9.4.4 Corrective action

Where monitoring results indicate a deviation from target criteria or critical limits, appropriate corrective actions and process adjustments should be instituted to maintain water quality. Examples of corrective actions are:

• repairing fences;

• removing dead animals from catchment areas;

• increasing catchment controls;

• inspecting the water supply system for faults;

• altering the flow rate of the water treatment plant to reduce loading;

• manual backwashing of filters;

• adjusting process control;

• inspecting and calibrating monitoring equipment;

• engaging back-up equipment;

• adjusting pH;

• selecting an alternative raw water source, if available;

• increasing disinfection dose;

• booster disinfection;

• flushing of mains; or

• increasing monitoring and observation.

Additional monitoring will be required throughout the system to verify the effectiveness of any corrective actions.