The City of Montreal's controversial plan to dump eight billion litres of raw sewage into the St. Lawrence River, which started just after midnight, is going swimmingly according to Mayor Denis Coderre.

"We're overseeing it, we are recording data and I want to reassure people that it's going well," Coderre told a scrum of journalists from the site, noting that the week-long effort is on schedule.

Some observers had noticed a discoloration in the water but Richard Fontaine, the head of city's waste water management, said colour is not a clear indicator of the water's quality.

"What's most important is the tests that we did before and during and after, that's the best way to judge." The test results will be made public as soon as they are known, he said.

Fontaine also noted that the places which smelled the worst, such as the St-Pierre facility, routinely emit an odour even in normal conditions.

Coderre vowed to visit the site tomorrow and said that video images would be made available for the public to see.

Started at the stroke of midnight

The dump project will continue for the next seven days, despite a protest by about 40 people.

Coderre said the city met the conditions imposed by Environment Canada to proceed with its plan.

The protesters took to the foot of the Mercier Bridge on Montreal's South Shore on Tuesday night, in hopes of stopping the dumping of the sewage, but to no avail.

On Wednesday, students at Kahnawake Survival School joined other Kahnawake Mohawks at a bonfire close to the bridge, where a statement denouncing the city's plan wil be read. The fire was set Tuesday night, also in protest of the sewage dump.

Coderre stood by the city's decision to dump untreated wastewater into the river on Wednesday morning.

"We don't have a choice but to do planned work," he said.

The project is part of construction work on the Bonaventure Expressway.

The city says it needs to shut down an interceptor — a major sewer that collects the effluent from a network of other sewer lines on its way to the water treatment plant — for maintenance and to link it to a new snow dump site. The wastewater will be diverted into the river as a result.

Over the next week, the sewage will be diverted to discharge points along the river.

There are 12 boroughs and seven cities which had some or all sewage diverted to the southeast interceptor.

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Sewage dump could finish ahead of schedule

At 6 p.m. ET on Wednesday, work crews will begin working on the interceptor to repair it. They will work in shifts, 24 hours a day, until work is completed.

The dumping could be over in less than a week if the work is finished ahead of time.

Richard Fontaine, director of Montreal's wastewater treatment plant, told Radio-Canada that the project is going smoothly.

"I adamantly hope that it will be shorter but you have to let me go inside the interceptor before I can confirm that " Fontaine said.

On Tuesday Coderre said there would not be any odours. Fontaine told Radio-Canada that while he hopes that is the case, it is possible there could be some odours emanating from the river.

"It's normal. We're changing the current of the river and we're mixing the sediments that are present in the collectors," said Fontaine.

Others take extra precautions

The municipality of Longueuil, located on Montreal's South Shore, will take daily samples from the river for testing.

The town will also have its own patrol team composed of biologists and emergency services monitoring the north and south ends of the river. Workers on the boat will document photos of the state of the St. Lawrence.

Radio-Canada confirmed that Bota Bota, a spa located in Montreal's Old Port along the river, will close its doors on Thursday and Friday as a preventive measure.