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St. Paul, Minn. – As Minnesota prepares for a return to wintery weather
this week, most of us will rely on a crucial tool to clear the roads and
sidewalks: salt. It is estimated that we toss more than 350,000 tons of salt on
the metro area roads, parking lots and sidewalks annually.
According to the Minnesota Pollution Control Agency (MPCA), our waters
should follow the advice our doctors have been giving for years: stick to a
low-salt diet. Road salt, which contains chloride, is the most commonly used
de-icer. But, much like table salt, road salt’s
benefits are peppered with danger. Salt keeps us safe on icy roads but can have the
opposite effect on the nearby environment. Its public safety benefits come with
environmental drawbacks like polluted waters and poisoned aquatic wildlife.
In the Twin Cities metro area, 78 percent of the salt applied to roads
stays within the region’s watershed. Chloride from road salt is washed away
into our lakes, streams, and wetlands and eventually finds its way into the groundwater.
Once in the water, it becomes a permanent pollutant and continues to accumulate
in the environment over time.
As our winters become harsher, the piles of salt we dump are becoming a
bigger problem. The MPCA assessed Minnesota’s groundwater and found that
one-third of all wells across the state showed an increase in chloride concentration.
This year the number of chloride-impaired water bodies
more than doubled. Currently, that includes are 21 lakes, 22 streams, and 4
wetlands. Of the impaired waterways, 40 are in the seven-county metro area.
De-icing material was singled out as a major culprit and the salt we use
is becoming a bigger problem. High chloride levels are toxic to aquatic life. De-icing
salt can also kill plants and trees along the roadways and those that soak up
salty water through their roots. Salt in the groundwater can affect the taste
of drinking water and can be a health issue for those restricted to low-sodium
diets.
“Too much chloride has serious
water quality consequences.” said Brooke Asleson, chloride project manager at
the MPCA. “We are trying to spread the word that less is more when it comes to
applying road salt. It only takes one teaspoon of road salt to pollute five
gallons of water. MPCA is collaborating with MnDOT, cities, counties, and local
partners to tackle this dilemma.”
Asleson’s study on the real
cost of salt use shows that chloride comes with economic consequences too. Cities
throughout the state have been able to reduce salt use thought smart salt use
and by taking advantage of additional trainings. The
City of Waconia has been able to reduce their use by 70 percent with an
estimated total cost savings of $8,600 annually. Last year’s nasty winter depleted salt
stockpiles and caused salt prices to rise. This year, some places will
experience cost increases of 23-30 percent.
The MPCA remains concerned about the need to provide safe roads and
paved areas, while also protecting surface and ground water resources from
contamination. The agency recommends the following tips for reduced salt use
while maintaining safety:
Shovel first.
The more snow and ice you remove, the less salt you will have to use and
the more effective it can be. After the ice has been broken up, you can decide
if deicer is even necessary to maintain traction.
Apply
salt before the storm. Salting before can prevent snow and ice
from building up on roads, therefore reducing overall salt use.
Slow down. Drive for winter conditions, and
be courteous to slow-moving plows. The slower they drive, the more salt will
stay on the road where it’s needed.
More salt does not mean more melting. Use less than four pounds of salt per 1,000 square feet (an average
parking space is about 150 square feet). One pound of salt is approximately a
heaping 12-ounce coffee mug. And be patient: salt takes time to work. Applying
more will lead to unnecessary contamination.
15 degrees is too cold for most salt to work. Most salts stop working at this temperature. In frigid conditions, use
sand for traction.
Sweep 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.
For more on what you can do to reduce chloride in our waters, or to read
more about MPCA’s role on this issue, visit the agency’s Twin Cities Metro Area Chloride Project webpage.
Broadcast version
As Minnesota prepares for a return to wintery weather this week, most of us will rely on a crucial tool to clear the roads and
sidewalks: salt. It is estimated that we toss more than 350,000 tons of salt on
the metro area roads, parking lots and sidewalks annually.
Road salt, which contains chloride, enters our surface
waters and groundwater after snow melts. Once in the water, salt becomes a permanent
pollutant and causes harms to fish, insects and plants.
There are many ways to reduce salt use while maintaining high safety
standards. One is shoveling. The more
snow and ice you remove manually, the less salt you will have to use and the
more effective it can be.
Remember, most salts stop working when the temperature drops below 15
degrees. For more winter maintenance tips, visit the M-P-C-A website at www.pca.state.mn.us.
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The mission of the MPCA is to protect and improve the environment and enhance human health.
St. Paul • Brainerd • Detroit Lakes • Duluth • Mankato • Marshall • Rochester • Willmar
www.pca.state.mn.us • Toll-free and TDD 800-657-3864
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