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De-icing Solutions at WUSM

Last fall, WashU and the St. Louis Higher Education Sustainability Consortium (HESC) hosted a Brining Workshop to bring together authorities from the St. Louis region to discuss the use of road salt during snow and ice events. The workshop featured speakers from the St. Louis Metropolitan Sewer District (MSD) and a Biologist from SLU to present on the use of road salt in the region and the impacts on the environment.

A popular alternative to traditional rock salt, brining is a method of dissolving salt into a solution that can then be sprayed onto roads and parking lots. It uses the same deicing product, but drastically reduces the amount needed. By distributing less road salt, there are fewer negative impacts on the surrounding environment and infrastructure. The MSD presentation stated that in our region, 1 ton of road salt costs around $60; however, it is estimated that roughly $600 of damage is caused to cars, roads, and drainage pipes from that ton of salt.

In addition to causing infrastructure damage, road salt negatively impacts our landscaping and wildlife, especially aquatic animals living in freshwater streams and rivers. When road salt is applied, the excess washes into storm drains, which typically lead directly into streams without any filtration or treatment. Research by Danelle Haake, a PhD candidate at SLU, shows that salt levels in local freshwater streams increases dramatically during winter. Some streams she has studied in St. Louis County even become as salty as ocean water!

This sudden shift from a freshwater environment to oceanic conditions can have dramatic impacts on the plants and animals living in that aquatic ecosystem; notably, species diversity decreases in the places with high salt levels. These types of ecosystem changes can have noticeable impacts. For example, if diversity of freshwater invertebrates dramatically drops there could be a buildup of dead plant material leading to excessive bacterial and fungal growth because the invertebrates would have typically eaten that detritus on the stream floor.

The WashU School of Medicine grounds and landscaping teams are consistently looking for ways to improve our operations while maintaining a healthy environment for our community members and ecosystems. This winter, the team began taking steps to reduce the amount of road salt used on campus during snow and ice events. Each snow and ice event is unique and the same de-icing procedures cannot be used for each one. Our snow removal team must closely examine weather predictions to make the best decision for the course of action.

While the grounds team has already been using a non-corrosive ice melter product on the sidewalks, the priority remains to reduce the amount of all chemicals used on campus grounds. One strategy the team has used to reduce the amount of ice melt used on campus sidewalks is to use a secondary traction material. In the past, the crunchy ice melt crystals melt the ice and provide something for our shoes and tires to grip onto when traveling on potentially slick surfaces. An alternative is to add another material for the traction aspect; like gravel. The appropriate amount of ice melt is applied to melt the ice and the gravel provides additional traction on potentially slick surfaces.

Because of these new strategies, the team has already reduced the amount of de-icing products needed compared to previous years! They will continue to monitor every winter weather event closely and use the most appropriate methods to ensure safety, accessibility, and minimal environment impacts.

This winter weather is a great opportunity to start practicing smart snow and ice removal at your own home! There are many alternatives to using salt or chemical deicers, particularly to increase traction on slick surfaces.

  1. Shoveling to remove snow is a first easy step, particularly during the snow event or early after the snow stops.
  2. Next, several alternatives can be used to provide traction instead of salt – gravel, sand, ash, and kitty litter are all good options when used in appropriate amounts. Birdseed can be a fun way to create traction on icy surfaces while also feeding the overwintering native birds!
  3. Finally, if you must use salt or chemicals to melt ice, be sure to follow the instructions and only spread the appropriate amount. More salt does not melt ice any faster and it will typically just end up washing away when the snow melts or during the next rain event.
  4. If there is still visible salt on your driveway and paths after the ice has melted, sweep it up for reuse or proper disposal instead of letting it sit and slowly wash away. Our freshwater ecosystems are depending on all of us to de-ice responsibly!


You can find more details about Haake’s research on this page