|
As
Minnesota endures heavy snowfall and bitter cold temperatures, 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 annually.
The
Minnesota Pollution Control Agency (MCPA) recommends a low-salt diet for our
lakes, streams, and rivers. Rock salt, which contains chloride, is the most
commonly used de-icer. But, much like table
salt, rock salt’s benefits are peppered with danger. Salt helps keep our roads
free from ice and safe for drivers, 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. Governor Mark Dayton has declared a Year of Water Action in Minnesota, which makes this winter an ideal time to learn more about the impact of salt on Minnesota's lakes and streams.
How does salt get into the
water?
The
primary source of chloride, particularly in urban areas, is salt applied in the
winter months to roads, parking lots and sidewalks. A secondary source of
chloride, particularly in more rural areas, is water softeners.
The state of Minnesota has
thousands of miles of roads to maintain and managing ice and snow is necessary
to the safety of residents. The use of salt, primarily sodium chloride, is
currently the common method for ice control during the winter. However, when
snow and ice melt, the salt goes with it, washing into our lakes, streams, rivers,
wetlands and groundwater.
Why does it matter?
High levels of salt can be
harmful to fish and other freshwater aquatic life and can also negatively affect
infrastructure, vehicles, plants, soil, pets, wildlife as well as groundwater
and drinking water supplies.
Roughly 75% of Minnesotans
rely on groundwater for their drinking water. The MPCA has found 30% of the
shallow monitoring wells, often in urban areas, have exceeded the state
standard for salt levels. As water moves from shallow to deeper aquifers, the
salt contamination could penetrate our sources of drinking water.
Once in the water, chloride
becomes a permanent pollutant and continues to accumulate in the environment
over time. The only known method of removing chloride in
groundwater and wastewater is through reverse osmosis, which can be a costly
and challenging large scale treatment process.
What is happening with salt
in the water?
There are currently 47
waterbodies in Minnesota that tested above the water quality standard for
chloride, with 39 in the metro. An additional 39 surface waters in the metro
are near the chloride standard and many others are unknown. The data show that
salt concentrations are continuing to increase in both surface waters and
groundwater across the state.
How can you make a difference?
How can we protect our
waters, maintain safe roads in the winter and have desirable water in our
homes? Currently, there are not environmentally safe, effective and inexpensive
alternatives to salt. However, we can reduce salt at the source through smart
salting application strategies. Smart salting will also save money as well as
reduce damage
to infrastructure, vehicles, plants and water supplies.
Each person contributes to
the attitudes and practices that have created a high and steadily growing
volume of salt to be used each year. Shifting public attitude toward more
sustainable salt application is required to meet demands. You can do your part
to prevent chloride pollution by following these simple tips.
Winter Safety – a few ideas to reduce salt use
-
Support local and state winter maintenance
crews in their efforts to reduce their salt use.
-
Work together with local government,
businesses, schools, churches and non-profits to find ways to reduce salt use
in your community. Shovel. The more snow and ice you remove manually, the less salt you will have to use and the more effective it will be.
-
15 degrees F is too cold for salt.
Most salts stop working at this temperature. Use sand instead for traction, but
remember that sand does not melt ice.
-
Slow down. Drive for the
conditions and make sure to give plow drivers plenty of space to do their work. Consider purchasing winter (snow) tires.
-
Be patient. Just because you don’t
see salt on the road doesn’t mean it hasn’t been applied. These products take
time to work.
- Apply less. More salt does not mean more melting. Use less than 4 pounds of salt per 1,000 square feet. One pound of salt is approximately a heaping 12-ounce coffee mug. Leave about a 3-inch space between granules. Consider purchasing a hand-held spreader to help y9ou apply a consistent amount.
-
Sweep up extra. If salt or sand is
visible on dry pavement it is no longer doing any work and will be washed away.
Use this salt or sand somewhere else or throw it away.
-
Hire a certified Smart Salting
contractor, visit the MPCA website for a list of certified contractors: https://www.pca.state.mn.us/water/training
-
Watch a video. This video, produced
by the Mississippi Watershed Management Organization, provides tips to
homeowners about more environmentally friendly snow and ice removal: Improved Winter Maintenance: Good Choices for
Clean Water
-
For more information about Governor Dayton's Year of Water Action, visit
mn.gov/governor.
Broadcast version
As Minnesota endures heavy snowfall and bitter cold temperatures,
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 metro area
roads annually.
Unfortunately, salt does not disappear in our local lakes and streams. Currently, there are no environmentally
safe, effective and inexpensive alternatives to salt. However, we can reduce
salt at the source through smart salt application strategies, like using less salt, sweeping up excess, and applying salt only at temperatures above 15 degrees. . Smart salting
will also save money and reduce damage to infrastructure, vehicles,
plants and water supplies.
More information is available on the Minnesota Pollution Control Agency's website.
###
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
| 
