EPA/540/AR-92/019
                                    December 1992
  Low Temperature Thermal
Treatment (LT3®) Technology

      Roy F. Weston,  Inc.

 Applications Analysis Report
        Risk Reduction Engineering Laboratory
         Office of Research and Development
        U.S. Environmental Protection Agency
            Cincinnati, Ohio 45268
                                Printed on Recycled Paper

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                                            Notice
                                         !         ' , i '  i n|',   '  ' Mi1 ",  •' • I   ' •       •            I    <
    The information in this document has been prepared for the U.S. Environmental Protection Agency (EPA)
Superfund Innovative Technology Evaluation (SITE) program under Contract No. 68-CO-0047. This document
has been subjected to EPA peer and administrative reviews  and has been approved for publication as an EPA
document.   Mention  of trade names or commercial products does not constitute an  endorsement  or
recommendation for use.
                                                u

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                                           Foreword
    The Superfund Innovative Technology Evaluation (SITE) program was authorized by the 1986 Superfund
Amendments and Reauthorization Act (SARA).  The SITE program is a joint effort between the EPA Office
of Research and Development (ORD) and the Office of Solid Waste and Emergency Response (OSWER). The '
purpose of the program is to accelerate the development and use of innovative cleanup technologies applicable
to Superfund and other hazardous waste sites. This is accomplished through field technology demonstrations
designed to provide performance and cost data on selected technologies.

    A field demonstration was conducted under the SITE program to evaluate the Low Temperature Thermal
Treatment (LT3®) technology.  The technology demonstration took place at the Anderson Development Company
(ADC) site in Adrian, Michigan. The purpose of the demonstration effort was to obtain information on the
performance and cost of the technology and to assess its use at this and other uncontrolled hazardous waste sites.
Documentation of the demonstration consists of two  reports: (1) a Technology Evaluation Report, which
describes field activities and laboratory results, and (2) this Applications Analysis Report, which interprets the
demonstration data and discusses the technology's potential applicability.

    A limited number of copies  of this report will be available at no  charge from the EPA Center for
Environmental Research Information, 26 West Martin Luther King Drive, Cincinnati, Ohio 45268. Requests for
this report should include the  EPA document number found on the report's cover. When the limited supply is
exhausted, additional copies may be purchased from the National Technical Information Service, Ravensworth
Building, Springfield, Virginia 22161, (703)487-4600.  Reference copies will be available at EPA libraries as part
of the Hazardous Waste Collection.  To inquire about the availability of other reports, call ORD Publications
in Cincinnati, Ohio,  at (513)569-7562.
                                                             E. Timothy Oppelt, Director

                                                             Risk Reduction Engineering Laboratory
                                                 in

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                                             Abstract
    This report evaluates the Low Temperature Thermal Treatment (LT3®) system's ability to remove volatile
 organic compounds (VOC) and semivolatile organic compounds (SVOC) from solid wastes. This evaluation is
 based on treatment performance and cost data from the Superfund Innovative Technology Evaluation (SITE)
 demonstration and five other case studies.

    The LT3* system thermally desorbs organic compounds from contaminated soil without heating the soil to
 combustion temperatures.  The LT3® system is divided into three treatment areas:  soil treatment, emissions
 control, and condensate treatment. End products include treated soil, fabric filter dust, treated condensate, and
 treated stack gas.  The transportable system is comprised of equipment assembled on three flat-bed trailers.
                                                                         1
    The LT3® system demonstration was conducted under the SITE program at the Anderson Development
 Company (ADC) site in Adrian, Michigan. During the demonstration, the LT3® system treated lagoon sludge
 from the site contaminated with VOCs and SVOCs,  primarily 4,4' -methylenebis(2-chloroaniline) (MBOCA).
 During the development of the LT3® system, Weston conducted bench-  and pilot-scale  tests and collected
 treatability data for the following wastes: coal tar, drill cuttings (oil-based mud), leaded and unleaded gasoline,
 No. 2 diesel fuel, JP4 jet fuel, petroleum hydrocarbons, halogenated and nonhalogenated solvents, VOCs, SVOCs,
 and polynuclear aromatic hydrocarbons (PAH).

    Based on the results of the SITE demonstration and other case studies, the following conclusions can be
 drawn:  (1) the LT3® system can  process a  wide  variety of soils with differing moisture and contaminant
 concentrations; (2) The LT3® system removes VOCs to below detection limits; (3) The LT3® system generally
 decreases SVOC  concentrations, but some SVOC concentrations may  increase, most likely due to chemical
 transformations during heating; (4) under certain conditions, dioxins and furans maybe formed during treatment
 in the LT3* system and maybe distributed in process residuals; and (5) remediation costs, including all activities
 from  site preparation through demobilization, may range from $373 to $725 per ton of soil, depending on soil
 moisture content and regulatory requirements.

   The report also  discusses the applicability of the LT3® system based on compliance  with regulatory
requirements,  implementability, short-term  impact,  and long-term effectiveness.  In addition,  the  factors
influencing the technology's performance in meeting these criteria are discussed.
                                                 IV

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                                           Contents
Notice	   ii
Foreword	  iii
Abstract	  iv
Acronyms, Abbreviations, and Symbols	viii
Conversion Factors	   x
Acknowledgements	xi

1.  Executive Summary	   1
       1.1     Conclusions	   1
       1.2     Results	   2

2.  Project Background	 .	   5
       2.1     Purpose, History, and Goals of the SITE Program  	   5
       2.2     Documentation of the SITE Demonstration Reports	   5
               2.2.1    Technology Evaluation Report	   6
               2.2.2    Applications Analysis Report	   6
       2.3     Technology Description	   6
               2.3.1    Principal Treatment Operations	   6
               2.3.2    Innovative Features of the UT3® Technology	   7
               2.3.3    LT3® Technology Limitations	   7
       2.4     Key Contacts	   7

3.  Technology Applications Analysis	11
       3.1     Treatment Effectiveness for Toxicity Reduction  	  11
               3.1.1    VOC Removal  	  11
               3.1.2    SVOC Removal  .	13
               3.1.3    Formation of Thermal Transformation By-Products	14
               3.1.4    Stack Emissions  	: .  14
       3.2     Compliance with Regulatory Requirements		15
               3.2.1    Comprehensive Environmental Response, Compensation, and Liability Act   ...  15
               3.2.2    Resource Conservation and Recovery Act  	  15
               3.2.3    Clean Air Act	  16
               3.2.4    Occupational Safety and Health Administration	  16
       3.3     Implementability	16
               3.3.1    Mobilization	16
               3.3.2    Operations and Maintenance Requirements	17
               3.3.3    Reliability	18
               3.3.4    Personnel Requirements	  19
               3.3.5    Demobilization	19
       3.4     Short-Term Impact 	19
               3.4.1    Worker Safety	  19
               3.4.2    Potential Community Exposures  	20
       3.5     Long-Term Effectiveness	20
               3.5.1    Permanence of Treatment	20
               3.5.2    Residuals Handling	20

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        3.6     Factors Influencing Performance 	21
                3.6.1    Size of the Waste Feed	21
                3.6.2    Moisture Content of the Waste Feed	21
                3.6.3    Particle Size Distribution of the Waste Feed  	21
                3.6.4    pH of the Waste Feed  	21
                3.6.5    Contaminated Sludge Flow Rate	22
                3.6.6    Heating Fluid Temperature	22
                3.6.7    Climatic Conditions	22

 4.  Economic Analysis	23
        4.1     Site-Specific Factors Affecting Costs	23
        4.2     Basis of Economic Analysis	23
                4.2.1    Assumptions about the LT3® Technology and Capital Costs  	23
                4.2.2    Assumptions about the Soil and Site Conditions	23
                4.2.3    Assumptions about LT3® System Operation  	26
        4.3     Cost Categories	26
                4.3.1    Site Preparation Costs	26
                4.3.2    Permitting and Regulatory Costs	27
                4.3.3    Equipment Costs  	27
                4.3.4    Startup Costs  	28
                4.3.5    Labor Costs	28
                4.3.6    Consumable  Material Costs	28
                4.3.7    Utility Costs	29
                4.3.8    Effluent Monitoring Costs	29
                4.3.9    Residual Waste Shipping, Handling, and Transportation Costs 	29
                4.3.10   Analytical Costs  	29
                4.3.11   Equipment Repair and Replacement Costs   	30
                4.3.12   Site Demobilization Costs	30

 References	30

 Appendix A - Developer's Claims	31
        A.I     Introduction  	31
        A.2     Potential Application	31
        A.3     System Advantages 	31
        A.4     System Limitations 	32
        A.5     Costs  	32
 Appendix B - SITE Demonstration Results	33
        B.I     Introduction  	33
        B.2     Site Description	33
        B.3     Contaminant Characteristics	33
        B.4     Technology Demonstration Testing and Sampling Procedures	34
        B.5     Treatment Results	34
                B.5.1    VOC Removal 	35
                B.5.2    MBOCA Removal  	35
                B.5.3    SVOC Removal	! . ! 36
                B.5.4    The Fate of Chloride in the LT3® System	37
                B.5.5    The Formation and Distribution of Dioxins and Furans  	37
                B.5.6    The Fate of Metals in the LT3® System  	39
                B.5.7    Stack Emissions  	39
                B.5.8    Physical Properties of Sludge	40
                B.5.9    Toxicological Properties of Sludge	41
        References	42
Appendix C - Case Studies	45
                                                 VI

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                                            Figures
2-1    LT3® System Block Flow Diagram  .	7
2-2    LT3® System Layout	  8
2-3    Internal View of Thermal Processor	  9
B-l    MBOCA Concentrations in Untreated and Treated Sludge  	37
B-2    AC-MBOCA Concentrations in Untreated and Treated Sludge 	38
B-3    3- and 4-Methylphenol Concentrations in Untreated and Treated Sludge 	39
B-4    Phenol Concentrations in Untreated and Treated Sludge .	;	40
B-5    BOX Concentrations in Untreated and Treated Sludge and in Fabric Filter Dust	41
B-6    Chloride Concentrations in Untreated and Treated Sludge and Fabric Filter Dust	42


                                            Tables

3-1    Treatment Conditions of the SITE Demonstration and Other Case Studies	12
4-1    Cost Analysis for Operating the LT3® System	24
B-l    LT3® System  Operating Conditions During SITE Demonstration	35
B-2    Arithmetic Mean Concentrations of CDDs and CDFs	43
B-3    Liquid Condensate Concentrations (ppt) Averaged by Run	 . .	44
C-l    Results of Full-Scale Cleanup of No.2 Fuel Oil and Gasoline-Contaminated Soil  	47
C-2    Results of Pilot-Scale Demonstration on VOC-Contarainated Soil	49
C-3    Results of Engineering Technology Laboratory	50
C-4   • Results of Bench-Scale LT3® Test on Coal Tar-Contaminated Soil	51
C-5    Results of Bench-Scale LT3® Testing on Petroleum Hydrocarbon-Contaminated Soil 	52
C-6    Results of Bench-Scale LT3® Testing on Chlorinated Benzene-Contaminated Soil	53
                                                vu

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                       Acronyms, Abbreviations, and Symbols
/xm
AC-MBOCA
ADC
AFB
ARAR
ASTM
BTEX
Btu
CAA
Canonic
CBR
CCJM
CDD
CDF
CEM
CERCLA
cm
CO
CO2
DAC-MBOCA
DOD
ORE
EA
BOX
EPA
fpm
FS
GC/MS
g
gpm
gr/dscm
HC1
hr
kWh
Ib/hr
LC50
LT3®
LDR
MBOCA
m2/g
mg/kg
mg/L
mg/m3
Micrograms per kilogram
Micrograms per liter
Micron
N-acetyl-MBOCA
Anderson Development Company
Air Force Base
Applicable or relevant and appropriate requirement
American Society of Testing and Materials
Benzene, toluene, ethylbenzene, and xylenes
British thermal units
Clean Air Act
Canonie Environmental Services Corporation
California bearing ratio
C.C. Johnson & Malhotra
Polychlorinated dibenzo(p)dioxins
Polychlorinated dibenzofurans
Continuous emissions monitoring
Comprehensive Environmental Response, Compensation, and Liability Act
Centimeters
Carbon monoxide
Carbon dioxide
N,N' -diacetyl-MBOCA
Department of Defense
Destruction and removal efficiency
Endangerment assessment
Extractable organic halide
U.S. Environmental Protection Agency
Feet per minute
Feasibility study
Gas chromatography/Mass spectroscopy
Gram
Gallons per minute
Grains per dry standard cubic meter
Hydrogen chloride
hour
Kilowatt-hour
Pounds per hour
Median lethal concentration
Low temperature thermal treatment
Land Disposal Restrictions
4,4'-Methylenebis (2-chloroaniline)
Square meters per gram
Milligrams per kilogram
Milligrams per liter
Milligrams per cubic meter
                                             vui

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mg/dscm       Milligrams per dry standard cubic meter
ND            Nondetectable
ng/dscm       Nanogram per dry standard cubic meter
NPDES        National Pollutant Discharge Elimination System
NPL           National Priorities List
O2            Oxygen
O&M         Operation and maintenance
OCDD        Octachloro dibenzo(p)dioxin
ORD          Office of Research and Development
OSHA         Occupational Safety and Health Administration
OSWER       Office of Solid Waste and Emergency Response
PAH          Polynuclear aromatic hydrocarbon
PCE           Tetrachloroethene
ppb            Parts per billion
ppbv           Parts per billion by volume
PPE           Personal protection equipment
ppm           Parts per million
ppmv          Parts per million by volume
ppt            Parts per trillion
psi            Pounds per square inch
QA            Quality assurance
QC            Quality control
RCRA         Resource Conservation and Recovery Act
ROD          Record of Decision
RH            Relative humidity
rpm            Revolutions per minute
RREL         Risk Reduction Engineering Laboratory
RI            Remedial investigation
SITE          Superfund Innovative Technology Evaluation
SARA         Superfund Amendments and Reauthorization Act
START        Superfund Technical Assistance Response Team
SVOC         Semivolatile organic compounds
TCE           Trichloroethene
TCDD         Tetrachloro dibenzo(p)dioxin
TCLP         Toxicity characteristic leaching procedure
THC           Total hydrocarbon concentration
TNMHC       Total nonmethane hydrocarbon concentration
TOX          Total organic halides
TOC           Total organic carbon
tons/hr        Tons per hour
USATHAMA   U.S. Army Toxic and Hazardous Materials Agency
UST           Underground Storage Tank
VOC          Volatile organic compounds
WESTON      Roy F. Weston, Inc.
                                               IX

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r
                                                         Conversion Factors
                    Length:
                    Area:
               English

           1 inch (in)
           1 foot (ft)
           1 mile (mi)
           1 square foot (ft2)

Volume:   1 gallon (gal)
           1 cubic foot (ft3)

Mass:      1 grain (gr)
           1 pound (Ib)
           1 ton (t)

Pressure:   1 pound per square inch (psi)
x
x
x
                                                                 x
                                                                 X


                                                                 X
                                                                 X
                                                                 X
Factor

2.54
0.305
1.61

0.0929

3.78
0.0283

64.8
0.454
907

0.0703
Metric

centimeter (cm)
meter (m)
kilometer (km)

square meter (m2)

liter (L)
cubic meter (m3)

milligram (mg)
kilogram (kg)
kilogram (kg)

kilogram   per  square
centimeter (kg/cm2)
                    Energy.    1 British Thermal Unit (Btu)
                               1 kilowatt hours (kWh)
                                             x
                                             x
        1.05
        3.60
                       kilojoule (kJ)
                       megajoule (MJ)
                    Temperature:   ("Fahrenheit - 32)
                                                     0.556
                              "Celsius

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                                    Acknowledgements


    This report was prepared under the direction and coordination of Mr. Paul R. dePercin, U.S. Environmental
Protection Agency (EPA) Superfund Innovative Technology Evaluation (SITE) Project Manager at the Risk
Reduction Engineering Laboratory (RREL) in Cincinnati, Ohio. Mr. Mark Meckes of the RREL Superfund
Technical Assistance Response Team (START) provided invaluable technical guidance and support throughout
the project. The efforts of Mr. James Hahnenberg of EPA Region 5, Mr. James Huerta and Ms. Denise Muck
of Anderson Development Company, and Mr. Michael Cosmos and Mr. Michael lanni of Roy F. Weston, Inc.,
were essential to the project's success.

    This report was  prepared for the EPA SITE Program by Mr. Robert Foster, Dr. Chriso Petropoulou, Mr.
David Berestka, Mr. Jeffrey Swano, Mr. Tim Oliver, Ms. LouAnn Unger, Ms. Tammara Muhic, Mr. Michael
Johnson, and Ms. Carol Adams of PRC Environmental Management, Inc. (PRC). Technical input was provided
by Ms; Suzanne Smidt of Versar,  Inc.; Mr. Mike Steele of Radian  Corporation; and Mr. Alan Todruss of
Construction Technology Laboratories. The report was edited by Ms. Regina Bergner and Ms. Shelley Fu of
PRC. Peer reviewers were Ms. Michelle Simon, Mr. Richard G. Eilers, and Mr. Mark Meckes of RREL.
                                              XI

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                                                   Section  1
                                            Executive Summary
    This report summarizes the findings of an evaluation for
the Low  Temperature Thermal Treatment  (LT3®)  system
(U.S. Patent No. 4,738,206 and 5,076,674) developed by Roy
F. Weston, Inc. (Weston).  This study was conducted under
the U.S. Environmental Protection Agency (EPA) Superfund
Innovative Technology Evaluation (SITE) program. A series
of demonstration tests of the technology were performed by
EPA as part of this program. The demonstration tests were
conducted  in November and December  1991,   at  the
Anderson Development Company (ADC) Superfund site in
Adrian, Michigan.  The evaluation of the LT3® system was
based on the results of the SITE demonstration, subsequent
remediation of the ADC Superfund site, and five other case
studies performed  by Weston for  several  private  and
governmental clients.

    The LT3® system thermally desorbs organic compounds
from contaminated  soil without  heating the  soil  to
combustion temperatures. The LT3® system is divided into
three treatment areas: soil treatment, emissions control, and
water treatment. End products include treated soil, fabric
filter dust, treated condensate, and treated stack gas.  The
transportable system can be assembled on three  flat-bed
trailers.

1.1 Conclusions

    Based  on the SITE  demonstration and  other  case
studies, the following conclusions may  be  drawn for the
applicability of the LT3® system:

    •  The LT3® system  can process a wide variety of soils
       with   differing   moisture   and   contaminant
       concentrations.  Bench-, pilot-,  or  full-scale LT3®
       systems have been used to effectively treat  soil
       contaminated with the following wastes: volatile
       organic  compounds (VOC),  semivolatile organic
       compounds (SVOC),  coal tar,  drill cuttings  (oil-
       based mud), No. 2 diesel fuel, JP4 jet  fuel, leaded
       and unleaded  gasoline,  petroleum hydrocarbons,
       halogenated  and nonhalogenated  solvents,  and
       polynuclear aromatic hydrocarbons  (PAH).
•   Contaminant  removal mechanisms  in  the LT3®
    system include thermal transformation and thermal
    desorption.    The  LT3®  system  desorbs  and
    permanently removes VOCs and certain SVOCs
    from contaminated soil and sludge.  Contaminant
    removal efficiency varies with analyte.  In general,
    VOC  removal efficiencies are greater than SVOC
    removal  efficiencies.     Also,   among   SVOCs,
    compounds with lower boiling points are removed
    more effectively than compounds with higher boiling
    points.

•   The LT3® system is most appropriate for wastes
    with a moisture content of about 20 percent. Water
    can be added to  dry wastes to  control  excessive
    dusting.  To  enhance the efficiency of the LT3®
    system, wastes with free liquids or with a moisture
    content  of greater  than 50  percent must be
    dewatered.    Sludge  dewatering  affects  site
    preparation costs significantly. In addition, chemical
    additives used as  sludge conditioning agents may
    affect chemical reactions in the system.

•   Screening or  crushing oversized  material  (greater
    than 2 inches in size) or  clay shredding may be
    required for some applications.

•   Treatment residuals are not destroyed on site and
    require off-site treatment.  Two types of residuals
    are generated from the  LT3® system: (1) liquid
    condensate and (2) fabric filter dust. The long-term
    effectiveness of the LT3® system ultimately depends
    on the methods used to treat or dispose  of these
    residuals.

•   The concentration of contaminants in fabric filter
    dust is significantly higher than the concentration of
    contaminants  in the treated material. These results
    indicate that contaminants adsorbed on smaller size
    particles  are  not  effectively  desorbed  during
    treatment.

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    •  Dry,  warm  weather  conditions are  ideal  for
       operating the LT3® system.  However, the SITE
       demonstration  was  conducted  hi  subfreezing
       temperatures, and remedial activities at  the  site
       were conducted hi subfreezing or wet  weather
       conditions.   Cold and wet  weather caused only
       minor operational problems.

    •  The  economic   analysis  of  the LT3®  system's
       performance compared the costs associated with
       treating soils containing  20, 45, and 75 percent
       moisture; the treatment  cost per ton  of treated
       material was estimated to be $373, $537, and $725,
       respectively.  Waste-related factors affecting costs
       include waste volume,  waste type,  soil moisture
       content, treatment goals, and  regulatory permit
       requirements. Site-specific features affecting costs
       Include site area, accessibility, availability of utilities,
       and geographic location. Also, the characteristics of
       the residual waste affect disposal costs.

    •  Several operational problems with the LT3® system
       were  observed   during  shakedown  and  startup
       operations, during the  SITE demonstration,  and
       during routine remedial activities at the ADC site.
       Operational  problems resulted from mechanical
       difficulties with  the screws, an inadequately sized
       oil-water separator, oversized  debris hi the feed
       material,  leaking  sweep ah-  gas,  excess dust
       generation from reprocessed material, and leaking
       pipes  in the heat transfer  fluid  system.   All
       problems were  corrected over  the  course  of the
       remediation.

    •  Treatability studies are highly recommended before
       large-scale  applications  of the  technology  are
       considered.  Because results may vary greatly with
       different solid matrices and waste characteristics,
       the LT3® system's performance is best predicted
       with preliminary bench-scale testing.

1.2 Results

    This section summarizes the results of the LT3® system's
performance during the SITE demonstration and during five
other  case  studies.    A  full-scale  LT3®  system  was
demonstrated  at the ADC site.   A  major advantage of
demonstrating a full-scale system is that the results  achieved
are more likely to be duplicated by other systems at similar
sites, especially compared to results from, smaller, pilot-scale
or prototype units.  Also, the nature of operational problems
encountered during the  demonstration should be indicative
of problems at other sites.

