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Current Status: State Adoption of Numeric Nutrient Standards

December 2008

"State Adoption of Numeric Nutrient Standards 1998–2008," is the first national report on progress made by the 50 States in adopting numeric nutrient water quality standards (WQS) for their major water body types (lakes and reservoirs, rivers and streams, estuaries, and wetlands).

This report covers progress since 1998, when the Agency released its national strategy for helping states develop and adopt numeric nutrient WQS. The report also follows up on EPA's 2007 commitment to periodically report state progress in adopting such standards. This report will serve as an important baseline reference for EPA and the States as we continue to partner in the development, adoption, and implementation of numeric nutrient standards. It can also be a tool that helps us jointly identify pathways of success for the future.

Background

Nitrogen and phosphorus pollution (or nutrient pollution) is one of the top three causes of impairment of the nation's waters. Collectively, 49 states have listed over 10,000 nutrient and nutrient-related water quality impairments. EPA, the states, and the public have placed high priority on public partnerships, collaboration, better and improved tools to reduce nutrient pollution. Numeric nutrient WQS will drive water quality assessment and watershed protection management, as well as facilitate more effective and efficient program implementation, including easier and faster development of Total Maximum Daily Loads (TMDLs) and National Pollution Discharge Elimination System (NPDES) permits. Consequently, EPA has encouraged all states to accelerate adoption of numeric nutrient WQS or numeric translators for narrative standards for all waters that contribute nutrient loadings to the Nation's waterways.

In a May 2007 memorandum from the Assistant Administrator for Water, EPA reaffirmed the need for the states to adopt numeric nutrient WQS and for EPA to assist states, territories and authorized tribes with that effort. The memorandum also stated EPA's intent to periodically report on the progress of state adoption of those standards.

Report Summary

EPA has encouraged States to adopt numeric nutrient WQS for both casual (Total Nitrogen and Total Phosphorus) and response (chlorophyll-a and clarity) parameters for all of their water body types (lakes and reservoirs, rivers and streams, estuaries, and wetlands). Over the past ten years, the States have adopted numeric nutrient WQS for a range of waters according to their own priorities and needs. The report captures State progress in adopting numeric nutrient standards in the following ways:

  1. Adopted numeric criteria into WQS for all four parameters for all water body types.
  2. Adopted numeric criteria into WQS for one or more parameters for at least one entire water body type.
  3. Adopted numeric criteria into WQS for one or more parameters for selected waters in one or more water body types.
  4. Has not adopted numeric criteria into WQS.

Table 1 shows the number of states that have adopted numeric nutrient WQS as of 1998 and 2008.

Table 1. Number of States with Adopted Numeric Nutrient Standards by Year and Waterbody Type
Numeric Nutrient Standards
Status by Year		 4 Parameters
4 Waterbody Types 1 		 1+ Parameters
1+ Entire Waterbody Types 2 		 1+ Parameters
Selected Waters 3 		 No Numeric Criteria 4 
1998 0 6 7 37
2008 0 7 18 25
2008 Numeric Nutrient Standards
Status by Waterbody Type		 4 Parameters
4 Waterbody Types 5 		 1+ Parameters
1+ Entire Waterbody Types 6 		 1+ Parameters
Selected Waters 7 		 No Numeric Criteria 4 
Lakes/Reservoirs 0 6 13 31
Rivers/Streams 0 5 9 36
Estuaries
(24 eligible States)		 0 3 7 14
Wetlands 0 0 4 46
  1. Adopted numeric criteria for all four parameters for all waterbody types.
  2. Adopted numeric criteria for one or more parameters for at least one entire waterbody type.
  3. Adopted numeric criteria for one or more parameters for selected waters in one or more waterbody types.
  4. Has not adopted numeric criteria.
  5. Adopted numeric criteria for all four parameters for the entire waterbody type.
  6. Adopted numeric criteria for one or more parameters for the entire waterbody type.
  7. Adopted numeric criteria for one or more parameters for selected waters in a waterbody type.

For more information

Download the report, State Adoption of Numeric Nutrient Standards 1998–2008 (PDF) (96 pp., 477 K; EPA 821-F-08-007 About PDF). You can also contact Jacques L. Oliver (oliver.jacques@epa.gov).

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