Settling Down
Dust control strategies for everything from horses to helicopters.
As vehicle traffic heads down country roads on a hot summer day, you often see a plume of dust rising into the atmosphere. In addition to reducing vision for other drivers and contributing to poor air quality, continued use of these roads without some kind of treatment for dust control can cause soil stabilization and erosion problems, which can lead to expensive road repair projects.
It is a problem many counties throughout the country face, especially those with large rural areas. Most jurisdictions have developed tried-and-true solutions that are custom-made to their environment. And while many of these counties handle dust control with their own crews, others hire the job out to specialists who go by nicknames such as "The Dust Dr." and "Dust Control Man."
Visibility, Maintenance, and Toxicity Concerns
The Dust Dr. is also known as Marty Koether, and he is a managing partner in EarthCare Consultants LLC, a Tucson, AZ–based company that he started with his two partners in 1995. Before that, the exuberant Koether worked in paving and asphalt restoration, along with erosion control using geotextiles and hard armor.
"It was while I was working on erosion control projects that I discovered a real need for dust control, and I found the product that I wanted to use," explains Koether. "To me, soil stabilization is synonymous with dust control and sediment and erosion control. Unless you have a stable surface, you will always have dust during the dry season, and you will have sediment runoff and erosion during rain events. Basically, by stabilizing the soil, we achieve both dust control and erosion control."
The product that intrigued Koether and his partners was Soil-Sement, which is manufactured by Midwest Industrial Supply Inc. in Canton, OH. "I did over six months' worth of research on the different soil stabilization products that were on the market, and in my opinion, Soil-Sement is the grandfather of the dust control industry regarding environmental stewardship."
Koether describes a 3.3-mile section of road in Pima County, AZ, known as Snyder Hill Road. "This road is in the Avra Valley, which is about 15 miles west of Tucson. In the morning, when you topped the hill coming into the valley, you could see the dust. This is the main bus route for the kids going to school, so there are visibility concerns, and there are also health concerns as well as safety and road maintenance concerns. The county did not want to pave the road due to easements, right-of-way issues, and available funds. They would grade the surface, compact it, and wet it down, but within a few days, the road would be a mess again. We are under contract to Pima County to deliver and apply products for soil stabilization and dust control, and it is up to the county to determine where their greatest needs for dust control are. For the Snyder Hill Road, we designed a long-term solution that would make it a safer, stabilized, dust-free transportation route."
The resulting treatment included an initial application to a depth of approximately 4 inches. The top surface of the road was removed and taken to the sides, and the subgrade was treated with Soil-Sement. The removed surface was then put back in place while the specified amount of Soil-Sement was blended into it, and then the road was graded and compacted. Finally, top coats of Soil-Sement were applied to seal the surface. "We did the first treatment on April 22, 2005, and we will go back and do a maintenance treatment in approximately eight to nine months," explains Koether. "We will then monitor the road so that we can apply additional maintenance treatments before we see any degradation of the surface. We find that it is much better to treat more often with less product than the other way around."
In addition to the bonding and cohesion properties of Soil-Sement, Koether was also impressed with the cost-effectiveness and the environmental performance of the product, which derives its strength from a polymer formulation that has the ability to bond with surface materials. Its chemical structure is made of molecules that are attached in relatively straight-linked chains and then cross-linked among other chains or grids. Environmentally, Soil-Sement is non-toxic, non-corrosive, and non-flammable and does not pollute groundwater.
"Environmental concerns of using dust control products are a significant issue nationwide," says Koether. "Effective dust control improves air quality, but we have to remember that we must protect other resources, such as water. Soil-Sement does not carry any chemicals into the stormwater system because it is not water-soluble, so in the same way paint doesn't run off your house when it rains, it doesn't run off the surface that it has been applied to during wet conditions." He notes that Midwest Industrial Supply has subjected the product to tests according to EPA guidelines regarding water quality, toxicity, and carcinogenic properties.
