[Federal Register Volume 81, Number 228 (Monday, November 28, 2016)]
[Rules and Regulations]
[Pages 85417-85437]
[FR Doc No: 2016-28424]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 131

[EPA-HQ-OW-2015-0174; FRL-9955-40-OW]
RIN 2040-AF56

Revision of Certain Federal Water Quality Criteria Applicable to
Washington

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: On September 14, 2015, the Environmental Protection Agency
(EPA) proposed revisions to the federal Clean Water Act (CWA) human
health criteria applicable to waters under the State of Washington's
jurisdiction to ensure that the criteria are set at levels that will
adequately protect Washington residents, including tribes with treaty-
reserved rights, from exposure to toxic pollutants. EPA promulgated
Washington's previous criteria for the protection of human health in
1992 as part of the National Toxics Rule (NTR) (amended in 1999 for
Polychlorinated Biphenyls (PCBs)), using the Agency's recommended
criteria values at the time. EPA derived those previously applicable
criteria using a fish consumption rate (FCR) of 6.5 grams per day (g/
day) based on national surveys. The best available data now demonstrate
that fish consumers in Washington consume much more fish than 6.5 g/
day. There are also new data and scientific information available to
update the toxicity and exposure parameters used to calculate human
health criteria. On August 1, 2016, the State of Washington adopted and
submitted human health criteria for certain pollutants, reflecting some
of these new data and information. Concurrent with this final rule, EPA
is taking action under CWA 303(c) to approve in part, and disapprove in
part, the human health criteria submitted by Washington. For those
criteria that EPA disapproved, EPA is finalizing federal human health
criteria in this final rule.

EPA is not finalizing criteria in this final rule for those state-
adopted criteria that EPA approved, or for certain criteria that EPA
has determined involve scientific uncertainty, as explained below.

DATES: This final rule is effective on December 28, 2016.

ADDRESSES: EPA has established a docket for this action under Docket ID
No. EPA-HQ-OW-2015-0174. All documents in the docket are listed on the
http://www.regulations.gov Web site. Although listed in the index, some
information is not publicly available, e.g., CBI or other information
whose disclosure is restricted by statute. Certain other material, such
as copyrighted material, is not placed on the Internet and will be
publicly available only in hard copy form. Publicly available docket
materials are available electronically through http://www.regulations.gov.

FOR FURTHER INFORMATION CONTACT: Erica Fleisig, Office of Water,
Standards and Health Protection Division (4305T), Environmental
Protection Agency, 1200 Pennsylvania Avenue NW., Washington, DC 20460;
telephone number:<PHONE_NUMBER>; email address<EMAIL_ADDRESS>
SUPPLEMENTARY INFORMATION: This final rule is organized as follows:

I. General Information
    A. Does this action apply to me?
    B. How did EPA develop this final rule?
II. Background
    A. Statutory and Regulatory Background
    B. EPA's CWA 303(c) Action on Washington's Human Health Criteria
    C. General Recommended Approach for Deriving Human Health
Criteria
III. Derivation of Human Health Criteria for Washington
    A. Scope of Pollutants and Waters Covered by This Final Rule
    B. Washington's Designated Uses and Tribal Reserved Fishing
Rights
    C. Washington-Specific Human Health Criteria Inputs
    D. Final Human Health Criteria for Washington
    E. Applicability of Criteria
    F. Alternative Regulatory Approaches and Implementation
Mechanisms
IV. Economic Analysis
    A. Identifying Affected Entities
    B. Method for Estimating Costs
    C. Results
V. Statutory and Executive Order Reviews
    A. Executive Order 12866 (Regulatory Planning and Review) and
Executive Order 13563 (Improving Regulation and Regulatory Review)
    B. Paperwork Reduction Act
    C. Regulatory Flexibility Act
    D. Unfunded Mandates Reform Act
    E. Executive Order 13132 (Federalism)
    F. Executive Order 13175 (Consultation and Coordination With
Indian Tribal Governments)
    G. Executive Order 13045 (Protection of Children From
Environmental Health and Safety Risks)
    H. Executive Order 13211 (Actions That Significantly Affect
Energy Supply, Distribution, or Use)
    I. National Technology Transfer and Advancement Act of 1995
    J. Executive Order 12898 (Federal Actions To Address
Environmental Justice in Minority Populations and Low-Income
Populations)
    K. Congressional Review Act (CRA)

I. General Information

A. Does this action apply to me?

    Entities such as industries, stormwater management districts, or
publicly owned treatment works (POTWs) that discharge pollutants to
waters of the United States under the State of Washington's
jurisdiction could be indirectly affected by this rulemaking, because
federal water quality standards (WQS) promulgated by EPA are applicable
to CWA regulatory programs, such as National Pollutant Discharge
Elimination System (NPDES) permitting. Citizens concerned with water
quality in Washington could also be interested in this rulemaking.
Categories and entities that could potentially be affected include the
following:

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                                      Examples of potentially affected
             Category                             entities
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Industry..........................  Industries discharging pollutants to
                                     waters of the United States in
                                     Washington.
Municipalities....................  Publicly owned treatment works or
                                     other facilities discharging
                                     pollutants to waters of the United
                                     States in Washington.
Stormwater Management Districts...  Entities responsible for managing
                                     stormwater runoff in the State of
                                     Washington.
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This table is not intended to be exhaustive, but rather provides a
guide for readers regarding entities that could be indirectly affected
by this action. Any parties or entities who depend upon or contribute
to the water quality of Washington's waters could be indirectly
affected by this rule. To determine whether your facility or activities
could be indirectly affected by this action, you should carefully
examine this rule. If you have questions regarding the applicability of
this action to a particular entity, consult the person listed in the
FOR FURTHER INFORMATION CONTACT section.

B. How did EPA develop this final rule?

    In developing this final rule, EPA carefully considered the public
comments and feedback received from interested parties. EPA originally
provided a 60-day public comment period after publishing the proposed
rule in the Federal Register on September 14, 2015.\1\ On October 28,
2015, in response to stakeholder requests,\2\ EPA extended the public
comment period for an additional 45 days.\3\ In addition, EPA held two
virtual public hearings on December 15th and 16th, 2015, to discuss the
contents of the proposed rule and accept verbal public comments.
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    \1\ See Revision of Certain Federal Water Quality Criteria
Applicable to Washington: Proposed Rule, 80 FR 55063, September 14,
2015.
    \2\ EPA received requests from the Association of Washington
Business--Washington State's Chamber of Commerce, Washington Public
Ports Association (on behalf of the Association of Washington Cities
and the Washington State Association of Counties), Western Wood
Preservers Institute, ALCOA, American Forest and Paper Association,
McFarland Cascade, Schnitzer Steel Industries, and Weyerhaeuser.
    \3\ See Extension of Public Comment Period for the Revision of
Certain Federal Water Quality Criteria Applicable to Washington, 80
FR 65980, October 28, 2015.
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    Over 60 organizations and individuals submitted comments on a range
of issues. EPA also received over 400 letters from individuals
associated with mass letter writing campaigns. Some comments addressed
issues beyond the scope of the rulemaking, and thus EPA did not
consider them in finalizing this rule. In each section of this
preamble, EPA discusses certain public comments so that the public is
aware of the Agency's position. For a full response to these and all
other comments, see EPA's Response to Comments document in the official
public docket.

II. Background

A. Statutory and Regulatory Background

    CWA section 101(a)(2) establishes as a national goal ``water
quality which provides for the protection and propagation of fish,
shellfish, and wildlife, and recreation in and on the water, wherever
attainable.'' These are commonly referred to as the ``fishable/
swimmable'' goals of the CWA. EPA

interprets ``fishable'' uses to include, at a minimum, designated uses
providing for the protection of aquatic communities and human health
related to consumption of fish and shellfish.\4\
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    \4\ USEPA. 2000. Memorandum #WQSP-00-03. U.S. Environmental
Protection Agency, Office of Water, Washington, DC https://www.epa.gov/sites/production/files/2015-01/documents/standards-shellfish.pdf.
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    CWA section 303(c) (33 U.S.C. 1313(c)) directs states to adopt WQS
for their waters subject to the CWA. CWA section 303(c)(2)(A) and EPA's
implementing regulations at 40 CFR part 131 require, among other
things, that a state's WQS specify appropriate designated uses of the
waters, and water quality criteria that protect those uses. EPA's
regulations at 40 CFR 131.11(a)(1) provide that ``[s]uch criteria must
be based on sound scientific rationale and must contain sufficient
parameters or constituents to protect the designated use. For waters
with multiple use designations, the criteria shall support the most
sensitive use.'' In addition, 40 CFR 131.10(b) provides that ``[i]n
designating uses of a water body and the appropriate criteria for those
uses, the state shall take into consideration the water quality
standards of downstream waters and ensure that its water quality
standards provide for the attainment and maintenance of the water
quality standards of downstream waters.''
    States are required to review applicable WQS at least once every
three years and, if appropriate, revise or adopt new standards (CWA
section 303(c)(1)). Any new or revised WQS must be submitted to EPA for
review and approval or disapproval (CWA section 303(c)(2)(A) and
(c)(3)). If EPA disapproves a state's new or revised WQS, the CWA
provides the state 90 days to adopt a revised WQS that meets CWA
requirements, and if it fails to do so, EPA shall promptly propose and
then within 90 days promulgate such standard unless EPA approves a
state replacement WQS first (CWA section 303(c)(3) and (c)(4)(A)). CWA
section 303(c)(4)(B) authorizes the Administrator to determine that a
new or revised standard is needed to meet CWA requirements. Upon making
such a determination, the CWA specifies that EPA shall promptly
propose, and then within 90 days promulgate, any such new or revised
standard unless prior to such promulgation, the state has adopted a
revised or new WQS that EPA determines to be in accordance with the
CWA.
    Under CWA section 304(a), EPA periodically publishes criteria
recommendations for states to consider when adopting water quality
criteria for particular pollutants to protect the CWA section 101(a)(2)
goal uses. In 2015, EPA updated its 304(a) recommended criteria for
human health for 94 pollutants.\5\ Where EPA has published recommended
criteria, states should establish numeric water quality criteria based
on EPA's CWA section 304(a) criteria, section 304(a) criteria modified
to reflect site-specific conditions, or other scientifically defensible
methods (40 CFR 131.11(b)(1)). In all cases criteria must be sufficient
to protect the designated use and be based on sound scientific
rationale (40 CFR 131.11(a)(1)). CWA section 303(c)(2)(B) requires
states to adopt numeric criteria for all toxic pollutants listed
pursuant to CWA section 307(a)(1) for which EPA has published 304(a)
criteria, as necessary to support the states' designated uses.
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    \5\ Final Updated Ambient Water Quality Criteria for the
Protection of Human Health, (80 FR 36986, June 29, 2015). See also:
USEPA. 2015. Final 2015 Updated National Recommended Human Health
Criteria. U.S. Environmental Protection Agency, Office of Water,
Washington, DC https://www.epa.gov/wqc/human-health-water-quality-criteria.
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    In 1992, EPA promulgated the NTR at 40 CFR 131.36, establishing
chemical-specific numeric criteria for 85 priority toxic pollutants for
14 states and territories (states), including Washington, that were not
in compliance with the requirements of CWA section 303(c)(2)(B). When
states covered by the NTR subsequently adopted their own criteria for
toxic pollutants that EPA approved as consistent with the CWA and EPA's
implementing regulations, EPA amended the NTR to remove those criteria
for those states.

B. EPA's CWA 303(c) Action on Washington's Human Health Criteria

    On September 14, 2015, EPA made a CWA 303(c)(4)(B) determination
that new or revised WQS for the protection of human health in
Washington were necessary to meet the requirements of the CWA, and
proposed revised human health criteria for the state (see 80 FR 55063).
At that time, Washington had not yet adopted its own criteria for the
protection of human health.\6\ On August 1, 2016, Washington adopted
and submitted statewide human health criteria and new and revised
implementation provisions. Concurrent with this final rule, EPA
approved 45 and disapproved 143 of Washington's human health criteria
under CWA 303(c). EPA is finalizing 144 human health criteria in this
rule in accordance with CWA section 303(c)(3) and (c)(4)
requirements.\7\ After the effective date of this final rule, these
federal criteria will be in effect for CWA purposes along with the
human health criteria that Washington adopted and EPA approved.
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    \6\ Washington adopted criteria for the protection of aquatic
life from toxic pollutants at WAC 173-201A-240.
    \7\ EPA is finalizing a different number of human health
criteria (144) than it is disapproving (143) in Washington's 2016
submittal. Washington did not adopt organism-only criteria for
methylmercury or water-plus-organism and organism-only criteria for
bis(2-chloro-1-methylethyl) ether. These are priority pollutants
listed pursuant to CWA section 307(a)(1) for which EPA has 304(a)
recommended criteria, and, as such, CWA section 303(c)(2)(B)
requires that states adopt numeric criteria for these pollutants, as
necessary to support the states' designated uses. Therefore, EPA is
including these three criteria in this final rule for Washington.
This final rule, however, does not include revised water-plus-
organism and organism-only criteria for arsenic, as explained below
in section III.A, even though EPA is disapproving the arsenic
criteria in Washington's submittal.
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    Several commenters provided comments on the timing of EPA's rule,
and the relationship between EPA's federal rulemaking and the state
rulemaking process. These comments are now, for the most part, mooted
by EPA's finalization of its federal rule and action on the state's
submittal. For additional responses to specific comments, see EPA's
Response to Comment document in the docket for this rule.

