sewer system vs installation

sewer system and installation both are nouns.

Word	Noun	Adjective	Verb	Adverb
sewer system	Yes	No	No	No
installation	Yes	No	No	No

As nouns, installation is a hypernym of sewer system; that is, installation is a word with a broader meaning than sewer system:

sewer system: facility consisting of a system of sewers for carrying off liquid and solid sewage
installation: a building or place that provides a particular service or is used for a particular industry

Other hypernyms of sewer system include facility.

sewer system (noun)	installation (noun)
facility consisting of a system of sewers for carrying off liquid and solid sewage	the act of installing something (as equipment)
	a building or place that provides a particular service or is used for a particular industry
	a formal entry into an organization or position or office