In the fall of 1997, 35 springs in the carbonate rocks of the Valley and Ridge Physiographic Province of the upper Tennessee River Basin were sampled for nutrients, fecal-indicator bacteria, pesticides, and volatile organic compounds (VOCs) as part of the National Water-Quality Assessment (NAWQA) Program. About half of the randomly selected springs were used as untreated domestic drinking-water supplies, either by direct pumpage from the spring or as roadside filling sites. Nutrient concentrations generally were less than 2 milligrams per liter. Nitrate, the most frequently detected nutrient, ranged from 0.091 to 2.17 milligrams per liter, with a median concentration of 1.16 milligrams per liter. Fecal-indicator bacteria were detected at all springs, with total coliform ranging from 10 to 1,900 colonies per 100 milliliters and Escherichia coli ranging from less than 1 to 660 colonies per 100 milliliters. Concentrations of bacteria at all springs sampled exceeded bacteriological drinking-water standards for public water supplies.
Eight pesticides or degradation byproducts, all below U.S. Environmental Protection Agency drinking-water maximum contaminant levels, were detected in samples from 24 of the 35 springs. The most frequently detected pesticide was atrazine and its degradation byproduct, deethylatrazine, which were found in water samples from 57 and 54 percent of the springs, respectively. Some pesticides were detected more frequently in water samples from the springs than in ground-water samples from wells in similar NAWQA studies nationwide. Concentrations of VOCs in the springs also were below maximum contaminant levels. The most frequently detected VOCs were chloroform (20 springs), methyl chloride (18 springs), styrene (12 springs), and tetrachloroethene (11 springs). These detection frequencies of VOCs are consistent with the national NAWQA results when comparing wells and springs in a mixture of urban and rural land uses.