Snow Plowing

Missoula County Public Works road crews begin plowing roads on weekdays outside city limits between 5 and 6 a.m. following a snowstorm, with the goal of having school bus routes cleared first. 

The Operators and Teamsters union employees (including snow plow drivers) are not required to work beyond their regular shift hours, including the weekends, per the current union contract. There is no guarantee maintenance will be performed outside of the road crew’s regular work hours. Be sure to check the weekend weather forecast. If Public Works Department staff determines that winter road maintenance is warranted, individual road crew members will be contacted and offered the opportunity to work during the weekend or weeknights.

Work outside of the road crew’s regular schedule is up to supervisors’ discretion, with consideration of the needs and the costs associated with plowing.  Generally, priority one roads are considered during off hours for maintenance unless staff determines that lower priority roads should be maintained. 

Each winter, Missoula County Public Works keeps roads clear and safe across the county while preserving the water quality of our rivers. 

Pure salt is never used to de-ice roads. Salt is mixed with sand to create salted sand at about a 1:15 ratio (one scoop of salt per fifteen scoops of sand). The grit size may vary but the goal is the same: to melt snow and ice. Salt works to lower the freezing point of water and sand acts as additional traction for tires. Public Works can also use a brine solution to keep roads safe for vehicles. This is often referred to as Mag, and the standard solution has about 32% magnesium chloride.  Public Works uses liquid deicer specifically on roads that have higher traffic volumes (like South Avenue and Clements Road) or that have hills and curves combined with high or moderate traffic volumes like Grant Creek Road and Big Flat Road.  

The sanders apply the salted sand or brine solution at a specific rate of pounds per acre. The salted sand or brine liquid then spreads out over a larger area, minimizing impact on runoff into rivers and aquifers. The real danger of contamination to ground water is in the storage of undiluted pure salt. Missoula County Public Works avoids this by processing salt with sand and storing this in salt shacks. The department purchases the brine solution and holds it in storage tanks until use. They apply salted sand and liquid deicer on paved roads but not on gravel roads. Gravel roads aren’t treated with melting agents to help avoid mid-winter thawing which creates muddy, soft roads.  

The Missoula Valley Water Quality District monitors the distribution and application of these deicers each winter. The components of these solutions can be a problem for ground and surface water if not regulated correctly.