Trash is a Gas for More PA Landfills

These days, almost anything can be a renewable energy source – even trash. But Pennsylvania's waste industry already knew that: 37 landfills in the state collect the combustible gas created naturally by rotting trash and use it for energy.

That number of landfill-gas-to-energy programs is second in the U.S. only to California, and 13 other in-state landfills are candidates for programs, according to the U.S. Environmental Protection Agency's Landfill Methane Outreach Program.

Houston-based Waste Management plans to soon add another one of its facilities to that list. It announced in August the construction of a processing station and pipeline at its Alliance Landfill in Lackawanna County to send the gas to a nearby electricity generator.

The rest of the infrastructure needed to collect the gas already exists. The gas is captured by boring holes through the waste and inserting perforated pipes. Air is suctioned out of the pipes, creating a vacuum that sucks in the gas as it's emitted by the decomposing organic material.

About 300 of these "wells" already exist, according to landfill spokesman John Hambrose, because the landfill had been, until 2003, selling the gas to a company that used chemical processes to extract methane from the mixture.

The company left the region, however, and, since then, the gas has simply been burned off as required by regulations, he says. "We have to control our gas as a matter of simple landfill operations," he says.

The gas is composed almost entirely of methane and carbon dioxide, at almost 50 percent each, with a variety of gases constituting the rest, Hambrose says.

With the construction of the processing station and pipeline, the gas will be chilled, dried, filtered, compressed to 60 pounds per square inch and piped 19 miles to PEI Power Corp.'s 25-megawatt cogeneration plant  in Archbald. UGI/Penn Natural Gas will build and operate the pipeline. Various other local contractors are building the rest of the system.

With completion expected by year's end, the pipeline is projected to provide enough gas daily to supply energy to 20,000 homes for at least 20 years beyond the operation of the landfill. The current 196 acres approved for garbage disposal are permitted through 2010, but Alliance is seeking permitting for an 87-acre expansion at the 742-acre facility that would extend its operating life about another 20 years.

The project will add to Waste Management's existing waste-to-energy operations throughout North America that supply enough material to power about a million homes.

In Pennsylvania, the company owns landfill gas-to-energy operations in Washington, Northampton, Bucks, Erie, Cambria, Allegheny, Franklin, Schuylkill, Montgomery, Somerset and Westmoreland counties. Some burn the gas for electricity, while others use it directly for heating and other applications.

Gas-to-energy became popular quickly in Pennsylvania. The EPA's Landfill Methane Outreach Program estimates that 20 such projects have come online and two existing ones have been expanded in the state in 2009.

In May, a project at Conestoga Landfill in Lancaster County opened to great fanfare, being named the LMOP's "2008 Project of the Year." Created by UGI Utilities, Republic Services Inc. and Granger Energy, the project consists of a nine-mile pipeline linking two independent landfills, a utility, and seven businesses in Lancaster and Berks counties to fuel a variety of appliances, including about two dozen boilers, four hot oil heaters, four ovens, five heaters, two remote thermal oxidizers, and two process water heaters.

Another Keystone State project that earned LMOP honors is in Lebanon County. Since 2007, the Greater Lebanon Refuse Authority Landfill has been capturing its gas to power two 1.6-megawatt generators that currently produce enough electricity to power 2,500 homes. Heat recovery offsets nearly 9,000 gallons of propane used to heat office and maintenance buildings.

In conjunction with a 2,000-watt wind turbine and a 1,000-watt solar array, the project helps demonstrate the benefits of renewable energy resources at the refuse authority's education facility in North Annville Township.

As trash continues to be made and sources of energy become scarcer, finding ways to make waste useful again will likely increase. Waste Management hopes to double its waste-to-energy output to provide enough for 2 million homes by 2020.

"The big benefit here is we're taking a renewable energy source and we're turning it into power and we're, somewhere, offsetting fossil fuel," Hambrose says.

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Rory Sweeney writes on energy and the environment when he's paid to and sits around talking about them when he's not. Send feedback here.

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Photos:

A worker installs a flange on a piece of pipe by a pair of scrubbers on the job site

Steve Cochrane, site superintendent, talks with John Hambrose, the community relations coordinator for Waste Management

Gas wells are scattered throughout the landfill

A heavy loader pushes garbage around on the working face of the landfill

Enclosed gas flairs handle gas when the processing plant is offline

All Photographs by Fred Adams