    The LT3* system SITE demonstration was conducted as
part of a proof-of-process test for full-scale remediation of
the ADC lagoon sludge.  The ADC lagoon sludge  was
contaminated   with  VOCs,   and   SVOCs,   primarily
4,4'-methylenebis(2-chloroaniline)  (MBOCA).  Six 6-hour
replicate tests were conducted during the  demonstration.
During the tests, contaminated sludge was heated to above
500 °F for a residence tune of 90 minutes.   Sludge was
processed at a rate of 2.1 tons per hour (tons/hr); a total of
80 tons  of contaminated sludge was treated during the six
SITE demonstration tests.  Key findings from  the  SITE
demonstration include the following:

    •   The LT3® system removed most VOCs to below
        method detection limits [less than 60 micrograms
        per kilogram (/*g/kg) for most compounds].  VOC
        concentrations in untreated sludge ranged from 35
        to 25,000 jig/kg.

    •   The  LT3® system  achieved  MBOCA  removal
        efficiencies ranging from  79.82  to 99.34 percent.
        MBOCA concentrations hi untreated sludge ranged
        from 43.6 to 860 milligrams per kilogram (mg/kg).
        MBOCA concentration hi the treated sludge ranged
        from 3 to 9.6 mg/kg.

    •   The LT3® system decreased the concentration of all
        SVOCs initially present hi  the  sludge with two
        exceptions. First,  phenol concentrations increased
        after  treatment,  probably because  of chemical
        transformations during heating.  Second, a minor
        leak   of  heat transfer  fluid,  which  contains
        triphenylene,  probably resulted  hi the  measured
        concentrations of chrysene hi the treated material;
        chrysene and  triphenylene  are  indistinguishable
        under  the analytical  method used  during the
        demonstration.

    •   Polychlorinated  dibenzo(p)dioxins  (CDD)  and
        polychlorinated dibenzofurans (CDF) were formed
        in the LT3® system and distributed hi treated sludge,
        fabric filter dust, exhaust gas, and liquid condensate.
        CDD and CDF concentrations hi untreated  liquid
        condensate increased with successive test runs. The
        condensate was treated through  a liquid-phase
        carbon adsorption system before being sent off site
        for disposal.   A  vapor-phase  carbon  column
        removed CDDs and CDFs from the exhaust gas;
        removal efficiencies varied with congener, from 20
        to 100 percent.

    •   The total nonmethane hydrocarbon concentration
        (TNMHC) hi stack emissions from the LT3® system
        increased consistently.  During the first test run,
        TNMHC  was  6.7  part per  million by  volume
        (ppmv); during the second test run TNMHC was 7.6
        ppmv;  and during the  third run TNMHC was 11
        ppmv.  The particulate concentration hi the stack
        gas ranged from less than 8.5X10"4 to 6.7xlO"3 grains
        per dry standard  cubic meter (gr/dscm), and the

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        participate emissions ranged from less than
        to  9.2X10"4  pounds per hour  (Ib/hr).   Chloride
        concentrations were below the method detection
        limit,   which  had    an   average   value   of
        2.8xlO'2 milligrams  per dry standard cubic meter
        (mg/dscm).   Chloride emissions were less than
        6.0xlO's Ib/hr.

    The five case studies evaluated included two full-scale
applications for fuel contaminated sites, a pilot-scale study,
and bench-scale studies at Weston's laboratory and at a
private client's site.  Key findings from other case studies
include the following:

    •   Full-scale remedial activities using the LT3® system
        were conducted at a confidential site in Springfield,
        Illinois.     About  1,000  cubic  yards  of  soil
        contaminated with  No. 2 fuel oil and gasoline was
        successfully  treated  at 350 °F for  a 70-minute
        residence tune.

    •   The  U.S.  Army Toxic and  Hazardous Materials
        Agency (USATHAMA) selected Tinker Air Force
        Base (Tinker AFB) in Oklahoma City, Oklahoma,
        for the demonstration of a full-scale LT3® system.
        About 3,000 cubic  yards of soil contaminated with
        trichloroethene (TCE), chlorobenzene,  and JP4 jet
        fuel were  treated during the demonstration.  The
        LT3® system reduced the concentrations of all target
        contaminants to below cleanup levels.
A pilot-scale test of the LT3® system was conducted
for USATHAMA at the Letterkenny Army Depot
in Chambersburg, Pennsylvania. More than 7.5 tons
of  soil  contaminated with TCE,  dichloroethene,
tetrachloroethene (PCE), and xylene were treated at
320 °F for a residence time  of 60 minutes.  The
LT3®  system achieved removal efficiencies greater
than 99.99 percent.

Weston  has conducted several  studies using  a
bench-scale LT3®  system at  its  Environmental
Technology Laboratory in Lionville, Pennsylvania.
Soils  contaminated with VOCs, coal tar, and PAH
were  treated at temperatures  varying from 250 to
450 °F and residence times ranging from 30 to 45
minutes. In general, target VOCs were removed to
below detection limits and PAH removal efficiencies
were  greater than 93 percent.

Weston  also conducted bench-scale studies for a
confidential client in  Colorado on soil contaminated
with chlorinated benzene.  Soil was treated at 400
°F for a residence time of 44 minutes, achieving
removal efficiencies greater than 99.9 percent.

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                                                   Section 2
                                            Project Background
    This  section provides background information on the
SITE program, discusses the purpose of this applications
analysis report, and describes the LT3® system developed by
Weston.  The LT3® system  was  demonstrated under the
SITE program at the ADC Superfund site in Adrian,
Michigan.  For additional information about the SITE
program, this technology, and the demonstration site, key
contacts are listed at the end of this section.

2.1 Purpose,  History,  and  Goals of the SITE
Program

    The  SITE program is  a unique, international effort
dedicated to  advancing the  development, evaluation, and
implementation  of  innovative  treatment  technologies
applicable to hazardous waste sites. The SITE program was
established  in response to the 1986 Superfund Amendments
and Reauthorization Act (SARA), which recognized a need
for  an alternative  or  innovative  treatment  technology
research  and development program.  The SITE program is
administered  by the  EPA Office  of  Research  and
Development   (ORD)   Risk   Reduction   Engineering
Laboratory (RREL).

    The  SITE  program consists  of  four component
programs:    (1)  the  Demonstration Program,  (2) the
Emerging Technology Program,  (3)  the Monitoring and
Measurement   Technologies  Program,   and   (4)  the
Technology Transfer Program. This document was produced
as part of the SITE Demonstration Program.  The objective
of  the  Demonstration  Program is  to provide reliable
performance and cost data on innovative technologies so that
potential users can assess  a technology's  suitability for
specific site cleanups. To produce useful and reliable data,
demonstrations are conducted at hazardous waste sites or
under conditions that closely simulate actual wastes and site
conditions.

    Data collected during a demonstration are used to assess
the performance of the technology, the potential need for
pretreatment  and posttreatment  processing  of the  waste,
applicable types of waste and media, potential operating
problems, and  approximate capital and operating costs.
Demonstration  data  can  also  provide  insight  into  a
technology's long-term operating and maintenance (O&M)
costs and long-term application risks.

    Technologies are selected for the SITE Demonstration
Program primarily through annual requests for proposals.
Proposals are reviewed by ORD staff to determine which
technologies have the most promise for use at hazardous
waste sites. To be eligible, technologies must be developed
to the pilot- or full-scale stage, must be innovative, and must
offer some advantage over existing technologies.  Mobile
technologies are of particular interest.

    Cooperative agreements between EPA and the developer
determine responsibilities for conducting the demonstration
and evaluating the technology. The developer is responsible
for demonstrating the technology at the selected site and is
expected to pay the costs to transport, operate, and remove
its equipment.  EPA is responsible for project planning,
sampling  and analysis,  quality  assurance  (QA), quality
control   (QC),   preparing  reports,   and   disseminating
information.

    Each SITE demonstration evaluates the performance of
a  technology in  treating  a  particular  waste  at  the
demonstration site. To obtain data with broad applications,
EPA and the technology developer try to choose a waste
frequently found at other contaminated sites.  In many cases,
however, waste characteristics at other sites will differ  in
some way from  the waste tested.   Thus, a successful
demonstration of the technology at one site does not ensure
that it will work equally well at other  sites.  Data obtained
from the SITE demonstration may have to be extrapolated
and combined with other information  about  the technology
to estimate the operating range and limits of the technology.

2.2 Documentation of the SITE Demonstration
Reports

    The results of each SITE demonstration are presented
in two documents, each with a distinct purpose:  (1) the
Technology  Evaluation Report  and (2) the Applications
Analysis Report.  These documents are described below.

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2.2.1 Technology Evaluation Report

    The  Technology   Evaluation   Report  provides  a
comprehensive description of the SITE demonstration and
its results. It is intended for engineers making a detailed
evaluation of the  technology's  performance  for  the
demonstration site and waste situation.   These technical
evaluators seek to understand, in detail, the performance of
the technology during the demonstration and the advantages,
risks, and costs of the technology for a specific application.
The report also provides a detailed discussion of QA and
QC measures during the demonstration.

2.2.2 Applications Analysis Report

    To encourage wider use of technologies demonstrated
under the SITE program, the Applications Analysis Report
provides  information  on  a technology's costs  and  its
applicability to other sites and wastes.   Prior to a SITE
demonstration, the  amount  of data  available  for  an
innovative technology may vary widely.  Data may range
from limited  laboratory tests  on  synthetic  wastes   to
performance  data on actual wastes treated in pilot- or full-
scale treatment systems. The Applications Analysis Report
synthesizes available information on the technology and
draws  reasonable  conclusions  about  its  broad-range
applicability.   This report is intended for those who are
considering a technology for  hazardous site cleanups;  it
represents a  critical  step   in  the  development  and
commercialization of a treatment technology.

    The principal use of the Applications Analysis Report is
to assist in determining whether a technology should be
considered further as an  option for a particular cleanup
situation.  The Applications Analysis Report is intended for
decision makers  responsible for implementing remedial
actions. The report discusses advantages, disadvantages, and
limitations of the technology. Costs for different applications
may be estimated using 12 cost categories that are based on
available data from pilot-  and  full-scale  applications. The
report also discusses specific factors, such as site and waste
characteristics, that may affect performance and cost.

2.3 Technology Description

   The LT3* system thermally desorbs organic compounds
from contaminated  soil  without  heating  the  soil  to
combustion  temperatures.   The  full-scale  transportable
system can be assembled on three flat-bed trailers. With
ancillary and support equipment, the system requires an area
of about 5,000 square feet.

2.3.1 Principal Treatment Operations

   The LT3® system consists of three main treatment areas:
soil treatment, emissions control, and condensate treatment.
A block flow diagram of the system (see Figure 2-1) is
described below.

    Soil  is treated  in the LT3® thermal processor.  The
thermal  processor consists of two  jacketed troughs, one
above  the other.  Each  trough  houses  four intermeshed,
hollow-screw conveyors. A front-end loader transports feed
soil  (or  sludge) to a  weigh scale  before depositing the
material onto  a  feed  conveyor.   The  feed  conveyor
discharges the soil into a surge  hopper  located above the
thermal processor. The surge hopper is equipped with level
sensors and provides a seal over the thermal processor to
minimize air infiltration and  contaminant  loss.   The
conveyors move soil across the upper trough of the thermal
processor until the soil drops to the lower trough.  The soil
then travels  across the processor and exits at the same end
that it entered. Hot oil circulates through the hollow screws
and trough jackets and acts as a heat transfer fluid.  During
treatment in the processor,  each hollow-screw conveyor
mixes,  transports, and heats  the contaminated  soil.  The
thermal processor discharges treated soil into a conditioner,
where  it is sprayed with  water to cool it and to minimize
fugitive dust emissions.  An inclined belt conveys treated soil
to a truck or pile.

    A  burner heats the circulating oil to an operating
temperature of 400 to 650 °F (about 100  °F higher than the
desired soil  treatment temperature).  Combustion gases
released from the burner are used as  sweep gas in the
thermal processor.  A fan draws sweep  gas and desorbed
organics from the thermal processor into a  fabric filter.
Dust collected  on the fabric filter may be retreated  or
drummed for off-site disposal.  Exhaust gas from the fabric
filter is drawn into an air-cooled condenser to remove most
of the water vapor and organics.  Exhaust gas is then drawn
through a second, refrigerated condenser, which lowers the
temperature further and reduces the moisture and organic
content of the off-gases.   Electric resistance heaters then
raise  the off-gas  temperature  back to  70 °F.   This
temperature optimizes the performance of the vapor-phase,
activated carbon column, which is used to  remove any
remaining organics.  At some sites, caustic scrubbers and
afterburners have been employed as part of the air pollution
control system, but they were not used at the ADC site.

    Condensate streams from the air-coded and refrigerated
condensers are typically treated in a three-phase, oil-water
separator. The oil-water separator removes light and heavy
organic phases from the water phase. The aqueous portion
is then treated in the carbon adsorption system to remove
any residual organic  contaminants;  after separation and
treatment, the  aqueous  portion is often used  for soil
conditioning. The organic phases are disposed of off site.
When processing extremely wet materials like sludge, the oil-
water separation step may not be appropriate due to the
high volume of condensate  generated.   In such cases,
aqueous streams from the first and second condensers may

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                                                                      To atmosphere
    Oversized
    material or
    wastewater
                                                                             Hot oil burner off-gases

                                                                                         Fuel/combustion air
             Key
            — Solids Flow
               Aqueous Flow

               Vapor Flow
                                                          V
                                                     To atmosphere
                                                                       To off-site
                                                                        disposal
                                         To discharge
                                          or off-site
                                           disposal
Figure 2-1 LT3® System Block Flow Diagram
be pumped through a disposable filter to remove particulate
matter prior to  carbon adsorption treatment  and off-site
disposal.

2.3.2 Innovative Features of the LT3® Technology

    The LT3® system is a U.S.-patented process for the
treatment of organic contaminants in soils and sludges.
Figure  2-2  presents  a general  layout  of  the  process
equipment.  The most innovative feature of the system is the
use of  hollow-screw  augers for  mixing, conveying, and
indirectly heating the feed material. Figure 2-3 presents an
internal view of the  screw augers.   The system's  other
process treatment  units, including the residuals treatment
units, are not unique.

2.3.3 LT3® Technology Limitations

    Weston reports that the LT3® system can process a wide
variety of soils  with differing moisture  and contaminant
concentrations.   The developer reports that the technology
is best suited for soils with a moisture content of less than 20
percent and VOC concentrations of up to 1 percent. SVOCs
with boiling points greater than 500 °F can also be treated,
but  treatment  must  be  evaluated  based  on cleanup
objectives.  Wastes with a moisture content between 20 and
50 percent can be treated at a  reduced capacity basis.
Wastes with a moisture content greater than 50 percent need
to be dewatered to enable treatment in the LT3® system.
Pretreatment screening or crushing of oversized material
(greater than 2 inches in size) or clay shredding may also be
required for some applications.

2.4 Key Contacts

    Additional  information  on the LT3® technology, the
SITE program, and the ADC site can be obtained from the
following sources:

    1.   Vendor concerning the LT3® technology:

        Mr. Michael Cosmos
        Roy F. Weston, Inc.
        1 Weston Way
        West Chester,  Pennsylvania 19380
        (215) 430-7423

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                                                   THERMAL PROCESSOR
                                                      DRIVE UNITS
                                               VENT  _/
                                             CONDENSER
                                                                                          LIQUID-PHASE
                                                                                         CARBON COLUMNS

                                                                                           LIQUID
                                                                                        CONDENSATE
                                                                                            TANK

                                                                                          DISPOSABLE
                                                                                            FILTERS
                                                                                         REFRIGERATION
                                                                                            UNIT
                                                                                          ORGANIC
                                                                                         COLLECTION
                                                                                           DRUM

                                                                                            OIL-WATER
                                                                                            SEPARATOR
                                                                                   VAPOR-PHASE
                                                                                    CARBON
                                                                                    COLUMN
                NOTE: LOCATIONS ARE APPROXIMATE; SOME ANCILLARY EQUIPMENT NOT SHOWN.
Ftgura 2-2 LT*° System Layout
   2.  The EPA Project Manager concerning the SITE
       Demonstration:

       Mr. Paul R. dePercin
       U.S. Environmental Protection Agency
       Office of Research and Development
       Risk Reduction Engineering Laboratory
       26 West Martin Luther King Drive
       Cincinnati, Ohio  45268
       (513) 569-7797
3.   Concerning the ADC Site:

    Mr. James Hahnenberg
    U.S. Environmental Protection Agency
    Region 5, Remedial Response Branch
    77 W. Jackson Boulevard
    Chicago, Illinois  60604
    (312) 353-4213

    Mr. James Huerta
    Anderson Development Company
    1415 E. Michigan Street
    Adrian, Michagan  49221
    (517) 263-2121

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Figure 2-3 Internal View of Thermal Processor

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                                                    Section 3
                                    Technology Applications  Analysis
    This  section addresses the applicability of the LT3®
system to treat soils contaminated with VOCs and SVOCs.
Weston's claims regarding the applicability and performance
of the LT3® system are included in Appendix A.

    The applicability of the LT3® system was evaluated hi
terms of technical criteria used to select remedial actions at
Superfund sites. These criteria, which can also be applied to
Resource Conservation  and  Recovery  Act  (RCRA),
underground storage tank (UST), or other corrective action
decisions, include the following: (1) treatment effectiveness
for toxicity reduction, (2)  compliance with  regulatory
requirements, (3) implementability,  (4) short-term impact,
and (5) long-term effectiveness. These criteria are discussed
below.   In  addition,  factors influencing the technology's
performance in meeting these criteria are discussed at the
end of this section.

    The  evaluation presented below is based on results of
the  LT3®  system   SITE  demonstration,  subsequent
remediation of the ADC lagoon sludge  (see Appendix B),
and five other case studies (see Appendix C). The treatment
conditions  of the SITE  demonstration and subsequent
remediation of the ADC site, as well  as  the other  case
studies are summarized in Table 3-1. The  results indicate
that the LT3® system can process a wide variety of soils with
differing moisture and contaminant concentrations.  The
LT3®  system  can   effectively   treat  soil  and  sludge
contaminated with the following  wastes:  VOCs, SVOCs,
coal tar,  drill cuttings (oil-based mud), No. 2 diesel fuel, JP4
jet  fuel,  leaded  and  unleaded  gasoline,  petroleum
hydrocarbons, halogenated and nonhalogenated solvents, and
PAHs.

    Although an extensive data base has been generated on
the LT3® system's effectiveness in  treating various waste
types under differing operating conditions, results  may vary
greatly with different solid matrices and waste characteristics.
Therefore, the technology's performance is best predicted
with some preliminary bench-scale  testing.  Contaminants
may  also  behave  differently in  association with  other
compounds and with differing soil types, making preliminary
testing very important in  determining the  technology's
applicability to meet treatment objectives.   Treatability
studies are  recommended  before  considering large-scale
applications of the technology. Testing prior to mobilizing
the full-scale system may eliminate problems associated with
applying the system to compounds  and soils for which it is
not suited.  Preliminary treatability studies may also be able
to approximate process rates and  cleanup  capabilities,
allowing an assessment of the LT3® system's applicability for
a specific site.

3.1   Treatment   Effectiveness   for   Toxicity
Reduction

   The LT3® system's effectiveness for toxicity reduction
was  evaluated based on the following criteria: (1)  VOC
removal, (2) SVOC removal,  (3) formation of thermal
transformation by-products, and (4) stack emissions.  These
criteria are discussed below.

3.1.1 VOC Removal

   The  LT3®  system removes most VOCs present in
untreated soil to  below method detection limits.  Specific
compounds treated to  date include benzene,  toluene,
ethylbenzene,  and xylenes  (BTEX); TCE; and   PCE.
Removal efficiencies ranged from 96 to greater than 99
percent.

    Toluene and PCE were identified as critical VOCs for
the LT3®  technology SITE demonstration.   Toluene was
present in untreated sludge at concentrations ranging from
1,000 to 25,000 jttg/kg.   The  concentration of toluene hi
treated sludge was below the detection limit of 30  /ig/kg.
The  concentration of toluene in fabric filter dust ranged
from less than 28 to 410 /ig/kg. For most samples analyzed,
the concentration of toluene in the condensate was below the
detection limit of 5 milligrams per liter (mg/L). However,
toluene was detected in the off-gas before the carbon column
at concentrations ranging between 8,000 and 10,000 parts per
billion by volume (ppbv).  Toluene was effectively removed
by the vapor-phase activated carbon column.
                                                          11

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 Table 3-1 Treatment Conditions of the SITE Demonstration and Other Case Studies
Study
SITE
Demon-
stration




Case
Study 1


Case
Study 2


Case
Study 3


Case
Study 4




Scale
Full-
Scale





Full-
Scale


Full-
Scale


Pilot-
Scale


Bench-
Scale




Site
Adrian,
Michigan





Springfield,
Illinois


Tinker AFB,
Oklahoma City,
Oklahoma

Letterkenny
Army Depot,
Chambersburg,
Pennsylvania
Environmental
Technology
Laboratory,
Lionville,
Pennsylvania

Client Treatment
Conditions
ADC Temperature:
500 to 530 °F
Residence
Time: 90 min
Processing
Rate: 2.1
tons/hr
Confidential Temperature:
350 °F
Residence
Time: 70 min
USATHAMA Processing
Rate: 9
tons/hr

USATHAMA Temperature:
320 °F
Residence
Time: 60 min
Various Temperature:
Industrial 250 to 450 °F
and Federal
Clients Residence
Time: 30 to 50
min
Soil
Type
Sludge
and
Clay




NS



Clay



NS



NS





Amount
of Soil
Treated
80a tons






1,000
cubic
yards

3,000
cubic
yards

7 tons



NS





Contaminants
VOCs, SVOCs,
MBOCA





VOCs, SVOCs,
PAHs,
Gasoline,
No. 2 Fuel Oil
VOCs, SVOCs,
Chlorinated
Solvents, JP4
Aviation Fuel
VOCs



VOCs, SVOCs,
PAHs, Coal
Tar,
Petroleum
Hydrocarbons,
Oiland
              Case       Bench-    Colorado
              Study 5     Scale     Springs,
                                  Colorado
Confidential
            Temperature:
            400 °F
            Residence
            Time: 44 min
NS
NS
Grease, VOCs,
SVOCs, PAHs

Chlorinated
Benzene
              * - During the SITE demonstration at the ADC site, Weston treated 80 tons of sludge.  Through July 1992, over
              3,000 tons of sludge were treated during the remediation of the ADC site.

