Remediation

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Dual Phase Extraction (DPE)

Dual Phase Extraction (DPE) is an in-situ remedial technology used to reduce the concentration of VOCs in the groundwater and soil mass.

Utilizing a high negative pressure (vacuum), the system simultaneously removes contaminants from three different sources:

• Volatilized contaminants in the unsaturated zone;
• Free Product contaminants perched on the water table [Light Non Aqueous Phase Liquids (LNAPL)]; and,
• Contaminants dissolved in the groundwater.

The vacuum extraction well is screened in the zone of the contaminated soils and groundwater. Contaminant removal occurs from above, below and throughout the groundwater table. As contaminated groundwater and free product is removed, the water table drops, exposing more of the contaminated soils now in the unsaturated zone. Once the liquid and vapour phase contaminants are drawn above ground, the phases can be separated and treated accordingly using various technologies.

DPE has been shown to be effective in the reduction of VOC and hydrocarbon fuel concentrations at petroleum hydrocarbon impacted sites. Nichols Environmental’s role in a DPE System includes the installation, supervision and monitoring of extraction wells, piping and the treatment system.

Nichols Environmental has installed and maintained a number of DPE systems with great success.