Federal Aluminum Aquatic Life Criteria Applicable to Oregon, 14834-14846 [2021-05428]
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Federal Register / Vol. 86, No. 52 / Friday, March 19, 2021 / Rules and Regulations
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[FR Doc. 2021–05514 Filed 3–18–21; 8:45 am]
BILLING CODE 6560–50–P
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
Environmental Protection
Agency (EPA).
ACTION: Final rule.
AGENCY:
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
SUMMARY:
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?
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
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:
Category
Examples of potentially affected entities
Industry ...............................................................
Municipalities ......................................................
Industrial point sources discharging pollutants to fresh waters of the United States in Oregon.
Publicly owned treatment works or similar facilities discharging pollutants to fresh waters of the
United States in Oregon.
Entities responsible for managing stormwater in the State of Oregon.
Stormwater Management Districts .....................
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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 https://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 https://
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: (202) 566–1192;
email address: soo-hoo.mimi@epa.gov.
SUPPLEMENTARY INFORMATION: This final
rule is organized as follows:
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
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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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
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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).
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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
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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.
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 onehour 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
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/201602/documents/guidelines-water-quality-criteria.pdf.
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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
III. Freshwater Aluminum Aquatic Life
Criteria
A. EPA’s National CWA Section 304(a)
Recommended Freshwater Aluminum
Criteria
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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).
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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The 2018 national recommended
criteria are based upon Multiple Linear
Regression (MLR) models for fish and
invertebrate species that use sitespecific 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-chemistrycondition-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
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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
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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.
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.
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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 mg/L) and
the CCC as a four-day average total
recoverable aluminum concentration (in
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).’’
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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mg/L). The CMC and CCC are not to be
exceeded more than once every three
years.
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.
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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
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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
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-mm 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.
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
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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.
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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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
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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
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 sitespecific 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
8 See Endnote ‘‘N,’’ https://www.oregon.gov/deq/
RulemakingDocs/tables303140.pdf.
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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 sitespecific 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
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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.
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
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, https://
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.
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14839
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.
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 lowend 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
10 Oregon Administrative Rules, Copper Standard
Implementatoin (Chapter 340, Division 041, Section
0033), https://www.oregon.gov/deq/wq/Pages/WQStandards-Copper.aspx.
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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
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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.
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, sitespecific 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.
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.
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.
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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.
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
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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
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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.
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,
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.
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14841
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-criteriaaluminum.
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
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. https://
www3.epa.gov/npdes/pubs/owm0264.pdf.
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concentrations could exceed criteria
values when low flows occur.15
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
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:
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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 sevenconsecutive-day average flow event
expected to occur once every ten years,
on average. Using the biologically-based
method, 1B3 represents the lowest oneday average flow event expected to
occur once every three years, on
average, and 4B3 represents the lowest
four-consecutive-day average flow event
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. https://
www.epa.gov/sites/production/files/2014-09/
documents/handbook-chapter5.pdf.
16 The same principle holds for developing a
TMDL target, the total load.
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. https://
www3.epa.gov/npdes/pubs/owm0264.pdf.
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expected to occur once every three
years, on average.18
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
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).
18 See
USEPA, 2014.
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.
19 See
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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 EPAapproved 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
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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).
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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
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)).
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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
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14843
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:
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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 https://www2.epa.gov/lawsregulations/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.
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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
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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.
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
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.
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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 governmentto-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
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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, Indianslands, 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
14845
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
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
■
2. Add § 131.47 to read as follows:
§ 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
Metal
CAS No.
Aluminum 1 2 ........
7429905
Criterion maximum concentration (CMC) 3
(μg/L)
I
Criterion continuous concentration (CCC) 4
(μg/L)
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
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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: (202) 566–1143, 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
fedreg.legal@nara.gov 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
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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
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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
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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
ENVIRONMENTAL PROTECTION
AGENCY
40 CFR Part 147
[EPA–HQ–OW–2020–0595; FRL 10018–31–
OW]
RIN 2040–ZA35
State of Michigan Underground
Injection Control (UIC) Class II
Program; Primacy Approval
Environmental Protection
Agency (EPA).