              NS - Not Specified
    PCE  was  also  present  in   untreated   sludge  at
concentrations ranging from 690  to 1,900 fig/kg.  The
concentrations of PCE in treated sludge and fabric filter dust
were below the detection limit of 30 jtgAg for most samples
analyzed.  The concentration of PCE in the condensate was
below the detection limit of 5 mg/L. PCE was detected in
the off-gas before the carbon unit at concentrations ranging
from 210 to 220 ppbv.  PCE was effectively removed by the
vapor-phase activated carbon column.

    Results from the first case study (see Table 3-1) also
showed  that  VOCs  were  effectively   removed from
contaminated soil.   VOCs  of  concern included  BTEX.
Concentrations of these VOCs in untreated soil ranged from
1,000 to 110,000 fig/kg.   Concentrations  of the VOCs in
treated soil ranged from less than 1 to 5.2 jug/kg. Removal
              efficiencies greater than 99.48 percent were achieved.

                  Results  from the second  case  study (see  Table 3-1)
              showed that TCE,  the primary VOC  of concern, was
              effectively removed. The concentration of TCE in untreated
              soil was 6,100 mg/kg. The concentration of TCE in treated
              soil was below the cleanup goal for the site.

                  During the third case study (see Table 3-1), untreated
              soil  was  contaminated  with  the  following  VOCs:
              dichloroethene, PCE, TCE, and xylene.  Concentrations of
              VOCs in untreated  soil ranged from 586,000 to 27,20J,QCO
              /tg/kg.  Concentrations of VOCs in  the treated soil ranged
              from 730 to 1,800 /tg/kg. Removal efficiencies greater than
              99.88 percent were achieved.
                                                          12

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    Results from the  fourth case study (see Table  3-1)
showed that soil contaminated with the following VOCs was
treated effectively: methylene chloride; adetone; n-butanol;
1,2-dichloroethane;    1,2-dichloropropane;    isoprqpanol;
methanol;  and cyclohexane.  Concentrations of VOCs  in
untreated  soil  ranged  from   120   to 120,000  fig/kg.
Concentration of VOCs in treated soil ranged 340 to less
than 6,000 |*g/kg.  Removal efficiencies greater than  98.9
percent were achieved.

    In  addition,   during   the   fourth  case  study,  soil
contaminated with ethylbenzene and methylene chloride was
effectively treated. The concentration of ethylbenzene before
treatment  was 78,000 fig/kg,  and the  concentration  of
methylene chloride was 14,000 Mg/kg. After treatment both
contaminants were reduced to below the detection limit  of
5
3.1.2 SVOC Removal

    In general, the LT3® system reduces the concentration of
SVOCs.  Removal efficiencies ranged from 57 to greater
than 99 percent.  Among SVOCs, compounds with lower
boiling points are removed more effectively than compounds
with higher boiling points.

    MBOCA,   4-methylphenol,   and   bis(2-ethylhexyl)-
phthalate were identified as critical analytes for the LT3®
system   SITE   demonstration.     During   the  SITE
demonstration the LT3® system achieved MBOCA removal
efficiencies ranging from 79.82 to 99.34 percent.  MBOCA
concentrations in untreated sludge ranged from 162 to 860
mg/kg. MBOCA concentrations in treated sludge ranged
from 3 to 9.6 mg/kg.   MBOCA was detected in the
condensate  at  concentrations   ranging from  100  to
257 micrograms per liter (/tg/L).  No MBOCA was detected
in the exhaust gas from the refrigerated condenser.  The
decrease in MBOCA  concentration  after treatment was
accompanied by an increase in the measured concentration
of N-acetyl-MBOCA  (AC-MBOCA).  AC-MBOCA is a
known metabolite of MBOCA, indicating that the removal
of MBOCA was probably due partially to thermal desorption
and  partially  to the  degradation of  MBOCA  to  the
AC-MBOCA metabolite.  However,  the  presence of co-
eluting compounds may have interfered with the quantitation
of AC-MBOCA.   The concentration  of N,N'-diacetyl-
MBOCA (DAC-MBOCA), another metabolite of MBOCA,
decreased after treatment in most samples analyzed. The
decrease in DAC-MBOCA concentration was probably due
either  to  thermal   desorption   or  to  conversion  to
AC-MBOCA.

    The LT3® system  also decreased the concentration of
other SVOCs initially present in the sludge. 4-Methylphenol
and  bis(2-ethylhexyl)phthalate were  identified  as critical
analytes for the LT3®  system  SITE  demonstration.  The
concentrations of 3- and 4-methylphenol  ranged from 3,100
to 20,000 /tg/kg in the untreated sludge. After treatment, 3-
and 4-methylphenol concentrations ranged from 540 to 4,000
/ig/kg, representing removal efficiencies of between 57.0 and
97.4 percent. The concentration of 3- and 4-methylphenol in
fabric filter dust ranged from 1,200 to 5,100 /ig/kg. Liquid
condensate   contained   3-    and   4-methylphenol  at
concentrations ranging from 7,900 to 25,000 /ig/L. However,
no 3- or 4-methylphenol was detected in the exhaust gas
exiting the refrigerated condenser.

    Bis(2-ethylhexyl)phthalate  was  present in  untreated
sludge at concentrations ranging from  1,100  to 7,900 /ig/kg.
After   treatment,  the   concentration   of  bis(2-
ethylhexyl)phthalate was reduced to  below the detection
limit, which was less than 820 Mg/kg for most samples. The
concentration of bis(2-ethylhexyl)phthalate  in fabric filter
dust ranged from 650 to 3,600 Mg/kg-  Because of its high
boiling point (723.2 °F), bis(2-ethylhexyl)phthalate  is not
likely to  be desorbed during heating in the LT3® system,
because the sludge treatment temperature ranged from only
500 to 530 °F. Therefore, the  decreased concentration of
bis(2-ethylhexyl)phthalate  was  probably  due  to thermal
decomposition during heating.  The decomposition scenario
is supported by the sampling results of the liquid condensate
and the exhaust gas from the refrigerated condenser. The
concentration of bis(2-ethylhexyl)phthalate in the condensate
was below the detection limit of 3,000 /tg/L. Similarly, the
concentration of bis(2-ethylhexyl)phthalate in the exhaust gas
was below the detection limit of 28 ppbv.

    Although concentrations of most SVOCs decreased with
treatment, the concentration of the following two SVOCs
increased with treatment:   phenol and chrysene.   The
increased phenol concentration after treatment is most likely
due to chemical transformations during heating, most likely
the dehalogenation  of 1,2-dichlorobenzene,  a reaction that
has been reported to take  place  at elevated temperatures
and alkaline pH   conditions  (Larock,   1989).    The
dehalogenation scenario is supported by other demonstration
results, which also indicate that the  extractable organic
halide  (BOX)  concentration hi  sludge is  reduced  after
treatment, while the concentration of chloride is increased.

    During   the   SITE  demonstration,   chrysene  (or
triphenylene), which  was  not  originally present in the
untreated sludge, was detected in  treated sludge and fabric
filter dust.  A minor leak of  heat transfer fluid,  which
contains triphenylene, probably caused the apparent increase
in chrysene  concentration.   Triphenylene  and chrysene
produce   indistinguishable   responses   in   the   gas
chromatography/mass  spectroscopy (GC/MS)  analytical
technique used.

    During  the  fifth case  study (see Table 3-1),  soil
contaminated with SVOCs was also effectively treated. The
total concentration of SVOCs in the soil was  530 mg/kg.  Of
that amount,  523  mg/kg  was  1,4-dichlorobenzene; the
                                                         13

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 remaining portion  consisted  of other  SVOCs.    The
 concentration of 1,4-dichlorobenzene after treatment was
 6.25 / representing a removal efficiency of greater than
 99.9 percent.

    Soils contaminated with PAHs were treated during the
 first and fourth case studies.  Concentrations of PAHs in
 untreated soil  ranged from 890  to  580,000 jtg/kg.   The
 concentration of PAHs in treated soil ranged from less than
 330 to 14,000 M?/kg. Removal efficiencies ranged from 62.9
 to greater than 99 percent.

 3.1.3 Formation of Thermal Transformation By-
 Products

    Chemical characteristics of contaminants hi the waste
 feed determine the types of by-products formed during heat
 treatment. Under certain conditions, dioxins and furans may
 form in the  LT3* system  as  thermal transformation by-
 products.  The  following specific treatment conditions tend
 to encourage the formation of dioxins and furans:  (1) the
 presence of chemical precursors, (2) alkaline pH, (3) high
 concentrations  of free chloride, (4)  temperatures  greater
 than  500 °F, and (5) long residence times.   For  some
 applications,  such as the SITE demonstration,  the  LT3®
 system will operate under these conditions.

    The following groups of compounds are associated with
 the formation of dioxins (EPA, 1980):

    Class I -    Polyhalogenated Phenols
    Class II -    Ortho-Halophenols and Ortho-Halophenyl
                Ethers
    Class III-   Aromatic   Compounds   and   Ortho-
                Substituted Aromatic Compounds

    Analytical results of the SITE demonstration showed
 that the following potential dioxin precursors were present
 in untreated and treated  sludge samples: phenol;  1,2-
 dichlorobenzene;4-chloroaniline;4,6-dinitro-2-methylphenol;
 2,4-dibromophenol; o-chloroaniline; aniline; 2-chlorophenol;
 4-bromophenol; and  2,4-dibromophenol.    Alkaline pH
 resulted from the addition  of lime; high concentrations of
 free chloride  resulted from the addition of ferric chloride.
 Both  chemicals were added to the sludge prior to  LT3®
 processing as conditioning agents before sludge dewatering.
Treatment temperatures ranged from 500 to 530 °F.

    Polychlorinated  dibenzo(p)dioxins   (CDD)   and
 polychlorinated dibenzofurans  (CDF) were formed in the
LT3*  system  and distributed in fabric filter dust, treated
sludge,  condensate, and exhaust  gas.   Fabric filter  dust
 consistently contained higher concentrations of CDD and
 CDF  than treated sludge, and the dust was the only  solid
matrix containing measurable amounts of 2,3,7,8-tetrachloro
dibenzo(p)dioxin   (2,3,7,8-TCDD).      The   average
concentrations of CDD and CDF in treated sludge  ranged
from 0.066  to  2.42 /^g/kg.   Octachloro  dibenzo(p)dioxin
(OCDD)  was the only congener found in  one sample of
untreated sludge.  OCDD was detected  at 0.63 parts per
billion (ppb), near the detection limit of 0.54 ppb. CDD and
CDF concentrations in condensate increased with successive
test runs.  The condensate was treated through a liquid-
phase carbon adsorption system before being sent off site for
disposal.  The vapor-phase carbon column removed CDDs
and CDFs from the exhaust gas; removal efficiencies varied
with congener, from 20 to 100 percent.

3.1.4 Stack Emissions

    Stack gas  emitted from  the LT3®  system generally
contains low concentrations  of chloride and particulate
matter.   However, the  total hydrocarbon  concentration
(THC) in the stack gas should be continuously monitored to
determine when the  vapor-phase activated  carbon unit
should be replaced. Contaminant breakthrough should be
monitored to prevent  emissions of VOCs and any thermal
transformation by-products.

    During  the  SITE  demonstration  and  subsequent
remediation at the ADC site,  THC was monitored through
a continuous emission monitoring (CEM) system operating
as part of the  LT3® system.  The CEM system recorded
THC values as high as 100 ppmv.  To control emissions,
Weston replaced the vapor-phase carbon adsorption column
regularly.

    During the SITE  demonstration (see Table 3-1), the
TNMHC in stack gas was determined. TNMHC  includes
both VOCs  and SVOCs.  VOC emissions from the stack
were  predominately  composed   of   propylene   and
chloromethane. SVOC stack emissions did not contain any
predominant contaminants, and testing indicated  that all
compounds  were present in  concentrations at or below
instrument detection limits.   TNMHC hi stack emissions
from the LT3®  system increased consistently.  During the
first test run, TNMHC was 6.7 ppmv; during the second test
run, TNMHC  was 7.6 ppmv; and  during  the third run
TNMHC  was  11 ppmv.   Because a  new  vapor-phase
activated  carbon  column  was  used  during the  SITE
demonstration,  the  results  suggest  that   breakthrough
occurred after a relatively short period of time.

    The particulate concentration in  the stack gas ranged
from less than S.SxlO"4 to 6.7xlO"3 gr/dscm, and particulate
emissions  ranged from less than 1.2X10"4 to  9.2X10"4 Ib/hr.
Chloride concentrations were below the method detection
limit, which had an average value of 2.8xlO"2 mg/dscm;
chloride emissions were less than 6.0xlO'5 Ib/hr.

    During  the  SITE  demonstration  and  subsequent
remediation  at the ADC site, fugitive dust emissions from
the treated  sludge pile area  were occasionally observed.
Dust levels ranged from 0.16 to 0.99 milligrams per cubic
                                                        14

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meter (mg/m3) downwind of the treated sludge pile and
inside the  control  trailer near  the treated  sludge  pile.
Fugitive dust concentrations were higher than the action
level of 0.15 mg/m3.

    During the first case study (see Table 3-1), the following
specific  air  emission  limitations were met:   (1) carbon
monoxide (CO) less than 100 ppmv,  (2) THC less than 100
ppmv, and (3) no visible dust emissions.

    During  the third case  study  (see  Table  3-1),  an
afterburner was used as part of the emissions control system.
No VOCs were detected in the stack, and stack emissions
were in compliance with federal and state  regulations for
hydrogen chloride (HC1), CO, and particulates.

3.2 Compliance with Regulatory Requirements

    This  subsection   discusses  specific  environmental
regulations pertinent to the  operation of  the LT3® system,
including the transport, treatment, storage,  and disposal of
wastes and treatment residuals.  Applicable  or relevant and
appropriate requirements (ARAR) include the following: (1)
the Comprehensive EnvironmentalResponse, Compensation,
and Liability Act (CERCLA); (2) the Resource Conservation
and Recovery Act (RCRA); (3) the Clean Air Act (CAA);
and (4) the Occupational Safety and Health Administration
(OSHA). These four general ARARs are discussed below;
specific ARARs must be identified for each site.

3.2.1  Comprehensive  Environmental   Response,
Compensation, and Liability Act

     CERCLA,  as amended by SARA, provides for federal
authority to  respond  to releases of hazardous substances,
pollutants, or contaminants to air, water, and land. Section
121 of SARA provides cleanup standards and requires that
selected remedies be cost-effective and protective of human
health and the environment. The federal cleanup standards
of SARA prefer highly reliable remedial actions that provide
long-term   protection.     Preferred  remedial   actions
permanently and significantly reduce the volume, toxicity, or
mobility   of   hazardous   substances,    pollutants,   or
 contaminants.  The LT3® system permanently reduces the
toxicity of the feed wastes; a substantially reduced volume of
residuals may  require additional treatment  or long-term
management.

     Federal  cleanup standards  also require that remedies
 selected at Superfund sites comply with  federal and state
ARARs.   ARARs for a remedial action  may be waived
 under six conditions:  (1) the action is an interim  measure,
 and the ARAR will be met at  completion; (2) compliance
 with the ARAR would pose a greater risk to health and the
 environmental than  noncompliance; (3) it is technically
 impracticable  to meet the ARAR;  (4) the  standard of
 performance of  an ARAR can be met by an equivalent
method; (5) a state ARAR has not been consistently applied
elsewhere; and (6) ARAR compliance would not provide a
balance between the protection achieved at a particular site
and demands on the Superfund for other sites. These waiver
options apply only to Superfund actions taken on site, and
justification  for the waiver  must be  clearly demonstrated
(EPA, 1988).

    The ADC site was being remediated under CERCLA
authority. Two significant ARARs were considered: state air
pollution regulations and state ground-water protection and
health risk  standards.   At  a Superfund  site,  only the
substantive requirements of an air pollution discharge permit
must be met through appropriate pollution control. In most
cases, the site manager will obtain a permit for the system.
With the appropriate use of air pollution control equipment,
such as  vapor-phase  carbon adsorption  units to remove
uncondensed toxic organics, the LT3® system can meet state
requirements.  The  LT3®  system  cannot,  however,  meet
ground-water  protection standards  for  metals, because
metals  are  not  removed  from  soils during  treatment.
Pretreatment, posttreatment, or off-site disposal of treated
material at  a Subtitle D landfill may be required if the
CERCLA substances are contaminated with metals.

3.2.2 Resource Conservation  and Recovery  Act

     RCRA regulations define hazardous wastes and regulate
thek transport,  treatment,  storage, and disposal.  Wastes
defined as hazardous under RCRA include characteristic and
listed  wastes.    Criteria  for  identifying characteristic
hazardous wastes are included in 40 CFR Part 261 Subpart
C.  Listed wastes from nonspecific and specific industrial
sources, off-specification products,  spill cleanups, and other
industrial sources are itemized in 40 CFR Part 261 Subpart
D.

     Residual wastes from  the LT3® system  include both
liquid and solid wastes that maybe hazardous under RCRA.
Operation of the LT3® system generates the following wastes:

     •   Fabric filter dust — Contaminants may adsorb on
         fine particles, thus precluding retreatment.

     •   Condensate organics — Organic contaminants are
         generally condensed and then prepared for off-site
         disposal.

     •   Condenser water ~ If oil-water separation or other
         suitable on-site treatment is not practical, discharge
         or off-site disposal may be possible.

     •   Condenser water filters - Disposable filters contain
         solid-phase contaminants.

     •   Activated carbon — Activated carbon units must be
         disposed of as waste if regeneration is not possible.
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     •  Personal protection equipment (PPE) — Disposable
        PPE is generally incinerated or landfilled.

    Under both CERCLA and RCRA, treatment residuals
 generated by the LT3® system are subject to land disposal
 restrictions (LDR).  Dioxins and furans may be present in
 low concentrations in treatment residuals  from the LT3®
 system  and other  thermal desorption systems.  Under 40
 CFR Section 268.31, F020 to F023 and F026 to F028, dioxin-
 containing wastes are prohibited from land disposal unless
 the treatment standard of 1 part per billion (ppb) for each
 dioxin or furan isomer is met. Fabric filter dust generated
 during the SITE demonstration exceeded this value for some
 isomers, but concentrations of the 2,3,7,8-TCDD congener,
 which is considered the most toxic, were less than 1 ppb.

    Requirements  for corrective  action at RCRA-regulated
 facilities are provided in  40  CFR  Part  264,  Subpart F
 (promulgated) and Subpart S  (proposed).  These subparts
 also  generally  apply to  remediation at Superfund  sites.
 Subparts F  and S include requirements for initiating and
 conducting RCRA corrective  actions, remediating ground
 water, and ensuring that corrective actions comply with other
 environmental regulations.  Subpart S also details conditions
 under which particular RCRA requirements may be waived
 for temporary treatment units operating at corrective action
 sites.   Thus,  RCRA  mandates requirements  "similar to
 CERCLA, and as proposed, allows treatment units such as
 the LT3® system to operate without full permits.

 3.2.3 Clean Air Act

    The CAA requires that treatment, storage, and disposal
 facilities comply with primary and secondary ambient air
 quality  standards.  ' To monitor gas emissions, the LT3®
 system includes CEM at the discharge stack for CO, carbon
 dioxide (COj), oxygen (Oj), and THC. A state air pollution
 permit is required, except at CERCLA sites where only the
 substantive requirements of a permit must be addressed. In
 addition to  CEM  parameters,  permit  limits may  be
 established for total suspended particulates, acid gases, toxic
 organics such as dioxins and furans, and stack height.  The
 LT3* off-gas treatment system can be modified to include an
 afterburner  or  caustic  scrubber  to  meet site-specific
 requirements.

 3.2.4   Occupational   Safety    and   Health
Administration

    CERCLA response actions and RCRA corrective actions
 must be performed in accordance with OSHA requirements
 detailed in 29 CFR Parts 1900 through 1926, especially Part
 1910.120, which provides for the health and safety of workers
 at hazardous wastes sites.  On-site construction activities at
 Superfund  or RCRA corrective  action   sites  must  be
performed in accordance with Part 1926 of OSHA, which
provides safety and health regulations for construction sites.
3.3 Implementability

    The LT3® system implementation includes mobilization,
O&M requirements, reliability, personnel requirements, and
demobilization.   These aspects  of implementation  are
discussed below. In general, the system is easy to set up and
operate.  However, waste feed characteristics  can impact
system reliability if the feed is not adequately prepared.

3.3.1 Mobilization

    The first step for the implementation of the LT3® system
is equipment mobilization.  Site characteristics are important
factors to be considered prior to the mobilization of the
LT3®  system.  These characteristics include  site area, site
preparation, and site access.

Site Area

    Weston  has  developed  three   different  thermal
processors, each of a different size and capability.  The
bench-scale LT3® unit with two 3-foot screws was initially
used to evaluate the treatment concept.  This unit led to a
pilot-scale unit with two 10-foot screws, which was used hi
initial field tests. Finally, the full-scale production unit was
built with eight 20-foot screws. This full-scale unit was used
during the SITE  demonstration.   The mobile  unit  is
comprised of equipment assembled on three flat-bed trailers,
with ancillary  and support equipment on  another three
trailers. The entire system requires a relatively flat area of
about 5,000 square feet.

Site Preparation

    Site preparation is typically needed prior to operating
the LT3® system. For the SITE demonstration the following
site preparation was needed:

    •  Placement of gravel in areas where the LT3® system
       was to be located;  gravel was needed to maintain a
       roughly consistent grade across the processing area.

    •  Placement of supports, such as steel plates, wood,
       concrete blocks, and so  on in areas  where the
       heaviest equipment would be situated.  Support
       material should be placed below the tires and drop
       legs to prevent equipment from leaning or sliding in
       soft soil.

    •  Placement of gravel in areas of expected  heavy
       vehicular traffic, as necessary.

    •  Construction of earthen ramps, as  necessary,  to
       provide access for excavation and  transportation
       equipment.
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    •   Establishment  of health  and  safety  zones  to
        accommodate both on-site operating and off-site
        support personnel.

Site Access

    Site access requirements for the  LT3® equipment are
minimal.  The site  must  be accessible to trailer trucks
delivering the LT3® equipment, and the bed of the access
road must be able to support these vehicles. Because the
LT3® unit trailer is oversized, some highway restrictions may
apply.  State and local authorities should be contacted for
specific requirements and restructure.

3.3.2  Operations  and Maintenance Requirements

    O&M requirements for the LT3® system include general
utility  services as well as services and  supplies.  These
requirements are  discussed below.

