EPA Develops Draft Technical Guidance Manual On Wetlands

On Dec. 14, 2006, EPA announced the release of a draft technical guidance manual to help states and tribes establish water quality criteria and standards for nutrients in their wetlands.

The "Draft Nutrient Criteria Technical Guidance Manual: Wetlands" is one in a series of waterbody-specific documents that support the National Nutrient Strategy, agency officials said. The manual explains how to consider water, vegetation and soil conditions and develop regionally based numeric nutrient criteria for wetland systems.

Human activities can increase runoff from the land surface and increase the input of nutrients into surface waters, including wetlands. The addition of plant nutrients stimulates the growth of algae and other plants. Eutrophication is a process whereby water bodies receive excess nutrients that stimulate excessive plant growth. This enhanced plant growth, often called an algal bloom, reduces dissolved oxygen in the water when dead plant material decomposes and can cause other organisms to die. EPA is developing recommended nutrient criteria to help states and authorized tribes address the problem of eutrophication.

Nutrient criteria are numerical values for both causative (in this case, phosphorus and nitrogen) and response (vegetation changes, chlorophyll and turbidity) variables associated with preventing and assessing eutrophic conditions. The agency expects that states and tribes will use these criteria to help identify problem areas, serve as the basis of state water quality standards for nutrients, and evaluate success in reducing cultural eutrophication. The guidance manual describes the elements of wetland nutrient criteria development.

In 1998, EPA published a report titled "National Strategy for the Development of Regional Nutrient Criteria." This report outlined a framework for development of waterbody-specific technical guidance that can be used to assess nutrient status and develop region-specific numeric nutrient criteria. The agency has released the companion nutrient criteria technical guidance manuals for rivers and streams, lakes and reservoirs, and estuarine and coastal marine waters.

The technical guidance manuals can be accessed at http://www.epa.gov/waterscience/criteria/nutrient/guidance/index.html.

More information on the National Nutrient Strategy can be found at http://www.epa.gov/waterscience/criteria/nutrient/strategy.html.

This article originally appeared in the 01/01/2007 issue of Environmental Protection.

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