Bloomington Jefferson welcomed Bailey Hadnott, Wastewater Engineer from Barr Engineering to speak to their classes in mid-December. Since (we assumed) winter was upon us, the topic of discussion was the impacts of salt (chloride) pollution on our water, infrastructure, and livelihood.
Salt is a natural part of the environment, but humans have dramatically increased the amount of salt in our environment through practices like salting roads and sidewalks to prevent ice from forming. Salting during the winter is an effective way to keep people safe, however, many people overestimate how much salt is actually needed to work effectively. The result is that unnecessary amounts of salt are spread across our city, and most of that salt makes its way into our freshwater resources.
All of this excess salt causes a number of problems for humans and animals alike. Due to salt’s solubility in water, it requires an incredible amount of energy to remove it from water. Most drinking water filtration plants and wastewater treatment plants do not have the equipment necessary to remove salt, so once salt is in the water it is unlikely to be filtered out. Consequently, our natural waters are becoming saltier, which causes great harm to freshwater organisms, and our drinking water is becoming saltier, which can lead to long term health effects like hypertension and kidney damage. On top of that, salt water is corrosive, and degrades infrastructure like plumbing, bridges, and roads. As pipes corrode they can release lead and other toxic metals into the water, like Flint, MI experienced in 2018.
Reducing and avoiding the ill effects of salt water requires us to reduce the amount of salt we spread across our cities and towns. The good news is that lower amounts of salt are still effective at eliminating ice from forming. Please check out the graphic below for proper salting practices.
Let me end this with a big thank you to Bailey for sharing her expertise and preparing students with the knowledge necessary to make decisions that reduce their impact on water quality.