Capturing the Fugitives

Before the era of city dumps and landfills, the common practice was to take your trash outside, burn or bury it, or maybe take it out into open land and dump it there. Years later backyard gardening often turns up fascinating finds of the past: old bottles, a rusted hand mirror, or a bent spoon. But then in 1937, the City of Fresno, CA, opened what is considered the first landfill. The concept spread nationwide into organized trash collection and disposal. Our snapshot of landfills today has, however, some surprising eye-openers. Nevada, a state of wide-open spaces, reports 38 tons of trash per person each year, but population-dense Massachusetts produces only 10 tons per person each year.

Nonetheless, with just over 3,000 landfills across the country, irrespective of location, size, or daily processing numbers, all of them have two issues in common: dust and odor. Both pose a daily headache for municipality managers and plant operators who must keep them under control for regulatory compliance, labor force safety, and the happiness of their neighbors.

According to David Biderman, Executive Director and CEO of SWANA, “Landfills strive to be good neighbors, but dust and odor issues do occasionally arise that need to be addressed. There are a variety of products and systems that can help landfill operators reduce dust and odor.”

He also adds, "With a new administration turning to increase the focus on environmental justice, landfills and other solid waste disposal facilities should be evaluating the impact their operations are having on neighboring communities."

 More Dangerous Than It Looks

At Colorado-based Envirotech, Steve Clark, PhD and Tech Service Manager explains that the dust on landfill roads is a serious issue that affects the operation but also adjacent communities, even those miles away.

“Most haul roads to the landfill are unpaved and that’s a big source of dust for them. The trucks coming in might be traveling a short three-fourths of a mile or up to several miles to reach the dumping site, depending on the location. That traffic on these roads, short or long, can cause fugitive dust, not just at the road area affecting surrounding properties.”

He explains that fugitive dust is that very small particulate matter that can stay suspended in airstreams and is primarily composed of mineral elements.

“Depending on where you are this dust affects farms if they are nearby; it can settle on leaves and impact the growth of fruit and vegetables. Or affect the nearby business and residential property. In one case, I know of a landfill where there was no dust abatement program until we came on the scene, and neighbors who had million-dollar homes nearby were very upset their properties and cars were covered with dust. People don’t move into exclusive neighborhoods to have this sort of thing happen to their investments.”

Moreover, he says the microscopic particles “are airborne dust particles and, being so small, they can get into the deep recesses of your lungs and cause silicosis.”

Since they are minerals they cannot be broken down and can cause permanent lung scarring known medically as pulmonary fibrosis.

"Not something you want to expose to your drivers or site staff."

Clark says the Envirotech X-Hesion Pro is a perfect solution “that is so safe being made from organic compounds that it is a USDA Certified BioPreferred Product.

“This certification is something that is hard to earn and demonstrates to customers a level of superior environmental sensitivity. As more municipalities and sites are being mandated to use these products, it makes your decision easy.”

The way it works is pretty simple, Clark explains.

“If you are simply spraying water on the road, you lose a lot to evaporation, and a constant stream of trash trucks are constantly churning up the surface, exposing more surface to air, and then creating more dust.

“These dynamic landfill roads are different than county roads where there is not a constant parade of heavy equipment up and down every hour. On roads where people are just going to a destination once a day you can use calcium or magnesium chloride-based agents and these are great for being moisture hygroscopic (water-attracting) products.

The issue on dynamic roads stems from large vehicle tires moving dirt from one area of the landfill to another. This castoff of dirt on the road overloads chlorides' ability to maintain a damp surface.

“So, for landfills what you want to do is apply our product which is also a humectant: it likes to hold onto water. But unlike the chlorides, these are our proprietary ultra-low chloride formulations. We use agriculturally derived, complex organic polymers which not only keep road surfaces stable and dust-free but, moreover, keeps them hard yet flexible. In fact, the more you use X-Hesion Pro the harder and better the road becomes.”

