&EPA
United States
Environmental Protection
Agency
Off ice of Water
4304
EPA 822-R-98-002
June 1998
National Strategy for the
Development of Regional
Nutrient Criteria
June 1998
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CONTENTS
PREFACE BY ROBERT PERCIASEPE, ASSISTANT ADMINISTRATOR, OFFICE OF
WATER iii
NOTE TO THE READER vi
I. INTRODUCTION 1
A. Background 1
B. Nutrient Pollution Problems 2
C. Past Nutrient Reduction Efforts 2
D. Other Current Nutrient-Related Efforts 3
II. THE NATIONAL NUTRIENT STRATEGY 5
A. The Five Key Elements of the Strategy 6
B. How the Elements are Integrated 14
III. WATERBODY-TYPE TECHNICAL GUIDANCE 15
A. Indicators 17
B. Data Storage and Processing 22
C. Management and Evaluation 25
D. Research Needs 30
APPENDIX A: Summary of Water Quality Criteria and Standards for Nutrient
Overenrichment 35
APPENDIX B: Nutrient Criteria Activities and Timeline 41
APPENDIX C: Draft Outline for the Development of Nutrient Criteria for Rivers,
Lakes, Reservoirs, Estuarine and Coastal Systems 45
APPENDIX D: Drafting Committee for the National Nutrient Strategy 49
APPENDIX E: Excerpt from the Clean Water Action Plan 50
REFERENCES 52
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PREFACE
In February of this year, President Clinton and Vice President Gore released a
comprehensive Clean Water Action Plan. The Action Plan provides a blueprint for Federal
agencies to work with States and others stakeholders in restoring and protecting the Nation's
water resources and addresses three major goals:
• enhanced protection from public health threats posed by water pollution;
• more effective control of polluted runoff; and
• promotion of water quality restoration and protection on a watershed basis.
A key part of the Action Plan provides for expanded efforts to reduce nutrient
overenrichment of waters.
Nutrients, in appropriate amounts, are essential to the health of aquatic systems.
Excessive nutrients, however, can result in excessive growth of macrophytes or phytoplankton
and potentially harmful algal blooms leading to oxygen declines, imbalance of aquatic species,
public health threats, and a general decline in the aquatic resource.
Recent reports on water quality conditions provided by States indicate that nutrients are
the leading cause of impairment in lakes and coastal waters and the second leading cause of
impairment to rivers and streams. Nutrient overenrichment has also been strongly linked to the
large hypoxic zone in the Gulf of Mexico and to recent outbreaks of the toxic microorganism
Pfiesteria along the Gulf and Mid-Atlantic coasts.
The Action Plan calls on EPA to accelerate the development of scientific information
concerning the levels of nutrients that cause water quality problems and to organize this
information by different types of waterbodies (e.g. streams, lakes, coastal waters, wetlands) and
by geographic regions of the country. EPA is also to work with States and Tribes to adopt
criteria (i.e. numeric concentration levels) for nutrients, including nitrogen and phosphorus, as
part of enforceable State water quality standards under the Clean Water Act.
This National Strategy for Development of Nutrient Criteria describes the approach
that EPA will follow in developing nutrient information and working with States and Tribes to
adopt nutrient criteria as part of State water quality standards. Some key aspects of the Strategy
are described below.
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Region and Waterbody Approach
Section 304(a) of the Clean Water Act directs EPA to develop scientific information on
pollutants and to publish "criteria guidance," often expressed as pollutant concentration levels,
that will result in attainment of a designated use of the waterbody (e.g. fishing, swimming) that is
determined by the State. These concentration levels generally are the same for all types of
waterbodies and to all areas of the country. States consider these EPA "criteria guidance" when
they adopt water quality standards for waterbodies. A water quality standard commonly includes
a designed use for the waterbody and criteria (i.e. concentration levels) for a range of pollutants
that will assure that the waterbody will support the designated use.
In the case of nutrients, however, there is a great deal of variability in inherent nutrient
levels and nutrient responses throughout the country. This natural variability is due to differences
in geology, climate and waterbody type. Because of this variation, EPA's custom of developing
scientific information about a pollutant and recommending a single pollutant concentration
number to support a designated use for nationwide application is not appropriate for nutrients.
EPA believes that distinct geographic regions and types of waterbodies need to be evaluated
differently and that recommended nutrient concentration levels need to reflect geographic
variation and waterbody types.
Waterbody-Type Guidance Documents
An essential element of this Strategy is development of waterbody-type guidance
documents describing the techniques for assessing the trophic state of a waterbody and
methodologies for developing nutrient criteria appropriate to different geographic regions.
Separate guidance documents will be developed for rivers, lakes, coastal waters, and wetlands.
Each waterbody guidance document will provide scientific information required by section
304(a) of the Clean Water Act, including recommended nutrient concentration levels that are
appropriate for the waterbody type, the geographic region, and various designated uses. EPA will
use State databases to develop these criteria guidance documents, supplemented with new
regional case studies and demonstration projects to provide additional information. EPA expects
that these levels will be expressed as numerical target ranges for variables such as phosphorus,
nitrogen, and other nutrient indicators. Guidance documents for rivers, lakes, and coastal waters
will be completed by the end of the year 2000 and the guidance document for wetlands will be
developed by the end of 2001.
Adding Nutrients to Water Quality Standards
EPA expects States and Tribes to use the waterbody type guidance documents and
nutrient target ranges as a guide in developing and adopting numeric levels for nutrients that
support the designated uses of the waterbody as part of State water quality standards. EPA will
work with States to support and assist in this process. States should have adopted nutrient
criteria that support State designated uses by the end of 2003.
EPA will review and approve the new or revised nutrient elements of water quality
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standards under Section 303(c)(3) of the Clean Water Act. If EPA disapproves the new standard
submitted by a State or Tribe (because EPA determines that it is not scientifically defensible), or if
EPA determines that a new or revised nutrient standard is necessary for a State or Tribe (because
EPA determines that the State or Tribe has not demonstrated reasonable progress toward
developing numerical nutrient standards), EPA will initiate rulemaking to promulgate nutrient
criteria values that will support the designated use of the waterbody and are appropriate to the
region and waterbody types. Any resulting water quality standard would apply until the State or
Tribe adopts, and EPA approves, a revised standard.
Once adopted as part of State or Tribal water quality standards, the nutrient criteria in
State standards will become the basis for identifying waters where nutrients result in impairment
of water quality and making many management decisions to reduce excessive nutrient levels in
these waters.
National and Regional Nutrient Teams
The Office of Water will provide additional technical and financial assistance to the
Regions and States to accelerate the development of nutrient criteria.
This effort will include the establishment of a National Nutrient Team, including
coordinators from each EPA Region. The Regional Coordinator will foster the development and
implementation of State projects, databases, nutrient criteria and standards, and the award of
financial assistance to States and Tribes to support these endeavors. Each Regional coordinator
will be responsible for nutrient management activities for that Region and its member States and
Tribes consistent with decisions of the national nutrient program.
Each Regional Coordinator will form a Regional Nutrient Team that includes State and
Tribal representatives and other federal and local representatives, as needed, to develop nutrient
databases and nutrient target ranges.
I am confident that this effort to include nutrient concentration levels in State water
quality standards will be a major step forward for efforts to restore and protect the Nation's
waters. I look forward to working with water program managers and other interested parties in
this important initiative.
Robert Perciasepe Date
Assistant Administrator
Office of Water
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NOTE TO THE READER
This document sets forth EPA's strategy to develop scientific information (i.e., criteria documents
under section 304(a) of the Clean Water Act) which EPA will recommend that States use to
adopt nutrient criteria to support State water quality standards. These nutrient criteria provide a
critical foundation to address overenrichment problems in the Nation's surface waters. It also
provides guidance to States, Tribes and the public regarding how EPA intends to exercise its
discretion in implementing the provisions of the Clean Water Act concerning the adoption of
water quality standards.
This document is designed to implement national policy on the issues it addresses. It does not,
however, substitute for the Clean Water Act or EPA's regulations; nor is it a regulation itself.
Thus, it cannot impose legally binding requirements on EPA, States, Tribes or the regulated
community and may not apply to some particular situations. EPA, State and Tribal
decisionmakers retain the discretion to adopt approaches on a case-by-case basis that differ from
this guidance where appropriate. EPA also retains discretion to change the guidance contained in
this strategy in the future.
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I. INTRODUCTION
A. Background
Nutrients, in the appropriate amounts, are essential to the health and continued functioning of
natural ecosystems. Depending upon specific characteristics of the receiving waterbodies, they
can be present in excessive, limiting, or optimal amounts. Insufficient nutrients will result in less
than optimal growth of primary producers (i.e., plants, including phytoplankton and submerged
aquatic vegetation). Adequate primary productivity is essential to support all the other trophic
levels and a healthy, diverse, and productive ecosystem.
Excessive nutrient loadings will, however, result in excessive growth of macrophytes or
phytoplankton and potentially harmful algal blooms (HAB), leading to oxygen declines, imbalance
of prey and predator species, public health concerns, and a general decline of the aquatic resource.
It is the excesses of these nutrients resulting from human activities, rather than natural spatial and
temporal variations, that are the concern of this document and it is this cultural eutrophication
that is most appropriately the subject of management efforts.
When nutrient inputs exceed the assimilative capacity of a waterbody system, the system
progresses toward hypereutrophic conditions. Symptoms include an overabundance of primary
producers, decreased biological diversity, algal blooms (some toxic), low dissolved oxygen,
episodic anoxia, loss of vascular plant life, and fish kills. Investigations have shown that the key
causative factors are excessive concentrations of the primary nutrients phosphorus and nitrogen.
The term nutrient is loosely used to describe a compound that is necessary for metabolism.
Nitrogen (N) and phosphorus (P) are required in relatively large amounts by cells and are called
macronutrients, as opposed to micronutrients such as iron or molybdenum.
Nutrient criteria is intended to be interpreted in its broadest sense, covering both legal and
scientific interpretations. Legally, a nutrient criterion is the numeric value which supports a
particular beneficial designated use in defining a water quality standard. Scientifically, a nutrient
criterion is meant to encompass both causal and response variables (e.g., nitrogen or phosphorus
levels), as well as aquatic community response parameters such as but not limited to algal
biomass, chlorophyll a, and secchi depth.
Similarly, in this text the problem of eutrophication is used to describe an increase of nutrients in
a waterbody which results in an overabundance of plant biomass (Flemer, 1972).
The terms water quality measurement and water resource measurement are both intended to
mean a comprehensive array of measurements including chemical, physical, and biological
parameters.
