Landscaping Irrigation Safe Work Method Statement

Irrigation installation licensing requirements vary by state but generally require licensed plumbers for water supply connections and backflow prevention device installation. In most Australian jurisdictions, connection to potable water supply (mains water) must be conducted by licensed plumber holding appropriate class of plumbing licence. This includes installation of backflow prevention devices which are mandatory under plumbing codes preventing contaminated water siphoning back into potable supply. Backflow devices must be tested by licensed testers and registered with water authorities in most areas. The irrigation system installation downstream of backflow device (pipes, valves, sprinklers) can often be conducted by non-licensed irrigation technicians or landscapers, though some states require specific irrigation contractor licensing or certification. Electrical connections for irrigation controllers fall under electrical regulations - 240V mains power connections must be conducted by licensed electricians holding A-grade or equivalent electrical licence. Low-voltage (24V AC) wiring from controller to valves generally does not require electrical licence but must comply with wiring standards. Some water authorities impose additional requirements including approved contractor lists, connection permits, metering requirements, and water efficiency standards that must be met. PCBUs engaging irrigation contractors must verify appropriate licensing before permitting work, maintain copies of licence documentation, and ensure work complies with relevant plumbing and electrical standards. Penalties for unlicensed plumbing or electrical work include fines, liability for defective work, insurance policy voidance, and potential prosecution for serious breaches.

All irrigation installation requiring excavation must commence with Dial Before You Dig enquiry contacted minimum two business days before work starts. Contact via phone (1100) or online portal providing accurate work location using street address, lot/DP number, site plan or aerial photograph marked with proposed work area. The enquiry generates automated notification to all asset owners (electricity, gas, water, telecommunications, transport authorities) who provide service plans showing infrastructure locations in the work area. Plans received show indicative locations only with actual positions potentially varying several metres from shown locations particularly for older infrastructure. Upon receiving plans, review carefully identifying all services noting type, depth, and location information. Engage qualified service locator with electromagnetic cable and pipe locating equipment to verify actual service positions on ground before excavation. Cable locators detect electrical cables and some metallic pipes but cannot detect all service types including non-metallic water and sewer pipes which require different detection methods. Mark verified service locations on ground using appropriate colour coding per AS 5488: red for electrical, yellow for gas, blue for water, orange for telecommunications. Photograph marked services providing record of pre-work conditions. During excavation, maintain 500mm minimum clearance from marked services when using mechanical equipment. Within 500mm zone, use hand tools only (shovels, spades, no powered equipment) allowing tactile feedback if services contacted. If unexpected services are encountered - immediately cease excavation, secure the area preventing further disturbance, contact Dial Before You Dig or emergency service contact number on plans for guidance, engage qualified service locator to identify the service type, contact the relevant asset owner for advice on safe working procedures, and do not proceed until authority approval received. Never attempt to work around, over, or remove unknown services as this creates extreme safety and liability risks. For damaged services during excavation, implement emergency procedures: electrical contact requires immediate site evacuation and emergency services call, gas leaks require evacuation, ignition source elimination, and emergency services notification, water or sewer damage requires immediate reporting to relevant authority. Document all service encounters and authority contacts providing evidence of compliance with due diligence requirements.

Irrigation system pressure testing requires systematic procedures balancing need for thorough leak detection with worker protection from stored pressure energy hazards. Before pressurisation, conduct comprehensive visual inspection of all joints, fittings, connections, and pipe runs checking for proper solvent cement application showing excess cement squeeze-out around joints, correct fitting orientation and positioning, adequate pipe support preventing joint stress from pipe weight or soil pressure, and absence of obvious defects including cracks, gaps, or missing components. Install calibrated pressure gauge with range exceeding test pressure (typically 0-1000 kPa gauge for residential systems) providing accurate pressure monitoring. Use manual hand pump or controlled water source allowing gradual pressure increase - rapid pressurisation can cause sudden failures before workers can evacuate safely. Establish exclusion zone minimum 5 metres radius around all pressurised components including mainlines, laterals, valve assemblies, and test point preventing worker exposure during pressure hold period. Increase pressure gradually to 50% of target test pressure (typically test at 1.5 times normal operating pressure meaning 50% increment is 75% of normal operating pressure), hold for 5 minutes observing gauge for drops and visually inspecting for obvious leaks or weeping joints. If stable, increase to 75% of test pressure, hold and inspect. Finally increase to 100% test pressure and maintain for specified duration typically 1-2 hours per specification or manufacturer recommendations. Monitor pressure continuously during hold period - significant pressure drop (typically more than 50 kPa over test period) indicates leaks requiring investigation. Maintain exclusion zone throughout test - never approach pressurised systems even to observe suspected leaks. After successful pressure hold, release pressure slowly and completely before approaching system to verify and inspect. If leaks found, mark locations, assess cause, release pressure, conduct repairs (re-glue joints, replace fittings, repair pipe damage), allow adequate cure time for repairs, then repeat pressure test to verify. For failed fittings during test causing blowouts, assess cause which may include inadequate cleaning before gluing, insufficient cement application, inadequate cure time before pressurising, wrong fitting type or specification, or excessive pressure from water hammer or surge. Never bypass pressure testing to save time as undetected leaks cause ongoing water waste, pressure loss affecting system performance, and potential erosion or property damage from leaks in concealed locations discovered only after problems develop.

Valve pits and underground irrigation infrastructure may constitute confined spaces triggering specific regulatory requirements under Work Health and Safety Regulations. A confined space is defined as enclosed or partially enclosed space that is not designed or intended primarily as workplace, is entered only for specific purpose, and may have atmospheric hazards, engulfment risks, or configuration preventing easy escape. Irrigation valve pits exceeding approximately 1.2m depth with restricted entry opening (typically 600-750mm diameter access) potentially meet confined space classification requiring formal assessment. Conduct confined space assessment considering depth, entry/exit configuration, potential for hazardous atmosphere development from organic decomposition, flooding risk, structural stability, and work to be performed. If classified as confined space, implement comprehensive entry controls: obtain confined space entry permit documenting atmospheric testing results, isolation procedures, emergency equipment, communication protocols, and authorised personnel. Conduct atmospheric testing before every entry using calibrated multi-gas detector measuring oxygen percentage (must be 19.5-23.5%), combustible gases (must be below 5% lower explosive limit), carbon monoxide and hydrogen sulphide (must be below 10ppm), and any other anticipated contaminants specific to site conditions. If testing indicates deficiencies, implement mechanical ventilation using portable blowers introducing fresh air before and during entry. Provide personal gas monitors for entrants with alarms set for hazardous conditions allowing immediate evacuation if atmosphere deteriorates. Station competent standby person at pit opening maintaining continuous communication with entrant, monitoring conditions, preventing unauthorised entry, and capable of initiating emergency retrieval without entering space themselves. Provide and require use of harnesses with retrieval lines attached to mechanical retrieval system (tripod and winch) positioned over entry allowing victim extraction without rescuer entry. Ensure adequate lighting eliminating hazards from poor visibility. Install permanent access ladder or steps in pits used frequently providing safe climbing rather than relying on edge grip or jumping. Isolate irrigation system and electrical controls preventing inadvertent valve operation or energisation during entry work. Train all personnel in confined space hazards, entry procedures, emergency response, and use of required equipment with competency documented and current. For shallow pits or boxes not meeting confined space classification, still implement precautions including atmospheric testing if organic materials or flooding present, adequate lighting and ventilation, and positioning of ladder or step stool providing safe access. Never enter pits during or immediately after rainfall when drowning risk exists from accumulation or if pit shows signs of instability including cracked walls, loose soil, or undermining.