Seagrass Conservation Plan for Texas
. This plan
has been endorsed by the Texas Parks and Wildlife Department, the General
Land Office, and the commission. However, the commission is soliciting specific
comment on whether inclusion in the Texas Surface Water Quality Standards
is the most effective way to provide that protection.
The existing Texas Surface Water Quality Standards require the protection
of aquatic life uses, including seagrass propagation. Based upon the existing
rules, the commission has been taking regulatory actions to maintain and protect
seagrass propagation. Examples of these regulatory actions include setting
terms and conditions for TPDES permits and consideration of seagrass as part
of state water quality certification of U.S. Army Corps of Engineers permits
authorizing the fill of water in the state.
In addition, preservation and protection of submerged aquatic vegetation
is an established goal and policy of Texas's approved Coastal Management Plan
per 31 TAC §501.1(a). The commission has established procedures to consider
impacts of its regulatory actions on coastal water resources, including seagrass.
In accordance with §281 subchapter B of this title, the executive director
produces a written summary of its proposed regulatory action and its determination
of consistency with the goals and policies of the Coastal Management Plan.
In view of the existing regulatory framework, the commission is soliciting
public comment on whether the proposed amendment of §307.7(b)(5) would
be either necessary or more effective in implementing the Seagrass Conservation
Plan. Since seagrass propagation is an aquatic life use and habitat is already
protected by the Texas Surface Water Quality Standards, would there be an
additional benefit from its specific mention as a protected aquatic life use?
Is there some added protection of this important natural resource which would
result, considering that this would not increase the commission's existing
regulatory authority? Are there other alternatives to the amendment of the
Texas Surface Water Quality Standards available to the commission that would
increase the protection of seagrass propagation? Receipt of public comment
on this proposal will assist the commission in determining whether final adoption
of the standard is beneficial or necessary.
Proposed changes to §307.8, relating to Application of Standards,
clarifies the stream flow conditions where acute toxic criteria apply. The
revisions specify that acute toxic criteria apply at stream flows above 1/4
of 7Q2. The revisions also clarify that pollutants in storm water will not
impair existing or designated uses. The revisions go on to explain that short
term exceedances of numerical criteria may not be considered a violation of
water quality standards unless the exceedance is due to human activity and
would not occur without that activity.
Proposed changes to §307.9, relating to Determination of Standards
Attainment, update procedures such as the required approval by the commission
of sampling locations and the procedures for the collection and preservation
of water samples--for assessing instream standards compliance. This proposed
revision is needed to maintain consistency and quality assurance in reporting.
The revisions provide new provisions for measuring biological integrity which
is assessed by sampling the presence and abundance of aquatic organisms. This
proposal is in accordance with EPA guidance and current technical practices.
Proposed changes to §307.10, relating to Appendices A-E, include changes
to aquatic life uses for the lower Pease River (new segment 0230) from High
to Intermediate, the upper arm of Sam Rayburn reservoir (new segment 0615)
from High to Intermediate, and the Nueces River Tidal (segment 2101) from
Exceptional to High in Appendix A. These proposed changes are based on the
results of Use Attainability Assessments that have been performed. Proposed
changes in Appendix A also include (1) the creation of two new segments (1256--Brazos
River/Lake Brazos and 1257--Brazos River Below Whitney Lake) from existing
segment 1242 which has been renamed to Brazos River Above Navasota River,
and (2) the creation of segment 1802--Guadalupe River Below San Antonio River
from existing segment 1803--Guadalupe River Below San Marcos River to account
for different hydrological conditions and dissolved minerals (total dissolved
solids, chlorides, and sulfates) gradients and different ambient concentrations.
Another new segment, segment 0502--Sabine River Above Tidal, has been created
from the upper portion of segment 0501--Sabine River Tidal and the lower portion
of segment 0503--Sabine River Below Toledo Bend Reservoir, which has been
renamed Sabine River Above Caney Creek, to account for different hydrological
conditions. Dissolved minerals criteria revisions are proposed for numerous
segments based on new calculations using updated information. Other proposed
changes to §307.10 include the addition of the aquifer protection use
to 14 existing segments (1243--Salado Creek, 1244--Brushy Creek, 1248--San
Gabriel/North Fork San Gabriel River, 1249--Lake Georgetown, 1250--South Fork
San Gabriel River, 1251--North Fork San Gabriel River, 1804--Guadalupe River
Below Comal River, 1806--Guadalupe River Above Canyon Lake, 1809 Lower Blanco
River, 1810--Plum Creek, 1811--Comal River, 1814--Upper San Marcos River,
1815--Cypress Creek, and 1903--Medina River Below Medina Diversion Lake),
and the addition of the public water supply use to segment 2308--Rio Grande
Below International Dam. The protection of these segments is included in the
Chapter 213 Edwards Aquifer rules and noted in Appendix A. The pH range for
segment 0507--Lake Tawakoni has been revised as a result of additional data.
Proposed new indicator bacteria and criteria for recreational uses are also
included in Appendix A. Proposed changes to Appendix B include a recalculation
of critical-condition flows to incorporate more recent instream flow data.
Appendix C proposed changes include descriptions for new segments, and revised
descriptions for those segments affected by the creation of the new segments
in Appendix A. Segment boundary revisions are also proposed for segments 0608--Village
Creek, 0823--Lewisville Lake, 0839--Elm Fork Trinity River Below Ray Roberts
Lake, 1013--Buffalo Bayou Tidal, 1107 and 1108--Chocolate Bayou Tidal and
Above Tidal, 1245--Oyster Creek, and 2003 and 2004--Aransas River Tidal and
Above Tidal. Other segment description revisions are proposed to clarify or
to correct clerical errors in existing descriptions of segments found in Appendix
A. Proposed changes to Appendix D include the addition of 106 sites with designated
aquatic life uses and dissolved oxygen criteria, an addition of a seasonal
dissolved oxygen criterion and site-specific flow for Rabbit Creek (tributary
to segment 0505), an upgrade of dissolved oxygen criteria from 3.0 mg/L to
5.0 mg/L for Alto Branch and Larisson Creek in segment 0604, a lowering from
4.0 mg/L to 3.0 mg/L of the dissolved oxygen criterion for Jefferson County
canals in segment 0702, and an extension of site-specific dissolved oxygen
criteria in Bear Creek, South Mayde Creek, and Mason Creek in segment 1014
to include channelized portions of the creeks. Aquatic life use for the portion
of Brushy Creek upstream of the segment 1244--Brushy Creek boundary has been
upgraded from intermediate to high based on a recent receiving water assessment
using current commission protocols for field collections. Changes to Appendix
E include the addition of site specific toxic criteria for 16 sites. Criteria
in Appendix E have been recalculated to incorporate EPA conversion factors
for metals. The proposed changes in Appendices A-E were made to incorporate
results of numerous studies and monitoring and sampling assessments on individual
water bodies conducted by the commission, river authorities, and in some cases,
individual permittees.
FISCAL NOTE
Bob Orozco, Technical Specialist with Strategic Planning and Appropriations,
has determined that for the first five-year period the proposed amendments
are in effect there will be significant fiscal implications for the cities
of Fairfield and Yoakum. The proposed amendments may require certain wastewater
facilities that discharge into Texas bodies of water to perform additional
monitoring and reporting and/or upgrade their facilities. These upgrades will
include renovation or construction of new wastewater treatment facilities.
The only Texas local units of government that are known to be affected by
the proposed amendments are the cities of Fairfield and Yoakum. The only state
agencies that are known to have wastewater facilities that discharge into
Texas bodies of water and could potentially be affected by the proposed amendments
are the Texas Department of Criminal Justice, Texas Parks and Wildlife Department,
the Texas Department of Transportation, and certain state universities. The
commission staff conducted a review of related wastewater permits for the
Texas Department of Criminal Justice, Texas Parks and Wildlife, Texas Department
of Transportation, and public colleges and universities. In all cases, permit
limits were not at levels that would be affected by the proposed amendments
or were not affected by the proposed revisions to standards. In addition,
the commission staff did not identify any units of state and local government
that would be affected by revisions to toxic criteria or recreational use
standards. As a result, no significant fiscal implications are anticipated
to state and local units of government, except as noted for the cities of
Fairfield and Yoakum, as a result of administration and enforcement of the
proposed amendments.
The proposed amendments may require certain units of local government and
agricultural and industrial businesses that own and operate wastewater facilities
that discharge into Texas bodies of water to perform additional monitoring
and reporting and/or upgrade their facilities. These upgrades may range from
making changes to treatment processes or renovation or construction of new
wastewater treatment facilities. No state agencies are known to be affected
by the proposed amendments. Two municipal wastewater facilities, the City
of Fairfield and the City of Yoakum wastewater treatment facilities, are projected
to need more stringent treatment limits than are currently imposed in the
existing permit in order to meet the proposed site-specific standard. The
costs to upgrade these facilities are estimated to be approximately $1.9 million
and $1.8 million, respectively.
The proposed amendments apply to state, municipal, agricultural, and industrial
facilities that discharge wastewater directly into bodies of water in Texas.
The proposed amendments may have cost implications associated with revised
criteria for toxic substances to protect human health and aquatic life, revised
criteria for recreational uses, and revised dissolved oxygen criteria and
aquatic-life use for classified and unclassified water segments. Potential
costs are associated with substance screening and monitoring and the additional
treatment of wastewater which may be needed to meet the standards for water
quality. A minimal number of industrial dischargers may have to change or
employ new wastewater treatment methods or techniques in order to meet the
proposed standards. Cost implications for screening and monitoring are anticipated
to be minimal because, in most cases, the screening and monitoring is already
being done.
Although the proposed amendments include four new substances and various
criteria changes to existing substances, which will result in both increases
and decreases in permit limits, there are no anticipated additional costs
to facilities or the commission for monitoring these substances because the
commission currently screens applications and requires permit holders to monitor
for those substances. The four new substances in the proposed amendments are
acrylonitrile, atrazine, perchlorate, and 1,3 dichloropropene. However, there
are cost implications associated with potential treatment for toxic substances
in wastewater.
In the proposed amendments, 27 toxic substances have criteria more stringent
than in current rules; 8 toxic substances have criteria less stringent than
in current rules; and 34 toxic substances remain unchanged. There are potential
additional costs associated with the proposed criteria for the 27 toxic substances
with more stringent standards in unclassified segments of water bodies. Where
applicable, the costs associated with conforming to toxic standards will be
determined by the size and current condition of a treatment facility, the
extent of current controls, and the nature of the wastewaters, and the receiving
waters. Because of the variability in receiving waters, the number of toxic
substances, and the current condition of treatment facilities, an engineering
study and design may be required to determine the extent of facility or process
changes and associated costs that will be required in order to comply with
the proposed requirements. This variability would require a site-specific
analysis in order to determine the costs associated with achieving proposed
standards for toxic substances. Such site-specific analyses are not available
at this time. In order to gain some insight into costs associated with toxic
treatment, the commission analyzed current wastewater discharge permits and
generalized costs associated with end-of-pipe activated carbon adsorption
technology. The review of current wastewater discharge permits indicated that
there are approximately 66 industrial wastewater discharges which potentially
contain one or more of the organic toxic pollutants for which more stringent
criteria are proposed. These 66 discharges represent all industrial discharges
in the state which potentially have the pollutants of concern to the extent
those pollutants are identified in existing commission databases. The commission
staff anticipates that the actual number of discharges that will be affected
by the proposed amendments to toxic criteria are much less than the 66 noted
above. In most cases, these dischargers will not be affected by the proposed
amendments. In those instances where a new or more stringent effluent limit
might be required, the effluent limit is expected to be achieved by changes
in industrial processes or changes in operating procedures. Should a discharger
be required to construct an additional wastewater treatment system, the commission
staff has estimated that construction cost could be as high as $4.9 million
for an added treatment system for discharge of 1 million gallons per day (MGD).
Although EPA estimates that such costs may range from approximately $1.3 million
per million gallons of discharge for a 20 MGD treatment facility to $12.1
million per million gallons of discharge for a .01 MGD treatment facility,
the commission staff anticipates that the upper ranges are unlikely to be
required. These estimates are based upon the use of end-of-pipe activated
carbon adsorption technology, which is only one possible type of treatment
to reduce the concentration of toxic pollutants. The commission recognizes
that other types of treatment are likely, each with a unique cost associated
with site-specific circumstances. This fiscal note does not purport to mandate
a method of treatment nor to provide all of the costs some facilities may
incur in process or facility upgrades to meet the requirements in the proposed
amendments. The commission invites public comment concerning direct costs
attributable to the proposed amendments.
Unclassified perennial water bodies are assigned a presumed high aquatic
life use and associated dissolved oxygen criteria in the absence of site-specific
information. In the proposed amendments to Appendix D, 55 of the 77 unclassified
perennial water bodies have proposed standards based on the most recent site-specific
assessments and testing which more accurately describe the ambient conditions
of the water segment, are less stringent, and are still protective of water
quality. Each of the 199 facilities that currently discharge into the unclassified
water bodies was evaluated to determine if substantial wastewater treatment
upgrades were needed to meet proposed site-specific standards. For this evaluation,
commission staff modeled in-stream dissolved oxygen to determine treatment
levels necessary to meet the proposed standard, and if necessary, estimated
potential upgrade costs using EPA construction costs for wastewater treatment
plants. Two wastewater facilities, the City of Fairfield and the City of Yoakum
facilities, are projected to need more stringent treatment limits than are
currently imposed in the existing permit in order to meet the proposed site-specific
standard. The costs to upgrade these facilities are estimated to be approximately
$1.9 million and $1.8 million, respectively. If the estimated $1.9 million
capital costs to upgrade the Fairfield wastewater facility were capitalized,
annualized, and divided evenly among ratepayers, rates are estimated to increase
by approximately $13 per month (assuming 2.5 members per family and a population
of 3391). If the estimated $1.8 million capital costs to upgrade the Yoakum
wastewater facility were capitalized, annualized, and divided evenly among
ratepayers, rates are estimated to increase by approximately $6.36 per month
(assuming 2.5 members per family and a population of 6364).
