Ecology Ottawa delegated at City Council's Environment and Climate Change Committee today to support Councillor King's motion calling for a review of the City's Salt Management practices. Our Executive Director William van Geest drew heavily from water sampling conducted by our partners Ottawa Riverkeeper over 5 years to show that such a review is necessary. You can read our delegation below, or simply watch the proceedings.
As for next steps, the motion comes to Council at an upcoming meeting, possibly with a brief detour to the Public Works and Infrastructure Committee. For tips on how you can take action—like signing our petition—please see our campaign page.
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Our Executive Director William van Geest fields questions about the need for salt reductions from councillors on the Environment and Climate Change Committee at City Hall.
Thank you for the opportunity to address you.
I’d like to begin with salt in our waterways. Ottawa Riverkeeper has done valuable work on this, taking over 500 water samples at 45 sites from 2019 to 2024.
Before discussing results, we need to discuss two important thresholds for chloride concentration: chronic toxicity and acute toxicity. Chronic toxicity is when chloride concentrations are between 120 mg/L and 640 mg/L for more than 4 days; and acute toxicity is when chloride concentrations are higher than 640 mg/L. Chronic toxicity typically isn’t immediately fatal to biodiversity, although prolonged levels will have deleterious effects. Acute toxicity, by contrast, is potentially fatal: organisms will die, even if high levels aren’t prolonged.
Now to results. The next slide shows chloride concentrations across the five seasons that Riverkeeper has tested—the last five winters. I’ll draw your attention to the bottom of the figure, to the two dotted lines. The green one below is chronic toxicity, and the red one is acute toxicity—that is, anything above the green line is toxic, and anything above the red line is really toxic. Next, I’ll draw your attention to the blue boxes. These represent the chloride concentrations of the middle 50 per cent of lab-tested samples. You’ll notice that every one of the blue boxes at least touches the acute toxicity line, and one—2019—clears that line completely.
Riverkeeper reports that “out of all samples collected, about 45% exceeded the threshold for acute toxicity.” They also report that 15 samples in Ottawa surpassed 5,000 mg/L, with the highest reaching 25,000 mg/L. So, chloride levels in our waterways are toxic, sometimes extremely.
But how do chloride levels play out across the year? The next slide shows sampling by month. You’ll see the familiar green and red threshold lines on the bottom, and that the blue boxes are all above the chronic toxicity line. (There’s a line in each box representing the median, but it’s hard to see on the slide.) What this chart shows, then, is that high chloride levels persist throughout the year. This in turn suggests that chloride is slowly being released from groundwater and soil, which would suggest that salt is accumulating in our ecosystem.
I want to briefly touch on infrastructure. The NCC is replacing the Alexandra Bridge, principally because of damage from road salt. The cost? $800 million, according to a 2018 estimate—so likely much higher today. One reason we rely so much on salt is because it’s cheap—about $65 per tonne. But if we factored in ecosystem and infrastructure damage—to say nothing of damage to personal property like vehicles and clothing—would we make the same decision?
Finally, it must be acknowledged that we’re doing something wrong in Ottawa. An article published in the Citizen in January reported that the City of Ottawa uses more road salt than any other Canadian municipality—not the type of leadership we want.
But the community knows our salt use is excessive. They brought oversalting to our attention earlier this year—particularly, but not exclusively, in OC Transpo facilities. As we contacted City officials, community members sent us dozens of photos of egregious oversalting. I’ve attached a couple in slides. Of course, after Sunday’s rains, this salt is now seeping into our soil and making its way into our waterways.
Quickly on Councillor King’s motion: it fundamentally asks for information. We believe that the forgoing more than makes a case that the review he calls for is necessary. We have a few additional recommendations on the motion, but for now, I’ll simply ask that you support this request for information.
Thank you.
