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Technical Support for Numeric Nutrient Water Quality Criteria Development

EPA has developed a number of resources to help states with developing criteria. In March 2011, EPA issued a comprehensive framework 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.

Draft Ambient Water Quality Criteria Recommendations for Lakes and Reservoirs of the Conterminous United States: Information Supporting the Development of Numeric Nutrient Criteria


At this time EPA is unable to provide hard copies of docket materials and/or receive hard copies of comments (i.e. scientific views) relevant to this draft document due to precautions being taken to prevent the transmission of COVID-19. For assistance accessing docket materials, please visit the online EPA Docket Center. If you are interested in submitting scientific views, please do so via (Docket ID No. EPA–HQ–OW–2019–0675).

EPA is requesting scientific views on its draft ambient numeric nutrient water quality criteria recommendations for lakes and reservoirs. Scientific views can be submitted on (Docket ID No. EPA–HQ–OW–2019-0675). In response to stakeholder requests, the comment period has been extended for an additional 30 days, from July 21, 2020 to August 20, 2020. Once final, these recommendations will replace those published by EPA in 2000 and 2001 for lakes and reservoirs.

Reference Documents

Other Resources