Ground investigations FAQs

The first phase of our ground investigations started in February. The duration of individual ground investigations varies depending on the type of work being carried out. For example, a cable percussion borehole - the most common ground investigation technique, which is used to gather soil samples - might take around two to three days, with time before this to set up and time afterwards to demobilise and put the land back to its original condition. A trial pit survey however, which is also used to gather soil samples, will typically take one to two hours to complete.

There are different types of ground investigations that we will need to carry out, and we have described these to each landowner in the access licences we have sent to them about their land. These are also described, alongside photographs, in our  Guide to Intrusive Surveys. They range from boreholes dug using a drilling rig to trial trenches dug using an excavator. 

We are committed to minimising the potential for any disruption to landowners and local communities as we carry out ground investigations and our contractors have strict procedures in place to manage any potential impacts. Trackway will be laid to allow vehicles to enter and leave sites without bringing mud onto the roads. Other ways we will look to minimise disruption include carefully timing our work so that surveys in neighbouring areas can be carried out during the same period; with the aim of limiting working hours to 8am to 6pm, Monday to Friday. 

We are writing to local parish councils, MPs and local authorities to let them know when ground investigations are due to take place in their area. We are also notifying immediate neighbours to where the work is taking place. As our survey contractors continue to work closely with local landowners to make specific arrangements for accessing their land, the timings of the ground investigations may sometimes shift. We will keep local stakeholders updated of any significant changes to our programme.

 

Archaeological trial trenching FAQs

The first phase of our archaeological trial trenching will start from December 2025 and will continue through to Spring/Summer 2026. How long we are on each site will depend on the number of trenches that need to be dug. Our team will work as quickly as possible to complete the trial trenching on each site.

Trial trenching is a survey technique where we dig trenches to expose and investigate any potential buried archaeological deposits. The trenches are typically up to 2m wide, between 20m and 50m long, and normally excavated down to the horizon between the top and sub-soil. It is normally conducted by a team of two to five archaeologists at each location who look for the presence and significance of archaeological finds and features.

Our archaeologists will usually need to access the site by van or a four-wheel drive vehicle. A mechanical excavator will also be needed and will usually be on tracks, to reduce disturbance to the ground, but sometimes it may be wheeled.

Trial trenching is also described, alongside photographs, in our Guide to Intrusive Surveys.

We are committed to minimising the potential for any disruption to landowners and local communities as we carry out archaeological trial trenching. Whilst our survey contractors have strict procedures in place for this, the nature of this work means any potential impacts should be localised to the fields in which they are operating and temporary. Other ways we will look to minimise disruption include the careful timing of our work so that surveys in neighbouring areas can be carried out during the same period; and by generally limiting working hours to 8am to 6pm, Monday to Friday.