For the purpose of this Charter Ordinance, the words and phrases “sewer,” “sewer system” or “sewer systems” shall mean sanitary and/or storm sewers that exist at the time this Charter Ordinance is adopted or that are hereafter established and all appurtenances necessary in the maintenance and operation of the same, including, but not limited to, pumping stations, sewage treatment plants, main sewers, intercepting sewers, outfall sewers, surface drains, channels, rivers, streams and other flood control facilities and works for the collection, transportation, pumping, treating and disposing of water carried wastes or storm or surface waters. (C.O. 84 § 2, 6-11-96.)