Statewide baseline study, 1992 - 1996

The statewide baseline study, conducted between 1992 and 1996, established median and 95th percentile concentrations for chemicals in the state's principal aquifers and identified potential ground water quality concerns. Researchers collected 954 groundwater samples across Minnesota (see figure below). About 95% of the samples were obtained from private drinking water wells identified using County Well Index. To accomplish this, we used nine-square-mile grids established on 11 mile-centers. Within each grid, one sample was collected from each identified aquifer.

Comprehensive reports for each of the MPCA's six regions are linked below. Several fact sheets provide information for specific chemicals. Results are presented for 30 aquifers and seven aquifer groups.

Report series: Baseline water quality of Minnesota's principal aquifers

Groundwater sampling locations