The Catoctin Mountain National Park area, located in the Blue Ridge physiographic province of central Maryland, is characterized by high local relief, an average annual precipitation of 44 inches, and stony soils underlain by weathered and fractured metamorphic rocks. The park is mostly forested land and includes several camps and roads. The groundwater reservoir consists of regolith and underlying fractured bedrock and is recharged by precipitation. Discharge from the groundwater flow system is mainly to nearby streams adjacent to areas of recharge. Approximately 56% of annual streamflow is contributed by groundwater. Wells located at Camp Round Meadow and Staff Quarters No. 5 can sustain pumping rates of 45 to 60 gal/min for several hours, with drawdown of 40 to 50 ft. Water quality samples from wells, springs, and streams indicate that groundwater is slightly affected by septic waste and road salt. Groundwater in remote areas is not affected by either source. Concentrations of chloride from road salt and concentrations of nitrate plus nitrite (as N) were below U.S. EPA drinking water limits in all groundwater and surface water samples.
