Salt Water Intrusion Testing and Monitoring

Tidal Signature in Coastal Well

Under its data collection program, the Plymouth Saltwater Intrusion Task Force installed a datalogging transducer in a coastal Ellisville well located about 450 feet from the shoreline. The transducer measured water level, specific conductance (SC) and temperature. The plot below shows how tidal variations in Cape Cod Bay affect water levels in the well. The salinity (expressed as SC) was not affected by tidal variations. Groundwater quality shows low salinity and is not impaired relative to drinking water standards.

A datalogging transducer installed in a near-shore Ellisville well shows the effect of tidal variations in Cape Cod Bay.

By Peter Schwartzman
August 7, 2023