The Phase 1 Environmental Site Assessment (ESA) is an important first step in understanding the environmental history of a site and may be necessary as a condition of property sale/purchase, to secure bank financing, or to obtain a record of site condition (RSC) to allow for changes in site use.

The Phase 1 investigation consists of the following:

  • A review of available historical information on the site and surrounding area, and other resources (e.g., online aerial photography) obtainable within the project delivery date.
  • The completion and analysis of a Site Owner’s Survey.
  • A Site Walkover supervised by a Qualified Person (QP), including a walk-through of any structures present on the property.

Based on the information provided through the Phase 1 investigation, there may be no need for further investigation of the site. If the Phase 1 ESA identified any area(s) of potential environmental concern (APEC) on the subject site, a recommendation may be made to investigate these area(s) through a Phase 2 ESA.

Area(s) of Potential Environmental Concern (APEC) consist of any area on, in or under the site and surrounding area where one or more contaminants of potential concern may be present, as identified through an initial Phase 1 investigation. There are some key indicators that an APEC exists on a site:

  • Current/past site use consisted of potentially contaminating activities (PCAs). There are fifty-nine (59) potentially contaminating activities listed under O. Reg. 153/04, the guiding legislation for ESAs in Ontario.
  • Visual and/or olfactory evidence of a potentially contaminated area during the site walkover. Visual evidence typically consists of surficial stains present on the floor/ground of the site.
  • Analysis of available environmental reports, chain of title documentation, fire insurance plans and historical aerial photographs provides information leading to an APEC on-site.
  • The current and historical information available on the area(s) surrounding the subject site (particularly areas up-gradient of the site) leads to an APEC along the site boundaries.

A Phase 1 ESA ranges in cost and timelines based on the size and location of the property, and the reason for undertaking environmental due diligence on the site. For example, environmental due diligence to allow for land conversion of a site requires a more comprehensive report than a Phase One ESA to allow for financing/refinancing.

With hundreds of successfully completed Phase 1 ESAs, including many since the 2011 O. Reg. 153/04 amendments, AEL is a proven leader in environmental site assessments.

Read more about Phase One pricing in our resource page, How Much does an ESA Cost, or contact us to discuss your site-specific needs and request a free quote.

Generic Fire Insurance map

Every Property Has a History, We Can Help You Interpret the Past to Prepare for the Future

Property financing decisions and regulatory approvals often require an Environmental Site Assessment (ESA), and that process typically starts with a Phase One ESA. We’ve developed a tool to let you estimate your own Phase One ESA quickly and easily, to either CSA or O.Reg 153/04 standards. Give it a try!

What Our Customers Have To Say

In my two decades plus as a specialist in Environmental Law, I have dealt with numerous environmental consulting firms right across Canada, and from big to small, Not all of them are able to deal with sophisticated scientific questions and not all of the ones with greater scientific skills are practical. AEL Environment have the necessary science skills and their advice is always practical. They have never failed to help me and my clients.

Michael Peterson, Environmental Law
Sky Counsel Group

Our Process

  • 1. Discover

    Every property is unique. We will listen carefully and seek clarity to ensure we understand your site’s unique details and goals.

  • 2. Identify

    We will recommend an optimal approach, innovative and cost-effective services and solutions for your site, focused on achieving your desired outcome.

  • 3. Analyze

    Once authorized, we will complete the required research, testing, consulting or reports to required standards. We take the time to review any results and reports together.