*To ensure the images in the report print correctly, select "Advanced > Print as Image" from the print dialog box.
This compilation includes only the counties with existing pollution sensitivity maps for the bedrock surface and units. As future county atlas work continues, new counties will be added to this compilation.
The pollution sensitivity rating corresponds to estimated travel time through the glacial sediments burying the bedrock surface. as defined by the Geologic Sensitivity Workgroup (1991). The assumptions that relate the geologic factors to travel time were tested with chemistry data from groundwater samples (e.g., tritium age and carbon-14). For more information see the Definition of pollution sensitivity.
This statewide atlas for the pollution sensitivity of the bedrock surface respects the legacy of the previous maps, with minimal alterations made to the original product data. The county maps were created by various authors using different geologic factors. A unified rating code was applied for ease of use and visual continuity based on the current geological sensitivity rating for bedrock as defined by vertical travel time (Geologic Sensitivity Workgroup, 1991).