United States
           Environmental Protection
           Agency
Office of Emergency and
Remedial Response
Washington, D.C. 20460
EPA/540/2-91/020A
September 1991
                    for Conducting
           Treatability Studies
            Under CERCLA:
            Soil Washing

            Interim Guidance
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                                                              EPA/540/2-91/020A
                                                                September 1991
                        GUIDE TO CONDUCTING
             TREATABILITY STUDIES UNDER CERCLA:
                              SOIL WASHING
                        INTERIM  GUIDANCE
                            Risk Reduction Engineering Laboratory
                             Office of Research and Development
                            U.S. Environmental Protection Agency
                                  Cincinnati, OH 45268

                                       and

                           Office of Emergency and Remedial Response
                          Office of Solid Waste and Emergency Response
                            U.S. Environmental Protection Agency
                                 Washington, D.C. 20460
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                                           DISCLAIMER
                         This material has been funded wholly or in part by the United States
                         Environmental Protection Agency (EPA) under contract No. 68-C8-0061.
                         Work Assignment No. 2-06, to Science Applications International Corpo-
                         ration (SAIC). It has been subj ect to the Agency' s peer and administrative
                         reviews and it has been approved for publication as an EPA document.
                         Mention of trade names or commercial products does not constitute
                         endorsement or recommendation for use.
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                                                FOREWORD
                            Today's rapidly developing and changing technologies and industrial
                            products  and practices  frequently carry with  them  the  increased
                            generation of materials that, if improperly dealt with, can threaten both
                            public health and the environment. The U.S. Environmental Protection
                            Agency (EPA) is charged by Congress with protecting the Nation's land,
                            air, and water resources. Under a mandate of national environmental laws,
                            the Agency strives to formulate and implement actions leading to a
                            compatible balance between human activities and the ability of natural
                            systems to support and nurture life. These laws direct the EPA to perform
                            research to define our environmental problems, measure the impacts, and
                            search for solutions.

                            The Risk Reduction Engineering Laboratory (RREL), is responsible for
                            planning, implementing, and managing research,  development,  and
                            demonstration  programs  to provide   an authoritative,   defensible
                            engineering basis in support of the policies, programs, and regulations of
                            the EPA  with respect to drinking water, wastewater, pesticides, toxic
                            substances, solid and hazardous wastes, and Superfund-related activities.
                            This publication is one of the products  of that research and provides a
                            vital communication link between the researcher and the user community.

                            This  document  provides guidance for planning, implementing,  and
                            evaluating soil washing treatability tests to support the remedy evaluation
                            process for Comprehensive Environmental Response, Compensation, and
                            Liability Act  (CERCLA)  sites. Additionally, it describes a three-tiered
                            approach, which consists of 1) remedy screening, 2) remedy selection, and
                            3) remedy design, to soil washing treatability testing. It also presents a
                            guide for conducting treatability studies in a systematic and stepwise
                            fashion to determine the effectiveness of soil washing in remediating a
                            CERCLA site. The intended audience for this guide comprises Remedial
                            Project Managers (RPMs), On-Scene Coordinators (OSCs), Potentially
                            Responsible Parties (PRPs), consultants, contractors, and technology
                            vendors.
                                                                  E. Timothy Oppelt, Director
                                                        Risk Reduction Engineering Laboratory
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                                                ABSTRACT
                           Systematically conducted, well-documented treatability  studies are an
                           important component  of the remedial investigation/feasibility study
                           (RI/FS) process and the remedial design/remedial action (RD/RA) process
                           under the Comprehensive Environmental Response, Compensation, and
                           Liability Act (CERCL A). These studies provide valuable site-specific data
                           necessary to aid in the selection and implementation of the remedy. This
                           manual focuses on soil washing treatability studies conducted in support
                           of remedy selection prior to developing the Record of Decision (ROD).

                           This manual presents guidance for designing and implementing a soil
                           washing treatability study. The manual gives an overview of general
                           information for determining whether soil washing technology may be
                           effective, guidance on designing and conducting soil washing treatability
                           studies for remedy selection, assistance in interpreting data obtained from
                           remedy selection treatability studies, and guidance for estimating costs
                           associated with remedy design and full-scale soil washing remedial action.

                           The manual is not intended to serve as a substitute for communication
                           with experts or regulators nor as the sole basis for the selection of soil
                           washing as a  particular remediation technology. Soil washing must be
                           used in conjunction with other treatment technologies since it generates
                           residuals. This manual is designed to  be used in conjunction with the
                           Guide for Conducting Treatability  Studies  Under CERCLA (Interim
                           Final).'' ^ The intended audience for this guide comprises Remedial Proj ect
                           Managers  (RPMs),  On-Scene  Coordinators  (OSCs),  Potentially
                           Responsible Parties (PRPs). consultants, contractors, and technology
                           vendors.
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                                    TABLE  OF  CONTENTS
       Section                                                                                       Page
               DISCLAIMER 	ii
               FOREWORD 	in
               ABSTRACT	iv
               FIGURES	vi
               TABLES 	 vii
               ACKNOWLEDGMENTS	vm

        1.      Introduction	1
               1.1      Background  	1
               1.2      Purpose and  Scope	1
               1.3      Intended Audience	2
               1.4      Use of This Guide	2

        2.      Technology Description and Preliminary Screening	3
               2.1      Technology Description 	3
               2.2      Preliminary Screening and Technology Limitations  	5

        3.      The Use of Treatability Studies in Remedy Evaluation	9
               3.1      Process of Treatability Testing in Evaluating a Remedy 	9
               3.2      Application of Treatability Tests 	11

        4.      Treatability Study Work Plan  	15
               4.1      Test Goals	15
               4.2      Experimental Design	18
               4.3      Equipment and Materials 	20
               4.4      Sampling and Analysis	21
               4.5      Data Analysis and Interpretation	22
               4.6      Reports  	24
               4.7      Schedule	25
               4.8      Management and Staffing	26
               4.9      Budget	26

        5.      Sampling and Analysis Plan 	29
               5.1      Field Sampling Plan	29
               5.2      Quality Assurance Project Plan  	30

        6.      Treatability Data Interpretation	33
               6.1      Technology Evaluation  	33
               6.2      Estimation of Costs	34

        7.      References 	37
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                                                 FIGURES
        Figure                                                                                         Page
        2-1.    Schematic Diagram of the Major Elements of the Aqueous Soil Washing Process	3
        3-1.    Flow Diagram of the Tiered Approach	10
        3-2.    The Role of Treatabihty Studies in the RI/FS and RD/RA Process	11
        4-1.    Soil Washing Applicable Particle Size Range	23
        4-2.    Hypothetical Contaminant Distribution by Soil Fraction Before and After Treatment 	23
        4-3.    Plot of Agitated Contact Time Versus Contaminant Removal Efficiency and Final
              Contaminant Concentration in the >2 mm Soil Fraction 	24
        4.4.    Example Project Schedule for a Treatability Study	25
        4-5.    Organization Chart  	26
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                                                 TABLES
        Table                                                                                         Page
        2-1.    Physical Prescreening Soil Characterization Tests  	7
        4-1.    Suggested Organization of Soil Washing Treatability Study Work Plan	15
        4-2.    Major Cost Elements Associated with Remedy Selection Soil Washing Studies	26
        5-1.    Suggested Organization of Sampling and Analysis Plan  	30
        6-1.    Potential Major Cost Estimate Components in a Remedy Design Soil Washing Field Test	35
        6-2.    Major Cost Estimate Components in a Full-Scale Soil Washing Operation	36
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                                    ACKNOWLEDGMENTS
                          This  document was prepared for the U.S. Environmental Protection
                          Agency,  Office  of  Research  and Development.  Risk  Reduction
                          EngineeringLaboratory (RREL), Cincinnati Ohio, by Science Applications
                          International Corporation (SAIC), with the support of its subcontractors,
                          Bruck, Hartman & Esposito, Inc.. and Chapman. Inc.. under Contract No.
                          68-C8-0061. Mr. Mike Borst and Ms. Malvrna Wilkens served as the EPA
                          Technical Project Monitors. Dr. Thomas Fogg and Mr. Jim Rawe were
                          SAIC's Work Assignment Managers. The project team included Kathleen
                          Hurley, Curtis Schmidt, Cynthia Eghbalnia, and Yueh Chuang of SAIC; Pat
                          Esposito  of Bruck, Hartman & Esposito, Inc.; and James Nash of
                          Chapman, Inc. Dr. Robert Shokes and Mr.  Clyde Dial served as SAIC's
                          Senior Reviewers, and Robert Coleman served as Technical Editor.
                          The following Agency and Contractor personnel have contributed their
                          time and comments by participating in the protocol workshop and/or peer
                          reviewing the draft document:
                                   Michael Amdurer
                                   Robin Anderson
                                   Ben Blaney
                                   Clyde Dial
                                   Chi-Yuan Fan
                                   Howard Feiler
                                   Frank Freestone
                                   Paul Leonard
                                   Jim Orban
                                   Caroline Roe
                                   Ronald Taylor
                                   Richard Traver
                                   Thomas Wagner
                                   Darlene Williams
                                   Andre Zownir
  Ebasco
  EPA, OERR
  EPA, RREL
  SAIC, Cincinnati
  EPA, RREL
  SAIC, Paramus
  EPA, RREL
  EPA, Region III
  EPA, Region IV
  EPA, OERR
  USD A, Soil Conservation Service
  EPA, RREL
  SAIC, Cincinnati
  EPA, RREL
  EPA. OSWER
                          The document was also reviewed by the  Office of Waste Programs
                          Enforcement and the Technology-' Innovation Office. We sincerely hope
                          we have not overlooked anyone who participated in the development of
                          this guide.
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                                             SECTION  1
                                         INTRODUCTION
1.1     BACKGROUND

Section 121  (b)  of the  Comprehensive  Environmental
Response, Compensation,  and Liability Act  (CERCLA)
mandates the Environmental Protection Agency (EPA) to
select  remedies that  "utilize permanent  solutions  and
alternative treatment technologies or resource recovery
technologies to the  maximum extent practicable'' and to
prefer remedial actions in which treatment that "permanently
and significantly reduces the volume, toxicity, or mobility of
the hazardous substances, pollutants, and contaminants is a
principal element."  Treatability studies provide data to
support treatment  technology  selection   and  remedy
implementation. If treatability studies are used, they should
be performed  as  soon as  it is evident that  insufficient
information is  available to support the  remedial decision.
Conducting  treatability  studies  early  in  the  remedial
investigation/feasibility  study  (RI/FS)  process  reduces
uncertainties associated with  selecting the remedy  and
provides a sound basis for the Record of Decision (ROD).
EPA  Regional planning should  factor in the  time  and
resources required for these studies.

Treatability studies  conducted during  the  RI/FS  phase
indicate whether the technology can meet the cleanup goals
for the site.  Treatability  studies   conducted  during  the
remedial design/remedial action (RD/RA) phase  establish
design   and  operating  parameters for optimization  of
technology performance. Although the purpose and scope of
these  studies differ, they complement  one  another since
information obtained in support of remedy selection may also
be used to support the remedy design.(24)

This document refers to three levels or tiers  of treatability
studies: remedy screening,  remedy selection, and remedy
design. Three tiers of treatability studies  are also defined in
the Guide  for Conducting  Treatability  Studies  Under
CERCLA, Interim  FinaF5), referred  to as  the ''generic
guide" hereafter in this document. The generic guide refers
to the three treatability study tiers, based largely on the scale
of test  equipment,  as  laboratory  screening, bench-scale
testing,  and   pilot-scale   testing.   Laboratory
screening is typically used  to  screen potential remedial
technologies  and  is  equivalent  to  remedy  screening.
Bench-scale testing is typically used for remedy selection,
but may  not  provide enough information for remedy
selection. Bench-scale studies can, in some cases, provide
enough information for full-scale design. Pilot-scale studies
are normally used for remedial design, but may be required
for remedy selection in some cases. Because of the overlap
between these  tiers, and  because of differences in the
application  of  each  tier to  different technologies,  the
functional description of treatability study tiers (i.e., remedy
screening, remedy  selection,  and remedy design) has been
chosen for this document.

Some or all of the levels may be needed on a case-by-case
basis. The need for  and the level of treatability testing
required are management decisions.  The time and cost
necessary to perform the testing are balanced against the
improved confidence  in  the  selection  of treatment
alternatives. These decisions are based on the quantity and
perceived quality of data available and on other factors (e.g.,
State and community acceptance of the remedy or new site
data on experience with the technology). Section 3 discusses
using treatability studies in remedy selection in greater detail.
1.2    PURPOSE AND SCOPE

This guide helps ensure a reliable and consistent approach in
evaluating  soil  washing  as  a  consideration  for  site
remediation. This guide discusses the remedy screening and
remedy selection levels  of treatability  testing. Remedy
screening studies provide a quick and relatively inexpensive
indication  of whether soil  washing is a potentially viable
remedial technology. The remedy selection treatability test
provides data to help determine if reductions in contaminant
volumes will  allow  cost-effective treatment of residual
contamination  to meet  cleanup goals. Remedy selection
studies also provide preliminary estimates of the cost and
performance  data necessary  to design  either  a remedy
design study or a full-scale soil washing system.
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In general, remedy design studies will also be required to
determine if soil washing is a viable treatment alternative for
a site. Remedy design studies are conducted after the ROD
and are typically vendor-specific. Therefore, remedy design
is not discussed in this guidance document.
1.3   INTENDED AUDIENCE

This  document is intended for the use of Remedial Project
Managers  (RPMs),  On-Scene  Coordinators   (OSCs),
Potentially   Responsible  Parties   (PRPs),  consultants,
contractors, and technology vendors. Each has different roles
in conducting treatability studies under CERCLA.  Specific
responsibilities for each can be found in the generic guide.(15)
1.4  USE OF THIS GUIDE

This guide is organized into seven sections, which reflect the
basic  information required  to  perform treatability  studies
during the RI/FS process. Section 1 is an introduction which
provides background information on the role of the guide and
outlines its intended audience. Section 2 describes different
soil washing processes currently available and discusses how-
to conduct a remedy screening to determine if soil washing
is  a potentially viable remediation  technology. Section 3
provides an overview of the levels of treatability testing and
discusses how to determine  the need for treatability studies.
Section 4 provides an overview of the remedy screening and
remedy selection treatability studies,  describes the contents
of a typical work plan,  and discusses the major issues to
consider when conducting a treatability  study.  Section 5
discusses sampling and analysis and quality assurance project
plans. Section 6 explains how to interpret the data produced
from treatability studies and how to determine  if further
remedy design  testing  is  justified.  Section 7  lists  the
references.

This guide,  along with  guides being developed  for other
technologies, is a companion document to the generic guide.
In an effort to limit redundancy, supporting information in the
generic guide and other readily available guidance documents
is not repeated in this document.

The document is not intended to serve as a  substitute for
communication with regulators and/or experts  in the field of
soil washing. This document should never be  the sole basis
for  selecting soil washing as a remediation technology  or
excluding soil washing from consideration.

