Millions of litres of sewage spilled into Montreal rivers

Though water quality has improved enough around Montrealin recent decades to spur plans to develop citybeaches, 150 pipes still dump sewage into the the St. Lawrence River and the Rivire-des-Prairies during heavy rains.

Duringthe worst spill in July 2013, the amount of fecalcoliformmeasured in the water on the banks of Verdun was almost20 times the limit considered safe for swimming.

The problem lies in the fact that 60 per cent of Montreal's sewer network combines waste waterfrom drains and toilets with rainwater collected in the streets.

We have some catching up to do.There were decades during whichalmost nothing wasdone.-ChantaleRoulea, Rivire-des-Prairies-Pointe-aux-Tremblesmayor

During heavy rains, when the island'ssewer networkreaches full capacity,valves are opened to allow water to overflowinto rivers in order to prevent backups in businesses and residences.

The city says it is not able to estimate the quantitydischarged into the river during overflows, however, according to figures from the city'swaste water treatment plant, 99.3 per cent of sewage is treated.

Given that up to 76 billion litres of water the equivalent of three Olympic Stadiums full comes to theplant duringa day of heavy rain, that 0.7 per cent spilled is potentially 530 million litres of sewage being emptiedalong the shores of the island.

No spill warning

The city does not publishwarnings of possible contaminationeven major spillsinto the riverwhich the Socit pour vaincre la pollution environmental group says is unacceptable.

"To have a beach inMontreal, it is imperative that the city make overflowspublicwhen they occur so people can safely swim," said the group'sco-chair Daniel Green.

MonitoringMontreal's water quality

The city has adatamonitoring network to surveyMontreal'saquatic environmentat various points around the island.They indicate that in 2013, these discharges would lead to closuresat the sites ofproposed beaches in Verdun.

The City of Montreal recommends waiting 48 hours after the rains to swim in the river, as strong currents carrycontaminated water downstream.

The mayor of Rivire-des-PrairiesPointe-aux-Trembles says the city is aware of the problem and is investing in solutions.

"[The city]has adopted a water plan and has goals for the next 10 years, including a $4.6 billion investment for upgrading our network. We have some catching up to do.There were decades during whichalmost nothing wasdone," said Rivire-des-Prairies-Pointe-aux-TremblesMayor Chantale Rouleau, who is also in charge of Montreal's water dossier.

The city says it plans to build several underground reservoirs to store excess water during heavy rains and prevent sewage overflows into the river.

In the mean time, thecity says that if it does opena beach, it will close monitorthe water quality will be necessary to ensure the safety of the swimmers.