Power to the poop: one Colorado city is using human waste to run its vehicles

Renewable natural gas is a growing industry for fuel, electricity and heat, but advocates says it's a largely untapped market in the US

No matter how you spin it, the business of raw sewage isn't sexy. But in Colorado, the city of Grand Junction is making huge strides to reinvent their wastewater industry - and the result is like finding a diamond in the sludge.

The Persigo Wastewater Treatment Plant is processing 8m gallons of Grand Junction's human waste into renewable natural gas (RNG), also known as biomethane. The RNG is then used to fuel about 40 fleet vehicles, including garbage trucks, street sweepers, dump trucks and transit buses.