[Federal Register Volume 60, Number 86 (Thursday, May 4, 1995)]
[Rules and Regulations]
[Pages 22229-22237]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-10148]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 131
[WH-FRL-5196-1]
Water Quality Standards; Establishment of Numeric Criteria for
Priority Toxic Pollutants; States' Compliance--Revision of Metals
Criteria
AGENCY: Environmental Protection Agency (EPA).
ACTION: Interim final rule, notice of data availability and request for
comments.
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SUMMARY: EPA is promulgating new aquatic life metals criteria for nine
States, Puerto Rico, and the District of Columbia, that are subject to
EPA's 1992 National Toxics Rule (``NTR''). These new metals criteria
reflect EPA's current policy for setting water quality criteria for
metals. This interim final rule establishes metals criteria that are
protective of aquatic life and approximate, better than the 1992
criteria, the biologically available fraction of water borne metals to
aquatic organisms. Use of the new metals criteria will allow permitting
authorities in the nine States, Puerto Rico and the District of
Columbia, to establish effluent limitations based on the new metals
criteria rather than the 1992 criteria which EPA now considers to be
more stringent than may be necessary to protect designated uses for
aquatic life. The interim final rule will be in effect while EPA
considers public comments and develops a final rule. This rule
terminates the Administrative Stay published elsewhere in this issue of
the Federal Register.
DATES: This interim final rule is effective April 15, 1995. Comments on
the interim final rule and other data noticed in this preamble will be
accepted until July 3, 1995.
ADDRESSES: An original and 3 copies of all comments and references on
the interim final rule and data should be addressed to: Revision of the
National Toxics Rule-Dissolved Metals Criteria, Comment Clerk; Water
Docket (MC-4101), U.S. Environmental Protection Agency, 401 M Street
SW., Washington, DC 20460. The administrative record for this
rulemaking is available for review and copying at the Environmental
Protection Agency, Office of Water Docket, 401 M Street SW, Washington
DC, 20460, Room L102, on weekdays during EPA's normal business hours of
8 a.m. until 4:30 p.m. For access to the Docket materials, call (202)
260-3027 between 9:00a.m.-3:30p.m., for an appointment. A reasonable
fee will be charged for photocopies.
FOR FURTHER INFORMATION CONTACT: Timothy J. Kasten, telephone 202-260-
5994.
SUPPLEMENTARY INFORMATION:
A. General Background
1. Regulatory Background
In the NTR, EPA promulgated numeric water quality criteria for 12
States, Puerto Rico, and the District of Columbia, that failed to
comply fully with Section 303(c)(2)(B) of the Clean Water Act. (57 FR
60848, December 22, 1992 codified in the Code of Federal Regulations at
40 CFR 131.36).1 Those criteria became the legally enforceable
water quality standards in the named States, Puerto Rico, and the
District of Columbia, for all purposes and programs under the Clean
Water Act on February 5, 1993. Included among the water quality
criteria promulgated in the NTR were numeric criteria for the
protection of aquatic life for 11 metals: arsenic, cadmium, chromium
(III), chromium (VI), copper, lead, mercury, nickel, selenium, silver,
and zinc.
\1\In the NTR, EPA determined compliance with Section
303(c)(2)(B) based on the status of State compliance as of 1991, the
date of the proposed rulemaking, and then took into account EPA
approval actions between the proposed and final rulemaking for those
States included in the proposed rule. EPA acknowledges that, due to
subsequent State actions to delete or otherwise modify toxics
criteria (e.g., see Table 1, 57 FR 60856, December 22, 1992), all
States and Territories currently may not be in full compliance with
Section 303(c)(2)(B).
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The Agency received extensive public comment during the development
of the NTR regarding the most appropriate approach for expressing the
metals criteria. The principal issue was the correlation between metals
that are measured and metals that are bioavailable and toxic to aquatic
life.
2. Policy on Aquatic Life Metals Criteria
At the time of the NTR promulgation, Agency policy was to express
metals criteria, as recommended in its Section 304(a) criteria
documents, as total recoverable metal measurements. Agency guidance
prior to the NTR promulgation indicated that metals criteria may be
expressed either as total recoverable metal or dissolved metal.2
[[Page 22230]] Because the NTR was to cover a substantial number of
water bodies of varying water quality, EPA selected what it considered
the simplest, more conservative approach and the approach reflected in
its criteria documents, to implement the metals criteria, namely the
total recoverable method. Accordingly, the metals criteria promulgated
in the NTR were expressed as total recoverable metals, although EPA
also provided for site-specific criteria development.3
\2\Interim Guidance on Interpretation and Implementation of
Aquatic Life Criteria for Metals, U.S. EPA, May 1992. (Notice of
availability published at 57 FR 24041, June 5, 1992.)
\3\See Interim Guidance on the Determination and Use of Water-
Effect Ratios for Metals, February 1994, EPA 823-B-94-001.
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Thereafter, EPA continued to work with States and other interested
parties on the issue of metals bioavailability and toxicity. EPA held a
workshop of invited experts on this issue; the results of the
consultations were published at 58 FR 32131, June 8, 1993. As a result
of these consultations, the Agency issued a policy memorandum on
October 1, 1993, entitled: Office of Water Policy and Technical
Guidance on Interpretation and Implementation of Aquatic Life Metals
Criteria (``Metals Policy''). (The complete October 1, 1993 memorandum
can be obtained from EPA's Office of Water Resource Center (202) 260-
7786 or the Office of Water Docket.) The Metals Policy states:
It is now the policy of the Office of Water that the use of
dissolved metal to set and measure compliance with water quality
standards is the recommended approach, because dissolved metal more
closely approximates the bioavailable fraction of metal in the water
column than does total recoverable metal.
