Sewer Manhole / Pit Construction & Lid Replacement SWMS
Safe work method statement for the construction and reinstatement of sewer manholes and access chambers including confined space, traffic management, and connection to live sewer mains.
SWMS variants reference your state’s WHS legislation. Instant download after payment.
Sewer manhole construction covers the construction of sewer maintenance holes (manholes) and access chambers — excavating, constructing or placing the chamber, connecting it into the sewer, and completing the access structure. It is civil-plumbing work that combines deep excavation, confined space entry into the chamber and the connecting sewer, the biological and atmospheric hazards of the live sewer, the manual handling and placement of heavy precast components, and connection to the network. This document is written on the basis that sewer manhole construction is carried out with the deep excavation supported, the confined-space and biological hazards controlled, and the heavy components placed mechanically.
Sewer manhole construction is carried out in connection with AS/NZS 3500.2 and the network utility's requirements. The work involves deep excavation controlled to the excavation Code of Practice with existing services located first, confined space entry into the chamber and the connecting sewer with its toxic and flammable gases, and the placement of heavy precast chamber components. This document coordinates the excavation, confined-space, biological, manual-handling and connection controls so the manhole is constructed safely.
Hazards identified
9 hazards covered, sorted by priority.
Burial and crush injury from collapsing deep excavation walls
Oxygen deficiency, toxic and flammable gases and restricted egress
Poisoning or fire from sewer gases in the chamber and sewer
Infection from contact with sewage during the connection
Crush and musculoskeletal injury placing heavy chamber components
Electrocution, gas release or service damage where services are not located
Engulfment and contamination from flow or surcharge during the work
Trench instability and working in water in the excavation
Crush and run-over injury where plant and workers are not separated
Control measures
Hierarchy-of-controls order: elimination → substitution → isolation → engineering → administrative → PPE.
- 1Engineering: control the deep excavation for the manhole to the excavation Code of Practice with shoring, benching or battering and ground assessment, with existing services located first and a SWMS for the excavation.
- 2Administrative: apply the confined space entry permit, atmospheric testing for oxygen, hydrogen sulphide and methane, ventilation, standby and rescue controls to the chamber and connecting sewer to the confined spaces Code of Practice.
- 3Administrative: manage the biological hazard from the live sewer with hygiene controls, washing facilities and protective clothing, and prohibition of eating, drinking and smoking until decontaminated.
- 4Engineering: use mechanical lifting and rated equipment to place the heavy precast chamber components, controlling the crush hazard.
- 5Engineering: control surcharge and flow from the live sewer during connection so the work is carried out without engulfment, and connect the manhole to the network correctly to AS/NZS 3500.2.
- 6Engineering: manage water ingress in the deep excavation, and maintain plant-and-pedestrian separation with a spotter.
- 7Engineering: locate, prove and protect existing underground services before any ground penetration using plans, Dial Before You Dig information, a service locator and potholing, so services are not struck.
- 8Administrative: ensure the work is carried out and certified by an appropriately licensed plumber or drainer under the relevant state or territory plumbing 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) before entering any construction workplace, with the plumbing, excavation, confined space and any other competencies and licences required for the work.
- 10Administrative: conduct a daily 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 sanitary plumbing and drainage standard for the sewer manhole and its connection to the network.
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.
Controls for the plant and equipment used in the work, including guarding and plant-and-pedestrian separation.
The risk management process and hierarchy of controls applied to the hazards of the work.
High-Risk Construction Work triggered
Sewer manhole construction requires deep excavation greater than 1.5 metres, which is high risk construction work requiring a SWMS before the work commences.
Entry into the manhole chamber and the connecting sewer is work in a confined space with a contaminated or flammable atmosphere, which is high risk construction work requiring a SWMS before the work commences.