Estimates were also completed to determine potential costs to dischargers
if permittees are required to meet the current presumed high aquatic life
use criteria. It was determined that the adoption of the proposed amendments
would remove adverse fiscal impacts to certain permittees by replacing presumed
standards with more accurate site-specific standards. The analysis identified
five wastewater dischargers that would have to complete substantial upgrades
to their facilities if the proposed amendments are not adopted. These five
dischargers are not currently required to meet a high aquatic life use because
the presumed aquatic life use for the receiving water at the time of their
last permit application was "intermediate". Information recently provided
the commission indicates that the receiving water body is "perennial" rather
than "intermittent", so the actual applicable presumed use is high aquatic
life use. The estimated cost to upgrade each of these facilities for high
aquatic life use ranged from approximately $300,000 to $4 million. These costs
are avoided if the proposed amendments are adopted. The combined avoided costs
for the five facilities totaled $6.8 million. In addition, if the current
high aquatic life use and associated 5 milligrams per liter of dissolved oxygen
criteria remained in place for Segment 1014, the 58 facilities that discharge
to Buffalo Bayou would receive a "No Discharge" recommendation and would not
be permitted to discharge into that segment. It is anticipated that the costs
to transport or pump the effluent to another area for disposal would be economically
extremely adverse. This situation is also avoided by adopting the proposed
site-specific standards.
Site-specific metals criteria proposed for 16 sites in Appendix E of Chapter
307 are also less stringent than existing criteria. The site-specific criteria
in the proposed rule are expected to avoid the imposition of inappropriately
stringent standards criteria and the associated upgrade costs for 16 industrial
discharge permits.
PUBLIC BENEFIT
Mr. Orozco has also determined that for each year of the first five years
the proposed amendments to Chapter 307 are in effect, the public benefit anticipated
from enforcement of and compliance with the proposed amendments will be increased
protection of public drinking water supplies and aquatic life resources, an
improved regulatory process for permitted wastewater discharges, and potentially
improved quality of the surface water resources of the state.
SMALL BUSINESS AND MICRO-BUSINESS ANALYSIS
There are no significant fiscal implications anticipated for small and
micro-businesses as a result of implementing the proposed amendments. Few
small or micro-businesses hold TPDES permits with the commission. Small and
micro-businesses ordinarily dispose of wastewater by conveyance into city
sewer systems. Facilities that discharge into municipal waste systems are
required to pre-treat their waste prior to discharge. Complying with more
stringent water quality standards is the responsibility of the city holding
the TPDES permit. Since the revisions to the toxic criteria are not expected
to affect municipalities, it is anticipated that small and micro-businesses
will not be directly affected by the proposed amendments.
Small and micro-businesses served by municipal or commercial wastewater
facilities may incur indirect additional costs from increased service rates
from local governments or other operators of treatment facilities who must
recover increased wastewater treatment costs from their customers. These costs
are not anticipated to be significant. Because of the variability in treatment
costs and the variability in facility characteristics and rates, the costs
to individual customers would require a case-by-case analysis for each customer.
The commission staff anticipates that in most cases, the fiscal impact of
the proposed amendments will be minimal. If facility upgrade costs are capitalized
and annualized, the effect on wastewater ratepayers should be minimal if the
customer base is of a moderate size. For smaller cities such as Fairfield
and Yoakum, the average additional costs per rate payer per month are not
anticipated to be significant. If the estimated $1.9 million capital costs
to upgrade the Fairfield Wastewater Treatment Plant were capitalized, annualized,
and divided evenly among ratepayers, rates are estimated to increase by approximately
$13 per month (assuming 2.5 members per family and a population of 3391).
If the estimated $1.8 million capital costs to upgrade the Yoakum wastewater
facility were capitalized, annualized, and divided evenly among ratepayers,
rates are estimated to increase by approximately $6.36 per month (assuming
2.5 members per family and a population of 6364).
DRAFT REGULATORY IMPACT ANALYSIS
The commission has reviewed the proposed rulemaking in light of the regulatory
analysis requirements of Texas Government Code §2001.0225, and has determined
that the rulemaking may meet the definition of a major environmental rule
as defined in that statute. "Major environmental rule" means a rule the specific
intent of which is to protect the environment or reduce risks to human health
from environmental exposure and that may adversely affect in a material way
the economy, a sector of the economy, productivity, competition, jobs, the
environment, or the public health and safety of the state or a sector of the
state. The proposed amendments to Chapter 307 will require 2 cities and may
require certain agricultural, and industrial wastewater dischargers to change
or employ new treatment methods or techniques in order to comply with the
proposed standards. These changes or methods may range from developing new
techniques or changing best management practices to renovating, expanding,
or building an entirely new treatment facility. The proposed rules are intended
to protect the environment or reduce risks to human health and safety from
environmental exposure and may have adverse effects on certain wastewater
dischargers which could be considered a sector of the economy. Although the
proposed amendments may meet the definition of a major environmental rule
as defined in the act, it does not meet any of the four applicability requirements
listed in §2001.0225(a) which states that this section applies only to
a major environmental rule, the result of which is to:
1. exceed a standard set by federal law, unless the rule is specifically
required by state law;
2. exceed an express requirement of state law, unless the rule is specifically
required by federal law;
3. exceed a requirement of a delegation agreement or contract between the
state and an agency or representative of the federal government to implement
a state and federal program or;
4. adopt a rule solely under the general powers of the agency instead of
under a specific state law.
Specifically, the standards and requirements within this proposal were
developed in order to conform to the Federal Clean Water Act and the Texas
Water Code. The proposed amendments do not exceed a standard set by federal
law, exceed an express requirement of state law, nor exceed a requirement
of a delegation agreement. The proposed amendments were not developed solely
under the general powers of the agency but were specifically developed to
meet water quality standards established under federal and state law. In addition,
the proposed standards are being proposed under authority of the Texas Water
Code, which authorizes the commission to set water quality standards by rule.
The code directs the commission to consider the existence and effects of nonpoint
source pollution, toxic materials, and nutrient loading in developing water
quality standards. The commission invites public comment on the draft regulatory
impact analysis.
TAKINGS IMPACT ANALYSIS
The commission has prepared a takings impact assessment for these rules
pursuant to Texas Government Code Annotated, §2007.043. The following
is a summary of that assessment. The Texas Surface Water Quality Standards
(30 TAC Chapter 307) establish instream water quality standards for Texas
streams, rivers, lakes, estuaries, and other waterbodies such as wetlands.
The commission is required to establish water quality standards in Texas Water
Code, §26.023. The Federal Clean Water Act requires states to publicly
review and revise the state's surface water quality standards every three
years. The current proposed revisions will satisfy federal requirements for
a triennial review. The adjustments of criteria for dissolved metals and consideration
of new procedures for human health criteria are needed to incorporate new
EPA requirements. These revised criteria will be more protective of human
health and provide a public benefit. The site-specific standards are needed
to incorporate new sampling data and to establish the appropriate revisions
in the rule so that permit issues related to specific waterbodies may be resolved.
Site-specific standards more accurately describe the ambient quality of the
water body. These site-specific standards also provide more accurate permit
requirements that are protective of human health, in most cases economically
affordable, and enhances water quality.
The specific purpose of the proposed action is to satisfy state statute
requirements,§26.023 Texas Water Code, and Federal Clean Water Act, §303(d),
requirements, and to more accurately assess water quality in the state and
revise requirements to protect human health and water quality. The proposed
rules would substantially advance this stated purpose by adopting water quality
criteria and requirements that are supported by site-specific studies, federal
and state research, and statewide monitoring and sampling data. Promulgation
and enforcement of these rules will not burden private real property which
is the subject of the rules because the proposed amendments revising the state's
surface water quality standards do not limit or restrict a person's rights
in private real property.
COASTAL MANAGEMENT PROGRAM CONSISTENCY REVIEW
The executive director has reviewed the proposed rulemaking and found that
the proposal is a rulemaking that will affect an action/authorization identified
in the Coastal Coordination Act Implementation Rules, 31 TAC, §505.11,
and will, therefore, require that applicable goals and policies of the Coastal
Management Plan (CMP) be considered during the rulemaking process.
The commission has prepared a consistency determination for the proposed
rules pursuant to 31 TAC, §505.22 and has found the proposed rulemaking
is consistent with the applicable CMP goals and policies. The following is
a summary of that determination. The proposed rulemaking would be consistent
with the CMP goal of protecting, preserving, restoring and enhancing the diversity,
quality, quantity and functions, and values of coastal natural resources by
establishing standards and criteria for instream water quality for Texas streams,
rivers, lakes, estuaries, and other waterbodies such as wetlands. These proposed
water quality standards and criteria will provide parameters for permitted
discharges that will protect, preserve, restore and enhance the quality, functions
and values of coastal natural resources. The proposed rulemaking will also
provide for clearer and more protective conditions for variances that will
ensure sound management of all coastal resources by allowing for compatible
economic development and multiple human uses of the coastal zone. These variance
conditions will allow dischargers an opportunity to examine options for upgrades
while maintaining water quality that will allow for human uses of the coastal
waters.
The proposed rulemaking will require wastewater discharge permit applicants
to provide information and monitoring data to the commission so that the commission
may make an informed decision in authorizing the discharge permit and ensuring
that the authorized activities in the permit comply with all applicable requirements,
thus making the rulemaking consistent with the administrative policies of
the CMP. The proposed rulemaking also provides clarity and identifies the
circumstances in which the commission will consider and grant variances from
the standards.
The proposed rulemaking considers information gathered through the yearly
assessments of water quality in the commission's Water Quality Inventory to
prioritize those coastal waters for studies and analysis in reviewing and
revising the state's surface water quality standards. The standards are established
to protect designated uses of coastal waters including protection of uses
for recreational purposes and propagation and protection of terrestrial and
aquatic life. The proposed rulemaking is consistent with the CMP's policies
for discharges of municipal and industrial wastewater to coastal waters and
how they relate to specific activities and coastal natural resource areas.
The proposed revisions to §307.2, relating to Description of Standards, §307.3,
relating to Definitions and Abbreviations, §307.4, relating to General
Criteria, §307.5, relating to Antidegradation, §307.6, relating
to Toxic Materials, §307.7, relating to Site-specific Uses and Criteria, §307.8,
relating to Application of Standards and Appendices A-E as they pertain to
designated tidal segments within the CMP boundary, will need to be submitted
to the Coastal Coordination Council for recertification.
PUBLIC HEARING
A public hearing on the proposal will be held March 21, 2000 at 10:00 a.m.
in Room 201S of the commission Building E, located at 12100 Park 35 Circle,
Austin. The hearing is structured to receive oral or written comments by interested
parties. Individuals may present oral statements, when called upon, in order
of registration. Open discussion will not occur during the hearing; however,
a commission staff member will be available to discuss the proposal 30 minutes
prior to the hearing and will answer questions before and after the hearing.
PUBLIC COMMENT PERIOD
Written comments on the proposal should refer to Rule Log Number 98055-307-WT
and may be submitted to Bettie Bell, Texas Natural Resource Conservation Commission,
Office of Environmental Policy, Analysis, and, Assessment, MC 205, P.O. Box
13087, Austin, Texas, 78711-3087, (512) 239-6087. Comments may be faxed to
(512) 239-5687, but must be followed by the submission and receipt of the
written comments within three working days of when they were faxed. Written
comments must be received by 5:00 p.m., March 31, 2000. For further information
concerning this proposal, please contact James Davenport, Texas Natural Resource
Conservation Commission, Water Quality Assessment Section, at (512) 239-4585.
STATUTORY AUTHORITY
These amendments are proposed under the Texas Water Code, §26.023,
which provides the Commission with the authority to make rules setting water
quality standards for all waters in the state, and under the Texas Water Code, §5.103,
which authorizes the commission to adopt any rules necessary to carry out
its powers and duties under the Water Code and other laws of this state.
No other codes or statutes will be affected by this proposal.
§307.2.Description of Standards.
(a)
Contents of the Texas Surface Water Quality Standards.
(1)-(9)
(No change.)
(10)
Section 307.10 of this title (relating to Appendices
A-E) lists site-specific standards and supporting information for classified
segments (Appendices A-C), partially classified
water bodies
[
waterbodies
] (Appendix D), and site-specific criteria that may be derived
for any
water
[
waters
] in the state (Appendix E). Specific
appendices are as follows:
(A)-(C)
(No change.)
(D)
Appendix D--Site-specific Receiving Water Assessments;
and,
[
.
]
(E)
(No change.)
(b)-(c)
(No change.)
(d)
Modification of standards.
(1)-(2)
(No change.)
(3)
The narrative provisions, designated uses, and numerical
criteria of the Texas Surface Water Quality Standards may be amended for a
specific
water body
[
waterbody
] to account for local
conditions. A site-specific standard is an explicit amendment to this title,
Chapter 307 (Texas Surface Water Quality Standards), and adoption of a site-specific
standard requires the procedures for public notice and hearing established
under the Texas Water Code, §26.024 and §26.025. An amendment which
establishes a site-specific standard will require a use-attainability analysis
which demonstrates that reasonably attainable water-quality related uses will
be protected. Upon adoption, site-specific amendments to the standards will
be listed in §307.10 of this title
(relating to Appendices A-E).
(4)
Factors which may justify the development of
site-specific standards are described in §307.4 of this title (relating
to General Criteria), §307.6 of this title (relating to Toxic Materials), §307.7
of this title (relating to Site-specific Uses and Criteria), and §307.8
of this title (relating to Application of Standards).
[
When preliminary
evidence indicates that a site-specific standards amendment is appropriate,
the commission may allow a temporary variance to the water quality standards.
A temporary variance is only applicable to an existing discharge facility.
A permittee may apply for a temporary variance prior to or during the permit
application process. The temporary variance request shall be included in the
public notice for the permit application, and the request may be considered
in any public hearing on the permit application. The temporary variance must
have the approval of the Texas Natural Resource Conservation Commission before
issuance of a final permit. A temporary variance for an NPDES permit will
also require approval by the U.S. Environmental Protection Agency. The permit
shall contain interim limits based upon the variance approval, and final limits
based upon existing water quality standards. A variance shall not exceed a
time period of three years. A temporary variance may be extended to allow
additional time for a site-specific standard to be adopted in this title.
This extension can be granted only after a site-specific study that supports
a standards change has been completed. If the commission adopts the proposed
site-specific standard prior to the expiration of the variance period, then
the permit may be amended to meet the revised water quality standards. If
the commission does not adopt the proposed site-specific standard prior to
the expiration of the variance period, then the final effluent limits based
on existing water quality standards will remain in effect, but the permit
may be amended to include a permit schedule to meet standards in accordance
with subsection (f) of this section.
]
(5)
Temporary variance. When preliminary evidence
indicates that a site-specific standards amendment is appropriate, the commission
may allow a temporary variance to the water quality standards in a permit
for a discharge of wastewater.
[
Factors which may justify the development
of site-specific standards are described in §307.4 of this title (relating
to General Criteria), §307.6 of this title (relating to Toxic Materials), §307.7
of this title (relating to Site-specific Uses and Criteria), and §307.8
of this title (relating to Application of Standards).