"Research and testing proves that stormwater runoff from areas treated with Soil-Sement will not contain concentrations that exceed benchmark values of the parameters designated in the National Pollutant Discharge Elimination System Storm Multi-Sector General Permit for Industrial Activities," he notes, adding that the product's Material Safety Data Sheets (MSDSs) "do not contain any of the disclaimers found in the majority of the other manufacturers' products' MSDSs. This industry isn't really regulated. It is a ‘buyer beware' market, and people really need to study the products they intend to use in great detail."
Accommodating Horses and Heavy Vehicles
Jeff Brill has more to deal with when it comes to road maintenance than just motor-powered vehicles. Brill is the superintendent of the Highway Department for LaGrange County, a rural county with a population of about 35,000 people in the northeast corner of Indiana. The southwestern portion of the county is home to a large Amish population, who use the horse and buggy as their main means of transportation.
 |
PHOTO: MARION COUNTY PUBLIC WORKS |
"The horseshoes are extremely hard on asphalt roads, so we have tried to maintain gravel roads as much as possible in the Amish communities," explains Brill. "However, many members of the Amish community manufacture furniture in small factories, so we also have to consider that these roads will have a fairly significant amount of truck traffic that will be making deliveries of supplies and picking up finished products. Because of this, dust control is very important."
Brill says that since he took over the job of dust control in 1990, the county has used a 42% calcium chloride solution for dust control, which right now is supplied by Dow Chemical. "The county has been applying dust control on gravel roads for more than 25 years, and the person who was in the job before me had tried various products including oil-based solutions, but we have found that calcium chloride holds up the best under our specific conditions," explains Brill. "The calcium chloride will penetrate 2 inches to 4 inches into the surface, so we can generally do one treatment at the beginning of May that will last all summer long, and then in the winter dust is not a concern. If we use anything else, the horseshoes break right through the dust control layer."
The trick, according to Brill, is to grade the road a few days before applying the calcium chloride, which helps the application adhere better to the surface and allows the calcium chloride to penetrate. He also says that in the areas of the roads the county doesn't treat for dust control, he sees more destabilization, which can require additional maintenance. "Right now on some of the roads we treat only the areas in front of homes, but I can see in the future that we will be treating the entire road, not only for health reasons, but also because the areas we don't treat tend to get rough within a few weeks of grading. The dust control treatment has the added benefit of stabilizing the roads."
Agricultural Roads and Sediment Concerns
As vegetation crew leader for the Public Works Department in Marion County, OR, Tom Shamberger also deals with a high percentage of gravel roads. Marion County is home to the Oregon state capital of Salem, but it is also the largest agricultural county in the state in terms of revenue. And with all those farms come gravel roads. Of the more than 1,100 miles of road in the county, 197 miles are gravel.
"Marion County has a lot of agricultural businesses, wineries, nursery stock growers, and Christmas tree farms, and that impacts what we do in the way of dust control," says Shamberger. "Dust and dust mites can impact all of these businesses, but they have a significant effect on the Christmas tree growers."
Additionally, Shamberger says the county has to protect salmon stocks from dust while also protecting water quality, which means crews must be careful as to what they apply and how they apply it.
"Marion County is the only county in Oregon that has its best management practices [BMPs] approved by the National Oceanic and Atmospheric Administration," says Shamberger. "The BMPs address dust control near salmon and steelhead streams. Fish don't appreciate dust, and if a lot of dust settles on the streams, that can be a concern, especially in the North Santiam River. In addition to being a salmon spawning stream, it is one of the tributaries to the Willamette River, which runs the entire length of the Willamette Valley and is part of the watershed for the city of Salem."
Although Shamberger says not many county roads parallel the North Santiam, there are some, and these sections of road are treated for dust. "There are concerns with any type of siltation in fish streams, and although you wouldn't think of road dust as contributing much to this, it can be cumulative. Because road dust is manmade, we can do things to control it, and we want to do whatever we can to bolster the natural salmon and steelhead runs."
