Underground Service Locating (DBYD/EM/GPR) SWMS
A Safe Work Method Statement for underground service locating covering all key hazards, controls and regulatory requirements.
SWMS variants reference your state’s WHS legislation. Instant download after payment.
Underground service locating and Dial Before You Dig covers the location, identification and marking of existing underground services before excavation — obtaining the Dial Before You Dig information, using electronic service locators and ground-penetrating equipment, and potholing to prove the position of services so they are not struck during the work. It is the foundational control that prevents service strikes, which can cause electrocution, gas release, explosion and serious injury. This document is written on the basis that service locating is carried out by a competent locator, with the services located, identified, proved and marked before any ground penetration.
Underground service locating is the process that underpins safe excavation under the excavation Code of Practice, which requires existing services to be located before excavation. It involves obtaining the Dial Before You Dig (Before You Dig Australia) information for the site, using electronic service locators to detect and trace services, and potholing — often by vacuum excavation — to physically prove the position and depth of services. The defining purpose is to prevent the strike of an energised cable, gas main or other service. This document coordinates the information, detection, potholing and marking controls so services are located and protected before the work.
Hazards identified
9 hazards covered, sorted by priority.
Electrocution and arc-flash from contacting an energised cable
Gas release, explosion or service damage from contacting a gas main
A service struck because it was not identified or located
Service strike where a service was not detected or marked
Excavation, high-pressure or plant hazards during potholing
Wrong assumptions about a service from misidentification
Being struck by traffic or plant while locating in the work area
Musculoskeletal injury from the locating equipment
A strike during excavation where located services are not protected
Control measures
Hierarchy-of-controls order: elimination → substitution → isolation → engineering → administrative → PPE.
- 1Administrative: obtain the Dial Before You Dig (Before You Dig Australia) information for the site before the work, and review the service plans and records for all services in the area.
- 2Engineering: use electronic service locators and ground-penetrating equipment to detect, trace and identify the services, and mark their position on the surface.
- 3Engineering: pothole — often by vacuum excavation — to physically prove the position and depth of services before the work, particularly near critical services such as energised cables and gas mains.
- 4Administrative: where a cable or gas main is located, apply the electrical and gas controls and safe approach distances, and treat unidentified services as live and hazardous until proven otherwise.
- 5Administrative: clearly mark and record the located services, communicate them to the excavation crew, and maintain the protection of located services throughout the subsequent excavation.
- 6Administrative: apply traffic and site controls while locating in the work area, separating the locator from traffic and plant.
- 7Engineering: use the potholing and excavation controls during potholing, and not rely on locating alone without ongoing care during excavation.
- 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
Trenching and excavation controls including support against collapse, ground assessment and existing services.
Electrical safety and safe approach distances where an energised cable is located.
The service information and plans obtained for the site before excavation.
The risk management process and hierarchy of controls applied to the hazards of the work.
Controls for the plant and equipment used in the work, including guarding and plant-and-pedestrian separation.
Who this is for
- →Competent underground service locators.
- →Service-locating and non-destructive excavation contractors.
- →Plumbing and civil contractors locating services before excavation.
- →Asset owners and PCBUs requiring services located before work.
- →PCBU safety managers and supervisors coordinating the locating, potholing and marking 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 underground service locating and dial before you dig hazards — each with a documented consequence, inherent risk rating on a 5x5 likelihood-consequence matrix, hierarchy-of-control measures, and residual risk rating.
- ✓Service locating prompts referencing the excavation Code of Practice and Dial Before You Dig, an information and electronic-locating section, a potholing and proving section, and a marking and protection 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 competent service locator is engaged to locate the underground services at a site before plumbing excavation. The Dial Before You Dig information is obtained for the site, and the service plans and records reviewed for all services in the area. Electronic service locators and ground-penetrating equipment are used to detect, trace and identify the services, and their position marked on the surface. The services are potholed by vacuum excavation to physically prove their position and depth, particularly near an energised cable and a gas main in the area. Where the cable and gas main are located, the electrical and gas controls and safe approach distances are applied, and any unidentified service treated as live and hazardous until proven otherwise. The located services are clearly marked and recorded, communicated to the excavation crew, and their protection maintained throughout the subsequent excavation. Traffic and site controls are applied while locating. The services are located and protected, 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 is Dial Before You Dig?
Dial Before You Dig (now Before You Dig Australia) is the service that provides information and plans about the underground services in an area before excavation. Obtaining the Dial Before You Dig information for the site is the first step in locating services, so that all services in the area are identified before any ground penetration.
Why is service locating so important?
Service locating is the foundational control that prevents service strikes, which can cause electrocution, gas release, explosion and serious injury. By locating, identifying, proving and marking existing services before excavation, the work can be carried out without striking an energised cable, gas main or other service, which is why it underpins safe excavation.
What is potholing?
Potholing is the physical proving of the position and depth of a located service by carefully exposing it, often by vacuum excavation, before the main excavation. Potholing confirms where a service actually is, particularly near critical services such as energised cables and gas mains, so the excavation can avoid it with certainty rather than relying on detection alone.
What happens when a cable or gas main is located?
Where an energised cable or gas main is located, the electrical and gas controls and safe approach distances are applied, and any unidentified service is treated as live and hazardous until proven otherwise. Treating located critical services with these controls ensures the excavation is carried out without striking them.
Does locating services once make excavation safe?
Locating services is essential, but the protection of located services must be maintained throughout the subsequent excavation, and ongoing care taken during the dig. The located services are clearly marked, recorded and communicated to the excavation crew, and not relied on without ongoing care, so a strike is prevented throughout the work.