Odor Control: Managing A Lingering Problem

Susan DeGrane

When a woman selling insurance paid a visit to a compost facility in the Northeast, she refused to go inside, and asked that someone come outside to her car to conduct business. Did the facility have a serious odor problem, or was this woman's olfactory sense just highly developed? In many cases, odor is a personal perception.

"What smells to one person may not bother someone else," said Matthew Calderiso, process monitor at the compost facility in Bristol, R.I., which combines yard waste and sludge from Bristol and four other Rhode Island communities.

"Odor depends on what offends a person," Calderiso said. "People who live next to farms smell strong odors, too, like when the manure is used to fertilize the fields. We were chipping some pine trees after Christmas and somebody complained about smelling the pine needles."

But no matter how conscientious the waste handler may be in handling odor, whether or not the scents given off by a particular facility are offensive depends on who inhales the aroma.

"The problem with odor is, how do you judge it?" says Peter T. Roselle, manager of the Ellesor Transfer Station in Elizabeth, N.J. "I don't know. What we do know is if a neighbor complains, there's a problem."

The Nose Knows But why has the odor problem be-coming such a concern to today's waste handlers?

Urban sprawl has brought homes and businesses to the doorstep of landfills and transfer stations which were once considered to be in desolate areas.

Compost and recycling operations are springing up everywhere due to a need to conserve landfill space. Composting can produce offensive smells, especially when space is limited for handling the materials. Recycling operations can give off many odors when waste producers are reluctant to thoroughly clean beverage and food containers.

In order to further conserve space, some landfills have even taken to excavation, in which materials for recycling and incineration are removed and cover reused.

"If you think garbage stinks going into the landfill, try smelling it after it has been buried for a couple of years," said Herb Flosdorf, executive director of the Lancaster County Solid Waste Management Authority, Lancaster, Pa. "The biological process is most rapid in the first two or three years."

In many instances, the trash may travel greater distances through populated areas en route to regional landfills and incinerators.

"Most regulations on the state and federal level don't require odor control," said Ed Repa, director for environmental programs for the Washington D.C.-based Environmental Industry Associations (EIA). He added that most odor in landfills is controlled by the federal regulation that requires operators to apply a daily cover.

"Odor is very subjective and difficult to regulate, but most facilities will bend over backwards to make the neighbors happy," Repa said.

Neutralizing sprays and products that mask odors can help, but Repa said that sound operating practices and good public relations are just as important. Some transfer stations and landfills take extra pains to control odor, then concentrate on their image by maintaining equipment and facilities and installing attractive landscaping.

The Keystone Landfill in Scranton, Pa., went so far as to open a diner on-site for waste truck drivers so that the trucks would remain out of the community, at least during meal times, Repa said.

Odor becomes a concern to waste handlers when neighbors complain. Too many complaints can shut a business down, said Roselle.

Words To The Wise What can be done about odor? Eliminating odor altogether may be unrealistic, but many things can be done to curb it. Many waste handlers seem to use a variety of methods to control odor, not just one.

* Keep the waste moving. "We never leave garbage overnight. We're always moving it in and out," said Roselle. Garbage is not allowed to re-main at the Ellesor transfer station more than 24 hours. As a result, methane does not have a chance to build up.

Compactor boxes that have been exposed to the summer sun for a few days present a tough odor challenge, Roselle said. "We get these out as quickly as we possibly can."

* Keep the facility clean. The floor of the transfer station in New Bed-ford, Mass., is cleaned and completely disinfected every night after the trash has been removed. Bruce Duarte, superintendent, says that cleanliness retards the growth of bacteria.

* Contain the odors. The Waste System Authority of East Montgomery County, Pa., operates a transfer station within 100 feet of a school, a church, houses and a playground. Operations Supervisor James Root says the facility has had no complaints since a sprinkler system with timers was installed to apply neutralizing compounds to the trash through nozzles placed over the tipping floor and in other locations at the transfer station. The process not only works to control odor, "It also keeps the dust down, which is a health issue when your people are working in it all day," Root said. "I've been in this business 34 years, and I've found it's the best way to contain the odor and hold it down."

* Use vacuum and filtration systems. These systems draw air through the transfer station and clean it before it is returned to the atmosphere. The Ellesor Transfer Station, Elizabeth, N.J., installed a vacuum system to keep the air from drifting freely out of the facility.

At the compost facility in Bristol, R.I., which combines yard waste and sludge, a bio-filter cleanses the air. Electronic doors on the building are vacuum-sealed so that air is contained and directed to the biofilter. The bio-filter's perforated pipes route the air through pine bark mulch, stone and compost that contains special organisms to receive an organic cleansing.

* Apply neutralizing compounds directly to the trash. At the transfer station operated by the Lancaster County Solid Waste Management Authority, excavated trash is loaded onto trucks and hauled 25 miles to an incinerator in Rochester, N.Y. The trek takes the waste through a couple of small towns. Residents of Co-lumbia, Pa., complained loudly a-bout the smelly trucks, prompting the local waste authority to secure a solution.

The search for the right product was arduous, according to Robert Garner, operations manager for the Lancaster County Solid Waste Management Authority, Lancaster, Pa. "We must have searched and used 10 different products before we found the right one," Garner said. "Of course there's every conceivable application available. You have granular, liquid or powder forms in every scent, from peach to almond."

Testing the products was not exactly a dignified process. "You send a guy along the road to sniff the trucks as they pass by," Garner said. "We tried doing this for each product on a windy day, a dry, hot day, a humid day - but with so many products, we found it hard to be consistent with all of our tests."

The neutralizing agent is sprayed on the trash after it has been loaded on the trucks and is ready for tarping.

* Aerate piles frequently. Con-trolling compost odors is important, and products can be applied. But one of the best odor-controlling methods may be frequent aeration of the piles to prevent anaerobic conditions from developing. The New Bed-ford compost facility, which turns the compost every two days, has "no bad odor," according to Duarte.

The Bristol, Mass., compost facility, which handles sludge, is dealing with compost of a different composition that presents different problems. Improper handling can result in the production of ammonia and other foul odors. Aeration becomes crucial at this facility, which is turned every day.

* Communicate with the public. The last layer of protection a waste handler can achieve in handling odor problems seems to be good public relations. Getting to know the neighbors and remaining sensitive to their concerns can be extremely important, said Roselle.

"Many of the neighbors know me," he said. "We know each other on a first-name basis. They always come over and speak to me. They've never needed to approach a city official. We might as well face it. We're in a smelly business, and we've got to make it as pleasant as possible."