Municipal wastewater treatment plants receive inputs from homes, from commercial
properties (e.g. laundries) and from industries. In addition, water
can leak into sewers from the groundwater (infiltration)
and can be discharged (usually illegally) from cellar and roof drains.
person in a community generates ~75 gallons of wastewater per day.
For the city of Detroit, this amounts to almost 700 million gallons
per day. That's enough to fill the central tower of the Renaissance
Center in 4 days!