Water  |  4 Mar 2021

Workers have completed a critical piece of work at L’Aube Hill Reserve in Akaroa to construct a piping connection between the contaminated reservoir’s temporary bypass and the local water supply network.

A remote-controlled underwater vehicle, equipped with an on-board camera and a modified grabbing tool, was used to enter the reservoir and place a bung inside one of the two outlet pipes. The bung was then inflated with an air compressor to seal off the pipe.

“With the reservoir’s main outlet pipe fully sealed off, we were able to cut into the pipe network to install new branches and valves. We’re now in a position to hook up the new piping from the temporary tanks, which will effectively bypass the old, contaminated reservoir,” says Council Head of Three Waters and Waste Helen Beaumont.

“We’ve since removed the bung and we’re continuing to use the reservoir’s main outlet until the bypass is fully ready. This ensures the Akaroa–Takamātua water supply network will continue to meet peak demands and any potential emergency needs such as firefighting.”

Ms Beaumont says the next step is to hook up the bypass and fully prepare it for use in the water supply network.

“Part of that preparation involves carefully disinfecting all of the fourteen 30,000-litre tanks and associated pipes that make up the bypass, so we can be sure everything is clean, safe and ready to receive the drinking water that comes from the local treatment plant,” she says.

“We expect to have the bypass fully connected to the water supply network by the end of next week, and then to be in a position to lift the boil water notice shortly after that.

“We’re working closely with the Drinking Water Assessor and the Canterbury Medical Officer of Health to keep them fully informed so we can move as quickly as possible to lift the notice once ready.”

Ms Beaumont says the final approval for the Council to lift the boil water notice will come from the Canterbury Medical Officer of Health.

“In the meantime, it’s very important residents keep boiling their tap water until further notice. There is still a health risk until the boil water notice is officially lifted.

“If you can’t boil water, use bottled water or collect safe, clean water from the tankers available in Akaroa. The water in the tankers comes from Christchurch. It is chlorinated and tested twice daily to make sure it’s completely safe to drink.”