Electrical Resistive Heating at a Former Manufacturing Facility, Skokie, Illinois

Site Name:

Former manufacturing facility (confidential commercial client)

Location:

Skokie, Illinois

Period of
Operation:

June 4, 1998 to November 20, 1998 (initial area treated); December 1998 to April 30, 1999 (additional area treated)

Cleanup
Type:

Full scale

Vendor:

William Heath
Current Environmental Solutions
1100 Laurel Crest Way
Marietta, GA 30064
E-mail: bill@cesiweb.com

David Fleming, Corporate Development Leader
Current Environmental Solutions
P.O. Box 50387
Bellevue, WA 98015
Telephone: (425) 603-9036
Fax: (425) 643-7590
E-mail: david@cesiweb.com

Technology:
Electrical Resistive Heating - Six-Phase Heating™ (SPH), and air stripping for extracted groundwater condensate
- Initial network of 107 electrodes (85 beneath the floor of a warehouse building) operated from June to November 1998; 78 electrodes added (185 total) and operated from December 1998 to April 1999 to treat additional area of contamination
- Electrodes designed to be electrically conductive throughout a depth interval of 11 to 21 feet bgs and to increase the subsurface temperature in the depth interval of 5 to 24 feet bgs to the boiling point of water
- Electrical power input - 1,775 megawatt hours (MW-hrs.) consumed from June 4 to November 20, 1998; information not provided for Dec. 1998/Jan. 1999 through May 1999
- Temperature - 100°C; operating pressure/vacuum - 7.5 inches of mercury (Hg)
- Network of 37 soil vapor extraction wells, screened to 5 feet bgs, were used to capture vapors
- Off-gas was condensed and sent through an air stripper prior to discharge to the atmosphere

Cleanup Authority:
State Voluntary Cleanup

Contacts:
State Regulator
Stan Komperda
Illinois EPA
Bureau of Land, No. 24
1021 East North Grand Avenue
Springfield, IL 62794-9276
Telephone: (217) 782-5504
E-mail: epa4207@epa.state.il.us

Contaminants:
Chlorinated Solvents
- TCE and TCA, as well as degradation products cis-and trans-1,2-dichloroethene, 1,1-dichloroethene, 1,1-dichloroethane, vinyl chloride and chloroethane
- Concentrations in groundwater at start of SPH remediation (June 1998) - TCE (130 mg/L maximum; 54.4 mg/L average), TCA (150 mg/L maximum; 52.3 mg/L average) and DCE (160 mg/L maximum; 37.6 mg/L average)
- DNAPL present

Waste Source:
Leaks from spill contaminant systems and underground storage tanks

Type/Quantity of Media Treated:
Source zone (saturated and unsaturated)
- Initial source zone area - approximately 23,100 cubic yards of soil and groundwater, based on a treatment area of 26,000 square feet and a depth of 24 feet below ground surface (bgs). Additional source zone area - 11,500 cubic yards of soil and groundwater
- Soil at site - heterogeneous silty sands with clay lenses to 18 feet bgs (hydraulic conductivity -10-4 to 10-5 cm/sec); underlain by dense clay till aquitard (hydraulic conductivity -10-8 cm/sec)
- Depth to groundwater- 7 feet bgs

Purpose/Significance of Application:
Use of SPH to remediate chlorinated solvents in soil and groundwater

Regulatory Requirements/Cleanup Goals:
- Tier III cleanup criteria for groundwater; developed by ENSR and approved by Illinois EPA as the cleanup goals for the site
- Tier III goals were TCE (17.5 mg/L); TCA (8.85 mg/L); and DCE (35.5 mg/L)
- No criteria established for soil

Results:
Results for the remediation of the initial 23,000 cubic yards of contamination:
- By December 1998 (six months of operation), the Tier III cleanup goals were achieved for TCE, TCA, and DCE in all wells in the initial area of contamination
- During this time, average groundwater concentrations were reduced by more than 99% for TCE (54.4 mg/L to 0.4 mg/L); more than 99% for TCA (52.3 mg/L to 0.2 mg/L), and more than 97% for DCE (37.6 mg/L to 0.8 mg/L)
Results for the remediation of the additional 11,000 cubic yards of contamination:
- By April 1999 (five months of operation), the Tier III cleanup goals were achieved for TCE, TCA, and DCE in all wells in the additional area of contamination
- During this time, average groundwater concentrations were reduced by more than 96% for TCE (4.16 mg/L to 0.15 mg/L); more than 92% for TCA (14 mg/L to 1 mg/L); and more than 90% for DCE (2.39 mg/L to 0.24 mg/L)

Cost Factors:
- Cost data were provided on a unit cost basis; total project cost data were not provided
- The unit cost for this technology of $32 per cubic yard is based on a calculated treatment volume of 23,100 cubic yards, or a treatment area of 26,000 square ft and a depth of 24 ft bgs
- The unit cost for the treatment from December 1998 through May 1999 also was $32 per cubic yard, based on a calculated treatment volume of 11,500 cubic yards

Description:
The Skokie site is a former electronics manufacturing facility located in Skokie, Illinois. From 1958 to 1988, manufacturing operations included machining and electroplating. Soil and groundwater at the site was found to be contaminated with solvents (TCE and TCA), including large pools of dense nonaqueous phase liquids (DNAPL). The site is being remediated under Illinois' voluntary Site Remediation Program. From 1991 to 1998, steam injection combined with groundwater and vapor extraction reduced the area of contamination from about 115,000 square feet to about 23,000 square feet. As of early 1998, the remaining area to be remediated represented four source locations where manmade subsurface features limited the effectiveness of the previously used steam-based remediation system. To complete the remediation, the site owner selected SPH.

The SPH process operated at the Skokie site from June 4, 1998 to November 20, 1998 to remediate the initial estimated 23,000 cubic yards of contaminated soil and groundwater. Based on the results of sampling conducted in December 1998 that indicated there was a potential for vinyl chloride to be produced outside the initial treatment area at levels in excess of the cleanup levels, a decision was made to expand the SPH system to cover an additional 11,500 cubic yard treatment area. The SPH system restarted in December 1998 and operated until April 30, 1999 when cleanup goals were achieved in the additional area. The unit cost for this technology was $32 per cubic yard for the initial 23,000 cubic yards of contaminated soil and groundwater and also for the additional 11,500 cubic yards of contaminated media.