Managing the environmental impacts of chemicals used for snow and ice control

Abstract

Departments of Transportation (DOTs) and other winter maintenance agencies are continually challenged to provide safe, reliable winter highways in a cost-effective and eco-friendly manner, while minimizing adverse effects to the environment, vehicles, and transportation infrastructure. Increasing concerns about the anti-icers available on the market due to their corrosion to metals (chlorides), impact on concrete and asphalt (acetates), and toxicity to aquatic resources (agro-based products) have directed agencies to explore alternatives. The objective of this project is to provide winter maintenance agencies various strategies to effectively reduce the environmental impacts related to winter maintenance operations by presenting strategies focused on alternative deicer compounds, mitigation measures, and management procedures. A series of anti-icers designed to reduce the environmental footprint of deicers and to meet the varying requirements of highway anti-icing performance, cost-effectiveness, and minimized corrosion impacts was developed. The research was accomplished through literature review, agency surveys, and laboratory investigation. A review of various new developments and available products is presented in order to identify the current state of the art and gain a better understanding of commercially available snow and ice control materials. Performance evaluations are presented with respect to ice melting capacity, corrosion effects, and impacts to the environment of various deicers to determine trends and future research needs. In addition, it was identified that roadway maintenance equipment in cold climates is exposed to high amounts of chloride-based deicers that are inherently corrosive. This work aims to identify current approaches available to manage the risk of deicer corrosion to equipment assets, including design considerations, materials selection, and maintenance strategies. Furthermore, this research summarizes the current practices and methods available to mitigate the water quality risks associated with chloride based deicers. Two common approaches used for reducing the impacts of chloride based deicers were examined. The first method known as a proactive approach focuses on reducing the amount of chloride based deicers introduced into the environment. The second method known as a reactive approach consists of effective practices used to reduce the impacts of chloride based deicers after they have been introduced into the environment, which is accomplished using treatment methods and controlling chloride transport through the environment.