C. General Recommended Approach for Deriving Human Health Criteria

    Human health criteria are designed to minimize the risk of adverse
cancer and non-cancer effects occurring from lifetime exposure to
pollutants through the ingestion of drinking water and consumption of
fish and shellfish obtained from inland and nearshore waters (by
nearshore waters, EPA refers to waters out to three miles from the
coast). EPA's practice is to establish a human health 304(a)
recommended criterion for both drinking water and consumption of fish
and shellfish from inland and nearshore waters combined, and a separate
human health criterion based only on ingestion of fish and shellfish
from inland and nearshore waters. This latter criterion applies in
cases where the designated uses of a waterbody include supporting fish
and shellfish for human consumption but not drinking water supply
sources (e.g., in non-potable estuarine waters).
    The criteria are based on two types of biological endpoints: (1)
Carcinogenicity and (2) systemic toxicity (i.e., all adverse effects
other than cancer). EPA takes an integrated approach and considers both
cancer and non-cancer effects when deriving human health criteria.
Where sufficient data are available, EPA derives criteria using

both carcinogenic and non-carcinogenic toxicity endpoints and
recommends the lower value. Human health criteria for carcinogenic
effects are calculated using the following input parameters: Cancer
slope factor (CSF), cancer risk level, body weight, drinking water
intake rate, fish consumption rate, and a bioaccumulation factor(s).
Human health criteria for non-carcinogenic and nonlinear carcinogenic
effects are calculated using a reference dose (RfD) in place of a CSF
and cancer risk level, and a relative source contribution (RSC) factor,
which is intended to ensure that an individual's total exposure to a
given pollutant from all sources does not exceed the RfD. Each of these
inputs is discussed in more detail below and in EPA's 2000 Human Health
Methodology (hereafter referred to as EPA's ``2000 Methodology'').\8\
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    \8\ USEPA. 2000. Methodology for Deriving Ambient Water Quality
Criteria for the Protection of Human Health. U.S. Environmental
Protection Agency, Office of Water, Washington, DC EPA-822-B-00-004.
https://www.epa.gov/wqc/human-health-water-quality-criteria.
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a. Cancer Risk Level

    EPA's 304(a) national recommended human health criteria are
typically based on the assumption that carcinogenicity is a ``non-
threshold phenomenon,'' which means that there are no ``no-effect''
levels, because even extremely small doses are assumed to cause a
finite increase in the incidence of cancer. Therefore, EPA calculates
304(a) human health criteria for carcinogenic effects as pollutant
concentrations corresponding to lifetime increases in the risk of
developing cancer.\9\ EPA calculates its 304(a) human health criteria
values at a 10-6 (one in one million) cancer risk level and
recommends cancer risk levels of 10-6 or 10-5
(one in one hundred thousand) for the general population.\10\ EPA notes
that states and authorized tribes can also choose a more stringent risk
level, such as 10-7 (one in ten million), when deriving
human health criteria.
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    \9\ As noted above, EPA recommends the criterion derived for
non-carcinogenic effects if it is more protective (lower) than that
derived for carcinogenic effects.
    \10\ EPA's 2000 Methodology also states: ``Criteria based on a
10-5 risk level are acceptable for the general population
as long as states and authorized tribes ensure that the risk to more
highly exposed subgroups (sport fishers or subsistence fishers) does
not exceed the 10-4 level.'' Since EPA is establishing
final criteria to protect a target general population of tribes with
reserved subsistence fishing rights in Washington waters, the
applicable EPA-recommended cancer risk levels would relate to that
target general population, as opposed to the general population of
Washington residents overall. See section III for additional
discussion.
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    If the pollutant is not considered to have the potential for
causing cancer in humans (i.e., systemic toxicants), EPA assumes that
the pollutant has a threshold (the RfD) below which a physiological
mechanism exists to avoid or overcome the adverse effects of the
pollutant.
b. Cancer Slope Factor and Reference Dose
    A dose-response assessment is required to understand the
quantitative relationships between exposure to a pollutant and the
onset of human health effects. EPA evaluates dose-response
relationships derived from animal toxicity and human epidemiological
studies to derive dose-response metrics. For carcinogenic toxicological
effects, EPA uses an oral CSF to derive human health criteria. The oral
CSF is an upper bound, approximating a 95 percent confidence limit, on
the increased cancer risk from a lifetime oral exposure to a stressor.
For non-carcinogenic effects, EPA uses the RfD to calculate human
health criteria. A RfD is an estimate of a daily oral exposure of an
individual to a substance that is likely to be without an appreciable
risk of deleterious effects during a lifetime. A RfD is typically
derived from a laboratory animal dosing study in which a no-observed-
adverse-effect level (NOAEL), lowest-observed-adverse-effect level
(LOAEL), or benchmark dose can be obtained. Uncertainty factors are
applied to reflect the limitations of the data. EPA's Integrated Risk
Information System (IRIS) \11\ was the primary source of toxicity
values (i.e., RfD and CSF) for EPA's 2015 updated 304(a) human health
criteria.\12\ For some pollutants, however, more recent peer-reviewed
and publicly available toxicological data were available from other EPA
program offices (e.g., Office of Pesticide Programs, Office of Water,
Office of Land and Emergency Management), other national and
international programs, and state programs.
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    \11\ USEPA. Integrated Risk Information System (IRIS). U.S.
Environmental Protection Agency, Office of Research and Development,
Washington, DC www.epa.gov/iris.
    \12\ Final Updated Ambient Water Quality Criteria for the
Protection of Human Health, (80 FR 36986, June 29, 2015). See also:
USEPA. 2015. Final 2015 Updated National Recommended Human Health
Criteria. U.S. Environmental Protection Agency, Office of Water,
Washington, DC https://www.epa.gov/wqc/human-health-water-quality-criteria.
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c. Exposure Assumptions
    EPA's latest 304(a) national human health criteria use a default
drinking water intake rate of 2.4 liters per day (L/day) and default
rate of 22 g/day for consumption of fish and shellfish from inland and
nearshore waters, multiplied by pollutant-specific bioaccumulation
factors (BAFs) to account for the amount of the pollutant in the edible
portions of the ingested species. EPA's 2000 Methodology for deriving
human health criteria emphasizes using, when possible, measured or
estimated BAFs, which account for chemical accumulation in aquatic
organisms from all potential exposure routes.\13\ In the 2015 national
304(a) human health criteria update, EPA primarily used field-measured
BAFs, and laboratory-measured bioconcentration factors (BCFs) with
applicable food chain multipliers available from peer-reviewed,
publicly available databases, to develop national BAFs for three
trophic levels of fish. If this information was not available, EPA
selected octanol-water partition coefficients (Kow values)
from peer-reviewed sources for use in calculating national BAFs.\14\
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    \13\ USEPA. 2000. Methodology for Deriving Ambient Water Quality
Criteria for the Protection of Human Health. U.S. Environmental
Protection Agency, Office of Water, Washington, DC EPA-822-B-00-004.
https://www.epa.gov/wqc/human-health-water-quality-criteria.
    \14\ Final Updated Ambient Water Quality Criteria for the
Protection of Human Health, (80 FR 36986, June 29, 2015). See also:
USEPA. 2015. Final 2015 Updated National Recommended Human Health
Criteria. U.S. Environmental Protection Agency, Office of Water,
Washington, DC https://www.epa.gov/wqc/human-health-water-quality-criteria.
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    EPA's national default drinking water intake rate of 2.4 L/day
represents the per capita estimate of combined direct and indirect
community water ingestion at the 90th percentile for adults ages 21 and
older.\15\ EPA's national default FCR of 22 g/day represents the 90th
percentile consumption rate of fish and shellfish from inland and
nearshore waters for the U.S. adult population 21 years of age and
older, based on National Health and Nutrition Examination Survey
(NHANES) data from 2003 to 2010.16 17 EPA calculates

human health criteria using a default body weight of 80 kilograms (kg),
the average weight of a U.S. adult age 21 and older, based on NHANES
data from 1999 to 2006.
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    \15\ USEPA. 2011. EPA Exposure Factors Handbook. 2011 edition
(EPA 600/R-090/052F). http://cfpub.epa.gov/ncea/risk/recordisplay.cfm?deid=236252.
    \16\ USEPA. 2014. Estimated Fish Consumption Rates for the U.S.
Population and Selected Subpopulations (NHANES 2003-2010). United
States Environmental Protection Agency, Washington, DC EPA 820-R-14-
002.
    \17\ EPA's national FCR is based on the total rate of
consumption of fish and shellfish from inland and nearshore waters
(including fish and shellfish from local, commercial, aquaculture,
interstate, and international sources). This is consistent with a
principle that each state does its share to protect people who
consume fish and shellfish that originate from multiple
jurisdictions. USEPA. January 2013. Human Health Ambient Water
Quality Criteria and Fish Consumption Rates: Frequently Asked
Questions. https://www.epa.gov/wqc/human-health-ambient-water-quality-criteria-and-fish-consumption-rates-frequently-asked.
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    Although EPA uses these default values to calculate national 304(a)
recommended human health criteria, EPA's 2000 Methodology notes a
preference for the use of local data to calculate human health criteria
(e.g., locally derived FCRs, drinking water intake rates and body
weights, and waterbody-specific bioaccumulation rates) over national
default values, where data are sufficient to do so, to better represent
local conditions.\18\ It is also important, where sufficient data are
available, to select a FCR that reflects consumption that is not
suppressed by concerns about the safety of available
fish.19 20 Deriving human health criteria using an
unsuppressed FCR furthers the restoration goals of the CWA and ensures
protection of human health-related designated uses (as pollutant levels
decrease, fish habitats are restored, and fish availability increases
over time). See section III for additional discussion regarding use of
an unsuppressed FCR to protect a subsistence or sustenance fishing use,
especially where the subsistence or sustenance use is based in whole or
in part on tribal treaty or other reserved fishing rights.\21\
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    \18\ USEPA. 2000. Methodology for Deriving Ambient Water Quality
Criteria for the Protection of Human Health. U.S. Environmental
Protection Agency, Office of Water, Washington, DC EPA-822-B-00-004.
https://www.epa.gov/wqc/human-health-water-quality-criteria.
    \19\ USEPA. January 2013. Human Health Ambient Water Quality
Criteria and Fish Consumption Rates: Frequently Asked Questions.
https://www.epa.gov/wqc/human-health-ambient-water-quality-criteria-and-fish-consumption-rates-frequently-asked.
    \20\ National Environmental Justice Advisory Council, Fish
Consumption and Environmental Justice, p.44 (2002) available at
https://www.epa.gov/sites/production/files/2015-02/documents/fish-consump-report_1102.pdf.
    \21\ The term ``subsistence'' is coterminous with ``sustenance''
in this context. Hereafter, the document uses the term
``subsistence.''
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d. Relative Source Contribution
    When deriving human health criteria for non-carcinogens and
nonlinear carcinogens, EPA recommends including a RSC factor to account
for sources of exposure other than drinking water and fish and
shellfish from inland and nearshore waters, so that the pollutant
effect threshold (i.e., RfD) is not apportioned to drinking water and
fish consumption alone. The rationale for this approach is that for
pollutants exhibiting threshold effects, the objective of the human
health criteria is to ensure that an individual's total exposure from
all sources does not exceed that threshold level. These other exposures
include exposure to a particular pollutant from ocean fish and
shellfish consumption (which is not included in EPA's default national
FCR), non-fish food consumption (e.g., fruits, vegetables, grains,
meats, poultry), dermal exposure, and inhalation exposure. EPA's
guidance includes a procedure for determining an appropriate RSC value
ranging from 0.2 to 0.8 for a given pollutant.

