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SURFAC® is EcoVac Services’ patented process combining the elements of dual/multi phase extraction (DPE/MPE) with surfactant injection. Nick Athens, co-owner of EcoVac Services, building upon the Enhanced Fluid Recovery (EFR®) technology invented and developed by co-owner David M. Goodrich, developed a patent relating surfactant enhanced aquifer remediation with DPE/MPE. This patent was awarded in December 2000.
This technology targets sites with light non-aqueous phase liquids (LNAPLs), dense non-aqueous phase liquids (DNAPLs), and/or high concentrations of their dissolved constituents. This surfactant enhanced aquifer remediation approach incorporates the use of non-ionic, non-toxic and biodegradable proprietary surfactants to mobilize and/or solubilize LNAPL or DNAPL, which is subsequently “captured” by DPE/MPE. SURFAC® typically requires 80% to 95% less remediation time than traditional technologies while simultaneously reducing the carbon footprint--and energy consumption--by approximately 75%, as compared to traditional surfactant enhanced aquifer remediation approaches.
EcoVac employs DPE/MPE in advance of surfactant injection to create vacuum and hydraulic gradients at injection points, creating a vacuum and hydraulic controlled gradient for proper placement and enhanced distribution of the emplaced surfactant. The combined elements of DPE/MPE with surfactant emplacement provides for maximum horizontal and vertical distribution of surfactant while also maximizing direct and undiluted contact with the contaminant and impacted media. High pressure injection, which can result in displacement of the contaminant plume and/or harmful vapors, is not a component of the SURFAC® process.
Surfactants facilitate contaminant removal by two primary mechanisms: first, through enhancing the mobility of the contaminant by reducing interfacial tension; and secondly by increasing contaminant solubility. Contaminant mobility, increased by interfacial tension reduction, allows the LNAPL or DNAPL to flow more readily through the subsurface. Contaminant solubility will also increase by the formation of micro-emulsions. Following surfactant injection--generally within 16 to 48 hours-- DPE/MPE is utilized to “capture” the mobilized contaminant, surfactant, and the micro-emulsions formed during this process. Aerobic biodegradation may also be enhanced during the SURFAC® process, as surfactants are considered a co-metabolite to aerobic hydrocarbon digesting microbes.
In the final phase of the process, we implement multiple spaced episodic DPE/MPE “capture” events to allow for “vertical” flushing of the impacted soil column. The extraction pattern varies to assure the most efficient sweep of the contaminant zone.
EcoVac Services has become the leading provider of surfactant remediation services in the United States, having completed over 50 SURFAC® projects. Removal of NAPL (LNAPL and DNAPL) utilizing our patented SURFAC® process has provided a cost cutting, quick and effective remediation process for our many satisfied customers.