A flooded wet well area on Jan. 14, 2009. (Halifax Regional Municipality)It will likely be a year before Halifax's damaged sewage treatment plant is working properly again.

The plant near the naval dockyard malfunctioned on Jan. 14. Until it's fixed, raw sewage will continue to flow directly into Halifax harbour.

Halifax regional council was told Tuesday that it's still not clear what went wrong.

"We're not much further along in terms of being able to tell the citizens any more than we have in the past few months," said Brad Anguish, director of the $332-million Halifax Harbour Solutions project.

What is known is that a power failure set off a sequence of events that eventually caused the station to overflow with raw sewage.

Once the power was out, the sewage treatment station switched to generators. But when electricity was restored and it was time to reintroduce the flow of sewage, a valve malfunctioned, causing extensive flooding. Several kilometres of cable and other electronic equipment were destroyed.

Municipal officials said a thorough cleanup is underway and some auxiliary systems are partly operational again.

Anguish told regional council the plant is expected to be fixed by spring 2010.

A wet, sludgy floor in the plant after Jan. 14. (HRM)That timeline disappoints several councillors, including Linda Mosher.

"I'm not impressed with the delay," said Mosher. "It's already been four months. I'm hoping that we're under-promising and that we're going to over-deliver and this is going to be up and running soon."

Anguish said he doesn't know how much it will cost to repair the sewage treatment station, but he expects it to be no more than $50 million.

He said the municipality expects insurance to cover the cost of the cleanup and repair of the plant, which is in the fourth month of a three-year warranty.

"We absolutely expect the insurance that citizens pay for, to pay — period," Anguish said.

"Of course, they're not going to jump out in front of potentially millions of dollars and say they're in. They're doing their investigations."

The sewage treatment plant was opened in the fall of 2007. Bacteria counts in Halifax harbour plummeted, allowing the municipality to reopen three public beaches last summer for the first time in decades.

Mayor Peter Kelly said once the sewage treatment plant is fully operational next spring, the water quality of the harbour should be back to what it was before the malfunction. He said the municipality likely won't have lifeguards at Black Rock and Dingle beaches this summer.