In all aquatic ecosystems some general processes determine whether N or P is the limiting
macronutrient and can be expressed as the nitrogen-to-phosphorus ratio (N:P). The Redfield
ratio of N:P for primary producers in marine systems is approximately 16:1 on a molar scale
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(Redfield, 1958). In freshwater systems the phosphorus limitation tends to be greater at an N:P
ratio of up to about 26:1. Ecosystems that deviate substantially from these ratios are likely to
experience nutrient limitation of either N or P (i.e., if the ratio in marine or estuarine waters is less
than 16, N could be limiting; if the ratio is greater than 16, P is probably the limiting nutrient).
B. Nutrient Pollution Problems
According to the U.S. Environmental Protection Agency's (EPA's) National Water Quality
Inventory: 1996 Report to Congress (required under section 305(b) of the Clean Water Act) , 50
States, Tribes, and other jurisdictions surveyed water quality conditions in 19 percent of the
Nation's total 3.6 million miles of rivers and streams.
Some 36% of these surveyed waters were impaired by various pollutants. The leading cause of
impairment was siltation, contributing to impairments in 51% of these waters. Nutrients were the
second most significant cause of impairment, contributing to impairment of 40% of waters.
Excessive nutrients were the leading cause of impairment of affected lakes and impaired coastal
waters at 51% and 57% respectively.
Excessive nutrients have also been linked to hypoxia conditions in the Gulf of Mexico and have
been associated with outbreaks ofP/iesteria in several Gulf and Mid-Atlantic States.
Sources historically associated with nutrient overenrichment are fertilizers, sewage treatment
plants, detergents, septic systems, combined sewer overflows, sediment mobilization, animal
manure, atmospheric deposition and internal nutrient recycling from sediments. Other factors that
can influence overenrichment are light attenuation, land-use practices, and imbalance of primary,
secondary, and tertiary producers and consumers (plankton, macrophytes, epiphytes, grazers,
predators, and decomposers).
C. Past Nutrient Reduction Efforts
Over the years, the EPA's Office of Water has issued a number of technical guidance documents
and has supported the development of water quality simulation models and loading estimating
models that can be used to assess the impacts of urban, rural, and mixed land use activities on
receiving waters.
In addition, some States currently have water quality standards that incorporate criteria, primarily
narrative, aimed at controlling problems associated with nutrient overenrichment (see Appendix A
for a list of water quality criteria and standards currently in use by States). However, for State,
Tribal and local agencies to better understand and manage nutrient impacts to surface waters,
additional work is necessary.
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According to a State Nutrient Water Quality
Standards 1994 EPA Survey:
417 States have no WQS for nitrates/nitrites
421 States have no WQS for phosphorus
4 Many States have narrative standards only
410 States have adopted EPA criteria unrelated
to eutrophication (e.g., 10 mg/L for nitrate, or
0.10 ug/L elemental phosphorus)
4 Only 9 criteria (N and P) are waterbody-based
In 1993, the EPA Nutrient Task Force gathered existing data on nutrient problems and currently
available tools. It recommended that EPA provide additional assistance to States in developing
and implementing appropriate nutrient indicators, assessment methodologies, and models. The
first step in carrying out the recommendations of the task force was the nutrient overenrichment
assessment workshop held in Washington, DC, on December 4-6, 1995. The workshop was
organized around plenary and breakout group discussions on four major waterbody types:
• estuarine and coastal marine water;
• lakes, impoundments/reservoirs, and ponds;
• rivers and streams; and
• wetlands.
Issue papers describing the state of the science, gaps, and user needs in terms of nutrient
assessment tools and methodologies for each waterbody type were developed and used as
foundations for these group discussions. The results of this workshop, compiled in National
Nutrient Assessment Workshop Proceedings (EPA 822-R-96-004, 1996), form the basis of this
Strategy.
D. Other Current Nutrient-Related Efforts
In addition to this Strategy, there are a number of other evolving efforts that focus on elements
related to the nutrient overenrichment problem. These include the following:
• Criteria and Standards Plan. The Plan describes six new criteria and standards
program initiatives that EPA and the States/Tribes will pursue over the next
decade including the nutrient criteria effort. The Plan presents a "vision" and
strategy for meeting these important new initiatives and improvements. The Plan
will guide EPA and the States/Tribes in the development and implementation of
criteria and standards and will provide a basis for enhancements to the Total
Maximum Daily Load (TMDL) program, National Pollutant Discharge Elimination
System (NPDES) permitting, nonpoint source control, wetlands protection and
other water resources management efforts.
• Nonpoint Sources: Picking Up the Pace; A National Strategy for
Strengthening Nonpoint Source Pollution Management (draft, September
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1997). This strategy envisions that all States/Tribes, with the active assistance and
participation of all stakeholders, will implement dynamic and effective nonpoint
source pollution programs to achieve and maintain beneficial uses of water by the
end of calendar year 2013.
Strategy for Addressing Environmental Public Health Impacts from Animal
Feeding Operations (AFOs) (draft, March 1998). This strategy strives to
minimize environmental and public health impacts from AFOs through an effective
mix of voluntary and regulatory measures. EPA is working with the US
Department of Agriculture to develop a joint USD A/EPA national strategy on
Animal Feeding Operations. This joint strategy — which will supersede the draft
EPA AFO Strategy — will be published in draft form in July and in final form in
November.
The National Harmful Algal Bloom Research and Monitoring Strategy. This
strategy was developed as an effort to coordinate Federal research and monitoring
activities on Pfiesteria and other HABs. Federal HAB programs are spread across
several Federal agencies, including the National Oceanic and Atmospheric
Administration (NOAA); EPA; the Department of Health and Human Services-
Centers for Disease Control and Prevention, the Food and Drug Administration,
and the National Institute of Environmental Health Sciences (DHHS- CDCP,
FDA, and NIEHS); the National Biologic Service (NBS); the National Science
Foundation (NSF); and the U.S. Fish and Wildlife Service (USFWS), and an
interagency workgroup was formed to address a diverse list of current and planned
HAB activities.
After reporting relevant research and programmatic activities, questions were
formulated that addressed the objectives of a comprehensive research strategy.
The research questions and objectives were differentiated into near-term and long-
term activities, and the workgroup classified each agency activity into groups that
reflect the eight objectives cited in Marine Biotoxins and Harmful Algae: A
National Plan (Anderson et a/., 1993). Agency activities have been categorized
into these objectives allowing the workgroup to identify obvious coordination
points, and data/research gaps.
Water Quality Standards Regulation: Advance Notice of Proposed Rule
Making (ANPRM). EPA is about to publish an Advance Notice of Proposed
Rulemaking (ANPRM) on the Water Quality Standards Regulation in the Federal
Register. The ANPRM solicits public comment on potential revisions to the basic
water quality standards program regulation governing State adoption and EPA
approval of water quality standards under Section 303(c) of the Clean Water Act.
The ANPRM also requests comment on changes in policy and guidance that
support the regulation.
The ANPRM expresses current EPA thinking in a number of areas addressed by
the current regulation, policy and guidance and requests comment on that thinking.
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One of the main themes of the ANPRM is updating and modernizing water quality
standards so that standards may be better implemented on a watershed basis using
refined use designations and tailored criteria. New science and assessment
methodologies, as well as better data, and new types of data and analysis would
need to be used by States and Tribes to refine water quality standards in this
manner. The ANPRM highlights the potential resource challenge for States and
Tribes and requests comment regarding concerns over resource constraints and
ideas for how to address them.
• The USDA Nutrient Management Policy. The USD A's Natural Resources
Conservation Service (NRCS) proposed a revised nutrient management policy to
its National Agronomy Manual. This revised policy will impact the NRCS national
conservation practice standards for Nutrient Management (Code 590) and Waste
Utilization (Code 633). The nutrient policy discusses certification of plans,
describes what is in nutrient management plans, and discusses soil and plant tissue
testing, nutrient application rates, record keeping and other special considerations.
The revised policy will be adopted after the June 22, 1998 comment period closes.
The groups developing the strategies are all investigating related problems ... land use-nutrient
loading relationships, ecological responses, and appropriate mitigation activities. As all of these
strategies progress, it will be essential to coordinate the information and activities that result so
that consistent policy is developed.
II. EPA NATIONAL STRATEGY FOR DEVELOPING REGIONAL NUTRIENT
CRITERIA
This Strategy proposes to build on the work accomplished to date and to establish an objective,
scientifically sound basis for assessing nutrient overenrichment problems. Improving the basis for
assessing nutrient overenrichment problems will provide critical support for expanded efforts to
control nutrient levels in waters and meet the Nation's clean water goals.
Specifically, this Strategy proposes a two-phase process for the development of water quality
standards for nutrients:
1) EPA will develop "nutrient criteria guidance" for nitrogen, phosphorus,
and other nutrient parameters such as chlorophyll a, secchi depth, and algal
biomass. These criteria will be developed under section 304(a) of the
Clean Water Act and will represent EPA's guidance regarding the amounts
of those contaminants that may be present in waters without impairing their
designated uses. Unlike other criteria guidance that EPA has developed,
EPA intends to express nutrient criteria guidance as numerical ranges,
reflecting a menu of different values based on the type of waterbody (i.e.,
streams and rivers, coastal waters and estuaries, lakes and reservoirs, and
wetlands) and the region of the country in which the water is located.
2) EPA expects States and Tribes to adopt nutrient water quality criteria
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(including N and P concentration levels) to support designated uses of
waters. These "nutrient criteria" will be based on EPA's nutrient criteria
guidance or other scientifically defensible methods and will be incorporated
into the States' water quality standards. The goal is for the States/Tribes
to establish these criteria as part of their water quality standards as soon as
the appropriate criteria guidance is developed. The target date for
adoption of nutrient criteria as part of water quality standards is within
three years of completion of the guidance, (i.e., by the end of the calendar
year 2003). EPA will step in and promulgate nutrient water quality criteria
for a State or Tribe if EPA determines that federal action is necessary.
Adding nutrient criteria to State water quality standards is essential for Federal,
State and local agencies, and the public, to better understand, identify, and manage
nutrient overenrichment problems in surface waters.
The following sections will present the key elements of the Strategy and describe the tasks and
activities that EPA will undertake to promote nutrient assessment and criteria development over
the next several years.
A. The Five Key Elements of the Strategy
1) Geographic Region Approach.
EPA intends to develop nutrient criteria guidance on a regional, rather than a national, basis. The
Agency expects States and Tribes to develop water quality criteria and standards for nutrients in
their geographic regions based on the guidance provided by EPA. The criteria established would
therefore be the product of a joint EPA-State/Tribal effort tailored to that part of the country.
This approach permits the objective of overenrichment abatement to be met by recognizing the
ambient "natural" background levels of nutrients in each region and then concentrating on the
"cultural" eutrophication which exceeds this. As noted below, regional criteria information will
be presented for four categories of waterbodies.
Although this Strategy is organized around the four major waterbody types specified below, it is
recognized that approaches for assessing regional and waterbody-specific nutrient concerns must
consider that waterbody types are not independent from each other, but are part of an
interconnected and larger system. With that in mind, the need for integration of concepts
associated with the assessment and control of nutrient overenrichment between waterbody types
is clear. This understanding of an integrated approach is an important concept to keep in mind
during the implementation of this Strategy.
