[Federal Register Volume 86, Number 52 (Friday, March 19, 2021)]
[Rules and Regulations]
[Pages 14834-14846]
[FR Doc No: 2021-05428]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 131

[EPA-HQ-OW-2016-0694; FRL-10019-00-OW]
RIN 2040-AF70

Federal Aluminum Aquatic Life Criteria Applicable to Oregon

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: The Environmental Protection Agency (EPA or Agency) is
promulgating Federal criteria for fresh waters in the State of Oregon
that are jurisdictional under the Clean Water Act (CWA) to protect
aquatic life from the effects of exposure to harmful levels of
aluminum. EPA disapproved of Oregon's freshwater acute and chronic
aluminum criteria in 2013. The CWA directs EPA to promptly propose
water quality standards (WQS) addressing the Agency's disapproval and
to promulgate those WQS unless, prior to such promulgation, the state
adopts WQS addressing EPA's disapproval that the Agency determines meet
the requirements of the CWA and EPA approves. Since Oregon has not
adopted and submitted revised freshwater acute and chronic aluminum
criteria to address EPA's 2013 disapproval, EPA is promulgating Federal
freshwater acute and chronic aluminum criteria to protect aquatic life
uses in Oregon as the applicable WQS under the CWA. If, at some point
in the future, Oregon submits and EPA approves revised freshwater acute
and chronic aluminum criteria to address EPA's 2013 disapproval, EPA
would withdraw this regulation.

DATES: This rule is effective on April 19, 2021. The incorporation by
reference of certain publications listed in the rule is approved by the
Director of the Federal Register as of April 19, 2021.

ADDRESSES: EPA has established a docket for this action under Docket ID
No. EPA-HQ-OW-2016-0694. All documents in the docket are listed on the
http://www.regulations.gov website. Although listed in the index, some
information is not publicly available, e.g., confidential business
information (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: Mimi Soo-Hoo, 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 Authority
    B. EPA's Disapproval of Oregon's Freshwater Aluminum Criteria
    C. General Recommended Approach for Deriving Aquatic Life
Criteria
III. Freshwater Aluminum Aquatic Life Criteria
    A. EPA's National CWA Section 304(a) Recommended Freshwater
Aluminum Criteria
    B. Final Acute and Chronic Aluminum Criteria for Oregon's Fresh
Waters
    C. Implementation of Final Freshwater Acute and Chronic Aluminum
Criteria in Oregon
    D. Incorporation by Reference
IV. Critical Low Flows and Mixing Zones
V. Endangered Species Act
VI. Under what conditions would Federal standards be withdrawn?
VII. Alternative Regulatory Approaches and Implementation Mechanisms
    A. Designating Uses
    B. WQS Variances
    C. NPDES Permit Compliance Schedules
VIII. Economic Analysis
IX. Statutory and Executive Order Reviews
    A. Executive Order 12866 (Regulatory Planning and Review) and
Executive Order 13563 (Improving Regulation and Regulatory Review)
    B. Executive Order 13771 (Reducing Regulations and Controlling
Regulatory Costs)
    C. Paperwork Reduction Act
    D. Regulatory Flexibility Act
    E. Unfunded Mandates Reform Act
    F. Executive Order 13132 (Federalism)
    G. Executive Order 13175 (Consultation and Coordination With
Indian Tribal Governments)
    H. Executive Order 13045 (Protection of Children From
Environmental Health and Safety Risks)
    I. Executive Order 13211 (Actions That Significantly Affect
Energy Supply, Distribution, or Use)
    J. National Technology Transfer and Advancement Act of 1995
    K. Executive Order 12898 (Federal Actions To Address
Environmental Justice in Minority Populations and Low-Income
Populations)
    L. Congressional Review Act (CRA)

I. General Information

A. Does this action apply to me?

    Entities such as industrial facilities, stormwater management
districts, or publicly owned treatment works (POTWs) that discharge
pollutants to fresh waters of the United States under the State of
Oregon's jurisdiction could be affected by this rule because Federal
WQS promulgated by EPA in this rule will be the applicable WQS for
fresh waters in Oregon for CWA purposes after the effective date of
this rule. These WQS are the minimum standards which must be used in
such CWA regulatory programs as National Pollutant Discharge
Elimination System (NPDES) permitting \1\ and identifying impaired
waters under CWA Section 303(d). Categories and entities that could
potentially be affected by this rule include the following:
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    \1\ Before any water quality based effluent limit is included in
an NPDES permit, the permitting authority (here, the State of
Oregon), will first determine whether a discharge ``will cause or
has the reasonable potential to cause, or contribute to an excursion
above any WQS.'' 40 CFR 122.44(d)(1)(i) and (ii).

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           Category            Examples of potentially affected entities
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Industry.....................  Industrial point sources discharging
                                pollutants to fresh waters of the United
                                States in Oregon.
Municipalities...............  Publicly owned treatment works or similar
                                facilities discharging pollutants to
                                fresh waters of the United States in
                                Oregon.
Stormwater Management          Entities responsible for managing
 Districts.                     stormwater in the State of Oregon.
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    This table is not intended to be exhaustive, but rather provides a
guide for readers regarding entities that could ultimately be affected
by this action. Any parties or entities who depend upon or contribute
to the water quality

of Oregon's fresh waters could be affected by this rule. To determine
whether your facility or activities could be 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?

    EPA carefully considered the public comments and feedback received
from interested parties on the proposal published in the Federal
Register at 84 FR 18454 on May 1, 2019. EPA provided a 45-day public
comment period and held two public hearings on June 11 and June 12,
2019, to provide clarification on the contents of the proposed
rulemaking and to accept verbal public comments.
    A total of eight organizations and individuals submitted comments
either to the docket or during the public hearings on a range of issues
prior to the close of the public comment period on June 17, 2019. Some
comments addressed issues beyond the scope of this rule. Brief
summaries of specific comments and EPA's responses are provided in this
action. For a full accounting of the comments and the Agency's
responses, see EPA's Response to Comments document in the official
public docket for this rule.

II. Background

A. Statutory and Regulatory Authority

    CWA Section 303(c) (33 U.S.C. 1313(c)) directs states to adopt WQS
for state waters subject to CWA jurisdiction. CWA Section 303(c)(2)(A)
provides that WQS shall consist of designated uses of the waters and
water quality criteria based on those uses. EPA's implementing
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 [and] [f]or
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 [s]tate shall take into consideration the water
quality standards of downstream waters and shall ensure that its water
quality standards provide for the attainment and maintenance of the
water quality standards of downstream waters.''
    States review applicable WQS at least once every three years and,
if appropriate, revise or adopt new WQS (CWA Section 303(c)(1); 40 CFR
131.20). Any new or revised WQS must be submitted to EPA for review and
approval or disapproval (CWA Sections 303(c)(2)(A) and (c)(3); 40 CFR
131.20 and 131.21). If EPA disapproves a state's new or revised WQS as
not consistent with CWA requirements, the state has 90 days to adopt a
revised WQS that adopts the changes specified by EPA to meet CWA
requirements. If the state fails to do so, EPA must promptly propose
and then, within 90 days, promulgate such WQS unless the state has
adopted a revised or new WQS that EPA determines to be consistent with
CWA requirements (CWA Sections 303(c)(3) and (c)(4)).
    Under CWA Section 304(a), EPA periodically publishes national
criteria recommendations for states to consider when adopting water
quality criteria for particular pollutants to meet the CWA Section
101(a)(2) goal. When EPA has published recommended criteria, states
should establish numeric water quality criteria based on the Agency's
CWA Section 304(a) recommended criteria, CWA Section 304(a) recommended
criteria modified to reflect site-specific conditions, or other
scientifically defensible methods (40 CFR 131.11(b)(1)). Water quality
criteria must protect the designated use and be based on sound
scientific rationale. For waters with multiple use designations, the
criteria shall support the most sensitive use (40 CFR 131.11(a)(1)).

B. EPA's Disapproval of Oregon's Freshwater Aluminum Criteria

    As explained in the preamble of the proposed rulemaking, EPA
disapproved the State's freshwater aluminum criteria in 2013 because
the State had not supplied a scientific rationale for the pH range
under which the State's criteria would apply, which differed from the
applicable pH range specified in EPA's 1998 national CWA Section 304(a)
recommended criteria for aluminum (84 FR 18456-57, May 1, 2019) that
existed at that time but have since been updated.
    Under the terms of a consent decree (as amended) to resolve
litigation in Northwest Environmental Advocates v. U.S. EPA, 3:15-cv-
00663-BR (D. Or. 2015), EPA is required, no later than six months after
the date on which the National Marine Fisheries Service (also known as
National Oceanic and Atmospheric Administration (NOAA) Fisheries)
issues its Biological Opinion on the aluminum criteria previously
proposed by EPA, to either approve aluminum criteria to protect aquatic
life in fresh waters submitted by Oregon or sign a notice for
publication in the Federal Register to finalize the aluminum criteria
EPA proposed for Oregon. NOAA Fisheries transmitted its Biological
Opinion to EPA on July 1, 2020. Since Oregon has not yet adopted
freshwater aluminum criteria to meet CWA requirements, EPA is
promulgating freshwater aluminum criteria for Oregon waters in
accordance with CWA Sections 303(c)(3) and (c)(4).

