Andrew Sims has ruled the guards should instead receive unpaid suspensions of between one and three months.
Guy Smith, president of the Alberta Union of Provincial Employees, said Thursday that the workers want to get back as soon as possible to their supervisor jobs at the Fort Saskatchewan Correctional Centre. Three of the guards were dismissed last July; the fourth was let go in September.
"I know it's been very tough on them and their families and their colleagues, and I think there's a huge amount of relief on their part that now they can get back to their jobs," Smith said.
He said it's not clear when that might happen.
The government can request a judicial review of the decision. Smith hopes the province doesn't put up any roadblocks.
"We're encouraging the government to accept the ruling and place these officers back to work."
The guards also have the option of appealing the suspensions, said Smith. "That is still disciplinary action and we have to discuss with those members how they want to proceed."
Dan Laville, a spokesman for the solicitor general, said his office is "weighing its options" and wants to see the arbitrator's written reasons, which have not yet been released.
The guards were part of a strike that flared up across the province last spring when two fellow guards at Edmonton's new remand centre were suspended after voicing safety concerns about the facility.
An agreement was reached to end the job action after the courts got involved and began to levy fines for defying back-to-work orders.
At the time, the union said the province promised not to seek retribution against striking workers. The government said no amnesty was ever offered and that it would judge each member on a case-by-case basis.