As for product, Marion County specifies a magnesium chloride product and caps it with lignon, which is a byproduct of the pulp and paper industry. "We used to use a straight lignon product for dust control, but a few years ago it looked like there might be a shortage of lignon, so we started to try some alternatives, including magnesium chloride," explains Shamberger. "We did test plots, shooting different rates and combinations, and we found that either product on its own was not as effective as combining the two products. The best results were achieved by using the magnesium chloride as a base at a shot rate of 0.6 gallon per square yard of road, followed two to three days later by a cap of lignon at a shot rate of 0.5 gallon per square yard of road. On its own, the magnesium chloride draws moisture out of the air and creates a road that is as hard as a brick, but as the day goes on, it dries out and you start to get some dust. When you add the lignon, it acts as a sealer."
To stop any runoff from reaching the water system, Shamberger says crews grade first and blade the loose rock off to the side of the road. This provides them with a tightly packed roadbed and also creates a berm, which stops the magnesium chloride and lignon from running into the ditches and entering the waterways.
Shamberger says the county works with a contractor on dust control and goes out for bid every year. The contractor supplies the magnesium chloride and lignon, along with the application service, and works together with Marion County crews. The contract was recently awarded to Blue Line Transport of Portland, OR.
As an added bonus, Shamberger says the magnesium chloride and lignon combination can also be used to reduce maintenance costs. "Last year, I shot 52 full-width road miles of dust control, but half of that was more for road stabilization. Our roads that go into the foothills of the Cascade Mountains can be quite hilly, and in the summer you can't grade these gravel roads because you don't have any moisture. In the winter if we have too much moisture, our BMP doesn't allow us to grade due to concerns of silt running into the water. I have found that if we shoot the hills, it keeps the washboards out and reduces our maintenance costs. Even on our other roads, we find that if we shoot the road in mid-June for dust control, it will stay in good shape until November, and this will also significantly reduce grading costs, probably cutting them in half."
Industrial Applications
Delbert Dawson used to be involved in the waste control business, but when he sold his company to BFI in 1987, he made a switch to dust control. It was a natural fit for Dawson, who was always looking for innovative ways to control dust in the landfill while he was still in waste control. Today, Dawson is involved with two companies from his base in Mansfield, OH, which is halfway between Columbus and Cleveland. He owns Dustlock Inc., which offers dust control solutions, and he is a half owner of D&D Emulsion, which manufactures and distributes a dust retardant product called Coherex, under license to Tricor Refining LLC.
"D&D sells the Coherex product to Dustlock and other companies and townships in the Midwest," notes Dawson. "At Dustlock, we only do dust control work, and Coherex is the only product we use. We specialize in one thing and we do it well, and we pride ourselves on being the guru in the dust control business."
Most of Dustlock's customers are industrial, ranging from steel mills to scrap yards and rail yards to lumber yards. "Ninety-five percent of our business is repeat business that we get from year to year," adds Dawson. "We really work with our customers to develop long-term recommendations for dust control. This can include establishing certain traffic patters or just slowing traffic down. What we always try to do is evaluate the problem and then develop a cost-effective solution. In some cases, our customers come back to us and say, ‘We are spending a little more on dust control, but we are saving on washing costs, filters, and repairs,' and that makes our solution a winner in the long run."
For many of the customers Dustlock serves, dust control is important because paving is not a viable option. "This is especially true in scrap yards, where an area you treat for dust might be covered with scrap material two months later," says Dawson. "There are also certain situations where asphalt or concrete just won't hold up due to the type and volume of traffic using the surface. For example, in a limestone quarry, you may have 500 to 600 large trucks a day, and the reality of this is that paving would not be a long-term solution."
Coherex is a petroleum resin and water emulsion that contains no volatiles or cutback solvents. Sixty percent of the product is semi-liquid natural petroleum, and 40% is a wetting solution. Coherex creates cohesive membranes that attach themselves to adjacent particles, resulting in agglomerates that are too heavy to be dislodged by wind.
