Geotechnical Investigations: What Is A Phase 1 Desk Study?

by | Oct 20, 2020

Phase 1 Desk Studies are amongst the very first stages which are usually carried out in any geotechnical investigations. They are either carried out as a form of due diligence before property transactions or prior to site development. That’s what we’re interested in, here at Borehole Solutions. But what is this study? And why exactly is it necessary? We spoke to Rob Lewis, geotechnical consultant at the Borehole Group, about exactly that.

What Is It?

In short, these studies are a collection of documents, within which potential hazards are outlined – these hazards might be environmental in nature, or geotechnical, engineering-based, contamination or operational. They’re often required before any full planning permissions can be granted or secured. These studies are, above anything else, investigative processes, and the engineer carrying one out will draw upon many different resources to come to their conclusions.

They may go to the Coal Authority, for instance, in order to highlight any former mining activity or developments. Similarly, they might apply for archival development records from the Local Authority. In other words, these studies, by using information from various sources, look to put together a comprehensive picture of risk at a site.

Objectives Of A Phase 1 Desk Study

There are several main objectives to any Phase 1 Desk Study. These include:

  • Considering whether any form of intrusive geotechnical investigationis required.
  • Assessing the environmental value of the site, with regards to its flora, fauna and sensitive receptors.
  • Assessing the possibility of finding contaminants at the site.
  • The production of a CSM (Conceptual Site Model). These are representations of the various processes that determine the ways in which contaminants move throughout the environment.

Site Walkovers

In some instances, the geotechnical consultant might be required to go to the proposed site, as part of the wider desk-based study, in order to verify certain site characteristics (such as the presence of contaminants) or to highlight any other potential problems such as access issues. If a site walkover is required, then it will be stipulated within the initial planning condition.

Review And Recommendations

Alongside identifying areas of risk, the geotechnical investigation company will also provide extensive recommendations within the Phase 1 Desk Study. There’ll often be a variety of recommendations, and each one might be broken down into levels of recommendation, dependent on your planning condition’s requirement. The study will determine, for instance, whether an intrusive investigation is required to validate any findings or whether a simple visual inspection of exposed subsurface soils during associate ground works would instead be adequate.

Contact Borehole Solutions

Whilst sometimes a tedious piece of documentation, these studies are imperative in safely developing a site, and in ensuring that no stakeholders are left in the lurch before development commences. So, if you’d like to find out more about our phase 1 desk studies, or about any of our geotechnical investigation services, then get in touch! Contact Borehole Solutions today on 01733 200 501 or by emailing us on Why not head over to our Instagram to check out more of our latest work and projects.