shall evaluate the relative abilities and effectiveness of 
potential remedies to achieve the requirements for remedies described in 
sec.335.561 of this title (relating to Attainment of Risk Reduction Standard 
Number 3) when considering the evaluation factors described in sec.335.562 of 
this title (relating to Remedy Evaluation Factors). Using this information, the 
person shall prepare a corrective measure study which recommends the remedy 
which best achieves the requirements for remedies described in sec.335. 561 of 
this title. Persons may seek to satisfy the requirements of sec.335.564 of this 
title (relating to Post Closure Care not required for Risk Reduction Standard 
Number 3) by demonstrating in the corrective measure study using the procedures 
of sec.335.563 of this title (relating to Media Cleanup Requirements for Risk 
Reduction Standard Number 3) that no remedy needs to be performed since the 
existing conditions of the facility or area conform to the media cleanup 
requirements without the use of removal, decontamination or control measures. 
Persons may also seek to satisfy the requirements of sec.335.564 by 
demonstrating in the corrective measure study that following completion of their 
recommended removal and/or decontamination activities the conditions of the 
facility or area will conform to the media cleanup requirements of sec.335. 563 
without the use of control measures. Upon review of the corrective measure 
study, the executive director may require the person to further evaluate the 
proposed remedy or to evaluate one or more additional remedies. 
   
  (4)  The person shall submit to the executive director, for review and 
acceptance, a final report containing sufficient documentation which 
demonstrates that the remedy has been completed in accordance with the approved 
plan and also a document that the person proposes to use to fulfill the 
requirements of  sec.335.566 of this title (relating to Deed Recordation for 
Risk Reduction Standard Number 3). 
 
  
   
  [graphic] 
       
  (c) For risk reduction standards Numbers 1, 2, and 3. In order for a treatment 
process to achieve decontamination in contrast to being a control measure, the 
person must demonstrate to the satisfaction of the executive director that the 
treatment process permanently alters all contaminants to levels that will not 
pose a substantial present or future threat to human health and the environment, 
and must further demonstrate that any residue remaining in place from the 
treatment will not pose the threat of any future release that would increase the 
concentrations of contaminants in environmental media above the cleanup levels 
determined for that particular risk reduction standard. 
   
  (d) For risk reduction standards Numbers 1, 2, and 3, attainment of cleanup 
levels shall be demonstrated by collection and analysis of samples from the 
media of concern. Persons shall utilize techniques described in SW 846, Test 
Methods for Evaluating Solid Waste, United States Environmental Protection 
Agency, or other available guidance in developing a sampling and analysis plan 
appropriate for the distribution, composition and heterogeneity of contaminants 
and environmental media. A sufficient number of samples shall be collected and 
analyzed for individual compounds to both accurately assess the risk to human 
health and the environment posed by the facility or area and to demonstrate the 
attainment of cleanup levels. Non compound-specific analytical techniques (e.g., 
Total Petroleum Hydrocarbons, Total Organic Carbon, etc.) may, where appropriate 
for the nature of the wastes or contaminants, be used to aid in the 
determination of the lateral and vertical extent and volume of contaminated 
media; however, such non compound-specific analyses will serve only as indicator 
measures and must be appropriately supported by compound-specific analyses. 
Comparisons may be based on the following methods: 
 
  (1) direct comparison of the results of analysis of discrete samples of the 
medium of concern with the cleanup level; 
   
  (2) for a data set of ten or more samples, statistical comparison of the 
results of analysis utilizing the 95% confidence limit of the mean concentration 
of the contaminant as determined by the following expression: Cleanup Level 
_________ where ____ is the mean concentration, s is the standard deviation and 
t is a value from Table 2 (located following paragraph (3) of this subsection) 
based on the number of samples, and sqrt (n) is the square root of the sample 
size; or 
   
  (3) other statistical methods appropriate for the distribution of the data, 
subject to prior approval by the executive director. 
 
  [graphic] 
     
  (e) For Risk Reduction Standards Numbers 2 and 3, in determining toxicity 
information for contaminants (e.g., Environmental Protection Agency carcinogen 
classification, type of toxicant, reference doses, carcinogenic slope factors, 
etc.), persons shall utilize values from the following sources in the order 
indicated. For Risk Reduction Standard Number 2, persons may utilize data from 
these sources that are more current than those used to derive the unadjusted 
MSCs listed in sec.335.568 of this title (relating to Appendix II), provided 
that substantiating information is furnished to the executive director in the 
report required by sec.335.555(f) of this title (relating to Attainment of Risk 
Reduction Standard Number 2): 
 
  (1)  integrated Risk Information System (IRIS); 
   
  (2) health Effects Assessment Summary Table (HEAST); 
   
  (3) united States Environmental Protection Agency Criteria Documents; 
   
  (4) agency for Toxic Substances and Disease Registry (ATSDR) Toxicological 
Profiles; and 
   
  (5) other scientifically valid published sources. 
     
  (f) For risk reduction standards Numbers 2 and 3, persons determining cleanup 
levels for contaminated media characterized by non compound-specific analytical 
techniques (e.g., Total Petroleum Hydrocarbons, Total Organic Carbon, etc.) and 
for which individual compounds such as hazardous constituents are not present as 
contaminants, must at a minimum consider other scientifically valid published 
numeric criteria to address: adverse impacts on environmental quality; adverse 
impacts on the public welfare and safety; conditions that present objectionable 
characteristics (e.g., taste, odor, etc.); or conditions that make a natural 
resource unfit for use. 
 
     
  sec.335.554. Attainment of Risk Reduction Standard Number 1: 
Closure/Remediation to Background. 
 
  (a) Compliance with this standard is attained when the criteria set forth in 
subsections (b)-(g) of this section are met. 
   
  (b) For closure of hazardous waste management units and response to 
unauthorized discharges of hazardous waste, all hazardous waste and hazardous 
waste residues and contaminated design and operating system components such as 
liners, leachate collection systems and dikes must be removed from the unit or 
area of the unauthorized discharge. For remediation of media that have become 
contaminated by releases from a hazardous waste management unit or by other 
unauthorized discharge of hazardous waste, the contaminated media must be 
removed or decontaminated to cleanup levels specified in this section. 
   
