In an age where everyone is going green, San Antonio, Texas stands out as the lone vanguard city going brown. City officials recently announced a new plan to become the first U.S. city to transform methane gas into fuel. Methane, a byproduct of human waste, will be used to power furnaces, generators, and even power plants. The city produces approximately 140,000 tons of what they refer to as 'biosolids' each year, and they estimate they'll be able to recycle about 90% of the human waste being flushed down the toilets and sinks of the San Antonio metro area.