ft-.98-' I OQ
GUIDANCE FOR STATE
IMPLEMENTATION
OF
WATER QUALITY STANDARDS
FOR
CWA SECTION 303(C)(2)(B)
December 1988
U.S. Environmental Protection Agency
Office of Water
Office of Water Regulations and Standards
Criteria and Standards Division
-401 M Street S.W. (WH-385)
Washington, DC 20460
EWlftflUHEKTAL
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON. D.C. 20460
DEC 121988
, OFFICE OF
MEMORANDUM WATER
SUBJECT: Transmittal of Final "Guidance for State
plementation of Water Quality Standards
CWA Section 303 (c) (2) (B) "
.-Imp
(. tr
FROM: Rebecca W. Hanroer, Acting Assistant Administrator
for Water (WH-556)
.TO: Water Management Division Directors
Regions I-X
Directors
State Water Pollution Control Agencies
Attached is the final guidance on State adoption of criteria
for priority toxic pollutants. We prepared this. guidance to help
States comply with the new requirements of the 1987 amendments to
the Clean Water Act. We have made only minor changes to the
September .2, 1988 draft which was distributed to you earlier.
The guidance focuses specifically on the 'new' effort 'to
control toxics in water quality standards. It does not supersede
other elements of the . standards program which .address
conventional and . non-conventional pollutants as well as priority
toxic pollutants. These other elements . are described in other
Office of Water guidance such as the Water Quality Standards
Handbook and continue in full force and effect.
. Some commenters on the draft expressed a concern that the
guidance places an unnecessary burden on States to demonstrate a
need to regulate toxics before State criteria are adopted. This
comment related primarily to Option 2 which provides for a more
targetted approach than Option 1. We wish to clarify that no
such requirement for the States to develop a demonstration of
need is included in or intended by the guidance. We do urge
States, as a minimum, to use their identifications of impacted
segments under Section 304U) as a starting point for identifying
locations where toxic pollutants are of concern and . in need of
coverage in State standards. In addition, the presence or
potential construction of facilities that manufacture or use
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priority toxic pollutants or. other information indicating that
such pollutants are or may be discharged strongly suggests that
States should set standards since such pollutants have the
potential to or could be interfering with attaining designated
uses. We believe it would be reasonable to take such an approach
and a State need not demonstrate any actual impairment to justify
setting a standard.
For your information, the Office of Water is now drafting
revisions to the water quality standards regulation (especially
40 CFR 131.11) to incorporate the requirements for complying with
Section 303(c)(2)(B) as reflected in this guidance. We will be
seeking your suggestions and comments as this process proceeds.
Enclosure
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GUIDANCE FOR STATE
IMPLEMENTATION
OF
WATER QUALITY STANDARDS
FOR
CWA SECTION 303(C)(2)(B)
December 1988
U.S. Environmental Protection Agency
Office of Water
Office of Water Regulations and Standards
Criteria and Standards Division
401 M Street S.W. (WH-585)
Washington, DC 20460
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GUIDANCE FOR STATE IMPLEMENTATION
' ' OF
WATER QUALITY STANDARDS
FOR
CWA §303(c:)(2)(B)
PURPOSE ' .
This guidance addresses the adoption of toxics criteria in
water quality standards pursuant to. new section 303(c)(2)(B) of
the Clean Water Act (CWA), as added by the Water Quality Act of
1987 (WQA). This guidance pertains to toxic pollutants listed
pursuant to Section 307(a) of the,Clean Water Act (CWA).
GENERAL GUIDANCE . , . / .
EPA is proposing that a State may meet these requirements
in the law in one of. three ^scientifically and technically . , .
sound ways (or some combination,thereof). These options are:
(1) Adopt Statewi.de numeric: criteria in State water r
quality standards for all section 307(a) toxic
. pollutants for which EPA has developed criteria
, guidance , regard!ess, of whether the pollutants are^
known to be present; .
(2) Adopt specific numeric criteria in State water quality
standard,? for sect i on 307 (a) toxic pollutants as
, necessary to support designated uses where such
pollutants are discharged or are present in the
affected waters and could reasonably be expected to
interfere with designated uses;
..(3) Adopt a procedure ..-to be applied to a 'narrat i ve water
quality standard provision that prohibits toxicity
in receiving Waters. Such a procedure -would be used
by the State in calculating derived numeric criteria,
which criteria shall be used for all purposes .under
section 303(c) of the ' CWA. At a mini mum, such criteria
need to be developed 'for Section 307(a) toxic pollutants,
'as necessary to support; designated uses , where these
pollutants are discharged or present in the affecte'd
waters and could reasonably be expected to interfere
with designated uses. .
