On an unseasonably cool summer morning in the north Texas town of Denton, Tyler Hurd, the planning and public outreach manager for the city’s landfill, spoke proudly of the rubbish beneath his feet. “Doesn’t smell so bad, does it?” Hurd asked with a smile.
Denton’s landfill is special: It is the first in the world to employ a new technique for dealing with city waste that will combine established eco-friendly measures with “mining”. This involves going through a long-established tip to find metals, plastics and other goods that can be re-sold, to create a sustainable waste disposal system.
Pointing towards a large, sealed-off hill, Hurd explained that this would be the first to be mined. “We recently drilled down into the mound and found a newspaper from the 1980s, and it was readable. It’s a ‘dry tomb’,” he explained. “Should be good for mining.”
Being dry is out of the ordinary for waste in the Denton landfill. Since 2009, the dump has injected leachate, or percolated wastewater, into its rubbish-filled plots to speed up the decomposition of organic waste and generate methane gas, which is then collected by gas wells that burrow into the mounds.
The gas is then used to power a generator that currently supplies electricity for some 1,600 homes in the city. This carbon-catching process is referred to as “biomass energy” and the project is administered in conjunction with DTE Denton, a renewable energy company.
According to DTE’s website, the amount of “greenhouse gas emissions destroyed annually at the Denton project are equivalent to removing the emissions from approximately 11,610 passenger vehicles from the road each year”.
Soon, equipment will be added to extend the supply of power nearly 4,000 homes. This is far from the only ecologically friendly project on the landfill’s grounds. For example, human waste from the city’s sewage treatment plant is combined with garden clippings to make compost, all the tip’s lorries are fuelled by biodiesel, and bee hives have been established in the grounds to help pollinate surrounding flowers.
“We’re trying to become a sustainable landfill, to have as little impact on the environment as possible,” Hurd said. One of the impacts landfills have is their expansion. Normally, once a plot is filled, it is covered and a new location is found. With the mining technique, the search and purchase of new lands will be unnecessary.
To read the full story, visit http://www.aljazeera.com/indepth/features/2016/08/texas-city-world-eco-friendly-landfill-160816094911055.html.