The province issued a legally binding order last August directing the paper mill in Abercrombie Point to replace its precipitator and get its emissions in line.
The plant shut down on May 30 to complete the installation of the precipitator.
The government says the equipment is expected to reduce emissions at the mill, which were above legal limits last year.
Environment Minister Randy Delorey told reporters Thursday it will take some time to fine tune the equipment, but he expects it will soon start reducing emissions.
"My understanding from ... the technical team is that we should expect to see the improvement right away, but with any large and complicated piece of equipment like this there is no absolute guarantees," he said.
"But certainly the expectation is to see some improvement right out of the gate."
The province says the new equipment will now go through a commissioning phase as it's fine-tuned and that should be finished by Oct. 16.
After that, the mill must comply with a new emissions limit set last year, which is almost 80 per cent lower than the old standard.