Considerations for monitoring water quality of the Schenectady aquifer, Schenectady County, New York

Six public water-supply systems in Schenectady County, N.Y., obtain water from sand and gravel units that form a more or less continuous aquifer system contiguous to the Mohawk River. The aquifer is under water-table conditions and in hydraulic contact with the river, so that pumping wells induces recharge from the river. Direct recharge to the aquifer from precipitation and runoff occurs throughout the valley floor. Chemical analyses since 1972 have indicated no water-quality deterioration from toxic substances, including pesticides. Geohydrologic conditions at each of the six well fields were evaluated to determine the feasibility of a monitoring system to provide warning of contamination before it reaches a pumping center. Potential contamination sources in the area are landfills, gravel pits, industrial sites, and transportation corridors. Only two of the well fields have wells that could be used for monitoring; at most sites, two or more wells would need to be installed to provide minimal means of detecting contaminants migrating toward a pumping center. (USGS)