If you’ve ever driven on an unpaved road, you’ve experienced the billowing dust clouds. That might look cool, but dust can harm people, property, and the environment.
Dust control helps mitigate and suppress dust to protect people and the environment. There are many dust control products for unpaved roads, although they generally fit into five key dust categories:
We’ll begin with a brief overview of why we need dust control. Then, we’ll dive into the pros and cons of these five dust control methods. Hopefully, you’ll develop a better idea of what will work best for your dirt or gravel road.
Road dust control is necessary for health and safety. If it goes unchecked, road dust causes:
Those serious problems have a cumulative effect on areas around dirt and gravel roads. After all, nearly one-third of U.S. roads are unpaved, and they produce more dust than comparable paved roads.1 So, we need road dust control to keep people safe.
Water is a simple method to control dust. Spraying water onto a dirt or gravel road moistens the dust particles so they stick together. Be sure to spray water lightly on a regular basis, rather than watering the road heavily and muddying it.
Spraying water works best in humid areas where moisture in the air slows the water’s evaporation from the road. In low-humidity areas like deserts, water evaporates quickly, making it a less-than-ideal solution.
However, water is a short-term solution, only lasting for a day or two. Quantity and hauling are also drawbacks. Let’s say you use one gallon of water per square yard per day, and you have a one-mile, 15-foot wide road. That’s around 2,000 gallons of water per day! And if your road is far from a water source, you’ll spend additional time and money transporting it.
Excessive water use is also not eco-friendly. Recycling water after using it for dust suppression is difficult. And in dry areas, limited water sources can’t keep up with the dust control needs of all the dirt and gravel roads nearby.
Key Takeaway: Water is a short-term, daily dust control solution for unpaved roads in humid places with nearby water sources.
Applying gravel on an unpaved road can reduce dust by creating a buffer between the road and vehicles. This helps prevent cars from kicking up dust particles from the road into the air.
Gravel lasts longer than water, but it’s still a relatively short-term solution, as it only lasts a few weeks to a few months. You’ll deal with material loss and constant maintenance as water and traffic carry gravel off the road’s surface.
Anchoring gravel to roads with soil adhesives or geotextiles reduces material loss. The mix of aggregate sizes also impacts how long it lasts. You need some bigger pieces of crushed aggregate in the mix because traffic will push smaller pieces of gravel down into the road, especially on wet roads. But the aggregate must also contain enough fine material, since traffic will displace larger rocks.
Worse, gravel can be full of dust. And if it’s poor quality, traffic will pulverize it and turn it into even more dust. So sometimes, gravel contributes to the problem.
Key Takeaway: Gravel is a short-term solution that controls dust on unpaved roads for a few weeks or months at a time, but it can add to the problem.
Chlorides like magnesium chloride and calcium chloride are popular dust control methods. Chlorides are salt compounds that pull moisture from the air and lock it into the treated road, keeping it damp and reducing dust. They also stabilize an unpaved road's surface, helping lock soil particles together and create a hard crust to drive on.
Chlorides are effective, but they have significant disadvantages. Some states and counties have even started limiting chloride use because of problems like these:
Key Takeaway: Chlorides work well for up to a year at a time. However, they have enough disadvantages that some communities limit or ban their use.
A safer alternative to chlorides is using a natural dust suppressant like Surfa-Zyme. Surfa-Zyme is an organic, enzyme-based dust suppressant, so it’s completely safe for the environment. It’s also 100% non-hazardous and non-toxic, so crews can apply it without wearing any PPE.
Surfa-Zyme creates a hard crust over the unpaved road’s surface to effectively trap dust particles. It does take multiple applications. To get started, spray it onto the road every five days for 20 days. At first, the surface will crack, and when you reapply it, the new Surfa-Zyme will seep through the cracks to create a harder, stronger crust. Eventually, the crust will thicken enough that it won’t crack. Once it cures, you can expect it to last up to several months before you need to reapply it.
Surfa-Zyme works in various climates, making it an excellent solution for dust control in dry areas. It works with various soil types, as long as they contain at least 15 percent clay.
Key Takeaway: Like other dust suppressants, Surfa-Zyme requires regular reapplication, but it does offer an effective, environmentally friendly solution.
Soil stabilizers offer longer lasting dust control because they don’t just keep dust down; they prevent other types of erosion, too. There are many different soil stabilizers, each with unique pros and cons. Some traditional options include:
These soil stabilization methods help hold soil in place, or they cover the road’s surface and seal the dust under a hard shell. So, while they aren’t technically dust suppressants, soil stabilizers can provide some dust control. That said, many traditional options are cost-prohibitive, short-lived, or not eco-friendly. A newer, safer option is Perma-Zyme.
Perma-Zyme is an enzyme-based soil stabilizer that’s effective for constructing unpaved roads, paved road subbase, and over a dozen other types of projects. It bonds clay particles in soil together to create a hard, concrete-like surface that significantly reduces dust for up to two years or more. The soil stabilization benefits are long-lasting as well: after one easy application, a Perma-Zyme treated road can resist potholes, ruts, and other erosion for up to 10 years with little to no maintenance.
Since Perma-Zyme is enzyme-based and organic, it’s safe for the environment and the people who apply it. It works in all climates, so customers from Alaska to South America to Africa have used Perma-Zyme with great success.
Key Takeaway: While technically not dust control agents, many soil stabilizers have dust suppressant properties. Perma-Zyme is one of the most eco-friendly, versatile, and long-lasting soil stabilizers thanks to its unique enzyme formula.
Choosing a dust control solution depends on factors such as the local climate, budget, and how much maintenance you can (or want to) do. Here are some times when you might want to use each of the dust control solutions from this article:
Remember, it’s okay to try and compare products. Maybe you treat one mile of road with one product and treat another mile with a different product to see which one works best for your road. You may also find that it’s best for your road or your budget to combine multiple dust control options, such as applying Perma-Zyme with a gravel topcoat.
The key is to find the dust control solution—or combination—that works best for your roads. We hope this blog helps you choose!
