This section of the manual is currently under construction
Low Salt Design is a series of design concepts aimed to create safer winter surfaces by improving pavement recovery and reducing the re-entry of snow and meltwater onto saltable surfaces. Safer surfaces reduce the need for salt.
As such, Low Salt Design is a pollution prevention best management practice that can be implemented at the site design phase to minimize chloride pollution exported from developed land areas.
Low Salt Design Goals
The goal of Low Salt Design is to improve winter performance of saltable surfaces for safety and to reduce the need for salt. Low Salt Design takes some pressure off of winter maintenance by reducing demand for deicers.
Potential benefits of implementing Low Salt Design practices include preservation and protection of:
- soils and vegetation
- surface and ground water quality
- aquatic habitat
- buildings and other infrastructure that can be damaged by deicing chemicals
and cost-savings associated with each.
There are two basic strategies in Low Salt Design.
- Increase the speed of pavement recovery (before the use of chemicals).
- Control the repeat offenders. Repeat offenders are the reentry of blowing snow and meltwater onto saltable surfaces.
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Definition of key terms
- Critical Area: Area that requires excellent winter friction. Examples of critical areas are front steps, high traffic sidewalks, braking zones, bridges, underpasses, ramps, curves, hills, and ADA routes. The volume of traffic and speed of traffic influence what is deemed as a critical area.
- Fetch: The distance wind blows across water or open land without impedance. For Low Salt Design, look at the prevailing winter wind direction to calculate fetch.
- Horizontal drainage is the near lateral movement of meltwater (meltwater running across a highway ramp) whereas vertical drainage has a more extreme elevation change (i.e., Roof to sidewalk).
- Meltwater footprint: The wet surface area created on a dry pavement from the movement of snowmelt water.
- Meltwater sprawl: The movement of snowmelt onto saltable surfaces.
- Pavement Recovery: The time it takes after snow removal for the pavement to regain traction that meets user expectations. Several of the Low Salt Design strategies help here. This could also refer to the time it takes after a freezing rain event to regain traction that meets user expectations.
- Plowability: A way to rate the site for ease or difficulty of motorized snow removal.
- Plowshed: Delineated surface from where snow is pushed into a snow pile.
- Precision Winter Maintenance: Winter maintenance strategies that minimize the amount of salt to meet the level of service targets.
- Salt: Generic term that represents chloride-based deicers.
- Saltable surfaces: Includes sidewalks, parking lots, roads, trails, bridges, ramps, and steps, most outdoor hard surfaces that are used for walking or driving in cold climates.
References
Fortin, Connie. Low Salt Design Guide, A guide to winter infrastructure design. Bolton & Menk, Inc.