
[Federal Register Volume 83, Number 245 (Friday, December 21, 2018)]
[Notices]
[Pages 65663-65665]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-27745]


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ENVIRONMENTAL PROTECTION AGENCY

[EPA-HQ-OW-2017-0260; FRL-9988-42-OW]


Aquatic Life Ambient Water Quality Criteria for Aluminum in 
Freshwater

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of availability.

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SUMMARY: The Environmental Protection Agency (EPA) is announcing the 
availability of Aquatic Life Ambient Water Quality Criteria for 
Aluminum in Freshwater. The EPA first released freshwater criteria for 
aluminum in 1988 to protect aquatic life from harmful effects of 
aluminum toxicity. The EPA updated its recommended aluminum criteria to 
reflect the latest science and to provide users the flexibility to 
develop criteria based on site-specific water chemistry. The document 
provides a scientific assessment of ecological effects and is not a 
regulation. The EPA submitted the draft document for external expert 
peer review and edited the document considering peer review comments. 
The EPA subsequently released the draft criteria document for a 90-day 
public comment period in July 2017. The EPA has considered the public 
comments and revised the document based on consideration of those 
comments. The final criteria document provides recommendations for 
states and authorized tribes to establish water quality standards under 
the Clean Water Act. The recommendations found in this document 
supersede the EPA's 1988 national recommended criteria for aluminum in 
ambient water.

FOR FURTHER INFORMATION CONTACT: Diana Eignor, Health and Ecological 
Criteria Division, Office of Water (Mail Code 4304T), Environmental 
Protection Agency, 1200 Pennsylvania Avenue NW, Washington, DC 20460; 
telephone: (202) 566-1143; or email: eignor.diana@epa.gov.

SUPPLEMENTARY INFORMATION:

I. General Information

A. How can I get copies of this document and other related information?

    1. Docket. EPA has established a docket for this action under 
Docket ID No. EPA-HQ-OW-2017-0260. Publicly available docket materials 
are available either electronically through www.regulations.gov or in 
hard copy at the Water Docket in the EPA Docket Center, (EPA/DC) EPA 
West, Room 3334, 1301 Constitution Ave. NW, Washington, DC. The EPA 
Docket Center Public Reading Room is open from 8:30 a.m. to 4:30 p.m., 
Monday through Friday, excluding legal holidays. The telephone number 
for the Public Reading Room is (202) 566-1744, and the telephone number 
for the Water Docket is (202) 566-2426.
    2. Electronic Access. You may access this Federal Register document

[[Page 65664]]

electronically from the Government Printing Office under the Federal 
Register listings FDSys (http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR).

II. What is aluminum and how does it affect aquatic life?

    Aluminum is found in most soils and rocks and is the third most 
abundant element and the most common metal in the earth's crust. 
Aluminum can enter the water via natural processes, like weathering of 
rocks and as a result of human based activities, such as drinking and 
waste water treatment and mining. Aluminum is considered a non-
essential metal because fish and other aquatic life do not need it to 
function. Elevated levels of aluminum can affect some species' ability 
to regulate ions and inhibit respiratory functions. Aquatic plants are 
generally less sensitive than fish and other aquatic life to aluminum.

