Underground Utility Detection

GPR can detect some non-metallic utilities when there is sufficient contrast between the target, trench backfill and surrounding material. Results depend on diameter, depth, material and ground conditions, so complementary methods and verification are often recommended.

Electromagnetic locating is effective for many conductive or traceable utilities while GPR can provide evidence of both metallic and non-metallic features. Combining methods reduces dependence on a single detection technique and improves interpretation confidence.

Traceable conductive cables can often be located using electromagnetic methods, and GPR may provide supporting evidence. A geophysical survey does not replace electrical isolation procedures, permits or safe excavation practices.

Depending on scope, deliverables can include field markings, CAD drawings, GIS-compatible data, X/Y/Z utility schedules, interpreted radar information, survey coverage plans and technical reports describing findings and limitations.

Depth is an estimate derived from the measured response and assumed or calibrated radar-wave velocity. Where depth is critical, it should be verified using appropriate physical exposure, trial pits or other project-approved methods.

No non-intrusive survey can guarantee detection of every buried object. Detection is affected by access, depth, target properties, interference and ground conditions. Reports should therefore state limitations and recommend verification where consequences are high.