Client:
Services: Concerns: | Clarke County School Bus Maintenance, Athens, Georgia
Soil/Groundwater Investigation for Leaking UST Site Corrective Action Plans–Part A and B Soil/Groundwater Remediation to Achieve “Monitor Only” Status Georgia USTMP Standards Remediation of Free-Phase Product, Soil, and Groundwater Approval for “Monitor Only” Status from USTMP |
Scope of Services:
AEM was contracted by the Clarke County School Bus District to perform site investigation and corrective action work at a Clarke County school bus maintenance facility in Athens. AEM performed a soil and groundwater investigation for the primary release of gasoline from USTs at the site and some addition diesel fuel contamination from another tank. Free-phase product was detected in the bedrock monitoring wells on site, at levels as high as five feet.
AEM prepared a CAP-A and then a CAP-B for the site. During the implementation of the CAP-B, AEM designed and provided construction oversight for a DVE remediation using high-velocity entrainment. The primary remediation goal was to ensure protection of a nearby down-gradient surface water body according to the in-stream water protection standard under Georgia EPD-USTMP requirements.
The system design included vapor extraction wells installed in the vadose zone to address contaminated soil and bedrock groundwater extraction wells to address contaminated groundwater. The system included high-vacuum liquid ring pumps for extraction and air stripping treatment to reduce VOC concentrations to below laboratory detectable levels. Electrical wiring requirements were designed according to National Electrical Code standards for hazardous atmospheres in view of flammability hazard.
During O&M activities, vapor-phase and dissolved-phase extraction rates of VOC contamination were routinely monitored. The monitoring results indicated that all regulatory requirements were met; in addition, AEM was able to optimize system operation based on the individual wellhead and system monitoring data.
Free product was successfully reduced from more than 5 feet in thickness to non-detect levels, and groundwater dissolved-phase contamination was reduced more than 90% at the primary monitoring wells. Subsequently, Georgia EPD approved discontinuing active remediation on site and a two-year “Monitor Only” period was implemented. The site was then issued a “No Further Action” letter by Georgia EPD.
AEM prepared a CAP-A and then a CAP-B for the site. During the implementation of the CAP-B, AEM designed and provided construction oversight for a DVE remediation using high-velocity entrainment. The primary remediation goal was to ensure protection of a nearby down-gradient surface water body according to the in-stream water protection standard under Georgia EPD-USTMP requirements.
The system design included vapor extraction wells installed in the vadose zone to address contaminated soil and bedrock groundwater extraction wells to address contaminated groundwater. The system included high-vacuum liquid ring pumps for extraction and air stripping treatment to reduce VOC concentrations to below laboratory detectable levels. Electrical wiring requirements were designed according to National Electrical Code standards for hazardous atmospheres in view of flammability hazard.
During O&M activities, vapor-phase and dissolved-phase extraction rates of VOC contamination were routinely monitored. The monitoring results indicated that all regulatory requirements were met; in addition, AEM was able to optimize system operation based on the individual wellhead and system monitoring data.
Free product was successfully reduced from more than 5 feet in thickness to non-detect levels, and groundwater dissolved-phase contamination was reduced more than 90% at the primary monitoring wells. Subsequently, Georgia EPD approved discontinuing active remediation on site and a two-year “Monitor Only” period was implemented. The site was then issued a “No Further Action” letter by Georgia EPD.
