EPA/540/AR-93/508
                                     August 1993
          EPA RREL's
Mobile Volume Reduction Unit
    Applications Analysis Report
  Risk Reduction Engineering Laboratory
   Office of Research and Development
  U.S. Environmental Protection Agency
         Cincinnati, Ohio 45268
                                     Printed on Recycled Paper

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                                               Notice
The information hi this document has been funded by the U.S. Environmental Protection Agency (EPA) under the
auspices of the Superfund Innovative Technology Evaluation (SITE) Program under Contract No. 68-CO-0048 to Science
Applications International Corporation (SAIC). It has been subjected to the Agency's peer and administrative review,
and it has been approved for publications as an EPA document.  Mention of trade names or commercial products does
not constitute an endorsement or recommendation for use.

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                                               Foreword
The Superfund Innovative Technology Evaluation (SITE) Program was authorized in the 1986 Superfund Amendments.
The Program is a joint effort between the U.S. Environmental Protection Agency's (EPA)  Office of Research and
Development and Office  of Solid Waste and Emergency Response.  The purpose of the program is to enhance the
development of hazardous waste treatment technologies necessary for implementing new cleanup standards that require
greater reliance on permanent remedies. This is accomplished by performing technology demonstrations designed to
provide engineering and economic data on selected technologies.

This project consists of an analysis of the EPA Risk Reduction Engineering Laboratory's mobile Volume Reduction Unit.
The Demonstration Test took place at the Escambia Treating Company Superfund Site in Pensacola, Florida. The goals
of the study,  summarized in this Applications Analysis Report, are:  1) to evaluate the technical effectiveness and
economics of this technology relative to  its ability to treat soils contaminated with  organics; and 2) to establish the
potential applicability of the process to other wastes and Superfund sites.  The primary technical objective of this project
is to determine the ability of the process to  reduce the concentration of organic contaminants in contaminated soil
through particle size separation and solubilization.

Additional copies of this  report may be  obtained at no charge from the EPA's Center for Environmental Research
Information, 26 West Martin Luther King Drive, Cincinnati, Ohio 45268, using the EPA document number found on the
report's front cover. Once this supply is exhausted, copies can be purchased from the National Technical Information
Service, Ravensworth Building, Springfield, Virginia 22161, (800) 553-6847.  Reference copies will be available in the
Hazardous Waste Collection at EPA libraries. Information regarding the availablity of other reports can be obtained
by calling the Office of Research and Development Publications  at (513) 569-7562.  To obtain further information
regarding the SITE Program and other projects within SITE, telephone (513) 569-7696.
                                                     E. Timothy Oppelt, Director
                                                     Risk Reduction Engineering Laboratory
                                                     111

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                                                Abstract
This document is an evaluation of the performance of the U.S. Environmental Protection Agency (EPA) Risk Reduction
Engineering Laboratory's (RREL's) mobile Volume Reduction Unit (VRU) and its applicability as a treatment technique
for soils contaminated with organics.  Both the technical and economic aspects of the technology were examined.

A demonstration of the VRU was conducted in the fall of 1992 using RREL's pilot-scale unit at the Escambia Treating
Company Superfund Site in Pensacola, Florida. Operational data and sampling and analysis information were carefully
compiled to  establish  a database against which other available data,  as  well  as  the project objectives for the
demonstration, could be compared and evaluated. Conclusions concerning the technology's suitability for use in treating
contaminated  soils with organic compounds through particle  size separation  and solubilization were reached.
Extrapolations regarding applications to different contaminants and soil types were made.

Under optimal conditions, when surfactant was added and pH and temperature of the wash water were increased, the
VRU achieved average removal efficiencies of 97 percent for pentachlorophenol (PCP) and 95 percent for polynuclear
aromatic hydrocarbon (PAH) contaminants. In addition, 86 percent of the solids in the feed soil were returned as washed
soil (on a normalized basis).
                                                     IV

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                                                Contents
Section

Notice	
Foreword	
Abstract	
Contents  	
Tables	      ™
Figure  .	       ^
Abbreviations	
Acknowledgments	

1.  Executive Summary	

    1.1   Introduction	
    1.2   Conclusions  	
    1.3   Results	
                                                                                                           3
2.  Introduction	•	