EPA believes option 2 above most directly reflects the
new Clean Water Act requirements and is the option recommended
by the Agency. Option 3, while considered by EPA also to meet
the requirements'of the Act, is "best suited for use as a
supplement to option 2. Option ]. is consistent with State
authority to establish water quality standards. Later in this
guidance, each of the options is discussed.
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EPA believes that an effective State water quality standards
program should include both the chemical specific (i.e., ambient
criteria) and narrative approaches. Numeric criteria for
specific chemicals are important where the cause of toxicity.
is known or for protection against potential human health
impacts. Numeric water quality criteria may also be the best
way to address certain nonpoint source pollution problems. The
narrative standard can be the basis for limiting toxicity where
a specific toxic pollutant can be identified as causing* the
toxicity, but there is no numeric criterion in State standards.
The narrative standard can also be used to limit whole effluent
toxicity where it is not known which chemical or chemicals are
causingthetoxicity.
For several years now, EPA has required States to adopt a
narrative standard to use as the basis for deriving whole
effluent toxicity limits. The procedure described in this
document is not the same as the procedure States have been
using to derive whole effluent toxicity limits.! The
procedure described in this guidance is applied to the
narrative provision to derive numeric criteria for specific
toxic pol1utants.
In order to determine whether waters are attaining
designated uses, and to develop appropriate total maximum daily
loads (TMDL), waste load allocations (WLA) , and National ,
Pollutant Discharge Elimination System (NPDES) permit limits to
meet the applicable water quality standards, a State must also
consider pollution from nonpoint sources since both point and
nonpoint sources may contribute to exceedances of water quality
standards. EPA recognizes that current water quality standards
are most often applied only to point sources because of problems
with concentration and duration, and is beginning to look at
ways to enhance water quality standards to better address
problems created by nonpoint sources.
1. For further information, consult EPA's Techni cal Support
Document for Water Qua!ity-based Toxics Control , EPA 440/4-85-032
September 1985.
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BACKGROUND
Section ,303(c)'(2).(B) of the CWA, as added by the WQA of
1987, provides that: ,
"Whenever a State reviews water quality standards,
pursuant to paragraph (1) of th1s.subsection, or
revises or adopts new standards pursuant to this
paragraph, such State shall adopt-criteria for,all
toxic pollutants listed pursuant to section 307(a)(l)' . .
of this Act for which criteria have been published
under section ' 304{a.) ,-the discharge or presence of
which in the affected waters could reasonably be ex-
pected to interfere with those, designated uses adopted
by the State, as necessary to support such designated
uses. Such criteria shall be specific numerical
criteria for such toxic pollutants. Where such
numerical criteria are not available, whenever
a State reviews water quality standards pursuant to
paragraph (1), or re vise s ,or adopts new standards
pursuant to this paragraph, such State shall.adopt
criteria based on biological monitoring or assess-
ment methods consistent with information published
pursuant to section'304(a)(8). Nothing in this
section shall be construed to limit or delay, the
use of effluent limitations or other permit con-
ditions based on or involving biological monitoring
or assessment methods or previously adopted numerical '
criteria."
To carry -out these new requirements, whenever a State
revises its water quality, standards, it must review a.l 1 available
information and data 'to first determine whether the discharge
or the presence of, a toxic pollutant is interfering or is .likely
to interfere with the attainment of the designated uses of any
stream segment. If the data indicate that it is reasonable to
expect the toxic pol1utant to-interfere with the use, or it
actually is interfering with the use, then th'e State must adopt
a numeric limit for the specific pollutant. If a State is
unsure whether a toxic pollutant is interfering witht or is
likely to interfere with the designated use and therefore is
unsure that" control . of 'the pollutant, is necessary to support
the designated use, the State should undertake to develop
sufficient information u,pon which to make such a determination.
Presence of facilities that manufacture or use the section -307 (a)
toxic pollutants or:other information indicating that such
pollutants are discharged or will be discharged strongly suggests
that such pollutants could be interfering with attaining
designated uses. If a State expects the pollutant not to
interfere with the designated use, then section 303(1)(2)(B)
does not require a numeric standard for that pollutant.
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Section 303(c)(2)(B) addresses only pollutants listed as
"toxic" pursuant to section 307(a) of the Act, which are codified
at 40 CFR §40.1.15. The section 307(a) list contains 65 compounds
and families of compounds, which potentially include thousands
of specific compounds. The Agency has interpreted that list to
include 126 "priority" toxic pollutants for regulatory purposes.
Appendix A contains a listing of the 126 priority toxic
pollutants. Reference in this guidance to toxic pollutants or
section 307(a) toxic pollutants refers to the 12fi priority
toxic pollutants unless otherwise noted. Both the list of
priority toxic pollutants and recommended criteria levels are
subject to change.
