The Saskatchewan government has directed four municipalities in the province to put weight restrictions on bridges in their RMs because there is a risk of the "potential failure of the bridge if a heavy truck drives over it."

The restrictions are being placed on five total bridges. Two of them are in the RM of Perdue and the others are in the RMs of Caledonia, Mervin and Scott. All five were built by Can-struct Systems.

Deputy Minister of Highways Fred Antunes told CBC that the Ministry decided to do a wider review after the collapse in the RM of Clayton last year of the Dyck Memorial Bridge.

The ministry hired a consultant to review bridges known to have a similar design and construction to the one that collapsed and that had been built by Can-struct.

We felt we couldn't wait for the final report to come in because there was an issue of public safety. - Fred Antunes - Deputy Minister of Highways

On Tuesday, the consultant gave a preliminary report to the ministry. It said that for the the five bridges in question, the superstructures, the decks and girders were designed in such a way that they may not be able to bear a heavy load.

"I guess we were significantly concerned after we saw the presentation that we felt we couldn't wait for the final report to come in because there was an issue of public safety," said Antunes.

He said that once the consultant has completed that report it will be forwarded to the Association of Professional Engineers and Geoscientists of Saskatchewan, the professional body that oversees the work of engineers in the province.

Weight restrictions begin Friday

The ministry ordered the weight restrictions to begin at 3 p.m. CST Friday. Some bridges are now restricted to vehicles weighing up to three tonnes while others are restricted to loads up to 12 tonnes.

The ministry said heavier vehicles will have to avoid these bridges until the problems have been fully assessed and remediated. There's no timeline on that yet.

"Some of these bridges impact heavy haul routes throughout the province, including one Alternate Truck Route and one Clearing the Path corridor," said a news release from the ministry Friday.

The ministry said it will be up to the municipalities to bear the costs of that remediation, though officials say the ministry is offering its expertise to the RMs.

Antunes said the ministry's consultant found that the bridges weren't constructed to provincial standard and may not be able to bear the load of heavy vehicles.

He said the chief concern that arose after the collapse of the RM of Clayton bridge was the fact that it was built on screw piles and that a geotechnical investigation of the riverbed hadn't been conducted.

He said the consultant tried to learn if these five bridges had been built in a similar way but was unable to answer that question.

"We were not able to get any information about the design when we did these inspections," said Antunes. "So we don't actually know if they in fact did you screw piles or not. We don't know if they did geotechnical investigations or not."

He said he's not sure precisely why that documentation wasn't obtained. He said it could be because of confidentiality concerns or it could be that the RM's didn't have that paperwork.

This is 'an aberration' says deputy minister

Antunes said that despite the concerns with these five bridges and the RM of Clayton's bridge, he doesn't believe additional government regulation is necessary.

He said Saskatchewan's engineers are, for the most part, doing just fine.

"They are regulated and you have continuing professional development that they have to go through," he said. "So I think this is really more an aberration. You hire an engineer to do the work to design a bridge and you expected it's going to be designed in accordance with the appropriate bridge codes."

Antunes put out a call to the public, both in Saskatchewan and other provinces too.

"If anybody else has had a bridge designed and built by this company that they should come forward."

CBC asked Can-struct for an interview but the company has not yet responded.