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Changes to the guidelines for completing a Phase I Environmental Site Assessment

Posted by Greg Chew on May 5, 2015 11:02:00 AM

Estimated reading time: 3 minutes 

Phase I Environmental Site Assessment

In late 2011, the Ministry of the Environment (MOE) implemented changes to the guidelines for completing a Phase I environmental site assessment (ESA). These changes affected the requirements and conditions of various components of conducting an ESA including the term of validity of an ESA. Property owners need to be aware of these new conditions when looking to sell their industrial or commercial land. This blog highlights the important changes that you need to be aware of.

Note: the changes only apply to ESA’s that are being submitted as part of a record of site condition (RSC).


Canadian Standards Association (CSA) Standards replaced

New stand-alone rules have been prepared for ESAs, replacing the tired cross-referencing standards with the CSA. The new rules help to standardize ESAs, making the ESA more widely accepted and improved in quality.


Record of Site’s to be reviewed by the MOE 

Before an RSC is filed to the Environmental site registry it will now be checked or reviewed. The MOE can now ask questions about an RSC prior to it’s filing.  

New rules for Qualified Persons

  • A qualified person (QP) must be a member of either the Association of Professional Geoscientists of Ontario or license holders of Professional Engineers Ontario

  • If the QP or his employers have interests in the property to be assessed, they are prohibited from supervising or conducting the ESA

  • After a report is prepared the OP and owner must retain the report for seven years

  • Steps must be taken by the QP and owner to obtain relevant information on the property, owners must provide the information

  • a QP must prepare a conceptual site model. This is to provide a tool for QP’s to summarize a sites conditions and using the ESA and risk assessments.  

Changes to Phase II ESA requirements

If a potentially contaminating activity (PCA) is currently taking place or has taken place at the property a Phase II ESA is required. Additionally, if a QP discerns that a PCA within the study area would result in an area of potential environmental concern then a Phase II ESA is also mandatory.  

Why your 2009 Phase I ESA will now be invalid under the changes  

With the new rules and standards, a Phase I ESA cannot be submitted with a RSC report if it is older than 18 months from the filing. This means that if you had an ESA done in 2009 and you are submitting a RSC in 2015 your Phase I ESA is no longer acceptable. You will be required to hire a QP to complete a Phase I ESA update in order to file the RSC.


Standards for acceptable contamination levels have also been changed by the MOE, what was once considered clean under the act may not be, under the new regulations. We explore the new contaminate concentration levels in our next blog on environmental site assessments. 

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