The St. Laurent Pipeline System is a vital part of Enbridge Gas’ natural gas distribution network in the National Capital Region. It directly and indirectly supplies natural gas to approximately 165,000 customers in Ottawa and the surrounding area, including in Gatineau, Quebec. These customers include homes, businesses and institutions like the Cliff Street Heating Plant and hospitals, that depend on reliable energy sources for daily operations.

Enbridge Gas is taking decisive action to enhance the safety and reliability of its pipeline infrastructure by proposing to replace specific portions of its St. Laurent Pipeline System. These portions are currently located along St. Laurent Boulevard in Vanier and Ottawa South.

The proposed St. Laurent Pipeline Replacement Project will involve the installation of approximately 13 km of new 6-inch, 12-inch and 16-inch extra high-pressure steel pipeline segments as well as approximately 4 km of 2-inch, 4-inch and 6-inch diameter intermediate pressure polyethylene pipeline segments.

Enbridge Gas originally applied to the Ontario Energy Board (OEB) for approval of this work in March 2021. In its Decision and Order issued in May 2022, the OEB urged Enbridge Gas to conduct further testing and provide additional physical evidence of the pipeline’s condition.

Enbridge Gas has completed detailed inspections, intensive analyses and safety evaluations of the St. Laurent Pipeline System and has determined that an immediate replacement is required to ensure the continued safe and reliable delivery of natural gas service.

If approved, construction may begin in 2025.

Project status/timeline

  • Feasibility


  • Environmental studies


  • Regulatory review


  • Regulatory approval


  • Under construction


  • In-service


Project status/timeline

  • Feasibility


  • Environmental studies


  • Regulatory review


  • Regulatory approval


  • Under construction


  • In-service



Project information