[Federal Register Volume 66, Number 6 (Tuesday, January 9, 2001)]
[Pages 1671-1674]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-569]




Nutrient Criteria Development; Notice of Ecoregional Nutrient 

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of Ecoregional Nutrient Criteria for Lakes and 
Reservoirs, Rivers and Streams, and Wetlands.


SUMMARY: The Environmental Protection Agency (EPA) is publishing 
seventeen Ecoregional Nutrient Criteria Documents for lakes and 
reservoirs, rivers and streams and wetlands within specific geographic 
regions (ecoregions) of the United States. These recommended section 
304(a) water quality criteria for nutrients were developed with the aim 
of reducing and preventing eutrophication on a National scale. Each 
document presents recommended criteria for causal parameters (total 
phosphorus and total nitrogen) and response variables (chlorophyll a 
and some form of turbidity). This information is intended to serve as a 
starting point for States, authorized Tribes and others to develop more 
refined nutrient criteria, as appropriate, using EPA waterbody-specific 
technical guidance manuals and other scientifically defensible 
approaches. EPA will work with States and authorized Tribes as they 
adopt water quality criteria for nutrients into their water quality 
standards. EPA expects States and authorized Tribes to adopt or revise 
EPA ecoregional nutrient criteria published in 2000 into State or 
Tribal water quality standards by 2004.
    Under the Clean Water Act, States, Territories, and authorized 
Tribes adopt into their water quality standards water quality criteria 
to protect designated uses. The criteria recommendations presented in 
these documents are guidance that States, territories, and authorized 
Tribes may use as a starting point for developing their own criteria as 
part of their water quality standards. EPA strongly encourages States, 
Territories and authorized Tribes to refine these recommendations based 
on the key elements of nutrient criteria development (historical 
information, reference conditions, models, consideration of downstream 
effects, and expert judgment) discussed in EPA's published Technical 
Guidance Manuals (Lakes and Reservoirs: EPA-822-B00-001; Rivers and 
Streams: EPA-822-B-00-002). While the seventeen documents available 
today contain EPA's scientific recommendations regarding ecoregional 
nutrient criteria, the information and recommendations are not 
regulations, and do not impose legally binding requirements on EPA, 
States, Territories, authorized Tribes, or the public. As 
recommendations, they might not apply to a particular situation based 
upon the circumstances. States, Territories, and authorized Tribes 
retain the discretion to adopt water quality criteria based on other 
scientifically defensible approaches to developing regional or local 
nutrient criteria that differ from these recommendations. EPA may 
revise these section 304(a) water quality criteria in the future.
    EPA is making these recommended section 304(a) nutrient water 
quality criteria available to the public in accordance with the 
Agency's process for publishing new and revised criteria (see Federal 
Register, December 10, 1998, 63 FR 68354 and in the EPA document 
titled, National Recommended Water Quality--Correction EPA 822-Z-99-
001, April 1999). EPA invites the public to provide scientific views on 
these criteria. EPA will review and consider information submitted by 
the public on significant scientific issues and site-specific data that 
might not have otherwise been identified by the Agency during 
development of these criteria. After EPA reviews the submitted 
significant scientific information, the Agency may publish revised 
nutrient water quality criteria, or publish a notice informing the 
public that the submitted information does not warrant revision of the 
    EPA encourages the public to provide additional data that could 
help States and or authorized Tribes to refine these recommended 
nutrient water quality criteria. EPA has identified specific sections 
within each document where public input would greatly assist States and 
authorized Tribes in the task of augmenting the database for deriving 
ecoregional nutrient water quality criteria. For example, the public 
can provide information concerning the historical conditions and trends 
of the water resources within an ecoregion related to cultural 
eutrophication. EPA will forward all comments received on a particular 
ecoregional criterion or set of criteria to the appropriate State or 
Tribe to help foster water quality criteria refinement.
    EPA's Office of Water, Office of Science and Technology has 
prepared this document for publication. Mention of trade names or 
commercial products does not constitute endorsement or recommendation 
for use.

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DATES: EPA will accept significant scientific information submitted to 
the Agency within 90 days of publication of this notice in the Federal 
Register. Any scientific information submitted should be adequately 
documented and contain enough supporting information to indicate that 
acceptable and scientifically defensible procedures were used and that 
the results are reliable.

