Surface and Soil Projects
Aerial view of capped landfills
A major part of the overall site cleanup involved addressing contaminated soils, underground tanks, and waste storage areas. All of the major soil projects have now been completed and some additional actions have been taken based on surveillance and monitoring data. Following is a list of major surface and soil cleanup projects that have been completed since 1994:
- Three out-of-service 100,000 gallon aboveground waste tanks were removed and disposed of at a licensed off-site disposal facility.
- Sixteen underground storage tanks (USTs) were removed between 1988 and 2005 under the cleanup program. The project included the removal, transportation, and disposal of the tanks and approximately 4,000 cubic yards of soil and debris.
- The meadow marsh project was completed. It consisted of removing sediment contaminated with heavy metals from an area used in the 1960s to test sewage treatment methods. Since the meadow marsh site had become an important habitat for the endangered tiger salamander, many of them were removed and later returned to the site after the cleanup was complete and habitat restored. The clean-up was timed to occur when the salamanders were not present in the marsh and the restoration was specifically designed to support long term survival of the tiger salamander population in the area. Tiger salamanders began utilizing the restored wetland the first season after completion.
- Three landfills were capped. These landfills had been identified as continuing sources of groundwater contamination, because Volatile Organic Compounds had been discarded in the unlined landfills over the years. The capping process eliminated that source of contamination by preventing rainwater infiltration and leaching of the contaminants.
- Landfill pits that were used between the 1960s and 1981 for disposal of laboratory chemicals and glassware were excavated. Broken glass and still intact bottles of chemicals were segregated and sent to a licensed off-site facility for disposal.
- The Building 650 sump and sump outfall project was completed. Building 650, which was the Reclamation Facility, was used for decontaminating radioactively contaminated clothing and heavy equipment. A sloping concrete pad where contaminated water from the steam cleaning operation collected was known as the Building 650 sump. Use of the concrete pad was discontinued in 1969. An estimated 1,800 cubic yards of contaminated concrete, piping, and soil were removed from the building and associated drainage area. The 650 sump area has become suitable tiger salamander habitat and is now managed for them.
- Landscape soils were excavated from several areas on site. About 2,800 cubic yards of soils containing low levels of cesium-137 were excavated from 12 separate areas. Landscape soils were identified as the primary source of cesium-137 in deer. Since completion of the clean-up of these soils, the level of cesium-137 in deer has dropped to or near background levels.
- The Former Hazardous Waste Management Facility was decommissioned and decontaminated in 2005. This project included demolition of eight buildings and the excavation and removal of 13,000 cubic yards of contaminated soils. Since the initial cleanup, additional soil removal actions have been taken around the perimeter of the facility. Phase 1 of the FHWMF Perimeter Soils project removed soils contaminated from facility runoff. Phase 2 removed contamination in an area to be utilized by the L. I. Solar Farm, and under Phase 3, approximately 600 cubic yards of soil is expected to be removed. Phase 3, to be completed in FY14, will finish the project.