Remedial Investigations Begin at Sewage Treatment Plant


The Operable Unit V Remedial Investigation (RI) of the Sewage Treatment Plant (STP) began in 1995. The RI is the first of many steps in the Superfund process. During the RI, sampling was conducted at the STP and in the Peconic River where the STP outfall was located. Elevated levels of mercury and silver and low levels of radionuclides including Cesium-137 were found in soils. PBCs were found downstream of the plants discharge site, and radionuclides and mercury and silver were also detected in sediment in the Peconic River. VOCs (trichloroethene) and tritium were found in the groundwater on and off site.

Following the completion of the RI, a Feasibility Study and preferred remedy were released for public comment in 2000. After considering community input the Department of Energy decided to separate cleanup of the STP (Area of Concern 4) from the cleanup of the Peconic River (Area of Concern 30).

To learn more on the cleanup of these two areas click on the STP and Peconic River listings under the Topological heading in the menu bar above or the Records of Decision below.

OU V STP Record of Decision

OU V Peconic River Record of Decision