by Adam Radlowski, M.Sc., R.P.Bio

The BC Contaminated Sites Regulation (CSR), under the Environmental Management Act, specifies the requirements for site remediation in the province. The BC CSR allows substances to be remediated to numerical standards and risk-based standards. Environmental risk assessments are undertaken when it is too costly or not feasible to safely remediate substances to numerical standards or where there is potential for contaminants to cause harm to people and the environment.

Environmental risk assessments can have a human health component, an ecological health component, or have both components. Environmental risk assessment reports that have a human and ecological health component are referred to as “human health and ecological risk assessments.” Environmental risk assessment reports identify the ways and circumstances that people and biological organisms can encounter substances and propose risk management measures to mitigate substances that pose potential unacceptable risks to those receptors.

Under the BC CSR, environmental risk assessments are used to support applications for a Certificate of Compliance, an Approval in Principle, and a Contaminated Soil Relocation Agreement. There are two types of provincial environmental risk assessments that can be prepared by a Qualified Professional to obtain one or more of these provincial instruments.

A BC Protocol 13 Screening Level Risk Assessment (SLRA) is the simplest form of evaluation that uses an exposure pathway questionnaire with site specific information, and a groundwater protection model developed by the BC Ministry of Environment and Climate Change. The SLRA can only be used if precluding conditions are met. For example, the evaluation of contaminants in soil vapour, surface water, and sediment are not permitted under BC Protocol 13 SLRA.

A Detailed Risk Assessment (DRA) is more versatile than a BC Protocol 13 SLRA as this type of risk assessment is not bound by the same restrictions as a BC Protocol 13 SLRA. DRAs generally use the same data that are collected during environmental site investigations. At times additional data may be required in a DRA. This could include a biological assessment of the site, collection and analysis of biological tissues, and submission of samples for toxicity testing in cases where contamination has reached or is likely to have reached an ecologically sensitive environment. DRAs are completed with BC Technical Guidance 7 supplemental guidance for risk assessments in mind.

Whether SLRA and DRA, environmental risk assessments allow clients to obtain financing from lenders, meet terms of land transactions and lease agreements between regulations parties, obtain other government approvals (such as an occupancy permit), and demonstrate compliance to environmental regulations.