"Coherex is well suited to applications where a regular treatment can be made," notes Dawson. "In some cases, townships have found that if we put down a good stable base of Coherex and then do a maintenance treatment on a regular basis, the surface will be hard enough after a couple of years that they can go straight to a chip seal, so essentially they are getting dust control and are building a base for chip seal at the same time."
Dawson says the product has been around since the 1950s and poses no threat to the environment. "It doesn't leach; it is non-toxic and non-flammable. There are states with certain requirements that need to be met for dust control products, and in some of these jurisdictions, Coherex is the only product they specify."
Dust in the Desert
In California's Palm Desert area, Justin Vermillion, a.k.a. "Dust Control Man," works as vice president of the family business, Environmental Products & Applications Inc. The company specializes in dust control using acrylic copolymers, and specifically a product it manufactures in Palm Desert called Envirotac II. But for Vermillion and his dad, John, who started the business 16 years ago, the market extends well beyond southern California. Envirotac II is used by the US military in the Middle East to prevent "brown outs," which are extremely hazardous situations for helicopter pilots trying to land in the desert.
"Brown outs can cause helicopter crashes, so we decided that to do our part in the Middle East we would donate $10,000 worth of Envirotac II to the military," explains Justin Vermillion. "We took the product to March Air Force Base in San Bernardino, California, where it was loaded onto C4 and C17 transport planes and delivered to Camp Rhino in Afghanistan."
The Envirotac II was quickly nicknamed "Rhino Snot" by the military personnel, but regardless of what they call it, it worked, and Environmental Products & Applications started to receive orders for more product. "They had tried a number of different products but now use Rhino Snot for not only the helicopter pads, but also for other applications such as supply roads, auxiliary roads, and runways."
Closer to home, Envirotac II is used for a number of less critical applications, from construction sites to recreation trails, and from gravel roads to baseball diamonds and playing fields. "Dust control is an issue in southern California as there are a lot of health concerns related to dust," adds Vermillion. "All of southern California is covered by the South Coast Air Quality Management District [AQMD], which regulates dust and air quality for health reasons. They have hotlines set up for the public to report excessive dust, so it is definitely something that is in the public eye,"
Vermillion says developers must post signs on construction sites providing the public with a phone number to report dust or other air-quality concerns. "If the dust situation is not corrected after calling that number, then the public is encouraged to call the AQMD toll-free hotline," he says. "When we do dust control on a construction site, we generally will treat the whole site, even if only part of the site is being worked on. We have found this to be the most cost-effective, as a water tanker costs approximately $65 per hour and our cost for a six- to 12-month treatment is approximately $300 per acre. Even if the developer is only working on 30 acres of a 200-acre site, this is the most cost-effective way to go, as they will probably finish the site before the dust control has to be reapplied, and it is much cheaper than having a water tanker on standby."
Envirotac II works by penetrating the soil on application to create a layer of protection. When dry, the product binds the soil's particles together, forming a clear plastic resin bond. The level and length of protection is determined by the amount of product used for each application. On a construction site that won't see much vehicle traffic, or on a hiking trail, a light application of Envirotac II causes soil particles to adhere for dust and erosion control but still allows water and air to penetrate the surface. A heavier application of the product builds up a durable and waterproof layer of protection, which is better suited for roads and other areas that will experience heavy vehicle traffic.
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In terms of environmental performance, Vermillion says the product is completely safe. "We have our product tested by an independent agency, and the results are submitted to the Environmental Protection Agency. Envirotac II is non-leaching, non-dissipating, non-flammable, and non-tracking. It is also odorless and is compliant with the AQMD standards."
Wherever dust control is required, from rural Indiana's Amish country to helicopter landing pads in Afghanistan, there is a product designed to meet specific needs. It's just a case of doing the research and determining which product is the best choice for the circumstances. And if you are not sure, call someone like the Dust Dr. or the Dust Control Man.
