Borehole Excavation Clearance

Before a borehole can go in, someone needs to be confident nothing’s in the way. Boreholes are typically drilled to a specific depth and location for a reason, whether that’s ground investigation, piling, monitoring wells or geotechnical testing, which means there’s usually little flexibility to simply move the position if a buried service turns out to be in the way. Confirming the ground is clear before drilling starts avoids the borehole having to be relocated, redesigned, or abandoned partway through.

Unlike a general excavation, a borehole is a fixed, narrow point of intrusion, often drilled to significant depth. This means there’s less margin to work around an unexpected utility than there would be with a wider excavation, where a service could sometimes be avoided by shifting the dig slightly. If a borehole position can’t be moved for engineering reasons, and there’s a live service beneath it, the drilling contractor needs to know before the rig arrives on site, not after.

Our surveyors use a combination of electromagnetic detection and GPR to check each proposed borehole location, adjusting the method to suit ground conditions and the type of services likely to be present. Electromagnetic detection traces live cables and metallic pipes, while GPR picks up non-metallic services and other subsurface features that electromagnetic methods alone would miss, similar to the non-intrusive approach used in our Virtual Trial Holes service. Where a site has multiple borehole positions, we clear each one individually rather than assuming uniform ground conditions across the whole site.

You’ll receive clearance confirmation for each borehole position, along with details of anything identified nearby that the drilling contractor needs to be aware of. This gives your geotechnical or drilling team the confidence to proceed with each position as planned, or the information needed to adjust a specific location if something is found where the borehole was due to go.

Subvision Surveys is SSIP and ISO accredited, and our team clears borehole positions for geotechnical contractors, drilling companies and site investigation teams across the UK, often as part of a wider ground investigation programme alongside our GPR services.

Get in touch to discuss borehole clearance for your project, or call 0333 920 9427.