Multiple Lines of Evidence Show CVOCs Degrading on PlumeStop, Leading Site to NFA Status

Case study highlights:

• Combined remedy approach proves successful in treating chlorinated solvents at former dry cleaner
• This site provided ideal challenge conditions to demonstrate complete biodegradation using a sorption-ERD approach
• The site was granted NFA status in June 2019 as a result of this pilot study

This case study reviews one of the original PlumeStop® pilot tests for in situ groundwater treatment of chlorinated volatile organic compounds (CVOCs or chlorinated solvents) at a former dry cleaner location in Marina, California. REGENESIS treated the CVOCs using a novel, sorption-enhanced reductive dechlorination (ERD) approach. This approach consisted of immediate sorption followed by the sequential elimination of chlorine from the CVOC molecules, transforming them into non-toxic end products such as ethene, carbon dioxide, and chloride. The CVOC, biogeochemical, and microbial data collected during the pilot test monitoring program provide multiple lines of evidence for post-sorption degradation of the target solvents on the PlumeStop carbon surface. Therefore, the pilot test results confirm the answer to the question: “Do Contaminants Biodegrade When Treated With PlumeStop?”. Biodegradation of CVOCs does occur once sorbed onto a PlumeStop-treated aquifer matrix. These findings led to the site being granted NFA status by the CCRWQCB.