The Elbow River carves through the middle of Calgary as a slow-moving ribbon of green, brown and blue water that is a popular spot for summertime swims and rafting. Unknown to many, the waterway has had elevated levels of fecal bacteria for three years.
Municipal officials have searched for the source of the pollution, but they say no leaking pipes have been detected along the meandering, nine-kilometre stretch of river covered by a public health advisory. Theories abound, but no clear solution.
The advisory, issued on July 8, 2016, and reiterated every summer since, has done little to stop people from using the river for water pursuits. The stretch under warning abuts some of the city’s most affluent neighbourhoods, as well as the Stampede grounds. The advisory covers an area from downstream of Calgary’s Glenmore Reservoir, one of the city’s main sources of drinking water, to the mouth, where it empties into the larger, faster-moving Bow River.
“We’re certainly working at figuring out why this has happened, and there are a number of theories," said Nancy Stalker, the manager of water quality services for the City of Calgary. "We know what it is not. There’s no evidence of a break in one of our main sewage lines.” If such a break were to occur, the contamination could reach the river in groundwater.
The presence of fecal bacteria is so well established in the river after three years of weekly sampling that Alberta’s health authority has stopped testing the water. Calgary still takes samples, but they are meant to help pinpoint the cause.
“We think it’s a variety of small things, given that the Elbow is a shallow, slow-moving river through an urban area. But it’s a real mystery. It’s a bit of a needle in a haystack,” Ms. Stalker added. The river’s lazy flow means bacteria from human and animal waste are not diluted quickly and can build up.
There’s no pattern to the presence of the bacteria. Sometimes, the water quality is better downstream, other times the flow from storm-water pipes is actually cleaner than the river, she said.
Eighteen square kilometres of central Calgary drain into the affected area of river, including more than 70,000 homes. Officials think small leaks in sewage pipes may be to blame, along with the owners of recreational vehicles improperly emptying sewage tanks. There may also be a simpler explanation, according to Ms. Stalker: “It may be people not using proper washroom facilities, quite frankly.”
Sewage and storm-water pipes can crack when tree roots dig into them, she said.
The city has put four signs along the river warning residents the water could make them sick. Playing with his five-month-old dog along the river at Sandy Beach Park, Matthew Bailey said he hasn’t seen the signs, but he heard of the advisory through news stories. A slight smell of sewage is in the air as his dog frolics in the water.
“The Bow and Elbow haven’t been the cleanest, but I’ve swam in both of them since I was a kid. If it’s good enough for me, it’s good enough for my dog,” Mr. Bailey said.
Jill Galarneau is standing nearby on the beach trying to get her golden retriever out of the water. When the dog goes missing from her backyard, she said, she comes down to the park and he’s always splashing around in the river, a short walk from her home.
“My kids don’t touch that river,” she said, pausing to tell one of her children not to pet the dripping retriever as he ran up the beach. “The water quality here really grosses me out.”
She said she was aware of the advisory, but thought it was sporadic warnings after heavy rains or some other event. She didn’t know it has been in place for years.
Ms. Galarneau is not the only Calgarian unfamiliar with the advisory, according to Harry Daley, the owner of Lazy Day Raft Rentals – one of the companies that rents out the rafts that crowd Calgary’s two main rivers on sunny days.
About 90 per cent of his customers float down the Bow. That river begins flowing about 250 km away in glacier-fed lakes up in the Rocky Mountains and has no fecal-bacteria advisories. The Elbow is about half that length and starts further to the south in the Rockies. Many don’t choose the Elbow, Mr. Daley said, because it is so shallow in many areas that rafters need to get out and walk around rocks and other barriers.
“We hear on the news that you’re not supposed to go into it, but everyone ignores that. You can just so easily go into it. People are biking through it, they’re playing Frisbee with their dog in it, they are swimming and rafting in it,” Mr. Daley said.
He added that most people who rent the rafts don’t tell him where they are going, but when they mention the Elbow, he warns them an advisory is in place. “It hasn’t stopped anyone,” he added.
Calgarians should avoid contact with the river, according to Christine Kennedy, a medical officer of health in Calgary for the Alberta Health Services. The bacteria can cause vomiting and diarrhea. People should never drink river water, avoid all contact with their eyes and ears, and wash their hands immediately if they touch the water, Dr. Kennedy said.
While other rivers have had high levels of fecal bacteria, Dr. Kennedy said she’s unaware of any other urban waterway in Alberta with a years-long advisory.
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