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Remediation Technologies Screening Matrix, Version 4.0 4.33 Bioslurping
(In Situ GW Remediation Technology)
  Description Synonyms Applicability Limitations Site Information Points of Contact
Data Needs Performance Cost References Vendor Info. Health & Safety
Table of Contents
Technology>>Ground Water, Surface Water, and Leachate

>>3.10 In Situ Physical/Chemical Treatment

      >>4.33 Bioslurping
Introduction>> Bioslurping combines the two remedial approaches of bioventing and vacuum-enhanced free-product recovery. Bioventing stimulates the aerobic bioremediation of hydrocarbon-contaminated soils. Vacuum-enhanced free-product recovery extracts LNAPLs from the capillary fringe and the water table.


Figure 4-33:
Typical In Situ Bioslurping System  

Bioslurping is the adaptation and application of vacuum-enhanced dewatering technologies to remediate hydrocarbon-contaminated sites. Bioslurping utilizes elements of both, bioventing and free product recovery, to address two separate contaminant media. Bioslurping combines elements of both technologies to simultaneously recover free product and bioremediate vadose zone soils. Bioslurping can improve free-product recovery efficiency without extracting large quantities of ground water. In bioslurping, vacuum-enhanced pumping allows LNAPL to be lifted off the water table and released from the capillary fringe. This minimizes changes in the water table elevation which minimizes the creation of a smear zone. Bioventing of vadose zone soils is achieved by drawing air into the soil due to withdrawing soil gas via the recovery well. The system is designed to minimize environmental discharge of ground water and soil gas. When free-product removal activities are completed, the bioslurping system is easily converted to a conventional bioventing system to complete the remediation.

Operation and maintenance duration for bioslurping varies from a few months to years, depending on specific site conditions.

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Free product recovery.

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Bioslurping can be successfully used to remediate soils contaminated by petroleum hydrocarbons. It is a cost-effective in situ remedial technology that simultaneously accomplishes LNAPL removal and soil remediation in the vadose zone.  Bioslurping is also applicable at sites with a deep ground water table (>30ft.).

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Factors that may limit the applicability and effectiveness of the bioslurping process include: 
  • Bioslurping is less effective in tight (low-permeability) soils. 
  • Low soil moisture content may limit biodegradation and the effectiveness of bioventing, which tends to dry out the soils. 
  • Aerobic biodegradation of many chlorinated compounds may not be effective unless there is a co-metabolite present. 
  • Low temperatures slow remediation.
  • Frequently, the off-gas from the bioslurper system requires treatment before discharge. However, treatment of the off-gas may only be required shortly after the startup of the system as fuel rates decrease.
  • At some sites, bioslurper systems can extract large volumes of water that may need to be treated prior to discharge depending on the concentration of contaminants in the process water.
  • Since the fuel, water and air are removed from the subsurface in one stream, mixing of the phases occurs. These mixtures may require special oil/water separators or treatment before the process water can be discharged.

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Data Needs:

A detailed discussion of these data elements is provided in Subsection 2.2.2. (Data Requirements for Ground Water, Surface Water, and Leachate). Determination of the radius of treatment influence and number of extraction wells during the feasibility study and pilot-scale testing is critical for the lay-out design of a full-scale bioslurping application. Additionally, a feasibility test and an air permeability test are necessary to determine design data, including time of release, quantity of release, and free product thickness.

Soil grain size and soil moisture significantly influence soil gas permeability. Perhaps the greatest limitation to air permeability is excessive soil moisture. A combination of high water tables, high moisture, and fine-grained soils has made bioslurping infeasible. Optimum soil moisture is very soil-specific because too much moisture can reduce the air permeability of the soil and decrease its oxygen transfer capability. Too little moisture will inhibit microbial activity. 

In situ aeration/respiration testing is also needed to provide rapid field measurement of the in situ degradation rate.

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Performance Data:

The U.S. Navy has used bioslurping at Naval Aviation Facility in Fallon, NV. This system was able to remove 6,500 gallons of JP-5 jet fuel during 1993, with operation 75% of the time. Bioslurping will also be initiated at MCAS Kaneohe Bay HI, which has extensive subsurface plumes of JP-5.

The U.S. Air Force used a bioslurper on the island of Diego Garcia to pull out JP-5 at the site where jet fuel leaked into the ground during the Persian Gulf War. The recovery rate of JP-5 averaged about 1,000 gallons per month.

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Bioslurping of LNAPL at Multiple Air Force Sites was $56/gal LNAPL recovered.

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Treatment Technologies for Site Cleanup: Annual Status Report (ASR), Tenth Edition, EPA 542-R-01-004

Innovative Remediation Technologies:  Field Scale Demonstration Project in North America, 2nd Edition

Abstracts of Remediation Case Studies, Volume 4,  June, 2000, EPA 542-R-00-006

Guide to Documenting and Managing Cost and Performance Information for Remediation Projects - Revised Version, October, 1998, EPA 542-B-98-007

American Petroleum Institute, 1989. A Guide to the Assessment and Remediation of Underground Petroleum Releases, Publication 1628, API, Washington, DC, pp.81.

Baker, R.S. and J.Bierschenk, 1996. "Bioslurping LNAPL contamination". Pollution Engineering, March, pp.38-40.

EPA, 1997. Analysis of Selected Enhancements for Soil Vapor Extraction, EPA OSWER, EPA/542/R-97/007.

Miller, R.R., 1996. Bioslurping, GWRTAC, TO-96-05.

U.S. Navy, 1996. Restoration Development Branch: Bioslurping, USN, Naval Facilities Engineering Service Center, Port Hueneme, CA.

USAF, 1994. Technology Profile: Vacuum-Mediated LNAPL Free Product Recovery/Bioremediation (Bioslurper), Air Force Center for Environmental Excellence (AFCEE), Brooks AFB, TX. March.

USAF, January 1995. Draft: Test Plan and Technical Protocol for Bioslurping, USAF, Air Force Center for Environmental Excellence, Brooks AFB, TX.

Wickramanayake, G.B., et al., 1996. "Best Practices Manual for Bioslurping", Technical Memorandum, Naval Facilities Engineering Service Center, TM-2192-ENV.

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Site Information:

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Points of Contact:

General FRTR Agency Contacts

Technology Specific Web Sites:

Government Web Sites

Non Government Web Sites

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Vendor Information:

A list of vendors offering In Situ Physical/Chemical Water Treatment is available from EPA REACH IT which combines information from three established EPA databases, the Vendor Information System for Innovative Treatment Technologies (VISITT), the Vendor Field Analytical and Characterization Technologies System (Vendor FACTS), and the Innovative Treatment Technologies (ITT), to give users access to comprehensive information about treatment and characterization technologies and their applications.

Government Disclaimer

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Health and Safety:

Hazard Analysis

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Introduction Contaminants Treatments/Profiles References Appendices Navigation