III. Derivation of Human Health Criteria for Washington

A. Scope of Pollutants and Waters Covered by This Final Rule

    In 1992, EPA did not establish human health criteria in the NTR for
some priority toxic pollutants because, as stated in the preamble to
the final rule at 57 FR 60848, December 22, 1992, EPA had no 304(a)
recommendations for those pollutants at the time. EPA now has 304(a)
recommendations for 99 priority toxic pollutants listed pursuant to CWA
section 307(a)(1) (85 for which EPA established criteria in the NTR,
plus 14 additional pollutants).
    After consideration of all comments received on EPA's proposed
rule, and EPA's CWA 303(c) action on Washington's submittal, EPA is
finalizing 144 new and revised Washington-specific criteria for
priority toxic pollutants in this rule. For arsenic, dioxin and
thallium, EPA is not revising Washington's existing criteria from the
NTR at this time, as explained below and in EPA's Response to Comments
document in the docket for the final rule. For those priority
pollutants for which EPA does not have 304(a) national recommended
criteria, and are therefore not included in Washington's submittal or
this final rule, EPA expects that Washington will continue to apply its
existing narrative toxics criterion in the state's WQS at WAC 173-201A-
260(2)(a).
    Several commenters raised concerns about the scientific
defensibility of EPA's proposed human health criteria for arsenic, and
one commenter raised similar concerns about EPA's proposed criteria for
2,3,7,8-TCDD (dioxin). Additionally, after EPA proposed revised human
health criteria for thallium in Washington, EPA further evaluated the
scientific uncertainty around the appropriate RfD for thallium. EPA
carefully considered all of these comments and information regarding
these three pollutants, along with the comments that articulated it is
important for Washington to have protective numeric criteria in place
for priority toxic pollutants such as arsenic and dioxin. Given the
scientific uncertainty regarding aspects of the science upon which the
proposed human health criteria for arsenic, dioxin, and thallium were
based, EPA is withdrawing its proposal of revised criteria for these
three pollutants at this time and leaving the existing criteria from
the NTR in effect for CWA purposes.\22\ EPA did not update the 304(a)
national recommended criteria for these three pollutants in 2015. As
noted earlier, IRIS was the primary source of toxicity values (i.e.,
RfD and CSF) for EPA's 2015 updated 304(a) human health criteria. For
thallium, EPA's IRIS database does not currently contain an estimate of
thallium's toxicity (i.e., a RfD).\23\ For dioxin, IRIS does not
currently contain a measure of dioxin's cancer-causing ability (i.e., a
CSF).\24\ Without such values, EPA has concluded that further analysis
is necessary in order to promulgate scientifically sound revised
criteria for these two pollutants. For arsenic, there is uncertainty
surrounding the toxicological assessment with respect to human health
effects. EPA's current plan for addressing the arsenic issues is
described in the Assessment Development Plan for the Integrated Risk
Information System (IRIS) Toxicological Review of Inorganic Arsenic
(EPA/630/R-14/101, November 2015). EPA intends to reevaluate the
existing federal arsenic, dioxin and thallium human health criteria for
Washington by 2018, with particular consideration of any relevant
toxicity and bioaccumulation information.
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    \22\ EPA is moving Washington's existing arsenic, dioxin and
thallium criteria from the NTR into 40 CFR 131.45 to have one
comprehensive human health criteria rule for Washington.
    \23\ http://cfpub.epa.gov/ncea/iris/index.cfm?fuseaction=iris.showQuickView&substance_nmbr=1012.
    \24\ http://cfpub.epa.gov/ncea/iris/index.cfm?fuseaction=iris.showQuickView&substance_nmbr=1024.
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    This rule revises the criteria that EPA promulgated for Washington
in the NTR (with the exception of criteria for arsenic, dioxin, and
thallium, and criteria that EPA approved in Washington's August 1, 2016
submittal), and establishes new human health criteria for 8 additional
chemicals for which EPA now has 304(a) recommended criteria (and for
which EPA did not approve Washington's submitted criteria): Selenium,
Zinc, 1,2-Trans-Dichloroethylene, Acenaphthene, Butylbenzyl Phthalate,
2-Chloronaphthalene, 1,1,1-Trichloroethane, and 1,2,4-Trichlorobenzene.
In 2001, EPA

replaced its 304(a) recommended human health criteria for total mercury
with a fish tissue-based human health criterion for methylmercury.\25\
Washington did not include human health criteria for mercury or
methylmercury in its August 1, 2016 submittal. Therefore, with this
final rule, EPA replaces the criteria for total mercury that EPA
promulgated for Washington in the NTR with a methylmercury fish tissue
criterion, based on EPA's 2001 304(a) recommendation but adjusted to
incorporate the 175 g/day FCR that EPA used to derive revised human
health criteria in Washington, as well as EPA's 2015 updated national
default body weight of 80 kg.
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    \25\ USEPA. 2001. Guidance for Implementing the January 2001
Methylmercury Water Quality Criterion. U.S. Environmental Protection
Agency, Office of Water, Washington, DC EPA-823-R-01-001. https://www.epa.gov/wqc/guidance-implementing-january-2001-methylmercury-water-quality-criterion.
---------------------------------------------------------------------------

    A few commenters expressed concern that Washington would not have
the data or implementation guidance to properly implement a fish tissue
criterion for methylmercury, and requested that EPA leave the NTR total
mercury criteria in effect in Washington. The fish tissue methylmercury
criterion reflects EPA's 2000 Methodology, the best available science,
and supersedes all previous 304(a) human health mercury criteria
recommendations published by EPA (except for the waters of the Great
Lakes System), including the 304(a) recommended criteria that served as
the basis for the total mercury criteria that EPA promulgated for
Washington in the NTR. EPA recommends a fish tissue water quality
criterion for methylmercury for many reasons. A fish tissue water
quality criterion integrates spatial and temporal complexity that
occurs in aquatic systems and affects methylmercury bioaccumulation.
For this pollutant, a fish tissue criterion is more closely tied to the
goal of protecting human health because it is based directly on the
dominant human exposure route for methylmercury in the U.S., which is
consumption of fish and shellfish. The concentration of methylmercury
is also generally easier to quantify in fish tissue than in water and
is less variable in fish and shellfish tissue over the time periods in
which WQS are typically implemented in water quality-based controls,
such as NPDES permits. Finally, fish consumption advisories for mercury
are also based on the amount of methylmercury in fish tissue.\26\ While
the purpose of a fish advisory is different from the purpose of a water
quality criterion, it will be helpful to the public to have water
quality criteria and fish consumption advisories for methylmercury
expressed using the same terms. In response to comments regarding
implementation of the methylmercury criterion, in 2010, EPA published
the comprehensive Guidance for Implementing the January 2001
Methylmercury Water Quality Criterion (EPA 823-R-10-001), to aid states
in implementing the fish tissue-based methylmercury water quality
criterion. EPA is confident that Washington will be able to implement
the fish tissue criterion using the information contained in that
document, and EPA remains available to offer assistance in doing so.
Thus there is no need or requirement to leave the NTR total mercury
criteria in place in Washington.
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    \26\ While both water quality criteria and fish consumption
advisories are designed ultimately to protect human health, they
represent very different values and goals. Water quality criteria
express or establish a desired condition and must protect the
designated use, such as subsistence fishing. Fish consumption
advisories start with existing levels of fish contamination
resulting from impaired water quality, and provide advice to
populations consuming such fish on limiting levels of consumption in
order to reduce risk from contamination.
---------------------------------------------------------------------------

    This final rule does not change or supersede any criteria that EPA
previously promulgated for other states in the NTR, nor does it change
any other elements of the NTR such as EPA's original basis for
promulgation. For clarity in organization, EPA is withdrawing
Washington from the NTR at 40 CFR 131.36 and incorporating the
Washington-specific criteria in this rule (as well as the existing NTR
criteria for arsenic, dioxin and thallium) into 40 CFR 131.45 so there
is a single comprehensive set of federally promulgated criteria for
Washington.
    This rule applies to waters under the State of Washington's
jurisdiction, and not to waters within Indian country,\27\ unless
otherwise specified in federal law. Some waters located within Indian
country already have CWA-effective human health criteria, while others
do not.\28\ Several tribes are working with EPA to either revise their
existing CWA-effective WQS, or obtain treatment in a similar manner as
a state (TAS) status in order to adopt CWA-effective WQS in the near
future. EPA will continue to work closely with tribes in Washington to
ensure that they adopt human health criteria that are scientifically
supported and protective of designated uses, in accordance with the CWA
and EPA's regulations. In addition, on September 29, 2016, EPA
published an Advanced Notice of Proposed Rulemaking in the Federal
Register that seeks input on an approach that involves EPA promulgating
baseline WQS for reservations that currently have no CWA-effective WQS,
including such reservations within the State of Washington.\29\
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    \27\ See 18 U.S.C. 1151 for the definition of Indian country.
    \28\ Indian country waters with CWA-effective WQS include those
where (a) EPA has authorized a tribe to adopt WQS under the CWA for
its reservation and the tribe has adopted standards that EPA has
approved, and (b) EPA has promulgated federal WQS.
    \29\ For more information, see: https://www.epa.gov/wqs-tech/advance-notice-proposed-rulemaking-federal-baseline-water-quality-standards-indian.
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B. Washington's Designated Uses and Tribal Reserved Fishing Rights

a. EPA's Consideration of Tribal Treaty Rights
    Under the Supremacy Clause of the U.S. Constitution, federal
treaties have the same legal force as federal statutes.\30\ As such,
the provisions of federal statutes should generally be read in harmony
with treaties where they both apply. In certain instances, statutes may
contain provisions indicating that they must be read in harmony with
treaties. Such is the case with the CWA, which provides that the Act
``shall not be construed as . . . affecting or impairing the provisions
of any treaty of the United States.'' \31\
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    \30\ U.S. Const. art. IV, Sec.  2: The ``Constitution . . . of
the United States . . . and all Treaties made, or which shall be
made, under the Authority of the United States, shall be the supreme
Law of the Land; and the Judges in every State shall be bound
thereby, any Thing in the Constitution or Laws of any State to the
Contrary notwithstanding.''
    \31\ CWA Section 511, 33 U.S.C. 1371.
---------------------------------------------------------------------------

    In determining whether WQS satisfy the CWA and EPA's regulations,
and when setting criteria for the protection of human health, it is
necessary to consider other applicable laws, such as federal treaties
(e.g., U.S. Treaties with Indians). While treaties do not expand EPA's
authority, they are binding on the federal government. As a result, EPA
has an obligation to ensure that its actions do not conflict with
tribal treaty rights.\32\ For the foregoing reasons, and

as further explained below, it is therefore necessary and appropriate
to consider tribal treaties to ensure that EPA's actions under the CWA
are in harmony with such treaties. See also EPA's Response to Comment
document in the docket for this rule.
---------------------------------------------------------------------------

    \32\ U.S. Const. art. IV, Sec.  2; see United States v. Forty-
Three Gallons of Whiskey, 93 U.S. 188, 196 (1833) (recognizing that
``the Constitution declares a treaty to be the supreme law of the
land,'' and that ``a treaty is to be regarded . . . as equivalent to
an act of the legislature'') and Worcester v. Georgia, 31 U.S. 515,
594 (1832) (``So long as . . . treaties exist, having been formed
within the sphere of the federal powers, they must be respected and
enforced by the appropriate organs of the federal government.'').
See also EPA policies on considering treaty rights: Working
Effectively With Tribal Governments: Resource Guide at pp. 49-52, 53
(August 1998) (explaining the key principles underlying the
application of Indian treaty rights, and noting that ``[f]ederal,
state, and local agencies need to refrain from taking actions that
are not consistent with tribal rights wherever they exist'');
Commemorating the 30th Anniversary of the EPA's Indian Policy,
Memorandum from Gina McCarthy to All EPA Employees, p. 1 (December
1, 2014) (reiterating that ``EPA must ensure that its actions do not
conflict with tribal treaty rights'' and stating that ``EPA programs
should be implemented to enhance the protection of tribal treaty
rights and treaty-covered resources when we have the discretion to
do so''); EPA Policy for the Administration of Environmental
Programs on Indian Reservations (November 8, 1984) (known as ``EPA
1984 Indian Policy'').
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b. Treaty-Reserved Subsistence Fishing Rights in Washington
    The majority of waters under the jurisdiction of the State of
Washington are subject to federal treaties with tribes.\33\ There are
eight Stevens-Palmer Treaties relevant to the State of Washington
through which 24 tribes reserved for themselves identical or nearly
identical fishing rights within the boundaries of present-day
Washington; specifically, the treaty-reserved ``right of taking fish at
usual and accustomed places, in common with all citizens of the
Territory.'' \34\ The right to take fish at usual and accustomed places
extends to lands formerly ceded by the tribes to the U.S. as described
in the treaties, as well as to all places beyond the boundaries of the
ceded territories that tribal members regularly used at treaty
time.\35\
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    \33\ See http://wdfw.wa.gov/hunting/tribal/treaty_history.html.
    \34\ See e.g. Treaty with the Yakima art. 3, June 9, 1855, 12
Stat. 951. In United States v. Winans, 198 U.S. 371 (1905), the
Supreme Court adopted a ``reservation of rights'' approach in
interpreting the Stevens Treaty with the Yakima Nation: ``the treaty
was not a grant of rights to the Indians, but a grant of rights from
them--a reservation of those not granted.'' Id. at 381. In contrast,
``off reservation fishing by other citizens and residents of the
state is not a right but merely a privilege which may be granted,
limited or withdrawn by the state as the interests of the state or
the exercise of treaty fishing rights may require.'' U.S. v
Washington, 384 F. Supp. 312, 332 (W.D. Wash. 1974) aff'd 520 F.2d
676 (9th Cir. 1975), cert. denied 423 U.S. 1086 (1976).
    \35\ See Seufert Bros. Co. v. U.S., 249 U.S. 194, 199 (1919). In
U.S. v Washington, the court stated, citing Seufert Bros. Co.,
``every fishing location where members of a tribe customarily fished
from time to time at and before treaty times, however distant from
the then usual habitat of the tribe, and whether or not other tribes
then also fished in the same waters, is a usual and accustomed
ground or station at which the treaty tribe reserved, and its
members presently have, the right to take fish.'' 384 F. Supp. at
332.
---------------------------------------------------------------------------

