Underground Utility Surveys

Trace and plot underground pipes and cables using RadioDetection RD8000 and IDS Opera Duo GPR equipment.
Read our FAQ on how we survey underground services.

Buried Utility Detection

Underground services and their locations can be a critical factor in any development – the cost and time scale factors in re-routing services or having non-existent services supplied can be the deciding factor on the viability of a scheme. We have many years experience and some of the best modern equipment to map these services without having to excavate.

Radio Detection

By using the latest Radio Detection (CAT type) equipment along with signal generators and plans supplied by the utility companies we can locate metal objects to provide details of the service locations and, if required, an estimate of depth.

Ground Penetrating Radar (GPR)

If pipes are made of non-metallic materials such as plastic or asbestos cement we use Ground Penetrating Radar which indicates the presence of services and voids by timing the radar signal reflected from the ground.

Please note:

Whilst we do our best to locate as many services as possible it is essential to note that it is not possible to trace all services on a site other than by physically exposing them. On sites which have a long history of different building phases and development or which are relatively restricted there are limitations due to the number of redundant services in the ground, the close proximity of different services, the number of times the ground has been disturbed and the degree to which the surface is obstructed. We would estimate that a 70-80% detection rate is probably the best anyone could achieve in this type of situation, with a detection rate of 90%+ on “Greenfield” sites. Whilst Radio Detection and Ground Penetrating Radar are very useful they both have their limitations, notably:

Radio detection

Can only trace metallic services unless a trace wire has been buried with non-metallic services.
Difficult to distinguish between services unless a positive trace signal can be applied at a stop valve or similar and even then signal can be transferred into adjacent pipes or cables.
Difficult to resolve signals within 1m of buildings, walls, parked cars etc.

GPR

Depth penetration limited to 3m and resolution is poor below 1.5m.
Resolution in made up ground, waterlogged ground or that which has been previously disturbed may be poor.
Unable to distinguish between services other than by size.
Unable to be used on very rough ground, in dense vegetation or close to obstructions.

Topographic Survey – The Cornhill, Ipswich

Description: Our brief was to survey the Cornhill, the current market place in Ipswich and the focal point of the town center, prior to a proposed regeneration of the area.

Survey type: Topographical survey of the square with special emphasis on the position and level of the surround building footprints.

Survey equipment: Leica reflectorless total station theodolite and Leica GNSS with Smartnet network RTK in order to provide control to Ordnance Survey national grid and level datum.

Completion time: 1 week.

Coastal Surveying

EDI Surveys has been involved with the Environment Agency’s coastal monitoring programme since 1991 and we are currently the holders of a 5 year contract to survey profile and grid surveys on the foreshore from Grimsby to Southend-on-Sea, approximately 400km of coastline.

The majority of the work involves the survey of level profiles along fixed transect lines from low water level to a point inland of the sea defence / cliff top or dune line, with these transects being spaced at intervals between 100m and 500m.

Using RTK GNSS survey units we take recordings of the locations position, height and ground covering type (i.e. grass, mud, sand etc) every few paces. Once back in the office the collected data is processed by software to create cross sections of the coast line. When this new data is laid over cross sections of the same coast line collected from previous years we can see a graphical representation of how our coastline is changing over time. This valuable information gives the Environment Agency data to create the defence polices needed to protect us from the risk of flooding and erosion.

Watercourse Surveys

We carry out a large number of watercourse surveys each year for the purposes of flood modelling and siltation assessment. Our main client for these projects is the Environment Agency but we also work for a number of consulting engineers and flood risk assessors. The surveys might be of anything from a dry ditch to the river Thames.

A recent project was the River Fynn here in Suffolk, a 12km long section of the watercourse from the village of Witnesham to the tidal Martlesham Creek on the river Deben. The survey requirement was to produce profiles of the watercourse at 100m intervals, profiles of all structures, a long section and digital data in ISIS and EACSD formats.