Contaminated Land

Geoenvironmental Ltd offers a comprehensive service in the field of contaminated land assessment and risk assessment and can undertake and manage all phases of the investigation. Geoenvironmental can manage projects ranging from domestic soil spills to larger industrial sites.

Phase 1: Desk Study

The Phase 1 desk study identifies any potential sources of contamination resulting from the current and historical activities at the site by reviewing available information from sources such as archives, plans and records, databases and information from regulatory authorities. In this way we can discover the past and current activities at a site and assess them for potentially contaminative processes, in order to determine the potential for the presence of contamination. A Conceptual Model is produced identifying the risk of contamination occurring on a site and determining what the risks are to future users of the site using the source-pathway-receptor model.

The Phase 1 study also identifies any potentially sensitive receptors, e.g. humans, surface watercourses, aquifers, buildings or ecological receptors and also collates the information relating to the site’s environmental setting i.e. geology, hydrogeology, industrial activity, location of controlled waters, pollution incidents and proximity to open/closed landfill sites.

This information is then used to undertake a qualitative Risk Assessment through the development of a conceptual model for the site. The conceptual model identifies any Significant Pollutant Linkages which may be present. If Significant Pollutant Linkages are present then a Phase 2 site investigation may be required to quantify the risk and also to assess the potential for environmental liability associated with the site.

Phase 2 : Site Investigation

An intrusive site investigation is undertaken to investigate each aspect highlighted by the Phase 1 desk study. The Phase 2 investigation is designed and implemented using a variety of in-situ exploratory methods, depending on the size of site and type of contaminants identified by the desk study as being potentially present.

Phase 3: Detailed Risk Assessment & Evaluation

Geoenvironmental Ltd can carry out detailed quantitative risk assessment. Risk assessment is a process in which information is analysed to determine if an environmental hazard might cause harm to exposed persons and ecosystems. Risks to the public are measured by direct observation or comparing contaminant concentrations to generic limit values. No matter how risks are defined or quantified, they are usually expressed as a probability of effects associated with a particular activity. Risk Evaluation involves the consideration of the qualitative or quantitative information derived from the hazard identification stage (ie previous desk study and hazard assessment (on-site sampling). The risk evaluation involves consideration of the results of the hazard assessment. The risk evaluation stage requires the identification of appropriate standard or criteria which provide an indicator of acceptability of the risk in human or ecotoxicological terms.

Phase 4: Remediation

If remediation is required following the Phase 2 works, then a site specific remediation methodology can be produced; this involves consultation with the regulatory authorities to ensure satisfactory design and implementation of the remediation programme.