Domestic Hot Water Systems

Warm/hot water systems in commercial premises generally operate at a temperature of above 60oC to prevent the growth of bacteria.  

More specific legislation exists in relation to health care and aged care facilities in certain States;

  • Disinfection temperatures of 70oC to be achievable should the presence of Legionella be detected during sampling, and in the absence of another disinfection process (chlorination, UV, ozone etc).
  • Supply temperatures must be tempered prior to reaching the outlet (tap, shower head) through the use of Thermostatic Mixing Valves (TMVs) to comply with legislation. TMVs make disinfection temperatures a challenge as they need to be dismantled or bypassed.
  • A Risk Management Plan is recommended nationally as per enHealth ‘Guidelines for Legionella Control in the operation and maintenance of water distribution systems in health and aged care facilities (2015)’.

Hydro Flow can assist you with your warm/hot water system by;

  • Water quality testing for Legionella, HCC, E.Coli, coliforms, chemicals, organics and metals
  • Developing a Risk Management Plan to help you identify and manage the risks.

Legionella risk management plans for domestic warm/hot water systems

6.2 HWSAs part of reducing the risk of Legionnaires disease in facilities that focus on aged care, health care, correctional services and public amenities, Hydro Flow offer comprehensive Legionella Risk Management Plans on warm/hot water systems. The populace within these facilities (elderly, immune compromised, children) are considered vulnerable and at high risk should they be exposed to Legionella bacteria within aerosols from warm water taps, showers, kitchens, and other water sources. The consequence of Legionaire’s disease can be fatal.

Hydro Flow will generate a detailed Legionella Risk Management Plan involving;

 1.  Online assessment of the facility, system pipework, critical points.

2.  Liaising with the custoner to determine operation and structural information of the system.

3.  Detailed write-up assessing the following Critical Risks, and apply a Risk Rating to each (low, medium, high);

  • Dead Legs (stagnant water)

Identifying Dead Legs as defined by AS 3666 (Part 1); "a section of the system that does not permit the circulation of water", and means for their activation or removal.

  • Use of Thermo-Mixing Valves (TMVs)

Identification of all TMVs and the maintenance program for each valve.  TMVs should be regularly serviced in line with AS 4032.2 (2004).

  • Water Tanks (open water)

Identify all  hot water tanks (HWTs) in the building and determine if a maintenance program is being implemented.  

  • Water Quality

Poor water quality can be an indication of increased risk of Legionella contamination.  Assess system for potential contamination sources, review water quality and water treatment, establish if testing is in place for TDS, pH and Legionella, and determine if disinfection temperatures can be achieved should the presence of Legionella be detected.

+ Detailed photographs

+ Legionella Monitoring Program

4.  Meeting to go through each element of the RMP in detail to ensure your understanding.

5.  Signing off.