The federal government has put a halt to the planned dumping of billions of litres of raw sewage into the St. Lawrence until at least Nov. 3.
In an interim order, Environment Minister Leona Aglukkaq said the delay would allow a scientific review of the dump to take place.
In a separate open letter addressed to Montreal Mayor Denis Coderre, Aglukkaq said Environment Canada had determined there were important risks to consider and that the city of Montreal had not conducted any studies into those risks.
Coderre fired back Friday night, quoted urging Montrealers to vote to change the government on Monday.
Earlier on Friday, Coderre called the actions of the federal environment minister "abusive" and failing to respect both the "spirit and the letter of the regulations" regarding the dumping of wastewater. Coderre said he would give Ottawa one week to change its mind regarding Montreal's week-long sewage dump.
This week, Aglukkaq said she could not permit Montreal to dump untreated wastewater for a one-week stretch, saying it required further study.
In an open letter to Aglukkaq, Coderre had reminded the minister that Environment Canada and Environment Quebec were informed of Montreal's plans in September of 2014.
Coderre also wrote that Montreal had complied with every request from officials for further information.
He also pointed out that many other cities in Canada dump untreated sewage, some doing it on a daily basis, without any disapproval from the federal ministry.
During the construction project to replace a snowmelt collector near the Bonaventure Expressway, approximately 30 kilometres of sewage lines will need to be drained, and the wastewater flow from about half of the city dumped directly into the river for one week.
This means about 8 billion litres of wastewater will enter the St. Lawrence -- or about the same volume as passes any point in the river in 30 minutes.
Coderre points out that the time frame chosen for the project, between mid-October and mid-November, was done at the behest of Quebec's Environment Ministry so as to minimize the impact to fish and those who use the river.
Coderre said the if the Environment Ministry waits too long to review its decision, allowing the work to proceed next spring would likely have a worse impact on the environment.
At a rally in Laval Saturday morning, Harper did not address the sewage dump plan, but a Conservative party spokesperson issued a statement saying the government is "aware of public concern, and will continue to work with the city and province."
