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Remediation Technologies Screening Matrix, Version 4.0 4.11 Biopiles
(Ex Situ Soil Remediation Technology)
  Description Synonyms Applicability Limitations Site Information Points of Contact
Data Needs Performance Cost References Vendor Info. Health & Safety
Table of Contents
Technology>>Soil, Sediment, Bedrock, and Sludge

>>3.4 Ex Situ Biological Treatment (assuming excavation)

      >>4.11 Biopiles
Introduction>> Excavated soils are mixed with soil amendments and placed in aboveground enclosures. It is an aerated static pile composting process in which compost is formed into piles and aerated with blowers or vacuum pumps.


Figure 4-11: Typical Biopile for Solid Phase Bioremediation Biopile treatment is a full-scale technology in which excavated soils are mixed with soil amendments and placed on a treatment area that includes leachate collection systems and some form of aeration. It is used to reduce concentrations of petroleum constituents in excavated soils through the use of biodegradation. Moisture, heat, nutrients, oxygen, and pH can be controlled to enhance biodegradation.

The treatment area will generally be covered or contained with an impermeable liner to minimize the risk of contaminants leaching into uncontaminated soil. The drainage itself may be treated in a bioreactor before recycling. Vendors have developed proprietary nutrient and additive formulations and methods for incorporating the formulation into the soil to stimulate biodegradation. The formulations are usually modified for site-specific conditions.

Soil piles and cells commonly have an air distribution system buried under the soil to pass air through the soil either by vacuum or by positive pressure. The soil piles in this case can be up to 20 feet high (generally not recommended, 2-3 meters maximum). Soil piles may be covered with plastic to control runoff, evaporation, and volatilization and to promote solar heating. If there are VOCs in the soil that will volatilize into the air stream, the air leaving the soil may be treated to remove or destroy the VOCs before they are discharged to the atmosphere.

Biopile is a short-term technology. Duration of operation and maintenance may last a few weeks to several months. Treatment alternatives include static processes such as: prepared treatment beds, biotreatment cells, soil piles, and composting.

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Heap pile bioremediation; Bioheaps; Biomounds; Static-pile composting.
DSERTS Code: H14 (Controlled Solid-Phase Bioremediation).

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Biopile treatment has been applied to treatment of nonhalogenated VOCs and fuel hydrocarbons. Halogenated VOCs, SVOCs, and pesticides also can be treated, but the process effectiveness will vary and may be applicable only to some compounds within these contaminant groups.

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Factors that may limit the applicability and effectiveness of the process include:
  • Excavation of contaminated soils is required.
  • Treatability testing should be conducted to determine the biodegradability of contaminants and appropriate oxygenation and nutrient loading rates.
  • Solid phase processes have questionable effectiveness for halogenated compounds and may not be very effective in degrading transformation products of explosives.
  • Similar batch sizes require more time to complete cleanup than slurry phase processes.
  • Static treatment processes may result in less uniform treatment than processes that involve periodic mixing.

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Data Needs:

A detailed discussion of these data elements is provided in Subsection 2.2.1 (Data Requirements for Soil, Sediment, and Sludge). The first steps in preparing a sound design for biotreatment of contaminated soil include:
  • Site characterization.
  • Soil sampling and characterization.
  • Contaminant characterization.
  • Laboratory and/or field treatability studies.
  • Pilot testing and/or field demonstrations.

Site, soil, and contaminant characterizations will be used to:

  • Identify and quantify contaminants.
  • Determine requirements for organic and inorganic amendments.
  • Identify potential safety issues.
  • Determine requirements for excavation, staging, and movement of contaminated soil.
  • Determine availability and location of utilities (electricity and water).

Laboratory or field treatability studies are needed to identify:

  • Amendment mixtures that best promote microbial activity.
  • Potential toxic degradation byproducts.
  • Percent reduction and lower concentration limit of contaminant achievable.
  • The potential degradation rate.

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Performance Data:

Biopile treatment has been demonstrated for fuel-contaminated sites. Specific site information is contained in the following site information Section.

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Costs are dependent on the contaminant, procedure to be used, need for additional pre- and post-treatment, and need for air emission control equipment. Biopiles are relatively simple and require few personnel for operation and maintenance. Typical costs with a prepared bed and liner are $130 to $260 per cubic meter ($30 to $60 per cubic yard).

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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

Remediation Technology Cost Compendium - Year 2000

Potential Applicability of Assembled Chemical Weapons Assessment Technologies to RCRA Waste Streams and Contaminated Media, August 2000, EPA 542-R-00-004

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

California Base Closure Environmental Committee (CBCEC), 1994. Treatment Technologies Applications Matrix for Base Closure Activities, Revision 1, Technology Matching Process Action Team, November, 1994.

Hartz, A.A. and R.B. Beach, 1992. "Cleanup of Creosote-Contaminated Sludge Using a Bioslurry Lagoon," in Proceedings of the HMC/Superfund '92, HMCRI, Greenbelt, MD.

Norris, et al., 1994. Handbook of Bioremediation, EPA-RSKERL, Lewis Publishers, CRC Press, 2000 Corporate Boulevard, Boca Raton, FL 33431.

Pope, D.F. and J.E. Matthews, 1993. Bioremediation Using the Land Treatment Concept, EPA Report EPA/600/R-93/164.

Sims, J.L., et al., 1989. Bioremediation of Contaminated Surface Soils, EPA, RSKERL, Ada, OK, EPA Report EPA/600/9-89/073.

von Fahnestock, F.M., et al., 1996. Biopile Design and Construction Manual, Navel Facilities Engineering Service Center Technical Memorandum, Port Hueneme, CA, TM-2189-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 Ex Situ Biological Soil 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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