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Public Comments and Responses on National Nutrient Strategy

Note: EPA no longer updates this information, but it may be useful as a reference or resource.

The following provides a summary of public comments received in response to publication of the National Strategy for the Development of Regional Nutrient Criteria (Nutrient Strategy: June 1998) and Agency response to those comments. Summarized comments have been sorted by topic into 23 broad categories (e.g., nutrient teams, consistency with other programs and agencies, nutrient management, etc.) Following each summarized comment is an acronym that identifies the agency providing the comment (a complete list of commenting agencies and their designated acronyms is presented below). Agency response to comments is shown in bold at the end of each comment category.


ADEQ-Arizona Department of Environmental Quality

ADPSPUB-Akron Department of Public Service, Public Utilities Bureau

AF&PA-American Forest & Paper Association

AI-Agriculture Industry(1)

AWWA-American Water Works Association

CMC-Center for Marine Conservation

GFLA-G. Fred Lee & Associates

HRSD-Hampton Roads Sanitation District

MAMWA-Maryland Association of Municipal Wastewater Agencies

MWRA-Massachusetts Water Resources Authority

NCDENR-North Carolina Department of Environment and Natural Resources

NCPIASI-National Council of the Paper Industry for Air and Stream Improvement

NLA-National Lime Association

NPPC-National Pork Producers Council

NYSDEC-New York State Department of Environmental Conservation

PADEP-Pennsylvania Department of Environmental Protection

SC-Sierra Club

SJRWMD-St. Johns River Water Management District

VAMWA-Virginia Association of Municipal Wastewater Agencies


WEF-Water Environment Federation®

WVMWQA-West Virginia Municipal Water Quality Association

WCRSA-Western Carolina Regional Sewer Authority


Nutrient Teams

Include industry scientific experts. (NPPC)

National and Regional Teams duplicating efforts of Technical Guidance Teams. (NCDENR)

Should develop a team for each ecoregion rather than Regional Teams. (NCDENR)

Nutrient Teams must be prepared to work closely with the states and state rulemaking processes in clearly identifying what is required to develop nutrient criteria effectively. (SC)

Persons responsible for developing nutrient criteria should be very knowledgeable about the unique characteristics of waterbodies within their jurisdiction. (WCRSA)

Because soil enrichment practices affect water quality, the USDA, EPA, and States/Tribes should work together to create national soil nutrient criteria for farming practices associated with Animal Feeding Operations. (ADEQ)

Because the Regional Nutrient Teams will be comprised of State members, additional clarification will be needed to resolve traditional political and jurisdictional issues that may emerge during the development of ecoregional or watershed-based nutrient criteria that span multiple State boundaries. (PADEP)

Coordination between each Regional Nutrient Coordinator and his/her member States should be started as early as possible to avoid delays in criteria guidance document development. (PADEP)

Because the Strategy indicates that State nutrient standards can be used to identify nutrient impaired waters, States should participate in the guidance process and develop numeric nutrient criteria that are relevant for the State. Note that under USEPA direction, TMDLs are currently being developed for nutrient impaired waters in the absence of nationwide nutrient criteria. (PADEP)

Recommend that a "State Nutrient Team" be established (comprised of representatives from each DEP region, Department of Agriculture, environmental organizations, educational or research interests, and other stakeholders) to provide support to the Regional Nutrient Team. (PADEP)

Full participation on the Regional Nutrient Teams is needed rather than limiting the teams to Federal and State agency personnel. The USEPA should include local experts (e.g., local water supply utility operators) as well as WEF representatives that have relevant expertise. (WEF)


EPA recommends that the Regional Nutrient Teams (a.k.a. Regional Technical Assistance Groups, RTAGs) include scientific and resource management expertise from all elements of the ecoregion or geographic region within EPA Region. RTAGs are comprised of scientific experts with local or regional knowledge and may include local, State, Tribal, and academic water resource managers; aquatic and estuarine/marine ecologists; oceanographers; wetland scientists; water chemists; and land use specialists. (The decision to develop RTAGs by EPA Region was reached at the first national meeting of EPA Regional Nutrient Coordinators in April 1998.) These experts can be recruited from Federal and State/Tribal agencies, universities and colleges, as well as other parts of the community. Each RTAG is expected to hold regular stakeholder meetings to keep interested parties within the ecoregion or geographic region apprised of the nutrient and algal criteria development process, progress to date, and to allow interaction and information exchange among interested and affected parties and the RTAG.

States/Tribes and other interested parties are welcome to participate in the guidance development process by attending RTAG meetings, stakeholder meetings, or accessing EPA's nutrient criteria website ( All draft waterbody guidance documents will be posted on the nutrient website. Correspondences on the documents can be forwarded to EPA, either directly to EPA lead scientist or through the website.

Consistency with Other Programs and Agencies

Nutrient Strategy should be consistent with USDA standards for fertilization and manure application to croplands and be flexible in developing appropriate criteria that considers local climate and parent geology. (NPPC)

Nutrient criteria development counter-productive; effective nutrient management controls/strategies already in place within many areas. (HRSD)

Numeric criteria ranges should defer to credible benchmarks previously established by waterbody-specific initiatives (e.g., Chesapeake Bay nutrient reduction goal). (MAMWA, VAMWA, WVMWQA)

Commend USEPA for beginning to coordinate with USDA on nutrient and animal waste issues. (NLA)

The USEPA and the States should continue their efforts to integrate a number of related programs (nonpoint source controls, watershed NPDES permitting, biosolids management, and assessment of land use activities). (PADEP)

It will be essential that Nutrient Strategy activities be coordinated with other related, evolving efforts (e.g., Criteria and Standards Plan; Nonpoint Sources: Picking Up the Pace, A National Strategy for Strengthening Nonpoint Source Pollution Management; Strategy for Addressing Environmental Public Health Impacts from Animal Feeding Operations (AFOs); The National Harmful Algal Bloom Research and Monitoring Strategy; Water Quality Standards Regulation: Advance Notice of Proposed Rule Making (ANPRM); and The USDA Nutrient Management Policy) so that information may be shared and consistent policy developed. (PADEP)

Nutrient guidelines and criteria adopted by States should not disrupt or supplant the efforts of effective volunteer clean-ups, such as those initiated and led by local watershed councils. (WEF)


EPA has included many other EPA programs as well as other Federal agencies on its National Nutrient Criteria Team. Offices within EPA that are on the Team include the Office of Wastewater Management (responsible for coordinating efforts on controlling concentrated animal feeding operations) and the Office of Wetlands, Oceans and Watersheds (charged with developing a nonpoint source control strategy as well as methods for developing total maximum daily loads for nutrients and other pollutants). The USDA, USGS, and NOAA have all had inputs into the development of the Nutrient Strategy and are active members on many of the RTAGs and guidance development workgroups. The Chesapeake Bay Program has also been involved with the Nutrient Strategy and discussions of consistency between the two programs have been ongoing in order to ensure that the two programs complement each other. The intent of EPA and the Nutrient Strategy is to supplement or help refocus voluntary efforts which have made great progress in nutrient assessment and control. The Nutrient Strategy is not intended to supplant or supercede State, Tribal, or regional efforts to assess and control nutrient enrichment.

