Texas Administrative Code
Title 30 - ENVIRONMENTAL QUALITY
Part 1 - TEXAS COMMISSION ON ENVIRONMENTAL QUALITY
Chapter 307 - TEXAS SURFACE WATER QUALITY STANDARDS
Section 307.5 - Antidegradation
Universal Citation: 30 TX Admin Code § 307.5
Current through Reg. 49, No. 52; December 27, 2024
(a) Application. The antidegradation policy and implementation procedures set forth in this section apply to actions regulated under state and federal authority that would increase pollution of the water in the state. Such actions include authorized wastewater discharges, total maximum daily loads (TMDLs), waste load evaluations, and any other miscellaneous actions, such as those related to man-induced nonpoint sources of pollution, that may impact the water in the state.
(b) Antidegradation policy. In accordance with the Texas Water Code, § 26.003, the following provisions establish the antidegradation policy of the commission.
(1) Tier 1. Existing uses and
water quality sufficient to protect those existing uses must 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 activities subject to
regulatory action that would cause degradation of waters that exceed
fishable/swimmable quality are 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 more than a de minimis extent, but not to the extent that
an existing use is impaired. Water quality sufficient to protect existing uses
must be maintained. Fishable/swimmable waters are defined as waters that have
quality sufficient to support propagation of indigenous fish, shellfish,
terrestrial life, and recreation in and on the water.
(3) Tier 3. 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 must be
maintained and protected.
(4)
Discharges that cause pollution that are authorized by the Texas Water Code,
the Federal Clean Water Act, or other applicable laws must not lower water
quality to the extent that the Texas Surface Water Quality Standards are not
attained.
(5) Anyone discharging
wastewater that would constitute a new source of pollution or an increased
source of pollution from any industrial, public, or private project or
development is 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 are achieved for nonpoint sources of
pollution.
(6) Application of
antidegradation provisions does 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.
(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 that 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 permitted and regulated activities that increase pollution of
water in the state are also subject to the provisions of the antidegradation
policy as established in subsections (a) and (b) of this section.
(2) General provisions for
implementing the antidegradation policy.
(A)
Tier 1 reviews must ensure that water quality is sufficiently maintained so
that existing uses are protected. All pollution that could cause an impairment
of water quality is 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 must include a preliminary
determination of existing uses and criteria. Existing uses must be maintained
and protected.
(B) Tier 2 reviews
apply to all pollution that could cause degradation of water quality where
water quality exceeds levels necessary to support propagation of fish,
shellfish, terrestrial life, and recreation in and on the water
(fishable/swimmable quality). Guidance for determining water bodies that exceed
fishable/swimmable quality is contained in the standards implementation
procedures. For dissolved oxygen, analyses of degradation under Tier 2 must
utilize the same critical conditions as are used to protect instream criteria.
For other parameters, appropriate conditions may vary. Conditions for
determining degradation are commensurate with conditions for determining
existing uses. The highest water quality sustained since November 28, 1975 (in
accordance with EPA Standards Regulation 40 Code of Federal Regulations Part
131) defines baseline conditions for determinations of degradation.
(C) Tier 3 reviews apply to all pollution
that could cause degradation of outstanding national resource waters.
Outstanding national resource waters are those specifically designated in this
chapter.
(D) When degradation of
waters exceeding fishable/swimmable quality is anticipated, a statement that
the antidegradation policy is pertinent to the permit action must be included
in the public notice for the permit application or amendment. If no degradation
is anticipated, the public notice must so state.
(E) Evidence can be introduced in public
hearings, or through the public comment process, 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 that bear upon the implementation of the antidegradation
policy.
(F) Interested parties are
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 that allow an increase
in loading. If the TMDL or waste load evaluation indicates that degradation of
waters exceeding fishable/swimmable quality is expected, the public hearing
notice must so state. Permits that are consistent with an approved TMDL or
waste load evaluation under this antidegradation policy are not subjected to a
separate antidegradation review for the specific parameters that are addressed
by the TMDL or waste load evaluation.
Disclaimer: These regulations may not be the most recent version. Texas may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
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