Landfill opposes methane rule

The Sioux Falls Regional Landfill was ahead of the curve five years ago when it installed a system to capture gas given off by decomposing trash and turn it into energy.

The landfill’s operators, though, have joined others in opposing proposed federal regulations that would require large landfills to control methane gas emissions as Sioux Falls does.

Landfill Superintendent Dave McElroy said the rules could require upgrades to its system, and it might jeopardize a financial incentive it currently collects for voluntarily reducing emissions.

Methane is a potent greenhouse gas that, like carbon dioxide, traps heat in the atmosphere, contributing to global warming. Landfills are among the top sources of methane emissions after livestock and natural gas production.

“Methane is 34 times more potent than carbon dioxide at heating the planet, and it must be addressed to prevent runaway climate change,” said Danielle Baussan, managing director of the energy policy team at the Center for American Progress, a progressive public policy think tank in Washington, D.C.

The Sioux Falls Regional Landfill installed a system of plastic pipes five years ago that collects methane gas and prevents it from being released into the atmosphere. The gas is shipped 11 miles via pipeline to a Poet ethanol plant near Chancellor, where it’s burned as fuel, providing 15 percent of the energy Poet needs for its boilers.

“We installed it because it’s the right thing to do,” McElroy said.

Poet pays the city of Sioux Falls $2 million per year for the gas. It also pays $150,000 annually for the carbon credits the city earns for voluntarily curbing emissions. The credits can be sold to companies that need or want to offset emissions for regulatory or marketing reasons.

The U.S. Environmental Protection Agency proposed new rules this summer to reduce methane emissions from landfills, coal mines, dairy farms, and oil and gas facilities.

Landfill operation manager Dustin Hansen said the city is concerned the requirements could cost the landfill its carbon credits if what it does voluntarily becomes a mandate.

More regulation could add costs, said Dean Frederickson, general manager at Poet’s Chancellor plant. Even without the carbon credits, though, Poet would continue using the methane, he said.

“At Poet, we really value our partnership with the city,” he said.

Environmental Protection Agency leaders are expected to make a decision on the new rules by next April.

In the meantime, Sioux Falls continues to upgrade its methane collection system. Contractors drilled new wells last week and replaced broken pipes.

The system includes more than 130 gas wells, and a few pipes are swapped out each year when they bend or collapse under the shifting weight of the trash.

This year, the pipes are being replaced with a longer-lasting material not usually used in the landfill industry. Sioux Falls is the second landfill in the nation to use polypropylene pipes, after one in Louisville, Ky. That’s according to Jon Dotterer, operations manager for Dot Energy Solutions, the company that drilled the wells.

Most use PVC plastic because it holds up to 110-degree temperatures created by decomposing trash, but it is rigid and can break under the trash piles. Another type of plastic, HDPE, would deform under high temperatures, Hansen explained.

“Our pipe vendor came to us with a solution,” he said, adding that the price was comparable to PVC.

Contractors from Dot Energy Solutions drilled two sets of wells at 110 feet and 55 feet deep and lined them with 6-inch polypropylene.

“It’s something they’ll start using more and more,” Dotterer said.

Sioux Falls Regional Landfill

Located: 5 miles west of Sioux Falls off 41st Street

Serves: Five counties -- Lake, Lincoln, McCook, Minnehaha, and Turner

Opened: 1979

Expected to serve through: 2078

Methane collection started: 2009

Source: EPA Landfill Methane Outreach Program