Indigenous communities, environmental groups and other concerned citizens who monitor toxic waste are increasingly concerned about the dumping of radioactive matter and other contaminants into the Ottawa River from an inactive nuclear reactor northwest of the capital.

A scientific report released in February details the dumping of thousands of litres of water contaminated with radioactive tritium, PCBs and other toxins into the river from the inactive nuclear power demonstration (NPD) reactor in Rolphton. Ont., about 200 kilometres from Ottawa.

The contaminants are at levels above Ontario and Canadian surface water quality standards, according to the report.

It was written by geoscientist Wilf Ruland, who was retained by the Algonquin Anishinabeg Nation Tribal Council to review the proposed decommissioning of the demonstration reactor.

Norm Odjick is director general of the Algonquin Anishnabeg Nation Tribal Council.

Radioactive tritium dumped

"The site is so close to the Ottawa River, only being 100 metres [away], and for us the environment and the water are two of our priorities," said Norm Odjick, the tribal council's director general.

In the report, Ruland notes releases of contaminated water into the river "appear to have been ongoing for decades and [continue] to the present day."

"The regulatory guidelines for surface water quality were vastly exceeded in the contaminated water being dumped untreated into the Ottawa River from the NPD facility in 2015."

Ottawa Riverkeeper Meredith Brown said radioactive tritium has been dumped into and diluted by the river, but cannot be filtered out or treated like other toxins.

Discharge below limit, CNL says

Canadian Nuclear Laboratories (CNL) is a private-sector consortium that runs Canadian nuclear facilities owned by the federal government, including the demonstration reactor at Rolphton.

CNL maintains the contaminants it releases into the Ottawa River fall well below allowable limits.

"The discharge limits of tritium are 10,000 times below the actual dose limits that the Canadian Nuclear Safety Commission requires us to meet," said Meggan Vickerd, the reactor's decommissioning manager.

But just what makes an "acceptable" limit is a matter of debate.

Ole Hendrickson, a scientist and researcher for the group Concerned Citizens of Renfrew County and Area, questions the safety of the discharge limits for the facility.

Regulations vs. impact

"Aquatic organisms are being exposed to very high concentrations of toxic substances, and there's nothing to stop boaters from drawing and filtering river water near the discharge point for drinking," Hendrickson said.

Hendrickson also pointed out Ontario's limit for tritium in drinking water greatly exceeds limits in other jurisdictions, and is thousands of times higher than natural levels.

Ottawa Riverkeeper Meredith Brown calls the method of dumping radioactive waste into the river 'pollution by dilution.' (Kate Porter/CBC)

"They release it at a rate so that they will always be below the drinking water quality standards, which in Canada are really high for tritium," Brown said.

"They're making really sure to meet their regulatory obligations based on release limits, based on diluting it in the Ottawa River," she said.

"Meeting the regulations is not the same as environmental impact."

Nuclear history

The reactor at Rolphton made history in 1962 as the first in Canada to produce electricity from nuclear power. It stopped operating in 1987, and now CNL is developing a plan to decommission the site and deal with the nuclear waste.

That plan involves entombing the reactor in a form of concrete grout and capping it with an engineered barrier.

Vickerd said CNL is now two years into that planning process, and recently submitted a draft environmental impact statement to provincial and federal authorities.

Environmentalists, Indigenous groups and scientists have been reacting to that initial plan to entomb the nuclear waste, and worry about future contamination of the river.

The NPD reactor "will remain a radiological hazard for tens of thousands of years," according to nuclear scientist Jim Walker in his submission to the nuclear facility's operator.

Walker is one of several retired scientists to submit their concerns. Ruland's hydrogeological report was also sent to CNL.

Hendrickson said entombment is only supposed to be used in emergencies according to the International Atomic Energy Agency, and doing so at Rolphton will set a bad precedent.

But Vickerd said that so far, CNL hasn't "seen any red flags."