Question: Our company is planning to carry out some excavation work and we need to identify any buried services. How can we do this?
Answer: Prior to any excavation work, it is essential to identify existing buried services in order to avoid unplanned contacts. Out of sight does not mean out of danger. Work must be well planned and implemented, with the buried services correctly identified to ensure safe working.
Start with a risk assessment, which should consider how the work is to be carried out; ensuring local circumstances are taken into account, including the location of buried services.
Accurate location of buried services is vital. Assistance should be sought from the relevant service provider, who will be able to provide information and plans detailing the positions and depths of cables and pipes. Present and previous site-users may also be able to provide information and site diagrams. Other indicators, such as hydrants, substations and manholes will provide useful clues. It must be remembered that plans and indicators may give a false picture, owing to unauthorised movement of services, etc.
Cable and pipe locators are useful tools for refined location work once the approximate route of a service is established. Various types exist, such as hum detectors (used for detecting electric cables via the magnetic field generated) and ground-probing radar. Persons using cable locators should be specially trained in their use.
The utilities now use a colour-coding system for buried services:
Older services are harder to distinguish and advice should be sought from the service provider. As a general rule, black cables should be regarded as electrical, and cast-iron and steel pipes should be treated as gas pipes, unless proven otherwise.
Before work commences, the position of the buried service should be marked on the ground using paint, or similar. Where there is uncertainty about a pipe’s position, particularly plastic pipes, hand-dig trial holes to confirm the location of the service, the type of service, and the condition of the pipe or cable. If possible, the buried service should be killed, or isolated. If this cannot be established before digging commences, always assume the service is live.
As part of the overall planning of the work, an emergency plan should be prepared. This will differ according to the service, but the main requirements are: to inform the appropriate service provider immediately; not to attempt repairs; to evacuate and isolate the area; to avoid touching plant and equipment (for example, electrical cables); and to ensure smoking is prohibited and that there are no naked flames present (for gas leaks).
Every care is taken in the preparation of these questions and answers, which are supplied by Croner Consulting, a trading division of WoltersKluwer(UK) Ltd. The information is correct at the time of going to press. However, the answers given can only address the general principles involved. Professional advice must be sought on any specific query or problem your business has relating to any issue or area raised.
DISCLAIMER
Every care is taken in the preparation of these questions and answers, which are supplied by Croner Consulting, a trading division of WoltersKluwer(UK) Ltd. Any advice or guidance contained herein is not to be taken as the official advice or guidance of IOSH or SHP/UBM. The information is correct at the time the answer was formulated and posted. However, the answers given can only address the general principles involved. Professional advice must be sought on any specific query or problem your business has relating to any issue or area raised.
