Polychlorinated Biphenyl Contaminated Soil Remediation
When a train partially derailed and impacted a Central Ohio Transit Authority (COTA) maintenance facility, Trihydro personnel supported response efforts and soil remediation in coordination with US Environmental Protection Agency requirements.
One of the tank cars was punctured during the derailment and spilled hazardous denatured ethanol. The denatured ethanol from this railcar fueled a large pool fire. The two other tank cars carrying denatured ethanol were engulfed in the pool fire and split open.
Removing PCB Waste
During the emergency response efforts to contain the railcar spills, buried drums were discovered in the railroad embankment that likely dated back to industrial use from before COTA occupied the site. Once the site was secure in the aftermath of the derailment response, the team conducted soil and groundwater investigations to examine the contents of the drums and potential environmental impacts. Our team detected on-site polychlorinated biphenyl (PCB) concentrations related to the buried drums. We recommended the removal of the PCB waste under the Toxic Substances Control Act (TSCA). The US Environmental Protection Agency (EPA) retains primacy over TSCA remediation. Consequently, cleanup and regulatory control for the site were transferred to EPA.
Remediation Work Plan
COTA submitted a soil remediation work plan to EPA Region V that outlined the anticipated characterization to delineate the extent of PCB contamination and the proposed excavation activities. EPA approved the work plan and requested an initial cleanup goal of ≤ 1 part per million (ppm), which would allow unrestricted closure of the site. COTA requested a cleanup level of ≤25 ppm to limit the excavation extent and additional investigation costs. This required a deed restriction limiting the site to low-occupancy industrial use, which EPA approved.
The site investigation was completed in one month. The team excavated areas with PCB concentrations greater than 25 ppm. No surficial soils in the area exceeded the Ohio Voluntary Action Program Direct Contact level of 18 ppm.
Additional Remediation
About 8 years later, COTA began plans for constructing a compressed natural gas fueling station at this facility. General maintenance and use would involve personnel accessing a portion of the deed-restricted area, requiring the deed restriction in this area to be removed by achieving a cleanup level of ≤ 1 ppm to allow for unrestricted land use in a high-occupancy setting.
Over three months, Trihydro performed additional investigation activities during pre-construction of the facility to assist with soil management surrounding the facility. We also undertook delineation around the formerly excavated area to determine the area that would need to be further excavated to the 1 ppm cleanup level.
COTA submitted an amended work plan to EPA outlining the anticipated additional characterization activities, excavation and site cleanup verification activities, reporting requirements and notification, and certification requirements. EPA approved the amended work plan with a cleanup goal of ≤1 ppm to remove a portion of the deed-restricted area.
Trihydro excavated about 2,000 tons of additional soil. The portion of the site within the fence is now available for unrestricted general use. Some areas could not be excavated due to access issues, and an institutional control remains over this small, inaccessible area of the site.
