HALIFAX -- A faulty pipe that caused an effluent leak at the Northern Pulp mill in Pictou County last month has been repaired, but the cleanup process will require more time, Nova Scotia's environment minister said Thursday.

Margaret Miller said she doesn't know at this point how large an area was affected by the spill or how many litres of effluent leaked from the pipe.

But Miller said the leak is smaller than one that occurred in 2014.

"It was only a fraction of what the last spill was," said Miller.

The company has said it was first notified of the leak on Oct. 21, a day after the mill began its annual maintenance shutdown.

Miller said her department is continuing to investigate.

"We've had staff there on a continual basis," said Miller. "We will continue to follow up."

The Environment Department said the 2014 spill saw the release of 47 million litres of effluent that flowed into a nearby wetland and into the East River Estuary.

The mill was fined $225,000 by Environment and Climate Change Canada.

Meanwhile, Miller said her department still hasn't received a proposal from the company for a new effluent treatment facility.

Under provincial legislation passed in 2015, the mill has until 2020 to replace its current treatment plant in nearby Boat Harbour

But, in a controversial move that has split opinion in the surrounding area, Northern Pulp wants to pipe treated wastewater into the nearby Northumberland Strait.

Tensions are high, with many fishermen and the local Mi'kmaq community saying the pipe plan will threaten the Strait's ecology, including lucrative lobster fishing grounds.

The company has said if it doesn't get its pipe plan the mill will close.

On Thursday, Premier Stephen McNeil said the possibility of Northern Pulp simply walking away from Pictou County is "always a concern."

"But I think it's important though for us to recognize that we have made a commitment around Boat Harbour and that commitment (deadline) is coming," he said.

Still, McNeil said he believes the parent company, Paper Excellence of Richmond, B.C., is committed to the mill. He pointed out that it has made investments in the operation and has taken steps to shore up pension plans for its 300 employees.

McNeil said the deadline would remain in place unless there is a request to change it by the Pictou Landing First Nation, and that hasn't happened to date.

Opponents of the effluent plan have called for a more comprehensive Class 2 provincial environmental assessment, but Miller said Thursday that the province has no plans to change from a Class 1, which includes a 30-day public consultation period followed by a 20-day departmental review.

Those opposed have also called for an environmental review by Ottawa, but local Liberal MP Sean Fraser said there can be no decision on that until the mill submits its proposal.

"I don't mean to suggest for one moment that the federal government isn't watching the file with interest," said Fraser, who is also parliamentary secretary to federal Environment and Climate Change Minister Catherine McKenna.

"In fact the Canadian Environmental Assessment Agency has been conducting a preliminary investigation ... to get as much information as they can so they can make an informed decision."

Fraser said the provincial deadline would not influence any potential federal decision.