One well-defined spatial framework which can be used to define a region for nutrient assessment
is the "ecoregion" system developed by James Omernik of the EPA Corvalis, OR laboratory.
While it is acknowledged that several other classification schemes have been developed, for the
purposes of this strategy, EPA plans to use Ecoregions as defined by Omernik et al., to initiate
development of regional nutrient indicator ranges and, ultimately, to include them in the State and
Tribal nutrient water quality criteria. A draft map has been created as a starting point for this
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process (See figure 1). Still to be determined is what scale of ecoregion is appropriate for the
development of regional nutrient criteria guidance within a short period of time (by the end of
calendar year 2000). The degree of variability within each of these 14 nutrient ecoregions will
determine whether the map needs further refinement. These issues will be resolved once data has
been reviewed, analyzed, and discussed at meetings of the National Nutrient Team and its
Regional components (see item 4 below). In addition, this does not preclude the use of other
classification schemes by Regions and States and Tribes if they are judged to be more appropriate
for that part of the country. For more details on the ecoregion concept and how it can be applied
in a nutrient assessment see Omernik (1995) and Omernik et al (1988).
Upon determination of the best ecoregion scale, the next task which is integral to the development
of nutrient ecoregional ranges is the identification of reference conditions within each of the
nutrient ecoregions. Reference conditions refer to information from relatively undisturbed areas
within each ecoregion. The concept of reference conditions and how they are selected will be
described in more detail in the technical guidance documents.
2) Waterbody-Type Technical Guidance.
A major element of this Strategy will be the technical nutrient criteria guidance manuals, which
will provide methodologies for developing region-specific nutrient criteria by waterbody type:
• streams and rivers,
• lakes and reservoirs,
• estuaries and coastal marine waters, and
• wetlands.
These manuals will also include discussions on overenrichment indicators, sampling and analytical
techniques, and management methods. The manuals will be designed to be adapted in the various
regions of the country.
The manuals will also provide technical assistance to implement nutrient abatement practices and
will include data processing and manipulation techniques, best management practices, and case
study demonstrations. An outline of the proposed content of the guidance document is in
Appendix C, and elements of the technical material are presented in part III of this document.
EPA plans to publish guidance documents for streams and rivers, and lakes and reservoirs in
1999; a guidance document on estuaries and coastal marine waters in 2000; and a guidance
document on wetlands in 2001. In each document, where data is available, EPA will also
provide target regional nutrient ranges for phosphorus and nitrogen (and potentially other
parameters), which States and Tribes may elect to use as the basis of their nutrient criteria and
standards in lieu of applying the methodology. Where appropriate, they may also use these values
as the basis for TMDLs and NPDES permit limits.
EPA and the Regional teams will collect and organize nutrient data on a geographic basis and
develop target nutrient ranges based on historical nutrient data, reference conditions, and expert
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Draft Aggregations of Level III Ecoregions
for the National Nutrient Strategy
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panel opinion. Where adequate data is available, EPA intends to append these ranges to its
waterbody-type guidance manuals. This information can be used by individual States/Tribes
which lack sufficient data of their own. Each appendix will be a "stand alone," peer reviewed
document for a specific nutrient ecoregion.
As a preliminary measure for development of these nutrient criteria ( i.e., the particular indicators
used to assess the overenrichment or potential for overenrichment of a waterbody), EPA is
seeking the cooperation of States and Tribes to pool available information in the determination of
such ranges of target values for each region of the country. EPA will initially develop ranges for
phosphorus, nitrogen, chlorophyll and secchi depth.
Collecting the data necessary to establish ranges for these parameters will be the first priority of
the National Nutrient Team and Regional Coordinators. These ranges are intended to reflect the
variability of conditions typically associated with particular waterbody types within an ecoregion.
In addition, the ranges of target values serve as a starting point for making the proper
measurements of waterbody enrichment and overenrichment so the appropriate management can
be initiated. The guidance manuals are designed to provide the best methods for such measuring
and evaluation.
An essential element of this process is the determination of the natural, background trophic state
representative (Reference condition) of that area and waterbody so that abatement management
can be directed at the cultural eutrophication of concern. It is not the intention of this strategy or
the subsequent program to require States or Tribes to correct a natural enrichment process typical
of their region; rather it is the purpose of the strategy to help States and Tribes develop
mechanisms to remedy the enrichment effects of human development and commerce which
impede the biota and beneficial uses of that waterbody.
3) Nutrient Criteria and Standards Development.
Upon completion of all the waterbody-type guidance documents, EPA expects all States and
Tribes to adopt and implement numerical nutrient criteria into their water quality standards within
three years of publication of waterbody type guidance documents and to complete adoption of
nutrient criteria for all waterbodies in the State by no later than December 31, 2003. EPA expects
States and Tribes to accomplish this by developing their own regional values in watersheds where
applicable data are available, or by using the EPA target nutrient ranges. EPA expects States and
Tribes to select a single value within the range as their water quality criterion where data is
sufficient.
With regard to criteria and standards development, State and Tribes can choose to use the
following approaches:
- The EPA target ranges, or values within those ranges, can be directly adopted
by the States or Tribes as their criteria and standards and used to interpret narrative
standards.
- The States or Tribes can use the EPA target ranges together with their own
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databases to develop their own criteria or to evaluate the protectiveness of any
numerical nutrient criteria they may already have.
- States or Tribes may elect to use the EPA methodology described in waterbody-type
guidance to develop criteria or employ their own approach, independent of the ranges,
as long as it is scientifically defensible.
Once submitted to EPA, the Agency will review the new or revised standards under Section
303(c)(3) of the Clean Water Act. If EPA disapproves the new standard submitted by a State
or Tribe (e.g., because EPA determines that it is not scientifically defensible), or if EPA
determines that a new or revised nutrients standard is necessary for a State or Tribe (e.g.,
because EPA determines that the State or Tribe has not demonstrated reasonable progress
toward developing numerical nutrient standards), EPA will initiate rulemaking to promulgate
nutrient criteria values appropriate to the region and waterbody types. Any resulting water
quality standard would apply until the State or Tribe adopts and EPA approves a revised
standard. In the event EPA promulgates nutrient water quality standards for a State or Tribe,
EPA would likely use the point in the range of greatest confidence (i.e., central tendency).
When reviewing the adequacy of State/Tribe derived criteria and or ascertaining whether a
State or Tribe is making reasonable progress toward developing an adequate nutrient criterion
and standard, EPA is likely to use the target ranges.
When the initial target ranges have been established and the States or Tribes have begun the
criteria and standard development process, EPA through the Regional Nutrient Coordinators
will also provide technical and financial assistance for nutrient management planning and
application. This will be through guidance manuals and the services of regional and national
specialists associated with the Team, as well as financial assistance also administrated by these
Regional Nutrient Coordinators.
4) Nutrient Teams.
EPA Headquarters and Regional staff will work closely with State officials and other
interested parties in the development of the nutrient criteria. The overall national nutrient
criteria project will be managed by a National Nutrient Team. The EPA National Nutrient
Team will include Office of Water staff, a Coordinator from each EPA Region, State/Tribal
representatives, and representatives of other Federal agencies (See Figures 2 and 3). EPA will
provide guidance and support to States/Tribes in the form of technical and financial assistance
to help establish their regional programs.
In addition, each Regional Office will select a Regional Nutrient Coordinator and will establish
a Regional Nutrient Team. The Regional Coordinator will promote the development and
implementation of State and Tribal projects, databases, and nutrient criteria and standards, as
well as manage the award of financial assistance to support this endeavor. Specifically,
Regional Coordinators will have a large role facilitating the collection of nutrient data from
States and Tribes within their Regions. Ultimately, the Regional Coordinators and National
Team will work together to develop nutrient ranges for each ecoregion wherever appropriate
data is available.
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FIG. 2
National Nutrient Team
EPA HQ Offices (OW, ORD)
10 Regional Coordinators
3-5 States
Other Federal Agencies (USGS, NOAA, USDA, et. al.)
Function:
Establish ecoregion maps for nutrients
Establish best process for collecting data from all sources
Establish best process for analyzing data and developing
nutrient criteria (minimum data and statistics)
FIG. 3
Regional Nutrient Team
1 Regional Nutrient Coordinator
1 HQ Representative
1 State Representative from each State in the Region
Other Federal/State/Local Representatives as needed
Function:
Collect and analyze regional nutrient data
Establish nutrient ranges (criteria)
Award assistance grants to State/Academia where gaps exist
in our knowledge
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Ten Regional Nutrient Coordinators, one from each Region, have been selected and they have
begun the process of forming their Regional Nutrient Teams. Regional Teams will likely
include representatives from each State in the Region and other federal, State, local
representatives, as needed (including water quality managers, NPDES permit writers, field
biologists, monitoring and modeling experts). For example, a regional team could include
other Regional EPA specialists such as those in Regional and ORD laboratories, as well as
specialists from such agencies as the U.S. Geological Survey (USGS); NOAA- National
Marine Fisheries Service (NOAA-NMFS); the U.S. Department of Agriculture-Natural
Resources Conservation Service and Cooperative State Research, Education, and Extension
Service (USDA- NRCS and CSREES); the U.S. Forest Service (USFS); and the USFWS.
State/Tribal counterparts of these agencies and States and Tribes regulatory specialists should
also be included. University specialists should be considered, as well as the local communities
and environmental and special interest groups. While this list of participants might be the
ideal, in reality local circumstances will probably dictate a smaller group whose composition is
likely to change with time and needs. However, the agency and community resources
described above should, at the very least, be consulted for information and historical
perspectives on the waters in question.
As technical guidance and assistance is established in the various States and Tribes, periodic
meetings of the Regional Nutrient Team Coordinators should be held to compare experiences,
including successes and failures of approaches taken and techniques tried. Key participants, in
addition to the Coordinators, should be the specialists and natural resource managers (as
described above) who conducted the work so detailed question-and-answer sessions can be
held. A proceedings document for each of these meetings should be prepared and circulated
among the States and Tribes and agencies promptly so nutrient measurement and management
information can be rapidly disseminated.
Following organizational meetings at which the objectives of the program are established, the
business of obtaining State and Tribal cooperation in providing nutrient and other enrichment
indicator data must be addressed. This is best accomplished by indicating the positive
consequences of the information exchange. A trial watershed project, in which the
information is actually applied to help solve an overenrichment problem significant to the
State/Tribe, is an appropriate way to start. This demonstration project can be initiated in
tandem with the overall data-gathering effort and will serve as an incentive to other
States/Tribes to become involved.
5) Management and Evaluation.
While the primary focus of this Strategy is to develop regional nutrient criteria guidance, it is
essential to understand the role criteria and standards play in overall nutrient management.
