Ontario Environmental Assessment — EA Act, Federal IAA, and Contaminated Sites

Provincial EA Framework — Environmental Assessment Act RSO 1990

The Environmental Assessment Act RSO 1990 c E.18 (EAA) governs the assessment of environmental effects of major projects in Ontario. It applies to "undertakings" — broadly defined to include projects, activities, and plans — by public sector proponents (provincial government, Crown agencies, municipalities) and designated private sector proponents.

The purpose of the EAA is to ensure that environmental effects of major undertakings are considered before approval — the "look before you leap" principle. Undertakings subject to the EAA require approval from the Minister of the Environment, Conservation and Parks (MECP) before proceeding.

Three EA tracks under the Ontario EAA:

• •Individual EA — for major provincial infrastructure projects (highways, transit, waste management facilities). Full assessment process including terms of reference, EA document, agency/public review, and Minister approval. Can take 5–10 years.
• •Class EA — pre-approved process for routine categories of projects (municipal road upgrades, transit projects, waste diversion). Proponent follows a pre-approved schedule including public notices and consultation. Only individual opponents may "bump up" to a full EA.
• •Streamlined EA (post-2021 amendments) — Bill 197 (COVID-19 Economic Recovery Act 2020) and Bill 257 amended the EAA to add a more expedited process for certain resource sector and economic projects, with reduced public consultation requirements — controversial amendments that face ongoing legal challenges from First Nations and environmental groups.

Federal Impact Assessment Act 2019

The federal Impact Assessment Act SC 2019 c 28 (IAA) replaced the previousCanadian Environmental Assessment Act 2012. The IAA governs federally designated projects — a defined list of project types with federal environmental effects (s.7 and Physical Activities Regulations SOR/2019-285).

Designated projects under the IAA include: nuclear facilities, interprovincial pipelines, federal lands facilities, offshore oil and gas, international/interprovincial bridges, certain electrical transmission lines, and mining projects over specified thresholds. Note: in Reference re Impact Assessment Act 2023 SCC 23, the Supreme Court declared significant portions of the IAA unconstitutional as exceeding federal jurisdiction — Parliament responded with amendments under Bill C-69 amending legislation, and the IAA is under ongoing constitutional revision.

For projects with both federal and provincial EA requirements, the federal Impact Assessment Agency of Canada and Ontario MECP have entered substitution and cooperation agreements to run joint or substituted processes — avoiding full parallel assessments.

Conditions of Approval and Enforcement

EA approvals are accompanied by conditions — binding requirements on the proponent addressing mitigation measures, monitoring programs, and reporting. Conditions are enforceable: violation is an offence under the EAA (s.40) and the proponent may face stop-work orders, remediation orders, and fines.

Post-2021 changes to the Ontario EAA reduced the public consultation requirements and timelines for many projects. Environmental groups argue this weakened the EA process; the government argues it was necessary to reduce backlog and facilitate economic development. These changes are significant context for any current EA proceeding in Ontario.

Environmental Liability — Contaminated Sites

The Environmental Protection Act RSO 1990 c E.19 (EPA) is the primary Ontario statute governing contamination and environmental liability. Key provisions:

Section 18 Environmental Compliance Approvals (ECAs): facilities that discharge contaminants into the natural environment require an ECA. Operating without an ECA, or exceeding ECA conditions, is an offence.

Section 93 Remediation Orders: the MECP Director may order a "person responsible" to remediate a contaminated site. The "person responsible" is broadly defined to include the owner of the contaminant, the owner of the land where contamination occurred, and successors in title. Innocent purchasers who had no knowledge of contamination at time of purchase may still face remediation orders — the EPA creates a form of strict liability for the current owner.

Retroactive liability: the EPA applies to existing contamination from past industrial activity, not just future discharges. This is significant for brownfield development — purchasers acquiring contaminated commercial/industrial land may inherit historic contamination liability.

Personal liability: s.194 of the EPA and s.148 of the Ontario Water Resources Act create personal liability for directors and officers of corporations who "direct, authorize, assent to, acquiesce in or participate in" corporate EPA violations. No mens rea is required for most EPA offences — due diligence is the only defence.

Records of Site Condition (RSC) / O.Reg. 153/04

Ontario Regulation 153/04 (Records of Site Condition — Part XV.1 of the Act) establishes the framework for voluntary site assessment and filing of Records of Site Condition (RSCs) — also called Phase I and Phase II Environmental Site Assessments (ESAs).

Phase I ESA: desktop review of site history, records search, and site reconnaissance — no sampling. Identifies "areas of potential environmental concern" (APECs).

Phase II ESA: intrusive investigation — soil sampling, groundwater monitoring wells, laboratory analysis — to characterize the nature and extent of contamination. Compared against O.Reg. 153/04 Table 2 (generic site condition standards) based on site use (residential/parkland/institutional vs commercial/industrial).

A filed RSC (filed in the Environmental Site Registry) is required before a zoning change or building permit that increases land sensitivity (e.g., industrial to residential). The RSC filed by a Qualified Person (QP — P.Eng. or P.Geo.) limits future liability claims to the extent of the representations in the RSC.

CERB — Certificates of Property Use

A Certificate of Property Use (CPU) is issued by the MECP Director where a contaminated property cannot meet the full site condition standards but can be used safely for a specified purpose with risk management measures (institutional and engineering controls). CPUs restrict property use, require ongoing monitoring, and bind the current and future owners.

CPUs must be disclosed in real estate transactions — failure to disclose is a civil tort and regulatory offence. Real estate lawyers representing purchasers of commercial/ industrial properties should always conduct an Environmental Site Registry search to identify filed RSCs, filed CPUs, and notices of contamination.

First Nations Consultation in EA

The duty to consult Aboriginal peoples regarding proposed projects that may affect Aboriginal or treaty rights is a Crown constitutional obligation under s.35 of theConstitution Act 1982 (Haida Nation v British Columbia (Minister of Forests) [2004] 3 SCR 511). The duty extends to the EA process.

Ontario's EAA and the IAA both include provisions for Indigenous consultation. Failure to adequately consult can result in judicial review — courts have quashed both EA approvals and regulatory approvals that failed to meet the Crown's duty to consult. Indigenous communities may also be interveners in EA proceedings.

Practical Checklist for Environmental Counsel

• ✓Determine EA triggering — is the project subject to provincial EAA (public sector proponent or designated private sector), federal IAA (Physical Activities Regulations designated project), or both?
• ✓Confirm jurisdiction for any Class EA — review the applicable Class EA document for the project type (municipal Class EA for roads/sewers vs transit Class EA)
• ✓For commercial real estate transactions: search the Environmental Site Registry, Ontario Ministry of Environment database, and fire marshal records — Phase I ESA minimum
• ✓Due diligence for purchasers of contaminated land: Phase II ESA, quantify remediation cost, obtain representations and warranties or price reduction reflecting liability assumed
• ✓Corporate due diligence for EPA compliance: s.194 EPA personal liability for directors — confirm ECA compliance, spill prevention and response plans, and monitoring programs
• ✓Brownfield redevelopment: RSC filing requirement before rezoning; CPU restrictions bind future owners — disclose in purchase and sale agreement
• ✓First Nations consultation: identify affected First Nations in the project area early — inadequate consultation is the most common ground for successful judicial review of EA approvals