[Federal Register Volume 80, Number 143 (Monday, July 27, 2015)]
[Pages 44350-44354]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-18348]



[EPA-HQ-OW-2004-0019; FRL-9931-21-OW]

Request for Scientific Views: Draft Recommended Aquatic Life 
Ambient Water Quality Chronic Criterion for Selenium--Freshwater 2015

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of availability.


SUMMARY: The Environmental Protection Agency (EPA) is opening the 
comment period for the Agency's draft recommended aquatic life water 
quality chronic criterion for selenium in freshwater. EPA released a 
previous draft entitled ``External Peer Review Draft Aquatic Life 
Ambient Water Quality Criterion for Selenium--Freshwater, 2014'' for 
public comment on May 14, 2014. EPA received scientific views from the 
public and stakeholders, and convened a contractor-led expert external 
peer review. EPA considered the results from the expert peer review and 
scientific views and comments from the public and stakeholders to 
develop the current draft document, which is now available for comment. 
Following closure of this public comment period, EPA will consider 
scientific views from the public on this draft document as well as any 
new data or information received. EPA will then publish Federal 
Register notice(s) announcing the availability of the final selenium 

DATES: Comments must be received on or before September 25, 2015.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-OW-
2004-0019, by one of the following methods:
     www.regulations.gov: Follow the on-line instructions for 
submitting comments.
     Email: ow-docket@epa.gov. Attention Docket No. EPA-HQ-OW-
     Fax: 202-566-1140.
     Mail: EPA Water Docket, Environmental Protection Agency, 
Mailcode 2822-IT 1200 Pennsylvania Ave. NW., Washington, DC 20640, 
Attention Docket No. EPA-HQ-OW-2004-0019. Please include a total of two 
copies (including references).
     Hand Delivery: EPA Water Docket, EPA Docket Center, 
William Jefferson Clinton West Building, Room 3334, 1301 Constitution 
Avenue NW., Washington, DC 20004, Docket No. EPA-HQ-OW-2004-0019. Such 
deliveries are only accepted during the Docket's normal hours of 
operation, and special arrangements should be made for deliveries of 
boxed information.
    Instructions: Direct your comments to Docket ID No. [EPA-HQ-2004-
0019]. EPA's policy is that all comments received will be included in 
the public docket without change and may be made available online at 
www.regulations.gov, including any personal information provided, 
unless the comment includes information claimed to be Confidential 
Business Information (CBI) or other information whose disclosure is 
restricted by statute. Do not submit information that you consider to 
be CBI or otherwise protected through www.regulations.gov or ow-docket@epa.gov. The www.regulations.gov Web site is an ``anonymous 
access'' system, which means EPA will not know your identity or contact 
information unless you provide it in the body of your comment. If you 
send an email comment directly

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to EPA without going through www.regulations.gov, your email address 
will be automatically captured and included as part of the comment that 
is placed in the public docket and made available on the Internet. If 
you submit an electronic comment, EPA recommends that you include your 
name and other contact information in the body of your comment and with 
any disk or CD-ROM you submit. If EPA cannot read your comment due to 
technical difficulties and cannot contact you for clarification, EPA 
may not be able to consider your comment. Electronic files should avoid 
the use of special characters, any form of encryption, and be free of 
any defects or viruses.

FOR FURTHER INFORMATION CONTACT: Kathryn Gallagher, Ph.D., Office of 
Water, Health and Ecological Criteria Division (4304T), Environmental 
Protection Agency, 1200 Pennsylvania Avenue NW., Washington, DC 20460; 
telephone: (202) 564-1398; fax: 202-566-1140, or email: 

    Docket: All documents in the docket are listed in the 
www.regulations.gov index. Although listed in the index, some 
information is not publicly available, e.g., CBI or other information 
whose disclosure is restricted by statute. Certain other material, such 
as copyrighted material, will be publicly available only in hard copy. 
Publicly available docket materials are available either electronically 
in www.regulations.gov or in hard copy at the EPA-HQ-OW-2004-0019 
Docket, EPA/DC, EPA West, Room 3334, 1301 Constitution Ave. NW., 
Washington, DC. The 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 EPA-HQ-OW-2004-0019 is (202) 566-2426. For additional 
information about EPA's public docket, visit the EPA Docket Center 
homepage at http://www.epa.gov/epahome/dockets.htm.


