Download GIS Data for Level III Ecoregions

The U.S. is divided into 14 distinct eco-regions.

We publish recommended water quality criteria to reduce problems associated with excess nutrients in waterbodies in specific areas of the country. We work with states and tribes to adopt regional-specific and locally appropriate water quality criteria for nutrients in lakes, reservoirs, rivers, streams, and wetlands in fourteen ecoregions.

Criteria Documents

• Criteria Documents for Lakes & Reservoirs
• Criteria Documents for Rivers & Streams
• Ecoregional Criteria Document for Wetlands
• Summary Table for the Nutrient Criteria Documents (July 2002)
  These tables present the recommended criteria for each of the aggregate nutrient ecoregions for the following parameters: Total Phosphorus, Total Nitrogen, Chlorophyll a, and Turbidity or Secchi. Criteria are presented for both Lakes & Reservoirs and Rivers & Streams.

History

We finalized nine water quality criteria documents for lakes and reservoirs, and rivers and streams. See below for documents and peer review comments.

• Fact Sheet (October 2002)
• Federal Register Notice (January 6, 2003)
  • Correction of significant figures for Aggregate Ecoregion I, X and XIII Nutrient Criteria Recommendations
• EPA Response to Peer Review Comments for Lakes and Reservoirs
• EPA Response to Peer Review Comments for Rivers and Streams
• Public Comments

We solicited submissions of significant scientific information on nine nutrient water quality criteria documents for lakes and reservoirs, and rivers and streams.

• Fact Sheet (December 2001)
• Federal Register Notice (February 28, 2002)

We published 17 ecoregional nutrient criteria documents for lakes and reservoirs, rivers and streams, and wetlands. See below for documents.

• Fact Sheet (December 2000)
• Federal Register Notice (January 9, 2001)
• External Expert Peer Review Comments (June 2001)
• Public Comments (June 2001)

Top of Page