  (c) For closure of non-hazardous industrial solid waste management units, 
response to unauthorized discharges of non-hazardous industrial solid waste, and 
the remediation of media that have become contaminated by discharges of non-
hazardous industrial solid waste or other contaminants, all waste and waste 
residues, contaminated design and operating system components such as liners, 
leachate collection systems and dikes, and contaminated media must be removed or 
decontaminated to cleanup levels specified in this section. 
   
  (d) Background as represented by results of analyses of samples taken from 
media that are unaffected by waste management or industrial activities shall be 
used to determine compliance with the requirements of this section. If the 
Practical Quantitation Limit (PQL) is greater than background, then the PQL 
rather than background shall be used as the cleanup level provided that the 
person satisfactorily demonstrates to the executive director that lower levels 
of quantitation of a contaminant are not possible. 
   
  (e)  Attainment of cleanup levels shall be demonstrated by collection and 
analysis of samples from the media of concern using the procedures of sec.335. 
553(d) of this title (relating to Required Information). 
   
  (f) The person must submit a report to the executive director in accordance 
with sec.335.553(a) of this title (relating to Required Information) that 
documents compliance with the requirements of this section. 
   
  (g) Provided that attainment of this risk reduction standard for the facility 
or area can be demonstrated to the executive director pursuant to this section, 
the person is released from deed recordation requirements of sec.335.5 of this 
title (relating to Deed Recordation of Waste Disposal) and post-closure care 
responsibilities. 
 
     
  sec.335.555. Attainment of Risk Reduction Standard Number 2: 
Closure/Remediation to Health-Based Standards and Criteria. 
 
  (a)  Compliance with this standard is attained when the criteria set forth in 
subsections (b)-(f) of this section are met. 
   
  (b) For closure of hazardous waste management units and response to 
unauthorized discharges of hazardous waste, all hazardous waste and hazardous 
waste residues must be removed from the unit or area of the unauthorized 
discharge. Contaminated design and operating system components such as liners, 
leachate collection systems and dikes must be removed from the unit or area of 
the unauthorized discharge. For remediation of media that have become 
contaminated by releases from a hazardous waste management unit or by other 
unauthorized discharge of hazardous waste, the contaminated media must be 
removed or decontaminated to cleanup levels specified in this section or such 
other lower levels necessary to be in conformance with current hazardous waste 
regulations. 
   
  (c)  For closure of non-hazardous industrial solid waste management units, 
response to unauthorized discharges of non-hazardous industrial solid waste, and 
the remediation of media that have become contaminated by discharges of non-
hazardous industrial solid waste or other contaminants, all waste and waste 
residues, contaminated design and operating system components such as liners, 
leachate collection systems and dikes, and contaminated media must be removed or 
decontaminated to cleanup levels specified in this section. 
   
  (d) The concentration of a contaminant in contaminated media of concern such 
as ground water, surface water, air or soil shall not exceed cleanup levels as 
defined in sec.335.556 of this title (relating to Determination of Cleanup 
Levels for Risk Reduction Standard Number 2). 
 
  (1) If the Practical Quantitation Limit (PQL) and/or the background 
concentration, determined in a manner consistent with sec.335.554 of this title 
(relating to Attainment of Risk Reduction Standard Number 1) for a contaminant 
is greater than the cleanup level, the greater of the PQL or background shall be 
used for determining compliance with the requirements of this section. 
   
  (2) Attainment of cleanup levels shall be demonstrated by collection and 
analysis of samples from the contaminated media of concern using the procedures 
of sec.335.553(d) of this title (relating to Required Information). 
     
  (e) The person must prepare a document that he intends to use to fulfill the 
deed certification requirements of sec.335.560 of this title (relating to Post 
Closure Care and Deed Certification for Risk Reduction Standard Number 2) and 
include this document as part of the report of subsection (f) of this section. 
   
  (f) The person must submit a report to the executive director in accordance 
with sec.335.553(a) of this title (relating to Required Information) that 
documents compliance with the requirements of this section. The executive 
director may require additional information or analysis, such as but not limited 
to, consideration of cumulative health effects and cross-media contamination, 
prior to accepting a certification of closure or remediation under this 
performance standard. Upon approval of the report by the executive director, the 
person shall comply with the requirements of sec.335.560 of this title (relating 
to Post Closure Care and Deed Certification for Risk Reduction Standard Number 
2). 
 
     
  sec.335.556. Determination of Cleanup Levels for Risk Reduction Standard 
Number 2. 
 
  (a) For purposes of this risk reduction standard, cleanup levels for 
individual contaminants are represented by Texas or federal promulgated health-
based standards, or, when these are not available or do not provide appropriate 
protection for human health or the environment, persons must develop cleanup 
levels based on procedures specified or referenced in this section for 
determining other numeric criteria, referred to as Medium Specific 
Concentrations (MSCs), and are required to perform any necessary adjustments to 
these numeric criteria. The MSCs address a single contaminant in a medium and 
consider one or more exposure pathways, specifically, water ingestion (Water 
MSC) and soil ingestion with inhalation of volatiles and particulates (Soil 
MSC). Where a contaminant in one medium has the potential to contaminate another 
medium, defined as cross-media contamination, additional numeric criteria are 
developed as cleanup levels (e.g., the soil-to-ground water contaminant 
pathway). To determine cleanup levels for contaminated media of concern, persons 
must perform the evaluations of subsections (b)-(e) of this section. 
   
  (b) In addition to the exposure pathways defined or referenced in this 
section, the person must evaluate other exposure pathways at or near the 
facility (e.g., dermal absorption, ingestion of contaminated fish, etc.) by 
which human populations (including sensitive subgroups) or environmental 
receptors (e.g., aquatic organisms, food-chain crops, etc.) are likely to be 
exposed to contaminants. If such evaluation indicates the need for additional 
remediation at the facility to adequately protect human health or environmental 
receptors, then the person shall develop numeric criteria by utilizing available 
guidance or scientific literature to serve in place of, or in addition to, 
cleanup levels determined pursuant to this section. 
   