    2.1   The SITE Program	        ^
    2.2  SITE Program Reports	        3
    2.3   Key Contacts  	        4

3.  Technology Applications Analysis	

    3.1  Introduction	
    3.2  Conclusions  	
    3.3  Technology Evaluation  	        "
         3.3.1    VRU Operating Conditions	        6
         3.3.2    Contaminant Removal Efficiencies	        7
         3.3.3    Washed Soils Recovery	        8
         3.3.4    Mass Balances  	        "
         3.3.5    Particle Size and Fines Distribution	       9
         3.3.6    Water Treatment Effectiveness	       10
    3.4  Ranges of Site Characteristics Suitable for the Technology	       H
         3.4.1    Site Selection	       11
         3.4.2    Load, Surface, and Subsurface Requirements	       H
         3.4.3    Clearance and Site Area Requirements	       H
         3.4.4    Climate Characteristics	       ^

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                                       Contents (Continued)
  Action
         3.45   Geological and Topographical Characteristics	      12
         3.4.6   Utility Requirements	      12
         3.4.7   Size of Operation	'.'.'.'.'.'.'.'.'.'.      12
    35   Applicable Wastes 	              12
    3.6   Regulatory Requirements 	      12
         3.6.1   Federal Regulations  	            13
                3.6.1.1 Clean Air Act (CAA)	      13
                3.6.1.2 CERCLA	       	      !3
                3.6.1.3 RCRA  	           	      14
                3.6.1.4 CWA	      14
                3.6.1.5 Safe Drinking Water Act (SDWA)	'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.      14
                3.6.1.6 Toxic Substances Control Act (TSCA)	   ''      14
         3.63.   State and Local Regulations 	         15
    3.7   Personnel Issues	          15
         3.7.1    Training	             J5
         3.7.2    Health and Safety	'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.      15
         3.73    Emergency Response 	      15
    3.8  References	                 15

4.  Economic Analysis 	                   lg

    4.1  Introduction	           ^
   42  Conclusions  	*' *	       -^
   43  Issues and Assumptions	                             lg
        43.1   Costs Excluded from Estimate	                     16
        43.2   Utilities	          16
        433   Operating Times	         17
        4.3.4   Labor Requirements	              17
        435   Capital Costs  	°	       17
        43.6   Equipment and Fixed Costs	             lg
   4.4  Basis of Economic Analysis	                              lg
        4.4.1   Site Preparation Costs	'       ig
        4.4.2   Permitting and Regulatory Costs	\       lg
        4.43   Equipment Costs  	          lg
        4.4.4   Startup and Fixed Costs	       19
        4.4.5   Labor Costs	                      20
        4.4.6   Supplies Costs  	             20
        4.4.7   Consumables Costs	                  20
        4.4.8   Effluent Treatment and Disposal Costs	       20
        4.4.9   Residuals and Waste Shipping, Handling, and Transport Costs	          21
        4.4.10  Analytical Costs	         21
        4.4.11  Faculty Modification, Repair, and Replacement Costs  	        21
        4.4.12  Site Demobilization Costs	                          21
   45   Results of Economic Analysis	                       21
   4.6   References	    	       24
                                                  VI

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                                      Contents  (Continued)
Section

Appendix A - Process Description	      25

   A.1  Introduction	      25
   A.2  Process Description 	      25
   A.3  References	      27

Appendix B - Developer Claims  	      29

   B.I  Introduction	      29
   B.2  SITE Demonstration Claims	      29

Appendix C - SITE Demonstration Results	      31

   C.1  Introduction	      31
   C.2  Operating Conditions  	      31
   C.3  Contaminant Removal	      32
   C.4  Washed Soils Recovery	      33
   C.5  Mass Balances	      34
        C.5.1  Total Material  	      34
        C.5.2  Dry Solids	      34
        C.5,3  PCP	      36
        C.5.4  PAHs		      36
   C.6  Particle Size and Fines Distributions	      37
   C.7  Water Treatment Effectiveness	      37
   C.8  References	      42

Appendix D - Case Studies	      43

   D.I  Bench-and Pilot-Scale Treatment of Soil from a Wood Treating Facility	      43
   D.2  Pilot-Scale Treatment of Pesticide-Contaminated Soil	      43
                                                   Vll

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Tables
Number
1
2
3
4
5
6
7
8
9
10
H
12
13
14
15
16

