Northern Pulp report on effluent pipe proposal forecasts no significant impacts

The Northern Pulp Nova Scotia Corporation mill is seen in Abercrombie, N.S. on Wednesday, Oct. 11, 2017. THE CANADIAN PRESS/Andrew Vaughan

HALIFAX -- A report by the Northern Pulp mill on its controversial effluent treatment plant proposal says the millions of litres of treated wastewater to be pumped daily into the nearby Northumberland Strait will have no significant impact on water quality or marine life.

The Nova Scotia Environment Department, which ordered the report last March, posted thousands of pages of documents from the company on its website for public comment Thursday afternoon.

The report's marine survey confirms there are rock crab in the areas of Caribou Harbour where the plant's diffusers would create a jet of expelled effluent.

"Based on testing, modelling and the incorporation of mitigation activities, no significant residual impacts to marine water quality are expected to arise on any fisheries or fish habitat as a result of this project," the report states.

That includes the impact on the lobster population which is one of the Northumberland Strait's key fisheries.

The report says the impact on lobster in the area around the pipeline outfall would be "generally minor, localized and generally reversible." The report used a similar phrase to describe the impact on plankton diversity and abundance in the area.

In its report summary, the company says it has provided a science-based review including data beyond its submission to the department last January.

It says its submission includes environmental baseline studies, archaeological investigations, water modeling, engineering designs, and Mi'kmaq ecological knowledge studies.

The report confirms that the 15-kilometre pipeline to the strait will be installed "generally parallel" to Highway 106 along the easternmost portion of the province's right-of-way until it meets its outflow point in Caribou Harbour.

The Transportation Department had previously made it known that it didn't want the pipeline along the highway and preferred it to be built on a route along secondary roads.

The focus report is aimed at addressing the province's outstanding questions on such things as the route of the pipeline, potential environmental effects and the impact on marine life and on the town of Pictou's water supply.

Another question the province had was the potential for leaks or spills along its proposed overland route.

As it stated in its original submission, the company says its pipeline design has been adjusted as a "risk management measure," including the use of thicker pipe to increase safety.

"This, coupled with a modern leak detection system using advanced detection technologies that can detect very small leaks, provides a robust system design that can be operated with confidence," the report says.

As for the underwater portion of the pipe, the report says the company's analysis indicates burying the pipeline three metres under the seabed in Caribou Harbour is appropriate, given the ice conditions present.

"Detailed engineering will be completed to determine final burial depths," it says.

The company says its environmental management of the project will include a monitoring program once it is completed.

The public now has until Nov. 8 to submit comments to the Environment Department. Environment Minister Gordon Wilson will make a final decision on the effluent treatment plant by Dec. 17. When the report was submitted Wednesday, Wilson committed to reading all of the submissions from the public.

This report by The Canadian Press was first published Oct. 3, 2019.