Health and safety paperwork for drainlayers

The hazards that actually matter

Every trade has a long list and a short one. The short one is what the task documents have to deal with properly, because it is where the serious harm comes from.

Trench collapse

A cubic metre of soil weighs well over a tonne and a collapse happens without warning. Ground type, water, surcharge from spoil at the edge and vibration from plant all change the answer, and the support method is chosen before the dig. Benching, battering, shoring or a trench box, and a safe means of getting in and out within reach of where the person is working.

Underground services

Drainage runs cross everything else. Electricity, gas, fibre, water and existing wastewater, with plans that are an indication and not a location. Locate, pothole by hand near anything marked, and treat an unmarked find as live.

Confined spaces

Manholes, chambers, pits and large-diameter pipe. Atmosphere testing before and during entry, an entry permit, forced ventilation, and a rescuer outside who is equipped to do the rescue rather than to call for one. Sewer gas can be immediately fatal and is heavier than air in a chamber.

Biological exposure

Wastewater, sewage and contaminated ground carry gastrointestinal and respiratory infection and leptospirosis. Covered cuts, gloves, eye protection against splash, and washing before eating rather than at smoko's convenience.

Plant working alongside people

An excavator placing pipe while a person is in the trench bedding it. Slew radius, blind spots, agreed signals, and a rule about who may be in the trench while the machine is live.

Traffic and the public

Connections in the carriageway, open trenches across a footpath, and plates and barriers that have to hold overnight. Where the work affects a road, the road controlling authority's requirements apply.

Water, dewatering and drowning

Trenches fill, and a flooded trench hides what the walls are doing. Pumps, discharge that does not undermine the dig, and the recognition that water changes the support design.

Dust, cutting and manual handling

Cutting concrete and clay pipe releases silica, and pipe, bedding and chamber components are heavy items handled at the bottom of a hole.

What applies beyond the general duties

The Health and Safety at Work Act 2015 and the General Risk and Workplace Management Regulations 2016 apply to every business. These sit on top of them for this trade:

• Plumbers, Gasfitters and Drainlayers Act 2006, for authorisation to carry out or supervise drainlaying
• Health and Safety in Employment Regulations 1995, reg 26, notification of excavation deeper than 1.5 m and deeper than it is wide
• The New Zealand Guide to Temporary Traffic Management, and the road controlling authority's requirements where work affects a road

Competence and licensing

Drainlaying is restricted work and must be carried out or supervised by a person authorised by the Plumbers, Gasfitters and Drainlayers Board holding a current practising licence. A certifying drainlayer may work unsupervised and supervise others; a registered drainlayer works under supervision. On top of that, confined space entry requires its own training and a permit, excavator operation requires operator competence, and traffic management where the work affects a road is a qualified role.

Notifying WorkSafe

Excavation deeper than 1.5 m and deeper than it is wide requires 24 hours' notice to WorkSafe, which drainlaying reaches routinely rather than occasionally. Tunnelling, including thrust boring of any length a person could enter, is separately notifiable. The full list and its exclusions are in notifiable work: the 10 categories.

What a main contractor will ask you for

• Practising licence details for the authorised drainlayer, and who supervises whom
• A Task Analysis for each task: excavation, pipe laying, connections, chamber and confined space entry
• The trench support method, and the engineering behind it where the ground requires one
• Service location records and the method for digging near a marked service
• The confined space entry permit, atmosphere testing and rescue arrangement
• The traffic management layout where the work affects a road
• Sign-on sheets against each document

A document per task, not one for the job. The crew doing one task should not have to read past three others to find their controls, and a site manager checking one task should not have to either.

Where to start

If you are writing from scratch, how to write a Task Analysis sets out the order. If you have been asked for something and are not sure which document it is, which document do you need covers the difference between a site plan and a task document. Our prepared documents for this trade are the Drainlaying Task Analysis Pack, or single documents from the catalogue.

Sources

• Health and Safety at Work Act 2015, s22 (reasonably practicable), s34 and s36
• Health and Safety at Work (General Risk and Workplace Management) Regulations 2016, regs 5 to 8
• Health and Safety in Employment Regulations 1995, reg 26 (particular hazardous work requiring notice)
• Plumbers, Gasfitters and Drainlayers Act 2006, for authorisation to carry out or supervise drainlaying
• Health and Safety in Employment Regulations 1995, reg 26, notification of excavation deeper than 1.5 m and deeper than it is wide
• The New Zealand Guide to Temporary Traffic Management, and the road controlling authority's requirements where work affects a road
• WorkSafe New Zealand, Identifying, assessing and managing work risks

This guide is general information about New Zealand health and safety law as at the review date. It is not legal advice and it does not describe your site. Confirm what applies to you with WorkSafe New Zealand or your adviser.