17
18
19

20

^H
VRU SITE Demonstration Test Results 	
Contaminant Concentrations in the Feed Soil 	
VRU SITE Demonstration Operating Conditions 	
PCP Reductions from Feed Soil to Washed Soil 	
PAH Reductions from Feed Soil to Washed Soil 	 	 	 	
Washed Soil Residual Contaminant Concentrations 	
Feed Soil Recovered as Washed Soil 	 „ 	
Average Mass Balance Closures 	
Distribution of Fines & Coarse Gravel and Sand 	
Average PCP and PAH Concentrations in CPI Underflow & Floc/Clarifier Solids 	 	
Water Treatment Subsystem Effluent Quality 	
Proportional Costs of Major Fixed Capital Investment Components 	
Excavation Costs 	
Fully Burdened Salaries for Onsite Personnel Using 10-tph VRU 	
Treatment Costs for 10-tph VRU Treating 20,000 Tons of Contaminated Soil 	
Treatment Costs as Percentages of Total Costs for 10-tph VRU
Treating 20,000 Tons of Contaminated Soil 	
Treatment Costs for 10-tph VRU Operating with a 90% On-line Factor 	
Treatment Costs as % of Total Costs for 10-tph VRU Operating with a 90% On-line Factor . . .
Treatment Costs for the Remediation of 200,000 Tons of Contaminated Soil Using
the VRU Operating with a 90% On-line Factor
Treatment Costs as Percentages of Total Costs for VRU
Treating 200,000 Tons of Contaminated Soil
viii
Page
2
6
7
8
8
8
9
9
10
10
11
17
18
20
22

22
23
23

24

24


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                                        Tables (Continued)
Number

C-l   Average Contaminant Concentrations in the Feed Soil  	       31

C-2   VRU SITE Demonstration Operating Conditions	       32

C-3   Removal Efficiencies for PCP and PAHs  .	       33

C-4   Feed Soil Recovered as Washed Soil	       34

C-5   Total Material Mass Balance	       35

C-6   Dry Solids Mass Balance	       35

C-7   PCP Mass Balance	       36

C-8   PAH Mass Balance	       37

C-9   Particle Size Distribution within the Feed Soil,
      Washed Soil, and Fines Slurry	       38

C-10  Particle Size Distribution within the Underflow from
       the CPI and Floe Tank  	       39

C-ll   Disposition of Fines	       40

C-12   Disposition of Coarse Gravel and Sand	•	       40

C-13   PCP Concentration in Fines Slurry Solids	       40

C-14   PAHs Concentration in Fines Slurry Solids	       40

C-15   TOC Levels in Water Streams	       41

C-16   TR Levels in Water Streams  	      41

D-l   Heptachlor Results	,	      44

D-2   Dieldrin Results	      44
                                                    IX

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                                            Figure
Number




A-l  Typical VRU Operational Setup
26

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                                          Abbreviations
AAR      Applications Analysis Report

ARAR     Applicable or Relevant and Appropriate
           Requirements

ASTM     American Society for Testing and Materials

CAA      Clean Air Act

CERCLA  Comprehensive Environmental Response,
           Compensation, and Liability Act

cfm       cubic feet per minute

CFR      Code of Federal Regulations

CPI       Corrugated Plate Interceptor

CPR      cardiopulmonary resuscitation

CWA     Clean Water Act

DRE      destruction and removal efficiency

EPA      U.S. Environmental Protection Agency

gph        gallons per hour

gpm       gallons per minute

kWh       kilowatt hours

MCL      maximum contaminant level

 MSW      Municipal Solid Waste

 NAAQS    National Ambient Air Quality Standards

 NPDES    National Pollutant Discharge Elimination
            System

 ORD      Office  of Research and Development
OSC       On-scene Coordinator

OSHA     Occupational Safety and Health Act

OSWER   Office of Solid Waste and Emergency
           Response

PAH       polynuclear aromatic hydrocarbon

PCB       polychlorinated biphenyls

PCP       Pentachlorophenol

PPE       personal protective equipment

ppm       parts per million

POTW     Publicly-Owned Treatment Works

psi        pounds per square inch

psig       pounds per square inch gauge

RCRA     Resource Conservation and Recovery Act

RPM      Remedial Project Manager

RREL     Risk Reduction Engineering Laboratory

SARA     Superfund Amendments & Reauthorization
           Act

SDWA    Safe Drinking Water Act

SITE      Superfund Innovative Technology
           Evaluation

SVOC      semi-volatile organic compound

TCLP      Toxicity Characteristic Leaching Procedure

 TDS       total dissolved solids
                                                   XI

