The Quail Hollow Landfill, located in southeastern Bedford County on the Highland Rim overlooking the Central Basin karst region of Tennessee, is constructed on the gravelly, clay-rich residuum of the Fort Payne Formation of Mississippian age. A conceptual hydrologic model of the landfill indicated that Anderton Branch was at risk of being affected by the landfill. Ground water flowing beneath the landfill mixes with percolating rainwater that has passed through the landfill and discharges to the surface from numerous weeps, seeps, and springs present in the area. Anderton Branch, adjacent to the landfill site on the north and east, receives most of the discharge from these weeps, seeps, and springs. Anderton Branch also receives water from the Powell Branch drainage basin to the west and south because of diverted flow of ground water through Harrison Spring Cave. The U.S. Geological Survey, in cooperation with the Bedford County Solid Waste Authority, conducted a study to evaluate the effect of the Quail Hollow Landfill on ground- and surface-water quality. During storm runoff, specific conductance was elevated, and cadmium, iron, manganese, lead, and nickel concentrations in Anderton Branch frequently exceeded maximum contaminant levels for drinking water for the State of Tennessee. High chloride inputs to Anderton Branch were detected at two locations?a barnyard straddling the stream and a tributary draining a pond that receives water directly from the landfill. The chloride inputs probably contribute to chloride load levels that are three times higher for Anderton Branch than for the control stream Anthony Branch. Although toxic volatile organic compounds were detected in water from monitoring wells at the landfill, no organic contaminants were detected in domestic water wells adjacent to the landfill or in Anderton Branch. Sons Spring, a karst spring near the landfill, has been affected by the landfill as indicated by an increase in chloride concentrations from 4 milligrams per liter in 1974 to 59 milligrams per liter in 1996. Analysis of water samples from Sons Spring detected concentrations of nickel that exceeded primary drinking-water standards and Tennessee Department of Environment and Conservation fish and aquatic life chronic standards. Trichloroethene, 1,1-dichloroethene, and 1,1-dichloroethane also were detected at Sons Spring. The presence of these chlorinated solvents imply the landfill origin of the contaminants in Sons Spring. Continuous monitoring at Sons Spring indicated a pattern of decreased specific conductance and lower contaminant concentrations after a storm. Contaminant concentrations increased with specific conductance to pre-storm levels after several days. The benthic macroinvertebrate community in Anderton Branch adjacent to the landfill was not different from the communities at control sites upstream and in Anthony Branch. Sons Spring, however, has low abundance and numbers of benthic macroinvertebrate taxa. Toxicity studies using Ceriodaphnia dubia indicated no toxicity in the base flow or storm water in Anderton Branch or in a tributary draining a pond that receives water from the landfill and Sons Spring; however, water collected from Sons Spring resulted in 100 percent mortality to all organisms within 48 hours. High concentrations of nickel were detected in crayfish tissue from control sites and Anderton Branch. Analysis of sediment samples also indicates nickel concentrations are high at control sites upstream of the landfill. Increased levels of the biomarker metallothionein detected in crayfish from Anderton Branch likely are not caused by nickel or cadmium because the levels present in the tissue are not correlated with metallothionein levels. Despite the high levels of certain metals in Anderton Branch during storm flow, the lack of toxicity and the health of the benthic community imply no detectable negative effect from the landfill to the stream. Sons Spring, howe