Septic Tank Installation (Conventional) SWMS
Safe work method statement for the excavation, installation, and commissioning of conventional septic tanks and absorption trenches including council approval, confined space, and effluent management.
SWMS variants reference your state’s WHS legislation. Instant download after payment.
Septic tank and on-site wastewater installation covers the installation of septic tanks and on-site wastewater systems at unsewered properties — installing the tank, the drainage and the land application or disposal area that treats and disposes of wastewater on site. It combines the sanitary drainage with the excavation for the tank and disposal area, the manual handling and placement of the heavy tank, the biological hazards, the potential for confined space entry, and the protection of the environment and any water sources. This document is written on the basis that septic and on-site wastewater installation is carried out by a licensed drainer with the excavation, manual-handling, biological and environmental controls in place.
Septic tank and on-site wastewater installation is carried out to AS/NZS 1547, the on-site domestic wastewater management standard, and AS/NZS 3500.2, with the local authority's approval, under which the system, the tank and the land application area must be installed to treat and dispose of the wastewater on site without harming the environment or water sources. The excavation, the heavy tank placement, the biological hazards, the confined space and the environmental protection are the considerations. This document coordinates the excavation, manual-handling, biological, confined-space and environmental controls so the septic system is installed safely.
Hazards identified
9 hazards covered, sorted by priority.
Burial and crush injury from collapsing excavation walls
Crush and musculoskeletal injury placing the heavy septic tank
Electrocution, gas release or service damage where services are not located
Infection from the wastewater during installation and connection
Atmospheric and restricted-access hazards where entry into the tank is required
Environmental contamination where the system is not installed correctly
Health and environmental hazard where treatment or disposal is inadequate
Crush and run-over injury where plant and workers are not separated
Structural and stability hazards from the weight of the full tank
Control measures
Hierarchy-of-controls order: elimination → substitution → isolation → engineering → administrative → PPE.
- 1Engineering: locate and protect existing services first and control the excavation for the tank and disposal area to the excavation Code of Practice with benching, battering or shoring, with a SWMS where it reaches the regulated depth.
- 2Engineering: place the heavy septic tank using mechanical lifting and the correct method on an adequate base, controlling the crush and manual-handling hazard.
- 3Administrative: manage the biological hazard with hygiene controls, washing facilities and protective clothing, and prohibition of eating, drinking and smoking until decontaminated.
- 4Administrative: install the system to AS/NZS 1547 and AS/NZS 3500.2 and the local authority's approval, so the wastewater is treated and disposed of on site without harming the environment or water sources.
- 5Administrative: where entry into the tank is required, apply the confined space entry permit, atmospheric testing, ventilation, standby and rescue controls to the confined spaces Code of Practice.
- 6Engineering: protect the environment and any water sources, set back the disposal area as required, and maintain plant-and-pedestrian separation with a spotter.
- 7Administrative: confirm the system, treatment and disposal on commissioning.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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
The on-site domestic wastewater management standard for the septic and on-site wastewater system.
The sanitary plumbing and drainage standard for the sanitary and drainage work.
Trenching and excavation controls including support against collapse, ground assessment and existing services.
Atmospheric testing, ventilation, entry permit and rescue controls where the work involves entry into a confined space.
The risk management process and hierarchy of controls applied to the hazards of the work.
High-Risk Construction Work triggered
Installing the septic tank and disposal area can require excavation deeper than 1.5 metres, which is high risk construction work requiring a SWMS before the work commences.
This is licensed plumbing, drainage, gasfitting or specialist work that, in the circumstances described, is high risk construction work — in or near a shaft or trench with an excavated depth greater than 1.5 metres — so a SWMS must be prepared before the work commences, kept readily accessible, reviewed as necessary, and given to the principal contractor if one is appointed. The work is carried out to the relevant AS/NZS 3500 plumbing and drainage standards and the relevant gas, pressure, excavation, confined space or demolition requirements, which are called up by the relevant legislation, with the controls for the specific hazards applied. A failure in this work can cause serious injury, burial, an atmospheric incident, a loss of containment or harm to the water supply, and breaches of the relevant legislation and the primary duty of care under the model WHS Act are actively enforced, with offence categories running from failure-to-comply through to reckless conduct, and the most serious breaches carrying imprisonment for individuals. Body-corporate maxima are substantial and indexed; the current maximum follows the prevailing schedule of the responsible regulator.
