Geology topics

Research about Swatara Creek

Source-linked reports with geographic coverage including Swatara Creek.

3 recordsLinked to original sources

USGS2000

Relations among sulfate, metals, sediment, and streamflow data for a stream draining a coal-mined watershed in East-Central Pennsylvania

Streamflow and water-quality data for the northern part of Swatara Creek, which drains a 112-km 2 area in the Southern Anthracite Field of east-central Pennsylvania, indicate iron, copper, and lead, and to a lesser extent manganese and zinc, are transported with suspended particles during stormflow conditions. During stormflow conditions, concentrations of these constituents typically peak prior to peak stream stage as a result of scour and transport of streambed deposits. In contrast, sulfate is transported mostly as a dissolved ion. Concentrations of sulfate, specific conductance, and pH are inversely related to streamflow, indicating dilution and acidification during stormflow. This effect is attributed to the mixing of poorly buffered stream water having pH 6.0-6.5 with weakly acidic storm runoff having pH 4.0-4.5 and low dissolved solids.

Pennsylvania↗

USGS1988

Preimpoundment hydrologic conditions in the Swatara Creek (1981-84) and estimated postimpoundment water quality in and downstream from the planned Swatara State Park Reservoir, Lebanon and Schuylkill counties, Pennsylvania

The hydrology and water quality of Swatara Creek were studied by the U.S. Geological Survey in cooperation with the Pennsylvania Department of Environmental Resources, Bureau of State Parks, from July 1981 through September 1984. The purpose of the study was to determine the effects of anthracite-coal mining and other point and nonpoint sources on the water quality of a planned 10,500 acre-foot reservoir. The Swatara State Park Reservoir is planned to be used for recreation and drinking-water supply for the city of Lebanon and surrounding communities. Annual precipitation during 1982, 1983, and 1984 was about 8 percent below, near normal, and 29 percent above the long-term average, respectively. The average annual precipitation during a year with near-normal precipitation, the 1983 water year, was 47 inches at Pine Grove. Mean streamflows during 1982, 1983, and 1984 were about 15 percent below, 4 percent above, and 50 percent above the long-term average, respectively. The average streamflow to the planned reservoir area during the 1983 water year was about 220 cubic feet per second. Inflows to, and downstream discharge from, the planned reservoir wer poorly buffered. Median alkalinity ranged from 4 to 7 mg/L (milligrams per liter) and median acidity ranged from 2 to 5 mg/L at the three sampling locations. Maximum total-recoverable iron, aluminum, and manganese concentrations were 100,000, 66,000, and 2,300 micrograms per liter, respectively. During 1983 the annual discharges of total-recoverable iron, aluminum, and manganese to the planned reservoir area were estimated to be 692, 300, and 95 tons, respectively. About 87 percent of the total-recoverable iron and 91 percent of total-recoverable sluminum measured was in the suspended phase. The data indicated that mine drainage affects the quality of Swatara Creek and will affect the quality of the planned reservoir. In addition to mine drainage, point-source nutrient and metal discharges will probably affect the planned reservoir. For example, in September 1983, Swatara Creek was sampled downstream from a point source. A dissolved- phosphorus concentration of 14 mg/L and total ammonia plus organic nitrogen concentration of 8.2 mg/L were measured. At the same location, concentrations of total-recoverable aluminum, chromium, copper, iron, and lead were 35, 300, 110, 1,300, and 32 micrograms per liter, respectively. Inflows to the planned Swatara State Park Reservoir are estimated to be acidic and rich in nutrients and select metals. Unless an effort is made to improve the quality of water from point and nonpoint sources, these conditions may impair the planned uses for the reservoir. Conservation releases from the reservoir need to be carefully controlled or these conditions also may degrade the water quality downstream.

Pennsylvania↗

USGS1986

Results of a preimpoundment water-quality study of Swatara Creek, Pennsylvania

The water quality of Swatara Creek prior to impoundment by the proposed Swatara Creek Reservoir in south-central Pennsylvania was studied from July 1981 through October 1982. The report, done in cooperation with the Pennsylvania Department of Environmental Resources (PaDER), Bureau of State Parks, presents information on existing water-quality conditions. A discussion of possible water-quality conditions in and downstream from the planned impoundment is also included. Precipitation measured near the study area at Lebanon, Pennsylvania from October 1981 through September 1982 was 8 percent below normal. Streamflow for the same period at Swatara Creek at Harper Tavern just downstream from the study area was 15 percent below the average annual flow. Swatara Creek above Highway 895 has been degraded by acid mine drainage. The main inflow to the planned impoundment has 2.1 times the discharge of Lower Little Swatara Creek--a forested and agricultural basin that is also tributary to the proposed impoundment. During the 1982 water year, 17,400 tons of suspended sediment were transported from the study area. About 46 percent of the annual load was transported during 3 days of high flow. Inflows to the planned impoundment from both Lower Little Swatara Creek and Swatara Creek above Highway 895 were poorly buffered. Measured concentrations of alkalinity and acidity were usually less than 10 mg/L (milligrams per liter) and 5 mg/L as CaCO3, respectively. The inflows contain high concentrations of nutrients and metals that would probably stratify in a reservoir. Maximum concentrations of dissolved nitrate and total phosphorus were 2.6 mg/L and 0.31 mg/L, respectively. At Lower Little Swatara Creek; these concentrations are well above those needed for growth of algae. Maximum observed concentrations for total recoverable iron, aluminum, and manganese at Swatara Creek above Highway 895 at Pine Grove were 100,000 ug/L (micrograms per liter), 66,000 ug/L, and 2,300 ug/L, respectively. Large increases in metal concentrations along with simultaneous decreases in pH and increases in acidity confirm that mine drainage continues to degrade the water quality of Swatara Creek and may have a large impact on water quality of the planned impoundment. Iron, lead, copper, and zinc concentrations periodically exceeded the U.S. Environmental Protection Agency (U.S. EPA) criteria for freshwater aquatic life. Concentrations of manganese and lead also exceeded the U.S. EPA criteria for domestic water supplies and human health, respectively. The water quality of the Swatara Creek Reservoir will depend on characteristics such as (1) the detention time of water in the lake, (2) the timing and extent of thermal and chemical stratification, (3) sedimentation, and (4) the chemical loading and concentrations in the lake. Each of these characteristics may depend in part, on streamflow. The impoundment will act as a sediment trap and thus reduce the concentrations of total phosphorus, iron, aluminum, lead, copper, and zinc immediately downstream from the impoundment. Large storm discharges and releases from the hypolimnion of the reservoir to attain the winter-pool level may contain low oxygen concentrations and elevated concentrations of iron, aluminum, lead, copper, and zinc. Unless conservation releases from the multi-level release gates are carefully controlled, low dissolved-oxygen levels and high metal concentrations may degrade the downstream water quality and be detrimental to the aquatic community.

Pennsylvania↗