Programmatic Information on Numeric Nutrient Water Quality Criteria
In 1993, the U.S. Environmental Protection Agency established a Nutrient Task Force to gather existing data on nutrient problems and available tools. By 1995, the EPA published the proceedings of a National Nutrient Assessment Workshop designed to gather information that can aid states in developing and implementing appropriate nutrient endpoints, assessment methodologies and models.
In 1998, the EPA published a Numeric Nutrient Strategy describing the approach the agency would follow to develop nutrient information and work with the states and Tribes to help them adopt numeric nutrient criteria into their water quality standards.
- Fact Sheet: National Strategy for the Development of Regional Nutrient Criteria (pdf)
- Report: National Strategy for the Development of Regional Nutrient Criteria (pdf)
In 2001, the EPA issued a memorandum to states and authorized Tribes that provided additional guidance for developing nutrient criteria plans and describing the role of the plans, the flexibility available to states and Tribes, and the EPA’s expectations for the time frame in which states and Tribes should develop a plan and adopt nutrient criteria into their water quality standards.
Then, in 2007, the EPA issued a memorandum providing a national update on the development of numeric nutrient water quality standards and described the EPA’s commitment to accelerating the pace of state and Tribal progress.
In 2008, the EPA published the first national report on progress made by the states in adopting numeric nutrient water quality standards (WQS).
In recognition of the urgency of addressing nitrogen and phosphorus pollution in U.S. waters, the EPA formed the Nutrient Innovations Task Group (NITG). In 2009, the NITG published a report and fact sheet to draw public attention to the need for nutrient reduction strategies.
- An Urgent Call to Action: Report of the State-EPA Nutrient Innovations Task Group (August 2009) (pdf)
- Nutrient Innovations Task Group, Report Fact Sheet (August 2009) (pdf)
In 2011, the EPA published a comprehensive memorandum reaffirming its commitment to partnering with states and stakeholders to address nitrogen and phosphorus pollution. This memorandum presents a framework that states can use to reduce nitrogen and phosphorus pollution while developing numeric criteria.
In 2016, the EPA reaffirmed its commitment to support states and stakeholders to collaborate in reducing nutrient pollution. This memorandum announces support for state planning or implementation of watershed-based, multi-stakeholder projects to reduce public health impacts from nitrates in drinking water sources and from nitrogen and phosphorus pollution contributing to harmful algal blooms in water bodies.
In 2022, the EPA reaffirms its commitment to accelerate progress in controlling excess nutrients entering our nation’s waters by scaling up existing, foundational approaches and more broadly deploying new data assessments, tools, financing approaches, and implementation strategies. The EPA is relying in promising innovation, creative partnerships, a holistic One Water approach, and five governing principles to drive three major strategies leading to durable solutions to the challenges and costs associated with reducing nutrient pollution.