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                                 Abbreviations (Continued)
TER       Technology Evaluation Report




TOG       total organic carbon




tph        tons per hour




tpd        tons per day




TR        total residue
TSD       Treatment, Storage, and Disposal




TSS        total suspended solids




VOC       volatile organic compounds




VRU       Volume Reduction Unit
                                              xu

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                                        Acknowledgments
This report was prepared under the direction and coordination of Teri Richardson, U.S. Envirnomental Protection
Agency (EPA) Superfund Innovative Technology Evaluation (SITE) Program Manager in the Risk Reduction
Engineering Laboratory (RREL), Cincinnati, Ohio.  The EPA (RREL, Cincinnati) contributors and reviewers for this
report were Ms. Laurel Staley and Mr. Jack Hubbard. The EPA (RREL, Edison) contributor  and reviewer was Mr.
Richard Griffith.

This report was prepared for EPA's SITE Program by the Technology Evaluation Division of Science Applications
International Corporation (SAIC) in Cincinnati, Ohio for the U.S. EPA under Contract No. 68-CO-0048.  The Work
Assignment Manager for  this project was Ms. Margaret M. Groeber.
This report is dedicated to the memory of Mr. Patrick Augustin.
                                                  xui

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                                               Section 1
                                        Executive Summary
1.1    Introduction
This report summarizes the findings of an evaluation of
the mobile Volume Reduction Unit (VRU) developed by
the U.S. Environmental Protection Agency (EPA) Risk
Reduction Engineering Laboratory (RREL).  The study
was conducted under the Superfund Innovative Technology
Evaluation (SITE) Program. A demonstration test and an
evaluation of the VRU technology  were performed by
EPA as part of this study.  The results of this test and
supporting data from other testing performed by RREL
constitute the basis for  this report.
1.2    Conclusions

The demonstration took place at the former Escambia
Wood Treating Company  site  in Pensacola,  Florida
between November 5 and November 13, 1992. The 26-
acre facility, now closed, used pentachlorophenol (PCP)
and creosote to treat wood products from 1943 to 1982.
The site is currently undergoing a Superfund cleanup being
managed by EPA Region IV.

During the demonstration, the VRU operated at a feed
rate of approximately 100 Ibs/h with a wash water-to-feed
ratio of about 6 to 1. The physical condition of the wash
water was modified during the demonstration as follows:

•    Condition 1:  no surfactant, no pH adjustment, no
      temperature adjustment

•    Condition 2:  surfactant addition, no pH adjustment,
      no temperature adjustment

 •    Condition 3:   surfactant addition, pH adjustment,
      temperature adjustment

 The VRU soil washing system successfully separated the
 contaminated soil into two unique streams:  washed soil
 and fines slurry.  The washed soil was safely returned to
 the site following  treatment.  The fines  slurry, which
carried the majority of the pollutants from the feed soil,
underwent additional treatment to separate the fines and
contaminants from the water.

A review of the demonstration test data, as compared to
the established project objectives, indicates the following
results:

•    One of the project objectives was to demonstrate the
     VRU's ability  to achieve an average PCP removal
     from the feed soil of 90 percent or greater. Average
     PCP  removals were 76, 92, and  97 percent for
     Conditions 1, 2, and 3, respectively.

•    A second project objective was to demonstrate the
     VRU's ability to achieve an average creosote-fraction
     polynuclear  aromatic hydrocarbon  (PAH) removal
     from the feed soil of 90 percent or greater. Average
     PAH  removals were  70, 83,  and 95 percent for
     Conditions 1, 2, and 3, respectively.

•    The average percentages of feed  soil returned as
     washed soil  on a normalized basis were 90, 88, and
     86 for Conditions 1,  2, and 3, respectively.   The
     remaining solids were contained in the fines slurry
     and underwent further treatment

•    Total material balances in the soil washing segment
     of the VRU achieved closures  of 104, 113,  and 98
     percent for Conditions 1, 2, and 3, respectively.  The
     closures obtained for Conditions 1 and 3 met the
     project objective of total material  balance closures
     between 90  and 110 percent.  Although a closure of
     113 percent  was obtained for Condition 2, a sampling
     procedure may have inflated this closure.

