The MWMO provided $131,800 to the City of Columbia Heights to construct a heated sidewalk snowmelt system as part of its city hall redevelopment project at 3989 Northeast Central Avenue. The snowmelt system helps prevent use of salt deicers and addresses the issue of chloride in the Mississippi River.
Chloride pollution in our waterways is a major issue in Minnesota, and removal of snow and ice is a significant cost for our communities. Chloride is non-biodegradable and negatively impacts soils, vegetation, groundwater, surface water, and air quality. A single teaspoon of road salt is enough to permanently pollute five gallons of water. At high concentrations, chloride is lethal to aquatic plants and animals.
The heated sidewalk snowmelt system uses an outdoor slab sensor that senses moisture and temperature. When moisture is present in colder temperatures, the system circulates heated glycol to prevent ice on sidewalks and driveways.
Assuming salt is used whenever snow accumulates by one or more inches (which occurs around 16 times per year historically), around 320 pounds of salt would have been applied over the course of an average winter to the project’s sidewalks and driveway if they were unheated. Using these assumptions, this project will help prevent salt contamination of up to 121,000 gallons of stormwater runoff reaching the Mississippi River annually.
Financially, the system is projected to save the city the cost of snow removal over the 5,000-square-foot sidewalk and driveway and an estimated $200 per year for salt deicers. Due to prevention of ice and salt application, the heated sidewalks and driveway will also last much longer than traditional concrete. This effort will serve as a pilot project for the MWMO, and its costs and benefits will help determine the cost effectiveness and scalability of these types of systems.