Stump Grinder Operations SWMS

Stump grinder operations involve high-speed rotating cutter wheels removing timber stumps below ground level, generating significant projectile, noise, vibration and underground service strike risks. Self-propelled and tow-behind units operate cutter teeth at tip speeds exceeding 60 metres per second, capable of ejecting wood chips and stones beyond 15 metres if exclusion zones fail. Because the work involves powered mobile plant with energy sources capable of causing crushing or laceration injuries, and routinely occurs near buried electrical, gas, water and telecommunications assets, it falls within High Risk Construction Work under WHS Regulation 2025 Schedule 1. A documented Safe Work Method Statement is therefore mandatory before work commences, must be prepared in consultation with operators, and must be available at the workplace for the duration of the task. This SWMS addresses BYDA underground service verification, projectile exclusion zone management, hearing and face protection, machine guarding, and emergency shutdown procedures aligned with AS 2727 and the Amenity Tree Industry Code of Practice.

Hazards identified

7 hazards covered, sorted by priority.

Control measures

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

1. 1Elimination — Where stump location, soil conditions or proximity to services make grinding unsafe, eliminate by selecting chemical stump treatment or excavation removal instead.
2. 2Elimination — Remove all loose stones, metal stakes, fencing wire and concrete fragments from the stump zone before commencing to eliminate projectile sources.
3. 3Substitution — Substitute petrol units with battery-electric or hydraulic remote-controlled grinders on confined or noise-sensitive sites to reduce noise, fumes and operator vibration exposure.
4. 4Engineering — Obtain BYDA referral response, pothole all services within two metres, and fit OEM cutter wheel shrouds and chip deflector curtains before starting.
5. 5Engineering — Use radio-remote controlled grinder where available to remove operator from projectile zone, and ensure dead-man control and emergency stop function tested pre-start.
6. 6Administrative — Establish and barricade a minimum 15-metre exclusion zone with hi-vis fencing and signage, with spotter stationed to intercept public entry per AS 2727.
7. 7Administrative — Conduct documented pre-start inspection, BYDA plan review and toolbox talk recorded against this SWMS with all operators and ground crew signed on before work.
8. 8Administrative — Limit continuous operating time to 50 minutes per hour with rotation between operators to reduce noise dose and hand-arm vibration exposure below ESL.
9. 9PPE — Full face shield to AS/NZS 1337.1 worn over safety glasses, Class 5 earmuffs to AS/NZS 1270, AS/NZS 2210.3 protective footwear and cut-resistant gloves.
10. 10PPE — High-visibility long-sleeve clothing to AS/NZS 4602.1, anti-vibration gloves to AS/NZS 2161, and P2 respirator when grinding in dry dusty soil conditions.

Applicable Codes of Practice

High-Risk Construction Work triggered

Worked example

On a suburban verge stump removal job for a local council streetscape upgrade, the crew leader arrives with a self-propelled 27hp grinder to remove four eucalypt stumps adjacent to a footpath. At the pre-start tailgate, she opens this SWMS on a ruggedised tablet and walks the two operators and the spotter through the hazard register. The BYDA response is cross-checked against the printed site plan — a Telstra conduit runs 800mm from stump three, so she marks that stump for hand excavation rather than grinding, applying the elimination control. The team sets out hi-vis bunting at the 15-metre exclusion radius, positions the spotter at the footpath entry, and each worker signs the SWMS register confirming they have read the controls and hold current ticket. Mid-task, a parent with a pram approaches the bunting. The spotter activates the dead-man stop, the cutter wheel halts within two seconds, and the operator waits until the public has cleared before resuming. The supervisor notes the interruption in the SWMS dynamic risk log, increases the spotter coverage to two persons for the remaining stumps near the school crossing, and re-briefs the crew. At job completion the signed SWMS, BYDA receipt and inspection record are uploaded to the council compliance portal.

Related legislation

• WHS Act 2011 (model)
• WHS Regulation 2025
• AS 4373 — Pruning of amenity trees; AS 2727 — Chainsaw safety