Case studies

Soil Vapour Extraction

Case studies

Northwich - Ex-situ soil vapour extraction remediation

RemedX was commissioned by AstraZeneca to remediate a contamination hotspot at the former Wade Alloprene works in Northwich. From 1941 until the plant ceased operations in 1992, the site had been subjected to a range of chemical manufacturing processes resulting in contamination, principally volatile organic compounds (VOCs).

RemedX was enlisted to remediate the contaminants to make the site suitable for future development and to protect the local watercourses

In summary, the remediation works included:

  • civil works to prepare the site for vapour extraction treatment cell
  • construction of the treatment cell
  • preparation of mobile vapour extraction plant, including groundwater treatment plant
  • excavation of contaminated soils from former tankage area, including segregation of highly contaminated and difficult cells
  • covering of the filled treatment cell with polythene sheeting
  • VOC testing of site atmosphere (continuous during works)
  • VOC testing of water on site
  • operation of vapour extraction plant, including monitoring of plant and treatment cell
  • reinstatement and compaction of treated soils
  • disposal of excavated concrete and untreatable soils to landfill
  • decommissioning and removal of plant.

Added value

  • RSK’s remediation approach reduced carbon tetrachloride and chloroform concentration in the soils to an acceptable level in an economically sustainable manner.
  • Ex situ remediation ensured speedy delivery of targets: total time for remediation, from drilling of soil vapour extraction boreholes for pilot testing to removal of plant from site took 159 days.
  • All client targets were met.