Preliminary screening of contaminants in the off-site surface water environment downstream of the US Department of Energy Oak Ridge Reservation. Environmental Restoration Program

摘要

Previously reported concentrations of radionuclides and of inorganic and organic compounds in the surface water environment off-site of the US Department of Energy/Oak Ridge Reservation (DOE/ORR) suggest the presence of a large number of substances of possible concern to the protection of human health and the ecosystem. Screening of these data, as part of the initial scoping phase of the Clinch River Resource Conservation and Recovery Act Facility Investigation, is necessary to develop a field sampling plan for the acquisition of additional data through the identification of potential contaminants of concern for further evaluation and investigation. The results of this report are based on human health risk end points. For the purposes of screening, conservative and nonconservative estimates of potential maximum exposures were used to identify, respectively, definitely low- and definitely high-priority pollutants. Because of relatively high concentrations of contaminants in sediment, the presence of industrial and agricultural wastes not related to DOE/ORR operations, and the use of a lifetime risk for carcinogens of 10(sup (minus)6) as a lower screening criterion, no surface water reach considered in this study was identified as low priority. In contrast to this result, three contaminants, arsenic in water and thallium in fish of McCoy Branch and (sup 137)Cs in the sediment of the White Oak Creek embayment downstream from White Oak Lake, were tentatively identified as definitely high-priority substances. These locations are within the boundaries of ORR. Nonconservative estimates of exposure identified arsenic, antimony, thallium, uranium, polychlorinated biphenyls 1254 and 1260, chlordane, (sup 60)Co, and (sup 234)Pa as potentially high-priority contaminants in at least one or more locations. These are the contaminants that should receive the most scrutiny in future investigations.