Calgary Mayor Jyoti Gondek said if all goes to plan, the city could see water service return to normal sooner than expected.
Last week, city officials said they were eyeing July 5 as the potential completion date – the same day the Calgary Stampede starts.
“That date is still a good guideline, but what we’ve heard from the team today is that it’s possible if things go according to plan, that we might see an earlier timeline. It’s hard to say,” Gondek said.
In an update Tuesday afternoon, Gondek said the repair work on the five hot spots along the main feeder line is done.
Paving the sections of 16th Avenue Northwest that were dug up for the repairs will begin “very soon,” Gondek added, along with site cleanup.
From there, the pipe will be filled and flushed, then the water will be tested to ensure it is safe to drink. The entire system will then need to be stabilized.
Gondek said work to return to regular water service “could be done sooner than expected.”
However, officials warned there is still a lot of work to be done and there is still a risk of setbacks along the way.
“Our concern is that something will break as we begin to bring this pipe back into service,” said Michael Thompson, general manager of infrastructure services with the city.
4 steps to go until water restrictions can be eased
Filling the feeder main with water is the first step.
Francois Bouchart, director of capital priorities and investment with the city, said a 4.5-kilometre section of pipe is currently empty. It will take 14 million litres of water to refill it.
Bouchart said that work could begin as early as Wednesday night or Thursday morning. If all goes well, he said it could take a day or two to refill the pipe.
As the pipe refills, pressure will increase. Acoustic monitors will be used to listen for pings which could indicate further breaks. Sensors will also be used to detect pressure spikes.
“We feel that the risk for additional breaks … is low, but if they occur they could set back our progress,” Bouchart said.
Once the feeder main is refilled, crews will flush the line, which Bouchart said will take one day.
The water will then need to be tested to ensure it’s safe to drink, which will be done with the help of Alberta Health Services and Alberta Environment and Protected Areas.
Testing water samples takes between 18 to 20 hours, Bouchart said. If the results show the water is safe, they can move on to the next stage of work. If there are issues with the water quality, the line will need to be flushed again and testing will be redone.
Once the water quality meets or exceeds regulatory standards, the system will be stabilized, which will take another three to five days.
“This phase has the highest level of risk,” Bouchart said. “Each time pressure changes are introduced into the feeder main or other feeder mains within the system – whether from filling, flushing or adding additional pumping capacity – pipe connections and pipe walls experience additional stress.”
The city said contingency plans are in place at each stage should issues arise.
“If things go according to schedule, we could be done earlier than expected, but there is still a significant amount of risk,” Thompson said.
The failure on the feeder main happened on June 5 and Calgarians have been under water restrictions ever since. The city said easing water restrictions will be done in phases, but more information on that process will come at a later date.
Water use
City officials urged Calgarians to continue conserving water, as usage has been creeping up over the last week to a 10-day high on Monday.
Gondek said 476 million litres of water was used on Monday, and she doesn’t believe it was a one-day blip.
More non-potable water on the way
The city has set up six non-potable water distribution sites around the city, for people to take for outdoor water use like watering their plants and gardens.
Calgary Emergency Management Agency chief Susan Henry said the sites have been very popular and starting Wednesday, one additional site will open.
The new site will be located at the Bankside day use area in Fish Creek Park. Henry said the site will be for commercial and residential non-potable water distribution.
In addition, the hours of operation for the residential use site will be expanded to 8 a.m. to 8 p.m., which is an hour later than it has been up until now.
The hours of operation at the commercial sites will remain 7 a.m. to 7 p.m., Henry said.
Comments