Winter’s impact on water quality: de-icers and sand

It is important to remember that streams continue to flow, ponds and lakes continue to ‘live’ under their ice and our responsibility to maintain healthy water ecosystems continues throughout the winter. During significant snow and ice storms, road safety requires the application of salts to melt ice and provide safe traction. Each winter local road departments, commercial parking lot owners, home contractors and homeowners use salt to melt snow and ice and to maintain road and other surfaces.imgres

As the snow melts or when it rains or snows, salt eventually makes its way to nearby rivers and streams through run off. These chemical de-icers, salt and sand can change the composition of the water and can harm resident insects, fish, and wildlife.

Even when applied in relatively small quantities, salt can:

  • Deplete the oxygen supply needed by aquatic animals and plants
  • Leach into the ground and change the soil composition, affecting the growth of plants
  • Leach into the groundwater and flow into surface water contaminating sources of drinking water
  • Deteriorate paved surfaces, buildings, and infrastructures.

Sand, which is carried away in runoff, can have the following effects:

  • Bury the aquatic floor life, fill in habitats, and cloud the water
  • Erode the stream banks and other landscapes as it is carried to the surface waters by stormwater runoff
  • Carry phosphorus which acts as an aquatic fertilizer, causing algae blooms and increased vegetation
  • Fill catch basins, stormwater devises and storm drains, affecting their effectiveness if not cleaned
  • Contribute to plugged storm drains, which can cause flooding

What can you do?

Once the snow falls and the lakes freeze:

  • Cover Up: Cover stored de-icing chemicals and road salt.
  • Reduce: Instead of spreading de-icers, shovel.
  • Use alternatives: Non-toxic de-icing substances such as biodegradable cat litter, sand or fireplace ash don’t necessarily melt snow but they do improve traction.
  • Go for the center: Apply de-icer only down the center of your driveway or walkway. As it melts it will flow to the sides.
  • Less is enough: Use de-icer sparingly because more does not mean more melting. Be patient: it takes time for de-icers to work. Applying more will lead to unnecessary contamination.
  • Wait for warmer temperatures: Most de-icers don’t work when the temperature is below 15 degrees. Before granular de-icers melt snow and ice, they must dissolve to form a brine solution. If the air temperature or the temperature of the pavement is below freezing, water may not be available to dissolve the granular de-icer. If you can’t wait, use a liquid de-icer or a pre-wetted de-icer, or focus on sand for traction.
  • Sweep: Clean up extra salt. If salt or sand is visible on dry pavement, it is no longer doing any work and will be washed away. The excess can be swept up and reused for the next snow or disposed of in the trash.
  • Drive for winter conditions: The slower you drive, the more salt will stay on the road where it’s needed. And don’t forget — be courteous to slow-moving plows. We all need to remember, anything we put on exposed manmade surfaces and our land ends up in the water. That’s the way our ecosystem works. Do your part to keep our waters clean in the winter.

Sources: University of New Hampshire Cooperative Extension, University of Maryland Extension, University of Michigan Cooperative Extension

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