A separate and independent building sewer shall be provided for every building. Where one building stands to the rear of another on a single lot and no private sewer is available or can be constructed to the rear building through an adjoining alley, courtyard, or driveway, the city may grant permission for the building sewer from the front building to be extended to the rear building and the whole considered as one building sewer, upon a showing by the applicant that it is not feasible that the two buildings so connected will ultimately be on separate building lots. (Prior code § 4-1-24)