The St. Laurent Station needs to undergo a multi-million-dollar rehabilitation to address falling concrete leakage into the tunnel that could force the closure of the major O-Train Station to trains for several weeks. The City of Ottawa issued a request for proposals this week for an engineering firm to conduct design and engineering services for the renewal of the St. Laurent LRT and Bus Rapid Transit tunnel structures, looking to extend the life of the tunnel by 15 years. The tender proposal includes a report from engineering firm Stantec Consulting Ltd., which says “leakage into the tunnel has been a historic concern” and concrete falling onto the LRT platform “poses a serious and ongoing risk to the travelling public.” “Leakage is an ongoing issue at several locations, particularly where water propagates onto publicly accessible areas, despite the recent Phase 2 upper platform renewal mitigating leakage,” the report said. “Within the tunnel, there are several large areas of delamination and spalling in the soffit, particularly along the expansion joints where water has leaked.” The St. Laurent Station tunnel was originally constructed in 1985, and consists of an upper-level platform, a lower-level platform, pedestrian bridges and a concourse mezzanine level. In 2024, OC Transpo closed sections of the O-Train line and the St. Laurent Station several times due to falling concrete and evidence of corrosion and possible damage to the tunnel. The report says the City of Ottawa is looking to develop a rehabilitation strategy to extend the life of the LRT tunnel by 15 years, but the city admits further renewal measures may be required after that. The work inside the LRT tunnel and pedestrian tunnels would take 11 to 13 months, with an estimated cost of $7.9 million. The work would include repairs to the concrete in overhead and abutment walls, installing a cathodic protection system in/on concrete for extended service life, drainpipe repairs and replacement, and installing troughs at soffit below all expansion joints. Stantec says accessing the soffit to complete the rehabilitation work will be “challenging and costly.” “Track closures will be required to complete work above the tracks,” the report says. “Setting up and disassembling scaffolding would be time-consuming and would require long track closures.” According to Stantec, there would be nine to 10 weeks of single-track closures in each direction in the St. Laurent tunnel for the work, and platforms would be closed for four to five weeks per platform. The full closure of the St. Laurent Station and both tracks would be required for five to six weeks for the work. The work on the upper level would be to apply waterproofing to areas of the tunnel’s deck top that are not currently waterproofed and reinstated on the pavement. The upper-level work would cost $1.6 million. The report by Stantec doesn’t provide a date for the work and shutdown of O-Train Line 1 in St. Laurent Station, but the report provides a construction timeline of 2027-2028.
