Citadel EHS Partnership with Provect-IR Leads to Rapid Reduction of Chlorinated VOCs
A case study from a former dry cleaner site in San Rafael, California, where in situ chemical reduction achieved PCE concentration reductions exceeding 99% in 11 of 14 target monitoring wells within 20 months.
Case Study: Former Dry Cleaner, San Rafael, California
A former dry cleaner site in San Rafael, California implemented an in situ chemical reduction remedy targeting chlorinated volatile organic compound contamination. The site was identified under California's Spills, Leaks, Investigation & Clean-Up Program in 2007. Investigation revealed impacts extending approximately half a mile downgradient.
Pilot Program Details
In July 2017, a permeable reactive barrier pilot test deployed 6,800 lbs of Provect-IR and 8 liters of Dehalococcoides inoculum across six direct push injection locations. Within eight months, PCE and TCE concentrations at monitoring well MW-10 reached non-detect levels below 0.5 ug/L.
Full-Scale Implementation
Between June-August 2021, approximately 67,900 pounds of Provect-IR and 77 liters of DHC were injected within 12 strategic areas. An additional injection phase occurred July-September 2023, deploying 64,750 pounds of Provect-IR and 66 liters of DHC.
Results and Conclusions
Within 20 months post-injection, PCE concentration reductions exceeded 99% in 11 of 14 target monitoring wells. The 3,000-foot plume no longer exists as originally characterized. Provect-IR barriers are engineered for lifespan exceeding 7 years, with continued reductions anticipated.
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