Sewage is a
water-carried
waste, in
solution or
suspension, that is intended to be removed from a community. Also known as domestic or municipal
wastewater, it is more than 99% water and is characterized by
volume or
rate of flow, physical condition, chemical and toxic constituents, and its
bacteriologic status (which organisms it contains and in what quantities). It consists mostly of
greywater (from sinks, tubs, showers, dishwashers, and clothes washers),
blackwater (the water used to flush
toilets, combined with the
human waste that it flushes away); soaps and detergents; and
toilet paper (less so in regions where
bidets are widely used instead of paper). Whether it also contains
surface runoff depends on the design of
sewer system.