The Eagle Harbor West Operable Unit NPL Site remediation involved the mitigation of contaminated sediments and upland soil contamination by dredging, excavation, treatment and placement of material within a confined disposal facility constructed onsite.  Soils were impacted with lead and mercury associated with paint and blasting grits utilized in the repair and maintenance of ships during and after World War II.

Upland soils were excavated, cement stabilized in Wilder’s pugmill plant and placed onsite in a one-acre, confined disposal facility.  A groundwater intercept and diversion trench was installed to eliminate intrusion to the placed material. Two 10,000-gallon diesel/bunker and one 2,000-gallon gasoline underground storage tanks were also removed.  Approximately 1,000 tons of TPH contaminated soil were hauled and disposed of in a subtitle D landfill. 

Highly contaminated marine sediments were removed by clamshell dredging to depths in excess of 30 feet and placed within an onsite disposal facility designed to accommodate tidal influences.  Because of the non-leaching characteristics of the heavy metals in marine conditions, the disposal facility design allows for seawater to infiltrate into the cell, thereby maintaining the non-leaching properties of the sediments, but restricts the exfiltration of seawater.  Sediments with lead and mercury concentrations in excess of the site action levels, but less than the removal criteria, were isolated and contained by in-place capping.  Both thin and thick layer caps were constructed as dictated by heavy metal concentrations.  All upland and CDF placement area surfaces were completed to final grade with imported buffer material and the installation of an impermeable asphalt cap.

The project was constructed from May to October of 1997 in close coordination with Washington State Ferries’ maintenance facility adjacent to, and sharing, the site.  The U.S. Environmental Protection Agency oversaw the project.  The State of Washington Departments of Fisheries, Transportation, Ecology, and  Natural Resources formed the Technical Steering Committee to coordinate governmental interests and responses during this privately funded Superfund action.  Wilder achieved all EPA mandated deadlines and milestones well ahead of schedule.  Upon completion of site remediation, the site was capped with asphalt and turned over to the Washington State Ferries for use in on-going operations.