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When Would I Need Mobile Dual Phase Extraction (MDPE)?


MDPE stands for Mobile Dual Phase Extraction. Remediation of sites contaminated with petroleum hydrocarbons (PH) and volatile organic chemicals (VOCs) can be a challenge. This is true especially when the contamination occurs in more than one phase including product and soil vapor, and above and below the water table.
Traditional PH or VOC remediation has employed excavation of contaminated soil for disposal in appropriate landfills, and other in-situ remediation methods such as installation of PH product recovery wells, sparging air through the subsurface groundwater contamination zone and extraction of contaminated groundwater and PH or VOC vapors from the vadose zone. Using a more cost-effective and quicker remediation approach can offset the steadily climbing costs for landfill disposal, extraction and treatment methods, and lengthy remediation projects.

What Is Dual Phase Extraction?

Dual Phase Extraction (DPE), or vacuum-enhanced or multi-phase extraction, combines in-situ methods for vapor, product and contaminated groundwater remediation into one multi-phase method that provides a more robust and cost-effective approach. Most DPE systems include extraction wells that are screened through the vadose zone and the contaminated portion of the water table.

A calculated vacuum is applied in the subsurface at the same time that groundwater is pumped to create a flow gradient to the extraction well in both the vadose and saturated zones. The combination of vacuum and groundwater extraction results in lowering of the water table to expose more of the contaminated soil zone; induces a cone of depression and flow to the well of product that may be floating on the water table; and enhances volatilization of soil contamination and flow of soil vapor to the well. The ground surface must be sealed to contain the vacuum.

The DPE system includes several steps in a media recovery and treatment train. Liquids and vapors may be extracted separately using dual pumps and each stream is treated separately. The vapor stream may be treated or vented depending upon chemicals present, their concentrations and local/state discharge regulations. Any additional liquids resulting from vapor treatment are returned to the liquid stream. The liquid stream is separated into product and groundwater containing dissolved contamination. Both the liquid and contaminated groundwater are managed separately; product may be recycled or re-refined depending on whether other contaminants are present, and contaminated groundwater can be treated by several onsite or offsite methods to meet regulatory discharge limits.

When Does Dual Phase Extraction Become Mobile?

When the DPE system is packaged into a portable system, by mounting onto a trailer or truck, it then becomes a Mobile Dual Phase Extraction System (MDPE). These mobile systems are gaining in use because they can better address sites that may have access limitations or are more cost effective than permanently installed systems where site geology or a thinner layer of product floating on the groundwater indicates a shorter expected remediation time. MDPE systems can reach depths of up to 100 feet in optimal geologic conditions.

Who Can Do Mobile Dual Phase Extraction?

Talon/LPE  provides MDPE remediation services throughout Texas, New Mexico and Oklahoma for government, private and industrial clients. We have successfully used MDPE for remediation of petroleum hydrocarbon contamination at petroleum storage tank, pipeline release and oil and gas plant sites and boast a combined 25 years of MDPE experience. Our MDPE rigs are trailer and truck mounted, equipped with stingers or submersible pumps for fluid extraction for site remediation or to conduct pilot studies for design of larger and permanent remediation systems. Contact us at today to learn more MDPE and other environmental drilling services.

Topics: Remediation, Spill Management, MDPE