May 16, 2017 09:49

Dust Control

dust_soil
It was February when the problems started. Just north of Sacramento, nestled among outdoor recreation areas, the Oroville Dam started falling apart. The world’s tallest dam’s main spillway partially collapsed; dam managers started using an emergency spillway that sent water down a bare hillside, which quickly eroded. As 200,000 people were evacuated downstream with more rain on the way, a problem with dust probably wasn’t on the minds of the folks at the California Department of Water Resources (DWR).

But on March 16, the Los Angeles Times reported that air and soil analysis at the Oroville dam site, where debris was being removed, revealed one of the most dreaded airborne particulates out there: cancer-causing asbestos. Naturallyoccurring asbestos is not uncommon in California, but still, the state was obliged to produce dust-control measures, to protect workers at the site and residents in the area who may be affected. News releases from the dWR indicated that they were using water, at least at first, to keep the dust down. Methods included wetting the soil with water trucks and things like washing the trucks and truck tires on the vehicles used at the site.

Dust is a microscopic nuisance so serious that it’s regulated by the federal government. Even when the airborne particulate matter isn’t something like asbestos, it can still wreak serious havoc with the environment and with human life.

“People are starting to realize that there are a number of economic, safety, and health impacts associated with dust that weren’t previously quantified to the degree that they needed to be. Obviously, from a respiratory standpoint, dust can have an impact on human health,” says Synermulch’s Trevor Kloeck, a business development manager with a biology background.

“From a safety standpoint, if you’ve traveled in some of these remote areas where dust is a major issue, like an industrial site, and they’ve got these large dust clouds coming, people get killed because they essentially lose sight of the road. And those kind of incidences have an impact on the economic efficiency of the business that’s functioning there, not to mention the loss of life.”

The focus is always on a single basic tenet: protect human health and safety. Particulate matter of this size causes a host of respiratory problems and has caused deaths due to lack of visibility when operating at an industrial site in the field. So we must control it.

The simplest, oldest and cheapest method is to use water, but it’s also one of the most temporary approaches to controlling dust. “It’s certainly the least-effective option out there,” says Kloeck.

“Water is going to last 45 minutes, maybe an hour,” says Chris Rider, chief technical officer with dirt Glue. To keep up with natural evaporation, frequent reapplications may be needed to keep fugitive dust at bay, which means paying someone to spray a site over and over.

The need for creative solutions has created a market for various dustcontrol suppressants. Choosing a dust-control product out of the multitude of options available from a plethora of companies requires examining a laundry list of variables, from the climate to the traffic, from the environment to the price.

According to Rider, using a synthetic polymer is a more long-term solution that can have a positive effect on your bottom line. “You take that operator out of the truck after the first application,” he says, “and put him into a piece of equipment that’s making you money instead of costing you money.”

Synthetic polymers outlast water because they are designed to be UV-and water-resistant. But when choosing synthetic polymers, Keep in mind that not all polymers are created equal. The industry is still relatively new. In some cases, employing multiple lines of defense against dust make the most sense.

In late March, the DWR announced that it was considering something other than water to control the dust at the Oroville dam site. “In a second phase of dust-control mitigation, additional measures may include the use of polymers, calcium chloride, cellulose or other innovative products,” Lauren Bisnett, an information officer with the dWR, wrote in an email. “The DWR is pursuing all appropriate actions, and as the weather changes, the methods may shift as well.”

This missive from the dWR mentions the weather, which is one of the many considerations that go into selecting effective dust-control plans. Other basic variables also come into play, each with their own subset of considerations: the climate, the environment, the type of soil, the traffic, the reclamation plan and the price.

Before you do anything, check the requirements for ambient air quality standards in your area. Federal regulations apply, but some states have specific standards as well. Statutes concerning wastewater or stormwater runoff from the product application may also be in effect, so be sure to check the local regulations.