Nutrient Management

Nutrient criteria establishment will not effectively manage NPSs (viewed as major contributors) but will instead ratchet down on PSs. (HRSD)

Strategy fails to provide effective nutrient input controls (e.g., better NPS control programs, treatment technology, incentives to reduce nutrients, substantial cost share funds to assist landowners). (NCDENR)

Nonpoint source nutrient loadings are currently more dominant than point sources in the Upper Cuyahoga River and should be evaluated more aggressively. (ADPSPUB)

The effects of nutrient management on water quality should be evaluated separately for each constituent. (ADEQ)

Because nutrient application rates, cropping patterns, and precipitation levels are constantly changing, changes in water quality should be evaluated regularly to evaluate the effectiveness of nutrient management practices. (ADEQ)

Nutrient management based exclusively on nitrogen removal may result in build-up of other nutrients (e.g., phosphorus, potassium) over time. (ADEQ)

Nutrient management plans should recognize that excessive applications of animal wastes may contaminate water supplies and potentially decrease crop yields. (ADEQ)

A comprehensive nutrient management plan should characterize and quantify the addition and removal of each specific nutrient within its respective watershed or sub-basin. (ADEQ)

Nutrient management plans should consider supplementation with microbial phytase to reduce phosphorus loadings from animal waste. (ADEQ)

Community development reviews and Best Management Practices should be considered as potential components of nutrient management plans. (ADEQ)

Should mandate implementation of stormwater Best Management Practices to improve water quality. (ADEQ)

Management tools mentioned in the Strategy are questionable. Specifically, Strategy emphasizes preservation of natural vegetation in buffer zones, which may potentially pre-empt management of buffer zones to maintain optimal nutrient uptake. (AF&PA)

Note that it is important that the Strategy made the distinction that excessive nutrients resulting from human activities rather than naturally-occurring sources will be the focus of management efforts. (PADEP)

An essential feature of effective nutrient management requires consideration of the net flow of nutrients in and out of an ecoregion. Often nutrient flow may cross regional or even international boundaries, making relevant data difficult to collect and determination of impacts difficult. (PADEP)

Strategy fails to address whether nutrient removal from point and nonpoint sources to natural or near natural levels will achieve reductions in nuisance growths of vegetation. (WEF)

The Management Response element of the guidance document Draft Outline should first identify the expected outcomes to be achieved. This information will be particularly important when selecting a management response. (WEF)

The National Strategy fails to incorporate key information from the literature developed in the 1960s and 1970s related to managing the excessive fertilization of waterbodies. (GFLA)

The proposed approach of developing numeric chemical specific N and P criteria can lead to technically invalid nutrient management programs required for (and paid for by) public and private interests. (GFLA)

Recommend a watershed-based excessive fertility control program (outline of program approach provided in comment letter) be included as part of the Strategy. (GFLA)

Disagree that problems associated with toxic algal blooms will be meaningfully addressed through the eutrophication control approach outlined in the Strategy. (GFLA)

Disagree that light attenuation (except in severely light-limited conditions) is a major factor in controlling excessive fertilization of waterbodies. (GFLA)

Disagree that an imbalance of primary, secondary, and tertiary producers and consumers influences overenrichment. Rather, the number and types of consumers/producers are site specific factors that should be considered when examining eutrophication response and water quality relationships. (GFLA)

To date Congress has prohibited the USEPA and State agencies from developing effective pollution controls for agricultural nonpoint sources. Until such control is in place and implementable, the USEPA cannot develop a reliable national nutrient control program. (GFLA)

The Strategy should address the issue of nutrient input control and its effects on fishery quality and production. A decrease in the available limiting nutrient load to a waterbody will result in a reduction of fish biomass, which is of concern to sports fishermen. The formulation of a national nutrient control strategy must include an approach for addressing the conflict of interest between fisheries groups and those that want to minimize eutrophication. (GFLA)


Nutrient criteria are tools that can be used to assess and ultimately control nutrient loads. Criteria can be used to set water quality standards and total maximum daily loads for a State, Tribe, or ecoregion. It is intended that criteria be met by controlling both point and nonpoint sources within a given geographic region or watershed.

The management tools mentioned in the Strategy are not meant to be comprehensive or recommended as EPA's only set of guidance on the subject. Each waterbody-type guidance manual will present management techniques specific to that waterbody type. The material cited in the waterbody-type guidance manuals is not meant to supercede the guidance provided by EPA over the years, especially from the Office of Science and Technology (OST) and the Office of Wetlands, Oceans and Watersheds (OWOW). EPA reiterates that the Nutrient Strategy is focused on the assessment and control of nutrients from human activities, not naturally-occurring nutrient sources.

Regulatory vs. Non-Regulatory Approaches

The CWA does not authorize enforceable WLAs for NPS pollutants. (NPPC)

Reduced costs associated with non-regulatory approaches vs. regulatory approaches should be taken into consideration. (HRSD)

Because many sources of nutrients fall outside of the regulatory jurisdiction of the Clean Water Act , non-regulatory approaches may be more effective mechanism for achieving nutrient criteria. (MAMWA, VAMWA, WVMWQA)

Imposition of nutrient criteria/standards could undermine the efforts and achievements made through voluntary programs within the Chesapeake Bay as well as other ongoing and potential voluntary efforts. The Strategy should recognize these efforts and allow for nonregulatory approaches where applicable. (WEF)


EPA applauds non-regulatory, voluntary approaches to nutrient control that have effectively reduced and managed nutrients across the country. However, over the last decade 305(b) reports continue to implicate nutrients as one of the leading causes of impaired water uses. This indicates that to some degree, voluntary efforts are either too few or too slowly implemented to affect a change in water quality with regard to nutrients. Nutrient criteria are intended to accelerate the process of controlling nutrients nationwide by creating benchmarks that can be used to assess and manage nutrients. EPA intends nutrient criteria to be complementary tools that enhance ongoing voluntary programs such as the Chesapeake Bay program and similar coastal, estuarine, wetland, and lake management initiatives.

Spatial Considerations

Strategy should propose a mechanism for establishing site-specific criteria. (HRSD)

Ecoregions too large, need smaller spatial scale to effectively address nutrient issues. (HRSD)

Proposed regional numeric target ranges will necessarily be site-specific due to variations in land use, flow, geomorphology, turbidity, etc. (NCDENR)

Omernik's ecoregion system is based on streams and natural lakes and does not adequately differentiate large reservoirs and estuaries (e.g., Tar-Pamlico and Neuse River basins [shallow, wind-driven systems] in same ecoregion as Cape Fear, Chesapeake Bay estuarine systems). (NCDENR)

Recommend that proposed Ecoregion IX be subdivided further to differentiate between (1) northeastern and southeastern waterbodies and (2) mountain/predominantly rural terrain and highly developed Piedmont areas. (WCRSA)

Soil types, existing nutrient concentrations, topography, erosion potential, crop productivity potential, crop systems, and land application sites should be considered when defining ecoregions. (ADEQ)

Unclear how criteria can be developed for ecoregions and specific watersheds simultaneously. (ADEQ)

Criteria may need to be developed for waterbody segments. (MAMWA, VAMWA, WVMWQA)

The Strategy fails to provide the basis for choosing the Omernik ecoregion-based system over other regional classification schemes. (AF&PA)

The Major Land Resource Area system developed by USDA-NRCS should be given serious consideration by the Agency as an alternative classification method. (AF&PA)

Omernik ecoregions completely ignore historically defined watershed boundaries. (AF&PA)

USEPA should perform an unbiased comparison of Omernik ecoregions, MLRA, and other existing classification systems to determine which is best suited for use in criteria development. (AF&PA)

The USEPA and the States should continue their efforts to emphasize water quality management and protection, including nutrient controls, on a watershed basis. (PADEP)

The role of ecoregions is unclear. Will States/Tribes adopt only one criterion for all similar waterbody types within an ecoregion? Because ecoregions can cross State/Tribal boundaries, will multiple States/Tribes potentially be required to agree on one criterion for each waterbody type? (WEF)

Ecoregions are too large to reflect the variability found within their boundaries. Nutrient criteria development should be focused at the watershed level. The USEPA should refine their ecoregions and each State/Tribe should further subdivide ecoregions within State/Tribal boundaries. (WEF)