I. What are recommended water quality criteria?

    EPA's recommended water quality criteria are scientifically derived 
numeric values that protect aquatic life or human health from the 
deleterious effects of pollutants in ambient water. Section 304(a)(1) 
of the Clean Water Act (CWA) requires EPA to develop and publish and, 
from time to time, revise, criteria for protection of aquatic life and 
human health that accurately reflect 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.
    EPA's recommended section 304(a) criteria provide technical 
information to states and authorized tribes in adopting water quality 
standards (WQS) that ultimately provide a basis for assessing water 
body health and controlling discharges or releases of pollutants. Under 
the CWA and its implementing regulations, states and authorized tribes 
are to adopt water quality criteria to protect designated uses (e.g., 
public water supply, aquatic life, recreational use, or industrial 
use). EPA's recommended water quality criteria do not substitute for 
the CWA or regulations, nor are they regulations themselves. EPA's 
recommended criteria do not impose legally binding requirements. States 
and authorized tribes have the discretion to adopt, where appropriate, 
other scientifically defensible water quality criteria that differ from 
these recommendations.

II. What is Selenium and why is EPA concerned about it?

    Selenium is a naturally occurring chemical element that is 
nutritionally essential in small amounts, but toxic at higher 
concentrations. Selenium can be released to the environment by a number 
of anthropogenic sources, such as coal mining, coal-fired power plants 
(fly ash), irrigated agriculture, and phosphate mining. Selenium is a 
bioaccumulative pollutant. Fish and other aquatic organisms are exposed 
to and accumulate selenium primarily through their diet, and not 
directly through water. Selenium toxicity in fish occurs primarily 
through maternal transfer to the eggs and subsequent reproductive 
effects. Consequently, EPA is updating its national recommended chronic 
aquatic life criterion for selenium in freshwater to reflect the latest 
scientific information, which indicates that selenium toxicity to 
aquatic life is primarily driven by organisms consuming selenium-
contaminated food rather than by being directly exposed to selenium 
dissolved in water.

III. Information on the Draft Aquatic Life Ambient Water Quality 
Criterion for Selenium--Freshwater 2015

    EPA prepared a draft aquatic life criterion document for selenium 
based on the latest scientific information and current EPA policies and 
methods, including EPA's Guidelines for Deriving Numerical National 
Water Quality Criteria for the Protection of Aquatic Organisms and 
Their Uses (1985) (EPA/R-85-100) and Guidelines for Ecological Risk 
Assessment (1998) (EPA/630/R-95/002F). Toxicity data and other 
information on the effects of selenium were obtained from reliable 
sources and subjected to both internal and, in some cases, external 
peer review. EPA considered public comments previously collected in 
response to EPA's 2004 notice of availability (published on December 
17, 2004 at 69 FR 75541) and new toxicity data for selenium developed 
in response to those comments (EPA-822-F-08-005) in the development of 
the external peer review draft criterion document. EPA also considered 
information submitted in 2014 during the external peer review and 
public comment on the ``External Peer Review Draft,'' including 
additional toxicity data, in developing the current draft criterion.
    The draft criterion has four elements (Table 1), consisting of two 
fish tissue-based and two water column-based elements. The draft 
criterion document contains a recommendation that states and authorized 
tribes adopt into their WQS a selenium criterion that includes all four 
elements. Because fish tissue-based concentration is a more direct 
measure of selenium toxicity to aquatic life than water column 
concentrations, EPA recommends that fish tissue elements be given 
precedence over the water column elements when both types of data are 
available, except in certain situations.
    The available data indicate that freshwater aquatic life would be 
protected from the toxic effects of selenium by applying the following 
four-element criterion:
    1. The concentration of selenium in the eggs or ovaries of fish 
does not exceed 15.8 mg/kg, dry weight;
    2. The concentration of selenium (a) in whole-body of fish does not 
exceed 8.0 mg/kg dry weight, or (b) in muscle tissue of fish (skinless, 
boneless fillet) does not exceed 11.3 mg/kg dry weight;
    3. The 30-day average concentration of selenium in water does not 
exceed 3.1 [micro]g/L in lotic (flowing) waters and 1.2 [micro]g/L in 
lentic (standing) waters more than once in three years on average;