    The parties to the treaties all recognized the importance of the
fishing right for the tribes' subsistence, ceremonial, as well as
commercial purposes.\36\ In U.S. v Washington, the district court made
detailed findings of facts regarding the reserved fishing right,
including the importance of subsistence fishing to the treaty tribes:
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    \36\ For a thorough discussion on the treaty negotiation and
execution and meaning of the reserved fishing right, see e.g., U.S.
v Washington, 384 F. Supp. at 348-359 (containing finding of facts
regarding, inter alia, treaty status, pre-treaty role of fishing
among northwest Indians, treaty background, negotiation and
execution of the treaties, and post-treaty Indian fishing); see also
id. at 340 (``The right to fish for all species available in the
waters from which, for so many ages, their ancestors derived most of
their subsistence is the single most highly cherished interest and
concern of the present members of plaintiff tribes, with rare
exceptions even among tribal members who personally do not fish or
derive therefrom any substantial amount of their subsistence.'');
id. at 343 (``The evidence shows beyond doubt that at treaty time
the opportunity to take fish for personal subsistence and religious
ceremonies was the single matter of utmost concern to all treaty
tribes and their members.''); and U.S. v. Washington, No. 13-35474,
2016 U.S. App. LEXIS 11709, at *29 (9th Cir. June 27, 2016) (``The
Indians reasonably understood Governor Stevens to promise not only
that they would have access to their usual and accustomed fishing
places, but also that there would be fish sufficient to sustain
them.'').

    At the treaty negotiations, a primary concern of the tribes,
whose way of life was so heavily dependent upon harvesting
anadromous fish, was that they have freedom to move about to gather
food, particularly salmon, . . . at their usual and accustomed
fishing places. . . . Subsequent to the execution of the treaties
and in reliance thereon, the members of the [treaty tribes with
reserved fishing rights in Washington] have continued to fish for
subsistence, sport, and commercial purposes at their usual and
accustomed places. Such fishing provided and still provides an
important part of their livelihood, subsistence and cultural
identity. The Indian cultural identification with fishing is
primarily dietary, related to the subsistence fishery, and
secondarily associated with religious ceremonies and commercial
fishing.\37\
---------------------------------------------------------------------------

    \37\ U.S. v Washington, 384 F. Supp. at 355-358 (internal
citations to exhibits omitted).

    Relevant case law, including Supreme Court precedents,
unequivocally confirms that the treaty-reserved right to take fish
includes the right to take fish for subsistence purposes.\38\
Historical and current evidence of tribal members' exercise of the
treaty-reserved subsistence fishing right can be found in heritage FCR
reports and contemporary FCR surveys (for tables of relevant FCRs, see
EPA's Response to Comment document in the docket for this rule).
---------------------------------------------------------------------------

    \38\ See e.g., Washington v. Washington State Commercial
Passenger Fishing Vessel Ass'n, 443 U.S. 658, 678-679 (1979)
(Because the Indians had always exercised the right to meet their
subsistence and commercial needs by taking fish from treaty area
waters, they would be unlikely to perceive a ``reservation'' of that
right as merely the chance, shared with millions of other citizens,
occasionally to dip their nets into the territorial waters.
Moreover, the phrasing of the clause quite clearly avoids placing
each individual Indian on an equal footing with each individual
citizen of the State.''); U.S. v. Washington, 2016 U.S. App. LEXIS
11709 at *28 (Observing that to the Tribes, the Stevens Treaties'
``principal purpose was to secure a means of supporting themselves
once the Treaties took effect,'' and to that end, ``[s]almon were a
central concern.'').
---------------------------------------------------------------------------

    As explained above, the Stevens-Palmer Treaties provide tribes the
right to exercise subsistence fishing practices on waters throughout
the State of Washington. EPA concludes that the purpose for which
tribes reserved such fishing rights through treaties with the U.S. has
important implications for water quality regulation under the CWA.
Fundamentally, the tribes' ability to take fish for their subsistence
purposes under the treaties would be substantially affected or impaired
if it were not supported by water quality sufficient under the CWA to
ensure that tribal members can safely eat the fish for their own
subsistence.
    Many areas where treaty-reserved fishing rights are exercised
cannot be directly protected or regulated by tribal governments to
ensure adequate water quality, and therefore the responsibility falls
to the federal government (and the states) to ensure their protection.
It is therefore appropriate and necessary for EPA (and states) to
consider the tribal reserved rights within the framework of the CWA, to
ensure water quality protection for treaty-reserved subsistence fishing
rights. EPA's consideration of treaty-reserved fishing rights within
the framework of the CWA leads to the conclusion, as described below,
that the human health fishing uses for waters in Washington include
subsistence fishing, as informed by the tribes' legally protected right
to continue to take fish for subsistence purposes.\39\
---------------------------------------------------------------------------

    \39\ While EPA's action is based on harmonizing the requirements
of the CWA with the terms of the treaty-reserved subsistence fishing
right, the action also is consistent with federal Indian law
principles addressing subsidiary treaty rights. A written legal
opinion from the Solicitor of the U.S. Department of Interior (DOI)
to EPA analyzed whether tribal reserved fishing rights include
subsidiary rights to sufficient water quality. Letter from Hilary C.
Tompkins, Solicitor, DOI, to Avi Garbow, General Counsel, EPA,
regarding Maine's WQS and Tribal Fishing Rights of Maine Tribes
(January 30, 2015). Although DOI's legal opinion primarily involved
an analysis of fishing rights of tribes in Maine in connection with
EPA's February 2, 2015 decision to disapprove WQS applied to waters
of Indian Lands in Maine, its discussion of tribal fishing rights
and water quality has relevance to tribes with reserved fishing
rights in Washington. DOI's legal opinion identified several court
decisions, including Supreme Court decisions interpreting the
reserved fishing right in the Stevens Treaties, which have held that
fishing rights for tribes encompass subsidiary rights that are
necessary to render those rights meaningful. In Washington v. Wash.
State Commercial Passenger Fishing Vessel Ass'n, the United States
Supreme Court held that tribes with reserved fishing rights are
entitled to something more tangible than ``merely the chance . . .
occasionally to dip their nets into the territorial seas.'' 443 U.S.
658, 679 (1979). Consistent with this reasoning, courts have held
that treaty-reserved fishing rights entail the right to access
fishing grounds and the right to water quantity sufficient to
support fish habitat. See e.g., United States v. Winans, 198 U.S.
371, 384 (1905) (tribe must be allowed to cross private property to
access traditional fishing ground); Seufert Bros. Co. v. United
States, 249 U.S. 194 (1919) (tribe entitled to cross over and
temporarily use any sites which they were accustomed to using at
treaty time, including sites outside their ceded territories);
United States v. Adair, 723 F .2d 1394, 1409-10 (9th Cir. 1983)
(holding that the tribe's fishing right implicitly reserved
sufficient waters to ``secure to the Tribe a continuation of its
traditional . . . fishing lifestyle''; Colville Confederated Tribes
v. Walton, 647 F.2d 42, 47-48 (9th Cir. 1981) (implying reservation
of water to preserve tribe's replacement fishing grounds).
Consistent with these precedents, in June 2016 the U.S. Court of
Appeals for the Ninth Circuit affirmed the district court's finding
that barrier culverts constructed by the State of Washington
obstructing fish passage were in violation of tribal fishing rights
set forth in the Stevens Treaties, noting that ``the Tribes' right
of access to their usual and accustomed fishing places would be
worthless without harvestable fish.'' United States v. Washington,
2016 U.S. App. LEXIS 11709 at *31. The court also acknowledged that
the fishing clause of the Stevens Treaties could give rise to other
environmental obligations, but that those would need to be addressed
on a case-by-case basis depending on the precise nature of the
action. Id. at *18-19. Consistent with this body of case law, DOI's
legal opinion concludes that ``fundamental, longstanding tenets of
federal Indian law support the interpretation of tribal fishing
rights to include the right to sufficient water quality to
effectuate the fishing right.'' DOI Letter at 10.

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c. Use(s) of the Water(s) in Question
    Consistent with EPA's September 14, 2015 proposed rule for
Washington, in order to effectuate and harmonize treaty-reserved
fishing rights with the CWA, EPA has determined that such rights must
be appropriately considered when determining which criteria are
sufficient to adequately protect Washington's designated uses. Looking
at the treaty-reserved subsistence fishing right within the CWA water
quality framework, the first step is to examine the use of the water(s)
in question. The CWA generally assigns to a state the responsibility of
determining the designated uses of its waters (subject to certain
restrictions at 40 CFR 131.10),\40\ and in Washington the state's
designated uses include fish and shellfish harvesting.\41\ As explained
above, through treaties, tribes reserved specific fishing rights in
Washington's waters, including the right to take fish from such waters
for their subsistence. In order to effectuate these rights in harmony
with the CWA, EPA has interpreted the state's EPA-approved designated
fish and shellfish harvesting use to include or encompass a subsistence
fishing component based on, and consistent with, the rights reserved to
the tribes through the treaties. As discussed in more detail below, EPA
construes the CWA to require that, when establishing WQS for these
waters, the tribal members must be considered the target general
population for the purposes of setting risk levels to protect the
subsistence fishing use.
---------------------------------------------------------------------------

    \40\ 33 U.S.C. 1251(a)(2), 1313(c)(2)(A).
    \41\ See WAC 173-201A-600 and WAC 173-201A-610.
---------------------------------------------------------------------------

d. Target General Population for Deriving Criteria Protective of the
Use(s)
    Developing criteria to protect the fish and shellfish harvesting
use, which includes subsistence fishing as informed by reserved fishing
rights, necessarily involves identifying tribal members with reserved
fishing rights as the target population for protection. EPA's
conclusion to identify tribes as the target population is based on
EPA's CWA implementing regulations requiring criteria to support the
most sensitive use (i.e., subsistence fishing) and EPA's 2000
Methodology recommendation that priority be given to identifying and
protecting highly exposed populations. Further, in order to derive
water quality criteria sufficient under the CWA to ensure that the
tribes' treaty-reserved right to take fish for subsistence purposes is
not substantially affected or impaired, it is reasonable and
appropriate to identify tribes as the target general population for
protection, rather than a subpopulation, and apply the 2000
Methodology's recommendations on exposure for the general population to
the tribal target population.
    Per EPA's regulations at 40 CFR 131.11(a)(1), water quality
criteria must contain sufficient parameters or constituents to protect
the designated use, and for waters with multiple uses, the criteria
must support the most sensitive use. In the case of Washington's human
health-related uses, the most sensitive use is fish and shellfish
harvesting, which, as explained above, EPA has interpreted to include
or encompass a subsistence fishing component based on, and consistent
with, the rights reserved to the tribes through the treaties.
Developing water quality criteria to protect the subsistence fishing
component of the fish or shellfish harvesting use necessarily involves
identifying the population exercising that use.
    EPA's decision to identify tribes as the target population is
further supported by EPA guidance for developing water quality criteria
to protect human health. As explained in EPA's 2000 Methodology, the
choice of the particular population to protect is an important decision
to make when setting human health criteria.\42\ EPA recommends that
states provide adequate protection from adverse health effects to the
general population, as well as to highly exposed populations, such as
recreational and subsistence fishers, two distinct groups with FCRs
that may be greater than the general population.\43\ In fact, EPA's
2000 Methodology recommends considering how to protect both susceptible
and highly exposed populations when setting criteria:
---------------------------------------------------------------------------

    \42\ EPA's 2000 Methodology, 2-1.
    \43\ Id. at 2-2.

