Mainway Site Assessment and Remediation
XCG was retained by Barnes Group Inc. (BGI) to conduct site assessment and remediation activities at a former automotive component manufacturing facility in Burlington, Ontario.
As a result of Phase I and II Environmental Site Assessment (ESA) activities completed by another consultant, elevated concentrations of chlorinated volatile organic compounds (CVOCs) were identified in both the shallow overburden groundwater and the deep fractured bedrock groundwater in the vicinity of a former chemical storage room. BGI retained XCG to further investigate and delineate the extent of the CVOC-related impacts and to conduct pilot-scale remediation activities using sodium permanganate to assess the effectiveness of in-situ chemical oxidation (ISCO) as a remedial approach. The combined cost of the site assessment and remediation activities completed to-date by XCG at the former manufacturing facility has been approximately $800,000. The final project cost is projected to be approximately $1,500,000.
XCG completed additional subsurface investigation activities at the site to provide further delineation of the shallow groundwater impacts and to better characterize the deep bedrock groundwater quality. XCG also investigated the potential migration of shallow groundwater impacts along potential preferential flow pathways (e.g. utility trenches).
Pilot Scale In-Situ Chemical Oxidation (ISCO)
XCG completed a pilot scale ISCO injection program in the vicinity of the former chemical storage room. XCG injected a dilute solution of sodium permanganate into several shallow injection wells and compared pre- and post- injection monitoring data to evaluate remedial performance of the ISCO process. XCG’s interpretation of key field parameters and laboratory analytical results identified that the sodium permanganate solution had been successfully distributed within the subsurface and that the concentrations of CVOCs had been significantly reduced at some of the groundwater monitoring locations.
XCG prepared a detailed scope of work and cost estimate to remediate the on-site CVOC-related soil and groundwater impacts over a three-year period. Following approval of the work plan by BGI, XCG proceeded with the remedial activities, including demolition of the former chemical storage room, excavation of a total of 1,795 metric tonnes of CVOC-impacted soil, placement of 4,000 kilograms of potassium permanganate along the base of the remedial excavation, installation of an infiltration gallery, and completion of ISCO injection events.
Based on the size and complexity of this project, XCG implemented several innovative technologies in order to better understand, monitor, and document the remedial activities, including the use of multi-parameter groundwater quality instruments, electrical conductivity data loggers, high-resolution geo-referenced air photos, high-accuracy GPS surveying equipment, and advanced 2D/3D visualization software.