If Northern Pulp is allowed to build its proposed effluent treatment facility, it will affect the marine life immediately surrounding the discharge point, says a UPEI professor.
“Is there potential for very localized effects to the fishery?” said Michael van den Heuvel, the Canada Research Chair in watershed ecological integrity, based at the University of Prince Edward Island.
“Yes, there is. But it will be a very small area. The question is, are the level of the effects acceptable to society?”
That, and whether taxpayers are willing to pay for another effluent treatment facility for the 51-year-old mill are proving to be more of a debate than a discussion as Northern Pulp prepares to register its environmental assessment.
With the latter question largely answered for us by a 1995 indemnity agreement signed by the province that puts the taxpayer on the hook for most or all of a replacement effluent treatment facility, we will concentrate on Question 1.
For a biologist like van den Heuvel, everything humanity does has an effect on the natural world.
Maintaining lawns of shorefront homes along nearly the entire length of the Northumberland Strait has a negative effect on the biological productivity of the ecosystem.
Spreading nitrogen and phosphorus fertilizer on potato fields near rivers draining into the Strait has an effect.
Pouring between 60 to 80 million litres of treated effluent a day just outside the mouth of Pictou Harbour will have an effect.
Van den Heuvel has spent much of his career studying the effects of pulp mill pollution in North America and New Zealand.
“If you dammed off the Northumberland Strait it would take 20,000 years for the mill to fill it, so if you ask me if it will affect fisheries the length of the strait, the answer is absolutely not,” he said.
“The mill says you won’t be able to measure any effects within a hundred or 200 metres. Let’s be more liberal, let’s say it may have effects within a thousand metres. What will those effects be?”
That is a topic that has been the focus of significant scientific study.
“The two issues around pulp mills are that if there are large amounts of nitrogen and phosphorous they can cause eutrophication, which can lead to algae blooms and invertebrates changing in numbers and size,” said Deborah MacLatchy, a biologist who has studied the effects of pulp mills and currently serves as president of the University of Waterloo.
“The other issue is compounds that cause what we call endocrine disruption. So the fish are bigger because of eutrophication but also their gonads are smaller and have less reproductive ability.”
Eutrophication happens when an influx of nutrients causes excessive plant growth that in turn sucks the oxygen out of the water so that sea creatures can’t breathe.
As for the small gonads, the jury remains out on exactly which chemical compounds cause those.
“What we’ve seen is as the mills tighten up their spill processes, become more effective at recycling chemicals and optimize their treatment plants, we see much less endocrine disruption happening in the fish,” said MacLatchy.
But “much less” is not zero.
The Abercrombie Point mill is classified as a northern bleached softwood kraft mill.
That means it digests chipped spruce and fir trees in a giant pressure cooker filled with sodium hydroxide, sodium sulfide and water to separate the long cellulose fibres that give a tree its strength from the glue that binds them together. Those fibres are used as an additive to strengthen products like toilet paper.
The lignin (tree glue separated in the digestion process), sulphides and other chemicals go to a giant furnace. The sulphides don’t burn and the solid particulates are caught in the smokestack by an electrostatic precipitator sending them to a lime kiln so that they can be reused.
What doesn’t burn or get reused heads to the treatment pond.
Aided by an as-yet undeclared amount of government money, Northern Pulp is proposing to build this activated sludge treatment facility adjacent to the Abercrombie Point plant.
The “activated” part of the sludge are the bacteria that consume the parts of the tree and some of the chemicals when they enter the ponds.
“In a kraft process when you are adding chemicals that is a cost to the mill, so what they do is try to recycle as much as they can because that is in their own economic best interest,” said MacLatchy.
“You do end up with compounds that are part of the process eventually being released. What you are doing in the mill and treatment pond is getting them to levels of less and less toxicity.”
By law, pulp mill effluent is checked multiple times a year in Canada with what is colloquially known by scientists like van den Heuvel as the “kill ’em and count ’em test.”
Environment Canada calls it the “acute lethality test.”
It involves putting 10 rainbow trout in a 20-litre pail of treated effluent and seeing how many are still alive after 96 hours.
If five or more are still alive, then you pass the federal regulations governing pulp and paper effluent.
The key is dilution.
So Northern Pulp says that within 100 metres of its six-port diffuser, the effluent will have been diluted enough that it won’t be harmful to the marine environment — i.e. it wouldn’t kill any fish in the pail.
Those opposed to the project, like the Friends of the Northumberland Strait, point out that the “kill ’em and count ’em” test doesn’t account for long-term effects on the ecosystem.
Activated sludge treatment systems have been built in British Columbia, which has its own set of regulations regarding pulp effluent that are more stringent than Environment Canada’s.
Nova Scotia doesn’t have those.
Previous provincial governments put taxpayers on the hook for providing an effluent treatment facility until 2030 for the mill while the current one passed legislation demanding Boat Harbour be closed by Jan 31, 2020.
It’s here that we return to Question 1, posed by van den Heuvel at the beginning of this story: “Are the level of effects acceptable to society?”
We’ll soon find out.