    EPA recommends that priority be given to identifying and
adequately protecting the most highly exposed population. Thus, if
the State or Tribe determines that a highly exposed population is at
greater risk and would not be adequately protected by criteria based
on the general population, and by the national 304(a) criteria in
particular, EPA recommends that the State or Tribe adopt more
stringent criteria using alternative exposure assumptions.\44\
---------------------------------------------------------------------------

    \44\ EPA's 2000 Methodology, 2-1--2. See also EPA's 2000
Methodology, 4-17 (``When choosing exposure factor values to include
in the derivation of a criterion for a given pollutant, EPA
recommends considering values that are relevant to population(s)
that is (are) most susceptible to that pollutant. In addition,
highly exposed populations should be considered when setting
criteria.'').

Therefore, consistent with the guidance, EPA identifies the tribal
population as the target population for protection and the subsistence
fishing use must be the focus of the risk assessment supporting water
quality criteria to adequately protect that use. Deriving criteria
protective of the tribal target population necessarily involves
determining the appropriate inputs for calculating protective criteria
---------------------------------------------------------------------------
for tribal subsistence fishers, such as the FCR and cancer risk level.

    EPA's approach in the 2000 Methodology, and its approach used for
deriving national 304(a) recommended criteria, is for human health
water quality criteria to provide a high level of protection for the
general population (for example, FCRs designed to represent ``the
general population of fish consumers,'' or a cancer risk level that
``reflects an appropriate risk for the general population''), while
recognizing that more highly exposed ``subpopulations'' may face
greater levels of risk.\45\ The 2000 Methodology does not, however,
speak to or envision the unique situation of setting WQS that cover
areas where tribes have treaty-reserved rights to practice subsistence

fishing.\46\ Nevertheless, it is possible to apply the general
principles outlined in the 2000 Methodology to this situation, as
informed by the treaties.
---------------------------------------------------------------------------

    \45\ See EPA's 2000 Methodology, 2-6--7, 4-24--25.
    \46\ In response to comments on EPA's 1998 draft Human Health
Methodology revisions, the Agency responded: ``As stated in the 1998
draft Methodology revisions, `risk levels and criteria need to be
protective of tribal rights under federal law (e.g., fishing,
hunting, or gathering rights) that are related to water quality.' We
believe the best way to ensure that Tribal treaty and other rights
under Federal law are met, consistent with the Federal trust
responsibility, is to address these issues at the time EPA reviews
water quality standards submissions.'' (See 65 FR 66444, 66457
November 3, 2000).
---------------------------------------------------------------------------

    In light of the presence of the treaty-reserved fishing rights in
Washington, interpreted by the U.S. Supreme Court to encompass, among
other things, subsistence fishing, and EPA's interpretation of
Washington's fish and shellfish harvesting use to include subsistence
fishing, it is reasonable and appropriate to require that tribes with
such rights be considered as the target general population for deriving
criteria protective of the use rather than a sensitive subpopulation
within the overall population of Washington. Treating tribes as the
target general population will help derive water quality criteria
sufficient under the CWA to ensure that the tribes' treaty-reserved
right to take fish for subsistence purposes is not substantially
affected or impaired. Therefore, the 2000 Methodology's recommendations
on exposure for the target general population can be applied
accordingly. EPA's conclusion to treat tribes as the target general
population, as opposed to a subpopulation, is further supported by
relevant case law interpreting the treaty-reserved fishing rights
applicable in Washington; specifically the phrase ``in common with all
citizens of the territory.''
    Treating tribes as the target population instead of a sensitive
subpopulation also impacts another important input parameter used to
derive human health criteria, the cancer risk level. For carcinogenic
pollutants, EPA's 2000 Methodology recommends that states protect the
general population to a level of incremental cancer risk no greater
than one in one hundred thousand to one in one million (1 x
10-5 to 10-6). For over 20 years, Washington has
used 10-6 as the level of risk that must be used to
establish human health criteria for carcinogenic pollutants. EPA's 2000
Methodology indicates that if there are highly exposed groups or
subpopulations within that target general population, such as
subsistence consumers, WQS should protect those consumers to a level of
incremental risk no greater than one in ten thousand (1 x
10-4).\47\ However, where treaty-reserved tribal fishing
rights apply to particular waters, it would be unreasonable to expose
the communities exercising those rights to levels of risk above what
would be reasonable for the general population of the state. See
section III.C.b for more information on cancer risk level.
---------------------------------------------------------------------------

    \47\ 2000 Methodology, 2-6.
---------------------------------------------------------------------------

e. Water Quality Criteria Sufficient To Protect the Use(s)
    The data used to determine the FCR are critical to deriving
criteria that will protect the subsistence fishing portion of the fish
and shellfish harvesting designated use. EPA provides a recommended
national default FCR for the general population but strongly recommends
the use of local or regional data, where available, over default
values.\48\ Further, as EPA explained in its January 2013 Human Health
Ambient Water Quality Criteria and Fish Consumption Rates: Frequently
Asked Questions, it is important to avoid selecting a FCR that reflects
consumption that is suppressed due to concerns about the safety of
available fish. Under certain circumstances, it may also be relevant to
look at the availability of fish when considering suppression effects
on current FCRs.\49\ EPA maintains that it is important, as a CWA goal,
to avoid the suppression effect that may occur when criteria are
derived using a FCR for a given target population that reflects an
artificially diminished level of fish consumption from an appropriate
baseline level of consumption for that population.\50\ To use a FCR
that is suppressed would not result in criteria that actually protect a
fishing use because it would merely reinforce the existing suppressed
use, or worse, set in motion a ``downward spiral'' \51\ of further
reduction/suppression of fish consumption due to concerns about the
safety of available fish or depleted fisheries. The CWA is meant not
merely to maintain the status quo, but to restore and maintain the
chemical, physical, and biological integrity of the Nation's waters.
Therefore, deriving criteria using an unsuppressed FCR furthers the
restoration goals of the CWA and ensures protection of human health-
related designated uses (as pollutant levels decrease, fish habitats
are restored, and fish availability increases over time).
---------------------------------------------------------------------------

    \48\ EPA's 2000 Methodology, 4-24--4-25 (``EPA's first
preference is that States and authorized Tribes use the results from
fish intake surveys of local watersheds within the State or Tribal
jurisdiction to establish fish intake rates that are representative
of the defined populations being addressed for the particular
waterbody.'')
    \49\ As noted by the National Environmental Justice Advisory
Council in the 2002 publication Fish Consumption and Environmental
Justice, ``a suppression effect may arise when fish upon which
humans rely are no longer available in historical quantities (and
kinds), such that humans are unable to catch and consume as much
fish as they had or would. Such depleted fisheries may result from a
variety of affronts, including an aquatic environment that is
contaminated, altered (due, among other things, to the presence of
dams), overdrawn, and/or overfished. Were the fish not depleted,
these people would consume fish at more robust baseline levels. . .
. In the Pacific Northwest, for example, compromised aquatic
ecosystems mean that fish are no longer available for tribal members
to take, as they are entitled to do in exercise of their treaty
rights.''). National Environmental Justice Advisory Council, Fish
Consumption and Environmental Justice, p.44, 46 (2002) available at
https://www.epa.gov/sites/production/files/2015-02/documents/fish-consump-report_1102.pdf.
    \50\ See id. at 43.
    \51\ See id. at 47.
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    CWA section 303(c)(2)(A) requires that water quality criteria be
``based upon'' applicable designated uses, and that such uses and
criteria ``shall be such as to protect the public health or welfare,
enhance the quality of water and serve the purposes of this [Act].''
The ``purposes of this [Act]'' are in section 101, and include, among
other things, ``to restore and maintain the chemical, physical, and
biological integrity of the Nation's waters'' and ``water quality which
provides for the protection and propagation of fish, shellfish, and
wildlife and provides for recreation in and on the water.'' EPA's
implementing water quality regulations at 40 CFR 131.11 require water
quality criteria to be based on sound scientific rationale and
sufficient to protect the designated use, regardless of whether that
use is currently being met. A subsistence fishing designated use, by
definition, represents a level of fish consumption that is adequate to
provide subsistence, regardless of whether such consumption is
occurring today. It is entirely consistent with the CWA and regulations
for EPA to determine that to protect the designated use, it is
necessary and appropriate to derive the human health criteria using a
fish consumption rate that reflects a subsistence level of consumption
that is not artificially suppressed as a result of concerns about
pollution or fish contamination where such data are available.
    Any fish consumption rate used in setting criteria to protect a
subsistence fishing use must allow for the consumption of fish from
local waters at levels that could sustain and be protective of members
of the target population practicing a subsistence lifestyle. Water
quality criteria derived

using a FCR below a level that would be adequate to sustain members of
the target population exercising a subsistence use, such as tribal
members who have a history of subsistence fishing in Washington, would
not be protective of that use. In this context, use of an unsuppressed
rate, where data to determine that rate are available, would ensure
that the resulting criteria are protective of the subsistence use.
    The importance of relying on an unsuppressed FCR, where data are
available, is especially evident where the subsistence use is based in
whole or in part on tribal treaty and other reserved subsistence
fishing rights. This is because if human health criteria are set at a
level that assumes only suppressed fish consumption, the waters will
only be protected to support that level of suppressed fish consumption
and thus never fully support--and potentially even may directly
impair--the tribes' legal right to take fish for subsistence purposes.
Accordingly, where adequate data are available to clearly demonstrate
what the current unsuppressed FCR is for the relevant target
population, the selected FCR must reflect that value. In the absence of
such data, states, tribes, and EPA could consider upper percentile FCRs
of local contemporary fish consumption surveys (such as the 95th or
99th percentile), heritage FCR data for the target population, and/or
FCRs that provide for a subsistence fishing lifestyle. Consultation
with tribes is important to ensure that all data and information
relevant to this issue are considered.
    Although treaties do not cover all waters in Washington, they cover
the vast majority of the state's waters. Additionally, where treaty and
non-treaty reserved rights apply on waters downstream of waters without
reserved fishing rights, upstream WQS must provide for the attainment
and maintenance of downstream WQS in accordance with EPA's regulations
at 40 CFR 131.10(b). Based on a GIS analysis included in the docket for
this final rulemaking, EPA concluded that greater than 90 percent of
waters in Washington are covered by treaty rights and/or are upstream
of waters with such rights or waters in Oregon (see section III.C.a).
For any remaining waters in Washington, where reserved rights do not
apply and that are not upstream of waters with such rights or waters in
Oregon, it would be administratively burdensome to develop separate
criteria to apply to such a small subset of waters, and would be
difficult to implement separate criteria with a patchwork of protection
among these areas when administering the WQS, NPDES permitting, and
other programs. Therefore, EPA applies these final criteria to all
waters under Washington's jurisdiction.
    Many commenters supported EPA's decisions to derive criteria
protective of the tribal population exercising their treaty-reserved
fishing rights in Washington as the target general population, and to
apply the resulting criteria to all waters under Washington's
jurisdiction. Many other commenters did not support these decisions,
and argued that EPA did not have a scientific or legal basis to
interpret Washington's designated uses to encompass subsistence fishing
and to treat the tribal population with treaty-reserved fishing rights
as the target general population for protection under such use. For
additional responses to these comments, see EPA's Response to Comment
document in the docket for this rule.