As  treatability study experience is gained, EPA anticipates
further comment and possible revisions to the document. For
1his reason, EPA encourages constructive comments from
outside sources. Direct written comments to:

        U.S. Environmental Protection Agency
        Releases Control Branch (MS 104)
        Risk Reduction Engineering Laboratory
        2890 Woodbridge Ave.
        Bldg. 10, 2nd Floor
        Edison, New Jersey 08837-3679
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                                           SECTION  2
                       TECHNOLOGY DESCRIPTION  AND
                              PRELIMINARY SCREENING
This section presents a description of various full-scale soil
washing technologies and a discussion of the information
necessary for prescreening the technology before committing
to a treatability test program.  Subsection 2.1  describes
several  full-scale  soil washing  systems.  Subsection  2.2
discusses the literature and data base searches required, the
technical assistance available,  and the review of field data
required  to  prescreen  these  technologies.  Technology
limitations are also reviewed in this subsection.
             and soil clods  and then washed with fluids to remove
             contaminants. To be effective, soil washing must either
             transfer the contaminants to the wash fluids or concentrate
             the contaminants in a fraction of the original volume, using
             size separation techniques. °2) In either case, soil  washing
             must  be  used  in  conjunction  with other  treatment
             technologies. Either the washing fluid or the fraction of soil
             containing most of the contaminant, or both, must be treated.
             Figure 2-1 presents a schematic diagram of a soils washing
             process.(12)
2.1   TECHNOLOGY DESCRIPTION

Soil washing is a physicallchemical separation technology in
which excavated soil is pretreated to remove large objects
             The first stage in the soil washing process is preparation of
             the excavated soil. Soil preparation involves mechanical
             screening of the soil  feedstock to remove debris such as
             rocks, roots, etc. The maximum size of particles allowed
                                           Volatile*
          Contaminated
              Soil
                              Makeup Water
                               Extracting Agent(s)
                               (Surfactants, etc.)
                       Soil
                    Preparation
                       0)
                                Prepared
                                  Soil
Soil Washing
  Process
    (2)
                                          -Mixing
                                          -Washing
                                          -Rinsing
                                          -Size Separation
                                                                  Emission
                                                                  Control
                                                                               Treated
                                                                               Air Emissions
                                                            Recycled Water
                                                            Chemicals
Slowdown
 Water
          Wastewater
          Treatment
             (3)
Treated
Water
                                                                           Sludges/
                                                                           Contaminated Fines
                                                                            Clean Soil
                                                                            Oversized Rejects
               Figure 2-1. Schematic diagram of the major elements of the aqueous soil washing process.
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in the feedstock varies with the equipment used, ranging
from 10 mm (3/8 inch) up to 50 mm (2 inches).

The next stage is the soil washing process. Typically, soil
washing involves mixing, washing, rinsing, and size separation
steps. During mixing, the wash fluid is introduced to the soil
in measured proportions. At  some installations, this is a
separate  step.  Other installations  combine mixing and
washing into one step (as shown in Figure 2-1).

The intimate energetic mixing of the wash fluid with soil
constitutes the "washing" step.  Intensive contact between
the soil  grains  and the  wash fluid causes  the soil
contaminants to dissolve and disperse into the water. Energy
is introduced into the mixture by high-pressure water jets,
vibration devices, and  other means,  depending upon the
equipment.

After the appropriate contact time, treated soil is separated
from the wash  water. Coarse soil particles are separated
with a trammel or vibrating screen device. Fine particles are
separated in  a sedimentation tank,  sometimes with the
addition  of  flocculating  agents.  Silt  is removed  in  a
hydrocyclone or centrifuge device. The coarse soil fraction
is rinsed with clean water to remove residual  contaminants
and fine soil particles which may stiff be adhering to coarse
particles. The coarse fhaction is recovered from the process
as clean soil.

The final steps  treat the remaining fine soils  (fine silt and
clay) and the contaminated water mixture. The contaminated
water mixture may require precipitation and clarification to
remove the metals and fine soils as  a sludge.  If organic
contaminants are present,  the clarifier effluent may require
treatment, typically using activated carbon, before recycling.
The  fine  soils, in  which  contaminants  have  been
concentrated, will normally require  further  treatment.  If
contaminants are volatile, emission controls may be required.

In actual operation,  there  are more  sidestreams and
equipment involved than shown in  the Figure  2-1. This
equipment typically includes soil feedstock and treated soil
conveyors and earthmoving equipment for stockpiling soil.
This  equipment is, however,  ancillary'  and not  critical  to
understanding the basic soil washing process.

2.1.1    Soil  Washing by Phase Transfer

During soil washing, some contaminants dissolve or become
suspended in the aqueous wash fluid and are removed for
further treatment. If the washed soil meets the established
cleanup goals in the ROD, it may be returned to the original
excavation site.  If unacceptable  levels of contaminants
remain, the soil should be stockpiled or fed directly to the
next step for additional treatment.

Chemical agents  may be added to the wash water  to
increase the efficiency of contaminant removal. Acids, such
as hydrochloric acid, sulfuric acid, and nitric acid, may be
added to improve the solubility of certain contaminants,
especially  heavy  metals.  Sodium  hydroxide,  sodium
carbonate,  and other bases can  be used to precipitate
contaminants in  the  extraction  fluid.  Clay and  humus
fractions, which may contain a large percentage of organic
contaminants, are dispersed by bases.0'0 Dispersion of oily
contaminants can be facilitated by the addition of surface
active agents. Various chelating or sequestering agents, such
as citric acid, ammonium acetate, nitrilotriacetic acid (NTA),
and ethylenediaminetetraacetic  acid (EDTA), will remove
the available fraction of inorganic contaminants. Combining
chemicals may improve process performance in some cases,
although limited information is available on the performance
of these  combinations.  Contaminant  removal may be
improved, in certain cases, by  elevation of the  extraction
temperature or by chemical oxidation of the contaminants
using an oxidizer (e.g., hydrogen peroxide or ozone).(3)

2.1.2  Soil Washing Using  Particle Size
         Separation

EPA  research  shows that  a large percentage  of soil
contamination (especially organic) is sometimes  associated
with, or bound to, very small (silt and clay) soil particles. In
these  situations,  a physical  separation  of the  large soil
particles  (sand and gravel) from the silt, clay, and humic
material  effectively  concentrates  the  contaminants.  Soil
washing significantly reduces the volume of contaminated
soil when  this  condition occurs.  Following mixing and
washing,  sand particles larger than 50 to 80 um can be easily
separated from the washing fluid because of their relatively
high settling velocity. Simple, inexpensive equipment, such as
settling chambers, can be used.

Most of the clay particles and humus remain suspended in
the wash  water supernatant after  sand  and  gravel
sedimentation. These small,  slow-settling particles  pass
through the settling chambers. They ultimately end up in the
wastewater treatment sludge.(3)

2.1.3   Use  In Conjunction  With Other
         Treatment Technologies

Soil washing is  not  usually  a stand-alone technology.
Typically, both the fine soils (silts and clays) recovered after
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washing and the spent wash water are subject to further
specific treatment and disposal techniques, as appropriate, to
complete the cleanup. Wash water is normally treated using
standard wastewater treatment practices. Sludges generated
during wash water treatment may need subsequent treatment
by such methods as solidification/stabilization, biodegradation,
and incineration. The EPA document entitled, "Technology
Screening  Guide for Treatment of CERCLA Soils  and
Sludges."  contains  a detailed  description of  potential
treatment  technologies.(22) Sidestreams generated during
treatment,  such as spent solvents, exhausted  resins,  air
emissions, etc., must also be treated.

2.2   PRELIMINARY SCREENING AND
      TECHNOLOGY LIMITATIONS

The need for and the appropriate level of treatability studies
required are  dependent on  available literature,  expert
technical judgment, and site-specific factors. The  first two
elements~the literature search and expert consultation—are
critical factors in determining if adequate data are available
or whether a treatability  study is needed to provide those
data.

2.2.1   Literature/Data Base Review

Several reports and electronic data bases exist which should
be consulted to assist in planning and conducting treatability
studies, and to  help prescreen soil washing for  use  at a
specific site. Existing reports include:

•   Guide  for  Conducting   Treatability  Studies  Under
    CERCLA, Interim Final. U.S. Environmental Protection
    Agency, Office of Research and Development  and
    Office  of  Emergency  and   Remedial  Response,
    Washington, D.C. EPA/540/2-89/058, December 1989.

•   Guidance for Conducting Remedial Investigations  and
    Feasibility Studies Under CERCLA, Interim Final. U.S.
    Environmental Protection Agency, Office of Emergency
    and   Remedial   Response,   Washington,  D.C.
    EPA/540/G-89/004, October 1988.

•   Superfund Treatability Clearinghouse Abstracts. U.S.
    Environmental Protection Agency, Office of Emergency
    and   Remedial   Response,   Washington,  D.C.
    EPA/540/2-89/001, March 1989.

•   The Superfund  Innovative  Technology  Evaluation
    Program:  Technology  Profiles.  U.S.   Environmental
    Protection   Agency,   Office  of  Solid Waste  and
    Emergency  Response and  Office of  Research  and
    Development, Washington,  D.C.  EPA/540/5-90/006,
    November 1990.

•   Summary of Treatment Technology Effectiveness for
    Contaminated Soil.  U.S.  Environmental  Protection
    Agency, Office of Emergency and Remedial Response,
    Washington, D.C., 1989 (in press).

•   Technology S creening Guide for Treatment of CERCLA
    Soils  and  Sludges.  U.S.  Environmental  Protection
    Agency. EPA/540/2-88/004, 1988.

•   U.S.  Environmental  Protection  Agency, Applications
    Analysis Report - CF Systems Organics  Extraction
    System,  New  Bedford,  MA,  EPA  Report to  be
    published.

Currently, RREL in Cincinnati is expanding its Superfund
Treatability Data Base. This data base will contain data from
all  treatability studies  conducted  under  CERCLA.  A
repository for treatability study reports will be maintained at
RREL in Cincinnati. The contact for this data base is Glenn
Shaul at (513) 569-7408.

Office of Research and Development (ORD) headquarters
maintains the Alternative Treatment Technology Information
Center (ATTIC), a comprehensive, automated information
retrieval system that integrates hazardous waste data into a
unified, searchable resource. The intent of ATTIC  is to
provide  the user community with technical data  and
information on available alternative treatment technologies
and to  serve as an initial decision  support system. Since
ATTIC functions as a focal point for users, it facilitates the
sharing of information with the user community and creates
an effective network of individuals and organizations involved
in hazardous waste site remediation.

The  information  contained in  ATTIC  consists  of a  wide
variety of data obtained from Federal  and State agencies.
The core of the ATTIC system is the ATTIC Data Base,
which contains abstracts and executive summaries from over
1,200 technical documents and reports. Information in the
ATTIC Data Base has been obtained  from the following
sources:

•   The Superfund Innovativ e Technology Evaluation (SITE)
    Program

•   California   Summary   of  Treatment  Technology
    Demonstration Projects

•   Data collected  for  the  Summary  of  Treatment
    Technology   Effectiveness   for  Contaminated  Soil
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•   North   Atlantic  Treaty   Organization  (NATO)
    International Data

•   Innovative Technologies Program Data

•   Removal Sites Technologies Data

•   Resource Conservation and Recovery Act (RCRA)
    Delisting Actions

•   USATHAMA Installation Restoration and Hazardous
    Waste Control Technologies

•   Records of Decision (from 1988 on)

•   Treatability Studies

•   Superfund Treatability Data Base (also available through
    ATTIC)

In addition, the ATTIC system contains a number of resident
data bases that have been previously developed, as well as
access to  on-line  commercial data  bases.  For  more
information, contact the ATTIC System Operator at (301)
816-9153.

The Office of  Solid  Waste  and Emergency Response
(OSWER) maintains an Electronic Bulletin Board System
(BBS) as a tool for communicating  ideas and disseminating
information and as a gateway for other Office of  Solid
Waste (OSW) electronic data bases. Currently, the BBS has
eight different components, including news and mail sendees
and conferences  and publications on specific technical areas.
The contact is James Cummings at (202) 382-4686.

2.2.2   Technical Assistance

Technical assistance can be obtained from the Technical
Support Project (TSP) team,  which is  made up of six
Technical Support Centers and two Technical  Support
Forums. It is a joint service of the Office of Solid Waste and
Emergency  Response,  the  Office  of  Research  and
Development, and the Regions.  The TSP offers direct
site-specific technical assistance to  On-Scene Coordinators
(OSCs) and RPMs and  develops  technology workshops,
issue papers, and other information for Regional staff. The
TSP:

•   Reviews  contractor  work  plans, evaluates remedial
    attematives, reviews RI/FS, and assists in the selection
    and design of the final remedy

•   Offers  modeling  assistance  and data analysis and
    interpretation

•   Assists in developing and evaluating sampling plans

•   Conducts field studies (soil  gas, hydrogeology, site
    characterization)

•   Develops technical workshops and training, issue papers
    on groundwater topics, and generic protocols

•   Assists in performing treatability studies.

The following support centers provide technical information
and advice related to soil washing and treatability studies:

1.  GroundwaterFate and Transport Technical Support
    Center

    Robert  S. Kerr Environmental Research Laboratory
    (RSKERL), Ada, Oklahoma
    Contact: Don Draper
    FTS 743-2202 or (405) 332-8800

RSKERL in Ada, Oklahoma, is EPA's center for fate and
transport research. It focuses its efforts on transport and fate
of contaminants in the vadose and saturated zones of the
subsurface,  methodologies  relevant  to  protection  and
restoration  of groundwater  quality,  and  evaluation of
subsurface processes for the treatment of hazardous waste.
The Center provides technical assistance, such as evaluating
remedial alternatives; reviewing RI/FS and RD/RA  work
plans; and providing technical information and advice.

2.  Engineering  and  Treatment  Technical  Support
    Center

    Risk Reduction Engineering Laboratory (RREL),
    Cincinnati, OH
    Contact: Ben Blaney
    FTS 648-7406 or (513) 569-7406

The Engineering and Technical Support  Center (ETSC) is
sponsored by OSWER but operated by RREL. The center
handles  site-specific  remediation  engineering  problems.
Access to this support Center must be obtained through the
EPA Remedial Project Manager.

RREL offers  expertise in  contaminant  source control
structures; materials handling and decontamination; treatment
of soils, sludges and sediments; and treatment of aqueous
and organic liquids. The following  are examples of the
technical assistance that can be obtained through ETSC:

•   Screening of treatment alternatives
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•   Review of the treatability aspects of RI/FS

•   Review of RI/FS treatability study Work Plans and final
    reports

•   Oversight of RI/FS treatability studies

•   Evaluation of alternative remedies

•   Assistance with studies of innovative technologies

•   Assistance in full-scale design and start-up

2.2.3   Prescreening Characteristics

The need for a treatability study  is determined near the
beginning of the RI/FS when a literature survey of remedial
technologies  is   performed.  Remedial technologies  are
identified based  on  compatibility  with  the  type  of
contaminants and the media (soil, water, etc.) present at the
site, and the anticipated  cleanup  objectives.  Remedial
technologies  are   prescreened   for  effectiveness,
implementability, and cost. The  prescreening is done using
available technical literature, data bases and manufacturer's
information. Based on this initial technology prescreening, soil
washing may  be  one  of  several  candidate remedial
technologies eliminated before or during the RI/FS.  See the
generic  guide for more  specific details on  screening of
treatment technologies and on determining the need and type
of treatability tests  which may be required for evaluating
treatment technology alternatives.05'

Prescreening activities for  soil  washing treatability testing
include   interpreting   any   available   site-related  field
measurement data. The purpose of prescreening is to  gain
enough  information  to eliminate from further treatability
testing treatment technologies  that have  little chance of
achieving the cleanup goals.
                              Table 2-1 lists physical parameters that may be measured or
                              available  before designing treatability  tests. Particle  size
                              distribution   and   cation   exchange   capacity  (CEC)
                              measurements are particularly useful when evaluating soil
                              washing.