September-October 2005
Settling Down
Dust control strategies for everything from horses to helicopters.
As vehicle traffic heads down country roads on a hot summer day, you often see a plume of dust rising into the atmosphere. In addition to reducing vision for other drivers and contributing to poor air quality, continued use of these roads without some kind of treatment for dust control can cause soil stabilization and erosion problems, which can lead to expensive road repair projects. It is a problem many counties throughout the country face, especially those with large rural areas. Most jurisdictions have developed tried-and-true solutions that are custom-made to their environment. And while many of these counties handle dust control with their own crews, others hire the job out to specialists who go by nicknames such as "The Dust Dr." and "Dust Control Man."
Visibility, Maintenance, and Toxicity Concerns
The Dust Dr. is also known as Marty Koether, and he is a managing partner in EarthCare Consultants LLC, a Tucson, AZ–based company that he started with his two partners in 1995. Before that, the exuberant Koether worked in paving and asphalt restoration, along with erosion control using geotextiles and hard armor.
"It was while I was working on erosion control projects that I discovered a real need for dust control, and I found the product that I wanted to use," explains Koether. "To me, soil stabilization is synonymous with dust control and sediment and erosion control. Unless you have a stable surface, you will always have dust during the dry season, and you will have sediment runoff and erosion during rain events. Basically, by stabilizing the soil, we achieve both dust control and erosion control."
The product that intrigued Koether and his partners was Soil-Sement, which is manufactured by Midwest Industrial Supply Inc. in Canton, OH. "I did over six months' worth of research on the different soil stabilization products that were on the market, and in my opinion, Soil-Sement is the grandfather of the dust control industry regarding environmental stewardship."
Koether describes a 3.3-mile section of road in Pima County, AZ, known as Snyder Hill Road. "This road is in the Avra Valley, which is about 15 miles west of Tucson. In the morning, when you topped the hill coming into the valley, you could see the dust. This is the main bus route for the kids going to school, so there are visibility concerns, and there are also health concerns as well as safety and road maintenance concerns. The county did not want to pave the road due to easements, right-of-way issues, and available funds. They would grade the surface, compact it, and wet it down, but within a few days, the road would be a mess again. We are under contract to Pima County to deliver and apply products for soil stabilization and dust control, and it is up to the county to determine where their greatest needs for dust control are. For the Snyder Hill Road, we designed a long-term solution that would make it a safer, stabilized, dust-free transportation route."
The resulting treatment included an initial application to a depth of approximately 4 inches. The top surface of the road was removed and taken to the sides, and the subgrade was treated with Soil-Sement. The removed surface was then put back in place while the specified amount of Soil-Sement was blended into it, and then the road was graded and compacted. Finally, top coats of Soil-Sement were applied to seal the surface. "We did the first treatment on April 22, 2005, and we will go back and do a maintenance treatment in approximately eight to nine months," explains Koether. "We will then monitor the road so that we can apply additional maintenance treatments before we see any degradation of the surface. We find that it is much better to treat more often with less product than the other way around."
In addition to the bonding and cohesion properties of Soil-Sement, Koether was also impressed with the cost-effectiveness and the environmental performance of the product, which derives its strength from a polymer formulation that has the ability to bond with surface materials. Its chemical structure is made of molecules that are attached in relatively straight-linked chains and then cross-linked among other chains or grids. Environmentally, Soil-Sement is non-toxic, non-corrosive, and non-flammable and does not pollute groundwater.
"Environmental concerns of using dust control products are a significant issue nationwide," says Koether. "Effective dust control improves air quality, but we have to remember that we must protect other resources, such as water. Soil-Sement does not carry any chemicals into the stormwater system because it is not water-soluble, so in the same way paint doesn't run off your house when it rains, it doesn't run off the surface that it has been applied to during wet conditions." He notes that Midwest Industrial Supply has subjected the product to tests according to EPA guidelines regarding water quality, toxicity, and carcinogenic properties.
