Flushing the line is finishing up as workers continue the final process of Calgary’s water feeder main return to service.

Mayor Jyoti Gondek, in her morning update, said the Bearspaw water feeder main, under repair since June 5, was filled at 6 p.m. Friday night. Workers began flushing the line shortly after, with that work carrying on today, she said. In her afternoon briefing, she said that flushing is probably complete.

After the line is flushed, the mayor said that Alberta Health Services would test the water chlorine levels, sediment and clarity (turbidity) and bacteria.

“Once the water quality is deemed to be high, we will ease pressure in the pipe back upwards towards regular flow,” Mayor Gondek said.  

“When we know the system is stable, after turning the pressure back up, that’s when we will advise you that the network is restored, and you can begin leaving those water savings efforts behind.”

Francois Bouchart, director of capital priorities and investments with the City of Calgary, said they are cautiously optimistic they can still reach the July 1 target date for water service to return. Bouchart said there are still steps that need to be taken before the system is ready for full use.

“As we’ve been flushing, we’ve been taking samples to see whether or not we’re achieving the water quality needs for safe water that meets or exceeds our water quality standards,” he said.

“Once the feeder main is back in service, there are a number of steps that we have to take, including turning the pumps at the Bearspaw water treatment plant and also making operational changes within the system. During that time is the highest period of risk in terms of a potential break within our system, and therefore we’re being very cautious in the way that we’re transitioning from the current state with the feeder main out of service into putting that main into service.”

According to Infrastructure Services GM Michael Thompson, throughout the process of filling and flushing, they’ve been conducting acoustic and pressure monitoring.

“So far, there have been no areas of concern. While we are very pleased with the progress so far, I want to stress that we are not out of the woods yet,” he said.

“We still need to move through the next steps, including stabilization, which will create pressure changes that could cause some issues to the pipe and throughout our water network.”

Water conservation rebound

After going a week with water consumption numbers creeping up, and two pleas from the mayor on Friday as Calgary had risen to 500 million litres of water used on Thursday, water use dropped 23 per cent to 460 million litres. That’s presumably with seven million litres used to fill the feeder main pipe. Earlier Friday, the mayor said that as of midnight on Thursday, seven million litres had already been used to fill the feeder main, and 14 million is needed to fill it.

“You answered the call to action and dramatically dropped your water usage,” she said.

While the system is being flushed, the mayor said they are monitoring dechlorinated water entering the river. They’re also taken erosion and sediment control measures to protect the riverbank downstream from where the flush points are into the river.

“We need the all clear on water quality before we can move to stabilization, and that may involve more than one test and one round of flushing,” Mayor Gondke said.

“That’s why the timeline is our best estimate, and we still need to be saving water daily.”

Mayor Gondek also noted that the City of Calgary sent the San Diego County Water Authority a token of their gratitude for delivering much-needed pipe.

“We sent a Calgary white hat covered in signatures and messages from people that have been working on returning Calgary to regular water service to San Diego County as a thank you,” she said.

“We included a bunch of little treats from a local chocolatier for their team. It’s a small token of appreciation from 1.6 million people for San Diego playing its part in helping us.”