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.
maintenance duration for bioslurping varies from a few months to years, depending on
specific site conditions.
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.
Technologies for Site Cleanup: Annual Status Report (ASR), Tenth Edition,
Technologies: Field Scale Demonstration Project in North America,
of Remediation Case Studies, Volume 4, June, 2000, EPA
American Petroleum Institute, 1989. A Guide to the Assessment and
Remediation of Underground Petroleum Releases, Publication 1628, API, Washington,
Guide to Documenting and Managing Cost and Performance Information for
Remediation Projects - Revised Version, October, 1998, EPA 542-B-98-007
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,
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.
Points of Contact:
General FRTR Agency Contacts
Technology Specific Web Sites:
Government Web Sites
Non Government Web Sites
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
Health and Safety: