Water-Quality Assessments of Principal Aquifers

Background A major focus of the NAWQA Program in its second decade (2002-2013) is on regional- and national-scale assessments of groundwater-quality status and trends in principal aquifers. The U.S. Geological Survey Office of Groundwater has identified 62 principal aquifers in the U.S. ( U.S. Geological Survey, 2003 ). About 1/3 of the Nation's principal aquifers are the focus of water-quality assessments at the regional scale by NAWQA. The NAWQA framework for principal aquifer assessments considers the physical setting of the aquifer, in addition to its susceptibility and vulnerability to contamination. More information (USGS Fact Sheet 2005-3013, PDF, Adobe reader is freely available to read a PDF) Publications Contact Information [...]