National Water-Quality Assessment (NAWQA) Program
Domestic wells sampled in this study (colored circles) are located in 48 states and within 30 regionally extensive aquifers used for water supply in the United States. The aquifers represented by wells in the study are shown, with aquifers and symbols for well locations color-shaded to indicate aquifer rock or sediment type.
This study from the National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey (USGS) assesses 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. The large number of contaminants assessed and the broad geographic coverage of the present study provides a foundation for an improved understanding of the quality of water from the major aquifers tapped by domestic supply wells in the United States.
The results of this study are described in two USGS publications, including an overview of the study findings (Circular 1332) and a detailed technical report on data sources, analyses, and results (Scientific Investigations Report 2008-5227). Both publications can be downloaded in PDF format from the NAWQA website (see below). Also available in PDF format are two related articles in the Water Well Journal of the National Ground Water Association, which briefly summarize USGS study findings and general information on domestic well maintenance, siting, and testing.
Maps, graphics, and tables
Frequently Asked Questions
Presentation of Findings to Congress on March 27, 2009
-- Power point slides
-- Text to accompany power point slides
U.S. Geological Survey
10 Bearfoot Road
Northborough, MA 01532