PROJECT: Site Investigation and Remediation

Western Oregon

In 1999, concentrations of tricholoroethylene (TCE) were identified in soil and groundwater at a facility in western Oregon (confidential client.) GSI staff members began working at the facility while employed by another firm. A fast-track investigation was conducted to determine the extent of the TCE plume in groundwater and to characterize the source. The client contemplated several response actions and implemented a bioremediation pilot test. The goal of the pilot test was to promote reductive dechlorination of TCE in the subsurface by augmenting the natural system with emulsified oil substrate (electron donor) and a specific strain of microbes that is known to reduce TCE to the non-toxic end products, ethane and ethene. The pilot test was highly successful, reducing TCE concentrations to well below risk-based criteria. The pilot test was followed by three full-scale projects to reduce contaminant concentrations and establish a permanent biological treatment barrier downgradient of source areas to degrade residual concentrations.