HALIFAX -- Nova Scotia's premier declined comment Tuesday after federal input on a plan to pump millions of litres of treated wastewater from a pulp mill into the Northumberland Strait was made public.

Stephen McNeil said that if he were to comment on the federal criticism ahead of a provincial Environment Department decision on Northern Pulp's project, he would be accused of interfering in the process.

"It's a very difficult position to be in, but it's the one I'm in," he told reporters. McNeil also reiterated that there are no plans to change the legislated Jan. 31 date for the closure of the mill's current treatment facility in Boat Harbour, N.S.

"There's nothing before me that says it needs to go beyond that date," he said.

Provincial Environment Minister Gordon Wilson is to make a final decision on the new treatment plant by Dec. 17 following a review of the mill's so-called focus report. The department asked for the report following an environmental review in March, when then environment minister Margaret Miller said the government needed more information about the plan.

Northern Pulp plans to build a new treatment plant for its mill near Pictou, N.S., and move the treated effluent through a 15-kilometre-long pipeline into the strait.

Five federal departments made submissions to the Environment Department during a public comment period for the report, which ended on Nov. 8 -- Environment Canada, Health Canada, the Department of Fisheries and Oceans, Transport Canada and Public Services and Procurement Canada.

In documents obtained by several media outlets, including The Canadian Press, the departments were largely critical of the focus report, saying it lacked necessary information and noting the province's 36-day comment period was not long enough for a detailed analysis of its more than 2,000-pages.

"The report was, overall, found to be cumbersome to navigate and incomplete in certain areas," Public Services and Procurement Canada said in its submission.

"Additionally, several review participants noted that the volume of information was such that a 30-day review period was insufficient to complete an in-depth review of related material."

Officials also pointed out that there appeared to be an "underlying assumption" that potential leaks in the buried marine portions of the pipeline are not an issue.

"If this is accurate, Northern Pulp Nova Scotia would need to expand on the rationale used to support this," the department said.

Environment Canada raised concerns about the mill's use of two-dimensional rather than three-dimensional modelling to estimate the dilution of the treated effluent, saying it was not the best approach.

"There are a number of underlying deficiencies in the assumptions used in the models and the fundamental baseline information," the department said. "There remains a high level of uncertainty regarding the fate of effluent particles and their potential impacts on the receiving environment."

DFO said it identified a number of gaps in the mill's information, particularly on marine species, which it found to be "lacking and at times, factually inaccurate."

Meanwhile, Health Canada said it didn't have adequate information to assess whether the project "may pose unacceptable or un-mitigatable risks/adverse effects to human health."

Last week several groups, including area fishermen, the Pictou Landing First Nation and the Friends of the Northumberland Strait, called on the province to reject the mill's report, saying it lacked information and minimized the risk to fishing grounds.

Jill Graham-Scanlan of the Friends of the Northumberland Strait said the federal submissions bolster their position. "It really, I think, sends a strong message to the province that they can't approve this project," she said.

Those opposed to the project have also called for a federal review, something Ottawa has previously said is under consideration with the passage in August of the new federal Impact Assessment Act.

In an emailed response Tuesday, federal Environment Minister Jonathan Wilkinson wasn't specific about the Northern Pulp file but said he is still reviewing a "series of designation requests" from the Impact Assessment Agency and would make a definitive decision on all of them by Dec. 20.

This report by The Canadian Press was first published Nov. 26, 2019.