                              If contamination exists  at different  soil zones, a  soil
                              characterization profile should be developed for each soil
                              type or zone. Available chemical and physical data (including
                              averages and ranges) and the volumes of the contaminated
                              soil requiring treatment should be identified. Hot spots require
                              separate characterizations so they can be properly addressed
                              in the treatability tests. Soil washing may be applicable to
                              some, but not all, parts of a site.

                              Characterization test results should be broadly representative
                              of the waste profile of the site. Grab samples taken from the
                              site ground surface may represent only a small percentage of
                              the  contaminated  soils  requiring  remediation.  Deeper,
                              subsurface strata affected by contaminants may vary widely
                              in composition  (grain size, clay  content, cation exchange
                              capacity, total organic carbon, and contamination levels) from
                              those found at the surface and should also be characterized.
                              If significant sand  or clay  lenses are  present  in the
                              contaminated zone, the  location  and  volume  should be
                              estimated.  This information is critical to determine the mix of
                              feedstocks to be used. The quantity' and distribution of rubble
                              and  debris  should  also be  determined  as  part  of the
                              characterization. This material must be removed from the
                              feedstock material during any full-scale treatment operations.
                              In general, existing commercial soil washers cannot accept
                              material larger  than 3/8 to 2 (10  to  50 mm)  inches in
                              diameter.

                              The three  most important soil parameters to be evaluated
                              during  prescreening and remedy  screening tests are the
                              grain size distribution, clay content, and cation exchange
                              capacity'.  Soil  washing performance  is closely  tied to
                          TABLE 2-1. Physical Prescreening Soil Characterization Tests
Parameter
Grain size analysis/
Description of Test
Sieve screening using #10
Standard Analytical
Method
ASTM D422
Reference
1
 particle size distribution
 Cation exchange capacity
 (CEC)
and #60 screens or
equivalent

Ammonium acetate
Sodium acetate
Method 9080
Method 9081
23
23
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these three factors. Soils with relatively large percentages of
sand and gravel (coarse material >2 mm) respond better to
soil washing than soils with small percentages of sand and
gravel. Larger percentages of clay  and silt (fine particles
smaller than  0.25  mm)  reduce  contaminant  removal
efficiency. In general, soil washing is most appropriate for
soils that contain at least 50 percent sand/gravel, i.e., coastal
sandy soils and soils with glacial deposits. Soils rich in clay
and silt tend to be poor candidates for soil washing. Cation
exchange  capacity  measures the  tendency of the soil to
exchange weakly held cations in the soil for cations in the
wash solution. Soils with relatively low CEC values (less than
50 to 100 meq/kg) respond better to soil washing than soils
with higher CEC  values.  Early characterization of these
parameters and their variability throughout the site provides
valuable information for the initial screening of soil washing
as an alternative treatment technology.  Appendix C  of the
generic  guide   lists   other  specific   characterization
parameters.(15)

Chemical and physical properties of the contaminant should
also be investigated. Solubility in water (or other washing
fluids) is one of the most important physical characteristics.
Reactivity with wash fluids may, in  some cases, be another
important  characteristic to consider.  Other  contaminant
characteristics  such  as volatility  and  density  may  be
important for the design of remedy screening studies and
related residuals treatment systems. Speciation, is important
in metal-contaminated  sites.  Specific  metal compounds
should  be quantified rather than total metal concentration for
each  metal   present   at  the  site.  Soil  prescreening
characterization data should be assembled and organized in
a  concise  tabular form   before   designing  the remedy
screening tests.

2.2.4   Soil Washing Limitations

Soil washing limitations may be defined as characteristics
that hinder cost-effective soil treatment. The limitation may
be due to the soil particle distribution (high percentage of silt,
clay, or organic matter), the contaminant (high concentration
of mineralized metals  or  hydrophobic organics), or the
process itself.  High concentrations  of additives may be
required in some cases to meet the necessary  performance
goals. Difficulties are sometimes encountered in treating and
recycling  additives  in  the spent wash  water.  If these
conditions occur, process costs may be prohibitive due to the
cost of treating washing fluids and replenishing additives.
Hydrophobic contaminants can be difficult to separate from
soil particles into the aqueous  washing  fluid. Estimated
aqueous distribution coefficients (KJ, also known as partition
coefficients. (Kp), indicate the fraction of the contaminant
expected to remain on the soil particle versus the fraction of
the contaminant  dissolved  in  the water. (6) Alternative
methods can be used to estimate these values when tabulated
values cannot be  located.(S) A contaminant with a high K,,
(e.g., PCB > 10,000) is more difficult to wash off the soil
particles using water than a contaminant with a lower K,,
(e.g., TCE=3).  Additives  such  as  surfactants may  be
required to improve removal efficiencies.  However, larger
volumes of washing fluid may be needed when additives are
used.

Complex mixtures of contaminants in the soil, such as  a
mixture of metals, nonvolatile organics, sernivolatile organics,
etc., make it difficult to formulate a single suitable washing
fluid that will remove all the different types of contaminants
from  the  soil.  Sequential washing steps,  using different
additives,  may  be  needed. Frequent  changes  in the
contaminant type and concentration in the feed  soil can
disrupt  the  efficiency of the soil washing  process.  To
accommodate  changes  in  the  chemical  or  physical
composition of the feed soil, modifications to the wash fluid
formulation and  the operating  settings may  be required.
Alternatively, additional feedstock preparation steps, such as
blending soils to  provide a consistent feedstock;  may be
appropriate.

High  humic content in the soil makes separation of
contaminants very difficult.  Humus consists of decomposed
plant  and animal residues  and  offers binding sites  for
accumulation of both organics and metals. A high percentage
of clay and silt (e.g., more than 30 to  50 percent) in the soil
usually indicates that soil washing will be unfavorable due to
the amount of time and money required to treat this volume
of contaminated soil. A volume reduction process like soil
washing is most cost-effective when the cleaner soil fraction
is much larger than the more contaminated soil fraction.

Chelating agents, surfactants, solvents, and other additives
are often difficult  and expensive to recover from the spent
washing fluid and then recycle in the soils washing process.
The presence of additives may make the spent washing fluid
difficult to treat by conventional treatment processes such as
settling, chemical precipitation, or activated  carbon.  The
presence of additives in the contaminated soil and treatment
sludge residuals may cause increased  difficulty in disposing
of these residuals.
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                                           SECTION 3
                    THE  USE  OF TREATABILITY  STUDIES
                               IN  REMEDY  EVALUATION
This section presents an overview of the use of treatability
tests  in  confirming the selection of soil washing as the
technology remedy under CERCLA. It also provides  a
decision tree that defines the tiered approach to the overall
treatability study program with examples of the application of
treatability studies to the RI/FS and remedy evaluation
process. Subsection 3.1 presents an overview of the general
process  of conducting  treatability  tests.  Subsection 3.2
defines the tiered approach to conducting treatability studies
and the  applicability of each tier of testing, based on the
information obtained, to assess, evaluate, and confirm soil
washing technology as the selected remedy.

3.1    PROCESS OF TREATABILITY
      TESTING IN  EVALUATING A
       REMEDY

Treatability studies should  be performed in a systematic
fashion to ensure that the data generated can support the
remedy evaluation process. This section describes a general
approach that should be followed  by  RPMs,  PRPs, and
contractors  during all  levels  of treatability  testing.  This
approach includes:

•  Establishing data quality objectives

•  Selecting a contracting mechanism

•  Issuing the Work Assignment

•  Preparing the Work Plan

•  Preparing the Sampling and Analysis Plan

•  Preparing the Health and Safety Plan

•  Conducting community relations requirements

•  Complying with regulatory requirements
•   Executing the study
•   Analyzing and interpreting the data

•   Reporting the results

These elements are described in detail in the generic guide.
(15)  That document  gives  information  applicable  to  all
treatability studies. It also presents information specific to
each of the levels of treatability testing.

Treatability  studies  for a particular site will  often entail
multiple tiers of testing. Duplication of effort can be avoided
by recognizing this possibility in the early planning phases of
the project.  The Work Assignment, Work Plan, and other
supporting documents should include all anticipated activities.

There are three levels or tiers of treatability studies: remedy
screening, remedy selection, and  remedy design testing.
Some or all  of the levels may be needed on a case-by-case
basis. The  need  for and the level of treatability testing
required are management decisions in wrhich the time and
cost necessary to perform the testing are balanced against
the risks inherent in the decision (e.g., selection of an
inappropriate treatment alternative). These decisions are
based on the quantity and perceived quality of data available
and on other decision factors (e.g., State and community
acceptance  of the remedy or new site data). The flow
diagram for the tiered approach in Figure 3-1 traces the
stepwise review of data with the decision points and factors
to be considered.

Technologies generally are evaluated  first at  the remedy
screening level and progress through remedy selection to the
remedy design testing. A technology may enter the selection
process, however, at whatever level is appropriate based
on  available  data  on  the  technology  and site-specific
factors.   For  example,  a  technology  that  has  been
successfully applied  at a site with similar conditions and
contaminants may not require remedy screening to determine
whether it  has  the potential to  work.  Rather,  it may
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                    I

                    h
                                                                                                 •s


                                                                                                 I

                                                                                                 i
                                                                                                 ZE
                                                                                                 eg
                                                                                                 _
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                          Remedial Investigation/
                          Feasibility Study (RI/FS)
                                         Identification
                                         of Alternatives
                                            Record of
                                            Decision
                                             (ROD)
                                             Remedy
                                            Selection
                              Remedial Design/
                              Remedial Action -
                                  (RD/RA)
           Scoping
           - the  -
            RI/FS
           Literature
           Screening
             and
          Treatability
         Study Scoping
        Site
   Characterization
   and Technology
     Screening
    REMEDY
   SCREENING
   to Determine
Technology Feasibility
 Evaluation
of Alternatives
                                             REMEDY SELECTION

                                              to Develop Performance
                                                  and Cost Data
Implementation
  of Remedy
                                                                               REMEDY DESIGN

                                                                             to Develop Scale-Up, Design,
                                                                               and Detailed Cost Data
                       FIGURE 3-2. The role of treatability studies in the RI/FS and RD/RA process.
go  directly  to remedy  selection  testing  to  verify  that
performance standards can be met and generate preliminary
cost estimates. Treatability  studies,  at some level,  will
normally be needed to  assure that the technology  can
achieve site target cleanup goals even if previous studies or
actual  implementation  have  encompassed  similar  site
conditions. Figure 3-2 shows the relationship of the three
levels of a treatability study to each other and to the RI/FS
process.


3.2   APPLICATION OF TREATABILITY
       TESTS


Before conducting treatability studies, the objectives of each
tier of testing must be established. Soil washing treatability
study objectives are based  on the specific needs of the
RI/FS. There are nine  evaluation criteria specified in the
document, Guidance for Conducting Remedial Investigations
and Feasibility Studies Under CERCLA (Interim Final);(14)
the treatability studies provide data for up to seven of these
criteria. These seven criteria are:
                                    Overall protection of human health and environment


                                    Compliance with applicable or relevant and appropriate

                                    requirements (ARARs)


                                    Reduction  of toxicity,  mobility,  or volume through

                                    treatment


                                    Short-term effectiveness


                                    Implementability


                                    Long-term effectiveness and permanence


                                    Cost
                                The first four  of these evaluation criteria deal with the

                                degree of contaminant  reduction achieved by  the soil

                                washing process. What will be the remaining contaminant

                                concentrations? Will the residual contaminant levels be

                                sufficiently low to meet the established ARARs and the

                                risk-based contaminant  cleanup  levels? What  are the

                                contaminant concentration and physical and chemical differ-
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ences between the untreated and the washed soil fractions
(i.e., has contaminant toxicity, mobility, and volume been
reduced)? The fourth criterion, short-term effectiveness,
addresses the risks posed by the treatment technology during
construction and implementation of a remedy.

The implementability assessment evaluates the technical and
administrative feasibility of the technology and the availability
of required goods and services. The following questions must
be answered in order to address the implementability of soil
washing:

•   What is the  percentage of clay, silt, and humic matter
    requiring additional treatment?

•   What additives will be required (e.g., chelating agents or
    surfactants)  that might make residuals treatment and
    disposal difficult?

•   What are  the  characteristics  and the  volume  of the
    sludge that will be produced?

•   Is sufficient  water available at the site, and is it suitable
    for process use?

Normally, the required equipment and washing solutions are
available. However, alterations to  process  design may be
necessary on a site-by-site basis to accommodate  different
soils and contaminants.  Sidestreams and residual soil from
the soil washing process require additional treatment. The
implernentability assessment must  include these additional
treatments.

Long-term effectiveness assesses how effective treatment
technologies are  in maintaining protection of human health
and the environment  after  response objectives have been
met. The magnitude of any residual  risk and the adequacy
and reliability of controls must be evaluated. Residual risk, as
applied to soil washing, assesses the risks associated with the
treatment residuals at the conclusion of all remedial activities.
Analysis of residual risk from sidestream and other treatment
train processes should be included in this step. An evaluation
of the reliability of treatment process controls assesses the
adequacy and  suitability of any long-term controls (such as
site access restrictions and deed limitations on land use) that
are necessary to manage treatment residuals at the site. Such
assessments are usually beyond the scope of a remedy
selection  treatability   study,  but  may  be addressed
conceptually based on remedy selection results. Performance
objectives must consider the existing site soil contaminant
levels and relative cleanupgoals for the  site.  In  previous
  years,  cleanup  goals  often  reflected  background  site
  conditions,  Attaining background cleanup levels  through
  treatment has proven impractical in many situations. The
  present trend is  toward the development of site-specific
  cleanup target levels that are risk-based rather than based on
  background levels.

  The final EPA evaluation criterion that can specifically be
  addressed during a treatability study is cost. Soil washing is
  basically  a volume reduction  technology that uses wash
  water to  separate contaminated soil  into two fractions: a
  large fraction of relatively clean, coarse soil  and a smaller
  fraction  of fine soil/sludge containing the  concentrated
  contaminants.

  Remedy selection treatability studies can  provide data to
  estimate the following important cost factors:

  •   Recoverable  clean soil fraction (the achievable volume
      reduction)

  •   The volume and characteristics of the concentrated fine
      soil and sludge fractions requiring treatment or disposal
  •   The degree  to which the  additives  can  enhance  the
      process efficiency

  •   The degree to which the additives can be recovered and
      recycled
  •   The ratio of additives to soil

  •   The ratio of soil to wash water

  The first three factors provide information about the costs of
  downstream treatments by  determining the  amount  and
  character  of  the contaminated residuals. The  last three
  factors help estimate the costs of supplies and utilities.

