There’s a network of pipes underneath the Milam Landfill in East St. Louis. The pipes gather the methane and carbon dioxide given off when organic matter heats up and decomposes. And soon, the landfill will be using it to produce natural gas.
The landfill’s operator, Waste Management, received a $2.4 million dollar grant from the state of Illinois to build the facility, which is the first of its kind in the state. Total construction costs reached $19 million, according to the company.
The gas it produces will be sold and pumped into a natural gas pipeline owned by Ameren-Illinois, which will distribute it throughout the state — enough to heat a few hundred homes.
The project received a strong endorsement from Illinois Environmental Protection Agency director Lisa Bonnett, who said Milam should be a model for the rest of the country.
“Illinois has about 20 years of overall landfill space left,” said Bonnett. “We need to think about how we can use the waste we’re generating, and how we can conserve space and use what’s being generated in our landfills.”
During a ribbon-cutting and tour of the plant on Wednesday, project manager Tom Kappelmeier demonstrated a model of the filtration system which is comprised of a network of tubes stretching from floor to ceiling.
“In each one of these tubes, there are 360 miles of fiber, the size of human hair that’s woven back and forth,” Kappelmeier said. “When the gas comes in, the smaller molecule, the methane, can pass right through it. Like it’s a hollow drinking straw.”
The Malin facility isn't Waste Management's only plant than converts landfill gas. Since the 1990s it has also operated a facility that converts emissions to electricity. The remainder is usually burned off with flares, which is inexpensive but creates air pollution.
The idea of landfills converting their emissions to energy they can sell is beginning to catch on in other states as well, said Pratim Biswas, department chair of energy, environmental and chemical engineering at Washington University in St. Louis. He said there is a risk to converting landfill gas to useable gas, because it may contain impurities that need to be filtered out.
“In this case you really have to make sure what you’re putting into the network, because it’s going to be distributed,” Biswas said. “There should be testing, and one has to use appropriate caution or have a treatment system for it.”