In Situ treatment of toluene in groundwater, Helsingborg, Sweden

Case study highlights:

• Pilot trials were used to determine the best remediation options for full-scale works.
• Engagement with multiple stakeholders to complete remediation of a toluene plume extending over several site boundaries.
• In Situ injection works were completed on two separate industrial facilities without disturbance to their operations.

Multiple historic leakages from stored chemicals on an industrial site led to hydrocarbon contamination of the underlying groundwater, predominantly with toluene. Multiple site investigations indicated that the plume had migrated beyond the site boundary and into land owned by the neighbouring harbour authorities. An initial treatment comprised a pump and treat system which had successfully recovered 14m3 of toluene. However, the contaminant concentrations exceeded the legal limits for less sensitive or industrial land use (Swedish MKM values). Therefore, additional remediation phases were required to address the residual dissolved phase. An in situ remedial approach was chosen, using RegenOx and ORC Advanced.