Scientists at the Savannah River Site in South Carolina are calling for more research to understand why mercury is being produced in local tributaries that flow into the Savannah River waterways and how the environment is impacted when that mercury discharges into the Savannah River. During a June 8 presentation to a committee of the SRS Citizens Advisory Board (CAB), Wendy Kuhne, a principal scientist with the Savannah River National Laboratory (SRNL), also said that a full inventory and multiyear studies are needed to determine mercury levels in surrounding, swampy areas. Though more information is needed, SRNL has concluded that mercury levels among fish in the Savannah River carry less levels of mercury than the fish in other South Carolina rivers.
Site officials have for years been examining ways to reduce the amount of mercury in the river, though they say it poses no direct threat to humans. During the committee meeting, Kuhne referenced a 2012 report from the Agency for Toxic Substances and Disease Registry (ASTDR). The agency noted that mercury is a nonradioactive contaminant, but is a chemical of concern based on records of measurement in the plants and animals of a region. “Mercury contamination in fish from the Savannah River, both upstream, along, and downstream of SRS, has been well documented,” the agency wrote. “However, the contribution of mercury from SRS-related activities to the river system is not known.”
While there are uncertainties about how much mercury is in the water, levels have been evaluated in a number of other ways, including measuring the average tissue concentrations in large-mouth bass at the mouths of the SRS streams into the Savannah River, and comparing that to South Carolina rivers in the Southeastern Plains. Results in a 2010 report from the South Carolina Department of Health and Environmental Control (SCDHEC) show that mercury levels in the Savannah River, near Aiken, S.C., are less than those found in the other rivers in the area, such as the Little Pee Dee River in Dillon, S.C.
Between 1959 and 1982, nearly 4,500 pounds of mercury were used to make nuclear weapons at SRS. The mercury has since been considered waste and resides in the site’s storage tanks, along with about 36 million gallons of liquid waste on-site.
