Each year, state and local agencies spend more than $100 million on salt to treat Minnesota’s roadways. Homeowners, businesses, and other property owners also use vast amounts of salt to clear their driveways, sidewalks, and parking lots. While this reduces ice buildup between snowfalls, the sobering reality is that every teaspoon of salt permanently pollutes about five gallons of water in our lakes, rivers, and aquifers.
Earlier this year, Bolton & Menk released a new 38-page guide, Low Salt Design Guide: A Guide to Winter Infrastructure Design, to help agencies and planners minimize the need for salt application. Low-salt design aims to create safer paved surfaces from the outset by reducing the amount and duration of snow and ice coverage and limit its return by wind and meltwater.
The 10 principal strategies of low-salt design are:
- Use the sun. Evaluate how long a site’s critical areas will be in the shade and position infrastructure to take advantage of direct sunlight.
- Outsmart the wind. Create intentional snow fences, remove unintentional snow fences, and integrate other aspects of drift-free road and ditch design.
- Visualize horizontal drainage. Work to reduce meltwater flow and ponding in critical, frequently salted surfaces such as sidewalks, parking lots, and braking road zones.
- Assess vertical drainage. Look up and design to direct meltwater away from paved surfaces. For example, route sidewalks around (not under) obstacles such as awnings, decks, and bridges.
- Make snow removal easy. Think like plow drivers—their work is made harder when they need to back up and navigate around unnecessary obstacles.
- Create snow storage. Plan for and label/sign snow storage in low areas to reduce meltwater sprawl.
- Plan salt storage. Store granular salt at a higher elevation than the snow storage area. Liquid salt/deicer needs secondary containment.
- Minimize salted surface footprint. Consider a road diet—less pavement means less maintenance and more potential savings.
- Consider pavement alternatives. Explore solar, heated, or porous pavement, permeable pavers, and similar options after other strategies have been exhausted.
- Ponder vegetation choices. Plant types and placement influence many of the categories above.
Low-salt design can improve safety, save money, and drive down the need for salt. Additionally, these design concepts may extend the life of vegetation and infrastructure, better protect freshwater resources, and reduce the stress on winter maintenance crews.