Written by Lorena La Osa Gomez, Senior Project Manager, Environmental Due Diligence & Remediation, Pinchin Ltd.
What is an Environmental Risk Assessment (ERA)?
An Environmental Risk Assessment (ERA) is a scientific evaluation of the human and/or ecological health risks associated with contaminants of concern (COCs) present in soil and groundwater. Human and ecological “receptors” may be exposed to these COCs through multiple exposure pathways including ingestion/uptake of soil or water, inhalation of vapours, and direct contact with contaminated media. Receptor exposures are estimated, and risks quantified, using established models and toxicological data.
What is a Site-Specific Risk Assessment (SSRA)?
The Alberta Ministry of Environment and Protected Areas (formerly Alberta Environment and Parks) uses the ERA process to derive generic standards. Because these are “one-size-fits-all” standards, intended for any site in Alberta, they can often be overly conservative. However, the same models used to derive regulatory criteria, and associated guidance documents, can be followed using site-specific characteristics to produce a more “tailored” outcome, or Site-Specific Risk Assessment (SSRA). The SSRA can be conducted using soil and groundwater data obtained through Phase II Environmental Site Assessments, however, more detailed ERAs will also incorporate information such as soil vapour concentrations from below ground, beneath buildings or within indoor air, sediment and surface water sampling data, or ecological surveys. All of this additional information helps make the SSRA more unique to the particular site.
In Alberta, an SSRA is an ideal tool for deriving more achievable remedial targets, or for supporting an Exposure Control Plan to manage environmental impacts in place, when remediation is not cost effective or technically practicable. The SSRA is an acceptable approach under the Alberta Tier 2 Guidelines, where conditions violate Tier 1 Guideline assumptions or where modifications are outside the scope of the prescriptive Tier 2 Guideline approaches. SSRAs that do not require restrictions on the typical land use activities and do not require ongoing risk management may be acceptable for regulatory closure.
For additional clarification on the requirements and expectations for completing site-specific risk assessments (SSRAs) for contaminated sites in Alberta, visit: https://open.alberta.ca/publications/supplemental-guidance-on-site-specific-risk-assessments-in-alberta
If you’d like more information about Environmental Risk Assessments or need help with a Site-Specific Risk Assessment, contact your local pinchin office or call us at 1.855.PINCHIN (746.2446).