The Western Beaches Tunnel Project is an upgrade to an existing storm water collection and treatment system along the City of Toronto’s waterfront. The 3km tunnel system is connected by a series of retention chambers and collection shafts that extend along Lakeshore Boulevard W from Parkside Drive to Strachan Avenue. The stormwater is eventually collected, screened and treated by a UV disinfection system before being discharged to Lake Ontario. ASCO’s work involved the construction of utilities and services required to perform upgrades to process equipment, electrical system, instrumentation and control system, structural work, architectural work, site work, and mechanical system (HVAC and plumbing) facilities and other miscellaneous works. After the project is complete, the public can expect better stormwater control and subsequent water quality in and around Toronto’s vibrant downtown waterfront beaches and parks.