A Phase I Desk Study, also known as a Preliminary Risk Assessment, Desktop Survey and Phase I Land Contamination Assessment, among others, includes a review of all accessible sources of information such as site plans, photographs, maps (current and historical), environmental data records, local authority records, petroleum officer records, mining records and any previous site investigation reports. Such information may be available electronically from various online sources, or as hard copies from the current or former site owners and occupiers, the local council, libraries, public record offices or even local history groups. 

 

The desktop review should be combined with a site walkover survey undertaken by an experienced geo-environmental engineer, with the aim of identifying any significant site features, particularly those which may represent potential contamination sources, such as tanks (above and below ground), chemical storage areas, industrial process areas, evidence of waste disposal, areas of stressed vegetation, unusual landforms etc.  Furthermore, the opportunity to speak with site personnel, or anyone else with knowledge of past and current site operations, can be an invaluable source of anecdotal evidence for site activities that would not otherwise be recorded (such as undocumented waste disposal).  Together, the findings of the desktop review and the site walkover are used to establish the following: 

 

• Geology and Hydrogeology

• Hydrology / Flooding

• Environmental Sensitivity

• Mining susceptibility

• Potential Contamination Sources

​

Having established the above, a Conceptual Site Model (CSM) is developed which is a visualization or descriptive representation of the site setting which clearly highlights the source-pathway-receptor pollutant linkages that may be present on a site in its current state, or that may be created based on future development proposals.  The CSM is an essential component of the Preliminary Risk Assessment, the purpose of which is to determine the likelihood of any of the potential pollutant linkages being present and significant, and therefore whether any further works (a Phase II Site investigation) are required. The Preliminary Risk Assessment is the primary output of the Phase I Desk Study report.

​​

​

​

A robust Phase I Desk Study is the minimum requirement of contaminated land planning conditions and an essential foundation for any subsequent stages of contaminated land investigation, the design of which will be informed by the CSM developed as part of the Phase I. In some cases a thorough desk study may demonstrate that no potentially significant pollutant linkages are present, and that no further investigation works are required.  A high quality desk study will ensure only the necessary ground investigation works are undertaken, and that any potential liabilities are identified, thus resulting in potentially substantial cost savings. 

​

​

​

G&J have many years experience undertaking Phase I Desk Studies for sites of all sizes, from individual plots to former industrial sites covering several hectares, in locations throughout the Midlands and across the UK. We can also combine the walkover survey with a basic exploratory investigation (sampling and analysis of near-surface soils) which can be a cost-effective way of satisfying planning conditions on sites that are low risk, but for which a Phase I Desk Study alone may not be sufficient.

 

Costs: 

The cost of most of our Phase I Desk Studies, including a walkover survey, is £895* plus VAT.
On some very straightforward sites we may be able to undertake a desk study without a walkover survey, for which the cost is £695 plus VAT

*Costs may be higher for larger, more complex sites.