Before being placed into service, all new mains and repaired portions of or extensions to existing mains shall be chlorinated so that a chlorine residual of not less than 25 parts per million remains in the water after standing 24 hours in the pipe.
(A) Form of applied chlorine. Chlorine shall be applied by one of the methods which follow, subject to approval by the Village Engineer.
(1) Liquid chlorine. A chlorine gas-water mixture shall be applied by means of a solution-feed chlorinating device or the dry gas may be fed directly through proper devices for regulating the rate of flow and providing effective diffusion of the gas into the water within the pipe being treated. Chlorinating devices for feeding solutions of the chlorine gas or the gas itself must provide means for preventing the backflow of water into the chlorine.
(2) Chlorine-bearing compounds in water. In certain instances, when the usage of chlorine gas is not practical, such as in congested or confined areas, upon approval of the Village Engineer, a chlorine-bearing compound of known chlorine content, prepared in solution form, may be substituted for chlorine gas.
(B) Point and rate of application.
(1) Point of application. The preferred point of application of the chlorinating agent is at the beginning of the pipeline extension or any valved section of it, and through a corporation stop inserted in the pipe. The water injector for delivering the chlorine-bearing water into the pipe should be supplied from a tap made on the pressure side of the gate valve controlling the flow into the pipeline extension. Alternate points of application may be used when approved or directed by the Village Engineer.
(2) Rate of application. Water from the existing distribution system or other approved source of supply shall be controlled to flow very slowly into the newly laid pipeline during application of the chlorine. The rate of chlorine mixture flow shall be in such proportion to the rate of water entering the newly laid pipe that the dosage applied to the water will be at least 50 parts per million unless otherwise directed by the Village Engineer.
(3) Retention period. Treated water shall be retained in the pipe at least 24 hours. After this period, the chlorine residual at pipe extremities and at other representative points shall be at least 25 parts per million.
(4) Chlorinating valves and hydrants. In the process of chlorinating newly laid pipe, all valves or other appurtenances shall be operated while the pipeline is filled with the chlorinating agent and under normal operating pressure.
(5) Preventing reverse flow. Valves shall be manipulated so that the strong chlorine solution in the line being treated will not flow back into the line supplying the water. Check valves may be used if desired.
(Ord. 07-57, passed 12-17-2007)