The spatial (ecoregional) scale proposed by USEPA is too coarse to adequately support valid regional nutrient criteria. (AI)

The ecoregion approach also fails to address temporal variations in nutrient concentrations. Seasonal differences in nutrient concentrations for some systems may vary by as much as two to three orders of magnitude and therefore cannot accurately be reflected in narrow criteria ranges. (AI)

Disagree that geographic regions should be evaluated differently when deriving nutrient criteria. Instead, morphological and hydrologic characteristics of the waterbody should be the focus when examining nutrient load/eutrophication relationships. (GFLA)


The nutrient ecoregions presented by J. Omernik in the Nutrient Strategy are meant to be used as a starting point for geographic classification and are the current Agency standard. They are being used by EPA to develop default regional nutrient criteria for the entire country but will be subdivided depending on the amount, quality, and variability of data that exist in each of the draft level III nutrient ecoregion aggregates. EPA will initially develop waterbody-specific nutrient criteria (criteria for total phosphorus, total nitrogen, chlorophyll a, and some measure of turbidity) for each of the 14 nutrient ecoregions. Nutrient ecoregions are based on common geologic, climatic, ecological, land use, and nutrient conditions. However, EPA acknowledges that the draft nutrient ecoregions are based on limited historical data, a general knowledge of land use, and the ecology of each ecoregion. EPA is in the process of updating the nutrient ecoregion boundaries using more recent water quality data from each waterbody type. States/Tribes are encouraged to subdivide and refine nutrient ecoregions as needed to reflect more regional and site-specific conditions and variability when developing their own nutrient criteria.

Criteria Variables

Nutrient criteria should be based on the protection and enhancement of living resources rather than water quality parameters. (HRSD)

Concerned over the use of Secchi disc measurements given the subjectivity of the test and its limited correlation with nutrient concentrations. (W)

Recommend development of criteria for Total N rather than nitrate to ensure that N species found under anaerobic conditions are accounted for. (AWWA)

When using Secchi depth data, nonalgal turbidity contribution should be evaluated and discounted. (WCRSA)

Strategy should mention nutrients other than nitrogen and phosphorus (e.g., potassium, sodium, sulfate) that may impact water quality. (ADEQ)

Should list specific indicators other than nitrogen and phosphorus that are being considered for criteria development; specifically, DO should be addressed. (CMC)

Nitrogen and phosphorus speciation should be discussed in more detail. (CMC)

USEPA should determine ranges for DO levels. (CMC)

Should include topography as an early warning watershed indicator. (CMC)

USEPA should strongly encourage N and P speciation measurements for all of the four waterbody types, not just lakes and reservoirs. (CMC)

Chlorophyll and Secchi depth should be treated as indicators of nutrient overenrichment, as opposed to pollutants requiring criteria development. (AF&PA)

It is uncertain whether nutrient criteria exclusively will be developed under the program or if indicator parameter criteria will also be developed. (NCPIASI)

Recommend that USEPA develop criteria for soluble phosphorus rather that total phosphorus. (NLA)

Given complex ecosystem interactions, it is recommended that USEPA develop a suite of biological criteria that reflect the overall state of the waterbody in relation to nutrient enrichment rather than numerical standards for N and P alone. Recommend that standards could be developed that account for some of the specifics of each waterbody (e.g., N criterion = function(waterbody, temperature, critical species)). (WEF)

The Strategy does not address chemical speciation and uptake availability. Recommend that the development of N criteria include consideration of bioavailability and exclude organic forms that are not nutrient sources. (WEF)

The approach USEPA is taking to provide guidance to States and Tribes differs from that provided in USEPA Waste Load Allocation guidance. The WLA guidance suggested use of the indicator approach (i.e., N, P, chlorophyll a concentrations; Secchi disk depths; algal biomass; and N:P ratios), nutrient kinetics approach, and incorporation of waterbody hydraulic features. The Strategy appears to ignore nutrient kinetics and waterbody hydraulics. (WEF)

The USEPA should consider that Secchi depth may be unrelated to nutrient levels and phytoplankton growth given that natural color may reduce Secchi depth. Therefore, the USEPA should allow flexibility in meeting Secchi depth criteria. (WEF)

Reduced dissolved oxygen levels are related to thermal or salinity stratification and thus, complex and more difficult to address. Reductions in DO could become one of the most important, eutrophication-related impacts because these reductions represent potential violations of water quality standards. Dissolved oxygen depletion in sediments is also the most important cause of sediment toxicity. (GFLA)

The proposed causal and response variables approach ignores the attached algae and floating/attached macrophyte problem. (GFLA)

The focus of nutrient control should be on available nutrient forms rather than total nutrients. (GFLA)

Caution should be exercised when using Secchi depth as a eutrophication parameter since natural color and inorganic turbidity can significantly impact the Secchi depth of a waterbody. (GFLA)

The Strategy should include extent of areal coverage by floating macrophytes, macroalgae, and attached algae as parameters that cause major national eutrophication-related water quality problems.


At a minimum, EPA will develop nutrient criteria for four variables: total nitrogen, total phosphorus, chlorophyll a, and some measure of turbidity (e.g., Secchi depth or transmissivity). These variables were selected because they represent two causal variables (TN and TP) and two response variables (chlorophyll a and turbidity), and are historically the most frequently sampled. While EPA urges States/Tribes to add other parameters, at a minimum EPA will require States to set water quality standards for the four variables stated above. In some cases, States/Tribes may be allowed to substitute a particular response parameter for chlorophyll a or turbidity, such as algal biomass or biovolume, SAV (submerged aquatic vegetation) growth, or dissolved oxygen, although the State/Tribe must scientifically justify such a substitution. In addition, States/Tribes can develop site-specific criteria (values for N, P, chlorophyll a, and turbidity) that reflect site-specific conditions within their State, Tribal lands or ecoregion, as long as the criteria set are as protective as the National default criteria. Methods for developing site-specific criteria will eventually be developed and included in each of the waterbody-type guidance manuals.

Reference Conditions

Attainment of pristine conditions could be impossible; National Strategy should require States to conduct use attainability analyses to ensure that developed standards are attainable. (HRSD)

Difficult to establish background conditions. (HRSD)

Page 6 of Strategy that refers to "natural" background levels should be changed to ambient "reference" levels in order to recognize that reaching natural background conditions may be impossible or undesirable based on public opinion. (NCDENR)

Waterbody protection achieved by attaining natural conditions may be overprotective and beyond what is required to prevent adverse effects. It may be difficult to justify large public expenditures if adverse effects are not occurring. (NYSDEC)

USEPA should identify reference sites for each ecoregion and make the sites the basis for goals that should be met in the future by States and Tribes. (CMC)

Concern over whether "pristine" waterbodies will be selected as references, resulting in all other waterbodies not in a pristine or natural state being treated as impaired and not meeting their designated uses. Also, there is concern over the type of data (i.e., dry or wet weather data) that will be used in determining reference condition, as this distinction may have significant impact on nutrient introductions to waterbodies under evaluation. (PADEP)

The USEPA's assumptions related to measuring cultural eutrophication are invalid. The comprehensive historical databases needed to define natural ambient nutrient concentrations in each ecoregion do not exist. (AI)

Establishing natural background nutrient levels for many waterbodies may be impossible due to impairments derived from a long history of human activity. (WEF)

Reference conditions specified by USEPA for a specific waterbody type within one ecoregion may not be applicable to all sites (for that waterbody type) within that ecoregion. The USEPA should allow permittees to select site-specific reference conditions that describe their site better than the reference condition selected by USEPA for use in that ecoregion. (WEF)

Nutrient criteria based on averages of reference area indicators will not necessarily represent concentrations that will limit and control the growth of vegetation in waterbodies. (WEF)


EPA defines reference conditions as the sum of data associated with reference sites. Reference sites are those sites that are either pristine or minimally impacted. However, for ecoregions in which a great deal of historical impairment has occurred, EPA is taking the position that the "reference condition" is the best of what exists. Details of this concept are discussed in the Lakes and Reservoirs Technical Guidance Manual. It is also important to note that reference conditions associated with a waterbody type within an ecoregion may not be applicable to all sites within an ecoregion. There will always be variability and local conditions which dictate site-specific criteria development. In some cases, State/Tribes may have to subdivide the nutrient ecoregion further to account for these regional differences. Seasonal variations may also suggest the need for seasonally-based reference conditions and nutrient and algal criteria.