ADDRESSES: This notice contains a summary of the Ecoregional Nutrient 
Criteria Documents. Copies of the all or any document may be obtained 
from the U.S. National Service Center for Environmental Publications 
(NSCEP), 11029 Kenwood Road, Cincinnati, OH 45242; (513) 489-8190 or 
toll free (800) 490-9198. The documents are also available 
electronically at http://www.epa.gov/ost/standards/nutrient.html. The 
waterbody-specific technical guidance manuals, which present the 
nutrient criteria derivation methodology used by EPA to develop the 
nutrient water quality criteria, are also available from EPA's nutrient 
website. An original and two copies of written significant scientific 
information should sent to Robert Cantilli (MC-4304), U.S. EPA, Ariel 
Rios Building, 1200 Pennsylvania Ave., NW , Washington, DC 20460. 
Written significant scientific information may be submitted 
electronically in ASCII or Word Perfect 5.1, 5.2, 6.1, or 8.0 formats 
to OW-General@epa.gov.

Ecological Criteria Division (4304), Office of Science and Technology, 
Ariel Rios Building, 1200 Pennsylvania Ave., NW, Washington, DC 20460; 
or call (202) 260-5546; or e-mail cantilli.robert@epa.gov.


What Are Section 304(a) Nutrient Criteria?

    Section 304(a)(2) of the Clean Water Act directs EPA to develop and 
publish information on the factors necessary ``to restore and maintain 
the chemical, physical and biological integrity of the Nation's waters, 
including the protection and propagation of shellfish, fish and 
wildlife, the protection of recreational activities in and on the 
water, and the measurement and classification of water quality.''
    Section 304(a)(1) of the Clean Water Act directs EPA to publish, 
and from time to time revise, recommended criteria for water quality 
accurately reflecting the latest scientific knowledge, ``including 
information on the factors affecting rates of eutrophication.'' The 
intent of EPA's recommended ecoregional nutrient criteria is to 
represent water quality conditions of surface water that are minimally 
affected by human development activities and to provide for the 
protection and propagation of aquatic life and recreation.
    Water quality criteria developed under section 304(a) are based 
solely on data and scientific judgments and do not reflect 
consideration of economic impacts or the technological feasibility of 
meeting any specific level of water quality in ambient water. They 
provide guidance for States and authorized Tribes in adopting water 
quality standards that ultimately provide a basis for controlling 
discharges or releases of pollutants. They also provide guidance to EPA 
when promulgating water quality standards under section 303(c), when 
such action is necessary.
    EPA published a National Strategy for the Development of Regional 
Nutrient Criteria in June 1998 that described the approach the Agency 
would follow in developing nutrient criteria and working with States 
and authorized Tribes as they adopt nutrient criteria into State and 
Tribal water quality standards (see Federal Register, June 25, 1998, 63 
FR 34648; this document is also available from the nutrient website: 
http://www.epa.gov/ost/standards/nutrient.html.). The major focus of 
the strategy is the development of waterbody-type technical guidance 
manuals and recommended ecoregion-specific nutrient criteria by the end 
of 2000. In addition, EPA has established a national nutrient database 
that States and authorized Tribes can use to compile as well as 
evaluate nutrient data and perform alternative analyses. This database 
contains the information upon which today's recommendations were 
    EPA's Section 304(a) nutrient criteria recommendations are intended 
to protect against the adverse effects of cultural eutrophication. 
Cultural eutrophication (i.e., overenrichment of nutrient levels 
associated with human activities) of United States surface waters is a 
long-standing problem. States and Tribes consistently identify 
excessive levels of nutrients are a major reason why as much as half of 
the surface waters surveyed in this country do not meet water quality 
objectives, such as full support of aquatic life.
    Nitrogen and phosphorus are the primary causes of eutrophication; 
algal blooms are often a response to enrichment. Within various 
waterbody types (e.g., lakes, rivers, estuaries), chronic symptoms of 
overenrichment include low dissolved oxygen, fish kills, reduced water 
clarity, and changes from the natural types and diversity of species of 
flora and fauna. The problem is national in scope, but specific levels 
of overenrichment leading to these problems vary from one region of the 
country to another because of factors such as geographical variations 
in geology and soil types. For these reasons, EPA is developing its 
recommended nutrient water quality criteria on an ecoregional basis for 
use by States and authorized Tribes.
    Because EPA's nutrient water quality criteria are intended to 
represent water quality conditions that are reflective of those 
minimally impacted by human activities, they are presumed to protect 
any threatened or endangered species that reside in or make use of 
those waters. However, there remains a small possibility that the 
nutrient criteria will not protect all listed endangered or threatened 
species. Consequently, EPA recommends that States and authorized Tribes 
develop more protective, site-specific modifications of the criteria as 
necessary to protect threatened and endangered species, where 
sufficient data exist indicating that endangered or threatened species 
are more sensitive to a particular level of a nutrient parameter or 
overenrichment condition than that reflected by EPA's nutrient water 
quality criteria.

