Plans are a starting point
A service may be missing from plans, have been diverted or lie at a different depth after ground levels changed. Connections to lighting columns, buildings or equipment may also be absent. A blank area on a drawing does not demonstrate that excavation is safe.
Obtain information from service owners and compare records with the actual site. Chambers, valves and repaired road surfaces provide clues but are not conclusive identification. The person responsible must resolve discrepancies before authorising progress and keep relevant information available to the people carrying out the work.
Locate and identify
Detection requires people trained in the equipment and its limitations. A locator does not necessarily detect every material or installation arrangement. Non-metallic pipes may require complementary methods; the absence of a signal cannot be treated as proof that there is no buried service.
Mark the identified route clearly and confirm it through the planned investigation procedure. Traffic or earthmoving can erase markings. Shift changes and new contractors require communication of what has been found and what remains uncertain, rather than assuming everyone has seen the same plans or survey results.
Control the excavation method
The method must suit the service, proximity and ground conditions, involving the owner where appropriate. There is no single clearance valid for every utility or tool. Using hand tools does not, by itself, remove the possibility of damaging a cable or pipe during exposure.
This topic complements stability and access controls covered in Excavations and trenches. Damaged cables can cause arcing and burns; pipes can release gas, pressurised water or other substances. Assessment must address both direct contact and consequences for neighbouring services, occupied buildings and surrounding structures.
If an unexpected service appears
Stop the affected work and obtain identification before proceeding. Report damage to the owner even when there is no visible leak or interruption; do not conceal it during backfilling. The plan must define notifications, area restriction and emergency response. Recording the actual position helps future work, but does not replace the checks that the next excavation will need or establish that other services are absent.