It further states:
Until the scientific uncertainties are better resolved, a range
of different risk management decisions can be justified. EPA
recommends that State water quality standards be based on dissolved
metal. EPA will also approve a State risk management decision to
adopt standards based on total recoverable metal, if those standards
are otherwise approvable as a matter of law. (See Section 510,
Federal Water Pollution Control Act, Public Law 100-4, 33 U.S.C. 466
et seq.)
The adoption of the Metals Policy did not change the Agency's
position that the existing total recoverable criteria published under
Section 304(a) of the Clean Water Act continue to be scientifically
defensible. EPA developed the total recoverable criteria using high-
quality analytical data and are still scientifically defensible
criteria. When developing and adopting its own standards, a State, in
making its risk management decision, may wish to consider sediment,
food chain effects and other fate-related issues and decide to adopt
total recoverable or dissolved metals criteria.
In general, EPA continues to conduct research on metals toxicity to
further refine the criteria and their implementation. However, the aim
of both the Clean Water Act and EPA policy is that a more effective way
of incorporating new science into the water quality program is for the
States to promulgate their own standards and implementation policies.
The States can then make appropriate updates, rather than relying on
Federal promulgations such as today's rule.
3. Litigation and Settlement of NTR Metals Issues
A number of parties brought lawsuits challenging the NTR metals
criteria. See American Forest and Paper Ass'n, Inc. et al. v. EPA,
Consolidated case No. 93-0694 RMU (D.D.C.) The Plaintiffs in those
lawsuits wanted the permitting authorities in the NTR States to use
criteria based on dissolved metal rather than total recoverable. After
careful consideration of the issue, EPA concluded that it was in the
public interest to revise the metals criteria promulgated in the NTR to
reflect the Office of Water's new metals policy. On February 15, 1995,
EPA and the Plaintiffs filed a partial settlement agreement with the
court. Pursuant to the terms of the partial settlement agreement, EPA
agreed to issue an administrative stay of the numeric aquatic life
water quality criteria (expressed as total recoverable metal) for:
arsenic, cadmium, chromium (III), chromium (VI), copper, lead, mercury
(acute only), nickel, selenium (saltwater only), silver, and zinc. That
stay is published in a separate notice in today's Federal Register. The
stay is intended to be in effect only until EPA takes action to amend
the NTR by promulgating new metals criteria based on dissolved metal.
With today's interim final rule, EPA is promulgating new metals
criteria for those metals listed in the stay based on dissolved metal
and therefore this action will supersede the administrative stay.
B. Today's Interim Final Rule
EPA's action today revises the NTR that established numeric aquatic
life metals criteria for 9 States, Puerto Rico and the District of
Columbia (Table 1). (Of the 12 NTR States, aquatic life metals criteria
were only promulgated for nine.) The numeric criteria in today's rule
reflect the Office of Water's current policy with respect to metals.
This action promulgates dissolved metals criteria for those total
recoverable metals criteria subject to the Agency's administrative
stay.
Table 1.--States Subject to the Revised Metals Criteria\1\
Alaska
Arkansas
California
Idaho
Kansas
Michigan
New Jersey
Vermont
Washington
District of Columbia
Puerto Rico
\1\Today's interim final rule may have differing applicability for each
of the States in this table depending on the State's individual
compliance with Section 303(c)(2)(B) of the Clean Water Act. See 40
CFR 131.36(d) for State applicability.
C. Conversion Factors: Total Recoverable to Dissolved Metal
Because EPA's Section 304(a) criteria are expressed as total
recoverable metal, to express the criteria as dissolved, application of
a conversion factor is necessary to account for the particulate metal
present in the laboratory toxicity tests used to develop the total
recoverable criteria. Initially, EPA included a set of recommended
freshwater conversion factors with the Metals Policy. Based on
additional laboratory evaluations that simulated the original toxicity
tests, EPA has refined the procedures used to develop freshwater
conversion factors for aquatic life criteria. EPA made new conversion
factors available for public comment in the context of EPA's Proposed
Guidance for the Great Lakes System on August 30, 1994, at 59 FR 44678.
EPA has also conducted saltwater laboratory simulation tests for
the development of conversion factors for saltwater metals criteria.
The saltwater simulation tests were conducted using the same
methodology as the freshwater tests with minor modifications, necessary
to account for saltwater. The saltwater test results are being made
available with today's rule. The conversion factors in this rule and
other technical reports referenced herein, supersede the conversion
factors presented in Attachment #2 of the Metals Policy.
Total recoverable to dissolved metal conversion factors were
attached to the partial settlement agreement in the form of a draft
guidance entitled, Guidance to States Subject to the National Toxics
Rule For Setting NPDES Limits During the Stay of the Metals Criteria.
(The partial settlement agreement is available from the Water Docket.)
The draft guidance used data that were available through December 21,
1994. The [[Page 22231]] conversion factors presented in today's rule
reflect the best science available to EPA at the time of promulgation
and contain minor modifications from those in the attachment to the
February 15 partial settlement agreement. For each metal specific
conversion factor, the changes between the draft guidance and today's
rule are less than 10%. EPA has determined these changes to be minor.
1. Freshwater Criteria Conversion Factors
The final freshwater conversion factors used in today's rule are
contained in: ``Derivation of Conversion Factors for the Calculation of
Dissolved Freshwater Aquatic Life Criteria for Metals'' (U.S. EPA,
1995), available from the Water Docket and are presented in Table 2
below. This study did not include laboratory simulation tests for
mercury or silver, therefore, the freshwater conversion factors for
mercury and silver used today are from the Metals Policy.
The conversion factors for most freshwater metals were established
as constant values. For cadmium and lead however, EPA found that water
hardness mediated the conversion factor and should be taken into
account when converting total recoverable cadmium and lead criteria to
dissolved. Table 2 presents the hardness-dependent conversion factors
for cadmium and lead. The hardness-dependent conversion factor for lead
was included in the August 30, 1994 Notice of Availability (59 FR
44678). In today's action, EPA is specifically requesting comment on
the use of hardness-dependent conversion factor for cadmium.
