Investigation, Assessment and Risk Management at a Large Former Petrochemical Site, Port Talbot, UK

A large (c. 400ha)  petrochemical site was developed on an area of marine sand dunes; filling the site's closure, extensive investigations were undertaken resulting in a detailed model of the layered aquifer system at the site.  Detailed analysis of the data was undertaken, development of complex and transient flow and contaminant transport models which confirmed the presence of a complex flow pattern.

Risk management originally focused on limiting access to the site and controlling migration  of contaminants on a precautionary basis. However, following sale of the site, a more risk-based approach has been applied to managing the site.  This has included development of a detailed understanding of how neighboring land is used so that the risk from contaminants carried by groundwater flow could be estimated. This was in addition to more traditional groundwater risk assessment in accordance with UK guidance.  The risk assessment process indicated that risks from the site were generally acceptable, but some  targeted remediation has been undertaken to further reduce the risk to the environment.  This has included both source removal and pathway treatment.  Ongoing work continues to enable the site to return to beneficial use over the next few years.