 •   Mass balances of total dry solids in the soil washing
      segment of  the VRU achieved closures of 106, 108,
      and  94 percent  for  Conditions  1,  2,  and 3,
     respectively.  The project  objective for  this mass
     balance was closure between 85 and 115 percent.

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      The project objectives for mass balances of PCP and
      creosote-fraction PAHs in the soil washing segment
      of the VRU were to demonstrate whether closures
      between 80 and  175 percent could  be achieved.
      Closures within this range were  achieved only for
      Condition 1, which demonstrated closures of 101 and
      87  percent for  PCP  and PAHs,   respectively.
      Surfactant  added during Conditions 2 and 3 may
      have adversely affected the PCP and PAH analyses,
      which  would  have  affected the  mass balance
      calculations.

      The cost to remediate 20,000 tons of contaminated
      soils using a 10-ton-per-hour (tph) soil washer is
      estimated at $136.67 per ton when the  system is on-
      line 90 percent of the time.
1.3 Results

The objectives of this Applications Analysis Report (AAR)
are to assess the ability of the VRU process to comply
              with Applicable or Relevant and Appropriate Require-
              ments  (ARARs) and to estimate the cost of using this
              technology to remediate a Superfund site.  This analysis
              includes  determining  percent  removals  of  PCP and
              creosote-fraction  PAHs.    Table  1  summarizes  the
              performance during the demonstration test.

              EPA has established target cleanup levels for the soil at
              the Escambia Wood Treating Company  Superfund site.
              Although meeting these cleanup criteria was not a project
              objective for  this demonstration, they can be used  for
              comparison purposes.  The target cleanup levels are 30
              ppm PCP, 50 ppm  carcinogenic creosote, and  100 ppm
              total creosote. The target cleanup level for PCP was easily
              met during Conditions 2 and 3 but was not met during
              Condition 1. The cleanup criteria for total creosote was
              easily met during Condition 3 but was not met during
              Condition 1 or Condition 2. The target cleanup level for
              carcinogenic creosote was met by the washed soil produced
              during all three conditions.
Table 1. VRU SITE Demonstration Test Results
 Parameter (%)
Condition 1
                                                                      Condition 2
                                                                                             Condition 3
 PCP removal

   Average

   Range

 PAH removal

   Average

   Range

 Feed soil collected as washed soil

   Average

   Range

 Feed soil collected as washed soil,
 normalized basis

   Average

   Range
   76

  69-81


   70

  59-77


   95

  85-114



   90

  89-90
  92

 91-93


  83

 83-84


  95

86-103
                                                                        85-90
  97

97-98


  95

95-96


  82

69-94



  86

85-87

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                                               Section 2
                                             Introduction
2.1     The SITE Program

In 1986,  the  U.S. EPA Office  of Solid Waste and
Emergency Response (OSWER) and Office of Research
and  Development (ORD)  established  the  Superfund
Innovative Technology Evaluation (SITE)  Program  to
promote  the  development  and  use   of  innovative
technologies  to clean up  Superfund sites  across  the
country.   Now in its eighth year, the SITE Program is
helping to provide the treatment technologies necessary to
implement new Federal and State cleanup standards aimed
at permanent remedies rather than quick fixes.  The SITE
Program  is composed  of four major elements:   the
Demonstration Program, the  Emerging Technologies
Program,  the Measurement and Monitoring Technologies
Program,  and the Technology Transfer Program.

The major focus has been on the Demonstration Program,
which is designed to provide engineering and cost data for
selected technologies.  EPA and developers participating
in the program share  the  cost  of the  demonstration.
Developers are responsible  for mobilization,  operation,
and demobilization of their innovative systems at chosen
sites, usually Superfund sites.   EPA  is responsible for
sampling, analyzing, and evaluating all test results.  The
result is an assessment of the technology's performance,
reliability, and costs.   This   information is used in
conjunction with other data to select the most appropriate
technologies for the cleanup of Superfund sites.

Developers of innovative technologies  apply  to  the
Demonstration Program by responding to EPA's annual
solicitation.  EPA also accepts  proposals any  time a
developer has a Superfund  waste  treatment  project
scheduled. To qualify for the program, a  new technology
must be field-ready and offer some advantage over existing
technologies.   Mobile  technologies  are of particular
interest to EPA.

