Dual Phase Extraction

Dual Phase Extraction is a remedial process that essentially combines Soil Vapor Extraction (SVE) and Pump and Treat (P&T) methods at a single extraction point. An extraction well is constructed and screened in both the unsaturated zone and saturated zone, allowing the removal of contaminants in both the vapor and liquid phases. An important aspect of the DPE process is the lowering of the water table, thereby exposing previously saturated soils to treatment via vapor phase extraction, which is generally more efficient and effective than removal of the petroleum hydrocarbon component via liquid phase extraction. The extraction process employs a Liquid Ring Pump (LRP) that is capable (depending upon subsurface characteristics) of providing vacuum up to 400 inches of water, vapor flow rates up to 150 standard cubic feet per minute (SCFM), and water flow rates up to 50 gallons per minute (GPM). The total number of extraction points needed is contingent upon the size of the impacted zone and the radius of influence (ROI) induced by the extraction operations.

Dewatering of the saturated zone as induced by the DPE process allows treatment of the dewatered zones, including the capillary fringe and “smear” zone, via vapor phase processes. Thus, DPE can often promote faster remediation of contaminated sites than other in-situ treatment methodologies.

EBA Engineering’s trailer mounted DPE treatment system is mobile and easily adapted to fit various project site conditions. EBA Engineering offers complete DPE pilot testing and treatment services. Please feel free to contact EBA Engineering for additional information.