Whitehorse’s city manager has approved $30,000 in emergency funds to pay for the assessment of a broken pipe in Porter Creek, council heard at the Nov. 20 standing committees meeting.
The Porter Creek flush tank system takes in waste water generated by the Porter Creek and Whistle Bend subdivisions and takes it across the Yukon River to the the city’s sewage lagoon, the Livingstone Trail Environmental Control Facility, via a twin force main.
A leak has been discovered at a valve chamber near where the mains cross the river and the system is now running on only the backup pipe, Geoff Quinsey, the city’s newly-appointed water and waste manager, told council.
There is no alternative means of getting the waste to the sewage lagoon, he said. If the pipe is not repaired, up to 20 per cent of the city’s waste water would be discharged into the Yukon river, which would be a violation of the territorial Waters Act and fisheries regulations.
Additionally, fresh water to Porter Creek and Whistle Bend would have to be stopped, which could result in frozen pipes and possible replacement of all water mains and services in the area. This is “an unacceptable public risk to health,” Quinsey said.
“The presence of a leak on the (system) constitutes a bona-fide emergency, because of the risk to public health, city property, private property and the environment,” he said. “For that reason, emergency funding has been approved … to ensure the risk may be addressed as quickly and effectively as possible.”
The $30,000 will go to hiring an engineering consultant to assess the damage and develop a repair plan and cost estimate, he said. The funds will come out of the water and sewer reserve.
A total estimated repair cost will not be available until this work is completed, but the required repairs are of an “extraordinary nature” because of how deep construction crews will need to dig and the need to stabilize a 12-metre tall concrete valve chamber.
Excavation and backfill costs are expected to be “significant” as a result, Quinsey said.
Additionally, the pipe repair will be complex because the system has to be reinforce to “avoid future failures.”
There will be “significant environmental risk” to be mitigated, because the river bank will need to be excavated and because how bad the leak is will be unknown until the work begins.
Council unanimously agreed with the decision. Coun. Dan Boyd said there was simply no choice but to do the repairs. He thanked city staff for quickly finding the problem.
“It’s good we found the leak,” he said. “Hopefully the backup pipe doesn’t break.”
Contact Lori Fox at firstname.lastname@example.org