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SPEARS as a Delineation and Monitoring Tool for PCBs and DDx in EPA Region 9

Location: Region 9 | Published: August 2, 2023

ecoSPEARS was contracted by a client to deploy multiple SPEARS mats along a shoreline in Region 9 for passive porewater sampling of PCBs and DDx contamination. DDx refers to a group of chlorinated pesticides including DDT, a pesticide banned in 1972, as well as DDD and DDE, which are byproducts when DDT breaks down.

According to the EPA, both DDx and PCBs have been recognized as carcinogens, posing potential risks to human health and the environment. Conventional sampling techniques often fail to account for the dynamic tides of oceans and the complex nature of these contaminants. As an alternative to ordinary passive samplers, the SPEARS mats were deployed to identify known contaminants, delineate contaminant concentrations across the site to identify hotspots, and record continuous contaminant uptake over time to reduce bioavailability to the local biota.

After an 8-month deployment period, the SPEARS mats were removed by the ecoSPEARS team, and sent to an accredited third-party laboratory for analysis of PCBs and DDx concentrations. The study’s results confirmed the detection of PCBs and/or DDx in multiple decision units through the presence of contaminants in the SPEARS. The data from this study indicated the SPEARS’ ability to accurately detect variations in concentration of contaminants in contaminated sites and identify hotspots that require treatment.

The SPEARS mats proved effective in the passive sampling of PCBs and DDx contaminants in shoreline environments based on the results from the Region 9 shoreline. The study’s results confirmed the SPEARS’ ability to detect the presence of these harmful substances in multiple decision units, demonstrating the potential for SPEARS as a monitoring tool.