What Guidance Will EPA Develop and Publish for Nutrients Under 
Section 304(a)?

    To assist EPA Regions, States, and authorized Tribes to establish 
protective and scientifically defensible nutrient criteria, EPA will 
publish specific technical guidance manuals for various waterbody 
types. In 2000, EPA published guidance manuals for lakes and reservoirs 
and for rivers and streams. These documents are available from EPA's 
nutrient website: http://www.epa.gov/ost/standards/nutrient.html. EPA 
is currently developing guidance manuals for estuarine and coastal 
waters and for wetlands.
    In addition to developing this waterbody-type specific guidance, 
EPA is working to publish specific nutrient water quality criteria 
recommendations under section 304(a) for every type of waterbody, i.e., 
lakes and reservoirs, rivers and streams, wetlands and estuaries and 
coastal waters (where applicable) for all of the 14 nutrient ecoregions 
that EPA has identified in the continental United States. Today's 
notice announces the availability of Ecoregional Nutrient Criteria 
Documents for lakes and reservoirs in a set of eight ecoregions, for 
rivers and

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streams in a set of eight ecoregions (several of which overlap with the 
set of eight ecoregions for lakes and reservoirs), and for wetlands in 
one ecoregion. These ecoregions were chosen based on the availability 
of nutrient data within each ecoregion. Following development of 
technical guidance manuals for estuarine and coastal waters and 
wetlands (in general), EPA intends to publish water quality criteria 
for these waters on an appropriate regional basis.
    EPA expects States and authorized Tribes to use the technical 
guidance manuals, together with today's recommended water quality 
criteria and the national nutrient database, to develop State and 
Tribal quantified water quality criteria for nutrients, to help 
identify water quality impairments, and to evaluate success in 
increasing the number of waterbodies across the U.S. which meet State 
and Tribal water quality standards.

How Should States and Authorized Tribes Establish Nutrient Criteria 
in Their Water Quality Standards?

    EPA will work with States and authorized Tribes as they adopt water 
quality criteria for nutrients into their water quality standards. EPA 
recognizes that States and authorized Tribes have several options 
available to them. EPA recommends the following approaches, in order of 

    (1) Wherever possible, develop nutrient criteria that fully 
reflect localized conditions and protect specific designated uses 
using the process described in EPA's Technical Guidance Manuals for 
nutrient criteria development. Such criteria may be expressed either 
as numeric criteria or as procedures to translate a State or Tribal 
narrative criterion into a quantified endpoint in State or Tribal 
water quality standards.
    (2) Adopt EPA's section 304(a) water quality criteria for 
nutrients, either as numeric criteria or as procedures to translate 
a State or Tribal narrative nutrient criterion into a quantified 
    (3) Develop nutrient criteria protective of designated uses 
using other scientifically defensible methods and appropriate water 
quality data.

    The key parameters addressed in the Ecoregional Nutrient Criteria 
Documents are total phosphorus, total nitrogen, chlorophyll a, and 
turbidity (e.g., Secchi depth for lakes; turbidity for rivers and 
streams). These are the parameters which EPA considers important in 
nutrient assessment because the first two (nitrogen and phosphorus) are 
the main causal agents of enrichment, while the two response variables 
(chlorophyll a and turbidity) are early indicators of system 
overenrichment for most surface waters. States and authorized Tribes 
are encouraged to develop additional criteria for additional parameters 
such as dissolved oxygen, algal biomass, and biological integrity 
indices. EPA believes that quantitative endpoints are needed for both 
causal and biological and physical response variables.
    Based on the information available to the Agency at the time of 
publication, the values presented in these documents generally 
represent nutrient levels that protect against the adverse effects of 
nutrient overenrichment in aquatic environments. However, these 
recommended water quality criteria should be viewed as starting points 
that should be further refined. As set forth in each document, the 
elements that EPA expects States and authorized Tribes to consider in 
developing a nutrient criterion are:
    (1) Historical data and other information (published literature);
    (2) Current reference conditions;
    (3) Models to simulate physical and ecological processes or 
determine empirical relationships among causal (nutrients) and response 
(biological or physical conditions) variables; and
    (4) Evaluation of downstream effects.
    EPA also expects States and authorized Tribes to make use of expert 
judgment when examining the information and establishing criteria.

What Are Regional Technical Assistance Groups?

