Use of road salt is damaging to many urban and suburban stream ecosystems in the St. Louis region, as well as in other urban areas across the globe where winter brings frozen precipitation. Techniques are available that allow road crews to reduce the amount of salt (generally sodium chloride and calcium chloride) needed to keep streets clear. One of these is the application of anti-icing solutions (brine) before a winter storm hits.
I’ve been collecting data this winter that will allow me to compare chloride concentrations in stormwater in six municipalities. Each municipality has its own public works department that uses their own management strategies for winter storms. Within these communities, equipment placed in the stormwater system is collecting water level and conductivity data every 5 minutes. These data will allow me to estimate the amount of chloride that flows through the stormwater system for each storm.
In the coming months, I will combine the chloride data from each location with the area of roadway that drains into that portion of the stormwater system along with information from the public works teams. With this information, I will be able to identify what management practices are most useful in reducing road salt use.