The national criteria recommendations published by EPA
under section 304(a) of the Act include values for. both acute and
chronic aquatic life protection; only chronic criteria recom-
mendations have been established to protect human health. To
comply with the statute, a State needs to adopt aquatic life
and human health criteria where necessary to support the appro-
priate designated uses. Criteria for the protection of human
health are needed for waterbodies designated for public water
supply. The Agency policy on use of section 304(a) human health
criteria or maximum concentration lim'its (MCLs) developed under
the Safe Drinking Water Act is stated at 45 FR 7931R, November
28, 1980. Basically, for protection of public water supplies,
EPA encourages the use of MCLs. When fish ingestion is
considered an important activity, then the human health related
water quality criteria recommendation developed under section
304(a) of the CWA should be used; that is, the portion of the
criteria recommendation based on fish consumption. For those
pollutants designated as carcinogens, the recommendation for a
human health criterion is generally more stringent than the
aquatic life criterion for the same pollutant. In contrast,
the aquatic life criteria recommendations for non-carcinogens are
generally more stringent than the human health recommendations.
When a State adopts a human health criterion for a carcinogen,
the State needs to select a risk level. EPA has estimated risk
levels of -10-5, in-6, and 10-7 ,n its criteria documents under one
set of exposure assumptions. However, the State is not limited
to -choosfng among the risk levels published in the -section 304(a)
criteria documents nor is the State limited to the base case
exposure assumptions; it must choose the risk level for its
conditions and explain its rationale.
EPA does not intend to propose changes to the current
requirements regarding the bases on which a State can adopt
numeric criteria (40 CFR §131.11(b) (1)). Under our regulation,
in addition to basing numeric criteria on EPA's section 304(a)
criteria documents, States may also base numeric criteria on
site-specific determinations or other scientifically defensible
methods. Guidance on developing site-specific criteria may be
found in the Water Qua! ity Standards Handbook', December 1983.
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Section 303(c.)(2)(B) also provides that where EPA-recommended
numeric criteria are not available, States shall adopt criteria
based on biological monitoring or assessment methods consistent
with information published pursuant to new section 304(a)(8) of
the Act. At a minimum, whole effluent toxicity tests must be
required of all point source' di scha rges. thought to be discharging
such pollutants. EPA previously developed several guidance
documents that help meet the intent of section 304(a)(8),
including the "Technical Support Document for Water Quality-based
Toxics Control" (EPA 440/4-85032, September 1985); "Guidelines
for Deriving National Water Quality Criteria for the Protection
of Aquatic Organisms and Thei r. Uses" (45 FR 79341, November 28,
1980, as amended at 50 FR 30784, July 29, 1985); and "Guidelines
and Methodology Used in the Preparation of Health Effect Assess-
ment Chapters of the Consent Decree Water Criteria Documents"
(45 FR 79318, November 28, 1980). ,
It should be noted that nothing in the Act or in the water
quality standards regulation restricts the right of a State to
adopt numeric criteria for any pollutant not listed pursuant to
section 307(a)(l), and -that such -criteria may be expressed as
concentration limits for an individual pollutant or for a
toxicity parameter itself as- measured by whole effluent toxicity
testing.,
THE OPTIONS: PROS, CONS, REQUIREMENTS
Option 1 , ...
o Adopt Statewide numeric criteria in. State water quality
-standards for all Section 307(a) toxic pollutants for which
EPA has developed criteria guidance, regardless of whether
» the pol1utants a re known to.be present.
Pro:
--simple, straight forward implementation . ,
--ensure-that States will satisfy statute
--makes maximum uses.of EPA recommendations
--gets specific numbers into State water quality standards
--fast, at first
Con :
--some priority toxic pollutants may not be discharged
in State ' .
--may cause unnecessary monitoring by States
--without variance procedure,, could cause unreasonable
economi c impacts
. --might result in "paper standards"
--could halt progress underway to develop criteria for
toxics
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Discussion: , >
Option 1 is within a State's legal authority under the CWA
to adopt broad water quality standards. EPA's concern with
this option, which has been adopted by several States (some
prior to passage of the WOA of 1987), is that the numeric
criterion established in the State's standard may not have been
found in advance to be reasonable for all waters of the State.
EPA is confident "of the scientific validity of its section
304(a) national criteria recommendations, but blanket application
of the criteria to all waters under all circumstances may not
always be prudent or reasonable. In some States, severe economic
'impacts may occur if the State does not exercise its authority
to use one or more of the techniques for adjusting water quality
standards: (1) establish or "revise designated stream uses based
on use attainability analyses, (2) develop site-specific criteria
or (3) allow short-term variances when appropriate.