C. General Recommended Approach for Deriving Aquatic Life Criteria

    Under the Agency's CWA Section 304(a) authority, EPA develops
national recommended criteria and methodologies to protect aquatic life
and human health for specific pollutants and pollutant parameters. EPA
invites public comment on draft recommended criteria and methodologies
and seeks scientific expert review before EPA finalizes them as formal
national water quality criteria recommendations for states to consider
when developing and adopting applicable water quality criteria. EPA's
Guidelines for Deriving Numerical National Water Quality Criteria for
the Protection of Aquatic Organisms and Their Uses (referred to as the
``Aquatic Life Guidelines'') \2\ describe the systematic way in which
EPA establishes concentrations for a pollutant in water that will
support the aquatic life designated use.
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    \2\ USEPA. 1985. Guidelines for Deriving Numerical National
Water Quality Criteria for the Protection of Aquatic Organisms and
Their Uses. U.S. Environmental Protection Agency, Office of Research
and Development, Duluth, MN, Narragansett, RI, Corvallis, OR. PB85-
227049. https://www.epa.gov/sites/production/files/2016-02/documents/guidelines-water-quality-criteria.pdf.
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    Numeric criteria derived using EPA's Aquatic Life Guidelines are
expressed as acute and chronic values representing short-term and long-
term exposures, respectively. The combination of a criterion maximum
concentration (CMC), typically expressed as a one-hour average value,
and a criterion continuous concentration (CCC), typically specified as
a four-day average value, protects aquatic life from acute and chronic
toxicity, respectively. Neither value is to be exceeded more than once
in three years. An exceedance occurs when the average concentration
over the duration of the averaging period is above the CMC or the CCC.
EPA based its maximum exceedance frequency recommendation of once every
three years on the ability of aquatic ecosystems to recover from the
exceedances.
    The Aquatic Life Guidelines recommend reliance on toxicity test
data from a minimum of eight taxa of aquatic organisms in order to
derive

criteria. These taxa are intended to be representative of a wide
spectrum of aquatic life, such that the representative taxa serve as
surrogates for untested species. Therefore, the representative test
organism species do not need to be present in the water(s) where the
criteria will apply. A state is not precluded from relying on toxicity
data using resident species to develop site-specific criteria to apply
at a localized site. In developing site-specific criteria, EPA
recommends that the state maintain similar broad taxonomic
representation in calculating the site-specific criteria to ensure
protection of the most sensitive species at the site. If a state
chooses to carry out the ``deletion of data'' portion of the species
re-calculation process, the state should consider how to demonstrate
that the species included in the derivation of EPA's national
recommended criteria are not present and would not serve as surrogates
for other species that occur at the site.\3\
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    \3\ USEPA. 2013. Revised Deletion Process for the Site-Specific
Recalculation Procedure for Aquatic Life Criteria. U.S.
Environmental Protection Agency, Office of Water, Washington, DC.
EPA-823-R-13-001. https://www.epa.gov/sites/production/files/2015-08/documents/revised_deletion_process_for_the_site-specific_recalculation_procedure_for_aquatic_life_criteria.pdf.
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III. Freshwater Aluminum Aquatic Life Criteria

A. EPA's National CWA Section 304(a) Recommended Freshwater Aluminum
Criteria

    EPA's 2018 national CWA Section 304(a) recommended freshwater
aquatic life criteria for aluminum (Final Aquatic Life Ambient Water
Quality Criteria for Aluminum 2018, EPA 822-R-18-001, as cited in the
Federal Register at 83 FR 65663, December 21, 2018), referred to in
this action as the ``2018 national recommended criteria,'' were
developed following the Aquatic Life Guidelines. These recommended
criteria update and replace EPA's 1988 national CWA Section 304(a)
recommended freshwater aquatic life criteria for aluminum. The 2018
national recommended criteria apply to fresh waters and include a
calculator that takes into account three water chemistry
characteristics that affect aluminum toxicity. The 2018 national
recommended criteria reflect the latest scientific knowledge and
understanding of the interaction between water chemistry and aluminum
toxicity, and represent a scientifically defensible method upon which
EPA is basing this CWA action to establish WQS for fresh waters in
Oregon (83 FR 65663, December 21, 2018).
    The 2018 national recommended criteria are based upon Multiple
Linear Regression (MLR) models for fish and invertebrate species that
use site-specific pH, dissolved organic carbon (DOC), and total
hardness inputs to quantify the effects of these water chemistry
parameters on the toxicity of aluminum to aquatic organisms. The MLR
models normalize the available toxicity data to accurately reflect the
effects of the site-specific water chemistry (pH, DOC, total hardness)
on the toxicity of aluminum to tested species. The normalized toxicity
test data are then used in a criteria calculator to generate criteria
for specific ambient water chemistry conditions. The numeric outputs of
the 2018 national recommended criteria calculator for a given set of
conditions vary depending on the site-specific pH, DOC, and total
hardness entered into the calculator. The calculator outputs (CMC and
CCC) for a given set of input conditions are numeric values that would
be protective for that set of input conditions (i.e., water-chemistry-
condition-specific CMC and CCC outputs).
    Users of the 2018 national recommended criteria can generate
criteria magnitude values in two ways: (1) Use the lookup tables
provided in the criteria document to find the numeric aluminum CMC and
CCC most closely corresponding to the local conditions for pH, DOC, and
total hardness; or (2) use the provided Aluminum Criteria Calculator
V2.0 Excel spreadsheet to enter the pH, DOC, and total hardness
conditions at a specific site to calculate the numeric aluminum CMC and
CCC corresponding to the local input conditions.
    In its 2018 national recommended criteria, EPA expressed the
aluminum criteria as ``total recoverable'' metal concentrations. The
primary reason for the expression of the criteria as total recoverable
aluminum concentrations is because the laboratory toxicity tests used
in the effects assessment in the development of the aluminum criteria
reported the aluminum concentrations as total recoverable aluminum. The
use of total aluminum concentrations is justified for laboratory
toxicity test data where the total aluminum concentration is in either
a dissolved monomeric form or precipitated forms (e.g., aluminum
hydroxides) of aluminum. The laboratory dilution waters in tests used
for EPA's criteria development did not contain suspended solids, clays,
or particulate matter where aluminum could be bound. However, total
recoverable aluminum concentrations measured in natural waters may
overestimate the potential risks of toxicity to aquatic organisms if
suspended solids, clays, or particulate matter to which aluminum may be
bound are present, because total recoverable methods measure
bioavailable and non-bioavailable forms of aluminum.
    As discussed in Section 2.6.2 of EPA's 2018 national recommended
criteria document, the different forms of aluminum vary in toxicity.
The criteria document discusses differences between aluminum toxicity
in a controlled laboratory setting and the toxicity of aluminum in
natural waters that contain suspended particles, clays, and
aluminosilicate minerals not present in lab waters. Dissolved and
particulate (e.g., aluminum hydroxides) aluminum, as well as small
sized colloids containing aluminum, exhibit toxic effects on aquatic
life depending on the pH, DOC, and total hardness of the waters. Total
recoverable aluminum methods determine the total concentration of
monomeric (both organic and inorganic) forms of aluminum, polymeric and
colloidal forms, as well as particulate forms and aluminum sorbed to
clays present in a sample. Total recoverable methods use a strong acid
(pH <2) digestion step to prepare the sample for measurement. In
contrast, methods to determine dissolved concentrations of aluminum
involve filtering test samples prior to digestion, which excludes
particulate forms of aluminum from the test sample. Methods to
determine dissolved concentrations of aluminum, therefore, may
underestimate the toxicity of the aluminum in a sample if the
particulate forms including aluminum hydroxide precipitates that
contribute to toxicity are not measured. In conclusion, dissolved
aluminum measurements are not appropriate for comparison to the
aluminum criteria that EPA is promulgating for Oregon. EPA
acknowledges, as several commenters noted during the comment periods
for both EPA's 2017 draft national CWA Section 304(a) recommended
criteria for aluminum and EPA's proposed criteria for Oregon, that not
all forms of aluminum that may be present in ambient waters are
biologically available or ``bioavailable'' to aquatic species.
Bioavailable aluminum (or the bioavailable fraction of aluminum) is
defined as the amount of aluminum that is available to cause a
biological response in an aquatic organism. The best measures of
bioavailability involve interactions of aluminum with a membrane (e.g.,
aluminum binding to proteins of gill membranes), diffusion

through the cell membrane, and flocculation of precipitated aluminum on
the gill. Bioavailable aluminum is the toxicologically relevant
fraction of aluminum which results from a combination of dissolved and
precipitated aluminum, in contrast to mineralized (non-toxic) forms of
aluminum.\4\ The non-bioavailable fraction of aluminum includes large
suspended particles, clays, and aluminosilicate minerals.
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    \4\ Per Rodriguez et al. 2019: ``To properly characterize the Al
concentrations in the toxicity studies, a method was needed that
could discriminate bioavailable Al from mineral forms of Al. An
extraction method at pH 4 for bioavailable Al was developed and
evaluated using C. dubia chronic toxicity studies in the presence of
TSS. It is concluded that the proposed method is better able to
discriminate chronic toxicity effects attributable to bioavailable
Al from mineralized nontoxic forms of Al compared with existing
methods using total or total recoverable Al (i.e., extraction at pH
<= 1.5).''
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    EPA's 2018 national recommended criteria document (Section 2.6.2
from pp. 22-25) explains the science behind this understanding of
aluminum chemistry and toxicity in more detail. There is also relevant
discussion of aluminum chemistry (Section 2.2 from pp. 7-10) and mode
of action and toxicity (Section 2.3 from pp. 10-16) that help explain
the factors affecting bioavailability and toxicity.

