RESTON, Va., Feb. 11 (UPI) — U.S. Geological Survey scientists say they have discovered how and when contaminants might reach public-supply wells.
The researchers said public wells that supply drinking water to more than 100 million people in the United States are not equally vulnerable to contamination because of differences in three factors: The general chemistry of the aquifer, groundwater age and direct paths within aquifer systems that allow water and contaminants to reach a well.
The wells, however, can be vulnerable to naturally occurring contaminants such as radon, uranium, arsenic and man-made compounds, including fertilizers, septic-tank leachate, solvents and gasoline hydrocarbons.
The USGS study tracked the movement of contaminants in groundwater and in public-supply wells in four aquifers in California, Connecticut, Nebraska and Florida. The researchers said they found the importance of each factor differs among the various aquifer settings, depending upon natural geology and local aquifer conditions, as well as human activities related to land use and well construction and operation.
“Our findings can help public-supply well managers protect drinking water sources by prioritizing their monitoring programs and improving decisions related to land use planning, well modifications or changes in pumping scenarios that might help to reduce movement of contaminants to wells,” said Sandra Eberts, who led the research.
The full report as well as additional information is available at http://oh.water.usgs.gov/tanc/NAWQATANC.htm.
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