AEC, as the lowest responsive bidder, was contracted by the Washington State Department of Ecology to perform excavation of approximately 6,300 cubic yards of contaminated near shore marine sediment and approximately 5,600 cubic yards of upland soil to depth of 12 ft. We also performed subsequent transportation and disposal of contaminated soil off site. In an effort to reach the extent of contamination in a tidally influenced area, AEC developed and deployed a specialized coffer dam system made of steel sheetpile shoring. We worked with a subcontractor to design an approved shoring system that allowed us to excavation below ordinary high water and 3 feet below the original mudline. The sheetpile was driven during periods of low tide directly into exposed sediment using a vibratory hammer. It was critical that the system achieved proper stable sidewall slopes and prevented water from inundating the excavation. Most importantly, the system allowed this project to be completed on time, on budget with less impact to the environment. Upon completion of the remedial excavation, all areas were graded and backfilled and AEC installed an upland multi-component environmental cap, consisting of specialized geo membrane materials and a total of approximately 19,000 cub yards of clean soil capping material. Lastly, we performed final planting and revegetation of disturbed areas and decommissioning of groundwater monitoring wells.