B. Final Acute and Chronic Aluminum Criteria for Oregon's Fresh Waters

    EPA is promulgating aluminum criteria for Oregon that incorporate
by reference the calculation of CMC and CCC freshwater aluminum
criteria values for a site using the 2018 national recommended
criteria.\5\ Doing so means that the CMC and CCC freshwater aluminum
criteria values for a site shall be calculated using the 2018 Aluminum
Criteria Calculator V.2.0 (Aluminum Criteria Calculator V.2.0.xlsx) or
a calculator in R or other software package using the same 1985
Guidelines calculation procedure and underlying model equations as in
the Aluminum Criteria Calculator V.2.0 Excel spreadsheet, as
established in the 2018 national recommended criteria. Consistent with
the 2018 national recommended criteria, the final water quality
criteria for aluminum in Oregon fresh waters are expressed as the CMC
as a one-hour average total recoverable aluminum concentration (in
[micro]g/L) and the CCC as a four-day average total recoverable
aluminum concentration (in [micro]g/L). The CMC and CCC are not to be
exceeded more than once every three years.
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    \5\ USEPA. 2018. Final Aquatic Life Ambient Water Quality
Criteria for Aluminum. U.S. Environmental Protection Agency, Office
of Water, Washington, DC. EPA-822-R-18-001. https://www.epa.gov/sites/production/files/2018-12/documents/aluminum-final-national-recommended-awqc.pdf.
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    EPA is promulgating multiple footnotes to the criteria statement to
provide clarification on the criteria's intended application, and
highlights two in this paragraph. The first footnote specifies that to
apply the aluminum criteria for CWA purposes, criteria values based on
ambient water chemistry conditions must protect the water body over the
full range of water chemistry conditions, including during conditions
when aluminum is most toxic. The second footnote states that (1) these
criteria are based on aluminum toxicity studies where aluminum was
analyzed using total recoverable analytical methods; (2) Oregon may
utilize total recoverable analytical methods to implement the criteria;
(3) for characterizing ambient waters, Oregon may also utilize, as
scientifically appropriate and as allowable by State and Federal
regulations, analytical methods that measure the bioavailable fraction
of aluminum, as described above, (e.g., utilizing a less aggressive
initial acid digestion, such as to a pH of approximately 4 or lower,
that includes the measurement of amorphous aluminum hydroxide yet
minimizes the measurement of mineralized forms of aluminum such as
aluminum silicates associated with suspended sediment particles or
clays); and (4) Oregon shall use measurements of total recoverable
aluminum where required by Federal regulations.
    Commenters were generally supportive of EPA's proposal to base its
promulgation for Oregon on EPA's 2018 national recommended criteria for
aluminum. EPA acknowledged in the preamble to the proposal that the
Agency may consider future modifications to the criteria if warranted
based on, among other things, further public input, tribal
consultation, new data, or evaluations of listed species completed
during Endangered Species Act (ESA) consultation, or the results of ESA
consultation. On February 13, 2020 and July 1, 2020, EPA completed
consultation with the U.S. Fish and Wildlife Service (USFWS) and NOAA
Fisheries, respectively. After evaluating potential effects of the
Agency's action on federally-listed species during ESA Section 7(a)(2)
consultation with USFWS and NOAA Fisheries, in addition to
consideration of comments received during the public comment period
associated with the proposed rulemaking, EPA is promulgating aluminum
criteria consistent with the 2018 national recommended criteria.
    The 2018 national recommended criteria represent the latest
scientific knowledge on aluminum speciation, bioavailability, and
toxicity, and provide predictable and repeatable outcomes. Consistent
with the Aquatic Life Guidelines, the 2018 national recommended
criteria protect aquatic life for acute effects (survival and
immobility), as well as chronic effects (survival, growth, and
reproduction) at a level of 20% chronic Effects Concentration (EC20)
for the 95th percentile of sensitive genera. The docket for the 2018
national recommended criteria document contains detailed information on
the science underlying that recommendation (Docket ID: EPA-HQ-OW-2017-
0260).
Comments Regarding Total Recoverable Aluminum and Use of an Emerging
Analytical Method
    As mentioned above, commenters pointed out that, as EPA had
acknowledged in its 2018 national recommended criteria document, the
current test methods for total recoverable aluminum may, in some
waters, overestimate the amount of aluminum that will be toxic to
aquatic life in ambient waters in Oregon. Commenters suggested that in
order to better approximate the toxic fraction of aluminum, EPA should
allow use of an emerging analytical method that measures bioavailable
aluminum by using an initial digestion at pH 4. Commenters urged use of
such an analytical method to characterize aluminum concentrations in
ambient waters, particularly in waters with high levels of total
suspended solids suggesting the presence of colloidal, particulate, and
clay-bound aluminum. Some commenters requested that the final criteria
for Oregon be expressed as ``bioavailable or total recoverable''
aluminum to confirm availability for use of an alternative analytical
method.
    EPA acknowledges in the final rule that the promulgated criteria
are based on aluminum toxicity laboratory studies where aluminum was
analyzed using total recoverable analytical methods. However, EPA also
acknowledges that under natural conditions not all of these forms of
aluminum would be biologically available to aquatic species. All of the
approved total recoverable methods require that samples be preserved in
the field by acidifying to pH <2 and digested in the laboratory with
strong acid solution that dissolves the monomeric and polymeric forms
of aluminum, in addition to colloidal, particulate, and clay-bound
aluminum. Over the last three decades, the

scientific consensus has been that the total recoverable method for
aluminum potentially overestimates the biologically available fraction
and that a method that better addresses concerns with including
aluminum bound to particulate matter would be useful (e.g., He and
Ziemkiewics 2016; Ryan et al. 2019).\6\
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    \6\ He YT, Ziemkiewicz PF. 2016. Bias in determining aluminum
concentrations: Comparison of digestion methods and implications on
Al management. Chemosphere 159:570-576; Ryan AC, Santore RC,
Tobiason S, WoldeGabriel G, and Groffman AR. 2019. Total recoverable
aluminum: Not totally relevant for water quality standards.
Integrated Environmental Assessment and Management. 15(6): 974-987.
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    In an attempt to address concerns with measuring total recoverable
aluminum concentrations, researchers recently investigated new
analytical methods to measure biologically available forms of aluminum
(Rodriguez et al. 2019).\7\ This approach does not digest the sample at
pH of -0.05 to +0.7 but rather to pH 4 to better measure only the
bioavailable fraction of aluminum. Rodriguez et al. reported that
sodium acetate buffer is added to the sample to reach the desired pH,
followed by sample agitation for a specified period of time, and
finally 0.45-[micro]m sample filtration. The sample is then acidified
with nitric acid before inductively coupled plasma-optical emission
spectrometry analysis. These authors provided data that led them to
conclude that their proposed method is better able to discriminate
chronic toxicity effects attributable to bioavailable aluminum from
mineralized nontoxic forms of aluminum compared with existing methods
using total or total recoverable aluminum.
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    \7\ Rodriguez PH, Arbildua JJ, Villavicencio G, Urrestarazu P,
Opazo M, Cardwell AS, Stubblefield W, Nordheim E, Adams W. 2019.
Determination of bioavailable aluminum in natural waters in the
presence of suspended solids. Environmental Toxicology and
Chemistry. 38(8):1668-1681.
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    EPA expects that an analytical method that uses a less aggressive
initial acid digestion that liberates bioavailable forms of aluminum
(including amorphous aluminum hydroxide), yet minimizes dissolution of
mineralized forms of aluminum such as aluminosilicates associated with
suspended sediment particles and clays (referred to as a bioavailable
analytical method), will better estimate the bioavailable fraction of
aluminum in ambient waters. EPA is not prescribing use of any specific
method and looks to further research and method standardization efforts
to identify best practices.
    For the reasons articulated above, EPA is including the option for
Oregon to use a bioavailable analytical method for characterizing
aluminum concentrations in ambient waters, except where measurements of
total recoverable aluminum are required by Federal regulations (e.g.,
NPDES permit limits for aluminum and compliance reports, by regulation
at 40 CFR 122.45, 40 CFR 122.44, and 40 CFR 122.48, must be expressed
as ``total recoverable aluminum'' and measured using analytical methods
approved at 40 CFR part 136). Doing so, particularly when testing
ambient samples expected to contain significant amounts of colloidal,
particulate, and clay-bound aluminum, will better approximate the
fraction of aluminum that is ``available'' to aquatic life in Oregon
waters. The footnote in the criteria statement that speaks to Oregon's
use of a bioavailable analytical method specifies that such a method
may utilize ``a less aggressive initial acid digestion, such as to a pH
of approximately 4 or lower, that includes the measurement of amorphous
aluminum hydroxide yet minimizes the measurement of mineralized forms
of aluminum such as aluminum silicates associated with suspended
sediment particles or clays.'' Oregon may use such methods ``as
scientifically appropriate and as allowable by State and [F]ederal
regulations.'' For more discussion on analytical methods
considerations, refer to Section C. Implementation of Final Freshwater
Acute and Chronic Aluminum Criteria in Oregon of this preamble.
Comments Regarding Language Included in the Aluminum Criteria Table
    In addition to addressing comments pertaining to the use of
analytical methods described above, EPA also addressed separate and
unrelated comments regarding language included in the proposed criteria
table. In the proposed rulemaking, the proposed criteria table included
the following text: ``Calculator outputs shall be used to calculate
criteria values for a site that protect aquatic life throughout the
site under the full range of ambient conditions, including when
aluminum is most toxic given the spatial and temporal variability of
the water chemistry at the site.'' Commenters requested that the text
be moved out of the criteria table because they suggested that it
referred to implementation of the criteria and that the criteria
regulation should only contain a reference to the 2018 national
recommended criteria for aluminum. In response, the final rule removes
the proposed text from the criteria table and instead includes a
modification of EPA's statement as a footnote to the criteria table.
The Agency is using Oregon's adopted water quality criteria for the
copper Biotic Ligand Model (BLM) as its guide, specifically Endnote N,
Subpart 3(a), which states that Oregon ``will apply the BLM criteria
for Clean Water Act purposes to protect the water body during the most
bioavailable or toxic conditions.'' \8\
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    \8\ See Endnote ``N,'' https://www.oregon.gov/deq/RulemakingDocs/tables303140.pdf.
---------------------------------------------------------------------------

    Commenters also requested that EPA edit the above-referenced
statement to avoid the implication that a static set of criteria values
must be calculated for each site for CWA implementation purposes. EPA
affirms that the State need not calculate static criteria values for
each site and has revised the statement to provide that for CWA
purposes, criteria values based on ambient water chemistry conditions
must protect the water body over the full range of water chemistry
conditions, including during conditions when aluminum is most toxic.
The intention of the statement is to reflect that site-specific pH,
DOC, and total hardness conditions vary both spatially and temporally
and that the State must apply the criteria in a manner that ensures
protection over the full range of variability.
    The State may ensure protection over the full range of water
chemistry conditions in different ways for different CWA implementation
purposes. For example, for NPDES permitting, the permit protects the
water body during critical conditions and therefore under other
foreseeable conditions. The State could use multiple outputs of the
calculator to generate a static set of criteria values that would be
protective for the range of ambient conditions at a site, and use these
to calculate a water quality-based effluent limit (WQBEL) for an NPDES
permit for a water body. For assessment, the State could concurrently
measure the aluminum concentration and the input parameters at the
site. The calculator would generate instantaneous criteria values
against which the concurrently collected aluminum monitoring data would
be compared.
Comments Regarding Default Criteria Values
    Regarding the topic of default criteria values, Oregon will need to
use ambient water chemistry data (i.e., paired pH, DOC, total hardness)
as inputs to the calculator in order to determine protective aluminum
criteria values when implementing the criteria, unless the State
provides protective default

