to characterize selected physical, chemical, and biological components of streams draining undeveloped, forested basins in North Carolina. Nine sampling sites were established on streams that drain forested basins ranging in size from 0.67 to 11.2 square miles. The basins were selected to represent drainage from each of five geochemical zones across the State. Samples for water-quality analyses were taken during low-flow and stormflow conditions and compared with precipitation analyses and streamflow analyses from an earlier study. The water analyses included specific conductance, dissolved oxygen, water temperature, suspended sediment, pH, major dissolved constituents, nutrients, minor constituents, organochlorine insecticides, and biochemical oxygen demand. Biological characteristics included sampling for fish tissue analyses for minor constituents and synthetic organic compounds, fish community structure, and benthic macroinvertebrates. Stream-water quality in undeveloped, forested basins is largely influenced by the quality of precipitation, soil and rocks, and the intensity of runoff. Precipitation is the source of about 10 to 40 percent of the chloride concentration in stormflows and constituted a greater percentage in the eastern half of the State. Mean concentrations of sulfate in precipitation commonly ranged between 20 and 30 percent of mean concentrations of sulfate in stormflow with no geographic distribution preference. Soil and rocks were the major source of the other major dissolved constituents and minor constituents. Mean total nitrogen concentrations ranged from 0.16 milligrams per liter during low-flow conditions to 1.2 milligrams per liter during stormflow. Organic nitrogen accounted for 60 to 85 percent of the total nitrogen concentration. The ratios of mean concentrations of total nitrogen to total phosphorus ranged, from 11:1 to 110:1 indicating that phosphorus is the limiting nutrient factor in stream water from forested basins. Stream water was free of organochlorine insecticides; but DDD, DDE, DDT, Lindane, and Mirex were detected in 18 of 60 samples of strearnbed material. Concentrations ranged from 0.1 to 3.3 micrograms per kilogram. About 35 percent of the fish tissue analyses showed detectable concentrations of copper, lead, mercury, and nickel. Compared with the North Carolina ambient fish tissue data base, two fish samples contained relatively high concentrations of mercury (0.34 and 0.30 milligram per kilogram), and one fish sample contained a relatively high lead concentration of 1.2 milligrams per kilogram. Synthetic organic chemicals were not detected in fish tissue. The fish community structure data were scored and rated using Karr's Index of Biotic Integrity as modified for North Carolina. The streams draining forested basins rated from poor to good primarily because of natural stresses on fish communities resulting from low-flow and no-flow conditions and from low nutrient conditions in these headwater streams. Other than nutrients, water quality was not a factor in these lo...
