(1) The owner(s) of any house, building or property used for human occupancy, employment, recreation or other purposes, situated within the city, or within the area served by the city sewer system, and abutting on any street, alley or right-of-way in which there is located a public sanitary sewer of the city, is required at the owner’s or owners’ expense to install suitable toilet facilities therein according to the building code adopted by the city, and to connect such facilities directly with the proper public sewer in accordance with the provisions of this chapter within 90 days after the date of official notice to do so; provided, that: