All dwellings or buildings used for human habitation within the limits of the city shall be connected with a public or private sewer and have sufficient and adequate modern plumbing facilities installed therein. Any such dwelling or building not so connected nor having modern plumbing facilities shall be deemed a public nuisance; provided, however, that if any dwelling or building used for human habitation does not adjoin a street or alley in which there is a sewer, then an adequate septic tank must be properly installed, according to specifications designated by the city engineer.
(1964 Code, § 12-9)