No water pipe of the city water supply system shall be connected with any pump, well or tank that is connected with any other source of water supply. When any connection is found, the City Administrator shall notify the owner to sever the connection and if this is not done immediately, the city shall turn off the water supply forthwith. Before any new connection to the city system is permitted, city employees shall ascertain that no cross-connection will exist when the new connection is made.
(`87 Code, § 402.01)