GROUNDWATER TREATMENT METHODS: THE EFFECTIVENESS OF REMEDIATION SYSTEMS ON PETROLEUM IMPACTS

Underground storage tank (UST) systems can release hazardous substances which impact soil, surface, and groundwater with devastating consequences to environment and human life. Impact to groundwater is particularly concerning in Indiana where groundwater is the primary drinking water source. Petroleum products released into the subsurface typically breakdown naturally over time. However, when natural attenuation of petroleum contaminants does not effectively reduce constituent-of-concern (COC) concentrations, active remediation may be necessary. Presented here are three remediation projects in Southern Indiana, hereafter referred to as the Vincennes, Evansville, and Martinsville Sites, and their subsequent treatment using active remediation techniques. The use of multi-phase and dual-phase extraction (MPE and DPE) and DPE coupled with air sparge systems are well-documented forms of active remediation proven successful in a number of hydrogeologic settings as a way to treat groundwater contamination caused by petroleum impacts. Since system start-up, COC concentrations decreased dramatically; Vincennes in particular shows benzene and naphthalene concentrations decreased one to two orders of magnitude immediately following the start-up event. System run-time was also significantly shorter than projected, demonstrating the effectiveness of DPE. Use of remediation systems can eliminate exposure risks and reduce cleanup costs significantly. Remediation systems are successful in treating groundwater where other remediation techniques fall short.