Where can we put all this dirty snow?

Hey there, time traveller!
This article was published 22/01/2018 (3045 days ago), so information in it may no longer be current.

Every winter, people express concern about snow dumping along the Seine River. I receive photos showing large mounds of dirty snow that have been pushed off parking lots toward the river. It is often unclear if the snow piles are on private property or park land. Some are very close to the river.

Condos, apartments, townhouses and housing complexes have replaced many single-family homes along the river. Some of these properties have limited space to store snow until spring.
People are concerned about snow dumping for two reasons: Will the snow pile damage the park vegetation? Will pollutants enter the river when the snow melts?

Both are valid concerns.

Snow from roads and parking lots contains dirt, road salt, de-icing chemicals, petrochemicals, heavy metals, litter, and pet waste.

If snow is piled on vegetation, the blanket of dirt and salt left behind in spring often kills the underlying plants. This encourages weeds. If snow is piled too close to the river, the meltwater will carry harmful pollutants into the river.

According to the Parks Bylaw (85/2009), dumping snow in a city park is illegal. Depositing any substance that would pollute a body of water within a park is also illegal.

So where should all the dirty snow go?

If space is very limited, the best way to protect the river and the park (and avoid being fined) is to truck dirty snow to a designated snow dump located away from the river. This may be the best option for many properties designed without snow management in mind.

Ideally, every property should have a designated place for snow storage before plans are approved. The landscape plan should include an attractive natural space that would remove pollutants from the dirty meltwater.

A decanting pond or constructed wetland can be isolated from the river. Dirty water flows into the basin, where the water either evaporates or percolates into the soil. Dirt settles out. Other pollutants break down in the presence of the sun and micro-organisms. If the basin fills up, the cleanest water from the top “decants” into the storm drain system without disturbing the sediment.

When choosing a location for a snow pile on smaller properties, imagine which direction the snowmelt will flow. Plant a rain garden or a buffer strip to intercept and clean the snowmelt before it enters the storm drain or the river.

Michele Kading is a community correspondent for St. Vital and the executive director of Save Our Seine — www.saveourseine.com