A previous assessment of the site had identified the need for a soil and groundwater remediation in order to be protective of the surface water features bounding the site. A variety of remediation techniques were recommended to achieve the defined remedial targets. Due to the nature and extent of the contamination and the stringent nature of the remedial targets, the potential for success and feasibility of the proposed remedial works were not guaranteed.
ASL were contracted to completed a detailed quantitative risk assessment to further assess the potential risk to controlled waters from dissolved phase contamination in groundwater.
ASL completed a Tier 4 quantitative risk assessment to determine the potential risk to controlled waters. Based on the findings of the Tier 4 assessment, remediation of groundwater was recommended at two exploratory locations only. A monitoring programme was recommended as part of the development programme to confirm the conclusions of the assessment. The assessment was issued to the Environment Agency to their approval.
The works completed by ASL comprise the following:
- Review of previously completed reports, historical data, the site’s environmental setting and land use;
- Detailed assessment of the contaminant source area and flow path;
- Interpretation and quantitative assessment of results for contamination issues;
- Design of a monitoring programme during the construction phase to validate the quantitative risk assessment.