waste pipe vs sewerage

waste pipe and sewerage both are nouns.

Word	Noun	Adjective	Verb	Adverb
waste pipe	Yes	No	No	No
sewerage	Yes	No	No	No

As nouns, sewerage is a hyponym of waste pipe; that is, sewerage is a word with a more specific, narrower meaning than waste pipe:

Other hyponyms of waste pipe include culvert, scupper, cloaca, sewer, soil pipe, trap.

waste pipe (noun)	sewerage (noun)
a pipe through which liquid is carried away	a waste pipe that carries away sewage or surface water
	waste matter carried away in sewers or drains