Truck applying dust control product. 

Dust Control

Dust control products are applied to gravel roadways when the vehicle traffic count exceeds 150 vehicles per day. These products may be applied when there is a residence within 500 feet of these roadways.

Boulder County Road Maintenance uses two different products for dust control:

  • Magnesium Chloride: is an environmentally-friendly dust control and soil stabilization product. It attracts moisture to provide maximum control of dust. After the road has been prepared for a dust control treatment, magnesium chloride is applied. Each year previously treated roads must be retreated with magnesium chloride and as the roads are retreated dust abatement improves. Magnesium chloride is a great intermediate solution to reducing dust on low volume roads.
  • Lignin Sulfonate: is a water soluble, non-toxic chemical, otherwise known to most people as "tree sap". Lignosulfonates are left over after the pulping process removes the cellulosic material from the wood. They work best in arid regions or regions where there are substantial periods of "drought".

Either one of these products may occasionally be used for base stabilization on some sections of roadway in Boulder County.

During the warmer months, we use water to wet gravel roads, which helps compact the surface. Tankers that place water are labeled with a statement such as "non-potable water". During winter months, several tankers apply a de-icer to paved roads. The material tends to leave a film on the road surface, but this is easily removed with a soap and water wash. It is recommended that you wash your vehicle frequently during winter months due to de-icers and salts used during icy conditions.


Road Maintenance Division

Main: 303-441-3962
Fax: 303-682-6714



5201 St. Vrain Road, Building 5
Longmont, CO 80503
Map & Directions

Mailing Address

Main: PO Box 471
Boulder, CO 80306-0471


Mid-April to October
6 a.m.-4:30 p.m. M-Th

October to Mid-April
7 a.m.-3:30 p.m. M-F