U.S. EPA Contaminated Site Cleanup Information (CLU-IN)

U.S. Environmental Protection Agency
U.S. EPA Technology Innovation and Field Services Division

In Situ Flushing Site Profiles


photoThe U.S. Environmental Protection Agency (EPA) has developed this website to summarize timely information about selected full- and field-scale applications of in situ flushing technologies. In situ flushing involves the injection or infiltration of an aqueous solution into a zone of contaminated soil or groundwater, followed by extraction and aboveground treatment of the elutriate (the flushing solution mixed with contaminants). The flushing solution and treated contaminants may be left in place in some rare cases. The solutions used for in situ flushing may consist of surfactants, cosolvents, acids, bases, oxidants, chelants, solvents, or water. Recent applications have also documented the use of cyclodextrin, a nontoxic modified sugar, as a flushing agent. These flushing solutions typically increase the mobility or solubility of the contaminants. Many organic contaminants are susceptible to in situ flushing, including nonaqueous phase liquids (NAPLs), volatile organic compounds (VOCs), semivolatile organic compounds (SVOCs), polychlorinated biphenyls (PCBs), halogenated pesticides, dioxins/furans, cyanides, and corrosives. Inorganic compounds such as volatile and nonvolatile metals, corrosives, cyanides, and radioactive contaminants may also be removed using in situ flushing.

photoThis database provides information about ongoing and completed applications of in situ flushing technologies to treat chlorinated solvents, petroleum products, metals, explosives, and PCBs in groundwater and soil. The project profiles provide summary information about each application, including site information, contaminants, and media treated, technology design and operation, cost information, and performance results, as well as points of contact and references. Projects for this website are collected using information from technical journals and conference proceedings, as well as other published sources, including records of decision (ROD) or 5-year reviews. As of December 2013, the website included information on 56 profiles in situ flushing project profiles, both completed and on-going applications.

As further information is obtained, EPA plans to update and expand this website with updated and new in situ flushing projects.

For more information or to update or add a new profile*, please use the project submittal form and e-mail the completed form to For further information, contact:

Ed Gilbert, EPA
(703) 603-8883

* Information about new projects must be published in peer-reviewed journals, conference proceedings, or other published sources, including RODs or 5-year reviews. Unpublished data will not be accepted.

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