Tunnel Excavation Begins at Western Beaches|
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The City of Toronto moved one step closer today to its goal of reducing western
beach closings by 75 per cent in 2001. A 64-tonne tunnel boring machine moved
to the Strachan Avenue shaft to begin excavation of the four-kilometre tunnel
that will form part of the Western Beaches Storage Tunnel.
Heavy rainfalls often result in combined sewer overflow which contains raw
sewage that spills into Lake Ontario from the City's sewer system. To alleviate
this problem, the Western Beaches Storage Tunnel will capture and hold excess
wasterwater from 10 storm and combined sewer outlets that run between High Park
and Exhibition Place. The Eastern Beaches Detention Tanks, constructed in 1989
and 1994, already perform a similar function and have led to a substantial
improvement in lake-water quality.
"We've seen excellent results with the Eastern Beaches Detention Tanks, with no
closings at Woodbine Beach this year compared to 75 days of closings at the
Western Beaches," said City Engineer Werner Wichmann. "It's clear that the new
tunnel, with its 85,000 cubic metre storage capacity will tremendously improve
lake-water quality at the Western Beaches."
The first phase of the $57-million project was awarded to McNally-Frontier
Joint Venture Incorporated. Phase I includes the completed excavation of the
Strachan Avenue shaft and tunnelling 1.5 kilometeres from Strachan Avenue to
Dufferin Street. The Strachan Avenue shaft is 18 stories deep and almost 30
metres in diameter. Works and Emergency Services staff will seek authorization
from City Council in November to award Phase II of the Western Beachs Storage
Tunnel project, which includes tunnelling 2.5 kilmetres from Dufferin Street to
Glendale Avenue and excavation of two additional shafts.
|Werner Wichmann, P.Eng|
|Toronto Works and Emergency Services|