A Phase 1 Preliminary Risk Assessment is the initial part of a phased site investigation to look at the ground conditions of a site, review existing information, and help plan the scope of the subsequent stages of investigations in accordance with the recommended approach set out in the Environment Agency’s guidance, Land Contamination: Risk Management https://www.gov.uk/guidance/land-contamination-how-to-manage-the-risks.
This guidance is set to supersede the previous Environment Agency’s Model Procedures for the Management of Land Contamination (CLR11).
The phase 1 assessment involves a visual inspection conducted during a site walkover survey followed by a review of geo-environmental and geotechnical information from statutory and non-statutory sources relating to the site, including:
- Published geological, hydrogeological and hydrological information to establish the Site’s environmental setting;
- Published historical and current Ordnance Survey maps to establish the history of the Site and its immediate surroundings;
- Publicly available information from regulatory authority databases;
Following the review of available information areas of likely contamination will be identified, along with ‘pathways’ in which it could be transmitted, and possible ‘receptors’ (site users, surface water features, underlying aquifers, controlled waters adjacent buildings, wildlife etc.) on site and in the surrounding area. These ‘potential pollutant linkages’ are then used to develop a Conceptual Site Model.
The development of a Conceptual Site Model allows the assessment of any identified ‘potential pollutant linkages’ as part of an Environmental Risk Assessment.