
[Federal Register: December 30, 2009 (Volume 74, Number 249)]
[Notices]               
[Page 69086-69087]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr30de09-45]                         

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ENVIRONMENTAL PROTECTION AGENCY

[FRL-9097-8; OW-2009-0921]

 
Draft 2009 Update Aquatic Life Ambient Water Quality Criteria for 
Ammonia--Freshwater

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of availability of draft criteria and request for 
scientific views.

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SUMMARY: Pursuant to section 304(a) of the Clean Water Act (CWA), the 
Environmental Protection Agency (EPA) is announcing the availability of 
draft national recommended water quality criteria for ammonia for the 
protection of aquatic life. The draft criteria are based on EPA's 
Guidelines for Deriving Numerical National Water Quality Criteria for 
the Protection of Aquatic Organisms and Their Uses (1985), (EPA/R-85-
100). EPA's recommended section 304(a) water quality criteria provide 
guidance to States and authorized tribes in adopting water quality 
standards for protecting aquatic life and human health and provide 
guidance to EPA for promulgating Federal regulations under CWA section 
303(c), when such action is necessary.

DATES: Scientific views must be received on or before March 1, 2010. 
Comments postmarked after this date may not be considered.

ADDRESSES: Submit your scientific views, identified by Docket ID No. 
EPA-HQ-OW-2009- 0921, by one of the following methods:
     http://www.regulations.gov: Follow the on-line 
instructions for submitting comments.
     E-mail: OW-Docket@epa.gov.
     Mail: U.S. Environmental Protection Agency; EPA Docket 
Center (EPA/DC) Water Docket, MC 28221T; 1200 Pennsylvania Avenue, NW., 
Washington, DC 20460.
     Hand Delivery: EPA Docket Center, 1301 Constitution Ave, 
NW., EPA West, Room 3334, Washington DC. 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-OW-2009-
0921. EPA's policy is that all comments received will be included in 
the public docket without change and may be made available online at 
http://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 http://
www.regulations.gov or e-mail. The http://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 e-mail comment directly to EPA without 
going through http://www.regulations.gov your e-mail 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 additional information about EPA's public 
docket visit the EPA Docket Center homepage at http://www.epa.gov/
epahome/dockets.htm.
    Docket: All documents in the docket are listed in the http://
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 http://www.regulations.gov or in hard copy at the Office of Water 
Docket/EPA/DC, 1301 Constitution Ave, NW., EPA West, Room 3334, 
Washington DC. This Docket Facility is open from 8:30 a.m. until 4:30 
p.m., EST, Monday through Friday, excluding legal holidays. The 
telephone number for the Public Reading Room is (202) 566-1744, and the 
telephone number for the Office of Water Docket is (202) 566-2426.

FOR FURTHER INFORMATION CONTACT: Lisa Huff, Health and Ecological 
Criteria Division (4304T), U.S. EPA, 1200 Pennsylvania Ave., NW., 
Washington, DC 20460; (202) 566-0787; huff.lisa@epa.gov.

SUPPLEMENTARY INFORMATION:

I. What Are Water Quality Criteria?

    Water quality criteria are either narrative descriptions of water 
quality or 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 requires 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.
    Section 304(a) criteria provide guidance to States and authorized 
tribes in adopting water quality standards that ultimately provide a 
basis for controlling discharges or releases of pollutants. The 
criteria also provide guidance to EPA when promulgating Federal 
regulations under section 303(c) when such action is necessary. 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. Thus, 
EPA's recommended criteria do not impose legally binding requirements. 
States and authorized tribes have the discretion to adopt, where 
appropriate, other scientifically

[[Page 69087]]

defensible water quality criteria that differ from these 
recommendations.