All three of these techniques may apply to standards
developed under any of the three options discussed in this
guidance. It is likely that States electing to use option 1
will rely more on variances because the other two options are
implemented with more site-specific data being available. It
should be noted, however, that permits issued pursuant to such
water quality variances must still comply with any applicable
antidegradation and antibacks!iding requirements.
In the water quality standards regulation promulgated on
November 8, 1983, there is only a brief mention of variances
with a discussion in the Preamble suggesting that only wide-
spread economic and social impact can be used as the basis for
granting a variance (a variance is granted by the State- subject
to review and approval' by EPA). On March 15, 1985, EPA issued
an interpretation of variances to water quality standards that
allows short-term variances (not to exceed three years) to be
granted from water quality standards to individual dischargers
based on any of the six factors listed in section 131.10(g) of.
the regulation for justifying removal -of a designated use. Our
previous interpretation was flawed as it allowed more opportunity
for a permanent change in standards that it did for a temporary,
short-term change which could be granted by a variance. Without
a short term variance procedure, there is a danger that permits
may contain excessively long compliance dates which don't force
the attainment of water quality standards.
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The six factors on which a variance may be based are:
(1) Naturally occurring pollutant .concentrations prevent the
, attainment of the use; or .
(2) Natural, ephemeral, intermittent or -low flow conditions
or- water leve.ls prevent the attainment of the use1,
unless these conditions may be compensated for by the
discharge of sufficient volume of effluent discharges
without violating State water conservation requirements
to enable uses to be met; OP
(3) Human caused conditions or sources of pollution prevent
the attainment of the use and cannot be remedied or
would cause more environmental damage to-correct than t'o
leave inplace; or
(4) Dams, diversions or other types of' hydro! ogic modifications
preclude the attainment of the use, and it is not feasible
to restore the water body 'to its original condition or
to operate such modification in a way that would result
in the attainment of the use; or
. (5) Physical conditions related'to the natural features- of the
water body, such as the lack of a proper substrate, cover,
flow, depth , pool s , ri ffl e's , and the 1 i ke, unrelated to .
water quality, preclude attainment of aquatic life
protection uses; or
(fi) Controls more stringent than those required by section
301(b) and 306 of the Act would result i'n substantial
and widespread economic and social impact.
A State, using option 1 necessarily must follow all its
legal and administrative requirements for adopting water . ,
quality standards. Since the specific numeric criteria for
toxics adopted under option 1 are, part of the .State's water
quality standards, they will be reviewed and either a-pproved or
disappproved by EPA when such standards are submitted by the
State to EPA. ' ' ;
Option 2
Adopt specific numeric criteria in .State water quality
standards for section 307(a) toxic pollutants as necessary
to support designated uses where such pol1utants are
discharged or are present in the affected waters an'd
could reasonably be expected to interfere with designated
uses. , ,, ' '
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Pro:
--directly reflects statutory requirement
--standards based on demonstrated need to control
problem pollutants,
--State can use EPA's section 304(a) national criteria
recommendations or other scientifically acceptable
alternative, including site-specific criteria
--State can consider current or potential "toxic
pollutant problems
--State can go beyond section 307(a) toxics list, as
desi red
Con:
--may be difficult and time consuming to determine if,
and which, pollutants are interfering with the designated
use
--adoption of standards can require lengthy debates on
correct criteria limit to be included in standards
--successful State toxic control programs based on narrative
criteria may be halted or slowed as the State applies
its limited resources to developing numeric standards
--difficult to update criteria once adopted as part of
standards
--to be absolutely technically defensible, may need site-
specific criteria in many situations, leading to a
large workload for regulatory agency
Discussion:
This is the option EPA recommends a State use to meet the
statutory requirement. It directly reflects all the Act's
requirements and is flexible, resulting in adoption of numeric
water quality standards as needed. To assure that the State' is
capable of deal-ing with new problems as they arise, EPA also
recommends that States adopt a translator procedure which is
the same as, or similar to, that described in Option 3, but
applicable to all chemicals causing toxicity and not just priority
pollutants as is the case for option 3.
In the short term, EPA intends for States to rely on their
section 304(1) water quality assessments to identify those water
segments that will need new and/or revised water quality standards
for section 307(a) toxic pollutants. In addition, in FY 1988,
EPA is conducting reviews of State toxic control programs as
they relate to toxic pollutants. Following these reviews, EPA
will work with each State to develop an action plan to cover
the steps that the State should take to correct any program
deficiencies identified during the review. In the short term,
Action Plans should be the vehicle for reaching agreement between
EPA and the States on the most expeditious schedule for revising
State water quality standards to meet the CWA requirements. In
the longer term, EPA expects similar determinations to occur
during each triennial review of water quality standards as
required by section 303(c).