[[Page 44352]]

    4. The intermittent concentration of selenium in water does not 


    The draft criterion document does not include a draft acute 
criterion (based on water-only exposure) because selenium is 
bioaccumulative and toxicity primarily occurs through dietary exposure. 
EPA will consider the public comments, revise the document as 
necessary, and issue a final updated selenium criterion document. This 
draft criterion document does not represent and should not be construed 
to represent any final EPA policy, viewpoint, or determination.

IV. What is the relationship between the Draft Chronic Water Quality 
Criterion and Your State or Tribal Water Quality Standards?

    As part of the WQS triennial review process defined in section 
303(c)(1) of the CWA, the states and authorized tribes are responsible 
for maintaining and revising WQS. Standards consist of

[[Page 44353]]

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 WQS at least once 
every three years.
    States and authorized tribes must adopt water quality criteria that 
protect designated uses. Protective criteria are 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 can:
    (1) Establish numerical values based on recommended section 304(a) 
    (2) Adopt section 304(a) criteria modified to reflect site-specific 
    (3) Adopt criteria derived using other scientifically defensible 
methods; or
    (4) Establish narrative criteria where numeric criteria cannot be 
established or to supplement numerical criteria (40 CFR 131.11(b)).
    It is important for states and authorized tribes to consider any 
new or updated section 304(a) criteria as part of their triennial 
review to ensure that state or tribal WQS reflect current science and 
protect applicable designated uses. The recommendations in the draft 
selenium criterion document may change based on scientific views shared 
in response to this notice. Upon finalization, the updated selenium 
criterion would supersede EPA's previous 304(a) freshwater criteria for 
    Consistent with 40 CFR 131.21, new or revised water quality 
criteria adopted into law or regulation by states and authorized tribes 
on or after May 30, 2000 are in effect for CWA purposes only after EPA 
    To support EPA's upcoming CWA section 304(a) ambient water quality 
criteria recommendations for selenium, EPA is developing informational 
materials to aid state and tribal adoption. These informational 
materials will be released when the final selenium criterion is 

V. Solicitation of Scientific Views

    EPA is soliciting additional scientific views, data, and 
information regarding the science and technical approach used by the 
Agency in the derivation of this draft freshwater chronic criterion for 
selenium. The Agency has identified two particular issues (detailed 
below), for which additional data and information are solicited.

