How Vulnerable are Public-Supply Wells?

The USGS has conducted a new study to determine the contaminant vulnerability of public-supply wells around the country, and also to discover which pollutants in an aquifer will make their way into those wells.

In the U.S. Geological Survey (USGS) public-supply well study, ten study areas were the main focus. Those areas included Modesto, Calif., Woodbury, Conn., near Tampa, Fla., York, Nebr., near Carson City and Sparks, Nev., Glassboro, N. J., Albuquerque, N. Mex., Dayton, Ohio, San Antonio, Tex., and Salt Lake City, Utah.

"Improving the understanding of the vulnerability of public-supply wells to contamination is needed to safeguard public health and prevent future contamination," said Suzette Kimball, acting USGS Director. "By examining ten different aquifers across the nation, we have a more thorough and robust understanding of the complexities and factors affecting water quality in our public supplies."

Results of the study indicated that some aquifers allow contaminants to stay in groundwater longer or travel to wells much quicker than other aquifers because of direct pathways, such as fractures in rocks or wellbores of non-pumping wells. Irrigation and high-volume pumping were also found as human-induced contaminants in groundwater. Arsenic and uranium were found as natural contaminants in drinking water as a result of geochemical changes.