Hydro Seeding Operations SWMS

Hydro seeding operations involve applying a pressurised slurry of seed, fertiliser, mulch, tackifier and water across prepared earthworks using a truck-mounted hydroseeder fitted with a centrifugal or piston pump. The work combines high-pressure discharge (typically 700-2,000 kPa at the nozzle), repetitive manual handling of 25 kg fertiliser and mulch bags, working at height on tank platforms, and movement around mobile plant on civil sites or batter slopes. Under WHS Regulation 2025, the activity is classified as construction work because it forms part of site revegetation contracts following earthworks, road formation or subdivision development. A documented Safe Work Method Statement is mandatory before work commences because the task triggers High Risk Construction Work categories under section 291, specifically high-pressure spray discharge and structural manual handling demands. The PCBU must consult workers during preparation, sign off the SWMS before mobilisation, and keep it available at the workface for the duration of the contract.

Hazards identified

7 hazards covered, sorted by priority.

Control measures

Hierarchy-of-controls order: elimination → substitution → isolation → engineering → administrative → PPE.

1. 1Elimination — Where slope and access permit, substitute hand-broadcast or drill seeding for small patches to remove pressurised slurry discharge entirely from the task scope.
2. 2Elimination — Pre-blend dry mulch and fertiliser at depot using mechanical hoppers so on-site loading of individual 25 kg bags onto the tank platform is eliminated.
3. 3Substitution — Replace granular ammonium-based fertilisers with lower-toxicity coated prills and use non-staining biodegradable tracer dyes per the product Safety Data Sheet.
4. 4Substitution — Specify low-pressure cannon nozzles (under 1,200 kPa) for flat terrain instead of high-pressure long-throw guns where coverage distance allows.
5. 5Engineering — Fit whip-checks, hose restraints and pressure relief valves on all discharge lines; pressure-test hoses quarterly to AS 2554 and tag inspection date.
6. 6Engineering — Provide fixed guardrailed loading platform with kickboards, grated decking and powered bag hoist on the hydroseeder to eliminate platform falls and lifting strain.
7. 7Administrative — Conduct documented pre-start brief using this SWMS, exclusion-zone the discharge arc to 15 metres, and rotate nozzle operators every 45 minutes to manage fatigue.
8. 8Administrative — Implement two-person loading rule, heat stress monitoring per the Managing Risks of Working in Heat CoP, and emergency hose-shutdown drills weekly.
9. 9PPE — Issue chemical-splash goggles to AS/NZS 1337.1, nitrile gauntlets, hi-vis long-sleeve coveralls, P2 respirator during dry loading, and AS/NZS 2210.3 safety boots.
10. 10PPE — Provide broad-brim hard hat attachments, SPF50+ sunscreen, and impact-resistant face shields for the nozzle operator during high-pressure discharge operations.

Applicable Codes of Practice

High-Risk Construction Work triggered

Worked example

On a regional highway upgrade, a revegetation crew mobilises a 6,000 L hydroseeder to stabilise a 1.5 km batter following bulk earthworks completion. At the 6:45 am pre-start, the leading hand opens the Hydro Seeding Operations SWMS on a site tablet and walks the four-person crew through each hazard line. The nozzle operator identifies that today's batter pitch (1V:2H) and an overnight rain event mean the access track is greasy, so the team selects the 'mobile plant on uneven slopes' control and repositions the hydroseeder on the compacted shoulder rather than the batter toe. The loader notes the fertiliser delivery arrived as 25 kg bags rather than the planned bulk hopper, so the SWMS manual handling control triggers the two-person lift rule and rotation every 45 minutes. Each worker signs the SWMS sign-on register, including the casual labour-hire operator inducted that morning. Mid-shift, wind picks up to 35 km/h and drift threatens the adjacent sealed carriageway. The supervisor pauses work, reopens the SWMS, and applies the documented 'exclusion zone and discharge arc' control by repositioning traffic cones and reducing nozzle pressure to 900 kPa. The change is annotated on the SWMS field-amendment page, re-signed by the crew, and photographed for the project HSE record before work resumes safely.

Related legislation

• WHS Act 2011 (model)
• WHS Regulation 2025
• AS 4373 — Pruning of amenity trees; AS 2156 — Walking tracks

Frequently asked questions