"Research and testing proves that stormwater runoff from areas treated with Soil-Sement will not contain concentrations that exceed benchmark values of the parameters designated in the National Pollutant Discharge Elimination System Storm Multi-Sector General Permit for Industrial Activities," he notes, adding that the product's Material Safety Data Sheets (MSDSs) "do not contain any of the disclaimers found in the majority of the other manufacturers' products' MSDSs. This industry isn't really regulated. It is a ‘buyer beware' market, and people really need to study the products they intend to use in great detail."
Accommodating Horses and Heavy Vehicles
Jeff Brill has more to deal with when it comes to road maintenance than just motor-powered vehicles. Brill is the superintendent of the Highway Department for LaGrange County, a rural county with a population of about 35,000 people in the northeast corner of Indiana. The southwestern portion of the county is home to a large Amish population, who use the horse and buggy as their main means of transportation.
|
PHOTO: MARION COUNTY PUBLIC WORKS |
"The horseshoes are extremely hard on asphalt roads, so we have tried to maintain gravel roads as much as possible in the Amish communities," explains Brill. "However, many members of the Amish community manufacture furniture in small factories, so we also have to consider that these roads will have a fairly significant amount of truck traffic that will be making deliveries of supplies and picking up finished products. Because of this, dust control is very important."
Brill says that since he took over the job of dust control in 1990, the county has used a 42% calcium chloride solution for dust control, which right now is supplied by Dow Chemical. "The county has been applying dust control on gravel roads for more than 25 years, and the person who was in the job before me had tried various products including oil-based solutions, but we have found that calcium chloride holds up the best under our specific conditions," explains Brill. "The calcium chloride will penetrate 2 inches to 4 inches into the surface, so we can generally do one treatment at the beginning of May that will last all summer long, and then in the winter dust is not a concern. If we use anything else, the horseshoes break right through the dust control layer."
The trick, according to Brill, is to grade the road a few days before applying the calcium chloride, which helps the application adhere better to the surface and allows the calcium chloride to penetrate. He also says that in the areas of the roads the county doesn't treat for dust control, he sees more destabilization, which can require additional maintenance. "Right now on some of the roads we treat only the areas in front of homes, but I can see in the future that we will be treating the entire road, not only for health reasons, but also because the areas we don't treat tend to get rough within a few weeks of grading. The dust control treatment has the added benefit of stabilizing the roads."
Agricultural Roads and Sediment Concerns
As vegetation crew leader for the Public Works Department in Marion County, OR, Tom Shamberger also deals with a high percentage of gravel roads. Marion County is home to the Oregon state capital of Salem, but it is also the largest agricultural county in the state in terms of revenue. And with all those farms come gravel roads. Of the more than 1,100 miles of road in the county, 197 miles are gravel.
"Marion County has a lot of agricultural businesses, wineries, nursery stock growers, and Christmas tree farms, and that impacts what we do in the way of dust control," says Shamberger. "Dust and dust mites can impact all of these businesses, but they have a significant effect on the Christmas tree growers."
Additionally, Shamberger says the county has to protect salmon stocks from dust while also protecting water quality, which means crews must be careful as to what they apply and how they apply it.
"Marion County is the only county in Oregon that has its best management practices [BMPs] approved by the National Oceanic and Atmospheric Administration," says Shamberger. "The BMPs address dust control near salmon and steelhead streams. Fish don't appreciate dust, and if a lot of dust settles on the streams, that can be a concern, especially in the North Santiam River. In addition to being a salmon spawning stream, it is one of the tributaries to the Willamette River, which runs the entire length of the Willamette Valley and is part of the watershed for the city of Salem."
Although Shamberger says not many county roads parallel the North Santiam, there are some, and these sections of road are treated for dust. "There are concerns with any type of siltation in fish streams, and although you wouldn't think of road dust as contributing much to this, it can be cumulative. Because road dust is manmade, we can do things to control it, and we want to do whatever we can to bolster the natural salmon and steelhead runs."
