About NWQL
The U.S. Geological Survey (USGS) gathers data for determining the location, amount, availability, and quality of ground and surface water throughout the United States and its territories. About 75 to 80 percent of the water-quality samples used in this effort are analyzed by the National Water Quality Laboratory (NWQL). The NWQL determines organic and inorganic constituents in samples of ground and surface water, river and lake sediment, aquatic plant and animal material, and inprecipitation samples. The NWQL receives about 30,000 samples every year for chemical analysis.
