Hypothetical oil spills were assessed from the proposed Enbridge Northern Gateway Pipeline that would transport Alberta oil sands crude to the British Columbia coast for export to overseas markets. This project involved construction of a new twin pipeline system running between Bruderheim, Alberta near Edmonton, to a new marine terminal in Kitimat, on the British Columbia coast. 525,000 barrels of crude oil per day would be piped west from Alberta to Kitimat, while 193,000 barrels of condensate per day would be brought to Kitimat on tankers and transported east through the pipeline to Alberta. The pipeline system would pass through many physiographic regions on its way to the coast, including prairies, foothills, and mountains, as well as crossing numerous streams. Hypothetical release modelling was carried out to support the environmental assessment being conducted.
The goal was to determine the range of expected effects in the event of a release from the pipeline considering multiple sites, river flow rates, and oil types. SIMAP model results were also used as the foundation of the chronic toxicological and human health assessments conducted by project partners Stantec Inc. and Amec. Together, these studies made up the Ecological and Human Health Risk Assessment (EHHRA).
Enbridge Northern Gateway Pipeline Oil Spill Modelling
RPS needed to identify potential effects released at any point along the proposed oil pipeline. Every oil spill is different, so the study was to quantitatively identify and bound the range of effects following potential hydrocarbon releases. Work was conducted to identify the criteria that would be used to consider the range of biophysical and environmental conditions, as well as public and tribal concerns to include sensitive and representative locations. This comprehensive assessment included an Ecological and Human Health Risk Assessment (EHHRA) assessing the range of potential acute and chronic effects affecting both ecological and human receptors. Comprehensive spill modeling was used to assess route alternatives to minimize potential effects and inform oil spill response plans.
Hypothetical releases of multiple oil types from points along the pipeline right-of-way were modeled using the OILMAPLand modeling system developed by RPS. This study was conducted for response planning purposes and a Semi-Quantitative Risk Assessment (SQRA) to provide hypothetical maximum extents and estimates of downstream travel times for spilled oil at over a thousand sites along the pipeline. A second modeling study was carried out using the SIMAP model system developed by RPS to assess the transport and fate of hydrocarbons as well as their acute toxicological effects.