values. To ensure that all subject waters will be protected by the
aluminum criteria, EPA recommends the State have either protective
default input values for DOC, default criteria magnitude values, or
procedures for how to calculate criteria values for waters for which
there are insufficient data to adequately characterize site-specific
conditions in the water body. EPA recommends that pH values be directly
measured rather than estimated, given the variability of pH in the
environment and the sensitivity of criteria calculations to differences
in pH. EPA solicited comment in the preamble to the proposed rulemaking
on whether it should promulgate default criteria values for aluminum to
ensure protection of the aquatic life designated use when available
data are insufficient to characterize a site. EPA agrees with comments
that while default values may be needed in some situations, it is
preferable to collect the needed ambient data and use the calculator to
calculate criteria values. Commenters supported the use of default
ecoregional criteria values for situations when data for more than one
input parameter are unavailable, but requested that the final rule not
include promulgation of default criteria values. In consideration of
these comments, EPA has elected not to finalize default criteria
procedures or values in this rule.
    Although Oregon is not required to identify default input
parameters or default criteria values for aluminum, the State is
required to protect the designated uses of the waterbodies within its
jurisdiction. As described in more detail below, EPA has elected to
provide the procedures for developing default criteria values and
default DOC inputs in the docket to this rulemaking. These procedures
are available to Oregon to use at the State's discretion, in the event
the State does not yet have sufficient site-specific ambient data upon
which to rely for a particular location. EPA expects that the State
will provide publicly available default procedures or values so that
the public and implementing entities will be aware of how all of the
State's fresh waters subject to the rule will be protected by the
criteria when available data are insufficient to characterize a site.
    Per commenters' suggestions, this final preamble briefly describes
a suggested procedure for calculating default ecoregional criteria, but
does not include a table of pre-calculated values. Comments supported
the option of ``ecoregional criteria default values'' based on the 10th
percentile of the distribution of calculator outputs calculated within
an ecoregion, which is similar to the approach that EPA suggested in
the preamble to the proposal and described in a technical analysis
included in the docket (``Analysis of the Protectiveness of Default
Ecoregional Al Criteria Values'' Docket ID: EPA-HQ-OW-2016-0694-0114).
In this procedure, EPA calculated ecoregional default aluminum criteria
values based on publicly available data from each of Oregon's Level III
Ecoregions.\9\ To calculate ecoregional default criteria values, (1)
EPA identified paired measurements of the three calculator input
parameters where available, and (2) where paired measurements of the
three calculator input parameters were unavailable, EPA identified
paired ambient data measurements for available input parameters along
with estimated DOC and/or total hardness estimated from measured Total
Organic Carbon (TOC) and specific conductivity, respectively as needed.
EPA then calculated the 10th percentile CMC and CCC (and other
percentiles) for each ecoregion from the distributions of calculator
outputs. Finally, depending on the ecoregion and data censoring method,
EPA selected the 5th or 10th percentile as a statistic that represents
a lower bound of spatially and temporally variable conditions that will
be protective in the majority (>90%) of cases. This procedure is
available for the State to use to generate default criteria values for
areas for which the Aluminum Criteria Calculator v.2.0 will be used and
there are insufficient site-specific ambient data. The State may also
use another scientifically defensible procedure to generate default
criteria values.
---------------------------------------------------------------------------

    \9\ USEPA. 2013. U.S. Environmental Protection Agency, 2013,
Level III ecoregions of the continental United States: Corvallis,
Oregon, U.S. EPA--National Health and Environmental Effects Research
Laboratory, map scale 1:7,500,000, http://www.epa.gov/wed/pages/ecoregions/level_iii_iv.h. Omernik, J.M. 1987. Ecoregions of the
conterminous United States. Annals of the Association of American
Geographers. 77:118-125.
---------------------------------------------------------------------------

    In addition to soliciting comment on including default ecoregional
criteria, EPA also solicited comment on whether the final rule should
include default DOC input values. Among the input parameters, ambient
DOC data are the least likely to be available out of the three input
parameters. DOC influences aluminum toxicity unidirectionally. Higher
levels of DOC provide more mitigation of aluminum toxicity. For water
bodies for which sufficient pH and total hardness data are available,
but sufficient DOC data are not available, Oregon may develop default
DOC input values to use with ambient pH and total hardness data, as an
alternative to using default criteria values. Comments supported the
use of default DOC inputs when DOC input parameter data are
unavailable. Commenters requested the final rule afford the State the
discretion to develop its own DOC defaults, including a comment
requesting that the State be able to use its own DOC default inputs
from its copper BLM criteria rule.\10\ EPA has elected not to finalize
default DOC inputs for this aluminum rule so that the State may use its
discretion to develop or apply its own.
---------------------------------------------------------------------------

    \10\ Oregon Administrative Rules, Copper Standard Implementatoin
(Chapter 340, Division 041, Section 0033), https://www.oregon.gov/deq/wq/Pages/WQ-Standards-Copper.aspx.
---------------------------------------------------------------------------

    Per commenters' suggestions, EPA briefly describes a possible
procedure for calculating default DOC input values. One such approach
would be to mirror the approach EPA described in the preamble to the
proposed rulemaking, which also is described in technical support
materials associated with EPA's proposed rulemaking and included in the
docket to this rulemaking (``Analysis of the Protectiveness of Default
DOC Options'' Docket ID: EPA-HQ-OW-2016-0694-0116). In that analysis,
EPA analyzed the State's DOC default procedures for its copper water
quality standard and found that in most of the ecoregions, the default
values those procedures would generate would be protective as default
inputs for aluminum as well, with some exceptions and considerations.
EPA derived its suggested default DOC input values as the 15th or 20th
percentile of the distribution of data from a compilation of high
quality data available for Oregon's georegions (aggregated ecoregions
with similar water quality characteristics). Depending on the ecoregion
and the data censoring method, EPA selected the 5th, 15th, or 20th
percentiles as low-end percentiles of georegional DOC concentrations
that represent a lower bound of spatially and temporally variable
conditions that will be protective in the majority of cases. EPA
encourages the State to continue refining its DOC default input
procedures to ensure the calculated aluminum criteria values will be
protective for all of Oregon's fresh waters subject to this rule.

C. Implementation of Final Freshwater Acute and Chronic Aluminum
Criteria in Oregon

    EPA understands that states have certain flexibilities under 40 CFR
part 131 regarding how each implements water quality standards, such as
today's

freshwater aluminum criteria for Oregon. To support the State, the
proposed rulemaking identified a range of acceptable approaches for the
State and the commenting public to consider. The State may elect to
utilize one or more of the approaches or to implement the final
aluminum criteria in other ways that are consistent with 40 CFR part
131.
    For CWA implementation purposes, the State will need to identify
one or more outputs from the calculator or a value derived from a
scientifically defensible percentile of the distribution of the output
values as the magnitude(s) of the criteria, to be applied together with
duration and frequency, to protect the water body under the range of
water chemistry conditions at a site. In practice, EPA expects the
State to collect sufficient data to characterize the most toxic
conditions at a site. The State could collect samples for the input
parameters concurrently or as close to the same time as possible while
representing the same environmental condition, and could use default
values if appropriate where data are unavailable or insufficient to
capture the variability in conditions. The ways by which the State may
evaluate sufficiency are described in more detail below.
    The proposal preamble described three example approaches that the
State could use to calculate criteria values when multiple calculator
outputs, representing different ambient conditions over time, are
available (i.e., how to reconcile multiple calculator outputs). EPA
agrees with commenters' suggestions that further development and
implementation of these approaches should be left to the State's
discretion, and that the term used to identify one or more protective
values, ``reconcile,'' was not appropriate to describe how the State
should manage multiple calculator outputs. The appropriate approach for
each circumstance will depend primarily on data availability and on the
programmatic purposes for which criteria values are being calculated.
For purposes which require forecasting a protective loading allocation
under varying ambient conditions, for example, the State could
calculate a single set of numeric criteria values (CMC and CCC) by
choosing the lowest output or a low percentile of the outputs of
multiple calculator runs, or use conservative default values.
    Oregon should ensure that sufficiently representative data are
collected for the calculator's input parameters (pH, DOC, and total
hardness) to have confidence that the most toxic conditions are
adequately characterized. To accomplish this, Oregon may evaluate the
input parameter data and resultant criteria values that are calculated
over time for different flows and seasons through the use of
appropriate statistical methods, such as Monte Carlo \11\ simulation.
One consideration when defining a site to which to apply criteria for
aluminum is whether the concentration of metals are generally
consistent throughout the area. As the size of a site increases, the
spatial and temporal variability is likely to increase; thus, more
water samples may be required to adequately characterize the entire
site. Implementation materials that outline the State's approaches will
help provide transparency for the public and predictable, repeatable
outcomes. Additional transparency and public accountability will be
achieved if Oregon makes publicly available each site's ambient water
chemistry data, including the inputs used in the aluminum criteria
value calculations, resultant criteria values, and the geographic
extent of the site.
---------------------------------------------------------------------------

    \11\ Given sufficient data, Monte Carlo simulation or equivalent
analysis can be used to determine the probability of identifying the
most toxic time period for a series of monitoring scenarios. From
such an analysis, the State can select an appropriate monitoring
regime.
---------------------------------------------------------------------------

    Similarly, NPDES permit effluent limits that are derived from the
aluminum criteria calculator should be sufficiently explained in Fact
Sheets or Statements of Basis. This includes providing an explanation
of how the aluminum criteria values were calculated; the input data or
summary of input data and source of data; and how criteria values were
used to determine whether the discharge would cause or have the
reasonable potential to cause or contribute to an excursion above the
aluminum criteria, and if so, how the values were used to derive WQBELs
for aluminum. The State's assessment methodology and any TMDLs
developed for waters impaired for aluminum criteria developed using the
calculator should also be adequately explained for transparency and
public accountability in TMDL documents and Integrated Reports, as
appropriate.
    Substantial changes in a water body's ambient input parameter
concentrations will likely affect aluminum toxicity at that site. In
addition, as a robust, site-specific dataset is developed with regular
monitoring, criteria values previously calculated by the State can be
updated to more accurately reflect site conditions. The State may wish
to revisit calculated aluminum criteria values periodically (for
example, with each CWA Section 303(d) listing cycle or WQS triennial
review) or when changes in water chemistry are evident or suspected at
a site and as additional monitoring data become available. This will
ensure that the criteria values used for implementing CWA programs
accurately reflect the toxicity of aluminum and remain protective of
the aquatic life designated uses including when aluminum is most toxic.
Analytical Methods Considerations
    As discussed earlier, the forms of aluminum introduced into the
laboratory toxicity tests upon which EPA relied for criteria
development do not include suspended solids or clays where aluminum may
be bound. Aluminum bound in suspended solids or clays would be
extracted when using total recoverable methods that have a strong acid
(pH <2) digestion step, but these forms of aluminum would not be
biologically available to aquatic species in ambient waters. Empirical
laboratory chronic (7-day) testing with Ceriodaphnia dubia
investigating survival and reproduction endpoints indicates that total
recoverable (pH -0.05 to +0.7 digestion) and bioavailable measurements
of aluminum in lab waters are essentially equal up to approximately 1
mg/L of aluminum.\12\ Studies are currently being conducted at Oregon
State University with test solutions with greater than 1 mg/L of
aluminum to better understand the relationship between the total
recoverable and bioavailable analytical methods at concentrations above
1 mg/L. Initial studies indicate there is little variability between
total recoverable and bioavailable aluminum above 1 mg/L in lab waters
because the laboratory waters do not include clays or suspended solids.
---------------------------------------------------------------------------

