Work is proceeding on the reinforcement of the Bearspaw South Feeder Main pipe, says Michael Thompson, general manager of services with the City of Calgary.
“On Friday, we started slowly refilling the pipe and completed this step on Sunday afternoon,” says Thompson. “Water sampling and testing are now underway to confirm our water meets or exceeds all regulatory standards. Testing is continuing and our focus is on taking our time to ensure the safety of our drinking water.”
Once tests show the water is safe, crews will open valves along the pipe and turn on pumps at the Bearspaw water treatment plant.
“Once the pumps have started, customers across the system may notice cloudy water, says Thompson. “This will be temporary, and the water is still safe to drink.”
“We will be closely monitoring the pipe and the water system throughout this process. If everything goes as planned, we will lift water restrictions when the system is stable, as early as Thursday, April 2. If any issues come up, we will stop and evaluate the situation.”
There's an increased risk of another break during pressure changes in the pipe, says Thompson.
“The reinforcement work to date has improved stability in the nine pipe segments in the worst condition, but the existing feeder main remains in poor condition and at risk of another break,” he says. “The risk is higher during pressure changes, including when pumps restart and water flows increase.”
Safety measures remain in place in the areas closest to the feeder main in case another break occurs, adds Thompson.
“In January, we removed two segments of the flood barrier along Montgomery Blvd. NW to allow water from a break to flow to the river. We also installed temporary barriers near the Bow River pathway by Parkdale Blvd. NW, and they remain in place,” he says. “As we prepare to restart the pumps, we have cleared catch basins and river outflows and made drainage improvements where needed.”
“Pumps and equipment will be ready for rapid response, and we are working with first responders.”
A new process will be implemented to increase the inspection of the existing feeder main coming out of the Bearspaw Water Treatment Plant using a specialized mechanical tool called a pipe diver.
“The inspection is planned for April 9 to 11,” says Thompson. “The pipe diver will be placed in the pipe and travel through it. Then, our crews will briefly stop water flow to remove the pipe diver from the feeder main. Additional water testing will be required before restarting the pumps. If all goes well, we do not expect water restrictions will be needed.”
“We are not planning additional water restrictions until fall, when we will need to shut down the pipe again to connect the new pipe to our water system,” says Thompson. “However, the risk of a break is always there until the new pipe is operational.”
For more information visit calgary.ca/savewater.
