Water Jetting Drains Safe Work Method Statement

Equipment operating pressure depends on drainage material, blockage type, and pipe condition. For PVC and modern plastic drains with general debris blockages, 2,000-3,000 PSI is typically adequate and reduces pipe damage risk. For tree root cutting in concrete or earthenware drains, 3,500-4,000 PSI provides effective cutting while maintaining control. For severe grease blockages particularly in commercial kitchen drains, 3,000-4,000 PSI combined with hot water (if equipment capable) delivers best results. For older fragile pipes or pipes in unknown condition, start with lower pressure (2,000 PSI) and increase only if clearing is ineffective. Never exceed equipment maximum rated pressure. Always select nozzle appropriate for blockage type and adjust pressure based on clearing effectiveness and water return flow. If blockage does not clear with sustained jetting at appropriate pressure, consider alternative methods such as mechanical cutting or pipe replacement rather than continuing to increase pressure which may damage pipes or create safety hazards.

If hose becomes stuck, immediately shut down equipment and release all pressure from the system. Never attempt to force stuck hose by increasing pressure or pulling forcefully—this can damage both hose and drainage system. First, verify pressure is completely released by checking gauge reads zero. Gently attempt to rotate hose while pulling slowly to determine if it is kinked or snagged. If hose is accessible at entry point, carefully pull hose back a short distance, then feed forward again attempting to work past obstruction. If hose remains stuck, consider using CCTV camera to inspect pipe and locate snagging point. In some cases, accessing pipe from alternative point downstream may allow hose retrieval. For severe snags, excavation to access pipe at stuck point may be necessary. Prevention is critical—avoid forcing hose around sharp bends, never exceed pipe capacity with over-sized nozzles, and monitor hose feeding constantly noting any unusual resistance. If clearing difficult blockage, withdraw periodically checking hose is free rather than continuing to feed until stuck.

Plumbers regularly conducting water jetting operations should have comprehensive vaccination coverage including hepatitis A (two-dose series providing long-term protection against this sewage-borne virus), hepatitis B (three-dose series with blood test confirming immunity development), tetanus (booster every 10 years to maintain protection, with immediate booster if deep contaminated wound occurs), and consideration of typhoid vaccination for workers in areas with known issues. Beyond vaccinations, health monitoring should include baseline health assessment before commencing sewage work documenting any pre-existing conditions, education on disease symptoms particularly leptospirosis, hepatitis, and gastroenteritis, requirement for workers to report any potential exposure incidents or concerning symptoms, and medical assessment for any significant sewage exposure or development of symptoms. Employers must maintain confidential health records documenting vaccination status and any exposure incidents. Workers should be aware leptospirosis symptoms include sudden fever, severe headache, muscle pain, chills, and jaundice typically appearing 5-14 days after exposure, requiring immediate medical attention. Any worker developing symptoms after sewage exposure should inform medical practitioners of sewage contact as this influences diagnosis and treatment.

Water jetting can be performed by a single operator in specific circumstances with appropriate controls, but working alone increases risks significantly. Lone worker considerations include ensuring someone knows worker location and expected duration, regular check-in procedures to confirm worker safety, immediate access to communication device for emergency assistance, and increased attention to hazard management since assistance is not immediately available. However, water jetting should never be performed alone if confined space entry is required—this mandates standby person maintaining communication with worker in space. Similarly, if working in isolated locations, at heights, or in other high-risk conditions, two-person teams provide critical safety backup. For routine residential drain clearing from ground level access points, single operator work is acceptable provided communication and check-in procedures are established. Operators working alone must be particularly diligent with equipment inspection, pressure isolation procedures, and maintaining safe work positioning since no one is present to intervene if unsafe practices develop. Equipment should include dead-man controls ensuring automatic shutdown if operator loses control. Employers must assess lone worker risks and implement appropriate controls per WHS legislation requirements.

Water jetting creates multiple public hazards requiring effective exclusion zones and controls. Establish physical barriers preventing public access to work area—witches hats and tape are insufficient for sewage-contaminated areas where children may be present. Use temporary fencing or solid barriers creating clear separation. Position barriers to account for splashback reach and hose routing—minimum 3 metre exclusion zone around active jetting point, extending to 5 metres if significant splashback occurs. Install appropriate signage at barriers warning of sewage contamination and construction hazards in plain language. For work in driveways or footpaths, position barriers to maintain safe pedestrian access away from work area. Coordinate with property occupants ensuring they understand work area restrictions and timing. For work in shopping centres or commercial premises, coordinate with management regarding appropriate barriers meeting building fire safety and access requirements. High-visibility clothing helps public identify workers. Schedule high-disruption work to minimise public exposure—early morning or after-hours for commercial areas. Control water discharge preventing contaminated water flowing into public areas—use temporary bunding or wet vacuum to contain discharge. At completion, thoroughly clean work area removing sewage contamination before reopening to public. Consider signage warning of recent sewage work if residual contamination possible.

Water jetting equipment requires rigorous maintenance to prevent failure causing serious injuries. Implement scheduled maintenance based on manufacturer recommendations and operating hours including pressure pump servicing at specified intervals typically every 100-200 operating hours, engine servicing per engine manufacturer specifications, and hydraulic system checks if applicable. Hoses require particular attention including replacement at maximum age regardless of visual condition (typically 3-5 years depending on UV exposure and use intensity), immediate replacement of any hose showing cuts, abrasions, bulging, or coupling damage, and pressure testing of hoses after any suspected over-pressure incident. Pressure gauges should be calibrated annually to ensure accurate pressure indication critical for safe operation. Safety systems including pressure relief valves must be tested monthly for correct operation. Maintain detailed equipment log recording maintenance performed, defects identified and rectified, operating hours, and any incidents or unusual occurrences. Equipment showing any safety system malfunction must be removed from service immediately until repaired and tested. Annual comprehensive inspection by qualified technician should verify all safety systems, pressure components, and structural integrity. Documentation of maintenance and inspection should be readily accessible to operators and available during WorkSafe inspections. Equipment depreciation and operating hours should guide retirement decisions—equipment subject to severe service should be retired conservatively before failure risk increases significantly.