How a Bucks landfill produces enough gas to power 63,000 homes

The Fairless Hills Landfill complex in Bucks County owned by waste hauler WM spans 6,000 acres populated by four landfills and two lakes.

That’s nine square miles of property, exceeding some neighboring towns in size.

Texas-based WM recently began tapping two of those sprawling landfills to harness what lies beneath: gas on a big scale from decomposing solid waste that can ultimately generate electricity, heat homes, and even fuel the company’s fleet.

The gas is extracted from 290 wells in the closed GROWS-North Landfill and 314 wells in the active Fairless Landfill. It undergoes a transformation into renewable natural gas at WM’s new $131 million facility, located nearby. It can produce the equivalent energy to power 63,000 homes annually.

The processed gas is funneled into a pipeline operated by the Williams Cos., an energy company based in Tulsa, and sold for various energy uses.

“This renewable natural gas goes into the pipeline and offsets fossil fuels that would otherwise be released into the atmosphere,” said Tara Hemmer, WM senior vice president and chief sustainability officer.

Hemmer said the company considers the process an environmental win given that it taps a fuel source that would otherwise have to be flared and vented into the atmosphere.

“You end up with pure pipeline quality methane that can be pushed right into the Williams pipeline,” Hemmer said. “It’s considered a renewable natural gas at that point.”

Landfills produce gas when bacteria breaks down organic materials contained in solid waste, releasing methane, carbon dioxide, nitrogen, and oxygen in the process.

Tapping landfills for that gas is not new. The U.S. Environmental Protection Agency has long urged waste companies to use the gas, saying that landfills are the third largest source of methane emissions. Capturing those emissions, the EPA says, taps a significant energy resource that would otherwise go unused.

WM, the nation’s largest waste disposal company, has been tapping landfill gas for years, partly to power its fleet of waste hauling vehicles.

But this plant operates on a grand scale as part of a company plan that began in 2022. That plan calls for WM to build 20 new renewable natural gas facilities by 2026. The cost: $1.6 billion

Eight plants are now operational. Fairless Hills is the biggest.

WM houses the new gas processing equipment in twin 20,000-square-foot buildings near the landfills.

On a recent tour of the new facility, Brian Snyder, WM’s director of operations, said gas from the landfill gets routed through a series of filters and compressors that separate carbon dioxide, methane, nitrogen and oxygen. Carbon dioxide and methane are both greenhouse gases.

The gas from wells at the landfills is sent into the plant via pipes labeled simply “landfill gas.”

Carbon dioxide gets separated out first, then the rest of the process is spent making methane that’s pure as possible. Natural gas is composed primarily of methane, a potent greenhouse gas.

The gas gets routed to a series of 30 cylinders costing $35,000 each. There, carbon and methane get separated by their molecular structures after being forced through the equivalent of straws with tiny openings.

Carbon dioxide gets removed first.

Then, there’s more processing along a route of compressors, filters, and pipes.

The now-separated carbon dioxide, nitrogen, and oxygen are pumped to another location at the complex to be burned and flared off at high temperatures according to EPA regulations.

The methane, now renewable natural gas, gets pressurized with enough force to pump into the Williams Cos. pipeline where it can be transported and sold for a range of energy uses.

On the plant tour, Snyder stopped to peer at a control panel. He noted that the renewable natural gas flowing into the pipeline was being sent with more than 700 pounds per square inch of pressure. Though most of that will be sold, some will be used by the company.

The Fairless Hills facility has the ability to produce 12,000 standard cubic feet per minute of gas. That number should grow. As the Fairless Hills landfill continues to get filled, WM plans more gas-extracting wells.

WM has 18,000 trucks, and 13,000 of them run on compressed natural gas — including some that haul waste from Philadelphia’s streets. Snyder said the company is converting 500 to 1,000 trucks a year from gasoline to compressed natural gas.

“The collections trucks go and pick up the trash at homes and bring it to the landfill,” Snyder said. “That material starts to breakdown and produces methane gas that gets captured and processed here to fill trucks with compressed natural gas.”

That’s the “renewable” part of the cycle, he said.

“We’re the largest natural gas fleet in North America,” Snyder said. “By the end of this year, we will be able to produce enough gas to be fuel that entire fleet of 13,000.”