C. Washington-Specific Human Health Criteria Inputs

a. Fish Consumption Rate
    In Washington there are 24 tribes with treaty-reserved fishing
rights, rights that encompass the right to fish for subsistence
purposes, and several local and regional FCR surveys and heritage
tribal consumption reports with widely varying estimates of tribal FCRs
in Washington (for tables of relevant FCRs, see EPA's Response to
Comment document in the docket for this rule). Available heritage FCRs
range from 401 to 995 g/day, and contemporary survey FCRs range from 63
to 214 g/day (mean FCRs) and from 113 to 489 g/day (90th percentile
FCRs). The discrepancy between contemporary and heritage FCRs suggests
that current FCRs for certain tribal consumers in Washington may be
suppressed.52 53 It is currently unclear how a contemporary
fish consumption survey might quantitatively account for suppression,
resulting in estimates of current FCRs that are unsuppressed to the
maximum degree practicable. There is no local survey of contemporary
fish consumption in Washington adjusted specifically to account for
suppression, and no survey is a clear representation of current
unsuppressed consumption for all tribes in Washington. Consistent with
the principles outlined above, EPA considered the available,
scientifically sound fish consumption data for Washington tribes and
consulted with tribal governments to select a FCR for this final
rulemaking.
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    \52\ The number of fish advisories and closures due to
contamination also suggest that contemporary FCRs may be suppressed
due to concerns about pollution. See Washington Department of
Health, Fish Consumption Advisories, available at http://www.doh.wa.gov/CommunityandEnvironment/Food/Fish/Advisories.
    \53\ Heritage rates refer to the rates of fish intake consistent
with traditional tribal practices, prior to contact with European
settlers.
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    The Washington tribes have generally agreed that 175 g/day is
acceptable for deriving protective criteria at this time, when
accompanied by other protective input parameters to calculate the
criteria. However, EPA recognizes that some tribes have raised concerns
as to whether a FCR of 175 g/day reasonably reflects current
unsuppressed consumption rates of tribes within the State of
Washington, based on the best currently available information. A FCR of
175 g/day approximates the 95th percentile consumption rate of surveyed
tribal members from the CRITFC study \54\ and includes anadromous fish,
which is reasonable given that these marine species reside in
Washington's nearshore (i.e., within three miles of the coast) waters,
especially Puget Sound, and accumulate pollutants discharged to these
waters during a significant portion of their lives. The CRITFC survey
also includes four tribes (three of which have treaty-reserved rights
in Washington, the most of any one contemporary FCR survey in
Washington) along the Columbia River in Washington, Idaho, and Oregon.
Given this, and also considering the variability in heritage and
contemporary FCRs and the uncertainty regarding suppression effects on
current FCRs, the CRITFC survey provides scientifically sound estimates
of fish consumption for the purpose of deriving a Washington statewide
FCR for the tribal target general population.
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    \54\ Fish Consumption Survey of the Umatilla, Nez Perce, Yakama,
and Warm Springs Tribes of the Columbia River Basin (Columbia River
Inter-Tribal Fish Commission (CRITFC), 1994).
---------------------------------------------------------------------------

    Additionally, Oregon, much of which is downstream from Washington
(or cross-stream in the Columbia River where it forms the border
between the two states), used a FCR of 175 g/day to derive statewide
human health criteria, which EPA approved in 2011. Use of this FCR to
derive Washington's criteria will thus help ensure the attainment and
maintenance of downstream WQS in Oregon.
    Many commenters supported EPA's selected FCR, as well as the
Agency's position that it is important to consider suppression effects
on the FCR in general, and necessary and appropriate to do so where
subsistence fishing is a reserved right and encompassed by the
designated use of the waters. Some

commenters expressed concern that 175 g/day was not high enough to
reflect current or historical consumption rates of all tribes in
Washington. Many other commenters expressed the opposite concern, that
175 g/day was unreasonably high in order to protect Washington
residents, and argued that treaty-reserved rights do not confer the
right to eat fish at unsuppressed levels. Some of those commenters also
argued that the CWA does not mention suppression. For detailed
responses to these comments, see EPA's Response to Comment document in
the docket for this rule.
b. Cancer Risk Level
    EPA derives final human health criteria for carcinogens in
Washington using a cancer risk level of one in one million
(10-6), based on Washington's longstanding use of that
cancer risk level, EPA guidance, tribal reserved fishing rights, and
downstream protection requirements.
    To derive final human health criteria for each state in the NTR,
EPA selected a cancer risk level based on each state's policy or
practice regarding what risk level should be used when regulating
carcinogens in surface waters. In its official comments on EPA's
proposed NTR in 1992, Washington asked EPA to promulgate human health
criteria using a cancer risk level of 10-6, stating, ``The
State of Washington supports adoption of a risk level of one in one
million for carcinogens. If EPA decides to promulgate a risk level
below one in one million, the rule should specifically address the
issue of multiple contaminants so as to better control overall site
risks.'' (57 FR 60848, December 22, 1992). Accordingly, in the NTR, EPA
used a cancer risk level of 10-6 (one in one million) to
derive human health criteria for Washington. Subsequently, Washington
adopted and EPA approved a provision in the state's WQS that reads:
``Risk-based criteria for carcinogenic substances shall be selected
such that the upper-bound excess cancer risk is less than or equal to
one in a million'' (WAC 173-201A-240(6)). In Washington's August 1,
2016 submittal, the cancer risk level is identified in the new text and
reformatted toxics criteria table at WAC 173-201A-240.
    Subsequent to promulgating the NTR, EPA issued its 2000
Methodology, which states that when promulgating water quality criteria
for states and tribes, EPA intends to use the 10-6 cancer
risk level, which reflects an appropriate risk for the general
population.\55\ In this action, as described above, tribes with treaty-
reserved rights in Washington are the target general population for the
purpose of deriving revised criteria to protect the subsistence fishing
uses of Washington's waters. Because those tribes are the general
population in this case, EPA's selection of a 10-6 cancer
risk level for the tribal target general population is consistent with
current EPA guidance, specifically the 2000 Methodology.
---------------------------------------------------------------------------

    \55\ EPA's 2000 Methodology, pages 2-6.
---------------------------------------------------------------------------

    In addition, use of a cancer risk rate of 10-6 ensures
that the resulting human health criteria for carcinogens protect the
subsistence fishing component of the designated use. Due to uncertainty
regarding suppression effects (see sections II.C, III.B, and III.C.a,
and EPA's Response to Comment document in the docket for this rule),
using a cancer risk level of 10-6 along with a FCR of 175 g/
day ensures that tribal members with treaty-reserved fishing rights
will be protected at an acceptable risk level for the target general
population. Throughout tribal consultation, the tribes generally
supported 175 g/day as an acceptable FCR for purposes of revising
Washington's human health criteria at this time, when accompanied by
other protective input parameters (e.g., a cancer risk level of
10-6), to account for the uncertainty around an appropriate
FCR value reflective of tribal subsistence fishing.
    Finally, as discussed in section III.C.a, many of Washington's
rivers are in the Columbia River Basin, upstream of Oregon's portion of
the Columbia River. Oregon's criteria are based on a FCR of 175 g/day
and a cancer risk level of 10-6. EPA's decision to derive
human health criteria for Washington using a cancer risk level of
10-6 along with a FCR of 175 g/day helps ensure that
Washington's criteria will ensure the attainment and maintenance of
Oregon's downstream WQS as required by 40 CFR 131.10(b).
    Many commenters supported EPA's selection of a 10-6
cancer risk level, and EPA's rationale for doing so. Many other
commenters disagreed and argued that deriving human health criteria for
Washington using a 10-5 cancer risk level is appropriate and
consistent with EPA guidance and past practice. Many of these
commenters stated that tribal treaties did not confer rights to a
particular level of risk. Additionally, some commenters supported EPA's
consideration of downstream WQS in Oregon when establishing the
criteria upstream, while others expressed concern that EPA was
suggesting that Washington's upstream criteria must be identical to
Oregon's downstream criteria and in doing so, acting inconsistently
with its 2014 Frequently Asked Questions document on downstream
protection.\56\ For detailed responses to these comments, see EPA's
Response to Comment document in the docket for this rule.
---------------------------------------------------------------------------

    \56\ https://nepis.epa.gov/Exe/ZyPDF.cgi/P100LIJF.PDF?Dockey=P100LIJF.PDF.
---------------------------------------------------------------------------

c. Relative Source Contribution
    EPA recommends using a RSC for non-carcinogens and nonlinear
carcinogens to account for sources of exposure other than drinking
water and consumption of inland and nearshore fish and shellfish (see
section II.C.d). In 2015, after evaluating information on chemical
uses, properties, occurrences, releases to the environment and
regulatory restrictions, EPA developed chemical-specific RSCs for non-
carcinogens and nonlinear carcinogens ranging from 0.2 (20 percent) to
0.8 (80 percent) following the Exposure Decision Tree approach
described in EPA's 2000 Methodology.57 58 EPA proposed to
use these same RSCs to derive human health criteria for Washington, and
where EPA did not update the nationally recommended criteria for
certain pollutants in 2015, EPA proposed to use a RSC of 0.2 to derive
human health criteria for those pollutants in Washington to ensure
protectiveness.
---------------------------------------------------------------------------

    \57\ USEPA. 2000. Methodology for Deriving Ambient Water Quality
Criteria for the Protection of Human Health. U.S. Environmental
Protection Agency, Office of Water, Washington, DC EPA-822-B-00-004.
https://www.epa.gov/wqc/human-health-water-quality-criteria.
    \58\ Final Updated Ambient Water Quality Criteria for the
Protection of Human Health, (80 FR 36986, June 29, 2015). See also:
USEPA. 2015. Final 2015 Updated National Recommended Human Health
Criteria. U.S. Environmental Protection Agency, Office of Water,
Washington, DC https://www.epa.gov/wqc/human-health-water-quality-criteria.
---------------------------------------------------------------------------

    Several commenters supported EPA's use of RSCs to account for other
sources of pollutant exposure. Several others disagreed, arguing that
water quality criteria under the CWA cannot control or consider sources
of exposure other than from drinking water and eating fish and
shellfish, so human health criteria should not account for these
sources. Many of the commenters, in addition to criticizing the concept
of RSCs as overly-conservative, argued that EPA was double-counting
exposure to anadromous fish (which EPA considers marine in the national
dataset) by both including them in the FCR and using the pollutant-
specific RSCs that EPA pairs with an inland and nearshore-only

FCR in its 304(a) national recommended human health criteria.
Commenters argued that this is inconsistent with EPA's guidance, which
recommends that states adjust the RSC to reflect a greater proportion
of the RfD being attributed to water, fish and shellfish intake in
instances where the FCR includes freshwater, estuarine and all marine
fish consumption.\59\ For detailed responses to the comments, see EPA's
Response to Comment document in the docket for this rule.
---------------------------------------------------------------------------

    \59\ USEPA. January 2013. Human Health Ambient Water Quality
Criteria and Fish Consumption Rates: Frequently Asked Questions.
https://www.epa.gov/wqc/human-health-ambient-water-quality-criteria-and-fish-consumption-rates-frequently-asked.
---------------------------------------------------------------------------

    Additionally, after further evaluation of the proposed revised
human health criteria for antimony, EPA determined that the existing
304(a) national recommended criteria for antimony (last updated in
2002) use a pollutant-specific RSC of 0.4. EPA intended to apply a 0.2
RSC as a protective approach only where pollutant-specific RSCs were
not already developed, which is not the case for antimony.\60\
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    \60\ http://nepis.epa.gov/Exe/ZyPDF.cgi?Dockey=20003IEI.txt See
also: National Primary Drinking Water Regulations-Synthetic Organic
Chemicals and Inorganic Chemicals; National Primary Drinking Water
Regulations Implementation, 57 FR 31776, July 17, 1992.
---------------------------------------------------------------------------

    While the selected FCR of 175 g/day does not include all marine
fish (e.g., it does not include consumption of species such as
swordfish, tuna, etc.), EPA acknowledges that the criteria as proposed
may have double-counted potential exposure to some pollutants in
certain marine fish that are anadromous (e.g., salmon). Therefore, EPA
reviewed the RSCs in the proposed rule in light of EPA's guidance,
which includes both the Exposure Decision Tree and associated
discussion in EPA's 2000 Methodology, as well as EPA's recommendation
to adjust the RSC when the FCR includes freshwater, estuarine, and all
marine fish consumption. Arguably, EPA's guidance does not consider
this exact scenario where the selected FCR includes some, but not all,
species that EPA classifies as marine in the national NHANES dataset
(and excludes some species that EPA classifies as nearshore in the
national NHANES dataset, i.e., shellfish).
    One way to adjust the RSC values to account for inclusion of marine
fish in the FCR is to examine the ratio of the national data
characterizing all fish consumption rates versus inland and nearshore-
only fish consumption rates derived from the NHANES dataset, and apply
this ratio to the proportion of the RfD reserved for inland and
nearshore fish consumption in the RSC. This approach assumes that the
pollutant concentrations in anadromous fish are the same as the
pollutant concentrations in inland and nearshore fish, which is the
same assumption inherent in including multiple fish categories in the
FCR for criteria calculation. This approach further assumes that the
ratio of all fish to inland and nearshore fish from NHANES data
approximates the ratio of inland, nearshore, and anadromous fish to
just inland and nearshore fish from CRITFC data. At the 90th percentile
rate of consumption, the national adult consumption rate from NHANES
data for all fish is 53 g/day and 22 g/day for inland and nearshore-
only fish, or a ratio of 2.4. Applying this to a RSC of 0.2 yields
0.48, or 0.5 rounding to a single decimal place. Because the selected
FCR includes some but not all marine species, EPA decided to use this
approach to adjust the RSC values. However, EPA only adjusted RSC
values to 0.5 for criteria calculations previously using a RSC between
0.2 and 0.5.
    There are important considerations in assigning a RSC, such as the
total number of potential exposure routes from sources other than fish
consumption, which compels caution in using this approach in all cases.
As such, EPA decided to retain RSC values of 0.5 and above, recognizing
the compelling need to account for the other potential exposure
sources, including marine fish not accounted for in the FCR of 175 g/
day, consistent with the logic and procedures used in establishing the
national 304(a) criteria recommendations. The Exposure Decision Tree in
EPA's 2000 Methodology only recommends using a RSC above 0.5 when there
are no significant known or potential uses/sources other than the
source of concern (Box 7, Figure 4-1 in EPA's 2000 Methodology) or
there are sufficient data available on each source to characterize the
exposure to those sources (Box 8C, Figure 4-1). Neither of these
conditions are met for most of the pollutants in the final rule for
Washington. EPA is not adjusting the RSCs for pollutants that already
have national recommended RSCs greater than or equal to 0.5 (2-
Chloronaphthalene (0.8), Endrin (0.8), gamma-BHC/Lindane (0.5), and
methylmercury (2.7 x 10-5 subtracted from the RfD, which
equates to a RSC of approximately 0.73). See Table 1, column B2 for a
list of EPA's final RSCs by pollutant.
d. Body Weight
    EPA calculates final human health criteria for Washington using a
body weight of 80 kg, which represents the average weight of a U.S.
adult and is consistent with EPA's 2015 updated national default body
weight (see section II.C.c).\61\ Local tribal survey data relevant to
Washington are also consistent with EPA's national adult body weight of
80 kg.\62\ Most commenters were silent on EPA's proposal to use a body
weight of 80 kg to calculate human health criteria for Washington. A
few commenters were concerned that 80 kg would not ensure adequate
protection of women and children, and may not be representative of all
residents in Washington based on limited local or regional data on body
weight specific to Washington residents. EPA understands these
concerns, but decided that the survey on which EPA's national default
of 80 kg is based provides the most comprehensive dataset to establish
a body weight value for deriving statewide human health criteria for
Washington, and is consistent with the local tribal survey data
mentioned above. The data cited by commenters do not provide sufficient
evidence to come up with an alternative statewide body weight input
parameter since the studies cited are limited in scope and pertain to
specific subpopulations. For detailed responses to the comments, see
EPA's Response to Comment document in the docket for this rule.
---------------------------------------------------------------------------

