Ground-water resources of Chester County, Pennsylvania

Fifty gallons per minute (3 liters per second) or more may be obtained from wells in almost all parts of the county, but not at all locations. Adequate exploration to find fracture or solution openings is required. Five hundred gallons per minute (30 liters per second) or more may be obtained from some of the carbonate rocks. Linear features are visible on 1:1,000,000-to 1:24,000-scale aerial imagery. Many linear features, but not all, have geologic or hydrologic significance, and some may indicate fractured rock that might be tapped by wells. Dissolved-solids concentration of most ground water is less than 500 milligrams per liter. Chemical-quality problems are predominantly caused by acidity, iron and manganese, or nitrate. Base (ground-water) runoff during a near-average year, 1968, was about 420 million gallons per day (18 cubic meters per second).