Client’s Guide to Phase 1 Geoenvironmental Risk Assessments (Desk Studies)
A Phase 1 Geoenvironmental Risk Assessment (desk study) is a review of information available about a site and it is carried out at an early stage of appraisal. Often described as Phase 1 assessment, it forms the basis of the preliminary environmental risk assessment and forms the essential first part of investigation.
The desk study examines existing information about a site from a wide variety of sources. The aim is to make an initial assessment of ground conditions and to review the past-history and current use of the site. This information is used to create conceptual ground model (CGM for geotechnical purposes) or a conceptual site model (CSM) for potentially contaminated sites. The main categories of information considered are:
Review of information provided by the owner or vendor of the site.
Previous site investigation reports, drawings and information about current and past uses and site services (buried and overhead). This information can be used to adjust the requirements for the current investigation.
Nature of the soil, the bedrock geology and groundwater conditions including radon.
Investigated by reference to geological and hydrogeological maps and publications together with existing borehole data on or near the site. This initial information may provide an indication of particular ground condition hazards associated with certain strata, for example past mining or Coal Measures rocks, dene holes and dissolution features in Chalk, or ‘gulls’ and cambering in a variety of strata.
Past-history of the site.
Examined by reference of historical maps and aerial photographs, local historical records, environmental disclosure reports and anecdotal information. This knowledge can then be used to assess the potential contamination or geotechnical problems which may have been caused by, for example, particular industrial processes, mining or landfill.
Consultation with regulators and authorities such as the Environment Agency and the Coal Authority.
Flood Risk Assessment and Hydrogeology, review of information provided by the owner or vendor of the site.
To gain information on factors such as flooding potential or past underground mining. Service providers are consulted for details of public utilities on the site to avoid damage or danger in the course of subsequent investigation.
The desk study includes a walk-over survey of the site and includes consideration of:
- Topography
- Geology
- Surface Water and Groundwater
- Ecology
- Contamination
- Structures
- Local Knowledge
- Access and Services.
Due diligence audits are essential in the assessment of a site’s saleability or viability. Environmental liabilities associated with ownership of a site can often run to significant sums, and may represent significant risk. Due Diligence Audits allow a full determination of the site’s value and liabilities to be made.
- Assessment of Processes and Operations for potential to cause pollution
- Pollutant Linkage Assessment for the site and its environmental setting (i.e. Source-pathway-receptor models)
- Conceptual Site Modelling
- Effectiveness of environmental control measures
- Compliance with relevant environmental legislation
- Review of waste disposal, hazardous materials management and emissions
- Qualitative Risk Assessment based on environmental and management of liabilities, regulatory searches and site inspection
- Recommendations.
Michael D Joyce Associates LLP has a proven track records of assisting land owners and land purchasers to assess environmental risks and liabilities. Contaminated land services include:
- Desk Studies
- Ground Investigation design, supervision and interpretation
- Detailed Quantative Risk Assessments:
- Human health using CLEA, SNIFFER, Risc4, etc
- Groundwater using R&D20, Consim, etc
- Risks and Liabilities
- Advice on remediation strategies; recommendations for action
- Determination of site-specific target levels for remediation
- Liaison with regulatory bodies
- Development of remediation strategies
- Supervision of remedial works
- Production of Completion and Validation reports
- Land Condition Reports.
