Plans for a generator that would turn methane at the county landfill in Marriottsville into energy are in turn generating concerns about noise and air quality.
At least two residents say they are worried about noise from the generator, emissions from burning the gases, and whether the county will try to turn trash into treasure by bringing in more garbage so that it can sell more energy back to the power grid.
County officials counter that measures will be in place to limit noise and that the generator will not only destroy more landfill gases, but provide electricity for the facility as well. And, they say they have no plans to take in more trash.
"We will have a project here that we hope will, depending on the market, break even or perhaps help to offset some of our costs," said Evelyn Tomlin, chief of the county Public Works Department's bureau of environmental services.
The cost of designing and constructing the generator is about $3.9 million. Construction is expected to begin this winter or spring, and the generator due to be up and running before the end of 2012. It is expected to last about 25 years, Tomlin said.
The generator will be housed in a container about 41 feet by 11 feet by 11 feet, or about the size of a small tractor-trailer container, according to county government spokesman Kevin Enright.
Geff Ottman, a Marriottsville resident who lives nearby and attended a hearing on the generator in early October, said he is concerned about air quality.
"The wind eventually blows toward our neighborhood," said Ottman, 38, the father of three children. "If there's a chance that we're exposing our children to something they wouldn't otherwise have put up with, that's unacceptable to me."
But county officials say adding the generator will improve the environment.
Since 1999, the landfill has had a flare that burns methane produced by the trash, destroying toxins, including greenhouse gases, in the process, Tomlin said. The flare will continue running, and the generator will burn more methane, she said.
Landfill gas is about 50 percent methane, 40 percent carbon dioxide, and the rest is oxygen and a gas thought to be nitrogen, Enright said. With much of the landfill capped, gas must be removed so that it does not rupture the cap and possibly contaminate the soil and groundwater.
The gas is collected using a network of wells, pipes and a blower. The methane, a greenhouse gas which traps much more heat than carbon dioxide, is destroyed, while the carbon dioxide, oxygen and nitrogen are released into the atmosphere, Enright said.
Even without systems in place, the landfill's emissions were at an acceptable level, "but we wanted to go that extra step," Tomlin said. And while there will be byproducts from the combustion process, the generator will be regulated by the state Department of the Environment, which in turn is regulated by the federal Environment Protection Agency, she said.
Chuck Lacey, a Marriottsville resident who lives about a mile from the landfill, said he was concerned about noise from the generator.
"There has been a gradual erosion of the tranquillity here," he said.
Tomlin said the government has "done some extra things to make sure the sound is reduced," including adding a silencer, and also had a noise study done.
"We wanted to make sure this did not provide an impact," she said. "Based on the study's results, it looks fine."
Both Ottman and Lacey said they hoped the county government would not take advantage of its ability to sell energy back to the power grid.
"My concern is now that we've got a revenue generation tool based upon trash that we're going to change the way we operate the landfill in Howard County," Ottman said. "I don't think anyone wants to see the landfill cranked back up to the level it was in the early '90s."
Said Lacey: "With governments being strapped for cash, it doesn't take a stretch of imagination to do things where they increase the generation of methane so they can run the generator continuously around the clock."
The generator is not intended to be a money-making venture, Tomlin said.
The county government exports "the vast majority of our waste," she said, sending it to a landfill in Virginia. The project is designed to handle the garbage that is presently there.
It would be a "major effort to expand it," Tomlin said. "It could be done, but we're not planning on that. That's not the purpose of this.
"The purpose of this is to get some beneficial use for Howard County and the environment — and the energy market as well."