    \61\ Final Updated Ambient Water Quality Criteria for the
Protection of Human Health, (80 FR 36986, June 29, 2015). See also:
USEPA. 2015. Final 2015 Updated National Recommended Human Health
Criteria. U.S. Environmental Protection Agency, Office of Water,
Washington, DC https://www.epa.gov/wqc/human-health-water-quality-criteria.
    \62\ USEPA Region 10. August 2007. Framework for Selecting and
Using Tribal Fish and Shellfish Consumption Rates for Risk-Based
Decision Making at CERCLA and RCRA Cleanup Sites in Puget Sound and
the Strait of Georgia. Appendix B. http://yosemite.epa.gov/r10/
CLEANUP.NSF/7780249be8f251538825650f0070bd8b/
e12918970debc8e488256da6005c428e/$FILE/
Tribal%20Shellfish%20Framework.pdf.
---------------------------------------------------------------------------

e. Drinking Water Intake
    EPA calculates final human health criteria for Washington using a
drinking water intake rate of 2.4 L/day, consistent with EPA's 2015
updated national default drinking water intake rate (see section
II.C.c).\63\ Most commenters were

silent on or agreed with EPA's proposal to use a drinking water intake
rate of 2.4 L/day to calculate human health criteria for Washington.
However, two commenters stated this input was unnecessary in human
health criteria derivation. Since at least the 1980s, EPA has included
the drinking water exposure pathway in the development of human health
criteria in order to protect water bodies with a drinking water
designated use. EPA also provides the option of using organism-only
human health criteria for water bodies where there is no drinking water
use. One commenter stated that 2.4 L/day was an underestimate, and
expressed concern that this value is not protective of tribal members
who consume more water. EPA determined that it is appropriate to use
its 2015 final national default drinking water intake rate, since it
was adjusted pursuant to public comments after EPA issued the draft
national default rate of 3 L/day in 2014. EPA acknowledges the concerns
about members of the target general population who may consume larger
amounts of water, but EPA does not have data (and did not receive any
during the public comment period) with which to calculate a Washington-
specific drinking water intake rate. For detailed responses to the
comments, see EPA's Response to Comment document in the docket for this
rule.
---------------------------------------------------------------------------

    \63\ Final Updated Ambient Water Quality Criteria for the
Protection of Human Health, (80 FR 36986, June 29, 2015). See also:
USEPA. 2015. Final 2015 Updated National Recommended Human Health
Criteria. U.S. Environmental Protection Agency, Office of Water,
Washington, DC https://www.epa.gov/wqc/human-health-water-quality-criteria.
---------------------------------------------------------------------------

f. Pollutant-Specific Reference Doses and Cancer Slope Factors
    As part of EPA's 2015 updates to its 304(a) recommended human
health criteria, EPA conducted a systematic search of eight peer-
reviewed, publicly available sources to obtain the most current
toxicity values for each pollutant (RfDs for non-carcinogenic effects
and CSFs for carcinogenic effects).\64\ EPA calculates final human
health criteria for Washington using the same toxicity values that EPA
used in its 2015 304(a) criteria updates, to ensure that the resulting
criteria are based on a sound scientific rationale. Where EPA did not
update criteria for certain pollutants in 2015 and those pollutants are
included in this final rule, EPA uses the toxicity values that the
Agency used the last time it updated its 304(a) criteria for those
pollutants as the best available scientific information. See Table 1,
columns B1 and B3 for a list of EPA's final toxicity factors by
pollutant.
---------------------------------------------------------------------------

    \64\ Final Updated Ambient Water Quality Criteria for the
Protection of Human Health, (80 FR 36986, June 29, 2015). See also:
USEPA. 2015. Final 2015 Updated National Recommended Human Health
Criteria. U.S. Environmental Protection Agency, Office of Water,
Washington, DC https://www.epa.gov/wqc/human-health-water-quality-criteria.
---------------------------------------------------------------------------

    In general, commenters were supportive of EPA using the latest and
most scientifically defensible toxicity values to derive human health
criteria for Washington. Some commenters expressed concern that where
EPA did not update its 304(a) national recommended human health
criteria for particular pollutants in 2015, the toxicity values from
the existing 304(a) criteria for those pollutants were no longer valid.
In particular, those commenters expressed concern about the CSFs for
arsenic and PCBs, and the RfD for methylmercury, and argued that EPA
should not revise Washington's criteria for those pollutants until
toxicity factors are updated in the future. Unlike the situation with
the toxicity factors for arsenic, dioxin and thallium (see section
III.A), there is not sufficient scientific uncertainty surrounding the
CSF for PCBs or the RfD for methylmercury to warrant delaying revision
to Washington's human health criteria for these pollutants. For
detailed responses to the comments, see EPA's Response to Comment
document in the docket for this rule.
g. Pollutant-Specific Bioaccumulation Factors
    For the 2015 national 304(a) human health criteria update, EPA
estimated chemical-specific BAFs using a framework for deriving
national BAFs described in EPA's 2000 Methodology.\65\ Because the
surveyed population upon which the 175 g/day FCR is based consumed
almost exclusively trophic level four fish (i.e., predator fish
species), EPA uses the trophic level four BAF from the 2015 304(a)
human health criteria updates in conjunction with the 175 g/day FCR, in
order to derive protective criteria.\66\ Where in 2015, EPA estimated
BAFs from laboratory-measured BCFs and therefore derived a single
pollutant-specific BAF for all trophic levels, EPA uses those single
BAFs from the 2015 304(a) human health criteria updates. Where EPA's
existing 304(a) recommended human health criteria for certain
pollutants still incorporate a BCF, and those pollutants are included
in this final rule, EPA uses those BCFs as the best available
scientific information. See Table 1, columns B4 and B5 for a list of
EPA's final bioaccumulation factors by pollutant.
---------------------------------------------------------------------------

    \65\ USEPA. 2000. Methodology for Deriving Ambient Water Quality
Criteria for the Protection of Human Health. U.S. Environmental
Protection Agency, Office of Water, Washington, DC EPA-822-B-00-004.
https://www.epa.gov/wqc/human-health-water-quality-criteria.
    \66\ Fish Consumption Survey of the Umatilla, Nez Perce, Yakama,
and Warm Springs Tribes of the Columbia River Basin (Columbia River
Inter-Tribal Fish Commission (CRITFC), 1994)
---------------------------------------------------------------------------

    Many commenters supported EPA's choice to use the latest and most
scientifically defensible BAFs to derive human health criteria for
Washington, and to use BCFs only when BAFs were not available for a
given pollutant. Other commenters asserted that BCFs are no less
scientifically defensible than BAFs, and that EPA did not provide
sufficient information regarding how it developed BAFs in 2015 for
commenters to fully evaluate EPA's proposed approach.
    EPA's 2000 Methodology recommends use of BAFs that account for
uptake of a contaminant from all sources by fish and shellfish, rather
than BCFs that only account for uptake from the water column. EPA's
2015 national recommended BAFs are based on peer-reviewed, publicly
available data and were developed consistent with EPA's 2000
Methodology and its supporting documents. EPA provided the basis for
its 2015 BAFs in individual pollutant-specific criteria documents. The
final human health criteria for Washington are consistent with EPA's
2000 Methodology, which makes clear that BAFs are a more scientifically
defensible representation of bioaccumulation than BCFs. For detailed
responses to the comments, see EPA's Response to Comment document in
the docket for this rule.

D. Final Human Health Criteria for Washington

    EPA finalizes 144 human health criteria for 74 different pollutants
(72 organism-only criteria and 72 water-plus-organism criteria) to
protect the applicable designated uses of Washington's waters (see
Table 1). The water-plus-organism criteria in column C1 and the
methylmercury criterion in column C2 of Table 1 are the applicable
criteria for any waters that include the Domestic Water (domestic water
supply) use defined in Washington's WQS (WAC 173-201A-600). The
organism-only criteria in column C2 of Table 1 apply to waters that do
not include the Domestic Water (domestic water supply) use and that
Washington defines at WAC 173-201A-600 and 173-201A-610 as the
following: Fresh waters--Harvesting (fish harvesting), and Recreational
Uses; Marine waters--Shellfish Harvesting (shellfish--clam, oyster, and
mussel--harvesting), Harvesting (salmonid and other fish

harvesting, and crustacean and other shellfish--crabs, shrimp,
scallops, etc.--harvesting), and Recreational Uses.

