Whether or not public sewers exist or are installed in public streets or rights-of-way abutting annexed and developed properties, existing acceptable private sewerage disposal systems may continue to be maintained and used by the property owners for service of the dwellings and structures existing at the time of adoption of this chapter only, except as hereinafter restricted or excepted. Acceptable private sewerage disposal systems include adequate earth-covered underground septic tanks, cesspools, leach lines and wells, and/or combinations thereof. Determination of the acceptability of a private system shall be the responsibility of the city. (Ord. 2006-02 (part), 2006: Prior code § 4204)