Case study: Ford Getrag

ISTR Overview

Consultant: ICF

Neighborhood: Downtown

Heating Tubes: 130

Target Temp: 100 ˚C

Heating Period: 49 Days

Target: 6 mg/kg

Destruction Rate Efficiency: > 99%

Contaminant:
Petroleum Hydrocarbons
PAHs, Other Inorganics

Geology: Fine Alluvium

Volume: 50-500

A pilot test preceded the full scale thermal remediation. The subsurface soils were impacted by DNAPL trapped in a layer of motor oil, with levels of Perchloroethylene reaching 60 mg/L. The target treatment zone consisted of a 3000 ft² area to an average depth of 15 ft.

Pilot Test

Six thermal conduction heating wells and one multi-phase extraction well were used for the pilot test. Subsurface heating progressed for 20 days until thermocouple data confirmed an averagetemperature of 100°C. LNAPL extraction rates increased from 17 ft3/h at 18°C to 52 ft3/h at 50°C, as measured by multiple extraction and bailing tests. Over 99% of chlorinated solvents (DNAPL) were removed from the test volume during the pilot test.

Full Scale Remediation

Forty-eight thermal conduction heating wells were added during the full scale ISTR project. Subsurface heating and CVOC / LNAPL extraction continued for an average duration of thirty-five days, at a target treatment temperature of 100°C. Treatment zone sampling indicated that > 99% of the CVOC mass was removed during thermal remediation operations. An average of 157 kW per ton of soil was used to thermally remediate the treatment volume. The ISTR project was completed without disruption of normal manufacturing activities in the building.