Abstracts of Remediation Case Studies, Volume 7 - Federal ...

In Situ Conductive Heating at a Confidential Chemical Manufacturing Facility,
Portland, Indiana (continued)
Results:
Results of confirmatory sampling showed that concentrations of PCE and TCE in both areas were reduced to below the
cleanup goals; no data were provided for DCE
Prior to discontinuing heating, 50 soil samples were collected from the coldest locations (centroids) furthest from each
heater well and analyzed for VOCs; based on these results, along with data from temperature profiles and HCl
monitoring, heating was discontinued in December 1997
Confirmation sampling was conducted about six months later, after soil temperatures within the treatment area had
cooled to below 100°F.
Costs:
No cost data was provided for this application.
Description:
The 16 acre site is a chemical manufacturing facility located in the southern portion of Portland, Indiana, From 1937 to the
mid-1970's, the site was used for the manufacture of hard rubber products used in automobiles and then for the
manufacture of plastic exterior automobile parts and is currently being used for reworking automotive parts. Sampling
showed the presence of volatile organic compounds (VOCs) in in subsurface soils in two areas at the site that had been
used as loading docks. Area GP-31 was contaminated primarily with PCE and TCE; Area GP-28 was contaminated
primarily with DCE. VOCs were not found above the cleanup goals in groundwater.
In situ conductive heating was used from July to December 1997 to treat the unsaturated source zone in these two areas. A
total of 130 heater/vacuum wells were installed in the larger area (GP-31) and 18 in the smaller area (GP-28). These wells
were used to injected heat into the subsurface (1,400 - 1,600 °F) using the vacuum to extract soil gas. Off-gases were
treated with a flameless thermal oxidizer. Prior to discontinuing heating, about 50 soil samples were collected from the
coldest locations (centroids) furthest from each heater well and analyzed for VOCs. The results from the soil samples,
along with data from temperature profiles and HCl monitoring, were used to determine whether additional heating was
required. Based on the results, heating was discontinued in December 1997. Before confirmation sampling was
conducted, soil temperatures were monitored for about 6 months as the soil within the treatment area cooled to below
100°F. Results of confirmation sampling showed that PCE and TCE concentrations were below the cleanup goals.
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