Download - Ert Student Manual 3ppg 2012-01-09
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Off ce of Solid Waste andEmergency Response(5201G)
December 2011www.epa.gov/superfund
Environmental Remediation Technologies
Superfund
United StatesEnvironmental ProtectionAgency
Student Manual
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ENVIRONMENTAL REMEDIATION TECHNOLOGIES TABLE OF CONTENTS
Section 1 ................................... Successful Treatment Design
Section 2 ................................... Fate and Transport
Section 3 ................................... Capping and Containment
Section 4 ................................... Basic Water Treatment
Section 5 ................................... Chemical Reactions and Separations
Section 6 ................................... Sediment Remediation
Section 7 ................................... Bioremediation
Section 8 ................................... Monitored Natural Attenuation
Section 9 ................................... In-situ Treatments
Section 10 ................................. Soil Washing and Immobilization
Section 11 ................................. Thermal Treatment
Section 12 ................................. Phytoremediation
Section 13 ................................. Process Testing
Section 14 ................................. Technology Selection
Section 15 ................................. Exercises
Acronyms and Abbreviations
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ENVIRONMENTAL REMEDIATION TECHNOLOGIES 3 DAYS
This introductory-level course provides participants with an overview of the treatment technologies most frequently used for cleanups of contaminated media. The emphasis of the course is on the technology description, applicability, and limitations of appropriate treatment technologies. It is intended for new On-Scene Coordinators, Remedial Project Managers, Waste Site Managers, and other environmental personnel interested in remediation.
Topics that are discussed include site characterization; fate and transport; technology screening; capping and containment; basic water treatment; chemical reactions and separations; in-situ treatments; sediment remediation; phytoremediation; bioremediation; soil washing and immobilization; thermal treatment; and process testing.
Training methods include lectures and group problem-solving exercises. Case studies are used to demonstrate applications of the treatment technologies. Group discussions relevant to the course are encouraged.
After completing the course, participants will be able to:
Evaluate appropriate techniques to assess, stabilize, and screen potential remedies for contaminated sites.
Identify the processes and explain the limitations of the most frequently used treatment technologies.
Identify resources that describe innovative treatment technologies.
Note: Calculators are recommended.
Continuing Education Units: 1.9
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Orientation and Introduction
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
presented byTetra Tech NUS, Inc.
for theU.S. Environmental Protection Agency'sEnvironmental Response Team
OSWER
U.S. EPA
Office of Solid Waste and Emergency Response (Superfund)
United States Environmental Protection Agency
Environmental Response TeamERT
Office of Superfund Remediationand Technology Innovation
OSRTI
Are offered tuition-free for environmental and response personnel from federal, state, and local agenciesVary in length from one to five daysAre conducted at EPA Training Centers the United States
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Orientation and Introduction
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Course Descriptions, Class Schedules, and Registration Information are available at:
www.trainex.org
www.ertpvu.org
Evaluate appropriate techniques to assess, stabilize, and screen for potential remedies for contaminated sites
Identify the processes and explain the limitations of the most frequently-used treatment technologies
Identify resources that describe innovative treatment technologies
Student Registration Card
Student Evaluation Form
Course Agenda
Student Manual
Facility InformationStudent Handouts
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Orientation and Introduction
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Parking
Classroom
Restrooms
Water fountains, snacks, refreshments
LunchTelephones
Emergency telephone numbers
Alarms and emergency exits
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Environmental Remediation Technologies - REFERENCES
SUCCESSFUL TREATMENT DESIGN U.S. EPA. Guidance for Conducting Remedial Investigations and Feasibility Studies Under CERCLA. U.S. Environmental Protection Agency. Office of Emergency and Remedial Response. Washington, DC. October 1988.
Wong, Jimmy H. C. et al. Design of Remediation Systems. Lewis Publishers reprint of CRC Press, Inc. Boca Raton, FL. 1997.
Nyer, Evan K. et al. In Situ Treatment Technology. Lewis Publishers reprint of CRC Press, Inc. Boca Raton, FL. 1996.
Rodriguez, Rey and Rosenfeld, Paul. Successful Remediation Technologies. National Groundwater Association. Columbus, Ohio. October 2003.
Monroe, James S. and Wicander, Reed. Physical Geology, Exploring the Earth. West Publishing Company. Saint Paul, MN. 1995
Heath, Ralph C. Basic Ground-Water Hydrology. U.S. Geological Survey. Water Supply Paper 2220. U.S. GPO. Washington, DC. 1987.
Interstate Technology & Regulatory Council. Technical and Regulatory Guidance for the Triad Approach: A new Paradigm for Environmental Project Management. Interstate Technology & Regulatory Council. Sampling, Characterization, and Monitoring Team. Washington, DC. December 2003.
Dupont, R. Ryan et al. Bioremediation, Innovative Site Remediation Technology: Design and Application. American Academy of Environmental Engineers. Annapolis, MD. 1997.
FATE AND TRANSPORT OF CHEMICAL CONTAMINANTS Brady, Wyle. The Nature and Properties of Soils. 8th ed. Macmillan Publishing Co. New York, NY. 1974.
Dragun, James. The Soil Chemistry of Hazardous Materials. 2nd ed. Amherst Scientific Publishers. Amherst, MA. 1998.
Ney, Ronald. Where Did That Chemical Go? A Practical Guide to Chemical Fate and Transport in the Environment. Van Nostrand Reinhold. New York, NY. 1990. Schwarzenbach, Rene et al. Environmental Organic Chemistry. John Wiley & Sons, Inc. New York, NY. 1993.
U.S. EPA 1989. Transport and Fate of Contaminants in the Subsurface (Seminar Publication). EPA/625/4-89/019. U.S. Environmental Protection Agency. Center for Environmental Research Information. Cincinnati, OH. 1989
U.S. EPA 1990. Subsurface Contamination Reference Guide. EPA/540/2-90/011. U.S. Environmental Protection Agency. Office of Emergency and Remedial Response. Washington, DC. 1990.
U.S. EPA 1991a. Assessing UST Corrective Action Technology - A Scientific Evaluation of the Mobility and Degradability of Organic Contaminants in Subsurface Environments.
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EPA/600/2-91/053. U.S. Environmental Protection Agency. Office of Research and Development. Washington, DC. 1991.
U.S. EPA 1991b. Seminar Publication - Site Characterization for Subsurface Remediation. EPA/625/4-91/026. U.S. Environmental Protection Agency. Office of Research and Development. Washington, DC. 1991.
U.S. EPA 1999. Groundwater Issue: Fundamentals of Soil Science as Applicable to Management of Hazardous Waste. EPA/540/5-98/500. U.S. Environmental Protection Agency. Office of Research and Development/Office of Solid Waste and Emergency Response. Washington, DC. 1999.
CAPPING AND CONTAINMENT U.S. EPA. Requirements for Hazardous Waste Landfill Design, Construction, and Closure. Pub. EPA/625/4-89/022. Center for Environmental Research Information. Office of R & D. U.S. Environmental Protection Agency. Cincinnati, OH. 1989
U.S. EPA. Evaluation of Subsurface Engineering Barriers at Waste Sites. Pub. EPA542-R-98-005. U.S. Environmental Protection Agency. Office of Solid Waste and Emergency Response (5102G). Washington, DC. 1998
BASIC WATER TREATMENT Kemmer, Frank N. The NALCO Water Handbook. 2nd Edition. McGraw-Hill Book Company. New York, NY. 1988.
CHEMICAL REACTIONS AND SEPARATIONS U.S. EPA. E. I. Dupont De Nemours and Company/Oberlin Filter Company Microfiltration Technology. EPA/540/A5-90/007. U.S. Environmental Protection Agency. Risk Reduction Engineering Laboratory. Cincinnati, OH. 1991.
IN-SITU TREATMENTS; NATURAL ATTENUATION, SVE, AND AIR SPARGING. National Research Council. Natural Attenuation for Groundwater Remediation. National Academy Press. Washington, DC. 2000.
ITRC. Innovative Site Remediation Technology: Technical/Regulatory Guidelines, Natural Attenuation of Chlorinated Solvents in Groundwater: Principles and Practices. Interstate Technology and Regulatory Cooperation Work Group. Washington, DC. 1999
Wong, Jimmy H. C. and et al. Design of Remediation Systems. Lewis Publishers reprint of CRC Press, Inc. Boca Raton, FL. 1997.
Nyer, Evan K. and et al. In Situ Treatment Technology. Lewis Publishers reprint of CRC Press, Inc. Boca Raton, FL. 1996.
IN-SITU TREATMENTS; PERMEABLE REACTIVE BARRIERS AND CHEMICAL OXIDATION U.S. EPA. Permeable Reactive Barrier Technologies for Contaminant Remediation. U.S. Environmental Protection Agency. Office of Solid Waste and Emergency Response. Washington, DC. 1998.
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ITRC. Innovative Site Remediation Technology: Technical/Regulatory Guidelines, Technical and Regulatory Guidance for In Situ Chemical Oxidation of Contaminated Soil and Groundwater. Interstate Technology and Regulatory Cooperation Work Group. Washington, DC. 2001.
