Re-assessment of sediment contamination at Palos Verdes Superfund site completed

The U.S. Environmental Protection Agency, Region 9 has finalized an assessment of the state of sediment contamination along the Palos Verdes shelf – an effort that included participation by SCCWRP, which measured contaminant levels to support the study.

The study, summarized in an EPA technical report published last summer, found that levels of the pesticide DDT and an industrial class of chemicals known as PCBs have been slowly decreasing in seafloor sediment, overlying water column, and fish tissue, but still exceed the target levels for cleanup.

SCCWRP was not a co-author on the study, but contributed to the study by using passive samplers to measure the levels of DDT and PCBs that are leaching out of surface layers of sediment into the water column above.

The EPA will use the study’s findings and updated human health and ecological risk assessments to develop recommendations for cleanup remedies. The study’s findings may also inform ongoing efforts to evaluate additional instances of offshore DDT contamination.