PICTOU, N.S. -- A group opposing a plan to pump millions of litres of treated effluent through a pipeline into the Northumberland Strait is calling on the Nova Scotia government to answer questions about an Oct. 21 leak from the existing system operated by Northern Pulp.

Friends of the Northumberland Strait issued a news release Tuesday saying its membership is frustrated that after more than three months, the province has released no information about the size or cause of the leak last year near Pictou, N.S.

Jill Graham-Scanlan, president of the group, said the public should be told the composition of the effluent that leaked and why the pipe break went initially undetected by the pulp and paper firm owned by Paper Excellence.

Provincial spokeswoman Rachel Boomer said the Environment Department is still investigating, and noted a 2014 inquiry into a prior leak required a year for completion.

"As a result, we won't be able to provide information today on the size of the leak or what happened in this incident. We would be happy to provide this information once the investigation is complete," she wrote in an email.

Boomer also said no compliance action has been taken at this point, since the investigation is still underway.

Consequences for violating an industrial approval range from warnings to summary offence tickets, ministerial orders or long-form prosecution.

Mill spokeswoman Kathy Cloutier said in an email the leak was "very small in size," and added that it "did not make its way into Middle River."

She said the effluent was "contained promptly and transported to the Boat Harbour facility where it was then treated and released into the Northumberland Strait via the existing system and route."

Cloutier said the leak was at a fibreglass joint, the technology of the day in the 1960s, and the proposed new treatment system will have fusion welded joints that "are leak proof and as strong as the pipeline itself."

However, in her release, Graham-Scanlan said she "wonders why Northern Pulp did not know about the leak, when the company's industrial approval requires that they 'operate and maintain real time flow monitoring equipment ... designed to immediately notify the approval holder in the event of a total loss of flow or a reduction of flow below normal operating conditions'."

Graham-Scanlan said the public has a right to know whether Northern Pulp was in compliance with its approval conditions, and whether records identify any problems in the days before the effluent leak.

The company's industrial approval also requires regular internal and external inspections of the pipe, and said her group would like to know when the inspections were last carried out.

"Given the company's history, and the fact that Northern Pulp now wants approval to discharge their treated effluent into the Northumberland Strait, it's important that the public knows the facts," she wrote.

Boomer said a Northern Pulp report dated March 22 of last year indicated the pipeline inspection activities for 2017 were satisfactory.

"Northern Pulp's industrial approval requires them to conduct annual external pipeline inspections during 2018, and submit the results to the Nova Scotia Environment Department by the end of March 2019," she added.

Premier Stephen McNeil has said he has no intention of changing a legislated deadline to close the Northern Pulp mill's wastewater treatment plant in Boat Harbour -- but he is open to debating proposed changes in the legislature.

McNeil said any changes to the January 2020 deadline would have to evolve out of a community consensus in Pictou County, and would have to be brought to the floor of the legislature by the area's Opposition members.

In the meantime, McNeil said the government will keep its word that he will stick to the deadline for closing the Boat Harbour treatment plant.

The heavily polluted treatment lagoon is on the edge of the Pictou Landing First Nation.

The province received the environmental assessment application for the pipeline on Jan. 31, and the project will formally register this Thursday.

Once the project formally registers, the province posts the documents on its website, and the public comment period begins.

Mill officials have said in the past that no pipe would mean no mill, and company officials recently indicated they need an extension on the original deadline.

-- By Michael Tutton in Halifax.