During the afternoon of October 15, 2007 an NRC report was made concerning a release of oil containing PCB's from a transformer and 3 regulators in a storage yard in Clinton, SC. The reason for the release appears to be vandalism in order to steal the copper contained inside the transformers. The approximate volume of oil released was approximated to be 1600 gallons and traveled past the site fence and into a drainage ditch where it migrated to a culvert. No oil was found past the outlet of the culvert. The concentration of PCB's in the oil was 223 ppm in the transformer and less than 50 ppm in each of the three voltage regulators. The area where the transformer was located was a former voltage substation.
OSC Crowley was dispatched in late afternoon of October 15 to provide oversight and technical assistance to the State and local responders. During the afternoon of the 15th, members of the Clinton Public Works (CPW) department worked to dig up PCB contaminated soil. It should be said that all of the oil soaked into the ground and there was no visible pooling of oil anywhere along the flow path. Poly sheeting was placed on the ground and all dirt dug up was placed on this sheeting to prevent leaching of the PCB's from the dirt piles should a rain event occur. Crews continued this work until dark on the 15th. SC DHEC was also on scene during the afternoon of the 15th to check on progress on the spill.
On the morning of the 16th the OSC was met on site by members of the public works department. The crews continued the work of digging up contaminated soil and placing it on plastic sheeting. The total depth the crews dug to was approximately 6 inches where a clay layer was located and no visible contamination was observed.
The OSC spoke with DHEC and they assured him that they are happy with site conditions and progress and will maintain oversight. The OSC demobilized from the site on October 16th, 2007.
CPW continued the response by collecting confirmation samples to demonstrate that all PCB contaminated soil was removed. After receiving soil confirmation sampling results that indicated no PCB contamination remained, CPW backfilled the excavation with clean fill dirt. The storage yard is no longer a active substation and the transformer and voltage regulators were removed.
CPW continued to coordinate disposal activities with the OSC as well as EPA Toxic Substances Control Act (TSCA) personnel. CPW was provided information by EPA TSCA via the OSC that required CPW to follow the Spill Clean-up Policy of TSCA. This policy states that when a spill of PCBs occurs and the concentration of the spilled PCBs is known before they were spilled, the responsible party must clean up the contaminated media at the known concentration of PCBs prior to the spill. The known concentration prior to the spill was 273ppm of PCBs and therefore would require disposal at a hazardous waste facility. After this direction by TSCA, CPW indicated they would not be able to pay to dispose of the soil.
Over time the OSC worked with the EPA attorney and TSCA personnel to determine that the spill clean-up policy was not the correct guideline to follow for this PCB spill. The correct rule that the CPW should follow is 761.61 of TSCA under a risk based clean-up. Under this rule, TSCA allows the responsible party to dispose of contaminated media at as found concentrations. As found concentrations in the soil piles on site were 5ppm or below. This enabled CPW to dispose of soils at a nonhazardous facility. CPW then indicated they would be able to pay for the disposal.
CPW verbally agreed to dispose of the soils as part of the on going emergency response initiated by OSC Crowley. CPW provided their own heavy equipment and personnel to excavate the stockpiled soils and their own trucks for transport of the contaminated soils. CPW secured local Republic Union County Landfill to accept the nonhazardous contaminated soils. On June 15, 2009 the OSC mobilized to the site to oversee soil load out. 57 truck loads totaling 385 tons of soil were transported to the Republic Union County Landfill. Confirmation sampling was conducted during the original soil excavation in October of 2007 to ensure no PCB contamination was left in place. The results are documented in a report written by CPW’s environmental contractor Hart and Hickman. The Report is titled Soil Excavation report and was dated December 28, 2007. The results demonstrate that soil was excavated until there were no detections of PCBs left in soil.
No future removal actions are planned.
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