Human health and ecological risk assessment, remedial action plan design, and verification: for contaminated sites requiring cleanup before redevelopment or regulatory closure.

What triggers the need for risk assessment?

Risk assessment is needed when Phase II results exceed the applicable Ontario standards (Table 1/2/3/9) and the property owner wants to pursue a risk-based approach rather than excavation to standards. It is also required for RSC filing when land use is changing to a more sensitive category.

Key Deliverables

• Screening-level or detailed HHRA (Human Health Risk Assessment)
• Ecological risk assessment
• Tier 2 Modified Generic Risk Assessment (MGRA) for Ontario RSC pathway
• Remedial action plan (RAP) design
• Remediation oversight and verification sampling

How long does the RSC process take?

From Phase I through RSC filing, the typical timeline is 6–18 months for straightforward sites. Complex sites with multiple contaminant groups, groundwater impacts, or Tier 2 risk assessment can take 2+ years. MECP review of the RSC filing itself takes 2–6 months.