ITRC. Innovative Site Remediation Technology: Regulatory Guidance for Permeable Reactive Barriers Designed to Remediate Chlorinated Solvents. Interstate Technology and Regulatory Cooperation Work Group. Washington, DC. 1999. Wong, Jimmy H. C. and et al. Design of Remediation Systems. Lewis Publishers reprint of CRC Press, Inc. Boca Raton, FL. 1997.
Nyer, Evan K. et al. In Situ Treatment Technology. Lewis Publishers reprint of CRC Press, Inc. Boca Raton, FL. 1996.
BIOREMEDIATION U.S. EPA. 1992b. Engineering Bulletin: Rotating Biological Contractors. Office of Emergency and Remedial Response. U.S. Environmental Protection Agency. Washington, DC.
Wolfe, David W. Tales From the Underground: A Natural History of Subterranean Life. Perseus Publishing. Cambridge, MA. April, 2001.
Dupont, R. Ryan. Innovative Site Remediation Technology: Design and Application, Bioremediation. American Academy of Environmental Engineers. U.S. EPA. Manual, Ground-water and Leachate Treatment Systems. Office of Research and Development. U.S. Environmental Protection Agency. Washington, DC. January, 1995.
In Site Bioremediation When does it work? Committee on In Situ Bioremediation. National Academy Press. Washington, DC. 1993
Operation of Wastewater Treatment Plants. Subcommittee on Operation of Wastewater Treatment Plants. Water Pollution Control Federation. Washington, DC. 1976.
U.S. EPA. Use of Bioremediation at Superfund Sites. Office of Solid Waste and Emergency Response. U.S. Environmental Protection Agency. Washington, DC. 2001.
Norris, Robert D. et al. Handbook of Bioremediation. Lewis Publishers reprint of CRC Press, Inc. Boca Raton, FL. 1994.
PHYTOREMEDIATION Pivetz, B. E. Ground Water Issue-Phytoremediation of Contaminated Soil and Ground Water at Hazardous Waste Sites. USEPA-ORD EPA/540/S-01/500. U.S. Environmental Protection Agency. Washington, DC. 2001.
ITRC. Technical and Regulatory Guidance Document-Phytotechnology. ITRC Phytotechnologies Work Team. Interstate Technology and Regulatory Cooperation Work Group. Washington, DC. 2001.
U.S. EPA. Introduction to Phytoremediation. EPA/600/R-99/107. National Risk Management Research Laboratory. U.S. Environmental Protection Agency. Cincinnati, OH. 2000.
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Schnoor, J. L. Phytoremediation. TE-98-01. Ground-Water Remediation Technologies Analysis Center. Pittsburgh, PA. 1997.
MONITORED NATURAL ATTENUATION National Research Council. Natural Attenuation for Groundwater Remediation. National Academy of Sciences, Washington, DC, 2001.
U.S. EPA. How to Evaluate Alternative Cleanup Technologies for Underground Storage Tank Sites a Guide for Corrective Action Reviewers. EPA 510-R-04-002. Solid Waste and Emergency Response. Washington D. C. May 2004.
SOIL WASHING AND SOLVENT EXTRACTION U.S. EPA. Engineering Bulletin: Soil Washing Treatment. EPA/540/2-90/017. U.S. Environmental Protection Agency. Office of Emergency and Remedial Response. Washington, DC; and Office of Research and Development. Cincinnati, OH. 1990.
U.S. EPA. Engineering Bulletin: In Situ Soil Flushing. EPA/540/2-91/021. U.S. Environmental Protection Agency. Office of Emergency and Remedial Response. Washington, DC; and Office of Research and Development. Cincinnati, OH.1991a.
U.S. EPA. Guide for Conducting Treatability Studies Under CERCLA: Soil Washing. (Quick Reference Fact Sheet). EPA/540/2-91/020B. U.S. Environmental Protection Agency. Office of Solid Waste and Emergency Response; and Office of Emergency and Remedial Response. Washington, DC. 199lb.
U.S. EPA. Guide for Conducting Treatability Studies Under CERCLA Solvent Extraction. (Interim Guidance). EPA/54O/2-92/016a. U.S. Environmental Protection Agency. Office of Emergency and Remedial Response. Washington, DC. 1992a.
U.S. EPA. Guide for Conducting Treatability Studies Under CERCLA: Solvent Extraction. (Quick Reference Fact Sheet). EPA/5401R-92/016b. U.S. Environmental Protection. Agency. Office of Solid Waste and Emergency Response; and Office of Emergency and Remedial Response. Washington, DC.1992b.
U.S. EPA. Applications Analysis Report: Resources Conservation Company B.E.S.T. Solvent Extraction Technology. EPA/540/AR-92/079. U.S. Environmental Protection Agency. Office of Research and Development. Washington, DC. 1993.
U.S. EPA. Engineering Bulletin: Solvent Extraction. EPA/540/S-94/503. U.S. Environmental Protection Agency. Office of Emergency and Remedial Response. Washington, DC; and Office of Research and Development. Cincinnati, OH.1994a.
U.S. EPA. Superfund Innovative Technology Evaluation: Technology Demonstration Summary: EPA RREL's Mobile Volume Reduction Unit.EPAI54O/SR-93/508. U.S. Environmental Protection Agency. Risk Reduction Engineering Laboratory. Cincinnati, OH. 1994b.
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IMMOBILIZATION U.S. EPA. Immobilization Technology Seminar: Speaker Slide Copies and Supporting Information U.S. Environmental Protection Agency. Risk Reduction Engineering Laboratory. Cincinnati, OH. 1990
U.S. EPA. Stabilization/Solidification of CERCLA and RCRA Wastes: Physical Tests, Chemical Testing Procedures, Technology Screening and Field Activities. U.S. Environmental Protection Agency. Office of Research and Development. Washington, DC. 1989
U.S. EPA. Stabilization/Solidification of Organics and Inorganics. EPA/540/S-92/015. U.S. Environmental Protection Agency. Office of Emergency and Remedial Response, Washington, DC; and Office of Research and Development, Cincinnati, OH. 1993
U.S. EPA. Engineering Bulletin: In-situ Vitrification Treatment. EPA/540/S-94/504. U.S. Environmental Protection Agency. Office of Emergency and Remedial Response. Washington, DC. 1994
THERMAL TREATMENT U.S. EPA. Engineering Bulletin: Mobile/Transportable Incineration Treatment.EPA/540/2-90/014. U.S. Environmental Protection Agency. Office of Research and Development. Risk Reduction Engineering Laboratory. Cincinnati, OH. 1990.
U.S. EPA. Superfund Engineering Issue: Issues Affecting the Applicability and Success of Remedial/Removal Incineration Projects. EPA/540/2-91/004. U.S. Environmental Protection Agency. Office of Research and Development. Office of Solid Waste and Emergency Response. Washington, DC. 1991a.
U.S. EPA. Treatment Technologies. 2nd Ed. ISBN: 0-86587-263-5. U.S. Environmental Protection Agency. Office of Solid Waste. Government Institutes, Inc. Rockville, MD. 1991b.
U.S. EPA. Engineering Bulletin: Thermal Desorption Treatment. EPA/540/S-94/501. U.S. Environmental Protection Agency. Office of Emergency and Remedial Response. Washington, DC; and Office of Research and Development. Cincinnati, Ohio. 1994.
TECHNOLOGY SELECTION Federal Remediation Technologies Roundtable. Remediation Technologies Screening Matrix and Reference Guide, Version 4.0. Web address http://www.frtr.gov/matrix2/top_page.html U.S. EPA. How to Evaluate Alternative Cleanup Technologies for Underground Storage Tank Sites. EPA 510-R-04-002. Office of Solid Waste and Emergency Response. U.S. Environmental Protection Agency. Washington, DC. 2004
U.S. EPA. Seminar Publication, Guide for Conducting Treatability Studies under CERCLA. Publication EPA/540/R-92/071a. Office of Solid Waste and Emergency Response. Office of Research and Development. U.S. Environmental Protection Agency. Washington, DC. 1992
U.S. EPA. Presumptive Remedy for CERCLA Municipal Landfill Sites. EPA 540-F-93-035. Office of Solid Waste and Emergency Response. Office of Research and Development. U.S. Environmental Protection Agency. Washington, DC. 1993
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U.S. EPA. Presumptive Remedies: Site Characterization and Technology Selection for CERCLA Sites with Volatile Organic Compounds in Soils. EPA 540-F-93-048. Office of Solid Waste and Emergency Response. Office of Research and Development. U.S. Environmental Protection Agency. Washington, DC. 1993
U.S. EPA. Presumptive Response Strategy and Ex-Situ Treatment technologies for Contaminated Ground Water at CERCLA Sites. EPA/540/R-96/023. Office of Solid Waste and Emergency Response. Office of Research and Development. U.S. Environmental Protection Agency. Washington, DC. 1996
U.S. EPA. Presumptive Remedies for Soils, Sediments, and Sludges at Wood Treater Sites. EPA/540/R-95/128. Office of Solid Waste and Emergency Response. Office of Research and Development. U.S. Environmental Protection Agency. Washington, DC. 1995
PROCESS TESTING U.S. EPA. Innovative Site Remediation Technology-Design and Application-Thermal Desorption Volume 6. EPA 542-B-93-011. U.S. Environmental Protection Agency. Washington, DC. 1993.