]
(A)
A temporary variance is only applicable
to an existing discharge.
(B)
A permittee may apply for a temporary
variance prior to or during the permit application process. The temporary
variance request shall be included in the public notice for the permit application,
and the request may be considered in any public hearing on the permit application.
(C)
A temporary variance for a TPDES permit
will also require review and approval by the EPA during the permitting process.
(D)
The permit shall contain effluent limitations
that preclude degradation of existing water quality, and the term of the permit
shall not exceed three years. Effluent limitations that are needed to meet
the existing standards will be listed in the permit and will go into effect
immediately as final permit effluent limitations in the succeeding permit,
unless the permittee fulfills the requirements of the conditions for the variance
in the permit.
(E)
When the permittee has complied with the
terms of the conditions in the temporary variance, then the succeeding permit
may include a permit schedule to meet standards in accordance with subsection
(f) of this section. The succeeding permit may also extend the temporary variance
in accordance with subsection (f) of this section in order to allow additional
time for a site-specific standard to be adopted in this title. This extension
can be granted only after a site-specific study that supports a standards
change has been completed.
(F)
Site-specific standards which are developed
under a temporary variance will be expeditiously proposed and publicly considered
for adoption at the earliest opportunity.
(e)
(No change.)
(f)
Permit schedules to meet standards. Upon permit amendment
or permit renewal, the
executive director
[
commission
]
may establish interim
effluent limitations
[
discharge limits
] to allow a permittee time to modify effluent quality in order to attain
final effluent
limitations
[
limits
]. The duration of
any interim
effluent limitations
[
limit
] may not be
longer than three years from the effective date of the permit issuance
, except in accordance with a temporary variance as described in subsection
(d)(5) of this section.
[
An interim limit may be extended to allow
additional time for a site-specific standard to be adopted in this title.
This extension can be granted only after a site-specific study that supports
a standards change has been completed, and the extension will only be granted
for effluent limits that are affected by the site-specific standard under
consideration.
]
(g)
Temporary standards. Where a criterion
is not attained and cannot be reasonably attained for one or more of the reasons
listed in 40 CFR 131.10(g), then a temporary standard for specific water bodies
may be adopted in §307.10 of this title (relating to Appendices A-E)
as an alternative to changing uses. A criterion which is established as a
temporary standard must be adopted in accordance with the provisions of subsection
(d)(3) of this section. A temporary standard shall identify the water body
or water bodies where the criterion applies. A temporary standard will identify
the numerical criteria that will apply during the existence of the temporary
standard. A temporary standard does not exempt any discharge from compliance
with applicable technology-based effluent limits. A temporary standard shall
expire no later than the completion of the next triennial revision of the
Texas Surface Water Quality Standards. When a temporary standard expires,
subsequent discharge permits will be issued to meet the applicable existing
water quality standards. If a temporary standard is sufficiently justified
in accordance with the provisions of subsection (d)(3) of this section, it
can be renewed during revisions of the Texas Surface Water Quality Standards.
A temporary standard cannot be established which would impair an existing
use.
§307.3.Definitions and Abbreviations.
(a)
Definitions. The following words and terms, when used in
this chapter, shall have the defined meanings, unless the context clearly
indicates otherwise:
(1)
(No change.)
(2)
Ambient--Refers to the existing water quality in a
particular
water body
[
waterbody
].
(3)
Attainable use--A use which can be
reasonably achieved by a water body in accordance with its physical, biological,
and chemical characteristics. Guidelines for the determination and review
of attainable uses are provided in the standards implementation procedures.
(4)
[
(3)
] Background--Refers to
the water quality in a particular
water body
[
waterbody
]
that would occur if that
water body
[
waterbody
] were
relatively unaffected by human activities.
(5)
[
(4)
] Bedslope--Stream gradient,
or the extent of the drop in elevation encountered as the stream flows downhill.
One measure of bedslope is the elevation decline in meters over the stream
distance in kilometers.
(6)
[
(5)
] Best management practices--
Schedules of activities, maintenance procedures, and other management practices
to prevent or reduce the pollution of water in the state from point and nonpoint
sources, to the maximum extent practicable. Best management practices also
include treatment requirements, operating procedures, and practices to control
plant site runoff, spillage or leaks, sludge or waste disposal, or drainage
from raw material storage.
[
A practice or combination of practices
determined to be the most practicable means of preventing or reducing, to
a level compatible with water quality goals, the amount of pollution generated
by point and nonpoint sources.
]
(7)
[
(6)
] Bioaccumulative toxic--A
chemical which is taken up by aquatic organisms from water directly or through
the consumption of food containing the chemicals.
(8)
Bioconcentration factor--A unitless
value describing the degree to which a chemical can be concentrated in the
tissues of an organism in the aquatic environment. The bioconcentration factor
is the ratio of a chemical's concentration in the tissue of an organism compared
to that chemical's average concentration in the surrounding water.
(9)
Biological integrity--The species composition,
diversity, and functional organization of a community of organisms that contributes
to overall stability and ecological vitality.
(10)
[
(7)
] Chronic toxicity--Toxicity
which continues for a long-term period after exposure to toxic substances.
Chronic exposure produces sub-lethal effects, such as growth impairment and
reduced reproductive success, but it may also produce lethality. The duration
of exposure applicable to chronic toxicity is normally seven days or more.
(11)
Classified--Refers to
a water body that is listed and described in Appendix A or Appendix C in §307.10
of this title (relating to Appendices A-E). Site-specific uses and criteria
for classified water bodies are listed in Appendix A.
(12)
[
(8)
] Commission--The Texas Natural
Resource Conservation Commission.
(13)
[
(9)
] Contact recreation--Recreational
activities involving a significant risk of ingestion of water, including wading
by children, swimming, water skiing, diving, and surfing.
(14)
[
(10)
] Criteria--Water quality
conditions which are to be met in order to support and protect desired uses.
(15)
[
(11)
] Critical low-flow--Low-flow
condition (e.g., 7Q2 flow) below which some standards do not apply. The impacts
of permitted discharges are analyzed at critical low-flow.
(16)
Designated use--A use which is assigned
to specific water bodies in Appendix A or in Appendix D in §307.10 of
this title. Typical uses which may be designated for specific water bodies
include domestic water supply, categories of aquatic life use, recreation
categories, and aquifer protection.
(17)
[
(12)
] Discharge permit--A
permit issued by the state
or a federal agency
to discharge treated
effluent or cooling water into waters of the state.
(18)
[
(13)
] EC
50
--The concentration of a toxicant that produces an adverse effect
on 50% of the organisms tested in a specified time period.
(19)
E. coli
--
Escherichia coli
, a subgroup of fecal
coliform bacteria that is present in the intestinal tracts and feces of warm-blooded
animals. It is used as an indicator of potential pathogens.
(20)
[
(14)
] Effluent--Wastewater
discharged from any point source prior to entering a
water body
[
waterbody
].
(21)
Enterococci--A subgroup of fecal
streptococci bacteria (mainly
Streptococcus faecalis
and
Streptococcus faecium
) that is
present in the intestinal tracts and feces of warm-blooded animals. It is
used as an indicator of potential pathogens.
(22)
[
(15)
] Epilimnion--The upper
mixed layer of a lake (including impoundments, ponds, and reservoirs).
(23)
Existing use--A use which is currently
being supported by a specific water body and which was attained on or after
November 25, 1975.
(24)
[
(16)
] Fecal coliform--
A
[
That
] portion of the coliform bacteria group which is
present in the intestinal tracts and feces of warm-blooded animals
; heat
tolerant bacteria from other sources can sometimes be included. It is used
as an indicator of potential pathogens
.
(25)
[
(17)
] Freshwaters--Inland
waters which exhibit no measurable elevation changes due to normal tides.
(26)
General contact recreation--A subcategory
of contact recreation that is descriptive of areas where limited contact recreation
can occur when conditions of flow, depth, and weather are suitable.
(27)
[
(18)
] Halocline--A vertical
gradient in salinity under conditions of density stratification that is usually
recognized as the point where salinity exhibits the greatest difference in
the vertical direction.
(28)
[
(19)
] Harmonic mean flow--A
measure of mean flow in a water course which is calculated by summing the
reciprocals of the individual flow measurements, dividing this sum by the
number of measurements, and then calculating the reciprocal of the resulting
number.
(29)
High-use contact recreation--A subcategory
of contact recreation that is descriptive of areas where contact recreation
is common.
(30)
Incidental fishery--A level of fishery
which applies to water bodies that are not considered to have a sustainable
fishery but which have an aquatic life use of limited, intermediate, high,
or exceptional.
(31)
[
(20)
] Industrial cooling
impoundment
[
impoundments
]--An impoundment which is owned or operated
by, or in conjunction with, the water rights permittee, and which is designed
and constructed for the primary purpose of reducing the temperature and removing
heat from an industrial effluent.
(32)
[
(21)
] Intermittent stream--A
stream which has a period of zero flow for at least one week during most years.
Where flow records are available, a stream with a 7Q2 flow of less than 0.1
ft
3
/s is considered intermittent.
(33)
Intermittent stream with perennial
pools--An intermittent stream which maintains persistent pools even when flow
in the stream is less than 0.1 ft
3
/s.
(34)
[
(22)
] LC
50
--The concentration of a toxicant that is lethal (fatal) to 50% of
the organisms tested in a specified time period.
[(23)
Marine waters--Coastal waters which
have measurable elevation changes due to normal tides. Marine waters are considered
to be saltwater for purposes of standards application. In the absence of tidal
information, marine waters are generally considered to be coastal waters which
typically have salinities of two parts per thousand or greater in a significant
portion of the water column.]
(35)
[
(24)
] Method detection limit--The
minimum concentration of a substance that can be measured and reported with
99% confidence that the analyte concentration is greater than zero and is
determined from analysis of a sample in a given matrix containing the analyte.
The method detection limit (MDL) is estimated in accordance with 40
CFR
[
Code of Federal Regulations,
]136, Appendix B.
(36)
[
(25)
] Minimum analytical level--The
lowest concentration at which a particular substance can be quantitatively
measured with a defined
accuracy and
precision level, using approved
analytical methods. The minimum analytical level is not the published method
detection limit for an EPA-approved analytical method, which is based on laboratory
analysis of the substance in reagent (distilled) water. The minimum analytical
level is based on analyses of the analyte in the matrix of concern (i.e.,
wastewater effluents). The
executive director
[
commission
] will establish general minimum analytical levels that will be applicable
when information on matrix-specific minimum analytical levels is unavailable.
(37)
[
(26)
] Mixing zone--The area
contiguous to a discharge where mixing with receiving waters takes place and
where
[
which may not meet
] certain criteria applicable to
the receiving water
can be exceeded, as long as conditions of acute toxicity
to aquatic organisms are prevented
.
[(27)
No significant aquatic life use--The
instream use that is typically assigned to a waterbody, such as an intermittent
stream, which is not appropriate for an aquatic life use category of limited
or greater. There can be some aquatic life present in a waterbody which is
designated as having no significant aquatic life use. Basic water quality
standards--such as the general criteria in §307.4 of this title, the
numerical acute aquatic life criteria in §307.6(c) of this title (relating
to Toxic Materials), and the biomonitoring requirements to preclude acute
toxicity to aquatic life in §307.6(e) of this title--apply to waterbodies
with no significant aquatic life use.]
(38)
[
(28)
] Noncontact recreation--
Aquatic recreational
[
Recreational
] pursuits not involving
a significant risk of water ingestion; including fishing, commercial and recreational
boating, and limited body contact incidental to shoreline activity.
(39)
[
(29)
] Nonpersistent toxic--A
toxic substance that readily degrades in the aquatic environment, exhibits
a half-life of less than 96 hours, and does not have a tendency to accumulate
in organisms.
(40)
[
(30)
] Oyster waters--Waters
producing edible species of clams, oysters, or mussels.
(41)
[
(31)
] Persistent toxic--A
toxic substance that is not readily degraded and exhibits a half-life of 96
hours or more in an aquatic environment.
(42)
Pollutant--Dredged spoil, solid
waste, incinerator residue, sewage, garbage, sewage sludge, filter backwash,
munitions, chemical wastes, biological materials, radioactive materials, heat,
wrecked or discarded equipment, rock, sand, cellar dirt, and industrial, municipal,
and agricultural waste discharged into any water in the state. The term "pollutant"
does not include tail water or runoff water from irrigation or rainwater runoff
from cultivated or uncultivated rangeland, pastureland, or farmland.
(43)
Point source--Any discernible, confined
and discrete conveyance, including but not limited to any pipe, ditch, channel,
tunnel, conduit, well, discrete fissure, container, rolling stock, concentrated
animal feeding operation, or vessel or other floating craft, from which pollutants
or wastes are or may be discharged into or adjacent to any water in the state.
(44)
Presumed use--A use which is assigned
to generic categories of water bodies (such as perennial streams). Presumed
uses are superceded by designated uses for individual water bodies in Appendix
A or Appendix D of §307.10 of this title.
(45)
Public drinking water supply--A
water body which provides water to a public water system as defined in 30
TAC, Chapter 290 of this title (relating to Public Drinking Water).
(46)
Saltwater--A coastal water which
has a measurable elevation change due to normal tides. In the absence of tidal
information, saltwater is generally considered to be a coastal water which
typically has a salinity of two parts per thousand or greater in a significant
portion of the water column.
(47)
[
(32)
] Salinity--The total
dissolved solids in water after all carbonates have been converted to oxides,
all bromide and iodide have been replaced by chloride, and all organic matter
has been oxidized. For most purposes, salinity is considered equivalent to
total dissolved salt content. Salinity is normally expressed in parts per
thousand.
(48)
Seagrass propagation--A water-quality
related use which applies to saltwater where significant stands of submerged
seagrass occur.
(49)
Segment--A water body or portion
of a water body which is individually defined and classified in the Texas
Surface Water Quality Standards. A segment is intended to have relatively
homogeneous chemical, physical, and hydrological characteristics. A segment
provides a basic unit for assigning site-specific standards and for applying
water quality management programs of the commission. Classified segments may
include streams, rivers, bays, estuaries, wetlands, lakes, or reservoirs.
(50)
[
(33)
] Settleable solids--The
volume or weight of material which will settle out of a water sample in a
specified period of time.
(51)
[
(34)
] Seven-day, two-year
low-flow
(7Q2)
--The lowest average
stream
flow for
seven consecutive days with a recurrence interval of two years, as statistically
determined from historical data.
As specified in §307.8 of this
title, some water quality standards do not apply at stream flows which are
less than the 7Q2 flow
[
It is the flow used for determining the
allowable discharge load to a stream
].
