For Repaired Mains and Mains for Making ConnectionsAll fractured mains, and every main into which an opening has been made for any causes whatsoever, should be sterilized with chloride of lime (or sodium hypochlorite solution) so as to achieve a concentration of free chlorine of at least 30 ppm in the water before putting back to service. Sterilization should be carried out on the whole section of the main which has been shut down for the purpose of making the repair and opening. The point of application of chloride of lime (or sodium hypochlorite solution), whether it be a ferrule or a hydrant, should be as near to the charging valve as possible. The applied chloride of lime (or sodium hypochlorite solution) should be flushed out through the fire hydrants or washout valves in the vicinity.An exception can be made where a gate valve is dismantled for repair, cleaning, etc. In such cases, the valve parts should be swabbed with chloride of lime. The main is then charged with sufficient water for discharge through the hydrant or washout on the downstream side of the repaired valve until it is certain that the discharged water has passed through the repaired valve.Water samples should be taken from the pipes for testing of bacteriological content in order to ensure that the pipes have been adequately sterilized.