Chu, C. Observations of Performance Test. WA#R1A00111, Trip Report. FCX Engineering. April 17, 2000.
WEBSITES www.epa.gov www.clu-in.org www.frtr.gov
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Student Performance ObjectivesUpon completion of this unit, students will be able to:
1. Understand the general principles of the Triad approach
2. Describe the key components of the conceptual site model
SUCCESSFUL TREATMENT DESIGN
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Successful Treatment Design
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
A successful treatment design requires a clear understanding of specific site conditions.
During many earlier environmental restoration projects, the collection of site-specific data proved to be a lengthy and expensive process.
Clear project goals are established through the use of:
Systematic Project Planning
Dynamic Work Strategies
Real-time Measurement Technologies
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Successful Treatment Design
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Image Courtesy of USGS
Initial investigation for the source of the oil release discovered high Concentrations of a chlorinated solvent (TCE) north of the mill building
In developing a CSM, key elements include:
General physical site description
Regional environmental setting
Land use
Contaminant information and site activities
Potential exposure pathways and risk estimation
On-going data evaluation and data gap identification
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Successful Treatment Design
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
In developing a CSM, key elements include:
General physical site descriptionRegional environmental setting
Land use
Contaminant information and site activities
Potential exposure pathways and risk estimation
On-going data evaluation and data gap identification
Facility descriptionSite addressGeneral site operation
Physical settingArea topographyArea land use
Chem-Dyne general site operations:
Operated from 1974 to 1980 on a 10-acre site
Stored, recycled, and disposed of many types of industrial chemical wastes
Thousands of 55-gallon drums
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Successful Treatment Design
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Facility descriptionSite addressGeneral site operation
Physical settingArea topographyArea land use
Site
Site is bounded to the south by residential property
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Successful Treatment Design
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Site is bounded to the north by the Ford Hydraulic Canal and, further north, by agricultural fields
In developing a CSM, key elements include:
General physical site description
Regional environmental settingLand use
Contaminant information and site activities
Potential exposure pathways and risk estimation
On-going data evaluation and data gap identification
Geology
Site is located on the Great Miami River alluvial deposits glacial outwash materials consisting of poorly sorted, poorly bedded silt and sand.
Depth of Ordovician limestone bedrock is greater than 100 feet below the surface.
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Successful Treatment Design
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Hydrogeology
Site is located on permeable sand and gravel deposits in ancestral drainage channels
Deep aquifer groundwater wells yield 5001000 gpm
Site includes a shallow unconfined aquifer and a deep confined aquifer
Site
Site
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Successful Treatment Design
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Ecological ProfileDescribes the physical relationship of the organisms on the developed and undeveloped portion of the site and adjacent off-site properties
In developing a CSM, key elements include:
General physical site description
Regional environmental setting
Land useContaminant information and site activities
Potential exposure pathways and risk estimation
On-going data evaluation and data gap identification
Land use descriptionsLand use historyCurrent land use
The Triad approach works toward a viable end use of the land. Current use and proposed use are important.
Example Chem-Dyne site:Currently a remediation project operated by the Chem-Dyne TrustNo future use has been proposed at this time
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Successful Treatment Design
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Federal, state, and local operating permitsReported releases or spillsFacility RecordsPublic Records
Title historyCity directoriesAerial photographsSanborn Fire Insurance MapsLocal agencies
Public records (title history & city directories):1910 to 1960s Ford Motor Co. 1960s to 1974 Nimrod Camping Trailer 1974 to 1980 Chem-Dyne Recycling Facility1980 to present Chem-Dyne Trust
(remediation project)
Chem-DyneHamilton, OH
Aerial photoDecember, 1979
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Successful Treatment Design
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Sanborn Fire Insurance maps:1927 Ford Motor Co. forge and
manufacturing facility1950 Ford Motor Co. metal
stamping and wheel manufacturing facility
1969 Ward Manufacturing (Nimrod Camping Trailer Division)
Local agency reports (ChemDyne):
Hamilton Fire Department reported numerous fire responses. Firemen became ill and fire hoses dissolved in standing puddles. Reports led to a health department and Ohio EPA investigation. Site operations were suspended in 1980.
In developing a CSM, key elements include:General physical site description
Regional environmental setting
Land use
Contaminant information and site activitiesPotential exposure pathways and risk estimation
On-going data evaluation and data gap identification
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Successful Treatment Design
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
This component of the CSM includes the following information:
Previous site activitiesContaminants of concernPotential contaminant source areasContaminant fate and transportContaminant susceptibility to treatment options
This component of the CSM includes the following information:
Previous site activitiesContaminants of concern
Potential contaminant source areas
Contaminant fate and transport
Contaminant susceptibility to treatment options
Removal Action
Stabilization
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Successful Treatment Design
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
General rule at many sites:80% of the contamination removed during immediate remedial action often is completed for 20% of the total project cost
Chem-Dyne:Removal of drums and standing liquidExcavation of grossly contaminated soil
This component of the CSM includes the following information:
Previous site activities
Contaminants of concernPotential contaminant source areas
Contaminant fate and transport
Contaminant susceptibility to treatment options
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Successful Treatment Design
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Identification from recordsLocal Emergency Planning CommitteeRCRA listingOperator knowledge
Identification by sample analysisField screeningTarget Compound List (TCL) and Target Analyte List (TAL) analysisRegulatory agency-specific list
At the Chem-dyne site, many TCL and TAL hazardous materials were detected, including:
Volatile organic compounds (VOC)Semi-volatile organic compoundsPCBsTAL (metals)
This component of the CSM includes the following information:
Previous site activities
Contaminants of concern
Potential contaminant source areasContaminant fate and transport
Contaminant susceptibility to treatment options
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Successful Treatment Design
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Areas where hazardous material is stored, used, or disposed, such as:
Drum padsAST & USTsWaste storage & Disposal areas
Hazardous material usage areas:Paint boothsPlating operationsTreating operationsPipe runs
This component of the CSM includes the following information:
Previous site activities
Contaminants of concern
Potential contaminant source areas
Contaminant fate and transportContaminant susceptibility to treatment options
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Successful Treatment Design
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Relates how a contaminant reacts or travels through the environment to a receptorBased on the Contaminant characteristics:
VolatilitySolubility
Characteristics of the medium, using soil as an example, could include:
PermeabilityOrganic carbon contentGrain size distribution
This component of the CSM includes the following information:
Previous site activities
Contaminants of concern
Potential contaminant source areas
Contaminant fate and transport
Contaminant susceptibility to treatment options
Contaminants detected at the Chem-Dyne site included:
Volatile organic compoundsSemi-volatile organic compoundsPCBsTAL (metals)
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Successful Treatment Design
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
In developing a CSM, key elements include:General physical site description
Regional environmental setting
Land use
Contaminant information and site activities
Potential exposure pathways and risk estimationOn-going data evaluation and data gap identification
Groundwater (Chem-Dyne site)
Source Onsite hazardous materials
Fate-and-transport mechanism
Through soil into shallow and deep Great Miami River Aquifers
Exposure route Ingestion and/or dermal contact
Receptors Residents using deep-aquifer groundwater
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Successful Treatment Design
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Surface Water (Chem-Dyne site)
Source Onsite hazardous materials
Fate-and-transport mechanism
Surface water runoff during heavy rains
Exposure route Direct contact (e.g. burned feet)
Receptors Employees of adjacent business
Emissions (Chem-Dyne site)
Source Hazardous materials released by onsite activities
Fate-and-transport mechanism
Fugitive dust released into the air, migrating off site
Exposure route Inhalation
Receptors Neighbors
EmissionsExposure pathway: contaminated fugitive dust migrated offsite to neighboring habitats
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Successful Treatment Design
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Ensures that the selected remedial activities will protect human health and the environment.
Examples:Risk Based Corrective Action (RBCA)Brownfield ProgramSite Specific Risk Assessment
In developing a CSM, key elements include:General physical site description
Regional environmental setting
Land use
Contaminant information and site activities
Potential exposure pathways and risk estimation
On-going data evaluation and data gap identification
As the CSM develops, data gaps may be identified and specific site information may need to be collected, such as:
Soil CharacteristicsHydrogeologic & geologic informationSurface water & sediment informationAdditional information
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Successful Treatment Design
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
MeteorologicalAnnual rainfallAverage temperatureEvapotransporation
Offsite informationNearby populationOffsite land useZoning issues
Chem-Dyne Superfund Sitevs.
