[Music only video - Opening screen shows City of Toronto logo]
[Ashbridges Bay Treatment Plant Outfall – Don River and Central Waterfront & Connected Projects]
[Cleaning up our waterways: Toronto is embarking on the largest and most significant stormwater management program in the city’s history.]
[With an overall budget of more than $3 billion,]
[this program will greatly improve the water quality in the Lower Don River, Taylor-Massey Creek and along Toronto’s Inner Harbour.]
[Ashbridges Bay Treatment Plant Outfall: one of the oldest wasterwater treatment plants in Canada
and the largest of Toronto's four sewage treatment plants.]
[A new outfall will be built to replace the existing outfall which has insufficient capacity,]
[does not meet current regulatory standards and is nearing the end of its service life.]
[Major outfall components – diagram showing onshore shaft, risers, tunnel liner, tunnel riser connection.]
[Shaft construction: A watertight shaft is excavated adjacent to the shoreline to support tunneling directly below Lake Ontario.]
[shows animation of excavation]
Riser Installation: 50 riser pipes are installed in line with the tunnel extending from the lakebed to just above the tunnel crown.]
[shows animation of riser installation]
[TBM Tunneling: A tunnel is excavated below each riser using a Tunnel Boring Machine (TBM)]
[shows animation of the tunnel boring machine]
[Riser to Tunnel Connections: 50 vertical in-line risers are connected to the top of the tunnel along the last 1,000 metres of the tunnel.]
[Port Installation: after the tunnel is flooded, ports are installed at the top of each riser to improve treated effluent dispersion in the lake.]
[On-shore Work: Tunneling operations are supported from a working compound locates south of the Ashbridges Bay Treatment Plant.]
[image shows a map of Toronto, highlighting the Tunneling Work Zone]
[Mobilization: Initial site works include a new fence, access roads, local utilities, temporary offices, and erosion and sediment control. ]
[Shaft Excavation: An 85 metre deep on-shore shaft is excavated through soil and rock.]
[Starter Tunnel: A starter tunnel is constructed to provide sufficient space to assemble and launch a Tunnel Boring Machine (TBM). ]
[Off-Shore Work: Off-shore construction is supported from over-water barges and marine vessels located approximately 3 kilometres from the shoreline.]
[Off-Shore Work – Riser Shaft Excavation: Barges are mobilized in Lake Ontario to support riser shaft excavation using containment cans and casings.]
[Off-Shore Work – Riser Pipe Installation: Riser pipes are lowered into the excavated riser shafts, grouted along their entire depth and then leak-tested.]
[TBM Delivery: Major tunnel boring machine components arrive via marine shipping vessel at Port of Hamilton.]
[TBM Delivery: Major tunnel boring machine components are delivered to the site at night to avoid traffic interruptions.]
[Rear TBM Shield: The first major tunnel boring machine component is lowered into the shaft for TBM assembly.]
[TBM Cutterhead: The heaviest tunnel boring machine component (86,000 kg) is safely and successfully lowered to the shaft bottom.]
[TBM Assembly: All remaining tunnel boring machine components are lowered into the shaft and the tunnel boring machine is assembled within the starter tunnel.]
[TBM Assembly: The tunnel boring machine is moved into the starter tunnel as the remaining tunnel boring machine assembly is completed.]
[TBM Commissioning: Tunnel boring machine is fully assembled, operational and ready for tunneling.]
[Closing screen shows City of Toronto logo Consultant – Hatch/Jacobs/Baird Contractor – Southland Astaldi Joint Venture]