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Immediate Mobilisation, With Same Day Results*

Updated: Jan 31

Immediate Mobilisation, With Same Day Results

Locating Manholes you can’t even see with SUMO’s Engineering and Geo-Environmental surveys!

As part of our standard utility survey we lift every manhole and trace the contents in order to map the services that are running below your site, but what if the manhole is buried?

Our client Balfour Beatty was recently working on a housing site where two manholes were clearly shown on the original construction drawings, however there had apparently been technical issues with their location on site and they were subsequently repositioned. Unfortunately however, their new position was never updated on the site plans and to make matters worse, they were subsequently lost after being completely buried.

SUMO was asked to investigate the site and to deliver a solution to a very tight timescale:

  • Wednesday 10am – first contact with SUMO

  • Wednesday 11am – quote issued after telephone consultation with client

  • Friday – survey completed and initial findings marked out on site

  • Monday – client located both buried manholes and exposed one, without any problems

In order to achieve this result, a high density Ground Penetrating Radar (GPR) Survey was employed, taking readings every 8cm. The survey revealed two anomalies which did not correlate with any visible manholes on the ground, which were plotted on the site drawing issued to the client.

Plan view of the high density GPR data

Above: Example plan view of the high density GPR data, showing the location of one of the buried manholes and three manholes which were clearly visible to the naked eye on site.

SUMO also used a GSSI Dual Frequency GPR system (the data from which can be interpreted on site), to immediately reveal the location of one buried manhole in a time critical area. This was located through excavation the very next working day, meaning that there were no site delays whilst waiting for the data to be processed and interpreted. Site disruption was also kept to a minimum, as the excavation was highly targeted, saving on breaking grounding and reinstating multiple times, which would have been costly and time consuming.

Muried manholes

Above: Photograph taken on site by the clients after one of the buried manholes was exposed, clearly showing the depth of cover.


“Thanks to the team at SUMO who played a key part in identifying buried infrastructure at our site. Your GPR survey has been invaluable in helping unlock and drive forward the project to completion”

Edward Pearson, Design Manager, Balfour Beatty


SUMO offers a range of Engineering and Geo-Environmental surveys which can be employed at all stages of the construction process. We can also offer immediate mobilisation in most cases, meaning that you can get the survey results you need, without having to delay any site works.

*What’s more, we can often offer same day results, where on site interpretation techniques can be employed.

Whatever your issues, our team are here to offer a range of methodologies to investigate the ground below your site.

  • Air Raid Shelters

  • Badger Setts

  • Buried Fuel Tanks

  • Chimney Flues

  • Foundations

  • Ground Earthing

  • Mineshafts

  • Rebar

  • Sink Holes

  • Stray Current testing

  • Void Detection

So… if you want more than a standard utility survey, you know who to call!!!

Please pick up the phone and speak to Simon Haddrell or Richard Fleming on 01684 592266.
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