  (c) The person must determine the appropriate exposure factors from 
sec.335.557 of this title (relating to Criteria for Selection of Non-Residential 
Soil Requirements for Risk Reduction Standard Number 2). 
   
  (d) The person must calculate MSCs in accordance with sec.335.558 of this 
title (relating to Medium Specific Concentrations for Risk Reduction Standard 
Number 2). 
   
  (e) The person must determine any cross-media requirements and modifications 
to cleanup levels in accordance with sec.335.559 of this title (relating to 
Medium Specific Requirements and Adjustments for Risk Reduction Standard Number 
2). 
 
     
  sec.335.557. Criteria for Selection of Non-Residential Soil Requirements for 
Risk Reduction Standard Number 2. All facilities or areas shall be subject to 
the residential soil requirements unless one of the conditions of paragraphs 
(1)-(3) of this section is satisfied for use of the non-residential soil 
requirements. 
 
  (1) For property located within the jurisdictional area of a zoning authority, 
persons may provide documentation that the property is zoned for commercial or 
industrial use. 
   
  (2) For property not located within the jurisdictional area of a zoning 
authority, persons may provide documentation that the activities being conducted 
on the property satisfy the definition for non-residential property (sec.335.553 
of this title (relating to Definitions)). 
   
  (3) For government-owned (local, state, or federal) property which does not 
satisfy either of the conditions of subsections (a) or (b) of this section but 
does have non-residential activities occurring on all or portions of the 
property, the person may provide documentation that access will be restricted 
such that the exposure assumptions remain valid for the duration of government 
control. 
 
     
  sec.335.558. Medium Specific Concentrations for Risk Reduction Standard Number 
2. 
 
  (a) Medium specific concentrations (MSCs) for ingestion of surface water and 
ground water, and soil ingestion along with inhalation of volatiles and 
particulates are calculated according to the procedures specified in subsections 
(b)-(d) of this section based on residential exposure factors. MSCs are subject 
to additional numeric criteria and adjustments of sec.335.559 of this title 
(relating to Medium Specific Requirements and Adjustments for Risk Reduction 
Standard Number 2). The derivation of all equations is presented in sec.335.567 
of this title (relating to Appendix I). 
   
  (b) For a contaminant which is a carcinogen, the MSC is the concentration 
which represents an excess upper bound lifetime cancer Target Risk (TR) of 
0.000001 (also expressed as one in one million) for Class A and B carcinogens, 
or 0.00001 (also expressed as one in 100,000) for Class C carcinogens due to 
continuous lifetime exposure as calculated using the equations and factors 
listed in paragraghs (1) and (2) of this subsection. 
 
  (1) Water MSC for Ingestion, in units of milligrams per liter (mg/L): 
 
  [graphic] 
   
  (2) Soil MSC for Ingestion with Inhalation of volatiles and particulates, in 
units of milligram per kilogram (mg/kg): 
 
  [graphic] 
     
  (c) For a contaminant which is a systemic toxicant, the MSC is the 
concentration to which human populations (including sensitive subgroups) could 
be exposed by direct ingestion or inhalation on a daily basis without 
appreciable risk of deleterious effects during a lifetime. The MSC is calculated 
using the equations and factors listed in paragraphs (1) and (2) of this 
subsection. 
 
  (1) Water MSC for Ingestion in units of milligram per liter (mg/L): 
 
  [graphic] 
   
  (2) Soil MSC for Ingestion with Inhalation of volatiles and particulates, in 
units of milligram per kilogram (mg/kg): 
 
  [graphic] 
     
  (d) Examples of unadjusted MSCs, standards and criteria are listed in 
sec.335.568 of this title (relating to Appendix II: "Examples of Medium Specific 
Concentrations, Standards and Criteria for Health-Based Closure/Remediation 
(sec.335.558)." The Commission will revise Appendix II on an annual basis to 
reflect newly promulgated standards and MSCs based on current toxicological 
data. 
 
     
  sec.335.559. Medium Specific Requirements and Adjustments for Risk Reduction 
Standard Number 2. 
 
  (a) Numeric cleanup levels. The subsections (b)-(h) of this section specify 
requirements that can define or modify numeric cleanup levels such as MSCs or 
require non-health based criteria to be addressed. 
   
  (b) Surface water. In determining the necessity for remediation at the 
facility, persons shall utilize Chapter 307 of this title (relating to Texas 
Surface Water Quality Standards) or, if those values are not available, Maximum 
Contaminant Levels (MCLs) promulgated under the Safe Drinking Water Act, or if 
MCLs are not available or appropriate, MSCs based upon human ingestion of the 
water. Any discharge or release into or adjacent to surface water, including 
storm water runoff, occurring during or after attainment of Risk Reduction 
Standard Number 2, shall be compliant with the Texas Surface Water Quality 
Standards of Chapter 307 of this title and may be subject to the permitting 
requirements of Chapter 305 of this title (relating to Consolidated Permits) or 
other authorization from the commission. 
   
  (c) Air. In determining the necessity for remediation at the facility, persons 
shall observe limitations established by the National Ambient Air Quality 
Standards (NAAQS) and the National Emission Standards for Hazardous Air 
Pollutants (NESHAPS) as found in the 40 Code of Federal Regulations Parts 50 and 
61, respectively, and other applicable federal standards and guidelines of the 
United States Environmental Protection Agency. Also, limitations established by 
the Texas Air Control Board (TACB) under the Texas Clean Air Act, the State 
Implementation Plan or other federal requirements must be observed. Permit 
requirements, limitations established by Standard Exemptions, or other 
requirements of the TACB relative to atmospheric emissions and/or air quality 
may also apply. 
   
  (d) Ground water. The ground-water cleanup levels shall be determined by a 
consideration of the following. 
 
  (1)  For residential exposure, the concentration of a contaminant dissolved in 
ground water must not exceed the Maximum Contaminant Level (MCL), if promulgated 
pursuant the Federal Safe Drinking Water Act, sec.141, otherwise the water MSC 
for ingestion determined pursuant to sec.335.556 of this title (relating to 
Determination of Cleanup Levels for Risk Reduction Standard Number 2). Phase-
separated non-aqueous liquids released from the unit that is undergoing closure 
or remediation must be removed or decontaminated. 
   