Table 2.--Freshwater Criteria Conversion Factors for Dissolved Metals
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Conversion factorsa
Metal ---------------------
Acute Chronic
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Arsenic........................................... 1.000 1.000
Cadmiumb.......................................... 0.944 0.909
Chromium (III).................................... 0.316 0.860
Chromium(VI)...................................... 0.982 0.962
Copper............................................ 0.960 0.960
Leadb............................................. 0.791 0.791
Mercury........................................... c0.85 dN/A
Nickel............................................ 0.998 0.997
Silver............................................ c0.85 eN/A
Zinc.............................................. 0.978 0.986
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aThe conversion factors are given to three decimal places because they
are intermediate values in the calculation of dissolved criteria.
bConversion factors are hardness-dependent. The values shown are with a
hardness of 100 mg/L as calcium carbonate (CaCO3). Conversion factors
(CF) for any hardness can be calculated using the following equations:
Cadmium
Acute: CF=1.136672-[(ln hardness) (0.041838)]
Chronic: CF=1.101672-[(ln hardness) (0.041838)]
Lead (Acute and Chronic): CF=1.46203-[(ln hardness)(0.145712)]
cConversion factor from: Office of Water Policy and Technical Guidance
on Interpretation and Implementation of Aquatic Life Metals Criteria,
October 1, 1993. Factors were expressed to two decimal places.
dCCC for mercury cannot be converted to dissolved, because it is based
on mercury residues in aquatic organisms rather than toxicity.
eNot applicable, EPA has not published final chronic criteria values for
silver.
2. Saltwater Criteria Conversion Factors
Acute saltwater conversion factors are being made available through
today's rule. The data and the acute criteria conversion factors for
saltwater are contained in: ``Derivation of Conversion Factors for the
Calculation of Dissolved Saltwater Aquatic Life Criteria for Metals''
(U.S. EPA 1995). This summary report and its supporting data are
available from the Water Docket. Saltwater chronic conversion factors
have not been developed separately and therefore are not available for
today's rule. Based on close similarities between the freshwater acute
and chronic conversion factors, EPA believes that, if calculated, the
chronic saltwater conversion factors would be nearly the same as the
acute saltwater factors. In the absence of these chronic conversion
factors, the saltwater acute conversion factors will apply. The
saltwater conversion factors are presented in Table 3 below. Saltwater
simulation tests were not completed for mercury or silver, therefore
the conversion factors from the Metals Policy will continue to apply.
Table 3.--Saltwater Criteria Conversion Factors for Dissolved Metals
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Conversion
Metal factorsa
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Arsenic..................................................... 1.000
Cadmium..................................................... 0.994
Chromium (III).............................................. (d)
Chromium (VI)............................................... 0.993
Copper...................................................... 0.83
Lead........................................................ 0.951
Mercury..................................................... bc0.85
Nickel...................................................... 0.990
Selenium.................................................... 0.998
Silver...................................................... b0.85
Zinc........................................................ 0.946
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aConversion factors on this table were calculated for acute criteria
only. Conversion factors for chronic criteria are not currently
available. In the absence of chronic conversion factors saltwater
acute conversion factors are used.
bConversion factor from: Office of Water Policy and Technical Guidance
on Interpretation and Implementation of Aquatic Life Metals Criteria,
October 1, 1993. Factors were expressed to two decimal places.
cCCC for mercury cannot be converted to dissolved, because it is based
on mercury residues in aquatic organisms rather than toxicity.
dNo saltwater criteria.
D. Applicability Requirements for Metals Criteria
Through today's action, EPA is also requesting comments on the
applicability requirements in 40 CFR 131.36(c) as they apply to the
metals criteria. In particular, EPA is requesting comments on
Sec. 131.36(c)(4)(i) regarding the calculation of hardness-dependent
freshwater metals criteria. Section 131.36(c)(4)(i) describes the
minimum and maximum hardness values (25 mg/L and 400 mg/L as
CaCO3, respectively) to be used when calculating hardness-
dependent freshwater metals criteria. This requirement is not changed
by today's interim final rule, however EPA is requesting comment on an
alternative approach. Most of the data used to develop these hardness
formulas were in the hardness range of 25 mg/L to 400 mg/L as
CaCO3. The formulas are therefore most accurate in this range.
Using a hardness of 25 mg/L for calculating criteria, when the actual
ambient hardness is less than 25 mg/L, could result in criteria that
are under-protective of aquatic life. EPA is therefore requesting
comments on the use of the actual ambient hardness for calculating
criteria when the hardness is below 25 mg/L as CaCO3.
Most freshwaters of the U.S. have an ambient hardness of less than
400 mg/L as CaCO3. Using 400 mg/L to calculate criteria, for
waters with an ambient hardness of greater than 400 mg/L, may result in
over-protective criteria because at a hardness above 400 mg/L, other
confounding factors, which may cause this hardness, can also affect the
toxicity. EPA is requesting comment on an approach that would make two
options available for calculating metals criteria for waters with a
hardness of greater than 400 mg/L as CaCO3: Option 1--use 400 mg/L
as CaCO3 for the criteria calculation or, Option 2--use the actual
hardness and require the use of the water-effect ratio to modify the
final criteria value to more accurately reflect ambient conditions.