    \12\ Rodriguez PH, Arbildua JJ, Villavicencio G, Urrestarazu P,
Opazo M, Cardwell AS, Stubblefield W, Nordheim E, Adams W. 2019.
Determination of bioavailable aluminum in natural waters in the
presence of suspended solids. Environmental Toxicology and
Chemistry. 38(8):1668-1681.
---------------------------------------------------------------------------

    It is not necessary to apply a conversion or translation factor to
compare field measurements using a bioavailable method against the
promulgated aluminum total recoverable criteria. This is because both
bioavailable and total recoverable analytical methods quantify the
toxic fraction of aluminum equivalently in laboratory test waters given
that standard toxicity test waters do not include suspended solids or
clays per test protocols. For NPDES compliance monitoring and
reporting, total recoverable measurements for metals are required. By
comparison, for ambient water measurements, analytical methods that
measure bioavailable

aluminum should provide more accurate quantification of the toxic
fraction of aluminum. EPA has included a footnote to the final criteria
statement specifically noting that for characterizing ambient waters,
Oregon may utilize, as scientifically appropriate and as allowable by
State and Federal regulations, analytical methods that measure the
bioavailable fraction of aluminum. The State's use of such a method
would need to comply with other requirements in the State's own
program, for example, any applicable Quality Assurance/Quality Control
requirements. For assessment and listing purposes, ambient field
measurements analyzed using a bioavailable analytical method may be
compared directly to the criteria because both represent the toxic
fraction of aluminum.
    EPA recognizes that in some circumstances, assessing waters using
the total recoverable analytical method could result in the listing of
some waters (i.e., those with high amounts of total suspended solids)
as impaired even though the elevated aluminum measurements could be
largely attributed to non-bioavailable forms of aluminum. EPA's
existing regulations do not require use of analytical test methods
promulgated at 40 CFR part 136 in the implementation of CWA Section 303
programs, including assessment and listing of waters, nor in the
determination of the need for a WQBEL. However, EPA's regulations
require that states assemble and evaluate all existing and readily
available water quality-related data and information for use in
developing their CWA Section 303(d) lists. 40 CFR 130.7(b)(5). The
requirement to assemble and evaluate all data and information for
assessment and listing purposes includes situations where only total
recoverable aluminum data and information are available. However, in
those circumstances, the State is not required to rely on that data for
listing purposes as long as it provides a technical, science-based
rationale for not using the data and information. 40 CFR
130.7(b)(6)(iii). This technical, science-based rationale documenting
the State's consideration of existing and readily available data and
information is referenced in the additional footnote language to the
criteria statement, which speaks to Oregon's ability to use analytical
methods that measure the bioavailable fraction of aluminum for
characterizing ambient waters ``as scientifically appropriate.'' For
example, the State may be able to demonstrate that total recoverable
aluminum samples are not representative of water quality conditions
because non-toxic, non-bioavailable forms of aluminum are leading to an
exceedance above the criterion. When data and information are available
for both total recoverable and bioavailable aluminum, the State must
evaluate all of it, but need not rely on all of it for assessment and
listing purposes. Applicable regulations do not prohibit the State from
assigning more weight to data and information about bioavailable
aluminum than total recoverable aluminum for assessment and listing
purposes.
    For developing TMDLs and load allocations, field measurements
analyzed using a bioavailable method also may be used as the basis for
identifying allocations for TMDLs, both wasteload allocations (WLA) for
point sources and load allocations (LA) for nonpoint sources. For
implementing a WLA, the associated WQBEL must be assessed for NPDES
compliance purposes using total recoverable methods just as would be
the case for other NPDES applications consistent with permitting
regulations (NPDES permit limits for aluminum and compliance reports,
by regulation at 40 CFR 122.44, 40 CFR 122.45, and 40 CFR 122.48, must
be expressed as ``total recoverable aluminum'' and measured using
analytical methods approved at 40 CFR part 136). For implementing a LA,
a bioavailable analytical method could be used to measure nonpoint
source contributions because significant solids with colloid and clay-
bound aluminum could be present (He and Ziemkiewics 2016; Ryan et al.
2019),\13\ and should not contribute to the measured aluminum for
comparison to a LA.
---------------------------------------------------------------------------

    \13\ He YT, Ziemkiewicz PF. 2016. Bias in determining aluminum
concentrations: Comparison of digestion methods and implications on
Al management. Chemosphere 159:570-576; Ryan AC, Santore RC,
Tobiason S, WoldeGabriel G, and Groffman AR. 2019. Total recoverable
aluminum: not totally relevant for water quality standards.
Integrated Environmental Assessment and Management. 15(6): 974-987.
---------------------------------------------------------------------------

    The contexts where use of an EPA approved method is required are:
(1) Applications for NPDES permits, specifically, measurements of
effluents, (2) reports required from dischargers, and (3)
certifications issued by states under CWA Section 401. 40 CFR 136.1(a).
NPDES permit limits for metals must be expressed as ``total
recoverable'' metals with the exception of circumstances that would not
apply for the aluminum criteria in this rule. 40 CFR 122.45(c).

D. Incorporation by Reference

    The regulatory text incorporates an EPA document by reference,
specifically, EPA's Final Aquatic Life Ambient Water Quality Criteria
for Aluminum--2018, December 2018 (EPA-822-R-18-001). The 2018 national
recommended criteria document is an update to the 1988 recommended
aluminum aquatic life ambient water quality criteria, in accordance
with the provisions of CWA Section 304(a) directing EPA to revise
criteria from time to time to reflect the latest scientific knowledge.
The criteria for aluminum that protect aquatic life in fresh water
depend on a site's water chemistry parameters. Using those inputs,
users can enter a site's pH, DOC, and total hardness into the aluminum
criteria calculator or use the lookup tables in the criteria document's
appendix. Incorporating this document by reference will allow the State
to access all of the underlying information and data EPA used to
develop the 2018 national recommended criteria for aluminum. With
access to this information, the State will have the flexibility to
create its own version of the calculator built upon the underlying
peer-reviewed models. EPA has made, and will continue to make, this
document publicly available electronically through www.regulations.gov
at the docket associated with this rulemaking and at www.epa.gov/wqc/aquatic-life-criteria-aluminum.

IV. Critical Low Flows and Mixing Zones

    To ensure that the final criteria for aluminum are applied
appropriately to protect Oregon's aquatic life uses, EPA recommends
Oregon use critical low flow values consistent with longstanding EPA
guidance \14\ when calculating the available dilution for the purposes
of determining the need for and establishing WQBELs in NPDES permits.
Dilution is one of the primary mechanisms by which the concentrations
of contaminants in effluent discharges are reduced following their
introduction into a receiving water. During a low flow event, there is
less water available for dilution, resulting in higher instream
pollutant concentrations. If criteria are implemented using
inappropriate critical low flow values (i.e., flow values that are too
high), the resulting ambient

concentrations could exceed criteria values when low flows occur.\15\
---------------------------------------------------------------------------

    \14\ USEPA. 1991. Technical Support Document For Water Quality-
based Toxics Control. U.S. Environmental Protection Agency, Office
of Water, Washington, DC EPA/505/2-90-001. http://www3.epa.gov/npdes/pubs/owm0264.pdf.
    \15\ 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. http://www.epa.gov/sites/production/files/2014-09/documents/handbook-chapter5.pdf.
---------------------------------------------------------------------------

    EPA notes that in ambient settings, critical low flow conditions
used for NPDES permit limit derivation purposes may not always
correspond with conditions of highest aluminum bioavailability and
toxicity. EPA's NPDES Permit Writers' Manual describes the importance
of characterizing effluent and receiving water critical conditions,
because if a discharge is controlled so that it does not cause water
quality criteria to be exceeded in the receiving water under critical
conditions, then water quality criteria should be attained under all
other conditions.\16\
---------------------------------------------------------------------------

    \16\ The same principle holds for developing a TMDL target, the
total load.
---------------------------------------------------------------------------

    EPA's March 1991 Technical Support Document for Water Quality-based
Toxics Control recommends two methods for calculating acceptable
critical low flow values: The traditional hydrologically-based method
developed by the USGS and a biologically based method developed by
EPA.\17\ The hydrologically-based critical low flow value is determined
statistically, using probability and extreme values, while the
biologically-based critical low flow is determined empirically using
the specific duration and frequency associated with the criterion. For
the acute and chronic aluminum criteria, EPA recommends the following
critical low flow values, except where modeling demonstrates that the
most significant critical conditions occur at other than low flow:
---------------------------------------------------------------------------

    \17\ USEPA. 1991. Technical Support Document For Water Quality-
based Toxics Control. U.S. Environmental Protection Agency, Office
of Water, Washington, DC EPA/505/2-90-001. http://www3.epa.gov/npdes/pubs/owm0264.pdf.