The management of nutrient overenrichment is not just the development of nutrient criteria
and the application of standards; it is a management process which must integrate a number of
programs and methods including but not limited to: Nonpoint and Watershed programs;
NPDES Permitting program; Biosolids Management program.
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These various programs offer many options for the resource manager to consider and there
are many new programs still being developed. However, there are some fundamental
management concepts that should apply in most of these situations. Presented below are ten
sequential elements to consider.
This comprehensive approach incorporates all of the key elements essential to good
management planning, but the user might find that some steps can be consolidated or that
circumstances necessitate a different sequence in the chronology.
1. Problem identification
Make sure a problem exists and is clearly defined in terms that make it possible to seek
a solution.
2. Background investigation
Use literature searches, questionnaires, interviews, and other background
investigations to better describe the problem and determine the information available
about it.
3. Data gathering
Conduct an assessment of water quality including physical, chemical, and biological
parameters and related loading sources in the watersheds. This step should usually be
of one or more years' duration to accommodate seasonal and annual variation.
4. Identification of key problem areas
Conduct a thorough assessment of all of the above information.
5. Alternative management options
Evaluate each possibility and its impact on present uses with respect to scientific
validity, cost-effectiveness, and sociopolitical feasibility. Involve local and States and
Tribal governments, property owners, citizen groups, and public and business interests
in discussions about the optimal approach.
6. Detailed management plan
Prepare a plan that discusses how to address each key element of the nutrient problem
in the most effective sequence. Include a stepwise sequence of coordinated activities
in detail. Usually such a management plan is of a maximum 5-year duration. Such a
duration accommodates sufficient measurement and seasonal variation but is short
enough in planning scope to be included in most budget systems. Longer projects
might require sequential management plans.
7. Implementation and communication
Initiate the management program, including adoption of nutrient water quality criteria
and standards and, where appropriate, establishment of nutrients limitations inNPDES
permits and development of TMDLs as elements of the program. Maintain
community, interest group, and other agency involvement through regular updates on
the process. This communication may begin earlier, e.g., at step 4 or sooner, but it
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should be emphasized here.
8. Monitoring and periodic review
Incorporate water quality monitoring before, during, and after the project to
demonstrate relative response of the system to management efforts. Build in specific
intervals for management review to allow response to changing circumstances;
modifications of methods and schedules; and changes in emphasis as needed.
9. Completion and evaluation
Has the water resource been protected or improved? Give credit to the community
and other participants. Report on successes and failures for future applications and on
lessons learned.
10. Continue monitoring and maintenance
Water resource monitoring stations and parameters should continue on a reduced
scale. Ensure regular maintenance of management efforts to preserve the effects
achieved. Monitoring provides warning of any future degradation, so, if necessary,
resource managers can intervene in a timely, cost-effective manner. Close the cycle by
returning to step 1 for next generation response.
With a good database predicated on reliable indicators and the development of regional
nutrient criteria guidance, States, Tribes, and other jurisdictions will be capable not only of
assessing the trophic status of their waters, but also should be able to establish their criteria
and plan, prioritize, and evaluate their management responses. In doing so, all five strategy
objectives are interrelated at the regional level where problem recognition and remediation are
most effective.
B. How the Elements are Integrated
This national Strategy consists of a regional, waterbody-type approach which permits the
variability in natural nutrient loadings to waterbodies around the country to be recognized,
and criteria to be established which account for this variability. The criteria so developed will
also be waterbody-type specific because different waterbodies respond differently to nutrient
loadings. Also, in recognition of this discrete, but interrelated enrichment process, the finally
developed criteria must limit not only the unacceptable enrichment of a given waterbody or
watercourse, but also must factor in the effects of that enrichment on downstream receiving
waters.
The waterbody-type technical guidance manuals being developed will provide specific
guidance to the States and Tribes for making the necessary measurements and for developing
the criteria from those measurements, including the establishment of regional target values as
guidelines. These manuals (including wetlands) are scheduled to be completed by the end of
2001. Each technical guidance manual will include ecoregional target ranges. If there is
sufficient data within each of the 14 ecoregions available to develop a nutrient range within
each of the ecoregions for the four waterbody types, 56 nutrient range appendices will be
developed by the end of 2000. If sufficient nutrient data is not available or is insufficient to
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develop an acceptable peer reviewed nutrient range, EPA will continue to promote data
development in these ecoregions after publication of guidance.
Once the nutrient guidance and ecoregional ranges are completed it is expected that
States/Tribes will develop nutrient criteria (see Figure 4).
The implementation of the criteria will be supported by the regional nutrient teams by
providing technical and logistical expertise as well as funding assistance. The criteria can then
be used in management planning and evaluation on a watershed basis with community
involvement so the ultimate objective of enhancing and protecting our nations water resources
is achieved.
III. WATERBODY-TYPE TECHNICAL GUIDANCE.
Waterbody-type guidance manuals will provide the standardized methods available to the
States/Tribes and other jurisdictions to promote the development of consistent regional
databases that reflect conditions in each part of the country. This is important because
overenrichment and natural levels of enrichment differ from one geographic area to another, in
part because of differing cultural, geologic, and climatologic influences. These factors change
the ambient background from one region to another and necessitate a regional approach to
these measurements and to the nutrient criteria to be developed.
A key element of each waterbody-type guidance manual is the recommended list of reliable
indicators of overenrichment, how they might best be measured, and how and when to collect
the necessary samples for this measurement. (These manuals may also include sections
addressing the remaining objectives of this strategy, i.e., data storage and assessment, research
needs, and best management practices for nutrient impact mitigation.) EPA intends that the
publication of these technical guidance documents will help standardize assessments and
promote regional interstate cooperation for nutrient control.
The following is a partial listing of overenrichment indicators, data requirements, management
options, and research needs recommended by the component nutrient workgroups at the
December 1995 meeting in Washington DC, and by subsequent reviewers. Some of these
recommendations are qualitative in nature; such indicators are also valuable and definitive in
their own right. All of the indicators are meant to serve as a starting point for enrichment
assessments, which are expected to be expanded and refined into more quantitative
evaluations as the guidance is further developed and as individual States/Tribes make regional
adjustments to the methods.
Even as a partial listing, this material may seem remarkably detailed to the general reader for a
strategy document. It must be recognized that this strategy is predicated upon the proper
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Figure 4
14ECOREGION \
NUTRIENT CRITERIA \
RANGES APPENDED TO )
WATERBODY GUIDANCE/
DOCUMENT /
NATIONAL NUTRIENT STRATEGY
LAKES AND
RESERVOIRS
GUIDANCE
DOCUMENT
|>
RIVERS AND
STREAMS
GUIDANCE
DOCUMENT
ESTUARINE
AND COASTAL
GUIDANCE
DOCUMENT
1
WETLANDS
GUIDANCE
DOCUMENT
1
I
STATE/TRIBAL IMPLEMENTATION OF GUIDANCE AND CRITERIA
/^ PROMULGATION IF STATES/TRIBES TAKE NO ACTION TO ^>
VDEVELOP NUMERICAL NUTRIENT WATER QUALITY STANDARDS/
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measurement of valid environmental indicators for the establishment of scientifically defensible
nutrient criteria. The identification of the premises upon which these criteria are based is
essential to a fair and objective review of this strategy by the public.
A. INDICATORS
The indicators (parameters) listed below are the initial candidates for inclusion in the guidance
documents. Each EPA technical guidance drafting committee will make final
recommendations as they further explore the scientific veracity and practicality of the material.
Additionally, each document will include recommendations for the most appropriate sampling
and analytical techniques.
LAKES AND RESERVOIRS
A focus of this guidance will be to establish the connection between lake nutrient
environmental impacts to public health concerns, e.g., septic and sewage effluent discharges.
This twofold approach relating environmental degradation to potential public health risks (as
well as recreational uses and biodiversity concerns) should further stimulate public support of
these initiatives. An outline of this proposed guidance document is attached as Appendix C.
The guidance will include and emphasize watershed-scale assessments and management
approaches, illustrated by case histories and demonstration projects.
Surveys should address both spatial and temporal variability, including seasonality and in some
instances variation over the course of a day. Whenever possible, year-round sampling is
advisable. For in-lake surveys, it is presumed that the investigator will design for optimal
spatial and bathymetric placement of the stations for that waterbody and that these data will
be compared to reference lakes in that classification. Some of the parameters or indicators to
consider follow:
• Early Warning Watershed Indicators
— Land use/loading assessments and changes in watersheds (geographic information
systems (GIS) are effective tools for evaluating nutrient loadings as a function of
land use at a variety of scales). In areas of the country where agriculture and/or
animal feeding operations exist, it is imperative to identify and assess these
locations of potential sources of nutrients by collecting data on size and location of
farms/animal feeding operations within a given watershed.
— Changes in hydrologic regimes
Chemical/Biomass Parameters
— Phosphorus (P) concentration (total P (TP) and total dissolved P in hypolimnion )
— Nitrogen (N) Concentration (total KN, NO2 as N, NO3 as N, and NH4 as N, e.g.,
total N (TN), also N:P ratios)
— Chlorophyll (total or chlorophyll a)
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— Secchi disk depth (m)
— DO (hypolimnetic)
• Community Structure Parameters
— Algal community (composition and biomass)
— Macroinvertebrate structure (composition and biomass)
— Fish (composition and biomass)
— Macrophytes (composition and biomass)
• Secondary Parameters
— Total suspended solids (TSS)
— Total organic carbon (TOC)
• Indicators for Immediate Assessment
— Preliminary survey data in addition to early warning land use information: TP, total
chlorophyll, Secchi depth and DO. These should have established validity, low
cost, and they should be readily used in prediction and modeling.
A historical perspective might be helpful to the data assessment process by integrating
paleolimnological surveys with an evaluation of land use practices and changes.
STREAMS AND RIVERS
It is useful, for assessment purposes, to separate streams and rivers into two categories with
optimal reference systems: for plankton-dominated systems and periphyton-dominated
systems. The major differentiating characteristic between these two systems is that nutrients
saturate the biomass at a much lower level in the periphyton-dominated systems than they do
in the plankton-dominated systems. Summarized below are potential nutrient indicators for
the plankton- dominated and periphyton-dominated systems. Early warning indicators of
potential excess nutrient loadings may be significant shifts in land use patterns or in
climatological events or other activities contributing to extreme runoff.
The indicators that follow are not presented in any order of sensitivity or utility.
