Gentle Remediation Options (GRO) for Brownfield Sites in Canada: Case Studies, Comparative Insights, and Policy Pathways
Rainier Macalalag, MLWS 2025
Brownfields are properties where past uses left real or perceived contamination that constrains reuse and investment. They are common across Canadian cities and carry social, economic, and ecological costs. This paper evaluates whether gentle remediation options that use plants, microbes, fungi, and supportive soil amendments can deliver protective cleanup while restoring soil function and enabling redevelopment. The approach is a systematic literature review of peer reviewed studies and credible government and NGO reports, organized by contaminant class and Canadian conditions such as short growing seasons and urban density. Three case studies (Vancouver’s Southeast False Creek, an industrial tract in Montreal, and smelter affected lands in Sudbury) ground the analysis. A policy scan assesses provincial guidance, evidence standards, and approval pathways. Performance is evaluated against risk reduction, measurable contaminant change, soil and vegetation recovery, life cycle costs, and social outcomes. Limitations include uneven data across provinces, variable monitoring endpoints, few long-term field results for some contaminants, and reliance on grey literature where Canadian studies are sparse. Case study findings may not transfer to dissimilar sites. The review finds that gentle remediation options are technically credible and competitive on life cycle terms, especially for diffuse metals and lighter petroleum fractions. They are most effective with clear risk-based objectives, adaptive monitoring, and procurement and approvals that value soil function and community outcomes. With these shifts, brownfields can move from liabilities to renewed urban assets.
