The pre-treatment concentrations of Toluene and Xylene were 1,198ppb and 2,408 ppb, respectively. Ten units of Petrox aerobic microbes were injected into the ground water on about June 2, 2002. Within six weeks the concentrations decreased to 515ppb and 690 ppb, Toluene and Xylene, respectively. After a second inoculation in August 2002, the concentrations decreased to 3.7ppb and 16.4 ppb, respectively. There has been a slight rebound in Xylene to 23.8 ppb, and a third inoculation will be implemented to finish the treatment.
The cost to treat this quarter acre plume with Petrox was about $20,000.