Phase 2 Environmental Site Assessment

At Ben Engineering, we provide both Phase 1 and Phase 2 Environmental Site Assessments (ESAs), performed by a Professional Engineer (P. Eng.) and Professional Geoscientist (P. Geo.).

In Ontario, there are two options to conduct these assessments, which although their title is identical (i.e. Phase 2 Environmental Site Assessment) they are significantly different. One is based on the Canadian Standard Association (CSA) Z769-00 standard, while the other is based on the Ontario Regulations O.Reg. 153/04 and 511/09.

The CSA-based assessment is primarily used for real estate transactions (i.e. financing and due diligence). On the other hand, the O. Reg. 153/04-based is mostly used for rezoning, filing a Records of Site Condition (RSC), building permits applications, and other submissions to governmental applications.

Phase II Environmental Site Assessment (ESA) is generally conducted following a Phase 1 ESA. While the Phase 1 ESA is more theoretical and only determine any potential issues that may affect the site (based on reviewing the current and historic uses of the property and the surrounding area), the purpose of the Phase II Environmental Site Assessment is to determine if such contamination actually exists, and to what extent.

Commonly, a Phase 2 Environmental Site Assessment is required if a site or an adjacent property is or has been used for potentially contaminating activities. Such activities/uses may include dry cleaning, auto repairs, manufacturing, gas service station, or scrap yard. Additionally, the presence of any aboveground storage tanks (ASTs) or underground storage tanks (USTs) within the site is also considered a potential area of environmental concern.

Types of soil or groundwater contamination commonly found include petroleum hydrocarbons, organic compounds, metals and polychlorinated biphenyls (PCBs). The process typically includes an intrusive on-site sampling program, which consists of the following steps:

While the scope of work is not absolutely defined in the Standard and can be modified in accordance with the client's needs, there are four principles involved in the Phase 1 Environmental Site Assessment process:

If soil or groundwater contamination is a concern, the process includes superficial and sub-surficial sampling. This may include drilling boreholes at a few strategic locations throughout the site (preferably to a depth that reaches the groundwater), installing monitoring wells as needed, and collecting soil and groundwater samples at each borehole.
If materials present at the site are suspicious (for example, construction materials containing asbestos or lead), collecting samples of these elements is required.
On-site measurement of the samples’ moisture level.
Laboratory analysis of the samples collected in order to determine if contaminating materials exist, what type of materials, and their concentration.
Analysing the results received from the laboratory is order to determine if the concentrations of the contaminating materials exceed the regulations of other guideline limits.
Preparing a written report, which includes the description of the borehole locations, description of the content of each individual borehole, the laboratory results, the analysis of the findings, and conclusions and recommendations for further actions (if required).

The Phase 2 Environmental Site Assessment can be completed in accordance to the CAN/CSA-Z769-00 Standard or O.Reg. 153/04 (Records of Site Condition). The sampling procedure typically follows the Ontario Ministry of the Environment guidelines.

Phase 2 Environmental Site Assessments can be conducted based on the CSA Z769-00 Standard or based on the O.Reg. 153/04 (for obtaining a Record of Site Condition). The major differences between these reports are listed in the following table: