City managers, developers, and homeowners look for effective ways to control dust.

By Dan Rafter

When Bob Stacey needs a reminder of how bad airborne dust can get in Heartland, VT, he needs only to drive past the yellow house.

This particular house sits on the corner of one of the town's busiest gravel roads. Stacey, town manager of Heartland, says about 800 cars zip past it every day, and all of these cars kick up thick clouds of dust. The house is yellow, and has been for years. But when workers first built it, it was a gleaming white.

And while that house might have suffered the most from Heartland's dust problem, it's certainly not the only victim. Stacey deals with 65 mi. of unpaved gravel roads in this town of 3,223 residents. The dust from these roads covers houses and businesses. It hangs in the air and clouds the vision of drivers. During the summer months, the town spends 35 hours a week grading these roads.

"How bad does the dust get? You should answer my phone," Stacey remarks. "It can get pretty atrocious in some spots. Sometimes you'll travel down one of these roads behind a large truck. If you're not paying attention and that truck stops, you won't see it because the dust is so bad."

Stacey isn't the only town official across the country battling airborne, or fugitive, dust. He's joined by countless construction-site foremen, strip-mining operators, and highway department officials. All these folks, and more, are constantly battling their dust problems, especially if they happen to work in arid, dry environments.

Fugitive dust can create a number of hazards, from reducing visibility among motorists to aggravating respiratory illnesses to increasing wear and tear on construction equipment. Not surprisingly, municipalities, federal agencies, and other regulatory bodies are putting more pressure on builders, miners, developers, and others to control the amount of dust their projects generate.

There is good news, though. As the demand for effective dust control rises, so does the number of dust suppressants available. Companies specializing in this field not only are providing tried-and-true products, such as liquid and dry forms of magnesium and calcium chloride, they also are experimenting on new, more powerful products. This comes as welcome news to people like Stacey.

Stacey reports that Heartland invests about $22,000 a year fighting its dust problem, spending most of that money on liquid magnesium chloride from Carbondale, PA - based Schoenberg Salt & Chemical Company. The product is used every time the town's road department workers treat its gravel roads. These workers treat some of the roads two times per summer, and other roads, depending on the amount of traffic, eight to 10 times.

The most permanent solution to Heartland's dust woes, of course, would be paved roads. But paving all 65 mi. of gravel road is a solution that doesn't fit in the town's budget. Then there's the nostalgia some residents have concerning the town's unpaved roads.

"That's the way things have always been here," Stacey points out. "We get a large influx of people from the city here. They move up here in part for the romance of the gravel roads. We try to pave them and they put up a stir. There's a lot of romanticism that goes with living on a gravel road here."

This means that Heartland will always have a demand for dust suppressants. And because Stacey isn't alone, the business of dust control will keep growing, as will the demand for even more effective products.

One example of a company working to create new dust-control products is Midwest Industrial Supply in Canton, OH. The company currently is testing two new products it has been developing for five years: EK-35 and EnviroKleen. Midwest Industrial has tested the products at a variety of facilities, including steel mills, coal mines, construction sites, and wineries. The company also has used the products in Kandahar, Afghanistan, for dust control and to help stabilize landing zones and runways used by the United States military.

Officials with EPA's Environmental Technology Verification Program recently published the results of a 100-day study of the two suppressants. The results were good: The products achieved 100% control efficiency at the end of three months, and almost 100% elimination of silt loading. Both products are now involved in a 12-month study.

According to Midwest Industrial, EK-35 stays effective longer than ordinary chemical suppressants and is suited to rugged surfaces and sites featuring intense traffic. The product will not dry or cure and requires fewer maintenance applications. It is applied without water. EnviroKleen is environmentally friendly and safe for humans, animals, and plants, and does not stick to vehicles or onto materials placed on its treated surfaces. Workers can spray it year-round, both in summer and winter.

These two products join the company's roster of dust-control products, including Dust Fyghter, a chloride dust suppressant, and Dustract, an additive injected into pumped water streams.

Bob Vitale, president of Midwest Industrial, notes that it's important for companies such as his to constantly develop new and more effective products because it's what end users are demanding.

"Unfortunately, there is a high degree of failure with so many of the products now on the market," Vitale points out. "The cost of failure to the end user, who wants to be a good neighbor and wants to comply [with] air-quality regulations and stormwater runoff regulations, is completely unacceptable. The failures can do a lot to brunt the enthusiasm that the end user has for the implementing and use of dust suppressants."

End users today are concerned not only about air-quality issues when it comes to dust control but also about water quality and the impact dust-control suppressants have on groundwater and stormwater, Vitale notes.

"Historically the issue has been air-quality compliance matters," he says, "and a great variety of chemical types have been used successfully to bring air quality into compliance. Now, since all of these chemical suppressants are being evaluated for impact on water quality and groundwater and stormwater, there is a whole new level of questioning as to what is the environmental impact of chemistry being used to produce better air quality? Are any of these chemicals having an adverse impact on stormwater or groundwater? The development of new products is being driven by this need for not only providing a product that has a high level of performance in improving air quality but also products that do nothing to adversely impact water."

Midwest Industrial's new products, designed to meet water-quality needs, are already on the market. Company officials are using EK-35 and EnviroKleen on construction sites, campgrounds, steel mills, and agricultural areas. The company also is conducting field trials to see how the products will work on county, township, and municipal roads.

John Leslie, president of SynTech Products in Toledo, OH, also sees a greater demand for dust-control products. While Leslie doesn't disagree that residents tired of dust blowing into their homes and businesses are a big source of this demand,  he adds that end users themselves are also pushing for innovative new products.

"Demand is coming from the inside, not only from the outside," maintains Leslie, whose company produces a host of products designed to control dust, including synthetic blends, polymers, and hygroscopic agents. "End users are seeing that the products work and that they provide a good working environment for their employees. They want to see continuous improvement in that. I really commend management for wanting to do this, for putting the demand out there for better dust suppression." SynTech maintains an online database where customers can get information about EPA regulations, and the company can help tailor dust-control programs to assist clients with staying in compliance.

Randy Bills is the project manager for a major residential development in Palm Desert, CA. Contractor Legacy Home California and developer Sevrin and Company are building 414 residential units on 75 ac. of land. It's a big project, and a messy one. Unfortunately for the builders, residences and buildings surround the project. This means a huge potential for dust-related complaints.

But so far, the complaints have been few and far between. Bills, who works for Villa Portofino Construction Company, credits the dust suppressants builders have used on the site: Soil Sement for the site's less-trafficked areas and EK-35 for its busier ones.

"It's been more than a year since we put these products in, and they're still effective," Bills relates. "They've done their jobs. Now we're in the process of applying them again."

If the site's workers weren't applying dust-control measures, Bills is sure complaints would skyrocket, and not only from the owners of the many businesses and homes that surround the site. Inspectors from the local municipality, as well as from the South Coast Air Quality Management District, are frequent visitors to the site.

"If you don't keep up with the requirements, they fine you. And the fines can be pretty hefty—$10,000 or $25,000," Bills notes. So far, though, so good: The site has received no fines related to dust-control measures.

Mel Everhart, grading supervisor for Weld County in Colorado, spends much of his time battling fugitive dust. One of his main weapons in this fight is DustGard, a form of liquid magnesium chloride created by Overland Park, KS - based North American Salt. Everhart's department has applied the product to local dirt and gravel roads for the last two years, making these applications twice every 12 months: once in the fall and once in the spring.

The product has worked well, Everhart remarks, and this is important because Weld County features about 2,500 mi. of gravel roads. Some, of course, are of better quality than others are. But some suffer from extreme dust problems.

"There is such a wide variance in what these roads are made of, but some of them are really bad if they're not treated," Everhart explains. "On some of them, if an 18-wheeler goes through, you can't see a quarter-mile behind him, the dust's so thick."

Dust had long been a problem in this county, but it became even more serious when the state mandated that Weld County, along with Colorado's other counties, develop a plan to deal with its dust problems. That's when Everhart turned to magnesium chloride as an alternative to more short-term, ineffective solutions, such as watering trucks.

"It seems that the best solution to handling these roads is to treat them with chemicals. Watering them was only a very temporary solution. Since we started using the chemicals, our dust complaints have gone down," Everhart notes.

Similar to other municipal officials, Everhart doesn't expect to ever fully conquer his dust problems. On high-volume roads, and on windy days, the dust still kicks up. And, as in many other counties, the unpaved roads aren't going anywhere soon. While Weld County counts more than 2,500 mi. of unpaved road, it has only 700 mi. of paved streets.

"I think we're stuck with these unpaved roads for a while," Everhart predicts. "They're not going anywhere."

Cindy Enderle of North American Salt isn't surprised that Everhart has seen success with her company's product. DustGard—along with several other dust-control agents—recently went through extensive testing by EPA at the Fort Leonard Wood Army Base in Missouri. DustGard, she reports, performed as well as any other product during this testing.

"Depending on traffic and on the way the road is used, our product can be a long-term solution to dust control," Enderle explains. "The best-guess estimate is that it can be effective for six months. But that all depends on the amount of traffic on the road and what type of traffic it is."

For example, when treating haul roads for the silver mines that North American Salt counts among its users, workers apply DustGard as often as once a month. On a county gravel road featuring normal traffic, though, workers need only apply the product once a year, Enderle says.

The dust-control business is booming across the country. But this is especially true in certain parts of the US that feature arid climates. Municipalities and government agencies there are putting more pressure on builders, developers, miners, and others to control their dust.

That's why Colin Kimball, a geologist and product manager with McKinney, TX - based American Refining Group, has seen sales of his company's dust-control product, PennzSuppress D, soar recently. PennzSuppress D is an environmentally safe petroleum resin designed to suppress dust and stabilize soil.

Users include state and local governments, steel mills, power plants, metal and coal mines, and cement quarries. The product is first diluted with water and then applied to roads or construction sites. The water, which evaporates, serves as a carrying agent that allows the product to penetrate into a road's surface. The resin then helps dust particles to form larger masses, thereby increasing the cohesive properties of the aggregates in the road.

"In certain sectors of the country, we are seeing more and more pressure on people to control dust," Kimball notes. "In the Southwestern states, places like Arizona or southern California, PM10 particles [particles that are smaller than 10 microns] have been designated as air pollutants. There has been a trickle-down of regulatory requirements, with the result being that businesses within these areas have to meet certain requirements to control their PM10 particles."

Of course, even though many commercial and municipal end users are looking for new products, many others are satisfied with the ones they already use.

Shannon Duffy, sales manager with Schoenberg Salt & Chemical Company of Carbondale, PA, sells the staples when it comes to dust-control products: magnesium and calcium chloride in both liquid and dry forms. He points out that while towns and other users want effective products, they don't necessarily want anything unfamiliar or overly expensive. Because of this, magnesium and calcium chloride will continue to be the dust-control products of choice for most, he believes.

"Some are receptive to new material. But others want to stay with the calcium chloride flake material or want it applied in a liquid form," Duffy observes. "From what I see, there are not that many new things in dust control that are catching on fire."

Economics plays a large role in determining which products people seek for dust control, Duffy notes. A product such as calcium chloride, for example, makes sense for towns and municipalities. An average municipal client of Schoenberg might use calcium chloride to protect $150,000 worth of aggregate soil and sand. The product's cost, then, doesn't seem too high.

Duffy also says he hasn't seen much increased pressure put on towns to control their dust but, rather, it's long been an ongoing responsibility. "I think it's the same as it's always been. I think it's part of a regular maintenance routine for a town to do something to handle dust. It's like sweeping, plowing, or picking up garbage. It's part of a town's responsibility if they have dirt roads. This is especially true if they have a lot of tourists. I don't think this is anything that has changed much."

Some companies, though, are looking at ways to expand their dust-control business. At Soil Seal Corporation in Pico Rivera, CA, for instance, company officials currently are developing a dust-control product targeted to individual homeowners. The product would be pitched to residents who live on large properties or on the side of hills and are interested in slowing erosion. Another potential client might be a landlord who owns a vacant lot or two and has been receiving complaints from neighbors or local government officials about dust.

Soil Seal's main product, though, continues to be Soil Seal Concentrate, and its main customers continue to be construction-site operators and other commercial clients. The product is composed mainly of high-grade latex acrylic that typically is reduced with water and spray-applied to various types of soils. It penetrates the soil surface and forms a cohesive bond between the soil's particles.

Soil Seal has gotten around. Workers in Seoul, South Korea, have used it to prevent dust during a construction project at the Kyongbok Palace. It's also been used closer to home, of course. Workers recently used Soil Seal to help prevent petroleum coke dust from billowing around a remediation project at an Exxon Mobil refinery in Torrance, CA.

"In general, I think there is an increase in demand for dust-control products," maintains Guy Nishida, vice president of operations with Soil Seal Corporation. "I think the whole issue of dust is appearing more and more on the radar screen. People are more aware of the need to suppress dust before they get fines."

And, Nishida adds, his clients are looking for innovative products. As an answer to this request, Soil Seal has created a version of its signature product that comes with a color tint, something that allows people to more easily see where they have and haven't applied the product. Most users ask for green tint, Nishida says, to give the appearance of vegetation.

While Soil Seal works well with dust control, that's not the only use for the product. Many companies use it to control erosion.

FCI Constructors, a construction company based in Vista, CA, has used Soil Seal for about four years. Currently the company is using the product in conjunction with the building of an interchange between Highways 94 and 125 in San Diego. The $65 million project has been going on for three and a half years.

"The product has worked well," comments Don Riese, general superintendent with the company. "It's part of our stormwater plan. We use it to control any runoff. Basically we use it as a temporary erosion control measure."

Dan Rafter is a writer based in Indiana.

EC - July/August 2003