EPA Cleanups: GE-Pittsfield/Housatonic River Site
Silver Lake - Overview
The Silver Lake Cleanup Area is located directly west of and across from Silver Lake Boulevard from the 30s Building Complex Removal Action Area (RAA) and includes the lake and its banks. It is bounded to north by Silver Lake Boulevard and Fourth Street, and the west and south by residential and commercial properties. Silver Lake is approximately 26 acres large with a maximum water depth of about 30 feet. The lake currently receives stormwater flow from several City outfalls and one NPDES-permitted outfall. The NDPES-permitted outfall receives stormwater from a portion of the GE Plant Area that has been transferred to PEDA. Silver Lake drains to the Housatonic River by an underground 48-inch diameter, concrete, culvert pipe located near the intersection of Fenn Street and East Street.
Silver Lake has a history of extensive contamination. PCBs have been detected in moderate to high amounts in the lake's sediment, bank soils and surface water. Historic discharges of PCBs and other chemicals in process water and wastewater from GE's operations have been reported.
Remediation of the Silver Lake Area
The Consent Decree and the August 2011 Final Removal Design/Removal Action Work Plan require that GE dredge 400 cubic yards of "hot spot" sediment adjacent to one of the historic GE outfalls, remove additional near-shore sediment around the perimeter of the lake, clean up contaminated bank soil, and place a silty sand-based cap on the entire bottom of the lake. A 2005 bench-scale study and a 2006 one-acre pilot project of capping techniques was conducted to assist in finalizing the design of an effective cap and material delivery system.
Full-scale remediation was imitated in the summer of 2012 and was substantially completed in December 2013. This consisted of the removal and off-site disposal of approximately 13,500 cubic yards of bank soil and sediment. The riverbanks were restored with clean fill and the sediment throughout the lake was capped. As part of the final bank restoration, a 2,000 foot long walking path was installed along the north and east shores, and over 1,000 native trees and shrubs were planted among native grasses and wildflowers. In addition, woody debris was placed in the near shore sediment areas to restore and enhance the wildlife habitat.
In 2014, GE initiated post-removal site control activities, including inspection, monitoring and maintenance activities, to verify that the cap is functioning as designed and to ensure other components of the remediation are functioning properly. Also, in 2014, GE is expected to submit for EPA review a draft Final Completion Report (FCR). Included in the Draft FCR will be a proposal for a final Post-Removal Site Control Plan.
Documents related to this portion of the cleanup are available under the "Reports" tab for the Silver Lake Area.