Publication Date: October 2005
This Procedure document contains plain language guidance on how to conduct risk assessment work and draft a risk assessment report for submission to the Ministry of the Environment (the ministry) under section 168.5 of the Environmental Protection Act (EPA) and Schedule C in Ontario Regulation 153/04 Records of Site Condition (RSC) (the RSC Regulation). The RSC Regulation governs the preparation of risk assessment in Ontario for chemical contaminants in support of the submission of a Record of Site Condition for an individual property. Risk assessment reports must comply with the mandatory requirements specified in Section 4 of Schedule C (Table 1). References to the RSC Regulation and the EPA and exact quotes, taken from Schedule C are provided which identify the mandatory requirements for all risk assessment reports and identify the characteristics of risk assessments that may use alternate procedures and be subject to alternate time lines. However, stakeholders are still required to understand what is in the legislation and regulations and where necessary, seek legal counsel. Stakeholders should ensure that they refer to the most recent version of this document and any amendments to the RSC Regulation or Act.
Where the guidance document refers to mandatory requirements for risk assessment reports, as set out in regulation, these actions are signified by the word “must”. Failure to meet these mandatory requirements means that the risk assessment work undertaken and the subsequent risk assessment report will not be considered by the ministry to be completed in accordance with the RSC Regulation. Where the guidance document indicates that something “should” be done, this is an expression of what the ministry considers to be a best practice. If the best practice is not undertaken, it is advisable that the reasons why the best practice was not followed be set out in the risk assessment report. It is the discretion of the approving Director to determine whether, and to what extent, best practices have been met, and whether to accept the risk assessment report, under Section 168.5 of the Environmental Protection Act.
This Procedure document provides the minimum requirements for conducting both the human health and ecological components of risk assessment for contaminated properties. It is not a comprehensive description of the risk assessment approach required for every potential contaminant situation or site condition. Since site conditions differ at each property and decisions may have to be made that are unique to existing circumstances, some risk assessment options are provided. Sound scientific judgment should be exercised throughout the risk assessment, however, in all cases.
In general, this Procedure document does not provide details for biological or hydrogeological monitoring, or epidemiological studies or address all activities required for the design of community-based or area-wide risk assessment studies.
This Procedure document is intended for use by experienced risk assessors in conjunction with best professional judgment. Additional information sources are provided at the end of this Procedure document for reference purposes.