Utilities

    Operating  the  LT3® system  requires  the   following
utilities:

    •   Electrical Power -- The LT3® system requires 460-
        volt,  three-phase,  600-ampere electrical service.
        Transformers  in  the  LT3®  system  reduce  the
        electrical service to 240-volt, three-phase and 120-
        volt,  single-phase  service  to  operate the  CEM
        system and control circuits, respectively.

    •   Diesel Fuel  — Diesel fuel for heavy equipment,
        supplied  by  a tank-mounted pickup truck may be
        purchased from a nearby retailer.

    •   Fuel — Natural gas at a pressure of 15 pounds per
        square inch  (psi) is  required for the burner that
        heats the heating fluid.  The LT3® system's total
        maximum natural  gas  consumption is 7.2 million
        British thermal units per hour (Btu/hr).  Propane
        can also be used as an alternative fuel.

    •   Process Water — Process water is primarily needed
        for    quenching   treated   material   and   for
        decontamination purposes.  Water may be supplied
        by an existing on-site water distribution system.  In
        many applications, treated condensate may be used
        for this purpose.

Services and Supplies

    A number of readily obtainable services and supplies are
required to  operate  the LT3® system.    Major services
needed for   remedial activities  may  include  (1)   heavy
equipment rigging, (2) sludge dewatering, (3) regular vacuum
cleaning of the LT3® system off-gas ducts, and (4) laboratory
analyses to monitor the system's performance.

    During  the  SITE  demonstration and  ADC  site
remediation, subcontractors or off-site facilities furnished the
major services required by the remedial activities.  Weston
hired a national hazardous waste services subcontractor to
dewater the sludge using a filter press.  Weston hired local
industrial services subcontractors to set up the unit and to
vacuum ducts that carry off-gas and dust from the thermal
unit to the fabric filter. When the system operated 24 hours
per day, vacuuming was required about once a month.  To
monitor the performance of the LT3® system, samples were
collected every 12 hours and sent to an off-site laboratory for
analysis.

    Supplies required for the remedial activities included (1)
lime and ferric chloride stabilizing agents, (2) heat transfer
fluid, (3) absorbing cloth and oil-dry material, (4) diesel fuel,
(5) plastic  sheeting,  (6)  steel drums, (7) fiber drums, (8)
vapor-phase carbon adsorption  columns, (9) paper filters,
and (10) liquid-phase carbon adsorption columns.  These
supplies are discussed below.

    At the ADC site, lime and ferric chloride were added to
the untreated  sludge  before dewatering as  conditioning
agents at a rate of 0.1 pound of each chemical per gallon of
raw sludge.  Both  chemicals were  added  directly to  the
mixing tank from 50-pound paper bags.

    The heating fluid system has a capacity of about 1,000
gallons. At the beginning  of LT3® operations, the heating
fluid tank  is filled with heating  fluid; no additional heating
fluid is normally needed for further operation of the system.
However,  heat transfer fluid is occasionally added to the
LT3® system to replace heating fluid lost from accidental
leaks.    Absorbing  cloth  and  oil-dry  material  were
occasionally applied to the ground beneath the heating fluid
sj'stem to contain accidental spills of the heating fluid.

    Heavy equipment operation requires about 35 gallons of
diesel fuel per day.  Diesel fuel  was supplied every week by
a local retailer and stored on site in an aboveground storage
taink.

    A 20-foot by 20-foot plastic  sheet was used to cover the
pile of treated sludge produced every 12 hours. In addition,
two 55-gallon  steel drums are  needed every 12  hours to
collect  and store fabric filter dust, and one  55-gallon fiber
drum is needed each shift to  store used PPE.

    During  the ADC  site remediation, one  vapor-phase
carbon adsorption column was replaced every 5 to 10 days
of LT3® system operation.  The frequency with which the
vapor-phase carbon adsorption units need to be changed
depends  on   site-specific  factors   and  contaminant
concentrations.
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    The condensate treatment system at the ADC site used
two paper filters with a nominal pore size of 50 micron
(ftm).  The filters operated in series to remove particulate
matter. Filters were changed after every 12 hours of system
operation.  Two liquid-phase carbon adsorption columns
were used in series to treat liquid  condensate  exiting the
paper  filters.   Both  liquid-phase  carbon  columns  were
replaced about every 2 months of operation.

3.3.3  Reliability

    The LT3* system may be subject to several operational
problems.  This section summarizes operational problems
observed during (1) shakedown and startup operations, (2)
the SITE  demonstration, and (3) remedial activities at the
ADC site. Operational problems resulted from mechanical
difficulties with the  screws,  a malfunctioning oil-water
separator, oversized debris  hi  the  feed material,  leaking
sweep  air gas, excess dust generation from reprocessed
sludge, and leaking pipes in the heat transfer fluid system.
Operational problems with the  LT3® system resulted in an
on-line efficiency of about 70 percent.  These problems are
discussed below.

    Startup operations at the ADC site lasted about 2 weeks,
largely because of troubleshooting associated with the screws
and the heating fluid system.   Before the LT3® system
arrived at the ADC site, the screws had been resurfaced to
prevent heating fluid from leaking during processing. The
screws were filled with water to check for leaks.  However,
after the leak check was completed, Weston estimated that
about 400 gallons of water remained in the screws.  When
hot heating fluid passed through the screws,  this water
vaporized, causing a potentially  dangerous pressure buildup
in the system.  To avoid this potential problem, the system
was drained and filled with new heating fluid.  Several days
of operation were needed to evaporate the residual water,
which was released through pressure control valves.

    Another operational problem  during  shakedown was (
associated with the rotational speed of the screws.  The
residence  time required to  achieve proper treatment was
approximately 90 minutes.  However, the LT3® system was
equipped  with motor drives that  could  not  provide  a
residence time longer than about 70 minutes. To rectify this
problem, Weston replaced the motor drives with units that
were capable of sustaining a longer residence time.

    The  LT3*  system  includes a  three-phase oil-water
separator  and a liquid-phase  carbon adsorption unit for
treating liquid streams exiting the air-cooled and refrigerated
condensers.   However, the oil-water  separator did not
function properly during shakedown operations at the ADC
site because of the unexpectedly large volume of condensate
produced. The liquid stream flowed out of the air-cooled
condenser at a rate of about 2 gallons per minute (gpm),
and the liquid stream exited the refrigerated condenser at a
rate of about 0.6 gpm.  Both liquids were routed into a
holding tank and were treated through a paper filtration unit
prior to the carbon adsorption system.

     The most severe and  common operational problems
during the ADC site remediation resulted from large rocks
or oversized debris in the feed sludge. On several occasions,
large rocks became wedged in the screw conveyors, resulting
in several days of downtime. In two instances, the gear box
broke when rocks became wedged between screws. On both
occasions, machining new parts and reinstalling the gearbox
took about 11 days.  On another occasion, a rock hi the feed
sludge broke the coupling that  connects the screws to the
gearbox.  Machining new parts and repairing the system
required about 15 days of downtime.

    In each case, before repairs could begin, the LT3" system
had to be shut down and allowed to cool. After about 12
hours of cooling, Weston personnel could enter the LT3®
system's thermal processor to remove the remaining sludge
and locate the obstruction  hi the screws.  This operation
requires a confined space entry  permit. In some cases, the
jammed rock had to be chipped  out using  a  pneumatic
hammer.

    On several other occasions when the screws became
jammed, downtime was avoided by repeatedly  reversing the
screws' rotation until the obstructive rock worked free. On
these occasions, Weston personnel cleared the system by
manipulating it from the control room, eliminating any need
for a confined space entry.

    Following repeated shut downs due to jammed screws,
Weston rented a diesel-powered shaker screen.  Initially, a
screen with 2.5-inch openings successfully removed oversized
material from  the feed.  However, additional downtime
resulted when a 2-inch-diameter rock jammed the screws.
To ensure that the LT3® system would continue operating
with no downtime, Weston installed a screen with 1.25-inch
openings below the screen with 2.5-inch openings. The two
screens successfully prevented oversized material  from
jamming the screws, however, it increased screening time for
the wet, clay  material at the ADC site.

    Several operational changes could minimize  or prevent
downtime caused by rocks hi the feed. First, screening the
feed with the shaker screen proved to be a successful, but
not  foolproof, method of  keeping the  screws free  of
obstructions.  Failure of the gearbox and couplings could be
avoided by replacing the steel phi that connects the screw
couplings to  the gearbox couplings.  If the steel phi  were
replaced with a phi of weaker material, the expendable phi
would break before more expensive and intricate parts of the
system failed.  Keeping a ready supply of spare parts and
then- specifications could also minimize replacement time.
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   Another operational problem was associated with sweep
air leaking from the LT3® system feed hopper.  Sweep air is
held in the LT3® system by sludge in the feed hopper.  As
sludge was drawn in to the LT3® system, gaps formed in the
feed flow in the hopper, allowing sweep  air to escape.
Sweep air  leaked  approximately  once every 3  hours of
operation.  Weston rectified the  situation  in less  than 5
minutes by adding more feed and manually poking the feed
with a shovel to make the feed flow more uniform.

    Other  operational  problems  occurred  when treated
sludge was reprocessed to meet MBOCA  cleanup goals.
Treated sludge had a  low moisture content  and a large
amount of small particles. When it was reprocessed, large
amounts of dust were picked up by the sweep air, clogging
the sweep  air ducts.   The  ducts  had to be cleaned out
periodically, resulting in several 1-hour periods of downtime.

    During remedial activities at the ADC site, heating fluid
leaked from a valve in the return line running from the LT3®
system to the heating system. To repair the leak, the heating
system's burner  was  turned off, and the  leaking pipe  was
isolated. Heating fluid contained in the leaking part of the
pipe was then drained into  a drum.  After the valve  was
replaced, the heating fluid no longer  leaked.  Operations
began again after about 5 hours of downtime. Only about 10
to 20 gallons of heating fluid was lost due to the leak, a
relatively  small amount  compared  to  the  1,000-gallon
capacity of the  heating  fluid system.  The heating  fluid
discharged was not reused;  it was kept on site for future
disposal.

3.3.4 Personnel Requirements

    Operation of the LT3® system requires six people.  This
number includes  a  field  project manager,  an O&M
supervisor,  a site  safety  officer,  and  three equipment
operators.  Two equipment operators supply a constant feed
of untreated sludge, one operating a front-end loader while
the other inspects the feed traveling up the feed conveyor.
These two persons are also responsible for ensuring a steady
flow from the feed hopper into the LT3® system. The other
operator performs general site activities, including moving
treated waste.  For sludge  dewatering, feed screening, or
under special circumstances such  as ambient air sampling,
additional personnel are required  on site.

3.3.5 Demobilization

    After  the   SITE  demonstration, the LT3®  system
remained on site to perform remedial  activities at the ADC
site.  Therefore, equipment demobilization  was not part of
the SITE demonstration.  This section summarizes typical
demobilization activities, such as those planned by Weston
at the completion of the remedial activities at the ADC site.
    Demobilization includes removal of the LT3® system and
the  trailer  containing  the  control  room  and  office.
Decontamination of the exterior of the LT3® system trailers
and ductwork and all excavation and material handling
equipment will be conducted using a high-pressure spray
washer in the decontamination area.  The interior of the
LT3® processor will be decontaminated by operating the heat
processor for several hours  at the maximum operating
temperature to remove remaining  contaminants.  Other
demobilization activities include the removal and  off-site
disposal of all plastic liners from the material staging area.
Liners will be decontaminated with high-pressure water and
detergent, if practical.

    All decontamination water will be  treated on site using
granular activated carbon.  Spent activated carbon units will
be  returned to the supplier for regeneration.  Disposable
PPE will be collected in drums, manifested, and sent off site
for disposal.

3.4 Short-Term Impact

    The  potential  short-term impact  of  the  LT3® system
application includes worker safety and potential community
exposures.   Personnel  operating the LT3® system and
performing remedial activities are required to have health
and safety training in order to perform site activities in a
safe manner. Also, with proper operation and monitoring of
the LT3® system,  community  exposures are minimal.  The
LT3® system's impact on workers and the nearby community
is discussed below.

3.4.1 Worker Safety

    Worker  safety considerations  associated with  LT3®
operations can be grouped in two categories: (1) physical site
hazards and  (2) potential chemical hazards.  General site
hazards during the operation of the LT3® system include the
following:

     •   Heavy equipment hazards

     •   Occupational noise exposure

     •   Potential slip, trip, or fall hazards

     •   Potential for contact with  mechanical equipment
        (motors,   fans,  and  conveyors)  and  electrical
        equipment or utility lines
     •   Open trench and  excavation hazards

     •   Airborne dust hazards

     •   Potential splashing of liquid

     •   Confined space entry
                                                         19

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     In addition, the heating fluid system presents potential
 burn  hazards.  The hot oil  circulates through the LT3®
 processor at up to 650° F, presenting a great  hazard  at
 transfer points in the lines or in the event of a line rupture.
 Potential  chemical hazards  involve  inhaling,  absorbing,
 ingesting, and coming in contact with constituents of concern
 in contaminated material. The exposure  likelihood  of this
 activity is  high  during  excavation  and handling   of
 contaminated sludge. At the ADC site, primary constituents
 of concern included MBOCA; manganese; 4-methylphenol;
 phenol; 1,2-dichlorobenzene; and toluene.

     All personnel working at the site had  a minimum of 40
 hours of health and safety training,  and all were  under
 routine medical surveillance. Remedial activities at the ADC
 site were conducted using Level C PPE.

 3.4.2 Potential Community Exposures

     Potential community exposures to health hazards from
 the operation of the LT3® technology include exposure to (1)
 stack gas emissions, (2) fugitive dust emissions,  (3) liquid
 spills resulting from condensate handling, and (4) noise from
 the operation of the LT3® system.  When the LT3® system
 operates properly and is regularly maintained, the potential
 for community exposures are minimal.

 3.5 Long-Term Effectiveness

    The LT3® system permanently removes contaminants
 from soil.  However, treatment residuals are not destroyed
 on site and require proper off-site treatment and disposal.
 Long-term effectiveness of the LT3®  system was assessed
 based on the permanence of the treatment and the handling
 of process residuals. These items are discussed below.

 3.5.1 Permanence of Treatment

    The LT3* system  desorbs and permanently removes
 contaminants from the contaminated soil. Approximately 25
 tons of treated material were  produced every 12 hours of
 LT3* system  operation at  the ADC site.  Treated material
 from each processing period was staged separately. During
 remedial activities at the  ADC  site, treated material was
 transported to a clean staging area to await analytical results.
 If analytical results indicated that the thermal treatment had
 not achieved the  required level of treatment, the material
 was reprocessed in the LT3® system.

3.5.2  Residuals Handling

    Two types of residuals are generated from the  LT3®
process: (1) condensate and (2) fabric filter dust. The long-
term effectiveness of the LT3® system ultimately depends on
the methods used to treat or dispose of these residuals.
     Operation of the LT3® system generated condensate at
 a rate of about 2 to 2.8 gpm.  The amount of condensate
 produced may differ significantly, depending on the moisture
 content of the sludge. During the SITE demonstration and
 full-scale remediation at the ADC site, condensate from the
 LT3® process was routed to a holding tank.  From the tank
 it was pumped through a filter to remove particulate matter
 and through a liquid-phase carbon adsorption system to
 remove organic contaminants. Treated condensate was then
 shipped off site for  disposal at a hazardous waste disposal
 facility.    In  other LT3®  system applications, treated
 condensate was  used  to quench and control dust from
 treated sludge.

    Another  residual  generated  from  the  condensate
 treatment  system is a  separated organic stream. At the
 ADC  site, the organic stream  was a heavy residue that
 accumulated in the bottom of the holding tank.  This heavy
 residue most likely consisted of organic solids settling in the
 bottom of the tank. After the SITE demonstration tests, the
 solid residue was removed from the bottom of the holding
 tank and mixed with contaminated sludge for reprocessing
 during  remedial activities.   However, during  remedial
 operations at the site, the heavy residue was drummed for
 future off-site disposal.

    In previous LT3® system applications, condensate was
 treated by a three-phase, oil-water separator, which allowed
 water to separate from insoluble  light and heavy organic
 components.  Light  organics were removed by a skimmer
 and weir. The heavy organic phase was removed through a
 manually operated drain at the bottom of the separator.
 Both organic phases removed from the oil-water separator
 were  drummed for  off-site disposal.  Drummed organics
 were  manifested  and shipped off site for treatment and
 disposal at a RCRA-permitted facility. Water flowing out of
 the  separator was  directed to  a liquid-phase carbon
 adsorption system.   The water  treatment  system can be
 modified to include other standard processes to meet site-
 specific discharge disposal requirements.

    At the ADC site, approximately two 55-gallon  drums of
 fabric filter dust  were  collected every 12  hours  of LT3®
 system operation. Three disposal options were considered
 for fabric filter dust. Depending on sample analytical results,
 the dust would be (1) mixed with treated material for on-site
 disposal, (2) recycled for further treatment, (3) or drummed
 for off-site  disposal.  SITE demonstration analytical results
 showed that the concentrations of contaminants in the fabric
 filter dust were above cleanup goals.  Dust produced during
 the SITE demonstration and during full-scale operation was
 drummed for off-site  disposal. Special care should be taken
when retreating fabric filter dust.  The dust contains large
amounts of small particles, which can easily be carried away
by the off-gas, clogging the system's off-gas ducts.
                                                         20

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3.6 Factors Influencing Performance

    Several  factors  may  influence  the  LT3®  system's
performance,  including  waste  characteristics, operating
parameters,  and climate.  Waste characteristics that may
influence the performance of the LT3® system include the
waste feed material's size, its moisture content, its particle
size  distribution, and  its pH.   Two primary operating
parameters found to affect contaminant removal efficiency
were  optimized  during  shakedown  operations before the
SITE demonstration: (1) contaminated sludge flow rate and
(2) heating  fluid temperature.  The effects of the feed
materials waste characteristics, the LT3® system operating
parameters,  and the climate are discussed below.

3.6.1 Size  of the Waste Feed

    The LT3® system operates best when the waste feed
material   consists  of  small,  uniformly  sized  particles,
preferably less than 2 inches in diameter. Severe operational
problems may result from large rocks or oversized debris in
the feed material. Large rocks may become  wedged in the
screw conveyors, resulting in several days  of downtime.
During the SITE demonstration, oversized material in the
sludge was removed manually before dewatering operations
and before  the waste feed entered  the LT3® system.   In
previous LT3® applications, feed material was shredded, and
only material smaller than 2 inches in size was processed.
During remedial activities at the ADC site, a vibrating screen
was used to pretreat dewatered sludge.

3.6.2 Moisture Content of the Waste Feed

    The LT3® process is most efficient for  wastes with a
moisture content of about 20 percent. Wastes with a high
moisture  content  require additional thermal energy  to
maintain the  treatment  temperature while  removing the
water, thereby increasing operating  costs.  Wastes with a
high  moisture content also  generate more  condensate,
thereby increasing handling requirements. Wastes with a low
moisture  content produce large amounts of dust during
treatment, and they may create  operational  problems.  To
enhance  the efficiency of the LT3®  system,  wastes with a
moisture content greater than 50 percent must be dewatered.
Water can  be added to  dry wastes to  control  excessive
dusting.

    The ADC lagoon sludge had a fluid consistency, with a
moisture content ranging from 65 to 70 percent.  Thermal
desorption by the LT3® system cannot be used when the feed
material contain free liquids.  Free liquids may leak through
the seals  of the thermal processor and flush through the
system without being treated. To maximize the efficiency of
the LT3® system, ADC lagoon sludge was excavated with a
Mudcat hydraulic dredge and was dewatered using a plate
and frame filter press. The average dewatering time was 40
minutes.  Before dewatering, lime and ferric chloride were
added to the sludge as stabilizing agents.  For each gallon of
sludge,  0.1  pound  of each  chemical  was added.   The
moisture content of the dewatered sludge ranged from 41 to
44 percent.  Dewatered sludge was stockpiled hi a storage
building prior to treatment.

3.6,.3 Particle Size Distribution of the Waste Feed

    The waste feed's particle size distribution and available
surface  area   are   important  factors   that  affect  the
performance of the LT3® system.  Contaminants tend to be
adsorbed on smaller soil particles, because soil composed of
small particles has a larger surface area, making more sites
available for contaminant sorption. In general, sandy soils
are more effectively treated  compared  to clay type soils,
which consist of small particles.

    SITE demonstration results indicated that the available
surface area of the contaminated sludge ranged from 49.1 to
52.3 square meters per gram (m2/g).   These values are
comparable to the surface area of kaolinite, a clay material,
which has been reported to be 25 m2/g (Stumm  and
Morgan, 1981). During excavation and stockpiling activities,
ADC lagoon sludge was mixed with clay from the base of
the lagoon, which may account for the similarity between the
surface area of the sludge and the surface area of kaolinite.

    SITE  demonstration  results  also  showed that  the
contaminant concentration in  the fabric filter dust  was
significantly higher than the contaminant concentration in the
treated  material. These results indicate that contaminants
were adsorbed  on  smaller  soil  particles and were not
effectively  desorbed during heating;  instead contaminants
remained attached  to the smaller particles,  which were
carried  away hi the  sweep gas stream  and trapped hi the
fabric filter.

    Large amounts of small particles hi the feed material
could possibly cause operational problems by blocking the
system's off-gas ducts.  During the full-scale remediation of
the ADC lagoon sludge, Weston reprocessed treated sludge
that did not  meet  cleanup  requirements.   Because the
treated sludge consisted of very small particles, reprocessing
produced  large  amounts of  dust,  causing  operational
problems and increased maintenance requirements.

3,6.4 pH of the Waste Feed

    The pH  of the  waste  feed may  also  affect  the
performance of the LT3® system.  The pH of the waste feed
controls the net surface charge of the soil particles, which is
hi turn related to contaminant sorption. In addition, soil pH
determines the type and extent of chemical reactions that
occur during heat treatment in the LT3® system.  Because
lime was added to the ADC lagoon sludge as a conditioning
agent, the pH of the untreated sludge was alkaline, ranging
from 10.9 to 11.2. The alkaline pH of the sludge may have
                                                         21

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 induced  several chemical transformation reactions during
 heat  treatment.    For  example,  based  on  the  SITE
 demonstration results, the phenol concentration hi the sludge
 was  found  to  increase   after  treatment,  while  the
 concentration of 1,2-dichlorobenzene, which was originally
 present, decreased.  The increase in phenol concentration is
 most  likely   due  to   the   dehalogenation  of   1,2-
 dichlorobenzene, a reaction that has been reported to take
 place at  elevated temperatures and alkaline  pH (Larock,
 1989). The dehalogenation scenario is supported by other
 demonstration  results,  which also indicate that the BOX
 concentration in sludge is reduced after treatment, while the
 concentration of chloride is increased.  In addition, the pH
 of treated sludge was lower than the pH of untreated sludge,
 ranging from 9.1 to 9.6.  The reduction  in pH is probably
 caused by  the formation of HC1 during dehalogenation
 reactions.

