Collocations for sewage - noun

raw, untreated
treated

discharge, dump, pump
In some parts of the country raw sewage is pumped straight in the ocean.

treat
Sewage should be treated in a proper disposal system.

disposal, treatment
farm (BrE), plant (esp. AmE), works (BrE)
a sewage treatment plant

system
pipe
discharge, effluent, sludge
pollution