The site remediation strategy employed use of light, non-aqueous phase liquid (LNAPL) recovery, in conjunction with in situ bioremediation and soil vapor extraction and air sparge (SVE/AS) systems, to address multiple hydrocarbon releases at a large natural gas processing facility. Following extensive site characterization and analysis of potential risks to human health and the environment, JBR negotiated a phased, remedial strategy deemed acceptable to the WDEQ and JBR’s client. The areal extent of contaminated, subsurface soil and groundwater approximated 25-acres and comprised two separate plumes of contaminated groundwater, migrating in two separate directions beneath the property.
Sequenced, remedial efforts included design, pilot testing, and field testing of the SVE/AS system, orchestrated to remediate the most contaminated areas initially, followed by sequential expansion of the SVE/AS system to remediate less-contaminated, downgradient areas. Sub-slab, soil gas monitoring and analysis is also being used to monitor subsurface conditions beneath a utility building that is located above the center of mass of one of the plumes of contaminated groundwater. A Proposed Work Plan for localized, selective soil excavation and on-site, bio-remedial landfarming is pending WDEQ approval, presently. Currently, JBR is monitoring contaminant mass reduction within both plumes, while ensuring the site poses no unacceptable risks to human health or the environment.