Facility Odor Control: Deodorizing Your Pits

"As people start moving closer together - and closer to waste management facilities - I see the odor control field changing," said Ralph Landano, president of Maspeth, N.Y.-based Aireactor Inc.

"Odor is the primary problem at facilities, followed by truck traffic and rodents," he explained. "A good design takes care of the trucks, and rodents have a lot to do with how the place is run, but controlling the smell takes a specialized effort. This industry is looking for solutions that are cheap and effective."

As waste facilities become a familiar part of urban and suburban landscapes, operators are on the lookout for innovative ways to handle the inevitable stench. But take heart: With the help of technology and heightened environmental concerns, odor is becoming a refreshingly manageable problem.

The type of odor control practices depend on the facility as well as on its location and contents. Transfer stations, trucking companies, landfills and composting facilities face sundry challenges as they try to make garbage, and its accompanying smells, disappear.

"We tried everything to make this place not smell so bad," said Will Fullerton, former environmental manager at Wood Recycling, a transfer station in Peabody, Mass. "We tried sprinkling lime on the floor - even these ion things that are supposed to zap the smell right out of the air - but nothing worked. We use a misting system now, and that works better than anything we've tried yet. This place never will smell like a daisy, but at least the workers can stand it and the neighbors aren't complaining."

Fullerton relies on a misting system, manufactured by Ecolo Odor Control Systems, Mississauga, Ontario, which sprays a lightly-scented substance containing a chemical composition to break down the odor. "Depending on the strength of the smell, we set a timer for when the spray should be released. In the summer, when it's hot and smelly, we use it at one minute intervals and spray for 30 seconds," he explained.

Although Fullerton finds this traditional method effective, he also sees a new wave of odor controlling opportunities. "One thing I've seen is the equipment that's designed to control odor," he said. "There's a front-end loader that's specially rigged so that the chemicals are put directly onto the garbage. That's as close as you can get to stopping the smell before it starts, because it takes care of the smell before it gets to the transfer station."

Landano agrees that squashing the stench thoroughly - and at its source - is an effective means of odor control in an enclosed solid waste facility. He suggests that when a high-pressure atomization process is used, "the odor is controlled both at its source and in the air."

Landano's method has a militaristic precision; he recommends that odors first are contained within the facility and then they are attacked at the source.

"By using a pipe system, you can secure the building's perimeter and then bring the product to the exact place where the odors are," he said.

"The metering device [allows you to] measure how much you need and how much your are using," Landano continued. "It works like a gas meter on your house."

Odor On Wheels Controlling smells in a transfer station requires attention to detail, but can be somewhat less demanding than wrangling roving smells at less contained facilities. Jack Yingling, fleet manager at Gephardt Trucking in Bigler, Pa., whose company is responsible for transporting municipal solid waste (MSW) and sludge faces unique odor problems.

Because of trucking's transitory nature, crevices can attract stray waste, causing odors to linger even when the truck is empty. It is vital that truck beds are cleaned between hauls to avoid an overwhelming stench.

Yingling oversees odor control at two company sites: at Gephardt Trucking and in the trailers before and after hauling. He has found that atomizers are effective at the facility because the spray is contained in a designated area, but he believes that a granulated product works well when sprinkled on the ground outside the loading bays and on the trailers' floors.

Between loads, trucks are sprayed with highly pressurized water to remove the remaining garbage. Truck drivers also are equipped with hand-held sprayers to disburse odor-controlling substances directly onto the load.

"The innovations I've seen in the odor control industry aren't so much in the products, but rather in the way they are used," Yingling said. "Spraying the product early and often takes care of the problem. It has allowed the drivers to deal with the odors in their trucks. They can get to the smell more quickly that way, and it saves us the time and cost of having to fix the problem after it becomes really bad."

Yingling has discovered that because products are developed to be chemically stable to avoid hazardous situations, they also can be used in conjunction with products manufactured by other companies. "We use products from a couple of companies in the Northeast," he said. "We tried different things and have found products here and there that have worked." However, it is wise to double-check with the source before playing chemist.

What's Best For Your Smell? The odor control manufacturers vie for consumer attention in a crowded market. Some tout their natural ingredients, while others stress their use of an in-house chemist. While the outcome is inevitably a product that pleases even the most finicky of noses, the process illustrates the constant experimentation required to continually develop safer, more effective products.

