Groundwater provides nearly 50 percent of the Nation’s drinking water. To help protect this vital resource,the U.
S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) Project assesses groundwater quality in aquifers that are considerable sources of drinking water (Burow and Belitz, 2014). The glacial aquifer system constitutes one of the considerable areas being evaluated.
Source: usgs.gov