Dust control prevents wind transport of dust from disturbed soil surfaces.
Use dust control practices in areas (including roadways) subject to surface and air movement of dust where onsite and offsite impacts to streets, the stormwater system, or receiving waterbodies are likely.
1.17.3 Design and Installation Specifications
Vegetate or mulch areas that will not receive vehicle traffic. In areas where planting, mulching, or paving is impractical, apply gravel or landscaping rock.
Limit dust generation by clearing only to those areas where immediate activity will take place, leaving the remaining area(s) in the original condition, if stable. Maintain the original ground cover as long as practical.
Construct natural or artificial windbreaks or windscreens. These may be designed as enclosures for small dust sources.
Sprinkle the site with water until surface is wet. Repeat as needed. To prevent carryout of mud onto street, refer to Stabilized Construction Entrance (BMP C105 - Stabilized Construction Entrance and Exit).
Irrigation water can be used for dust control. Install irrigation systems as a first step on sites where dust control is a concern.
Spray exposed soil areas with a dust palliative, following the manufacturer’s instructions and cautions regarding handling and application. Used oil is prohibited from use as a dust suppressant.
PAM (BMP C127 - Polyacrylamide for Soil Erosion Protection) added to water at a rate of 2/3 pounds per 1,000 gallons of water per acre and applied from a water truck is more effective than water alone. This is due to the increased infiltration of water into the soil and reduced evaporation. In addition, small soil particles are bonded together and are not as easily transported by wind. Adding PAM may actually reduce the quantity of water needed for dust control. There are concerns with the proper use of PAM, refer to BMP C127 - Polyacrylamide for Soil Erosion Protection for more information on PAM application. PAM use requires COT approval.
Lower speed limits. High vehicle speed increases the amount of dust stirred up from unpaved roads and lots.
Upgrade the road surface strength by improving particle size, shape, and mineral types that make up the surface and base materials.
Add surface gravel to reduce the source of dust emission. Limit the amount of fine particles to 10 to 20 percent.
Use geotextile fabrics to increase the strength of new roads or roads undergoing reconstruction.
Encourage the use of alternate, paved routes, if available.
Restrict use of paved roadways by tracked vehicles and heavy trucks to prevent damage to road surfaces and bases.
Apply chemical dust suppressants using the admix method, blending the product with the top few inches of surface material. Suppressants may also be applied as surface treatments.
Pave unpaved permanent roads and other trafficked areas.
Remove mud and other dirt promptly so it does not dry and then turn into dust.
Limit dust-causing work on windy days.
Contact the Puget Sound Clean Air Agency for guidance and training on other dust control measures. Compliance with the Puget Sound Clean Air Agency’s recommendations/requirements constitutes compliance with this BMP.
Evaluate the potential for dust generation frequently during dry periods. Complete the actions outlined above as needed to limit the dust.