Once EPA  has accepted  a  proposal,  EPA and the
developer work with the EPA regional offices and State
agencies  to identify a site containing waste suitable  for
testing the capabilities of the technology. EPA prepares
a detailed sampling and analysis plan designed to evaluate
the technology thoroughly and to ensure that the resulting
data are reliable. The duration of a demonstration varies
from a few days to several years, depending on the length
of time  and quantity of  waste needed  to  assess the
technology.  After   lie completion  of  a  technology
demonstration,  EPA  prepares two reports,  which are
explained in more  detail  in the following subsections.
Ultimately,  the  Demonstration  Program  leads  to an
analysis  of   the technology's   overall applicability to
Superfund problems.

The second principal element of the SITE Program is the
Emerging Technologies Program, which fosters the further
investigation and development of treatment technologies
that are  still at the bench- and pilot-scale.  Successful
validation  of  these   technologies  can  lead  to the
development of a system ready for field demonstration and
participation in the Demonstration Program.  The third
element  of  the  SITE Program, the Measurement and
Monitoring Technologies Program, provides assistance in
the  development   and  demonstration  of  innovative
technologies that can  be used to characterize Superfund
sites better.  Technical information is disseminated to the
public and private sectors through the Technology Transfer
Program.

2.2    SITE Program  Reports

The  analysis  of   a  technology participating  in the
Demonstration Program is contained in two documents: a
Technology Evaluation Report  (TER) and anAAR. The
TER contains a comprehensive description of the demon-
stration sponsored by the SITE Program and its results. It
gives  detailed  descriptions of the technology, the waste
used for the demonstration, sampling and analysis during
the  test, the data generated, and the Quality Assurance
Program.

The scope of the AAR is broader than the TER's scope;
it encompasses estimations of Superfund applications and

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costs of a technology based on all available data.  This
report compiles and summarizes the results of the SITE
demonstration, the developer's design and test data, and
other laboratory and field applications of the technology.
It discusses the advantages, disadvantages, and limitations
of the technology.

Costs  of the  technology  for different applications are
estimated based on available data on pilot- and full-scale
applications. The AAR discusses the factors, such as site
and waste characteristics, that have a major impact on
costs and performance.

The amount of available  data for the evaluation of an
innovative technology varies widely. Data may be limited
to laboratory  tests on synthetic waste or may  include
performance data on actual wastes treated at the pilot- or
full-scale level. In addition, there are limits to conclusions
regarding Superfund applications that can be drawn from
a  single  field  demonstration.    A  successful  field
demonstration  does  not  necessarily ensure   that  a
technology will be widely applicable or fully developed to
the commercial scale.  The AAR attempts to synthesize
the information  that  is available and draw reasonable
conclusions.    This  document is  very useful  to those
considering a  technology for Superfund cleanups  and
represents  a  critical  step  in  the  development  and
commercialization of the treatment technology.
2.3    Key Contacts

For more information on the VRU demonstration, please
contact:

1.      EPA Project Manager for the SITE
        Demonstration Test:

        Ms. Teri Richardson
        U.S. Environmental Protection Agency
        Risk Reduction Engineering Laboratory
        26 W. Martin Luther King Drive
        Cincinnati, Ohio  45268
        (513) 569-7949

2.      Process Developer:

        Mr. Richard Griffith
        U.S. Environmental Protection Agency
        Risk Reduction Engineering Laboratory
        Woodbridge Ave., Building 10
        Edison, New Jersey  08837
        (908) 321-6629

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                                                Section 3
                                Technology Applications Analysis
3.1     Introduction

This section addresses the applicability of soil washing to
soils  contaminated with  PCP and creosote-fraction
PAHs.  Recommendations  are based on  the  results
obtained from the SITE demonstration of the VRU as
well as additional data provided by the developer.  The
results of the demonstration provide the most extensive
database, conclusions on the technology's effectiveness,
and  information  regarding  its applicability to other
potential cleanups. A thorough description of the VRU
technology is provided in Appendix A. The developer's
claims are presented in Appendix B, a summary of the
demonstration results is provided in Appendix  C, and
other case studies are presented in Appendix D.
3.2    Conclusions

The soil  washing segment of the VRU successfully
separated the contaminated soil into two unique streams:
washed soil and fines slurry. The washed soil was safely
returned to the site following treatment, while the fines
slurry, which carried the majority of the pollutants from
the feed soil, underwent additional treatment to separate
the fines from the water. The water was further polished
and then discharged onsite, while the fines were disposed
in a secure area of the site.

