Vacuum Enhanced Recovery (VER) – This is an active remediation method that is used to remediate impacted groundwater and soils. Remediation is achieved by applying vacuum to a targeted well and extracting either Volatile Organic Vapours (VOCs), Light Non-Aqueous Phase Liquid (LNAPL) and impacted groundwater or both. The most common used VER methods include Soil Vapour Extraction (SVE) and Multi-Phase Extraction (MPE) or Dual-Phase Extraction (DPE).


How?It involves injecting air (and nutrients) into the targeted contaminated zone via vertical injection wells, with the expectation that volatile contaminants will volatilize. A soil venting system (SVE) is usually employed to capture the contaminated/volatilized air.

-Oxygenation of soil (and water) enhances in-situ biodegradation + volatiles hydrocarbons which can be extracted from nearby extraction wells.

-To treat contaminated soil situated above deep groundwater.

Soil remediation VER advantages


MPE a.k.a DPE is another physical in-situ treatment that uses a high-vacuum system to extract contamination in both the liquid and gas phases. Remediation can be achieved in both the unsaturated zone and saturated zone. There are two common pump configurations used for this method including single-pump MPE/DPE and multi-pump MDE/DPE.

Using the single-pump configuration the system relies on high-velocity airflow to lift suspended liquid droplets upwards by frictional drag. This system can be used to extract groundwater or a combination of separate phase products and groundwater.

The multi-pump configuration can be applied to a wider range of site conditions. A large volume of groundwater is extracted by use of a groundwater pump while extracting VOCs from the exposed unsaturated soil by simultaneously applying a vacuum.

The effectiveness of MPE/DPE is influenced by the permeability and volatility of the targeted compounds. The effectiveness of this method increases with permeability. With the same as SVE, the more volatile a compound the more effective the applied method will be.

Effective on soils with varying permeability. Requires both a vacuum pump and blower. Simultaneous removal of dissolved, vapour, residual, and non-aqueous phases of contamination. Potentially greater treatment requirements because of NAPL emulsions and VOC laden vapours. Creates a large radius of influence and an increased capture zone. Initial start-up and adjustment periods may be longer compared to conventional pumping approaches. Reduces the number of recovery wells required. Depth limitations apply to some pump configurations Effective for capillary zone remediation. Treatment of both VOCs and impacted groundwater is required Reduces the duration of remediation when compared to conventional pumping approaches.
Soil groundwater remediation VER MPE DPE

To request a quote or ask for more information regarding our Contaminated Land Services, please contact Magiel Lourens (CSM Unit Manager) at | +27 11 803 5726