Everytime you flush or put something down the sink disposal, energy is going down the drain. BOD stands for biological oxygen demand, the amount of oxygen needed to turn all those carbon molecules into CO2 via aerobic respiration. The world's best decomposers, bacteria, may accomplish this in a different way, anaerobically, which works but generally more slowly. Now scientists have created a fuel cell that turns 13% of the energy in sewage into electricity. Now this is a great thing because now treating sewage costs energy rather than generating energy. Image all that sewage sludge turned into electricity! Wow! This is very cool. Now maybe if some of those pig farms could just put their by-products into fuel cells, some akin to Bartertown's electrical system (Mad Max 3), now that would be progress if only an apocalypse can be avoided first.