It’s going to take $400 million and four years to tear down the Champlain Bridge.

With the replacement for the bridge scheduled to open at the end of next year, the preliminary plan for what will happen to the old roadway was announced Wednesday.

The plan outlines steps that would be taken over the course of four years to dismantle the bridge and involves barges, jetties, launchers, modular vehicles and explosives.

“This study gives us one way to go about it but we definitely will be working with the contractors because they have very ingenious methods as well and we will be able to really optimize the way to remove this bridge from the landscape,” said Glen Carlin, CEO of the federal Crown corporation that oversees the Jacques Cartier and Champlain Bridges.

The dynamite would be limited to removing the underwater foundation of the bridge. Those concrete slabs would be surrounded by bubble-making machines to keep marine life away. Holes would be drilled into the slabs and explosives inserted and the remains would be removed by a barge.

The rest of the bridge will be divided into sections and removed, piece by piece.

Bridge authority officials said the minimal use of explosives was a conscious decision made not only to minimize the effect the work had on marine life but also to ensure dust and debris did not become a hazard to those who reside near the bridge and to not risk structural damage to the nearby replacement bridge.

“It would produce a lot of dust that could impact both the South Shore residents and the Nun's Island residents,” said Francois Demers of the Federal Bridge Authority, adding that they don’t want to pose any risks to the new bridge, either. “We have to take care of that bridge as well.”

A processing site for the bridge’s dismantled components will be set up near the bridge’s South Shore access point. Hundreds of thousands of tons of concrete, asphalt, steel and other materials will be crushed and recycled for use in the area.

Work is scheduled to start at the beginning of 2019, after the new bridge opens.

In the meantime, the Champlain Bridge is still being monitored around the clock including the piers that hold up the bridge deck.

Almost 100 modular trusses have had to be installed over the years to ensure it remains safe to use.

“There are no concerns with the foundations and the shafts of the piers, but what we have is a pier cap and we're keeping an eye on those pier caps because, as you know we've added these trusses, so these are additional loads on the ends of the pier caps,” explained Carlin.

Some maintenance work still needs to be done, but all that's required this year is the replacement of four expansion joints.