(52)
[
(35)
] Shellfish--Clams, oysters,
mussels, crabs, crayfish, lobsters, and shrimp.
(53)
Significant aquatic life use--A
broad characterization of aquatic life which indicates that a subcategory
of aquatic life use (limited, intermediate, high, or exceptional) is applicable.
Some aquatic life is expected to be present even in water bodies which are
not designated for specific categories of aquatic life use. Some provision
to protect aquatic life applies to any water body in the state whether an
aquatic life use is assigned or not, except where specifically exempted in §307.6
of this title (relating to Toxic Material) or §307.8 of this title (relating
to Application of Standards). These provisions include the general criteria
in §307.4 of this title (relating to General Criteria), the numerical
acute aquatic life criteria in §307.6(c) of this title, and the whole
effluent toxicity requirements to preclude acute toxicity to aquatic life
in §307.6(e) of this title.
(54)
[
(36)
] Standard Methods for
the Examination of Water and Wastewater--A document describing sampling and
analytical procedures, which is published by the American Public Health Association,
American Water Works Association, and Water Environment Federation. The most
recent edition of this document is to be followed whenever its use is specified
by these rules.
(55)
[
(37)
] Standards--The designation
of
water bodies
[
waterbodies
] for desirable uses and
the narrative and numerical criteria deemed necessary to protect those uses.
(56)
[
(38)
] Standards implementation
procedures--Procedures entitled
Procedures to
Implement the Texas Surface Water Quality Standards in TPDES Discharge Permits
, which are adopted by the commission and approved by EPA as part of
the State Continuing Planning Process
[
Implementation of the Texas Natural Resource Conservation Commission Standards
via Permitting
].
(57)
Storm water--Rainfall runoff, snow
melt runoff, surface runoff, and drainage.
(58)
Storm water discharge--A point source
discharge which is composed entirely of storm water associated with an industrial
activity, a construction activity, a discharge from a municipal separate storm
sewer system, or other discharge designated by the commission. This term does
not include return flows from irrigated agriculture or agriculture storm water
runoff.
(59)
[
(39)
] Stream order--A classification
of stream size, where the smallest, unbranched tributaries of a drainage basin
are designated first order streams. Where two first order streams join, a
second order stream is formed; and where two second order streams join, a
third order stream is formed, etc. For purposes of water quality standards
application, stream order is determined from USGS topographic maps with a
scale of 1:24,000.
(60)
[
(40)
] Surface water in the
state--Lakes, bays, ponds, impounding reservoirs, springs, rivers, streams,
creeks, estuaries, wetlands, marshes, inlets, canals, the Gulf of Mexico inside
the territorial limits of the state, and all other bodies of surface water,
natural or artificial, inland or coastal, fresh or salt, navigable or nonnavigable,
and including the beds and banks of all water-courses and bodies of surface
water, that are wholly or partially inside or bordering the state or subject
to the jurisdiction of the state; except that waters in treatment systems
which are authorized by state or federal law, regulation, or permit, and which
are created for the purpose of waste treatment are not considered to be
water
[
waters
] in the state.
(61)
[
(41)
] Sustainable Fisheries--Descriptive
of
water bodies
[
waterbodies
] which potentially have
sufficient fish production or fishing activity to create significant long-term
human consumption of fish. Sustainable fisheries include perennial streams
and rivers with a stream order of three or greater; lakes and reservoirs greater
than or equal to 150 acre-feet and/or 50 surface acres; all bays, estuaries,
and tidal rivers.
Water bodies
[
Waterbodies
] which are
presumed to have sustainable fisheries include all designated segments listed
in Appendix A unless specifically exempted.
(62)
Tidal--Descriptive of coastal waters
which are subject to the ebb and flow of tides. For purposes of standards
applicability, tidal waters are considered to be saltwater. Classified tidal
waters include all bays and estuaries with a segment number that begins with
24xx, all streams with the word tidal in the segment name, and the Gulf of
Mexico.
(63)
To discharge--Includes to deposit,
conduct, drain, emit, throw, run, allow to seep, or otherwise release or dispose
of, or to allow, permit, or suffer any of these acts or omissions.
(64)
Total Maximum Daily Load (TMDL)--The
total amount of a pollutant that a water body can assimilate and still meet
the Texas Surface Water Quality Standards.
(65)
[
(42)
] Total dissolved solids--The
amount of material (inorganic salts and small amounts of organic material)
dissolved in water and commonly expressed as a concentration in terms of milligrams
per liter. The term is equivalent to the term filterable residue, as used
in the publication entitled
,
Standard Methods
for the Examination of Water and Wastewater
.
(66)
[
(43)
] Total suspended solids--Total
suspended matter in water, which is commonly expressed as a concentration
in terms of milligrams per liter. The term is equivalent to nonfilterable
residue, as used in the publication entitled
,
Standard Methods for the Examination of Water and Wastewater
.
(67)
[
(44)
] Total toxicity--Toxicity
as determined by exposing aquatic organisms to samples or dilutions of instream
water or treated effluent. Also referred to as whole effluent toxicity or
biomonitoring.
(68)
[
(45)
] Toxicity--The occurrence
of adverse effects to living organisms due to exposure to toxic materials.
Adverse effects caused by conditions of temperature and dissolved oxygen are
excluded from the definition of toxicity. With respect to the provisions of §307.6(e)
of this title (relating to Toxic Materials), which concerns total toxicity
and biomonitoring requirements, adverse effects caused by concentrations of
dissolved salts (such as sodium, potassium, calcium, chloride, carbonate)
in source waters are excluded from the definition of toxicity. Source water
is defined as surface water or groundwater that is used as a public water
supply or industrial water supply (including a cooling-water supply). Source
water does not include brine water that is produced during the extraction
of oil and gas, or other sources of brine water that are substantially uncharacteristic
of surface waters in the area of discharge. In addition, adverse effects caused
by concentrations of dissolved salts which are added to source water by industrial
processes are not excluded from the requirements of §307.6(e) of this
title, except as specifically noted in §307.6(e)(2)(B) of this title,
which concerns requirements for toxicity testing of 100% effluent. This definition
of toxicity does not affect the standards for dissolved salts in this chapter
other than §307.6(e) of this title. The standards implementation procedures
contain provisions to protect surface waters from adverse effects of dissolved
salts and methods to address the effects of dissolved salts on total toxicity
tests.
(69)
[
(46)
] Toxicity biomonitoring--The
determination of total toxicity. Documents which describe procedures for toxicity
biomonitoring are cited in §307.6 of this title
(relating to Toxic
Materials)
.
(70)
[
(47)
] Water-effects ratio--[
The quantifiable difference in the toxicity of a substance at an instream
site, in comparison to the toxicity that was measured in experiments using
laboratory water. The water-effects ratio provides an estimate of the bioavailability
and toxicity of a substance in a particular waterbody. It may be used to establish
site-specific criteria for aquatic life protection.
] The water-effects
ratio is calculated as the toxic concentration (LC
50
) of a substance in water at a particular site, divided by the toxic
concentration of that substance as reported in lab toxicity tests.
The
water-effects ratio can be used to establish site-specific criteria to protect
aquatic life from toxicity.
The site-specific criterion is equal to
the water-effects ratio times the statewide aquatic life criterion in §307.6(c)
of this title
(relating to Toxic Materials).
(71)
[
(48)
] Water quality management
program--The commission's overall program for attaining and maintaining water
quality consistent with state standards, as authorized under the Texas Water
Code, the Texas Administrative Code, and the Clean Water Act, §§106,
205(j), 208, 303(e) and 314 (33 United States Code §§1251 et seq).
(72)
[
(49)
] Wetland--An area (including
a swamp, marsh, bog, prairie pothole, or similar area) having a predominance
of hydric soils that are inundated or saturated by surface or groundwater
at a frequency and duration sufficient to support and that under normal circumstances
supports the growth and regeneration of hydrophytic vegetation. The term "hydric
soil" means soil that, in its undrained condition, is saturated, flooded,
or ponded long enough during a growing season to develop an anaerobic condition
that supports the growth and regeneration of hydrophytic vegetation. The term
"hydrophytic vegetation" means a plant growing in: water or a substrate that
is at least periodically deficient in oxygen during a growing season as a
result of excessive water content. The term "wetland" does not include irrigated
acreage used as farmland; a man-made wetland of less than one acre; or a man-made
wetland for which construction or creation commenced on or after August 28,
1989, and which was not constructed with wetland creation as a stated objective,
including but not limited to an impoundment made for the purpose of soil and
water conservation which has been approved or requested by soil and water
conservation districts. If this definition of wetland conflicts with the federal
definition in any manner, the federal definition prevails.
(73)
Wetland water quality functions--Attributes
of wetlands that protect and maintain the quality of water in the state, which
include storm water storage and retention and the moderation of extreme water
level fluctuations; shoreline protection against erosion through the dissipation
of wave energy and water velocity, and anchoring of sediments; habitat for
aquatic life; and removal, transformation, and retention of nutrients and
toxic substances.
(74)
[
(50)
] Zone of initial dilution--The
small area at the immediate point of discharge where initial dilution with
receiving waters occurs, and which may not meet certain criteria applicable
to the receiving water. A zone of initial dilution is substantially smaller
than a mixing zone.
[(51)
Bioconcentration factor (BCF)--A
unitless value describing the degree to which a chemical can be concentrated
in the tissues of an organism in the aquatic environment. The BCF is the concentration
of a chemical in one or more tissues of the organism divided by the average
exposure concentration the organism received.]
(b)
Abbreviations. The following abbreviations apply to this
chapter
:
[
.
]
(1)-(3)
(No change.)
(4)
CASN--Chemical Abstracts Service
number.
(5)
[
(4)
] CFR--Code of Federal Regulations.
(6)
[
(5)
] Cl
-1
--chloride.
(7)
[
(6)
] CR--contact recreation.
(8)
[
(7)
] DO--dissolved oxygen.
(9)
[
(8)
] E--exceptional aquatic
life use.
(10)
[
(9)
] EPA--United States Environmental
Protection Agency.
(11)
[
(10)
] degrees F--Degree(s)
Fahrenheit.
(12)
[
(11)
] ft
3
/s--cubic feet per second.
(13)
[
(12)
] H--high aquatic life
use.
(14)
[
(13)
] I--intermediate aquatic
life use.
(15)
[
(14)
] IS--industrial water
supply.
(16)
[
(15)
] L--limited aquatic life
use.
(17)
MCL--maximum contaminant level (for
public drinking water supplies).
(18)
[
(16)
] mg/L--milligrams per
liter.
(19)
[
(17)
] ml--milliliter.
(20)
MS4--municipal separate storm sewer
system.
(21)
[
(18)
] N--navigation.
(22)
[
(19)
] NCR--noncontact recreation.
(23)
[
(20)
] NPDES--National Pollutant
Discharge Elimination System, as set out in the Clean Water Act, §402
(33 United States Code 1342).
(24)
[
(21)
] O--oyster waters.
(25)
[
(22)
] PS--public water supply.
(26)
[
(23)
] 7Q2--seven-day, two-year
low-flow.
(27)
[
(24)
] SO
4
-2
--sulfate.
(28)
[
(25)
] TDS--total dissolved
solids.
(29)
TMDL--total maximum daily load.
(30)
TPDES--Texas Pollutant Discharge Elimination
System.
(31)
TSS--total suspended solids.
(32)
[
(26)
] USFDA--U.S. Food and
Drug Administration.
(33)
[
(27)
] USGS--U.S. Geological
Survey.
(34)
[
(28)
] WF--waterfowl habitat.
(35)
[
(29)
] WQM--water quality management.
(36)
[
(30)
] microgram/L--micrograms
per liter.
(37)
[
(31)
] ZID--zone of initial
dilution.
§307.4.General Criteria.
(a)
(No change.)
(b)
Aesthetic parameters.
(1)-(2)
(No change.)
(3)
Surface waters shall be essentially free of settleable
solids conducive to changes in flow characteristics of stream channels or
the untimely filling of
surface water in the state. This provision does
not prohibit dredge and fill activities which are permitted in accordance
with Section 404 and other requirements of the Federal Clean Water Act which
provide for the evaluation, minimization, and mitigation of impacts as appropriate.
[
reservoirs, lakes, and bays
]
(4)-(6)
(No change.)
(7)
Surface waters shall be maintained so that oil, grease,
or related residue will not produce a visible film of oil or globules of grease
on the surface or coat the banks or bottoms of the watercourse; or cause toxicity
to man, aquatic life, or terrestrial life in accordance with
subsection
(d) of this section
[
§307.4(d) of this title (relating to
General Criteria).
]
(c)
Radiological
substances
[
parameters
].
Radioactive materials shall not be discharged in excess of the amount regulated
by Chapter 336 of this title (relating to Radiation Rules).
(d)
Toxic
substances
[
parameters
]. Surface
waters will not be toxic to man from ingestion of water, consumption of aquatic
organisms, or contact with the skin, or to terrestrial or aquatic life.
Requirements and criteria
[
Additional standards requirements
]
for toxic
substances
[
materials
] are specified in §307.6
of this title (relating to Toxic Materials).
Criteria to protect aquatic
life from acute toxicity apply to all surface waters in the state. Criteria
to protect aquatic life from chronic toxicity apply to surface waters with
a significant aquatic life use of limited, intermediate, high, or exceptional
as designated in §307.10 of this title (relating to Appendices A-E) or
as determined on a case-by-case basis in accordance with subsection (k) of
this section. Toxic criteria to protect human health for consumption of fish
apply to waters with a sustainable or incidental fishery, as described in §307.6(d)
of this title. Additional criteria apply to water in the state with a public
drinking water supply use, as described in §307.6(d) of this title. The
general provisions of this subsection do not change specific provisions in §307.8
of this title (relating to Application of Standards) for applying toxic criteria.
(e)
Nutrients
[
Nutrient parameters
].
Nutrients from permitted discharges or other controllable sources shall not
cause excessive growth of aquatic vegetation which impairs an existing, attainable,
or designated use. Site-specific nutrient criteria, nutrient permit limitations,
and/or separate rules to control nutrients in individual watersheds will be
established where appropriate after notice and opportunity for public participation
and proper hearing.