  3.2.1   Remedy Screening

  Remedy screening is the first testing level. It establishes the
  ability of a technology to  treat  a specific  waste. These
  studies are generally low cost (e.g., $10,000 to $50,000) and
  usually require hours to days to complete. The lowest level
  of quality7 control is required for remedy  screening studies.
  They  yield  data enabling  qualitative  assessment of a
  technology's potential to meet performance goals.  Remedy
  screening  tests  can  identify  operating  conditions  for
  investigation during remedy selection or remedy design
  testing. They generate little, if any,  design or cost data and
  should never  be used as  the sole basis for selection of a
  remedy.
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Soil washing treatability studies are frequently slapped during
remedy screening. Often, there is enough information about
the physical and chemical characteristics of the soil and
contaminant to allow an expert to evaluate the potential
success of soil washing at a site. When performed, remedy
screening tests are jar tests. However, remedy selection tests
are normally the first level of treatability study executed.

3.2.2   Remedy Selection

Remedy selection testing is  the second level  of testing.
Remedy selection tests identify the technology's performance
for a site. These studies have a moderate cost (e.g., $20,000
to $100,000) and require several weeks to complete. Remedy-
selection tests yield data that verify that the technology can
meet expected cleanup goals, provide information in support
of the detailed analysis of alternatives (i.e., seven of the nine
evaluation criteria), and give indications of optimal operating
conditions.

The remedy selection tier of soil washing testing typically
consists  of  laboratory  tests  which  provide  sufficient
experimental controls such that a semi-quantitative mass
balance can be  achieved. Toxicity testing of the cleaned soil
is  typically employed  in  the  remedy selection  tier  of
treatability testing. The key question to be answered  during
remedy selection testing is how much of the soil will be
treated by either particle  size separation or solubilization to
meet the cleanup goal by this process. The exact removal
efficiency needed to meet the specified goal for the remedy
selection  test  is site-specific.  Pilot-scale tests  may  be
appropriate  to  support the remedy  selection  phase for
innovative technologies such as  soil washing. Typically,  a
remedy design study would follow a successful remedy
selection study.
   3.2.3   Remedy Design

   Remedy design testing is the third level of testing. It provides
   quantitative performance, cost, and design information for
   remediating an operable unit. This testing also produces the
   remaining  data required to optimize performance. These
   studies are of moderate to high cost  (e.g., $  100,000 to
   $500,000)  and require  several  months to complete.  For
   complex   sites   (i.e.,   sites  with  different  types   or
   concentrations in different areas or with different soil types
   in different areas), longer testing periods may be required,
   and costs will be higher. Remedy design tests yield data that
   verify performance to a higher degree than remedy selection
   tests  and  provide detailed design  information. They are
   performed after the ROD during the remedy implementation
   phase of a site cleanup.

   Remedy design tests  usually consist of bringing a mobile
   treatment unit onto the site, or constructing a  small-scale
   (pilot) unit for nonmobile technologies. Permit exclusions may
   be available for offsite treatability  studies under certain
   conditions. The goal of this tier of testing  is to confirm the
   cleanup levels and treatment times specified in the Work
   Plan (see Section 4.1.1). This is best achieved by operating
   a field unit under conditions  similar to those expected in the
   full-scale remediation project.

   Data obtained from the remedy design tests are used to:

   •   Design the full-scale unit
   •   Refine cleanup time estimates

   •   Refine cost predictions

   Given  the lack of full-scale experience with innovative
   technologies,  remedy   design  testing  will generally  be
   necessary- to support remedy selection and implementation.
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                                             SECTION 4
                       TREATABILITY STUDY  WORK PLAN
Section  4 of this document is  written assuming  that a
Remedial Project Manager is requesting treatability studies
through a work assignment/work plan mechanism. Although
the discussion focuses on this mechanism, it would also apply
to situations where other contracting mechanisms are used.

This section focuses on specific elements of the Work Plan
for soil washing treatability studies. The elements include test
objectives, experimental design and procedures, equipment
and materials, reports,  schedule, management and staffing,
and budget. These elements are described in Sections 4.1-
4.9. Complementing the  above subsections are Section 5,
Sampling and Analysis Plan, which contains a Field Sampling
Plan and a Quality Assurance Project Plan, and Section 6,
Treatability Data Interpretation. These sections address the
Sampling and Analysis  and Data Analysis and Interpretation
elements of the Work  Plan. Table 4-1  lists the other
remaining Work Plan elements

Carefully planned treatability studies are necessary to ensure
that the data generated  are useful for evaluating the validity
or performance of a technology. The Work Plan,  prepared
by the contractor when the Work Assignment is in place, sets
forth  the contractor's proposed  technical approach  for
completing the tasks outlined in  the Work Assignment. It
assigns responsibilities  and establishes the project schedule
and costs. The Work Plan must be approved by the RPM
before initiating subsequent tasks.  For more information on
each of these sections,  refer to the generic guide.050
4.1   TEST GOALS

Setting goals for the treatability study  is critical to the
ultimate usefulness of the data generated. Objectives must
be defined before starting the treatability study. Each tier of
treatability study needs performance goals appropriate to that
tier. For example, remedy selection tests are used to answer
the  question,  "Will  soil  washing  work  on  this  soil/
contaminant matrix?"  It is necessary to define "work"
  TABLE 4-1.   Suggested Organization of Soil Washing
               Treatability Study Work Plan
No.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
Work Plan Elements
Project Description
Remedial Technology Description
Test Objectives
Experimental Design and
Procedures
Equipment and Materials
Sampling and Analysis
Data Management
Data Analysis and Interpretation
Health and Safety
Residuals Management
Community Relations
Reports
Schedule
Management and Staffing
Budget
sub-
section


4.1
4.2
4.3
4.4

4.5



4.6
4.7
4.8
4.9
   (i.e., set the goal of the study). A contaminant reduction of
   approximately 90 percent in the >2 mm soil fraction indicates
   that further testing for remedy design is appropriate.

   The ideal technology performance goals  are the  cleanup
   criteria for the site. For several reasons, such as ongoing
   waste  analysis and ARARs determination, cleanup criteria
   are sometimes not finalized until the ROD is signed, long
   after  treatability  studies  must be initiated. Nevertheless,
   treatability study goals need to  be established before the
   study is  performed so  that the  success of the treatability
   study can be  assessed. In many instances, this may entail an
   educated guess as to what the final cleanup levels may be.
   In the absence of set cleanup levels, the RPM can estimate
   performance  goals for the treatability studies based on the
   first four  criteria  listed  on page  11.  Previous  treat-
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ability study results may provide the basis for an estimate of
the treatability study goals in this case.

4.1.1   Remedy Screening Goals

Remedy screening tests are not always performed for soil
washing processes (see Section 3). If remedy screening tests
are performed, an example of the goal for those tests would
be to show that the wash fluid will solubilize or remove a
sufficient percentage (e.g., 50 percent) of the contaminants
to warrant further treatability studies. Another goal might be
to show that contaminant concentrations can be reduced by
at least 50 percent in the >2 mm soil fraction, using particle
size separation techniques.
                            These goals  are only examples.  The remedy screening
                            treatability study goals must be determined on a site-specific
                            basis.


                            Achieving the goals at this tier merely indicates that soil
                            washing has a chance of success and that further studies
                            will be useful. Frequently, such information is available based
                            on the type of soil and contaminant present at the site. Based
                            on such information, experts in soil  washing technology can
                            often assess the potential applicability of soil washing without
                            performing remedy  screening.


                            Example 1 describes a hypothetical site and a series of
                            simple jar tests that were used to evaluate the potential to
                                    Example 1. Remedy Screening

 An industrial facility in the southeastern United States was built in 1960 and operated until 1990. During that
 time, various electronic component assembly and electroplating operations were conducted at the site.
 Between 1960 and 1980, sludges and other process related wastes generated at the plant were buried in
 onsite landfills. Sometimes, plating/etching solutions and other liquids were disposed of by open dumping
 onto the ground or into sand-filled pits constructed for this purpose.

 As a results of these past practices, soils in several areas at the site are contaminated with heavy metals,
 namely copper, chromium, lead, nickel, and cadmium. Initial site investigations have shown that the average
 and maximum sample values for metals found in soil borings are as follows:
          Metal
          Copper
          Lead
          Chromium
          Nickel
          Cadmium
Average
(MaLka)
2,500
1,000
1,200
450
75
Maximum
20,000
7,500
4,000
790
200
 Soil borings at the site have shown that most of the contamination is located 4 to 6 feet below grade. About
 5,000 to 10,000 cubic yards of soil are believed to be affected by the metals and volatile organic compounds
 (VOCs).

 Soils were described in the boring logs as clayey sands. A sample of soil, composited from soil borings
 cuttings from various areas and depths in the contaminated zone, was sent to the lab for dry sieve particle
 size analysis (ASTM methods);  results indicated that 38 to 45 percent of the soil particles are >2 mm in
 diameter,  and 5 to 11 percent are between 1 mm and 2 mm in diameter.

 Soil washing was considered as a potential technology to  reduce the volume of contaminated soil for two
 reasons. First, the sieve analysis showed that a large percentage of the soil (38 to 45 percent) was coarse
 sand or gravel (>2 mm in particle size diameter). This indicated that a large percentage of the soil was likely
 to respond favorably to soil washing and therefore could be eliminated from further treatment. Research at
 the EPA and elsewhere has  shown that soil washing is typically most effective in removing contaminants
 from the >2  mm fraction. Second, the large quantity of soil affected by metal contaminants could potentially
 justify the cost of assembling and operating on onsite washing system.
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 A series of simple jar tests was conducted on the site using both hot and cold water to wash a composite
 soil sample that broadly represented soil areas known to be contaminated with metals. Equal quantities of
 soil and water were placed in ajar, shaken, and then poured across a #10 sieve screen. The particles lying
 on the top of the sieve were rinsed with water and allowed to drip dry. The dry soil was then placed in a
 clean, tared sample jar, weighed, and sent to the laboratory for total metal analysis.  The tests were repeated
 three times to measure variability. Average results showed that the soil washed with hot water (>2 mm
 fraction) responded the best; the average metal concentrations in the soil before and after hot water washing
 are shown below:
        Metal
  Soil Concentration
   Before Washing
(i.e., whole soil, mg/kg)
  Soil Concentration After
    Hot Water Washing
(i.e., >2 mm fraction, mg/kg)
        Copper
        Lead
        Chromium
        Nickel
        Cadmium
         2,000
         1,200
          800
          400
           50
       500
       300
       100
         50
         15
(75% red.)
(75% red.)
(88% red.)
(88%red.)
(70% red.)
 The test results indicate that metal reductions on the order of 70 to 88 percent are readily achievable with hot water.
 Product/soil recovery rates on the order of 30 to 50 percent (based on comparison of recovered weights versus starting
 weight of soil in each test) are achievable. In order to further confirm these initial findings and to maximize the efficiency
 of the treatment process, bench tests are indicated.	
use soil washing  to  remediate the site.  The example
illustrates how to  decide whether the remedy selection
treatability studies using soil washing should be performed.

4.1.2   Remedy Selection Treatability
        Study Goals

The main objectives of this tier of testing are to:

•  Measure the percentage of the contaminant that can
   be removed from the soil through solubilization or from
   the >2 mm. soil fraction by particle size separation
               •   Produce the design information required for the next
                  level of testing, should the remedy selection evaluation
                  indicate remedy design studies are warranted.

               The actual goal for removal efficiency must be based on
               site- and process-specific characteristics. The specified
               removal efficiency must meet site cleanup goals, which are
               based on a site risk assessment or ARARs.

               Example 2 illustrates the goal of a remedy selection
               treatability study at the Superfund site introduced in
               Example 1. In this example, the remedy selection
               treatability studies
                                    Example 2.  Remedy Selection

 As followup to the jar test results discussed in Example 1, a series of bench tests were designed to more
 accurately determine the feasibility of using soil washing to reduce the volume of contaminated soil at the
 facility. The bench tests included a series of studies, each designed to measure a single variable while
 holding all others constant. The following treatment process variables were evaluated:

     •   Ratios of soil and wash water
     •   Washing/mixing/agitation time
     •   Wash water temperature
     •   Additives such as acids, surfactants, and chelating agents
     •   Rinse system cycles
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 In all, 24 different tests were completed and each test was performed in duplicate, as a measure of variance,
 for a total of 48 tests. Soils recovered on the sieves and from wash waters (filtered to remove very fine soil
 particles) were analyzed for the five metals of interest using standard EPA SW846 methods. The bench
 tests also evaluated the possibility of altering screen sizes to capture a larger segment of clean soil (particles
 >1 mm).

 The bench test results for the >2 mm fraction showed that optimal results (as measured by total metal
 concentration reductions) were obtained under the following conditions:

     •   Soil to wash water ratio of 1:2
        Mixing/agitation time of 15 minutes
     •   Wash water temperature  of at least 100°F
     •   Wash water pH of 4-5
     •   Single 60 second rinse of the screened soil using pressure sprayer

 This set of process conditions was able to reduce the concentration of all metals in the recovered  >2 mm
 fraction by at least 90 percent, and some by as much as 95 percent. Surfactants and chelating agents were
 found to  be counterproductive. They fouled the screening operations, and were not recommended  for further
 evaluation for this site. The tests  also showed that similar results (85 to 90 percent effective reductions in
 metal concentrations) could be obtained for the 1 to 2 mm particle size soil fraction. By separating  the
 washed soil into >1 mm and <1 mm size groups, over 50 percent of the original soil volume could  be
 effectively treated. However, particles smaller than 1 mm were not effectively cleaned by the process. In fact,
 the <1 mm soil fraction carried higher concentrations of metals after sieving than the whole soil carried
 before treatment. Hence, most of the metal  contamination in these site soils is associated with soil particles
 1 mm or less in diameter.

 Results from the study were compared to the proposed risk-based  soil cleanup goals for the site. Based on
 this comparison, the study showed that the proposed cleanup goals could be met for a least 50 percent of
 the soil volume through the applied use of soil washing technology.
show that site cleanup goals can be met. Soil washing is
chosen as the selected remedy in the ROD.

4.2    EXPERIMENTAL DESIGN

4.2.1   Remedy Screening Tier

Ajar test can be rapidly performed in an onsite laboratory to
evaluate the potential performance of soil washing as an
alternative technology.  Jar  tests  are performed at  the
equivalent of Analytical Levels I and II, which correspond to
field screening and field analysis, respectively.(n)

When assessing the need for jar tests, the investigator should
use available knowledge  of the  site location and  any
preliminary analytical data on the type and concentration of
contaminants present. Soil  engineering  properties  are
available from Soil Conservation Surveys. At this level of
treatability study, the most significant soil property is particle
size  distribution.  In  survey  documents,    particle  size
  distribution is categorized into five groupings: fragments or
  particles greater than 3 inches in diameter, and fragments
  passing through #4 (4.75 mm), #10 (2.0 mm), #40 (0.425
  mm), and #200 (0.07 mm) sieves. Generally, soils with a 10
  to 15 percent passing rate through a #200 mesh screen have
  proven ideal for soil washing.  However,  soil particle size is
  not the only property to consider. The collective effect of all
  soil and contaminant properties must be  investigated. Even
  soil characterized by a 95 percent passage through a #200
  screen may be a possible candidate for soil washing if the
  contaminant is  water  soluble or loosely  bound to soil
  particles.

  Contaminant  characteristics to  examine  during  remedy
  screening  include  solubility, miscibility,  and dispersibility.
  Properties of organic contaminants are generally easier to
  evaluate than those of inorganic contaminants. Inorganics.
  such as heavy metals, can exist in many compounds (e.g.,
  oxides, hydroxides, nitrates, phosphates,  chlorides, sulfates,
  and other more complex mineralized forms), which can
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greatly alter their solubilities. Metal analyses typically provide
only total metal concentrations. More detailed analyses to
determine chemical speciation may be wan-anted.

