The remediation work on three former gasworks sites involved:
- the installation of storage zones;
- the selective excavation and storage of the healthy soils;
- the selective excavation and storage or removal of polluted soils on a just-in-time basis;
- the treatment of polluted soils by thermal desorption;
- the removal of the top of the buried tanks and their drainage;
- the backfilling and compaction of the excavated zones;
- the restoration of the site to its original condition.
Most of the zones to be excavated were not directly accessible. A total of 11,200 tonnes of soil were excavated and stored in sealed areas or removed on a just-in-time basis. Excavation, drainage and cleaning of three former gasometers were executed. A number of underground tanks were drained and removed. The decontaminated areas were backfilled with healthy filler materials before being compacted. Returning the site to its original condition involved rebuilding the car parks, flower beds and landscaped areas.