Ground-water levels in the lower Paleozoic and Precambrian crystalline rocks, southeastern Chester County, Pennsylvania, July and August 1986

A water table contour map of the lower Paleozoic and Precambrian crystalline rocks of southeastern Chester County, Pennsylvania was constructed on the basis of water levels measured in 261 wells in July and August 1986, elevations of 11 springs that were flowing in July and August 1986, and water levels measured in 15 wells. Pre-1986 measurements were incorporated on the map to provide control in areas where more-recent data were not available. The area of crystalline rocks underlies Thornbury, Westtown, East Goshen, and West Goshen Townships, parts of East Whiteland and West Whiteland Townships; and West Chester Borough. Water table altitudes under natural conditions range from 544 ft. above National Geodetic Vertical Datum of 1929 (NGVD of 1929) near Immaculata College to 234 ft. above NGVD of 1929 near Cheyney College.