• Plankton-dominated Systems • Periphyton-dominated Systems
— Algal biomass — Algal biomass (mg/m2 percent
coverage)
— Transparency — Transparency
— TN — TN, dissolved inorganic nitrogen
(DIN)
• Appropriate to Either Plankton or Perivhvton-dominated Systems
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pH (maximum and diel)
DO (minimum and diel)
Ash Free Dry Weight (AFDW)/
Chlorophyll a
Aesthetics (foam, scum)
Benthic community metabolism
Secondary production (meiofauna,
index macroinvertebrates, fish)
Hydrologic characteristics
TP, soluble reactive
phosphorus (SRP)
ESTUARIES AND COASTAL MARINE WATERS
— Sediment composition
(physical/chemical)
— Ratios of summer/winter nutrient
concentration
— Ratios of dissolved/total nutrient
concentrations
— Temperature
— TSS, volatile to suspended solids
ratio
— Biointegrity (macroinvertebrate
community composition)
— Production/respiration
— Dissolved organic material
— Relative plankton composition of
Cyanophyta and dinoflagellates
Estuaries and coastal marine systems can be subclassified for assessment according to the
dominant vegetation type, as was done by the Estuaries Workgroup during the 1995
workshop. However, other systems of classification, such as classification by physical
characteristics, can also be used. The participants in the December 1995 workshop selected
the following categories: seagrass-dominated, plankton-dominated, and macroalgae-
dominated (as indicated below). The indicators associated with these categories can be
applied to either short-term or long-term assessments. It should also be noted that there are
physical, chemical, and biological indicators other than those listed below (such as fish kills,
suspended material, nutrient concentrations, toxins, and benthic invertebrate communities).
Early warning indicators of potential excess nutrient loadings might be significant shifts in land
use patterns or in climatological events or other activities contributing to extreme runoff. All
indicator measurements in these waters must be qualified by attention to tide cycles, density
and salinity gradients, and currents when they were made.
• Seagrass-dominated Systems
— Areal surveys of distribution, abundance, and depth of grasses
— Waterbody-type light requirements (seagrass depth vs. light attenuation)
— C:N:P ratios in plant leaves
— Leaf chlorophyll a
— Quantum irradience levels
— Chlorophyll a-to-b ratios
— Transparency
• Plankton-dominated Systems
— Chlorophyll a
— Algae such as cyanophyta, dinoflagellate, and diatom assemblages including HABs;
documentation of the incidence and location of blooms
— DO determinations that consider cyclic fluctuations and distinguish between natural
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and anthropogenic causes
— The role of silica relative to nitrogen and phosphorus in phytoplankton blooms
— Macroinvertebrate and other consumer community changes
• Macroalgae-dominated Systems
— Macroalgae influence on DO concentrations, dissolved organic carbon concentrations,
and lower trophic levels.
WETLANDS
Methods for assessing nutrient impacts to wetlands are perhaps less established and
standardized than those for the other waterbody types. This is due to the variability within
wetland types (e.g., bogs, swamps, etc.) and the lack of historic databases in these areas.
Some methods developed for lakes and rivers are applicable to wetlands with standing water,
but there are few methods appropriate for wetlands that have saturated soils or are
infrequently flooded. Surveys of wetlands should address both the spatial and temporal
variability in nutrient levels, including seasonal and diel variation. Surveys should also address
the variation in nutrient levels both within a wetland and between different wetland types.
Some wetlands are often naturally eutrophic and will respond to nutrient additions much
differently than bogs and other oligotrophic wetlands. The variability in plant communities
(i.e., succession) will also affect how a wetland assimilates nutrients.
The following are suggested methods for assessing the effects of nutrients in wetland habitats.
However, for most of these parameters, few baseline data are available with which to compare
collected data.
• Early Warning Watershed Indicators
— Land use/loading assessments and changes in watersheds
— Precipitation, in-flow, runoff, and any extreme climatological or anthropogenic events
• Chemical/Biomass Parameters
— Phosphorus concentration (total)
— Nitrogen concentration (total, also N:P ratios)
— Chlorophyll (total or chlorophyll a)
— Secchi disk depth (m) (for wetlands with standing water)
— DO and soil oxygen demand
• Biological Assemblage Parameters (e.g., composition, richness, diversity, and indicator
species)
— Attached microbial community
— Algae such as dinoflagellates and diatoms
— Macrophytes including emergent vegetation
— Macroinvertebrates
— Fish (for wetlands with standing water)
• Secondary Parameters
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— TSS
— TOC
Since wetlands differ in their capacity to assimilate nutrients, it might be difficult to evaluate
whether a given nutrient load will have a significant ecological impact on a wetland.
Biological monitoring is useful to assess the response of wetland plants and animal
assemblages to overenrichment and to detect degraded habitats. Microbial, macrophyte
communities and algae, such as dinoflagellate and diatom assemblages, are particularly useful
for detecting nutrient impacts by measuring their diversity, richness, composition, and
structure. These assemblages can be compared to the assemblages found in reference
wetlands that range from "minimally disturbed" to severely impacted by nutrient enrichment.
Thus, the biological integrity of a wetland can be determined relative to the biologic
assemblages present in the reference wetlands. The macroinvertebrate, fish, and plant
assemblages can also reflect direct impacts of overenrichment and indirect impacts such as
reduced levels of dissolved oxygen.
Another method of monitoring wetlands is to identify the accumulation of organic material
over time as an indication of a change in productivity. This can be done by placing pieces of
feldspar within wetlands and monitoring them for accumulation. Feldspar does not react with
other chemicals in the soil and, therefore, could be used as a benchmark for measuring the
buildup of organic material.
There are two systems of wetland classification that might be useful for selecting and
comparing wetlands. Cowardin et al. (1979) developed a hierarchical system of wetland
classification based largely on the structure of the plant community (e.g., forested,
scrub/shrub, emergent, etc.). In addition, Brinson (1993) developed a hydrogeomorphic
(HGM) framework for classifying wetlands based on a wetland's landscape position, source of
water, and hydrodynamics.
B. DATA STORAGE AND PROCESSING
Once a standardized methodology for data gathering is available, the States and Tribes will
also need a consistent and mutually compatible data storage, retrieval, and assessment system
to help them interpret data and convert them to meaningful management information. An
element of each waterbody-type guidance document should be convenient desktop, PC-based
data storage and modeling programs. Such programs will not only enhance data assessment,
but will, if consistent throughout a region, promote coordinated interstate surveys and data
sharing. Many States already have sufficient nutrient databases and such data storage systems
should be established in consultation with all potential partners. In fact, as Regions develop
this aspect of the strategy, it is imperative that they consult with the States/Tribes to establish
what systems are most efficient, cost-effective, and appropriate for data sharing without
violating resource management confidentiality. EPA is currently engaged in determining the
future design of a nationwide database, and this strategy should be compatible with that effort.
Ensuring compatibility would include standardization of both data storage systems and
models. The success of multi-State cooperation and coordination of monitoring activities will
depend on this.
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In all cases it will be essential that the quality of the data entered into these databases be
carefully documented. Documentation should include information on methods used, minimum
detection limits, and comparison to standards. Modelers should use due caution if quality
assurance aspects of the data are not available.
Once such a database system is in place, calibrated and verified models can be developed or
applied to help predict the likely consequences of management actions or, just as important,
the lack thereof. Listed below are suggested needs or available resources appropriate to each
waterbody type.
LAKES AND RESERVOIRS
Modeling:
Modeling is ideal in many ways for lake assessments. The BATHTUB and Reckhow-Simpson
technique are two of many examples of existing lake models used by managers to predict
trophic responses to estimating nutrient loading adjustments. The BATHTUB applies a series
of empirical eutrophication models to morphologically complex lakes and reservoirs. The
program performs steady-state water and nutrient balance calculations in a spatially segmented
hydraulic network that accounts for advective and diffusive transport, and nutrient
sedimentation. (For details, see National Nutrient Assessment Workshop Proceedings, EPA
822-R-96-004, July 1996.)
The goal of this strategy is to provide simple, user-friendly, desktop-based software models
for States and Tribes and local governments to aid them in waterbody management decision
making. Impoundments/reservoirs often have unique hydrographic profiles and therefore will
probably require models calibrated specifically for use with these waterbodies.
STREAMS AND RIVERS
Modeling:
It is necessary to identify ways to improve on the existing models to examine the
interrelationships and links between nutrient sources and nutrient impacts and help to tailor
these models to both plankton- and periphyton-dominated systems. Participants at the
December 1995 workshop noted in particular that modeling tools are lacking for periphyton-
dominated systems, including both simple mass balance or regression relationships and
complex process-based models. Below are ways to improve on the existing models'
capabilities. For more details on any of the models listed below, see the National Nutrient
Assessment Workshop Proceedings (EPA 822-R-96-004, July 1996).
• Provide land use connections in watershed-scale models.
• Conduct sensitivity analyses.
• Conduct carbon-based simulations.
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• Add temperature simulation to the WASPS model. WASPS is widely used in both water
quality assessment and toxic modeling. The model considers comprehensive dissolved
oxygen and algal processes, but does not include the carbon and silica cycles or full
sediment diagenesis model. In addition, its use is limited because it does not account for
temperature. Therefore, adding temperature simulation to WASPS would allow for
diurnal temperature variations.
• Add periphyton to the QUAL2E, WASPS, and HSPF models. QUAL2E and HSPF are
models that capture the longitudinal transport that dominates in most rivers and streams.
QUAL2E and HSPF both consider advection and dispersion. Adding periphyton to these
models would allow for simulation of periphyton biomass in the riverine system.
• Introduce load/response relationship (plankton) and concentration/response relationship
(periphyton) to pinpoint where nutrient loading reduction can be targeted.
• Develop desktop models that are easily transferred across waterbodies and use the
following parameters: TP, TN, total chlorophyll, DO, temperature and transparency
(Secchi disk and black disk).
ESTUARIES AND COASTAL MARINE WATERS
Modeling:
Estuarine and coastal marine models are in the process of development and testing around the
country, including efforts on the Chesapeake Bay. Much of this work is promising, and the
following are areas requiring further effort.
• Seagrass-dominated Systems
— Develop water quality models, from simple to complex, that look at simulation of
chlorophyll a concentrations over seagrass beds from nutrient loadings of the
surrounding watershed.
— Develop multiple regression analysis models that simultaneously consider such factors
as TSS, color, and chlorophyll a.
• Plankton-dominated Systems
— There is a need for an estuarine version of "Vollenweider" relationships to better
understand the relation of nutrient loadings to chlorophyll a.
• Macroalgae-dominated Systems
— Many databases exist that would allow identification of nutrient loading thresholds for
macroalgae-dominated systems.
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WETLANDS
Modeling:
Very few models exist that are capable of predicting wetland responses to nutrient loadings.
Of the literature reviewed, Mitsch and Gosselink (1993) and Howard-Williams (1985) offer
conceptual diagrams of potential relationships for nutrients in wetlands. Wetlands can
function as a source, sink, or transformer for a particular nutrient. A wetland is considered a
sink if it has a net accumulation of a nutrient. In contrast, a wetland is considered a source if
it exports more of a nutrient than it accumulates. A wetland is a transformer if it transforms a
chemical from one form to another, such as from dissolved to particulate form, but does not
change the amount going into or out of the wetland (Mitsch and Gosselink, 1993). In some
cases, a wetland can be a sink for one nutrient while it is simultaneously a source for another
nutrient.
