Toxic sewage discharged at Chalk River nuclear lab

Canadian Nuclear Laboratories (CNL) discharged toxic sewage at the Chalk River site along the Ottawa River during peak fish spawning season earlier this year, CBC Indigenous has learned.

Environment Canada confirms its enforcement officers in late April issued CNL a compliance direction, a tool used to correct violations of Fisheries Act regulations. 

It said Chalk River's sanitary sewage plant had an "acute lethality failure," meaning testing found the sewage effluent, or treated wastewater discharge, was toxic to fish.

Effluent is considered acutely lethal when, at 100 per cent concentration, or undiluted, it kills more than half the rainbow trout subjected to it during a 96-hour period, regulations say.

Neither CNL nor Environment Canada said what pollutants were in the effluent, how much toxic wastewater was discharged or where, sparking fears it may have landed in the Ottawa River.

Environment Canada said it "takes pollution incidents and threats to the environment seriously." CNL said it's "confident that the non-compliant discharge from the sewage treatment facility does not pose a threat to the environment or the public." 

But the lack of clarity around the incident is sparking questions and concerns.

Lance Haymond, chief of Kebaowek First Nation in Quebec upstream from the site, said he's shocked to learn the details.

"I'm upset. I'm not happy to find out that the operations at Chalk River again are posing harm to the Ottawa River," he said.

"That it's happening during one of the most important periods in the fishing season, which is the annual spring spawn, causes us great concern."

Earlier this year, the country's nuclear regulator approved CNL's plan to build a radioactive waste landfill at the Chalk River site. The disposal facility would contain about 400 Olympic-sized swimming pools worth of low-level nuclear waste.

Kebaowek and local groups have launched court challenges against the project's approval.

Haymond considers the problems at the existing sewage plant a bad omen, since the organization will need to manage wastewater contaminated with radionuclides like tritium if the landfill is built.

What's even more troubling, the Algonquin leader added, is the perception of secrecy. CNL learned of the problem in February but didn't inform the public of "non-compliance in sewage effluent" until late March.

Environment Canada also didn't notify the public until contacted with questions prompted by an anonymous tip.

"That's really upsetting, and that's probably more concerning," said Haymond.

Facility now passing toxicity tests: CNL

CNL is under contract to manage federally owned nuclear sites and liabilities, including the sprawling but aging Chalk River research hub about 180 kilometres northwest of Ottawa.

The organization said it detected the problem in February following a disruption at the sanitary sewage treatment facility, which serves 3,000 employees and contractors.

Environment Canada said its enforcement officers were alerted to the issue on March 7 and began to confirm "it was indeed a violation" of the wastewater regulations.

CNL didn't notify the public until nearly three weeks later, when it reported the non-compliance in a March 27 community information bulletin. CNL didn't say what requirements were breached but promised it was working to bring the effluent back into compliance.

Haymond received the communiqué directly but said he shrugged it off as vague and seemingly under control.

Coincidentally, Haymond had a Kebaowek member in the area, roughly 16 kilometres downstream from the nuclear facility, gathering information on fish spawning for the First Nation.

Mary-Lou Chevrier compiled her observations in an April 13 report, before she knew of the sewage issue. Chevrier reported encountering a distinct metallic odour at the junction of the Petawawa and Ottawa rivers, some dead fish, and lethargic behaviour among sturgeon. 

WATCH | Video of sturgeon in the Ottawa River:

She provided CBC Indigenous a video of her reaching into the river and touching one of the big bottom feeders. She was able to lift a sturgeon out of the water with her bare hands, something the avid angler and outdoor enthusiast said she's never seen before.

There is no evidence linking this to the sewage issue, but like Haymond, given the lack of clarity, Chevrier is worried about the incident's possible impact on fish.

"It's quite alarming, and I wish that I had learned about it earlier on. I've been coming across an awful lot of anglers who have been catching fish and eating them," Chevrier said.

"It's just not right to have something like that going on in our territory and find out about it after the fact."

On April 23, an Environment Canada enforcement officer issued a formal Fisheries Act direction to deal with the issue, spokesperson Samuel Lafontaine told CBC Indigenous.

These directions are "a compliance tool" that may be issued "when there is an unauthorized deposit of a deleterious substance into water frequented by fish or when there is a serious and imminent danger of such an incident, and immediate action is necessary."

CNL issued a second, more detailed bulletin April 24 that lists the corrective actions CNL is taking or being directed to take.

These include increased effluent toxicity testing, a third-party supported toxicity evaluation and review of all facility operations, and a detailed review plus chemical analysis of all effluent and influent at the plant.

CNL is also undertaking company-wide training on allowable releases, a review of all known discharges to the facility to identify abnormal activities, cessation of a routine release at one of its labs, and facility improvements to restore the treatment process.

The organization is providing biweekly progress reports to Environment Canada until the issue is resolved, which the department said is mandatory "when an acute lethality failure occurs."

CNL told CBC Indigenous the sewage plant is now passing toxicity tests but must secure another month of positive results before it can be declared back in compliance.

Biological treatment system disturbed

The plant is from 2019 and uses leading-edge environmentally friendly technology, CNL said.

The facility uses a biological treatment process known as activated sludge, which contains beneficial microorganisms, largely bacteria, that reduce pollutants in wastewater.

A civil engineering professor at the University of Ottawa who specializes in wastewater said breakdowns of such facilities are rare but can happen.

Biological treatment like this is more cost effective than chemical treatment, Robert Delatolla said, but one pitfall is that the microorganisms can be disturbed.

The system can go sideways if a chemical substance that is toxic to the microorganisms enters the system and renders them non-viable.

"They could be killed, essentially. That's a potential reason for what's happening in Chalk River, simply from the communication that went out," he said.

Delatolla cited one line from CNL's second bulletin — the cessation of a routine release within one of its research laboratories. This suggests something from the laboratory may have disturbed the microorganisms in the sludge, the professor said.

"It sounds like toxicity from something that was released from that lab. They want to look into that and indicate if that's where it's coming from."

Larissa Holman, director of science and policy at Ottawa Riverkeeper, a local registered charity that advocates to protect the watershed, said CNL's bulletins raised questions instead of providing answers.

"First of all, how severe was it? Because we have no idea with what's been provided," said Holman.

"It could be very minor, but because they failed compliance and they're going through all these steps, we don't know."

Both Holman and Delatolla said it was reassuring to see the list of extensive measures taken following the Environment Canada direction.

The Canadian Nuclear Safety Commission (CNSC) maintains a list of "nuclear-related event reports" on its website but the non-compliant effluent at Chalk River was not listed as of May 2.

CNSC declined an interview request, declined to answer written questions and referred inquiries to Environment Canada as the department responsible for wastewater regulations.