How To Control Road Dust

Controlling dust is a never-ending task for users and maintainers of unpaved haul roads. Dislodged material causing dust settles elsewhere on a site and builds up over time, which can lead to obstructions. It also causes other hazards, such as air pollution. Methods used to control dust can themselves lead to erosion and damage. In order to improve haul roads, controlling road dust is a major priority for site operators. Better roads mean more efficient operations, leading to cost savings and less environmental impact and consequent exposure to the risk of legal action.

Calming Measures

The most widely used dust control method is spraying water on and around areas that produce a lot of dust. Water absorbs the very small dust particles, then lands on more solid material such as gravel, rock or compacted road surface. This literally suppresses dust, as it pushes it down to ground level.

Water is not always readily available, and this type of dust control uses a lot of water. In hot climates, water evaporates very quickly, reducing its effectiveness, especially in windy conditions. Therefore, using water is inefficient as it is time and labour intensive, compared to what can be quite limited effectiveness.

Dust suppression is defined as the prevention or reduction of the number of fine particulates airborne or suspended in the air. There are mechanical and chemical methods for dust suppression. Mechanical methods include dust collection equipment (e.g. filters and cyclones), to capture entrained dust, induce dust to settle, and ventilate the area where dust is formed. Chemical methods include short and long-term residual suppressants. One of common short-term methods for mitigating dust is to apply a water spray, which is done from a water truck equipped with either a pressurised spray system or a gravity fed distribution box. Such water trucks are commonly used, for example, on mine haulage roads, quarry access and haulage roads, and other types of dusty areas supporting traffic. One disadvantage of water spray is the large quantity of water needed to effectively control the dust. Another problem is that dust is controlled for only a short period of time depending on weather conditions, and the application of the spray has to be repeated frequently.

On the Level

To find out more about using technology to improve haul roads, contact the Proof Engineers office on the Gold Coast on (07) 5522 0855.