Nova Scotia

Controversial mill treatment facility at Boat Harbour 'did its job' removing contaminants

There is little sign of pulp mill pollutants in sediments and marine life in the Northumberland Strait after decades of paper production in the area, according to a new study published in the journal Marine Pollution.

Study finds 'no evidence of significant impacts' on sediments or marine life in Northumberland Strait

Dalhousie University researcher Tony Walker looked for pulp mill contaminants in the Northumberland Strait, but said he didn't find them. (Robert Short/CBC)

There is little sign of pulp mill pollutants in sediments and marine life in the Northumberland Strait after decades of paper production in the area, according to a new study published in the journal Marine Pollution.

The results show effluent treatment at the Boat Harbour site in Pictou County, N.S., succeeded in removing harmful mill chemicals before they reached the Northumberland Strait, says a co-author of the study.

"It did its job," said Tony Walker, a professor at the school for resource and environmental studies at Dalhousie University.

In 2018 and 2019, researchers looked for contaminants in sediment, lobsters, rock crab and mussels at 16 sites near the outfall from the treatment facility that served the Northern Pulp mill.

Tens of thousands of litres of pulp wastewater was piped daily into Boat Harbour where the effluent was aerated, moved into a series of settling lagoons and eventually released into the Northumberland Strait.

"No evidence of significant impacts on sediments and biota in Northumberland Strait due to industrial effluents were observed," the article concludes.

This map shows the location of Northern Pulp, Boat Harbour and Pictou Landing First Nation. (Marine Pollution)

The sampling took place before Northern Pulp closed in January, ending 53 years of pulp paper production, by various owners, at the mill site in Abercrombie Point, Pictou County.

"We expected to find traces of metals, possibly dioxins and furans as a result of the residual effect of Boat Harbour. But in fact we actually didn't find that, even so close to the harbour mouth," Walker told CBC News.

"In terms of a lagoon effective at trapping contaminants in the organic sediments, it actually did its job. Certainly from the point of view of protecting the receiving environment in Northumberland Strait."

This map shows the sampling sites in Pictou harbour and the Northumberland Strait. Red squares represent sediment, American lobster and rock crab sampling stations. Blue circles represent blue mussel sampling stations. (Marine Pollution)

Elevated levels of arsenic were detected in some lobster and rock crab, a fact Walker attributes to the geology of Nova Scotia, which is naturally high in arsenic.

The study compared metal levels with data gathered in more than two dozen harbours around the province. Walker said concentrations were lower than the average in Nova Scotia, probably as a result of the low organic carbon on the sandy bottom ocean floor.

Sediment in Boat Harbour contains plenty of the harmful chemicals the scientists were looking for but did not find in the strait.

Design worked

The facility is located adjacent to the Pictou Landing First Nation, and has been cited as an example of environmental racism.

A burst effluent pipe in June 2014 leaked 47 million litres of toxic wastewater and triggered a protest that resulted in a commitment from the Nova Scotia government to act. The province ordered the facility shut down as an act of Indigenous reconciliation.

"Boat Harbour for all the wrong reasons has been in the media over the years and has been widely reported," Walker said.

"Yes, it did actually trap contaminants. There's lots of contaminants in there. Its design was actually working to protect the marine environment, but for Boat Harbour obviously we know how that turned out. And so that does need to be remediated."

Plan for Boat Harbour

The study was conducted on behalf of the Nova Scotia government, which owns Boat Harbour and is about to begin cleaning up the site. In 2019, the cleanup was estimated to cost $252 million.

Walker said the only other contaminant sampling in the strait was done decades ago.

"That was a gap that we identified several years ago. We needed current baseline information," he said.

When the contaminated soil is dredged, dried and disposed of, a dam that separated Boat Harbour from the Northumberland Strait will be removed to return the area to a tidal estuary.

Mill closed down

In 2015, the McNeil government passed a law setting a January 2020 deadline to close Boat Harbour.

The current owners of the mill proposed to build a new treatment facility on mill property that would discharge treated effluent directly into the Northumberland Strait.

The proposal angered local fishermen who claimed the treated effluent from the discharge pipe would damage lobster grounds.

Provincial regulators said the application needed more information on the environmental impacts. When the McNeil government refused to grant the company an extension to keep Boat Harbour open, Northern Pulp shut down the mill.

The absence of harmful chemicals in the Northumberland Strait came as a welcome surprise to Walker, who expected some "signature" of contaminants near the discharge point.

"But we didn't. The concentrations at the mouth were the same or comparable to our distant stations," he said. "And so in terms of the chemical concentrations in the local marine crabs or lobster or mussels are absolutely fantastic, and I think this is a great news story for the economic driver of this province, which is seafood."