As for product, Marion County specifies a magnesium chloride product and caps it with lignon, which is a byproduct of the pulp and paper industry. "We used to use a straight lignon product for dust control, but a few years ago it looked like there might be a shortage of lignon, so we started to try some alternatives, including magnesium chloride," explains Shamberger. "We did test plots, shooting different rates and combinations, and we found that either product on its own was not as effective as combining the two products. The best results were achieved by using the magnesium chloride as a base at a shot rate of 0.6 gallon per square yard of road, followed two to three days later by a cap of lignon at a shot rate of 0.5 gallon per square yard of road. On its own, the magnesium chloride draws moisture out of the air and creates a road that is as hard as a brick, but as the day goes on, it dries out and you start to get some dust. When you add the lignon, it acts as a sealer."
To stop any runoff from reaching the water system, Shamberger says crews grade first and blade the loose rock off to the side of the road. This provides them with a tightly packed roadbed and also creates a berm, which stops the magnesium chloride and lignon from running into the ditches and entering the waterways.
Shamberger says the county works with a contractor on dust control and goes out for bid every year. The contractor supplies the magnesium chloride and lignon, along with the application service, and works together with Marion County crews. The contract was recently awarded to Blue Line Transport of Portland, OR.
As an added bonus, Shamberger says the magnesium chloride and lignon combination can also be used to reduce maintenance costs. "Last year, I shot 52 full-width road miles of dust control, but half of that was more for road stabilization. Our roads that go into the foothills of the Cascade Mountains can be quite hilly, and in the summer you can't grade these gravel roads because you don't have any moisture. In the winter if we have too much moisture, our BMP doesn't allow us to grade due to concerns of silt running into the water. I have found that if we shoot the hills, it keeps the washboards out and reduces our maintenance costs. Even on our other roads, we find that if we shoot the road in mid-June for dust control, it will stay in good shape until November, and this will also significantly reduce grading costs, probably cutting them in half."
Industrial Applications
Delbert Dawson used to be involved in the waste control business, but when he sold his company to BFI in 1987, he made a switch to dust control. It was a natural fit for Dawson, who was always looking for innovative ways to control dust in the landfill while he was still in waste control. Today, Dawson is involved with two companies from his base in Mansfield, OH, which is halfway between Columbus and Cleveland. He owns Dustlock Inc., which offers dust control solutions, and he is a half owner of D&D Emulsion, which manufactures and distributes a dust retardant product called Coherex, under license to Tricor Refining LLC.
"D&D sells the Coherex product to Dustlock and other companies and townships in the Midwest," notes Dawson. "At Dustlock, we only do dust control work, and Coherex is the only product we use. We specialize in one thing and we do it well, and we pride ourselves on being the guru in the dust control business."
Most of Dustlock's customers are industrial, ranging from steel mills to scrap yards and rail yards to lumber yards. "Ninety-five percent of our business is repeat business that we get from year to year," adds Dawson. "We really work with our customers to develop long-term recommendations for dust control. This can include establishing certain traffic patters or just slowing traffic down. What we always try to do is evaluate the problem and then develop a cost-effective solution. In some cases, our customers come back to us and say, ‘We are spending a little more on dust control, but we are saving on washing costs, filters, and repairs,' and that makes our solution a winner in the long run."
For many of the customers Dustlock serves, dust control is important because paving is not a viable option. "This is especially true in scrap yards, where an area you treat for dust might be covered with scrap material two months later," says Dawson. "There are also certain situations where asphalt or concrete just won't hold up due to the type and volume of traffic using the surface. For example, in a limestone quarry, you may have 500 to 600 large trucks a day, and the reality of this is that paving would not be a long-term solution."
Coherex is a petroleum resin and water emulsion that contains no volatiles or cutback solvents. Sixty percent of the product is semi-liquid natural petroleum, and 40% is a wetting solution. Coherex creates cohesive membranes that attach themselves to adjacent particles, resulting in agglomerates that are too heavy to be dislodged by wind.