  (2)  For non-residential exposure, the concentration of a contaminant 
dissolved in ground water must not exceed the Maximum Contaminant Level (MCL) if 
promulgated pursuant to the Federal Safe Drinking Water Act, sec.141. If no MCL 
has been promulgated, the ground water concentration shall not exceed the water 
MSC for ingestion determined pursuant to sec.335.556 of this title (relating to 
Determination of Cleanup Levels for Risk Reduction Standard Number 2), which has 
been multiplied by a factor of 3.36 for carcinogens or 2. 8 for systemic 
toxicants to account for lower ingestion rates associated with non-residential 
worker exposure. Persons must be able to demonstrate that the quality of ground 
water at the facility property boundary will be protective for residential 
exposure. Phase-separated non-aqueous liquids released from the unit that is 
undergoing closure or remediation must be removed or decontaminated to the 
extent practicable. 
   
  (3) For residential and non-residential exposure, if the ground water at the 
facility or area has a naturally occurring background Total Dissolved Solids 
concentration greater than 10,000 milligrams per liter, the cleanup level for a 
contaminant dissolved in this ground water determined pursuant to paragraph (1) 
or (2) of this subsection, as appropriate, may be adjusted by multiplying by 
100. The resulting value becomes the maximum concentration for ground water for 
residential and non-residential exposure, respectively. 
   
  (4) The executive director may require the evaluation of additional exposure 
pathways or environmental receptors as part of the adjustment of paragraph (3) 
of this subsection. 
     
  (e) Soil. For all situations, concentrations of contaminants in soils must be 
protective of surface water, air and ground water as specified in subsections 
(b), (c), and (d) of this section. No soil remaining in place shall exhibit the 
hazardous waste characteristics of ignitability, corrosivity, or reactivity as 
defined in 40 Code of Federal Regulations, Part 261, Subpart C. The sum of 
concentrations of the volatile organic compounds in vapor phase in soil shall 
not exceed 1,000 parts per million by weight or volume, as measured by EPA Test 
Method 8015 or calculated by using soil concentrations and Henry's Law 
constants. 
   
  (f)  Residential soil requirements. In addition to the requirements of 
subsection (e) of this section, the concentration of a contaminant throughout 
the soil column (i.e., surface and subsurface soils) shall not exceed the lower 
of the Soil MSC, based upon residential human ingestion of soil and inhalation 
of particulates and volatiles (as defined in the preceeding section) , and the 
Residential Soil-to-Ground Water Cross-Media Protection Concentration, a numeric 
value which is determined as follows: 
 
  (1) a value which is one hundred times the residential ground water cleanup 
level determined by the procedures of paragraph (1) of subsection (d) of this 
section. Examples of such values are listed in Appendix II; or 
   
  (2) a concentration in soil that does not produce a leachate in excess of MCLs 
or MSCs for ground water when subjected to the Synthetic Precipitation Leaching 
Procedure, Method 1312 of SW 846, Test Methods for Evaluating Solid Waste, 
United States Environmental Protection Agency. Other test methods that more 
accurately simulate conditions at the facility may be used in the demonstration 
in place of this method, subject to prior approval of the executive director. 
     
  (g) Non-residential soil requirements. Non-residential soils shall conform to 
the requirements of subsection (e) of this section. The concentration of a 
contaminant in near-surface soils (i.e., within two feet of the land surface) 
shall not exceed the lower of the Non-Residential Soil MSC defined in paragraph 
(1) of this subsection, based upon worker ingestion of soil and inhalation of 
particulates and volatiles, and the Non-Residential Soil-to-Ground Water Cross-
Media Protection Concentration defined in paragraph (2) of this subsection. In 
no event shall compliance be achieved with the surface soil criteria by applying 
two feet of clean soil onto the surface of a facility or area without prior 
approval from the executive director. The concentration of a contaminant in 
subsurface soils (i.e., greater than two feet in depth from the land surface) 
shall not exceed the Non-Residential Soil-to-Ground Water Cross-Media Protection 
Concentration. 
 
  (1) Non-residential soil MSC. The MSC is calculated using the equations and 
factors listed in subparagraphs (A) and (B) of this paragraph. The chemical-
specific factors SF  [sub]o, SF [sub]i, RfD [sub]o, RfD [sub]i, and VF are the 
same as for the soil MSCs of the preceding section. The derivation of all 
equations is presented in Appendix I. 
 
  (A)  Carcinogenic Effects Equation, in units of milligram per kilogram 
(mg/kg): 
 
  [graphic] 
   
  (B) System: C Toxicant Effects Equation, in units of milligram per kilogram 
(mg/kg): 
 
  [graphic] 
     
  (2) Non-residential soil-to-ground water cross-media protection concentration. 
Persons must demonstrate that a contaminant in soil does not pose the potential 
for a future release of leachate in excess of the ground- water concentration 
considered to be protective for non-residential worker exposure. Persons may 
make this demonstration by showing that a contaminant occurs in soil at less 
than the concentration described in either subparagraph (A) or (B) of this 
paragraph: 
 
  (A) a concentration which is 100 times the non-residential ground-water 
cleanup level determined by the procedures of paragraphs (2) or (3), as 
applicable, of subsection (d) of this section; 
   
  (B) a concentration in soil that does not produce a leachate in excess of the 
ground-water concentration of this paragraph when subjected to the Synthetic 
Precipitation Leaching Procedure, Method 1312 of SW 846, Test Methods for 
Evaluating Solid Waste, U. S. Environmental Protection Agency. Other test 
methods that more accurately simulate conditions at the facility may be used in 
the demonstration in place of this method, subject to prior approval by the 
executive director. 
       
  (h) Other criteria. For contaminants that do not exceed standards or criteria 
protective of human health and environmental receptors as determined by the 
procedures of this section but otherwise adversely impact environmental quality, 
or the public welfare and safety, or present objectionable characteristics 
(e.g., taste, odor, etc.), or make a natural resource unfit for use, other 
scientifically valid published criteria may be utilized such as, but not limited 
to, Threshold Limit Values for air and secondary maximum contaminant levels for 
water. 
 
     
  sec.335.560. Post Closure Care and Deed Certification for Risk Reduction 
Standard Number 2. 
 
