We all breathe a sigh of relief when we see the road
maintenance crew salt, sand and shovel out the roads after a winter storm. The truth is however, too much road salt can
contaminate groundwater supplies. So
what can be done to make roads safe without harming the environment?
How do road salts
contaminate groundwater?
First, it’s important to understand how road salts
contaminate groundwater. When the snow melts and spring rains come, all the
salt that accumulated over the winter ends up in storm water catch basins and
streams. The salt that is carried to
surface water can harm fish and plants.
The salt can also damage vegetation and soil along the shoulders of
roads, causing erosion issues.
The salt can get into underground drinking water supplies by
infiltrating the groundwater and contaminating wells. Salt can remain in groundwater for
decades. If the salt does get into
groundwater supplies used for drinking water it can affect the taste of the
water, affect individuals with hypertension, and corrode plumbing
infrastructure.
Lowering salt
applications make roadways safer.
Although salt is used because many municipalities believe it
is one of the only ways to ensure roadways are safe, there are techniques,
equipment and chemicals that require less salt to be used and actually make
roads safer. In Kamloops, BC, Canada
following the change to a low-salt application technique, the city saw an 8%
decrease in accidents. Similarly, in
Idaho transportation officials switched from heavy salt and sand applications
to liquid magnesium chloride on one stretch of road and saw an 83% reduction in
accidents in that area. This sort of
success story probably won’t happen in every case, but by utilizing lower salt
application techniques, roadways become safer and the environment becomes
healthier.
What can you do?
Here are some ideas you can recommend to your local
municipality to protect groundwater supplies from salt contamination:
1.
Use the
right amount: The most important factor to remember when applying salt is
the surface temperature. When roads are
warmer, less salt is needed.
Municipalities might consider purchasing inexpensive infrared thermometers
for spreading trucks.
2.
Only use
it where it’s needed: Make sure salt is being used in areas where it is
most needed. Hills, curves, bridges,
etc. need more salt than other areas of the road. There are also times when salt won’t help
melt ice on roads. If the surface
temperature is below ~10ยบ F, a road won’t benefit from salt. Instead, use another chemical suited for
lower temperatures.
3.
Apply
early!: Don’t wait until the snow starts falling to apply salt. It takes more salt to melt snow that has
accumulated than it does to prevent the accumulation. Brine can be applied days before a weather
event in the right conditions.
You can also use these techniques when you apply salt on
your own driveway and sidewalks so you can stay safe while keeping groundwater
supplies clean!
[source: www.epa.gov]
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