Definify.com
Webster 1913 Edition
Sewerage
Sew′er-age
,Noun.
1.
The construction of a sewer or sewers.
2.
The system of sewers in a city, town, etc.; the general drainage of a city or town by means of sewers.
3.
The material collected in, and discharged by, sewers.
[In this sense
sewage
is preferable and common.]