The proposed solution for treating contaminated soil at AEC2 is currently being assessed.

Excavation planning

The source of contamination in the area known as AEC2 was due to original underground storage tanks that were constructed in the mid-1970s when the site was being built.

Over time, these tanks leaked and caused the contamination. Whilst they were removed following a decision to install over ground tanks on the site, remediation of the soil in the vicinity of the original underground tanks is a requirement. This area has therefore been identified as requiring remediation under the scope of the overall site decommissioning project.

The initial plan was to excavate this area as part of the remediation process and, while this option is possible, an alternative solution, known as In Situ Thermal Treatment (ISTT), is now proposed. This is a proven technique which effectively removes the nature of contamination in the area requiring remediation. It will achieve the same level of decontamination but provide significant benefits with regard to avoidance of excavation and reduce the level of HGV movements to and from the site.