1. Request for Additional Data and Information Related to the 
Sensitivity of Cyprinids (Minnow Species) to Selenium

    During the 2014 public comment process, EPA received comments that 
included data on zebrafish (Danio rerio) toxicity testing with 
selenium. (Public comment EPA-HQ-OW-2004-0019-0354; http://www.regulations.gov/). The commenters suggested that the data be used 
by the EPA in its revision of the egg-ovary criterion element, since 
the zebrafish study was a maternal transfer study similar to those used 
in the external peer review draft. In response to the comments, EPA 
solicited the study and all underlying data from the authors of the 
study referenced by the commenters (Thomas and Janz, 2014). EPA 
undertook a comprehensive data review of the study and data.
    During its review, EPA identified concerns regarding the 
concentration response curve of the zebrafish toxicity test compared to 
the other fish species toxicity tests that EPA used in derivation of 
the 2014 draft criterion. The zebrafish data showed an anomalously 
shallow concentration response curve compared to data from all other 
tested fish species. Further, high control mortality (47%) at the end 
of the study raised concerns about the study design as well as the 
health of the fish at the time of testing. In addition, since the 
zebrafish is a non-native cyprinid species, EPA assessed the 
information available on zebrafish sensitivity to selenium compared to 
the sensitivity of native cyprinid (minnow) species across the United 
States (Appendix D in the criteria document), including several studies 
where native cyprinids were investigated in selenium-impacted waters. 
Data from these studies suggest that native cyprinids are likely less 
sensitive to selenium than the currently available non-native zebrafish 
data suggest. The results of the study, particularly a comparison of 
the concentration response relationships of zebrafish vs. all of the 
other fish species for which we have similar data, raises a concern.
    Given these concerns, EPA has not used the zebrafish data 
quantitatively in the derivation of the revised criterion. EPA seeks 
additional information on cyprinid taxa sensitivity to selenium, and 
particularly additional data on zebrafish. These studies should be 
submitted to the docket in similar fashion as scientific views on the 
criterion document. EPA will then consider this information in 
finalizing the selenium criterion document.

2. Request for Additional Data and Information on the Dynamics of 
Selenium Equilibrium in Lentic and Lotic Waters Related to New or 
Increased Selenium Inputs

    EPA's draft selenium water quality criterion recommends that 
elements based on fish tissue (egg-ovary, whole body, and/or muscle) 
data should override the criterion elements based on selenium water 
column data. The criterion is structured this way because fish tissue 
concentrations generally provide the most robust and direct information 
on potential selenium effects in fish. However, because selenium 
concentrations in fish tissue are a result of selenium bioaccumulation 
via dietary exposure, there are specific circumstances where the fish 
tissue concentrations are not expected to fully represent potential 
effects on fish and the aquatic ecosystem: Waters with new or increased 
selenium inputs, prior to equilibrium within the food web; and 
``fishless waters'' (waters where fish have been extirpated or where 
physical habitat and/or flow regime cannot sustain fish).
    For the purposes of EPA's draft recommendations, EPA considers new 
inputs to be new activities resulting in selenium being released into a 
lentic or lotic waterbody. Increased inputs are increases from a 
current activity in which selenium is being released into a lentic or 
lotic waterbody. New or increased inputs of selenium into the water and 
hence into the food web, likely will result in increased 
bioaccumulation of selenium in fish over a period of time until the 
selenium from the new or increased selenium release achieves a quasi-
``steady state'' balance within the food web. EPA estimates that 
concentrations of selenium in fish tissue will not represent a ``steady 
state'' for up to several months in lotic systems, and longer time 
periods (e.g., 2 to 3 years) in lentic systems, dependent upon the size 
and bathymetry of a given system; the location of the selenium input 
related to the shape and internal circulation of the waterbody, 
particularly in reservoirs with multiple riverine inputs; and the 
particular food web. EPA recommends that in implementing a selenium 
water quality criterion to protect aquatic life, fish tissue 
concentrations of selenium not override water column concentrations 
until sufficient time has passed to allow equilibrium to be attained in 
the food web of lotic and lentic systems.

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Estimates of steady state under new or increased selenium input 
situations are expected to be site dependent. Local information should 
be used to better refine an estimate of time to steady state for a 
particular waterbody. EPA seeks data and information that EPA can 
include in its final recommendations on time intervals during which 
fish tissue concentrations should not override water column 

SUPPLEMENTARY INFORMATION: EPA will make the external peer review and 
public comments, as well as Agency responses to these comments on the 
previously published External Peer Review Draft Aquatic Life Ambient 
Water Quality Criterion for Selenium--Freshwater 2014 (EPA 822-P-14-
001) (External Peer Review Draft), available in the docket with the 
revised draft selenium criteria document at www.regulations.gov.

    Dated: July 17, 2015.
Kenneth J. Kopocis,
Deputy Assistant Administrator, Office of Water.
[FR Doc. 2015-18348 Filed 7-24-15; 8:45 am]