When one reads further into this, we see the reasoning behind it. To solve a bigger problem. Only 40 people protested it........ dont shoot the messenger.

The City of Montreal's controversial sewage dump project started just after midnight and will continue for the next seven days, despite a protest by about 40 people.

Montreal Mayor Denis Coderre said the city met the conditions imposed by Environment Canada to proceed with its plan to dump eight billion litres of raw sewage into the St. Lawrence River.

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The protesters took to the foot of the Mercier Bridge on Tuesday night, saying that had hoped to stop the dump, but to no avail.

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

The City of Montreal is dumping eight million litres of untreated wastewater into the St. Lawrence River over the next several days. (Radio-Canada)

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.