In-Situ Thermal Remediation at an EPA Region 9 Former MGP Site

GEO's case study describes an in-situ thermal remediation pilot at a former manufactured gas plant site in EPA Region 9. The treatment addressed petroleum hydrocarbons in the diesel and motor-oil ranges, benzene, naphthalene, and benzo(a)pyrene-related contamination in soil.

Thermal treatment installation at the EPA Region 9 former manufactured gas plant pilot.

The pilot used Gas Thermal Remediation (GTR), a form of thermal conduction heating. Fourteen heater wells treated a vadose-zone interval extending from the surface to 15 feet below ground surface. The heater wells extended below that interval to support heat distribution. The case study lists an approximately 325°C treatment temperature and a 130-day heating period.

The source reports that the analyzed completion samples met the project's benzo(a)pyrene-equivalent soil criterion. These are results from a defined pilot treatment volume. They do not establish that every contaminant or every part of a larger site met closure requirements.

Heater wells and connecting pipework within the pilot treatment area.

Heating and contaminant extraction must be considered together: mobilized contaminants require collection and appropriate aboveground treatment.