    The  pH of the condensate stream  was also alkaline,
 ranging from 10.1 to  10.2.  This alkaline pH may have
 resulted from lime particles being carried  away in the off-gas
 stream before becoming dissolved in the  condensate.

    If lime had  not been added to the waste feed, the pH of
 the treated material   and  the liquid  condensate would
 probably be acidic, due to the formation of HC1 from
 dehalogenation  reactions.    Acidic  pH  and" elevated
 temperatures can cause equipment corrosion, which could
 cause additional equipment problems.

 3.6.5 Contaminated Sludge Flow Rate

    The feed material's flow rate determines  its residence
 time in the LT3* processor.  At a selected heating fluid
 temperature, the residence time determines the treatment
 temperature. The treatment temperature  in turn determines
 the efficiency of contaminant  removal  and the extent of
 chemical transformations during heating.  The LT3® system
 can process contaminated material at a rate  of up to 10
 tons/hr.  However, during the SITE demonstration, sludge
was treated at a rate of only 2.1 tons/hr, which resulted in
a residence time of 90 minutes.  The sludge residence time
in the heat processor was  maintained  by adjusting  the
rotational speed of the screws.
3.6.6 Heating Fluid Temperature

    A heated, circulating fluid indirectly provides the thermal
energy   needed  to  maintain  the  desired  treatment
temperature  in  the  heat  processor.    The  treatment
temperature affects the rate and  degree  of contaminant
volatilization and formation  of thermal transformation by-
products.  For the SITE demonstration, the LT3®  heat
processor needed to maintain a sludge temperature of above
500 °F in order to volatilize organics from the contaminated
sludge.   The  heat  transfer fluid  used  during  the  SITE
demonstration and the full-scale remediation was Therminol
66, produced by  Monsanto.  According to  manufacturer
guidelines,  Therminol 66  performs best in  temperatures
ranging from 20 to 650 °F. During the SITE demonstration,
the operating temperature of the heating fluid was 650 °F.
In previous LT3® operations, Dowtherm HT, manufactured
by Dow Chemical, was used as heating fluid. The maximum
recommended temperature for continuous operation with
Dowtherm HT is also 650 °F.

    A heating fluid temperature of 650 °F and a 90-minute
residence tune resulted in a  sludge treatment temperature
between  500 °F and  530 °F.   The operating  treatment
temperature of the sludge was maintained by controlling the
temperature, pressure, and flow rate of the  heating fluid.
However, because the moisture content of the  contaminated
sludge varied, the sludge treatment temperature also varied.
Variations  in  treatment temperature  can influence  the
treatment efficiency of the LT3® system.

3.6.7 Climatic Conditions

    Dry, warm weather conditions are ideal for operation of
the LT3® system.  However, the  SITE demonstration was
conducted  in  subfreezing  temperatures,  and   remedial
activities at the site were conducted in subfreezing or wet
weather conditions.  Cold and wet weather caused minor
operational problems.  The  hose supplying  water to  the
treated sludge conditioner had to be covered with insulation
tape due to freezing temperatures.  The insulated tape was
occasionally   damaged,  and  the   water  supply  hose
subsequently froze. Weston personnel thawed the hose with
a portable heater. Snowy conditions hampered visibility at
the site but did not affect the performance of the  LT3®
system.   Wet  weather hampered  sludge  excavation and
handling. The LT3® system was not operated in  extremely
hot conditions at the ADC site.
                                                        22

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                                                    Section  4
                                              Economic Analysis
    This section presents cost data associated with the LT3®
technology.   Costs  have been placed in  12 categories
applicable to typical cleanup  activities  at Superfund and
RCRA sites.  This economic analysis discusses site-specific
factors affecting costs, assumptions the analysis is based on,
and each of the 12 cost categories as they apply to the LT3®
technology. Costs are presented in August 1992 dollars for
Weston's full-scale production unit with eight 20-foot screws.
Data was compiled during several pilot  studies and  during
the SITE demonstration and subsequent full-scale operations
at the ADC site. This analysis presents the costs associated
with treating  3,000 tons of VOC-contaminated soil,  with a
VOC concentration of 10,000 parts per million (ppm).  The
analysis also compares the costs associated with treating soils
containing 20 percent, 45 percent, and 75 percent moisture
content.

    An economic analysis of the LT3® technology reveals that
operating costs are most affected  by  the feed rate and
residence time.  The  soil  moisture content and the soil
treatment temperature (which is determined by contaminant
type and concentration) are site-specific factors that affect
costs.  The treatment temperature and the  soil moisture
content determine the feed rate and residence time needed
to properly treat soil and, to some  degree, the amount of
residual waste produced.

4.1 Site-Specific Factors  Affecting Costs

    Site-specific wastes and  features affect the costs of this
soil treatment technology.  Waste-related factors affecting
costs include waste volume, waste type, soil moisture content,
treatment goals, and regulatory permit requirements.  Site-
specific features affecting costs include site area, accessibility,
availability of  utilities,  and  geographic  location.    The
characteristics of the residual waste also affect supply and
disposal costs. Residual wastes produced by the LT3® system
and their characteristics determine  if  the wastes can be
recirculated for treatment in the system or if they must be
disposed of off site as hazardous wastes.
4.2 Basis of Economic Analysis

    Table  4-1   presents  a  breakdown  of  the  factors
considered for each of the 12 cost categories.  These costs
are considered to be order-of-magnitude estimates, with an
expected accuracy within 50 percent above and 30 percent
below the actual costs. The table presents a breakdown of
costs for a 3,000-ton remedial action site; it also compares
treatment costs for soils  containing 20, 45, and 75 percent
moisture. Larger or smaller projects may have different cost
per ton values.  Because fixed costs are not affected by the
volume of soil treated, larger projects will usually have a
lower  cost per  ton.    The  following  sections  present
underlying assumptions about (1) the LT3® technology and
capital costs, (2) soil and  site conditions, and (3) the LT3®
system used in this economic analysis.

4.2.1 Assumptions about the LI8® Technology and
Capital Costs

    This analysis is intended for potential clients needing to
treat  soils contaminated  with VOCs or  SVOCs.  This
analysis  assumes that Weston will subcontract the LT3®
system  to  government or private clients for  on-site soil
treatment. The LT3® technology will be delivered to the site
by six semitrailer trucks and will be assembled by Weston.
The assembled equipment will consist of the LT3® system
used at the ADC demonstration, with no deviations. Neither
depreciation nor salvage value  is applied  to the costs
presented in this analysis.

4.2.2  Assumptions  about   the  Soil   and Site
Conditions

    Soil and site conditions have  a great impact  on total
project cost, primarily because they determine how long the
LT^1 system will need to operate.  The amount and type of
contaminants in soil and the cleanup goals for the site will
determine the temperature and residence time necessary for
treatment.   High soil   moisture content will  increase
residence tune and the amount of residual water produced.
As a result, costs are affected by lower production speeds
                                                          23

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Tab/a 4-1 Cost Analysis for Operating the LI*® System
Cost Categories
Site Preparation Costs6
Administrative Costs
Fencing Costs
Construction Costs
Dewaterlng Costs
Total Site Preparation Costs
Permitting and Regulatory Costs'3
Permit
Engineering Support
Total Permitting and Regulatory Support
Equipment Costs
LT3® Rental0
Support Equipment Rental
Dumpsters0
Wastewater Storage Tanks9
Steam Cleaner
Portable Toilef
Optional Equipment Rental0
Total Equipment Costs
Startup Costs'1
Mobilization
Assembly
Shakedown
Total Startup Costs
Labor Costs0
Operations Staff
SHe Manager
Maintenance Supervisor
Site Safety Officer
Total Labor Costs
Supply and Consumable Costs
PPE°
PPE Disposable Drums
Residual Waste Disposal Drums
Activated Carbon"
Diesel Fuel0
Calibration Gases"
Total Supply and Consumable Costs
Cost Per Ton of Soil Treated*
Soil Moisture Content
20% 45% 75%

11.00
.40
.70
NA
12.10

3.30
80.00
83.30

13.00"

.70
1.00
.10
.10
12.00
26.90

10.00
25.00
15.00
50.00

39.00
21.60
7.20
7.20
75.00

6.00
.50
1.20
8.00
.65
.35
16.70

11.00
.40
.70
NA
12.10

3.30
80.00
83.30

22.00

1.35
2.00
.10
.20
20.00
45.65

10.00
25.00
15.00
50.00

79.50
44.30
14.60
14.60
153.00

10.00
1.00
1.20
24.00
1.00
1.10
38.30

11.00
.40
.70
187.90
200.00

3.30
80.00
83.30

22.00

1.35
2.00
.10
.20
20.00
45.65

10.00
25.00
15.00
50.00

79.50
44.30
14.60
14.60
153.00

10.00
1.00
1.20
24.00
1.00
1.10
38.30
24

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                                                            Cosf Per Ton of Soil Treated3
                                                               Soil Moisture Content
Cost Categories
20%
45%
75%
Utility Costs
Natural Gas (@ $1.43/1,000 ft3)
Electricity (@ $0. 18/kWh)
Water (@$ 1.00/100 gallons)
Total Utility Costs
Effluent Montitorina Costs'
Residual Waste and Waste Shipping, Handlina. and
Transportation Costs
Oversized Material (2% of feed soil)
Drums
Wastewater
Total Residual Waste and Waste Shipping,
Handling, and Transportation Costs
Analytical Costs
Treatability Study*
Sample Analysis for VOCs
Total Analytical Costs
Eouipment Repair and Replacement Costs
Maintenance
Design Adjustments'
Facility Modifications'
Total Equipment Repair and Replacement Costs
Site Demobilization Costs
TOTAL COST PER TON OF SOIL TREATED3

7.80
2.10
.60
10.50
0.00
5.40
27.00
7.20
39.60

10.00
4.20
14.20
11.70
0.00
0.00
11.70
33.00
373.00

26.00
6.30
.60
32.90
0.00
5.40
27.00
14.40
46.80

10.00
12.00
22.00
19.80
0.00
0.00
19.80
33.00
536.85

26.00
6.30
.60
32.90
0.00
5.40 .
27.00
14.40
46.80

10.00
12.00
22.00
19.80
0.00
0.00
19.80
33.00
724.75
NA = Not Applicable
" = Cost per ton of soil treated; figures are rounded and have been developed fora 3,000-ton project.
b = Fixed cost not affected by the volume of soil treated.
c = Costs are Incurred for the duration of the project.
d = Feed rate is double that of soils with 45 percent moisture content.
" = Costs are incurred only during soil treatment activities.
' = Cost included in the cost of renting the LT3® system.
                                                         25

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and increased handling requirements.  For example, soils
with 20 percent moisture content have a feed rate double
that of soils with 45 percent moisture content.  In addition,
a  higher  soil moisture content, such as 75 percent, may
require soil dewatering, a process that will further increase
costs.

    Site preparation costs are determined by the volume of
contaminated soil, the size of the site, and the availability of
utilities. This analysis assumes that a natural gas pipeline is
available  at  the  site.  Utility costs can be minimized if
natural gas is available to power the LT3® system's heating
units.  Otherwise, propane, which can be transported to the
site, is the  least  expensive  alternative fuel  capable  of
achieving  the  necessary operating  temperatures.    This
analysis also assumes that the contaminated soil is a fairly
homogenous clay-type soil, with a low moisture content and
only a minimal amount of  oversized material.  These soil
characteristics will lower site preparation costs.

4.2.3 Assumptions about LI6® System Operation

    For  soils with  a 45 percent  moisture content, this
analysis   assumes   that  the  LT3®  system   can   treat
contaminated soil in batch  cycles at 70 percent efficiency
until the  job is  done.   The  soil feed processing  rate is
assumed to be 2.1 tons per hour (tons/hr)  for a residence
time of 90 minutes.  This feed rate was used at the ADC
site. Operating at 70 percent efficiency, about 250 tons of
soil can be treated per week. At this rate, treating 3,000
tons of contaminated soil  would take about  3 months,
excluding mobilization  and demobilization.  Soil  with a
75 percent moisture content must first be dewatered. Once
the soil is dewatered to 45 percent moisture content, it can
be treated according to the  schedule described above.

    For soils with 20 percent moisture content, this analysis
assumes that the LT3® system  can treat contaminated soil in
batch cycles  at 70 percent efficiency until the job is done.
However, in  this scenario, the soil feed processing rate is
assumed to increase to 7 tons/hr for a residence time of
30 minutes.  Operating at 70  percent efficiency, about 820
tons of soil can be treated per week. At this rate, treating
3,000 tons of contaminated soil would take almost 1 month,
excluding mobilization and demobilization.

    The LT3* system requires three operators  and one
supervisor working two  12-hour  shifts  per  day.    One
maintenance technician and one site safety officer will be
employed during the first 12-hour shift and as needed during
the second shift.

    Weston's full-scale LT3®  system,  with eight 20-foot
screws, is the   only model   available.    Therefore, no
equipment cost  alternatives  are presented  here.    This
analysis presents  fixed and variable costs for operating the
full-scale LT3® model.
    This analysis is also based on the following assumptions:

    •   Residual wastes will be disposed of off site.

    •   Access  roads  exist  and  will  not  have  to  be
        constructed.

    •   Utility lines, such as electricity and telephone lines,
        exist on site.

    •   Air emissions monitoring will be continuous.

    •   Treated soil or sludge will be used as backfill at the
        site.

4.3 Cost Categories

    Cost data associated with the LT3® technology have been
assigned to the following 12 categories: (1) site preparation
costs; (2) permitting  and regulatory costs;  (3)  equipment
costs; (4) startup  costs;  (5) labor costs; (6) consumable
material costs; (7) utility costs; (8) effluent monitoring costs;
(9) residual  waste shipping, handling,  and transportation
costs; (10)  analytical costs;  (11)  equipment repair  and
replacement costs; and (12) site demobilization costs. Each
of these cost categories is discussed below.

4.3.1 Site Preparation Costs

    Site preparation  costs include  administrative, fencing,
and construction costs.   Site  preparation  costs will vary
depending on the amount of contaminated soil,  the  size of
the site, and the availability of utilities and access roads.  Site
preparation costs will be lower if the contaminated soil is
fairly homogenous and clay-like, with a low moisture content
and only minimal  amounts of oversized materials, such as
rocks and debris. Soils with high moisture content will need
to be dewatered.

    For this analysis,  site preparation administrative costs,
such as  legal searches, access rights, and other site planning
activities, are estimated to be  $33,000.  This analysis  also
assumes that minimal site grading is required, natural gas
and water supply lines exist at the site, and heavy equipment
is  rented.  The costs  for heavy equipment are included in
equipment costs (see Section 4.3.3), because the  equipment
will be on site for the duration of the treatment.

    A  6-foot-high, chain-link  security  fence with  a  12-
foot-wide gate will be needed to surround the 75-square-foot
LT3® system.  The site area totals 5,000 square feet.  The
fence will cost about  $730 for materials, and it is assumed
that the LT3® crew  will install it.  About 500 feet of
moveable snow fencing was used to enclose active excavation
areas at the ADC  site. The fence was intended to prevent
accidents near and  around  the excavation area.   Snow
fencing  is available in 50-foot bundles for about  $50.00 per
                                                          26

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bundle.  Other construction costs include assembling the
LT3®  system and installing  concrete foundations and soil
staging and storage areas.  These construction costs are
assumed to be 10 percent of total site preparation costs.

    The primary  costs associated with dewatering include
labor, rental of dewatering equipment (such as a filter press
and a  slurry pump), mobilization,  and  demobilization. At
the ADC site these costs were about $187.90 per ton of soil
dewatered from 75 to 45 percent moisture content (Weston,
1992). It is assumed that a filter press can process about 120
tons of soil per day  or 840 tons per week.  Once a stockpile
of  dewatered soil  is  available, dewatering and  thermal
processing  may occur  concurrently.  Because the  LT3® is
assumed to process 250 tons of soil per week, dewatering
will not significantly increase the amount of time needed to
complete the project and, therefore, is not considered in this
analysis.

    A treatability study will need to be  performed to
determine site- and waste-specific temperature requirements
and residence times.   Because treatability study costs are
primarily analytical, they are included in analytical costs (see
Section 4.3.10).

4.3.2 Permitting and Regulatory  Costs

    Permitting and regulatory costs include fees for  highway
permits for oversized vehicles and  air permits for the  LT3®
system's heating unit and monitoring equipment. These fees
are assumed to cost about $5,000 each.

    Weston estimates  typical  total permitting costs  to
average $240,000  for engineering support,  such as acting as
a  liaison to regulatory  agencies  and generating  various
reports.  Proof-of-process  testing, analysis, and reporting
increase  these  costs  by an  average   of  $100,000
(Weston, 1986).  In some cases, condensate from the  LT3®
system could  possibly be discharged to a publicly owned
treatment works,  which would require a National Pollutant
Discharge  Elimination System  (NPDES)  permit.   This
permit would  increase permitting and regulatory costs and
effluent monitoring costs.

    RCRA  corrective action  sites  require  additional
monitoring  records and  sampling protocols,  which  can
increase the regulatory costs by an additional 5  percent
(EPA,  1991b).   CERCLA and SARA  require remedial
actions to be consistent with ARARs of environmental laws,
ordinances, regulations, and statutes, including federal, state,
and local standards and criteria. In general, ARARs  must
be determined on a site-specific basis.

4.3.3 Equipment Costs

    Equipment costs include renting  the complete  LT3®
system and support equipment. Weston will only lease the
LT3® system to its clients. The rental rate is assumed to be
about $13,000 per month. Support equipment includes roll-
off dumpsters for oversized material; 2,000-gallon storage
tanks for treated wastewater; and a  steam-cleaner for
decontaminating equipment.  Support equipment costs are
discussed below.

    This analysis  assumes that oversized material removed
frorn contaminated soil is stored in  a 40-cubic-yard roll-off
dumpster prior to disposal.  Oversized material is assumed
to constitute 2 percent of the feed  soil.  By this estimate,
3,000 tons of  contaminated soil will contain 60 tons of
oversized material, which would fill nearly two dumpsters.
The average rental cost of a 40-cubic-yard roll-off dumpster
is $500  per  month (Ravenswood Disposal  Services, 1992).
Disposal costs for  oversized  material are  included in
residuals and waste shipping, handling,  and transportation
costs (see Section 4.3.9).

    Treated wastewater is  generated when processor off-
gasses  are  filtered  and  cooled in the  LT3® system's
condensers.  Condensate  is  treated in a vapor-phase carbon
adsorption unit before being stored in tanks prior to off-site
disposal. The costs associated with the vapor-phase carbon
adsorption unit are included in consumable material  costs
(see Section 4.3.6).   Storage tanks  are  needed for the
duration of  the project.  At the ADC site, the soil had a
45 percent moisture content,  which generated about 120
gallons of wastewater per hour, or 57 gallons per ton of soil
treated. If two 2,000-gallon  tanks are rented, wastewater will
have to be disposed of almost every other day. Each tank
can be rented for about $1,000 per month.

    The actual amount of wastewater  generated and the
subsequent  size  of  the  tanks depends on the  moisture
content of the feed soil. It is assumed that soils with 20
percent soil moisture  content will generate about half as
much water as soils with 45 percent moisture content.  In
this scenario two storage tanks should still be rented, but
they will be emptied  less  frequently and over a shorter
period of time. Disposal costs for wastewater  are included
in residuals and waste shipping, handling, and transportation
costs (see Section 4.3.9). Under some circumstances, treated
condensate water can be sprayed directly on the treated soil
to control dust, thus eliminating storage  and disposal costs.

    A steam-cleaner is needed at the end of the project to
decontaminate equipment.   Steam-cleaning units can be
rented for $300 per month (EPA, 1991a). No mobile office
trailer is necessary because it is included with the complete
LT3®  system.   However, portable toilets are not available
with the system  and  may have to be rented.   Weston
estimates the cost of renting a portable toilet to be $120 per
mouth.

    Optional support equipment needed  depends on the
depth and amount of soil to be treated. Either  front-end
                                                          27

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loaders or backhoes can be used to transport soil.  At a
minimum, one excavator and two loaders or backhoes are
needed for soil excavating, transporting, and regrading
activities.   All  this equipment  can be  rented for  about
$12,000 per month, based on normal use during the two-shift
days. It is assumed that LT3® personnel will be licensed to
operate this equipment.

4.3.4 Startup Costs

    Startup costs  include   mobilization,  assembly,  and
shakedown costs.   This analysis  assumes that  startup  will
take 5 weeks and that Weston will provide trained personnel
to deliver, assemble, operate, and maintain the LT3® system
and any necessary support equipment. Also, it is assumed
that Weston's personnel are trained in health and  safety
procedures. Therefore, training costs are not incurred as a
direct startup cost.  Total startup costs are about $150,000
and include the activities mentioned in this section.

    Mobilization involves transporting all equipment  to the
site.  Transportation costs  are site-specific and will vary
depending on the  location  of the site in relation  to  all
equipment vendors. Five semitrailers with five drivers are
required to ship the LT3® system to  the site from West
Chester, Pennsylvania. Mobilization is assumed to comprise
about 20 percent of total startup costs, costing about $30,000.

    Assembly costs include the costs of unloading equipment
from trailers  and  assembling the LT3®  system.    These
activities require a crane rental and a crew of four working
12 hours per day for about three weeks.  After assembly,
equipment must be hooked up to utilities.  Assembly is
assumed to comprise about 50 percent of total startup costs,
costing about $75,000.

    Shakedown costs include initial setup, initial startup, and
proof-of-process tests. About 600 tons of sand is used for 2
to 3  days  during  initial startup.   Trial runs  take  about
2 weeks to complete, after which full-scale operations may
begin. Shakedown costs are assumed to constitute about 30
percent of total startup costs, which total about $45,000.

4.3.5 Labor Costs

    Labor  costs include the total staff needed  for startup,
O&M of the LT3* system.  Startup costs were discussed in
the previous section.   Labor wage rates, which include
overhead and fringe benefits, are  discussed below.

