Lake Huron Primary Water Supply Electromagnetic Inspection
In January 2013, Lake Huron Primary Water Supply System (LHPWSS) verified the results of a condition assessment project completed in October 2012 that included leak detection and electromagnetic (EM) assessment. The verification allowed LHPWSS to proactively repair of three sections of Prestressed Concrete Cylinder Pipe (PCCP) along its major transmission main.
While the majority of Pipeline A – LHPWSS’s major water transmission that runs 47 kilometers (29 miles) – was found to be in good condition, the inspection showed seven pipe sections had a relatively high level of distress. Of these seven pipes, two were located within a twinned section and therefore had a lower consequence of failure.
The remaining five high-distress pipes were located within 3.5 kilometers (2 miles) of each other and are in the same vicinity of failures that occurred in 2010 and 2012. LHPWSS has since verified and replaced the three most distressed pipes from the five that didn’t have redundancy to mitigate the risk of another failure.
Although the pipeline is primarily in good shape, the identification of several highly-distressed pipe sections has allowed LHPWSS to proactively plan targeted rehabilitation to ensure the continued delivery of quality service and the prevention of a major pipeline failure.
By determining the baseline condition of their entire primary large-diameter pipeline, LHPWSS now has a better understanding of the overall health of their system and can make informed decisions as they move forward with their pipeline management program and the rehabilitation of their assets.
LHPWSS serves about 500,000 people in eight different municipalities in the London Region and provides about 170 million liters (44 million gallons) of water per day. Its major transmission main, the Lake Huron Pipeline A, runs from the Lake Huron Water Treatment Plant near Grand Bend, ON to a terminal reservoir located near the community of Arva, North West of the City of London and features mostly 1200-millimetre (48-inch) Prestressed Concrete Cylinder Pipe (PCCP).