Sheldon Murphy, president and CEO of Nature Plus Inc. in New Canaan, Conn., specializes in products that use a fermentation-based technique to control organic odors. The company's products neutralize odors by breaking down the chemical compounds creating the smell.

"We start with natural materials, such as molasses and coconut oil," he explained. "It's all renewable materials and safe enough that you could pour it on your flapjacks." These seemingly innocuous ingredients form a liquid which is sprayed onto smelly sites and can break down even sulfur and amines compounds.

Admittedly, such healthy-sounding products might not solve the most pungent problems, but in conjunction with filters and other treatment options, the products are not only edible but reportedly effective.

While Nature Plus' products lack a cover scent, NCM Marketing Co., Reeders, Penn., manufacturers a product that combats odors with the help of masking agents, in addition to bacterial neutralization.

"Let's face it: Garbage stinks," said president Marc Levine. "There is only so much you can do biologically, so it helps to put a natural scent into the mix as well."

So, NCM created a two-tiered odor control system which breaks down stench and masks the odor with an almond scent. According to Levine, neutralizers are most effective in controlled environments such as transfer stations, but scented products are less offensive to the neighbors of open areas.

Linda Westley of CoverFoam Services Inc., Florence, S.C., a company that manufacturers an odor-controlling foam spray, said that quick resolution of the odor is key. For example, she said, "we had a situation at an Army base in Texas where the mess hall was disposing huge quantities of eggshells each day. You could smell those eggs up to five miles away, and nobody was happy about it. However, within a day of the foam spray's application, the rotten egg smell was gone."

Deodorizing Compost No matter how precise the facility operator is in applying materials, some odors require more attention. Composting is one arm of the waste industry which produces unusually smelly organic odors which can be difficult to control. It is also particularly expensive. Tim Muirhead, composting manager for Professional Services Group Inc., Knoxville, Tenn., believes that despite the challenges composters face, smells can be dealt with effectively.

"One thing you see in the odor control industry is retro-fitting existing facilities so they can deal better with odors," he said. "It works well to retrofit your facility with an air-capture and collection system."

These systems capture the smelly air released from a facility and contain it in a vessel. The odors then can be filtered with chemical scrubbers and biofilters. Muirhead finds this two-stage process to be effective because each step removes different chemical compounds.

"An important innovation is a simple one; it's just stopping the odors before they start," Muirhead said. One such preventative approach is filling composting materials with wood ash. "It's cost effective, and it strips out the ammonia. The left-over smells are easy to take care of after that," he explained. However, he stressed that this process should not be overdone. "Believe it or not, you can try too hard and end up creating more odors than the ones that were there in the first place."

"Composting will bring about some important changes in odor control because it's expensive to get rid of the odors," said Chris Brockway, project manager at Black & Veatch, a Kansas City, Mo., firm that designs and constructs MSW facilities. "Chemical scrubbers work, but they're costly. Biofilters are a good idea, but aren't totally efficient."

The solution? "One site used a misting system and then ran the end product through a biofilter," he said. "This combination system wasn't especially cheap, but it worked pretty well."

Biofilters - a technique especially popular in Europe, where space is limited and people live near waste management facilities - are attracting attention in the States. Odorous gases are filtered through a 3- to 4-foot deep bed of organic material, such as wood chips or soil, and the odor-causing molecules are eaten by the material. This process both reduces odor and fertilizes the material through which the gas is passed. However, this process is high maintenance, resulting from the need to periodically shift the filtering media to maximize the surface area exposed to the malodorous substances.

Biofilters are perhaps an innovation which will become increasingly visible in future years. "Scrubbers work, but the operation cost is high because you have to pay for the chemical ingredients, and you have to have a wastewater facility nearby to deal with the end product," Brockway said. "Thermal oxidation - that's where you actually burn the odor away - is expensive because of fuel costs, but environmentally it's pretty sound. Biofilters, on the other hand, are high maintenance, but can have excellent results."

Whatever the odor control method employed, waste facility owners are not forced to battle expense, efficiency and environmental consciousness to solve their wide-ranging problems. Creativity and experimentation have proved that reasonable solutions are accessible and affordable.