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Bioventing Page 1 of 5 <br /> "raw, <br /> Underground Storage Tanks <br /> a � Recent Additions IC.ontact Us I Print Version Search: <br /> a .y. EPA Home> Underground Storage.Tanks >_Cleaning_UP UST System Releases>Bioventing <br /> 4 PR <br /> Basic Information Bioventing <br /> Where You Live <br /> A to Z Subject Index The following description of bioventing is an excerpt from Chapter Ill of OUST's <br /> Frequent Questions publication: How to Evaluate Alternative Cleanup Technologies for <br /> Underground Storage Tank Sites:A Guide for Corrective Action Plan <br /> Laws/Statutes Reviewers. (EPA 510-B-95-007). This publication also describes 9 additional <br /> Regulations/Standards alternative technologies for remediation of petroleum releases. You can download <br /> PDF files of every chapter of the document at: <br /> Policy Guidance http;//www,.epa.go_v/swerust1/pubs/tums.htm. <br /> Compliance Help <br /> Publications <br /> Bioventing is an in situ remediation technology that uses indigenous <br /> Related Links microorganisms to biodegrade organic constituents adsorbed to soils in the <br /> Program Facts unsaturated zone. Soils in the capillary fringe and the saturated zone are not <br /> affected. In bioventing, the activity of the indigenous bacteria is enhanced by <br /> Program Priorities inducing air(or oxygen) flow into the unsaturated zone (using extraction or injection <br /> State, Local&Tribal wells) and, if necessary, by adding nutrients. <br /> Programs <br /> Regional EPA Program When extraction wells are used for bioventing, the process is similar to soil vapor <br /> Offices extraction (SVE). However, while SVE removes constituents primarily through <br /> volatilization, bioventing systems promote biodegradation of constituents and <br /> minimize volatilization (generally by using lower air flow rates than for SVE). In <br /> practice, some degree of volatilization and biodegradation occurs when either SVE <br /> or bioventing is used. <br /> Application <br /> All aerobically biodegradable constituents can be treated by bioventing. In <br /> particular, bioventing has proven to be very effective in remediating releases of <br /> petroleum products including gasoline,jet fuels, kerosene, and diesel fuel. <br /> Bioventing is most often used at sites with mid-weight petroleum products (i.e., <br /> diesel fuel and jet fuel), because lighter products (i.e., gasoline) tend to volatilize <br /> readily and can be removed more rapidly using SVE. Heavier products (e.g., <br /> lubricating oils) generally take longer to biodegrade than the lighter products. <br /> Bioventing is not appropriate for sites with groundwater tables located less than 3 <br /> feet below the land surface. Special considerations must be taken for sites with a <br /> groundwater table located less than 10 feet below the land surface because <br /> groundwater upwelling can occur within bioventing wells under vacuum pressures, <br /> potentially occluding screens and reducing or eliminating vacuum-induced soil <br /> vapor flow. This potential problem is not encountered if injection wells are used <br /> instead of extraction wells to induce air flow. <br /> If a cleanup level lower than 0.1 ppm is required for any individual constituent or a <br /> reduction in TPH greater than 95 percent is required to reach the cleanup level for <br /> TPH, either a pilot study should be required to demonstrate the ability of bioventing <br /> to achieve these reductions at the site or another technology should be considered. <br /> Operation Principles <br /> http://www.epa.gov/swerustI/catibiovent.htm 6/17/2004 <br />