Updated USGS Ground Water Quality Mapper

The U.S. Geological Survey (USGS) National Water Quality Program has updated its interactive web tool that maps decadal changes in groundwater quality across the nation. The web tool, Decadal Change in Groundwater Quality, now includes more groundwater well networks and data analyzed over a longer time span. In the update, groundwater quality data were added for an additional 218 wells in 6 well networks, increasing the number of wells to 1,718 and the number of well networks to 73.  Additionally, data for 14 well networks resampled during 2012–14 were incorporated, allowing the user to visualize changes across three roughly decadal sampling events for those networks since the 1990s.

Users of the web tool can easily visualize changes in both inorganic and organic constituent concentrations in groundwater, including chloride, nitrate, several pesticides, and some drinking-water disinfection byproducts. The website also includes a description of the methods used to evaluate changes in groundwater quality and a link to the complete set of data. For additional information on the groundwater-quality web tool, or for data and methods used, contact Bruce Lindsey (blindsey@usgs.gov).