(f)
Temperature. Consistent with §307.1 of this title
(relating to General Policy Statement) and in accordance with state water
rights permits, temperature in industrial cooling lake impoundments and all
other surface water in the state shall be maintained so as to not interfere
with the reasonable use of such waters. Numerical temperature criteria have
not been specifically established for industrial cooling lake impoundments,
which in most areas of the state contribute to water conservation and water
quality objectives. With the exception of industrial cooling impoundments,
temperature elevations due to discharges of treated domestic (sanitary) effluent,
and
within
designated mixing zones, the following temperature criteria,
expressed as a maximum temperature differential (rise over ambient) are established:
freshwater streams--5 degrees Fahrenheit; freshwater lakes and impoundments--3
degrees Fahrenheit; tidal river reaches, bay and gulf waters--4 degrees Fahrenheit
in fall, winter, and spring, and 1.5 degrees Fahrenheit in summer (June, July,
and August). Additional temperature criteria (expressed as maximum temperatures)
for classified segments are specified in Appendix A of §307.10 of this
title (relating to Appendices A-E).
(g)
Salinity.
(1)
Concentrations and the relative ratios of dissolved
minerals such as chlorides, sulfates, and total dissolved solids will be maintained
such that existing, designated, and attainable uses will not be impaired.
[
Estuarine salinity criteria have not been established, despite
the recognition that proper salinity gradient maintenance is important for
the continuation of balanced and desirable populations of estuarine dependent
marine life, because weather is the dominant factor influencing salinity gradients
].
(2)
Criteria for chlorides, sulfates, and total dissolved
solids for classified freshwater segments are specified in Appendix A of §307.10
of this title (relating to Appendices A-E)
[
Absence of numerical
criteria shall not preclude evaluations and regulatory actions based on estuarine
salinity, and careful consideration will be given to all activities which
may detrimentally affect salinity gradientsin estuarine waters.
].
(3)
Salinity gradients in estuaries
[
Concentrations and the relative ratios of dissolved minerals such as chlorides,
sulfates, and total dissolved solids
] will be maintained
to support
the continuation of balanced and desirable populations of estuarine dependent
aquatic life. Numerical salinity criteria for Texas estuaries have not been
established because of the high natural variability of salinity in estuarine
systems, and because long-term studies by state agencies to assess estuarine
salinities are still ongoing
[
such that attainable uses will not
be impaired
].
Absence of numerical criteria shall not preclude
evaluations and regulatory actions based on estuarine salinity, and careful
consideration will be given to all activities which may detrimentally affect
salinity gradients.
(h)
Aquatic life uses and dissolved oxygen.
[
Dissolved oxygen and aquatic life uses.
]
(1)
Dissolved oxygen concentrations shall be sufficient
to support existing, designated, and attainable aquatic life uses. Aquatic-life
use categories and corresponding dissolved oxygen criteria are described in §307.7(b)(3)
of this title (relating to Site-specific Uses and Criteria).
[
Dissolved oxygen criteria for unclassified waters with aquatic life uses will
be sufficient to support appropriate aquatic life use categories, in accordance
with §307.7 of this title (relating to Site-specific Uses and Criteria).
Perennial streams, rivers, lakes, bays, estuaries, and other appropriate perennial
waters which are not specifically listed in Appendix A or D of §307.10
of this title are presumed to have a high aquatic life use and corresponding
dissolved oxygen criteria. In accordance with results from statewide ecoregion
studies, unclassified perennial streams in southeast and northeast Texas are
assigned dissolved oxygen criteria as indicated in §307.7(b)(3)(A)(ii)
of this title. Higher uses will be maintained where they are attainable.
]
(2)
Aquatic life use categories and dissolved oxygen
criteria for classified segments are specified in Appendix A of §307.10
of this title. Aquatic life use categories and dissolved oxygen criteria for
other specific water bodies are specified in Appendix D of §307.10 of
this title. Where justified by sufficient site-specific information, dissolved
oxygen criteria which differ from §307.7(b)(3) of this title may be adopted
for a particular water body in §307.10 of this title.
[
Intermittent
streams which are not specifically listed in Appendix A or D of §307.10
of this title will maintain a 24-hour dissolved oxygen mean of 2.0 mg/L and
an absolute minimum dissolved oxygen concentration of 1.5 mg/L. For intermittent
streams with seasonal aquatic life uses, dissolved oxygen concentrations commensurate
with the aquatic life uses will be maintained during the seasons in which
the aquatic life uses occur. Unclassified intermittent streams with significant
aquatic life uses created by perennial pools are presumed to have a limited
aquatic life use and corresponding dissolved oxygen criteria. Additional definitions
of significant aquatic life, perennial pools, and seasonal uses will be developed
in the standards implementation procedures. Higher uses will be maintained
where they are attainable.
]
(3)
Perennial streams, rivers, lakes,
bays, estuaries, and other appropriate perennial waters which are not specifically
listed in Appendix A or D of §307.10 of this title are presumed to have
a high aquatic life use and corresponding dissolved oxygen criteria. In accordance
with results from statewide ecoregion studies, unclassified perennial streams
in southeast and northeast Texas are assigned dissolved oxygen criteria as
indicated in §307.7(b)(3)(A)(ii) of this title. Higher uses will be maintained
where they are attainable.
(4)
When water is present in the streambed
of intermittent streams, a 24-hour dissolved oxygen mean of at least 2.0 mg/L
and an absolute minimum dissolved oxygen concentration of 1.5 mg/L will be
maintained. Intermittent streams which are not specifically listed in Appendix
A or D of §307.10 of this title are considered to not have a significant
aquatic life use except as indicated below in this subsection. For intermittent
streams with seasonal aquatic life uses, dissolved oxygen concentrations commensurate
with the aquatic life uses will be maintained during the seasons in which
the aquatic life uses occur. Unclassified intermittent streams with significant
aquatic life uses created by perennial pools are presumed to have a limited
aquatic life use and corresponding dissolved oxygen criteria. Additional definitions
of significant aquatic life, perennial pools, and seasonal uses will be developed
in the standards implementation procedures. Higher uses will be maintained
where they are attainable.
(i)
Aquatic life uses and habitat. Vegetative and physical
components of the aquatic environment will be maintained or mitigated to protect
existing aquatic life uses. Procedures to protect habitat in permits for dredge
and fill activities are specified in Federal Clean Water Act, §404 and
in Title 30 TAC Chapter 279 of this title (relating to Water Quality Certification).
[
Bacteria. A fecal coliform criterion of not more than 200 bacteria
per 100 ml shall apply to all water bodies not specifically listed in Appendix
A of §307.10 of this title (relating to Appendices A-E). Application
of this criterion shall be in accordance with §307.7(b)(1) of this title.
]
(j)
Aquatic recreation. Existing, designated,
and attainable uses of aquatic recreation will be maintained, as determined
by criteria that indicate the potential presence of pathogens. Categories
of recreation and applicable criteria are established in §307.7(b)(1)
of this title. General contact recreation is presumed as a use for all water
bodies that are not specifically listed in Appendix A of §307.10 of this
title. In addition, high-use contact recreation is presumed for lakes and
reservoirs and for saltwater bays that are not specifically listed in Appendix
A of §307.10 of this title.
(k)
[
(j)
] Antidegradation. Nothing in
this section shall be construed or otherwise utilized to supersede the requirements
of §307.5 of this title (relating to Antidegradation).
(l)
[
(k)
] Assessment of unclassified
waters. Waters which are not specifically listed in Appendices A or D of §307.10
of this title are designated for the specific uses that are attainable or
characteristic of those waters. Upon administrative or regulatory action by
the
executive director
[
commission
] which affects a
particular unclassified
water body
[
waterbody
], the
characteristics of the affected
water body
[
waterbody
]
will be reviewed to determine which aquatic life uses are appropriate. Additional
uses so determined shall be indicated in public notices for discharge applications.
Uses which are not applicable throughout the year in a particular unclassified
water body
[
waterbody
] will be assigned and protected for
the seasons in which such uses are attainable. Initial determinations of use
shall be considered preliminary, and in no way preclude redeterminations of
use in public hearings conducted [
by the commission
] under the
provisions of the Texas Water Code. For unclassified waters where the presumed
minimum uses or criteria specified in this section are inappropriate, site-specific
standards may be developed in accordance with §307.2(d) of this title
(relating to Modification of Standards). Uses and criteria will be assigned
in accordance with this section and with §307.7
(b)
(3) of this
title
(relating to Aquatic Life)
. Procedures for assigning uses
and criteria are described in the standards implementation procedures.
§307.5.Antidegradation.
(a)
Application. The antidegradation policy and implementation
procedures set forth in this section shall apply to actions regulated under
state and federal authority which would increase pollutant loads to the water
in the state. Such actions include authorized wastewater discharges,
TMDLs,
waste load evaluations, and any other miscellaneous actions,
such as those related to man-induced nonpoint sources of pollution, which
may impact the water in the state.
(b)
Antidegradation policy. In accordance with the Texas Water
Code, §26.003,
the following provisions establish
[
it
is
] the
antidegradation
policy of the commission
.
[
that:
]
(1)
Tier 1. Water
[
water
] quality sufficient
to protect existing uses will be maintained. Categories of existing uses are
the same as for designated uses, as defined in §307.7 of this title (relating
to Site-specific Uses and Criteria)
.
[
;
]
(2)
Tier 2. No
[
no
] activities subject
to regulatory action which would cause degradation of waters which exceed
fishable/swimmable quality will be allowed unless it can be shown to the commission's
satisfaction that the lowering of water quality is necessary for important
economic or social development. Degradation is defined as a lowering of water
quality
by
[
to
] more than a de minimis extent, but not
to the extent that an existing use is impaired. Water quality sufficient to
protect existing uses will be maintained. Fishable/swimmable waters are defined
as waters which have quality sufficient to support propagation of indigenous
fish, shellfish, and wildlife and recreation in and on the water
.
[
;
]
(3)
Tier 3. Outstanding
[
outstanding
]
national resource waters are defined as high quality waters within or adjacent
to national parks and wildlife refuges, state parks, wild and scenic rivers
designated by law, and other designated areas of exceptional recreational
or ecological significance. The quality of outstanding national resource waters
will be maintained and protected
.
[
;
]
(4)
Discharges of pollutants which are authorized
by the Texas Water Code or the Federal Clean Water Act will not lower water
quality to the extent that the Texas Surface Water Quality Standards are not
attained.
[
authorized wastewater discharges or other activities
will not result in the quality of any water being lowered below water quality
standards without complying with federal and state laws applicable to water
quality standards amendment;
]
(5)
Anyone
[
anyone
] discharging
wastewater which would constitute a new source of pollution or an increased
source of pollution from any industrial, public, or private project or development
will be required to provide a level of wastewater treatment consistent with
the provisions of the Texas Water Code and the Clean Water Act (33 United
States Code 1251 et seq.). As necessary, cost-effective and reasonable best
management practices established through the Texas Water Quality Management
Program shall be achieved for nonpoint sources of pollution
.
[
;
]
(6)
Application
[
application
] of
antidegradation provisions shall not preclude the commission from establishing
modified thermal discharge limitations consistent with the Clean Water Act, §316(a)
(33 United States Code 1326).
(c)
Antidegradation implementation procedures.
(1)
Implementation for specific regulatory activities.
[
The commission staff will review any wastewater discharge permit
application or amendment in accordance with permitting procedures described
in the standards implementation procedures. This review will include a preliminary
determination of the existing uses of the receiving water. These existing
uses will be maintained and protected.
]
(A)
For TPDES permits for wastewater, the
process for the antidegradation review and public coordination is described
in the standards implementation procedures.
(B)
For federal permits relating to the discharge
of fill or dredged material under Federal Clean Water Act, §404, the
antidegradation policy and public coordination is implemented through the
evaluation of alternatives and mitigation under Federal Clean Water Act, §404(b)(1).
State review of alternatives, mitigation, and requirements to protect water
quality may also be conducted for federal permits which are subject to state
certification, as authorized by Federal Clean Water Act, §401 and conducted
in accordance with Chapter 279 of this title (relating to Water Quality Certification).
(C)
Other state and federal permitting and
regulatory activities which increase pollutant loadings to water in the state
are also subject to the provisions of the antidegradation policy as established
in §307.5(a) and (b) of this title (relating to Antidegradation).
(2)
General provisions for implementing the
antidegradation policy.
[
For proposed permit applications or amendments
to discharge into waters exceeding fishable/swimmable quality, the commission
staff will preliminarily determine if the discharge is expected to cause a
degradation of water quality.
]
(A)
Tier 1 reviews will ensure that water
quality is sufficiently maintained so that existing uses are protected. All
pollutants which could cause an impairment of water quality are subject to
Tier 1 reviews. If the existing uses and criteria of a potentially affected
water body have not been previously determined, then the antidegradation review
will include a preliminary determination of existing uses and criteria. Existing
uses will be maintained and protected.
(B)
[
(3)
]
Tier 2 reviews apply to
all
[
All
] pollutants which could cause degradation of
water quality where water quality exceeds levels necessary to support propagation
of fish, shellfish, wildlife, and recreation in and on the water (fishable/swimmable
quality). Guidance for determining which water bodies exceed fishable/swimmable
quality is contained in the standards implementation procedures
[
waters which exceed fishable/swimmable quality will be considered in the evaluation
of waste discharge permits
]. For dissolved oxygen, analyses of degradation
under Tier 2
will utilize the same critical conditions as are used
to protect instream criteria
[
for permit reviews and waste load
evaluations
]. For other parameters, appropriate conditions may vary.
Conditions for determining degradation will be commensurate with conditions
for determining existing uses. The highest water quality sustained since November
28, 1975 (in accordance with EPA Standards Regulation 40
CFR
[
Code of Federal Regulations Part
] 131)
defines
[
define
] baseline conditions for determinations of degradation.
(C)
Tier 3 reviews apply to all pollutants
which could cause degradation of outstanding national resource waters. Outstanding
national resource waters are those specifically designated as such in §307
of this title.
(D)
When degradation of waters exceeding fishable/swimmable
quality is anticipated, a statement that the antidegradation policy will be
pertinent to the permit action will be included in the public notice for the
said permit application or amendment. If no degradation is anticipated, the
public notice will so state.
(E)
Evidence can be introduced in public hearings
concerning the determination of existing uses and criteria; the assessment
of degradation under Tier 1, Tier 2, and Tier 3; the social and economic justification
for lowering water quality; requirements and conditions necessary to preclude
degradation; and any other issues which bear upon the implementation of the
antidegradation policy.
(F)
Interested parties will be given the opportunity
to provide comments and additional information concerning the determination
of existing uses, anticipated impacts of the discharge, baseline conditions,
and the necessity of the discharge for important economic or social development
if degradation of water quality is expected under Tier 2.