Nutrient models for wetlands, as for all waterbodies, should account for atmospheric, surface,
and subsurface inflows and outflows. The models should account for gaseous, aqueous, solid,
and sediment-attached forms of the nutrients. The models should also account for the uptake
and release of nutrients by living biomass and by decomposition of biomass. In addition, the
models should address the seasonal and daily patterns of nutrient uptake and release by plants
and animals. Chemical transformations based on changes in pH and concentrations of other
chemicals should also be considered. All models should be validated on reference wetlands.
Sediment loading models used to predict TMDL loading rates from storm events can be useful
for estimating phosphorus inputs. Some traditional water quality models, such as CEQUAL-
W2 and WASPS, have been used for evaluating wetlands. Hydrodynamic models, such as
EFDC, are being applied to wetlands in Florida to assess hydrologic response. Analysis of
wetlands may also include the assessment of inputs/loadings using a variety of loading models
(e.g., SWMM, HSPF) that can be used to predict nutrient and sediment loads to local
wetlands (USEPA 1992). Further model development is needed, particularly for wetlands
that have saturated soils and are infrequently flooded.
C. MANAGEMENT AND EVALUATION
The material in this section is not intended to be an all-inclusive list of remediation, protection,
and management approaches. However, it is an introductory presentation of some of the
readily evident options States and Tribes and other responsible parties can use to make a
positive response to the nutrient information they obtain and the water quality criteria States
and Tribes develop.
Options also exist that might not be specific to waterbody-type, such as the watershed
approach. This approach allows communities to focus resources on a watershed's most
serious nutrient sources, which might include animal waste and excess fertilizer runoff.
Additional basic management measures can be found in other EPA documents such as
Guidance Specifying Management Measures for Sources of Nonpoint Pollution in Coastal
Waters (EPA 840-B-92-002). The following, as well as additional approaches (such as the
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development of TMDLs for nutrient-impacted waters, the control of animal waste discharges,
and the control of outbreaks ofPfiesteria and similar harmful algal blooms), will be explored
further in the guidance materials to be developed as part of this strategy.
MANAGEMENT
In considering the various management options, the resource manager should also keep in
mind that the different waterbody types described here may often be interrelated, e.g., streams
draining to and from lakes, and rivers entering estuaries and coastal waters. Under these
circumstances, the manager should be careful to select for a management plan practices that
do not have negative downstream effects. For example, it might not be appropriate to raise a
lake level to the detriment of riparian wetlands and influent streams.
LAKES AND RESERVOIRS
Examples of management options to consider when dealing with lakes and reservoirs are
provided below.
• Vegetative buffer zones— Preserve or reestablish natural, indigenous vegetation (ground
cover, shrubs, trees) in the riparian zone to intercept sediment and nutrient runoff before
the runoff reaches the waterbody.
• Watershed land use changes— Identify critical loading sources and promote changes of
these land use practices. Examples of practices to promote are implementation of
conservation farming; use of manure holding facilities; use of road, commercial, and
municipal runoff diversions and detentions; restoration of woodlots in critical drainage
areas; land use planning to avoid excessive tiers of lake residences; and on-site septic
system use and improvement.
• Habitat restoration— Improve lake nursery and spawning areas to restore a diverse
aquatic community and food chain.
• Fish stocking and removal— Perform adjustment offish communities disrupted by
overenrichment by the selective removal of undesired species, the addition of more
preferred species.
• Water column precipitation and sediment sealing techniques— Apply alum to the water
column to remove P and to seal nutrients into bottom sediments under precipitate.
• Macrophyte harvesting and flow regulation— Perform weed control by use of mechanical
harvesters to enhance lake use of nutrients and to remove some nutrients present in
biomass. Initiate winter or other episodic drawdowns of lake/reservoir waters to augment
sediment removal or consolidation.
• Biomanipulations— Ensure balanced predator stocking or grazer support to control blue-
green algae and other nuisance primary producers.
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• Relocation of sewage outfalls— Move sewage outfalls to locations that will minimize
deleterious impacts to the waterbody.
• Restoration and protection of strategic wetlands— Restore and protect wetlands located
in areas critical to water quality concerns.
• Hypolimnetic aeration— Implement techniques designed to aerate the hypolimnion.
• Point source nutrient removal— Remove nutrients at point sources using techniques such
as tertiary treatment and phosphorus precipitation.
• Storm water management— Implement storm water BMPs such as constructing ponds,
wetlands, infiltration and detention basins, and diversions.
STREAMS AND RIVERS
Issues and actions to consider associated with the abatement of nutrients in streams and rivers
include:
• Land use— Include land use as a separate early warning indicator (i.e., if development is
proposed in a watershed, an environmental impact study should be done to assess the
potential impact of such development on the surrounding waterbody).
• Designated use and biomass relationships— Employ public survey techniques to monitor
relationships between designated uses and algal biomass.
• Seasonal relationships— Investigate seasonal relationships between nutrients and biomass
across streams.
• Nitrogen-phosphorus cycling— Enhance nitrogen-phosphorus cycling on different land
uses to reduce mobilization (septic, forest systems).
• Riparian zone management— Introduce riparian buffers, shade the streams, or perform
canopy restoration to minimize direct sunlight on surface water. Shading can also reduce
the amount of direct air deposition of nitrogen and other nutrient sources.
• Channel restoration— Minimize the nutrient loadings by constructing channels to help
reduce the rapid nutrient flush from one segment of the waterbody to another.
• Biological controls— Introduce biomass eating organisms such as caddis fly larvae
(Dicomoecus gilvipes), which efficiently remove both periphytic diatoms and filamentous
algae from rock substrata.
• Hydrology, hydraulics (flow regime, storm water management, stream regulation)—
Identify natural hydrologic regimes and use such information in addressing dam operations
to better replicate natural conditions in the area while generating power or preserving
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intended reservoir levels.
• Impoundment removal— Remove man-made impoundments that have lost their utility and
are now causes of flow interruption and sources of excessive algae and water quality
degradation.
• Restoration of riparian and floodplain wetlands— Implement programs designed to restore
riparian and floodplain wetlands.
• Point source nutrient removal— Remove nutrients at point sources using techniques such
as tertiary treatment and phosphorus precipitation.
• Storm water management— Implement storm water BMPs such as constructing ponds,
wetlands, infiltration and detention basins, and diversions.
ESTUARIES AND COASTAL MARINE WATERS
The following are basic management options to consider for all vegetation system types:
• Land use and development controls— Promote natural vegetative cover in shore areas and
zoning restrictions on dense residential or commercial/industrial development along
shoreline areas.
• Discharge and dumping regulation and marine sanitation devices— Encourage enhanced
Publicly Owned Treatment Works (POTW) design and operation, and the diversion of
POTW effluent from sensitive or poorly circulated waters. Promote and enforce marine
sanitation device (MSD) regulations including providing adequate pumpout services.
• Restricted estuarine/coastal areas— Protect sensitive waters such as endangered
shellfish beds, spawning and nursery areas, and recovering weed beds.
• Shoreline erosion controls— Implement erosion controls on banks subject to wave or ice
damage. Restrict access to sensitive shorelines, dune restoration areas, and shorelines
susceptible to erosion.
• Seagrass replenishment— Restore weedbeds in estuaries, including wetland areas. Plant
and protect emergents and terrestrial riparian vegetation as further protection of tidal zone
wetlands from runoff.
WETLANDS
Best management options to consider for wetlands include:
• Wetland protection and restoration— Preserve and restore wetlands through the
implementation of voluntary and regulatory programs.
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Vegetative buffer zones— Preserve or reestablish natural, indigenous vegetation (ground
cover, shrubs, trees) as buffer zones adjacent to wetlands to intercept sediment and
nutrient runoff before the runoff reaches the wetland.
Watershed land use changes— Identify critical land loading sources and promote changes
of these land practices. Examples of changes that could be made include the
implementation of conservation farming techniques; the reduction of the use of fertilizers
on farms and lawns; the construction of manure holding facilities, runoff diversions and
detentions, filter strips, and vegetated drainage ways; the implementation of forestry
BMPs; the implementation of controls on urbanization and industrial development; and the
upgrading of on-site and municipal wastewater treatment systems.
Land use planning— Protect wetlands by limiting amounts of impervious surfaces, limiting
development near waterbodies or steep slopes, and minimizing discharges from storm
water, sewer, and septic systems.
Protect and restore streams entering wetland— Stabilize stream channels and establish
riparian buffers to reduce the amount of sediment-attached nutrients entering a wetland.
EVALUATION
Once the appropriate parameters or indicators have been established, EPA and the States or
Tribes will be able to evaluate the effectiveness of the management and regulatory approaches
taken. The databases and monitoring systems developed, together with the derived criteria,
should be used to assess actual management progress toward ameliorating overenrichment
conditions. (This process will be described in detail in each waterbody type specific technical
guidance manual.) Where methods and techniques have been successfully employed, the
experience may be applied to similar circumstances elsewhere. Where success has not been
achieved, the knowledge gained is valuable in developing alternative approaches and in
avoiding making the same mistake again. This information should be shared among the
Regional Nutrient Teams, through correspondence and national meetings, to enhance
management effectiveness.
Periodic program progress reports and budget statements will be prepared for the Office of
Water, based on the proceedings described immediately above, so continuity of the program
can be maintained, funding and other administrative support provided, and new needs
identified and addressed.
The sum total of these reports and proceedings of the periodic national team meetings will
provide the necessary feedback to EPA Headquarters to help further development and
shaping of national policy with respect to nutrient management of the Nation's waters.
D. RESEARCH NEEDS
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For all four major waterbody types, there are a number of research needs that should be
addressed. A number of these research needs are noted below. They are highlighted to
indicate areas which each technical guidance drafting group should address to attempt to
reduce uncertainty in the assessment process.
LAKES AND RESERVOIRS
• Phosphorus and nitrogen speciation investigations.
• Sedimentation and nutrient load impacts on trophic states.
• Internal loading and recycling of nutrients regarding biological responses.
• Biomanipulation techniques.
• Better understanding of cascading trophic interactions, i.e., the effects of nutrient changes
on one level of the food chain and how the rest of the community is affected.
STREAMS AND RIVERS
• Chlorophyll measurements (periphyton).
— Sampling methods
• Cladophora, diatom, and blue-green alga growth requirements.
— Field research
Literature search on stream models (periphyton system).
Stream bank, riparian zone, and denitrifi cation.
Investigation of dissolved oxygen and pH amplitude.
Investigation of community metrics to characterize rivers for nutrient effects.
— Ecoregions
— Which metrics are most sensitive?
