Environmental Assessments

Region: Ontario Answer # 373

An environmental assessment (EA) is a formal process in which the federal Impact Assessment Agency of Canada (IAA) or the Ontario Ministry of the Environment, Conservation and Parks evaluates the environmental impact of a proposed development or building. The law ensures that the environmental impact of many large-scale activities is evaluated before the activities are permitted. The environmental assessment process also informs the public about the project and gives interested parties the right to comment before the project is approved.

The IAA deals with projects or properties owned or regulated by the federal government. The Canadian Environmental Assessment Act outlines how and why assessments are done on federal projects. The Ontario Ministry of the Environment, Conservation and Parks, under the Environmental Assessment Actrequires that an assessment be done for activities that are proposed by the province, a municipality, or another public body. This includes activities such as building roads, hydro stations and landfill sites. The provincial Act also requires assessments for some major commercial undertakings such as waste-related projects. Most minor commercial undertakings will not require an environmental assessment.

Ontario has two common types of environmental assessments: streamlined (which includes class assessments), and individual assessments.


1. Streamlined assessments

The streamlined EA process is generally used for smaller projects that are routine and have predictable and manageable impacts. These types of projects follow a self-assessment and decision-making process. Approval is not directly granted for each project; rather, approval may be required for the type of assessment the project requires. This includes class environmental assessments, and Regulations for electricity, waste management and transit projects.

Class assessment

Class environmental assessments are used for most municipal infrastructure projects such as road, water and wastewater projects. Ministry approval is not required for these municipal infrastructure projects. Other class assessment projects that do require Ministry approval may include provincial and public sector activities such as highway construction and maintenance, and certain energy projects, such as power plants.

In a class EA, the proponent or developer of the project (e.g. Provincial Ministry of Transportation, Go Transit or Ontario Waterpower Association) will consult with the government and the public to determine the environmental impacts of the class of activities, and establish a set of rules (the streamlined process) that any project in the class will be subject to. The rules are designed to ensure that environmental impacts are limited.

2. Individual assessments

The second type of environmental assessment process is called the individual assessment. It applies to large projects such as landfills that have potential for significant environmental approval, and that do not qualify for the streamlined or class assessment process. Individual assessment projects do require Ministry of the Environment, Conservation and Parks approval.

For example, a local road would qualify for a class assessment and a highway often requires an individual assessment. Every landfill site requires an individual assessment. The proponent or developer of the project prepares an outline of the proposed project and proposes the rules that will govern the individual environmental assessment process. The outline and rules are called the Terms of Reference. The proponent must consult the public, and submit the outline to the Ministry. The Ministry reviews the Terms of Reference and the public comments and refuses, changes or approves the Terms of Reference.

The Terms of Reference

The individual assessment process follows the rules set out in the Terms of Reference. Often the Terms of Reference will establish the rules the proponent must follow in choosing a site for the project. Usually the Terms of Reference require the proponent to conduct technical studies to determine the potential environmental impacts of the proposed project. When all the studies have been completed, the proponent prepares a comprehensive document called the environmental assessment, that summarizes all the studies and describes in detail the site or route of the project and the type of construction and equipment proposed. It also describes the potential environmental impacts of the project and the steps proposed to minimize those impacts.

Review by the Minister

Each individual assessment is reviewed by the Ministry of the Environment, Conservation and Parks. The Minister can make a number of decisions:

  • approve the project,
  • approve the project with conditions,
  • reject the project,
  • refer it to mediation, or
  • refer it to the Environmental Review Board for a hearing.

If a decision is made to approve the project, the project can go forward, provided all terms and/or conditions that may have been placed on it by the Ministry are followed. As well, there may be other approvals needed as required by other legislation, such as the Planning Act, or Ontario Water Resources Act. If an EA is denied, then the project is not allowed to proceed.

To determine whether an environmental assessment and what kind is needed for a project that may affect you, whether you have the right to be consulted or to make submissions, or to get assistance conducting or opposing the process, visit the Ministry of the Environment, Conservation and Parks at ontario.ca, or the Impact Assessment Agency of Canada.

For legal advice, contact an environmental law lawyer.


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