    Unless  air  permits  or local  requirements  dictate
otherwise, the LT3® system will be operated during two 12-
hour shifts, 7 days per week in order to avoid shutting down
the system.  System shutdown should be avoided because it
takes about 12 hours  for  the  unit to reach treatment
temperatures.  Each shift will have three operators ($27 per
hour), one site manager ($45 per hour), one maintenance
supervisor ($30 per hour), and one site safety officer ($30
per hour).  The site safety officer will work during the first
shift and as needed  during the second shift.  In addition,
part-time project management and office support may be
needed.

4.3.6 Consumable Material Costs

    Consumable material costs include the costs of PPE,
drums for used PPE and residual wastes, activated carbon
for off-gas vapor and liquid treatment, diesel fuel for heavy
equipment,  and  calibration  gases  for air  monitoring
equipment.  The quantities of all consumables will depend
on the amount of soil treated.

    PPE includes hard hats, safety glasses, respirators, and
disposable protective clothing. Disposable clothing is worn
by three operators who  change PPE four times per shift,
costing about $200 per day. Used PPE fills about one 24-
gallon fiber drum per shift, costing about $12.30 per drum,
or $25.00 per day.

    The LT3® system typically generates residual wastes such
as dust and spent carbon, both of which require containers
and proper  off-site disposal.  Dust is removed from the
baghouse about once per shift and is collected in 55-gallon
drums. For the ADC site, about one 55-gallon carbon-steel
drum of dust is generated for every 12.5 tons of soil treated.
Drums cost about $15 each.

    The vapor-phase carbon adsorption unit is exhausted
every 10 days of operation and is replaced with a new one.
The  vapor-phase carbon adsorption unit contains  1,800
pounds of activated carbon and costs $5,000.  Beginning hi
the third month of operation, a monthly service charge  of
$420 is incurred for covering the  costs of handling spent
carbon and maintaining the unit.  Transportation costs for
carbon adsorption units are included in the round-trip freight
charges between Pittsburgh, Pennsylvania, and the site. The
carbon vendor will  either dispose of  or  regenerate the
carbon, the cost of which is included in the cost of the unit.

    The liquid-phase carbon  adsorption unit is exhausted
every 14 days of operation and is replaced with a new one.
The liquid-phase carbon adsorption unit contains 165 pounds
of carbon and costs  about $4,200,  plus round-trip freight
charges between  Pittsburgh,  Pennsylvania,  and  the  site.
Costs  can vary by up to $200 for the liquid-phase unit,
depending on the type of carbon used. The rate of carbon
use depends  on  contaminant types and  concentrations.
Vapor-phase carbon adsorption units are needed only during
treatment activities.

   Diesel fuel is used to  operate all heavy equipment. Fuel
costs are site-specific and will vary depending on the market
price of diesel fuel and the extent of equipment usage at the
                                                         28

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site. At the ADC site, about 250 gallons of diesel fuel were
used per week.

    Cylinders of CO, O2, CO2, and total hydrocarbon gases
are needed to calibrate LT3® air monitoring equipment.
Each cylinder of gas costs about $200 and is replaced every
3 weeks.  The LT3® system requires calibration once per day.

4.3.7 Utility Costs

    Utilities used by the LT3® system include natural gas,
electricity, and water. This analysis assumes that natural gas
lines will be available  at the site.  The LT3® heating unit
generates 6 million Btu/hr and is  usually powered with
natural gas, propane, or oil.  For soils with a  45 percent
moisture content, about 38,000 cubic feet of natural gas is
used to process about 2.1 tons of soil each hour. About 7
tons of soil are  processed per hour for soils  with a  20
percent soil moisture content.  Assuming current market
conditions, natural gas costs about $1.43 per 1,000 cubic feet.
Therefore, for soils with 45 percent moisture content, natural
gas usage costs about $25.88 per ton treated.  For soils with
20 percent soil moisture  content, using natural gas costs
about $7.80 per ton treated.

    Electricity runs the rest of the LT3® system. The system
is  estimated to  consume 8,750 kilowatt-hours (kWh)  per
week when operating at 70 percent capacity (Weston, 1986).
Electric costs per Kilowatt-hour (kWh) vary depending on
local utility rates. For this analysis, power is assumed to cost
$0.18 per kWh.  Therefore, electricity costs about $6.30 per
ton of soil with a 45 percent soil moisture content, and about
$2.10 for soils with a 20 percent soil moisture content. Total
electric power requirements depend on the amount of soil
treated.

    To eliminate fugitive dust emissions at the ADC site,
about  2  gpm of  potable water is sprayed on treated soil.
This action requires about 60 gallons of water  per ton of
soil.   Water costs are estimated to be  $0.01  per gallon
(Weston, 1986).  Therefore, water costs about $0.60 per  ton
of soil treated.   This  cost can vary by as  much  as 1,000
percent,  depending on the geographic location of the site,
availability of water, and distance to  the nearest water main
or uncontaminated well (EPA, 1991b). In future application,
it is anticipated that condensate wastewater can be treated
sufficiently to allow it to be used for  additional dust control.

4.3.8 Effluent Monitoring Costs

    Effluent monitoring costs include costs associated with
air emissions  monitoring for compliance with  air permit
limits.  Monitoring treated off-gas  vapors  emitted to  the
atmosphere is part of the LT3® system and is accounted for
in the rental cost of the system. The only variable  affecting
these  costs is the cost of calibration gas.  Gas costs  are
included hi supply and consumable costs (see Section 4.3.6).
In addition, condensate could possibly be discharged to a
publicly owned  treatment  works, which would require a
NPDES permit.  This permit would increase permitting and
regulatory costs as well as effluent monitoring costs.

4.3.9 Residual Waste  Shipping,  Handling,  and
Transportation Costs

    Disposal-related costs include costs associated with the
disposal  of  carbon  adsorption units,  PPE, and  other
residuals, such as oversized material, drums of fabric filter
dust, and wastewater. These costs  depend on geographic
location, distance to disposal  sites, and site-specific soil
conditions. Transportation costs for carbon adsorption units
are included  hi the round-trip freight charges  between
Pittsburgh, Pennsylvania, and the site.  The carbon vendor
will either dispose of or regenerate the carbon, the cost of
which is included in the cost of the unit.

    Wastes drummed or containerized on site include PPE,
oversized material, and fabric filter dust. Approximately one
24-gallon drum  of PPE is generated during each 12-hour
shift.  The  disposal cost is  $150 per  drum or $300 per day.
Drums of PPE are assumed to be transported by truck to
disposal facilities.  Oversized material is estimated to be 2
percent of feed soil.   The cost for  disposing of oversized
material is assumed to be $270 per ton.  The material will be
transported off site in the 40-cubic-yard roll-off container it
is collected in.  Filter dust at the ADC site is generated at a
rate of two 55-gallon drums per 12-hour  shift.   Disposal
costs are estimated to be $150 per drum or  $600 per day.

    For soil with a 45 percent moisture content, about 57
gallons  of  wastewater  is generated   per  ton  treated.
Wastewater is stored on site until it is transported off site by
5,000-gallon tanker trucks, approximately every other day.
Transportation  and  disposal   costs will   average  about
$0.24 for every  gallon of  water generated.   Soils with a
20 percent soil moisture content will generate about half as
much water.   For future applications, it  is anticipated that
filter  dust  can  be  recirculated into  the  system,  and
wastewater can be used for dust control. The actual amount
and type of residuals generated will vary from site to site.
For example,  soils  containing fewer  fine particles will
generate less dust.

4.3.10 Analytical  Costs

    A treatability study  will  need to  be  performed to
determine the temperature requirements and residence times
of soil to be treated. This study is estimated to cost $30,000.
Continuous air monitoring of stack emissions is included in
the rental cost of the LT3® system.

    During the ADC SITE demonstration, all samples were
shipped off site and  analyzed only for the  contaminant of
concern. Analytical samples typically consisted of one VOC
                                                          29

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sample shipment per shift, at a cost of approximately $210
per shipment. Total analytical costs depend on the number
and types of analyses that must be conducted and the site-
specific  contaminants  of  concern.  For example, if four
contaminants of concern by using  only  one technique,
analytical costs will be  significantly reduced. VOC analyses
cost about $210 per sample; SVOC analyses cost about $440
per sample.

4.3.11  Equipment Repair and Replacement Costs

    Maintenance labor has been included in labor costs (see
Section 4.3.5).  Maintenance material costs are assumed to
be  90 percent  of total rental costs.  Costs  for design
adjustment,   facility   modifications,   and   equipment
replacements are assumed to be incurred by Weston.

4.3.12  Site Demobilization Costs

    Site  demobilization  includes LT3®   shutdown  and
disassembly, site cleanup and restoration, rental equipment
return, and disconnection  of utilities.  These activities will
require  a crew of six.  Complete site demobilization is
assumed to take about 3 weeks and costs $100,000.

References

    Canonie Environmental  Services Corporation, 1990,
Treatability Study Report and Remedial Contracting Services
Proposal (September).

    Evans, G., 1990, Estimating Innovative Technology Costs
for  the  SITE Program,  Journal  of  Air  and Waste
Management Association 40:7 (1047-1051).
    Larock,   R.,   1989,   Comprehensive  Organic
Transformations:   A   Guide   to  Functional   Group
Preparations. VCH Publishers, Inc., New York, NY.

    Ravenswood  Disposal  Services,  1992,   Telephone
Conversation between Lenora Rodriguez and Jeffrey Swano,
PRC (May 20).

    Roy  F.  Weston,  Inc.  (Weston),  1986, Economic
Evaluation of Low Temperature Thermal  Stripping of
Volatile  Organic  Compounds  from Soil,  Report  No.
AMXTH-TE-CR-86085 (August).

    Weston, 1992,  Telephone Conversation  between  Al
Murphy and Jeffrey Swano, PRC (July 3).

    U.S.  Environmental Protection Agency (EPA), 1980,
Dioxins.  Prepared  by M. P.  Esposito, T. O. Tiernon, and
F.E.  Dryden,   EPA/600/2-80-197,  Cincinnati,  Ohio
(November).

    EPA,  1988, CERCLA Manual on  Compliance with
Other Laws, Interim Final, OSWER, EPA/540/G-89/006.

    EPA 1991a, Toxic Treatments, In Situ  Steam/Hot-Air
Stripping  Technology,  Applications  Analysis  Report.
EPA/540/A-90/008 (March).

    EPA,   1991b,  E.  I.   DuPont  De   Nemours  &
Company/Oberlin   Filter   Company   Microfiltration
Technology, Applications Analysis Report.  EPA/540/A5-
90/007 (October).

    Stumm, W. and J.J. Morgan, 1981, Aquatic Chemistry.
Second Edition, John Wiley & Sons, Inc., New York, NY.

    Versar,   1983,   Exposure   Assessment  for  4,4'-
methylenebis (2-chloroaniline) (MBOCA), Final Report.
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                                                  Appendix A
                                             Developer's Claims
    This appendix summarizes claims made by the developer
Roy F. Weston, Inc. (Weston), regarding its low temperature
thermal  treatment   (LT3®)   system.    The  information
presented therein represents the developer's point of view
and  does not constitute  U.S.  Environmental Protection
Agency (EPA) approval or endorsement of the statements
made in this appendix.

A.I Introduction

    The Weston LT3® system is a patented process (U.S.
Patents No. 4,738,206 and 5,072,674) used to remove volatile
and semivolatile organic compounds (VOC and SVOC) from
a  variety of solid  matrices, including soil, sludge,  and
sediments.   The  LT3®  system  desorbs  or evaporates
contaminants from the solid matrix using an indirect heat
exchanger. The main part of the heat exchanger is a hollow-
flight screw conveyor. Volatile contaminants and moisture
are evaporated from the solid matrix and drawn into an air
emission control system under vacuum. The air emission
control system collects  contaminants  using a  series of
condensers and adsorbers.

A.2 Potential Application

    The LT3® system can be used to treat solid matrices
contaminated by a variety of VOCs and SVOCs. The LT3®
system  has been  used  to  treat soil  contaminated with
chlorinated solvents, nonchlorinated solvents, fuel-derived
hydrocarbons,  polynuclear  aromatic  hydrocarbons,  and
chlorinated  anilines.    Following treatment,  solids may
typically be backfilled on site.

    The LT3® system is typically mounted on a  truck to
facilitate mobility.  However, fixed facility operations are
possible and, in specific cases, are more cost effective than
mobile operations, particularly for large sites or facilities that
continually generate wastes.  Remedial activities conducted
under the Superfund or Underground Storage Tank (UST)
programs have been successfully completed using the mobile
LT3® system.
    Resource  Conservation  and  Recovery Act (RCRA)
classified wastes have been treated in bench- and pilot-scale
tests.  Following treatment,  solid residuals have complied
with federal Land Disposal Regulations (LDR).   RCRA
wastes can be treated by using the mobile system or by
constructing  fixed   facilities  when  handling  routinely
generated solid wastes.

    Prior  to application, a  bench-scale  test should  be
performed to  determine the technology's ability  to meet
cleanup criteria and to establish the operating conditions
necessary.   Bench-scale  tests generally provide sufficient
information to develop full-scale processing systems. Weston
offers bench-scale testing through the Environmental Testing
Laboratory (ETL) in Lionville, Pennsylvania. The ETL has
a RCRA permit to receive and test hazardous waste samples
in order to determine their treatability.

A.3 System Advantages

    The LT3®  system offers the following advantages over
other remedial methods and thermal treatment systems:

    •   By heating soils to evaporate volatile contaminants
        and moisture at  temperatures well below  the
        combustion temperature associated with incineration
        operations, the system operates with substantial fuel
        and energy savings.

    «   Indirect heating of the soil reduces the quantity of
        off-gas   contacting   the   solid   matrix   and
        contaminants.   With gas flows 10  to 20 tunes
        smaller than direct-fired desorbers or incinerators,
        the emissions control equipment is greatly reduced
        in size. Furthermore, the total amount of off-gas to
        which the public could potentially be  exposed is
        greatly reduced.

    «   By  controlling emissions using condensation  and
        carbon adsorption,  the LT3® system  can recycle
        usable products, thus  avoiding the generation of
        harmful products of incomplete combustion that are
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        sometimes  associated  with improperly operated
        incinerators.

    •   The LT3® system can provide for retention times of
        up to 90 minutes, as demonstrated at the Anderson
        Development Company (ADC) site.  These long
        residence times are well above the residence times
        possible  in similar rotary-type  desorbers  and
        incinerators.

    •   The   hollow-flight  screw  conveyor  provides
        substantial  mixing  and  breakdown of soil clumps.
        Clay materials, which tend to ball and  clump, are
        broken down  and handled readily by the LT3®
        system.

A.4 System Limitations

    The LT3* system has the following physical and chemical
limitations:

    •   The LT3* system is intended for ex situ treatment of
        solids.  Material that is excessively wet must be
        dewatered or blended.  All solid material must be
        screened to remove material greater than 2 inches
        in  size. • Oversized material may  be shredded or
        crushed to meet this feed-restriction criterion.

    •   The  LT3®  system  is  designed  to  treat  solids
        contaminated by VOCs and SVOCs.   While the
        system's ability to treat metals has been tested, no
        removal of metals has been observed.

A.5 Costs

    The costs for applying the LT3® system are provided on
a lump sum basis for fixed costs, such as mobilization,
permits,  and  demobilization,  and unit  costs for solid
treatment.  Costs are developed on a site-specific basis  and
depend on (1) the quantity of solid to be  treated, (2) the
contaminants in the solid, the (3) solid moisture content, and
(4)  the location of the facility.
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                                                 Appendix B
                                      SITE Demonstration  Results
B.I Introduction

    Since early 1991, the U.S. Environmental Protection
Agency  (EPA) Superfund Technical Assistance Support
Team  (START)  and  its  Office  of  Research  and
Development (ORD) have provided technical support  to
EPA  Region  5  in  evaluating  remedial options  for the
Anderson Development Company (ADC) Superfund site in
Adrian, Michigan.  EPA determined that low temperature
thermal desorption was an appropriate technology to treat
contaminated sludge at the  site.  The record of decision
(ROD) for the site stated that, following successful proof-of-
process testing, the Low Temperature Thermal Treatment
(LT3®) system developed by Roy F. Weston, Inc. (Weston),
could be used to remediate organic contaminants. Proof-of
process  testing  would  be  conducted under  the  EPA
Superfund  Innovative   Technology  Evaluation  (SITE)
program. The SITE demonstration  of the LT3® technology
was conducted at the ADC site in November and December
1991,  in a cooperative effort among ORD, EPA Region 5,
ADC, and Weston. This appendix briefly describes the ADC
site and summarizes the SITE demonstration activities and
results.

B.2 Site Description

    The ADC facility covers approximately 12.5 acres within
a 40-acre industrial park.  The facility is located on the
southeast side of Adrian, Lewanee County, Michigan. ADC
manufactures specialty organic chemicals. Between 1970 and
1979  it manufactured  and  sold  4,4' -methylenebis  (2-
chloroaniline), also known as MBOCA or Curene 442.  In
1979,  sludge from the City of Adrian wastewater treatment
plant  was found to be contaminated with  MBOCA.  The
source of this contamination was a lagoon at the ADC site.
In  1983, the  ADC site was  included on the National
Priorities List (NPL).   A remedial investigation (RI),  an
endangerment assessment (EA), and a feasibility study (FS)
were subsequently conducted by C.C. Johnson & Malhotra,
P.C. (CCJM, 1989).
                                   ~\
    The RI indicated contamination of some surface soil in
the lagoon area, all the sludge in the lagoon, and some clay
on the side slopes of the lagoon and underneath the sludge.
MBOCA contamination in these areas exceeded the health-
based cleanup goal of 1.6 milligrams per kilogram (mg/kg),
as determined by the EA.   Volatile organic compounds
(VOC), semivolatile organic compounds (SVOC) other than
MBOCA, and some metals were also detected, primarily in
the lagoon sludge and clay.

   In September 1990, bench-scale tests conducted by
Canonie  Environmental Services  Corporation  (Canonie)
determined that low temperature thermal desorption was a
viable remedial technology to remove MBOCA from  the
ADC lagoon sludge and clay.   Treatability study results
indicated that thermal desorption was capable of reducing
MBOCA concentrations in the lagoon sludge and clay to
below the cleanup goal of 1.6 mg/kg. Bench-scale tests were
conducted using treatment temperatures greater than 520 °F
and a residence time of 12.5 minutes.  Because of scheduling
conflicts, Canonie could not perform the remediation of the
site.  ADC contracted Weston to perform remedial activities
at the site using the LT3® system.  Optimum operating
conditions were determined by Weston during shakedown
and startup operations before the  SITE demonstration.

B.3 Contaminant Characteristics

    MBOCA (CAS No. 101-14-4) is a yellow to light gray-
tan, nearly odorless,  crystalline solid.  The physical form of
MBOCA  is granular, with  a  size  range  of  0.5 to  1.0
centimeters  (cm). MBOCA is a member of the class of
compounds  known  as  aromatic  amines.  The  chemical
formula of MBOCA is CH2 (C6H3C1NH2)2. The structure of
MBOCA is presented below.
    H,N
                                          Cl
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    The  physical and chemical properties of MBOCA
determine its removal mechanisms during thermal treatment
in the LT3* system.  MBOCA has a relatively low solubility
in water and an extremely low vapor pressure, ranging from
3.7x10"* to 5.4X10"5 torr over a broad temperature range.
Several values have been reported  for its  melting  point,
ranging  from  210.2   to  230  °F.    Because  MBOCA
decomposes  at  above 392  °F,  physical  and chemical
transformations may govern the fate  of MBOCA during
thermal  treatment.    Two known  degradation products
(metabolites) are N-acetyl-MBOCA  (AC-MBOCA) and
N,N'-diacetyl-MBOCA (DAC-MBOCA) (Versar, 1983).

    Sorption  of MBOCA  to  organic material and clay
dominates  its  fate  in soil  and  aquatic  environments.
MBOCA is  easily adsorbed by granular activated carbon.
Soil adsorption of two similar aromatic amines, aniline and
parachloroaniline, has been found to depend both on  the
organic matter and the clay content of the soil.  The cationic
bonding  of  MBOCA  with  soil  may  be  irreversible.
Photooxidation  and  chemical oxidation   may  also  be
important transformation processes in  the atmosphere and
in  the  uppermost  layer  of  soil  and  water  systems.
Biodegradation  of MBOCA has been demonstrated,  and it
is probably effective in removing MBOCA from soil and
from wastewater with sufficiently acclimated microorganisms
(Versar,  1983).

B.4  Technology  Demonstration  Testing  and
Sampling Procedures

    The  original  experimental design  for  the  SITE
demonstration test  specified four  test runs  at optimum
conditions: two test runs for sludge and two test runs for clay
treatment.  However,'much of the clay was excavated and
stockpiled together with the sludge, and a  distinguishable
clay matrix could not be found.  Therefore, to collect  the
number of samples needed, three replicate tests for sludge
treatment were  conducted the week of November 25, 1991.
Approximately 40 tons of contaminated material (13 for each
of three  runs) were processed during the demonstration.
Each demonstration test required approximately 6 hours of
LT3*  system operation.    The  residence  time  and  the
temperature in the thermal processing  unit were optimized
during   Weston's   shakedown  period  prior  to  the
demonstration.    Table  B-l  summarizes  the  system's
operating parameters.

    Sampling began when the system reached steady-state
conditions in terms of temperature and sludge  flow rate.
For each run, sludge and liquid samples were collected every
30 minutes for  the 6-hour test period.  Stack gas samples
were collected over a period of about 4 hours during  the
middle of each run.

    During the demonstration, samples were collected from
six process points: (1)  untreated sludge, (2) treated sludge,
(3) fabric filter dust, (4) condensate (5) exhaust gas before
the carbon unit, and (6) stack gas after the carbon unit.
Samples were also collected from the City of Adrian service
water line.  Solid, liquid, and gas samples were analyzed for
the following critical parameters: MBOCA, VOCs, SVOCs,
dioxins, and furans. To trace the fate of chloride through
the system, samples were also analyzed for chloride, total
organic halide (TOX), and extractable organic halide (BOX).
Noncritical parameters were also analyzed to characterize
the feed and treated sludge. These parameters were metals,
toxicity characterisric leaching procedure  (TCLP) metals,
particle size distribution, moisture,  density,  total  organic
carbon (TOC), soil classification, available surface area, total
toxicity bioassay, California bearing ratio (CBR), and pH.
All sampling and analyses procedures met the requirements
of a EPA Category II quality assurance project plan (EPA,
1991).