(EPA notes that in the NTR States, the use of the water-effect ratio is
assigned a value of 1.0, unless otherwise specified by the permitting
authority. See 40 CFR 131.36(c)(4)(iii).) [[Page 22232]]
E. Calculation of Dissolved Metals Criteria
Metals criteria values in 40 CFR 131.36(b)(1), as amended today,
are now shown as dissolved metal. These criteria have been calculated
in one of two ways. For freshwater metals criteria that are hardness-
dependent (denoted by footnote ``e'' in the matrix), the dissolved
metal criteria value must be calculated separately for each hardness
using the table at Sec. 131.36(b)(2), as amended today. The hardness-
dependent freshwater criteria values presented in the matrix at
Sec. 131.36(b)(1) have been calculated using a hardness of 100 mg/L
CaCO3 for comparative purposes only. Saltwater metals criteria and
freshwater criteria that are not hardness-dependent (criteria denoted
by footnote ``m'' in the matrix) are calculated by taking the total
recoverable criteria values (from EPA National Ambient Water Quality
Criteria Documents) before rounding, and multiplying them by the
appropriate conversion factors from Table 2 or 3 of Section C of this
preamble. (The total recoverable criteria values are shown to four
figures, where available, because they are intermediate values in the
calculation of dissolved metals criteria.) The final dissolved metals
criteria values, as they appear in the matrix at Sec. 131.36(b)(1), are
rounded to two significant figures. Tables 4a and 4b below, summarize
the conversions for saltwater criteria and freshwater criteria that are
not hardness-dependent.
EPA notes that if a non-NTR State adopts standards, or an NTR State
adopts its own standards (for subsequent withdrawal from the NTR), it
may prefer a more conservative approach and adopt total recoverable
metals criteria. In doing so, the State may use EPA's total recoverable
criteria from Tables 4a and 4b (rounded to two significant figures) or,
for hardness-dependent freshwater criteria, omit the conversion factor
from the formula presented in Sec. 131.36(b)(2).
Tables 4a and 4b use the following abbreviations and formulas for
calculating dissolved metals criteria (CMC and CCC are defined in 40
CFR 131.36(b)(1), footnote d):
CMC--Criterion Maximum Concentration
CCC--Criterion Continuous Concentration
CF--Conversion Factor
Formulas for Calculating Dissolved Metals Criteria:
CMCdissolved = CMCtotal recoverable x Acute CF
CCCdissolved = CCCtotal recoverable x Chronic CF
Table 4a.--Calculation of Freshwater Dissolved Metals Criteria That are Not Hardness-Dependent
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Total Recoverable Metals Conversion factors\2\ Dissolved metals
Criteria\1\ (g/L) --------------------------- criteria\3\
METAL ---------------------------- --------------------------
CMC CCC Acute Chronic CMC CCC
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Arsenic....................... 359.1 188.9 1.000 1.000 360 190
Chromium(VI).................. 15.74 10.80 0.982 0.962 15 10
Mercury....................... 2.428 0.0122 0.85 N/A 2.1 N/A
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\1\From EPA National Ambient Water Quality Criteria Documents.
\2\From Table 2.
\3\Final dissolved metals criteria have been rounded to two significant figures.
Table 4b.--Calculation of Saltwater Dissolved Metals Criteria
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Total recoverable metals Conversion factors\2\ Dissolved metals
criteria\1\ (g/L) ---------------------------- criteria\3\
Metal ---------------------------- ---------------------------
CMC CCC Acute Chronic CMC CCC
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Arsenic..................... 68.55 36.05 1.000 1.000 69 36
Cadmium..................... 42.54 9.345 0.994 0.994 42 9.3
Chromium (III).............. N/A\4\ N/A\4\ N/A\4\ N/A\4\ N/A\4\ N/A\4\
Chromium (VI)............... 1079 49.86 0.993 0.993 1100 50
Copper...................... 2.916 2.916 0.83 0.83 2.4 2.4
Lead........................ 217.16 8.468 0.951 0.951 210 8.1
Mercury..................... 2.062 .0250 0.85 N/A\5\ 1.8 N/A\5\
Nickel...................... 74.60 8.293 0.990 0.990 74 8.2
Selenium.................... 293.8 70.69 0.998 0.998 290 71
Silver...................... 2.3 N/A\4\ 0.85 N/A\4\ 1.9 N/A\4\
Zinc........................ 95.10 86.14 0.946 0.946 90 81
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\1\From EPA National Ambient Water Quality Criteria Documents.
\2\From Table 3.
\3\Final dissolved metals criteria have been rounded to two significant figures.
\4\Not applicable, national criteria not available.
\5\The CCC for mercury is expressed as total recoverable.
F. Site-Specific Criteria Modifications
EPA has issued guidance (Water Quality Standards Handbook, Second
Edition-1993, EPA-823-B-93-002 and update #1, EPA-823-B-94-006, August
1994, at page 3-38 and Appendix L), describing three site-specific
criteria development methodologies: recalculation procedure, indicator
species procedure (also known as the water-effect ratio (WER)) and
resident species procedure. Only the first two of these have been
widely used.
In the NTR, EPA identified the WER as the method for optional site-
specific criteria development for certain metals. On February 22, 1994,
EPA issued Interim Guidance on the Determination and Use of Water-
Effect Ratios for Metals, EPA 823-B-94-001, now incorporated into the
updated Second Edition of the Water Quality Standards Handbook,
Appendix L. In accordance with the WER guidance and where application
of the WER is deemed [[Page 22233]] appropriate, EPA strongly
encourages the application of the WER on a watershed or waterbody basis
as opposed to application on a discharger-by-discharger basis. This
approach is technically sound, an efficient use of resources, and
allowable for permitting authorities under the NTR.
EPA's endorsement of the use of the WER is not affected by today's
rule. As noted in the NTR at 57 FR 60879, the WER is a more
comprehensive mechanism for addressing bioavailability issues than
simply expressing the criteria in terms of dissolved metal.
Consequently, expressing the criteria in terms of dissolved metal, as
done in today's rule, does not completely eliminate the utility of the
WER. This is particularly true for copper, a metal that forms reduced-
toxicity complexes with dissolved organic matter.
The Interim Guidance on Determination and Use of Water-Effect
Ratios for Metals, Appendix D, explains the relationship between WERs
for dissolved criteria, and WERs for total recoverable criteria.
