What extra due diligence should I do before buying near a former gas station or dry cleaner in Ontario?
Former gas stations and dry cleaners are two of the classic red-flag former uses in environmental due diligence, because both commonly involved underground fuel storage or chemical solvents that can migrate through soil and groundwater well beyond the original property's boundaries. Buying near, rather than on, such a site doesn't eliminate the risk, since contamination doesn't respect lot lines and can travel underground onto neighbouring land over time.
A Phase 1 Environmental Site Assessment is the standard first step, and its records search and government database check specifically look for exactly this kind of nearby historical activity, not just the subject property's own use. If the Phase 1 identifies a real risk of contamination migrating from the neighbouring site, a Phase 2 assessment with actual soil and groundwater sampling, and sometimes an assessment of vapour intrusion risk into any building, may follow. Buyers should also ask about any known ministry orders or remediation history affecting the nearby property, since a neighbour's contamination becoming a legal or practical problem for the subject property is a real and recognized risk in Ontario. Building in enough due diligence time before waiving conditions is essential here.
Key takeaways
- Contamination from a nearby former gas station or dry cleaner can migrate onto adjacent land.
- A Phase 1 ESA specifically checks nearby historical land uses, not just the subject site.
- Flagged risk may lead to Phase 2 sampling and, where relevant, a vapour intrusion assessment.
- Build adequate due diligence time into the offer before waiving conditions.