Lead-Contaminated Soil Stabilization Study & DQRA, Firing Range Soils Remediation at Landfill Site, Canadian Forces Base (CFB), Kingston, Ontario
XCG carried out testing of several large stockpiles of firing range backstop soils that had been moved from firing ranges to a landfill site at Canadian Forces Base Kingston. One stockpile area consisted primarily of clay-based soils and another area was primarily sandy soils. In total about 5,000 tonnes of firing range backstop soils were present on site. XCG completed a Phase Two ESA investigation that included borehole drilling and monitoring well installation as well as sampling of the firing range soils to characterize their quality. XCG’s testing revealed elevated concentrations of lead and other metals in the soils, and visible bullets and bullet fragments. XCG completed Remedial Options Analysis (ROA), including a laboratory bench scale study and a pilot scale study in the field to assess the effectiveness of various solidification/stabilization mixes in rendering the soil non-leachate toxic. The results of these studies were favourable, and resulted in a recommended mix for soil stabilization that was consistent in producing a non-leachate toxic soil and also cost-effective. This recommended approach was supported through the completion of a detailed quantitative risk assessment and risk management plan, to evaluate the risks associated with the contaminated soils before and after stabilization, and during the construction phase when stabilization was to be carried out. Risk-based criteria were established for the contaminants of concern (COCs) as part of this project.