AS/NZS 3666 Part 3 - Legionella Control Australia

Air-Handling and Water Systems of Buildings - Microbial Control - Performance Based Maintenance of Cooling Water Systems

AS/NZS 3666 Part 3 - The Australian Standard/New Zealand Standard AS/NZS 3666 Part 3 is concerned with the control of microorganisms, including Legionella bacteria within air handling and cooling water systems in commercial buildings.

Additional Standards

You should be aware that this standard, AS/NZS 3666 Part 3 only covers the performance of maintenance programs for cooling water systems and that it should be used together with AS/NZS 3666 Part 1 and the relevant clauses of AS/NZS 3666 Part 2.

It is also important to note that issues including facilities and building maintenance manuals, site log books and health and safety procedures, are as important for the application of AS/NZS 3666 Part 3 as they are for a prescriptive approach to maintaining clean cooling water systems.

Contents of AS/NZS 3666 Part 3 Include:




Section 1 Scope and General

1.1 Scope

1.2 Objective

1.3 Functional Statement

1.4 Performance Requirements

1.5 Referenced Documents

1.6 Definitions

1.6.1 Cycles of concentration
1.6.2 Key performance indicator
1.6.3 Total dissolved solids (TDS)

1.7 Testing

Section 2 Identification and Assessment of Risk Factors

2.1 Scope of Section

2.2 Risk Factors

2.3 Risk Assessment

2.4 Water Treatment

Section 3 Performance Monitoring and Control

3.1 Scope of Section

3.2 Presence of Legionellae

3.2.1 Monitoring
3.2.2 Assessment
3.2.3 Control

3.3 Presence of Other Heterotrophic Microorganisms

3.3.1 Monitoring
3.3.2 Assessment
3.3.3 Control

3.4 Water Quality Management

3.4.1 Monitoring
3.4.2 Assessment
3.4.3 Control

3.5 Water Temperature

3.5.1 Monitoring
3.5.2 Assessment
3.5.3 Control

3.6 Start Up

3.7 Results and Records

3.8 Evidence of Compliance

Appendix A – Cooling Water Sampling Procedure

A1 Scope
A2 Personnel Carrying Out Sampling
A3 Sample Storage and Transport
A4 Particulars of Sampling Containers
A5 Particulars of Sampling
A6 Technique of Sample Collection

Appendix B – On-Line Disinfection Procedure for Cooling Water Systems

B1 Scope
B2 Biodispersant
B3 Disinfection
B4 Circulation
B5 Operation

Appendix C – Decontamination Procedures for Cooling Water Systems

C1 Scope
C2 On-Line Decontamination
C3 System Decontamination

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