This property consists of two upland parcels that historically operated as an automotive repair facility adjacent to the Ballard Metal Works and as a Seattle utility pipe treatment facility. In 2007, SoundEarth Strategies coordinated the excavation of 20,000 tons of soil contaminated with metals, polycyclic aromatic hydrocarbons (PAHs), and petroleum hydrocarbons to facilitate development of a mixed use, retail and commercial building.
In conjunction with providing construction and remediation oversight on that parcel, SoundEarth also conducted a remedial investigation on the southernmost parcel. For the remedial investigation, we developed a conceptual site model that described the site’s physical characteristics (artesian wells, extensive utility corridors, exposure pathways) and evaluated the fate and transport of the metals and PAHs in the subsurface and surface soil. Based on findings from these investigations and associated historical research, the site of the former pipe treatment facility was defined to include metals-, PAH-, and petroleum hydrocarbon-contaminated soil both on the property and within the adjoining rights-of-way, as well as arsenic- and petroleum hydrocarbon-contaminated groundwater beneath the property. Based on the results of the RI and a feasibility study, and with the concurrence of the Washington State Department of Ecology, a combination of cleanup alternatives was selected, including installing an impervious shoring wall, excavating PAH- and arsenic-contaminated soil from within the proposed redevelopment footprint, capping contaminated soil beyond the boundaries of the proposed shoring system, and monitoring the discharge of arsenic-contaminated water within the building’s subgrade water intrusion control system.