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In, identifying the need for numeric criteria,- EPA is
encourag.ing States to use information and data such as: (1)
ambient water monitoring, data, including those for sediment and
aquatic, 1 ife' (e.g.. , fish tissue data); (2) NPDES permit appli-'.
cations and permittee self-monitoring reports; (3) effluent .
guideline development documents, many of which contain section
3f)7(a)(l) priority pollutant scans; (4) pesticide and herbicide
application information and other records of pesticide or
herbicide inventories; (5) public water supply source monitoring
data noting pollutants with Maximum Contaminant Levels (MCLs);
and (6) any other relevant information on toxic pollutants
collected by Federal, State, interstate agencies, academic
groups, or scientific organizations. (Note: For more detail,
see EPA's "Categories of Waters to be,. Screened for Listing Under
Section 304(1)" in EPA's section 304(1) guidance document).
Where the St.ate's review indicates that there is a reasonable
expectation of a problem from the discharge or presence of toxic
pollutants, the State should identify the pollutant(s) and the
relevant segment(s)." In making these determinations, States
should use their own EPA approved criteria or existing EPA
water quality criteria for purposes of segment identification.
After the review, the State may use other means to establish
the final, criterion as it revises its standards.
As with option 1, a State using option 2 must follow all
its legal and administrative requirements for adoption of
water qua!ity standards. Since'the resulting numeric criteria
are part of a State's water quality standards, they are required
to be submitted by the State to EPA for review and either
approval or disapproval.
- EPA believes this option offers the State optimum
flexibility. For section 307(a) toxic pollutants adversely
affecting designated uses, numeric criteria are available for
permitting purposes. For other situations, the State has the
option of defining site specific criteria.
Option 3 ' .
o Adopt a procedure to be applied to the narrative water
quality standard provision that prohibits toxicity in
receiving waters. Such a procedure would be used by a
State in calculating derived numeric criteria to be used
for all purposes of water quality criteria under section
303(c) of the CWA. At a minimum such criteria need to
be derived for section 307(a) toxic pollutants where the
discharge or presence of such pollutants in the affected
waters could reasonably be expected to interfere with
designated uses, as necessary to support such designated
uses. "
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Pro:
--allows a State flexibility to control priority
toxicpollutants
--reduces time and cost required to adopt specific numeric
criteria as water quality standards regulations
--allows immediate use of latest scientific information
available at the -time a State needs to develop a .derived
numeric criteria
--revisions and additions to derived numeric criteria can
be made without need to revise State law
--State can deal more easily with a situation where it did
not establish water quality standards for the section
307(a) toxic pollutants during the mo.st recent triennial
review
--State can address problems from non-section 307(a) toxic
pollutants
Con:
--EPA is currently on notice that a derived numeric criteria
may invite legal challenge
--Once the necessary procedures are adopted to enhance legal
defensibllity (e.o,., appropriate scientific methods and
public participation and review), actual savings in time
and costs may be less than expected
--public participation in development of derived numeric
criterion may be limited when such criteria are not
addressed in a hearing on water quality standards
Discussion:
EPA believes that adoption of a narrative standard along
with a translator mechanism as part of a State's water quality
standard satisfies the substantive requirements of the statute.
These criteria are subject to all the State's legal and
administrative requirements for adoption of standards plus
review and either approval or disapproval by EPA, and result
in the development of derived numeric criteria for specific
section 307(a) toxic pollutants. They are also subject to an
opportunity for public participation. Nevertheless, EPA believes
the most appropriate use of option 3 is as a supplement to
either options 1 or 2. Thus, a State would have formally adopted
numeric criteria for those toxic pollutants of frequent occurrence
and which have general applicability statewide for Inclusion in
NPOES permits, total maximum daily loads and waste load alloca-
tions, and would also have a sound and predictable method to
develop additional numeric criteria as needed. This combination
of options provides a complete regulatory scheme.
Although the approach 1n option 3 is similar to.that
currently allowed in the water quality standards regulation (40
CFR 131.ll(a)(2)), this guidance discusses several administrative
and scientific requirements EPA may clarify by revising the
regulation in order to ensure acceptable quality and full
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Involvement of the public and EPA. The remainder of this section
outlines the administrative and scientific requirements that EPA
believes are necessary to comply with section 303(c)(2)(B).