“On our initial application, we apply a 50% solution of the humectant on the surface of the road, all by itself. The concept is once we do that, we then water less, not more, even though the road has a dynamic nature. Its hygroscopic nature (that is, moisture-loving) grabs the water out of the ambient air, and as it is applied this solution combines with the road surface material and creates a barrier. Even in a dynamic road situation like a landfill or a mining road, this dramatically slows down the creation of dust. And it does it with less, not more water.”

To make an effective case for customers, EnviroTech collects baseline dust level data and determines the quality and composition of aggregates, and other road and use factors to design a best-use solution.

“We also find out what are your target goals and what are your economic targets as well,” Clark says.

He reports that after the initial application, the landfill operator can add small volumes of the product to their watering truck. But the watering itself is drastically curtailed, and he reports one customer situation where during the hottest time of year with sun and wind an operator was running 4,000 gallons of water eight times a day. But with the addition of 20% X-Hesion Pro to the water truck, they cut it down to one or two times a day, which amounted to about a 70% reduction.

“This is not only less use of expensive water but the fuel, labor, maintenance, and other costs to run water on a continuous basis at these sites. Plus, you can use any kind of water, fresh, used, brackish, non-potable; the product doesn’t react with anything so it’s perfect for whatever water source you have access to.

But the real success in making it work long-term, he says, comes from the culture of the landfill. The savvy and progressive operators will see the value to continue keeping dust down and manage their own “recipe” of water and X-Hesion Pro versus “a less motivated manager who works in a reactive mode and suddenly finds out that there is a serious dust problem and then must work to overcome that and get it under control,” Clark says.

“People have to be engaged and want to control this from both a dust abatement, safety, and good operation perspective. Don’t forget that it’s the road fine material that keeps a road together and makes it passable. When you lose the fines (in other words, the dust particles) you also lose the weight-bearing road material, which leads to purchasing new gravel for the road.

“Our X-Hesion Pro helps a good road, even a dynamic road, stay good and this helps make a quality road last, and will make you a good neighbor."

Controlling a Different Fugitive

While landfill odors and dust are perennial challenges, there is another fugitive on the loose: that stuff blowing in the air, scraps of all the lightweight material that define the term, “litter.” At the Rogers, AK, Southwestern Sales Company, Shannon Harrop talks about their solutions to handle both odor and corral litter in landfill operations.

“We offer a comprehensive line of landfill equipment that gives you very efficient operation of the working face.”

Harrop, the sales and marketing manager of tarpArmor, adds they can manage daily cover, mitigate odor, and control litter with their fully automated TDS-XS tarp-deployment system and their WindARMOR portable litter fences.

“The benefit is that these products are specifically designed to keep personnel off the working face which reduces risk and improves safety, plus virtually eliminates the need for laborers on the working face. Additionally, both the TDS tarp deployment system and the WindArmor PLF are optionally available with an on-board neutralizer system which really expands their use in the landfill environment.”

Using this system is a short putt, he says, “since the TDS is used already on the working face twice daily working over the source of the odor; in the morning when the reusable tarps are retrieved and at the end of the day when tarps are deployed are perfect times to apply the odor neutralizer solution.”

The solution is sprayed directly on the working face from their frame-mounted spray system.

“Since you operate the spray feature by wireless remote control from inside your dozer cab, it’s an efficient and safe means to control odor.”

But it’s not simply putting down a spray to mask odors, as Harrop explains.

“An odor counteractant that contains beneficial bacteria, enzymes, and essential oils such as ODOR-ARMOR BEL 200 is then diluted with water within the onboard 100- or 200-gallon systems of either the 30- or 40-foot tarpARMOR systems.

“When you apply this topically and directly on the working face just before the reusable tarps are applied, the odor is trapped. Then, chemical reactions occur that immediately attack the source of the odors.”

Harrop says that managing fugitive litter as close to the source as possible is also the best strategy, particularly when portable litter fences can be re-positioned with existing dozers or other working face equipment to quickly adapt to changing conditions.