Dissolved measurements are to be used in the site-specific toxicity
testing underlying the WERs for dissolved criteria. Because WERs for
dissolved criteria generally are little affected by elevated
particulate concentrations, EPA expects those WERs to be somewhat less
than WERs for total recoverable criteria in such situations.
Nevertheless, after the site-specific ratio of dissolved to total metal
has been taken into account, EPA expects a permit limit derived using a
WER for a dissolved criterion to be similar to the permit limit that
would be derived from the WER for the corresponding total recoverable
criterion.
Because WERs for dissolved criteria generally are little affected
by particulate concentrations, those WERS also may often exhibit less
time variability than WERs for total recoverable criteria.
Consequently, WER-adjusted dissolved criteria may have somewhat greater
certainty than WER-adjusted total recoverable criteria.
EPA expects the use of WERs for dissolved criteria to provide the
same level of protection as the use of WERs for total recoverable
criteria in the NTR. However, the increased reliability of the
dissolved criteria prior to WER adjustment (compared to the total
recoverable criteria unadjusted) will reduce the need for site-specific
WER determinations.
G. Technical Guidance
EPA continues to urge the States affected by this rule to adopt
their own standards and negate the need for Federal action. Should a
State choose to adopt dissolved criteria, EPA recommends use of the
Metals Policy, its attachments (as updated herein) and other guidance
referenced in this preamble for implementation of dissolved metals
criteria. Attachments to the Metals Policy include: guidance on dynamic
modeling and translators (Attachment #3), and clean analytical
techniques and monitoring (Attachment #4). Additional guidance on clean
and ultra-clean techniques is available and under development (see
discussion below). EPA will continue to update implementation guidance
as needed in the future.
1. Total Maximum Daily Loads (TMDLs) and National Pollutant Discharge
Elimination System (NPDES) Permits
EPA's NPDES regulations require that limits for metals in permits
be stated as total recoverable in most cases {see 40 CFR
Sec. 122.45(c)} except when an effluent guideline specifies the
limitation in another form of the metal, the approved analytical
methods measure only dissolved metal, or the permit writer expresses a
metal's limit in another form (e.g., dissolved, specific valence, or
total) when required to carry out provisions of the Clean Water Act.
This is because the chemical conditions in ambient waters frequently
differ substantially from those in the effluent and there is no
assurance that effluent particulate metal would not dissolve after
discharge. The NPDES permit regulations do not require that State water
quality standards be expressed as total recoverable; rather, the
regulations require permit writers to develop permit limits that are
expressed in terms of metals concentrations and loadings that are
measured using the total recoverable method. Expressing criteria as
dissolved metal requires translation between different metal forms in
the calculation of the permit limit so that a total recoverable permit
limit can be established that will achieve water quality standards.
Both the TMDL and NPDES permit use of water quality criteria in NTR
States now require the ability to translate between dissolved metal in
ambient waters and total recoverable metal in effluents. In addition to
the guidance on dynamic modeling and translators attached to the Metals
Policy, EPA's Interim Guidance on the Determination and Use of Water-
Effect Ratios for Metals, February 1994, EPA 823-B-94-001 (pages 116
and 128-130), presents an effluent-specific approach for calculating a
total recoverable metal permit limit from a dissolved metal criterion.
EPA is expecting to complete additional guidance on translators in
1995.
2. Monitoring
a. Use of Clean Sampling and Analytical Techniques
In assessing waterbodies to determine the potential for toxicity
problems due to metals, the quality of the data used is an important
issue. Depending on the concentration of metal present, the use of
``clean'' and ``ultra-clean'' techniques for sampling and analysis may
be critical to accurate data for implementation of aquatic life
criteria for metals.
``Clean'' techniques refer to those requirements (or practices for
sample collection and handling) necessary to produce reliable
analytical data in the microgram per liter (g/L) or part per
billion (ppb) range. ``Ultra-clean'' techniques refer to those
requirements or practices necessary to produce reliable analytical data
in the nanogram per liter (ng/L) or part per trillion (ppt) range.
Because typical concentrations of metals in surface waters and
effluents vary from one metal to another, the effect of contamination
on the quality of metals monitoring data varies appreciably.
EPA has developed protocols on the use of clean techniques in
coordination with the United States Geological Survey (USGS). The
guidance, entitled Method 1669: Sampling Ambient Water for
Determination of Trace Metals at EPA Water Quality Criteria Levels is
available from the Office of Water Resource Center as part of the Trace
Metals Package. Draft protocols for ultra-clean techniques will be
available in late calendar year 1995.
H. Saltwater Copper Criteria
The saltwater copper criteria in today's interim final rule are 2.4
g/L dissolved copper for both CMC and CCC based on conversion
of 2.9 g/L for both the CMC and CCC from total recoverable to
dissolved metal. New data collected from a study for the New York/New
Jersey Harbor indicate the potential need to revise the copper criteria
document to reflect a change in the saltwater CMC and CCC aquatic life
values. A comprehensive literature search was conducted and toxicity
test data for seven new species were added to the database for the
saltwater copper criteria. EPA believes these new data have national
implications and indicate the national criteria may be more accurate at
a CMC of 4.8 g/L dissolved and a CCC of 3.1 g/L
dissolved. In today's rulemaking, EPA is noticing the availability of
data to support these [[Page 22234]] potential changes in the national
saltwater copper criteria and solicits comments. The data can be found
in the draft document entitled, Ambient Water Quality Criteria--Copper,
Addendum 1995. This document is available from the Office of Water
Resource Center or Water Docket. Based on those comments, the saltwater
copper criteria in this interim final rule may be revised in the final
rule to reflect these new data.
I. Procedural Requirements
Section 553 of the Administrative Procedure Act provides that when
an agency, for good cause, finds that notice and public procedure are
impracticable, unnecessary or contrary to the public interest, it may
first issue a rule without providing notice and an opportunity to
comment. EPA has concluded that there is good cause to issue this
interim final rule without notice and comment and to make the rule
effective immediately.