  (a) Provided that attainment of this risk reduction standard for the facility 
can be demonstrated to the executive director pursuant to sec.335.555 of this 
title (relating to Attainment of Risk Reduction Standard Number 2), the 
conditions of subsections (b) and (c) of this section apply. 
   
  (b) The person is required to place in the county deed records of the county 
or counties in which such activities take place the information specified in 
paragraphs (1)-(4) of this subsection. The statements should be worded such that 
a lay person can easily understand them. An example format is provided in 
sec.335.569 of this title (relating to Appendix III). Proof of deed 
certification of the required information shall be provided to the executive 
director in writing no later than 90 days after acceptance of the report 
required by sec.335.555(f) of this title (relating to Attainment of Risk 
Reduction Standard Number 2): 
 
  (1) a certification signed by the person, showing the person's full name and 
title, and stating that closure or remediation of the facility or area was 
carried out in accordance with a plan designed to meet sec.335.555 of this title 
(relating to Risk Reduction Standard Number 2), which mandates that the remedy 
be designed to eliminate substantial present and future risk, such that no post-
closure care or engineering or institutional control measures are required to 
protect human health and the environment; 
   
  (2) a metes and bounds description of the portion or portions of the tract of 
land on which closure or remediation of industrial solid waste, municipal 
hazardous waste or contaminants was achieved; 
   
  (3)  for a facility that satisfies the conditions of sec.335.557 of this title 
(relating to Criteria for Selection of Non-Residential Soil Requirements for 
Risk Reduction Standard Number 2) for use of non-residential soil requirements, 
a statement that current or future owners of the facility must undertake actions 
as necessary to protect human health and the environment in accordance with the 
rules of the commission; 
   
  (4) a statement that information and documents concerning the closure or 
remediation of the facility or area are available for inspection upon request at 
the Texas Water Commission. The statement shall further describe the 
jurisdiction of the Texas Water Commission to review the establishment of the 
final cleanup criteria. 
     
  (c)  The person is released from post-closure care responsibilities upon 
acceptance by the executive director of the proof of deed certification required 
by subsection (b) of this section. 
 
     
  sec.335.563. Media Cleanup Requirements for Risk Reduction Standard Number 3. 
 
  (a) General. For closure/remediation in accordance with Risk Reduction 
Standard Number 3, persons shall propose media cleanup levels in accordance with 
the conditions set forth in subsections (b)-(j) of this section. 
   
  (b) Carcinogens. For known or suspected carcinogens, media cleanup levels 
shall be established at concentrations which represent an excess upperbound 
lifetime risk of between one in 10,000 and one in one million. The executive 
director will use one in one million as a goal in establishing such 
concentration limits. The cumulative excess risk to exposed populations 
(including sensitive subgroups) shall not be greater than one in 10,000. 
   
  (c) Systemic toxicants. For systemic toxicants, media cleanup levels shall 
represent concentrations to which the human population (including sensitive 
subgroups) could be exposed on a daily basis without appreciable risk of 
deleterious effect during a lifetime or part of a lifetime and where: 
 
  (1) the hazard quotient, which is the ratio of a single systemic toxicant 
exposure level for a specified time period to a reference dose for that systemic 
toxicant derived from the same time period, shall not exceed one; and 
   
  (2) the hazard index shall not exceed one. The hazard index is the sum of the 
hazard quotients for a single or multiple systemic toxicants which affect the 
same target organ or act by the same method of toxicity and act through a single 
or multiple media exposure pathways. 
     
  (d)  Additional considerations. In establishing media cleanup levels pursuant 
to subsections (b) and (c) of this section, the executive director may consider 
and may direct persons who submit plans or reports in accordance with 
sec.335.553(b) of this title (relating to Required Information) to address the 
following: 
 
  (1) multiple contaminants in a medium; 
   
  (2)  exposure to multiple contaminated media; 
   
  (3) reasonable expected future exposure conditions at the facility; and 
   
  (4) the technical limitations, effectiveness, practicability, or other 
relevant features of available remedies. 
     
  (e) Standard exposure factors. In determining media cleanup levels pursuant to 
subsections (b) and (c) of this section, persons shall use the standard exposure 
factors for residential use of the facility as set forward in Table 1 (located 
following  sec.335.553) unless the person documents to the satisfaction of the 
executive director that: 
 
  (1)  site-specific data warrant deviation from the standard exposure factors; 
or 
   
  (2) a land use other than residential is more appropriate based on: 
 
  (A) historical, current, and probable future land use; and 
   
  (B)  effectiveness of institutional or legal controls placed on the future use 
of the land. 
       
  (f) Air. Media cleanup levels for air will be established to meet the lowest 
of the values determined by the requirements of paragraphs (1)-(3) of this 
subsection. 
 
  (1) Concentrations of contaminants in air that emanate from a facility, area 
of soil contamination, or plume of contaminated ground water shall not exceed: 
 
  (A) National Ambient Air Quality Standards (NAAQS), National Emission 
Standards for Hazardous Air Pollutants (NESHPAS) (as found in 40 Code of Federal 
Regulation Parts 50 and 61 respectively) and other applicable federal standards 
and guidelines of the Environmental Protection Agency; and 
   
  (B)  concentrations established by the Texas Air Control Board (TACB) under 
the Texas Clean Air Act, the State Implementation Plan or other federal 
requirements. Permit requirements, limitations established by Standard 
Exemptions, or other requirements of the TACB relative to atmospheric emissions 
and/or air quality may also apply. 
     
  (2) For residential exposure conditions, concentrations of contaminants in air 
that emanate from a facility, area of soil contamination, or plume of 
contaminated ground water shall not exceed concentrations that satisfy 
subsections (b)-(e) of this section at exposure points located both within the 
contaminated area and at the property boundary. 
   
  (3) For nonresidential exposure conditions, concentrations of contaminants in 
air that emanate from a facility, area of soil contamination, or plume of 
contaminated ground water shall not exceed either OSHA permissible exposure 
limits, threshold limit values or other criteria applicable to an industrial 
exposure setting within the facility boundaries or concentrations that satisfy 
subsections (b)-(e) of this section at the property boundary. 
     
