Pressure Testing & Disinfection (AS/NZS 3500.1) SWMS

Pressure testing and disinfection covers the pressure testing of new and repaired water pipework and its disinfection before it is placed into service — proving the pipework is sound and leak-tight under pressure, and disinfecting it so it supplies safe drinking water. It combines the stored energy of pressure testing, where a failure under test pressure can release energy violently, with the chemical hazards of the disinfection, where chlorine-based disinfectants are hazardous and the disinfected water must be neutralised before discharge. This document is written on the basis that pressure testing and disinfection are carried out by competent personnel with the pressure-test, chemical, neutralisation and water-quality controls in place.

Pressure testing and disinfection are carried out to AS/NZS 3500.1 and the water utility's requirements, with the pipework pressure tested to the required test pressure and the test managed for the stored energy, and the pipework disinfected with chlorine-based disinfectant managed as a hazardous chemical, neutralised before discharge, and the water quality confirmed. The stored energy of the test, the chemical hazards, the neutralisation and the water quality are the considerations. This document coordinates the pressure-test, chemical, neutralisation and water-quality controls so the pipework is tested and disinfected safely.

Hazards identified

9 hazards covered, sorted by priority.

Control measures

Hierarchy-of-controls order: elimination → substitution → isolation → engineering → administrative → PPE.

1. 1Engineering: pressure test the pipework to the required test pressure to AS/NZS 3500.1, managing the stored energy of the test — restraining pipework and fittings, excluding personnel from the line of a potential failure, and not over-pressurising.
2. 2Engineering: secure pipework and fittings against whip and projectile failure under test pressure, and use rated test equipment.
3. 3Administrative: handle the chlorine-based disinfectant as a hazardous chemical to its safety data sheet, with chemical-resistant gloves, eye and face protection, and respiratory protection where vapour or gas is possible.
4. 4Administrative: disinfect the pipework to AS/NZS 3500.1 and the water utility's requirements — concentration, contact time and flushing — and neutralise the disinfected water before discharge so it does not harm waterways.
5. 5Administrative: confirm the water quality before the pipework is placed in service, so it supplies safe drinking water, and control contact with the disinfected water.
6. 6Engineering: use mechanical aids for the test and disinfection equipment, and dispose of the neutralised water in accordance with the environmental requirements.
7. 7PPE: protection against the test and the disinfectant, including chemical and pressure protection, in addition to the standard PPE.
8. 8Administrative: ensure the work is carried out and certified by an appropriately licensed plumber, drainer or gasfitter under the relevant state or territory plumbing and gasfitting licensing scheme, with the relevant competencies and a compliance certificate issued where required.
9. 9Administrative: all workers must hold a valid White Card (General Construction Induction Training, CPCCWHS1001) where the work is construction work, with the plumbing, gasfitting, confined space and any other competencies required for the work.
10. 10Administrative: conduct a pre-start toolbox talk covering the day's work, identified hazards, isolations, required PPE and emergency procedures, and record attendance in the consultation section.
11. 11Administrative: consult workers and any health and safety representatives on the work and its risks, record the consultation, and keep this document available at the workplace.
12. 12PPE: eye protection to AS/NZS 1337.1, hearing protection where required, gloves appropriate to the task, high-visibility clothing, and Class I or Class II safety footwear with protective toecap to AS/NZS 2210.3.
13. 13Administrative: review and update this SWMS whenever the work scope changes, after any incident or near miss, when a worker or health and safety representative raises a concern, when new hazards are identified, or at minimum every 12 months.

Applicable Codes of Practice

Worked example

A water contractor is engaged to pressure test and disinfect new water pipework before it is placed in service. The pipework is pressure tested to the required test pressure to AS/NZS 3500.1, managing the stored energy of the test — restraining pipework and fittings, excluding personnel from the line of a potential failure, and not over-pressurising — with rated test equipment and fittings secured against whip and projectile failure. The chlorine-based disinfectant is handled as a hazardous chemical to its safety data sheet, with chemical-resistant gloves, eye and face protection and respiratory protection. The pipework is disinfected to AS/NZS 3500.1 and the water utility's requirements — concentration, contact time and flushing — and the disinfected water neutralised before discharge so it does not harm waterways, and disposed of in accordance with the environmental requirements. The water quality is confirmed before the pipework is placed in service. Contact with the disinfected water is controlled. The pipework is tested, disinfected and the records retained.

Related legislation

• Model Work Health and Safety Act — primary duty of care; the duty to consult workers; the reckless-conduct offence; and notifiable-incident provisions, as enacted in each jurisdiction.
• Model Work Health and Safety Regulations — Section 291 high risk construction work and the SWMS preparation and review duties, and the confined space, excavation, demolition and electrical provisions where applicable, as enacted in each jurisdiction.
• The relevant plumbing and drainage standards AS/NZS 3500 (Parts 0–5), AS/NZS 5601.1:2022 for gas, the pressure piping and pressure equipment standards, the AS 4032 valve standards, and the hazardous chemicals, demolition and asbestos requirements, are called up by the relevant legislation, together with the relevant network utility, insurer and site requirements.
• Plumbing, drainage and gasfitting work is licensed under each state and territory's plumbing and gasfitting licensing scheme, with the relevant competencies for the specialist work, and compliance certification required for notifiable work; electrical work is carried out by a licensed electrician.
• Victoria operates under the Occupational Health and Safety Act 2004 and the Occupational Health and Safety Regulations 2017, with the high risk construction work, confined space, excavation and demolition provisions applying in place of the model instruments.

Frequently asked questions