Sub Surface provide Phase 1 Desktop Study and Walkover Surveys to satisfy the various regulatory requirements of Planning Departments, Environmental Health Departments, the Environment Agency, Building Control Departments, National House Building Council (NHBC) and property transactions.

A Phase 1 Desktop Study is the collation and review of published information about a site to obtain information regarding the sites historical, geological and environmental setting. The Phase 1 Desktop Study is normally carried out at the start of the Site Investigation process to characterise the site and provide information for the remainder of the site investigation. Our reports include:

  • Site Details – Walkover Survey Results
  • A Historical Appraisal – using Ordnance Survey plans
  • Geological Appraisal – Artificial ground, superficial strata, bedrock, mining, etc.
  • Environmental Appraisal – Potential contamination sources, pollution history, landfill sites, hydrogeology and hydrology, flooding
  • A Conceptual Ground Model – a preliminary assessment of contamination sources, pathways and receptors (human health, vegetation, controlled waters, structures and services) relating to potential hazards that exist or may potentially exist on the site.
  • Site Investigation Recommendations (if required) – Contamination analysis, Ground gas monitoring, etc.

What is a Phase 1 Desk Study? Q&As for everything you need to know about Phase 1 Desktop Studies.

Phase 1 Desktop Study in a Coal Mining Area

For sites located within an area that might be affected by mineworkings (parts of Manchester, Yorkshire, Derbyshire, West Midlands, etc.), a Coal Authority Mining Report will be required and incorporated within the Phase 1 Desktop Study. If the Coal Authority Mining Report indicates that there is a potential for shallow mining beneath the site, then a full Coal Mining Risk Assessment will be required.

Is my site within a Coal Mining Area?

Benefits of a Phase 1 Desktop Study

The benefits of carrying out a Phase 1 Desktop Study and Walkover Survey prior to commencing intrusive works include:

  • Allows the efficient targeting of project resources.
  • Formulation of the preliminary geological ground model.
  • Early identification of potential geohazards.
  • Avoid money being wasted on inappropriate intrusive ground investigations.
  • Provide early warning of possible delays or budget implications through previously unknown site characteristics.
  • Provide information on possible contaminants and anticipate areas of contamination.

Local Council’s Phase 1 Desktop Study Terminology

Local Council’s use a wide variation of names for a Phase 1 Desktop Study Report within their Planning Conditions, where they generally all mean the same thing. To avoid confusion these include:

  • Desk Study
  • Desktop Survey
  • Phase 1 Desk Study
  • Preliminary Risk Assessment
  • Contaminated Land Survey
  • Land Contamination Assessment
  • Contamination Risk Assessment
  • Phase 1 Site Investigation and Risk Assessment
  • Phase 1 Ground Investigation
  • Etc.

Whom to Contact

If you would like a quote for a Desktop Study and Walkover Survey or have any questions, please do not hesitate to contact your Regional Sub Surface Office.