1. The Option 3 Procedure Must be Used to Calculate Derived
Numeric Water Quality Criteria' ''
States must adopt a specific procedure to be applied
to a narrative water quality criterion. To satisfy section
303(c)(2)(B), this procedure shall be used by the State in
calculating derived numeric criteria, which criteria shall be
used for all purposes under section 303(c) of the CWA. Such
criteria need to be developed for section 307(a) toxic pollutants
as necessary to support designated uses, where these pollutants
are discharged or are present in the affected waters and could
reasonably be expected to interfere with the designated uses.
In order to assure protection from short-term exposures,
the .State procedure should ensure development of derived numeric
water quality criteria based on valid acute aquatic toxicity
tests that are lethal to half the affected organisms (LC50) for
those species that are representative of or similar to those
found in the State. In addition, the State procedure should
ensure development of derived numeric water quality criteria for
protection from chronic exposure by using an appropriate safety
factor applicable to this acute limit. If there are saltwater
components to the State's aquatic resources, the State should
establish appropriate derived numeric criteria for saltwater in
addition to those for freshwater.
The State's documentation of the tests should include a
detailed discussion of its quality control and quality assurance
procedures. The State should also include a description (or
reference existing technical agreements with EPA) of the procedure
it will use to calculate derived acute and chronic numeric
criteria from the test data, and how these derived criteria
will be used as the basis for deriving appropriate TMDLs, WLAs,
and NPDES permit limits. ' .'.'.
As-discussed above, the procedure for calculating derived
numeric criteria needs to protect aquatic life from both acute
and chronic exposure to specific chemicals. Chronic aquatic
life criteria are to be met at the edge of the mixing zone.
The acute criteria are to be met (l).'at the end-of-pipe 1f
mixing is not rapid .and complete and a high rate diffuser is
not present; or (2) after mixing if mixing 1s rapid and complete -
or a high rate diffuser'1s present. (See EPA's "Technical
Support Document for Water Quality Based Toxics Control"). EPA
has not established a national policy specifying the point of
application in the receiving water to be used with human health
criteria.
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In addition, the State should also Include an Indication
of potential bioconcentration or bioaccumulation by providing
for: (1) laboratory tests that measure the steady-state biocon-
centration rate achieved by a susceptible organism; and/or (2)
field data in which ambient concentrations and tissue loads are
measured to- give an appropriate factor. In developing a proce-
dure to be used in calculating derived numeric criteria for
the protection of aquatic life, the State should consider the
potential impact that bioconcentration has on aquatic and
terrestrial food chains.
The State should also use the. derived bioconcentration
factor to calculate chronically protective numeric criteria for
humans that consume aquatic organisms. In cal culating this de-
rived numeric criterion, the State should indicate data require.
ments to bfe met when dealing with either threshold (toxic) or
non-threshold (carcinogenic) compounds. The State should
describe the species and the minimum number of tests, which
may generally be met by a single mammalian chronic test if it
is of good quality and if the weight of evidence indicates
that the results are reasonable. The State should provide the
method to calculate a derived numeric criterion from the
appropriate test result.
Both the threshold and non-threshold criteria for protect-
ing human health should contain exposure assumptions, and the"
State procedure should be used to calculate derived numeric
criteria that address the consumption of water, consumption of
fish, and combined consumption of both water and fish. The
State should provide the.assumptions regarding the amount of
fish and the quantity of water consumed per person per day,,'as
well as. the rationale used to select the assumptions. It needs
to include the number of tests, the species necessary to estab-
lish a dose-response relationship, and the procedure to be
used to calculate the derived numeric criteria. For non-thres-
hold contaminants, the State should specify the model used to
extrapglate to low dose and the risk level. It should also
address incidental exposure from other water sources (e.g.,
swimming). When calculating derived numeric criteria for
multiple exposure to pollutants, the State should consider
additive effects, especially for carcinogenic substances, and
should factor in the contribution to the daily intake of toxi-
cants from other sources (e.g., food, air, etc.) when data are
available.
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2. The State Must Demonstrate That the Procedure Results in
Derived Numeric Criteria th"a"t are Protective
The State needs to demonstrate, that its procedures for
developing criteria, including translator methods, yield fully
protective criteria for human health and for aquatic life.,
EPA's review process will proceed according to EPA's regulation
at 40 CFR §131.11 which requires that criteria be based on sound
s.ci enti fi c" rational e and be protective of all designated uses.
fPA will use the expertise and experience it has gained in
developing section 304(a) criteria for toxic pollutants by
application of its own translator method (i.e., the Guidelines
for Deriving National Water Quality Criteria cited on Page 5
herein,) in reviewing State developed procedures.
