Island rainwater sewer dumping polluted water into the river

The problem isn't new, because it's happened often in this location. Le Magazine has mentioned the faulty sewer connections, which contaminate rainwater, by allowing water that should only travel through the toilet sewers to travel through the rainwater sewers.

However, that being said, it's highly unlikely that these faulty connections were the cause of this pollution, because there are only a few of them remaining. Their volume can therefore not explain the numbers presented by the daily paper.

Engineer Jean Cardin, head of the division, at the Verdun borough, confirmed that only 48 residences, out of a total of 8,292 homes in 2003, still had at least one toilet connected to the home's rainwater sewer.

If one compares the number of total volume (less than 0.6%), it would be surprising that these faulty connections would be at the origin of such a large-scale contamination. The borough is working at locating the origins of the problem and Mr. Cardin does not eliminate the possibility of faulty connections existing in the public sewer network, but thinks it highly unlikely.

An analysis is being undertaken by the Direction de l'environnement de la ville de Montréal. It consists of taking samples of water from the network, beginning with the problematic sewer located near Champlain Bridge, which is the only one out of the seven Island sewers that seems to have a problem with contamination.

The analysis is a complex one, because the Island's rainwater network is frequently inundated by water from the St. Lawrence River. The collection of water will have to take place when the river is at its lowest level, but results won't be available until mid September 2007.

In the meantime, the borough is studying various scenarios in order to solve the 48 faulty connections, which need to be corrected, even if they are probably not the cause of this pollution. Residents should not be alarmed, because the samples taken on June 9, within a radius of 15 metres from the contaminated sewer exit, presented an acceptable level of coliform bacteria (less than 100 units per 100 milliliters of water).