   After the first SITE demonstration, the truck carrying
gas samples and sample logbooks caught fire and burned
completely. Because the fire destroyed all stack samples for
particulate matter,  VOCs, SVOCs, chloride, and moisture,
SITE demonstration tests had to be repeated. The second
SITE demonstration was performed the week of December
15, 1991.

   The objective of the second SITE demonstration was to
collect liquid, solid, and gas  samples for all contaminants
sampled  in the gas phase.   Sampling was performed  for
VOCs, SVOCs, MBOCA, TOX, and chloride. All liquid and
solid  samples were collected as daily composites, because
their  purpose was primarily to  correlate contaminant
concentrations  in  the  gas,  liquid,  and  solid  phases.
Therefore, composite samples for each run were collected
and analyzed for each of the contaminants of concern.  In
addition, liquid  condensate  samples were  collected and
analyzed for pH.  No  sludge samples were collected  for
dioxins and furans, because gas samples from the November
testing were not lost in the truck  fire.  Also, noncritical
parameters were not included in the December sampling
program.

B.5 Treatment Results

   This  section  summarizes analytical results of the LT3®
system SITE  demonstration  and evaluates  the  system's
effectiveness in treating sludge contaminated with VOCs and
SVOCs.  SITE demonstration results are based on extensive
laboratory   analyses  under  rigorous  quality   control
procedures.  Analytical results from all six replicate runs
(three in November and three in December) were analyzed
to determine the system's efficiency. The following sections
discuss (1) VOC removal, (2) MBOCA removal, (3) SVOC
removal,  (4) the fate of chloride in the LT3® system, (5)  the
formation and distribution of dioxins and furans, (6) the fate
                                                        34

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Table B-1 LT3® System Operating Conditions During SITE Demonstration
    Equipment
Parameter
                                                Value
    Thermal Processor
    Fabric Filter

    Air-Cooled Condenser

    Refrigerated Condenser

    Vapor-Phase Carbon Units
    Liquid-Phase Carbon Units
    Oil-Water Separator
Temperature
Feed Material Flow Rate
Screw Rotational Speed
Residence Time

Air/Cloth Ratio
Cleaning Frequency

Ambient Air Temperature

Discharge Temperature

Empty Bed Velocity
Empty Bed Contact Time
Operating Temperature
Operating Humidity

Flow Rate
Surface Loading Rate
Empty Bed Contact Time

Surface Area Loading
Residence Time
 Greater than 500 °F
    2.1 tons/hour
  0.73 to 0.76 rprn"
     90 minutes

        4.27
Every 15 to 30 seconds

     20 to 30 °F

     60 to 70 °F

      55 fpmb
    0.07 minutes
       70 °F
     70% RH°

     See note d
     See note e
    a = rpm (revolutions per minute)

    b = fpm (feet per minute)

    0 = RH (relative humidity)

    d = The liquid-phase carbon adsorption units were not used as part of the condensate liquid treatment system during the SITE
    demonstration.

    e = The oil-water separator did not operate during the SITE demonstration or subsequent remedial activities.
of metals  in  the LT3® system, (7) stack emissions, (8)
physical properties of sludge, and (9) lexicological properties
of sludge.

B.5.1 VOC  Removal

    For most  VOCs present in untreated sludge, the LT3®
technology  achieved residual  concentrations  below  the
method detection limits, which for most VOCs were below
60 Aig/kg.   Toluene and tetrachloroethene  (PCE) were
identified as critical VOCs for the  LT3® technology SITE
demonstration.

    Toluene  was   present   in   untreated   sludge   at
concentrations ranging  from  1,000  to 25,000 MgAg-  The
concentration  of toluene  in treated sludge was below the
detection limit of 30 jig/kg.  The concentration of toluene in
fabric filter dust ranged  from less than 28 to 410 /tg/kg. For
most samples  analyzed, the concentration of toluene in the
condensate was below the detection limit of 5 milligrams per
liter (mg/L). Toluene was detected in the off-gas before the
carbon column at concentrations ranging between 8,000 and
10,000 parts per billion by volume (ppbv), and was effectively
removed by the vapor-phase activated carbon  column.
                             PCE was present in untreated sludge at concentrations
                         ranging from 690 to 1,900 jug/kg.  The  concentrations of
                         PCE in treated sludge and fabric filter dust were below the
                         detection limit of 30 jitg/kg for most samples analyzed. The
                         concentration of PCE in the condensate was below the
                         detection limit of 5 mg/L. PCE was detected in the off-gas
                         before the carbon unit at concentrations ranging from 210 to
                         220 ppbv; PCE was effectively removed by the vapor-phase
                         activated carbon column.

                             Toluene has a boiling point of 231.1 °F and PCE has a
                         boning point of 249.8  °F.   Because  of their low boning
                         points, toluene and PCE were apparently easily desorbed
                         from the sludge and remained hi the off-gas stream after the
                         air-cooled  and refrigerated condensers.  However,  both
                         contaminants were effectively removed by the vapor-phase
                         activated carbon column.

                         B.5.2 MBOCA Removal

                             The LT3® system achieved MBOCA removal efficiencies
                         ranging  from  79.8   to  99.3 percent,  with  MBOCA
                         concentrations in the treated sludge ranging from  3 to 9.6
                         mg/kg. MBOCA concentrations in untreated sludge ranged
                                                           35

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from  43.6  to 860  mg/kg.   The decrease  in  MBOCA
concentration  after  treatment  was  accompanied by  an
increase in the measured concentration of AC-MBOCA (see
Figures B-l and  B-2), a  known  metabolite  of MBOCA.
These  results indicate that the  removal of MBOCA  is
probably due partially to thermal desorption and partially to
its conversion to AC-MBOCA.  However, the presence of
co-eluting  compounds  may have  interfered with  the
quantitation of AC-MBOCA. The concentration of DAC-
MBOCA, another metabolite of MBOCA, decreased after
treatment for most samples analyzed, probably  due to
removal mechanisms similar to those described for MBOCA.

    MBOCA has a high tendency to sorb onto clay particles,
as indicated by its large adsorption coefficient of 1,500
(Versar,  1983).  This tendency may have affected the LT3®
system's  ability to completely remove MBOCA from the
sludge.   MBOCA  has  a sublimation point of 240.8 to
251.6 °F, which is well below the treatment temperature of
above  500 °F.  However, MBOCA  was not completely
removed during treatment,  probably because of its high
tendency to be  sorbed  onto  soil  particles.   MBOCA
concentrations in the fabric filter dust were significantly
higher than  MBOCA concentrations  in the treated sludge,
which supports this hypothesis.  MBOCA concentrations in
fabric filter dust ranged from 6.3 to 75 mg/kg. In addition,
MBOCA was detected in liquid condensate at concentrations
ranging from 100 to 257 micrograms per liter G*g/L)-  No
MBOCA was  detected  in  the  exhaust gas from  the
refrigerated  condenser.

    In fabric filter dust,  the  concentration of AC-MBOCA
is  significantly  higher  than the  concentration of DAC-
MBOCA.  Apparently,  MBOCA and DAC-MBOCA are
converted to AC-MBOCA during heating. However, AC-
MBOCA associated with  small particles  is not effectively
desorbed but remains attached to the small particles, which
are carried away in the sweep gas and are removed in the
fabric filter.

B.5.3 SVOC Removal

    The LT3® system generally decreased the concentration
of SVOCs in treated sludge.   4-Methylphenol and bis(2-
ethylhexyl)phthalate were  identified as critical analytes for
theLT3* system SITE demonstration.  The concentrations of
3- and 4-methylphenol ranged from 3,100 to 20,000 /tg/kg in
the  untreated   sludge.    After   treatment,  3-   and
4-methylphenol concentrations  ranged from  540 to 4,000
/
-------
                 1,000
                                                              8    9    10    11    12   13    14    15
!•
MBOCA
Untreated

MBOCA Treated
Figure B-1 MBOCA Concentrations in Untreated and Treated Sludge
B.5.4 The Fate of Chloride in the LT3® System

    The  dehalogenation  scenario  discussed  above  is
supported by other demonstration results, which indicate that
treatment reduced the EOX concentration in sludge but
increased the chloride concentration.  Figure B-5 shows the
reduced concentration of EOX after  treatment.  However,
the EOX concentration in the fabric filter dust was higher
than in the  untreated sludge.  This increase suggests that
EOX associated  with small particles  are not  effectively
removed.   Instead,  they remain  attached  to  the small
particles, which are carried away in the sweep gas and are
removed in the  fabric  filter or carried  through to  the
condensers.  The  concentration  of TOX in the condensate
ranged from 25 to 73 mg/L, which was significantly higher
than the 0.3 mg/L TOX concentration in the city water.

    Figure B-6  shows that the  chloride  concentration in
sludge increased  after treatment, probably as a result of
chloride mineralization from dehalogenation reactions. The
concentration of chloride in fabric filter dust was also higher
than in the untreated sludge. The concentration of chloride
in the liquid condensate ranged from 7.5 to 92.4 mg/L.

    The formation of HC1 during dehalogenation reactions
may have caused the  reduction in the pH of treated sludge.
The pH of untreated sludge ranged from 10.9 to 11.2. The
pH of treated sludge ranged from 9.1 to 9.6.  However, the
pH of the liquid  condensate stream  was alkaline, ranging
from 10.1 to 10.2. Alkaline pH could have resulted from
lime particles being carried away in the off-gas stream before
becoming dissolved in the condensate. The concentration of
HC1 in the exhaust gas from the refrigerated condenser was
below  the  detection limit  of 0.034 milligrams per day
standard cubic meter (mg/dscm).

5.5.5 The Formation and Distribution  ofDioxins
and Furans

    Dioxins  and furans were detected in process residuals.
Samples were analyzed for polychlorinated dibenzo(p)dioxins
(CDD) and polychlorinated dibenzofurans (CDF). Analytes
included2,3,7,8-tetrachlorodibenzo(p)dioxhi(2,3,7,8-TCDD)
and the following congeners:

Dioxins

tetrachloro dibenzo(p)dioxins (TCDD)
pentachloro dibenzo(p)dioxins (PeCDD)
hexachloro dibenzo(p)dioxins (HxCDD)
heptachloro dibenzo(p)dioxins (HpCDD)
octachloro dibenzo(p)dioxins (OCDD)

Furans

tetrachloro dibenzofurans (TCDF)
pentachloro dibenzofurans (PeCDF)
hexachloro dibenzofurans (HxCDF)
                                                         37

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                  8
                          1    2    3    4    5    6    7    8    9    10    11    12    13    14    15
                                   AC-MBOCA Untreated
     AC-MBOCA Treated
Figure B-2 AC-MBOCA Concentrations in Untreated and Treated Sludge
hcptachloro dibenzofurnas (HpCDF)
octachloro dibenzofurans (OCDF)

    The formation of dioxins and furans is encouraged by
sludge treatment  conditions such as elevated temperature
(greater than 500  °F), the presence of chemical precursors,
alkaline pH, and a high concentration of free chloride (EPA,
1980).  The following  potential dioxin precursors were
present in untreated and treated sludge  samples:  1,2-
dichlorobenzene;  4-chloroaniline; o-chloroaniline; aniline;
phenol; 4,6-dinitro-2-methylphenol; 2,4-dibromophenol; 2-
chlorophenol; 4-bromophenol; and 2,4-dibromophenol.  As
stated above, alkaline pH resulted from lime being added to
the sludge.  High concentrations of free chloride resulted
from  adding ferric chloride to the sludge as a conditioning
agent before dewatering.

    CDDs and CDFs were formed when sludge was treated
in the LT3* system. OCDD was the only congener found in
one sample of untreated sludge, at a level near the detection
limit [0.63 parts per billion (ppb) versus a detection limit of
0.54  ppb].    Table  B-2  shows  the  arithmetic  mean
concentrations of  CDDs and CDFs in samples from each
location.  Mean values were calculated by assigning zero to
all results reported  as nondetectable (ND).  As  a result,
these  mean values  may underestimate  CDD and CDF
concentrations.
    Fabric  filter  dust  consistently  contained   higher
concentrations of CDD and CDF than treated sludge, and
the dust was the only solid matrix containing measurable
amounts of 2,3,7,8-TCDD. No 2,3,7,8-TCDD was detected
in liquid condensate, but five of the 10 congeners were found
at  measurable  concentrations.    TCDD  and   TCDF
predominated, with lower concentrations of PeCDD, PeCDF,
and HxCDF. As with the treated soil samples, tetra and
penta congeners were more prevalent.

    The liquid  condensate  data suggest that TCDD and
TCDF,   and possibly  PeCDD, PeCDF,  and HxCDF,
increased measurably with each successive run (see Table B-
3).  The condensers were not  cleaned between runs, and a
small amount of particulate matter may have accumulated
within the condensers.   CDDs and CDFs are strongly
adsorptive, lipophilic, and only slightly water-soluble (EPA,
1980). The increasing concentrations of congeners may be
attributed to  the  release  of  CDDs  and  CDFs  from
particulate matter within the condenser.

    Vapor-phase activated carbon reduced all CDDs and
CDFs in the off-gas to  less  than 0.1 nanograms per dry
standard cubic meter (ng/dscm).  The  removal efficiency
varied with analyte, from 20 percent for HpCDD, to 100
percent   (or  to  nondetectable levels)  for  PeCDF  and
HxCDD.
                                                        38

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                                                                      10   11   12   13   14    IS
                             3- & 4-Methylphenol Untreated
    3- & 4-Methylphenol Treated
Figure B-3 3- and 4-Methylphenol Concentrations in Untreated and Treated Sludge
B.5.6 The Fate of Metals in the LT3® System

    Untreated and treated sludge samples had similar metal
concentrations, which  was  expected because  the LT3®
technology is not designed to remove metals.  However,
metal concentrations in fabric filter dust were, in general,
greater  than the concentration in untreated and  treated
sludge.    The  results  also  showed that  TCLP  metal
concentrations were below detection limits.

B. 5.7 Stack Emissions

    During the SITE demonstration, the total nonmethane
hydrocarbon concentration (TNMHC)  in  stack gas  was
determined  by separate analyses of samples collected in
SUMMA canisters.  Analytical results showed that TNMHC
was 6.7 parts per million by volume (ppmv) during the first
run, 7.6 ppmv during the second run, and 11 ppmv during
the last run. Because a new vapor-phase activated carbon
unit was used during the SITE demonstration, the results
suggest that breakthrough occurred after a relatively short
period of time.

    Similar observations were made during routine remedial
operations at the ADC site.  As part of  the LT3® system, a
continuous emissions monitoring (CEM) system was used to
monitor the total hydrocarbon concentration (THC).  The
CEM system  occasionally recorded THCs as high as 100
ppmv. To rectify the problem, Weston replaced the vapor-
phase  carbon unit  regularly.   However, CEM  results
indicaited that THC was below 10 ppmv for only about the
first 12 hours of operation of the new vapor-phase carbon
unit. After 12 hours, THC was significantly higher.

    TNMHC includes both VOCs and SVOCs.   VOC
emissions from the stack were predominately composed of
propylene and chloromethane. SVOC  stack emissions did
not contain any  predominant contaminants, and testing
indicated that all compounds were present in concentrations
at or below instrument detection limits.

    The particulate concentration in the stack gas ranged
from less than S-SxlO"4 to 6.7xlO"3 grains per dry standard
cubic meter (gr/dsem) and the particulate emissions ranged
from less than 1.2x10* to 9.2X10"4 pounds per hour (Ib/hr).
The chloride concentration in the stack gas was below the
detection limit,  which had  an  average  value of 2.8xlO"2
mg/dscm.

    In addition,  during both the SITE demonstration and
remedial operations at the site, unusual levels of fugitive dust
emissions from the treated sludge pile area were occasionally
observed. During remedial operations, dust levels ranging
from 0.16 to 0.99 milligrams per  cubic meter (mg/m3) were
recorded downwind  of the treated  sludge pile and in the
control trailer located near the treated  sludge pile.
                                                         39

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                      12,000..
                              1    2    3    4    5    6   7    8    9    10    11   12   13   14   15
                                            Phenol Untreated     j    |  Phenol Treated
figure B-4  Phenol Concentrations in Untreated and Treated Sludge
B.5.8 Physical Properties of Sludge

    Untreated sludge  consisted of wet, nonhomogeneous
clumps  of  soil.    Processed  sludge  consisted  of  dry,
homogeneous, fine particles.  Because of the decrease in
moisture content, the processed sludge had a tendency to
generate fugitive dust.

    The following physical properties of the  sludge were
determined:  (1)   particle   size  distribution,   (2)  soil
classification,  (3)   available  surface  area,  (4)  moisture
content, (5) density, and (6) CBR. Each of these properties
is discussed below.

    Particle  Size  Distribution  - The  arithmetic  mean
diameters of untreated sludge  and fabric filter  dust were
found to be 765 microns (/tm)  and 34.12 /tm, respectively.
The size of the fabric filter dust particles is important for the
operation  of the fabric filter,  which is  part of the LT3®
system.  Also, the size of the fabric filter dust is important
to determine health risks  associated with the inhalation of
the fabric filter dust during operations.

    Soil Classification - According to the American Society
of Testing and Materials (ASTM) soil classification system,
untreated  sludge was  classified hi the A-7-6 soil group.
Typical characteristics  of material in this group  are plastic
clay soil with 75 percent or more of the particles smaller
than 75  u,m.  in  diameter,  a  minimum liquid limit of
41 percent, and a plasticity index above 11. Materials in this
group usually have a high-volume change between wet and
dry states.

    Available Surface Area - The available surface area of
the untreated sludge ranged from 49.1 to 52.3 square meters
per gram (m2/g).  These values  are comparable to the
surface area of kaolinite, a clay material that has a reported
available surface area of 25 m2/g (Stumm  and Morgan,
1981).

    Moisture  Content  -  The  moisture content  of the
untreated sludge (after  dewatering) ranged from 41 to 44
percent.  The moisture content of the treated sludge (after
conditioning) ranged from 7.5 to 23 percent.

    Density - Treated  sludge  had higher  maximum dry
densities than untreated sludge.  Although no large changes
were observed, analytical results suggest that thermal

processing changed the sludge characteristics. In other case
studies, the density of the soil  decreased  after treatment
(Weston, 1986).

    CBR - To determine the stability of the treated sludge,
CBR values were determined as  a function of dry density at
10, 25,  and 56 blows per layer of sludge sample.  The results
indicated that CBR values  increase as a function of dry
density.  Treated  sludge  lacks  moisture and  is  likely to
                                                          40

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                          150
                                                         Sample No.
                                    EOX Untreated
[""""I  EOX Treated
                                                                                  EOX Dust
Figure B-5 EOX Concentrations in Untreated and Treated Sludge and in Fabric Filter Dust
 exhibit some instability. To obtain material with significant
 bearing capacity and moderate stability, water needs to be
 added and the moistened material needs to be compacted to
 increase the material's density and stability.  The level of
 compaction required can be determined from the CBR
 value.

 B.5.9 lexicological Properties of Sludge

    Toxicity tests were conducted on untreated and treated
 sludge and sludge leachate samples.  Sludge was tested using
 the earthworm (Eisenia foetidd) as the test organism.
 Leachate was tested using the fathead minnow (Pimephales
 promelas) and the water flea (Ceriodaphnia dubia) as the
 test organisms.

    Four replicate tests of each  sludge sample  were
 conducted with 10 worms per replicate. No dilutions were
 conducted, and test results represented 100 percent test soil.
All the  worms in the untreated and treated sludge  died
within 48 hours.  Therefore, a median lethal concentration
 (LC50) could not be calculated from the data to determine
if untreated sludge was more toxic.

    The  mortality of the earth worms in untreated and
treated sludge samples was attributed to the alkaline pH of
untreated and treated sludge.  The pH of untreated sludge
ranged from 10.9 to 11.2. The pH of treated sludge ranged
from  9.1 to 9.6.  Subsequent to the SITE demonstration,
         additional toxicity tests were conducted with untreated and
         treated sludge at controlled pH and at different dilutions.
         The sludge  samples were diluted using artificial soil at 15,
         25, 40, 60, and 100 percent.  The pH was adjusted using
         acidified  artificial  soil and  HC1.  The  resulting  pH of
         untreated and treated sludge samples ranged from 7,4 to 8.7
         at all dilutions ranging from 15 to 40 percent; at 60 and 100
         percent dilutions, the pH ranged from 8.3 to 9.6.  The 7-day
         LC50 was 56.3 percent for untreated sludge and 76.3 percent
         for treated sludge.  The  14-day LC50 was 49.1 percent for
         untreated sludge  and  75.2  percent  for  treated  sludge.
         Therefore, at controlled pH, untreated sludge was more toxic
         than treated sludge.

             The results of the leachate toxicity study also suggest
         that the LT3®  technology  reduces  the  toxicity of treated
         materials. For the fathead minnows,  toxicity was reduced
         from  a LC50 of about 40 percent in the  untreated sludge
         leachate sample to no toxicity in the treated sludge leachate
         sample.   For  Ceriodaphnia dubia,  toxicity  was  also
         reduced. Only 15 percent of the test organisms exposed to
         6.25  percent  leachate solution  from  untreated  sludge
         survived.  When the test  organisms  were exposed to a
         solution of 100 percent  leachate from  treated sludge, 85
         percent survived.
                                                         41

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                   20.000.
                    16,000.
                    12,000.
                     8,000..
                     4,000..
                        Chloride Untreated
['""" j  Chloride Treated
Chloride Dust
Figure B-6 Chloride Concentrations in Untreated and Treated Sludge and in Fabric Filter Dust
References

    C.C. Johnson & Malhotra, P.C. (CCJM),  1989, Final
Feasibility Study  for  Anderson  Development  Company,
Adrian, Michigan.

    Larock,   R.,  1989,   Comprehensive   Organic
Transformations:   A   Guide   to   Functional   Group
Preparations. VCH Publishers, Inc., New York, NY.

    Merck, 1989, The Merck Index:  An Encyclopedia of
Chemicals, Drugs and Biologicals. Eleventh Edition.

    Roy F. Weston, Inc.  (Weston), 1986, Installation and
Restoration   General   Environmental   Technology
Development,  Task   11.    Pilot  Investigation  of  Low
Temperature  Thermal   Stripping  of  Volatile  Organic
Compounds from Soil, Volume 1 (June).
                  Stumm, W. and J.J. Morgan, 1991, Aquatic Chemistry.
              Second Edition, John Wiley & Sons, Inc., New York, NY.

                  U.S. Environmental Protection Agency  (EPA), 1980,
              Dioxins. Prepared by M. P. Esposito, T. O. Tiernon, and
              F.E.   Dryden,  EPA/600/2-80-197,   Cincinnati,   Ohio
              (November).

