Large-scale on-site and in-situ bioremediation of xylene contaminated soil, soil vapor and groundwater

Greensoil conducts a full scale remediation at a heavily xylene impacted Seveso site in Westerlo, Belgium. Soil and groundwater show high concentration levels in two former production areas. The remediation is based on on site biopiling of the soil in the unsaturated and smearing zone and in situ aerobic bioremediation of soil and groundwater in the saturated zone.


Location Westerlo, Belgium
Client Confidential (multinational)
Duration Q3 2016 - Q3 2021
Contract Guaranteed outcome contract
Contamination BTEX  (highest: Xylene)
Techniques Biopiling and in-situ aerobic bioremediation
  • Biological groundwater treatment system (20-25 m³/hr)
  • Air abatement system consisiting of turn around biopile depots, bioscrubber, compost filter & GAC
  • Biopile depots (from 500m³ untill 5,000m³)
  • Blower unit (500 m³/hr for bioventing) 

In numbers

Project value > 2.000.000 €
Soil volume > 25.000 m³ (biopiling)


in soil

in water  

Max. conc. Remedial target value Status
> 25.000 mg/kg 379 mg/kg.ds Xylene ongoing
89.000 µg/l 5.320 µg/l Xylene start 2018
Number of wells
  • 75 injection and extraction wells
  • 100 biosparging wells

Project specs

Soil treatment: aerobic biopiling & excavation

In-situ: aerobic biodegradation, air-/biosparging, (D/L)NAPL removal & soil vapour extraction

Treatment system: biological groundwater treatment & biological air abatement

Contamination: BTEX & mineral oils