How much salt do you really need for de-icing a driveway and sidewalk?

How much salt is really needed for de-icing?

As it turns out, you probably don't need to use as much rock salt to melt ice on your property -- and overuse is having some ill effects on the environment.

MINNEAPOLIS (FOX 9) - You may not need as much rock salt to melt icy driveways and sidewalks as you think — and using too much is having some ill effects on the environment.

How much salt is needed?

What to know: The Minnesota Pollution Control Agency (MPCA) recommends that just a coffee mug’s worth of salt, around 12 ounces, should be enough to de-ice an entire driveway or 10 sidewalk squares. Focus on applying the salt evenly and only on essential areas, rather than covering an entire surface.

The more snow and ice you can remove ahead of time, the less salt is needed to be effective. If you notice leftover salt, you should probably use less the next time around.

Any leftover salt on dry surfaces can be swept up and reused. The MPCA explains that excess salt left on the sidewalks and roads serves no purpose and gets washed into the local waterways.

Salt impact on MN waterways

A little – or none – goes a long way when it comes to salting roads and sidewalks

The MPCA effort is called "Smart Salting," which trains public works departments and property managers on ways to cut down salt use. So far, she says, it’s been effective.

The big picture: Unfortunately, the safety measure also puts fresh water at risk of collecting chloride, which is a permanent pollutant.

Scientists say just one teaspoon of salt or ice melt is enough to pollute five gallons of fresh water. But Minnesota agencies spread 445,000 tons — or about 255 billion teaspoons — on our roads every year.

Once the snow melts, the salt finds its way into lakes, rivers, streams and groundwater, where it can pose a serious threat to freshwater fish and other wildlife. Some waterways have accumulated such high levels of chloride they have been added to the impaired waters list.

One of the easiest ways to protect fresh water is to not use too much salt or ice melt. The MPCA says your best bet is shoveling first and using sand or grit on top of compacted snow to create traction.

Keeping Minnesota roads safe

How much rock salt do you need to use?

As it turns out, you probably don't need to use as much rock salt to melt ice on your property -- and overuse is having some ill effects on the environment.

Dig deeper: The MPCA trains public works departments across the state to do ice prevention by using brine – a combination of salt and water, which drastically cuts down on the need for salt.

"They've been able to reduce their salt use anywhere from 30 to 70% and still maintain safe conditions for the public," Brooke Asleson, a Minnesota Pollution Control Agency (MPCA) chloride specialist previously told FOX 9.

Golden Valley crews previously told FOX 9 they’ve gotten the MPCA training and invested in technology giving them road temperatures and other data to help reduce the amount of chemicals they use while still keeping the roads safe.

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