USGS Map Reveals Long-Term Changes in America’s Groundwater Quality

Chloride and nitrate concentrations are rising and arsenic levels are holding steady or falling. Those are two of the conclusions from a U.S. Geological Survey assessment of changes in the nation’s groundwater quality in the last two decades. The federal science agency published the results on Thursday in an interactive online map.

The contaminants in the assessment are a roster of two dozen undesirable intruders that can cause health and environmental damage if not cleansed before consumption: cancer-causing chemicals, radioactive elements, and nutrients that foul the Great Lakes and Gulf of Mexico with algae.

More than 140 million people in the United States use groundwater as their primary source of drinking water. Of that group, some 45 million people use private wells, which are not subjected to the same legally enforceable quality standards as water utilities and therefore more vulnerable to contamination… Read more from Circle of Blue