Water quality returns to the levels not seen for 100 years
The amount of fecal coliform entering the North Saskatchewan River from Edmonton has now dropped to levels last seen in 1910, according to monitoring and data modelling from the city’s drainage department.
No one continuously monitors water quality in the river for recreational use, but local experts agree tests on nearly any dry day in August or September will meet Health Canada guidelines.
That news will likely surprise people, says Stephanie Neufeld, watershed specialist with Epcor.
“It’s a bit of a misconception that we have this river and it’s dirty and not usable. I just don’t think that’s true. It’s maybe that we lack understanding of the river,” she says.
Significant levels of harmful bacteria can enter the river from run-off on agricultural lands upstream, or from stormwater overflows in the city’s remaining combined sewer systems, but those events happen less often than most people think, and are usually associated with high water levels and silty, turbid flows, says Neufeld.
The presence of fecal coliform and E. coli bacteria indicate water may be contaminated with fecal material, which is likely to cause gastro-intestinal illness. Epcor tests for E. coli daily while drawing river water for the L.E. Smith and Rossdale drinking water facilities.
In the river, she says, “less than three per cent of the time, we’re actually exceeding (Health Canada recreational) guidelines.” It wasn’t always this way. Gord Thompson, a water engineer with the North Saskatchewan Watershed Alliance, likes to quote from one of the first local sanitation engineers, who took samples during the winter.
“Looking down through holes in the ice, one could see toilet paper, chicken feather, and fecal matter floating by,” University of Alberta professor Pat Bouthillier wrote in 1950.
In the postwar years, Edmonton had a few, small and poorly maintained sewage treatment facilities. The human waste went right into the river, sometimes spreading typhoid, and causing mass fish kills when all the organic matter decomposed and used up the oxygen.
“There were times downstream (of Edmonton) where the oxygen levels would go down to zero,” says Thompson. “No oxygen, no fish. That’s grossly polluted.”
Since then, Edmonton waste treatment has seen a series of steady improvements. Fecal coliform levels dropped when the Gold Bar plant was built in 1956. It dropped again when Gold Bar started treating the final effluent with U-V rays to kill any remaining bacteria.
After a major storm, raw sewage still makes it into river through the overflows in the city’s combined sewer system in older areas. But in 1999, the City of Edmonton approved a $150-million plan to reduce that by 86 per cent.
They finished expansions at the Gold Bar plant in 2011. Before next spring run-off, a 2.5-metre diameter tunnel under the river will be finished and most of the combined sewer water from the north side will flow directly to the Gold Bar plant rather than emptying into the river at Rat Creek.
This should reduce the amount of combined sewer water entering the river to 500,000 cubic metres a year, from the current 2 million, says Mohammad Tariq, the engineer who oversees combined sewers for the drainage department. “We’re working hard on this one.”
Ross Bulat oversees testing at the four main stormwater outfalls: Terwillegar, Quesnell, Groat and Kennedale. He also tests in the river, since the towns of Devon and Drayton Valley are upstream, as are large agricultural operations.
Test samples are free of most pesticides and the few that are detected are within guidelines. Water quality changes, because snow and storms west of Edmonton wash into the river.
But on a day when the water is clear in August, at least a couple days after a storm in Edmonton, he would let his daughter, who is almost two, splash and play where it is shallow. “Absolutely,” he says. “On a dry day like today, any point is fine.”