Remediation Equipment

HOW IT WORKS

Dual extraction is a method by which both groundwater and vapors can be extracted from the same well with a single vacuum pump located in the equipment compound. The recovered groundwater is then typically treated with an oil/water separator and air stripper, and the air discharged to atmosphere. The typical limit for dual extraction is from wells less than 25' deep. Extraction from deeper wells is possible, but requires some additional fittings. Most systems utilize a liquid ring vacuum pump as the vacuum source because they can achieve the high levels of vacuum required, typically 18-22 inches of mercury. Dual phse has been successfully implemneted in well up to 55 ft in depth without significant modifications in wellhead design.

In most dual extraction systems, a high vacuum is applied to an extraction tube placed down an extraction well, below the static groundwater table, with the bottom end of the tube at the elevation in which draw down is desired. The top of the well casing is sealed to atmosphere. The vacuum applied to the wellhead then begins to extract the groundwater from the well until the well is drawn down and the water surface in the well reaches the bottom of the extraction tube. At this point, the tube "breaks suction" and begins to apply the vacuum to the air space in the well and surrounding soil. As additional groundwater flows into the well, it is sucked up the extraction tube until it again breaks suction.

This process then continues indefinitely, with alternating slugs of groundwater and vapors pulled up the extraction tube, out of the well and on to the process equipment. The extracted vapors and groundwater then flow through piping from the well to the first groundwater remediation system's individual components. There, the liquids, groundwater and product are separated from the vapors by cyclonic action. The liquid flows into a sump where it is then pumped to the oil/water separator and air stripper for treatment. The contaminated vapors continue on into the liquid ring vacuum pump. It is then discharged, under pressure, out of the liquid ring pump, and into the atmosphere. Secondary treatment of vapors may be added. Contact your state's environmental regulatory agency for permit requirements.

The staff at Southeastern Environmental Products, Inc., have been involved with Dual Phase Extraction Systems since 1992. We offer service contracts for our clients and currently maintain over 15 systems in Mississippi. Please contact us for questions or quotations at 866-GO-SEPCO.