  (g) Surface water. In determining the necessity for remediation at the 
facility, persons shall utilize Chapter 307 of this title (relating to Texas 
Surface Water Quality Standards) or, if those values are not available, Maximum 
Contaminant Levels (MCLs) promulgated under the Safe Drinking Water Act or, if 
MCLs are not available or appropriate, values calculated pursuant to subsections 
(b)-(e) of this section based upon human ingestion of the water or other site-
specific exposure pathway. Any discharge or release into or adjacent to surface 
water, including storm water runoff, occurring during or after attainment of 
Risk Reduction Standard Number 3, shall be compliant with Chapter 307 of this 
title and may be subject to the permitting requirements of Chapter 305 of this 
title (relating to Consolidated Permits) or other authorization from the 
Commission. 
   
  (h) Ground water. Media cleanup levels for ground water that is a current or 
potential source of drinking water as defined in paragraph (1) of this 
subsection shall not exceed Maximum Contaminant Levels (MCLs) promulgated under 
the Safe Drinking Water Act or, if MCLs are not available, values calculated 
according to subsections (b)-(e) of this section based upon human ingestion of 
the water. Cleanup levels for ground water may be subject to the modifications 
of paragraphs (2)-(4) of this subsection. 
 
  (1) Ground water that has a background Total Dissolved Solids (TDS) content 
less than or equal to 10,000 milligrams per liter (mg/L) and that occurs within 
a geologic zone that is sufficiently permeable to transmit water to a pumping 
well in usable quantities shall be considered a current or potential source of 
drinking water for the purpose of determining cleanup levels. 
   
  (2) The cleanup levels shall be achieved throughout the plume of contaminated 
ground water, with the exception of the circumstances described in subparagraphs 
(A)-(C) of this paragraph: 
 
  (A) when Alternate Concentration Limits of sec.335.160(b) of this title 
(relating to Alternate Concentration Limits) have been approved in a permit 
issued by the Commission for a hazardous waste management facility; 
   
  (B) when the selected remedy calls for waste to be left in place and when 
appropriate control measures are installed or operated, the executive director 
may authorize the zone underlying the area encompassing the original source(s) 
of release to be excluded from this requirement; 
   
  (C) when the person documents to the executive director's satisfaction 
pursuant to subsection (e) of this section that a future land use other than 
residential is appropriate for the facility or area and further demonstrates 
that institutional or legal controls will effectively prevent use of the 
contaminated ground water, the extent of plume remediation may be determined in 
a manner consistent with sec.335.160(b) of this title (relating to Alternate 
Concentration Limits). 
     
  (3) The executive director may determine that remediation of ground water to 
the extent required in paragraphs (1) or (2) of this subsection is not necessary 
if the person demonstrates to the executive director's satisfaction that: 
 
  (A) the contaminant is present in ground water that is not a current or 
potential source of drinking water and the contaminated ground water is not 
hydraulically connected with and is not likely to migrate to either surface 
water or to ground water that is a current or potential source of drinking 
water. 
   
  (B) restoration of the ground water to these levels is technically 
impracticable. 
     
  (4) If a determination is made pursuant to paragraph (3) of this subsection, 
the executive director may require any alternative measures or cleanup levels 
that are necessary to protect human health and the environment. At a minimum, 
for all cases described in this subsection, phase-separated non-aqueous liquids 
shall be removed from ground water zones to the extent practicable. 
     
  (i)  Soil. Concentrations of contaminants in soil shall not exceed the 
following values: 
 
  (1) the values calculated pursuant to subsections (b)-(d) of this section 
based upon human ingestion of the soils at all points where direct contact 
exposure to the soils may occur; and 
   
  (2) values which will allow the air, surface water, and ground-water cleanup 
levels specified in subsections (f), (g), and (h) of this section, respectively, 
to be maintained over time taking into account the effects of engineering 
controls. 
 
  (A) Such determinations shall be based on sound scientific principles 
including fate and transport evaluation of contaminant migration. Procedures and 
conclusions shall be documented to the satisfaction of the executive director. 
   
  (B) The executive director may require the evaluation of additional migration 
pathways beyond those listed in this section if determined necessary. Such 
additional pathways may include but are not limited to food chain contamination, 
impairment of soil for agricultural purposes, phytotoxicity, accumulations of 
contaminants in sediment of surface water bodies, or other impairments of 
natural resources, land, or water use. 
       
  (j) Other adjustments. Cleanup levels may be adjusted according to paragraphs 
(1)-(3) of this subsection. 
 
  (1) If the Practical Quantitation Limit (PQL) or the background concentration 
(represented by results of analyses of samples taken from media that are not 
affected by waste management or industrial activities) for a contaminant is 
greater than the cleanup level determined by procedures of this section, then 
the greater of the PQL or background shall become the cleanup level. 
   
  (2) Other scientifically valid published criteria, such as, but not limited 
to, Threshold Limit Values for air and secondary maximum contaminant levels for 
water, shall be utilized as cleanup levels for contaminants for which the 
procedures of this section are not appropriate (e.g., mixtures or substances 
that do not have toxicological data) or that do not exceed standards or criteria 
protective of human health as determined by the procedures of this section but 
otherwise adversely impact environmental quality, or the public welfare and 
safety, or present objectionable characteristics (e.g., taste, odor, etc.), or 
make a natural resource unfit for use. 
   
  (3) More stringent cleanup levels may be established for a facility than are 
specified in this section if, by utilizing available guidance or scientific 
literature, the executive director determines that it is necessary to protect 
environmental receptors. 
 
       
  sec.335.566. Deed Recordation for Risk Reduction Standard Number 3. 
 
  (a) Within 90 days after acceptance by the executive director of the final 
report referenced in sec.335.561 (a) of this title (relating to Attainment of 
Risk Reduction Standard Number 3), the person must record in the county deed 
records of the county or counties in which such activities take place the 
information specified in subsections (b)-(e) of this section and submit written 
proof of such recordation to the executive director. The statements should be 
worded such that a lay person can easily understand them. An example format is 
provided in sec.335.569 of this title (relating to Appendix III). 
   
