Technical Support for Numeric Nutrient Water Quality Criteria Development

EPA has developed a number of resources to help states, territories, and tribes with developing criteria. In March 2011, EPA issued a comprehensive framework to assist states, territories, and tribes in addressing nitrogen and phosphorus pollution.

• Working in Partnership with States to Address Phosphorus and Nitrogen Pollution through Use of a Framework for State Nutrient Reductions (March 2011 EPA Memorandum) (pdf) (346.32 KB)

With respect to the framework, our goal is to assist in the development of numeric nitrogen and phosphorus criteria, which will help states, territories, and tribes move toward adopting water quality standards for nitrogen and phosphorus. Additionally, EPA has published technical resources, such as technical guidance documents that describe the techniques for developing numeric criteria for nitrogen and phosphorus pollution for different water bodies, technical documents describing ecoregional criteria, online databases and clearinghouses, and data concerning impaired waters and TMDLs.

• Technical Support Documents and Resources
• Other Resources

Technical Support Documents and Resources

• Nutrient Scientific Technical Exchange Partnership and Support (N-STEPS)
  • N-STEPS Online
• Nutrient Criteria Development Documents
  • Ambient Water Quality Criteria to Address Nutrient Pollution in Lakes and Reservoirs
• EPA’s Recommended Ambient Water Quality Criteria for Nutrients

Other Resources

• Overview of Numeric Nutrient Criteria Development for Scientific and Technical Assistance Groups
• Development of User Perception Surveys to Protect Water Quality from Nutrient Pollution: A Primer on Common Practices and Insights (pdf) (3.14 MB, April 2021, EPA 823-R-21-001)
• Preventing Eutrophication: Scientific Support for Dual Nutrient Criteria Fact Sheet (pdf) (269.87 KB, February 2015, EPA 820-S-15-001)
• BMP and Treatment Technologies Clearinghouse
• How’s My Waterway
• Implementation Frequent Questions