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Operational monitoring

Operational monitoring assesses the effectiveness of a control measure, at a specific point within your water distribution system, through scheduled, usually real-time monitoring of specific parameters, such as temperature and disinfection residual.


Operational monitoring provides an immediate/timely indication of key water quality parameters within a water distribution system and should trigger the implementation of corrective actions if monitoring results are not within the critical limits set for a particular parameter/hazard.

For example, if the control measure for Legionella is temperature, operational monitoring should include scheduled real‑time monitoring of temperature at specific points in your water distribution system to ensure the water distribution system is heating the water to the required temperature. Should operational monitoring indicate results outside the critical limits set for the parameter (for example, temperature), it should trigger a corrective action.

Key components of operational monitoring

The following details of operational monitoring should be documented in your water risk management plan (WRMP):

  • position responsible for undertaking the monitoring
  • parameters being monitored
  • location of monitoring
  • frequency of monitoring
  • critical limits for each parameter being monitored
  • corrective actions to be undertaken should the measurement for the parameter not be within the critical limits
  • the communication/notification protocol to be followed should the measurement for the parameter trigger a corrective action
  • a log of records for each monitoring and corrective action undertaken, including results from re-testing.

The procedures used for monitoring should be detailed and available to the people undertaking the task.


To check the temperature in the cold water system, select monitoring points:

  • close to the incoming water source;
  • in or after any cold water storage;
  • after pipes have passed through an area such as a roof space where it may have been warmed.

To check the temperature in the hot water system, select control points:

  • close to the outlet on your hot water plant/heater, if there is one that can be accessed safely;
  • on the return loop if one is accessible;
  • at taps without thermostatic control, such as a kitchen, laundry or cleaners’ taps.

If your system has thermostatic mixing at point of use (for example, to basins, showers and baths), check the warm water temperature provided from an outlet served by each thermostatic mixer.

To check the temperature of a warm water loop, select control points:

  • at points furthest from the 3-way mixing valve;
  • on the return loop close to the water heater.

Ensure the sample point is connected to the system you are monitoring. For example, a kitchen or laundry may have a separate water heater from the heater for the warm water loop that services patient bathrooms.

If there are no sample points available on return loops or close to water heaters, consider having a sample point added during the next plumbing maintenance event.

Disinfection residual

Checking the disinfectant residual in the water requires the purchase of the relevant test kit or digital analyser, depending on the type of disinfection used, if any. For example, a colorimetric analyser is used to test for free chlorine.

For the majority of facilities, a simple colour test kit should be adequate. These can range in price from a few dollars to several hundred dollars. Digital analysers are more expensive but they give more precise readings and therefore allow better feedback on disinfectant residuals.

  • ŸTo check the disinfection residual of the incoming water, select a sampling point close to the location where the water enters the property.
  • If disinfection is undertaken within the facility, one operational monitoring point could be immediately past the disinfection point, to verify that the disinfectant is being dosed according to the WRMP
  • To check the disinfection residual remains effective within the building pipework, select a distal point, that is, the point furthest from the water intake, or where the water age is expected to be greatest for example, at infrequently used outlets.

For facilities with multiple buildings, floors or wings, select multiple sampling points for each of the buildings, floors or wings, to provide a representative overview of the effectiveness of the disinfection residue throughout the facility.

Visual inspection

Some control measures may require physical checks. For example, checking for leaks and whether valves are open or closed, as required.


Last updated: 29 June 2017