Preventing Chloride from Damaging Minnesota Water

Road salt ends up in Minnesota lakes and rivers. Photo: (CC BY-NC-ND 2.0)

As Minnesotans, we love our waters — it’s part of who we are. But lakes and creeks in our cities are getting salty. Thirty-nine water bodies in the Twin Cities Metro Area are above EPA standards for chloride — a byproduct of salt — including Como Lake, Diamond Lake, Powderhorn Lake, Wirth Lake, Bassett Creek, Battle Creek, Elm Creek, and Minnehaha Creek!

In winter, salt is applied to roads and walkways to melt ice and snow — this is where most of the chloride in our water comes from. The salt dissolves, runs into storm drains, and most storm drains go directly into local waterways.

The problem with chloride is that it builds up over time so waterways are getting saltier and saltier every year. About one fifth of chloride ends up draining into the ocean through major waterways, but the vast majority stays in local waterways. That saltiness is hurting aquatic life and the health of our waterways — one of our most valuable resources. Over time, chloride will work its way into groundwater and other drinking water sources. It’s difficult and expensive to remove chloride from tap water.

Here are some tips that you can use at your home. But we also need the state legislature to act on this issue. Take action today!

  • Prevention is the first step! Shovel, sweep, or blow the snow off your surfaces before it builds and gets slippery.
  • Make sure you have the right tools – a sidewalk/ice scraper will go a long way.
  • The best alternatives are salt-free: sand, coffee grounds, kitty litter or an outdoor snow/ice carpet.
  • If you need to use salt, then use no more than 1 pound (about 1 coffee mug full) of salt per 1,000 square feet (about the size of a two car driveway).
  • Make sure salt is spread evenly and thinly – no big piles or clumps.
  • More salt does not mean more melting! Excess will just runoff into our favorite lakes and rivers.Regular road salt doesn’t melt ice and snow at temperatures less than 15°f!

Correct and incorrect road salt usage.

For winter maintenance professionals, you can get a free Smart Salt Certification.


Read the Minnesota Pollution Control Agency study on chloride in the Twin Cities Metro Area.