Former fueling operations at Scott Air Force Base resulted in soil contamination containing high levels of benzene, ethylbenzene, methyl tertiary-butyl ether (MTBE), and naphthalene. Underground storage tank removal and source area excavation were planned to treat the unsaturated soil. However, subsurface investigations revealed piping, fiber-optic communication lines and other utilities present which would inhibit excavation activities. A technology was needed to remediate the impacted area without physically disturbing or chemically corroding the sensitive underground infrastructure. RegenOx, a powerful but non-corrosive chemical oxidant, was used and injected around the underground piping and utility lines.
The source area was excavated to 8 feet below ground surface removing approximately 31,000 square feet of material. Following the excavation, RegenOx was injected in four separate events within the sensitive areas adjacent to the excavation.
As a result of effective chemical oxidation using RegenOx, the remedial objectives for ethylbenzene, MTBE, and naphthalene were met in all areas. Benzene concentrations were reduced below the objective in five of the eight monitored areas.