The City of Gatineau will be spilling a significant volume of raw sewage into a tributary of the Ottawa River later this month as it undertakes major repairs to one of its pumping stations.

The station on Chemin du Quai in the city's Masson-Angers sector is corroded and leaking and will have to be taken offline for 48 hours, Mayor Maxime Pedneaud-Jobin said following a technical briefing at Gatineau city hall Thursday afternoon.

The work is planned for Oct. 24-26. During that time, as much as 20 million litres of sewage could be released into the Lièvre River, which empties into the Ottawa River across from Cumberland.

"We are afraid of losing the station. It could break down, and if it does — and if we're not prepared — it could take us a few months to repair it," said Pedneaud-Jobin.

"There's no other option. We've tried trucking [away] the material. We've tried different technologies. And we can't find anything that's feasible."

One year after St. Lawrence spill

The municipality's decision comes almost one year after Montreal chose to dump eight billion litres of raw sewage into the St. Lawrence River, an act that city said was necessary as it demolished a major expressway.

The concentration of fecal bacteria in the St. Lawrence River ended up being much higher than normal during the four-day dump, although the levels did resemble what would typically be seen during heavy rains. Media outlets from across the globe reported on the spill and the resulting outcry.

Ottawa Riverkeeper Meredith Brown says that while the spill of as much as 20 million litres of raw sewage into the Lièvre River is not ideal, the city of Gatineau is at least being transparent about the fact it's happening. (CBC)

"It compares only in the sense that we've looked at other options and we can't find any. But the level [of sewage being released] is absolutely not comparable," Pedneaud-Jobin said.

"It's roughly 400 times smaller than what happened in Montreal. So we think that ... the amount we're putting in the river will limit the impact on the environment."

Transparency lauded

In a statement, the city of Gatineau said it had approached both the federal and the Quebec governments for permission to release the sewage into the Lièvre River.

Municipal officials on both sides of the river, in towns like Thurso, Que., and Rockland, Ont., had also been informed about the impending release, said Pedneaud-Joboin — as had the environment ministries in both Ontario and Quebec.

From Oct. 24-26, the pumping station in the Masson-Angers sector of Gatineau, Que., will be taken offline for much-needed repairs, the city says. (Michel Aspirot/CBC)

Ottawa Riverkeeper Meredith Brown told CBC News that while the release of up to 20 million litres of sewage into the Lièvre River was not "ideal," at least the city of Gatineau was being transparent about the fact it was happening.

"I think what happened in Montreal is almost certainly influencing [the city of Gatineau's] transparency in this case," Brown said.

"They saw how much the public created a stink, pardon the pun. And so they want to make sure that they're covering everything, and they're doing the right thing," she said.

Residents in both the Masson-Angers and Buckingham sectors are being urged to reduce their water usage during the upcoming work on the 21-year-old station by, for example, taking shorter showers and postponing their laundry and dishwashing.

If those advisories are heeded, the sewage spill could be reduced by as much as half, Pedneaud-Jobin said.