                                                      Table 1--Human Health Criteria for Washington
--------------------------------------------------------------------------------------------------------------------------------------------------------
                      A                                                              B                                                     C
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                               Cancer slope     Relative      Reference                           Bio-
                                                factor, CSF      source       dose, RfD   Bio-accumulation    concentration     Water &      Organisms
             Chemical                CAS No.     (per mg/    contribution,      (mg/        factor (L/kg      factor  (L/kg    organisms   only  ([mu]g/
                                               kg[middot]d)     RSC (-)     kg[middot]d)       tissue)           tissue)       ([mu]g/L)        L)
                                    .........          (B1)          (B2)           (B3)              (B4)              (B5)        (C1)            (C2)
--------------------------------------------------------------------------------------------------------------------------------------------------------
1. 1,1,1-4Trichloroethane.........      71556  ............          0.50              2                10  ................      20,000          50,000
2. 1,1,2,2-Tetrachloroethane......      79345           0.2             -   ............               8.4  ................         0.1             0.3
3. 1,1,2-Trichloroethane..........      79005         0.057             -   ............               8.9  ................        0.35            0.90
4. 1,1-Dichloroethylene...........      75354  ............          0.50           0.05               2.6  ................         700           4,000
5. 1,2,4-Trichlorobenzene.........     120821         0.029             -   ............               430  ................       0.036           0.037
6. 1,2-Dichlorobenzene............      95501  ............          0.50            0.3                82  ................         700             800
7. 1,2-Dichloroethane.............     107062        0.0033             -   ............               1.9  ................         8.9              73
8. 1,2-Dichloropropane............      78875  ............             -   ............  ................  ................  ..........  ..............
9. 1,2-Diphenylhydrazine..........     122667           0.8             -   ............                27  ................        0.01            0.02
10. 1,2-Trans-Dichloroethylene....     156605  ............          0.50           0.02               4.7  ................         200           1,000
11. 1,3-Dichlorobenzene...........     541731  ............          0.50          0.002               190  ................           2               2
12. 1,3-Dichloropropene...........     542756         0.122             -   ............               3.0  ................        0.22             1.2
13. 1,4-Dichlorobenzene...........     106467  ............          0.50           0.07                84  ................         200             200
14. 2,3,7,8-TCDD (Dioxin) **......    1746016       156,000             -   ............  ................             5,000     1.3E-08         1.4E-08
15. 2,4,6-Trichlorophenol.........      88062  ............             -   ............  ................  ................  ..........  ..............
16. 2,4-Dichlorophenol............     120832  ............          0.50          0.003                48  ................          10              10
17. 2,4-Dimethylphenol............     105679  ............             -   ............  ................  ................  ..........  ..............
18. 2,4-Dinitrophenol.............      51285  ............          0.50          0.002               4.4  ................          30             100
19. 2,4-Dinitrotoluene............     121142  ............             -   ............  ................  ................  ..........  ..............
20. 2-Chloronaphthalene...........      91587  ............          0.80           0.08               240  ................         100             100
21. 2-Chlorophenol................      95578  ............             -   ............  ................  ................  ..........  ..............
22. 2-Methyl-4,6-Dinitrophenol....     534521  ............          0.50         0.0003                10  ................           3               7
23. 3,3'-Dichlorobenzidine........      91941  ............             -   ............  ................  ................  ..........  ..............
24. 3-Methyl-4-Chlorophenol.......      59507  ............             -   ............  ................  ................  ..........  ..............
25. 4,4'-DDD......................      72548          0.24             -   ............           240,000  ................     7.9E-06         7.9E-06
26. 4,4'-DDE......................      72559         0.167             -   ............         3,100,000  ................     8.8E-07         8.8E-07
27. 4,4'-DDT......................      50293          0.34             -   ............         1,100,000  ................     1.2E-06         1.2E-06
28. Acenaphthene..................      83329  ............          0.50           0.06               510  ................          30              30
29. Acrolein......................     107028  ............             -   ............  ................  ................  ..........  ..............
30. Acrylonitrile.................     107131  ............             -   ............  ................  ................  ..........  ..............
31. Aldrin........................     309002            17             -   ............           650,000  ................     4.1E-08         4.1E-08
32. alpha-BHC.....................     319846           6.3             -   ............             1,500  ................     4.8E-05         4.8E-05
33. alpha-Endosulfan..............     959988  ............          0.50          0.006               200  ................           6               7
34. Anthracene....................     120127  ............          0.50            0.3               610  ................         100             100
35. Antimony......................    7440360  ............          0.50         0.0004  ................                 1           6              90
36. Arsenic **....................    7440382          1.75             -   ............  ................                44   \a\ 0.018        \a\ 0.14
37. Asbestos......................    1332214  ............             -   ............  ................  ................  ..........  ..............
38. Benzene.......................      71432  ............             -   ............  ................  ................  ..........  ..............
39. Benzidine.....................      92875  ............             -   ............  ................  ................  ..........  ..............
40. Benzo(a) Anthracene...........      56553          0.73             -   ............             3,900  ................     0.00016         0.00016
41. Benzo(a) Pyrene...............      50328           7.3             -   ............             3,900  ................     1.6E-05         1.6E-05
42. Benzo(b) Fluoranthene.........     205992          0.73             -   ............             3,900  ................     0.00016         0.00016
43. Benzo(k) Fluoranthene.........     207089         0.073             -   ............             3,900  ................      0.0016          0.0016
44. beta-BHC......................     319857           1.8             -   ............               180  ................      0.0013          0.0014
45. beta-Endosulfan...............   33213659  ............             -   ............  ................  ................  ..........  ..............
46. Bis(2-Chloroethyl) Ether......     111444  ............             -   ............  ................  ................  ..........  ..............
47. Bis(2-Chloro-1-Methylethyl)        108601  ............          0.50           0.04                10  ................         400             900
 Ether *..........................
48. Bis(2-Ethylhexyl) Phthalate...     117817         0.014             -   ............               710  ................       0.045           0.046
49. Bromoform.....................      75252        0.0045             -   ............               8.5  ................         4.6              12
50. Butylbenzyl Phthalate.........      85687        0.0019             -   ............            19,000  ................       0.013           0.013
51. Carbon Tetrachloride..........      56235  ............             -   ............  ................  ................  ..........  ..............
52. Chlordane.....................      57749          0.35             -   ............            60,000  ................     2.2E-05         2.2E-05
53. Chlorobenzene.................     108907  ............          0.50           0.02                22  ................         100             200
54. Chlorodibromomethane..........     124481          0.04             -   ............               5.3  ................        0.60             2.2
55. Chloroform....................      67663  ............          0.50           0.01               3.8  ................         100             600
56. Chrysene......................     218019        0.0073             -   ............             3,900  ................       0.016           0.016
57. Copper........................    7440508  ............             -   ............  ................  ................  ..........  ..............
58. Cyanide.......................      57125  ............          0.50         0.0006  ................                 1           9             100
59. Dibenzo(a,h) Anthracene.......      53703           7.3             -   ............             3,900  ................     1.6E-05         1.6E-05
60. Dichlorobromomethane..........      75274         0.034             -   ............               4.8  ................        0.73             2.8
61. Dieldrin......................      60571            16             -   ............           410,000  ................     7.0E-08         7.0E-08
62. Diethyl Phthalate.............      84662  ............          0.50            0.8               920  ................         200             200
63. Dimethyl Phthalate............     131113  ............          0.50             10             4,000  ................         600             600
64. Di-n-Butyl Phthalate..........      84742  ............          0.50            0.1             2,900  ................           8               8
65. Endosulfan Sulfate............    1031078  ............          0.50          0.006               140  ................           9  ..............
66. Endrin........................      72208  ............          0.80         0.0003            46,000  ................       0.002           0.002
67. Endrin Aldehyde...............    7421934  ............             -   ............  ................  ................  ..........  ..............
68. Ethylbenzene..................     100414  ............          0.50          0.022               160  ................          29              31
69. Fluoranthene..................     206440  ............          0.50           0.04             1,500  ................           6               6
70. Fluorene......................      86737  ............          0.50           0.04               710  ................          10              10
71. gamma-BHC; Lindane............      58899  ............          0.50         0.0047             2,500  ................        0.43            0.43

72. Heptachlor....................      76448           4.1             -   ............           330,000  ................     3.4E-07         3.4E-07
73. Heptachlor Epoxide............    1024573           5.5             -   ............            35,000  ................     2.4E-06         2.4E-06
74. Hexachlorobenzene.............     118741          1.02             -   ............            90,000  ................     5.0E-06         5.0E-06
75. Hexachlorobutadiene...........      87683          0.04             -   ............             1,100  ................        0.01            0.01
76. Hexachlorocyclopentadiene.....      77474  ............          0.50          0.006             1,300  ................           1               1
77. Hexachloroethane..............      67721          0.04             -   ............               600  ................        0.02            0.02
78. Indeno(1,2,3-cd) Pyrene.......     193395          0.73             -   ............             3,900  ................     0.00016         0.00016
79. Isophorone....................      78591  ............             -   ............  ................  ................  ..........  ..............
80. Methyl Bromide................      74839  ............          0.50           0.02               1.4  ................         300  ..............
81. Methylene Chloride............      75092         0.002             -   ............               1.6  ................          10             100
82. Methylmercury.................   22967926  ............       2.7E-05         0.0001  ................  ................  ..........   \b\ 0.03 (mg/
                                                                                kg)
83. Nickel........................    7440020  ............          0.50           0.02  ................                47          80             100
84. Nitrobenzene..................      98953  ............          0.50          0.002               3.1  ................          30             100
85. N-Nitrosodimethylamine........      62759  ............             -   ............  ................  ................  ..........  ..............
86. N-Nitrosodi-n-Propylamine.....     621647  ............             -   ............  ................  ................  ..........  ..............
87. N-Nitrosodiphenylamine........      86306  ............             -   ............  ................  ................  ..........  ..............
88. Pentachlorophenol (PCP).......      87865           0.4             -   ............               520  ................       0.002           0.002
89. Phenol........................     108952  ............          0.50            0.6               1.9  ................       9,000          70,000
90. Polychlorinated Biphenyls       .........             2             -   ............  ................            31,200   \c\ 7E-06       \c\ 7E-06
 (PCBs)...........................
91. Pyrene........................     129000  ............          0.50           0.03               860  ................           8               8
92. Selenium......................    7782492  ............          0.50          0.005  ................               4.8          60             200
93. Tetrachloroethylene...........     127184        0.0021             -   ............                76  ................         2.4             2.9
94. Thallium **...................    7440280  ............             -       0.000068  ................               116         1.7             6.3
95. Toluene.......................     108883  ............          0.50         0.0097                17  ................          72             130
96. Toxaphene.....................    8001352  ............             -   ............  ................  ................  ..........  ..............
97. Trichloroethylene.............      79016          0.05             -   ............                13  ................         0.3             0.7
98. Vinyl Chloride................      75014           1.5             -   ............               1.7  ................  ..........            0.18
99. Zinc..........................    7440666  ............          0.50            0.3  ................                47       1,000           1,000
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ This criterion refers to the inorganic form of arsenic only.
\b\ This criterion is expressed as the fish tissue concentration of methylmercury (mg methylmercury/kg fish). See Water Quality Criterion for the
  Protection of Human Health: Methylmercury (EPA-823-R-01-001, January 3, 2001) for how this value is calculated using the criterion equation in EPA's
  2000 Human Health Methodology rearranged to solve for a protective concentration in fish tissue rather than in water.
\c\ This criterion applies to total PCBs (e.g., the sum of all congener or isomer or homolog or Aroclor analyses).
* Bis(2-Chloro-1-Methylethyl) Ether was previously listed as Bis(2-Chloroisopropyl) Ether.
** These criteria were promulgated for Washington in the National Toxics Rule at 40 CFR 131.36, and are moved into 40 CFR 131.45 to have one
  comprehensive human health criteria rule for Washington.

E. Applicability of Criteria

    These new and revised human health criteria apply for CWA purposes
in addition to any existing criteria already applicable to Washington's
waters, including the state's narrative toxics criteria statement at
WAC 173-201A-260(2)(a), and those human health criteria that Washington
submitted on August 1, 2016, and EPA approved concurrent with this
final rule.
    EPA replicates in 40 CFR 131.45 the same general rules of
applicability for human health criteria as in 40 CFR 131.36(c), with
one exception. For waters suitable for the establishment of low flow
return frequencies (i.e., streams and rivers), this final rule provides
that Washington must not use a low flow value below which numeric
standards can be exceeded that is less stringent than the harmonic mean
flow (a long-term mean flow value calculated by dividing the number of
daily flows analyzed by the sum of the reciprocals of those daily
flows), so that the criteria are implemented to be protective of the
applicable designated use. Per the Revisions to the Methodology for
Deriving Ambient Water Quality Criteria for the Protection of Human
Health (65 FR 66444, November 3, 2000), EPA now recommends harmonic
mean flow be used to implement human health criteria for both
carcinogens and non-carcinogens.\67\ EPA received one comment on this
provision, asking for clarification on whether this is consistent with
Washington's current permitting approach of using the 30Q5 flow for
non-carcinogens.\68\ In response, Washington's use of low flow
statistics more stringent than the harmonic mean flow is consistent
with EPA's final rule.
---------------------------------------------------------------------------

    \67\ See also USEPA. 2014. Water Quality Standards Handbook--
Chapter 5: General Policies. U.S. Environmental Protection Agency.
Office of Water. Washington, DC EPA-820-B-14-004. https://www.epa.gov/wqs-tech/water-quality-standards-handbook.
    \68\ The 30Q5 flow is the lowest 30-day average flow event
expected to occur once every five years, on average (determined
hydrologically).
---------------------------------------------------------------------------

    Under the CWA, Congress gave states primary responsibility for
developing and adopting WQS for their navigable waters (CWA section
303(a)-(c)). Although EPA revises and establishes new human health
criteria for Washington in this final rule, Washington continues to
have the option to adopt and submit to EPA human health criteria for
the pollutants in this final rule, consistent with CWA section 303(c)
and EPA's implementing regulations at 40 CFR part 131.
    In its September 14, 2015 proposed rule, EPA proposed that if
Washington adopted and submitted human health criteria, and EPA
approved those criteria before finalizing its federal rule, EPA would
not proceed with finalizing those criteria and Washington's approved
criteria would be solely applicable for CWA purposes. EPA did not
receive any comments opposing this provision, thus EPA is proceeding
with such an approach. In this final rule, EPA is withdrawing
Washington from the NTR at 40 CFR 131.36, and, with the exception of
criteria for which EPA has approved Washington's criteria, EPA is
incorporating the Washington-specific criteria in this rule (as well as
the existing NTR criteria for arsenic, dioxin

and thallium) into 40 CFR 131.45 so there is a single comprehensive set
of federally promulgated criteria for Washington. Therefore, the CWA-
effective numeric human health criteria in Washington consist of the
federally promulgated criteria at 40 CFR 131.45 and those criteria that
EPA approved at WAC 173-201A-240 in Washington's August 1, 2016
submittal.
    Additionally, in its September 14, 2015 proposed rule, EPA proposed
that if Washington adopted and submitted human health criteria after
EPA finalized its rule, once EPA approved Washington's WQS, the
pollutant-specific or site-specific EPA-approved criteria in
Washington's WQS would become the solely effective criteria for CWA
purposes and EPA's promulgated criteria for those pollutants or for
that site would no longer apply. A few commenters supported this
provision, where Washington's criteria for specific pollutants or sites
become the only CWA-effective criteria upon EPA's approval, without any
delay caused by EPA's withdrawal of the corresponding federal criteria.
A few other commenters did not support this provision, and asked that
EPA either delete the provision, or make clear that criteria adopted by
the state would have to be at least as stringent as the federal
criteria for EPA to approve and make the state criteria effective for