| Abstract |
The 3,780-acre Wyckoff/Eagle Harbor site is located on the east side of Bainbridge Island, in Central Puget Sound, Kitsap County, Washington. The site consists of an inactive 40-acre wood treating facility owned by Wyckoff, the adjacent 500-acre Eagle Harbor and other upland sources of contamination to the Harbor, including a former shipyears. The selected remedial action for this site includes dredging, dewatering, excavating approximately 1,000 to 7,000 cubic yards of intertidal sediment that exceed levels of 5 mg/kg mercury and/or lower moderate PAH concentrations, followed by treatment using solidification/stabilization, if necessary, to comply with LDR as determined by bench scale tests; transporting sediment, which cannot be treated to meet LDR offsite for disposal at a RCRA-permitted landfill; treating wastewater from the dewatering process using carbon adsorption before discharge into the harbor; capping over sediment in areas of high concern with a 1-meter thick layer of clean sediment; placing a thin layer of clean sediment in subtidal areas of low to moderate concern to enhance natural sediment recovery; conducting long-term environmental monitoring; and implementing institutional controls to prevent exposure to contaminated fish and shellfish. The estimated present worth cost for this remedial action ranges from $6,200,000 to $16,000,000 which includes a present worth O&M cost of $1,100,000 for 10 years. |