III. What are EPA's updated recommended criteria for aluminum in 
freshwater?

    The recommended criteria concentrations for aluminum in freshwater 
to protect aquatic life depends on a site's water chemistry parameters. 
Bioavailability is the measure of whether a substance in the 
environment is available to affect living organisms like fish. The 
bioavailability of aluminum is dependent on specific water chemistry 
parameters. The more bioavailable the aluminum is, the more likely it 
is to cause a toxic effect. The water chemistry parameters that have 
the greatest impact on aluminum's bioavailability are pH, dissolved 
organic carbon (DOC) and total hardness.
    The final 2018 recommended national criteria are based upon 
Multiple Linear Regression (MLR) models for fish and invertebrate 
species that use pH, DOC, and total hardness to quantify the effects of 
these water chemistry parameters on the bioavailability and associated 
toxicity of aluminum to aquatic organisms. The MLR models are used to 
normalize the available toxicity data to reflect the effects of the 
water chemistry (pH, hardness, DOC) on the toxicity of aluminum to 
tested species. These normalized toxicity test data are then used in a 
criteria calculator to generate criteria for specific water chemistry 
conditions, yielding the water chemistry specific acute and chronic 
criteria concentrations. This flexible approach is based on the latest 
science and allows users to develop site-specific aluminum criteria for 
freshwaters that appropriately reflect important water chemistry 
parameters. The recommended acute criteria (known as the criteria 
maximum concentration or CMC) duration is a one-hour average and the 
recommended chronic criteria (criteria chronic concentration or CCC) 
duration is a four-day average. The EPA recommends that the CMC and CCC 
not be exceeded more than once every three years.
    These final 2018 recommended national aluminum criteria are 
expressed as total recoverable metal concentrations. The use of total 
recoverable aluminum includes monomeric (both organic and inorganic) 
forms, polymeric and colloidal forms, as well as particulate forms and 
aluminum sorbed to clays. However, toxicity data comparing toxicity of 
aluminum using total recoverable aluminum and dissolved aluminum 
demonstrated that toxic effects increased with increasing 
concentrations of total recoverable aluminum even though the 
concentration of dissolved aluminum was relatively constant. If 
aluminum criteria were based on dissolved concentrations, toxicity 
would likely be underestimated, as colloidal forms and hydroxide 
precipitates of the metal that can dissolve under natural conditions 
and become biologically available would not be measured. The criteria 
document contains more discussion of the studies that informed the 
choice to use total recoverable aluminum as the basis for the final 
2018 recommended national criteria. The current EPA-approved Clean 
Water Act Test Methods \1\ for aluminum in natural waters and waste 
waters measure total recoverable aluminum.
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    \1\ 40 CFR part 136.3 and Appendix C
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    The numeric outputs of the 2018 recommended National Aluminum 
Criteria Calculator will depend on the specific pH, DOC, and total 
hardness concentrations entered into the models. The model outputs (CMC 
and CCC) are numeric values that are protective for the set of input 
conditions. Criteria can be determined in two ways: Use the provided 
Aluminum Criteria Calculator V.2.0 to enter the pH, DOC, and total 
hardness conditions at a specific site to calculate the numeric 
aluminum CMC and CCC corresponding to those local input water-quality 
conditions, or (2) use the look-up tables provided in the criteria 
document, developed using the calculator, to find the numeric aluminum 
CMC and CCC most closely corresponding to the local conditions for pH, 
DOC, and total hardness. In order to calculate numeric water quality 
criteria for aluminum that will protect the aquatic life designated 
uses of a site over the full range of ambient conditions and toxicity, 
multiple model outputs will need to be considered.
    See Table 1 for a comparison of the EPA's 1988 criteria and the 
updated 2018 criteria for aluminum.

               Table 1--Summary of the EPA National Recommended Aquatic Life Criteria for Aluminum
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   EPA aquatic life criteria for      Freshwater acute \a\ (1 hour, total   Freshwater Chronic \a\ (4-day, total
              aluminum                       recoverable aluminum)                  recoverable aluminum)
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2018 Updated Criteria (Vary as a     1-4,800 [micro]g/L \b\...............  0.63-3,200 [micro]g/L \b\.
 function of a site's pH, total
 hardness, and DOC).
1988 Criteria (pH 6.5-9.0, across    750 [micro]g/L.......................  87 [micro]g/L.
 all total hardness and DOC ranges).
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\a\ Values are recommended not to be exceeded more than once every three years on average.
\b\ Values will be different under differing water chemistry conditions.

IV. What are recommended water quality criteria developed by the EPA?

    Section 304(a)(1) of the Clean Water Act directs the EPA to develop 
and publish and, from time to time, revise criteria for water quality 
accurately reflecting the latest scientific knowledge. Water quality 
criteria developed under section 304(a) are based solely on data and 
scientific judgments on the relationship between pollutant 
concentrations and environmental and human health effects. Section 
304(a) criteria do not reflect consideration of economic impacts or the 
technological feasibility of meeting pollutant concentrations in 
ambient water.

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    Section 304(a) criteria provide guidance to states and authorized 
tribes in adopting water quality standards that ultimately provide a 
basis for controlling discharges of pollutants. Under the Clean Water 
Act and its implementing regulations, states and authorized tribes are 
to adopt water quality criteria to protect designated uses (e.g., 
aquatic life, recreational use). The EPA water quality criteria 
recommendations are not regulations. Thus, the EPA recommended criteria 
do not constitute legally binding requirements. States and authorized 
tribes may adopt other scientifically defensible water quality criteria 
that differ from these recommendations. As part of the water quality 
standards triennial review process defined in section 303(c)(1) of the 
Clean Water Act, the states and authorized tribes are responsible for 
maintaining and revising water quality standards. Standards consist of 
designated uses, water quality criteria to protect those uses, a policy 
for antidegradation, and may include general policies for application 
and implementation. Section 303(c)(1) requires states and authorized 
tribes to review and modify, if appropriate, their water quality 
standards at least once every three years. Consistent with the EPA 
regulations at 40 CFR 131.11(a), protective criteria must be based on a 
sound scientific rationale and contain sufficient parameters or 
constituents to protect the designated uses. Criteria may be expressed 
in either narrative or numeric form. States and authorized tribes have 
four options when adopting water quality criteria for which EPA has 
published section 304(a) criteria. They may: (1) Establish numerical 
values based on recommended section 304(a) criteria; (2) Adopt section 
304(a) criteria modified to reflect site-specific conditions; (3) Adopt 
criteria derived using other scientifically defensible methods; or (4) 
Establish narrative criteria where numeric criteria cannot be 
established or to supplement numeric criteria (40 CFR 131.11(b)).

    Dated: December 14, 2018.
Anna J. Wildeman,
Acting Assistant Administrator, Office of Water.
[FR Doc. 2018-27745 Filed 12-20-18; 8:45 am]
 BILLING CODE 6560-50-P


