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Tetra Tech is helping the U.S. Environmental Protection Agency (EPA) assess the ecological condition of streams and lakes across the country. This ambitious effort is setting a positive course for intervention and protection of our water resources in the near future.

The effort began with a survey of some 1,200 streams. With the help of Tetra Tech scientists, the water quality agencies of states and tribes assessed the health of the stream ecosystems using key biological, physical, and chemical indicators.

The Wadeable Streams Assessment was a first-ever, statistically valid survey of the condition of streams throughout the United States. The study found that 28 percent of U.S. stream miles are in good condition, 25 percent are in fair condition, and 42 percent are in poor condition.

The Wadeable Streams Assessment establishes a national baseline to compare to results from future studies. This information will help evaluate the successes of national and regional efforts to protect and restore water quality.

Tetra Tech scientists next provided key technical support for a new effort to survey lakes nationwide. The Survey of the nation’s lakes requires collecting samples from nearly 1,000 lakes, ponds, and reservoirs. The EPA considered chemical, biological, and physical parameters to help evaluate the ecological condition, trophic state, and recreation potential of the lakes. By 2010 the data will be analyzed and a report issued on the condition of these water resources.

Currently, Tetra Tech scientists are providing technical and organizational support for a new effort to survey rivers and streams across the country. The National Rivers and Streams Assessment is a two-year effort that requires collecting samples from nearly 2,000 sites. Field crews are collecting data for indicators of ecological condition, recreational indicators, indicators of physical habitat condition, and basic water chemistry. A national report on rivers and streams is scheduled for 2011.

Highlight:

"Statistically representative surveys of the aquatic resources of the U.S. have begun providing us with the information we need to identify national priorities and evaluate the effectiveness of pollution control actions. These assessments report on core indicators using standardized field and lab methods and include a national quality assurance program. The surveys are designed to yield unbiased estimates of the condition of a whole resource, based on a representative sample of waters." -EPA Progress Report on the National Aquatic Resource Surveys

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