Climate considerations can narrow the types of dust-control products you choose. For example, humidity can be a key consideration in the selection process. In places where there is low humidity, magnesium chloride or other salt- or brinetype dust abatement measures may be restricted.

Performing a soil analysis will also help you select the right dust-control methods. Of course, a road heavily traveled by trucks and tractors is going to have different needs from a hillside. Incidentally, you should skip polymers if the area you’re covering is high-traffic, according to Rider. They can form a brittle crust that may break apart and get ground back into dust.

“In traffic areas, polymers are not the preferred choice,” Rider said. “Polymers sprayed on dirt typically form a thickness similar to a cookie, or brownie, if you get good penetration, but it can be as weak as a potato chip if you don’t get good penetration.”

Snack food comparisons aside, the variety of available options and potential situations may call for more than one shot. Said Kloeck: “We encourage guys to try lots of different things and to be patient with the process, because dust, as much as it’s been around forever, is still relatively new as a technical problem, in terms of being a major issue for the public and the industry as a whole.”

And then there’s price. Don’t be fooled by a deal that seems too good to be true, cautions Rider.

“Unfortunately, there are no regulations for ‘polymers on the dirt,’ so a company can buy polymer from any source, and call it dust control,” he said. “They squirt it on the dust, and because there are no industry regulations, there’s no quality control for the polymer. You have a bunch of fly-by-night organizations that are buying off-spec polymers, that don’t have good lifespans.”

But a carefully selected dust-control polymer that has been properly applied can be very effective. Some companies are developing and manufacturing their own dust-control concoctions in order to ensure consistency among their products.

There’s been a growing awareness of the need for dust control lately. “Awareness overall is better than it’s been in the past,” said Kloeck. And that awareness is spreading—as it should be. Dust is hardly a problem unique to North America.

“It’s really a global issue. A lot of the areas that have the biggest problems don’t have the means to solve them. There are very acute needs in some of the developing areas of the world, but there’s also a lack of infrastructure.”

Meager means can make for some unusual local solutions. Chris Carroll, general manager at PM10, Inc., in Palm desert, California, recalled a frustrating experience, common when working in the developing world, where this can be especially challenging: “Yeah, they’re a pain in the neck, actually. They’re just not used to doing business like we do business here. They’ll say, ‘Yeah, we got a water truck,’ and then they’ll show up with a camel pulling a cart with a hose or something on the back. There have been situations like that,” he said.

A lack of infrastructure in emerging towns and site locations around the world indicates opportunities for companies expanding their dust-control services to further-flung locations (Rider estimates the majority of his business comes from overseas). It also, unfortunately, reflects the great unmet needs of the people in those locations.

Most recently, dust-control measures have been taken to remediate noxious odors. In March, dust Control Technology, based out of Peoria, Illinois, used their product called OdorBoss to suppress the overwhelming smell of coal tar waste coming from a 10-acre site in Massachusetts that emanated during an urban renewal project. Residents in the area had begun to complain.

“The deeper we dug and the more soil we exposed, the worse the odor became,” explained Brian Burk, Field Technician for TRC. “When summer temperatures heated the soil, complaints from neighbors started coming in, so we immediately implemented our odor strategy.”

OdorBoss is an atomized mist deodorizer, and was used to treat ‘fugitive odor’ coming from the contaminated soil. This product has also been applied to landfills and sewage treatment areas.

When it comes to dust control, there is a veritable Wild West of opportunity out there, from supressing fugitive particulates to masking fugitive odors. Environmental standards are constantly being updated, and customers and community members will continue making requests, complaints and demands. Do you know where your business will be in this great frontier of burgeoning opportunity when the dust settles?

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In many ways, we are fortunate that, in our chosen profession, we are able to help people when certain disasters occur: the tornadoes in Missouri, Oklahoma, Louisiana and Georgia, the flooding in Louisiana, the snows in the northeastern part of the country, the rain in California, and the snow in Colorado....

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