Utility Mapping & GPR Surveys UK

PAS 128 Utility Survey Methodology
Our approach follows the PAS 128 specification for underground utility detection, divided into four quality levels.

QL-D
A desktop review of available statutory utility records.

QL-C
Site reconnaissance to correlate records with visible surface features.

QL-B
On-site detection using electromagnetic locating and GPR to determine horizontal position and depth.

QL-A
Verification of utilities through trial holes, performed only where specifically scoped.

Utility Detection Equipment and Survey Process
We utilise a range of non-invasive technologies and survey techniques to locate buried services.

Equipment and methods include:
• Electromagnetic locators (EML)
• Signal transmitters
• Ground Penetrating Radar (GPR)
• Visual inspection of access points such as manholes and chambers
• Topographical pickup of detected routes and surface features

Detection success depends on local ground conditions, surface access, the construction materials of the services, and the quality of available records.

Utility Survey Deliverables
Following the site works, we provide a clear set of deliverables to support design and construction planning.

Typical outputs include:
• A clear survey report detailing findings
• Marked utility routes
• Information on confidence levels and quality categories
• A summary of survey limitations
• Site photographs where relevant
• CAD, DWG and PDF outputs when included in the agreed scope

Accuracy, Limitations and Safe Use
A utility mapping survey reduces the likelihood of striking buried services, but it does not provide a guarantee that every service has been identified. All detection technologies have limitations, and results are influenced by ground conditions, access and available records.

Safe systems of work, including appropriate permits, method statements and physical verification, remain essential before any excavation begins.

Frequently Asked Questions
What is a PAS 128 utility survey?
A PAS 128 utility survey is a structured approach to detecting and mapping underground utilities in the UK, with defined quality levels that describe how the data was obtained.

Can GPR find non-metallic utilities?
GPR can indicate some non-metallic services, including plastic or clay pipes, but detection is not guaranteed and depends on size, depth, contents, surrounding material, soil conditions and antenna frequency.

What information do you need before attending site?
We typically require a clear site boundary, any available utility records, information on site access and any known constraints such as working hours or traffic management.

What deliverables are available?
Standard deliverables include a written survey report and CAD-compatible plans, such as DWG and PDF files, showing the detected service routes and key features.

How quickly can a utility survey be arranged?
Survey dates depend on current workload and project locations. Please contact the office to discuss your programme and we will confirm the earliest available dates.