ACTION: Direct final rule.
AGENCY:
The U.S. Environmental
Protection Agency (EPA or Agency) is
taking direct final action to approve the
State of Michigan’s Underground
Injection Control Class II (UIC) Program
for primacy. EPA has determined that
the State’s program is consistent with
the provisions of the Safe Drinking
Water Act (SDWA) at Section 1425 to
prevent underground injection activities
that endanger underground sources of
drinking water. EPA’s approval allows
Michigan to implement and enforce its
state regulations for UIC Class II
injection wells located within the State.
Michigan’s authority excludes the
regulation of injection well Classes I, III,
IV, V, and VI, and all wells in Indian
country, as required by rule under the
SDWA.
DATES: This rule is effective on June 17,
2021 without further notice, unless EPA
receives adverse comment by April 19,
2021. If EPA receives adverse comment,
the Agency will publish a timely
withdrawal in the Federal Register
informing the public that this rule will
not take effect. For judicial review
purposes, this final rule is promulgated
as of June 17, 2021. The incorporation
by reference of certain publications
listed in the rule is approved by the
Director of the Federal Register as of
June 17, 2021.
ADDRESSES: Submit your comments to
the public docket for this rule,
identified by Docket No. EPA–HQ–OW–
2020–0595, at https://
www.regulations.gov. Follow the online
instructions for submitting comments.
All submissions received must include
jbell on DSKJLSW7X2PROD with RULES
SUMMARY:
VerDate Sep<11>2014
16:22 Mar 18, 2021
Jkt 253001
the Docket ID No. for this rulemaking.
Comments received may be posted
without change to https://
www.regulations.gov, including any
personal information provided. For
detailed instructions on sending
comments and additional information
on the rulemaking process, see the
‘‘Public Participation’’ heading of the
SUPPLEMENTARY INFORMATION section of
this document. Out of an abundance of
caution for members of the public and
our staff, the EPA Docket Center and
Reading Room are closed to the public,
with limited exceptions, to reduce the
risk of transmitting COVID–19. Our
Docket Center staff will continue to
provide remote customer service via
email, phone, and webform. We
encourage the public to submit
comments via https://
www.regulations.gov or email, as there
may be a delay in processing mail and
faxes. Hand deliveries and couriers may
be received by scheduled appointment
only. For further information on EPA
Docket Center services and the current
status, please visit us online at https://
www.epa.gov/dockets.
FOR FURTHER INFORMATION CONTACT: Kyle
Carey, Drinking Water Protection
Division, Office of Ground Water and
Drinking Water (4606M), U.S.
Environmental Protection Agency, 1200
Pennsylvania Ave., NW, Washington,
DC 20460; telephone number: (202)
564–2322; fax number: (202) 564–3754;
email address: carey.kyle@epa.gov, or
Anna Miller, UIC Section, U.S.
Environmental Protection Agency, 77
West Jackson Boulevard, Chicago, IL
60604; telephone number: (312) 886–
7060; email address: miller.anna@
epa.gov.
SUPPLEMENTARY INFORMATION: This
supplementary information is organized
as follows:
I. Public Participation
II. Direct Final Rule
III. Entities Affected by This Action
IV. Legal Authorities
V. Michigan’s Application
A. Public Participation Activities
Conducted by the State of Michigan
B. Notice of Completion and Public
Participation Activities Conducted by
EPA
VI. Incorporation by Reference
VII. Statutory and Executive Order Reviews
A. Executive Order 12866: Regulatory
Planning and Review and Executive
Order 12563: Improving Regulation and
Controlling Regulatory Costs
B. Paperwork Reduction Act
C. Regulatory Flexibility Act
D. Unfunded Mandates Reform Act
E. Executive Order 13132: Federalism
F. Executive Order 13175: Consultation
and Coordination With Indian Tribal
Governments
PO 00000
Frm 00040
Fmt 4700
Sfmt 4700
G. Executive Order 13045: Protection of
Children From Environmental Health
and Safety Risks
H. Executive Order 13211: Actions
Concerning Regulations That
Significantly Affect Energy Supply,
Distribution, or Use
I. National Technology Transfer and
Advancement Act
J. Executive Order 12898: Federal Actions
To Address Environmental Justice in
Minority Populations and Low-Income
Populations
K. Congressional Review Act (CRA)
I. Public Participation
Submit your written comments,
identified by Docket ID No. EPA–HQ–
OW–2020–0595, at https://
www.regulations.gov. Follow the online
instructions for submitting comments.
