Case Study - Sparge Vac

Background

Due to the failure of an underground fuel storage tank at a petrol filling station approximately 23,000 litres of unleaded petrol was released into the environment.

 Following site investigation works, including the drilling of abstraction boreholes, and liaison with the Environment Agency, Oracle operated a groundwater treatment system and treated a total of over 13,000 cubic metres of petrol contaminated groundwater.

Air Sparge System

To further reduce the low residual hydrocarbons in groundwater and within the unsaturated zone OEE installed and operated an air sparging system. The system injected high pressure air directly into groundwater via a series of perforated injection lances.

The air volatilised the residual hydrocarbon within groundwater into the unsaturated zone where they were recovered using an ATEX certified vacuum system. Recovered vapours were passed through carbon filters prior to discharge to atmosphere with all VOC discharges < 0.1 ppm.