In  order  to  address system  performance thoroughly
under  a  number  of  operating  conditions, varying
combinations  of caustic, surfactant, and  temperature
were used to modify the physical conditions of the wash
water as follows:

•    Condition 1: no surfactant, no pH adjustment, no
     temperature adjustment

•    Condition   2:     surfactant   addition,  no  pH
     adjustment, no temperature adjustment
•    Condition 3:   surfactant addition,  pH  adjustment,
     temperature adjustment

Three runs, 4 hours in duration, were performed for each
of Conditions 1 and 2.  Two runs, 6 hours in duration,
were performed under Condition 3.

A review of the demonstration test indicates the following
results:

•    One of the project objectives was to demonstrate the
     VRU's ability to achieve an average PCP removal
     from the feed soil of 90 percent or greater. Average
     PCP removals were 76, 92, and  97 percent for
     Conditions 1,  2, and 3, respectively.

•    A second project objective was to demonstrate the
     VRU's ability to achieve an average creosote-fraction
     PAH removal from the feed soil of 90 percent or
     greater. Average PAH removals were 70, 83, and 95
     percent for Conditions 1, 2, and 3, respectively.

•    The average  percentages of feed soil returned as
     washed soil on a normalized basis were 90, 88, and
     86 for Conditions  1, 2, and 3, respectively.  The
     remaining solids were contained in the fines slurry
     and underwent further treatment.

•    Total material balances in the soil washing segment
     of the  VRU  achieved closures of 104,  113, and 98
     percent for Conditions 1, 2, and 3, respectively. The
     closures obtained for  Conditions 1 and 3 met the
     project  objective of total material balance closures
     between 90 and 110 percent. Although a closure of
     113 percent was obtained for Condition 2, a sampling
     procedure may have inflated this closure.

•    Mass balances of total dry solids in the soil washing
     segment of the VRU achieved closures of 106, 108,
     and 94 percent  for  Conditions  1,  2, and 3,
     respectively.   The project  objective for  this mass
     balance was closure between 85 and 115 percent.

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     The project objectives for mass balances of PCP
     and creosote-fraction PAHs in the  soil washing
     segment of the VRU were to demonstrate whether
     closures between  80 and 175  percent  could  be
     achieved. Closures within this range were achieved
     only for Condition 1, which demonstrated closures
     of  101  and 87  percent for  PCP  and  PAHs,
     respectively. Surfactant added during Conditions 2
     and 3 may have adversely  affected the  PCP and
     PAH analyses, which would have affected the mass
     balance calculations.
3.3    Technology Evaluation

The 100-lb/h VRU is a mobile research unit that was
developed for soil washing treatability studies on soils
containing a wide variety of contaminants. This unit is
composed of two distinct treatment segments:  the soil
washing subsystem and the water treatment subsystem.
The soil washing portion of the VRU is used to separate
contaminated soils into  two streams:  washed soil and
fines slurry. Ideally, the washed soil is clean enough to
return to the site or to use in some other capacity. The
fines slurry, which carries the majority of the pollutants
present in the feed soil, requires additional treatment
using the  water treatment subsystem.  By isolating and
concentrating the  contaminants within the  fines, the
volume of material requiring additional treatment  is
significantly reduced.

The VRU was developed by EPA, which by law cannot
develop commercial treatment systems. EPA can co-
develop technologies with private  companies or license
EPA-developed  technologies  to  private  companies
through the Federal Technology Transfer Act of 1986
(15 USC 3702-3714) [1].

In November 1992 the VRU soil washing system was
tested under the SITE Program. Soil contaminated with
PCP and creosote-fraction PAHs was excavated from the
former Escambia  Wood  Treating Company site in
Pcnsacola, Florida  and then  treated by the  VRU.
Contaminant levels in the soil ranged from the low parts
per million  (ppm) to percent levels.  For  the  SITE
demonstration, the excavated soil was homogenized and
manually processed through a  Vi-inch screen before it
was  fed  to   the  VRU.    Average  contaminant
concentrations in the feed soil on a dry weight basis after
homogcnization and screening are summarized in Table
2.

