Responsible management of stormwater runoff at Westridge Marine Terminal is a priority for the Trans Mountain Expansion Project.

Storm water originates from rainstorms. Unless appropriately managed, storm water may collect debris that could affect water quality. A Stormwater Pollution Prevention Plan (SPPP) has been developed, based on guidance from the Vancouver Fraser Port Authority. This plan includes mitigation measures to protect local water quality during storm events.

The plan is designed to ensure that stormwater released off-site meets applicable permitting requirements for quality and is directed to appropriate drainage infrastructure, such as ditches and storm drains. Aspects of the plan include prescriptions for site grading, the use of stormwater collection systems and water treatment equipment.

The SPPP applies to all contractors, sub-contractors and vendors working on-site during construction. Trans Mountain has environmental inspectors on-site to monitor and enforce the plan and prevent non-compliances.

During construction, contractors will take all reasonable precautions to collect or control storm water, surface water runoff and wash water that may contain suspended materials or contaminants. Any contaminated storm water that cannot be treated on-site is hauled off-site to an appropriate disposal facility.

During operations, storm water is regularly monitored and sampled, with mitigation actions taken wherever necessary. Trans Mountain Pipeline operators monitor local weather reports for upcoming storm events and conduct inspections during a period when a stormwater discharge is occurring.