An Outline of the Environmental Site Assessment Phases

Environmental Site Assessments (ESA) are conducted in order to monitor major projects and to assess their possible environmental impacts. They have become a requirement for developmental planning and management and they provide the opportunity to mitigate environmental liabilities associated with industrial and commercial land. There are three phases associated with an ESA, to conduct an ESA at any phase a  ‘Qualified Person’ (OP), recognized through the Ministry of the Environment (MOE), must be hired. This person should have a license under the Professional Engineers Act or hold a certificate of recognition from the Professional Geoscientists Act. If you require an ESA, read on for a brief explanation as to what each phase entails.

Phase I ESA

Phase I ESA’s are often conditioned by financial institutions, banks, buyers and sellers during property transfers, property developments or property financing. A Phase I ESA will allow the parties to attain complete clarity of potential environmental liabilities. In this phase the ESA report will determine if the property and it’s adjacent lands have any “areas of potential environmental concern” (APEC). An OP will review the property record, interview past and present owners, conduct a site reconnaissance and evaluate the information collected from each step in order to produce a Phase I report. This report will identify any APEC’s on the site and will help to plan the areas of investigation required by a Phase II ESA.


Phase II ESA

Generally, it is recommended that a Phase I ESA be completed before commissioning a Phase II ESA. An assessment at this stage will confirm if the area’s of concern identified in Phase I are in fact contaminated. A Phase II ESA is required if the site was or is used for industrial purposes, was or is a garbage or liquid dispensing facility and if the site operates or operated dry cleaning equipment. An ESA is also required if it is known that a contaminant has affected water or land on the property. In this phase an OP will plan and conduct a site investigation. They will provide an evaluation of the site investigation and draw up a Phase II ESA report that will be delivered to the owner of the property. During the investigation portion of the ESA an OP may collect water samples or complete boreholes and test pits to collect soil samples. They will then take these samples to a laboratory to determine any concerning soil conditions.



In Phase III, remediation of the contaminants identified in the Phase II ESA will take place. Once a Phase III ESA has been completed, all of the site condition standards required by the MOE should be satisfied. An OP will provide options and budgeting  for remediation, this may include digging up and removing the contaminated material or creating a biodegradation pile to treat the contaminated material. They will also conduct confirmatory sampling once the process is complete.

In late 2011, the MOE introduced new requirements for carrying out a Phase I ESA which amended the Record of Site Condition (RSC) Regulation 153/04. In our next blog on ESA’s we will explore these new requirements further.

Background on the environmental phases was provided by Oakhill Environmental Inc.

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