— Literature search on indicator taxa
— Is biointegrity sensitive as an early warning tool?
• Role of fluvial geomorphology as a factor in controlling algae development.
• Whole stream overenrichment studies.
• Investigation of seasonal relationships between nutrients and biomass across streams.
In addition to identifying the above research needs, the December 1995 workshop participants
discussed a number of other actions that should be taken to help managers and scientists
assess nutrient impacts on river and stream systems. These actions include the following:
• Conduct literature searches on stream modeling techniques, community metrics, and
designated use and biomass relationships (e.g., using survey techniques).
• Explore how biological indicators can be used to determine causes of systematic change.
• Explore, on an ecoregional basis, the level at which biomass and chlorophyll a
concentrations begin to impair beneficial uses of rivers and streams.
• Explore causal linkages observed in stream community metrics.
• Explore how the use of various management options, in addition to nutrient controls, will
help maintain designated uses of river and stream systems (e.g., sediment and erosion
controls, channel restoration, riparian zone management, etc).
• Involve other organizations in efforts to understand nutrient impacts on river and stream
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systems, including volunteer monitoring programs.
ESTUARIES AND COASTAL MARINE WATERS
Resolution of N-P limiting question with salinity gradients.
Role of dissolved oxygen in estuarine overenrichment.
Role of sedimentation-turbidity in overenrichment.
Biological community indicators.
Tidal and discharge dynamics in estuarine nutrient flux resources including marine
loadings vs. watershed resources.
• Impact of shore discharges on estuaries and coastal marine overenrichment including
better loading estimation models.
• Models to predict HAB events in eutrophic systems and appropriate response strategy as
described in National Harmful Algal Bloom Research and Monitoring Strategy: an initial
focus on Pfiesteria, fish lesions, fish kills and public health (draft, November 1997).
WETLANDS
• Development of an accepted national wetland classification system similar to the
hydrogeomorphic system developed by the Army Corps of Engineers.
• Development of a nationwide database for natural wetlands like that currently available for
constructed wetlands should be developed. The database should include wetland types
and statistical characteristics that apply to each type. A national database could be used to
compare the measurement parameters of assessed (impacted) wetlands to an established
set of reference conditions.
• Comprehensive literature search to determine what work has already been done on
nutrient-related wetland issues.
• Development and testing of biological assessment and monitoring methods for detecting
nutrient impacts.
— Which biological assemblages are most sensitive?
— Which metrics are most sensitive?
• Establishment of a regionalized network of wetlands of different types (e.g., bogs, swamp)
across a gradient of nutrient disturbance from "minimally impacted" to degraded.
• Further research on the impacts of nutrients on different wetland types (e.g., bog, marsh,
swamp).
• Further research on influence of land use within watersheds on the impacts of nutrients to
wetlands.
• Field experimentation to determine nutrient limitation to wetland type and to isolate the
effects of nutrients from other variables, such as hydrology, climate, and physical
alteration of habitat.
• Models for nutrient inflow, export, and transformation within different wetland types.
• Further investigation of how the bioavailability of nutrients is affected by water chemistry
(e.g., pH, dissolved metals) and substrate (e.g., percent clay, percent organic matter).
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31
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APPENDICES
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Appendix A: Summary of Water Quality Criteria and Standards for Nutrient
Overenrichment
In 1994, EPA commissioned a study that gathered information on State Water Quality Criteria
and Standards for Nutrients. The following is an abstract of that study. Table 1 is a summary
of water quality criteria and standards for nutrient enrichment listed by State.
Nitrogen
Seventeen States, the District of Columbia, and the Virgin Islands have no specified water
quality criteria for nitrates and/or nitrites. Seven States have only narrative criteria for
nitrogen. Four States have narrative and quantitative criteria. Nine States use only EPA-
recommended nitrate-nitrogen criteria (10 mg/L) for the protection of domestic drinking
water supplies. Twelve States and Puerto Rico use EPA-recommended criteria in conjunction
with other criteria, either quantitative or narrative. Five States and four U.S. territories have
quantitative water quality criteria for nitrogen but do not incorporate EPA-recommended
criteria into them.
Phosphorus
In the case of phosphorus, 21 States, the District of Columbia, and the Virgin Islands have no
specified water quality criteria. Twelve States have narrative criteria addressing phosphorus
in general. Seven States have both narrative criteria and quantitative criteria addressing
phosphorus. One state, Florida, uses the EPA-recommended phosphorus criterion of 0.10
ug/L for its estuarine and marine waters. Fifteen States and five U.S. territories have
quantitative water quality criteria addressing phosphorus but do not use the EPA-
recommended numerical criteria.
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TABLE 1
SUMMARY OF STATES' EXISTING WATER QUALITY CRITERIA AND STANDARDS
FOR NUTRIENT OVERENRICHMENT
Region/State
Nitrate
Ammonia
Total
Nitrogen
Total
Phosphorus
Region 1
Connecticut
Maine
Massachusetts
New Hampshire
Rhode Island
Vermont
/(2)
/(3)
/(2)
/(2)
/(3)
/(2)
/(3)
/ (7,3,8)
/(2)
/(2)
/(3)
/(2)
Region 2
New Jersey
New York
Puerto Rico
Virgin Islands
/(2)
/(9)
/(2)
/(9)
/ (9,3)
/(2)
/ (8,2)
/ (8,9)
Region 3
Delaware
District of Columbia
Maryland
Pennsylvania
Virginia
West Virginia
/(2)
/(2)
/(2)
/(4)
Region 4
Alabama
Florida
Georgia
Kentucky
Mississippi
North Carolina
South Carolina
Tennessee
/(2)
/(2)
/(2)
/ (7,2)
/(3)
/(2)
/(3)
/(3)
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TABLE 1
SUMMARY OF STATES' EXISTING WATER QUALITY CRITERIA AND STANDARDS
FOR NUTRIENT OVERENRICHMENT
Region/State
Nitrate
Ammonia
Total
Nitrogen
Total
Phosphorus
Region 5
Illinois
Indiana
Michigan
Minnesota
Ohio
Wisconsin
/(2)
/(I)
/(2)
/ (1,3,9)
/(1, 2)
/(2)
/ (2,4)
Region 6
Arkansas
Louisiana
New Mexico
Oklahoma
Texas
/(2)
/(2)
/(2)
/(2)
/(2)
/(2)
/(2)
/(2)
/(2)
/(2)
/(2)
/ (7,2)
/(2)
Region 7
Iowa
Kansas
Nebraska
Missouri
/(2)
Region 8
Colorado
Montana
North Dakota
South Dakota
Utah
Wyoming
/(2)
/(2)
/(2)
/(2)
/ (7,2,9)
/(3)
/ (7,3)
Region 9
American Samoa
Arizona
California
/(2)
/(5)
/n,5)
/(2)
/(5)
/(5)
/(1,9)
/(1, 2)
/(1,2)
/(1,9)
/(1, 2)
/ (1,6,7)
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TABLE 1
SUMMARY OF STATES' EXISTING WATER QUALITY CRITERIA AND STANDARDS
FOR NUTRIENT OVERENRICHMENT
Region/State
Guam
Hawaii
Nevada
Northern Mariana Islands
Trust Territories of the Pacific
Islands
Nitrate
/ (2,7)
/0,9)
/(5)
/(7)
/(2)
Ammonia
/(5)
/0,9)
/ (2,5)
/(5)
/(2)
Total
Nitrogen
/(2)
/0,9)
/(1 ,7,9)
/(7)
/(7)
Total
Phosphorus
/ (2,7)
/0,9)
/ (1,7,9)
/(7)
/ (7,9)
Region 10
Alaska
Idaho
Oregon
Washington
/(2)
NOTES FOR TABLE 1
Blank entry indicates that neither a narrative nor numeric criterion for the nutrient have been specified by the State.
(1) Site-specific numeric values for ambient nutrient levels.
(2) Narrative criteria related to natural conditions, eutrophication and nutrient overenrichment for nitrate, ammonia,
inorganic nitrogen, total nitrogen, or total phosphorus.
(3) Narrative criterion that is not related to natural conditions, eutrophication, or nutrient overenrichment issues.
(4) Numeric values for effluent nutrient levels.
(5) Numeric values related to public health (nitrate) or aquatic toxicity (ammonia).
(6) Habitat-based numeric values for ambient nutrient levels.
(7) Water use classification- or water use designation-based numeric values for ambient nutrient levels.
(8) State wide numeric values for ambient nutrient levels.
(9) Waterbody-based ( streams, rivers, lakes, estuaries, coastal/oceanic waters) numeric values for ambient nutrient
levels.
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Appendix B: Nutrient Criteria Activities and Timeline
Year Activities
1997 Publish Final National Nutrient
Strategy
Products
Date
Strategy & FR Notice of 6/98 FR notice
Availability
1998 Publish Technical Guidance
Document for:
Lakes and Reservoirs
Demonstrations and Case
Studies:
Initiate 3-5 case studies
Outreach Activities &
Communication Strategy:
Regional/State Meetings on
Strategy and Nutrient Criteria
Development
Final Guidance
Methodology validation
and regional criteria for
Lakes and Reservoirs
12/98
On-going
Proceedings
10/98
WQS Academy
Document availability via Internet
Presentations
Brochures & Fact
Sheets
Summer, 1998
National
Nutrient
Strategy
Link info to Regional Nutrient Training
Teams
On-going
1999 Publish Technical Guidance
Documents for:
Rivers and Streams
Final Guidance
03/99
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Year Activities
1999 Demonstrations and Case
Studies:
Initiate 5-10 case studies
Products
Outreach Activities:
Regional/State Meetings on Rivers
& Streams/Lakes Guidance
Methodology validation
and regional criteria for
Rivers and Streams
Methodology validation
and regional criteria for
Marine Coastal Waters
and Estuaries
Proceedings
Date
On-going
On-going
7/99
WQS Academy,
Presentations
Document availability via Internet Brochures & Fact
Sheets
On-going
Lakes and
Reservoirs
2000-2 Publish Technical Documents
for:
Coastal Marine Waters and
Estuaries
Wetlands
Data processing and assessment
Final guidance 03/00
Draft guidance 03/00
Final Guidance & 4/00
National Modeling
Database
Demonstrations and Case
Studies:
Maintain ongoing case studies and
publish regional criteria
Regional Criteria
Guidance
01-02
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Year
Activities
Products
Date
2000-02 Outreach Activities:
Regional/State Meetings on Coastal Proceedings
Waters and Estuaries Guidance
Presentations
WQS Academy
Brochures & Fact
Document availability via Internet Sheets
On-going
On-going
Rivers and
Streams
Coastal Waters
and Estuaries
Data processing
and Assessment
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Appendix C: Draft Outline for the Development of Nutrient Criteria for Streams and
Rivers, Lakes and Reservoirs, and Estuaries and Coastal Marine Waters.