Pristine, Inc. Superfund Site
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Successful Treatment Design
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Remediation of Chem-Dyne included:Excavation of top 10 ft. of soil
Deeper contaminated soil remainedGroundwater pump-and-treat system through 25 wellsTreated groundwater through air stripperTreated air stripper emissions through granular activated carbon
Remediation of Chem-Dyne included:Re-circulated half of the treated water into unsaturated zone to further leach remaining soil contaminationDischarged remaining half of the treated water Constructed impermeable cap to prevent surface water infiltration
Cost$11.6 million constructionApprox $18 million operation and maintenance (20 years)
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Successful Treatment Design
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
0
10000
20000
30000
40000
1988 90 92 94 96 98 2000
Year
Tota
l VO
Cs R
ecov
ered
Very similar to Chem-Dyne site:Urban industrial waste recycling facility located in Reading, Ohio
Operated from 1974 to 1981
Stored, treated, and incinerated hazardous wastes: 10,000 drums & gallons of waste onsite
Similar geology and hydrogeology
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Successful Treatment Design
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Excavation of all visibly contaminated soil to 4 bgs
Onsite thermal desorption of contaminated soil
SVE Treatment of unsaturated zone
Groundwater pump-and-treat system w/ GAC & air stripping
Cost$13.5 million construction
$6 million operation & maintenance (20 years)
On-track to reach cleanup goals
Triad approach supports the project goal of a successful treatment design by combining:
Site-specific informationContaminant-specific informationTreatment options
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FATE AND TRANSPORTOF CONTAMINANTS
Student Performance ObjectivesUpon completion of this module you will be able to:
1. Describe how chemicals travel through environmental media,
such as rock or soil, air, and water.
2. Describe how chemicals can become associated with (stored
by) various environmental media.
3. Describe chemical parameters which model (predict) the
distribution of contaminants among media.
4. Describe environmental conditions which promote or retard
the movement of chemicals in the subsurface.
5. Describe factors that affect organic chemical degradation.
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Fate and Transport of Chemical Contaminants
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Pour one cup of TCE onto the ground, and it will cost you $1 million to get it out.
WHY?
1 CUPTCE
$1 MILLION
+ =
Why would it cost so much?
Contaminant behavior is a function of the properties of both the contaminant and the environmental media.
Contaminant
Soil Air
Water
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Fate and Transport of Chemical Contaminants
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Degradation
Volatilization PercolationRunoff
RetardationAdsorption
DispersionDiffusion
Surface Water
Vadose zone
Degradation
Adsorption
Diffusion
Retardation
Dispersion
Groundwater
SolubilityCapillary forces
SurfaceSubsurfaceDistributionDegradation
Physical stateVolatilizationRunoffSolubilityPercolation
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Fate and Transport of Chemical Contaminants
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Solid Liquid
Leastmobile
Mostmobile
Organic vs. InorganicTransition temperatures, e.g., melting point, boiling point
Gas
PHASE DIAGRAM
0C 20C 100C
Pressure(mm Hg)
Temperature
17.5
760
H2OSolid Liquid
A B
C
(Not to scale)
327 to 1620
-100-200C 0 100 200 30020
0 to 100
5.5 to 80.1
87 to 87
86 to 80
39.9 to 357
188 to 310 (decomposes @ 310)
189.9 to 42
H2O
Benzene
MEK
TCE
Propane
PCP
Hg
Pb
LIQUID TEMPERATURE RANGE
39
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Fate and Transport of Chemical Contaminants
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Function of: Molecular weight"Cohesive forces"
Van der Waals forcesPolarity
Temperature
Vapor Pressure (VP): Pressure exerted above a compound in liquid or solid phase
Compound VP (mmHg @ 20c)
Benzene 80.0TCE 63.0H2O 17.5PCP .00011
MORE VOLATILE
LESS VOLATILE
Function of: Hydraulic gradient"Cohesive forces" (e.g., internal friction)
40
-
Fate and Transport of Chemical Contaminants
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Dynamic viscosity (): Indicates degree of resistance to flow
Compound (centipoise @ 20c)
TCE .57Benzene .65H2O 1.0Kerosene 2.5Phenol 8.5
MOST MOBILE
LEAST MOBILE
Function of: Cohesive forcesAdhesive forces
Van der WaalsPolarityIonization
OHH +
+
Met
al s
olub
ility
(mob
ility
)
7pH (s.u.)
Pb(OH)+1Pb(OH)2
Fe(OH)3
Fe(OH)+2
Al(OH)3Al(OH)+2
Al(OH)41
41
-
Fate and Transport of Chemical Contaminants
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Function of:Fluid height or "head"Fluid densityCohesive forces ("surface tension")Adhesive forces ("wetting")
h
Compound (centistokes @ 20c)TCE .39Benzene .74H2O 1.0
MOST MOBILE
LEAST MOBILE
Kinematic viscosity (): Indicates degree of resistance to downward flow (combines density with dynamic viscosity)
Function of:Preferential pathways (channeling)
MacroporesMicropores
SolubilitySorptionVolatility
42
-
Fate and Transport of Chemical Contaminants
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Physical movement stops when matric potential and hydrodynamic head are balancedMolecular movement continues as long as relative concentration remains "unbalanced"
Solubility
Organic carbon
NAPL
Pore water
Ped or particle
Pore air
Diffusion Process whereby molecules move from a region of higher concentration to a region of lower concentration as a result of Brownian motion.
43
-
Fate and Transport of Chemical Contaminants
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Contaminant movement
Soil particles
Dispersion Tendency for a solute to spread from the path that it would be expected to follow under advective transport
Dispersion and Diffusion
Contaminant movement
Soil particles
PercolationThrough
Saturated Zone
DNAPL
DissolvedcontaminantGroundwaterflow
H2O
LNAPL
Soil
44
-
Fate and Transport of Chemical Contaminants
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Air
Water
Water/Air
Water/soil
Vapor pressure (VP)
Solubility (Sol.)
Henry's Law (HL)
Sorption (KOC, CEC)
Compound VP (mmHg) Sol.(mg/L) HL
HL = VP Solubility
atm-m3mol
VC 2,300 1,100 6.9 10-1
Benzene 76 1,780 5.4 10-3
TCE 58 1,100 8.9 10-3
MEK 71.2 268,000 2.7 10-5
PCP 0 00011 1 2 8 10 6
Function of:ContaminantFraction of organic carbon in medium (fOC)Properties of soil, e.g., structure, texture (KOC)
The degree of attraction between a non-polar chemical and the natural organic matter associated with an aquifer (retardation)
45
-
Fate and Transport of Chemical Contaminants
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Function of: Soil texture (e.g., clay, silt, sand)Soil surface area (clay type, e.g., kaolinite)Organic matter content
Total cations adsorbed on a unit mass of soil (centimoles/kg)
Break down chemically (organics only)Examples of degradation processes:
Hydrolysis
Redox
Biodegradation
Function of:pHBond strengths of contaminantProperties of attacking agentRedox potential"Hospitable" environment (biodegradation)
46
-
Fate and Transport of Chemical Contaminants
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
chloride
carbon tetrachloride
PCE
1.0
0.5
0
200 400
Rel
ativ
e co
ncen
trat
ion
in M
W1
dow
ngra
dien
t of s
ourc
e
Time (days)0
GW flow
Source MW1
GWflow
What are you going to do?
Problem: Saturated soil contaminated with TCE (enough to contaminate groundwater to solubility limit for 15 years)
Problem: Chrome plating bath solutions have been disposed into unlined lagoon (now dry).Most of chromium has been adsorbed by underlying clay soils.Groundwater contamination was not detected.
What are you going to do?
47
-
48
-
CAPPING AND CONTAINMENT
Student Performance ObjectivesUpon completion of this module you will be able to:
1. State the application, limitations, working mechanisms, advantages
and disadvantages of the following capping technologies:
a. Clay caps
b. Resource Conservation and Recovery Act (RCRA) multi-stage
caps
2. State the application, limitations, working mechanisms, advantages
and disadvantages of the following groundwater containment
technologies:
a. Slurry trench cutoff walls
b. Grout curtain walls
49
-
50
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Capping and Containment
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Capping controls airborne contamination and surface water infiltrationContainment controls groundwater movement
ApplicationsSlows the movement of airborne or dustborne contaminants
Slows the movement of surface water into the ground
LimitationDoes not directly remediate contaminants
Makes soil recovery and further treatment difficult
51
-
Capping and Containment
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Capping materials may include natural or synthetic materials.