Acute Aquatic Life (CMC): 1Q10 or 1B3
Chronic Aquatic Life (CCC): 7Q10 or 4B3
Using the hydrologically-based method, the 1Q10 represents the lowest
one-day average flow event expected to occur once every ten years, on
average, and the 7Q10 represents the lowest seven-consecutive-day
average flow event expected to occur once every ten years, on average.
Using the biologically-based method, 1B3 represents the lowest one-day
average flow event expected to occur once every three years, on
average, and 4B3 represents the lowest four-consecutive-day average
flow event expected to occur once every three years, on average.\18\
---------------------------------------------------------------------------

    \18\ See USEPA, 2014.
---------------------------------------------------------------------------

    The final criteria must be attained at the point of discharge
unless Oregon authorizes a mixing zone. Where Oregon authorizes a
mixing zone, the criteria would apply at the locations allowed by the
mixing zone (i.e., the CMC would apply at the defined boundary of the
acute mixing zone and the CCC would apply at the defined boundary of
the chronic mixing zone).19 20
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    \19\ See USEPA, 1991.
    \20\ Oregon Administrative Rules, Mixing Zones (Chapter 340,
Division 41, Section 0053), https://secure.sos.state.or.us/oard/viewSingleRule.action?ruleVrsnRsn=68770.
---------------------------------------------------------------------------

V. Endangered Species Act

    Section 7(a)(2) of the ESA requires that each Federal agency ensure
that any action authorized, funded, or carried out by such Agency is
not likely to jeopardize the continued existence of any endangered or
threatened species or result in the destruction or adverse modification
of critical habitat. For this rule, EPA transmitted a Biological
Evaluation to NOAA Fisheries Service and USFWS on September 20, 2019.
NOAA Fisheries responded on October 18, 2019, that EPA's Biological
Evaluation was insufficient to initiate formal consultation. EPA
submitted a revised Biological Evaluation to NOAA Fisheries on January
2, 2020. On February 13, 2020, EPA received a final Biological Opinion
from USFWS that determined that EPA's proposed action is likely to
adversely affect, but will not jeopardize the continued existence of
bull trout and will not destroy or adversely modify its designated
critical habitat. USFWS also concluded that the proposed action may
affect, but is not likely to adversely affect, eight other federally-
listed species and is not likely to destroy or adversely modify the
critical habitat for the other species that were included in the
consultation. On July 1, 2020, EPA received a final Biological Opinion
from NOAA Fisheries that determined that EPA's proposed action is
likely to adversely affect, but will not jeopardize the continued
existence of 18 listed species and will not destroy or adversely modify
designated critical habitat for the species that were included in the
consultation. The receipt of the NOAA Biological Opinion concludes the
consultation for this rule under ESA Section 7(a)(2). Documents
associated with ESA consultation are available in the docket associated
with this rule (Docket ID: EPA-HQ-OW-2016-0694).

VI. Under what conditions would Federal standards be withdrawn?

    Under the CWA, Congress gave states and authorized tribes primary
responsibility for developing and adopting WQS for their navigable
waters (CWA Sections 303(a) through (c)). Although EPA is finalizing
aluminum aquatic life criteria for Oregon's fresh waters subject to
this rule on the basis of having disapproved Oregon's 2004 criteria in
February 2013, Oregon retains the option to adopt and submit to the
Agency acute and chronic aluminum criteria for the State's fresh waters
consistent with CWA Section 303(c) and the Agency's implementing
regulation at 40 CFR part 131. Indeed, EPA encourages Oregon to do so
expeditiously. The Agency would approve the State's criteria if the
criteria meet the requirements of CWA Section 303(c) and implementing
regulation at 40 CFR part 131. If EPA's federally promulgated criteria
are more stringent or prescriptive than the State's criteria, EPA's
federally promulgated criteria are and will be the applicable water
quality standard for purposes of the CWA until the Agency withdraws
those federally promulgated standards (40 CFR 131.21(c)). EPA would
expeditiously undertake such a rulemaking to withdraw the Federal
criteria if and when Oregon adopts, and the Agency approves,
corresponding criteria that meet the requirements of CWA Section 303(c)
and implementing regulation at 40 CFR part 131. After such a withdrawal
of EPA's federally promulgated criteria, the State's EPA-approved
criteria would become the applicable criteria for CWA purposes (40 CFR
131.21(c)).

VII. Alternative Regulatory Approaches and Implementation Mechanisms

    The Federal WQS regulation at 40 CFR part 131 provides several
tools that Oregon has available to use at its discretion when
implementing or deciding how to implement these aquatic life criteria,
once effective. Among other things, EPA's WQS regulation: (1) Specifies
how states and authorized tribes establish, modify, or remove
designated uses (40 CFR 131.10); (2) specifies the requirements for
establishing criteria to protect designated uses, including criteria
modified to reflect site-specific conditions (40 CFR 131.11); (3)
authorizes and provides regulatory guidelines for states and authorized
tribes to adopt WQS variances that provide time to achieve the
applicable WQS (40 CFR 131.14); and (4) allows states and authorized
tribes to authorize

the use of compliance schedules in NPDES permits to meet WQBELs derived
from the applicable WQS (40 CFR 131.15). Each of these approaches is
discussed in more detail in the next sections. Whichever approach a
state pursues, however, all NPDES permits would need to comply with
EPA's regulations at 40 CFR 122.44(d)(1)(i).

A. Designating Uses

    EPA's final aluminum criteria apply to fresh waters in Oregon where
the protection of fish and aquatic life is a designated use (see Oregon
Administrative Rules at Chapter 340 Division 41). The Federal
regulation at 40 CFR 131.10(g) provides requirements for establishing,
modifying, and removing designated uses when attaining the use is not
feasible for one of the six factors in the regulation. If Oregon
removes designated uses such that no fish or aquatic life uses apply to
any particular water body affected by this rule and adopts the highest
attainable use,\21\ the State must also adopt criteria to protect the
newly designated highest attainable use consistent with 40 CFR 131.11.
It is possible that criteria other than the federally promulgated
criteria would protect the highest attainable use. If EPA finds removal
or modification of the designated use and the adoption of the highest
attainable use and criteria to protect that use to be consistent with
CWA Section 303(c) and the implementing regulation at 40 CFR part 131,
the Agency would approve the revised WQS. EPA would then undertake a
rulemaking to withdraw the corresponding Federal WQS for the relevant
water(s).
---------------------------------------------------------------------------

    \21\ If a state or authorized tribe adopts a new or revised WQS
based on a required use attainability analysis, then it must also
adopt the highest attainable use (40 CFR 131.10(g)). The highest
attainable use is the modified aquatic life, wildlife, or recreation
use that is both closest to the uses specified in section 101(a)(2)
of the CWA and attainable, based on the evaluation of the factor(s)
in 40 CFR 131.10(g) that preclude(s) attainment of the use and any
other information or analyses that were used to evaluate
attainability. There is no required highest attainable use where the
state demonstrates the relevant use specified in section 101(a)(2)
of the Act and sub-categories of such a use are not attainable (see
40 CFR 131.3(m)).
---------------------------------------------------------------------------

B. WQS Variances

    Oregon's WQS provide authority to apply WQS variances when
implementing federally promulgated criteria for aluminum, as long as
such WQS variances are adopted consistent with 40 CFR 131.14 and
submitted to EPA for review under CWA Section 303(c). The Federal
regulation at 40 CFR 131.3(o) defines a WQS variance as a time-limited
designated use and criterion, for a specific pollutant or water quality
parameter, that reflects the highest attainable condition during the
term of the WQS variance. A WQS variance may be appropriate if
attaining the use and criterion would not be feasible during the term
of the WQS variance because of one of the seven factors specified in 40
CFR 131.14(b)(2)(i)(A), including if NPDES permit limits more stringent
than technology-based controls would result in substantial and
widespread economic and social impact. WQS variances adopted in
accordance with 40 CFR 131.14 (including a public hearing consistent
with 40 CFR 25.5) provide a flexible but defined pathway for states and
authorized tribes to issue NPDES permits with limits that are based on
the highest attainable condition during the term of the WQS variance
thereby allowing dischargers to make water quality improvements when
the WQS is not immediately attainable but may be in the future. When
adopting a WQS variance, states and authorized tribes specify the
interim requirements of the WQS variance by identifying a quantitative
expression that reflects the highest attainable condition (HAC) during
the term of the WQS variance, establishing the term of the WQS
variance, and describing the pollutant control activities expected to
occur over the specified term of the WQS variance. WQS variances
provide a legal avenue by which NPDES permit limits can be written to
comply with the WQS variance rather than the underlying WQS for the
term of the WQS variance. If dischargers are still unable to meet the
WQBELs derived from the applicable WQS once a WQS variance term is
complete, the regulation allows the State to adopt a subsequent WQS
variance if it is adopted consistent with 40 CFR 131.14. EPA is
promulgating criteria that apply to the use designation that Oregon has
already established. Oregon's WQS regulations currently include
provisions to use WQS variances when implementing criteria, as long as
such WQS variances are adopted consistent with 40 CFR 131.14 and
approved by EPA. Oregon may use the State's EPA-approved WQS variance
procedures when adopting such WQS variances.

C. NPDES Permit Compliance Schedules

    EPA's regulations at 40 CFR 122.47 and 131.15 address how
permitting authorities can use schedules for compliance with a limit in
the NPDES permit if the discharger needs additional time to undertake
actions like facility upgrades or operation changes to meet a WQBEL
based on the applicable WQS. EPA's regulation at 40 CFR 122.47 allows a
permitting authority to include a compliance schedule in the NPDES
permit, when appropriate and where authorized by the state, in order to
provide a discharger with additional time to meet a WQBEL implementing
applicable WQS. EPA's regulation at 40 CFR 131.15 requires that a state
that intends to allow the use of NPDES permit compliance schedules
adopt specific provisions authorizing their use and obtain EPA approval
under CWA Section 303(c) to ensure that a decision to allow a permit
compliance schedule is transparent and allows for public input (80 FR
51022, August 21, 2015). EPA already has approved Oregon's State law
provision authorizing the use of permit compliance schedules (see OAR
340-041-0061), consistent with 40 CFR 131.15. Oregon's compliance
schedule authorizing provision is not affected by this rule. Oregon is
authorized to grant permit compliance schedules, as appropriate, based
on the Federal water quality criteria for aluminum in Oregon, as long
as such permit compliance schedules are consistent with EPA's
permitting regulation at 40 CFR 122.47.

