UNDERGROUND UTILITY SURVEYS

We use a combination of Electromagnetic location (EML), Ground Penetrating Radar (GPR), lifting inspection covers and visual inspection to trace utilities below ground including sewers, gas and water pipes, electricity, telecom and other cables. We also have in house drainage CCTV teams for more detailed drain investigations. We can carry out anything from a clearance survey to a full site investigation. Through our partners we are also able to offer traffic management for safe access to utilities in the highway.

We carry out surveys to the PAS128:2022 standard – the accuracy and the quantity of information you receive is determined by the type of survey carried out:

• Survey Type D: Desktop utility records search
  This is where underground utilities are approximately identified through the collation and analysis of existing paper and digital utility records via a thorough search of potential asset owners.
• Survey Type C: Site reconnaissance
  This is where existing records are supported and validated by the visual inspection of above-ground physical evidence observed or recorded during a site visit (e.g. manhole covers, stop valves, hydrants, junction boxes, marker posts and trench scars).
• Survey Type B: Detection
  This is where underground utilities are detected by geophysical techniques, visual inspection, metadata collection and are geospatially located. One of four methodologies (M1 to M4) is specified with the density of inspection grid increasing accordingly. Typically M1 would be used for an undeveloped greenfield site and M4 for a city centre road junction. The quality level for each utility length is recorded as B1 to B4 with B1 indicating horizontal and vertical location surveyed by multiple techniques through to B4 being a utility not detected but suspected to exist from other evidence. GPR data can be recorded and post-processed in the office in which case the quality level has a “P” suffix.
• Survey Type A: Verification
  This is where underground utilities are visually identified via a manhole or inspection chamber or are excavated and exposed.

Utilities can be marked up on-site and also added to a topographic survey plan and supplied as a 2D or 3D CAD file and PDF.

Speak to our team today to discuss your project. Simply fill in the form below or call 01473 211 222