East Windsor Former Industrial Facility

An oxidation remedial event was conducted at a former industrial site to address a release of 1,1,1-trichloroethane (TCA) and its reaction products, 1,1-dichloroethene (DCE) and 1,2-dichloroethane (DCA).

The site was identified as having impacted soils and groundwater due to the historic use of TCA near a loading dock at the facility. The geology at the site consisted of a mixture of red and gray clay. A total of 41 direct push point injections were made in June 2012 utilizing a Geoprobe 6620 at a depth range of 9-15 feet bgs.

The objective of the remedial event was to promote in-situ conditions necessary for chemical oxidation and then as the site becomes reducing, biological mineralization via sulfate and iron reducing bacteria.

The injection program consisted of sodium persulfate, hydrogen peroxide, and 5-15 micron zero valent iron particles. The remedial mixture was designed to reduce concentrations of the two compounds present above the CT groundwater standard via chemical oxidation, free radicals, and later, biological mineralization.

Three sampling events were conducted at 30, 90 and 180 days after the initial injection event. The data indicate that the chemical oxidation event was successful in reducing groundwater concentrations to below Connecticut treatment objectives.