  (b) A certification, signed by the person, showing the person's full name and 
title, and stating: that remediation of the facility or area was carried out in 
accordance with a plan designed to meet sec.335.561 of this title (relating to 
Risk Reduction Standard Number 3), which mandates that the remedy be designed to 
eliminate or reduce to the maximum extent practicable, substantial present and 
future risk; and (2) whether continued post-closure care or engineering or 
institutional control measures (Post-Closure Measures) are required to protect 
human health and the environment together with a description of any required 
Post-Closure Measures: 
 
  (1) a description of any institutional or legal controls placed by the person 
on the future use of the property. The notice shall indicate that the current or 
future owner must undertake actions as necessary to protect human health and the 
environment in accordance with the rules of the commission. 
   
  (2) a metes and bounds description of the portion or portions of the tract of 
land on which closure or remediation of industrial solid waste, municipal 
hazardous waste, or contaminants was achieved; and 
   
  (3) A statement that information and documents concerning the closure or 
remediation of the facility or area are available for inspection upon request at 
the Texas Water Commission. The statement shall further describe the 
jurisdiction of the Texas Water Commission to review the establishment of the 
final cleanup criteria. 
 
       
  sec.335.567. Appendix I.  Derivation of Reduced Equations for Calculation of 
Medium Specific Concentrations of Risk Reduction Standard Number 2. 
 
  
   
  
   
  
   
  
   
  
       
  
  Reference: U.S. EPA, OSWER Directive 9285.7-01B, December 13, 1991, Human 
Health Evaluation Manual, Part B: "Development of Risk-based Preliminary 
Remediation Goals" 
 
   
  sec.335.568. Appendix II.  Examples of Medium-Specific Concentrations, 
Standards, and Criteria for Health-Based Closure/Remediation (See sec.335.558 of 
this title (relating to Medium Specific Consentration of Risk Reduction 
Standards Number 2.)) 
   
  CAS # = Chemical Abstracts Service Number for the Specific Compound. 
   
  GW = Groundwater. Maximum Concentration in Ground water (mg/L) for residential 
exposure conditions. 
   
  GWP-Res = Ground-Water Protection Standard for Residential Use. Concentration 
in Residential Soil Assumed Protective of Groundwater Considering Cross-media 
Contamination of Groundwater from Contaminated Soil (mg/kg). 
   
  GWP-Ind = Groundwater Protection Standard for Industrial Use. Concentration in 
Industrial Soil Assumed Protective of Groundwater Considering Cross-media 
Contamination of Groundwater from Contaminated Soil (mg/kg). 
   
  SAI-Res = Soil/Air and Ingestion Standard for Residential Use. Maximum 
Concentration in Residential Soil Considering Cross-media Contamination of Air 
and the Human Ingestion and Inhalation Pathways (mg/kg). 
   
  SAI-Ind = Soil/Air and Ingestion Standard for Industrial Use. Maximum 
Concentration in Industrial Soil. 
   
  Considering Cross-media Contamination of Air and the Human Ingestion and 
Inhalation Pathways (mg/kg). 
 
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  
   
  [graphic] 
   
  (1) Concentrations for constituents are expressed in scientific notation. 
Examples 2.20E-00 = 2.2; 2.20E+02 = 220; and 2.20E-01 = 0.22. 
   
  (2) The development of final cleanup levels may involve other factors as 
described in this subchapter, such as cumulative health effects, that are not 
considered in this table. 
   
  (3) Groundwater concentrations are based on Maximum Contaminant Levels (MCLs) 
or the formula and parameters for residential use of groundwater which are 
contained in sec.335.567 of this title (relating to Appendix I). For non-
residential exposure conditions, the groundwater concentrations are calculated 
using the procedures of sec.335.559(d) (2) or (3). 
   
  (4) For some constituents, the Practical Quantitation Limit (PQL) may be the 
appropriate Groundwater MSC as described in sec.335.555(d)(1) of this title. See 
40 Code of Federal Regulations, Part 264 (Appendix IX) for a list of groundwater 
PQLs. 
   
  (5) Residential soil groundwater protection concentrations are based on a 
multiplication factor of 100 times the ground-water MSC. 
   
  (6) Industrial soil groundwater protection concentrations are based on a 
multiplication factor of 100 times the MCL or, when an MCL is not available, a 
factor of 100 times the groundwater concentration calculated using the formula 
and parameters which are contained in sec.335.559(d)(2) or (3) of this title. 
   
  (7) Residential soil concentrations (maximum) are calculated using the formula 
and parameters for residential land use which are contained in sec.335.567 of 
this title (relating to Appendix I). The person must also demonstrate that 
groundwater is protected and that no nuisance conditions exist (sec.335.559(a)-
(h) of this title). 
   
  (8) Industrial soil concentrations (maximum) are calculated using the formula 
and parameters for industrial land use which are contained in sec.335. 567 of 
this title (relating to Appendix I). The person must also demonstrate that 
groundwater is protected and that no nuisance conditions exist (sec.335. 559(a)-
(h) of this title). 
   
  (9) The final, proposed or listed Maximum Contaminant Level (MCL), from 
Section 141 of the Federal Safe Drinking Water Act. For lead, the Action Level 
for lead in drinking water is used as the MSC. 
   
  (10) All concentrations were calculated using data from the Integrated Risk 
Information System (IRIS) Chemical Files, or data from the Health Effects 
Assessment Summary Tables (HEAST), developed by the United States Environmental 
Protection Agency, Office of Research and Development and Office of Health and 
Environmental Assessment, Washington, D.C. 20460. The toxicity information, and 
the MSCs, will be updated as new information becomes available. 
   
  (11) In some cases, an oral Reference Dose (RFD) or an oral Slope Factor (SF) 
was substituted for the inhalation RFD or inhalation SF in calculating MSC. This 
MSC will be updated when this information becomes available. 
   
  (12) The MSCs calculated for this compound are based on noncarcinogenic 
effects. The following formula was used for calculating the soil MSCs: MSC = 
[(oral RFD)(Body Weight)(ED)(365 days/yr)]/[(EF)(ED)(IR)(CF)]. For residential 
soils, the following exposure factors were used: BW = 15 Kg; ED = five years; EF 
= 350 days/year; IR = 200 mg/day. For industrial soils, the following exposure 
factors were used: BW = 70 Kg; ED = 25 years; EF = 250 days/year; IR = 100 
mg/day. In both cases, the CF is 0.000001 kg/mg. When oral slope factors become 
available, these MSCs will be revised. 
   
