After the snow and ice have melted away, the salt and deicing agents used to treat roads and sidewalks remain. These products flow over driveways, sidewalks and roads and go into the nearest catch basin. Once there, they go directly into our waterways, untreated.
The problem with salt, sand and deicer in our water:
Salt in our water is not good for plants, wildlife or people. Birds can mistake salt crystals for food, and it can be toxic to fish and others in aquatic systems. Salt is not good for plants, and in many wetlands, salt-tolerant invasives are crowding out native vegetation. This can lead to a loss of food source for local wildlife. An increase of salt in reservoirs can also impact drinking water.
Sand has been used as an additive to salt or as an alternative, but it is not effective in providing traction on slippery surfaces and it clogs catch basins and causes flooding. It can also carry other pollutants into our waterways. If used, excess sand should be swept up.
A deicing agent is a preferable alternative to both salt and sand, but it is still not perfect. These products contain sodium or potassium acetate and calcium magnesium acetate, which are less abrasive than salt, but are also pollutants in large quantities.
What can you do to keep your pavement safe while also keeping our water clean?
- Use deicer (sodium acetate, potassium acetate, and calcium magnesium acetate) instead of salt (sodium chloride, calcium chloride, and magnesium chloride).
- Shovel early and often. Remove as much snow and ice as you can, and only use deicer on what you can’t take care of with a shovel.
- Follow product instructions and only use as much deicer as you need. More is not better and can actually cause partial melting and then re-freezing if applied on top of snow and ice, making conditions worse.
- For wet snow or sleet and freezing rain, apply deicer product before it starts to snow to prevent snow and ice from bonding with pavement.
What is the City doing to curb salt use?
In 2018, the City piloted a new snow removal technique using a saltwater solution called brine which was sprayed on streets in advance of a predicted storm. This salt water solution uses a quarter of the salt normally used and is sprayed directly onto the travel lane of the road, preventing snow and ice from bonding with the street. The program expanded to 5 vehicles with brine tanks to pretreat thoroughfares, select bike lanes and sidewalks. Public Works also constructed its own brine farm with new tanks and a brine making machine. Applying brine to the pavement before snow or ice has bonded can be 10 times more effective than placing salt crystals on top of snow and ice. This results in an overall reduction in the amount of salt used.