With regard to reference conditions and designated uses, a criterion derived on the basis of a reference condition will only protect the uses associated with the waters from which the reference condition was derived. Therefore, depending on the quality of water associated with the reference condition, a reference condition may or may not result in criteria that protect the highest quality designated uses in a State. At a minimum, nutrient criteria developed by EPA will reflect the uses protected by the Clean Water Act. States/Tribes may be required to develop site-specific criteria to protect exceptional quality waters.

Nutrient Program Schedule and Funding

Concerned that the Regional Nutrient Teams will not have adequate time and resources to do a credible job. Recommend an additional five years of nutrient-related research so that realistic criteria can be set. (MWRA)

Concerned about the time frames for criteria development identified in the Strategy, particularly the feasibility of developing technical guidance by 2001 for more complex/less understood waterbody types (e.g., wetlands, darkwater streams, and coastal lagoons) for which modeling tools do not currently exist. (SJRWMD)

If technical guidance is not available until the end of 2001, it will be impossible to develop scientifically defensible criteria for all waterbody types by 2003 given current funding levels. As an alternative, recommend developing numerical nutrient criteria for a subset of the four waterbody types (e.g., lakes) by a specified date. (SJRWMD)

Due to limited resources, USEPA should limit initial criteria development to phosphorous and nitrogen exclusively, then reassess the need for additional criteria development after phosphorus and nitrogen criteria have been implemented by States. (AF&PA)

Time frames for standards development are unrealistic given State commitments to other water quality initiatives (e.g., TMDLs, unified watershed assessments). Recommend that States be (1) given more time to implement standards to ensure that they are scientifically defensible and (2) allowed to prioritize water bodies most in need of criteria development. (AF&PA)

Recommend an accelerated schedule for updating the phosphorus standard. (NLA)

There should be more flexibility in the proposed schedule for criteria development and subsequent standards implementation. The 2003 deadline for States to adopt nutrient criteria is extremely dependent on USEPA meeting their deadline of guidance document issuance by 2000. (PADEP)

Given the short time scale for implementation, the complexity of the nutrient processes, the lack of existing nutrient data on a regional scale, and the potential controls needed on existing nutrient sources, the Strategy's objectives may be unachievable and overly ambitious. (WEF)

A firm, scientifically defensible approach to nutrient control must be developed. However the combination of inadequate resources and an ambitious scope does not bode well for the

scientific rigor of this effort. The Strategy does not address how the scientific defensibility of criteria developed under this effort will be ensured. (WEF)

Given the Strategy's stated research needs and the "in development" status of nutrient models, there are concerns over the feasibility of this undertaking. (WEF)

The USEPA's time line to implement the Strategy is unrealistic and precludes the development of valid, scientifically-defensible regional nutrient criteria. A better understanding of nutrient biogeochemical processes is needed as well as a more comprehensive set of relevant State nutrient data for the four waterbody types, prior to criteria development. Rather than rushing to meet an arbitrary deadline, it is recommended that USEPA support critical research areas (e.g., natural/cultural contributions to system nutrient budgets, geographic and temporal nutrient variability, watershed land use/land cover criteria) and use this information to draft more useful guidance and more accurate nutrient criteria. (AI)

Instead of developing a rushed program that focuses on chemical specific nutrient criteria, the USEPA should reactivate the eutrophication research program terminated in the 1970s to develop the necessary information base needed for formulating technically valid, cost-effective nutrient control programs for U.S. waterbodies. (GFLA)

The proposed time frame is too short to develop technically valid, cost effective nutrient criteria. Considerable additional research is required before appropriate criteria can be derived. (GFLA)


EPA agrees its deadlines to develop guidance manuals and criteria by the end of 2000 are very ambitious and difficult to meet. However, progress is being made on the waterbody-type manuals with the Lakes and Reservoirs and Rivers and Streams manuals scheduled for final publication in calendar year 1999. At the same time, EPA RTAGs are working toward data compilation and analysis by Spring 2000. Whether there is enough high quality data to develop criteria for each of the fourteen ecoregions will be better understood by Summer 2000. However, once criteria are developed by EPA, it is incumbent upon States/Tribes to make a good faith effort to either adopt EPA criteria into standards or develop their own nutrient criteria within three years of criteria publication. EPA will consider the effort States/Tribes are making in developing criteria and adopting standards during their triennial reviews. For example, if a State or Tribe is making a good faith effort to develop site-specific criteria which may require a significant commitment of time and effort, EPA will likely grant States/Tribes additional time to comply with the goals of the strategy. However, if a State/Tribe is uncooperative and unwilling to develop their own criteria or adopt an EPA criterion, EPA will promulgate a nutrient standard for that State/Tribe to ensure that a legal benchmark is in place upon which nutrient reductions can be predicted.


Models described in Strategy are simple, empirical models. More sophisticated models will be required if costly controls are recommended. (NCDENR)

The assimilative capacity of the waterbody is one of the most important variables in deriving criteria and should be given appropriate consideration when used in nutrient assessment models. (WCRSA)

Land use type should be incorporated into watershed-scale models. (ADEQ)

Strategy should provide a better rationale for why models are needed and discuss some of their limitations. (CMC)

The Strategy modeling discussion oversimplifies the complexity inherent in applying models to different types of systems. In addition, several of the models are outdated and simplistic (e.g., BATHTUB, Reckhow-Simpson, QUAL2E, WASP5, HSPF, and Vollenweider). Several newer models are more sophisticated and user-friendly. Recommend that while developing its technical guidance, the USEPA should communicate with Water Environment Research Foundation on their (WERF's) ongoing assessment of available hydrodynamic models. (WEF)

There is a definite need for predictive modeling of algal productivity response to nutrient loading in river and stream systems. Because this type of modeling does not exist, the USEPA should develop appropriate models as part of the waterbody type guidance. (WEF)


The five elements of nutrient criteria development are: (1) utilize historical data and other information to provide an overall perspective on the status of the resource; (2) identify reference sites and a collective reference condition describing the current status; (3) apply appropriate models to predict system response where data are scarce and clarify inconsistencies identified during data analyses; (4) assess objectively (State/Tribal and RTAG) all data and information described in one through three to establish ecoregional criteria; and (5) consider downstream consequences prior to setting final criteria.

