Pulp mill effluent shouldn't affect fishery in Northumberland Strait, says UPEI expert

Plans by a Nova Scotia pulp mill to pipe treated effluent into the Northumberland Strait shouldn't pose a significant risk to water quality in the strait, says an expert on the subject — though he understands why fishermen are concerned about it.

'There is no legal reason or strong environmental concern to require stopping it'

Fishermen have expressed concern about Northern Pulp's plan to discharge its treated effluent into the Northumberland Strait in 2020 when it upgrades its treatment system. (Jeorge Sadi/CBC)

Plans by a Nova Scotia pulp mill to pipe treated effluent into the Northumberland Strait shouldn't pose a significant risk to water quality in the strait, says an expert on the subject — though he understands why fishermen are concerned about it.

"If the effluent is treated in a very state-of-the-art treatment system, consistently, I think the likelihood for there being effects is minimal, based on what I presently know," said Mike van den Heuvel, director of the Canadian Rivers Institute at UPEI. He's also a Canada Research Chair in watershed ecological integrity. 

Northern Pulp's mill in Pictou, N.S., wants to start discharging its treated effluent into the strait starting in 2020 when it upgrades its treatment system. 

Fishermen have expressed concern about contamination of a valuable fishing area in the strait — and van den Heuvel said they have every right to be — but he expects there will be little effect except perhaps in the 100 metres beyond the outflow pipe.

"Any impacts are going to be very localized," van den Heuvel said. 

"It's probably relatively negligible compared to, for example, the nutrients coming from Prince Edward Island as a whole. But you still have to consider these things in terms of what's the cumulative impact of all these things we're doing in the strait." 

"There is some truth to the fact that dilution is the solution," he said of the plan to move the effluent pipe from a small harbour into the open waters of the strait. 

Under Canadian regulations, the effluent has to be tested at least every three years, noted van den Heuvel, but he believes it would be beneficial to monitor more frequently. 

"There is no legal reason or strong environmental concern to require stopping it, so I don't know under what rationale you'd stop it."

With files from Laura Chapin