The wastewater treatment plant in Grand Junction, Colo., takes in 8 million gallons of raw sewage — what's flushed down the toilet and sinks.
Processing this sewage produces a lot of methane, which the plant used to just burn off into the air.
The process was "not good for the environment and a waste of a wonderful resource," says Dan Tonello, manager of the Persigo Wastewater Treatment Plant.
Now, using more infrastructure, the facility refines the methane further to produce natural gas chemically identical to what's drilled from underground.