Once, EPA has approved the State's procedure* the Agency's
review of derived numeric criteria, for example, for pollutants
other than section 307(a) toxic pollutants resulting from the
State's procedure, will focus on the adequacy of the data base
rather than the calculation method. EPA also encourages States
to apply such a procedure to calculate derived numeric criteria
to be used as the basis for deriving permit limitations for
nonconventional pollutants that also cause 16x1 city.
3. The State Must Provide Full Opportunity for Public Par-
ticipation in Adoption of the Procedure > ~~~ T '-
The water qua! i ty standards ' regul at io'n requi res States to
hold public heari.ngs for th'e purpose of reviewing and revising
water quality standards in accordance with provisions of State
law and EPA's public- participation regulation (40 CFR Part 25).1
Where a State plans to adopt a procedure to be applied to the
narrative criterion, it must provide full "opportunity for-
public participation in the development and adoption of the
procedure as part of the State's water quality standards.
While it is not.necessary for the State to adopt each
derived numeric criteria into its water quality standards and
submit it, to EPA for review and approval, EPA is very concerned
that all affected parties have adequate opportunity to partici-
pate in the development of a derived numeric criterion even
though it is not being adopted directly as a water quality
standard. .
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A State can satisfy the need to provide an opportunity for
public participation in the development of derived numeric
criteria in several ways including:
1. a specific hearing on the derived numeric criterion;
2. the opportunity for a public hearing on an NPDES permit
so long as public notice is given that a criterion for a
toxic pollutant as part of the permit issuance is being
contemplated; or
3. a hearing coincidental with any other hearing so long
as it is' made clear that development of a specific
criterion is also being" undertaken.
For example, as States develop their lists and individual
control strategies (ICSs) under- section 304(1), they may seek
full participation by the public. NPDES regulations also
specify public participation requirements related to State
permit issuance. Finally, States have public participation
requirements associated with Water Quality Management Plan
updates. States may take advantage of any of these public
participation requirements to fulfill the requirement for public
review of any resulting derived numeric criteria. In such cases,
the State must give prior notice that development of such
criteria is under consideration.
4. The Procedure Must be Formally Adopted and Mandatory
Where a State elects to supplement its narrative criterion
with an accompanying implementing procedure, it must formally
adopt such a procedure as a part of its water quality standards.
The procedure must be used by the State to calculate derived
numeric criteria that will be used as the basis for all standards
purposes, including: developing TMDLs, WLAs, and limits in
NPDES permits; determining whether water use designations are
being met; and identifying potential nonpoint source pollution
problems.
5. The Procedure Must be Approved by EPA as Part of the State's
Water Quality Standards Regulation!
To be consistent with the requirements of the Act, the
State's procedure to be applied to the narrative criterion
must be submitted to EPA for review and approval, and will
become a part of the State's water quality standards. (See
40 CFR §131.21 for further discussion.) This requirement
may be satisified by a reference in the standards to the
procedure which may be contained in another document, which
has legal effect and is binding on the State, and all the
requirements for public review, State implementation, and EPA
review and approval are satisfied.
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TIMING
- ' /
EPA expects each State to comply with the new statutory
requirements in any section 303(c) water quality standards
review initiated after enactment of the Water Quality Act
of 1987. .
To the extent feasible, States are to incorporate the
new statutory requirements into any ongoing review. If a
State does not fulfill the new requirements, EPA may
conditionally approve State-adopted water quality standards,
but will require a State;to immediately develop a schedule to
meet,the new requirements. EPA will not accept a delay to the
next triennial review for adherence to the new requirements
which have been in existence, by statute, since February 1987.
Also, the identification and control of toxic pollutants has
been a water quality standards'program priority for several
years as reflected in Agency operating guidance and as a
requirement 1h the water quality standards regulation.
ASSISTANCE . .
Persons having questions or needing assistance in
implementing water quality criteria for toxics may contact the
Standards Branch, Criteria arid Standards Div1si on , Office of
Water Regulations and Standards, EPA, WH-585, Washington, '
D.C. 20460, and whose telephone number is (202) 475-7315.
-15-
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APPENDIX A
126 SECTION 307(A) TOXIC POLLUTANTS
PRIORITY POLLUTANT
ACENAPHTHENE .
ACENAPTHYLENE (PAH)
ACROLEIN
ACRYLONITRILE -
ALDRIN
ANTIMONY -
ANTHRACENE ' .
ARSENIC
ASBESTOS
1,2 BENZANTHRACENE. (PAH) . .
BENZENE
BENZIDINE .-.
BENZO (A) PYRENE (3,4-BENZOPYRENE) (PAH)
3,4 BENZOFLUORANTHENK (PAH)
BENZO(K)FLUORANTHENE (PAH)
1,12 BENZOPERYLENE (PAH)
BERYLLIUM .
