New USGS Maps Show Areas Where Groundwater is Important Source of Drinking Water for Homeowners

New U.S. Geological Survey maps show where people across the Nation rely on private wells for their drinking water. The maps will help determine where focused groundwater-quality testing or further studies are needed to help ensure safe drinking water from private wells.
Groundwater is an unseen but crucial resource for drinking water. Over 44 million people in the U.S. rely on private wells for their drinking water.  The maps estimate the number of people using private wells in a given area, but do not show individual wells.  Until now, areas where private wells are predominantly used were not well known.
This study was done by the USGS National Water-Quality Assessment Project, which conducts regional and national assessments of the Nation’s water quality to provide an understanding of current water-quality conditions, whether conditions are getting better or worse over time, and how natural processes and human activities affect those conditions.