II. What Are the Ammonia Criteria?

    EPA is today publishing draft national recommended water quality 
criteria (NRWQC) for ammonia for protecting aquatic life. These draft 
criteria updates are based on EPA's Guidelines for Deriving Numerical 
National Water Quality Criteria for the Protection of Aquatic Organisms 
and Their Uses (1985), (EPA/R-85-100). These Guidelines describe the 
Agency's current approach for deriving national recommended water 
quality criteria to protect aquatic life. Toxicity data and other 
information on the effects of ammonia were obtained from reliable 
sources and subjected to both internal and external scientific peer 
review. The NRWQC for ammonia saltwater are not being updated at this 
time.
    Freshwater: Freshwater aquatic organisms and their uses should not 
be affected unacceptably if--
    1. The one-hour average concentration of total ammonia nitrogen (in 
mg N/L) does not exceed, more than once every three years on the 
average, the CMC (acute criterion), which is dependent on the aquatic 
organisms present.
    2A. The thirty-day average concentration of total ammonia nitrogen 
(in mg N/L) does not exceed, more than once every three years on the 
average, the CCC (chronic criterion), which is dependent on the aquatic 
organisms present.
    2B. In addition, the highest four-day average within the 30-day 
period should not exceed 2.5 times the CCC.
    The acute and chronic criteria concentrations are expressed as 
functions of temperature and pH, such that values differ across sites, 
and differ over time within a site. See draft criteria document (pp. 
34-38) for actual equations describing this function. As temperature 
decreases, invertebrates, but not fish, become less sensitive to 
ammonia, and below a particular temperature threshold, fish become the 
most sensitive genera.
    Acute Criteria: At pH=8, where freshwater mussels are present, the 
criterion concentration ranges from 1.90 mg N/L at 30[deg] C to 9.81 mg 
N/L at 0[deg] C. At pH=8, where freshwater mussels are absent the 
criterion concentration ranges from 3.29 mg N/L at 30[deg] C to 9.99 mg 
N/L at 0[deg] C.
    Chronic Criteria: At pH=8, where freshwater mussels are present, 
irrespective of whether fish early life stages (ELS) are present or 
absent, the criterion ranges from 0.186 mg N/L at 30[deg] C to 0.817 mg 
N/L at 0[deg] C. When freshwater mussels are absent, the values range 
from 1.33 mg N/L at 30[deg] C to 2.32 mg N/L at 0[deg] C at times when 
fish ELS are present, and from 1.33 mg N/L at 30[deg] C to 5.87 mg N/L 
at 0[deg] C at times when fish ELS are absent.

------------------------------------------------------------------------
                                 Draft 2009 ammonia      Current 1999
                                 criteria (at pH 8    criteria (at pH 8
                                   and 25[deg] C)       and 25[deg] C)
------------------------------------------------------------------------
Acute.........................  2.9 mg N/L mussels   5.6 mg N/L salmon
                                 present.             present.
                                5.0 mg N/L mussels
                                 absent.
Chronic.......................  0.26 mg N/L mussels  1.2 mg N/L fish
                                 present.             early life stages
                                                      present.
                                1.8 mg N/L mussels
                                 absent.
------------------------------------------------------------------------


    Note: These criteria values are appropriate at the standard 
normalized pH and temperature; the criteria values are a function of 
the variability of pH and temperature.

    The water quality criteria for ammonia saltwater are not being 
updated at this time.

III. What is the Relationship Between the Water Quality Criteria and 
State or Tribal Water Quality Standards?

    As part of the water quality standards triennial review process 
defined in Section 303(c)(1) of the CWA, the States and authorized 
Tribes are responsible for maintaining and revising water quality 
standards. Water quality standards consist of three principal elements: 
designated uses, water quality criteria to protect those uses, and 
antidegradation requirements, providing for protection of existing 
water uses and limitations on degradation of high quality waters. 
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.
    States and authorized Tribes must adopt water quality criteria that 
protect designated uses. States may develop their criteria based on 
EPA's recommended section 304(a) water quality criteria or other 
scientifically defensible methods. A State's criteria must contain 
sufficient parameters or constituents to protect the designated uses. 
Consistent with 40 CFR 131.21, new or revised water quality criteria 
adopted into law by States and authorized Tribes on or after May 30, 
2000 are in effect for CWA purposes only after EPA approval.

IV. Where Can I Find More Information About Water Quality Criteria and 
Water Quality Standards?

    For more information about water quality criteria and Water Quality 
Standards refer to the following: Water Quality Standards Handbook (EPA 
823-B94-005a); Advanced Notice of Proposed Rule Making (ANPRM), 
(63FR36742); Water Quality Criteria and Standards Plan--Priorities for 
the Future (EPA 822-R-98-003); Guidelines and Methodologies Used in the 
Preparation of Health Effects Assessment Chapters of the Consent Decree 
Water Criteria Documents (45FR79347); Methodology for Deriving Ambient 
Water Quality Criteria for the Protection of Human Health (2000), EPA-
822-B-00-004); Guidelines for Deriving Numerical National Water Quality 
Criteria for the Protection of Aquatic Organisms and Their Uses (EPA 
822/R-85-100); National Strategy for the Development of Regional 
Nutrient Criteria (EPA 822-R-98-002); and EPA Review and Approval of 
State and Tribal Water Quality Standards (65FR24641).
    You can find these publications through EPA's National Service 
Center for Environmental Publications (NSCEP, previously NCEPI) or on 
the Office of Science and Technology's Home-page (http://www.epa.gov/
waterscience).

    Dated: December 23, 2009.
Peter S. Silva,
Assistant Administrator for Water.
[FR Doc. E9-30992 Filed 12-29-09; 8:45 am]

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