Assessment of the Release of Floodplain Mercury Source to Downstream Aqueous Mercury in the Watershed of Oak Ridge, TN.

Historically as part of its national security mission, the U.S. Department of Energy’s Y-12 National Security Facility in Oak Ridge, TN, USA acquired a significant fraction of the world’s supply of elemental mercury. During the 1950’s and 1960’s, a large amount of elemental mercury escaped confinement and is still present in the buildings and grounds of the Y-12 Facility and in the Y-12 Watershed. Because of the adverse effects of elemental mercury and mercury compounds upon human health, the Oak Ridge Site is engaged in an on-going effort to monitor and remediate the area. The main thrust of the Oak Ridge mercury remediation effort is currently scheduled for implementation in FY09. In order to more cost effectively implement those extensive remediation efforts, it is necessary now to obtain an improved understanding of the role that mercury and mercury compounds play in the Oak Ridge ecosystem.

Most recently, concentrations of both total mercury and methylmercury in fish and water of lower East Fork Poplar Creek (LEFPC) of Oak Ridge increased. This drives the US DOE and the Oak Ridge Site to study the long-term bioavailability of mercury and speciation at the site.The release of mercury from floodplain source of East Pork Poplar Creek of Oak Ridge, Tennessee has been investigated. A series surface, subsurface and creek sediment have been sampled from the LEFPC. The mercury release from various sizes of particles of these samples will be presented, which aims to simulate the field surface runoff processes. The overall assessment of the role of floodplain mercury in contribution to downstream aqueous mercury in the creek will be summarized.