MassGIS produced an aquifer datalayer composed of 20 individual panels, generally based on the boundaries of the major drainage basins. Areas of high and medium yield were mapped. These panels, which were retiled for Librarian in the BASIN library, are called AQ. The layer is named AQUIFERS. The SDE layer is named AQUIFERS_POLY.
Aquifer polygons were not delineated for Cape Cod and the Elizabeth Islands. These areas in their entirety are considered by the Massachusetts Contingency Plan (MCP) as medium yield aquifers. The areas of Martha's Vineyard and Nantucket not delineated as high yield aquifers are also considered as medium yield under the MCP.
This datalayer NO LONGER includes polygon attribute coding to help in the identification of areas in which clean up of hazardous waste sites must meet drinking water standards, as defined in the Massachusetts Contingency Plan (MCP) (310 CMR 40.0000). Please refer to the DEP NPDWSA Datalayer for areas that are defined as Non Potential Drinking Water Source Areas.