IMPACT OF WINTER DE-ICING CHEMICALS ON WATER QUALITY AND THE ENVIRONMENT: WHAT DO WE KNOW AND WHAT DOES THE FUTURE HOLD?
The amount of road salt applied during a winter that is retained within a particular watershed can vary widely, depending on hydrogeological conditions and stormwater management practices. Published estimates vary between 14 – 77% annually. This retained road salt provides a long-term source of elevated TDS to aquifers and stream baseflow.
The societal and financial costs of road salt runoff can be enormous but have been largely uncalculated. These costs include increased treatment for drinking water, ecological damage, and increased corrosiveness of water. These costs must be weighed against public safety and local economic considerations. The good news is that research is drawing attention to these problems and many agencies and entities responsible for road de-icing are adopting more environmentally friendly application practices.