Phase I Environmental Site Assessment (CSA)

Updated November 25, 2016

A Phase I Environmental Site Assessment (ESA) is a non-destructive study of a property or properties based on current and historical activities on the site. 

A Canadian Standards Association (CSA) standard assessment would be presented as a "Phase I ESA". The CSA standard we use for the Phase I ESA is the Z768-01 (Reaffirmed 2012). This document must be purchased from the CSA website.

The CSA document describes the Phase I ESA as having four (4) main components:

• Records Review;
• Site Visit;
• Interviews; and,
• Evaluation of information and reporting.

The CSA Phase I ESA doesn't have a set search distance like the Ontario Regulation one does of 250 m radius around the property boundaries. It vaguely states to address the neighbouring properties that may affect your property of concern (herein after we will refer to this as the Phase I Property). The set back distance around the property is up to the author of the report and I have seen it range as low as 100 m up to the 250 m radius. It does state that at a minimum, the adjacent properties should be addressed.

The records review are to go as far back as reasonably ascertainable, however, there are mandatory record requirements as follows:

• Aerial Photographs - some municipalities offer this service for free online;
• Property Use Records - can be found in Fire Insurance Maps (FIPs) and city directories;
• Title Search and Assessment Rolls (conditional that they are either available or two other mandatory sources are unavailable) - typically we have to pay for title searches;
• Prior Phase I ESA reports - these we normally get from the client;
• Company Records - received by the client;
• Geological and Geotechnical Reports - this data is available online as a download and can be viewed from Google Earth; and,
• Regulatory Information - contacting Technical Standards & Safety Authority (TSSA) and Freedom of Information (FOI).

There are optional documentation for records review the CSA standard does mention and they include:

• Geological and Soil Maps - also available online as a download to be viewed on Google Earth;
• Topographic Maps - can be found free on the Ministry of Natural Resource website;
• Agreement of Purchase and Sale - usually from the client;
• Land Use Documents - zoning maps are often available either online or through the municipalities;
• Public Health Concerns - information from the municipalities;
• Utility Company Records - locates can be carried out, more in line if a Phase II ESA is required;
• Local Information Sources;
• Helpful Information - there is list but we get it from the Environmental Risk Information Services (ERIS) search. ERIS provides various types of reports that consolidates information from various databases and provides a comprehensive report (www.eris.ca).

Once the historical records have been collected and analyzed, a site visit provides additional information in line with current operation of the site and actual sources of concern from the Phase I Property and the surrounding area. It is an opportunity to walk around the site with a site representative that can provide information on the operations of the facility and maybe the past operations. This is generally when the interview is also carried out. The author will take photographs for both in-house notes and for the Phase I ESA report. 

The key items I tend to look for are gasoline service stations, signs of Underground Storage Tanks (USTs), industrial operations, automotive repair operations/garages and dry-cleaning facilities that do in-house services. These are the main culprits for petroleum and chlorinated Volatile Organic Compound (VOC) impacts to the soil and groundwater. 

Should the assessor deem it necessary that a potential or actual source of concern exists from on-site and/or off-site sources then a Phase II ESA will be recommended. There are often disputes between professionals on when a Phase II ESA is required and I believe this is based on a risk tolerance of the professional.  For instance, one professional may see a cross-gradient gasoline station as a minor risk and write a rationale as to why it was dismissed. A more conservative professional may not tolerate risk and justify that a Phase II ESA is required with the same information presented. 

The tolerance for risk is also based on which side of the transaction the consultant is responsible for.  When representing a seller, the consultant may dismiss low risk sources to present a better case for their client.  When representing the purchaser, the consultant will look out in the best interest of the client's purchase and want to ensure the site is pristine. 

It is often difficult to remained unbiased as a consultant.

The Phase I ESA report then brings the aforementioned information into one single document. Depending on the consultant, this report is often in excess of 100 pages. The interesting part of this is that the report is over 100 pages because of liability purposes. The entire report can be depicted into a single drawing.

The single drawing will show you the boundaries of the Phase I Property, the on-site sources of potential impact and off-site sources of potential impact. There will be times when actual sources of impact may also be present. The drawing should also show the inferred direction of groundwater flow. This single drawing can then be used to map out a design for a Phase II ESA (which will be discussed later).