"Assessing the nation's waters." "EPA-841-F-06-001."

The Wadeable Streams Assessment (WSA) is a first-ever statistically-valid survey of the biological condition of small streams throughout the U.S. EPA worked with the states to conduct the assessment in 2004-2005. The WSA is designed like an opinion poll: that is, 1,392 sites were selected at random to represent the condition of all streams in regions that share similar ecological characteristics. Wadeable streams were chosen for study because they are a critical natural resource and because we have a well-established set of methods for monitoring them. Participants used the same standardized methods at all sites, to ensure results that are comparable across the nation. The WSA establishes a national baseline we can use to compare to results from future studies. This information will help us evaluate the successes of our national efforts to protect and restore water quality. Along with upcoming studies of other water resource types - coastal waters, lakes, large rivers and wetlands - the WSA responds to criticisms that the nation's monitoring programs are not providing key answers about water quality. The WSA also provides funding and expertise that will enhance each state's ability to monitor and assess the quality of its waters in the future.