Nova Scotia Environment imposed — and then retracted — a $697 fine on Northern Pulp last year for violating air pollution limits.

The short-lived summary offence ticket was the lone punishment levied against the Pictou County mill for exceeding allowed air-contaminant emissions from its power boiler over the past three years.

"And even then they couldn't make it stick," says critic Matt Gunning, a member of the Clean the Mill watchdog group.

The pulp mill has struggled to meet limits contained in its 2015 Nova Scotia Environment Department industrial approval.

The $697.50 summary offence ticket was issued after emissions from its power boiler exceeded limits in June 2016. The government says the ticket was later withdrawn after a retest of the mill's power boiler showed emissions were below acceptable levels.

"It was discovered that there were some technical difficulties during the June and August tests that were immediately addressed," Environment Department spokesperson Chrissy Matheson said in a statement to CBC News. "The SOT [summary offence ticket] for June was retracted because of this."

Department defends enforcement record 

The department released a list of its enforcement and compliance activities after CBC reported the mill's power boiler failed its latest air emission test in June — for a third year running.

"Nova Scotia Environment's enforcement division has been working very closely with Northern Pulp to bring them into compliance with requirements in their industrial approval," Matheson said.

Northern Pulp mills

The mill is allowed particulate emissions of 150 milligrams per reference cubic metre (mg/Rm3). (Jeorge Sadi/CBC)

The latest result has frustrated some in Pictou County, including one of its best-known citizens.

"Why are they not meeting the tests and why are the tests not being enforced by the government?" asked former Empire Inc. CEO Paul Sobey on CBC's Mainstreet on Tuesday.

What are the limits? 

The mill is allowed particulate emissions of 150 milligrams per reference cubic metre (mg/Rm3).

The Nova Scotia Environment timeline shows emissions from the mill's power boiler have fluctuated in and out of compliance.

The limits were exceeded in March 2015 (155 mg/Rm3), September 2015 (190 mg/Rm3), June 2016 (164 mg/Rm3) and December 2016 (157 mg/Rm3). 

The mill confirmed this week that its June 2017 test was 224 mg/Rm3.

Paul Sobey

Former Empire Inc. CEO Paul Sobey has voiced frustration with the results of the latest tests. (CBC)

The department says it cannot release the June results — or discuss them — because they are under investigation.

"Any time a company does not comply with our regulations, we take it very seriously," says Matheson.

'A laughable amount'

When the power boiler exceeds limits, the department issues a directive and warning to Northern Pulp.

In each case, the mill has come into compliance, the department says. 

Tests show emissions from the power boiler have been compliant five times since 2015.

The summary offence ticket, later retracted, was the exceptional response from the province.

"The number itself is a laughable amount," says Gunning. "I guess where we are really frustrated is we still continue to see the same things over and over again." 

$35M fix reduced most emissions, mill says

"We continue to investigate all avenues that may be contributing to the fluctuating results," said Northern Pulp spokesperson Kathy Cloutier in a statement to CBC News earlier this week.

"Recent activities include having North American boiler experts on site conducting a full audit of scrubber operations. The recommendations stemming from this audit are now under review."

In 2015, the mill, owned by Paper Excellence, spent $35 million on a new precipitator, which captures particulate from its recovery boiler using static electricity. Since then, the mill says overall air-contaminant emissions have been reduced by 80 per cent.

In a statement provided after this story was published, Northern Pulp spokesperson Kathy Cloutier provided additional information about the rescinding of the fine.

"Detailed review of our June 2016 regulatory stack test reports by boiler experts revealed O2 levels measured were unattainable by our system design, prompting a deeper investigation with the testing company. Oxygen is used in the final particulate calculation," she said. 

"The contracted testing company recalculated the particulate concentration for the power boiler in June 2016 to be 114 mg/Rm3, therefore the June 2016 testing of the power boiler should not be considered an exceedance of the industrial approval limit."

Of the last 10 regulatory stack tests, three have been non-compliant, the company says.