Enhanced endogenous biological attenuation of aromatic hydrocarbons in groundwater: A case study (preliminary results)

EnviroSearch International has designed and is currently operating a groundwater treatment system to address a release of petroleum hydrocarbons at a site in Meridian, Idaho. Among those hydrocarbons, the principal compound of concern, benzene, was reported at concentrations of up to 4.0 mg/l prior to system operation. The system is designed to reduce hydrocarbon concentrations in groundwater and saturated soil through enhancement of naturally occurring aerobic microbial activity. An in situ treatment system was selected in order to simultaneously address hydrocarbons dissolved in groundwater and absorbed to the saturated soil matrix. Petroleum-utilizing bacteria were identified in groundwater samples collected from the project site. The in situ system was designed to create conditions more conductive to aerobic microbial by increasing the initially concentrations of dissolved oxygen and the nutrients and phosphorus. 11 refs., 14 figs