BROMOFORM (TRIBROMOMIITHANE)
BROMOMETHANE (METHYL BROMIDE) .
4-BROMOPHENYL PHENYL ETHER
CADMIUM
CARBON TETRACHLORIDE (TETRACHLORQMETHANE)
CHLORDANE ' . .
CHLOROBENZENE (MONOCHLOROBENZENE)
CHLORODIBROMOMETHANE (HALOMETHANE)
CHLOROETHANE (MONOCHI.OROETHANE)
CHLOROETHYL ETHER (B1S-2)
1"CHLOROETHOXY METHANE (BIS-2)
2 CHLOROETHYL VINYL ETHER
4-CHLORO-3-METHYLPHENOL
CHLOROMETHANE (METHYL CHLORIDE)
CHLOROFORM (TRICHLOROMETHANE) '
2 CHLOROPHENOL
CHLOROISOPROPYL ETHER (BIS-2)
2 CHLORONAPHTHALENE
4 CHLOROPHENYL PHENYIi ETHER
CHROMIUM (HEX)
CHROMIUM (TRI)
CHYRSENE (PAH)
COPPER
CYANIDE
4,4 DDT
4,4 DDE
4,4 DDD
DIBENZO(a,h)ANTHRACENE (PAH)
1,2 DICHLOROBENZENE
1,3 DICHLOROBENZENE
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APPENDIX A
126 SECTION 307(A) TOXIC POLLUTANTS
PRIORITY POLLUTANT
1,4 DICHLOROBENZENE
3,3 DICHLOROBENZIDINE
DICHLOROETEANE 1,1
DICHLOROETHANE 1,2
1,1 DICHLOROETHYLENE
1,2-TRANS-DICHLOROETHYLENE
DICHLOROBROMOMETHANE (HALOMETHANES)
DICHLOROMETHANE (HALOMETHANES)
2,4-DICHLOROPHENOL
DICHLOROPROPANE 1,2
DICHLOROPROPENE 1,3
DIELDRIN
DIMETHYLPHENOL 2,4
DIETHYLPHTHALATE
DIMETHYLPHTHALATE
DINITROTOLUENE 2,4
DINITROTOLUENE 2,6
2,4-DINITROPHENOL
DIOXIN (2,3,7,8-TCDD)
DIPHENYLHYDRAZINE 1,2.
ALPHA ENDOSULFAN
BETA ENDOSULFAN
ENDOSULFAN SULFATE
ENDRIN
' ENDRIN ALDEHYDE
ETHYLBENZENE
FLUORENE (PAH)
FLUORANTHENE
HEPATACHLOR
HEPATACHLOR EPOXIDE
HEXACHLOROETHANE
HEXACHLOROBENZENE
HEXACHLOROBUTADIENE
HEXACHLOROCYCLOHEXANE (LINDANE)
HEXACHLOROCYCLOHEXANE (ALPHA)
HEXACHLOROCYCLOHEXANE (BETA)
HEXACHLOROCYCLOHEXANE (DELTA)
HEXACHLOROCYC1OPENTADIENE
IDENO (1,2,3-cd) PYRENE (PAH)
ISOPHORONE
LEAD
MERCURY
NAPHTHALENE
NICKEL
NITROBENZENE
' 2 NITROPHENOL
4 NITROPHENOL
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APPENDIX A
126 SECTION 307CA) TOXIC POLLUTANTS
PRIORITY POLLUTANT
4,6-DINITRO-2-METHYLPHENOL
NITROSODIMETHYLAMINE N
NITROSODIPHENYLAMINE-N
NITROSODI-N-PROPYLAMINE-N
PCS 1242 .
PCB 1254
PCS 1221 '
PCB 1232
PCB 1248
PCB 1260
PCB 1016
PHENOL
PENTACHLOROPHENOL
PHENANTHRENE (PAH) '
BIS(2 ETHYL HEXYL) PHTHALATE
BUTYL BENZYL PHTHALATE ' '
DI-N-BUTYL PHTHALATE .
DI-N-OCTYL-PHTHALATE .
PYRENE (PAH)
SELENIUM .
SILVER
TETRACHLOROETHANE 1,1,2,2
TETRACHLOROETHYLENE
THALLIUM
TOLUENE ..'.
TOXAPHENE
1,2,4 TRICHLOROBENZENE '
TRICHLOROETHANE 1.1,1
TRICHLOROETHANE 1,1,2 ,
TRICHLOROETHYLENE '
TRICHLOROPHENOL 2,4,6
VINYL CHLORIDE (CHLOROETHYLENE)
ZINC
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