Water: Ecoregions

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

I: Willamette and Central Valleys•

II: Western Forested Mountains•

III: Xeric West•

IV: Great Plains Grass and Shrublands•

V: South Central Cultivated Great Plains•

VI: Corn Belt And Northern Great Plains•

VII: Mostly Glaciated Dairy Region•

VIII: Nutrient Poor Largely Glaciated Upper Midwest and Northeast•

IX: Southeastern Temperate Forested Plains and Hills•

X: Texas-Louisiana Coastal and Mississippi Alluvial Plains•

XI: The Central and Eastern Forested Uplands•

XII: Southeastern Coastal Plain•

XIII: Southern Florida Coastal Plain•

XIV: Eastern Coastal Plain (PDF)•

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You are here: Water Science & Technology Surface Water Standards & Guidance Water Quality Standards

Water Quality Criteria Nutrients Ecoregional Criteria

Ecoregional Criteria

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

(PDF) (236 K)

•

Summary Table for the Nutrient Criteria

Documents (PDF) (68 K) 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.

•

Ecoregional Criteria | Ecoregions | US EPA Page 1 of 2

http://water.epa.gov/scitech/swguidance/standards/criteria/nutrients/ecoregions/index.cfm 2/13/2012
Last updated on Thursday, September 29, 2011

http://water.epa.gov/scitech/swguidance/standards/criteria/nutrients/ecoregions/index.cfm 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 (PDF) (28 K)

• Federal Register Notice (January 6, 2003)

Correction of significant figures for Aggregate Ecoregion I, X and XIII Nutrient Criteria Recommendations

(PDF) (14 K)

◦

• EPA Response to Peer Review Comments for Lakes and Reservoirs (PDF) (48 K)

• EPA Response to Peer Review Comments for Rivers and Streams (PDF) (48 K)

• Public Comments (PDF) (47 K)

We solicited submissions of significant scientific information on nine nutrient water quality criteria documents for lakes

and reservoirs, and rivers and streams.

• Fact Sheet (PDF) (81 K)

• 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

• Federal Register Notice (January 9, 2001)

• External Expert Peer Review Comments (PDF) (57 K) (June 2001)

• Public Comments (PDF) (37 K) (June 2001)

Ecoregional Criteria | Ecoregions | US EPA Page 2 of 2

http://water.epa.gov/scitech/swguidance/standards/criteria/nutrients/ecoregions/index.cfm 2/13/2012