| (a) Uses and numerical criteria are established on
a site-specific basis in Appendices A, B, D, E, F, and G of §307.10
of this title (relating to Appendices A - G). Site-specific uses and
numerical criteria may also be applied to unclassified waters in accordance
with §307.4 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 human activity. Site-specific criteria do not apply to those instances
when surface waters exceed criteria 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 five categories--primary
contact recreation 1, primary contact recreation 2, secondary contact
recreation 1, secondary contact recreation 2, and noncontact recreation
waters. Classified segments are designated for primary contact recreation
1 unless sufficient site-specific information demonstrates that elevated
concentrations of indicator bacteria frequently occur due to sources
of pollution that cannot be reasonably controlled by existing regulations,
wildlife sources of bacteria are unavoidably high and there is limited
aquatic recreational potential, or primary or secondary 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 either noncontact recreation criteria or
criteria normally associated with primary contact recreation. A designation
of primary or secondary contact recreation is not a guarantee that
the water so designated is completely free of disease-causing organisms.
Indicator bacteria, although not generally pathogenic, are indicative
of potential contamination by feces of warm-blooded animals. Recreational
criteria are based on these indicator bacteria rather than direct
measurements of pathogens. Criteria are expressed as the number of
bacteria per 100 milliliters (mL) of water (in terms of colony forming
units, most probable number, or other applicable reporting measures).
Even where the concentration of indicator bacteria is less than the
criteria for primary or secondary contact recreation, there is still
some risk of contracting waterborne diseases. Additional guidelines
on minimum data requirements and procedures for evaluating standards
attainment are specified in the TCEQ Guidance
for Assessing and Reporting Surface Water Quality in Texas, as
amended.
(A) Freshwater.
(i) Primary contact recreation 1. The geometric mean
criterion for E. coli is 126 per 100
mL. In addition, the single sample criterion for E. coli is 399 per 100 mL.
(ii) Primary contact recreation 2. The geometric mean
criterion for E. coli is 206 per 100
mL.
(iii) Secondary contact recreation 1. The geometric
mean criterion for E. coli is 630
per 100 mL.
(iv) Secondary contact recreation 2. The geometric
mean criterion for E. coli is 1,030
per 100 mL.
(v) Noncontact recreation. The geometric mean criterion
for E. coli is 2,060 per 100 mL.
(vi) For high saline inland water bodies where Enterococci
is the designated recreational indicator in Appendix A of §307.10
of this title, Enterococci is the applicable recreational indicator
for instream bacteria sampling at all times for the classified water
body and for the unclassified water bodies that are within the watershed
of that classified segment, unless it is demonstrated that an unclassified
water body is not high saline. E. coli is
the applicable recreational indicator for instream bacteria sampling
at all times for unclassified water bodies where conductivity values
indicate that the water bodies are not high saline. For high saline
inland waters with primary contact recreation 1, the geometric mean
criterion for Enterococci is 33 per 100 mL and the single sample criterion
is 78 per 100 mL. For high saline inland waters with primary contact
recreation 2, the geometric mean criterion for Enterococci is 54 per
100 mL. For high saline inland waters with secondary contact recreation
1, the geometric mean criterion for Enterococci is 165 per 100 mL.
For high saline inland waters with secondary contact recreation 2,
the geometric mean criterion for Enterococci is 270 per 100 mL. For
high saline inland water bodies with noncontact recreation, the geometric
mean criterion for Enterococci is 540 per 100 mL.
(B) Saltwater.
(i) Primary contact recreation 1. The geometric mean
criterion for Enterococci is 35 per 100 mL. In addition, the single
sample criterion for Enterococci is 130 per 100 mL.
(ii) Secondary contact recreation 1. A secondary contact
recreation 1 use for tidal streams and rivers can be established on
a site-specific basis in §307.10 of this title if justified by
a use-attainability analysis and the water body is not a coastal recreation
water as defined in the Beaches Environmental Assessment and Coastal
Health Act of 2000 (BEACH Act). The geometric mean criterion for Enterococci
is 175 per 100 mL.
(iii) Noncontact recreation. A noncontact recreation
use for tidal streams and rivers can be established on a site-specific
basis in §307.10 of this title if justified by a use-attainability
analysis and the water body is not a coastal recreation water, as
defined in §307.3 of this title (relating to Definitions and
Abbreviations). The geometric mean criterion for Enterococci is 350
per 100 mL.
(C) Swimming advisory programs. 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 documents
entitled Recreational Water Quality Criteria (EPA-820-F-12-058)
and Ambient Water Quality Criteria for Bacteria
- 1986 (EPA 440/5-84-002). 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 three use subcategories - public water supply, sole-source surface
drinking 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 Public
Drinking Water).
(ii) Sole-source surface drinking water supplies and
their protection zones. Water bodies that are sole-source surface
drinking water supplies are listed in Appendix B of §307.10 of
this title. Sole-source surface drinking water supplies and their
protection zones are addressed in Chapter 321, Subchapter B of this
title (relating to Concentrated Animal Feeding Operations).
(iii) 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 that are designated for aquifer protection.
(B) Use criteria. The following use criteria apply
to all domestic water supply use subcategories.
(i) Radioactivity associated with dissolved minerals
in the freshwater portions of river basin and coastal basin waters
should not exceed levels established by drinking water standards as
specified in Chapter 290 of this title unless the conditions are of
natural origin.
(ii) Surface waters utilized for domestic water supply
must not exceed toxic material concentrations that prevent them from
being treated by conventional surface water treatment to meet drinking
water standards as specified in Chapter 290 of this title.
(iii) Chemical and microbiological quality of surface
waters used for domestic water supply should conform to drinking water
standards as specified in Chapter 290 of this title.
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