Client:
Services: Concerns: | WestPoint Stevens, Valley, Alabama
RCRA Facility InvestigationRCRA Clean Closure via Corrective Action Clean Closure of RCRA-Regulated Land Disposal UnitAvoidance of 30 Years of Post-Closure Care |
Scope of Services:
In 1995, an environmental audit identified a septic tank system that had collected wastewaters from a parts washing operation associated with various maintenance operations. Following the emptying of the septic tank, the soil and groundwater assessment identified a number of volatile organic compounds (VOCs) (including tetrachloroethylene, trichloroethene, and 1,1 dichloroethene) in soil and groundwater near the septic system. The septic tank and drain field were classified by the Alabama Department of Environmental Management (ADEM) as a RCRA-regulated land disposal unit. AEM was subsequently contracted to fully assess and remediate the impacted soil and groundwater (in accordance with an ADEM Consent Order, RCRA regulations, and other ADEM requirements) to achieve a RCRA clean closure.
AEM completed the delineation of the impacted area, and aquifer testing was performed. The horizontal and vertical extent of impacted groundwater was defined, as well as the groundwater flow direction and velocity. This hydrogeological information was used to develop a RCRA Closure Plan for clean closure. AEM’s risk assessor proposed Alternative Cleanup Levels (ACLs), which were approved by ADEM and were incorporated into the RCRA Consent Order.
The assessment indicated that the existing septic tank was a continuing source of groundwater contamination, and in 1996 AEM excavated and removed the septic tank. In addition to excavating and disposing of the septic tank, AEM sampled and characterized liquids from the tank, which along with more than 1,000 cubic yards of contaminated soil were disposed of at an approved off-site disposal facility.
AEM conducted a pilot study of air sparging and soil vapor extraction (AS/SVE). The results of the pilot study indicated that the AS/SVE technology would successfully remediate the impacted groundwater. AEM designed a full-scale groundwater remediation system utilizing the AS/SVE technology. AS/SVE was considered the optimal choice for remediation of groundwater, because all remaining VOCs would be treated on site, no groundwater discharge permit would be required, and air emissions associated with the AS/SVE systems complied with air quality standards without the installation of any emission controls.
After six months of operation, several of the monitoring wells that were being used as AS/SVE system performance monitoring wells had groundwater concentrations at or below the ACLs for the site. To ensure ultimate compliance with the Consent Order and site ACLs, AEM reconfigured several of the air sparging well clusters to reduce the relatively low VOC concentrations to below detectable levels. All VOCs that had concentrations previously above the ACLs were successfully remediated to below both ACLs and the method detection limits.
The site was approved by ADEM as "clean closed" and avoided RCRA post-closure care requirements. Monitoring wells were then properly plugged and abandoned according to the State of Alabama water well requirements.
AEM completed the delineation of the impacted area, and aquifer testing was performed. The horizontal and vertical extent of impacted groundwater was defined, as well as the groundwater flow direction and velocity. This hydrogeological information was used to develop a RCRA Closure Plan for clean closure. AEM’s risk assessor proposed Alternative Cleanup Levels (ACLs), which were approved by ADEM and were incorporated into the RCRA Consent Order.
The assessment indicated that the existing septic tank was a continuing source of groundwater contamination, and in 1996 AEM excavated and removed the septic tank. In addition to excavating and disposing of the septic tank, AEM sampled and characterized liquids from the tank, which along with more than 1,000 cubic yards of contaminated soil were disposed of at an approved off-site disposal facility.
AEM conducted a pilot study of air sparging and soil vapor extraction (AS/SVE). The results of the pilot study indicated that the AS/SVE technology would successfully remediate the impacted groundwater. AEM designed a full-scale groundwater remediation system utilizing the AS/SVE technology. AS/SVE was considered the optimal choice for remediation of groundwater, because all remaining VOCs would be treated on site, no groundwater discharge permit would be required, and air emissions associated with the AS/SVE systems complied with air quality standards without the installation of any emission controls.
After six months of operation, several of the monitoring wells that were being used as AS/SVE system performance monitoring wells had groundwater concentrations at or below the ACLs for the site. To ensure ultimate compliance with the Consent Order and site ACLs, AEM reconfigured several of the air sparging well clusters to reduce the relatively low VOC concentrations to below detectable levels. All VOCs that had concentrations previously above the ACLs were successfully remediated to below both ACLs and the method detection limits.
The site was approved by ADEM as "clean closed" and avoided RCRA post-closure care requirements. Monitoring wells were then properly plugged and abandoned according to the State of Alabama water well requirements.