Who this is for
- →Licensed drainers installing septic and on-site wastewater systems.
- →Drainage and civil contractors installing on-site wastewater.
- →Plumbing and drainage businesses providing septic installation.
- →Rural and unsewered-property owners and PCBUs.
- →PCBU safety managers and supervisors coordinating the excavation, manual-handling and biological controls.
What you receive
- ✓Editable Microsoft Word document (.docx) fully compatible with Microsoft Word 2016 and newer, Google Docs, and LibreOffice Writer.
- ✓Title page with editable fields for PCBU name, ABN, site address, project name, principal contractor details, and document revision date.
- ✓Hazard register with the septic tank and on-site wastewater installation hazards — each with a documented consequence, inherent risk rating on a 5x5 likelihood-consequence matrix, hierarchy-of-control measures, and residual risk rating.
- ✓Septic installation prompts referencing AS/NZS 1547 and AS/NZS 3500.2, an excavation and services section, a tank-placement and biological section, and an environmental-protection and commissioning record.
- ✓Licensing, competency and permit prompts for the relevant plumbing, gasfitting, confined space and specialist work, and a respiratory protection selection and fit-test record per AS/NZS 1715 where relevant.
- ✓Worker consultation record per the model WHS Act consultation duty and a worker sign-on register (blank, expandable).
- ✓Applicable legislation and Codes of Practice schedule pre-populated for the model WHS jurisdiction with a state-variance reference table covering the harmonised states, plus Victoria.
- ✓Emergency procedure template and a revision log.
Worked example
A licensed drainer is engaged to install a septic tank and on-site wastewater system at an unsewered property. Existing services are located and protected first, and the excavation for the tank and disposal area controlled to the excavation Code of Practice with shoring, with a SWMS where it reaches the regulated depth, and plant-and-pedestrian separation maintained. The heavy septic tank is placed using mechanical lifting on an adequate base, controlling the crush hazard. The biological hazard is managed with hygiene controls, washing facilities and protective clothing. The system is installed to AS/NZS 1547 and AS/NZS 3500.2 and the local authority's approval, so the wastewater is treated and disposed of on site without harming the environment or water sources, with the disposal area set back as required. Where entry into the tank is required, the confined space controls apply. The environment and any water sources are protected. The system, treatment and disposal are confirmed on commissioning, 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
What does septic tank installation involve?
Septic tank and on-site wastewater installation installs the tank, the drainage and the land application or disposal area that treats and disposes of wastewater on site at unsewered properties. It combines the sanitary drainage with the excavation for the tank and disposal area, the heavy tank placement, and the protection of the environment and water sources.
What excavation hazards apply?
Installing the tank and disposal area requires excavation, which can collapse and strike services, so existing services are located and protected first and the excavation controlled to the excavation Code of Practice with shoring, with a SWMS where it reaches the regulated depth. The excavation controls prevent collapse and service strikes.
How is the heavy tank placed?
The heavy septic tank is placed using mechanical lifting and the correct method on an adequate base, controlling the crush and manual-handling hazard. Managing the manual handling of the heavy tank and providing an adequate base are important parts of the installation, alongside the excavation controls.
How is the environment protected?
The system is installed to AS/NZS 1547 and the local authority's approval so the wastewater is treated and disposed of on site without harming the environment or water sources, with the disposal area set back as required. Protecting the environment and any water sources is a key requirement of on-site wastewater installation.
Who installs a septic system?
Septic and on-site wastewater installation is licensed work carried out by a licensed drainer to AS/NZS 1547 and AS/NZS 3500.2 and the local authority's approval, with the excavation, manual-handling, biological, confined-space and environmental controls. The system, treatment and disposal are confirmed on commissioning.