  (13) As described in sec.335.559(e) of this title, the sum of concentrations 
of the volatile organic compounds in vapor phase in soil shall not exceed 1,000 
ppm by weight or volume. 
   
  (14) The MSC for lead in soil is based on values calculated by the United 
States EPA using the Lead Uptake/Biokinetic Model, Version 0.4, which has been 
developed by the United States EPA Office of Health and Environmental 
Assessment. 
   
  (15) Soil MSCs for polychlorinated biphenyls are based upon the April 2, 1987 
TSCA regulations, 40 Code of Federal Regulation, sec.761.125 (see 52 FR 10688). 
   
  (16)  NHHB = Not Human Health Based. The SAI-Ind MSC for this compound exceeds 
10e+6 ppm, which means it is not toxic to humans when exposed to soils under 
these assumptions. Persons must consider other criteria of sec.335.559 of this 
title (relating to Medium Specific Requirements and Adjustments for Risk 
Reduction Standards Number 2) to develop numeric cleanup values. 
 
     
  sec.335.569. Appendix III. 
   
  MODEL DEED CERTIFICATION LANGUAGE 
   
  STATE OF TEXAS 
   
  (_____________) COUNTY 
   
  INDUSTRIAL SOLID WASTE 
   
  CERTIFICATION OF REMEDIATION 
   
  KNOW ALL MEN BY THESE PRESENTS THAT: Pursuant to the Rules of the Texas Water 
Commission pertaining to Industrial Solid Waste Management, this document is 
hereby filed in the Deed Records of__________ County, Texas in compliance with 
the recordation requirements of said rules: 
   
  I 
   
  (Company Name) has performed a remediation of the land described herein. A 
copy of the Notice of Registration (No.), including a description of the 
facility, is attached hereto and is made part of this filing. A list of the 
known waste constituents, including known concentrations (i.e., soil and ground 
water, if applicable), which have been left in place is attached hereto and is 
made part of this filing. Further information concerning this matter may be 
found by an examination of company records or in the Notice of Registration 
(No.) files, which are available for inspection upon request at the central 
office of the Texas Water Commission in Austin. 
   
  The Texas Water Commission derives its authority to review the remediation of 
this tract of land from the Texas Solid Waste Disposal Act, sec.361.002, Texas 
Health and Safety Code, Chapter 361, which enables the Texas Water Commission to 
promulgate closure and remediation standards to safeguard the health, welfare 
and physical property of the people of the State and to protect the environment 
by controlling the management of solid waste. In addition, pursuant to the Texas 
Water Code, sec.5.012 and sec.5.013, Texas Water Code, Annotated, Chapter 5, the 
Texas Water Commission is given primary responsibility for implementing the laws 
of the State of Texas relating to water and shall adopt any rules necessary to 
carry out its powers and duties under the Texas Water Code. In accordance with 
this authority, the Texas Water Commission requires certain persons to provide 
certification and/or recordation in the real property records to notify the 
public of the conditions of the land and/or the occurrance of remediation. This 
deed certification is not a representation or warranty by the Texas Water 
Commission of the suitability of this land for any purpose, nor does it 
constitute any guarantee by the Texas Water Commission that the remediation 
standards specified in this certification have been met by (Company name). 
   
  II 
   
  Being a acre tract, more or less, out of the (Company Name)'s acre tract in 
the (Name) League (No.), Abstract (No.), recorded in Volume (No.), Page (No.) of 
the Deed of Records__________ County, Texas, said_________ acre tract being more 
particularly described as follows: 
   
  (Insert metes and bounds description here) 
   
  For Standard 2 cleanups: (Contaminants/contaminants and waste) deposited 
hereon have been remediated (to meet residential soil criteria/to meet non-
residential (i.e., industrial/commercial) soil criteria)), in accordance with a 
plan designed to meet the Texas Water Commission's requirements in 31 Texas 
Administrative Code, sec.335.555), which mandates that the remedy be designed to 
eliminate substantial present and future risk such that no post-closure care or 
engineering or institutional control measures are required to protect human 
health and the environment. Future land use is considered suitable for 
(residential, non-residential (i.e., industrial/commercial)) purposes in 
accordance with risk reduction standards applicable at the time of this filing. 
Future land use is intended to be (residential, non-residential). 
   
  For Standard 3 cleanups: (Contaminants/contaminants and waste) deposited 
hereon have been remediated (to meet residential soil criteria/to meet non-
residential (i.e., industrial/commercial) soil criteria) in accordance with a 
plan designed to meet the requirements of 31 Texas Administrative Code  
sec.335.561 (Risk Reduction Standard Number 3), which mandates that the remedy 
be designed to eliminate or reduce to the maximum extent practicable, 
substantial present or future risk. The remediation plan (does/does not) require 
continued post-closure care or engineering or institutional control measures. 
Future use of the property is considered appropriate for (describe) in 
accordance with risk reduction standards applicable at the time of this filing. 
Institutional or legal controls placed on the property to ensure appropriate 
future use include (describe). 
   
  For both Standard 2 and 3 cleanups where the remedy is based upon non-
residential soil criteria: The current or future owner must undertake actions as 
necessary to protect human health or the environment in accordance with the 
rules of the Texas Water Commission. 
   
  III 
   
  The owner of the site is (Company Name), a Texas corporation, and its address 
is (P.O. Box or Street), (City), Texas (Zip Code), where more specific 
information may be obtained from the (plant manager, owner). 
 
  
   
  
  [graphic] 
       
  This agency hereby certifies that the rule as adopted has been reviewed by 
legal counsel and found to be a valid exercise of the agency's legal authority. 
 Issued in Austin, Texas, on June 7, 1993. 
 TRD-9323981 
  Mary Ruth Holder 
 Director, Legal Division 
 Texas Water Commission 
    Effective date: July 28, 1993 
 Proposal publication date: December 8, 1992 
 For further information, please call: (512) 908-6087