Landfills stink of energy, money

Md. counties, city join market selling methane from rot

October 07, 2006|By Timothy B. Wheeler | Timothy B. Wheeler,Sun reporter

Anyone who's been to or even by a landfill knows it can have a certain aroma. Lately, though, some of Maryland's landfills have begun to smell like money.

Businesses and local governments are teaming up to generate electricity or steam from the methane gas produced by decomposing garbage buried in landfills. The move is prompted by rising natural gas prices, federal tax breaks and recently enacted state requirements, but it also helps combat a major environmental problem - global climate change - by curbing releases of harmful "greenhouse" gases that trap heat in Earth's atmosphere.

Earlier this week, Anne Arundel County officials announced plans to sell Fort Meade the gas yielded by the county's 564-acre landfill in Millersville. If a deal can be struck, the gas would be piped five miles to the Army base and burned to produce heat or electricity for a new building planned to handle an influx of new workers expected in the next few years.

"We're just trying to make money off of some of our waste products," said James Pittman, deputy director of Anne Arundel's waste management services.

Meanwhile, without any fanfare, three massive engines have begun to generate up to 3 megawatts of electricity - enough to power 1,900 homes - from the methane-laden gas collected at Baltimore County's Eastern Sanitary Landfill near White Marsh.

And city officials say they are entertaining several suitors for the gas building up in the 149-acre Quarantine Road landfill in South Baltimore. The overseer of the city's waste disposal figures the fumes, now treated as an air pollutant or potential safety hazard, could yield millions of dollars worth of energy - and savings for taxpayers.

"This has been a quixotic quest of mine for a few years now," said Mark Wick, chief of the city's solid waste environmental services. He calls it a potential "win-win situation."

For years, operators of landfills have been required to monitor, collect and vent or burn the fumes produced by the millions of tons of garbage buried in them. Landfill gas is about 50 percent methane, the main ingredient in natural gas, and it has caused explosions and fires when it has seeped into nearby buildings.

Long-term gain

Methane is produced in landfills as microorganisms feed on the organic matter in garbage - such as food scraps - and break it down into its chemical components. The anaerobic, or airless, decomposition goes on for years, so a landfill can continue producing methane long after it gets filled with garbage and is closed.

Garbage landfills are the largest manmade source of methane emissions in the United States, according to the Environmental Protection Agency. Besides being a fire hazard, methane is a potent "greenhouse" gas. It's 23 times more effective at trapping heat in the atmosphere than carbon dioxide, the gas most closely associated with the global warming that scientists say is occurring.

For that reason, the EPA has been trying for more than a decade to encourage industries generating methane, including landfill operators, to stop releasing the gas into the air and cash in on its energy value.

About 400 landfills nationwide, by the EPA's count, are burning the gas they yield in boilers to produce steam for heating or in engines that generate electiricty. The voluntary efforts of landfills and other methane-generating industries have lowered emissions of the gas 10 percent since 1990, the agency calculates.

"Given its potency and short-term climate characteristics [methane breaks down in the atmosphere after 12 to 15 years, while carbon dioxide persists for decades], it makes a very effective gas to go after," said Paul M. Gunning, a branch chief in the EPA's climate change office.

Praise for effort

Though critical of the federal government's largely voluntary approach to fighting climate change, environmentalists applaud the landfill projects.

"Landfill gas not only reduces pollution, but it can act as a fuel source," said James S. Wang, a climate scientist with the group Environmental Defense. He said the federal government's encouragement of landfill gas energy projects represents "kind of an easy way to reduce greenhouse gases in an economically viable way."

EPA officials estimate 600 more landfills could join in, with the potential to capture far more gas.

Several of those are in Maryland, where to date only a handfull of landfills have climbed on the gas-to-energy bandwagon.

Prince George's County was among the first in the 1980s, providing heat and power to its detention center from gas generated at a landfill near Upper Marlboro. Montgomery County began generating electricity at a Rockville landfill about the same time.

But until lately, most of Maryland's 22 active municipal landfills did not produce enough gas to generate marketable amounts of electricity, experts say.

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