Nearly construction all sites produce dust, but why should dust be controlled? It’s better for the environment, including the work environment, and is likely mandated by one or more of your government agencies. So how can we make sure we are in compliance with these regulations? Fortunately, there are several different methods of dust control that contractors can implement on the jobsite.
1. Water
Sprinkling the ground surface with water until it becomes moist is effective and is especially useful on haul roads and other trafficked areas. Although, the frequency of application required for continued dust control can be quite high, which makes water an expensive option.
Excessive watering creates mud and erosion. Treated areas that see vehicle traffic require stone tracking pads, tire washing facilities, or other means of preventing wet soil adhering to tires from being carried off-site.
2. Chemical treatment
Spray-on chemical treatments (palliatives) bond dust particles together and can be effective but require extensive research and planning. Among other factors, the treatments must be customized to match the site’s
- Soil type
- Wind exposure
- Traffic patterns
- Proximity to environmentally sensitive areas
The chemicals used can also be corrosive, ignitable, or dangerous to human health or the environment. At the very least consult the SDS (safety data sheets); it may be best to contract out the formulation of chemicals or even the entire palliative process.
Conversely, dry polymers can be spread in non-traffic areas. An initial watering is required to activate the polymers. Tackifiers and soil stabilizers can also be used.
Note that the use of used oil or any product containing used oil for dust suppression is prohibited by Federal law (40 CFR Part 279.82).
3. Road upgrades
- Add surface gravel.
- Improve drainage and crown.
- If using chemical dust control, blend it into the top few inches of surface material. Spray-on chemical treatment helps but is less resistant to degradation from traffic.
- Reduce allowable travel speeds.
- Restrict the number or types of vehicles that can access the road, if possible.
- Use geotextiles to improve the strength and drainage of new roads or roads being reconstructed.
Paved surfaces generate up to 90-percent less dust than unpaved and can be further improved by sweeping up dust and winter traction materials, such as sand and salt.
On trucks, use load control measures such as covers, freeboard, bed liners, and watering. Make sure to cover stockpiles.
4. Vegetative cover
Areas without traffic can benefit from vegetative cover, which reduces wind speed at ground level and binds the soil. It can take time for vegetative cover to mature sufficiently to be effective. Hydroseeding is often used. It’s fast and cost-effective but there can be significant losses of seed to birds and other wildlife before the seeds sprout.
5. Wind breaks
Trees and shrubs can be planted or can be left in place during site prep to serve as windbreaks. Other common windbreak materials include hay bales, snow fences, and tarp curtains. Highly permeable barriers, such as snow fences, are less effective than impermeable barriers, such as tarps. As a general rule, each foot of barrier height creates a deposition zone of 8 to 10 feet on the leeward side so parallel lines of windbreaks may be necessary. Windbreak rows are installed perpendicular to the prevailing wind direction.
6. Tillage
Breaking up flat areas of exposed soil with chisel-point plows can lessen ground-level wind speed.
Indoor dust management
For indoor dust control, such as demolition work, spraying water is useful. Sticky floor mats at all entrance points will reduce dust being tracked outside the work area. Barrier protection at entrances may be required.
For high-sensitivity areas, such as healthcare and tech facilities, much more stringent measures will be required. These include exhaust fans sized so that negative air pressure is maintained within the work area. Care must be taken that flow from the exhaust fans cannot re-enter the structure through nearby air vents or a HEPA filter should be in the outflow. An entrance vestibule, also with negative air pressure, is where workers should remove disposable coveralls and shoe covers before leaving the work area. Air sampling should conform to the standards set by facility management.
Effective dust control does not result from haphazard responses; it requires a specific plan. All sources of dust should be identified, and a control measure should be chosen for each. For methods requiring the application of water or chemical controls, a schedule of how much and how often needs to be made and strictly followed. A backup plan should also be in place in the event the first plan does not work or proves inadequate. Contact information must be provided for the person in charge of dust control. Information in this article is an overview; consultation with local air quality assurance agencies will help ensure the plan meets applicable standards.
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