Epcor has lifted its ban on non-essential water use in Edmonton and the capital region after completing critical repairs at its E.L. Smith water treatment plant in the city's southwest.
The plant is back operating at full capacity, Frank Mannarino, senior vice-president, Epcor Water Services, told a news conference Friday morning after the ban was lifted.
"While we are still restoring supplies in the reservoir system, we are comfortable at this point that the system has stabilized enough that we can lift the water restrictions," Mannarino said.
"We know this has been a difficult week for residents and businesses in our area and we didn't take these measures lightly, but it was imperative that we preserve the ability to provide for drinking, sanitation and to fight any fires.
"For some, the restrictions were a significant inconvenience. But for businesses that had to reduce or halt their operations, there was a real impact for the owners and employees."
Since the ban was announced on Monday, consumption has been about 109 million litres lower than typical levels, Epcor reported. Typical usage for the system is between 350 million and 370 million litres a day, Mannarino said.
Mannarino thanked owners and workers at car washes and laundromats for the sacrifices they made during the ban.
Brewing, manufacturing and animal-processing businesses also "significantly curtailed" water use, he said.
Most businesses co-operated but in a few cases enforcement was needed, he said.
Sequence of events
Vicki Campbell, Epcor's director of water treatment plants, provided a breakdown Friday of events that began early Monday at the E.L. Smith plant.
Water entered a vault that contains two high-voltage electrical cables that feed two 4,000-horsepower pumps. The contact resulted in electrical gear failure and damage to other electrical components. Two smaller 2,000-h.p. pumps did not have any cable damage.
The plant could continue to produce and store clean water, but could no longer pump water into the distribution system, resulting in a plant shutdown. It was determined that the cables feeding the two large pumps would need to be replaced.
Water production continued at Epcor's other Edmonton water treatment plant in Rossdale. But it was undergoing planned capital improvement work and wasn't operating at full capacity.
Epcor officials decided to stop the construction at Rossdale and return the plant to full capacity. But Rossdale can't produce enough water to meet demand on its own, so a decision was made to bring in the water-use ban.
Repairs at E.L. Smith began on Monday and continued into the week. Cable replacement was completed by 6:30 a.m. Thursday. The plant then went into a phased restart and restoration of the reservoir system began.
Campbell said the repair work was completed by a team of 30 people working around the clock, with another 50 in supporting roles such as engineering modelling.
"It was done carefully and safely — and it could have been worse, but we are very pleased that we were able to get this plant running and the system restored," she said.
Review starts next week
Mannarino said Epcor will conduct a thorough review of the events starting next week. It will include an assessment of the measures taken to reduce demand and how the public responded.
"A big part of this is going to be to look at what decisions we made, when we made them, who did we impact, was that the right call, the wrong call, etc."
He said looking at how water customers responded to the measures is "really, really important" to the utility.
"We've been getting continuous feedback. I would have to say it's mixed," he said. "But for the most part, we've got data."
Epcor will provide an initial update to city council's utility committee on March 4.