In 1987, Congress amended the Clean Water Act to provide that
States must adopt numeric criteria to control the discharge of toxic
pollutants. Before this requirement was enacted, few States had adopted
numeric criteria for toxic pollutants and had to rely on ``narrative''
criteria (e.g., ``free from toxics in toxic amounts'') to set discharge
limits for such pollutants. Congress, expressing concern over the
calculation of discharge limitations for toxics without numeric
criteria, required States to adopt numeric, pollutant-specific criteria
for toxic pollutants (56 FR 58423-58424, Nov. 19, 1991).
Following promulgation of the NTR, EPA continued to evaluate
available information on metals. EPA held a public meeting of experts
in which a recommendation was made to express the ambient water
criteria as dissolved metal. This recommendation and others, were
noticed for public comment at 58 FR 32131, June 8, 1993. It is EPA's
judgment that aquatic life criteria for metals, when expressed as
dissolved metal provide a more accurate measurement of metals
bioavailability to organisms in the water column than when expressed as
total recoverable metal. Thus, in some situations, the total
recoverable metals criteria in the NTR may result in permit limits that
are more stringent than if the criteria were expressed in a dissolved
form. As a result, in these situations, permitting authorities in the
NTR States may be imposing more stringent (and potentially more costly)
effluent limitations on their dischargers than will be required to meet
the new dissolved metals aquatic life criteria put in place today.
EPA considered the impacts of a stay of the current metals criteria
while it undertook a standard rulemaking (i.e., proposed rule followed
by a final) to revise the aquatic life metals criteria to express them
in a dissolved form. However, during the effective period of the stay
(the interim between proposal and final rule), permitting authorities
for the NTR States would generally need to use the States' narrative
criteria (e.g., free from toxics in toxic amounts) to develop permit
limits for the discharge of toxics. Because the Congressional directive
is clear that States must have numeric criteria for toxic pollutants,
EPA rejected this approach in favor of an interim final rule.
By today's action the Agency upholds the intent of
Sec. 303(c)(2)(B) of the Clean Water Act and avoids the need for
permitting authorities to rely on narrative criteria to develop permit
limits. Further, this interim final rule is a temporary measure. The
Agency notes that considerable public comment has already been obtained
on the Metals Policy and the specific criteria being issued in this
interim final rule. EPA held a meeting with invited experts in January
1993 in Annapolis, Maryland to further elicit comment on the use of
dissolved metals for developing national metals criteria. The Agency
solicited comments on the recommendations made by presenters at that
meeting in the Federal Register on July 9, 1993 (58 FR 32131). The
Metals Policy issued in October 1993 has received wide-spread
distribution and informal response from many interested parties. In
August 1994, EPA issued a Federal Register notice indicating that the
Agency was considering the use of the Metals Policy to develop metals
criteria in the Great Lakes Initiative (59 FR 44678, August 30, 1994)
and comments were received on this issue. Today's action has the
additional benefit of the comments received from the August 1994 notice
on the Great Lakes Initiative.
EPA therefore concludes that public comment on this interim measure
is unnecessary because ample comment has already been received on the
numeric dissolved metals criteria and additional comment is being
solicited and will be considered before a final rule is issued.
Further, a public comment process before adopting the new metals
criteria is contrary to the public interest because: 1) the current
metals criteria place a potentially unnecessary regulatory burden on
dischargers in the States covered by this rule, without necessarily
providing additional protection to aquatic life in the water column and
2) it is in the public interest for the States to have numeric criteria
protective of aquatic life.
Because of the potential adverse effect on public interest noted
above, the Agency has determined there is good cause for making this
regulation effective immediately.
J. Regulatory Assessment Requirements
1. Unfunded Mandates Reform Act of 1995
Section 201 of the Unfunded Mandates Reform Act of 1995 (``Unfunded
Mandates Act''), signed into law on March 22, 1995, requires each
Agency, unless prohibited by law, to assess the effects of Federal
regulation on State, local and tribal governments and the private
sector under section 202 of the Act. EPA must prepare a written
statement to accompany any rules where the estimated costs to State,
local and tribal governments, in the aggregate, or to the private
sector will be $100 million or more in any one year. Under section 205,
for rules that require a written statement under section 202, EPA must
select the most cost-effective and least burdensome alternative that
achieves the objective of such a rule and that is consistent with
statutory requirements. Also, for such rules, section 203 requires EPA
to establish a plan for informing and advising any small governments
that may be significantly and uniquely affected by the rule.
EPA estimates that the costs to State, local, and tribal
governments, or to the private sector, from today's interim final rule
will not be $100 million or more. EPA has determined that this rule
should reduce current regulatory requirements imposed by the NTR. By
promulgating the metals criteria in the NTR as dissolved metals, rather
than total recoverable, EPA is reducing potential costs to discharge
permittees and other parties subject to the water quality criteria.
Therefore, an unfunded mandates statement pursuant to section 202 is
not necessary.
While an unfunded mandates statement is not necessary for this
rule, EPA notes that it has previously considered the costs and
benefits of promulgating Federal water quality criteria when the Agency
issued the NTR in 1992. See 57 FR 60903-60909 (December 22, 1992). That
analysis would continue to be relevant with respect to this issue of
costs and benefits arising from Federal promulgation of criteria for
states. Of course, to the extent today's interim final rule is putting
in place less burdensome [[Page 22235]] requirements than the 1992
rule, the Agency is reducing any potential costs. It is important to
note that the Federal criteria in today's rule, as the Federal criteria
in the 1992 rule, only impose requirements until the States adopt, and
EPA approves, criteria meeting the requirements of section 303(c)(2)(B)
of the Clean Water Act. EPA continues to work with the States to assist
them in adopting their own criteria thereby enabling EPA to withdraw
the Federal criteria.
