Technology:
Soil Vapor Extraction - 10 extraction wells (5 deep, 3 intermediate, 2 shallow) - 5 monitoring well probes - An air/water separator, vacuum pump, and vapor phase granular activated carbon unit
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Cleanup Authority:
CERCLA
- ROD Date: 9/26/89
- Fund Lead
SIC Code:
0723A (Crop Preparation Services
for Market, Except Cotton
Ginning-Grain Fumigation) | Point of Contact:
Diane Easley (RPM)
U.S. EPA Region 7
726 Minnesota Avenue
Kansas City, KS 66101
(913) 551-7797 |
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Contaminants:
Chlorinated Aliphatics - Carbon tetrachloride, chloroform, trichloroethylene (TCE), 1,1- dichloroethane (DCA), 1,1,1-trichloroethane (TCA), and perchloroethylene (PCA) - Highest carbon tetrachloride concentration measured in soil gas was 1,234 ppmv at 112 ft below ground surface |
Waste Source:
Spill; Other: Contaminated Aquifer |
Type/Quantity of Media Treated:
Soil - 185,000 yd3 - Shallow zone: moisture content 26.3%, air permeability 1.9 x 10[Sup - 10] cm2, TOC - 270 mg/kg - Deep zone: moisture content 5%, air permeability 6.2 x 10[Sup -8] cm2, TOC - < 50 mg/kg |
Purpose/Significance of Application:
Full-scale SVE application at a Superfund site to treat a large quantity of soil contaminated with carbon tetrachloride. |
Regulatory Requirements/Cleanup Goals:
Extraction rate for carbon tetrachloride of 0.001 lb/hr - Established in 1992 by EPA and Nebraska Department of Environmental Quality |
Results:
- The SVE system achieved the cleanup goal of 0.001 lb/hr extraction rate for carbon tetrachloride within 9 months of operation - Approximately 600 pounds of carbon tetrachloride extracted, about 45 pounds extracted within the first 2 months of operation |
Cost Factors:
- Total cost of $369,628 (including project monitoring and control, procurement support, construction management (drilling, construction, system dismantlement, and grouting of wells), operations, maintenance, and reporting) |
Description:
Soil Vapor Extraction (SVE) was used at the Hastings Groundwater Contamination Superfund site to treat approximately 185,000 cubic yards of soil contaminated with carbon tetrachloride (CCl4). The site had become contaminated through accidental spills of carbon tetrachloride which was used in the 1960s and 1970s as a fumigant at a grain storage facility. Concentrations of CCl4 were measured in soil gas at the site at levels as high as 1,234 ppmv. A Record of Decision (ROD) was signed in September 1989, specifying SVE as an interim source control measure.
A pilot-scale treatability study (2 deep and 2 shallow extraction wells), conducted from April to May 1991, removed 45 pounds of CCl4. The full- scale SVE system, based on the pilot-scale study, consisted of 10 extraction wells (5 deep, 3 intermediate, and 2 shallow) and was operated from June 1992 to July 1993. EPA and the Nebraska Department of Environmental Quality established an extraction rate for CCl4 of 0.001 lb/hr as the cleanup goal with operation of the system required until field analytical results were verified through laboratory analysis and confirmation of no rebounding of CCl4. The SVE system achieved the 0.001 lb/hr CCl4 extraction rate within 6 months (January 1993) with the results verified and no rebounding confirmed by July 1993.
The total cost for this treatment application was approximately $370,000. Actual costs were 17% less than projected. Cost savings were attributed to the effectiveness of the SVE system (the cleanup required only 9 months rather than the estimated 2 years based on treatability study results), and use of local contractors. |
