Since 1984, the U.S. Geological Survey (USGS) has been mapping the altitude and configuration of the potentiometric surface in Chester County as part of an ongoing cooperative program to measure and describe the water resources of the county. Areas where the potentiometric surface has been mapped are shown on figure 1. These maps can be used to determine the general direction of ground-water flow and are frequently referenced by municipalities and developers to evaluate ground-water conditions for water supply and resource-protection requirements (Wood, 1998).
The maps shows the potentiometric surface for an area along the western boundary of Chester County that includes parts of East Nottingham and West Nottingham Townships. The study area is mostly uderlain by metamorphic rocks of the Peters Creek Schist and Wissahickon Formation(Sloto, 1994). Ground water is obtained from these bedrock formations by wells that intercept fractures.