Use of models is encouraged to help clarify relationships among waterbody nutrient concentrations and biological responses. Models may also be used to predict the types of biological shifts that can occur at different nutrient levels under variable physical, chemical, and biological conditions. Models can also be used to infer outcomes when there is a lack of data for a particular ecoregion or waterbody type. For example, models can be used in the prediction or extrapolation of reference conditions or can be used in the development and implementation of nutrient criteria. For more details, the reader is referred to the National Nutrient Guidance Documents link on the Nutrients website:

Drinking Water Issues

Strategy should include greater consideration of nutrient criteria related to aesthetics and health effects of drinking water sources. (NYSDEC)

Strategy should mention public health threats caused by nutrient enrichment such as disinfection by-product precursor formation and taste/odor problems. (AWWA)

Delete listing of impoundments as source of excessive algae contributing to water quality degradation (p. 27 of Strategy). Source is actually nutrient enrichment caused by agricultural and urban land use. (AWWA)

Nitrate-N criteria of 10.0 mg/L too lax given (1) USGS reported background levels of 2.0 mg/L (groundwater) and 0.6 mg/L (streams), (2) the drinking water factor of safety for the nitrate MCL (Maximum Contaminant Level) is one, and (3) nitrate is not removed by typical drinking water treatment techniques. A total N standard in the range of 1-2 mg/L is recommended. (AWWA)


Nutrient criteria are designed to protect aquatic life uses. However, when criteria are based on a reference condition which supports drinking water uses as well as aquatic life uses, the resulting nutrient criterion will be protective of both use categories. If a State or Tribe wants to develop a nutrient criterion which will protect reservoirs and drinking water sources, it can collect data from reference site reservoirs (those reservoirs that are minimally impacted or pristine and support both drinking water and aquatic life uses) to develop a reference condition protective of the drinking water use.

A protective criterion based on the human health effects of nitrate (10 mg/L) was set by the Agency in 1976 in EPA "Red Book," Quality Criteria for Water and was supported by the National Academy of Sciences.

Downstream Effects

Need to consider effects of downstream waterbodies (e.g., acceptable river nutrient criteria may result in eutrophication of downstream lake) and advise NPDES permit writers how to handle these situations. (AWWA)

The Strategy concept of factoring in the downstream effects of nutrient enrichment requires additional explanation. (WEF)


The Nutrient Strategy requires the development of criteria which will not cause deleterious effects to receiving waters immediately downstream. This provision was established to prevent excessive nutrient loads that could cause impairments downstream even though concentration criteria were being met upstream. This principle is critical to protection from cumulative downstream increases in nutrient loads. Ultimately it is the load, or mass of nutrients over a specific time-frame that will cause adverse biological effects.

Land Use Considerations

Strategy should mention early warning indicators developed for lakes/reservoirs and streams/rivers (livestock density in watershed, percent land under cultivation, population density without central sewage treatment). (AWWA)

Early warning indicators for estuaries, coastal marine waters, and wetlands should be discussed in Strategy. (AWWA)

Establishing statistically valid cause and effect relationships between nutrient applications and water quality changes is difficult without long-term knowledge of nutrient applications and land use. (ADEQ)

Land use information should be included when developing nutrient criteria. (ADEQ)

Additional discussion among Nutrient Team members and additional clarification in the Strategy is needed relative to development of performance standards for land use. These standards will allow for tracking of water quality trends in addition to providing mechanisms to adequately monitor program activities and remedial progress. (PADEP)

The Strategy fails to include development and application of land use criteria as an essential element for assessing and reducing nutrient loadings from nonpoint sources. The USEPA must develop watershed land use and land cover criteria rather than rely solely on uniform nutrient criteria ranges for a specific ecoregion. (AI)

Recommend the use of national nutrient export coefficients in conjunction with OECD (Organization for Economic Cooperation and Development) phosphorus load eutrophication

response relationships to predict eutrophication-related, water quality impacts caused by altering land uses. (GFLA)


The Nutrient Strategy published in June 1998 was not intended to present quantitative measures for land use. Nutrient ecoregions (discussed previously) were delineated using land use as one of the primary considerations for aggregation. The Strategy discusses land use as an early warning indicator of changes in a watershed that could potentially increase nutrient and sediment loads to a waterbody. Each of the waterbody-type guidance manuals will discuss land use changes that will likely affect the nutrient load to a waterbody. In addition, a limited discussion of land management practices is included.

Lake/Reservoir Nutrient Criteria

Criteria for lake Total P concentrations should be developed for the epilimnion rather than hypolimnion as the former is where eutrophication problems are most severe. (AWWA)

The USEPA should consider the type (man-made, natural) and hydrologic conditions (closed or open source, with or without inflow and/or outflow) of the lake when developing baseline reference conditions. The USEPA should also identify which nutrient water quality criteria should be applied to different types of lakes and consider whether or not water quality objectives applied to man-made lakes should be the same as those applied to natural lakes. (PADEP)

The Strategy section discussing Lakes and Reservoirs places unwarranted focus the connection between lake nutrient environmental impacts and public health concerns (e.g., septic and sewage effluent discharges). Rather, the focus should be on all nutrient sources, including agriculture and stormwater inputs. (WEF)

Recommend that the management technique listed in the Strategy of adding alum to lakes/reservoirs to precipitate phosphorus and consolidate nutrients into bottom sediments be removed due to the potential for (1) increased aluminum concentrations in the water column and (2) resuspension of alum particulates should bottom sediments be disturbed. (WEF)

It is inappropriate to group all lakes and reservoirs into one waterbody type for the purposes of developing one nutrient criterion. This approach will lead to over-regulation of nutrient discharges. (GFLA)


The reader is directed to review the Nutrient Criteria Technical Guidance Manual: Lakes and Reservoirs for detailed information pertaining to the above comments on lake and reservoir criteria development. The Guidance includes discussions on identifying reference condition, nutrient sources, and nutrient management techniques and their relationship to criteria development. The Nutrient Criteria Technical Guidance Manual: Lakes and Reservoirs can be accessed through EPA nutrients website at:

River/Stream Nutrient Criteria

Unclear whether nutrient criteria will be derived for entire rivers including their tributaries or for specific river segments. (ADEQ)

Groundwater is a major contributor to many surface water streams and thus nutrient loadings from groundwater should be considered when developing nutrient criteria. (ADEQ)

Stream order, hydrologic characteristics, and other factors directly associated with in-stream nutrient problems should be considered when developing the rivers and streams guidance document. (PADEP)


The reader is directed to review the Nutrient Criteria Technical Guidance Manual: Rivers and Streams for detailed information pertaining to the above comments on rivers and streams criteria development. Nutrient criteria for river and streams will be derived for stream reaches, thus an individual river system may have criteria for tributaries as well as mainstem reaches. In addition, instream concentrations are being used for criteria development to incorporate all potential nutrient sources. The Guidance discusses classification of streams, system hydrology, nutrient sources, as well as other factors, and their role in criteria development. The Nutrient Criteria Technical Guidance Manual: Rivers and Streams can be accessed through EPA nutrients website at:

Wetland Nutrient Criteria

Solicit input from interested parties and regulated community on appropriate water quality criteria and standards for wetlands, bearing in mind that wetlands function efficiently at nutrient removal and may be able to receive higher nutrient concentrations without detrimental effects. (AWWA)

Question value of "extreme climatological events" as early warning indicator for wetlands due to the inability of permit writers to control weather events. (AWWA)

Given the natural nutrient variability of wetlands, it will be difficult to establish baseline ecoregion references for wetlands. It is also unclear which wetland component (water column, substrate, accumulated subsurface sediments/solids) will be targeted for nutrient level controls. (PADEP)

Given that wetlands are often recognized as serving an important function as nutrient sinks, it will be important to determine the overall objectives and goals for wetland nutrient protection as well as considering wetland function when developing nutrient criteria. (PADEP)

The Strategy mentions restoring and protecting wetlands, which could be interpreted as emphasizing preservation over management. Scientific studies have demonstrated that wetland forests can be managed for timber while maintaining wetland ecological function. (AF&PA)


The technical guidance for deriving wetland criteria is under development. However, it is anticipated that the variables selected for monitoring and assessing nutrient conditions in wetlands will be specific to wetland type. Due to the significant loss of wetlands nationally, the initial guidance is expected to focus on assessing natural (not created) wetlands with an emphasis on improving, protecting, and/or maintaining water quality and wetland function. Assimilative capacity of some wetland systems, an important wetland function, may be useful in nutrient control and management. However, only sustainable utilization of wetland assimilative capacity in natural systems is advocated for nutrient management. The Agency is aware that replicable scientific research is currently being conducted that explores sustaining ecological integrity and wetland functions while managing other natural resources. Until the weight of scientific evidence shows otherwise, the Agency supports protection over multiple use management for natural wetland systems.

