No person shall violate any provision of sections 25-23, 25-24 or 25-25. At locations of repeated or continued violations, the superintendent of waterworks shall have the authority to discontinue the supply of water. The contractor or installer, after notice of completion of the job is given to the city, shall be released from any implied responsibility to the city for the operation of the system. (1961 Supp., § 21.38)