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Reports, Research, and Resources on Nutrient Pollution

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EPA Reports

Case Studies on Implementing Low-Cost Modifications to Improve Nutrient Reduction at Wastewater Treatment Plants (August 2015)

Nutrient pollution is one of America’s costliest and most challenging environmental problems. However, many of the nation’s wastewater plants were not designed for nutrient removal and major retrofits may be a significant hurdle.

This report showcases communities where lower cost plant modifications can reduce nutrient discharge levels (ranging from about 20% to 70%), under specific circumstances. We found that in most cases, the activities’ effects were positive, allowing for better energy efficiency, lower operational costs and improved process performance.

EPA is interested in learning of additional communities’ successes and intends to update this document to help more of the nation’s wastewater treatment plants make progress towards additional nutrient reductions. Interested parties are invited to comment and recommend additional case studies by December 15, 2015 to

Compilation of Cost Data Associated with the Impacts and Control of Nutrient Pollution (PDF) (110 pp, 3 MB) (May 2015) - spreadsheet (excel)(1 pg, 329 K)

This report and its associated spreadsheet compile information on the costs associated with the impacts of nutrient pollution for a number of economic sectors and the costs to control nutrient sources. For the first time, costs of both controlling and not controlling nutrients are combined in one document. This report should help water program managers, legislators, and the public understand the potential costs of action and inaction and form conclusions about appropriate management actions to address nutrient pollution.

Six Municipalities, One Watershed: A Collaborative Approach to Remove Phosphorus in the Assabet River Watershed (March 2015)

This case study describes the activities of a consortium of wastewater treatment facilities along the Assabet River in Massachusetts who selected four different phosphorus removal technologies and successfully lowered effluent concentrations to less than 0.1 milligrams per liter of phosphorus. Each facility examined available technologies, costs, operational concerns and other factors before choosing the best option based on its own criteria. As a result of the facilities’ actions, water quality in the river has improved; phosphorus loads to the river have decreased more than 90 percent.

National Aquatic Resource Surveys

EPA, states, and tribes are conducting a series of surveys of the nation's aquatic resources. Often referred to as probability-based surveys, these studies provide nationally consistent and scientifically-defensible assessments of our nation's waters and can be used to track changes in condition over time.

  • Coastal Conditions Report III
  • National Lakes Assessment
  • Wadeable Stream Assessment

State-EPA Nutrient Innovations Task Group Report (August 2009)

An Urgent Call to Action - Report of the State-EPA Nutrient Innovations Task Group is a joint State-EPA review of both existing and innovative approaches to nutrient management. In 2008, State and EPA surface water and drinking water program managers agreed to form an ad hoc Nutrient Innovations Task Group to identify and frame key nutrient issues, questions, and options on how to improve and accelerate nutrient pollution prevention and reduction at the state and national level. In this report, the task group presents a summary of scientific evidence and analysis that characterizes the scope and major sources of nutrient impacts nationally and describes the current tools and authorities used to control nutrient pollution sources. The task group concludes with findings and suggests next steps needed to better address nutrient pollution.

Reactive Nitrogen in the United States: An Analysis of Inputs, Flows, Consequences, and Management Options - A Report of the EPA Science Advisory Board (August 2011)

The Science Advisory Board Integrated Nitrogen Committee conducted a study on the sources and fate of reactive nitrogen with the purpose of addressing the overarching question of how can we protect and sustain ecosystem services, while also assuring that societal needs for food and energy are met. This Report of the EPA Science Advisory Board calls for a comprehensive an integrated approach to manage reactive nitrogen, mitigate its damage, and restore ecosystems. This report also contains recommendations on the following areas: establishing the links among source and fate of reactive nitrogen, environmental and public health problems; identify actions to support an integrated nitrogen management strategy and to reduce reactive nitrogen losses by 25 percent; and make recommendations on the research necessary to support reduction activities.

Nutrients in Estuaries - A Summary Report of the National Estuarine Experts Workgroup (November 2010)

Nutrient criteria are benchmarks that help to establish the level of nutrient pollution below which waterbodies can maintain their designated uses—primarily aquatic life and recreation. Estuaries are very complicated bodies of water, and the task of setting nutrient criteria for them, in turn, is complex. The November 2010 Nutrients in Estuaries report describes some of the current science in estuarine nutrient criteria development. It does not set criteria, nor does it recommend a single methodology for doing so. Criteria can vary from site to site and from estuary type to estuary type, and the methods for setting criteria can vary depending on both the estuary type and availability of data.

Clean Air Interstate Rule, Acid Rain Program, and the former Nitrogen Oxide Budget Training Program Progress Reports

Find recent and historical EPA reports covering progress under air market programs including the Clean Air Interstate Rule, the Acid Rain Program, and the former Nitrogen Oxide Budget Program. These reports evaluate progress under these programs by analyzing emission reductions, reviewing compliance results and market activity, and comparing changes in emissions to changes in a variety of human health and environmental indicators.

External Reports

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Nutrient Research Topics

  1. Sustainable Watersheds
    EPA develops the models and tools needed to achieve sustainable solutions for managing nutrients in our watersheds.
  2. Nitrogen Mapping
    Researchers are creating an inventory of nitrogen sources in the U.S. and mapping the movement of nitrogen from its source into the air, water, and land. Using this data, researchers can better understand nitrogen trends in different regions across time periods.
  3. Nutrient Reductions in Water Runoff
    EPA is working with the U.S. Geological Survey and the state of Iowa to develop methods for lowering sediment and nutrient pollution in surface waters draining into the Mississippi River Basin. The results of this research will help protect and restore watersheds and improve water quality throughout the entire Midwest.
  4. Advanced Nutrient Monitoring
    EPA is studying new innovative technologies that will measure nutrient pollution in the air and water using satellites, portable and ground remote sensors as well as measurement and model data. These technologies enhance current monitoring activities and also provide cheaper and faster information on nutrients and other pollutants.
  5. Integrated Nitrogen Modeling
    Researchers are using a community multiscale air quality modeling system to understand the life cycle of nitrogen from its release into the atmosphere to deposition on land and water. Using this model, researchers can develop scenarios and compile information that can be used to manage nitrogen use and impacts.
  6. Nitrogen Deposition
    EPA is improving its knowledge of the total amount of reactive nitrogen in the air and how it is deposited onto land and water.
  7. Climate Change and Nitrogen Interaction
    Climate change may alter the impacts that nitrogen has on land and water. Researchers are using atmospheric monitoring, field measurements, and modeling to study the interactions between climate change and nitrogen and how this interaction may negatively impact land and water. The research is determining how to protect the environment and our natural resources from any negative effects of climate change and nitrogen.
  8. Nutrient Recovery
    One of EPA's research goals is to focus on recycling resources rather than only treating waste products. For example, the high levels of nitrogen and phosphorus in wastewater could be used as nutrient resources for farming, rather than being dumped back into water bodies already overloaded with these nutrients.
  9. Narragansett Bay Nutrient Case Study
    A case study involving an integrated and sustainable research and management approach is focusing on Narragansett Bay in Rhode Island, including its watershed and air shed. Researchers are investigating how changes in nitrogen release into water bodies and climate impact watersheds and water quality. The research will be used to help restore and protect watersheds and highly valued water resources.
  10. Gulf of Mexico Hypoxia Case Study
    EPA researchers are developing 3-D water flow and water quality models of the northern Gulf of Mexico dead zone as well as the Mississippi River Basin. The research is being done to understand the multiple nutrient sources, nutrient movement patterns, and impacts along the freshwater Basin and through to the Gulf's marine environment.
  11. Yakima River Basin Case Study
    EPA and US Geological Survey researchers are working together to identify sources and impacts of nitrogen in the lower Yakima River Basin, a local source of drinking water. Using USGS and EPA data and models, researchers are working to pinpoint the major sources of nitrogen pollution and track its movement through groundwater in the basin.
  12. Guánica Bay Case Study
    The multi-agency U.S. Coral Reef Task Force initiated a program to address sediment and nutrient pollution of coral reefs in the Puerto Rico's Guánica bay watershed.

EPA’s Research Articles and Reports


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