Contaminated Land

HARRISON GROUP ENVIRONMENTAL LIMITED offers a comprehensive range of in-house services to carry out successful site investigation and assessment of contaminated land both in the UK and abroad.

The majority of projects have been on brownfield sites, industrial and commercial facilities comprising landfill sites, chemical works and manufacturing plants.

Site Investigation

The assessment and regeneration of contaminated land is critical to the land use planning and environmental protection objectives. A structured approach is applied to evaluating contaminated land. Specifically, the following elements are incorporated:
Phase I assessments – involving desk based and literature surveys to assess the history and baseline environmental setting of potentially contaminated sites.  The information is applied to rank the environmental priorities and develop the site investigation strategy.

Intrusive site investigations – involving the collection of environmental samples – soil, groundwater, surface water, air, and biota -  to quantify the levels of contaminants in environmental media and assess the extent of contamination.

Risk assessment – quantify the potential risks to human health, the environment, and air and water resources.  The analysis is used to evaluate the need for, and extent of, land remediation.

Remediation strategy assessment – assess the potential remediation strategies that may be applied with respect to efficacy, technical practicability, and cost effectiveness.

The assessment and remediation of contaminated land involves working closely with Government institutions and other relevant bodies. Harrison Environmental Consulting has comprehensive experience in contaminated land assessment and remediation at sites both in the UK and overseas. The resources are available to investigate, test, report and where appropriate, design site remediation measures.

Staff also have broad ranging field experience with use of in-field equipment and chemical tests. These include; gas chromatography, infra-red absorption spectroscopy, mass spectroscopy, and NMR spectroscopy, geoprobe, window sampling equipment and membrane interface probe.

Health Risk Assessment

Quantitative human health risk assessment is a method that uses data on the inherent toxicity of chemicals, exposure patterns and population characteristics to estimate the potential harmful effects of chemicals on human beings. It
is a vital element in a variety of activities including industrial pollution prevention, contaminated land clean-up, and chemical regulation.

There are generally four steps in a quantitative human health risk assessment process:

Hazard identification:  evaluate available evidence regarding the potential for particular contaminants to cause adverse effects in exposed human populations

Exposure assessment:  identify the type, magnitude, and duration of exposure of humans to contaminated media..

Dose-response assessment:  estimate the relationship between the extent of exposure to a chemical and the increase of the likelihood and severity of adverse health effects.

Risk characterisation:  integrate the information from the three steps above, and characterize potential for adverse health effects to occur in the exposed population.

The staff at Harrison Environmental Consulting have extensive experience in applying health risk assessment for a variety of agents and land use scenarios.  Assessed agents include chemical, mineral, radiological, and microbiological under residential, industrial, and agricultural settings. The assessments have been used to support land use planning and site cleanup, waste management strategies, emergency response, industrial exposure assessments, and corporate environmental policies.

Risk assessments have been completed under a variety of technical methodologies and regulatory schemes including:

• Risk Based Corrective Action (RBCA)
• Contaminated Land Exposure Assessment (CLEA) – UK
• Risk Assessment Guidance for Superfund (RAGS) – USA

Groundwater Contamination Assessment and Remediation

Harrison Environmental Consulting have provided groundwater assessment, groundwater modelling and risk assessment, and site remediation services for contaminated land projects in the UK and Europe.

Staff have carried out hydrogeological investigations, using a variety of different drilling equipment and techniques on many sites. Groundwater modelling using a variety of methods and software packages have been undertaken. These include: -

• Risk Based Corrective Action (RBCA)
• R&D P20 (UK Environment Agency)
• MODFLOW
• BIOPLUME

Site Remediation Strategies