Site land use is critical to understanding the likely nature of the ground and the risks it may represent. Available editions of published historical Ordnance Survey maps are reviewed by our experienced engineers during the Desk Study, identifying recorded previous development on site; extent/type of any industry, both on and surrounding the site; the likelihood that ground disturbance has occurred; and the nature/occurrence of features which may impact the site via contamination e.g. tips, former ponds etc. or ground instability e.g. excavations, slopes etc. The information obtained from the historical research informs the site conceptual model which underpins land contamination assessment.
Our trained geologists obtain and interpret published geological maps, memoirs, technical reports, borehole logs and geological data during the Desk Study. The hydrogeological sensitivity of the site is also examined by consideration of ground permeability, aquifer status, Environment Agency Source Protection Zones, spring locations and private water supplies.
This ability to understand the nature and behaviour of the near surface superficial strata, underlying bedrock and geological structure, and groundwater regime beneath your site is paramount to the early assessment of geological, geotechnical and land contamination risk and liability and informs the site conceptual model which underpins the land contamination assessment.
Comprehensive statutory enquiries represent an important part of desk study research and are effectively and economically obtained from one of our approved suppliers.
Such enquiries include reference to statutory environmental information from databases including those held by the Environment Agency, Local Authorities, British Geological Survey, Coal Authority and Natural England. Typical data provided relates to landfill/waste sites, PPC processes, discharge consents, pollution incidents, hazardous substances, industrial and sensitive land uses. The environmental information is reviewed, assessed and is then presented within the Desk Study, as part of the site conceptual model underpins land contamination assessment.
Conceptual Site Models are diagrammatic or textual presentations of possible relationships between potential contamination sources, receptors and pathways linking the source and receptor. Source – receptor – pathway relationships underpin land contamination risk assessment. Information on the sources, receptors and pathways are obtained during the desk study from historical researches, geological/hydrogeological data and by statutory enquiries.
Development of the conceptual site model and identification of possible pollutant linkages represents the main part of a preliminary land contamination risk assessment and informs targeted site investigation. The conceptual site model is refined throughout the risk assessment process as more information and understanding is obtained.
The contaminated land regime under Part IIA of the Environmental Protection Act 1990 provides for the identification and remediation of statutorily defined Contaminated Land, but does not account for future development of land affected by contamination.
At the planning stages of projects, Wardell Armstrong work closely with our clients and environmental regulators, utilising expert knowledge and experience to determine the risks associated with contamination. Following accepted risk assessment procedures, we work in tandem with market leaders in land remediation and contracting and provide innovative and cost-effective solutions to our clients to allow contaminated sites to be brought forward for development.
Ground related constraints may represent a significant abnormal development cost to projects involving development of the land. Typical constraints may involve contamination and a site’s likely suitability for use; geological or geotechnical constraints associated with appropriate foundation solutions; ground stability relating to the natural soils or rocks; or constraints associated with mining or other anthropogenic activity.
The potential for ground constraints can be quickly assessed by our experienced geologists during the desk study stage. Constraints mapping, to inform master-planning and to minimise abnormal development costs, would be prepared and progressively reviewed and revised throughout the site investigation and design stages.
Current, former or future surface or underground mining activities represent a risk to existing property and future land development. The United Kingdom has been extensively mined, predominantly for coal, but also for other minerals including limestone, sandstone, salt, chalk and metals. Mining hazards e.g. subsidence, combustion and contamination, are quickly assessed at desk study stage, particularly using data from regional and ‘site specific’ geological maps and mining databases.
Our experienced geologists and mining engineers regularly carry out historic Coal Mining Risk Assessments to the standards required by The Coal Authority, to support planning applications in areas potentially affected by historic coal mining.
