Hart & Hickman is currently conducting soil and groundwater assessment and corrective action at a former research and development facility impacted with chlorinated organics and aromatic compounds. The site is located in a residential area not supplied with city water. An air injection and vapor extraction system had previously been installed by others. H&H conducted a review of existing assessment and remedial data and determined that the distribution of the groundwater impacts was primarily controlled by relict bedrock structures not groundwater flow direction. As such, the extent of the groundwater plumes was not known and was characterized further. In addition, H&H conducted an evaluation of geochemical data to evaluate on-going natural attenuation processes.
Hart & Hickman’s review of the groundwater remediation system installed by others indicated that the air injection pressures were inadequate to overcome hydraulic head and supply air to the aquifer. As such, the remediation system was not producing a benefit with regard to aquifer remediation and the system was shut down. H&H subsequently implemented an aquifer restoration program consisting of in-situ injection of emulsified oil substrate in conjunction with a biological media (BAC-9) to enhance bioremediation of the compounds of concern. Results of post-remediation monitoring indicate that there have been significant reductions in compound concentrations as a result of the remedial activities.