The liquid used in the jar test is typically water, or water with
additives that might enhance the effectiveness  of the soil
washing process.  To save  time and money,  chemical
analyses should not be performed on the samples until there
is visual evidence that physical separation has taken place in
the j ar tests. Jar tests can yield three separate fractions from
the original soil sample. These include a floating layer, a
wastewater with  dispersed solids, and a solid  fraction.
Chemical analysis can be performed on each fraction.
When performing the jar test,  observe  if any  floating
materials can be skimmed off the top.  Observe whether an
immiscible, oily layer forms, either at the top or the bottom,
indicating release of an insoluble organic material. Observe
and time the solids sealing rate and depth. Sand and gravel
settle first, followed by the silt and clay. The rate and the
relative volume of the settling material will provide some
indication of the particle size distribution in the contaminated
matrix and the potential for soil washing as a treatment
alternative. Further evidence can be gained by  analyzing the
settled  and filtered  wash water for  selected indicator
contaminants of concern. If simple washing releases a large
percentage of these contaminants into the wash water, then
soil washing can be viewed favorably, and more detailed
laboratory and bench tests must be conducted.
Variations on the jar tests can  include  the addition  of
surfactants, chelants, or other dispersant agents to the water;
sequential washing; heated water washing versus cold water;
acidic or basic wash water; and tests that include both a
wash and a rinse step. The rinse water and fine soil fraction
(<2 mm particle size) should be  separated from the coarse
soil fraction (>2 mm particle  size) using  a #10 sieve. No
attempt should be made during jar tests to  separate the soil
into  discrete size  fractions;  this is done at the  remedy
selection tier  of testing  as  described in Section 4.2.2.
Normally, only the coarse soil fraction should be analyzed for
contamination. In general,  at least a 50 percent reduction in
total contaminant concentration in the >2 mm soil fraction is
considered adequate to proceed to the remedy selection tier.
The separation of approximately  50 percent of the total soil
volume  as clean soil also indicates remedy selection studies
may be warranted.
To reduce analytical costs during the remedy screening tier,
a condensed list of known contaminants must be selected as
indicators of performance. The selection of indicator analytes
to track during jar testing should be based  on the following
guidelines:

1)  Select one or two contaminants present in the soil that
      are most toxic or most prevalent.

   2)  Select indicator compounds to represent other chemical
      groups if they are present in the soil (i.e., volatile and
      sentivolatile organics,  chlorinated and  nonchlorinated
      species, etc.)

   3)  If polychlorinated biphenyls (PCBs) and dioxins are
      known to be present, select PCBs as indicators in the jar
      tests  and analyze for them  in the washed soil.  It is
      usually not cost-effective to analyze for dioxins and other
      highly insoluble chemicals in the wash water generated
      from jar tests. Check for them later in the wash water
      from remedy selection tests.

   4.2.2    Remedy  Selection Tier

   This series of tests requires electricity, water, and additional
   equipment be  available. The tests are run  under  more
   controlled conditions  than the jar tests. The response of the
   soil   sample  to  variable  washing  conditions  is  fully
   characterized.  More precision is used in weighing, mixing,
   and particle size separation. There is an associated increase
   in quality assurance/quality' control (QA/QC) costs. Treated
   soil particles are separated during the sieve operations to
   determine contaminant  partitioning  with  particle  size.
   Chemical analyses  are performed on the sieved soil particles
   as well as on the spent wash waters. The impact of process
   variables on washing effectiveness is quantified. This series
   of tests is considerably more costly than jar tests, so only
   samples showing promise in the remedy screening phase (jar
   test) should be carried forward into the remedy selection tier.
   If sufficient data are  available in the prescreening step, the
   remedy screening step may be slapped. Soil samples showing
   promise in the prescreening step are carried forward to the
   remedy selection tier. The objective of the remedy selection
   soil washing design is to meet the goals discussed in Section
   4.1.2.

   A series of tests  should  be  designed that will provide
   information on washing and rinsing conditions best suited to
   the soil matrix under  study. The RREL data base  should be
   searched for information from previous studies. To establish
   percent of contaminant removal, particle size separation, and
   distribution of contaminants in the washed soil, the following
   should first be studied: 1) wash time, 2) wash water-to-soil
   ratio, and 3) rinse water-to-wash water ratio. Following those
   studies, the effect of wash water additives on performance
   should be evaluated.

   Several factors must be considered in the design  of soil
   washing treatability studies. A remedy  selection test design
   should  be geared  to the  type of system expected to
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be used in the field.  Soil-to-wash water ratios should be
planned using the results from the jar tests, if jar tests are
performed. In general, a ratio of 1 part of soil to 3 parts of
wash water will be sufficient to perform remedy selection
tests. The soil and wash water should be mixed on a shaker
table for a  minimum of 10 minutes  and a maximum of 30
minutes.  The soil-to-wash water  ratio and mix times
presented here are  rules  of thumb to be used if no other
information is available.

Another factor to consider is the variability of the  grain size
distribution. Gilsen Wet Sieve devices are recommended for
remedy selection studies. Ro-Tap or similar sieve systems
may  also  be used.  Such devices  will  enhance  the
completeness  and reproducibility of grain size separation.
However, they are messy, expensive, and very noisy when
in operation. An alternate choice is to complete a series of
four to six replicate runs under exactly the same set of
conditions to obtain information on the variability of the grain
size  separation  technique.  Variability  in  the  separation
technique can be  evaluated by comparing  sieve screen
weights across runs and soil contaminant data  for the same
fractions from  each  run.  By  identifying the  range of
variability  associated with repeated runs  at  the same
conditions,  estimates can  be made of the variability that is
likely to  be associated with other test runs under  slightly-
different conditions.

Normally, only the wash water and the soil particles captured
by the sieve screen need to be analyzed for contaminants.
Experience has  shown that little additional  contaminant
removal is  likely to be found in the  rinse water. Rinsing is
important and must be included in  the  procedure  since it
improves the efficiency of the grain size separation/sieving
process. Rinsing separates the fine from the coarse material.
This can result in a cleaner coarse fraction  and more
contaminant concentrated in the fine fraction.  Contaminant
concentration  in the  rinse water  may  be determined
periodically (e.g., 10 percent of the samples) to evaluate the
performance of the wash  solution.  However, very  little
contamination is typically dissolved  in  the rinse solution.
Therefore,  analyses of the rinse  solution may have limited
value in verifying wash solution performance.

Initially, only the coarse  soil fraction and  the wash water
should be analyzed for indicator contaminants. If the removal
of the  indicator contaminants confirms that the technology
has the potential to meet cleanup standards at the  site,
additional analyses  should  be  performed.  All  three  soil
fractions and all wash and rinse waters must be analyzed for
all contaminants to perform a complete mass  balance.  The
holding time of soil fractions in the lab before extraction and
analysis  can  be an  important consideration  for some
contaminants.
   The decision on whether to perform remedy selection testing
   on hot spots or composite soil samples is difficult and must be
   made on a site-by-site basis. Hot  spot  areas should  be
   factored into the test plan if they represent a significant
   portion of the waste site. However, it is more practical to test
   the specific waste matrix that will be fed to the full-scale
   system over the bulk of its operating life. If the character of
   the soil changes radically  (e.g.. from clay to sand) over the
   depth of contamination, then tests should be designed to
   separately  study  system  performance  on each soil type,
   Additional guidance on soil sampling techniques and  theory
   can be found in Soil Sampling Quality Assurance User's
   Guide/21:' and Methods for Evaluating the Attainment of
   Cleanup Standards.(1S)

   Additives such as oil and grease dispersants and chelating
   agents can aid in removing contaminants from some soils.
   However,  they  can  also  cause  processing  problems
   downstream from the washing step. Therefore, use of such
   additives should be approached with  caution. Use of one or
   a  combination   of those  additives  is  a  site-by-site
   determination. Some soils do not respond well to additives.
   Surfactants and chelating  agents may form suspensions and
   foams with soil particles during washing. This can clog the
   sieves and lead to inefficient particle size separation during
   screening.  The result can be the recovery  of soil fractions
   with higher contamination than those cleaned by water alone.
   Such results can make the data impossible to understand.
   Additives can also complicate the rinse water process that
   might follow the soil washing. Recent studies have shown
   that counter-current washing-rinsing  systems, incorporating
   the use of hot water for the initial wash step, offer the best
   performance in terms of particle size separation, contaminant
   removal, and wastewater management (treatment, recycling
   and discharge). Additional details regarding the performance
   of surfactants  and  chelating  agents  in  reducing lead
   contamination in soils from battery recycling Superfund sites
   can be found in Lead Battery  Site Treatability  Studies,
   Project Summary06)

   4.3   EQUIPMENT AND MATERIALS

   The Work Plan should specify the equipment and materials
   needed for the treatability test. For  example, the size and
   type  of glassware or containers to be used during the test
   should be specified. Standard laboratory methods normally
   dictate the types of sampling containers that can be used
   with various contaminant  groups. The RPM should consult
   such methods for the appropriate containers to be used for
   the treatability studies,(23) Normally, glass containers should
   be used.  Stainless steel  can  also be used  with  most
   contaminants.   Care   should   be  taken  when   using
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various plastic containers and fittings. Such materials will
absorb many contaminants and can also leach plasticizer
chemicals,  such as  phthalates, into  the  soil  matrix.
Appropriate methods for preserving samples and specified
holding times for those samples should be used.

The  following equipment is  recommended  for remedy
selection soil washing tests:

Basic Equipment

•  Reciprocating shaker table
•  Four to six 10-liter glass jars and lids
•  pH meter
•  Electric hot plate/magnetic stir mixer
•  Top-loading balance
•  Four 2-liter graduated cylinders
•  Timer
•  Stainless steel sieve screens (#10 and #60) - two sets
•  Four collection pans/buckets for rinse and wash water
   collection
•  Sample jars
•  Scoops (disposable)
•  Spray device for rinsing (stainless steel garden sprayers
   work well)
•  Filter and media
•  Vacuum pump

Optional Equipment

•  Ro-Tap
•  Gilsen Wet Sieve
4.4  SAMPLING AND ANALYSIS

The Work Plan should describe the procedures to be used in
field and treatability study sampling. The procedures to be
used will be site-specific.

4.4.1    Field Sampling

A sampling  plan  should be  developed  that  directs  the
collection of representative soil samples from the site for the
treatability  test.  The sampling  plan is   site-specific.  It
describes the  number, location,  and volume of samples.
Heterogeneous  soils,   variations   in  the   contaminant
concentration profile, and different contaminants in different
locations in the site will complicate sampling efforts. If the
objective of the remedy  screening  or remedy  selection
treatability tier study is to investigate the performance of soil
washing at the highest contaminant concentration, the sample
collection must be conducted  at a "hot spot." This will
   require conducting a preliminary site sampling program to
   identify the locations of highest contaminant concentration.
   (This information is generated early in the RI process.) If the
   soil and types of contaminants vary throughout the site,
   extensive sampling may be required. If soil washing is being
   considered only for certain areas of the site, the sampling
   program may be simplified by concentrating on those areas.

   If the objective of the remedy selection study is to investigate
   the use of the technology for a more homogenous waste, an
   '"average" sample for the entire site must be obtained. This
   will require a statistically based program of mapping the site
   and selecting sampling locations that represent the variety of
   waste  characteristics  and  contaminant  concentrations
   present. The selection of soil sampling locations  should be
   based on knowledge of the site.  Information from previous
   soil samples, soil gas analysis using field instrumentation, and
   obvious odors or residues are examples of information that
   can be used to specify sample locations.

   Chapter 9 of Test Methods  for Evaluating Solid Waste(23)
   presents a detailed discussion of representative samples and
   statistical   sampling methods.   Additional sources   of
   information on field sampling procedures can be found in the
   Annual Book of ASTM Standards/0 and NIOSH Manual of
   Analytical  Methods   (February   1984)/9)   The   EPA
   publications  Soil   Sampling  Quality  Assurance  User's
   Guide(21)  and Methods  for Evaluating the Attainment of
   Cleanup Standards(18) should be consulted to plan effective
   sampling programs for either simple or complex sites.

   The  method of  sample collection is site-specific. For
   example, drill rigs or hand  augers  can be used  to  collect
   samples, depending on the depth of the sample required and
   the soil characteristics. If the target contaminants are volatile
   and the  samples  are composited, care should be taken to
   minimize the loss  of  volatile  compounds.  Compositing
   samples on ice is a good method for minimizing the  loss  of
   volatile compounds. Compositing is usually appropriate for
   soils containing nonvolatile constituents.

   4.4.2   Waste  Analysis

   Section 2.2.3 detailed the physical tests that are useful in
   characterizing  the  soil matrix  at  the  site  during the
   prescreening  step. The  key for successful soil washing
   treatability studies is to properly select the soil  feedstock
   (e.g., sand, loam, clay, etc.) based on the initial prescreening
   and additional soil characterizations. Other important soil
   characteristics include the pH and moisture content of the
   soil. The pH is important in determining the  compatibility of
   soil washing fluids. The speciation of metal  compounds
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may also be affected by soil pH. The soil moisture content is
an important consideration for materials handling.

Standard analyses for contaminants at Superfund sites should
identify the  contaminants  of concern. It is important to
determine   the  solubility  and  volatility  of  organics.
Contaminant solubility will give  an indication of whether
washing solution additives will be required. Volatility will be
an important consideration for materials  handling.  If high
concentrations  of volatiles are present, pretreatment (e.g.,
using soil vapor extraction) or collection and treatment of air
emissions  may be  required.  Metal speciation will be an
important consideration in determining metal solubility.

The spatial distribution and variations in the concentrations of
contaminants will be important for the design of treatability
studies. Complex mixtures of contaminants may be difficult
to treat economically.  A number  of wash  stages  and
additives may  be required to  successfully remove many
contaminants. The cost of such a system may be prohibitive.
Frequent changes in contaminant composition can cause
dramatic changes in removal  efficiencies.

4.4.3   Process Control Sampling and
        Analysis

This is not applicable to remedy screening and remedy
selection.

4.4.4   Treatment Product Sampling and
        Analysis

Soil washing is not a stand-alone  process (see Section  2.1.
1). It generates residuals that must be treated further and
disposed of properly. Because the nature of soil washing
equipment   and  procedures  varies   greatly  between
manufacturers, remedy  design  testing  is  necessary to
evaluate the type, quantity, and properties of residuals.

Analyze  the  washed  soil  and each  of  the various
wastestreams  (wash water,  fine sediment, etc.) for the
contaminants identified in the original soil  analyses. In many
cases, indicator contaminants, which are representative of a
larger group of contaminants, can be analyzed in place  of a
full scan.  Caution  must be  exercised in using indicator
contaminants since soil washing efficiencies can vary from
one contaminant to another. The process efficiency may be
either understated or overstated when analyzing for indicator
compounds.

If several soil washing studies are run to  test the effects of
operating parameters on washing efficiency (i.e., the addition
of surfactants, chelating agents, etc.), samples should be
taken of each test before and after soil washing. Typically,
these tests are run in triplicate.

