The disinfection of the water treatment equipment can be carried out during a self-disinfection cycle.
The actual frequency should be decided by the user based upon known e. g. seasonal variations in the quality of water supplied to the WD and the operational history of the water treatment equipment.
The disinfection method shall not cause any damage to, nor impair the efficacy of, the treatment equipment.
The efficacy of the water equipment disinfection procedure to provide self-disinfection shall be deemed to have been established if, when tested in accordance with the methods given in 6.12.3 and 6.12.4 there shall be less than 10 cfu recovered from each of two 100 ml samples and other controlling parameters have been achieved.