Investigation of Effects of Ground Water Withdrawals from the Pamet and Chequesset Aquifers, Cape Cod National Seashore
Martin L. 1993. Investigation of Effects of Ground Water Withdrawals from the Pamet and Chequesset Aquifers, Cape Cod National Seashore. Technical Report NPS/NRWRD/NRTR-93/14 (NPS D-110). National Park Service,Water Resource Division. Washington, DC
Groundwater is pumped from the Pamet aquifer on outer Cape Cod to supply Provincetown with potable water. Groundwater withdrawals cause the water table to be lowered, resulting in decreased freshwater discharge from the aquifer to the wetlands and riparian areas. Ecosystems in these natural discharge areas are dependent on freshwater discharge from the aquifer to maintain water levels, hydroperiods, salinity, balances, and normal soil/sediment chemistry. The volume of freshwater discharging along ocean shores is trivial compared with the seawater into which it mixes so reductions in this discharge are unlikely to affect ecological processes there. Computer simulations of groundwater flow were conducted to evaluate the relative impact of various groundwater withdrawal scenarios. Locations and rates of withdrawals were varied to evaluate the effects of both existing wellfields and potential new sites. In general, wellfields located closer to the groundwater discharge areas near wetlands and riparian areas will have a greater effect on freshwater discharge from the aquifers. Computer simulations predict that about half the water withdrawn at the Knowles Crossing wellfield will come from a reduction of freshwater discharging from the aquifer to the Salt Meadow and Pilgrim Lake. Groundwater withdrawals from the wells at the North Truro Air Base and South Hollow wellfield will have the least effect on freshwater discharge to wetlands and riparian areas at the southern and northern boundaries of the Pamet aquifer. A comprehensive groundwater management and development plan is needed to provide guidance to towns regarding the limits of potential groundwater supplies in the area.
- Type
- Published Report
- Authors
- Martin, Larry
- Date of Issue
- 1993-02
- Publisher
- National Park Service,Water Resource Division
- Units
- CACO , WRD
- Keywords
- Aquatic Sciences, Aquifer, Chequesset aquifer, Discharge, Ecosystems, Freshwater, Groundwater, Hydrology, hydroperiods, Impacts, Management, Models, Nutrients, Pamet aquifer, Riparian, Salinity, soil-sediment chemistry, Water Quality, Water Table, Wells, Wetlands, withdrawal