SUDBURY -- Two new, 450-foot stacks are now fully installed and ready to replace the famous Superstack that has been in Sudbury for decades.

The $450 million project began in 2014, and managers with Vale say it was a companion effort to the Clean Atmospheric Emissions Reduction Project (AER).

“That Clean AER project was run in parallel to the service facilities upgrade,” said Darryl Cooke, Vale surface project and studies senior manager. "That was a billion-dollar project for atmospheric emissions reduction."

Company officials said the construction of the new stacks is the last phase of the AER project.

The manager of the smelter, Joe Costigan, said ending the use of the Superstack will make a huge difference to emissions from Vale operations in Sudbury.

“The Superstack was built to handle all of our processed gases and now all of the processed gases are directed to our acid plant, which captures all of the SO2," Costigan said. "So, the new stacks actually don’t vent any of the processed gases anymore, those are captured.”

Smaller, more efficient

He said the two smaller and more efficient stacks will require much less energy to operate than the Superstack. That will mean a 40 per cent reduction in the greenhouse gases emitted by the smelter.

“They essentially burn the same natural gas as 18,000 homes that we have in Sudbury," Costigan said. "Those will be shut off when we begin decommissioning the Superstack … We’re taking the smelter from 95 million cubic metres down to around 45 million cubic metres.”

Officials with Vale said decommissioning of the steel liner within the Superstack will begin soon, and it’s expected to take until 2023. As for the concrete outer shell, the company said there are no set plans as to what’s going to happen to Sudbury’s skyline.