Snow and ice have finally arrived in much of Minnesota, and that brings the winter chore of clearing pavement — sometimes with salt. But when the snow melts or it rains, salt, which contains chloride, runs into storm drains and into nearby lakes, rivers, and groundwater. Salt is commonly over-applied, sending too much chloride into our waterways and wreaking havoc for fish and other wildlife. Minnesotans can stay safe while doing their part this winter by minimizing salt use and using other tools to get the job done.

We scatter an estimated 445,000 tons of chloride-containing salt on our paved surfaces across Minnesota each year. Not only does salt damage our infrastructure and plants, but it is harmful to our waters. Chloride ends up in our lakes, rivers and streams and makes its way into our groundwater. It is toxic to our freshwater fish and other aquatic life. In fact, some waterways have so much chloride, they have been added to the state’s impaired waters list. 

It only takes one teaspoon of salt to permanently pollute five gallons of water. That’s right: once the chloride is in our water, it’s there for good, and continues to build up year after year. Chloride from de-icing salt is one of the largest contributors to a growing salty water problem in Minnesota and is one of two pollutants that continue to accumulate over time with no practical mechanism for removal in the environment.

Though no environmentally safe alternatives to de-icing salt are yet available, smart salting strategies that don't compromise on safety can help reduce chloride pollution in Minnesota waters:

• Shovel and scrape. The more snow and ice you remove, the less salt is needed to be effective. Watch this video about tools, techniques, and products that you can use to keep your driveways and sidewalks safe while protecting our waters.
• 15°F and below 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.
• Use the right amount. That crunch from sidewalk salt under your feet does not signify safety. People often think using more salt means more melting and safer conditions, but this is not true. Around 12 ounces — roughly a coffee mug full — effectively treats a 20-foot driveway or 10 sidewalk squares (about 1,000 square feet). Aim to apply salt evenly (e.g., with a spreader), and use only in critical areas. Using more than the recommended is simply a waste, costing you money.
• Sweep up visible salt on dry surfaces. Leftover salt is no longer doing any work and will just be washed away into local waters. You can keep it to reuse later. Next time, try cutting back on the amount you use. When the correct of salt amount is used, there should not be any visible salt left behind.
• Wear proper footwear. Wear shoes or boots with good traction and pay attention to where you are walking, avoiding icy spots, if possible. Take it slow and give yourself extra time to get where you’re going.

There are many ways to provide safe winter conditions and minimize impacts to the environment. The MPCA offers Smart Salting trainings for winter maintenance professionals, property managers, and others on how to provide safe surfaces in winter and minimize harmful environmental impacts. Those who hire professionals to manage snow and ice in winter should hire a trained and certified Smart-Salting contractor. The MPCA list of certified Smart Salters can be found on the MPCA’s Smart Salting training webpage.

Want to learn more and get involved? The MPCA has created a new online workshop for community leaders to learn how they can help. Check out the MPCA’s training calendar for upcoming dates. To stay current on smart salting best practices, subscribe to our newsletter or visit our chloride webpage.