24" Clay
6" Gas-venting layer/soil cushion
6" Topsoil with vegetative cover
30 mil PVC Liner
Waste Material
Cap
Cap
5' Recompacted Clay
24" Pea Gravel60 mil PVC Liner
Ground
80 mil PVC Liner
Leachate Collection System
Atlanta, GA Hickory Ridge Landfill
52
-
Capping and Containment
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Gas collection and process system
Phoenix Golf Course
California Gulch Superfund SiteCourtesy US EPA Region 8
53
-
Capping and Containment
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Explore alternative and more aesthetically-pleasing ways to cover mine waste piles with materials that will help preserve the historic appearance of the mining landscape
Water management strategyDivert clean waterEnhance/ enlarge collection system for acid rock drainageGradually eliminate Leadville Mine Drainage Tunnel use, with exception of emergency
54
-
Capping and Containment
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Alternative 1 Natural Face with Partial Cap (preserve areas visible from Mineral Belt Trail/roads)
Alternative 2 Shotcrete with No Liner on Slope
Alternative 2A Shotcrete with Liner on Slope
Alternative 3 Inert Mine Waste Rock with Liner
Alternative 4 Inert Mine Waste Rock with Cribbing
Before capping After capping
Before capping After capping
55
-
Capping and Containment
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
After capping
Before capping After capping
Before capping After capping
56
-
Capping and Containment
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Virtual Forum Web Address: www.merid.org/leadville
EPA Web Address: www.epa.gov/region8/superfund/co
57
-
Capping and Containment
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Bioreactor landfills are designed and operated by increasing the moisture content of the waste to enhance degradation and stabilization
Primary advantagesEfficient utilization of permitted landfill capacityStabilization of waste in a shorter timeReduced leachate handling costReduced post closure care
Secondary AdvantagesPotential for landfill gas can be a revenue streamPromotes more sustainable waste management Reduced air emissions containing VOC and hazardous air pollutants May possibly reduce long term costsReduced toxicity of leachate and waste materialConsistency with sustainable landfill design
58
-
Capping and Containment
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Primary Disadvantages and Challenges Slope stabilityHigher capital costsOperator skillsTemperature control in aerobic bioreactorsConfusion over regulations to permit bioreactorsLiner chemical compatibilityOdor controlDesign & construction of liquid handling systemsWaste heterogeneity
Subsurface walls to control groundwater movement
Slurry trench cutoff wall
Grout curtain
Sheet piling
ApplicationsSlows movement of groundwater-borne contaminants using subsurface walls
Can be used to dewater a site for remediation
LimitationsDoes not directly remediate contaminants
59
-
Capping and Containment
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Production well
Monitoring well
Aquitard
Groundwater flow
Keyed slurry trench cutoff wall
60
-
Capping and Containment
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Production well
Monitoring well
Aquitard
Groundwater flow
LNAPLs
Recovery well
Hanging slurry trench cutoff wall
WallSoil
Drain
Stream
Waste
Groundwater flow
Stream
Extraction well
Groundwater flow
WallSoil
Waste
61
-
Capping and Containment
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Soil
Injection tube
Grout curtain
Contaminant plume
Groundwater flow
62
-
Capping and Containment
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Zone of influenceInjection tube
Z-typeStraight web type
Deep arch web type
T-fitting
63
-
Capping and Containment
ENVIRONMENTAL REMEDIATION TECHNOLOGIES 64
-
Student Performance ObjectivesUpon completion of this module you will be able to:
1. State the advantages and disadvantages of basic water treatment
systems.
2. State the working mechanisms of the following basic water
treatment subsystems and/or components.
- Oil/water separators
- Iron removal systems
- Filters
- Clarifiers
- Air strippers
- Scale control systems
- Carbon adsorption units
BASIC WATER TREATMENT
65
-
66
-
Basic Water Treatment
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Treats most contaminantsHighly flexible and reliable
Could be very expensiveEnergy- and labor-intensiveRegulatory problems with dischargeFine-grained material a problem
67
-
Basic Water Treatment
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Oil / Water Separator
Reactor Tank
Sand Filter
Reactor Tank
Air Stripper
Carbon Contactor
pH Control
Courtesy State of Washington, Department of Ecology
Water
68
-
Basic Water Treatment
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Water
Oil
Sludge
69
-
Basic Water Treatment
ENVIRONMENTAL REMEDIATION TECHNOLOGIES 70
-
Basic Water Treatment
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Courtesy State of Washington, Department of Ecology
71
-
Basic Water Treatment
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Physically separates volatile or semi-volatile contaminants, usually organics, from waterProcess applies to volatile and semi-volatile organics with a Henry's Law Constant of >0.003 atm/mol/m3
Storage tank
Off-gas treatment
Air blower
Effluent treatment
Packing Saddles Packing Rings
Snowflakes
72
-
Basic Water Treatment
ENVIRONMENTAL REMEDIATION TECHNOLOGIES 73
-
Basic Water Treatment
ENVIRONMENTAL REMEDIATION TECHNOLOGIES 74
-
Basic Water Treatment
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
aBsorption aDsorption
75
-
76
-
Student Performance ObjectivesUpon completion of this module you will be able to:
1. State the advantages and disadvantages and describe the working
mechanisms of the following chemical reaction systems:
- Neutralization systems
- Precipitation systems
- Reduction and oxidation systems
2. State the advantages and disadvantages and describe the working
mechanisms of the following separation systems:
- Microfiltration systems
- Reverse osmosis systems
- Ion exchange systems
CHEMICAL REACTIONSAND SEPARATIONS
77
-
78
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Chemical Reactions and Separations
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
NeutralizationPrecipitationReductionOxidation
AdvantageEliminates corrosives
DisadvantagesProcess chemicals are hazardous
Generates a lot of heat
Heavy-duty process equipment may be needed
79
-
Chemical Reactions and Separations
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
AdvantagesRemoves dissolved heavy metals
DisadvantagesProduces metal sludge
Often produces high pH wastewater
Doesn't always work on highly soluble metals
80
-
Chemical Reactions and Separations
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Chemicalprecipitants
Liquidfeed
Mixing tank
Chemicalflocculants/settling aids
FlocculationpaddlesFlocculation
well
Flocculationclarifier
Sludge
Baffle
Effluent
Source: U.S. EPA 1991
81
-
Chemical Reactions and Separations
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Chemical reactionsAdvantages
Reduces solubility of heavy metals
Oxidizes and destroys organics
DisadvantagesUnintended reactions
Acid feed
pH control Mixer
Reducing agent feed Limeslurry hopper
Effluent
Hydroxide sludgeChrome
precipitation
Chrome reduction tank
Chrome wastewaterfeed
SOX
Cr6+
Ca(OH)2
H+
Cr3+Cr3++OH- Cr(OH)3
82
-
Chemical Reactions and Separations
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
UV lamps
Influent
EffluentO3
H2O2
MicrofiltrationReverse osmosisIon exchange
83
-
Chemical Reactions and Separations
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
SeparationProcess
Relative Size of
Common Materials
Microns 0.001 0.01 0.1 1.0 10 100 1000
ReverseOsmosis
Microfiltration
Ultrafiltration
Nanofiltration
Particle Filtration
AqueousSalt
Endotoxin Pyrogen
Metal Ion
Oil Emulsion
Lactose
Sediment
Red Blood Cells
Virus Bacteria
ColloidalSilica Cryptosporidium
Dredge, Fox River, WI
84
-
Chemical Reactions and Separations
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Microfiltration is a process which removes contaminants from a fluid by passing though a microporous membrane.
Typical microfiltrations membrane pore size range is 1 to 10 micrometers.
AdvantageRemoves very small particles
DisadvantagesDoes not remove dissolved contaminants
85
-
Chemical Reactions and Separations
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Source: U.S. EPA 1991
Filtraterecirculation
Lime slurry tankProFix slurry tank
TyvekUsed Tyvek
GroundwaterTo disposal
Air
Staticmixer
Filter cake
Filter cakestorage
Microfiltrationunit
Microfiltration Treatment System
Microfiltration Treatment System
Microfiltration Treatment System
86
-
Chemical Reactions and Separations
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Pressure
Contaminated water
Treatedwater
Concentratedwastewater
87
-
Chemical Reactions and Separations
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Sludge
FiltersReverse osmosis unitFeed
tank
Storagetank Clarifier
NaOHcausticsoda
HCI
88
-
Chemical Reactions and Separations
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Removes dissolved metals via transfer of ionsUses resin beads
Removes low concentrations of soluble metalRecovers concentrated metal streams for recycling
89
-
Chemical Reactions and Separations
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Suspended solids and organicsRegeneration chemicals are hazardous
Acid regenerant
Caustic regenerant
Removal:OH [An(s)] + XX [An(s)] + OH
Regeneration:X [An(s)] + OHOH [An(s)] + X
Removal:H+ [Cat(s)] + M+M+ [Cat(s)] + H+
Regeneration:M+ [Cat(s)] + H+H+ [Cat(s)] + M+
Waste containing MX
Deionized effluent
Spent regenerant
Anion exchanger
Cation exchanger
90
-
SEDIMENT REMEDIATION
Student Performance Objectives
1. Defi ne Sediments2. List common sediment remedy options3. List the advantages and disadvantages for the three common sediment remedy options
91
-
92
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Sediment Remediation
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Define SedimentsList common sediment remedy optionsList the advantages and disadvantages for the three common sediment remedy options
Source: USEPA 1999
Sediments - The organic and inorganic materials found at the bottom of a water body. Clay, silt, sand, gravel, decaying organic matter, shells & debris.The most common sediment contaminants:
PesticidesPCBsPAHsDissolved phase chlorinated hydrocarbons (to a lesser extent)
Source: USEPA 1999
93
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Sediment Remediation
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Pipeline or outfall dischargesChemical spills Surface runoff: waste dumps, chemical storage, mines, agricultural or urban areas Air emissions: Power plants, incinerators, pesticide applicationsUpwelling of contaminated ground waterShips, ship maintenance & in-water structures
Source: USEPA 1999
Health impacts from eating fish/shellfish and recreationEcological impacts on wildlife and aquatic speciesLoss of recreational & subsistence fishingLoss of recreational swimming and boatingLoss of traditional cultural practices by Indian tribes, etc.
