What happens to all the human waste?
Municipalities may have a sewage treatment facility where all of the household effluent is piped to be separated, and treated. The sludge is often then trucked to a landfill, possibly after being mixed with wood chips as a binder. There it rots out. Many homes not in urban centers have septic systems. Basically it is a large 1000 gal. holding tank that is underground, liquid and solid waste enter through a pipe, and are separated by gravity, (the solids fall to the bottom and the water decants off the top into a leaching field or a sand filter. The solids are reduced by bacteria in the tank to a fraction of their original volume. Some times (every few years) the tank needs to be pumped and the solids are trucked off to a treatment facility. In other countries, they haul it out to the garden as fertilizer.
