Technical Support for Numeric Nutrient Criteria Development

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EPA has developed a number of resources to help states with developing criteria. In March 2011, EPA issued a comprehensive framework (PDF) (6 pp, 401K) to assist states, territories and tribes in addressing nitrogen and phosphorus pollution. 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.

Reference Documents

• Technical criteria development guidance documents for various water body types
• Ecoregional criteria documents

Other Resources

• Online Technical Support for States (N-STEPS)
• Nitrogen and Phosphorus Pollution Data Access Tool
• Nutrients in Estuaries - November 2010 (PDF) (202 pp, 13MB)
• BMP and Treatment Technologies Clearinghouse
• Water Quality Assessment and Total Maximum Daily Loads Information (ATTAINS)
• Implementation Frequent Questions