Economic effects of loss of fisheriesEconomic effects on development and property valuesEconomic effects on tourismIncreased costs of drinking water treatmentLoss or increased cost of commercial navigation
94
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Sediment Remediation
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Source: Adapted from EPA Region 5, Sheboygan Harbor and River Site
Sediment grab samplers: Surface sediment chemistryCoring devicesWater column probes: pH and DOSurface water samplers: Dissolved and particulate chemical concentrationsSemi-permeable membrane devices: Dissolved contaminants at the sediment-water interface
Benthic analysis: Population and diversityToxicity testing: Acute and long-term lethal effects on organismsTissue sampling: Bioaccumulation, modeling trophic transfer potential, and estimating food web effects Caged fish/invertebrate studies: Change in uptake of contaminants by biota
95
-
Sediment Remediation
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Monitored natural recoveryIn situ cappingDredging & Excavation (most common)
Allows natural processes to contain, destroy, or otherwise reduce the bioavailability or toxicity of the contaminant in the sediment.
This remedy should include site specific cleanup levels, remedial action objectives, and monitoring to assess whether risk is being reduced as planned.
Physical processes Sedimentation, advection, diffusion, dilution, dispersion, bioturbation, volatilization
Biological processesBiodegradation, biotransformation, phytoremediation, biological stabilization
Chemical processesOxidation/reduction, sorption, or other processes resulting in stabilization or reduced bioavailability
96
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Sediment Remediation
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Human exposure is low (most important)Sediment bed is stable, cohesive, well-armoredContaminant concentrations decreasing on their own Contaminants are readily biodegradable or transform to lower toxicity forms Concentrations are low and cover diffuse areaContaminants have low ability to bioaccumulate
Long-term decreasing trend of contaminant concentrations in:
Higher trophic level biota (piscivorous fish) Water column (during low flow)Sediment core contaminant levelsSurface sediment
97
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Sediment Remediation
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
AdvantagesRelatively low implementation costsNon-invasive
LimitationsLeaves contaminants in placeSlower to reduce risks than active technologiesOften relies on institutional controls such as fish consumption advisories
Monitored natural recoveryIn situ cappingDredging & Excavation
In-situ capping is the placement of a subaqueous covering or cap of clean material over contaminated sediment.
In-situ capping is the placement of a subaqueous covering or cap of clean material over contaminated sediment.
98
-
Sediment Remediation
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Caps reduce risks by:
Physical isolation: Reduce exposure & bioturbation
Stabilization: Contaminant & erosion protection to reduce re-suspension
Chemical isolation:Prevent dissolved and bound contaminants from transporting into water column
Physical:Population density of organismsSand cap consolidation through compression
Stabilization: Potential erosion from bed shear stresses due to river, tidal, and wave-induced currents, turbulence generated by ships/vessels, etc.
ChemicalGas generation due to anaerobic degradation from organic content, can generate uplift forces on the cap (especially w/ less permeable cap material)
99
-
Sediment Remediation
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Upland sand-rich soils (preferred)Engineered clayReactive/adsorptive materials: activated carbon, apatite, coke, organoclay, zero-valent iron and zeolite Geotextiles: reduce mixing and displacement of cap materialImpervious materials: geomembranes, clay, concrete, steel, or plastic
Source: USEPA 1998d
Source: Modified from U.S. EPA 1998d
100
-
Sediment Remediation
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Advantages Quickly reduce exposureLess infrastructure for material handling, dewatering, treatment & disposalLess expensive than dredging or excavationQuick to implement
LimitationsRisk of re-exposure if cap is disturbed Cap materials may not promote native habitat
Monitored natural recoveryIn situ cappingDredging & Excavation
Dredging: Removal of contaminated sediment while it is submerged
Excavation: Removal of contaminated sediment after dewatering
Most often used treatment method at Superfund sites
Both include transport, treatment and disposal of impacted sediment and water
101
-
Sediment Remediation
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Suitable disposal site is nearby Suitable area for staging and handlingNavigational dredging is planned Water depth is adequateRisk reduction outweighs disturbanceContaminated sediment overlies clean sedimentContaminants cover discrete areas
Mechanical Dredging Clamshell: Wire supportedEnclosed bucket: Wire supported, watertightArticulated mechanical: Backhoe designs
Hydraulic DredgingCutterhead: pipeline dredge w/ cutterheadHorizontal auger: pipeline dredge with augerPlain suction: pipeline dredge w/ suctionPneumatic: Air operated submersible pump
Source: A = Cable Arm, Corp. B = Barbara Bergen, USEPA)
102
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Sediment Remediation
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Source: A = Jim Hahnenberg USEPA: B = Ernie Watkins USEPA: C = Ellicott Corporation
Air or Gas Residue
Treatment
TreatmentPretreatmentStagingTransportSediment Removal
DebrisRemoval
Water Effluent Treatment
and/or Disposal
Disposal and/or Reuse
Disposal and/or Reuse
Solids
Solids
ContaminatedSolids
Contaminated Solids
103
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Sediment Remediation
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Sheet piling & CofferdamsEarthen dams Geotubes, inflatable dams Rerouting the water body using temporary dams or pipesPermanent relocation of the water body
Example of excavation following isolation using sheet piling
Source: Pine River/Velsicol, EPA Region 5
Advantages Contaminant removal poses less risk uncertaintyLess limitation for water body uses
LimitationsComplex and costlyUncertainty of residual contamination Contaminant losses through re-suspension and volatilizationTemporary destruction of aquatic community
104
-
Sediment Remediation
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Fox River, WI
5 Operable Units (OU) due to large area of PCB contamination
PCB in Sediment includes 39 miles of river and 2700 square miles of Green Bay PCBs from a large number of papermills along the river producing and recycling carbonless copy paper (9 PRPs)PCBs released directly into the river or after municipal treatment plantFish consumption advisories have been in effect since 1976
105
-
Sediment Remediation
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Dredging and off-site disposal7-inch thick engineered cap of sand and armor stone3 to 6-inch sand cover where PCBs
-
Sediment Remediation
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Fox River MapBlue = Capping Areas
Capped 415 acres
Fox River MapYellow/Brown = Sand Cover Areas
Approximately 495 acres sand capped
Capping Slope Diagram
7-inch thick sand and armor stone3-6 inch sand cover where PCBs < 2 ppm
107
-
Sediment Remediation
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Cutterhead Dredge & Piping
Piping Suction Pump & Diesel Engine
Extended Ladder Cutterhead Dredge & Barge
108
-
Sediment Remediation
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Pipe flow to vibrating Screen of gravel and debris > 1/8 inchFurther hydrocyclone for fine grain sand removalThickening tanks using polymer addition for uniform flow & weir for water removalMembrane sediment cake press Conveyor to Transport off-site
Geotube Dewatering
Treated Sediment is Transported to landfill or TSCA landfill
Sand Filtration: fine vs. course sandBag FiltrationGAC FiltrationDiffuser to discharge treated water back to Fox River at ambient flow conditions to avoid disruption
109
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Sediment Remediation
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
EPA. 1998d. Assessment and Remediation of Contaminated Sediments (ARCS) Program Guidance for In-Situ Subaqueous Capping of Contaminated Sediments. Prepared for the U.S. Environmental Protection Agency, Great Lakes National Program Office, Chicago, Illinois. EPA 905/B-96/004. Available on the Internet at http://www.epa.gov/glnpo/sediment/iscmain.
USEPA. 1999. Introduction to Contaminated Sediments. EPA 823-F-99-006, Office of Science and Technology
USEPA. 2005. Contaminated Sediment Remediation Guidance for Hazardous Waste Sites, EPA-540-R-05-012. Office of Superfund Remediation and Technology Innovation
110
-
Student Performance ObjectivesUpon completion of this module you will be able to:
1. Discuss site considerations needed for the use of bioremediation
methods.
2. Discuss intrinsic and engineered bioremediation treatment methods
3. Discuss in-situ and ex-situ bioremediation treatment systems.
BIOREMEDIATION
111
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Principles of Bioremediation
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Define bioremediation Describe a basic oxidation-reduction reactionList the different microbial metabolic processesList the basic ways that microbes demobilize contaminantsList three indicators of microbial activityList factors that may complicate bioremediation
The treatment or remediation of contaminated soils, sediments, and groundwater through microbial metabolism.