    To assist States and authorized Tribes in developing and refining 
their own nutrient criteria, and to provide multi-jurisdictional 
coordination and consistency in the criteria development process, EPA 
established Regional Technical Assistance Groups (RTAGs). RTAGs are a 
collection of EPA, State, Tribal representatives who are working 
together to employ the processes and approaches recommended in EPA's 
waterbody-specific technical guidance manuals (e.g., those EPA has 
already published for lakes and reservoirs, and rivers and streams) for 
the purpose of developing more refined nutrient criteria than those 
made available today. Criteria refinement can occur by grouping data or 
performing data analyses at smaller geographic scales than an 
ecoregion, such as a subecoregion, the State or Tribe level, or 
specific class of lakes or streams. Refinement can also occur through 
further consideration of other elements of criteria development, such 
as published literature or models.
    EPA has used data and expertise provided by the RTAGs to date in 
the development of today's Ecoregional Nutrient Criteria Documents. EPA 
strongly encourages States and authorized Tribes to fully participate 
in their respective RTAG, and use this opportunity to pool expertise 
and resources at the State, Tribal, and federal level. In addition to 
the criteria development role, the RTAGs also function to facilitate 
dialogue among stakeholders through public meetings and technical 

How and When Does EPA Expect States and Authorized Tribes to Adopt 
Nutrient Criteria Into Their Water Quality Standards?

    EPA emphasizes that, in the course of carrying out its 
responsibilities under section 303(c) of the Clean Water Act, it 
reviews State and authorized Tribal water quality standards to assess 
the need for new or revised water quality criteria. The Agency views 
the criteria adoption process as a two phased approach. The first phase 
includes the development of a plan which outlines the process for 
adopting criteria. This plan should address items such as the criteria 
development process, staffing of personnel who will undertake specific 
tasks, and setting the internal schedule to complete the adoption 
process within the State and Tribal triennial review or another 
process. The second phase of the adoption process is implementing the 
criteria adoption plan. This may involve collecting existing data, 
sampling to obtain new data, developing a supporting data base, 
analyzing data to determine reference conditions and predictive 
relationships among variables, establishing nutrient water quality 
criteria, and facilitating appropriate public participation in the 
    The Agency presents the following schedule for the adoption of 
nutrient criteria into water quality standards, which includes a 
recommended period of time for the formation of a plan for developing 
and adopting nutrient criteria, as well as a specific period of time 
during which we expect States and Tribes to adopt the nutrient criteria 
into their water quality standards:
    (1) By the end of 2001, each State and authorized Tribe should 
complete a plan for developing and adopting nutrient criteria into 
State or Tribal water quality standards. The plan should describe how 
and when nutrient criteria will be adopted, either as part of a 
triennial review, or another process.
    (2) By the end of 2004, States and authorized Tribes should adopt 
nutrient criteria (either numeric criteria or as procedures to 
translate a narrative nutrient criteria into a quantified endpoint) for 
the waterbody type and ecoregions associated with the section

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304(a) water quality criteria that EPA publishes by the end of 2001. 
EPA intends to notify States and authorized Tribes by March 2001 which 
waterbody type and ecoregions EPA expects to address in section 304(a) 
criteria published by the end of 2001.
    EPA recognizes that the ecoregions addressed in the section 304(a) 
water quality criteria for nutrients published by the end of 2001 may 
not represent complete coverage across all State and Tribal waters, may 
not overlap with important watershed boundaries, and may not reflect 
high priority waters. In developing their own criteria for specific 
waters, States and authorized Tribes have the flexibility to first 
address geographic areas and waterbody types other than those specified 
in the section 304(a) criteria published by the end of 2001, 
particularly if a State or authorized Tribe has efforts underway to 
develop criteria for those areas. However, EPA would continue to expect 
States and authorized Tribes to adopt nutrient criteria by 2004 for all 
waterbody types and ecoregions addressed in the section 304(a) criteria 
published by the end of 2001. The plan for developing and adopting 
nutrient criteria, completed by the end of 2001, should address these 
    (3) EPA intends to propose to promulgate nutrient water quality 
criteria, relying substantially on EPA's section 304(a) water quality 
criteria, by the end of 2004, where States and authorized Tribes have 
not substantially completed their adoption of such criteria according 
to the plan completed by the end of 2001, if the Administrator 
determines that such new or revised standards are necessary to meet the 
requirements of the Clean Water Act.
    (4) As EPA issues additional section 304(a) nutrient criteria 
recommendations in 2002 and beyond, States and authorized Tribes should 
continue to adopt nutrient criteria for the remaining waterbody types 
and ecoregions. Such efforts should generally follow a schedule similar 
to the sequence in (1) through (3) above, with the years adjusted to 
reflect the date EPA issues each set of criteria.

    Dated: December 29, 2000.
J. Charles Fox,
Assistant Administrator, Office of Water.
[FR Doc. 01-569 Filed 1-8-01; 8:45 am]