Excessive Salt Use is Hurting MN Lakes, State Officials Warn

Salt helps keep roads free from ice and safe for drivers, but did you know it can have the opposite effect on the nearby environment? Its public safety benefits come with environmental drawbacks like polluted waters and poisoned aquatic wildlife.

It is estimated that we toss more than 350,000 tons of salt on the metro area roads annually, according to state officials.

When snow and ice melt, all of this salt goes with it, washing into lakes, streams, rivers, wetlands, and groundwater.

How does salt get into the water?

The main 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.

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 percent of Minnesotans rely on groundwater for their drinking water, according to a news release.

The Minnesota Pollution Control Agency (MPCA) has found 30 percent 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 way to remove chloride 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.

Can you make a difference?

Currently, there are no environmentally safe, effective and inexpensive alternatives to salt. However, officials say residents 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.

Here are tips provided by the MPCA to help 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 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.
• 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.

Image via Pat Pilon, Flickr, used under Creative Commons