SREL Reprint #3289

Are U, Ni, and Hg an Environmental Risk within a RCRA/CERCLA Unit on the U.S. Department of Energy's Savannah River Site?

Paul G. Edwards1, Karen F. Gaines1, A. Lawrence Bryan, Jr.2, James M. Novak1, and Susan A. Blas3

1Department of Biological Sciences, Eastern Illinois University, Charleston, IL, USA
2Savannah River Ecology Laboratory, University of Georgia, Aiken, SC, USA
3Savannah River Nuclear Solutions, Savannah River Site, Aiken, SC, USA

Abstract: The U.S. Department of Energy’s Savannah River Site (SRS) is a former nuclear weapon production facility. From 1954–1985, releases of Al, Cu, Cr, Hg, Ni, Pb, U, and Zn were discharged into the Tims Branch-Steed Pond water system. This study investigates whether metal concentrations in Tims Branch’s sediment, biofilm, and other biota exceed screening level risk calculations to determine if remedial actions should be pursued for the Contaminants of Potential Concern (U, Ni, Hg). Transfer factors (TFs) were calculated to determine metal concentration changes throughout lower trophic levels and results were compared with sediment benchmarks to create hazard quotients (HQs) to assess risk and a scientific-management decision point. Most TFs for Ni and U from lower to higher trophic level biota were <1, suggesting no biomagnifications; however HQs > 1 and cumulative distributions showed the majority of the samples exceeded action levels. Elevated TFs and HQs > 1 in the upper trophic levels for Hg indicated a high degree of bioavailability and biomagnification. Monte Carlo resampling analyses supported these empirical results. This system should continue to be closely monitored to ensure that contamination does not move off the SRS.

Keywords: hazard quotient, mercury, nickel, RCRA/CERCLA, transfer factors, uranium

SREL Reprint #3289

Edwards, P. G., K. F. Gaines, A. L. Bryan, Jr., J. M. Novak, and S. A. Blas. 2014. Are U, Ni, and Hg an Environmental Risk within a RCRA/CERCLA Unit on the U.S. Department of Energy's Savannah River Site? Human and Ecological Risk Assessment 20(2014): 1565-1589.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).