4.4.5   Sampling and Analysis Plan (SAP)
         and Quality Assurance Project
         Plan (QAPjP)

A SAP is required for all field activities conducted during the
RI/FS. The SAP consists of the Field Sampling Plan and the
QAFjP. This section of the Work Plan describes  how the
RI/FS  SAP is modified to  address field sampling, waste
characterization,   and  sampling  activities  supporting
treatability studies. It describes the samples to be collected
and specifies the level of QA/QC required. See Section 5 for
additional information on the SAP.

4.5   DATA ANALYSIS AND
      INTERPRETATION

The Work Plan should discuss the techniques to be used in
analyzing and interpreting the data. The objective of  data
analysis and interpretation is to provide sufficient information
to the RPM and EPA management to assess the feasibility
of soil washing as an alternative technology. After remedy
selection testing  is complete, the decision  must be made
whether to proceed to the remedy design testing tier, to a
full-scale soil washing remediation, or to rule out soil washing
as an alternative. The data analysis  and interpretation are a
critical part of the remedy selection process.

Methods commonly  used  to  analyze and  interpret  data
generated in the  soil  washing process, such as particle size
distribution of the soil, chemical analysis of the contaminants
present, and test process variables, apply to all three tiers of
the soil washing treatability study.

The particle size distribution of the soil is a standard physical
characterization  technique.  Recent studies indicate  that
contamination is often distributed as a function of soil particle
size. Treatment efficiency is a function of particle size as
well. Three particle size ranges have been frequently studied:
>2 mm, 0.25 to 2 mm, and O.25 mm. These fractions are
obtained from U.S.  Standard  Sieve Series  #10 and #60.
Figure 4-1 shows the applicable particle size ranges plotted
against the sieve throughput percent by weight.02°

Range I consists of coarse soils.  Soils in Range I are
economically washed with simple particle  size separation
when contaminants are concentrated in the smaller particles.
When fractionation  does  not  occur,  as is the   case
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                                                         Sand
                                                        Average  , Large
                       Gravel
                       Average  , Large
                              Soil Washing
                               (Range
                                                       Soil Wash with
                                                    Specific Washing Fluid
                                                         (Range II)
                       Economic Wash
                      with Simple Particle
                       Size Separation
                          (Range I)
                  0.001  0.002
                              0.006 0.01 0.02    0.063 0.1   0.2       0.6  1   2       6

                                              Diameter of Particle in Millimeters
                                 FIGURE 4-1.  Soil washing applicable particle size range.
                                                                                       20
                                                                                               60  100
with lead, there  is no improvement in the economics of
separation when the soil is in Range I.

Soils in the area to the right of Range I are primarily stone
and large gravel. Particle size  separation is normally not
feasible for these materials due to their, large size. However,
soluble contaminants may be removed from such soils in the
wash water.

Most contaminated soils  lie in Range  II.  The types of
contaminants present govern, the composition of wash fluids
and affect the overall process efficiency. Process efficiency
is also affected by soil  particle distribution patterns and the
                                    250.
   fractionation of contaminants in fine particles. Both particle
   size  separation  and  contaminant  solubilization  can  be
   important for cost-effective treatment of soils in Range II.

   Soils in Range III consist primarily of fine sand, silt, and clay.
   Frequently, such soils have high humic content and organics
   may be strongly adsorbed. Particle size separation may be
   effective in concentrating contaminants adsorbed to particles
   in this  size range into a smaller volume.0 2)

   Figure  4-2  is   a  hypothetical contaminant  distribution
   histogram  for  soil.  The histogram  represents results  of
   chemical analyses on contaminated bulk and fractionated soil
                                                                               0.45
                                                  2.0mm

                                                       Soil Size Fraction
                                 FIGURE 4-2.  Hypothetical contaminant distribution by soil
                                           fraction before and after treatment.
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before and after two treatments. The soil was treated with
water at ambient temperature and hot water. The data show
that contaminant is concentrated in the <2 mm soil fractions.
Water at ambient  temperature was  able  to  reduce the
contamination in the >2 mm fraction to 10 parts per million
(ppm) (a  contaminant reduction  of approximately  94
percent). Hot water improved the performance by reducing
the contaminant concentration  to 0.45 ppm in the >2 min
fraction (a contaminant reduction  of over 99 percent).
Contaminant concentrations in  the other fractions (0.25 to 2
mm and <0.25  nun) were not  appreciably affected by soil
washing.

Figure 4-3 shows  a plot of agitated contact time  against
contaminant  removal  efficiency  and final  contaminant
concentration in the >2 mm soil fraction. The contaminant
concentration in each soil fraction would normally be plotted
at each time point. In this graph, the initial concentration is
500 ppm and the contaminant cleanup goal is 200 ppm. It is
apparent that the agitated contact time must be a minimum
of 14 minutes to provide contaminant removal efficiencies
that meet the cleanup goals. The effectiveness of treatment
can be expressed as a percent reduction of contaminant. In
this case,  there is  a 60 percent reduction in  contaminant
concentration in the >2 mm soil fraction at 14 minutes. The
figure  also demonstrates that,  for  the soil studied,  mixing
times of greater than 14 to 15 minutes result in diminishing
returns. The shape of this  curve will be different for each
soil.
   An objective of the remedy selection soil washing treatability
   testing is to determine how the treatment is affected by the
   process  design variables. These variables  may  include
   soil-to-wash water ratio, type of mechanical agitation used,
   agitated  contact time, rinse-water-to-wash  water  volume
   ratio, wash water temperature, system pH, and wash water
   additives. Often, two or more of these variables may affect
   the results. Statistical analysis of the data can be performed
   using standard techniques to differentiate sources of change
   and interactions between these sources. For a  detailed
   discussion of the ANOV A techniques, refer to the document
   entitled Statistical Analysis of Groundwater Data at RCRA
   Facilities (Interim Final)(20) and Brookes, et al.(5)
   4.6    REPORTS

   The last step of the treatability study is reporting the results.
   The Work Plan discusses the organization and content of
   interim and final reports. Complete,  accurate reporting is
   critical because decisions about implementability will be
   partly based on the outcome of the study. The RPM may not
   require formal reports at each soil washing study tier. Interim
   reports should be prepared after each  tier. Project briefings
   should be made to  interested parties to determine the need
   for and  scope  of the next tier of testing. To facilitate the
   reporting of results and comparisons between treatment
   alternatives, a sug-
                     |  SO
                             Contaminant Claanup
                             Goal>200ppm
                                         _L
   J_
                                          10       16       2C       25
                                           Agitated Contact Tint (minutes)
                                                                           30
                   FIGURE 4-3. Plot of agitated contact time versus contaminant removal efficiency
                          and final contaminant concentration in the >2 mm soil fraction.
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TASK
Tatkl
Work Plan Preparation
Task 2
SAP, HSP, & CRP Preparation
TaskS
Treatability Study Execution
Task 4
Data Analysis & Interpretation
TaskS
Report Preparation
Task 6
Residuals Management
Span,
Weeks

4

6

12

2
12

12
Week* from Project Start
T|7
3
M-l









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4
M
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-2
7
d
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7 I8


9|lo|ll|l2


M-3 M-4
— '-7






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13




-5
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14(15(16




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19




20




-6 M-7
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-8









21(22(23(24




M-9
•w
^f
(^
JJ

25 26|27|28







M-12 M
29)30







13 M









15
M-10 M-ll M-14 M-16

1 1

       •••• - Administrative approval, document review, or sample turnaround

       M-l  Submit Work Plan                   Wk2
       M-2  Receive Work Plan Approval           Wk4
       M-3  Submit SAP, HSP, CRP               Wk8
       M-4  Receive SAP, HSP Approvals           Wk10
       M-5  Collect Sample                     Wk 12
       M-6  Receive Sample Characterization Results  Wk 16
       M-7  Collect Treatability Study Samples       Wk18
       M-8  Collect Project Residual Samples        Wk 18
 M-9.  Receive Treatability Study Analytical Results  Wk 22
 M-10 Receive Project Residual Analytical Results   Wk22
 M-11 Submit Waste Disposal Approval Form       Wk 24
 M-12 Submit Draft Report                    Wk26
 M-13 Receive Review Comments               Wk28
 M-14 Receive Waste Disposal Approval          Wk 28
 M-15 Submit Final Report; Conduct Briefing       Wk30
 M-16 Ship Wastes to TSDF                   Wk30
                            FIGURE 4-4.  Example Droiect schedule for a treatabilitv study.
gested table of contents is presented in the generic guide.(15)
At the completion of the study, a formal report is always
required.

OERR requires that a copy of all treatability study reports be
submitted to the Agency's Superfund Treatability DataBase
repository.  One copy of each treatability  study report must
be sent to:

    U.S. Environmental Protection Agency
    Superfund Treatability Data Base
    ORD/RREL
    26 West Martin Luther King Dr.
    Cincinnati, Ohio 45268

4.7   SCHEDULE

The Work Plan includes a schedule  for completing  the
treatability study. The schedule gives the anticipated starting
date and ending date for each of the tasks described  in the
Work Plan and shows how the various tasks interface.
The time span for each task accounts for the time required
to obtain the Work Plan, subcontractor, and other approvals
(e.g., disposal approval from a commercial TSDF); sample
curing time, if necessary; analytical turnaround time;  and
review and comment period for reports and other project
deliverables. Some slack time also should be built  into the
schedule to accommodate  unexpected  delays  (e.g.,  bad
weather, equipment downtime) without affecting the project
completion date.

The schedule is usually displayed in the form of a bar chart
(Figure 4-4). If the study involves multiple tiers of testing, all
tiers should be shown on one schedule. Careful planning
before the start of the tests is essential. Depending on the
review and approval process, planning can take up to several
months. Barring any difficulties, such as acquiring sampling
equipment and site  access, the  field  work  phase  can
generally be  accomplished in  two weeks. Setup  of the
laboratory and procurement of necessary equipment and lab
supplies for treatability studies may take a month. Analytical
results can be available in less than 30 days, depending on
how rapidly laboratory results can be pro-
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              LAB TECHNICIANS
           • Execute Treatability
            Studies
           • Execute sample collection
            and analysis
                                               CONTRACT WORK
                                            ASSIGNMENT MANAGER
                                            • Report to EPA Remedial
                                              Project Manager
                                            • Supervise overall project
     GEOLOGIST
> Oversee Treatability Study
 execution
> Oversee sample collection
> Prepare applicable sections
 of Report and Work Plan
                                     QA MANAGER
                                 > Oversee Quality
                                  Assurance Program
                                 > Prepare applicable
                                  sections of Report and
                                  Work Plan
      CHEMIST
• Oversee sample collection
 procedures and analysis
• Prepare applicable section
 of Report and Work Plan
                                         FIGURE 4-5. Organization chart.
vided. Shorter analytical turnaround time can be requested
but this will normally double the costs. Compounds such as
pesticides and PCBs may require longer turnaround times
due to the extractions and analyses involved. Depending on
the objectives., the duration of treatability  tests may  be
longer.
             Responsibility for various aspects of the project is typically
             shown in an organizational chart such as the one in Figure
             4.5
             4.9   BUDGET
Interpretation of the results and final report writing may take
1 to 2 months,  but this is highly dependent on the review-
process. Remedy screening tests typically take  from a few-
hours to several days. It is not unusual for the remedy
selection soil washing treatability test to be a 2 to 3 month
project.
4.8    MANAGEMENT AND STAFFING

The Work Plan discusses the management and staffing of
the remedy selection treatability study.  The Work Plan
specifically identifies the personnel responsible for executing
the treatability study by name and qualifacations.  Generally,
the following  expertise  is  needed  for the  successful
completion of the treatability  study:

•  Project Manager (Work Assignment Manager)
•  Chemist
•  Geologist
•  Lab Technician
             The Work Plan discusses the budget for completion of the
             remedy selection treatability study. Testing costs for remedy-
             selection depend on a variety of factors. Table 4-2 provides
             a list of potential major cost estimate components this tier.
             For most tests, the largest single expense is the
             analytical program.

             TABLE 4-2.Major Cost Elements Associated with
                 Remedy Selection Soil Washing Studies
                           Cost Element
              Initial Data Review
              Work Plan Preparation
              Field Sample Collection
              Field Sample Chemical Analysis
              Laboratory Setup/Materials
              Treatability Test Chemical Analysis
              Data Presentation/Report
                     Cost Range
                     (1,000s of dollars)
                     1 -10
                     1 -5
                     1 -10
                     5-25
                     5-25
                     5-20
                     2-5
              TOTAL COST RANGE
                     20-100
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Sites  where  the  soil  types,  contaminant  types,  and
contaminant concentration vary widely will usually require
more samples than sites where the soil and contamination is
more homogeneous.  It  is not unusual  for  the sampling,
analysis, and QA activities to represent 50 percent of the
total testing cost. In general, the costs for analyzing organics
are more expensive than for metals. Actual costs will vary
according to  individual laboratories, required turnaround
times,  volume discounts,  and  any customized  testing.
Sampling costs will be influenced by the contaminant types
and depth of contamination found in the  sod. The health and
safety  considerations during  sampling  activities  are more
extensive when certain contaminants (e.g., volatile organics)
are present in the soil. Level B personal protective equipment
(PPE)  rather than Level D PPE  can increase the cost
component an order of magnitude. Sampling equipment for
surface samples is much less complicated than equipment
used for depth  samples.  Depending on the  number of
samples and tests specified, residuals  management (e.g.,
contaminated soil  fraction and wash waters) will require
proper treatment and/or disposal. Treatment and disposal of
   the   residuals  as  hazardous  wastes   increases  costs
   significantly.

   Other factors to consider include report preparation and the
   availability  of vital  equipment and laboratory  supplies.
   Generally, an initial draft of the report undergoes internal
   review prior to the final draft. Depending on the process,
   final report preparation can be time consuming as well as
   costly. Procurement of testing equipment (e.g., reciprocating
   shaker table) and laboratory  supplies (e.g., reagents and
   glassware) will also increase the costs.

   Typical costs for remedy selection tests are estimated to be
   from  $20,000 to $100,000. Remedy screening, with  its
   associated lack of replication and detailed  testing, ranges
   from 25 to 50 percent of these costs. These estimates are
   highly  dependent on the factors  discussed  above.  Not
   included in these costs are the  costs of governmental
   procurement  procedures,  including soliciting  for  bids,
   awarding contracts,  etc.
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                                            SECTION 5
                         SAMPLING AND ANALYSIS PLAN
The  Sampling and Analysis Plan (SAP) consists of two
parts-the  Field  Sampling  Plan  (FSP)  and  the  Quality
Assurance  Project Plan (QAPjP).  The purpose  of this
section is to identify the contents and aid in the preparation
of these  plans.  The RI/FS  requires a SAP for all field
activities. The SAP ensures that samples obtained for
characterization and testing are representative  and that the
quality of the analytical data  generated  is  known and
appropriate.  The  SAP  addresses  field  sampling,  waste
characterization, and sampling and analysis of the treated
wastes and residuals from the testing apparatus or treatment
unit. The SAP is usually prepared after Work Plan approval.

5.1    FIELD SAMPLING PLAN

The  FSP component of  the SAP describes the sampling
objectives; the type, location and number of samples to be
collected; the sample numbering system; the equipment and
procedures  for  collecting  the  samples;  the  sample
chain-of-custody procedures; and the required packaging,
labeling, and shipping procedures.

