Operational infrastructure Controls
Each Health care facilities (HCF) should have an operational monitoring program to ensure that risk control measures are effective. Controls and therefore monitoring are based on managing water system risks or health risks.
These controls may include;
- For water system risks
o Installation of on-site disinfection systems that increase the level of free chlorine or other disinfectant circulating in the water system
o Ongoing maintenance and monitoring to ensure that water system risks are managed, including Contractor management procedure
o Outlets are flushed regularly – a minimum of weekly
o Point of entry filtration – to increase efficacy of disinfection and reduce turbidity
- For health risks
o For higher risk areas, e.g. those that accommodate immunocopromised patients, remove aerosol generating items ( i.e. showers, misting devices, aerators on taps) or switch to low aerosol generating showers to reduce likelihood of infection
o Point of use filters installed on showers or taps to prevent Legionella discharge in specific section of a water distribution system
o Modify hygiene practices, substitute showering with sponge bathing
o Point of use (POU) filtration installed in ward pantries, staff tearooms and water bubblers available for public use and provision of ice for patient consumption made using POU filtered water;
Operational monitoring involves the measurement of specific parameters within the HCF’s water distribution system as set out in the Water Risk Management Plan (WRMP). The results of operational monitoring provide immediate indication that the quality of water is within the required specifications and can trigger immediate corrective actions where the results are not within the acceptable parameters.
The operational monitoring plan should include:
- The parameters being tested
- Testing locations
- Frequency of monitoring
- Operational limits
- Corrective action, communication requirements and responsibilities if results are not within specified operational limits
- Record keeping of monitoring and corrective actions
This program needs to be specific to the HCF controls and can include chlorine (or other disinfectant level), temperature and turbidity monitoring.
Disinfectant (Chlorine) monitoring program
Where incoming water is sufficiently disinfected so that a minimum of 0.5 parts per million (ppm) of free chlorine for chlorinated systems or total chlorine for chloraminated systems is obtained at the distal outlets within a HCF additional on-site disinfection may not be required. However monitoring of the residual water disinfectant at the distal points in a HCF should be regularly undertaken.
HCFs using any additional water disinfection method will need to document desired minimum residual disinfectant level in their Water Risk management Plan (WRMP), e.g. The aim of chlorinating is to achieve a minimum of 0.5 ppm residual disinfectant at the distal outlets. The disinfection system needs to be documented in the WRMP,
EXAMPLE: Campus wide dosing of potable water is 1 ppm. Main water tanks dosed at 0.5ppm and then lifted to 1ppm at the main dosing station. Chlorine dosing will be conducted in accordance with the Infrastructure Safety Committee ( i.e. committee tasked to manage water safety in the WRMP) and as per HCF Work instruction - Free Available Chlorine Residual (FAC) in the Potable Water System.
- Service provider is contracted to perform a weekly service (Mondays) to all 5 chlorine dosing systems. Results of testing and corrective actions are emailed to Manager Engineering and reviewed at each committee meeting.
- Internal audits of chlorine levels at distal points are performed weekly by plumbing contractors and reviewed by Manager Engineering as per work instruction - Free Available Chlorine Residual (FAC) in the Potable Water System.
- Additional chlorine monitoring is attended during routine water sampling. Unacceptable levels are reported to the Engineering Department as per work instruction - Free Available Chlorine Residual (FAC) in the Potable Water System .
Temperature Monitoring Program
Hot Water Temperature Monitoring – Temperature return monitoring is to be installed on each line. Return hot water should be maintained above 55 degrees throughout the HCF.
- Hot water temperature monitoring should be a function of the Building Management System (BMS). Hot water flow and return temperatures are continuously monitored via the BMS or where not BMS is not utilised an alarm system should be in place for return temperature below 50 degrees. Any temperature variations are automatically monitored and emailed or otherwise alerted to the Manager of Engineering for action.
- As a backup manual temperature monitoring can be attended and recorded at the distal outlets when routine bacterial sampling is.
Control Strategies - Water operating outside recognised temperature range
As per WRMP Work instruction - Management and Response to Water Operational Monitoring Notifications, Alarms and Alerts, a return temperature less than 55 degrees will generate a BMS alarm via email or as otherwise alerted to the Engineering Manager who will undertake and/or coordinate the following action:
• Investigate the cause
• Advise the designated Hospital Manager if multiple system interruption/failure has occurred or is likely to occur
• Initiate a physical inspection of the system(s), if required
• If interruption to hot water supply is likely to exceed 8 hours or patient care may be compromised, notify the designated hospital manager or Executive On-Call.
The Hospital Manager or Executive On-Call will determine if an internal emergency - Code Yellow - should be called and Infrastructure Command Group activated as per WRMP.
Cold Water Temperature Monitoring - Monitoring of the cold water temperature is attended during routine water sampling. In some areas of Australiawhere the temperature of the cold water will frequently be above 20 degrees the HCF WRMP should clearly document that the acceptable cold water temperature will be above 20 °C.
Turbidity monitoring program
Turbidity is the cloudiness or haziness of water caused by particles of silt and clay, organic matter and microscopic plants that are generally invisible to the naked eye. The measurement of turbidity is a key test of water quality. The measurement unit for turbidity is the Nephelometric Turbidity Unit (NTU).The upper critical limit is 0.3 NTU. The HCF WRMP will record the internal turbidity monitoring program.
EXAMPLE: A turbidity probe is located in the circulation loop at the storage tanks. This level is monitored daily via Nalco 3D Trasar system and received by the Engineering manager/ delegate as per work instruction Management and Response to Water Operational Monitoring Notifications, Alarms and Alerts. In the event of high turbidity in the Queensland Urban Utilities (QUU) distribution system, QUU will advise users. The Manager of Engineering / delegate receives alerts for system wide turbidity issue and reports back to the ISC.
Flushing of outlets
The HCF WRMP will record the internal process and work instruction for the outlet flushing regime. The flushing regime must ensure every outlet has had a period of flushing that is sufficient to remove all stagnant water and maintain chlorine disinfection. Observational audits and documented records that flushing has been attended can be used to monitor compliance.
Table of Examples of Operational monitoring
En Health (2015). Guidelines for Legionella control in the operation and maintenance of water distribution systems in health and aged care facilities. Australian Government, Canberra.