VIII. Economic Analysis

    To best inform the public of the potential impacts of this rule,
EPA evaluated the potential costs associated with State implementation
of the Agency's aluminum criteria based on available information. This
analysis is documented in Economic Analysis for the Final Rule: Federal
Aluminum Aquatic Life Criteria Applicable to Oregon, which can be found
in the record for this rule. For this analysis, EPA assumed that Oregon
fully implements its existing narrative water quality criteria for
aluminum (i.e., ``baseline criteria'') and estimated the incremental
impacts for compliance with the aluminum criteria in this rule. For
point source costs, EPA assumed any NPDES-permitted facility that
discharges aluminum would have reasonable potential and would be
subject to effluent limits and would incur compliance costs if it chose
to continue discharging. EPA also evaluated nonpoint sources that
contribute aluminum loadings to waters that would be considered
impaired for aluminum under the final criteria, which may incur
incremental costs for additional best management practices (BMPs). The
total cost annualized of this final rule would range from $1.2 million
to $8.0 million at a 3% discount rate, and $1.2 million to $8.1 million
at a 7% discount rate, for the first 10 years. See Economic Analysis
for the Final Rule:

Federal Aluminum Aquatic Life Criteria Applicable to Oregon for a
detailed summary of the information and assumptions EPA relied on to
estimate potential costs for the final rule.

IX. Statutory and Executive Order Reviews

    Additional information about these statutes and Executive orders
can be found at http://www2.epa.gov/laws-regulations/laws-and-executive-orders.

A. Executive Order 12866 (Regulatory Planning and Review) and Executive
Order 13563 (Improving Regulation and Regulatory Review)

    This action is a significant regulatory action and was submitted to
the Office of Management and Budget (OMB) for review. Any changes made
during OMB's review have been documented in the docket. EPA prepared an
analysis of the potential costs to NPDES dischargers associated with
State implementation of the aluminum criteria in this rule. This
analysis, Economic Analysis for the Final Rule: Federal Aluminum
Aquatic Life Criteria Applicable to Oregon, is summarized in section
VIII of the preamble and is available in the docket.

B. Executive Order 13771 (Reducing Regulations and Controlling
Regulatory Costs)

    This action is considered an Executive Order 13771 regulatory
action. Details on the estimated costs of this final rule can be found
in EPA's analysis of the potential costs and benefits associated with
this action.

C. Paperwork Reduction Act

    This action does not impose any new information-collection burden
under the Paperwork Reduction Act. This action does not directly
contain any information collection, reporting, or record-keeping
requirements. OMB has previously approved the information collection
requirements contained in the existing regulations 40 CFR part 131 and
has assigned OMB control number 2040-0049.

D. Regulatory Flexibility Act

    The Agency certifies that this action will not have a significant
economic impact on a substantial number of small entities under the
Regulatory Flexibility Act. This action will not impose any
requirements on small entities. The EPA-promulgated WQS are implemented
through various water quality control programs including the NPDES
program, which limits discharges to navigable waters except in
compliance with a NPDES permit. CWA Section 301(b)(1)(C) \22\ and EPA's
implementing regulations at 40 CFR 122.44(d)(1) and
122.44(d)(1)(vii)(A) provide that all NPDES permits shall include any
limits on discharges that are necessary to meet applicable WQS. Thus,
under the CWA, EPA's promulgation of WQS establishes WQS that the State
implements through the NPDES permit process. While the State has
discretion in developing discharge limits, as needed to meet the WQS,
those limits, per regulations at 40 CFR 122.44(d)(1)(i), ``must control
all pollutants or pollutant parameters (either conventional,
nonconventional, or toxic pollutants) which the Director determines are
or may be discharged at a level that will cause, have the reasonable
potential to cause, or contribute to an excursion above any [s]tate
water quality standard, including [s]tate narrative criteria for water
quality.'' As a result of this action, the State of Oregon will need to
ensure that permits it issues include any limitations on discharges
necessary to comply with the WQS established in the final rule. In
doing so, the State will have a number of choices associated with
permit writing. Oregon's implementation of the rule may ultimately
result in new or revised permit conditions for some dischargers. EPA is
unaware of any current permit holders or other entities that would be
required to obtain new permits or update existing permits as a result
of this action, including small entities. EPA's action, by itself, does
not impose any requirements on small entities; that is, the
requirements are not self-implementing.
---------------------------------------------------------------------------

    \22\ CWA Section 301(b) Timetable for achievement of objectives.
In order to carry out the objective of this chapter there shall be
achieved--(1)(C): Not later than July 1, 1977, any more stringent
limitation, including those necessary to meet water quality
standards, treatment standards, or schedules of compliance,
established pursuant to any State law or regulations (under
authority preserved by section 1370 of this title) or any other
Federal law or regulation, or required to implement any applicable
water quality standard established pursuant to this chapter.
---------------------------------------------------------------------------

E. Unfunded Mandates Reform Act (UMRA)

    This action does not contain any unfunded mandate as described in
UMRA, 2 U.S.C. 1531-1538, and does not significantly or uniquely affect
small goverments. This action imposes no enforceable duty on any state,
local, or tribal governments or the private sector.

F. Executive Order 13132 (Federalism)

    This action does not have federalism implications. EPA believes,
however, that this action may be of significant interest to state
governments. Consistent with EPA's policy to promote communications
between EPA and state and local governemnts, EPA consulted with Oregon
early in the process of developing this rulemaking to permit them to
have meaningful and timely input into its development. EPA discussed
with Oregon the Agency's development of the Federal rulemaking and
clarified early in the process that if and when the State decided to
develop and establish its own aluminum standards, EPA would assist the
State in its process. During these discussions, EPA explained the
scientific basis for the aluminum criteria to protect aquatic life for
fresh waters in Oregon; the Agency's consideration of comments received
during the public comment period associated with this rulemaking; and
the overall timing of the Federal rulemaking effort. EPA took these
discussions with the State into account during the drafting of this
rule.

G. Executive Order 13175 (Consultation and Coordination With Indian
Tribal Governments)

    This action does not have tribal implications as specified in
Executive Order 13175. This rule does not impose substantial direct
compliance costs on federally recognized tribal governments, nor does
it substantially affect the relationship between the Federal Government
and tribes, or the distribution of power and responsibilities between
the Federal Government and tribes. Thus, Executive Order 13175 does not
apply to this action.
    Consistent with EPA Policy on Consultation and Coordination with
Indian Tribes, the Agency offered government to government consultation
to potentially affected tribes during the development of this action.
EPA sent letters to tribal leaders of potentially affected tribes in
the Pacific Northwest offering government-to-government consultation on
the proposed aluminum rule for fresh waters in Oregon. EPA held two
conference calls (June 4 and June 13, 2019) with the interested tribal
water quality staff to explain the Agency's proposed action and
timeline. No tribes requested formal government-to-government
consultation on this rulemaking. EPA has continued to apprise the
tribes of the status of its final action.

H. Executive Order 13045 (Protection of Children From Environmental
Health and Safety Risks)

    EPA interprets Executive Order 13045 as applying only to those
regulatory actions that concern environmental health or safety risks
that the Agency

has reason to believe may disproportionately affect children, per the
definition of ``covered regulatory action'' in section 2-202 of the
Executive order. This action is not subject to Executive Order 13045
because it does not concern an environmental health risk or safety
risk.

I. Executive Order 13211 (Actions that Significantly Affect Energy
Supply, Distribution, or Use)

    This action is not a ``significant energy action'' because it is
not likely to have a significant adverse effect on the supply,
distribution, or use of energy.

J. National Technology Transfer and Advancement Act of 1995

    This rule does not involve technical standards.

K. Executive Order 12898 (Federal Actions To Address Environmental
Justice in Minority Populations and Low-Income Populations)

    EPA believes that this action does not have disproportionately high
and adverse human health or environmental effects on minority
populations, low income populations and/or indigenous peoples, as
specified in Executive Order 12898 (59 FR 7629, February 16, 1994). The
freshwater criteria for aluminum in Oregon will support the health and
abundance of aquatic life in Oregon, and will therefore benefit all
communities that rely on Oregon's ecosystems.

L. Congressional Review Act (CRA)

    This action is subject to the CRA, and EPA will submit a rule
report to each House of the Congress and to the Comptroller General of
the United States. This action is not a ``major rule'' as defined by 5
U.S.C. 804(2).

List of Subjects in 40 CFR Part 131

    Environmental protection, Incorporation by reference, Indians-
lands, Intergovernmental relations, Reporting and recordkeeping
requirements, Water pollution control.

    This document of the Environmental Protection Agency was signed on
December 30, 2020, by Andrew Wheeler, Administrator, pursuant to the
Third Amended Consent Decree in Northwest Environmental Advocates v.
EPA, No. 15-cv-0663-BR (D. Ore., Mar. 16, 2020). That rulemaking
document with the original signature and date is maintained by EPA. For
administrative purposes only, and in compliance with requirements of
the Office of the Federal Register, the undersigned EPA Official re-
signs the document for publication, as an official document of the
Environmental Protection Agency. This administrative process in no way
alters the legal effect of this document upon publication in the
Federal Register.

    Signed in Washington, DC.
Jane Nishida,
Acting Administrator.

    For the reasons set forth in the preamble, EPA amends 40 CFR part
131 as follows:

PART 131--WATER QUALITY STANDARDS

0
1. The authority citation for part 131 continues to read as follows:

    Authority: 33 U.S.C. 1251 et seq.

Subpart D--Federally Promulgated Water Quality Standards

0
2. Add Sec.  131.47 to read as follows:

Sec.  131.47  Aquatic life criteria for aluminum in Oregon.

    (a) Scope. This section promulgates aquatic life criteria for
aluminum in fresh waters in Oregon that are jurisdictional under the
Clean Water Act.
    (b) Criteria for aluminum in Oregon. The aquatic life criteria in
Table 1 to this paragraph (b) apply to all fresh waters in Oregon that
are jurisdictional under the Clean Water Act to protect the fish and
aquatic life designated uses.