The  sampling objectives  must be  consistent with the
treatabiliry test objectives. The primary objective of remedy
selection treatability studies is to evaluate the extent to which
specific chemicals are removed from the soil.  The primary
sampling objectives include:
    Acquisition  of samples representative  of conditions
    typical of the entire site or defined areas within the site.
    Because a mass balance is required for this evaluation.
    statistically  designed  field sampling plans  may  be
    required. However, professional judgment regarding the
    sampling locations may be exercised to select sampling
    sites that are typical of the area (pit. lagoon, etc.) or
    appear above the average concentration of contaminants
    in the area being considered for the treatability test.
    Selection  may  be  difficult  because   reliable  site
    characterization data may not be available early in the
    remedial investigation.
   •   Acquisition of sufficient sample volumes necessary for
      testing,  analysis,  and quality  assurance and  quality
      control (QA/QC).

   From these two primary objectives, more specific objectives
   are  developed.  When  developing  the  more  detailed
   objectives, consider the following types of questions:

   •   Will  samples  be   composited  to   provide  more
      representative samples for the treatability test, or will the
      potential loss of target volatile  organic compounds
      prohibit this sample collection technique?

   •   Is there adequate data to determine sampling locations
      indicative of the more contaminated  areas of the site?
      Contaminants may be widespread or isolated in small
      areas (hot spots). Contaminants may be mixed with other
      contaminants in one location and appear alone in others.
      Concentration profiles may vary significantly with depth.

   •   Are the soils homogeneous or heterogeneous? Soil types
      can vary across a site  and will vary with depth. Changes
      in soil composition can reduce the effectiveness of soil
      washing.

   •   Is sampling of a "worst-case" scenario warranted? The
      decision on whether to perform remedy selection testing
      on specific areas or composite samples is difficult and
      must be made on a  site-by-site basis. Hot spots and
      areas with  soils that may be difficult  to treat should be
      factored into the test plan if they represent a significant
      portion of the waste site.

   After  identifying the  sampling  objectives, an appropriate
   sampling strategy is described. Specific items that should be
   briefly discussed in the FSP and QAPjP are listed in Table
   5-1.

   Table 5-1 presents the suggested organization of the Sam-
   pling and Analysis Plan.
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    TABLE 5-1. Suggested Organization of Sampling and
	Analysis Plan	
 Field Sampling Plan
 1 .     Site Background
 2.     Sampling Objectives
 3.     Sample Location and Frequency
        - Selection
        - Media Type
        - Sampling Strategy
        - Location Map
 4.     Sample Designation
        - Recording Procedures
 5.     Sample Equipment and Procedures
        - Equipment
        - Calibration
        -Sampling Procedures
 6.     Sample Handling and Analysis
        - Preservation and Holding Times
        -Chain-of-Custody
        -Transportation
 Quality Assurance Project Plan
 1.     Project Description
        -Test Goals
        - Critical Variables
        -Test Matrix
 2.     Project Organization and Responsibilities
 3.     QA Objectives
        - Precision, Accuracy, Completeness
        - Representativeness and Comparability
        - Method Detection Limits
 4.     Sampling Procedures
 5.     Sample Custody
 6.     Calibration Procedures and Frequency
 7.     Analytical Procedures
 8.     Data Reduction, Validation, and Reporting
 9.     Internal QC Checks
 10.    Performance and System Audits
 11.    Preventive Maintenance
 12.    Calculation of Data Quality Indicators
 13.    Corrective Action
 14.    QC Reports to Management
 15.    References
 16.    Other Items	


5.2    QUALITY ASSURANCE PROJECT
        PLAN

5.2.1     Experimental  Design

Section 1 of the QAPjP must include an experimental project
description that clearly defines the experimental design, the
experimental  sequence of events, each type  of critical
measurement to be made, each type of matrix (experimental
setup)  to be  sampled, and  each type of system  to  be
monitored. This section may reference Section 4 of the Work
   Plan. All details of the experimental design not finalized in
   the Work Plan should be defined in this section.

   Items to be included, but not limited to, are:

   •   Number of samples (area) to be studied

   •   Identification of treatment conditions (variables) to be
      studied for each sample (i.e., wash time,  wash water-
      to-soil ratio,  rinse water-to-wash  water ratio, and
      additives to be evaluated)

   •   Soil size fractions

   •   Target compounds for each  sample

   •   Number of replicates per treatment condition

   The Project Description clearly defines and distinguishes the
   critical measurements  and observations  made and system
   conditions (e.g., process controls, operating parameters, etc.)
   routinely  monitored.  Critical  measurements are  those
   measurements, data gathering, or data generating activities
   that directly affect the technical  objectives of a project. At a
   minimum,  the  determination  of the   target compound
   (identified above) in  the untreated and treated soil samples
   and the particle size distribution  of the untreated soil will be
   critical measurements.

   The purpose of the remedy selection treatability study is to
   determine whether soil washing  can meet cleanup goals and
   provide  information to support the detailed  analysis  of
   alternatives  (i.e., seven of the nine evaluation criteria). An
   example of a criterion for this determination is  a removal of
   approximately 90 percent  of the contaminants. The exact
   removal efficiency specified as the goal for the remedy
   selection test is site specific.

   5.2.2    Quality Assurance Objectives

   Section  2  lists  the  QA objectives   for  each  critical
   measurement and sample matrix defined in Section 1. These
   objectives are presented in terms of the six  data quality
   indicators:   precision,   accuracy,   completeness,
   representativeness, comparability, and,  where applicable,
   method detection limit.

   5.2.3    Sampling Procedures

   The procedure used to obtain field samples for the treatability
   study  is described  in  the FSP.   They  need  not be
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repeated in this section, but should be  incorporated by
reference.

Section 3 of the QAPjP contains a description of a credible
plan for subsampling the material delivered to the laboratory
or the treatability study. The methods  for aliquoting the
residual material in each size fraction for different analytical
methods must be described.
   determine if the analytical method performance is consistent
   (relatively  accurate). The method  blank will  show if
   laboratory contamination has had an impact on the analytical
   results.

   Selection of appropriate surrogate compounds will depend on
   the target compounds identified in the soil and the analytical
   methods selected for the analysis.
5.2.4    Analytical Procedures and
          Calibration

Section 4 describes  or references appropriate  analytical
methods and standard operating procedures for the analytical
method for each critical measurement made. In addition, the
calibration procedures and frequency  of calibration  are
discussed  or  referenced for  each  analytical system,
instrument,  device,   or  technique  for  each  critical
measurement.

The methods for analyzing the treatability study samples are
the same as those for chemical characterization of field
samples. Preference is given to methods in "Test Methods
for Evaluating Solid  Waste, SW-846, 3rd. Ed., November
1986.(23)  Other  standard methods  may  be  used,  as
appropriate.(17)   Methods   other   than    gas
chromatography/mass  spectra  (GC/MS)  techniques are
recommended to conserve costs when possible.

The purpose of the remedy selection treatability study is to
determine whether soil washing can meet cleanup goals and
provide information  to support  the detailed analysis of
alternatives (i.e., seven of the nine evaluation criteria). An
example of a criterion for this determination is a removal of
approximately  90  percent  of contaminants. The  exact
removal  efficiency specified as  the goal for the remedy
selection test is site-specific. The suggested  QC approach
will consist of:

•  Triplicate samples of both reactor and controls

•  The analysis of surrogate spike compounds

•  The extraction and analysis  of method blanks

•  The  analysis of  a matrix  spike in approximately 10
   percent of the samples.

The analysis of triplicate samples provides for the overall
precision measurements that are necessary  to determine
whether  the  difference is  significant  at the  chosen
confidence level. The analysis  of the surrogate  spike will
   5.2.5    Data Reduction, Validation and
            Reporting

   Section 5 includes, for each critical measurement and each
   sample matrix, a specific presentation of the following items:

   •   The data reduction planned for the collected data

   •   All equations used to calculate the final resultant value(s)
      from the raw critical  measurement  data, all unit
      conversions required and definitions of all terms, as well
      as the procedures for correcting analytical recovery

   •   The  procedures used to validate  data  during data
      collection, transfer, storage,  recovery,  processing,  and
      reporting steps

   •   The methods used  to identify and treat outliers (i.e., data
      that fall outside the specified QA objective windows for
      method precision and accuracy)

   •   The data reporting scheme, including the flow from raw
      data through transfer, storage, recovery, processing, and
      validation; a flowchart is usually needed

   •   Identification of the specific individuals responsible for
      data handling at each step in the reporting scheme.

   5.2.6    Internal Quality Control Checks

   Section 6 describes and references each specific internal QC
   method followed, and indicates the frequency of use. (The
   term internal refers to both soil washing tests and laboratory
   activities, and applies  to all  organizations and individuals
   involved in the project.) Examples of the types of QC checks
   include the following:

   •   Split samples

   •   Replicate samples

   •   Replicate check standards

   •   Matrix-spiked samples
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•   Matrix-spiked replicates

•   Laboratory pure water spikes (e.g., QC check samples)

•   Surrogate spike compounds

•   Internal standards

•   Blanks (method, reagent, and/or instrument)

•   Control charts (e.g., for calibration acceptance limits)

•   Calibration standards and devices (traceable)

•   Reagent checks (for all sample preparation and analysis
    methods involving the use of laboratory reagents)

•   In-house  proficiency  testing program  to  determine
    analyst's capabilities (including documented procedures).

5.2.7   Performance and  Systems Audits

Section 7 describes the internal performance evaluation and
technical system audits planned to monitor the capability and
performance   of  the systems  for  obtaining  critical
measurement data.

At a minimum, a person independent of the analysis submits
a quality  control  sample for all or  some  of the target
compounds to the analytical laboratory. The results of the
extraction  and analysis document the capabilities of the
personnel with the prescribed procedures.

5.2.8   Calculation of Data Quality
          Indicators

Section 8 describes the specific procedures that assess, on a
routine basis, the  precision,  accuracy, completeness, and
method detection limit  (MDL) characteristic of each critical
measurement  for each sample  matrix.  Specifically, the
following items are included:

•   A brief description of each test procedure for each data
    quality indicator, measurement, and sample type

•   Identification of the specific QC data used in each test
    procedure

•   A  brief discussion defining  the statistical  or  mathe-
    matical methods used
   •   Specific equations used to calculate each data quality-
      indicator, including definitions of reporting units of each
      term in the equations

   •   A statement of the frequency of each type of test.

   5.2.9   Corrective Action

   Section 9 describes the criteria and procedures by which
   initial corrective actions are implemented. These descriptions
   include the following elements:

   •   The  predetermined limits for data acceptability;  data
      outside these limits require corrective action

   •   The  procedures  for  corrective  action,  from initial
      recognition of the condition requiring corrective action,
      through reporting  of  the condition, approval  of the
      appropriate   corrective   action   to   be  taken,
      implementation, and reporting of the results

   •   Identification of the individuals responsible for initiating,
      approving, implementing, and reporting the effectiveness
      of corrective actions.

   5.2.10    Quality Control Reports

   Section 10 describes the QA/QC information that will be
   included in the final project report. As a minimum, reports
   include:

   •   Changes to the QA Project Plan, if any

   •   Limitations or constraints on the applicability of the data,
      if any

   •   The status of QA/QC  programs, accomplishments and
      corrective actions

   •   Results of technical systems and performance evaluation
      QC audits

   •   Assessments of data quality in terms  of precision,
      accuracy,   completeness,  method  detection   limit,
      representativeness, and comparability.

   The final report contains all the QA/QC information to
   support the credibility  of  the data and  the validity of the
   conclusions.  This information  may be presented in  an
   appendix to the report. Additional information on data quality
   objectives01\ quality assurance programs(13), and preparation
   of QAPjPs(19) is available in EPA guidance documents.
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                                           SECTION 6
                   TREATABILITY  DATA INTERPRETATION
Proper evaluation of the  potential of soil washing  for
remediating a site must compare the test results (described
in Section 4.5) to the test objectives (described in Section
4.1) for each tier. The evaluation is interpreted in relation to
seven of the nine RI/FS evaluation criteria, as appropriate.
The  remedy screening  tier establishes the  general
applicability of the technology.  The remedy  design  tier
provides information in support of the evaluation criteria. The
test objectives are based on  established cleanup goals or
other  performance-based specifications  (such as waste
volume reduction). Soil washing testing must consider the
technology as part of a treatment train.

Section 4.6 of  this guide  discusses the need  for  the
preparation  of interim and final  reports  and  provides a
suggested format. In addition to the raw and summary data
for the treatability study and associated QC, the treatability
report should describe what the results mean and how to use
them  in   the  feasibility  study  in  screening/selecting
alternatives. The report must evaluate the performance of
the technology and give an estimate of the costs of further
treatability studies and final remediation with the technology.
   6.1   TECHNOLOGY EVALUATION

   Remedy  screening treatability studies typically consist of
   simple jar tests. The contaminant concentration in the soil
   before  washing  is  compared   to  the  contaminant
   concentration in the  coarse soil fraction after washing. A
   reduction  of  approximately  50  percent  of the  soil
   contaminants during  the test indicates additional treatability
   studies are warranted. Contaminant concentrations can also
   be determined for wash water and fine soil fractions. These
   additional analyses add to the cost of the treatability test and
   may not  be  needed. Before and after  concentrations can
   normally  be based on duplicate samples  at each time period.
   The mean values are compared to assess the success of the
   study.  A number of statistical texts are available if more
   information is needed.(4)(7)

   Jar tests can  frequently be skipped when information about
   the soil type and contaminant solubilities is sufficient to
   decide whether remedy selection studies will be useful. An
   example of a prescreening evaluation and decision to bypass
   ajar test is provided in Example 3.
                                               Example 3

 A site in New Jersey has been used for the manufacture and storage of arsenic-containing pesticides. Soils
 at the site are contaminated with arsenic at levels ranging from 10 to 1,500 mg/ kg. The arsenic
 contamination is limited to the top 3 feet of soil. Sieve testing has shown that the upper 3 feet of soil contains
 75 percent coarse sand and gravel (75 percent >2 mm diameter particles) by weight. Risk assessment
 studies conducted during the Rl suggest that a cleanup goal of 100 mg/kg arsenic in onsite soils would be
 acceptable.

 Previous studies indicated that many contaminants tend to be adsorbed on fine soil particles. Given this
 scenario, one can predict that there is at least a moderate chance that soil washing will be effective. It is
 entirely possible that the process will be able to reduce the arsenic content in 75 percent of the soil to 100
 mg/kg or less. In this case, screening tests may be skipped in favor of conducting remedy selection tests
 that would determine optimal soil washing conditions (pH, additives, temperature, mixing/contact time,
 wastewater treatment) and performance at bench scale.
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Sections 4.1 and 4.2 of this guide discuss the goals and
design of remedy selection treatability studies, respectively.
Typically, soil   contaminant  concentrations  before  soil
washing and contaminant concentrations  in  the  coarse
fraction  after soil washing are measured in  triplicate. A
reduction of  approximately  90 percent  in  the  mean
concentration indicates soil washing is potentially useful in
site remediation. A number  of other  factors must be
evaluated before deciding to  proceed  to remedy  design
studies.

The final concentrations of contaminants in the recovered
(clean) soil fraction, in the  fine soil fraction and wastewater
treatment sludge, and in the wash water are important to
evaluating the feasibility of soil washing. The selection of
technologies to treat the fine soil and wash water waste-
streams  depends  on the types  and  concentrations  of
contaminants present. The volume reduction achieved is also
important to the selection of soil washing as a potential
remediation technology.

