Underground Utility Survey Mapping

Technics has been providing effective subsurface Utility surveys since 1999. In that time we have developed a reputable solution for a wide range of clients across multiple sectors.

Why choose Technics for your land, building or utility survey?

We understand the importance of determining the purpose of your survey right from the start of a project and this knowledge enables our team of project managers to tailor the methodology in line with industry specifications, including PAS 128, and provide cost effective solutions within your budget.

What is Underground Utility Survey Mapping?

We combine this knowledge with expertise in using the latest technology, including Ground Penetrating Radar (GPR) equipment, and we know how to overcome any limitations to ensure clients receive thorough, detailed and accurate results.

Technics uses the latest technology with expert methods to explore detectable features underground. With a suite of technology, including Ground Penetrating Radar and Electro-Magnetic Locators (EML), we can analyse reflected signals from structures, services, buried objects and layers beneath the ground. With statutory record plans, visual inspections of all lifted service covers on site – Technics creates an accurate plan of the subsurface environment in multiple formats including 3D.

With our Vacuum Excavation service, Technics can also expose utilities safely and efficiently to fulfil the PAS 128 specification quality level QL-A.

To find out more, download our Example Utility Survey.

What is underground utility survey mapping?

What are the benefits of Underground Utility Survey Mapping?

  • Reduce project planning time
  • Minimise risk
  • Gain confidence before excavation works
  • Comply with the health and safety regulation
  • Avoid surprises
  • Comply with BSI standard – PAS 128 Surveys

Project planning can be significantly reduced to minimise risk and in turn save money if all utilities are detected in advance of any below surface works.

A Utility Mapping Survey will provide you with the confidence to progress with your project and ensure there are ‘no surprises’.
Adhering to all health and safety regulations, this will also ensure you are following best practice for your company and your employees.

Identify ‘safe’ areas for excavation or confirm the safest route for proposed utilities.

To minimize the risk to your workers, neighbours and the public before any excavation works are undertaken.
The ability to check as-built information and verify that utilities were laid to specification.

Where can I find a specification of works for Underground Utility Survey Mapping?

Our industry has collaborated with international bodies to provide a detailed specification of works which will ensure surveys are carried out using skilled, experienced operatives to deliver a high standard of work to clients.

PAS 128

In 2014, Technics partnered with industry experts such as the Chartered Institute of Civil Engineers, Transport for London and the Highways Agency, to advise on how standardisation should and could be progressed. The result was the issuing of the new Publicly Available Specification (PAS) 128 by the British Standards Institution (BSI).

PAS 128 is aimed at practitioners; however it will also help clients to set the required level of Utility Survey to fulfil their criteria, with the added assurance that the correct process of detection, verification and location of utility assets has been adhered to. For more information on PAS 128, please click here.

TSA Guidance notes

The Survey Association (TSA) Technical committee produced ‘The Essential Guide to Utility Surveys’ several years ago. It was the first Utility Survey specification document in the UK. The objective was to enable clients to understand survey procedures and offer guidance on appointing the correct company to maintain the required high standard of professional competence. This very popular document has been downloaded over 4000 times. TSA is now in the process of updating the guide to align it with PAS128, the revised version will be issued by summer 2016.

How effective is Ground Penetrating Radar?

Ground Penetrating Radar (GPR) equipment transmits an Electro-magnetic/radio wave pulse into the ground at various frequencies, which are recorded on site. The signal is transmitted and then reflected back to the GPR unit, the quality of the signal in both directions can be dependent on the properties of the material it passes through. The recorded sections of scanned data (pictured below) are post-processed in the office. Each scan is assessed and analysed for any possible targets (services, anomalies and voids), these are then selected using specialist software and a highly trained surveyor. The output from this software is then integrated into the utility survey model and presented in a concise and easy to understand way.

GPR scan

GPR, unlike more traditional EMLs can pick up non-metallic objects and utilities in a completely non-intrusive way. This unique feature makes the use of GPR for Utility Surveys almost mandatory in an industry that is increasing its use of plastic piping on utilities.

GPR has more uses than just mapping utilities, with the right equipment and expertise it can be used for the following; pavement/bridge/roadway inspection, void detection, concrete slab analysis, rebar mapping, verifying as-built information of concrete walls and floors. To use this specialist tool effectively in so many ways has taken years of development and different GPR systems from the main industry manufacturers such as GSSI, IDS, IDS Stream EM and RadarTeam.

How Technics overcomes GPR limitations

Even though Ground Penetrating Radar is an incredible tool in mapping underground features, it does have the drawback of not being able to accurately identify utility type. This is why the Technics layered and modular approach to utility surveys combines GPR, EML, visual inspection and records to produce the best subsurface mapping information possible without digging. To help complement this further, Technics now employ a vacuum excavation service. This enables us to expose the utilities to provide an accurate visual of their type, depth and position.

To discuss your project with us, please call one of our offices and speak to our Project Management team or email enquiries@technicsgroup.com