(G)
The antidegradation policy and the general
provisions for implementing the antidegradation policy apply to the determination
of TMDLs and to waste load evaluations which allow an increase in pollutant
loading. If the TMDL or waste load evaluation indicates that degradation of
waters exceeding fishable/swimmable quality is expected, the public hearing
notice will so state. Permits which are consistent with an approved TMDL or
waste load evaluation under this antidegradation policy will not be subjected
to separate antidegradation review for the specific parameters that are addressed
by the TMDL or waste load evaluation.
[(4)
When degradation of waters
exceeding fishable/swimmable quality is anticipated, a statement that the
antidegradation policy will be pertinent to the permit action will be included
in the public notice for the said permit application or amendment. If no degradation
is anticipated, the public notice will so state. The determination of existing
use and the probability of degradation are issues upon which evidence can
be introduced in permit hearings.]
[(5)
Interested parties will be given
the opportunity to provide comments and additional information concerning
the determination of existing uses, anticipated impacts of the discharge,
baseline conditions, and necessity of the discharge for important economic
or social development if degradation of water quality is expected. The commissioners
will decide after full satisfaction of the intergovernmental coordination
and public participation provisions of the continuing planning process if
the economic or social development is important enough to allow the degradation.]
[(6)
Waste load evaluations conducted
by the commission will adhere to the provisions of the antidegradation policy.
If the waste load evaluation indicates that degradation of waters exceeding
fishable/swimmable quality is expected, the public hearing notice will so
state. The commission will not approve any waste load evaluation that would
allow degradation of waters exceeding fishable/swimmable quality unless and
until it has been demonstrated to the commission that the recommended lower
water quality is necessary for important economic or social development. Permits
which are consistent with an approved waste load evaluation under this antidegradation
policy will not be separately subjected to the antidegradation provisions
of this section unless the discharge may cause impacts on the receiving water
which were not addressed by the waste load evaluation.]
[(7)
Additional implementation procedures
for the antidegradation policy are described in the standards implementation
procedures.]
§307.6.Toxic Materials.
(a)
(No change.)
(b)
General provisions.
(1)
Water in the state shall not be acutely toxic to aquatic
life in accordance with §307.8 of this title [
(relating to Application
of Standards)
].
(2)
Water in the state with designated or existing aquatic
life uses shall not be chronically toxic to aquatic life, in accordance with §307.8
of this title [
(relating to Application of Standards)
].
(3)
Water in the state shall be maintained to preclude
adverse toxic effects on human health resulting from contact recreation, consumption
of aquatic organisms, consumption of drinking water or any combination of
the three.
Water
[
Waters
] in the state with sustainable
fisheries and/or public drinking water supply uses will not exceed applicable
human health toxic criteria, in accordance with subsection (d) of this section
and §307.8 of this title [
(relating to Application of Standards)
].
(4)
Water in the state shall be maintained to preclude
adverse toxic effects on aquatic
life,
[
and
] terrestrial
wildlife,
birds,
livestock, or domestic animals, resulting from
contact, consumption of aquatic organisms, consumption of water, or any combination
of the
five
[
three
].
(c)
Specific numerical aquatic life criteria.
(1)
Numerical criteria are established in Table 1 for those
specific toxic substances for which adequate toxicity information is available,
and which have the potential for exerting adverse impacts on water in the
state.
Figure: 30 TAC §307.6(c)(1)
(2)-(4)
(No change.)
(5)
Specific numerical aquatic life criteria for metals
and metalloids in Table 1 apply to dissolved concentrations
where noted.
Dissolved concentrations
[
(unless otherwise stated), which
]
can be estimated by filtration of samples prior to analysis, or by converting
from total recoverable measurements in accordance with procedures approved
by the commission in the latest revision of the standards implementation procedures.
Specific numerical aquatic life criteria for non-metallic substances in Table
1 apply to total recoverable concentrations unless otherwise noted.
(6)
Specific numerical acute criteria for toxic substances
are applicable to all
water
[
waters
] in the state except
for small zones of initial dilution (ZIDs) at discharge points. Acute criteria
may be exceeded within a ZID
and at extremely low streamflow conditions
(one-fourth of critical low-flow conditions) in accordance with §307.8
of this title (relating to Application of Standards).
[
, but
]
There
[
there
] shall be no lethality to aquatic organisms
which move through a ZID, and the sizes of ZIDs are limited in accordance
with §307.8 of this title [
(relating to Application of Standards)
]. Specific numerical chronic criteria are applicable to all
water
[
waters
] in the state with designated or existing aquatic
life uses, except inside mixing zones and below critical low-flow conditions,
in accordance with §307.8 of this title.
(7)
For toxic materials for which specific numerical criteria
are not listed in Table 1, the appropriate criteria for aquatic life protection
may be derived in accordance with current EPA guidelines for deriving site-specific
water quality criteria. When insufficient data are available to use EPA guidelines,
the following provisions shall be applied in accordance with this section
and §307.8 of this title:
(A)
(No change.)
(B)
concentrations of non-persistent toxic materials shall
not exceed concentrations which are chronically toxic (as determined from
appropriate chronic toxicity data or calculated as 0.1 of acute LC
50
values) to the most sensitive aquatic
species
[
organisms
]; LC
50
x (0.1) = chronic criteria;
(C)
concentrations of persistent toxic materials that do not
bioaccumulate shall not exceed concentrations which are chronically toxic
(as determined from appropriate chronic toxicity data or calculated as 0.05
of LC
50
values) to the most sensitive aquatic
species
[
organisms
]; and
(D)
concentrations of toxic materials that bioaccumulate shall
not exceed concentrations that are chronically toxic (as determined from appropriate
chronic toxicity data or calculated as 0.01 of LC
50
values) to the most sensitive aquatic
species
[
organisms
].
(8)
For toxic substances where the relationship of
toxicity is defined as a function of pH or hardness, numerical criteria are
presented as an equation based on this relationship. Appropriate pH or hardness
values for such criteria are listed for each basin in Table 2.
Site-specific
values for pH and hardness, are used where available. Site-specific values
for each segment are given in the standards implementation procedures.
[
The indicated pH and hardness values (Table 2) for each basin will be
assumed unless sufficient data are available to derive segment specific pH
and hardness values.
]
Figure: 30 TAC §307.6(c)(8)
(9)
Criteria for most metals are multiplied
by a water-effects ratio in order to incorporate the effects of local water
chemistry on toxicity. The water-effects ratio is assumed to be equal to one
except where sufficient site-specific data are available to determine the
water-effects ratio for a particular water body or portion of a water body.
A water-effects ratio is only applicable to those portions of a water body
which are adequately addressed by site-specific data. Water-effects ratios
and resulting site-specific criteria which have been determined for particular
water bodies are listed in Appendix E when standards are revised.
(10)
[
(9)
] Additional site-specific
factors may indicate that the numerical criteria listed in Table 1 are inappropriate
for a particular
water body
[
waterbody
]. These factors
are applied as a site-specific standards modification in accordance with §307.2(d)
of this title (relating to Modification of Standards). The application of
a site-specific standard must not impair an existing, attainable, or designated
use. Factors which may justify a temporary variance or site-specific standards
amendment include the following:
(A)
background concentrations of specific toxics of concern
in receiving waters, sediment, and/or indigenous biota;
(B)
persistence and degradation rate of specific toxic materials;
(C)
synergistic, additive, or antagonistic interactions of
toxic substances with other toxic or nontoxic materials;
(D)
measurements of total effluent toxicity;
(E)
indigenous aquatic organisms, which may have different
responses to particular toxic materials;
(F)
technological or economic limits of treatability for specific
toxic materials;
(G)
bioavailability of specific toxic substances of concern,
as determined by water-effect ratio tests or other analyses approved by the
commission; and
(H)
new information concerning the toxicity of a particular
substance.
(d)
Specific numerical human health criteria.
(1)
Numerical human health criteria are established in Table
3.
Figure: 30 TAC §307.6(d)(1)
(2)
Categories of human health criteria:
(A)-(B)
(No change.)
(C)
concentration criteria in
saltwaters
[
marine waters
] to prevent contamination of fish and other aquatic life
to ensure that they are safe for human [
health
] consumption. These
criteria apply to
saltwaters
[
marine waters
] which have
a
sustainable
fishery
[
fisheries
] (Column C in Table
3).
(3)
Specific assumptions and procedures (except where
noted in Table 3).
(A)
Sources for the toxicity factors to derive criteria
[
Criteria
] were derived from [
information on toxicity
in
] EPA's Integrated Risk Information
System
[
Systems
] (IRIS)
; EPA Health Effects Assessment Summary Tables (HEAST);
Assessment Tools for the Evaluation of Risk (ASTER); and the computer program,
CLOGP3. Bioconcentration factors were converted to an average lipid concentration
in fish tissue of 3%, except where noted.
[
for both cancer potency
slopes (q1*) and reference doses for non-carcinogens (Rfd). The values in
Table 3 reflect values found in IRIS as of January 1994.
]
(B)-(D)
(No change.)
(E)
For carcinogens, a body-weight scaling factor of 3/4
power is
[
The ratio of average body weights
] was used to
convert data on laboratory test animals to human scale.
Reported weights
of laboratory test animals are used, and an average weight of 70 kg is assumed
for humans.
[
When the weight of test animals was not specified,
the average weights were considered to be 0.35 kilograms for rats, 0.03 kilograms
for mice, and 70 kilograms for humans.
]
[(F)
Bioconcentration factors were obtained
from the Quantitative Structure Activity Relationships Database (EPA) and
corrected to an average lipid concentration in fish tissue of 3.0%.]
(F)
[
(G)
] Numerical human health criteria
were derived in accordance with the general procedures and calculations in
the EPA guidance documents entitled
Technical Support
Document for Water Quality-based Toxics Control
(EPA/505/2-90-001);
and
Guidance Manual for Assessing Human Health Risks
from Chemically Contaminated Fish and Shellfish
(EPA/503/8-89-002).
(G)
[
(H)
] If a calculated criterion to
prevent contamination of drinking water and fish to ensure they are safe for
human consumption (
Column
[
column
] A in Table 3) was
greater than the applicable maximum contaminant level (MCL) in Chapter 290
of this title (relating to Water Hygiene), then the
MCL
[
maximum contaminant level
] was used as the criterion. [
MCL's were
updated February 1993.
]
(H)
[
(I)
] If the concentration of a substance
in fish tissue used for these calculations was greater than the applicable
United States Food and Drug Administration Action Level for edible fish and
shellfish tissue, then the acceptable concentration in fish tissue was lowered
to the Action Level for calculation of criteria.
(4)
(No change.)
(5)
Specific human health concentration criteria for water
are applicable to
water
[
waters
] in the state which
have sustainable fisheries, and/or designation or use as a public drinking
water supply, except within mixing zones and below harmonic mean stream flows,
in accordance with §307.8 of this title
(relating to Application
of Standards)
. The following waters are considered to have sustainable
fisheries:
(A)-(E)
(No change.)
(6)
Waters which are not considered to have a sustainable
fishery, but which have an aquatic life use, will be considered to have an
incidental fishery. Consumption rates assumed for incidental fishery waters
are 1.0 grams per person per day for inland waters, and 1.5 grams per person
per day for
saltwaters
[
marine waters
]. Numerical criteria
applicable to incidental fishery waters are therefore 10 times the criteria
listed in Columns B and C of Table 3.
(7)
Specific human health criteria are applied as long-term
average exposure criteria designed to protect populations over a lifetime
(70 years). Attainment measures for human health are addressed in §307.9
of this title (relating to Determination of Standards Attainment).
(8)
For toxic materials of concern for which specific
human health criteria are not listed in Table 3, the following provisions
shall apply
.
[
:
]
(A)
For
[
for
] known or suspected carcinogens
(Types A, B, B
2
, or C in
EPA databases
[
IRIS
]), a cancer risk of 10
-5
(1
in 100,000) shall be applied to the
most recent
numerical criteria
adopted by EPA and
published
in the
Federal
Register
. If an MCL is less than the resulting criterion, then the
MCL shall apply to public drinking water supplies in accordance with paragraph
(3)(G) of this subsection.
[
in 57 FedReg 60848 December 22, 1992;
]
(B)
For
[
for
] toxic materials not defined
as carcinogens, the
most recent
numerical criteria
adopted
by EPA and published in the
Federal Register
shall
be applicable. If an MCL is less than the resulting criterion, then the MCL
shall apply to public drinking water supplies in accordance with paragraph
(3)(G) of this subsection. [
in 57 FedReg 60848 shall directly apply;
]
(C)
In
[
in
] the absence of available
criteria, numerical criteria may be
derived
[
developed
]
from
available
information [
available in IRIS and Quantitative
Structure Activity Relationships Database (QSAR)
] and calculated in
accordance with the provisions of paragraph (3) of this subsection.
(9)
(No change.)
(10)
Numerical human health criteria are expressed as
total recoverable concentrations for nonmetals, [
and for
] mercury,
and selenium
and as dissolved concentrations for other metals and metalloids.
(11)
Additional site-specific factors may indicate that
the numerical human health criteria listed in Table 3 are inappropriate for
a particular
water body
[
waterbody
]. These factors are
applied as a site-specific standards modification in accordance with §307.2(d)
of this title (relating to Modification of Standards). The application of
site-specific criteria shall not impair an existing, attainable, or designated
use or affect human health. Factors which may justify a temporary variance
or site-specific standards amendment include the following:
(A)-(I)
(No change.)
(e)
Total toxicity.
(1)
Total (whole-effluent) toxicity of permitted discharges,
as determined from biomonitoring of effluent samples at appropriate dilutions,
will be sufficiently controlled to preclude acute total toxicity in all water
in the state with the exception of small zones of initial dilution
(ZIDs)
at discharge points
and at extremely low streamflow conditions
(one-fourth of critical low-flow conditions) in accordance with §307.8
of this title (relating to Application of Standards)
[
(ZIDs)
].
Acute total toxicity levels may be exceeded in a ZID, but there shall be no
lethality to aquatic organisms which move through a ZID, and the sizes of
ZIDs are limited in accordance with §307.8 of this title [
(relating
to Application of Standards)
]. Chronic total toxicity, as determined
from biomonitoring of effluent samples, will be precluded in all water in
the state with existing or designated aquatic life uses except in mixing zones
and at flows less than critical low-flows, in accordance with §307.8
of this title
.
(2)
General provisions for controlling total toxicity.
(A)
(No change.)
(B)
In addition to the other requirements of this section,
the effluent of discharges to
water
[
waters
] in the
state shall not be acutely toxic to sensitive species of aquatic life, as
demonstrated by effluent toxicity tests. Toxicity testing for this purpose
shall be conducted on samples of 100% effluent, and the criterion for acute
toxicity shall be mortality of 50% or more of the test organisms after 24
hours of exposure. [
These observations for acute toxicity may be conducted
during either acute or chronic toxicity tests, which are described in the
standards implementation procedures.
