What geographic areas are covered in the NAWQA design?
NAWQA monitoring and assessment of nutrients were conducted in 51 major river basins and aquifer systems (referred to as “Study Units,”). Study units extend from Florida to the Pacific Northwest and including Hawaii and Alaska, plus the High Plains Regional Ground Water Study. Collectively, these areas account for more than 70 percent of total water use (excluding thermoelectric and hydropower), and more than 50 percent of the Nation’s supply of drinking water. The areas are representative of the Nation’s major hydrologic landscape settings, and agricultural and urban sources of nutrients. (Go to the NAWQA web site for a map of Study Units.) In addition, selected streams and groundwater were sampled through 2004 to assess the effects of nutrient enrichment (high concentrations of nutrients) on stream ecosystems and to assess trends in nutrient concentrations.