In scaling the cost and performance estimates from remedy
selection testing to remedy  design testing or a full-scale soil
washing system, the factors for consideration are:

Performance capabilities  of the soil  washing process.
including design  parameters

•   Contaminants and contaminant concentrations  in the
    coarse soil fraction

•   Contaminants and contaminant concentrations  in the
    used wash water and in the fine soils and  wastewater
    treatment sludges

•   Risk analysis evaluation for worker and  community
    protection

•   Quantity of large rocks,  debris, arid  other screenable
    material

The design parameters for the soil washing process include
soil throughput, in dry tons per hour, and optimum wash
water usage in gallons per dry ton of soil. The dosage  of
additives, if used, mixed with wash water is also important
for cost and performance estimates.

It  is important to  estimate the volume  and physical and
chemical characteristics of each soil fraction. Estimates  of
the volume of and contaminant concentrations in the fine soil
fraction are needed to design treatment systems and estimate
disposal costs. Recycled water can be used to evaluate the
   cost of filtration and other dewatering equipment. The ability
   to remove contaminants from spent wash water and recycle
   the  water  through  the  system  is  an  important cost
   consideration.

   Wash water is treated for recycle in the washing process.
   Treatment includes separation of fine soil particles. Other
   treatment  steps may  be  necessary to  remove organics,
   inorganics, and additive chemicals. Scale-up design requires
   estimates of wash water volume and quality.

   Contamination in excavated soil can pose safety concerns for
   workers and the community. Worker protection may  be
   required during soil excavation. The need for such protection
   is a site-specific decision. Health and safety plans should be
   prepared and risk analysis conducted for the site.

   The quantity of large rocks, debris, and other screenable
   material that must be removed is an important measurement.
   While this is not a "laboratory" measurement, it is important
   to determine which treatment method is most suitable for
   preparing the bulk soil for entry into the soil washing process
   (i.e., screening to remove large rocks, stumps, debris, and
   crushing of oversize rocks, etc.).

   6.2     ESTIMATION OF COSTS

   Accurate  cost estimates  for remedy design  treatability
   studies and full-scale remediation are crucial to the feasibility
   study process. Comparisons of various technologies must be
   based on the most  complete and accurate estimates
   available, Remedy screening treatability studies cannot
   provide this type of information. Remedy selection treatability
   studies can provide  relatively accurate cost estimates for
   remedy  design studies. Preliminary cost  estimates for
   full-scale remediation may  be made from remedy selection
   data. Such estimates may be good enough for comparisons
   to other technologies at the same tier of testing. On this basis,
   the estimates can form the  basis of the ROD.  Remedy
   design studies may be necessary to provide a more accurate
   estimate  of the eventual  cost of full-scale soil  washing
   remediation. This is  especially true since soil washing will
   form only one component of a treatment train. The treatment
   costs  for sludge and  wastewater  from the soil  washing
   process must also be evaluated.

   6.2.1   Soil Washing Remedy Design
           Cost Estimates

   If the results of remedy selection treatability testing indicate
   that soil washing  can be  effective, consideration may  be
   given  to remedy  design  testing.  Remedy  design tests
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yield more accurate estimates of full-scale performance and
costs. This discussion provides general guidance on the cost
estimating and scheduling of remedy  design soil washing
demonstrations.

Few remedy design soil washing demonstrations have been
done  in  the  United States.  A  solid  data base  of  cost
estimating and scheduling information does not yet exist. The
information in this section is largely derived from EPA RREL
experience  with its portable soil washing unit, informational
estimates by the few manufacturers offering remedy design
soil washing equipment and recent experience with the EPA
SITE Program. A summary of the performance data and a
review of the technology are presented in a Soil Washing
Engineering Bulletin.112)

Remedy Design Soil Washing Equipment Availability:
As of Fall  1989 only three sources of a portable remedy
design soil washing units were identified:

•  BioTrol, Inc.. Chaska, Minnesota

•  Ecova Corp.. Redmond, Washington

•  EPA RREL Laboratory, Edison, New Jersey

Mitarri, Inc., Golden, Colorado, reportedly plans to develop a
remedy design unit. For the SITE Program, a remedy design
BioTrol  soil washing unit was recently demonstrated and
evaluated in New Brighton, Minnesota.

Remedy Design Testing Cost: Many of the cost  consid-
erations in a remedy design soil washing test are similar to
those of the remedy selection. Table 6-1 lists potential major
cost  estimate components in a remedy design soil washing
field  test. Some of the items in  this table also pertain to
remedy  selection  testing. The cost considerations include
planning,   treatment,   laboratory   testing,   and   report
preparation. Substantial planning is necessary to assure that
tests  meet  desired objectives. Additional  insurance  and
permits   may  be  required.  As   with  remedy  selection
demonstrations, the analytical program can be the largest
cost component. It is not unusual for the sampling, analysis,
and QA activities to represent 50 to 60 percent of the  total
remedy design testing cost. Remedy design testing requires
personnel safety protection for soil excavation and handling.
Working under Level A or B protection can easily triple labor
costs. The treatment and disposal of contaminated residuals
(soil,  sludge,  water) can be a major expense. For these
reasons,  remedy design testing costs  are highly variable
depending on a variety of factors  discussed above.
   The cost of remedy design testing is highly site-specific and
   dependent upon the  test objective.  As a rough estimate,
   remedy design field tests could be expected to range from as
   low as $100,000 up to $500,000 (1989 costs) or more.

          TABLE 6-1. Potential Major Cost Estimate
           Components  in a Remedy Design Soil
                    Washing Field Test
    1.     Planning- substantial advanced planning is usually
          necessary to assure that the demonstration
          proceeds smoothly and meets the desired
          objectives, including any necessary insurance,
          permits,  etc.

    2.     Excavation, transport (if needed), and storage (if
          needed)  of the soil to be treated  during the
          demonstration.
    3.     Design and construction (as required) of temporary
          onsite support facilities, including water supply,
          power, wastewater discharge, storage of additive
          chemicals, and personnel facilities (office, storage,
          field testing space, restrooms, showers, etc.). A
          detailed  sampling analysis and QAPjP is
          necessary.
    4.     Analytical support, e.g., local laboratory, mobile
          field laboratory, etc. A detailed sampling analysis
          and QAPjP is necessary.
    5.     Treatment and/or disposal  of contaminated
          residuals, e.g., the contaminated soil fraction,
          sludges, screened-out debris, etc.
    6.     Supply of chemicals, water, power, spare parts,
          personnel protection equipment, etc.
    7.     Lease or rental of the remedy design unit and
          auxiliary equipment including transport to the site.

    8.     Provision for operating, maintenance, and
          analytical labor. Usually, personnel are trained for
          handling hazardous materials safely in addition to
          their other job-specific qualifications.
    9.     Implementation of the remedy design
          demonstration in accordance with the detailed
          Work Plan.
    10.    Decontamination, demobilization, and return
          transport of remedy design soil washing unit and
          auxiliary equipment.

    11.    Return of operating site to pre-agreed condition.
    12.    Laboratory testing.
    13.    Report preparation.
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6.2.2   Full-Scale Soil Washing Cost
         Estimates

There are no full-scale soil washing operations in use at
Superfund  sites identified at the present  time. A limited
number of firms (e.g., Ecova, BioTrol) are marketing  their
soil washing processes. In Europe, full-scale soil washing
facilities are operating in Germany and the Netherlands. Cost
information  is largely  in  technical  articles written by
representatives of the German firm, Harbauer GmbH. The
capital  cost of the Harbauer facility is  reported to be
approximately $6 million (1986 dollars) for a 15 to 20 ton/hr
facility. The reported  operation  and maintenance  (O&M)
costs for processing alone at the Harbauer Site are $150 per
ton of soil,  including  the cost of water treatment, but not
including sludge disposal. If sludge weight was assumed to
be 20 percent of the incoming soil  weight, and sludge disposal
cost assumed to be $250 per ton,  the estimated cost per ton
of treated soil would be about $200 including sludge disposal.

Other European  soil  washing  operations  that  are less
complex than the Harbauer GmbH Berlin  operation report
soil washing processing costs of about $80 to $120 per metric
ton  or  $73 to $110  per  ton. Their costs  are generally-
presented in mid-1980's dollars  and details of how these
costs were determined are lacking. Table 6-2 lists the major
cost components for a hypothetical  full-scale soil washing
operation.
      TABLE 6-2. Major Cost Estimate Components in a
             Full-Scale Soil  Washing Operation3
    1.    Soil excavation.
    2.    Transport of excavated soil to the processing unit.
    3.    Temporary stockpiling of excavated soil.
    4.    Prevention  of contaminant releases to the
          environment during Steps 1 through 3 above due to
          rain, wind, volatilization, carelessness, etc.
    5.    Bulk soil pretreatment steps  such as screening,
          crushing, and physicat/chemical characterization.
    6.    Management of the screened-out rocks, roots,
          debris, etc.
    7.    Wash water supply  facilities, e.g., storage tanks,
          pumps, piping, controls, etc.
    8.    Additive (if any) supply facilities, e.g., storage
          tanks,  pumps, piping, controls, etc.
    9.    The soil washing process  unit, which may consist
          of a series  of mixers, washers, screens,
          conveyors, cyclones, and  other units. It is
          assumed that generally this cost will be obtained
          from the manufacturer.
    10.   Temporary stockpiling, transport, and deposition of
          the adequately clean, washed soil product fraction.
    11.   The dirty wash water treatment process, which is
          usually a treatment  train that may include
          clarifiers, chemical reactors,  filters, carbon
          contactors, dewatering presses, and tanks, etc.
    12.   Recycle or disposal of the treated wastewater
          fraction.
    13.   Further treatment and disposal of the dirty soil
          fraction.
    14.   Further treatment and disposal of the water
          treatment sludge.
    15.   Permitting and legal services.
    16.   Engineering design.
    17.   Service during construction.
    18.   Contingencies.	
    a.    Note: where applicable, the engineer performing the cost
          estimate will usually break down the cost estimate
          components listed above into:
    (1)    construction (e.g., roads, foundations, buildings, etc.)
    (2)    process equipment (e.g., mixers, tanks, screens, pumps,
          clarifiers, etc,)
    (3)    material handling equipment (eg., power shovel, bulldozer,
          portable conveyor, trucks, etc.)
    (4)    labor (e.g., operators, supervisors, analytical, etc.), energy
          (e.g., electrical power, diesel fuel, etc.), utilities (e.g., water,
          sewage, etc.), materials (e.g., chemical additives, spare
          parts, etc.), and various overhead  administrative and profit
          items
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                                           SECTION 7
                                         REFERENCES
1.   American Society for Testing and Materials. Annual
    Book of ASTM Standards. November 1987.

2.   American Society of Agronomy, Inc. Methods of Soil
    Analysis, Part 1, Physical and Mineralogical Properties
    Including Statistics of Measurement and Sampling. 1982

3.   Assink, J.W.,  and  W. Van den Brink.  Extractive
    Methods for Soil Decontamination: A General Survey
    and Review of Operational Treatment Installations. In:
    Proceedings  from  the   First   International   TNO
    Conference on Contaminated Soil, Ultrecht, Netherlands,
    1985.

4.   Bevington, P.R. Data Reduction and Error Analysis
    for the Physical Sciences.  McGraw-Hill,  Inc..  New
    York, NY, 1969.

5.   Brookes,  C.J.,  I.G Bettefley,  and  S.M.  Loxston.
    Fundamentals of Mathematics and Statistics for Students
    of Chemistry and Allied Subjects.  John Wiley &  Sons,
    Chichester, Great Britain, 1979.

6.   Hites, R.A., and S.J. Eisenreich. Sources and Fates of
    Aquatic  Pollutants.  American  Chemical  Society,
    Washington, D.C., 1987.

7.   Kleinbaum, D.G, and L.L. Kupper. Applied Regression
    Analysis and Other Multivariable Methods.  Duxbury
    Press, North Scituate, MA,  1978.

8.   Lyman, W.J.,  W.F. Reehl, and D.H. Rosenblatt.
    Handbook of Chemical Property Estimation. Methods,
    Environmental  Behavior  of Organic  Compounds.
    American Chemical Society, Washington, D.C., 1990.

9.   National Institute for Occupational Safely and Health
    (NIOSH) Manual of Analytical Methods.
      U.S. Department of Health and  Human  Services,
      February 1994.

   10. U.S.  Environmental  Protection  Agency.  Cleaning
      Excavated  Soil  Using  Extraction Agents:  State-of-
      the-Art Review. EPA/600/2-89/034, 1989.

   11. U.S. Environmental Protection Agency. Data Quality
      Objectives   for  Remedial  Response  Activities.
      EPA/540/G-87/004,  OSWER  Directive 9355.0-713,
      1987.

   12. U.S. Environmental  Protection  Agency. Engineering
      Bulletin: Soil Washing. EPA/540/2-90/017, 1990.

   13. U.S. Environmental Protection Agency. Generic Quality
      Assurance Project Plan for Land Disposal Restrictions
      Program (BOAT). EPA/530-SW-87-011, 1987.

   14. U.S. Environmental Protection Agency. Guidance for
      Conducting  Remedial  Investigations  and  Feasibility
      Studies  Under  CERCLA,  Interim   Final.   EPA/
      540/G-89/004, OSWER-9335.3-01, 1988.

   15. U.S. Environmental Protection  Agency.  Guide  for
      Conducting Treatability Studies Under CERCLA, Interim
      Final. EPA/540/2-89/058, 1989.

   16. U.S. Environmental Protection Agency. Lead Battery
      Site Treatability Studies, Project Summary'. 1989.

   17. U.S. Environmental Protection Agency. Methods for
      Chemical  Analysis  of Water  and  Wastes.  EPA/
      600/4-79/020, 1979.

   18. U.S. Environmental Protection Agency. Methods for
      Evaluating the Attainment of Cleanup Standards, Volume
      1: Soils and Solid Media EPA/730/ 2-89/042, 1989.
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19.  U.S.  Environmental Protection Agency. Preparation.
    Aid for  HWER'Ls Category  III Quality  Assurance
    Project Plans. 1987.

20.  U.S. Environmental Protection Agency. Statistical Test
    Analysis of Groundwater Data  at RCRA  Facilities.
    Interim Final. 1989.

21.  U.S. Environmental Protection Agency.  Soil Sampling
    Quality Assurance User's Guide. EPA/  600/4-84/043,
    1984
   22. U.S. Environmental  Protection Agency. Technology
      Screening Guide for Treatment of CERCLA Soils and
      Sludges. EPA/540/2-88/004, 1988.

   23. U.S. Environmental Protection Agency. Test Methods
      for Evaluating Solid Waste. 3rd Ed., SW-846,1986.

   24. U.S. Environmental  Protection Agency. Treatability
      Studies  Under  CERCLA:  An Overview.  OSWER
      Directive 9380.3-02FS, 1987.
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 United States                Center for Environmental Research                                                               BULK RATE
 Environmental Protection      Information                                                                             POSTAGE & FEES PAID
 Agency                     Cincinnati OH 45268-1072                                                                         EPA
                                                                                                                     PERMIT No. G-35

Official Business
Penalty for Private Use, $300
EPA/540/2-91/020A
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