Lebanon Acts on Odor
West Lebanon — Get a whiff of this: The stench that prevails in parts of West Lebanon could disappear by the end of the year if all goes according to plan at the city landfill.
The city’s solid waste department is gearing up to deploy an arsenal of odor-control methods that it hopes will snuff out the “rotten egg” smell familiar to commuters and shoppers who travel through West Lebanon on Route 12A.
At noon yesterday, as the sun beat down on large heaps of decomposing material, Solid Waste Director George Murray drove around the landfill in a city-owned pickup truck, identifying the pipes lining the perimeter of a waste cell that vent hydrogen sulfide, the gas responsible for the odor, into the air.
Upon closer inspection, a wavy but clear haze of gas could be seen emanating from the small, white pipes.
At the bottom of a sloped landfill, Murray pointed to a wide metal pipe venting gases.
“There are times when there’s so much gas coming out of (the vent) that it whistles,” Murray said.
It’s enough to make some Upper Valley residents lose their appetites.
Gaal Crowl, a Woodstock resident who has lived in the area for 25 years, said that there are times when she is crossing the bridge from White River Junction to West Lebanon and the smell is “wrenching.
“On days when it’s bad, I will not eat in West Lebanon,” she said.
The city is looking to lessen the landfill gas by switching the ground-up substance it uses to cover the surface of the landfill. The substance is now made from ground wood, Sheetrock, and other construction materials.
According to the Environmental Protection Agency, hydrogen sulfide gas is produced by the decomposition of gypsum, which is commonly used in wall board. Murray also identified gypsum as the primary source of the gas.
The EPA has classified the gas as a toxic substance since 1993, and on its website said that the gas “can reasonably be anticipated to cause chronic health effects in humans and can reasonably be anticipated to cause, because of its toxicity, significant adverse effects in aquatic organisms.”
But Murray said that the gas ceases to pose a health risk after it dissipates into the air.
“If you were standing right up next to the vents, then there would be an issue,” Murray said. “But once it leaves the area, it’s not a problem.”
Murray said that a supplier in Greenfield, Mass. makes an alternative cover material that does not contain any construction by-products, and therefore no gypsum. Instead, the alternate cover material is made mostly of plastic, foam rubber and other materials sifted from sources which range from appliances to automobiles.
The city has already received a permit from the New Hampshire Department of Environmental Services to use the alternative material and is now working on a contract with the supplier to deliver it. The one-year contract includes an option for a second and a third year.
Another step in mitigating the odor involves a piping system that will collect the vented gases and burn them off in a landfill gas flare, which Murray said resembles a large Bunsen burner.
“We (would) put a vacuum on the collection system and bring all the gas to that flare and then it’s burned at a high temperature,” Murray said. “That eliminates the methane and contaminants and also the odors along with it.”
The city is waiting on an air permit from the DES to construct the collection system, which Murray said could be obtained in the next two months. After that, the city would need to purchase the flare, which could take another two to three months.
But there is another fix that could be in place by the end of July.
Murray said that the city is looking to install up to five temporary flares that would burn off some of the gas at the vents, which are interconnected and run around the perimeter of the landfill cells.
“It’s pretty remarkable, the amount of gas these vents give off,” said Murray, adding that the air pressure plays a role in how much gas is released on a typical day.
Murray said that burning the gas isn’t necessarily bad for the environment compared to venting it undisturbed.
“Just letting it escape naturally is actually worse than the little bit of pollutants that come out when you burn it,” he said.
Standing in front of a pile of the cover material, Murray scooped up the mixture of wood and construction materials into his hands and lifted it to his face, inhaling the smell, which was reminiscent of the woodchip-like material used at playgrounds.
Murray pointed out that the material on top of the pile had “started to cook,” and the material beneath the surface was still damp and cool where the decomposition occurs.
The material has been used in the Lebanon landfill for a number of years, which means that elimination of the smell won’t happen right away with the switching of cover material.
Murray said that other landfills that have switched cover material typically see an odor reduction in about two years. But he said he was confident the smell would be noticeably better by year’s end thanks to the flares.
The city had initially hoped to generate revenue from the gas, and had been lining up a project with Vermont-based Carbon Harvest Energy that would have converted the landfill gases into electricity and funneled it on to the power grid. The Planning Board approved the project nearly a year ago, but Carbon Harvest has since filed for bankruptcy, and the city has been looking for other vendors to complete the project. Murray said the uncertainty surrounding that project has delayed the city’s effort to reduce the odor.
At the recycling plant next to the landfill yesterday, Hanover resident Anne Hill was preparing to unload some recyclables from her car. Hill said she comes to the recycling center every four months, but she notices the smell on trips to the Fore-U Golf Center and Home Depot.
Hill said she was worried that burning the gas could create more pollution than simply letting it vent out of the landfill, but she was hopeful that the city could figure out how to harness the gas into energy.
As for the smell, Hill said it isn’t unusual for her to call off trips to get dessert at Ice Cream Fore-U “because the odor is so horrible.
“I’m glad I don’t live nearby,” she said.
Greg Fontaine, of Unity, works for the Department of Agriculture but is often at the landfill, where he described his role as “bird harasser.” His primary responsibility is to shoo away birds that might gather and disturb air traffic at the Lebanon Municipal Airport.
Fontaine said that he initially noticed the rotten egg smell, but has been working regularly at the landfill for nearly eight years and has since grown accustomed to it.
“I don’t think it’s too bad,” Fontaine said. “Certain days it can get pretty rancid, but for the most part it’s not too horrible.”
While the odors aren’t bothersome for Fontaine, the idea of a landfill flare was one he could get behind.
“From my standpoint, I think a flare would be good because I’ve seen that they help scare birds away,” Fontaine said. “So that would benefit me.”
Ben Conarck can be reached at email@example.com or 603-727-3213.