As the professional snow and ice management industry drives to find deicing products and techniques that more efficiently and less adversely impact our environment, much of the focus has been on performance of compounds and deicer blends. However, not enough attention has been given to the chemical profiles of the products. While we all have seen the undeniable improved performance of treated salt and deicing products that allow snow professionals to use less materials to do the same job, very little attention has been given to potential contaminants contained in those deicers.
Products like magnesium chloride and calcium chloride are predominately manufactured and have multiple steps in their respective manufacturing processes that help to remove unwanted contaminants, but this does not apply to products that are mined, evaporated, and then presented to the market in raw form.
For calcium chloride, there is essentially no “natural” calcium chloride that is 100 percent pure. Like magnesium chloride, it is generally coupled with other mineral chlorides that may or may not be removed and converted for other uses. The Great Salt Lake and the Dead Sea are both inland ancient seas that have evaporated and concentrated over many tens of thousands of years. Those mineral concentrations contain other beneficial minerals such as potassium, which is a primary ingredient in fertilizers, and in some cases lithium which is used in storage batteries. Those materials are macro-components of the brines. What we need to understand better going forward are the micro-components that find their way into these brines and all of their derivatives.
In 1984, the USGS conducted water sampling testing on fresh water in Jordan River that flows into the Great Salt Lake. While we expect to find some contaminants in river water like silt and minerals, we may not be expecting compounds in the form of lead, cyanide, mercury, phenol, chromium, arsenic, dioxins, furans, and hexachlorobenze. However, they were all detected in the USGS report along with pesticides, herbicides, and plenty of other surface run-off contaminants to cause concern. Mercury levels for example were 24 times greater than the state standard. Poly chlorinated biphenols, PCB’s, which were used in transformer oils and have been banned for use for 40 years also showed up from the now defunct US Magnesium Superfund site. All of this water flows into the Great Salt Lake and ultimately will be collected in brines harvested and dried for potash, salt, and other chemical product production. This is not unique to the Great Salt Lake. We have been carelessly managing waste products for hundreds of years as a planet, and now those wastes are showing up in our deicing products.
Recently, there has been more reporting and attention to microplastics in table salt, which is on your kitchen table and consumed by everyone. How in the world can microplastics get into salt for human consumption? These orphan disposed plastics are in the sea and when seawater is evaporated for use in food and other applications, the plastics come with it. Consuming “sea salt” because you believe that it is a healthier choice than manufactured salt is likely a false sense of security; 90 percent of salt sold around the world contains microplastics, according to a recent CBS news report.
This brings me to my main concern: Road salt and unwanted impurities. As we have widely embraced road salt for winter safety over the past 70 years since its first use, we may be moving contained contaminants from the source to our front doors. While is its pretty unlikely that you will find microplastics in salt mined underground, or that you will see pesticides and other surface-derived contaminants in deep-mined salt, surface sources are different.
Much of the focus and concern with road salt “contamination” has been towards runoff of the leftover salt from winter highway operations seeping into the groundwater and elevating chloride and sodium levels in drinking water sources, nearly no consideration is given to what else that salt may contain and may also be building up in our environment. Studies by the University of VA and Northeastern University found that Fishers Landing, NY, a small community along the St. Lawrence, River, began seeing substantially elevated levels of chlorides and sodium in drinking water. At this point, nobody is looking for the other potential contaminants that may come with the road salt depending upon its source.
This article attempts to raise awareness with snow management professionals about source-point contamination from winter snow and ice operations, and, to have contractors pay more attention to their deicing material sources and demand statements from your suppliers that attest to their product’s ingredients and trace analysis. If you are a private contractor applying salt to a property, and that property later develops a contamination problem, it is far better to be ahead of that problem and know if you were the source.
While I don’t have a lot of answers or recommendations, I feel strongly our industry needs to be the ones that drive the process for using less and much cleaner materials and full disclosure of ingredients. This begins with understanding exactly what is in the products you are applying to your own or your client’s property.