Project

Treatment of soils and groundwater impacted with Xylene contamination at a Former Industrial Site.

Contaminant

Xylene impacting groundwater as free phase product and soils.

Challenges

A low permeability silt layer was heavily impacted with Xylene, which was sandwiched between two permeable strata. This made the in-situ clean-up of the silt very difficult using conventional vacuum technology.

A solution was required that could release the impacted area in the minimum amount of time to enable other remediation to commence and hence release the site ready for redevelopment within 9 months of start of treatment

Churngold Solution

The solution comprised the injection of high pressure steam to mobilise the volatile contamination within the silt layer. The system significantly raised temperatures in the subsurface resulting in Xylene rapidly desorbing from the silts and being recovered as vapour or in the dissolved phase using a high vacuum extraction system.

The latter treatment of dissolved phase contamination was further enhanced during operations by injecting air. Adding oxygen via air injection into the heated groundwater resulted in contaminant destruction by hydrous pyrolysis.

The success of the treatment resulted in a further area being targeted in the proximity of a water course avoiding otherwise complex and expensive excavation and disposal.

Technologies/Methods Employed

• Steam Injection
• High Vacuum Extraction
• Hydrous Pyrolysis