Data Collection/Monitoring

Recommend that NCOD (National Contaminant Occurrence Database) data reporting elements be used as a starting point for standardizing nutrient data collection, storage, retrieval, and processing. (AWWA)

The AWWA Research Foundation report "Effective Watershed Management for Surface Water Supplies" has a chapter on designing sampling programs that should be used in preparing draft guidance. (AWWA)

Seasonal sensitivity of nutrient impacts should be factored into compliance measurements and data analysis and monitoring protocols should be rigorously adhered to so that data consistency is ensured. (WCRSA)

Sampling designs for reservoirs require special attention: discrete zones should be defined, distinct sampling protocols developed, and the role of each zone in determining waterbody impairment should be considered. (WCRSA)

A dynamic and objective nutrient monitoring protocol should be developed to reduce nutrient concentrations discharged from agricultural facilities. (ADEQ)

Strategy should address sampling procedures for determining overenrichment. (ADEQ)

Public survey techniques may be useful for increasing descriptive observations of water quality, but cannot be used as scientific measures of parameter changes. (ADEQ)

USEPA should provide better guidance on how monitoring programs should be set up by States and Tribes. Recommend basing monitoring on answering a specific scientific question. (CMC)

Support the Strategy's philosophy of cooperation (e.g., standardized metrics and data collection methods, sharing of data) across State boundaries and EPA regions. (PADEP)

The USEPA should be prepared to establish monitoring programs to provide data needed for criteria establishment. (WEF)

Recommend the use of Lee and Jones (1992) and Lee and Jones-Lee (1992) guidance on formulating the minimum monitoring program needed to implement Vollenweider eutrophication modeling results. (GFLA)


EPA is developing a National Nutrients Database application in desktop (Microsoft Access™) and web accessible (Oracle™-based) formats. These database applications will be used to uniformly screen data from all sources for quality and reliability. The Microsoft Access™ application will be operational by the end of 1999; the web-accessible version will be online in 2000. EPA is also developing technical guidance that defines minimum data quality objectives. These quality objectives are being established for sampling methods,analytical techniques, data analysis, and criteria development. Furthermore, each guidance manual discusses monitoring techniques and protocols to ensure data consistency.

Guidance Documents

Guidance to States should be specific; guidance manuals should contain federal criteria that can be adopted as State nutrient standards should states not wish to develop their own criteria. (SC)

Careful consideration should be given to developing technical guidance and modeling schedules to avoid erroneous conclusions and unnecessary expenditure of public and private funds. (SJRWMD)

The expert panel that will review data and final documents should include representatives from research universities, environmental organizations, lay people, and consultants and should not be restricted to government personnel. (CMC)

The USEPA should ensure that guidance documents provide the flexibility to accommodate the potential considerable variability found within systems of each waterbody type (e.g., cold water mountain streams versus low-grade tannin-stained streams) co-located within an ecoregion. (AF&PA)

Question the need for a management section in the guidance documents as it injects unnecessary issues that are not relevant to the focus of the document. (AF&PA)

Unclear whether the purpose of the guidance documents is to specify waterbody-type and ecoregion-specific numerical ranges for nutrient criteria or provide guidance to the States on how to collect appropriate information for developing their own nutrient criteria. (NCPIASI)

The purpose of the guidance documents is unclear given that case studies are currently ongoing without the benefit of the guidance. (NCPIASI)

Recommend that nutrient management discussions be placed in separate document; water quality criteria development should be a stand alone document based on the best available science. (PADEP)

The National Eutrophication Survey conducted originally in 1970 should be updated and serve as the basis for future guidelines. A comprehensive search for relevant case studies defining the current state of nutrient management-related technologies and policies should be conducted and results included in the guidance. (WEF)

For all waterbody types, knowledge of system hydraulics and hydrodynamics are critical to understanding the growth, transport, scour, and settling characteristics of vegetation groups. This information should be integrated into Section III (Waterbody-Type Technical Guidance) of the Strategy and should be gathered throughout the data collection process. (WEF)

The USEPA should consider developing seasonal guidance, particularly for waterbodies such as western coastal streams that typically experience eutrophication during the summer when coastal lagoons are closed to receiving ocean waters. (WEF)

Support the concept of watershed case studies to demonstrate the effectiveness of the guidance. (WEF)

Given the ambitious schedule, The USEPA should ensure that the logical steps between information sources and development of guidelines are recorded and clearly articulated in the final document. (WEF)

The proposed contents of the guidance manuals are overly ambitious. The guidance should focus on the criteria and supporting rationale and leave the remaining subjects (i.e., sampling design; analytical procedures; data processing, storage, and interpretation; management response; and evaluation monitoring) for other documents. (WEF)


Waterbody-specific technical guidance manuals will provide information on how to assess nutrient-related effects in a waterbody and how to develop nutrient criteria for a specific classification of waterbodies within an ecoregion. Eventually, default ecoregional nutrient criteria will be appended to the guidance manuals as they are developed, peer reviewed, and finalized by EPA. All guidance manuals will be peer reviewed by the best scientific experts available and concurrently posted on EPA nutrient website. Comments and correspondence on each document may be sent to EPA from the website via email or through regular mail.

Each guidance manual will have a section on nutrient management. However, these sections will focus only on the management activities needed to implement criteria. For the most part, these chapters will cite sources for resource management guidance and management procedures previously published by EPA and other agencies.

Implementation of Nutrient Criteria

If criteria developed incorrectly, States/localities may be able to evade tough nutrient control. (AWWA)

Overemphasis of ecoregional differences may result in delays by states in developing/adopting protective nutrient standards. (SC)

USEPA should make it clear to the States that it will promptly publish standards based on Federal guidance if any State fails to establish standards by the end of 2003. (SC)

USEPA must be prepared to evaluate NPDES permits and BMPs to ensure compliance with nutrient standards. In particular, USEPA should provide assistance in drafting CAFO permit limits. (SC)

Any nutrient criteria adopted will be ineffective unless states have statutory/financial ability to implement NPS controls. (NCDENR)

The 303(d) process already addresses nutrient impaired waters. Development of regional criteria will likely result in waters misidentified as nutrient impaired, increasing the financial burden of the States by requiring them to address waters that do not have a nutrient problem. (NCDENR)

Clear definitions and standard methods are needed to establish what constitutes excess nutrient loading and related consequences; e.g., causal links to nutrient loading should be clearly established before reduction measures are required. (WCRSA)

Proposed standards should be protective of waterbody designated uses and enforceable. (ADEQ)

Unclear how nutrient concentration ranges will be developed into water quality standards and subsequently interpreted. (ADEQ)

Should assess the economic impact of standards enforcement at the farm boundary level. (ADEQ)

Numeric criteria ranges should be sufficiently flexible to accommodate local application by delegated state agencies. (MAMWA, VAMWA, WVMWQA)

Effluent trading and technological innovation will be particularly important considerations in cost-effectively achieving nutrient criteria. (MAMWA, VAMWA, WVMWQA)

If used to derive permit limitations, nutrient water quality standards must allow sufficient flexibility to account for the variations in assimilative capacity and other factors within a particular waterbody, while continuing to achieve designated uses. (AF&PA)

Concern over how the USEPA will determine that a State has not shown reasonable progress towards development of numerical nutrient criteria once deadlines are reached. (PADEP)

Note that it is difficult to substantiate or support State criteria numbers that differ from Federal guidance values. (PADEP)

