What Happened

On July 15, 2005, a leak of light crude oil was identified from a buried 20-inch transfer pipeline connecting the Trans Mountain Sumas Station and the Trans Mountain Sumas Tank facility in Abbotsford, BC. Approximately 210 m3 of oil leaked onto the surrounding property.

The root cause of the pipeline failure was unauthorized stockpiling of soil (fill) on a nearby private property, which caused the underlying peat bog soils to fail and shift laterally. The soil movement in turn caused the pipeline to buckle, resulting in the leak.

Oil from the pipeline release migrated into a small creek and moved downstream approximately 750 metres. The leak and subsequent remediation affected a 14,300 m2 area of wetland, stream and riparian habitat.

Cleanup and Remediation

Upon detection of the spill, we shut down the pipeline for necessary repairs and to allow for safe access and remediation in area around the pipeline. First responders built several weir dams were built within the stream to prevent further downstream migration of oil.

A Restoration Plan and a Long-Term Monitoring Program were developed and finalized through discussions between Trans Mountain, the Department of Fisheries and Oceans Canada, the BC Ministry of Environment and the National Energy Board (NEB). Restoration goals included re-establishment of a functioning stream channel and restoration of any lost aquatic and terrestrial habitat.

The Long-Term Monitoring Program assessed the success of the restoration on an annual basis over a period of five years to determine if the incident resulted in any long-term or residual effects on biological resources and habitat quality. We completed long-term monitoring of the site in 2012 and results indicate the restoration was successful.

Preventing Future Issues

The cause of this leak was due to activity outside of the pipeline’s prescribed 30-metre safety zone. In response to the spill, our Natural Hazards Management Program was expanded to incorporate the identification of locations with soils that could be susceptible to lateral movement from adjacent loading. This identification ensures development of site-specific protection plans.

Regular aerial patrols monitor the pipeline right-of-way and these patrols report details of any construction activities near the pipeline. Trans Mountain’s Pipeline Protection and Technical Services groups follow up to determine whether any external loading hazards may exist at the reported location.

Added emphasis was also placed on right-of-way clearing in fast-growing vegetated areas to help ensure ready access and reliable aerial observation of any potential problems.