City of Ottawa’s Lemieux Island Transmission
Main Replacement Program
Low and High Pressure Transmission Mains
by
Mike Willmets, City of Ottawa
Derek Potvin, P.Eng., Robinson Consultants
Presentation Outline
Water Works History
Existing Conditions
Construction
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Project Location
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Project Overview
5 km of 1200, 1675, 1980 mm diameter
Transmission Main
Serves 400,000 people within
City of Ottawa.
Replaces three discharge
mains from Purification Plant.
One of the Transmission
Mains operates as a low
pressure (gravity) suction
supply for a Fleet Street
Pumping Station and the other
operates at distribution system
pressure.
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Water Wagon – Pre 1874
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Why Supply Drinking Water?
Water delivered by horse & wagon in
wooden barrels
Era of Great Fires: Quebec City in 1845,
Montreal in 1852, Carleton County in
1870, Chicago in 1871
Fire Insurance Underwriters
Toronto - 1841, Kingston - 1850, Hamilton
- 1860
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Thomas Coltrin Keefer
1821 - 1915
Father of the Ottawa Water
Works
One of Canada‟s greatest
engineers
Built similar water systems
in Montreal, Hamilton &
Toronto
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Harnessing the
Chaudiere Falls
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Fleet Street Pumping Station
Commissioned 1874
Utilizing hydraulic energy
of Chaudiere Falls
765m open aqueduct
built
Capital Cost of $266,000
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Ottawa Fire Brigade 1874
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Great Fire of
Ottawa-Hull
1900
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Ottawa’s Great Fire - 1900
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Typhoid Epidemics
1 epidemic in 1911, 2 epidemics in 1912
1900 to 1915 - 512 related deaths
1916 to 1925 - 18 related deaths
Nepean Bay pollution
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ABC Lines
Lemieux WPP
Fleet P.S.
Three of the most important mains
Critical to operation of system
Unique Pipes in a Unique Setting
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Lock Bar Pipe
Two semi-circular sections joined by a „lock bar‟
Lock bar is long strip of metal with an „H‟ shaped cross
section
Riveted joints to join pipe to pipe
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Delivery of “A” Line Piping 1915
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“C” Line Construction 1937 - 50
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Existing Pipe Condition
Corrosion pitting leads to leakage.
Corrosion of rivets & lock bar can
lead to pipe failure.
“A” & “B” Line‟s cement lining (circa
1950) was delaminating which
accelerated internal corrosion.
“C” Line was in good condition but
required relocation for planned
development.
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Site Constraints
Federal Land
LeBreton Flats
Development
Past Land Uses
Breezehill/Scott
Feedermains
Subsurface
Conditions
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Existing Site Conditions
Adjacent to former Municipal Waste Site » Contaminated Soils and Groundwater
» Highly Corrosive Environment.
Area formerly part of Ottawa River » Significant area of unconsolidated fill
material.
Adjacent to Ottawa River » Dewatering issue during construction.
Area formerly an industrial development » Subsurface remnants and
contamination.
Crossing major Lemieux Island WPP
transportation corridors »
Traffic Implications.
Construction within existing
aqueduct channel »
Protection of watermain.
Construction within existing
AWWA Canadian
Waterworks Landmark and Fleet Street
Heritage Structure » Fleet Pumping Station
Street Pumping Station.
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Historical
Land Uses
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Subsurface Conditions
Lemieux Island WPP
Bayview Yards
Low Pressure WM
Nepean Bay
High Pressure Transmission Main
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Geotechnical Conditions
Unconsolidated fill from Nepean Bay and Ottawa River Parkway
over bedrock
Long term settlement concerns and significant dewatering
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Dynamic Compaction
Large Un-consolidated Fill Zone on reclaimed land » former bay of
the Ottawa River.
Dynamic Compaction used to prepare watermain alignment prior to
construction.
Large steel weight dropped from crane to achieve consolidation.
Compaction can be achieved to
over 10m depth.
Compaction carried out using
grid pattern to cover area.
Compaction testing carried out
after completion.
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Corrosion Potential Investigation
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Preferred Alignment
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Design Requirements
100 Year Design Life Required.
Must maintain water supply to customers.
LPTM to serve dual purpose » Operate
primarily at low pressure with conversion to
high pressure based on demand.
HPTM to supply water to distribution system
from pumping station at WPP.
Must maintain access to existing
purification plant.
Must protect existing heritage
structures » Fleet Street Pumping
Station and Open Aqueduct.
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Watermain Materials
Concrete encased, polyurethane coated, steel
pipe and concrete pressure pipe utilized to
protect against corrosion.
Gasketless, double lap welded, bell and spigot
joints specified to protect against groundwater
ingress in landfill zones.
Transition between material types at valve
chambers.
Cathodic protection installed throughout.
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Ruins from Previous Development
Previous railway structures, bridge abutments, building foundations and
superstructure debris uncovered in the watermain excavations.
Previous factory foundation and tunnel uncovered within the
excavations.
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Concrete
Encasement
150 mm concrete encasement
Pipe strapped to concrete slabs to
counterbalance buoyancy
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Open Aqueduct Installation
Coated concrete pressure pipe installed in
existing open aqueduct channel.
Channel is a “neighbourhood feature” and a
designated heritage structure.
High density polyethylene shield added to protect
watermain from objects falling or being thrown
into water.
Gasketless expansion joints used between fixed
supports to allow for temperature movements.
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Fleet Street Pumping Station
Existing AWWA Canadian Water Works
Landmark and heritage structure.
Turbine pumps driven by water from
Ottawa River » fed by aqueduct system.
Connection of new transmission main with
valve chamber to switch to high pressure
operation » by-passes pumping station.
Included replacement of existing suction
header piping in station.
Installation of sluice gates to isolate
pump turbines from aqueduct flows
during maintenance.
Included measures to protect existing
structure from damage during
construction.
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Bridge Pipe Rehabilitation
Couplings repaired and
internal joints seals
installed.
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Tunnel Construction
Transmission Main constructed in casings across major roads,
parkways, railways and rapid transit bus route.
Steel pipe electrically isolated from casing pipe via casing
spacers.
Annular space grouted.
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Ottawa River Parkway Crossing
Crossing of existing federally owned
four-lane, divided parkway required.
Open trenching construction due to
presence of methane from landfill »
explosion hazard during jacking and
boring operation.
Existing fill material not suitable for
jacking and boring » large boulders.
Installation of concrete casing pipe
completed over one weekend road
closure.
Welded steel watermain inserted by
jacking methods after completion of
casing.
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Not all goes as planned!
Steel pipe partially
collapsed during grouting.
Protrusion cut out, grout
removed and new repair
sleeve welded in place.
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Valve Chambers
Steel pipe continued through the valve chambers.
Features: air valves, drain valves, line valves, branches and
access manholes
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Thank you !
Merci !
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