Continued national-synthesis assessments on nutrients, aquatic ecology, trace elements, pesticides, and, to a lesser extent, volatile organic compounds.
Regional and national assessments of status and trends. These assessments focus on
Topical studies of national water-quality priorities are conducted to better understand links between sources of contaminants, the transport of those contaminants through the hydrologic system, and the potential effects of contaminants on humans and aquatic ecosystems. These studies address: (1) the fate and transport of agricultural chemicals, (2) effects of urbanization on stream ecosystems, (3) effects of nutrient enrichment on stream ecosystems, (4) bioaccumulation of mercury in stream ecosystems, and (5) transport of contaminants to public-supply wells.
Special studies on source-water and drinking-water quality are conducted to characterize the occurrence and distribution of about 270 compounds, including pharmaceuticals, personal care products, industrial chemicals, pesticides, and microbes in selected drinking-water supply wells, stream intakes, and in finished drinking water associated with large community water systems.
A national assessment was done on water-quality conditions for about 2,100 domestic wells across the United States. As many as 219 properties and contaminants, including pH, major ions, nutrients, trace elements, radon, pesticides, and volatile organic compounds, were measured. Fecal indicator bacteria and additional radionuclides were analyzed for a smaller number of wells.