Repair job leads to fatal electrocution

A fatal incident currently being investigated by WorkSafe Queensland has underlined the dangers of working in proximity to underground cables, which might not always be obviously electrical in appearance.

In May 2023, a person was attempting to repair a water leak in an underground pipe. Early enquiries indicated that the person unearthed a black poly water pipe believed to be the water pipe that required repair, then cut into it using conduit shears.

While cutting the poly pipe, it appears the shears contacted the energised cable within, resulting in the person receiving a fatal electric shock.

While noting that these findings are not yet confirmed, and investigations are continuing into the exact cause, WorkSafe Queensland said the incident is a reminder that electrical cables may not always be correctly installed underground in orange electrical conduit or be compliant to installation safety standards.

The regulator advised that before digging, workers should:

• be aware that electric cables can be difficult to identify as sometimes they may be encased in other materials like concrete, steel or plastic pipe;
• look for the presence of underground electrical cables supplying buildings from the street or between buildings or to sheds, pools, garden lights, pumps etc;
• look for other signs of underground electric cables such as conduits and pipes on walls leading to the ground;
• look for changes in ground level over time such as ground levelling, which might indicate that underground electrical cables are located at a shallower depth than expected.
   

A voltage proximity detector (non-contact voltage checker) will provide an indication if voltages are present when dealing with underground pipes (for most situations).

The most common electrical risks and causes of injury associated with working near underground electric lines are:

• Electric shock
• Arcing, explosion or fire (arcing or explosion can occur when high fault currents are present)
• Electric shock from ‘step-and-touch’ potentials.
   

Examples of work that involves risk of contact with energised underground electric lines can include excavating a trench, digging fencing holes and driving posts or pegs.

For more information about electrical safety while digging, visit the WorkSafe website.

Image credit: iStock.com/MaYcaL