About this service
PAS 128 compliant underground utility surveys combining electromagnetic locating and GPR to map buried services before excavation, groundworks or borehole installation. We deliver Quality Levels B, C and D — from desktop records to full detection and verification surveys — providing the evidence needed for safe excavation and infrastructure planning.
What is PAS 128?
PAS 128 is the British Standard for underground utility detection, verification and location. It defines four Quality Levels (D, C, B and A) that describe the increasing rigour of the investigation — from desktop records review (D) through to intrusive verification (A). Most pre-excavation surveys are commissioned to Quality Level B, which combines electromagnetic locating and GPR to detect and map buried services. We deliver Quality Levels B, C and D and can advise on the appropriate level for your project.
Utility Surveys Before Excavation and Groundworks
Striking a buried utility during excavation can cause serious injury, project delays and significant cost. A PAS 128 utility survey identifies the location and depth of gas mains, water mains, electricity cables, telecoms ducts and drainage runs before any ground is broken. We produce CAD drawings showing the detected services overlaid on a site plan, giving your team a clear picture of what lies beneath.
What we cover
- Quality Level B detection surveys
- Quality Level C & D records
- Electromagnetic locating
- GPR utility mapping
- Borehole & excavation clearance
- CAD utility drawings
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Call or email us for a fast, no-obligation response.
Frequently asked questions
- What is a PAS 128 utility survey?
- PAS 128 is the British Standard for underground utility detection, verification and location. A PAS 128 survey uses electromagnetic locating and GPR to detect buried services and maps them to a defined quality level. Quality Level B is the most commonly specified level for pre-excavation surveys and involves both EM locating and GPR scanning.
- What Quality Levels do you deliver?
- We deliver Quality Levels B, C and D. Quality Level D is a desktop study of available utility records. Quality Level C adds a site walkover to verify surface features. Quality Level B adds electromagnetic locating and GPR scanning to detect buried services. Quality Level A (intrusive verification) can be arranged in conjunction with a groundworks contractor.
- Can GPR detect all buried utilities?
- GPR detects utilities by the contrast between the pipe or cable and the surrounding ground. It is effective on most metallic and non-metallic services but can struggle in heavily reinforced ground, wet clay or areas with dense existing services. Electromagnetic locating is used alongside GPR to improve detection rates for metallic services. No survey method guarantees 100% detection of all buried services.
- How quickly can you mobilise for a utility survey?
- We can typically mobilise within 24–48 hours for sites in London and the South East. For larger or more complex surveys, we will agree a programme with you in advance. Contact us with your site details and required Quality Level and we will confirm availability.
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Verified supply chain accreditation
SSIP Accredited
Health & safety pre-qualification
20+ Years Experience
Structural NDT specialists since 2003
Typical 24-Hour Response
Fast turnaround on quotes and bookings
Need a survey?
Call 07340 549892 or get a quote within 24 hours.