The flexibility provided to the States by requiring causal (nutrient concentration) variables as well as response (chlorophyll a, algal biomass, Secchi depths) variables lends itself well to follow-up monitoring and evaluation of the effectiveness of derived water quality standards. (PADEP)

Additional guidance may be required on how (if at all) nutrient criteria relate to antidegradation requirements. (PADEP)

It is questionable whether States have the resources necessary to adhere to EPA's target dates for implementation of the Strategy. (WEF)

Permit writers and State water quality personnel should be prepared through proper training to utilize resulting complex criteria. (WEF)

The Strategy is missing a discussion of designated uses and the impacts nutrients may have on these uses. (WEF)

The regulatory agency responsible for implementing the criteria through the permitting process should not expect permittees to expend local funds to conduct expensive experimentation related to nutrient management. Instead, Federal and State agencies should financially support demonstration studies until effective nutrient management technologies and BMPs are available. (WEF)

Because it has historically been difficult for the regulated community to properly incorporate the necessary factors required when developing technically valid, cost-effective eutrophication control programs, development of nutrient criteria may worsen the situation, resulting in misuse of criteria in the standards and NPDES permit development processes. (GFLA)


The Nutrient Strategy clearly states that once nutrient criteria are developed by EPA, States and Tribes will be given three years to adopt nutrient standards. If States or Tribes fail to establish standards by the end of 2003 (or three years after a nutrient criterion is developed), EPA will promulgate standards based on Federal guidance for that State or Tribe. EPA is aware that this time line is ambitious and may be difficult to meet, but maintains that a good faith effort must be made by States and Tribes indicating reasonable progress toward developing numerical nutrient standards. If this is not the case, EPA will take action through Clean Water Act authority.

There are a number of implementation issues and programmatic cross links that need to be discussed and resolved before EPA can present final guidance on nutrient criteria implementation. To this end, EPA has established a committee focusing on implementation issues. The tentative goal is to develop implementation guidance that will be sent out to EPA regions, States, and Tribes for review in 2000. The Agency recognizes the need for demonstration projects to validate the criteria development and implementation process and is pursuing funding to support such projects.

Nutrient Criteria Development Approach

Process for developing nutrient criteria should focus on defining optimal nutrient levels based on objective, replicable conditions. (WCRSA)

Over $2 million spent studying eutrophication in the Chesapeake Bay and no numeric standards have been adopted for N or P. (NCDENR)

Combination of chlorophyll a and narrative standard has proven to be an effective approach for controlling nutrients as compared to developing numeric nutrient standards. (NCDENR)

Criteria should be based on loadings rather than concentrations. (MWRA)

Strategy should clarify/identify the point at which enrichment becomes detrimental to a waterbody. (MWRA)

Should define "trophic state of a waterbody" and include assessments of waterbody bathymetry and circulation patterns which are critical in determining the effects of nutrient loadings. (CMC)

Unclear how Redfield ratios fit into nutrient criteria development. (CMC)

Should include physical parameters (e.g., low flow rivers and narrow trenches in estuaries) as factors that exacerbate overenrichment. (CMC)

Numeric mean nutrient concentrations should be derived for each season to account for seasonal variability. (CMC)

Should clarify what is meant by central tendency- median, mean, or standard deviation? (CMC)

Emphasis should not be on measuring natural nutrient levels, but on impairment of watershed by nutrient overenrichment. (CMC)

It is not clear that all waterbodies of the US require implementation of water quality criteria. The USEPA should consider prioritizing development of nutrient criteria for various regions of the country, particularly those regions that would most benefit from nutrient criteria. (AF&PA)

Nutrient criteria development should focus on threshold nutrient levels that protect designated uses rather than attempting to restore background levels. (AF&PA)

The USEPA should ensure that the criteria development process is based on peer reviewed science, so that criteria ranges are scientifically supported. (AF&PA)

The Strategy should include a discussion of how to incorporate episodic (e.g., storm water) nutrient loads into the criteria. (WEF)

The Strategy does not take into consideration the effect of toxic compounds present in receiving waters. In the presence of toxic compounds, the overall respiration rate of microbial populations responsible for nutrient removal may be repressed, resulting in cumulatively increasing nutrient concentration levels and waterbody eutrophication. Without toxicity screening, it would be difficult to determine the cause of eutrophication under this scenario. (WEF)

The USEPA fails to discuss the concept of thresholds for impairment in developing criteria ranges. Although reference condition information is important, it is equally important to define how thresholds will be assessed on a waterbody-specific basis. (WEF)

The Strategy includes few specifics on how criteria will be developed (which indicators will be used). (WEF)

The focus of USEPA's nutrient program should be on controlling nutrient impacts, not nutrient concentrations. The relationships between nutrient concentrations/loads and eutrophication response is poorly understood, making it impossible to establish reliable numeric chemical specific criteria. (GFLA)

The chemical specific criteria approach is fundamentally flawed, resulting in massive expenditures by the public to control chemical constituents beyond what is needed to protect the beneficial uses of a waterbody. Recommend that USEPA abandon the proposed approach in favor of nutrient guideline values for each of the waterbody types. However, even guideline values should be approached with caution and USEPA should ensure that guideline values are not used by States/local authorities as not-to-be-exceeded concentrations. (GFLA)

Narrative standards are more appropriate than numeric nutrient standards because the former focuses on aesthetic impacts (i.e., excessive growths of algae that impair recreational use). (GFLA)


The purpose of the Strategy was to define the general approach EPA is taking to develop nutrient criteria. The Guidance documents specifically describe the technical process for deriving criteria. This process entails classification of waterbodies, identification of reference condition, examination of nutrient and algal relationships, evaluation of system variability (including seasonal and hydrological differences), and their collective role in criteria development. Each of the Guidance documents is subject to peer review by a panel of scientific experts.

Nutrient Sources

Treatment plant loadings should be considered in concert with other factors including (1) loadings from other sources (rivers, stormwater runoff, other nonpoint sources); (2) discharge depth; (3) discharge location; (4) cost of additional treatment and monitoring. (MWRA)

EPA should be mindful that nutrient impairment can be attributed to a variety of sources including natural and man-made sources across multiple media (e.g., atmospheric deposition) and intrastate and interstate boundaries. (MAMWA, VAMWA, WVMWQA)

For some animal feeding operations, freshwater quantity requirements exceed water quality concerns. (ADEQ)

Need to identify groundwater as an important nutrient loading source. (CMC)

Nonpoint sources (e.g., groundwater and atmospheric deposition) should be listed and discussed as major contributors of nutrients in the final guidance. (CMC)

Because nonpoint sources are more significant contributors to nutrient problems than point sources, efforts should be directed to address nonpoint source controls (including airborne sources) within the same time frame as guidance document preparation. (WEF)

The Strategy does not discuss how nutrient sources will be identified and monitored. Quantifying natural and cultural sources of nutrients is an emerging field of research with no consensus on acceptable methods. (AI)

Do not concur with the Strategy that internal nutrient cycling is a major contributor to excessive fertilization of waterbodies. Excessive fertilization is controlled by nutrient loads to the waterbody rather than internal nutrient cycling. (GFLA)

Do not agree that sediment suspension always results in release of nutrients. While the statement is true for ammonia, it is not generally true for phosphorus due to the latter's precipitation from the water column when contacting ferric hydroxide. (GFLA)

Dairies should be included as a significant source of nutrients. (GFLA)


EPA is aware that there are many sources of nutrients contributing to excessive nutrient levels in a given waterbody, including nonpoint and point sources. EPA also expects that all nutrient sources will be affected by nutrient criteria as TMDLs, basin-wide plans, and permit limits are established. It is not the intention of the Nutrient Strategy to exclusively control nutrients from point sources. Therefore, criteria are based on water column concentrations which allows for the incorporation of all potential sources when assessing the nutrient condition of a waterbody.

