Planned Transmission Pipeline Repair
February 13, 2017 - The Lake Huron Primary Water Supply System is undertaking a
critical repair of the transmission pipeline in the Denfield area. In order to limit
the impact to the area municipalities and consumers, the repair is planned for Wednesday
The quality of the water supplied to area municipalities and consumers is not affected
and most consumers should not experience any change from their normal water supply.
Municipalities supplied by the Lake Huron Primary Water Supply System include Bluewater,
South Huron, Lambton Shores, Lucan Biddulph, North Middlesex, Middlesex Centre,
Strathroy Caradoc and the City of London.
Damaged Pipe Detected
The new Acoustic Fibre Optic Monitoring System detected a pipe in an un-twinned
section of the LHPWSS transmission main near Denfield is damaged beyond acceptable
tolerances and has been identified for a priority replacement. The replacement of
the damaged pipe will be undertaken on Wednesday February 15th starting at 2:00
a.m. Although the replacement of the pipe is anticipated to take approximately 20
hours to complete, it will take up to another 24 hours for the water supply system
to refill depleted reservoirs throughout the region before operations return to
a more normal operating condition.
The supply of treated drinking water to the City of London from the Elgin Area Primary
Water Supply System will be increased, however the majority of the water supplied
to the consumers by the Lake Huron Primary Water Supply System will be provided
from storage reservoirs while the pipe repairs are being undertaken. Some communities
in the region may experience lower than normal water pressures, including Ailsa
Craig. Consumers are encouraged to contact their local municipality if they experience
discoloured water or have no water.
Additional information about the regional water supply system is available at www.watersupply.london.ca and you
can now follow us on Facebook!
In 2012, the Lake Huron Primary Water Supply System (LHPWSS) completed a $1.5 million
condition assessment of the high pressure reinforced concrete pipe between the water
treatment plant located in the Municipality of South Huron near Grand Bend, and
the terminal reservoir in the Municipality of Middlesex Centre near the village
of Arva. The condition assessment utilized the Smart Ball® leak detection and the
Pipe Diver® electro-magnetic inspection technologies by Pure Technologies Ltd.
Until recently, electro-magnetic inspection of reinforced concrete pressure pipe
required the complete isolation and draining of the transmission pipeline for extended
periods of time to allow the equipment to be “driven” through the length of the
pipeline. In the case of the Lake Huron Primary Water Supply System, this would
not be feasible as several segments cannot be fully drained nor can the supply of
water to the area municipalities be interrupted for extended periods of time (weeks
or months). The Pipe Diver® inspection equipment is relatively new technology, and
can be deployed within the pipeline while in operation and supplying water to the
area municipalities. This allows for a complete and comprehensive assessment of
the pipeline with limited impacts to area municipalities and the consumers.
Subsequently, in 2015 an Acoustic Fibre Optic Monitoring System was installed in
the reinforced concrete pressure pipe to continuously monitor the condition and
degradation of the concrete portion of the transmission system. Although the majority
of the 1200mm (48 inch) transmission pipeline constructed in the 1960’s was found
to be in excellent condition, the regional water system determined that a pipe in
an un-twinned section of the LHPWSS transmission main in the Denfield area is in
poor condition and the risk of failure of this pipe has increased. On this basis,
the LHPWSS made plans for the proactive replacement of this pipe section.
The pipe segment will be replaced starting on Wednesday February 15th. It is anticipated
that the complete replacement of the two pipe segments will take approximately 20
hours to complete at a total estimated cost of $300,000.
During the replacement of the two pipe segments, area municipalities will be relying
on water which is stored in reservoirs throughout the various water distribution
systems. Typically low consumption during the month of February should ensure that
most consumers would not be adversely impacted by the repair operation; however
some communities in the region may experience lower than normal water pressure,
particularly in the Ailsa Craig area.
Following the completion of the pipe replacement, it could take up to an additional
24 hours to replenish all area reservoirs and return to normal operation.
Lake Huron Water Treatment Plant:
- Originally constructed in 1967
- Utilizes “conventional treatment” processes consisting of chemically assisted sedimentation
and dual-media filtration
- Current rated capacity = 340 million litres per day (3,935 litres per second)
- Current average day supply = 135 million litres per day (1,563 litres per second)
- Current peak day supply = 239 million litres per day (2,766 litres per second)
- Consumes approximately $5 million in electricity per year in treating and pumping
drinking water to area municipalities
Lake Huron Transmission Pipeline:
- 47 kilometres of 1200mm (48 inch) diameter reinforced concrete pressure pipe constructed
- 9,729 pipes
- 56 pipes found to be mildly distressed but within acceptable standards
- 21 kilometres of 1200mm diameter “twinned” in 1996 in high pressure “failure prone
- 7 kilometres of steel pipe
- Two sections of 7 kilometers each using reinforced concrete pressure pipe
- 8 kilometres of 1200mm diameter “twinned” in 2014 in high pressure “failure prone
- Two sections of 4 kilometers each of steel pipe
- Treated drinking water takes approximately 12 hours (on average) to travel from
the water treatment plant to the terminal reservoir near Arva
- Currently supplies eight municipalities in southwestern Ontario; Bluewater, South
Huron, Lambton Shores, Lucan Biddulph, North Middlesex, Middlesex Centre, Strathroy
Caradoc and the City of London.
Additional Reference Information:
Lake Huron Primary Water Supply:www.watersupply.london.ca
Pure Technologies: http://www.puretechltd.com