"Coherex is well suited to applications where a regular treatment can be made," notes Dawson. "In some cases, townships have found that if we put down a good stable base of Coherex and then do a maintenance treatment on a regular basis, the surface will be hard enough after a couple of years that they can go straight to a chip seal, so essentially they are getting dust control and are building a base for chip seal at the same time."
Dawson says the product has been around since the 1950s and poses no threat to the environment. "It doesn't leach; it is non-toxic and non-flammable. There are states with certain requirements that need to be met for dust control products, and in some of these jurisdictions, Coherex is the only product they specify."
Dust in the Desert
In California's Palm Desert area, Justin Vermillion, a.k.a. "Dust Control Man," works as vice president of the family business, Environmental Products & Applications Inc. The company specializes in dust control using acrylic copolymers, and specifically a product it manufactures in Palm Desert called Envirotac II. But for Vermillion and his dad, John, who started the business 16 years ago, the market extends well beyond southern California. Envirotac II is used by the US military in the Middle East to prevent "brown outs," which are extremely hazardous situations for helicopter pilots trying to land in the desert.
"Brown outs can cause helicopter crashes, so we decided that to do our part in the Middle East we would donate $10,000 worth of Envirotac II to the military," explains Justin Vermillion. "We took the product to March Air Force Base in San Bernardino, California, where it was loaded onto C4 and C17 transport planes and delivered to Camp Rhino in Afghanistan."
The Envirotac II was quickly nicknamed "Rhino Snot" by the military personnel, but regardless of what they call it, it worked, and Environmental Products & Applications started to receive orders for more product. "They had tried a number of different products but now use Rhino Snot for not only the helicopter pads, but also for other applications such as supply roads, auxiliary roads, and runways."
Closer to home, Envirotac II is used for a number of less critical applications, from construction sites to recreation trails, and from gravel roads to baseball diamonds and playing fields. "Dust control is an issue in southern California as there are a lot of health concerns related to dust," adds Vermillion. "All of southern California is covered by the South Coast Air Quality Management District [AQMD], which regulates dust and air quality for health reasons. They have hotlines set up for the public to report excessive dust, so it is definitely something that is in the public eye,"
Vermillion says developers must post signs on construction sites providing the public with a phone number to report dust or other air-quality concerns. "If the dust situation is not corrected after calling that number, then the public is encouraged to call the AQMD toll-free hotline," he says. "When we do dust control on a construction site, we generally will treat the whole site, even if only part of the site is being worked on. We have found this to be the most cost-effective, as a water tanker costs approximately $65 per hour and our cost for a six- to 12-month treatment is approximately $300 per acre. Even if the developer is only working on 30 acres of a 200-acre site, this is the most cost-effective way to go, as they will probably finish the site before the dust control has to be reapplied, and it is much cheaper than having a water tanker on standby."
Envirotac II works by penetrating the soil on application to create a layer of protection. When dry, the product binds the soil's particles together, forming a clear plastic resin bond. The level and length of protection is determined by the amount of product used for each application. On a construction site that won't see much vehicle traffic, or on a hiking trail, a light application of Envirotac II causes soil particles to adhere for dust and erosion control but still allows water and air to penetrate the surface. A heavier application of the product builds up a durable and waterproof layer of protection, which is better suited for roads and other areas that will experience heavy vehicle traffic.
In terms of environmental performance, Vermillion says the product is completely safe. "We have our product tested by an independent agency, and the results are submitted to the Environmental Protection Agency. Envirotac II is non-leaching, non-dissipating, non-flammable, and non-tracking. It is also odorless and is compliant with the AQMD standards."
Wherever dust control is required, from rural Indiana's Amish country to helicopter landing pads in Afghanistan, there is a product designed to meet specific needs. It's just a case of doing the research and determining which product is the best choice for the circumstances. And if you are not sure, call someone like the Dust Dr. or the Dust Control Man.