PAS 128 Utility Survey

Subscan UDS complete full PAS 128 Utility Survey for designers and contractors, producing detailed guides so everyone working on a project understands exactly what they are dealing with when preparing and working on a site. Our utility surveys allow workers to establish what buried obstacles they may face before coming across them, minimising costly delays from unknown obstacles.

It’s a legal requirement that before digging you should be aware of what is beneath the surface, ensuring there are no hidden surprises when you break ground. A hit gas main can not only be costly in terms of time and money, it can cause injury or worse. Subscan UDS use the latest detection techniques including Electromagnetic Detection, signal induced threading and Ground Penetrating Radar (GPR) to locate utilities.

  • Borehole/Trial Pit Excavation Clearance Surveys
  • Targeted Pipe/Cable/Utility Service Trace Surveys
  • Post Processing Underground Utility Trace Surveys
  • Pre/Post Demolition Underground Utility Surveys

Specialist detection & mapping

At Subscan our surveyors use a range of electromagnetic location methods, ground penetrating radar and visual inspection to provide utility mapping services to the highest standard. Each survey is presented in layered CAD models with an accompanying report ensuring you have all the information required to make informed, and safe, decisions on site.


We continually invest in the best equipment to allow us to offer you the very best levels of service. Our latest Ground Penetrating Radar can scan to a staggering 5 metres to ensure you get a more complete picture of the ground beneath your feet. Ground Penetrating Radar (GPR) is a form of non-destructive utility detection and can be used in a variety of materials including; rock, soil, ice, water and pavements. Electromagnetic radiation is used to transmit radar pulses below the surface. The GPR records the reflected signals to produce an image of the composition and location of sub-surface structures.

Quick Response

For contractors who are required to undertake excavation works at short notice, Subscan have a dedicated ad hock team who can be on site within 48 hours (location dependant) to locate and mark out underground utilities.

Subscan UDS offer different levels of survey. Please find below a brief explanation of each level of survey

  • Level D Survey – Desktop Utility Records Search
  • Level C Survey – Site Reconnaissance Survey
  • Level B Survey – Detection and Base Map Update
  • Level A Survey – Detection, Survey Location and Verification

Case Study

Wessex Water

Project type:
Underground utilities and topographical survey

Taunton, Somerset


Subscan were appointed by Wessex Water to carry out a full underground utilities and topographical survey to areas within Hinkley Nuclear Power Station and collate all information into one document.

Subscan were appointed by Wessex Water to carry out a full underground utilities and topographical survey to areas within Hinkley Nuclear Power Station.

This is an ongoing project due for completion on site Christmas 2018 and will be produced in a complete CAD DWG format with relevant PDFs. All high resolution photos from site and written day to day survey reports will be collated into one document by our surveyors and presented to the client on completion.

Client Testimonial

“The Subscan UDS team of surveyors and drainage engineers helped our minor works team out again and did a thoroughly professional job. We will continue to work with Subscan on LNE projects throughout the region.”

Lee Sanderson, Building & Civils Project Manager, Construction Marine Ltd