A little salt goes a long way for managing snow and ice. But too much salt – which may be less than you think – can cause irreversible damage to nearby lakes and streams.
 
The danger of ice and snow on roads and sidewalks is a fact of life in Minnesota, and salt and sand can help reduce ice and add traction. When that snow inevitably melts, however, most of that salt and sand wash directly into nearby waters.  
 
Currently, salt use is not regulated, but it poses a real threat to clean water. The chloride contained in one teaspoon of road salt can permanently pollute five gallons of water. Chloride upsets aquatic environments and can kill birds and some plants.
 
Many people use more salt than they need.  But using more salt does not melt more ice, or melt it faster. In reality, salt only works when there is enough snow or ice for it to react with and excess crystals will eventually become a pollutant. It's best to use less than four pounds of salt per 1,000 square feet. One pound of salt fills up a 12-ounce coffee mug.
 
Want to protect your local lake or stream from chloride pollution? Here are some easy ways you can help:

• Shovel! When you remove snow and ice manually the more effective salt can be. If possible, keep up with any major storms by doing a little at a time. 
• Shovel more! Break up ice and decide if application of a de-icer or sand is necessary to maintain traction.
• Use salt sparingly. As a general rule, use no more than a pound of salt (or one 12oz cup of salt) per 250 square feet. For comparison, an average parking space is about 150 square feet. Aim for a spread of 2-3 inches between salt crystals.   
• Don't use salt when temperatures fall below 15 degrees F. Salt stops working around this temperature. For traction use sand. Some de-icers do work in colder temperatures. Check the product's "practical melting point" not the "eutectic temperature."
  
• Sweep up extra. If salt is visible on dry pavement, it is no longer doing any work and will be washed away. Use this salt somewhere else or throw it in the trash.  

Watch training videos on proper sidewalk maintenance from the Minnesota Pollution Control Agency.

Use this reference guide to help you know what de-icer to use.

Below is a great video overview of good residential snow and ice practices, courtesy of the Mississippi Water Management Organization: