For more information on the DNAPL Website, please contact:
Linda FiedlerTechnology Assessment Branch
PH: (703) 603-7194 | Email: fiedler.linda@epa.gov
Dense nonaqueous phase liquids (dnapls)
treatment technologies
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Direct and Multiphase Recovery
Halogenated Alkanes
The following case studies describe the use of Direct and Multiphase Recovery at sites with halogenated alkane contamination.
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Bromochloromethane |
Methylene Chloride |
Chloroform
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Ellsworth Air Force Base, South Dakota
U.S. EPA, Superfund Site Progress Profile.
OU-1 contains the former fire-protection training area. Aqueous film-forming foam, halon, protein foams, carbon dioxide, chlorobromomethane, and dry chemicals were used as extinguishing chemicals during the fire-training exercises. OU-1 remedies include SVE, dual-phase extraction, and institutional controls. There is no cleanup goal for BCM; the focus is on BTEX and more commonly found halogenated alkenes and alkanes.
Pemaco, Maywood, California
U.S. EPA, Superfund Site Progress Profile.
MC is one of many organic contaminants found at this hydrogeologically complex site. The treatment technologies selected include electrical resistive heating, SVE, pump and treat, and dual-phase extraction.
Hitachi Global Storage Technologies, Inc., San Jose, California
California Department of Toxic Substances Control Web site.
Hitachi GST moved its R&D and administrative office operations to a different location in San Jose and demolished most of the R&D and administrative office buildings at the site, formerly owned and operated by IBM. A portion of land has been rezoned and will be sold and redeveloped. After chloroform was discovered in the site's soil, soil gas, and groundwater, remediation consisted of dual-phase vacuum extraction of soil vapor and contaminated groundwater using 4-in diameter extraction wells installed to the top of the AlB Aquitard at about 38 ft bgs. Dual-phase extraction was conducted selectively using 12 of 18 extraction wells installed to optimize mass removal performance. System operation lasted 56 weeks, or almost 13 months, with a 1-month shutdown occurring after ~3 months of system operation. During 7,968 hours of operation, the system removed 68.7 million cubic ft of soil vapor and 535,000 gallons of groundwater. The average system vapor extraction rate was 169 cubic feet per minute and the groundwater pumping rate was 1.2 gallons per minute.