This is licensed plumbing, drainage 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; and in or near a confined space — 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, the excavation, confined space and pressure-equipment requirements, and the relevant utility requirements, which are called up by the relevant legislation, with the excavation, confined-space, electrical, pressurised-pipe or work-at-height controls applied as relevant. A failure in this work can cause burial, an atmospheric incident, a service strike, a loss of containment or serious injury, 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 and civil contractors constructing sewer manholes.
- →Drainage and civil crews placing manhole chambers and connecting to sewers.
- →Plumbing and civil businesses providing sewer manhole construction.
- →Network utilities, developers and PCBUs requiring sewer manholes.
- →PCBU safety managers and supervisors coordinating the excavation, confined-space 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 sewer manhole construction hazards — each with a documented consequence, inherent risk rating on a 5x5 likelihood-consequence matrix, hierarchy-of-control measures, and residual risk rating.
- ✓Sewer manhole construction prompts referencing AS/NZS 3500.2, a deep-excavation control section, a confined-space chamber-and-sewer section, and a precast-placement and connection record.
- ✓Licensing, competency and permit prompts for the relevant plumbing, excavation, 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 civil drainage crew is engaged to construct a sewer manhole and connect it into the live sewer. Existing underground services are located, proved and protected before excavation, and the deep excavation for the manhole controlled to the excavation Code of Practice with shoring and ground assessment, with a SWMS prepared. Entry into the chamber and the connecting sewer is carried out under a confined space entry permit, with atmospheric testing for oxygen, hydrogen sulphide and methane, ventilation, standby and rescue controls. The biological hazard from the live sewer is managed with hygiene controls, washing facilities and protective clothing. The heavy precast chamber components are placed using rated mechanical lifting, controlling the crush hazard. Surcharge and flow from the live sewer are controlled during connection so the work is carried out without engulfment, and the manhole connected to the network to AS/NZS 3500.2. Water ingress in the excavation is managed, and plant-and-pedestrian separation maintained. The manhole is constructed and connected, 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 excavation, confined space and pressurised-pipe provisions where applicable, as enacted in each jurisdiction.
- The relevant plumbing and drainage standards AS/NZS 3500 (Parts 0–5), the excavation and confined space Codes of Practice, the pressure equipment and pipework standards, and the silica Code of Practice where cutting concrete, are called up by the relevant legislation, together with the Before You Dig Australia information and the relevant utility requirements.
- Plumbing and drainage work is licensed under each state and territory's plumbing licensing scheme, with the relevant competencies for excavation, confined space and 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, excavation and confined space provisions applying in place of the model instruments.
Frequently asked questions
What does sewer manhole construction involve?
Sewer manhole construction constructs a sewer maintenance hole or access chamber — excavating, constructing or placing the chamber, connecting it into the sewer, and completing the access structure. It is civil-plumbing work that combines deep excavation, confined space entry into the chamber and sewer, and the placement of heavy precast components, connected to the network.
What confined space hazards apply?
Entry into the manhole chamber and the connecting sewer is work in a confined space that can be oxygen-deficient or contain toxic hydrogen sulphide and flammable methane from the live sewer. The confined space entry permit, atmospheric testing for those gases, ventilation, standby and rescue controls apply, and the work is high risk construction work requiring a SWMS.
What excavation controls apply?
Sewer manhole construction requires deep excavation, which is controlled to the excavation Code of Practice with shoring, benching or battering and ground assessment, with existing services located first and a SWMS prepared. Water ingress is managed and plant-and-pedestrian separation maintained around the deep excavation.
How are the heavy precast components placed?
The heavy precast chamber components are placed using mechanical lifting and rated equipment, controlling the crush and manual-handling hazards. Using rated lifting equipment and a planned lift ensures the heavy components are placed without injury, which is one of the main hazards of manhole construction.
How is the live sewer managed during connection?
The live sewer can surcharge or flow during connection, so the flow and surcharge are controlled so the work is carried out without engulfment, and the biological hazard managed with hygiene controls and protective clothing. The manhole is connected to the network correctly to AS/NZS 3500.2, with the confined-space controls applied for the connecting sewer.