Environment Canada is expected to provide a response by Tuesday over the City of Montreal's plan to dump eight billion litres of its sewage into the St. Lawrence River.

Catherine Maurice, a spokesperson for Montreal Mayor Denis Coderre, confirmed that the city gave the federal government the necessary documentation on Friday. Environment Canada is expected to provide an answer early next week — Tuesday, at the latest.

Montreal's plan to shut down a major interceptor — a large pipe that feeds water from the sewers into a treatment plant — for maintenance has stirred up controversy among politicians and citizens.

The city would dump eight billion litres of wastewater into the St.Lawrence River over the span of a week, from Oct. 18-25.

The plan was approved by Quebec's Environment Ministry and the city says there are no alternatives for it to be able to carry out the required maintenance. However, the federal government criticized the plan and called on Montreal to suspend its work.

​Major construction work to lower the Bonaventure Expressway to street level in downtown Montreal requires moving a snow dump, which is connected to a big sewer. This sewer's pipe measures five metres in diameter and normally carries sewage to the city's water treatment plant.

However, in order to carry out the work to move the snow dump, the sewer's pipe must be drained.