] This provision does not apply
to mortality that is a result of an excess, deficiency, or imbalance of dissolved
inorganic salts (such as sodium, calcium, potassium, chloride,
or
carbonate)
which are in the effluent and are not listed in Table 1 in subsection (c)
of this section or which are in source waters.
(C)
The latest revisions of the following EPA publications
provide methods for appropriate biomonitoring procedures:
Methods for Measuring the Acute Toxicity of Effluents and Receiving Waters
to Freshwater and Marine Organisms, Short-term Methods for Estimating the
Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms,
Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving
Waters to Marine and Estuarine Organisms
, and the
Technical Support Document for Water Quality-based Toxics Control
.
The use of other procedures approved by the
executive director and EPA
[
commission
] is also acceptable. Toxicity tests must be
conducted using representative, sensitive aquatic organisms as approved by
the
executive director
[
commission
], and any such testing
must adequately determine if toxicity standards are being attained.
(D)-(E)
(No change.)
(F)
Discharge permit limits based on total toxicity may be
established in consideration of site-specific factors, but the application
of such factors shall not result in impairment of an existing, attainable,
or designated use. These factors are applied as a site-specific standards
modification in accordance with §307.2(d) of this title
(relating
to Description of Standards)
. A demonstration that uses are protected
may consist of additional effluent toxicity testing, instream monitoring requirements,
and/or other necessary information as determined by the
executive director
[
commission
]. Factors which may justify a temporary variance
or site-specific standards amendment include the following:
(i)-(v)
(No change.)
§307.7.Site- specific [ Specific ] Uses and Criteria.
(a)
Uses and numerical criteria are established on a site-specific
basis for classified segments in Appendix A of §307.10 of this title
(relating to Appendices A-E). Site-specific uses and numerical criteria may
also be applied to unclassified waters in accordance with §307.4(h) of
this title (relating to General Criteria) and §307.5(c) of this title
(relating to Antidegradation). Site-specific criteria apply specifically to
substances attributed to waste discharges or the activities of man. Site-specific
criteria do not apply to those instances in which surface waters exceed criteria
[
limits
] due to natural phenomena. The application of site-specific
uses and criteria is described in §307.8 of this title (relating to the
Application of Standards) and §307.9 of this title (relating to the Determination
of Standards Attainment).
(b)
Appropriate uses and criteria for site-specific standards
are defined as follows.
(1)
Recreation.
Recreational use consists of two categories--contact
recreation waters and noncontact recreation waters. Classified segments are
designated for contact recreation unless elevated concentrations of indicator
bacteria frequently occur due to sources of pollution which cannot be reasonably
controlled by existing regulations or contact recreation is considered unsafe
for other reasons such as ship or barge traffic.
[
Recreational
use consists of two subcategories--contact recreation waters and noncontact
recreation waters. Classified segments will be designated for contact recreation
unless elevated fecal coliform bacteria concentrations frequently occur due
to sources of pollution which cannot be reasonably controlled by the existing
regulations or contact recreation is considered unsafe for other reasons such
as ship or barge traffic.
] In a classified segment where contact recreation
is considered unsafe for reasons unrelated to water quality,
a designated
use of noncontact recreation may be assigned criteria normally associated
with contact recreation.
[
a designated use of noncontact recreation
may be assigned the fecal coliform criteria normally associated with contact
recreation.
] A designation of contact recreation is not a guarantee
that the water so designated is completely free of disease-causing organisms.
Indicator bacteria,
[
Fecal coliform bacteria,
] although not
generally pathogenic, are indicative of potential contamination by feces of
warm blooded animals. The criteria for contact recreation are based on these
indicator bacteria, rather than direct measurements of
pathogens. Even
where the concentration of indicator bacteria is less than the criteria for
contact recreation,
[
pathogenic bacteria. Even where the concentration
of fecal coliform is below the criteria for contact recreation,
] there
is still some risk of contracting waterborne diseases.
Subcategories
of contact recreation are general contact recreation and high-use contact
recreation. Numerical criteria for both categories are the same, but procedures
for assessing instream monitoring data are different for the two categories.
Additional guidelines on monitoring frequency and data evaluation are specified
in the latest version of the
TNRCC Guidance for Screening
and Assessing Texas Surface and Finished Drinking Water Quality Data
.
(A)
Freshwater
[
Contact recreation waters.
]
(i)
General contact recreation. The geometric mean of E. coli
should not exceed 126 per 100 ml. Sampling
data for
E. coli
apply when conditions are
suitable for contact recreation. Procedures to determine when sampling data
apply are specified in
TNRCC Guidance for Screening
and Assessing Texas Surface and Finished Drinking Water Quality Data
.
General contact recreation applies to all freshwater streams and rivers except
where specifically designated otherwise in §307.10 of this title (relating
to Appendices A-E).
[
Fecal coliform content shall not exceed 200
colonies per 100 ml as a geometric mean based on a representative sampling
of not less than five samples collected over not more than 30 days.
]
(ii)
High-use contact recreation. The geometric mean of E. coli
should not exceed 126 per 100 ml. Sampling
data for
E. coli
apply for all flow and weather
conditions. High-use contact recreation applies to all freshwater lakes and
reservoirs, except where specifically designated otherwise in §307.10
of this title. Other kinds of water bodies may be individually designated
for high-use contact recreation in Appendix A.
[
Fecal coliform
content shall not equal or exceed 400 colonies per 100 ml in more than 10%
of all samples, but based on at least five samples, taken during any 30-day
period. If 10 or fewer samples are analyzed, no more than one sample shall
exceed 400 colonies per 100 ml.
]
(iii)
Noncontact recreation. The geometric
mean of
E. coli
should not exceed 605 per
100 ml.
(B)
Saltwater
[
Noncontact recreation waters
].
(i)
General contact recreation. The geometric mean of
Enterococci should not exceed 35 per 100 ml. Sampling data for Enterococci
apply when conditions are suitable for contact recreation. Procedures to determine
when sampling data apply are specified in
TNRCC Guidance
for Screening and Assessing Texas Surface and Finished Drinking Water Quality
Data
. General contact recreation applies to all tidal streams and rivers,
except where specifically designated otherwise in §307.10 of this title.
[
Fecal coliform content shall not exceed 2,000 colonies per 100
ml as a geometric mean based on a representative sampling of not less than
five samples collected over not more than 30 days.
]
(ii)
High-use contact recreation. The geometric mean of
Enterococci should not exceed 35 per 100 ml. Sampling data for Enterococci
apply for all flow and weather conditions. High-use contact recreation applies
to all bays and to the Gulf of Mexico to the extent of the state's jurisdiction,
except where specifically designated otherwise in §307.10 of this title.
Other kinds of water bodies may be individually designated for high-use contact
recreation in Appendix A.
[
Fecal coliform content shall not equal
or exceed 4,000 colonies per 100 ml in more than 10% of all samples, but based
on at least five samples, taken during any 30-day period. If ten or fewer
samples are analyzed, no more than one sample shall exceed 4,000 colonies
per 100 ml.
]
(iii)
Noncontact recreation. The geometric
mean of Enterococci should not exceed 168 per 100 ml.
(C)
Fecal coliform bacteria. Fecal coliform
bacteria can be used as an alternative instream indicator of recreational
suitability until sufficient data are available for
E coli
or Enterococci. Minimum data requirements are specified in the
latest version of the
TNRCC Guidance for Screening
and Assessing Texas Surface and Finished Drinking Water Quality Data
.
For segments designated as oyster waters in §307.10 of this title, fecal
coliform can continue to be used as an indicator of recreational suitability
because fecal coliform is used as the indicator for suitability of oyster
water use as described in paragraph (3)(B) of this subsection. Fecal coliform
can also continue to be used as a surrogate indicator in effluent limits for
wastewater discharges. Fecal coliform criteria are the same for both freshwater
and saltwater, as indicated below.
(i)
General contact recreation. The geometric mean of fecal
coliform should not exceed 200 per 100 ml. Designations for general contact
recreation and the applicability of sampling data are as described in subparagraph
(A) of this paragraph for freshwater and as described in subparagraph (B)
of this paragraph for saltwater.
(ii)
High-use contact recreation. The geometric mean of fecal
coliform should not exceed 200 per 100 ml. Instream sampling data for fecal
coliform apply for all flow and weather conditions. Designations for high-use
contact recreation are as described in subparagraph (A) of this paragraph
for freshwater and as described in subparagraph (B) of this paragraph for
saltwater.
(iii)
Noncontact recreation. Fecal coliform shall not exceed
2,000 colonies per 100 ml as a geometric mean.
(D)
Single samples and short-term indicators.
No criteria or requirements are established in this title for assessing recreational
suitability based on single samples or other short-term indicators. For areas
where local jurisdictions or private property owners voluntarily provide public
notice or closure based on water quality, the use of any single-sample or
short-term indicators of recreational suitability are selected at the discretion
of the local managers of aquatic recreation. Guidance for single-sample bacterial
indicators is available in the EPA document entitled
Ambient Water Quality Criteria for Bacteria--1986
. Other short-term
indicators to assess water quality suitability for recreation--such as measures
of streamflow, turbidity, or rainfall--may also be appropriate.
(2)
Domestic water supply.
(A)
Use categories. Domestic water supply consists of two use
subcategories--public water supply and aquifer protection.
(i)
Public water supply. Segments designated for public water
supply are those known to be used
or exhibit characteristics that would
allow them to be used
as the supply source for public water systems,
as defined by Chapter 290 of this title (relating to Water Hygiene).
(ii)
Aquifer protection. Segments designated for aquifer protection
are capable of recharging the Edwards Aquifer. The principal purpose of this
use designation is to protect the quality of water infiltrating into and recharging
the aquifer.
The designation for aquifer protection applies only to those
portions of the segments so designated that are on the recharge zone, transition
zone, or contributing zone as defined in Chapter 213 of this title (relating
to the Edwards Aquifer). Chapter 213 of this title establishes provisions
for activities in the watersheds of segments which are designated for aquifer
protection.
(B)
(No change.)
(3)
Aquatic life. The establishment of numerical
criteria for aquatic life is highly dependent on desired use, sensitivities
of usual aquatic communities, and local physical and chemical characteristics.
Five subcategories of aquatic life use are established. They include limited,
intermediate, high, and exceptional aquatic life and oyster waters. Aquatic
life use subcategories designated for segments listed in Appendix A of §307.10
of this title recognize the natural variability of aquatic community requirements
and local environmental conditions.
(A)
Dissolved oxygen.
(i)
The
characteristics
[
definitions
]
and associated dissolved oxygen criteria for limited, intermediate, high,
and exceptional aquatic life use subcategories are indicated in Table 4.
Figure: 30 TAC §307.7(b)(3)(A)(i)
(ii)
The dissolved oxygen criteria and associated critical
low-flow values in Table 5 apply to [
unclassified
] streams which
have significant aquatic life uses, and to streams which are specifically
listed in Appendix
A or
D of §307.10 of this title. The criteria
in Table 5 apply to
streams in Texas
[
all parts of Texas
]
which are east of a line defined by Interstate Highway 35 and 35W from the
Red River to the community of Moore in Frio County, and by U.S. Highway 57
from the community of Moore to the Rio Grande. The critical low-flow values
in Table 5 (at the appropriate stream bedslope) will be utilized as headwater
flows
when the flows are larger than applicable 7Q2 flows, in order
to determine discharge effluent limits necessary to achieve dissolved oxygen
criteria.
For streams which have bedslopes less than the minimum bedslopes
in Table 5, the flows listed for the minimum bedslope of 0.1 m/km will be
applicable. For streams which have bedslopes greater than the maximum bedslope
in Table 5, the flows listed for the maximum bedslope of 2.4 m/km will be
applicable.
The required effluent limits will be those necessary to
achieve each level of dissolved oxygen (as defined in clause (i) of this subparagraph,
Table 4) at or below an assigned,
designated,
or presumed aquatic
life use. Presumed aquatic life uses will be in accordance with those required
by §307.4(h) of this title
(relating to General Criteria)
.
The dissolved oxygen criteria in Table 5 do not apply to tidal streams [
or streams which are specifically listed in Appendix A of §307.10 of
this title
].
Figure: 30 TAC §307.7(b)(3)(A)(ii)
(iii)
The dissolved oxygen criteria in Table 5 are based upon
data from the commission's least impacted stream study (Texas Aquatic Ecoregion
Project). Results of this study indicate a strong dependent relationship for
average summertime background dissolved oxygen concentrations and several
hydrologic and physical stream characteristics--particularly bedslope (stream
gradient) and stream flow. The dissolved oxygen criteria in Table 5 are derived
from a multiple regression equation for the eastern portion of Texas as defined
in clause (ii) of this subparagraph. Further explanation of the development
of the regression equation and its application will be contained in the standards
implementation procedures.
[
Figure: 30 TAC 307.7(b)(3)(A)(iii)
]
(iv)
The critical low-flow values in Table
5 may be adjusted based on site-specific data relating dissolved oxygen concentrations
to factors such as flow, temperature, or hydraulic conditions in accordance
with the standards implementation procedures. Site-specific, critical low-flow
values require approval by the commission. EPA will review any site-specific,
critical low-flow values that could affect permits or other regulatory actions
that are subject to approval by EPA. Critical low-flow values which have been
determined for particular streams are listed in §307.10 of this title
(relating to Appendices A-E) when standards are revised.
(B)
Oyster waters.
(i)
A 1,000 foot buffer zone, measured from the shoreline at
ordinary high tide, is established for all bay and gulf waters, except those
contained in river or coastal basins as defined in §307.2 of this title
(relating to Description of Standards). Fecal coliform content in buffer zones
shall not exceed 200 colonies per 100 ml as a geometric mean [
of not
less than five samples collected over not more than 30 days or equal or exceed
400 colonies per 100 ml in more than 10% of all samples taken during a 30-day
period
].
(ii)-(iii)
(No change.)
(4)
(No change.)
(5)
Additional uses. Other basic uses, such as navigation,
agricultural water supply, [
and
] industrial water
supply,
seagrass propagation, and wetland water quality functions
will be maintained
and protected for all water in the state in which these uses can be achieved.
§307.8.Application of Standards.
(a)
Low-flow conditions.
(1)
The following standards do not apply below seven-day, two-year
low-flows:
(A)-(B)
(No change.)
(C)
total chronic toxicity restrictions as established in §307.6
of this title [
(relating to Toxic Materials)
];
(D)
(No change.)