                Table 1 to Paragraph (b)--Aluminum Aquatic Life Criteria for Oregon Fresh Waters
----------------------------------------------------------------------------------------------------------------
                                                            Criterion maximum           Criterion continuous
                  Metal                     CAS No.      concentration (CMC) \3\       concentration (CCC) \4\
                                                              ([micro]g/L)                  ([micro]g/L)
----------------------------------------------------------------------------------------------------------------
Aluminum 1 2.............................    7429905  Acute (CMC) and chronic (CCC) freshwater aluminum criteria
                                                       values for a site shall be calculated using the 2018
                                                       Aluminum Criteria Calculator (Aluminum Criteria
                                                       Calculator V.2.0.xlsx), or a calculator in R or other
                                                       software package using the same 1985 Guidelines
                                                       calculation approach and underlying model equations as in
                                                       the Aluminum Criteria Calculator V.2.0.xlsx, as defined
                                                       in EPA's Final Aquatic Life Ambient Water Quality
                                                       Criteria for Aluminum.\5\
----------------------------------------------------------------------------------------------------------------
\1\ To apply the aluminum criteria for Clean Water Act purposes, criteria values based on ambient water
  chemistry conditions must protect the water body over the full range of water chemistry conditions, including
  during conditions when aluminum is most toxic.
\2\ These criteria are based on aluminum toxicity studies where aluminum was analyzed using total recoverable
  analytical methods. Oregon may utilize total recoverable analytical methods to implement the criteria. For
  characterizing ambient waters, Oregon may also utilize, as scientifically appropriate and as allowable by
  State and Federal regulations, analytical methods that measure the bioavailable fraction of aluminum (e.g.,
  utilizing a less aggressive initial acid digestion, such as to a pH of approximately 4 or lower, that includes
  the measurement of amorphous aluminum hydroxide yet minimizes the measurement of mineralized forms of aluminum
  such as aluminum silicates associated with suspended sediment particles or clays). Oregon shall use
  measurements of total recoverable aluminum where required by Federal regulations.
\3\ The CMC is the highest allowable one-hour average ambient concentration of aluminum. The CMC is not to be
  exceeded more than once every three years. The CMC is rounded to two significant figures.
\4\ The CCC is the highest allowable four-day average ambient concentration of aluminum. The CCC is not to be
  exceeded more than once every three years. The CCC is rounded to two significant figures.
\5\ EPA-822-R-18-001, Final Aquatic Life Ambient Water Quality Criteria for Aluminum--2018, December 2018, is
  incorporated by reference into this section with the approval of the Director of the Federal Register under 5
  U.S.C. 552(a) and 1 CFR part 51. All approved material is available from U.S. Environmental Protection Agency,
  Office of Water, Health and Ecological Criteria Division (4304T), 1200 Pennsylvania Avenue, NW, Washington, DC
  20460; telephone number:<PHONE_NUMBER>, www.epa.gov/wqc/aquatic-life-criteria-aluminum. It is also available
  for inspection at the National Archives and Records Administration (NARA). For information on the availability
  of this material at NARA, email<EMAIL_ADDRESS>or go to www.archives.gov/federal-register/cfr/ibr-locations.html.

    (c) Applicability. (1) The criteria in paragraph (b) of this
section are the applicable acute and chronic aluminum aquatic life
criteria in all fresh waters in Oregon that are jurisdictional under
the Clean Water Act to protect the fish and aquatic life designated
uses.
    (2) The criteria established in this section are subject to
Oregon's general rules of applicability in the same way and to the same
extent as are other federally promulgated and state-adopted numeric
criteria when applied to fresh waters in Oregon that are jurisdictional
under the Clean Water Act to protect the fish and aquatic life
designated uses.
    (3) For all waters with mixing zone regulations or implementation
procedures, the criteria apply at the

appropriate locations within or at the boundary of the mixing zones and
outside of the mixing zones; otherwise the criteria apply throughout
the water body including at the end of any discharge pipe, conveyance,
or other discharge point within the water body.

[FR Doc. 2021-05428 Filed 3-18-21; 8:45 am]
BILLING CODE 6560-50-P


From:
Jonelle S Scheetz<EMAIL_ADDRESS>Sent:
Wednesday, August 10, 2016 2:59 PM
To:
Jones, DonnaLee<EMAIL_ADDRESS>Cc:
Coleen Davis<EMAIL_ADDRESS>Raymond, Gabrielle<EMAIL_ADDRESS>Shappley, Ned<EMAIL_ADDRESS>Subject:
Re: [External]-Re: EPA questions: U. S. Steel Clairton Works - Coke Oven ICR Questions

Dr. Jones,

Please see the response below from the lab:

Per our discussion the other day, the three methods we are not able to perform in house are the PAH's by EPA method 610, chloride by Standard Methods 4110 or Standard Methods 4500-Cl and Total dissolved solids by EPA method 160.1.

Here are the reasons we are unable to perform these analyses:

PAH's by EPA method 610 is using a HPLC instrument, which our laboratory does not have this piece of equipment and not certified by the PADEP to perform this analysis.  However, our low level EPA method 625 by GC/MS instrument is just as sensitive and gives more definitive results and our laboratory is certified by the PADEP to perform this analysis.

Chloride Analysis by SM4110 is using an Ion Chromatography instrument which our laboratory does have this piece of equipment, but are not certified by the PADEP to perform the analysis by this method. However, EPA method 300 and SW9056 are both Ion Chromatography methods which our laboratory are certified by the PADEP to perform this analysis.

Chloride Analysis by SM4500-Cl-D is a Potentiometric method and our laboratory is not certified by the PADEP to perform this analysis.

Total Dissolved Solids by EPA method 160.1 our laboratory is not certified by the PADEP for this method, however the laboratory is certified by the PADEP for TDS by SM2540C method which are comparable methods.

Thank you,

Jonelle Scheetz
Clairton Environmental
United States Steel Corporation
Office:<PHONE_NUMBER>
Cell:<PHONE_NUMBER>

From:        "Jones, DonnaLee"<EMAIL_ADDRESS>To:        Jonelle S Scheetz<EMAIL_ADDRESS>Cc:        Coleen Davis<EMAIL_ADDRESS>"Shappley, Ned"<EMAIL_ADDRESS>GABRIELLE RAYMOND<EMAIL_ADDRESS>Date:        08/08/2016 10:20 AM
Subject:        Re: [External]-Re: EPA questions: U. S. Steel Clairton Works - Coke Oven ICR Questions

Does the lab lack the equipment or the expertise or both?

Regards,
Donna Lee Jones, Ph.D.
Senior Technical Advisor, Metals Sector
U. S. Environmental Protection Agency
Office of Air Quality Planning and Standards
Sector Policies and Programs Division / Metals & Inorganic Chemicals Group (D243-02)
Research Triangle Park, NC  27711  Tele:<PHONE_NUMBER>  Fax<PHONE_NUMBER>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
"Reasonableness never fails to be appreciated."  - anon.

________________________________________
From: Jonelle S Scheetz<EMAIL_ADDRESS>Sent: Monday, August 8, 2016 10:15:59 AM
To: Jones, DonnaLee
Cc: Coleen Davis; Shappley, Ned; GABRIELLE RAYMOND
Subject: Fw: [External]-Re: EPA questions: U. S. Steel Clairton Works - Coke Oven ICR Questions

Dr. Jones,

Please see answers below in green:

2. What do you see as the a potential problem with what you plan to do?

I do not see any problem with the intended sampling, I just wanted to verify that you have not problem with this plan.

3. Why do you not want to use the required water sampling methods? Do you mean you would want to substitute just the sampling parts or also the analysis parts of the other methods listed?

The lab that we are intending to use, does not perform the required methods in the ICR.  They do, however, perform the EPA approved methods that I inquired about.  We would like to be able to send all of the analyses to the same lab under the same project to avoid any confusion.

Thank you,

Jonelle Scheetz
Clairton Environmental
United States Steel Corporation
Office:<PHONE_NUMBER>
Cell:<PHONE_NUMBER>

----- Forwarded by Jonelle S Scheetz/MonValley/USS on 08/08/2016 09:16 AM -----

From:        "Jones, DonnaLee"<EMAIL_ADDRESS>To:        Jonelle S Scheetz<EMAIL_ADDRESS>Cc:        Coleen Davis<EMAIL_ADDRESS>"Shappley, Ned"<EMAIL_ADDRESS>GABRIELLE RAYMOND<EMAIL_ADDRESS>Date:        08/04/2016 02:05 PM
Subject:        [External]-Re: EPA questions: U. S. Steel Clairton Works - Coke Oven ICR Questions
________________________________

Thanks for contacting me for clarification. I have some comments and questions.

1. Yes, of course.
2. What do you see as the a potential problem with what you plan to do?
3. Why do you not want to use the required water sampling methods? Do you mean you would want to substitute just the sampling parts or also the analysis parts of the other methods listed?

Regards,
Donna Lee Jones, Ph.D.
Senior Technical Advisor, Metals Sector
U. S. Environmental Protection Agency
Office of Air Quality Planning and Standards
Sector Policies and Programs Division / Metals & Inorganic Chemicals Group (D243-02)
Research Triangle Park, NC  27711  Tele:<PHONE_NUMBER>  Fax<PHONE_NUMBER>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
"Reasonableness never fails to be appreciated."  - anon.

________________________________________
From: Jonelle S Scheetz<EMAIL_ADDRESS>Sent: Thursday, August 4, 2016 1:39:06 PM
To: Jones, DonnaLee
Cc: Coleen Davis
Subject: U. S. Steel Clairton Works - Coke Oven ICR Questions

Dr. Jones,

Please see the following questions regarding the ICR testing at U. S. Steel - Clairton Works for 7A Quench Tower:

1.  EPA Method 315.  Clarification.  "Toluene to be used instead of methylene chloride as solvent for extraction."  It will be assumed EPA intended toluene to replace methylene chloride for sample collection and extraction.

2.  H2S by EPA Method 15 or 16.  Language in ICR page 11 of 40 for hydrogen sulfide is unclear regarding duration of test runs.  "Perform all tests over a period of at least 3 clock hours."    A single quench sample period for one rail car of coke will last approximately 2 minutes and ~ 4 quenches per hour are expected.  U. S. Steel proposes to complete the sampling at the Quench Tower in three clock hours collecting approximately 16 quench events for this method.

3.  For water sampling specifically, can the following methods replace the required methods in Enclosure 2?

      Pollutant                Required Method        Proposed Method
      Mercury                EPA 200.7(2)                EPA 245.1 (3) [method is mercury specific]
      PAH                        EPA 610 (5)                EPA 625 (6)
      TDS                        EPA 160.1(7)                SM 2540D

Thank you very much for your consideration in this matter,

Jonelle Scheetz
Clairton Environmental
United States Steel Corporation
Office:<PHONE_NUMBER>
Cell:<PHONE_NUMBER>