False Creek sewer main repair hits $3 million and counting
Three months after city pipe failed, cause still hasn't been determined
Repairs to a sewer main leak on Terminal Avenue in Vancouver's False Creek have so far cost the city $3 million — and counting.
Nearly three months after the leak occurred outside Main Street-Science World SkyTrain station, crews are still trying to determine what caused the pipe to fail.
Most of the work had been focused on containing the leak, using vacuum trucks round the clock to suck up the sewage to prevent it from spilling into nearby False Creek and building a temporary bypass pipe so sewage can be diverted from the broken pipe.
That work has come with a hefty price tag, with the cost for equipment, contractors and staff estimated at more than $3 million. The cost is covered by the utility fees collected by the city.
“It's a significant amount,” said Lon LaClaire, head of engineering services for the city. He said it's too early to estimate the cost of the repair, as it's not yet known what the fix will involve. The bypass pipe, which goes along Terminal Avenue from Quebec to east of Main Street, was fully operational by Aug. 23, allowing crews to focus on investigating what caused the leak.
“It's quite complex in terms of the work we are doing there,” LaClaire said. “And very mysterious to us. Even failures of sewer force mains are just rare to begin with in old pipes.”
Crews are excavating around the area of the leak, using vacuum trucks to remove debris and gravel found at the bottom of the pipe. After the area is cleared, crews plan to use cameras and other technology to assess the pipe and find out what caused the break.
“So far we haven't yet found the source of the leak,” LaClaire said. “We expect that we will with this additional investigation work we are doing right now. It's hard for us to start on the repair unless we understand what caused the failure.”
He expects to be able to provide a timeline in the coming weeks after the source of the leak has been determined.
LaClaire said there were other challenges, including engaging the right contractors to do the work, working around other utilities in the area, and the proximity of the water as, during high tides, ocean water would flow into the pipes.
The pipe is about 30 years old, “relatively young” in terms of pipes, which have a life span of about 100 years, said LaClaire.
It's a pressurized force main, meaning gravity isn't needed to move the wastewater. About 10 per cent of the city's sewer mains are force mains, typically used in low-lying areas near sea level such as False Creek.
There have been only four sewer force main breaks in the city in the past decade.
On June 20, two days before the Terminal Avenue leak, another sewer main broke in Olympic Village, spewing wastewater on Columbia Street near West 2nd Avenue.
Metro Vancouver, which operates that pipe, was able to divert sewage to another pipe in order to facilitate repairs, which were completed by July 2.