112
-
Principles of Bioremediation
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Bioremediation
Ex-Situ
Natural AttenuationEngineered
Bio-stimulation Bio-augmentation
Addition of Oxygen, Nutrients & BacteriaAddition of oxygen-Bio venting
-Bio-sparging Addition of Oxygen & nutrients
In-Situ
Microbial metabolism is the basis of bioremediationIt is the transformation of organic and inorganic compounds by microscopic organisms
The biochemical transformation that occur in living organisms How cells derive energy and basic elements for reproduction Energy and essential elements are derived through oxidation-reduction processes
113
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Principles of Bioremediation
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
The breaking of chemical bonds and transferring electrons from electron donors to electron acceptors.
The organic contaminant often serves as the electron donor, yielding electrons (being oxidized) to microbial compounds (being reduced) to stimulate cell growth and reproduction.
The three modes of metabolism are:RespirationFermentationPhotosynthesis
114
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Principles of Bioremediation
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Respiration process is either aerobic or anaerobicAerobic respiration uses oxygen as an electron acceptorAnaerobic respiration uses a chemical other than oxygen as an electron acceptor such as nitrate, iron, sulfate, and carbon dioxide
An organic compound is used as both electron donor and electron acceptor, converting the compound to fermentation products such as alcohols, organic acids, hydrogen, and carbon dioxide.
The metabolic process where plants convert radiant energy into chemical energy, most often stored initially in glucose.
115
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Principles of Bioremediation
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
The key microorganism involved in bioremediation of organic and inorganic compounds is bacteria. Other microorganisms that may be involved in bioremediation are protozoans, fungi, and algae.
BacteriaSingle-celled organismsMetabolize soluble foodReproduce by binary fissionCellular composition:
70 90% water10 30% dry mass
92% of dry mass composed of carbon, oxygen, nitrogen, and hydrogen
C5H7O2N
C5H7O2NC5H7O2N
116
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Principles of Bioremediation
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Favorable physical and chemical conditions are necessary for optimum bacteria metabolism.
Physical conditions include:pHTemperaturePhysical structure for support
GROWTHAND
REPRODUCTION
NUTRIENTS
WATERCO2
Chemical requirements include:ENERGY SOURCE
CARBONSOURCECARBONHYDROGENS
ParentCell
DaughterCell
DaughterCell
117
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Principles of Bioremediation
ENVIRONMENTAL REMEDIATION TECHNOLOGIES
Energy SourceChemical compounds (organic or inorganic)Sunlight and Substrates
Carbon SourceOrganic CompoundsCO2
NutrientsNitrogenPhosphorusTrace Nutrients (sulfur, potassium, and iron)
Organic and inorganic carbonOrganic compounds and CO2
Ammonia (NH3), nitrate (NO3-), or nitrogen gas (N2)Various sources of phosphates (PO43-)Trace nutrients
Amino acids, sulfate, potassium, magnesium, and iron
Aerobic respirationAnaerobic respirationFermentationSecondary utilization and co-metabolismReductive dehalogenationInorganic compounds as electron donors
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C7H8 +9O2 7CO2 + 4H2O
Cell Growth and ReproductionAcceptorDonor
EnzymesBiological catalystsAre not altered by the reactionReaction specific
C7H8 +9O2 7CO2 + 4H2OENZYME
Anaerobic RespirationInorganic chemicals are used as electron acceptors
Nitrate (NO3-), sulfate (SO42-)Metals (Fe3+, Mn4+)C02
Byproducts = nitrogen gas, hydrogen sulfide, reduced forms of metals, and methane
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C7H8 + Nitrate (NO3-) CO2 + N2
Benzylsuccinic acid
Benzoyl Coenzyme-A
Can play an important role in an anaerobic environmentOrganic contaminant serves as both electron donor and acceptorByproducts can be biodegraded by other species of microbes
Non-beneficial biotransformationThe microorganism transforms the contaminant but does not benefit from the reaction
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Replacement of a halogen atom with an hydrogen atom.Electron donors include hydrogen and low-molecular weight compounds.
Ammonium (NH4+ ), nitrite (NO2-), reduced iron (Fe2+), reduced manganese (Mn2+), and H2SOxygen is usually the electron acceptorCarbon is most commonly taken from atmospheric CO2 (Carbon Fixation)
Water chemistry changesDecrease in parent compound, electron acceptorIncrease in byproducts Presence of specific metabolic products
C7H8 + 9O2 7CO2 + 4H2O
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Changes in native microbial communitiesGrowth of predators
Unavailability of the contaminant to the microbesToxicity of contaminant to microbesMultiple contaminants and natural organic chemicals
Incomplete degradation of contaminantsInability to remove contaminants to low concentrationsAquifer clogging
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Aqueous ex-situ treatment systemsTrickling filtersAerated lagoonRotating Biological ContactorAnaerobic digester
Solid ex-situ treatment systemIn-situ treatment systems
Trickling Filters
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Aerated Lagoon
Rotating Biological Contactor
Rotating Biological Contactor
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Anaerobic Digester
Contaminated soil
Water
Slurry
Nutrients
Mixer Bioreactor Centrifuge Water
Clean soil
Emission control
Vapor treatment
Vadose zoneGroundwater
Extraction wells Extraction wells
AirInjectionwell
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Microbes
Pre-treatment
Nutrients Oxygen
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Student Performance ObjectivesUpon completion of this unit, students will be able to:
1. Define monitored natural attenuation
2. Understand monitored natural attenuation processes
3. Review case studies that show monitored natural
attenuation processes
4. Understand two screening criteria for monitored natural
attenuation applicability
MONITORED NATURAL ATTENUATION
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Define monitored natural attenuationUnderstand monitored natural attenuation processesReview case studies that show monitored natural attenuation processesUnderstand two screening criteria for monitored natural attenuation applicability
Monitored natural attenuation (MNA) is the reliance on natural attenuation processes to achieve a site-specific remediation objective within a time frame that is reasonable compared to other more active methods (EPA,1999).
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MNA is often used in conjunction with or as a follow-up process to another active remedial activity.
AdvantagesAn in-situ treatmentMay be a lower cost alternativeMay be effective as a final process to treat residual contaminants
DisadvantagesMay not be accepted by the regulatory
agency or publicMay not treat contaminant within a reasonable timeMay not treat desired contaminantsRequires detailed site characterization
and continued monitoring
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The MNA natural processes are biological, chemical, and physical reactions.Under favorable conditions, these processes either transform contamination to less harmful forms or immobilize contaminants to reduce risks.
Examples of natural processes include:
Biodegradation by subsurface microbes
Naturally occurring chemical reactions
Physical sorption to subsurface media
Natural dilution of contaminants*
Physical volatilization of contaminants from the subsurface to the atmosphere*
* Not acceptable processes
Concerns MNA is site and contaminant specific. The success of MNA depends on many natural environmental conditions which will change as MNA proceeds.
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Water table
For example, biodegradation will continue as long as an adequate supply of electron acceptors is available.
Aerobic respiration
DenitrificationIron (III) reduction Sulfate
reduction
Residual NAPL
Methanogenesis
Plume of dissolved fuel hydrocarbons
Groundwater flow
The following case studies show examples of successful and common failures of MNA projects.
South Glen Falls, NY
Natural attenuation of a chlorinate solvent
St. Joseph, Michigan
No natural attenuation of a chlorinate solvent
Edwards Air Force Base
Vandenberg Air Force Base BTEX and MTBE release
Hudson River Sediment Incomplete natural attenuation of PCBs
Pinal Creek, Arizona Natural attenuation of inorganic compounds
Natural attenuation of PAHs following source removal
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This case study shows the value of source removal. In the 1960s, coal tar generated from an old manufactured gas plant was excavated and reburied in a sand sediment.During the 30 years the coal tar was left in place, an 200-foot by 1000-foot contaminated plume developed.
The contaminated plume consisted of PAHs including naphthalene from 0.01 ppm to >2 ppm. In 1991, the coal tar-contaminated soil was re-excavated, properly disposed, backfilled with clean native soil.Within 4 years of source removal, much of the plume was below detectable levels.
Evidence that biodegradation was the primary attenuation process that removed much of the contamination are:
Depletion of oxygen at the center of the plume where the concentrations were the highestRapid growth of the microbial population that consumed the contamination
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Additional data that suggests natural biodegradation reduced the contamination once the source was removed:
Increase of the protozoan population (predator of bacteria) inside the plumeDetection of a unique transient intermediary metabolite showing biodegradation of the contaminants
TCE released from a former factory contaminated the groundwater with concentrations as high as 100 ppm. A nearby disposal lagoon also leached a large amount of organic matter into the groundwater.
Microbial activity had completely converted the organic matter into methane, creating a reduced environment that dechlorinated the TCE.TCE biodegradation occurred because of the high chemical oxygen demand (COD) placed on the aquifer, as a result of the organic matter that leached from the nearby disposal lagoon.
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Evidence of biotransformation is supported by concentrations of cis-DCE, vinyl chloride, and ethene, daughter products of TCE reductive dechlorination. Samples collected near the source show that 825% of the TCE had been converted to ethene.
A site survey shows that the conversion of the TCE to ethene was most complete where methane production and loss of nitrate and sulfate by reduction were the highest.Although extensive dechlorinationtook place, complete breakdown of TCE and its daughter products did not occur.
