Brantford Field Test: Biopile, Air Sparging and Soil Vapour Extraction on Greenwich-Mohawk Brownfield Site

The City of Brantford, ON, will test on-site remediation measures at the city-owned Greenwich-Mohawk brownfield site, located two kilometres from the downtown area. The soil and groundwater of the 0.21 km2 site is heavily contaminated with petroleum hydrocarbons (PHCs) and volatile organic compounds (VOCs) from past industrial and manufacturing activities. After conducting a GMF-funded Environmental Site Assessment and a remedial action plan (GMF 10271) for the site, the city considered a number of options for cleaning up the area and chose on-site soil and groundwater treatment as the best way to remediate the site cost-effectively, with minimal environmental and social impacts. This initiative will also build on the results of a previous field test (GMF 12009) by assessing lower cost in-situ treatment options. The city will reduce PHCs to acceptable provincial levels in 1000 cubic metres of contaminated soil on-site by using biopiles, air sparging and soil vapour extraction. In a triple-bottom-line evaluation, the study will look at biopile design options, contaminant reduction, treatment duration, cost, and level of disruption to the community, among other factors. The study will also include a risk assessment to identify the root causes of contamination and help set remediation targets. While conventional remediation would involve the excavation, transport and replacement of large amounts of contaminated soil, on-site cleanup allows the soil to be re-used and reduces expenses. The use of multiple techniques concurrently allows for an integrated approach that may optimize performance. If the field test is successful, the full-scale project that will result is the remediation of the entire site to acceptable provincial standards for future residential or park redevelopment. Using the final optimized design of the biopiles, the city will treat approximately 68,000 m3 of soil (about 45 per cent of the total contaminated soil requiring remediation; the rest will be remediated using other techniques). The redevelopment of the Greenwich-Mohawk brownfield site would be a natural extension of steps to revitalize the downtown core. (Project description from original funding application)