The initial stage of site characterisation from a Geo Environmental perspective is the formulation of a Phase 1 Desk Top Study.

This involves a review of environmental databases and historical records, dating back to the late 1800’s. Often when working on sites that have a significant past use it is necessary to consult Planning Archives and undertake a detailed review of information held for the Local Area.

A key requirement of the Desk Top Study is to undertake a Site Audit, or Walkover, which will involve one of Omnia’s Environmental Specialist visiting site to review ongoing Contaminative processes and any evidence of past contaminative uses. The aim of the Walkover is to review these aspect, and consider site setting to determine whether any identified contaminative past uses post a significant risk to receptors.

Upon completion of the necessary reviews and site audit, a Conceptual Site Model (CSM) is prepared, which identifies potential sources of contaminations and determined whether a risk is posed to identified receptors, including future site users, construction workers, controlled waters and off-site receptors.

Upon completion of the Conceptual Site Model if any sources of contamination are considered to pose a risk, then Intrusive works, through a Phase 2 investigation will be necessary.

The requirement for a Phase 1 Desk Top Study is often driven by the Local Authority through a Planning Condition. Working for both developers and directly for the City Councils and Local Authorities Omnia have a good relationship with the regulators, and a strong reputation for robust defensible risk assessment. This allows us to streamline our approach to Phase 1 reports, allowing for submission within tight deadlines.