According to Dr. Xianming Shi, professor in civil and environmental engineering at Washington State University, the United States applies around 27 million tons of road salt to roadways annually. This road salt has the potential to contaminate up to 1,500 billion gallons of drinking water supply if 0.1% of the chloride made its way to groundwater.
“Road salt can induce substantial environmental risks and metallic corrosion when it washes into groundwater, lakes and rivers,” explained Shi, who is also director of the National Center for Transportation Infrastructure Durability and Life-Extension. “Road salt poses a toxicological concern to fish and other aquatic life. For instance, chloride will accumulate over time as a contaminant in water, as there is no cost-effective way to remove it.”
This is why Shi began his career as a chemist in 2003 by looking at ways to reduce the environmental footprint of winter road operations.
His research has covered many aspects of deicers, particularly their performance and impact. In 2001, he began developing “green” anti-icing formulations incorporating vodka distillery wastes. Since then, he has been testing the feasibility of this biotechnology in deriving “green” chemicals out of various agro-wastes, including peony leaves, sugar beet leaves, apple pomace and grape and cherry wastes.
“Compared with traditional salt brine, they contain less chloride and are less corrosive and induce less adverse impacts on the environment while featuring better performance in snow and ice control on pavement,” said Shi. “Compared with the popular ‘green deicer,’ a blend of beet juice and salt brine, they induce considerably less risk to aquatic species — through greatly reduced the oxygen demands — while offering comparable performance.”
The goal of the current product, referred to as the Sustainable Environmentally Friendly Deicer, is to provide safe driving conditions while also being less harmful to the environment.
“Many advances have been made to produce ‘greener’ anti-icers or deicers, which, however, still struggle to provide safe driving conditions on pavement in a cost-effective and environmentally friendly manner,” said Shi. “Imagine a renewable additive that greatly reduces the impacts on water quality, infrastructure and motor vehicles but maintains outstanding anti-icing — and thus safety — performance. This is the right step toward a more sustainable future.”
The university is currently working on the intellectual property licensing for the Sustainable Environmentally Friendly Deicer. The team has applied for funding to accelerate the commercialization process of the product.
Additionally, testing of this product will take place on a small scale in Kirkland, Wash., this winter.
“We’re going to work with the university, and they’re going to do some detailed measurements of chemical coming off the road,” said Ray Steiger, public works superintendent for Kirkland. “They’ll measure the water and they’ll measure any of the effluents that come off the road … They have parameters they’re looking at to see that it’s more environmentally friendly.”
This testing will take place on a.75-mile stretch of Forbes Creek Drive. This road was chosen because it is fairly straight with a little bit of grade. In addition, the road is located near a wetland, which will provide different weather conditions than the previous testing has seen.
Washington State University will be delivering the Sustainable Environmentally Friendly Deicer to Kirkland throughout the winter, but city of Kirkland employees will be applying it to the roadway.
Currently, the city of Kirkland already uses an environmentally friendly alternative to traditional salt — Calcium Chloride with Boost. The city went away from using salt, except in very minor quantities, in the early 2000s.
“Kirkland is very much like many cities, looking for things that are better for the environment,” said Steiger. “We feel the product we’re using now is probably the best you can get on the market. But there’s always something else that could be improved and so we’re interested in seeing how that will help.”
City employees will be looking at three main factors when considering whether to use the product on a larger scale if it becomes commercially available: safety, cost and environmentally friendly effectiveness.
“We don’t want to switch to a product that we then start seeing people sliding and going into ditches and (having) accidents, so it’s important that we stay safe. We don’t want people getting hurt,” said Steiger.
“If we see that maybe it’s less expensive or helps the environment but we have double the accidents, that doesn’t really serve the community.”
Steiger sees this testing opportunity as another way the city of Kirkland can get involved with green initiatives.
“The community really values the water and the lakes and the ocean out here, and if we can move the dial in that direction toward things that are more environmental, we need to be the leaders there,” said Steiger. “I really am excited about the partnership that we have before us.”
Municipal leaders considering the use of products such as the Sustainable Environmentally Friendly Deicer are encouraged to look at the long-term effects and cost of their current products. “The traditional salt seems quite affordable when you only look at the short-term and direct cost. Once you look into the long-term and hidden costs, the overall image would favor more environmentally sustainable, equipment-friendly and infrastructure-friendly alternatives,” explained Shi. “The general public needs to be better informed about the risks of seemingly cheaper products. It is a balance between meeting our current needs (we want to drive from point A to point B at high speed but do not want to pay for the more sustainable deicer products) and not compromising the ability of future generations to meet their own needs (e.g., our grandkids have to drink saltier water).”