Enhanced Reductive Dechlorination & Bioaugmentation Used to Remediate Chlorinated Solvents at a Brownfield Site

A real estate developer and their environmental consultant selected RRS to design and implement an in situ enhanced reductive dechlorination (ERD) remediation plan for this Brownfield site originally developed in the 1890s, called Belknap Crossings. The site was impacted by two groundwater plumes averaging 300 ug/L trichloroethylene (TCE). The remediation design included the use of 3-D Microemulsion® as a controlled-release electron donor and bioaugmentation using BDI® Plus. The two TCE plumes at this

former manufacturing facility covered an area of 58,000 square feet (ft2). A total of 26,000 pounds of 3-D Microemulsion and 22 liters of BDI Plus with over 1011 Dehalococcoides (DHC) cells per liter were injected over a period of less than two weeks on site.

Taking advantage of 3-D Microemulsion’s unique subsurface distribution characteristics, direct-push injection points were advanced every 480 ft2. RRS utilized retractable screen-tip injection tooling to apply the pH neutral 3-D Microemulsion with BDI Plus at discrete intervals across the vertical treatment interval from 24 feet below ground surface (bgs) to 34 feet bgs in a bottom-up approach. The RRS trailer and equipment configuration allowed for low pressure application of the remediation chemistry at up to three injection points simultaneously, up to 200 feet from the trailer while monitoring flow rates and injection pressures at each application point.

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