A boil water advisory was issued Saturday for the city of Fort Saskatchewan, after it experienced its largest water outage in 30 years.

A reservoir failure left the city of nearly 20,000 people without water for an hour on Saturday.

The failure temporarily halted the city's ability to monitor the water's chlorine content.

As a result, Alberta Health Services issued a boil water advisory for the city until further notice.

Water has been sent to the province for testing.

In a post made on Twitter, Fort Saskatchewan Mayor Gale Katchur said lab results would not be known until at least Sunday.

Residents are reminded to boil water for at least one minute prior to doing any of the following:

  • Drinking
  • Brushing teeth
  • Cleaning raw foods
  • Preparing infant formulas or juices
  • Making ice

Water used for bathing or washing clothes does not need to be boiled.

The reservoir initially failed around 12:30 p.m.

"We lost the distribution pumps. The main reservoir pumps quit working," said Grant Schaffer, the city of Fort Saskatchewan's public works director.

"The power drained and we lost pressure in the system."

A back up pump was activated by 1:30 p.m. and officials say full pressure was restored by 2:00 p.m.

It is unclear why the reservoir failed.

With files from Sean Amato