PM Environmental, Inc. was retained to complete a Data Acquisition Plan and a Risk Assessment. Well sampling results indicted dissolved phase petroleum hydrocarbons at concentrations above the Alabama Department of Environmental Management (ADEM) Initial Screening Levels and a Secondary Investigation was mandated to define the contaminant plume.
PM conducted additional phases of site characterization and performed several groundwater monitoring events. The release was located within a 500-foot radius of 12 private drinking water wells. Approximately 20 groundwater monitoring wells are associated with the site. Pilot Testing of Dual Phase Extraction Remediation Technology was performed and the technology was deemed appropriate and cost effective at the site. The Corrective Action Plan (CAP) and project costs were reviewed and approved by ADEM.
PM supervised the installation of 3 recovery wells, a trenching and piping system, and placement of 25 horsepower dual phase extraction and treatment system with liquid ring pump. The remediation system was modified to direct additional extraction in a hot spot near one monitoring well. Three additional recovery wells were installed and attached to the dual phase system.
PM conducted monthly operations and maintenance, quarterly groundwater monitoring of the impact, and other troubleshooting activities of the system on an as needed basis. The size of the groundwater plume continues to decrease, and will remain in operation until the impact is below Site Specific Target Levels.