Water quality in U.S. wells


  • Randy Showstack


More than 20% of private domestic wells sampled nationwide contain at least one contaminant at levels of potential health concern, according to a study released on 27 March by the U.S. Geological Survey (USGS). About 43 million people—or 15% of the U.S. population—use drinking water from private wells, which are not regulated by the federal Safe Drinking Water Act. In sampling about 2100 private wells in 48 states, USGS scientists found that the contaminants most frequently measured at concentrations of potential health concern were inorganic contaminants, including radon and arsenic, which are mostly derived from the natural geologic materials that make up the aquifers from which well water is drawn.