“If you arrange these portable litter fences as close as possible to the working areas, our modular catch cages will trap litter. The brackets are uniquely designed for handling both the front and back, which makes them efficient to maneuver with less handling than the front-only brackets. Plus, they can be fitted with factory-installed, optional odor mitigation atomizing systems to take advantage of the height of the fence and immediate downwind positioning.

“In combination, this system lets you enclose a perimeter and protect against windblown litter while at the same time keep down odor. Our quick-connect hydraulic system lets you connect the modular fences for complete perimeter coverage,” Harrop says.

With their “Own the Workface” mantra, as Harrop quotes, he says, “Equipment operators and site managers appreciate the multiple problem-solving capacities the tarpARMOR system offers.

“You can manage daily cover, mitigate odor, and manage litter all at the same time.”

Science From Down Under Grows Up Here

With just 16 inches of average rainfall, Australia has one of the driest climates in the world, and innovative technologies that save water are a forefront endeavor. Founder and President of Ocala, Florida-based Ecologel, Rick Irwin says the chemistry of their Hydretain water conservation product, first developed in Australia caught his attention. Irwin then brought that technology to Ocala, FL, and launched his company Ecologel, with its flagship products Hydretain and Geltrak.

Irwin says that the original product developed in 1992 was used to extend the retail life of greenhouse plants that would be sent from Florida nurseries to the big box chain store gardening centers.

“At the time, growers’ plant loss on the retail shelf could be as high as 50%, which is a huge economic impact. Our research was aimed at looking at how we could reduce watering, save plants, and improve those numbers. But as an offshoot, we saw that Hydretain had another, very important benefit in making nutrients more available to those plants.”

For landfills that need to control dust and odor, the two attributes of water savings and plant development combine to advantage.

“The best way to reduce dust and odor in the long term is to revegetate, which can often be less successful than hoped for. Operators are constantly battling the concept of big buildup but since you can’t leave it open with dust and odor and of course erosion, you have to plant cover. For landfills, this is a challenge; it’s not like vegetating your standard flat surface, and once you do it you don’t want to have to do it again because the plants fail to grow. In some climates, you can water constantly, but if you are losing huge amounts to evaporation, plant establishment can fail,” Irwin says.

“Our hygroscopic humectants in Hydretain have an affinity for moisture and are searching for equilibrium with the surrounding soil moisture. For example, on a cold glass of water, you see condensation droplets on the outside. These are free water molecules coming together, similar to the way Hydretain pulls water molecules together in the soil. This same hygroscopic humectant technology is in our dust control where it pulls water together to keep dirt surfaces nominally damp and hold dust fines to larger particles.

“But what we also found is that in the process this technology attaches to microscopic root hairs for plants making water and nutrients more available for uptake. In a study at Western Illinois University, they found that plants treated with Hydretain showed a greater nutrient value inside the leaf tissue.”

He explains how this benefits revegetating landfills.

“When you plant cover on your landfill you can use far less water to establish root systems, and the plants will establish quickly and robustly.”

Irwin also relates the benefits of Geltrak, their other water-loving product for use on high volume roads "to keep the dust down and condition the road."

“This product has a different ratio of binder materials to hold water and it binds to organic materials which is one of the reasons it works so well. We recommend adding this to your watering truck and putting down an initial higher volume of Geltrak to first treat the surface,” Irwin explains.

“Then, put down lighter applications periodically and the product will continue to work with less watering as it is taking water out of the air and soil, which would normally be lost to evaporation."

He cites a recent study that demonstrates the application in desert areas where established golf turf was maintained with a 50% reduced irrigation. Another case study at a cemetery in California showed a significant reduction in water consumption resulting in a lower water bill.

"Plus, with a big drop in their consumption, it pushed this ratepayer into a lower water tier so their bill saw a dramatic drop. They had huge savings to their bottom line while continuing to maintain turf quality."

