Reluctance to back clean energy plans led many to claim that Americans were just flushing it all down the drain. But this week, the city of San Antonio announced plans to take that very act of flushing and turn it into a valuable part of the country’s clean energy future.

Residents of the city produce what officials refer to obliquely as “biosolids” in massive quantities—some 140,000 tons a year—and each ounce is packed to the brim with energy rich methane gas.  As any 15-year-old boy can tell you, there’s tremendous energy in human emissions, and the city wants to put them to work. 

A firm named Ameresco has been contracted to separate the methane and refine it into natural gas, which will then be sold off to local energy firms.  Once the infrastructure is in place, a full 90% of San Antonio’s waste sewage will be recycled, either as water for irrigation, methane for energy or, uh, non-methane biosolids for fertilizers.

Odd though it might sound, this isn’t the first time mammalian waste has been turned into energy. Nor is it the first time that civic recycling has stacked up an impressive reuse rate.