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
2
Project Location
3
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.
4
Water Wagon – Pre 1874
5
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
6
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



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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
15
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
19
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.

Crossing major
transportation corridors »
Traffic Implications.

Construction within existing
aqueduct channel »
Protection of watermain.

Construction within existing
AWWA Canadian
Waterworks Landmark and
Heritage Structure » Fleet
Street Pumping Station.
Area formerly an industrial development » Subsurface remnants and
contamination.
Lemieux Island WPP
Fleet 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
23
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.

HPTM to supply water to distribution system
from pumping station at WPP.
Must maintain water supply to customers.
LPTM to serve dual purpose » Operate
primarily at low pressure with conversion to
high pressure based on demand.

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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