                  EPA, 1991.  Preparation Aids for the Development of
              Category II Quality Assurance Project Plans, Risk Reduction
              Engineering  Laboratory,   Cincinnati,    Ohio,
              EPA/600/8-9/1004 (February).

                  EPA, 1990. Methods Manual for Compliance with BIF
              Regulations.    Office  of  Solid  Waste, Publication No.
              EPA/530-SN-91-010.

                  Versar,  1983.    Exposure   Assessment  for  4,4'-
              methylenebis (2-chloroaniline) (MBOCA). Final Report.
                                                        42

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Table B-2 Arithmetic Mean Concentrations of CDDs and CDFs
                                                                     Sampling Location
Parameter
2,3,7,8-TCDD
TCDD
TCDF
PeCDD f
PeCDF
HxCDD
HxCDF
HpCDD
HpCDF
OCDD
OCDF
Untreated
Sludge
ng/kg
(PPb)
0
0
0
0
0
0
0
0
0
0.21
0
Treated
Sludge
ng/kg
(PPV
0
0.987
2.42
0.534
0.066
0
0
0
0
0
0
Filter Dust Liquid Exhaust Gas from
Condensate Refrigerated
Condenser
ng/kg ng/L
(ppt>) (ppt) ng/dscm
0.10
6.54
19.80
5.98
2.49
0.81
0.50
1.38
0.14
3.20
0.04
0
119.0
697.0.
60.0
47.7
0
2.8
0
0
0
0
0.010
0.137
"''"''. 0.178
0.20
0.14
0.0020
0.0004
0.023
0.005
0.121
0.0067
Stack Gas
ng/dscm
0.0010
0.0087
0.066
0.0089
0
0
0.0003
0.017
0.0012
0.025
0.0024
        All CDDs and CDFs not detected are assigned a value ofO.

        Detection limits in untreated sludge ranged from 0.04 to 0.80 nanograms per gram (ng/g). Detection limits in treated sludge
        ranged from 0.07 to 1.6 ng/g.  Detection limits in fabric filter dust ranged from 0.14 to 9.6 ng/g. Detection limits in the liquid
        condensate ranged from  1.4 to 17 ng/L.

        ng = nanogram

        ppt = parts per trillion
                                                                43

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Table B-3 Liquid Condensate Concentrations (ppt) Averaged by Run '
                                 Parameter1'
Run 1
                Run 2
                                 Run 3
TCDD
TCDF
PeCDD
PeCDF
HxCDF
11
0.92
0
0
0
67
490
0
23
0
280
1600
180
120
8.4
                            a = CDDs and CDFs not detected were assigned a value of zero.

                            b = HxCDD, HpCDD, HpCDF, OCDD, and OCDF were not detected in liquid
                            condensate samples.
                                                              44

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                                                   Appendix C
                                                   Case Studies
     This appendix summarizes case studies on the use of the
 Low Temperature Thermal Treatment (LT3®) system. These
 case studies were written and provided by Roy F. Weston,
 Inc. (Weston). During the development of the LT3® system,
 Weston conducted tests at the bench-  and  pilot-scale and
 collected  treatability data for the following contaminants:
 coal tar, drill cuttings (oil-based mud), leaded and unleaded
 gasoline,  No. 2  diesel  fuel,  JP4 jet  fuel,   petroleum
 hydrocarbons,  halogenated  and  nonhalogenated solvents,
 volatile organic compounds  (VOC), semivolatile organic
 compounds (SVOC), and polynuclear aromatic hydrocarbons
.(PAH).  Weston also completed a  full-scale remediation
 using the LT3® system.  The information available for these
 case studies ranged from detailed analytical data to relatively
 little information on system performance and cost. Results
 from the following five case studies are  summarized in this
 appendix:

 Case Study      Site and Location
   C-l
   C-2
                Confidential Site, Springfield, Illinois
                Tinker Air Force Base, Oklahoma  City,
                Oklahoma
   C-3          Letterkenny Army Depot, Chambersburg,
                Pennsylvania
   C-4          Environmental   Technology  Laboratory,
                Lionville, Pennsylvania
   C-5          Bench-Scale LT3® Test, Colorado Springs,
                Colorado

Case Study C-l

Project:    LT3® for Petroleum Contaminated Soil

Client:     Confidential

Site:       Confidential, Springfield, Illinois

Project Description

    While renovating  an existing  building, several leaking
underground storage tanks, previously holding No. 2 fuel oil
and gasoline, were  discovered.  Weston was awarded the
contract to process the contaminated soil in the LT3® system.
Approximately 1,000 cubic yards of material were excavated
and processed. The objective was to render the soil suitable
for on-site backfill and eliminate the need for transportation
and off-site disposal in a special waste landfill.

    Initial concentrations  of contaminants were less than
1,000 parts per million (ppm).  Stringent cleanup objectives
were established by the Illinois EPA for benzene, toluene,
ethylbenzene, xylene, and naphthalene. In addition, clean-up
objectives for  15 separate PAHs were established at below
the detection limit of 330 parts per billion (ppb).

    The Illinois EPA also established stringent air emission
limitations that included the following:

    •   Carbon monoxide (CO) less than 100 ppm

    •   Total hydrocarbons less than 100 ppm

    •   No visible dust emissions

    •   Development of detailed test and safety plans

    •   Environmental  permitting including air, operating,
        and  landfill  permits  for  residual  material  not
        suitable  for  processing (concrete,  scrap metal,
       oversize rock)

    •   Excavation and tank removal

    •   Mobilization  of the LT3® system

    •   Operating  of the  LT3® system including process
       sampling

    •   Clean soil storage in covered stockpile

   •   Analysis of soil to confirm that it is clean

   •   Site closure
                                                        45

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Results

    One thousand cubic yards of contaminated soil were
successfully processed, and all cleanup objectives were met.
Table C-l summarizes analytical results. Processed soil was
approved by the  Illinois EPA for on-site backfill.  Stack
emissions were in compliance with all state and federal
regulations.  Fugitive emissions of dust and organic vapors
were well controlled, with no complaints  from residents
located as close as 100 yards away from the LT3® system.

Case Study C-2

Project:   LT3® Processing of Soils  Contaminated with
            Chlorinated Solvents and JP4 Jet Fuel

Client:    U.S. Army Toxic  and Hazardous  Materials
            Agency (USATHAMA)

Site:       Tinker  Air  Force  Base,  Oklahoma  City,
            Oklahoma

Project Description

     In a continuing effort to identify and evaluate new and
 innovative technologies for remediation of Department of
 Defense (DOD) sites, USATHAMA wanted to perform a
 full-scale demonstration of the LT3®  system.   The LT3®
 system had already been proven effective in the pilot-scale
 during a field demonstration at Letterkenny Army Depot.
 The objective of the test would be to determine optimum
 operating conditions and maximum feed rates for feed soil
 contaminated with a wide variety of compounds, including
 chlorinated solvents, semivolatile organics, and JP4 aviation
 fuel  (all common  contaminants at  DOD  installations).
 Following a comprehensive search of remedial investigation
 reports, Tinker Air Force Base (Tinker AFB) was selected
 as the site for the full-scale demonstration.  Tinker AFB was
 selected because of the wide variety of contaminants present
 and the plastic clay soil matrix which provided a "worst case"
 test regarding material handling and contaminant removal.

     Weston  was  awarded  the  task of performing  the
  demonstration project at Tinker AFB. Weston excavated the
  existing clay and asphalt cap from  the previously closed
  landfill.  A total of approximately 3,000 cubic yards of
  contaminated soil was excavated for  treatment during the
  demonstration program.  Concentrations of trichloroethene
  (TCE) in the contaminated soil were as high as 6,100 ppm.
  Other significant contaminants included chlorinated organics
  (for  example, dichlorobenzene) and JP4 aviation fuel.

  Weston  Scope of Work

       •  Preparation  of  all advance plans, including the
          following:
              Detailed Test Plan
              Sampling and Analysis Plan
              All environmental permitting including a
              RCRA RD&D Permit from U.S.  EPA,
              Region 6
              Health and Safety Plan

   •  Site preparation and waste excavation

   •  Mobilization and operation of the LT3® system

   •  Analysis  of soil samples in on-site laboratory

   •  LT3® system demobilization, decontamination, and
       site closure

Results

    •  The LT3® system reduced the concentrations of all
       target contaminants below the goal cleanup levels
       and in most cases  to less than detection limits.

    •  The above excellent performance was accomplished
       while operating at  processing rates as high as 20,000
        Ib/hr, which was 33 percent higher than the design
        feed rate.

    •   As a result  of this program, estimated  costs for
        LT3® treatment have been significantly reduced due
        to the ability to successfully operate at significantly
        increased soil feed rates.

 Case Study C-3

 Project:   LT3® for VOC-Contaminated Soil

 Client:     USATHAMA

 Site:       Letterkenny  Army  Depot,   Chambersburg,
            Pennsylvania

 Project Description

     Contamination of soils  from past operations involving
 VOCs has become  one of the preeminent environmental
 concerns at several U.S.  Army installations.   TCE is the
 most  frequently found contaminant; however, other VOCs
 such as  dichloroethene, tetrachloroethene, and xylene have
 also been found.  If allowed to remain in the  soil, these
 contaminants can migrate to underlying ground water.

     USATHAMA  contracted with Weston to develop an
 innovative solution to this problem. The contract called for
 the demonstration of a new technology on a pilot scale at a
 site contaminated with VOCs.
                                                           46

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Table C-1 Results of Full-Scale Cleanup of No. 2 Fuel Oil and Gasoline-Contaminatad Soil*" b
Contaminant
Benzene
Toluene
Xylenes
Ethyibenzene
Napthalene
Carcinogenic Priority
PAHs
Benzo(a)-
anthracene
Benzo(a)pyrene
Benzo(b)-
fluoranthene
Chrysene
Dibenzo(a,h)-
anthracene
Noncarcinogenic
Priority PAHs
Acenaphthene
Acenaphthalene
Anthracene
Benzo(g,h,i)-
perylene
Benzo(k)-
fluoranthene
Fluoranthene
Fluorene
ldeno(1,2,3-c,d)-
pyrene
Phenanthrene
Pyrene
Boiling
Point
(°F)
176
231
291
277
,.424
850
923
896
875
975
534
518
644
995
896
707
560
950
644
759
Feed Soil
Concentration
fob)
1,000
24,000
110,000
20,000
4,900
<6,000
< 6,000
< 6,000
<6,000
<6,000
890
1,200
2,700
<6,000
<6,000
< 6,000
4,900
< 6,000
2,400
<6,000
Processed Soil
Concentration
(Ppt>)
5.2
5.2
<1.0
4.8
<330
<330
<330
<330
590
<330
<330
<330
<330
<330
450
<330
<330
<330
430
<330
Contaminant
Removal
Efficiency
(%)
99.48
99.98
> 99.999
99.98
>93.3
<94.5
<94.5
<94.5
00.2
<94.5
<62.9
<72.5
>87.8
<94.5
<92.5
<94.5
>93.3
<94.5
82.1
<94.5
Concentration In
TCLP Leachate
(ppb)
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
16J
4J
N/D
N/D
N/D
U
0.1 3J
3J
N/D
N/D
N/D
N/D
N/D
3J
N/D
a = Processed soil temperature was 350 °F.
b = Processed soil residence time was 70 minutes.
J = Present at less than detection limit.
N/D = Not detected; detection limit = 20 ppb.
                                                              47

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    USATHAMA selected a site at the Letterkenny Army
Depot in Chambersburg, Pennsylvania. Weston responded
with the first LT3®  system, much as it exists today.   The
system incorporated a thermal process 10 feet in length.
Previous experience was limited to laboratory work with a
unit only 3 feet hi length.

Weston Scope of Work

    •   Design of the pilot system

    •   Preparation of test and safety plans

    •   Environmental permitting

    •   Equipment selection

    •   Installation, start-up, and test operation

    •   Demobilization and site closure

    •   Identification of full-scale design criteria

    •   Preparation  of  a  technical  report  including
        economics and auxiliary pollution control equipment
        specifications

Results

    More than 15,000 pounds  of contaminated soils  were
processed in 28 operating days. Table C-2 summarizes the
analytical results.  A  removal efficiency of more  than
99.99 percent was demonstrated in the soil, and no VOCs
were detected hi the  stack of the afterburner, indicating a
destruction and removal efficiency (DRE) of 100 percent for
the system.

    Stack emissions were in compliance with all federal and
state regulations including VOCs, HC1, CO, and particulates.

    Regulatory authorities allowed the disposal of processed
soil on site as backfill.

Case Study C-4

Project:   LT3® Laboratory Testing of Contaminated Soil

Client:    Various Industrial and Federal Clients

Site:       Environmental  Technology  Laboratory  in
            Lionville, Pennsylvania

Project Description

    Initially to prove the concept  and now as a tool for
 determining feasibility and predicting LT3® performance,
Weston has established a laboratory complete with a thermal
processor, sample storage  and preparation facilities,  and
analytical capabilities. Clients with environmental problems
that might be addressed with the LT3® system can send a
sample of the material  to be processed to the laboratory
where testing will determine the feasibility and predict the
performance of the full-scale system.

    Testing prior to mobilization of the full-scale system will
avoid the  problems  of trying to apply  the  system to
compounds and soils for which it is not suited. Process rates
can  be   determined  and  approximations  of cleanup
capabilities  can  be made.  Weston has  tested a broad
spectrum of  materials,  but  each contaminant behaves
differently in association with other compounds and  with
differing soil types making testing of prime importance.

Weston Scope of Work

    •  Sample  collection (if required)

    •  Sample  preparation

    •  Initial feed soil analysis

    •  Preparation of a test and safety plan

    •  Test operation

    •  Data collection and analysis

    •  Return  of sample material to client

    •  Final report including  predictions of process  rates
        and cleanup capabilities

Results

    A wide range of contaminants hi varying types of soils
and  other  host matrices  have  been  successfully tested,
including  VOCs,  petroleum  hydrocarbons,   coal  tars,
chlorinated solvents, a  wide  range of carcinogenic and
noncarcinogenic PAHs, and many SVOCs, such as xylene
and hexachlorobenzene. In addition Weston has:

    •   Proven concept feasibility for specific applications

    •   Developed standard testing and safety plans

    •   Established the capability to predict process  rates
         and levels of contaminant reduction

    Weston has performance  parameters  for the generic
waste streams and specific compounds shown hi Tables C-3,
 C-4 and C-5.
                                                          48

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Table C-2 Results of Pilot-Scale Demonstration on VOC-Contaminated Soil* b

Contaminant
Benzene
Trichloroethene
Tetrachloroethene
Xylene
Other VOCs
Total VOCs
Boiling
Point
(°F)
141
189
250
293
N/A
N/A
Feed Soil
Concentration
(PPb)
586,106
2,678,536
1,422,031
27,197,367
39,127
31,923,167
Processed Soil
Concentration
(PPb)
730
1,800
1,400
550
BDL
4,480
Contaminant
Removal
Efficiency
(%)
99.88
99.93
99.90
99.998
N/A
99.99
Concentration in
TCLP Leachate
(PPb)
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
     ' = Processed soil temperature was 320 °F.

     * = Processed soil residence time was 60 minutes.

     N/A = Not Applicable.

     BDL = Below detection limit.
 Case Study C-5

 Project:    Bench-Scale LT3® Test for Chlorinated Benzene
            Contaminated Soil

 Client:     Confidential

 Location:  Colorado Springs, Colorado

    Bench-scale studies were conducted at Colorado Springs,
 Colorado, on soil contaminated with chlorinated benzene.
 The soil was treated at 400 °F for a residence time of 44
 minutes. The total concentration of contaminants was 530
mg/kg.      Of   that   amount,   523   mg/kg  was
 1,4-dichlorobenzene,   and the  rest   consisted of other
contaminants.  Table C-6 summarizes the results.  Removal
efficiencies greater than 99.9 percent were achieved.
                                                        49

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Table C-3 Results of Engineering Technology Laboratory6' b

Methylena Chloride
Acetone
n-Butanol
1,2-Dlchloroethane
1,2-D!chloropropane
Isopropanol
Methanol
Cyctohexane
Boiling
Point
(°F)
104
134
243
183
356
180
148
176
Feed Soil
Concentration
(PPb)
120,000
12,000
32,000
120
4,000
7,900
30,000
230
Processed Soil
Concentration
(PPb)
22
93
340
<5
<5
<100
<6,000
<10
Contaminant
Removal
Efficiency
(%)
99.98
99.2
98.9
>95.8
>99.9
>98.7
>80.0
>95.7
Concentration in
TCLP Leachate
(PPb)
<14
<473
< 1,200
<5
<5
< 1,700
<230
<10
     * « Processed soil temperature was 250 °F.
     b = Processed soil residence time was 45 minutes.
                                                                   50

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Table C-4 Results of Bench-Scale LT3® Test on Coal Tar-Contaminated Soil* b

Contaminant
Benzene
Toluene
Ethylbenzene
Methyl Chloride
Napthalene
Carcinogenic Priority
PAHs
Benzofa)-
anthracene
Benzo(a)pyrene
Benzo(b)-
fluoranthene
Chrysene
Dibenzo(a,h)-
anthracene
Noncarcinogenic
Priority PAHs
Acenaphthene
Acenaphthalene
Anthracene
Benzo(g,h,i)-
perylene
Benzofk)-
fluoranthene
Fluoranthene
Fluorene
ldeno(1,2,3-c,d)-
pyrene
Phenanthrene
Pyrene
Boiling
Point
(°F)
176
231
277
106
424


850
923
896
875
975


534
518
644
995
896
707
560
950
644
759
Feed Soil
Concentration
(PPb)
<150
<150
78,000
14,000
1,200,000


100,000
82,000
45,000
96,000
9,600


28,000
28,000
160,000
38,000
46,000
192,000
222,000
31,000
580,000
275,000
Processed Soil
Concentration
(PPb)
<5.0
<5.0
<5.0
<5.0
1,200


2,100
1,600
1,700
4,400
<660


<660
<660
<660
790
1,800
6,500
<660
670
14,000
3,100
Contaminant
Removal
Efficiency
(%)
>96.7
>96.7
> 99.994
> 99.96
99.9


97.9
98.0
96.2
95.4
>93.1


>97.6
>97.6
>99.6
97.9
96.1
96.6
>99.7
97.8
97.6
98.9
. Concentration in
TCLP Leachate
	 (ppb) 	
N/D
N/D
N/D
N/D
N/D


N/D
N/D
N/D
N/D
N/D


N/D
N/D
N/D
N/D
N/D
N/D
N/D
N/D
N/D
N/D
a = Processed soil temperature was 400 °F.
  = Processed soil residence time was 50 minutes.
N/D = Not detected; detection limit = 150 ppb.
                                                             51

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Tibia C-S Results of Bench-Scale IT*® Testing on Petroleum Hydrocarbon-Contaminted
Boiling Feed Soil Processed Soil
Point Concentration Concentration
Contaminant (°F) ' 	
Oil and Grease
(BylR)
Napthalene
Carcinogenic Priority
PAHs
Benzofa>
anthracene
Bonzo(a)pyrene
Benzo(b)-
fluoranthene
Chrysene
D!benzo(a,h)-
anthracene
Noncarclnogenic
Priority PAHs
Acenaphthene
Acenaphthalene
Anthracene
Benzo(g,h,i)-
perylene
Benzoft)-
iluoranthene
Fluoranthene
Fluorene
ldeno(1,2,3-c,d)-
pyrane
Phenanthrene
Pyrene
Volatile Organic
Compounds
1, 1, 1-Trichloroethane
Other Parameters
Moisture
N/A

424


850

923
896

875
975



534
518
644
995

896

707
560
950

644
759


165

212
100,000 ppm

23,000 ppb


66,000 ppb

110,000 ppb
90,000 ppb

80,000 ppb
19,000 ppb



28,000 ppb
20,000 ppb
49,000 ppb
19,000 ppb

59,000 ppb

57,000 ppb
55,000 ppb
65,000 ppb

52,000 ppb
50,000 ppb


2,600 ppb

21.80%
170 ppm

< 330 ppb


<330 ppb

< 330 ppb
<330ppb

< 330 ppb
< 330 ppb



< 330 ppb
< 330 ppb
< 330 ppb
< 330 ppb

< 330 ppb

< 330 ppb
390 ppb
< 330 ppb

20 ppb J
< 330 ppb


<250 ppb

0.01%
Soil* b
Contaminant Concentration in
Removal Eff. TCLP Leachate
(%) (ppb)
99.82

> 98.57


> 99.50

> 99.70
> 99.63

> 99.59
> 98.26



> 98.82
> 98.35
> 99.32
> 98.26

> 99.44

> 99.42
99.29
> 99.49

99.96
> 99.34


> 90.38

99.95
N/A

1J


N/D

N/D
N/D

N/D
N/D



N/D
2J
1J
N/D

N/D

N/D
7J
N/D

N/D
N/D


N/D

N/A
* = Processed soil temperature was 450 °F.
b = Processed soil residence time was 30 minutes.
N/A ~ Not Applicable
J = Present at less than detection limit.
N/D - Not detected; detection limit = 20 ppb.
                                                              52

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Table C-6 Results of Bench-Scale LT3® Testing on Chlorinated Benzene-Contaminated Soil *• b
Contaminant
Benzene
Monochlorobenzene
1,3-Dichlorobenzene
1,4-Dichlorobenzene
1,2-Dichlorobenzene
1,2,4-
Trichlorobenzene
1,2,3-
Trichlorobenzene
1,2,4,5-
Tetrachlorobenzene
1,2,3,4-
Tetrachlorobenzene
Totals
Boiling
Point
176
270
343
345
357
416
424
475
489
N/A
Feed Soil Processed Soil Contaminant
Concentration Concentration Removal
Efficiency
(PPb) (PPb) (%)
106
318
1,219
524,859
1,431
477
636
530
424
530,000
0.01
0.03
0.35
6.25
0.85
0.22
0.06
0.03
0.05
7.85
99.991
99.991
99.97
99.999
99.94
99.95
99.99
99.994
99.99
99.999
Concentration in
TCLP Leachate
(PPb)
N/D
N/D
N/D
0.0064
0.0048
0.0011
N/D
N/D
N/D
N/A
 a = Processed soil temperature was 400 °F.
 b = Processed soil residence time was 44 minutes.
 N/D = Not detected
 N/A = Not Applicable
*U.S. GOVERNMENT PRINTING OFFICE: 1993-753-169
53

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