Winter Snow and Ice Removal
Members of TMACOG’s Stormwater Coalition remind us to protect water quality even when the water is frozen.
With winter weather lingering, many of us are still hauling out the boots, gloves, and snow shovels to remove snow and ice from our driveways. But not all approaches to snow removal are stormwater-friendly. Snow- and ice-melting products, known as de-icers, can have negative environmental impacts - including fish and vegetation kills - if melted snow and ice carrying the chemicals ends up in streams. Snowmelt from city streets goes into storm drains and directly into waterways without any treatment. Some de-icers can release cyanide (used as an anti-caking agent) after they enter streams.
Overuse of certain de-icing products, such as salts, can damage driveways and vehicles and can also be a hazard for pets. Lawns and landscape plants are also at risk for damage from overuse of salts that includes browning of leaves or needles and preventing trees, shrubs, and other plants from getting water. Limiting the use of salt-based de-icers on driveways and sidewalks will help reduce these negative effects.
What you can do to help protect stormwater in winter:
- Shovel or plow your driveway and sidewalks before spreading de-icer. De-icer will not work on deep piles of snow anyway, and shoveling does not require chemicals that could harm streams.
- Limit the use of de-icers, especially those with the most environmental impacts.
- Only use as much de-icer as you need. Large snow piles and thick ice will not melt faster with more de-icer. You can always reapply if you used too little.
- Do not use fertilizer for snow and ice removal. Fertilizers are very poor at snow removal and increase nitrogen in streams when the snow melts.
- Only use sand for traction. Kitty litter and ash become clumpy and are difficult to clean up after use.
- Pets can be harmed by some de-icers. Wipe your pet’s paws if they walk on any salts or chemicals. This helps prevent ingestion and damage to their paws.
Not all de-icing products are equal in terms of cost, environmental impact, or effectiveness.
*Source: Snow, Road, Salt and the Chesapeake Bay by Tom Shuler, Center for Watershed Protection
||-25 degrees F
||3 times more than rock salt
||Less salt required
||5 degrees F
||Comparable to other salts
||Least toxic deicing salt
May cause tracking or discoloration
|Sodium Chloride ("rock salt")
||15 degrees F
||Around 5 dollars per 50 lb bag
||May contain cyanide
||20 to 25 degrees F
||5 times more than rock salt
||Contains excess nutrients
|Calcium Magnesium Acetate (CMA)
||22 to 25 degrees F
||20 times more than rock salt
||Does not melt snow/ice
||Around 3 dollars per 50lb bag
||Accumulates in streets and streams
Needs to be swept