Stakeholder Involvement

Nutrient criteria development process must include participation of all stakeholders. (WCRSA)

Criteria development process should be as interactive as possible and open to the public, especially local government representatives. (MAMWA, VAMWA, WVMWQA)

The USEPA should open its guidance development process to all relevant stakeholders. (AF&PA)

General public participation should begin early in the process (i.e., at Step 1- Problem Identification). (WEF)

The schedule provided in the Strategy appears far too aggressive for any level of stakeholder involvement, input, or detailed review, let alone scientific research. (WEF)

Because the USEPA avoided formal notice and comment on the rulemaking, the agriculture industry and public were precluded from fully commenting on the Strategy. Further, supporting information including peer review comments on the Strategy and references cited in the Strategy were not made available to the public. The agriculture industry requests that USEPA provide access to all of the Strategy's source documents so that the science underlying the Strategy can be reviewed and properly assessed and that the comment period be held open so that members of the agriculture industry have adequate opportunity to supplement their initial comments. (AI)


EPA is committed to involving stakeholders in the nutrient development process. EPA has already met with many stakeholders individually and collectively in national and regional stakeholder meetings. Every guidance document will be available for review and comment on the nutrient website. Stakeholders who are scientific experts in the fields of eutrophication and nutrient/biological effects are welcome to offer their expertise to an RTAG. Those interested in joining an RTAG should contact their EPA Regional Nutrient Coordinator. (A listing of Regional Nutrient Coordinators is posted on this website.)

The development of a National Nutrient Strategy and subsequent nutrient criteria guidance and criteria does not constitute a rulemaking and, as such, is not bound by formal notice and comment requirements. However, EPA has presented the Nutrient Strategy, peer review comments, public comments and responses, and summaries of stakeholder meetings on the nutrient website for informational purposes. In addition, EPA has made available any supporting information requested by stakeholders and has convened meetings and briefings with stakeholders to clarify program objectives.

Strategy Recommendations

Strategy should address under-enrichment. (ADEQ)

Strategy should place more emphasis on hypoxia/anoxia consequences of nutrient pollution, including a discussion of how hypoxia and anoxia occur. The role of bacteria in reducing DO levels should be discussed in the Background section of the Strategy. (CMC)

Cultural eutrophication should be better defined in the context of the continuum from oligotrophic to mesotrophic to eutrophic waterbodies and distinguishing between naturally eutrophic systems and those systems heavily impacted by anthropogenic activities. Recommend that cultural eutrophication be defined as excess nutrient loading occurring over a short time frame, e.g., years, that cannot be assimilated by the receiving system. (CMC)

Should clarify form of silica (soluble silica, silicates, or silica as sand) when discussing its role in phytoplankton blooms. (ADEQ)

Need to be more specific about the "work" that should be conducted to better understand and manage nutrients. (CMC)

Should better define what is meant by natural nutrient loadings to waterbodies. (CMC)

Need to discuss how groundwater intrusion will be addressed in Strategy. (CMC)

Discussion of buffer zones should be modified to indicate that vegetative zones effectively remove nitrogen contained in runoff, but not phosphorous. (CMC)

Groundwater as a waterbody type is absent from the Strategy. Consideration of groundwater would result in a truly comprehensive approach to nutrient control, although it is recognized that including groundwater requires additional effort with respect to defining groundwater/surface water boundaries within ecoregions. (PADEP)

The USEPA is defining over enriched waters as those in which nutrient levels are higher than concentrations in natural ambient waters. Given this definition, it would appear that all U.S. waterbodies could be defined as impaired by overenrichment. The difference between enrichment and over enrichment as defined by USEPA is a value judgment, objective only to the degree that it is defined by an actual impairment of a designated beneficial use. (WEF)

Rather than the Strategy focusing on eutrophication issues that are of limited public interest, its focus should be based on national eutrophication problems that are of concern to most of the U.S. public. The two most significant water quality issues related to excess nutrients are (1) impacts to domestic water supply raw water quality (e.g., taste and odor problems, increasing water treatment costs) and (2) impacts to recreational uses of waterbodies. (GFLA)

Disagree that biological diversity is reduced in eutrophic waters. Diversity in eutrophic or hypereutrophic lakes and reservoirs is as high as in oligotrophic waterbodies. (GFLA)

The so-called loss of vascular plant life related to hypereutrophication is a misnomer in that vascular plants will and do develop in hypereutrophic waterbodies. In fact, the excessive growth of vascular plants such as water hyacinth and other floating macrophytes is one of the major problems associated with impairment of waterbody uses. (GFLA)

Disagree that eutrophication is defined as an increase in nutrients resulting in an overabundance of plant biomass. Rather, eutrophication is defined as an enrichment process (not the result of a process) that may or may not result in an overabundance of aquatic plants. (GFLA)

Disagree that Redfield numbers as presented in the Strategy are reliable indicators of limiting nutrients. Recommend the use of the American Water Works Association Quality Control in Reservoirs Committee report on determining limiting nutrients (Lee and Lee-Jones, 1998). (GFLA)

Disagree that phosphorus in detergents has been a cause of excessive fertilization within waterbodies. The literature has documented that phosphorus in detergents is not sufficient to cause increased fertility of waterbodies that can be perceived by the public. (GFLA)

It is inappropriate to simultaneously list as an issue those 10 States that have adopted USEPA criteria unrelated to eutrophication with the failure of States to adopt nutrient criteria. (GFLA)


As stated previously, the purpose of the Strategy was to define the general approach EPA is taking to develop nutrient criteria. The Guidance documents specifically describe the technical process for deriving criteria. Many of the above comments are waterbody-type specific in nature and are addressed in the Guidance documents. For more details, the reader is referred to the National Nutrient Guidance Documents link on the Nutrients website:


Appendix A should reflect that for NC, a check and (5) should be found under the Nitrate column in addition to including other types of criteria and management strategies currently in place (e.g., NC's chlorophyll a/narrative criteria and Nutrient Sensitive Waters). (NCDENR)

Control of phosphorus is particularly important; a standard of 0.05 mg/l is appropriate. (AWWA)

In addition to nitrogen and phosphorus, trace minerals (e.g., copper, selenium, cadmium, zinc, potassium, and arsenic) are of concern in relation to water pollution. (ADEQ)

Water quality overenrichment can be a far field rather than near field concern. (MAMWA, VAMWA, WVMWQA)

Disagree that an environmental impact study exclusively should be required to assess the potential impact of development on adjacent waterbodies. Instead, it is recommended that an environmental impact study, environmental assessment, or other environmental document be prepared in accordance with State requirements. (WEF)

The USEPA has failed to consider an adequate range of input from the scientific community. Half of the twenty references listed in the Strategy are internal USEPA administrative documents and the remaining references are relatively dated. The USEPA should amass a broader, more up-to-date set of relevant scientific literature. In particular, it is recommended that members of the agricultural research scientific community (e.g., USDA-ARS, land grant university colleges of agriculture, agriculture-based industry, soil scientists) be involved in the nutrient criteria development effort. (AI)

Given the national significance of the Strategy and its potential for broad impact to the regulated community, the USEPA should initiate a formal rulemaking. (AI)

Those States listed as currently having nutrient standards have adopted technically invalid approaches due to the general lack of technical information required to develop appropriate criteria. (GFLA)


EPA appreciates these additional comments. It is not anticipated that the Stratgey will be revised. Details on criteria development and contacts for specific input can be found at EPA's nutrient criteria website: (

1 Comments represent the collective responses of agriculture industry members including: Agricultural Retailers Association, American Feed Industry Association, American Nursery & Landscape Association, National Cattlemen's Beef Association, National Corn Growers Association, National Grange, National Milk Producers Federation, The Fertilizer Institute, and USA Rice Federation.

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