Indicators of TCE reductive dechlorinationare:
Formation of cis-DCE, VC, and etheneLoss of COD in excess of what was needed for dechlorinationEvidence of anaerobic processes
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Between 1958 and 1967, approximately 5,500 gallons of TCE were released creating a large groundwater plume (about 2,800-feet by 2,100 feet).Groundwater modeling shows the contaminant had migrated from its source area, however, no degradation of the TCE had occurred.
Electron acceptors (nitrate and sulfate) are present in the plume, but there is no dissolved oxygen content or organic material present. The probable reason that there is no biotransformation of the TCE is that no primary substrate (organic material) is present to create a reducing condition.
Vandenberg Air Force Base:
572 gallon release of gasoline containing MTBE Estimated groundwater velocity is 400 ft/yearBTEX plume stops within 50100 feet from source MTBE plume is 250 feet wide and extends 1,700 feet from source
NE
S
W
Approximate extent of MTBE above 2 ppb
(11/97)
Surface drainage
Approximate extent of detectable TPH / BTEX (11/97)
0 100 200
Scale: feet
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Natural biodegradation appears to have affected the BTEX, but it had little or no affect on the MTBE.In general, simpler and naturally-occurring organic compounds, such as BTEX, are degradable. MTBE is notably resistant to biodegradation because of its stable molecular structure and its reactivity with microbial membranes.
A PCB release contaminated a 200 mile stretch of the Hudson River sediment from Hudson Falls to Manhattan. Studies show an incomplete natural attenuation of PCBs in the sediment.Studies show aerobic microorganisms present in the sediment. Active aeration pilot studies show co-metabolism created a reduced environment allowing the reductive dechlorination of the PCB.
Potential for PCB biodegradation exists in the Hudson River sediment, two requirements must be fulfilled for natural attenuation:
A mixing of deep and shallow sediments must occur to link aerobic and anaerobic process. This can occur naturally, but there is no guarantee it will occur often enough to achieve biodegradation.
Biodegradation must occur before the PCBs enter the food chain, e.g., the bioaccumulation of PCB in fish tissue.
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A 1997 study showed significant dechlorination of PCBs, but, even after decades, complete dechlorination has not occurred. The rate of dechlorination is insufficient to ensure that monitored natural attenuation will meet regulatory standards.
Acid drainage from copper mining in Pinal Creek, Arizona area caused a 25-km plume of metal contamination from several unlined mine tailings ponds. It is suspected the pH of the ponds were 2 to 3.The acid part of the plume extended 12 km with several metals having concentrations above MCLs.Many physical, chemical, and biological processes have affected the metal contaminants.
Physical dilution likely accounted for a 60% contaminant concentration decrease for the first 2 km of the plume.Chemical reaction of the acid plume with natural carbonate material raised the pH to 5-6. This pH raise caused precipitation or sorption of the iron, copper, zinc, and other metals.The neutralization reactions depleted the carbonate allowing some metals to continue to migrate to a discharge point in Pinal Creek. The increase in pH and oxygen caused manganese oxides to precipitate.
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The precipitation of the manganese oxides were enhanced by manganese-oxidizing bacteria which resulted in about 20% decrease of the dissolved manganese.Concentrations of other dissolved metals decrease because of sorption onto the manganese oxides.The natural process reduced the dissolved metals in groundwater. But as the carbonate material become depleted, the source may overwhelm the natural attenuation capacity of the aquifer.
The success of a project is based on:
The level of understanding of the dominant attenuation processesThe probability that site-specific conditions will result in an effective natural attenuation
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A number of factors must be considered to determine if MNA will be effective:
Initial Screening of MNA ApplicabilityDetailed Evaluation of MNA Effectiveness
Do regulations allow MNA as a remedial method?Has the source been removed to the maximum extent practical?Is the plume shrinking such that remediation will be achieved within a reasonable time?Are there any receptors that could be affected within a 2-year period?
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If the answer is "no" to any of the first three questions or yes to the fourth question:
MNA is not a remedial option at the site
If the answer is yes" to the first 3 questions and no to the fourth question:
MNA has the potential to be effective at the site, but a detailed evaluation should be conducted
Has the site been fully characterized in three dimensions?If groundwater is the issue, has the hydraulic conductivity of the most permeable transport zone been measured?If groundwater is the issue, has the retarded contaminant transport velocity been estimated?Have the geochemical parameters been measured for all monitoring points?
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Have rate constants or degradation rates been calculated?Is the estimated time to achieve remediation objective reasonable?Is there no current or future threat to potential receptors?
If yes to all above, then MNA may be effective
Key components of a MNA corrective action plan include:
Documentation of adequate source control
Comprehensive site characterizationEvaluation of time frame for meeting remediation objectivesLong-term performance monitoringA contingency plan
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Student Performance ObjectivesUpon completion of this module you will be able to:
1. Recognize the advantages and disadvantages of in-situ treatment.
2. Identify the different in-situ treatment methods for saturated and
unsaturated zones.
3. Describe the principles of natural attenuation, soil vapor
extraction, enhanced soil vapor extraction, and air sparging
treatment methods.
4. Understand the factors of a successful natural attenuation, soil
vapor extraction, enhanced soil vapor extraction, and air sparging
treatment system.
IN SITU TREATMENTS, PART ONE
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In place treatment of contaminants in soil,sediment, or groundwater using physical,chemical, or biological mechanisms.
Eliminates mass removal process
Reduces potential exposure
Reduces surface destruction
May reduce cost
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Increases treatment time
May be difficult to monitor results
May not treat all contamination
May cause contaminant to spread
Unsaturated Saturated
Physical
Chem
ical
Biological
Physical
Chem
ical
Biological
Monitored Natural Attenuation Soil Vapor Extraction (SVE)
SVE Enhancements Air Sparging Permeable Reactive Barriers Chemical Oxidation Soil Flushing * Bioremediation * Phytoremediation * Immobilization * *Covered in other lectures
Unsaturated Saturated
Physical
Chem
ical
Biological
Physical
Chem
ical
Biological
Monitored Natural Attenuation Soil Vapor Extraction (SVE)
SVE Enhancements Air Sparging Permeable Reactive Barriers Chemical Oxidation Soil Flushing * Bioremediation * Phytoremediation * Immobilization * *Covered in other lectures
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An in situ method that relies on natural processes to remediate contamination.
Relies on:Volatilization of contaminant
Biological processes
Chemical processes
Success depends on:Type and amount of contaminant
Size and depth of contaminated area
Favorable soil and groundwater conditions
Sufficient time
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Unsaturated Saturated
Physical
Chem
ical
Biological
Physical
Chem
ical
Biological
Monitored Natural Attenuation Soil Vapor Extraction (SVE)
SVE Enhancements Air Sparging Permeable Reactive Barriers Chemical Oxidation Soil Flushing * Bioremediation * Phytoremediation * Immobilization * *Covered in other lectures
Process draws fresh air through the unsaturated zone, allowing flux, mass transfer, and treatment.
VaporTreatment Blower
CondensateCollection
VaporTreatment Blower
CondensateCollection
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Flux: Contaminant vaporizes into the introduced fresh air.
VaporTreatment Blower
CondensateCollection
VaporTreatment Blower
CondensateCollection
Mass transfer: Vapors move to one or more extraction wells.
Treatment: Single- or multi-step process extracts and treats vapors.
VaporTreatment Blower
CondensateCollection
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Success depends on:
Contaminant characteristics
Soil properties
Site conditions
System design
Remediation manager can only control:
Contaminant characteristics
Soil properties
Site conditions
System design
Remediation manager can only control:
Contaminant characteristics
Soil properties
Site conditions (limited control)
System design
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Success depends on:
Contaminant characteristics
Soil properties
Site conditions
System design
The single most important criterion for a successful soil-vapor extraction (SVE)system is the volatility of the contaminant.
Volatility of contaminant influenced by :
Primary factor
Henry's Law Constant
Secondary factors
Affinity to medium
Contaminant composition
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Henry's Law Constant (KH)
Relationship between the contaminant's concentration in air and water
Function of vapor pressure (Pv) and its solubility (C) in water
KH =PvC
Expresses the ability of a contaminant to volatilize from a dissolved phase into a vapor.
Approximately 10-3 atm m3/mole
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Expresses the affinity of a soil to a chemical compound.
KOC
A complex mix of contaminants may impede the effectiveness of an SVE system.
Success depends on:
Contaminant characteristics
Soil properties
Site conditions
System design
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Coarse-grainedmaterial (gravel)
Fine-grainedmaterial (silt)
Soil permeabilitySecond only to Henry's Law Constant for success of an SVE system
Gravel
Silt
Soil permeability is affected by:Soil type and heterogeneity
Soil permeability is affected by:Soil type and heterogeneitySoil moisture content
High soil moisture content will limit vapor advection pathwaysOptimum soil moisture is less than 10% by weight
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Success depends on:
Contaminant characteristics
Soil properties
Site conditions
System design
Site conditions refer to above-ground and below-ground conditions, and include:
Depth to groundwater surfaceSubsurface cond