(E)
dissolved oxygen criteria for unclassified waters, as established
in §307.4(h)(1) of this title [
(relating to General Criteria)
];
and
[(F)
dissolved oxygen criteria for intermittent
streams, as established in §307.4(h)(2) of this title (relating to General
Criteria); and]
(F)
[
(G)
]
aquatic recreation
[
fecal coliform
] criteria for unclassified waters, as established
in §307.4
(j)
[
(i)
] of this title [
(relating
to General Criteria)
]
and in §307.7(b)(1) of this title.
(2)
Numerical acute criteria for toxic materials
and preclusion of total acute toxicity as established in §307.6 of this
title [
(relating to Toxic Materials)
] are applicable at
stream
flows which are equal to or greater than one-fourth of seven-day, two-year
low-flows (7Q2)
[
all flow conditions
].
(3)-(6)
(No change.)
(7)
The general criteria are applicable at all flow conditions
except as specified in this section or in §307.4 of this title [
(relating to General Criteria)
].
(8)
Specific human health criteria for concentrations
in water to prevent contamination of fish and shellfish so as to ensure safety
for human consumption, as established in §307.6 of this title [
(relating to Toxic Materials)
] do not apply at stream flows below the
harmonic mean flow.
(b)
Mixing zones. A reasonable mixing zone will be allowed
at the discharge point of permitted discharges into surface water in the state,
in accordance with the following provisions.
(1)
The following portions of the standards do not apply within
mixing zones:
(A)
(No change.)
(B)
numerical chronic aquatic life criteria for toxic materials
as established in §307.6 of this title [
(relating to Toxic Materials)
];
(C)
total chronic toxicity restrictions as established in §307.6
of this title [
(relating to Toxic Materials)
];
(D)
maximum temperature differentials as established in §307.4(f)
of this title [
(relating to General Criteria)
];
(E)
dissolved oxygen criteria for unclassified waters, as established
in §307.4(h)(1) of this title [
(relating to General Criteria)
];
(F)
dissolved oxygen criteria for intermittent streams, as
established in §307.4(h)(2) of this title [
(relating to General
Criteria)
];
(G)
aquatic recreation
[
fecal coliform
]
criteria for unclassified waters, as established in §307.4
(j)
[
(i)
] of this title
and in §307.7 (b)(1) of this title
[
(relating to General Criteria)
]; and
(H)
specific human health criteria for concentrations in water
to prevent contamination of drinking water, fish and shellfish so as to ensure
safety for human consumption, as established in §307.6 of this title
[
(relating to Toxic Materials)
].
(2)
Numerical acute aquatic life criteria for toxic
materials and preclusion of total acute toxicity as established in §307.6
of this title [
(relating to Toxic Materials)
] are applicable in
mixing zones. Acute criteria and acute total toxicity levels may be exceeded
in small zones of initial dilution (ZIDs) at discharge points, but there shall
be no lethality to aquatic organisms which move through a ZID. ZIDs shall
not exceed the following sizes:
(A)-(C)
(No change.)
(3)
Provisions of the general criteria in §307.4
of this title [
(relating to General Criteria)
] remain in effect
in mixing zones unless specifically exempted in this section.
(4)
(No change.)
(5)
Where a mixing zone is defined in a valid
permit
issued by the commission, Railroad Commission of Texas, National Pollutant
Discharge Elimination System (NPDES) and/or TPDES
[
commission and/or
national pollutant discharge elimination system (NPDES) permit
], the
mixing zone defined in the permit will apply.
(6)-(8)
(No change.)
(9)
Mixing zones will be individually specified for all
permitted domestic discharges with a permitted monthly average flow equal
to or exceeding one million gallons per day and for all permitted industrial
discharges to water in the state (excepting discharges which consist entirely
of
storm water
[
stormwater
] runoff). For domestic discharges
with permitted monthly average flows less than one million gallons per day,
a small mixing zone will be assumed in accordance with guidelines for mixing
zone sizes specified in the standards implementation procedures [
document
]; and the commission may require specified mixing zones as appropriate.
(10)
(No change.)
(c)
Minimum analytical levels. The specified definition of
permit compliance for a specific toxic material will not be lower than established
minimum analytical levels, unless that toxic material is of particular concern
in the receiving waters, or unless an effluent specific method detection limit
has been developed in accordance with 40
CFR
[
Code of Federal
Regulation Part
] 136. Minimum analytical levels are listed in the standards
implementation procedures.
(d)
(No change.)
(e)
Wet-weather conditions and storm water
discharges. Pollutants in storm water will not impair existing or designated
uses. Specific numerical criteria are frequently not applicable to the short-term
effects of storm water. Such short-term effects on water quality are transitory,
dynamic, and often of shorter duration than applicable averaging periods for
numerical criteria. Should a numerical criteria be exceeded during wet weather,
the commission may not consider it a violation of water quality standards
unless the exceedence is due to human activity and would not occur without
that activity. Therefore, controls on the quality of storm water discharges
are largely based on the implementation of best management practices and/or
technology-based limits, in combination with instream monitoring to assess
standards attainment and to determine if additional controls on storm water
quality are needed. The standards implementation procedures describe how TPDES
permits for storm water discharges are evaluated and developed to protect
water quality standards. The evaluation of instream monitoring data for standards
attainment should include the effects of storm water, and this approach is
utilized in §307.9 of this title (relating to the Determination of Standards
Attainment) and in the
TNRCC Guidance for Screening
and Assessing Texas Surface and Finished Drinking Water Quality Data
.
§307.9.Determination of Standards Attainment.
(a)
General standards attainment sampling procedures.Unless
otherwise stated in this chapter, additional details concerning sampling procedures
for the measurement, collection, preservation and laboratory analysis of water
quality samples are provided in the latest adopted version of the
TNRCC Surface Water Quality Monitoring Procedures Manual
, the most
recently published edition of the book entitled
Standard Methods for the Examination of Water and Wastewater
, 40 CFR
136, or other reliable procedures acceptable to the executive director. Unless
otherwise stated in this chapter, additional details concerning how sampling
data are evaluated to assess standards compliance is provided in the latest
adopted version of the
TNRCC Guidance for Screening
and Assessing Texas Surface and Finished Drinking Water Quality Data
[
Sampling locations
].
[(1)
Representative samples to determine standards
attainment will be collected at locations approved by the commission. To ensure
comparability with past sampling data, samples will be collected at established
monitoring stations. Monitoring stations may be established or discontinued
by the commission.]
[(2)
Field investigation samples may
be collected at points not established or approved as standards attainment
sampling locations at the discretion of the commission.]
(b)
Sampling locations. Representative samples
to determine standards attainment will be collected at locations approved
by the commission. Samples collected at non-approved locations may be accepted
at the discretion of the executive director.
(c)
[
(b)
] Collection and preservation
of water samples.
(1)
To ensure that representative samples are collected and
to minimize alterations prior to analysis, collection and preservation of
attainment determination samples will be in accordance with procedures set
forth in the most recently published edition of the book entitled
Standard Methods for the Examination of Water and Wastewater
, the
latest
[
most recent
] version of the
TNRCC Surface Water Quality Monitoring Procedures Manual
, 40 CFR 136,
[
quality assurance program plan for the commission
] or other
reliable procedures acceptable to the
executive director
[
commission
].
(2)
Bacterial and temperature determinations will be conducted
on samples or measurements taken
approximately one foot below
[
within one foot of
] the surface. Depth collection procedures for chloride,
sulfate, total dissolved solids, dissolved oxygen, and pH to determine standards
attainment may vary depending on the water body being sampled. Where standards
apply to the mixed surface layer, the depth of this layer is determined in
accordance with procedures in the latest
version of the
TNRCC Guidance for Screening and Assessing Texas Surface and Finished Drinking
Water Quality Data
[
published edition of the
Texas Surface Water Quality Inventory
]. Standards for chloride,
sulfate, total dissolved solids, and pH are applicable to the mixed surface
layer, but a single sample taken near the surface [
(at a depth of approximately
one foot)
] normally provides an adequate representation of these parameters.
[
For dissolved oxygen, the following procedures are generally applicable.
]
(3)
For dissolved oxygen, the following
procedures are generally applicable:
(A)
Non-tidal flowing streams.
The dissolved oxygen criteria
is applicable to the mixed surface layer, but a single sample taken near the
surface normally provides an adequate representation of this parameter.
[
In flowing streams, a profile should be obtained to determine if the
water column is uniformly mixed. Samples shall be collected one foot below
the water surface in streams exhibiting a vertically mixed water column. A
depth-integrated sample shall be used to determine attainment in unmixed streams.
Where depth is less than 1.5 feet, the collection depth shall be one-third
of the water depth measured from the water surface.
]
(B)
Impoundments. Representative samples shall be collected
from the entire water column in the absence of thermal stratification. Collection
of representative samples shall be confined to the epilimnion when an impoundment
is thermally stratified.
(C)
Tidal waters. Representative samples shall be collected
from the entire water column in the absence of density stratification. Under
conditions of density stratification, a composite sample collected from the
mixed surface layer shall be used to determine standards attainment
[
Bays. A depth-integrated (vertical composite) sample shall be collected
from the surface to the natural bottom. Dredged areas shall not be considered
part of the natural bottom
].
[(D)
Tidal streams. A surface to bottom profile
of DO, pH, conductivity, and temperature shall be obtained in all cases. Under
conditions of density stratification, a composite sample collected from the
mixed surface layer shall be used to determine standards attainment.]
(4)
[
(3)
]
For
[
Numerical aquatic life criteria for
] toxic materials
, numerical
aquatic life criteria
are applicable to water samples collected at any
depth. Numerical human health criteria are applicable to the average concentration
from the surface to the bottom.
For the purposes of standards attainment
for aquatic life protection and human health protection, samples which are
collected at approximately one foot below the water surface will also be acceptable
for comparison to numerical criteria.
(d)
[
(c)
] Sample analysis.
(1)
Numerical
criteria. Procedures for laboratory analysis
will be in accordance with the most recently published edition of the book
entitled
Standard Methods for the Examination of
Water and Wastewater
, the latest version of the
Texas Surface Water Quality Monitoring Procedures Manual
, 40 CFR 136,
or other reliable procedures acceptable to the executive director.
[
Values. Numerical values in the water quality standards shall be determined
by analytical procedures recommended in the most recently published edition
of the book entitled
Standard Methods for the Examination
of Water and Wastewater
, the quality assurance program plan for the
commission, Title 40 Chapter 136 of the Code of Federal Regulations, or other
reliable methods acceptable to the commission.
]
(2)
Radioactivity. Measurements will be made on filtered
samples to determine radioactivity associated with dissolved minerals
in accordance with current analytical methodology approved by the EPA
.
(3)
Toxicity. Bioassay techniques will be selected as
testing situations dictate but will generally be conducted using representative
sensitive organisms in accordance with §307.6 of this title (relating
to Toxic Materials).
[(4)
Bacteria. Bacteriological levels
shall be determined by either multiple-tube fermentation or membrane filter
techniques.]
(e)
[
(d)
] Sampling periodicity and evaluation.
(1)
Chloride, sulfate, total dissolved solids (TDS). Standards
attainment determinations shall be based on the
annual
average
of measurements [
taken on at least four different dates within one year
]. Results from all monitoring stations within the segment will be averaged
to allow for reasonable parametric gradients. TDS determinations may be based
on measurements of specific conductance. [
Conversion factors are presented
in the latest publication of the
Texas Surface Water
Quality Inventory
or may be based on additional site-specific data.
]
(2)
Radioactivity. The impact of radioactive discharges
on the surface waters in Texas will be evaluated utilizing information developed
by the Sanitary Engineering Research Laboratory at the University of Texas
and presented in the June 30, 1960, report entitled,
Report on Radioactivity--Levels in Surface Waters--1958-1960
.
(3)
Bacteria.
Standards attainment will be based
on an annual geometric mean of applicable samples, and data will be evaluated
in accordance with the provisions of
[
Standards attainment for
fecal coliform bacteria will be determined as described in
] §307.7(b)(1)
of this title (relating to Site-specific Uses and Criteria).
(4)
Toxic materials. Specific numerical acute toxic criteria
are applied as 24-hour averages, and specific numerical chronic toxic criteria
are applied as seven-day averages. Human health criteria are applied as long-term
average exposure criteria designed to protect populations over a life time
of 70 years.
Refer to the latest version of the
TNRCC Guidance for Screening and Assessing Texas Surface and Finished Drinking
Water Quality Data
for sampling periodicity and evaluation applicable
to standards [
Standards
] attainment for human health criteria [
will be based on the average of a minimum of four samples collected over at
least a one year period
].
(5)
Temperature and pH. Standards attainment
based
on single measurements will be evaluated according to the latest version of
the
TNRCC Guidance for Screening and Assessing Texas
Surface and Finished Drinking Water Quality Data
[
will be
evaluated for measurements or samples taken at a single point in time
].
(6)
Dissolved oxygen.
(A)
(No change.)
(B)
Criteria for minimum concentrations will be compared to
individual measurements. [
taken at night (from sunset until two hours
after sunrise).
]
(f)
Biological integrity. Biological integrity,
which is an essential component of the aquatic life categories defined in §307.7(b)(3)
of this title (relating to Site-specific Uses and Criteria), is assessed by
sampling the presence and abundance of aquatic organisms. Attainment of aquatic
life use may be assessed by indices of biotic integrity which are described
in publicly available documents such as in the latest version of the TNRCC Receiving Water Assessment Procedures Manual
.
(g)
Additional parameters. Assessment of narrative
criteria parameters shall be performed in accordance with the latest version
of the
TNRCC Guidance for Screening and Assessing
Texas Surface and Finished Drinking Water Quality Data
.
§307.10.Appendices A-E.
The following appendices are integral components of this chapter of
the Texas Surface Water Quality Standards.
(1)
Appendix A--Site-specific Uses and Criteria for Classified
Segments:
Figure: 30 TAC §307.10(1)
(2)
Appendix B--Low Flow Criteria:
Figure: 30 TAC §307.10(2)
(3)
Appendix C--Segment Descriptions:
Figure: 30 TAC §307.10(3)
(4)
Appendix D--Site-specific Receiving Water Assessments:
Figure: 30 TAC §307.10(4)
(5)
Appendix E--Site-specific Criteria:
Figure: 30 TAC §307.10(5)
This agency hereby certifies that the proposal has been
reviewed by legal counsel and found to be within the agency's legal authority
to adopt.
Filed with the Office of
the Secretary of State, on January 21, 2000.
TRD-200000418
Margaret Hoffman
Director, Environmental Law Division
Texas Natural Resource Conservation Commission
Proposed date of adoption: March 23, 2000
For further information, please call: (512) 239-6087