While section 205 of the Unfunded Mandates Act is not applicable to
today's rule because the rule does not require a written statement
under section 202, the Agency does believe that today's rule is
consistent with the intent of section 205. Section 205 directs agencies
to consider regulatory alternatives and to select the least costly,
most cost-effective or least burdensome alternative that achieves the
objectives of the rule. EPA's decision to promulgate metals criteria
expressed as dissolved rather than total recoverable represents the
Agency's selection of the least costly, most cost-effective and least
burdensome alternative for setting metals criteria. The Agency
addressed this issue in detail in the development of the Great Lakes
Water Quality Guidance, promulgated on March 13, 1995 (60 FR 15366,
March 23, 1995). For today's rule the Agency was obligated pursuant to
section 303 to promulgate water quality criteria for states not in
compliance with section 303(c)(2)(B). Today's rule achieves that
objective consistent with the intent of section 205.
Finally, because today's rule relieves a regulatory requirement,
EPA does not believe that the rule will establish requirements that
might significantly or uniquely affect small governments within the
meaning of section 203. However, the Agency is committed to working
with affected small governments by providing notice of requirements
that might potentially affect them, enable them to provide meaningful
and timely input, and to inform, educate and advise small governments
on compliance with any requirements. With respect to today's interim
final rule, representatives of State and local governments participated
in the development of, and provided comments to the Office of Water's
current metals policy. The Agency recognizes the importance of
soliciting the input of small governments and will be available to work
with them to address any issues related to compliance with today's
rule.
2. Executive Order 12866
Under Executive Order 12866 (56 FR 51735, October 4, 1993), the
Agency must determine whether the regulatory action is ``significant''
and therefore subject to all the requirements of the Executive Order
(i.e., Regulatory Impact Analysis and review by the Office of
Management and Budget). Under section 3(f), the order defines
``significant'' as those actions likely to lead to a rule: (1) Having
an annual effect on the economy of $100 million or more, or adversely
and materially affecting a sector of the economy, productivity,
competition, jobs, the environment, public health or safety, or State,
local, or tribal governments or communities (also known as
``economically significant''); (2) creating serious inconsistency or
otherwise interfering with an action taken or planned by another
agency; (3) materially altering the budgetary impacts of entitlements,
grants, user fees, or loan programs; or (4) raising novel legal or
policy issues arising out of legal mandates, the President's
priorities, or the principles set forth in this order. Pursuant to the
terms of this order, EPA has determined that this interim final rule
would not be ``significant''.
3. Presidential Review of the Code of Federal Regulations
On February 22, 1995, President Clinton announced a review of the
Code of Federal Regulations by all Federal agencies. The objective of
the review is to: eliminate obsolete regulations, withdraw outdated or
superseded regulations, propose modifications to simplify or reduce
burden, and to identify legislation for needed change. Today's rule,
revising the NTR, is consistent with the review announced by the
President. EPA has reviewed the NTR (40 CFR 131.36) and determined that
the use of dissolved metals criteria in the NTR States, for the metals
listed in this rule, should reduce potential regulatory burden.
4. Regulatory Flexibility Act
The Regulatory Flexibility Act (5 U.S.C. 601, et seq., Pub. L. 96-
354) requires EPA to assess whether its regulations create a
disproportionate effect on small entities. EPA discussed in the NTR
rulemaking (December 22, 1992, 57 FR 60909), the potential effects of
the rulemaking on small entities. The Agency concluded that the
rulemaking would not result in a significant impact on small entities
and a final regulatory flexibility analysis was not required.
Because the potential impact on small entities as a result of this
interim final rule revision will be less burdensome on small entities
than the original rule, EPA, based on the same factors discussed in the
previous final rulemaking, continues to conclude this action will not
result in a significant impact on small entities.
5. Paperwork Reduction Act
This interim final rule places no information collection activities
on the affected States and therefore no information collection
requirement will be submitted to the Office of Management and Budget
for review in compliance with the Paperwork Reduction Act, 44 U.S.C.
3501 et seq.
List of Subjects in 40 CFR Part 131
Environmental Protection, Water pollution control, Water quality
standards, Toxic pollutants.
Dated: April 14, 1995.
Carol Browner,
Administrator.
For the reasons set out in the preamble, title 40, chapter I part
131 of the Code of Federal Regulations is amended as follows:
PART 131-WATER QUALITY STANDARDS
1. The authority citation for part 131 continues to read as
follows:
Authority: 33 U.S.C. 1251 et seq.
2. Section 131.36 is amended by revising entries 2, 4,
5a,5b,6,7,8,9,10,11, and 13 of the table at paragraph (b)(1), revising
footnotes ``e'' and ``l'' adding footnotes ``o'' and ``p'' to the table
in paragraph (b)(1), removing the ``Note to paragraph (b)(1)'',
revising paragraph (b)(2) and by revising the first two sentences of
paragraph (c)(4)(iii) to read as follows:
Sec. 131.36 Toxics criteria for those States not complying with Clean
Water Act Section 303(c)(2)(B).
* * * * *
[[Page 22236]]
(b)(1) EPA's Section 304(a) Criteria for Priority Toxic Pollutants.
