What Happened

On January 24, 2012, approximately 90 m3 of light crude oil leaked from Tank 121 at Trans Mountain’s Sumas tank facility, located on Sumas Mountain. 

Rain and/or melted snow froze in roof drain piping during unseasonably cold weather. The resulting ice formation damaged the roof drain piping allowing oil to enter into the pipe and escape through the drain system. Oil then discharged into the tank containment area (this is the dyked, lined area around each tank that is required by engineering design codes as a precaution should there be a spill from a tank). 

While no oil flowed outside of the containment area, people in the surrounding area could smell odours. Air monitoring results indicated that the odours were well below levels harmful to neighbours or wildlife.

Cleanup and Remediation

The emergency phase of the response took place on January 24 and 25, 2012 while the remediation and monitoring activities continued until February 16, 2012. 

The oil was contained within the Tank 121 containment area, which has an impermeable synthetic liner, overlain by a protective layer of gravel. Vacuum trucks were used to remove the crude oil. The collected oil was temporarily stored on-site in portable tanks prior to being returned to the system pipeline. The contaminated gravel was removed and disposed of off-site at a bio-remediation facility.

Preventing Future Issues

Continuous air monitoring equipment has been installed at the Sumas tank facility and a new air monitoring program has been implemented for monitoring petroleum vapour concentrations in local neighbourhoods in the event of an incident.

Trans Mountain thoroughly investigates and addresses all odour complaints. Odours can be reported to 1.888.876.6711 24 hours a day, seven days a week. As a result of the January 2012 spill, additional notification measures have been put into place and include:

  • Notification of the local fire department dispatch
  • Early notification for residents in the vicinity via a no-cost, opt-in resident notification system; the early notification system will send an email or text message if there’s an incident that requires notification to area residents

Additionally, the drain system – found to be the cause of the spill – has been repaired and tested. Procedures have been put in place to prevent a similar incident. These include:

  • The installation of a heating system on the external roof drain system valves to prevent potential freezing
  • All drainage valves are now maintained in the closed position when the drainage system is not in use 

Finally, changes were made in the control centre process to initiate immediate field response for any observed deviations in tank volume. Additionally, a tank level monitoring device has been designed to improve the accuracy of tank level changes and minimize false alarms.