Irwin reports that the Ecologel products are now being exported for use in countries to help grow food in dry climates with few water resources.

As it is, environmental technology is safe for use in any environment. He adds, "We use only responsible chemistry and this is safe for use anywhere for kids, pets, and wildlife.”

Science of Gases, Magic in Application

This is what David A. Hill, founder and CEO of GOC Technologies, says about their product for odor management in landfill operations: The science of odors starts with a simple realization.

"You don't smell apple pie. You smell the volatile gases leaving the pie. This is also true of wastes, leachate, whatever the source of the odor. And these gases are the target of our system."

He says that when you have an expanded open-air situation like a landfill versus a condensed source like an exhaust stack or a confined area, the method to treat odors requires a different approach.

“From a scientific point of view, any water-based particle will be heavier than a gas particle, and all odors are gases. So, when we began creating our technology, we knew we wanted to attack gas with gas.”

“If I put a water-based product into the air, it will fall to the ground more quickly than any gas, but by using vapor as the deodorizer, we can stay in the air as long as the odors do. Our QuikAir Vapor Technology has been driving the company since 2014. The system converts a proprietary liquid composed of amino acids, hydroxyls, some sugars, and 1% active hydrocarbons into a gas.”

Hill says GOC has a bench-top model of their working system and a lab equipped to track and test treatment options on any odorous material.

“Clients send us samples of their odorous wastes or air. First, we analyze them. Then we try various amino acid blends until we find the one that works best on that respective sample and will successfully attack the odor onsite. The object is to convert the offensive odor to something that doesn't smell; to break it down into something harmless and natural."

While there are many different types of odors in landfills, two of the main culprits that make us turn up our noses are organic acids and sulfur compounds. He says these are the products of organic digestion and by using and reworking the chemistry that made them, you can attack and alter the stink causing chemistry. For example, he explains that “by replacing the sulfur/hydrogen bond with an oxygen/hydrogen bond, we get end products of H2O, hydrogen gas, and an amino acid with a sulfur side chain. None of which smell.

“These odorous compounds occur naturally wherever organics are decomposing. They can smell like dead animals, sewage, jet fuel, solvents, or rotten eggs. Our job is to analyze your particular problem and create a blend that will render it neutral.”

Hill says, however, that the success of his company and the vapor technology is largely due to the operating and delivery system developed by their engineering partners. He says the magic of it all is the successful design of a system that allows the vapor to contact the odors in the air.

"Our chemistry works by physical interaction with the odorous gases. Contact is critical. Once we knew the chemistry worked, deploying the product effectively was the next crucial step.

"The hardware is as simple as possible. We create a pipe manifold around the perimeter of the odor-causing area. Then a blower system is used to distribute air to the pipe. A conversion chamber evaporates the deodorizer liquid and this gas is then added to air stream passing through the pipe.”

The science is in designing where the pipe will be and at what height, and in where and what size the holes will be in the pipe. The holes release the deodorizer gas into the path of the odors. The engineers use topography, wind conditions, even barometric pressure in determining the design of an effective installation. On a multi-acre landfill, it seems a daunting task to control odors, but with the QuikAir V system, Hill says it can work beautifully.

"With one system we can cover 2,500 linear feet of the perimeter. Large sites may utilize multiple systems. Once installed, maintenance is minimal, and no water is added, creating large savings in man-hours from water-based systems."

He says a typical site will use 3 gallons of product per system per day at 24-hour operation.

“In the open-air extremes of a landfill, this is an amazingly effective solution to odor problems. It’s environmentally sound, safe, and available year-round. I need to preface this next statement by saying that water-based technologies have their place. In the right situations, they are very effective. We use them as well. But when you get out into the wide-open spaces, trying to chase a gas with anything but another gas is like trying to chase a Lamborghini with a bicycle.”

As to the impact on nearby communities, Hill says, "We have customers with housing developments, medical and professional offices, retail b