ABSTRACT

Disposal practices prior to RCRA caused the release of chlorinated hydrocarbons (CHCs) into the shallow ground water under a temporary pond at the facility. This impact was discovered through a due diligence survey and properly reported to the Louisiana Department of Environmental Quality (LDEQ). Through a phased investigation the company, in cooperation with LDEQ, has determined that the upper three water bearing units have been affected by multiple contaminants forming a DNAPL plume.

Remedial actions were proposed to the Agency and implemented with approval during 1994-95. The remedial system includes soil vapor extraction and air sparging for the uppermost zone and pump and treat for contaminated water removal in the second zone. Throughout 1995, the systems efficiency was evaluated and continuous adjustments were made to improve the recovery. A balanced approach to minimize downward movement of contaminants and achieve optimum recovery included: startup of system components, manipulation of recovery rates and installation of additional equipment.

Data assimilated over the past year of operation suggests the effective recovery of CHCs. Monitoring of the impacted zones shows a downward trend in contamination levels, however it is evident that control of the impacted zones is incomplete. Proposed alterations to the system include additional recovery wells, pump tests, and continued evaluations to improve the system. Further efforts will be required by the Agency to address the remaining contaminants.

This paper will address the implementation of the Corrective Action Program and present the current state of operations and proposed augmentations to improve the system.

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