Monday, February 11, 2013

Putting Minnesota Waters on a Low-Salt Diet

Tracy Leavenworth, Watershed District
K-12 consultant assesses the
salt use on school steps.
For years doctors have told people to stick to a low-salt diet. According to the Minnesota Pollution Control Agency (MPCA), our waters should follow the same advice. When snow and ice start to accumulate on Minnesota roads, parking lots and sidewalks, one of the more common reactions is to apply salt, which contains chloride, a water pollutant. When snow and ice melt, most of the salt goes with it, washing into our lakes, streams and rivers. Once in the water, there’s no way to remove the chloride, and it becomes a permanent pollutant.

“Salt is a real threat to water quality. It only takes one teaspoon of road salt to permanently pollute five gallons of water,” warns Brooke Asleson, MPCA project manager for the Twin Cities Metro Area chloride project. “We are trying to spread the word that less is more when it comes to applying road salt because at high concentrations, chloride can harm the fish, insect and plant life in our waters.” Trees and plants growing near salted sidewalks and driveways can be injured by exposure to salt, too (which is why it’s advisable to consider salt-resistant species for boulevard plantings).

Salt build-up
Winter build-up of salt residue.

 With the arrival of icy sidewalk season, it’s a good time for a refresher on how to limit the use of sand and de-icing salts this winter. There are many ways to reduce salt use while maintaining high safety standards. Here are some basic tips:
  • Shovel… Then shovel some more. Shovel early and often when the snow falls, before the job gets out of hand. The more snow and ice you remove manually, the less salt you will have to use and the more effective it can be. Break up ice with an ice scraper and decide whether application of a de-icer or sand is even necessary to maintain traction.
  • More salt does not mean more melting. Use less than four pounds of salt per 1,000 square feet. One pound of salt, nearly enough for two average-sized parking spots, would fill a 12 ounce coffee mug (an average parking space is about 150 square feet).
  • Below 15 degrees is too cold for most salt to work. Most salts stop working around this temperature. Instead, use sand for traction or use a product designed for lower temperatures.
  • Sweep up extra salt. If salt or sand is visible on dry pavement, it is no longer doing any work and will be washed away. When snow and ice are melted, sweep up any remaining sand and salt. Either use the leftovers or dispose of them in the trash.
  • Identify drainage issues, such as areas where water drains onto your steps or accumulates in low areas in your sidewalk, and fix them during the summer.
  • If you hire someone else to do snow removal, look for a contractor that has earned a voluntary Road Salt Education Certification.

What will protect your pet from heavy salt
use in the winter? Try booties!
Foung Hawj, videographer and newly elected Minnesota State Senator for District 67 from the east side of St. Paul near Lake Phalen, is a strong advocate for water quality in RWMWD. He just finished producing a video for residents in collaboration with Mississippi Watershed Management Organization called Improved Winter Maintenance: Good Choices for Clean Water. To get water-friendly advice on winter care of sidewalks and parking lots for residents check out this video on YouTube.

This video also contains useful information for pet-owners who want to protect their animals from the effects of salt on streets
and sidewalks.


In 2010, the MPCA more than doubled the number of waters that are listed as impaired for chloride. Too much salt results in costly damages and serious environmental consequences. The chloride in road salt enters our surface waters and groundwater after snow melts and is harmful to the aquatic ecosystems. While progress in Minnesota has been made in these areas, there is still much work to do in order to meet water quality standards and achieve a high level of road safety.
Dave Vlasin, Water Quality Technician for
RWMWD, discusses the issues of chloride
at Battle Creek Lake during a demonstration
for Crosswinds students.

Water quality staff at Ramsey-Washington Metro Watershed District are working with the MPCA in a metro-wide chloride study project. Currently RWMWD is monitoring 9 lakes including Lake Phalen, Tanners Lake and Gervais Lake. A zero to two meter composite sampling as well as a bottom sample are collected in the deepest hole of each lake and then samples are sent to the lab for analysis. The samples taken for the chloride study are collected four times a year (Spring, Summer, Fall, Winter), in addition to the normal sampling program. You can watch a short video on the metro wide project called Chloride and our Water - Monitoring the Mix by clicking here.  

To learn more about what you can do to reduce chloride in our waters, or to read more about MPCA’s role on this issue, visit the agency’s road salt and water quality webpage.

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