Projects & Programs
Heckathorn Superfund Site
The PNNL Marine Sciences Laboratory performed a remedial investigation and feasibility study of pesticide-contaminated marine sediment in Richmond Harbor, California. The site is a former pesticide packaging plant that handled chlorinated pesticides; sediment in the waterways adjacent to the site was contaminated, particularly with Dichlorodiphenyl-trichloroethane (DDT) and dieldrin. The PNNL's objectives were to:
- Determine the areal and vertical extent of contamination and volume of sediment requiring remediation
- Characterize biological effects of sediment and the quality of effluent derived from dewatered sediment
- Develop and evaluate alternatives for removing, containing, and/or treating contaminated sediment.
PNNL also provided oversight of remedial actions and designed and initiated a post-remediation biomonitoring study.
The Record of Decision called for remediation by dredging with offsite disposal, construction of an upland cap to prevent erosion, property use limitation to nonresidential and five years of post-remediation monitoring in the adjacent waterways. Between August 1996 and March 1997, approximately 85,000 cubic yards of DDT-contaminated sediment was dredged from Lauritzen Channel and Parr Canal and then capped with 0.5 to 1 feet of clean sand. Marine sediment remediation was completed in April 1997. Post-remediation monitoring was initiated six months later, in the winter of 1997-1998.