----------------------------------------------------------------------------------------------------------------
A B C D
----------------------------------------------------------------------------------------------------------------
Freshwater Saltwater Human health (10-6 risk
---------------------------------------------------- for carcinogens)
-------------------------
Criteria Criteria Criteria Criteria For consumption of:
(#) Compound CAS N. Maximum Continuous Maximum Continuous -------------------------
Conc.d (ug/ Conc.d (ug/ Conc.d (ug/ Conc.d (ug/ Water & Organisms
L) B1 L) B2 L) C1 L) C2 Organisms only (ug/L)
(ug/L) D1 D2
----------------------------------------------------------------------------------------------------------------
* * * * * *
*
2 Arsenic............ 7440382 m360 m190 m69 m36 a,b,c0.018
a,b,c a,b,c0.14
* * * * * *
*
4 Cadmium............ 7440439 e3.7 e1.0 m42 m9.3 (n) (n)
5a Chromium (III).... 16065831 e550 e180 ........... ........... (n) (n)
b Chromium (VI)...... 18540299 m15 m10 m1100 m50 (n) (n)
6 Copper............. 7440508 17e 11e m 2.4 m 2.4 ........... ...........
7 Lead............... 7439921 e65 e2.5 m210 m8.1 (n) (n)
8 Mercury............ 7439976 m2.1 i,p0.012 m1.8 i,p0.025 0.14 0.15
9 Nickel............. 7440020 e1400 e160 m74 m8.2 a610 a4600
10 Selenium.......... 7782492 p20 p5.0 m290 m71 (n) (n)
11 Silver............ 7440224 e3.4 m1.9
* * * * * *
*
13 Zinc.............. 7440666 e110 e100 m90 m81
* * * * * *
*
----------------------------------------------------------------------------------------------------------------
Footnotes:
a. Criteria revised to reflect current agency q1* or RfD, as contained in the Integrated Risk Information System
(IRIS). The fish tissue bioconcentration factor (BCF) from the 1980 criteria documents was retained in all
cases.
b. The criteria refers to the inorganic form only.
c. Criteria in the matrix based on carcinogenicity (10-6 risk). For a risk level of 10-5, move the decimal point
in the matrix value one place to the right.
d. Criteria Maximum Concentration (CMC) = the highest concentration of a pollutant to which aquatic life can be
exposed for a short period of time (1-hour average) without deleterious effects. Criteria Continuous
Concentration (CCC) = the highest concentration of a pollutant to which aquatic life can be exposed for an
extended period of time (4 days) without deleterious effects. ug/L = micrograms per liter
e. Freshwater aquatic life criteria for these metals are expressed as a function of total hardness (mg/L as
CaC03), the pollutant's water effect ratio (WER) as defined in Sec. 131.36(c) and multiplied by an appropriate
dissolved conversion factor as defined in Sec. 131.36(b)(2). For comparative purposes, the values displayed in
this matrix are shown as dissolved metal and correspond to a total hardness of 100 mg/L and a water effect
ratio of 1.0.
* * * * * *
*
i. If the CCC for total mercury exceeds 0.012 ug/l more than once in a 3-year period in the ambient water, the
edible portion of aquatic species of concern must be analyzed to determine whether the concentration of methyl
mercury exceeds the FDA action level (1.0 mg/kg). If the FDA action level is exceeded, the State must notify
the appropriate EPA Regional Administrator, initiate a revision of its mercury criterion in its water quality
standards so as to protect designated uses, and take other appropriate action such as issuance of a fish
consumption advisory for the affected area.
* * * * * *
*
l. [Reserved: this letter not used as a footnote].
m. Criteria for these metals are expressed as a function of the water effect ratio, WER, as defined in 40 CFR
131.36 (c).
CMC=column B1 or C1 value x WER
CCC=column B2 or C2 value x WER
n. EPA is not promulgating human health criteria for this contaminant. However, permit authorities should
address this contaminant in NPDES permit actions using the State's existing narrative criteria for toxics.
o. [Reserved: This letter not used as a footnote].
p. Criterion expressed as total recoverable.
* * * * * *
*
(2) Factors for Calculating Hardness-Dependent, Freshwater Metals
Criteria
CMC=WER exp {mA[ln(hardness)]+bA} x Acute Conversion Factor
CCC=WER exp {mC[ln(hardness)]+bC} x Chronic Conversion Factor
Final CMC and CCC values should be rounded to two significant figures.
[[Page 22237]]
----------------------------------------------------------------------------------------------------------------
Freshwater conversion
factors
Metal mA bA mC bC -------------------------
Acute Chronic
----------------------------------------------------------------------------------------------------------------
Cadmium........................... 1.128 -3.828 0.7852 -3.490 a0.944 a0.909
Chromium (III).................... 0.8190 3.688 0.8190 1.561 0.316 0.860
Copper............................ 0.9422 -1.464 0.8545 -1.465 0.960 0.960
Lead.............................. 1.273 -1.460 1.273 -4.705 a0.791 a0.791
Nickel............................ 0.8460 3.3612 0.8460 1.1645 0.998 0.997
Silver............................ 1.72 -6.52 bN/A bN/A 0.85 bN/A
Zinc.............................. 0.8473 0.8604 0.8473 0.7614 0.978 0.986
----------------------------------------------------------------------------------------------------------------
Note to table: The term ``exp'' represents the base e exponential function.
Footnotes to table:
aThe freshwater conversion factors (CF) for cadmium and lead are hardness-dependent and can be calculated for
any hardness [see limitations in Sec. 131.36(c)(4)] using the following equations:
Cadmium
Acute: CF=1.136672--[(ln hardness)(0.041838)]
Chronic: CF=1.101672--[(ln hardness)(0.041838)]
Lead (Acute and Chronic): CF = 1.46203--[(ln hardness)(0.145712)]
bNo chronic criteria are available for silver.
(c) * * *
(4) * * *
(iii) Except where otherwise noted, the criteria for metals
(compounds #2, #4-# 11, and #13, in paragraph (b) of this section) are
expressed as dissolved metal. For purposes of calculating aquatic life
criteria for metals from the equations in footnote m. in the criteria
matrix in paragraph (b)(1) of this section and the equations in
paragraphs (b)(2) of this section, the water-effect ratio is computed
as a specific pollutant's acute or chronic toxicity values measured in
water from the site covered by the standard, divided by the respective
acute or chronic toxicity value in laboratory dilution water. * * *
* * * * *
[FR Doc. 95-10148 Filed 5-3-95; 8:45 am]
BILLING CODE 6560-50-P