I Introduction
Concept of Nutrient Criteria
— Regional in nature
— Methods and guidance to support development of nutrient criteria
— Discussion of criteria vs. standards
— Narrative criteria vs. numeric, but always quantitatively based
Uses of Nutrient Criteria
— Basis for State/Tribal Water Quality Standards
— Resource assessment
— Setting of management priorities
— Evaluation of management projects
— Long-range planning
— Coordination of nutrient management planning and implementation with other
related programs
Rationale for Trophic Classification and Tiered Sampling Design
— Discussion of deriving nutrient reference conditions
— Discussion of cost-effectiveness of tiers, potential to evolve toward more
detailed sampling as needed
— Detailed discussion of importance of adequate data for decision making
compared to budget and level of certainty needed
II. Conducting Nutrient Surveys
Classification of the surface waters
Indicators
— How analyzed
— When to sample
— Where to sample
Survey Design
Data Storage and Processing
Interpretation
III. Trophic Classification
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How to establish regions
Size classifications
Watershed classifications
Cultural development classes
IV. Indicators
For each indicator:
— Method of collection
— Storage and time constraints
— Method(s) of analysis
— Expected range of results and trophic state indicated by geographic region and
season
V. Sampling Design
Number of stations based on waterbody size
Placement of survey stations relative to characteristics of the waterbody and suspected
loading sites
Time of year and frequency of sampling
VI. Data Processing and Storage
Discuss models and software packages
Regional databases and multi-State coordination of efforts
VII. Interpretation
Synopsis of indicator meanings
Discussion of interrelationships of trophic state and overenrichment indicators
Comprehensive interpretations
VIII. Detailed Nutrient Investigations for Cause and Effect Determination
Follow-up on initial surveys to generate definitive information
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Seasonal adjustments
Relocation of some stations and addition of others
— Importance of basic survey continuity
IX. Management Response
Should be broad-based and general to indicate potential as opposed to a directive to
the community
Types of loadings the indicators reflect
— BMPs and other protection or mitigation measures available
Approaches to achieve protection or change
— Local government
— Communities
— Property owners
— Businesses
Management Planning
— Incorporate the 10-step approach described in Chapter IV of this nutrient
strategy document
X. Evaluation Monitoring
A variation on the original survey plan is used to keep track of the response of the
waterbody to the protection or remediation effort
This information is used to assess the relative success of the project and to plan future
courses of action
— Evaluation of "before, during, and after" project data
Close the loop in the management process by returning to step 1 of the 10-step
process to plan the next phase of management or to apply these results to other
similar, nearby waterbodies.
Appendices
Discussion of how States get from data gathering to using the information in
management decision making to incorporation into State policies.
Illustration of these experiences with case studies and names of contacts for further
information.
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Appendix D: Drafting Committee for the National Nutrient Strategy
Office of Science and Technology Office of Wetlands, Oceans, and Watersheds
Nick Baer John Heisler
USEP A Office of Water USEP A Office of Water
Health and Ecological Criteria Division Oceans and Coastal Protection Division
(202) 260-1306 (202) 260-8632
Robert Cantilli, National Nutrient Program Kristen Martin
Coordinator USEP A Office of Water
USEPA Office of Water Assessment and Watershed Protection Division
Health and Ecological Criteria Division (202) 260-7108
(202) 260-5546
George Gibson
USEPA Office of Water
Health and Ecological Criteria Division
(202) 260-75807(410) 573-2618
Patrick Ogbebor
USEPA Office of Water
Permits Division
(202) 260-6322
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APPENDIX E: Excerpt from the Clean Water Action Plan
Reduce Nutrient Over-enrichment
Nutrients, in the appropriate amounts, are essential to the health and continued functioning of
aquatic ecosystems. Excessive nutrient loadings will, however, result in excessive growth of
macrophytes or phytoplankton and potentially harmful algal blooms (HAB), leading to oxygen
declines, imbalance of aquatic species, public health risks, and a general decline of the aquatic
resource. Nutrient over-enrichment has also been strongly linked to the large hypoxic zone in
the Gulf of Mexico and to recent outbreaks ofPfiesteria along the mid-Atlantic Coast.
State water quality reports indicate that over-enrichment of waters by nutrients (nitrogen and
phosphorus) is the biggest overall source of impairment of the nation's rivers and streams,
lakes and reservoirs, and estuaries. In the 1996 National Water Quality Inventory, states
reported that 40 percent of surveyed rivers, 51 percent of surveyed lakes, and 57 percent of
surveyed estuaries were impaired by nutrient enrichment. Agriculture is the most widespread
source of these impairments, followed by municipal sewage treatment plants, urban runoff and
storm sewers, and various other nonpoint pollution sources, including air deposition.
Define Nutrient Reduction Goals
Although nutrient over-enrichment is clearly a major challenge for the nation's waters, the
assessment of the seriousness and extent of the problem is often based on subjective criteria
that can result in widely varying assessments. Research to improve the basis for understanding
and assessing nutrient over-enrichment problems is critical to better control of nutrient levels
in waters and to meeting the nation's clean water goals.
EPA is developing a strategy to establish an objective, scientifically sound basis for assessing
nutrient over- enrichment problems. Specifically, EPA will develop nutrient criteria -
numerical ranges for acceptable levels of nutrients (i.e., nitrogen and phosphorus) in water.
Unlike other criteria that EPA has developed, nutrient criteria will be established as a menu of
different numeric values based on the type of water body (i.e., river, estuary, lake) and the
region of the country in which the water is located. It is vital that this work be done to provide
the technical basis for pollution reduction plans.
EPA will develop nutrient criteria for the various water body types and ecoregions of the
country by the year 2000. Under the Clean Water Act, states use pollutant criteria established
by EPA as the basis for adopting water quality standards. Within three years of EPA issuance
of applicable criteria, all states and tribes with water quality standards should have adopted
water quality standards for nutrients. Where a state or tribe fails to adopt a water quality
standard for nutrients within the three-year period, EPA will begin to promulgate the nutrient
criteria appropriate to the region and water body type. When promulgated, the EPA standard
would apply until a state or tribe adopts, and EPA approves, a revised standard.
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KEY ACTION: EPA will establish, by the year 2000, numeric criteria for nutrients (i.e.,
nitrogen and phosphorus) that are tailored to reflect the different types of water bodies (e.g.,
lakes, rivers, and estuaries) and the different ecoregions of the country, and will assist states in
adopting numeric water quality standards based on these criteria over the following three
years. If a state does not adopt appropriate nutrient standards, EPA will begin the process of
promulgating nutrient standards.
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REFERENCES
Anderson, D.M., S. B. Galloway, and J.D. Joseph. 1993. Marine Biotoxins and Harmful
Algae: A National Plan. Technical Report No. WHOI-93-02. Woods Hole Oceanographic
Institution.
Brinson, M.M. 1993. A Hydrogeographic Classification of Wetlands. Technical Report No.
WRP-DE-4. U.S. Army Corps of Engineers.
Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of Wetlands
and Deep Water Habitats of the United States. U.S. Fish and Wildlife Service.
Dennison, W. et al. 1993. Assessing Water Quality with Submersed Aquatic Vegetation.
BioScience 43:86-94.
Flemer, D.A. 1972. Current Status of Knowledge Concerning the Cause and Biological
Effects of Eutrophication in Chesapeake Bay. Journal of Ches. Sci. 13:8144-8149.
Howard-Williams, C. 1985. Cycling and Retention of Nitrogen and Phosphorus in Wetlands:
A Theoretical and Applied Perspective. Freshwater Biology 15:391-431.
Metropolitan Washington Council of Governments. 1982. A Review of State Water Quality
Standards Which Pertain to Nutrient Over enrichment. Metropolitan Washington Council of
Governments, Washington, D.C.
National Harmful Algal Bloom Research and Monitoring Strategy: an initial focus on
Pfiesteria, fish lesions, fish kills and public health (draft, November 1997).
Nixon, S.W., and V. Lee. 1986. Wetlands and Water Quality: A Regional Review of Recent
Research in the United States on the Role of Freshwater and Saltwater Wetlands as Sources,
Sinks, and Transformers of Nitrogen, Phosphorus, and Various Heavy Metals. Technical
Report Y 86 2, Final Report. University of Rhode Island, Kingston Graduate School of
Oceanography. October 1986.
Omernik, J.. M. 1995. Ecoregions: A Spatial Framework for Environmental Management in
Biological Assessment and Criteria: tools for Water Resource Planning and Decision
Making. Edited by W.S. Davis and T. P. Simon. Lewis Publishers.
Omernik, J.M, C. M. Rohm, S.E. Clarke and D.P. Larsen. 1988. Summer Total Phosphorus
in Lakes: a Map of Minnesota, Wisconsin and Michigan. Environmental Management 12:815-
825.
Redfield, A.C. 1958. The Biological Control of Chemical Factors in the Environment. Amer.
Sci. 46:205-221.
46
-------
U.S. Environmental Protection Agency. 1988a. Nitrogen-Ammonia/Nitrate/Nitrite: Water
Quality Standards Criteria Summaries: A Compilation of State and Federal Criteria. EPA
440-5-88-029. U.S. Environmental Protection Agency, Office of Water Regulations and
Standards, Washington, D.C.
U.S. Environmental Protection Agency. 1988b. Phosphorus - Water Quality Standards
Criteria Summaries: A Compilation of State and Federal Criteria. EPA 440-5-88-012. U.S.
Environmental Protection Agency, Office of Water Regulations and Standards, Washington,
D.C.
U.S. Environmental Protection Agency. 1992. Compendium of Watershed-Scale Models for
TMDL Development. EPA 841-R-94-002. U.S. Environmental Protection Agency, Office of
Water, Washington, D.C.
U.S. Environmental Protection Agency. 1993. Guidance Specifying Management Measures
for Sources of Nonpoint Pollution in Coastal Waters. EPA 840-B-92-002. U.S.
Environmental Protection Agency, Office of Water, Washington, D.C.
U.S. Environmental Protection Agency. 1994. National Water Quality Inventory: 1992
Report to Congress. EPA 841-R-94-001. U.S. Environmental Protection Agency, Office of
Water, Washington, D.C.
U.S. Environmental Protection Agency. 1994a. Report of the Nutrient Task Force: Findings
and Recommendations. U.S. Environmental Protection Agency, Office of Water, Office of
Science and Technology, Washington, D.C.
U.S. Environmental Protection Agency. 1995. National Water Quality Inventory: 1994
Report to Congress. EPA 841-R-95-005. U.S. Environmental Protection Agency,
Washington, D.C.
U.S. Environmental Protection Agency. 1996. National Nutrient Assessment Workshop
Proceedings. EPA 822-R-96-004. U.S. Environmental Protection Agency, Washington,
D.C.
Wetzel, R. 1997. Personal communication in peer review comments. University of Alabama,
Tuscaloosa, AL.
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