Once submitted, comments cannot be
edited or removed from the docket. EPA
may publish any comment received to
its public docket. Do not submit
electronically any information you
consider to be Confidential Business
Information (CBI) or other information
whose disclosure is restricted by statute.
Contact EPA if you want to submit CBI;
see FOR INFORMATION CONTACT section of
this document. Multimedia submissions
(audio, video, etc.) must be
accompanied by a written comment.
The written comment is considered the
official comment and should include
discussion of all points you wish to
make. EPA will generally not consider
comments or comment contents located
outside of the primary submission (i.e.,
on the web, cloud, or other file sharing
system). For additional submission
methods, the full EPA public comment
policy, information about CBI or
multimedia submissions, and general
guidance on making effective
comments, please visit https://
www.epa.gov/dockets/commenting-epadockets.
EPA continues to carefully and
continuously monitor information from
the Centers for Disease Control and
Prevention (CDC), local area health
departments, and our Federal partners
so that we can respond rapidly as
conditions change regarding COVID–19.
II. Direct Final Rule
EPA published this rule without a
prior proposed rule. The Agency views
this action as noncontroversial and
anticipates no adverse comment.
However, in the ‘‘Proposed Rules’’
section of the Federal Register, EPA is
publishing a separate document that
serves as the proposed rule if the
Agency receives adverse comment on
this direct final rule. The Agency will
not institute a second comment period
on this action. Any parties interested in
E:\FR\FM\19MRR1.SGM
19MRR1
Agencies
[Federal Register Volume 86, Number 52 (Friday, March 19, 2021)]
[Rules and Regulations]
[Pages 14834-14846]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-05428]
-----------------------------------------------------------------------
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.
-----------------------------------------------------------------------
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
https://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 https://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: (202) 566-1192; email address: [email protected].
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:
---------------------------------------------------------------------------
\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).
------------------------------------------------------------------------
Category Examples of potentially affected entities
------------------------------------------------------------------------
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.
------------------------------------------------------------------------
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
[[Page 14835]]
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.
---------------------------------------------------------------------------
\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.
---------------------------------------------------------------------------
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
[[Page 14836]]
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\
---------------------------------------------------------------------------
\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.
---------------------------------------------------------------------------
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
[[Page 14837]]
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.
---------------------------------------------------------------------------
\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).''
---------------------------------------------------------------------------
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.
---------------------------------------------------------------------------
\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.
---------------------------------------------------------------------------
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
[[Page 14838]]
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\
---------------------------------------------------------------------------
\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.
---------------------------------------------------------------------------
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.
---------------------------------------------------------------------------
\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.
---------------------------------------------------------------------------
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
[[Page 14839]]
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, https://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
[[Page 14840]]
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.
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\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
[[Page 14841]]
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
[[Page 14842]]
concentrations could exceed criteria values when low flows occur.\15\
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\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. https://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. https://www.epa.gov/sites/production/files/2014-09/documents/handbook-chapter5.pdf.
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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\
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\16\ The same principle holds for developing a TMDL target, the
total load.
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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. https://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\
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\18\ See USEPA, 2014.
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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.
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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
[[Page 14843]]
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).
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\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)).
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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:
[[Page 14844]]
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 https://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.
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\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.
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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
[[Page 14845]]
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: (202) 566-1143, 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 protected] 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
[[Page 14846]]
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