Most of us probably think of landfills as dead ends, less-than-pleasant destinations for one-way trips of trash.
But now we’re learning that if handled properly, our garbage may produce dividends — much of the material could eventually be used to help make our landfills sustainable and lessen negative environmental impact.
Some may not realize there is a connection between climate change and the household trash they set out at the curb, but scientists do.
The Environmental Protection Agency recently released new rules for landfills, the nation’s third-largest source of human-produced methane, which has 25 times the global warming potential of carbon dioxide.
Residential and business waste decomposes in landfills and forms “landfill gas,” which includes carbon dioxide, methane and other toxic emissions.
New landfills will be required to capture two-thirds of their methane and landfill gas by 2023, about 13 percent more than is required under current rules.
The EPA is also requesting broad public comment on updating the rules to further reduce methane emissions from existing landfills. About 1,000 municipal landfills, such as Denton’s, must follow rules drafted in 1996.
Vance Kemler, the city’s director of solid waste, knows some of the new rules will apply to Denton’s landfill, but he also told us that officials have already been working on the challenge.
Denton voluntarily built a system to capture landfill gas in anticipation of coming requirements, Kemler said, and it now powers about 1,600 homes with methane captured from the city landfill by a small power plant there.
The plant will eventually be able to triple that output, Kemler said. Researchers at the University of Texas at Arlington are hoping to increase the power-generating capacity by studying how to add water to the pile to better control decomposition and the production of gas.
Currently, any excess emissions not burned at the plant are treated and released as carbon dioxide, Kemler said.
In addition, the city hopes to be able to “mine” an older part of the landfill for paper, cardboard and other recyclable materials. Years ago, landfills operated under different rules and kept their piles dry. The city has sampled and found many valuable commodities in pristine condition, Kemler said.
Because landfill operators in Europe and on both U.S. coasts are already mining their piles, Kemler expects similar operating rules that will help control emissions as Denton begins its own mining program. The city may be able to mine other parts of the landfill, after biodegradable items have decomposed, for things like plastics and metals, Kemler said.
Both federal rules and voluntary programs have helped reduce emissions 30 percent since 1990, according to the EPA. But the agency says methane emissions will continue to increase in the next 15 years unless more steps are taken to reduce them.
Like it or not, it’s a problem we all share, and we appreciate the progressive efforts being made at the Denton Municipal Landfill.
All our trash may not be treasure, but thanks to local officials’ proactive approach, we may find many benefits buried there.