During the winter months, the City of Pleasant Hill’s Public Works Department uses salt brine to treat streets for snow and ice. Before a snow or ice event begins, the Public Works crew will line the streets with salt brine, a clear water and sodium chloride solution. It is composed of tap water and road salt, and is mixed in concentrations of 23-26% salt and has a freezing point of -6 degrees Fahrenheit.
The salt brine process is a cost-saving measure that enhanced the City’s ability to help keep streets clear in the winter, while conserving the sand/salt stockpile for more major storm events.
The strategy is to pre-treat streets by applying salt brine directly to the road whenever the road temperatures are predicted to drop below freezing even when there is no snow or ice in the immediate weather forecast. The brine liquid is placed on the roadway in small streams usually across only 1 driving lane at a time.
In clear weather, the brine will dry up leaving a bonded strip of fine salt on the pavement. During dry weather, these strips will remain on the pavement for several days, even under heavy traffic conditions. When snow or ice does contact the treated pavement, the moisture will activate the strips into brine and help prevent a snow / ice bond from forming.
Applying brine to the pavement before snow or ice has bonded can be 10 times more effective than placing salt crystals on top of snow and ice after the precipitation has bonded to the pavement. Additionally, pre-treating is labor efficient, since the process can be performed during normal shifts.
Pre-treating reduces overtime and greatly reduces the total cost of treatment, as once the snow/ice has bonded to the pavement, it is more expensive and time consuming to remove.
Beyond the material and labor savings, the ability to provide a treatment at the earliest stages of a winter event, when drivers are most likely to overestimate the driving conditions, provides an additional savings by reducing the frequency of traffic crashes.
Dry Salt Deicing
Placing dry granular salt on the roadway as a pre-treatment for deicing is less efficient than salt brine for several reasons:
It must be dissolved into brine before deicing can begin
Granular salt will not bond to the dry pavement; traffic will crush it and cause the powder to blow away