EMR completed a remedial investigation, feasibility study, remediation pilot study, corrective action plan, and an installation of an air sparging/soil vapor extraction remediation system (AS/SVE), long system O&M/optimization, and groundwater monitoring at a former gasoline service station. The site was placed in the Kansas Department of Health and Environment (KDHE) Petroleum Storage Tank Fund due to volatile organic compounds impacted soil and groundwater from leaking USTs.
Remedial investigation activities included an electrical conductivity logging survey, which detected minor variations in subsurface lithology to aid in the placement of AS/SVE wells. The detailed subsurface investigation proved valuable as buried paleo river channel deposits were transecting the site, resulting in preferential groundwater flow paths. An eight-hour pilot study was completed using multiple wellhead vacuums at two SVE pilot test wells, two observation wells, and two monitoring wells to enhance full-scale remediation system design. EMR conducted weekly and monthly system O&M, and quarterly groundwater monitoring to measure the effectiveness of the system and optimize as needed.
After one year of AS/SVE system operation, groundwater contaminant concentrations decreased by an order of magnitude and the contaminant plume was shrinking. After two years of treatment system operation, groundwater contaminant concentrations had been reduced by 99 percent and KDHE approved the shutdown of the remediation system. Quarterly groundwater monitoring for the following year confirmed post-active remediation stability in contaminant concentrations. EMR worked with KDHE, the client, and the City of Wichita and site closure was achieved.