185M litres of raw sewage dumped into Winnipeg rivers since 2004

Since 2004, Winnipeg's antiquated combined sewer system has dumped at least185 million litres of untreated raw sewage into the city's waterways,and it could cost the city up to $4billion to fix the problem.

A CBC Newsanalysis of incident reports going back to 2004 revealed that at least 73 million litres of raw sewage hasflowed into the Red,Assiniboineand Seine rivers due to system and mechanical failures.

That doesn't include the deluge of rain and snow that can overwhelm the system the city says storms can add 10 million more litres of raw sewage every year into the rivers.

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'Sewage isn't sexy'

Groups like theLake WinnipegFoundation have been keeping a close eye on the city's plans to address the issue.

"Sewage isn't sexy. But if we care about our water, we need to start paying attention to it. All the water that flows in and out of Winnipeg ends up in our great lake," said AlexisKanu, the foundation'sexecutive director.

Prior to the1940s, sewage and storm runoff flowed untreated into the rivers down the same sewer pipe. Gates called "weir dams" were later installed in each of the 79 outlet pipes in order to divert the mixed water toward municipal treatment plants. Approximately 30 per centof the city mostly older core neighbourhoods are built over this system.

Geoffrey Patton, the manager of engineering for the City of Winnipeg'swater and waste department, explains that during periods of heavyprecipitation about 20 times per year the system gets overwhelmed, leading to what the city calls "combined sewer outflows."

"The combined sewers are actually functioning properly when they're overflowing, because that'sthe way they were designed to protect private, like basements,and public property,"he said.

The city treats about onebillion litres of raw sewage annually and estimates that aboutone per centof that volume ends up in the river.

Sewer system breakdowns and unknowns

Heavy rainfallmight cause combined sewer outfalls (CSO), but according to an analysis of the 114 incident reports dating back 11 years, malfunctions andbreakdowns are responsible for close to 40 per centof the raw sewage flowing into waterways.

However, the analysis revealed that the true volume of raw sewage flowing into the river is significantly higher than what the data suggests, since about half of the incidents indicate that the total amount and duration time of each discharge is unknown.

The city says that until massive upgrades are made to the older sewer system, monitoring sensorshave been installed in 39 primary outfalls to gather data and sound the alarm bells whensewage is flowing.

"The model we're working on and the instruments that are going in will help more tighten that number up so we'll know exactlywhat'sgoing on,"saidPatton.

Blocked sewers andwatermainbreaks caused half of the reportedCSOs. Mechanical breakdowns of gates and equipment led to nineincidents. Weather-relatedpower outages, whichpreventedpumping stations from moving sewage to treatment facilities, occurredon 23 occasions.

"Twigs, lumber, bats, toys, you'll seealotof those things in sewers. The most unusual thing was a gecko lizard we basically saw crawling on the camera as we drove by it," said Patton.

He added that an increased use of so-called "disposable baby wipes" contribute to the problem.

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"People use them, but they'll clog pumps and cause these types of overflows," he said. "They don't degrade and we discourage these types of products in our system."

Paddlers notice smells after rainstorms

Those who spend the most time on the waterways are also mindful of the water conditions.

"TheCSOsare most noticeable along theAssiniboineRiver after a rainstorm, as it's narrower,"said RobinMcLureof the Manitoba Paddling Association.

"We'll notice odour and debris. It can be frothier and I think to myself,'Gee, it's not a good day to fall in!'"

The city is currently evaluating several options on how to reduce their number of CSOs, including infrastructure upgrades such as sewer separation, in-line storage, offline storage, end-of-pipe treatmentand green infrastructure. These options range in costfrom hundreds of millions to billions of dollars.

The Manitoba governmenthas set a deadline of 2017 for the city to submit a final master plan.

Notes from most recent incident report:

Sept.4, 2015

Dumoulin/Tach outfall

830,000 litres (14 hours 17 minutes)

"A crew attended the station at approximately 6:30 a.m. and found the station had flooded to the motor floor level however both pumps were found to be running. By 8:30 a.m. the water was pumped out and the cause of the flooding was determined to be a leaking pump seal. Pump #1 had to be taken off line for servicing at this time and was put back in service at 8p.m. to draw down the system and then again taken off-line for repairs once the overflow event had stopped.

"Due to the rain event occurring September 4the Dumulin combined system remained surcharged and overflowing for most of the day. Normal operation of the station is for both pumps to be running during overflow events."