The city will hire back 15 public works employees it fired in 2013 on allegations of time theft and breach of trust, but most will be on probation for the next two years.

Twenty-one terminations and four suspensions were scrutinized in a lengthy grievance hearing. On Wednesday morning, arbitrator Lorne Slotnick ruled that the city should rehire 15 of them, and give them some back pay.

But most will have 30-day suspensions on their records, which means they're on probation, says city manager Chris Murray. That means if there's an employment breach that results in a day-long suspension, the deal is off.

"We're going to treat them with the same respect that we'd treat anyone else," Murray said. But "to say they're on thin ice would probably be an accurate statement."

Of the rehired employees, five are getting back pay but have 30-day suspensions on record. Another nine will not get back pay, which means they've had about 27 months without pay, Murray said. This "reflects the severity of their behaviour."

To turn a blind eye to this would have been a mistake. - Chris Murray, city manager

The firings stem back to late 2012, when the city used video surveillance and GPS records of city vehicles, among other methods, to learn the workers were putting in fewer hours than billed. In some cases, the city said, they were working a handful of hours for a a day of pay. The city also investigated the workers regarding missing asphalt.

When the workers were fired, CUPE 5167 launched an automatic grievance hearing, which started in late 2013 and ended in February. During the sessions, the union argued inconsistencies in the city's accounts called the whole process into question.

Slotnick heard arguments from both sides and made the ruling on Wednesday. It will become public on May 4. The city "respectfully disagrees" with the arbitrator's decision, Murray said, but it will abide by it. That means the employees will be reinstated at yards in the next two weeks, and the city is deciding how to best place them.

The city is working out over the next couple of days what the case has cost taxpayers, Murray said. But early estimates from the director of human resources show it could be hundreds of thousands of dollars.

Murray says it was worth it, and led to more productivity and a culture change.

"Our culture is a culture that is here to perform," he said. "To turn a blind eye to this would have been a mistake."

Meanwhile, CUPE local president Sandra Walker, calls the hearings "a long and complicated process" that was hard on the workers.

"While we are pleased that a majority of our members will be returning to work, we are very disappointed that six of our members will not be coming back," she said in an email.

The fates of all 29 disciplined employees were as follows: