- November 14, 2022
McAlister GeoScience, doing business as EcoCompliance Corporation, and in cooperation with the Washington Department of Ecology, engaged in a Voluntary Cleanup Program located at an undeveloped property in Lacey, Washington. The Subject Property is situated within the area of Asarco Smelter Plume arsenic and lead contamination.
The Washington Department of Ecology (DOE) has conducted studies of potential arsenic and lead contamination in soil from air emissions from the former Asarco Smelter in Tacoma and surrounding areas. Based on these studies, the Subject Property is located within the Asarco Smelter plume area. Asarco Smelter began metal smelting operations in 1890 and would have impacted the Subject Property.
In communication with the DOE, EcoCompliance Corporation has analyzed soil samples from 0-6 inches below ground surface (bgs), 6-12 inches bgs, as well as a duff layer, deposited by the Asarco Smelter Plume, on the surface soil. From 0-6 inches bgs, average arsenic concentration was 12.4 mg/kg, and average lead concentration was 23.7 mg/kg. From 6-12 inches bgs, average arsenic concentration was 7.8 mg/kg, and average lead concentration was 6.9 mg/kg. Both results are below the Model Toxics Control Act (MTCA) Method A cleanup levels, of arsenic at 20 mg/kg, and lead at 250 mg/kg.
With the duff layer having an arsenic concentration of 5 mg/kg and lead concentration of 59 mg/kg, analytical results clearly displayed lead and arsenic concentrations decreasing with depth. With these results, EcoCompliance Corporation recommended the method of mixing surface soil to remediate the Asarco Smelter Plume contamination on the Subject Property. This method has been utilized at several other properties in the area affected by the former Asarco Smelter and overseen by the DOE. Additional sampling of soil at the Subject Property after performance of the soil mixing remedial actions and confirmation sampling showed average arsenic concentration of 8.12 mg/kg, and an average lead concentration of 11.58 mg/kg; below the MTCA Method A cleanup levels.
Based on this final remediation and analyzation of the soil at the Subject Property, Washington Department of Ecology issued a No Further Action letter for the Subject Property on July 26, 2022.
McAlister GeoScience and EcoCompliance Corporation engage in yet another successful remediation effort in partnership with state regulatory agencies.