Ecological and human health sediment risk assessment for a hydrocarbon-impacted site in Lake Athabasca

The operation of a public port facility near Uranium City, Saskatchewan has resulted in elevated levels of hydrocarbons in soil, groundwater and sediment. Remedial action in the uplands portion of the site was successful and a risk management approach was initiated for the aquatic portion of the site in order to resolve human health and ecological issues. Ecological risks were assessed using a sediment weight-of-evidence approach involving chemistry, toxicity, bioaccumulation and benthic community structure. Human health risks were assessed via fish consumption, water ingestion and direct contact according to Health Canada guidance. This presentation included an overview of the general risk assessment approach as well as site-specific data and findings. The primary focus was on the challenges confronted during the risk assessment process, such as the need to include alkylated PAHs as a COPC in the human health risk assessment and to evaluate ongoing propeller wash and sediment resuspension for sediment risk management, even though the facility is no longer operational.