Winter Salt (Sodium Chloride)
Winter salt, also known as sodium chloride, has become an environmental issue of great concern in this watershed and beyond. Winter salt is the substance we apply on roads, sidewalks and parking lots to keep them clear of ice and make them safer for travelling.
What's the problem?
In short, we're applying too much, chloride concentrations are steadily increasing, and it's having negative environmental consequences.
Our monitoring activities have identified a disturbing increase in salt in our rivers and streams and Lake Simcoe itself (see graph).
The problem with chloride is that it's highly soluble. This means that once it dissolves into the water, there's really no effective way at getting it out. And our plants and animals are accustomed to fresh water. So the increasing salt concentrations are hurting them.
So we need to address the issue by trying to reduce the amount of salt we use since it's really our only option. If we don't, salt is poised to overtake phosphorus as the biggest issue in the watershed.
A look at the numbers
To understand the extent of the problem, let's take a look at some numbers around chloride (salt) concentrations in the water.
The Canadian government sets out water quality guidelines that define the levels at which chloride effects aquatic life. There are two different guidelines: a level for chronic exposure and another for acute exposure.
Chronic or long-term exposure is a maximum of 120 milligrams of chloride per litre of water (120 mg/L). The exposure limit for acute or short-term exposure is 640 milligrams of chloride per litre of water (640 mg/L). Severe effects to aquatic life can be expected in as little as 24 hours when the acute exposure is exceeded.
LSRCA researchers estimate that each year we put down the equivalent of 100,000 tonnes of salt in the Lake Simcoe watershed alone. The result is that Lake Simcoe is seeing a fairly steady increase of 0.7 mg/L per year, but our streams and rivers are seeing much higher increases.
In our streams and rivers, particularly in urban areas, we are seeing regular exceedances of the chronic and even acute guidelines. For example, a concentration of 6,120 mg/L was found in Hotchkiss Creek (in Barrie) in February 2013.
Did you know that salt water crabs were found in Mimico Creek? Read more!
Not enough people realize how bad it is
Salt tastes great on your fries… so how bad can it be? Perhaps the reason people don't associate road salt with an environmental problem is exactly because we put the substance on our food.
The biggest problems are roads and commercial parking lotsMaking a dent in the amount of winter salt we use means addressing roads and parking lots, the largest contributors of winter salt.
While road authorities must abide by established provincial regulations around snow clearing and maintenance, the regulations aren't always straightforward, because they consider variables such as weather forecasts.
Commercial and institutional parking lots have no guidelines and protocols. While the Smart About Salt® Council has done extensive research on winter salt application and has implemented a best management practices protocol - including training and a certification program - it's a voluntary program.
Maybe it's all in our heads?In the absence of clear guidelines, fear of litigation is understandable. But the reality is we don't know if that fear is warranted. At present, there are no studies that have examined how many lawsuits have been filed and what the outcomes have been.
What We're DoingContinued monitoring
- We continue to undertake regular monitoring of chloride concentrations throughout the watershed.Partnering for change
- We think the answers depend on collaboration. We've created a Salt Working Group, bringing together experts from the public sector, private sector, non-governmental organizations, legal community and regulators.Research to inform guidelines
- This winter our researchers will be using a friction tester to track the results of salt application on various surfaces in the watershed. The goal is to determine the right amount of salt to achieve safe conditions. Our friction tester uses the same technology as airport testers.Parking lot design with winter in mind
- We've developed design guidelines for commercial and institutional parking lots
. If these guidelines are followed, less winter salt is required. We're also encouraging municipalities to incorporate these guidelines into their policies.
What You Can Do
You are key to the solution! What you can do for the environment when it comes to winter salt use is best summed up with three P's: Preparation, Patience and Pressure.
Preparation: Shovel your driveway and sidewalk as soon as possible so ice doesn't have a chance to form. Wear sturdy winter boots. Use snow tires. Redirect downspouts away from paved areas so ice can't form.
Patience: When it snows it often takes longer to get places. Consider leaving early, or accept that you may be late. This is winter in Canada!
Pressure: If you see excessive salt being applied, put pressure on the property owner. Tell them about the environmental consequences of applying too much. Ask them to contact us. We can direct them to agencies like Smart About Salt® to have their staff or contractors trained in correct winter salt use.
Check out this video from the U.S. Consulate General Toronto about salt!