The PAH concentrations presented hi Table 2 do not
include all  PAHs.   Analyses were  conducted for
 creosote-fraction PAHs, and five  compounds from the
 standard  set  of 16 creosote-fraction  PAHs  were not
 consistently detected in the field soil.  These five PAHs
 were not included in this evaluation and are not included
 in the PAH concentrations shown in Table 2.
 Table 2. Contaminant Concentrations in the Feed Soil
        (ppm, dry weight basis)
Contaminant
PAHs
PCP
Average
980
140
Range
550 to 1,700
48 to 210
33.1    VRU Operating Conditions

The  VRU  used  during  the demonstration  test was
designed to be flexible in  terms of equipment and wash
water additives  used.  During the demonstration test,
varying  combinations  of   caustic,   surfactant,  and
temperature  were  employed to modify the  physical
conditions of the wash water.  Water is a polar substance;
PCP  and PAHs (and  other  organic contaminants)  are
nonpolar.  Because polar substances do not  dissolve
nonpolar  substances well, the  addition  of a  nonpolar
surfactant  to  the  wash  water can  improve  organic
contaminant removal significantly. Adjusting the pH and
temperature  of the  wash   water  can  also  increase
contaminant solubilities and improve removal efficiencies.

In July 1992 EPA conducted treatability studies at  the
Escambia Wood Treating Company site. Twenty different
combinations  of wash water  temperature,  pH, and
surfactant concentration  were  tested.   These studies
provided the basis  for the parameters tested during  the
demonstration.  During the treatability studies, PCP and
PAH  removal efficiencies  hi  excess of 90 percent were
achieved under selected operating conditions.

Surfactant  concentration  and  wash  water  pH  and
temperature were monitored  to determine whether  the
VRU was functioning at the operating conditions specified
in the Demonstration Plan. The surfactant concentration
was determined by calculating the ratio of surfactant-to-
wash water on a mass basis. The pH was determined by
measuring the  pH of the fines  slurry  stream.  The
temperature  was   determined   by   measuring  the
temperature of the wash water just before it entered the
soil washing segment of the  VRU.   Actual  operating
conditions are summarized in Table 3.

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Table 3. VRU SITE Demonstration Operating Conditions

Condition 1
Average
Range
Condition 2
Average
Range
Condition 3
Average

Surfactant
Feed Rate Surfactant Flow Concentration in
(Ib/h) W/F Ratio (Ib/h) pH Wash Water (%)

84 8 0
64-95 7-10 0 7.1-7.3

104 6 13.7 - 0.22
97-108 6 13.4-14.1 6.9-7.0 0.22

133 5 11.4 - 0.18
117-148 4-5 11.0-11.7 10.1-10.2 0.17-0.18
Water
Temperature (°F)

57
55-60

61
59-65

142
139-145
33.2    Contaminant Removal Efficiencies

Most organic and inorganic contaminants present in soil
bind to fine-sized clay and silt particles (fines) primarily
by physical processes. Washing processes that separate
the  fine  particles from  the  coarser soil particles
effectively concentrate the contaminants into a smaller
volume. The clean larger fraction can be returned to the
site for continued use.  This process can also remove
some contaminants by dissolving or suspending them in
the wash water.

One of the main objectives of the demonstration test was
to assess  the VRU technology's ability  to  achieve
contaminant  removals  of 90  percent for  PCP and
creosote-fraction PAHs.

Removal  efficiencies  for  PCP  and  PAHs  were
 determined  by  comparing  the  total mass of  each
 contaminant,  on  a dry  weight  basis,  detected in the
washed soil with the total in the feed soil.  Removal
 efficiencies are calculated using the following equation:
PCP removal efficiencies were calculated for Conditions 1,
2, and 3. Under Condition 3, which employed surfactant
addition and pH and temperature adjustment, an average
of  97 percent  of the PCP  was removed.    Under
Condition 2, which employed surfactant addition only, an
average of 92 percent of the PCP was removed. These
removal  efficiencies achieve the  project  objective  of
demonstrating that the unit is capable of removing an
average of 90 percent of the PCP  from the bulk of the
feed soil.  An average of only 76 percent of the PCP was
removed from the feed soil treated under Condition 1.
These data, which illustrate the  impact of surfactant
addition and pH and temperature adjustment  on PCP
removal efficiencies, are listed in Table 4. PCP removal
efficiency is clearly enhanced by surfactant addition and
pH and temperature adjustment.

Creosote-fraction   PAH   removal   efficiencies   were
calculated for Conditions 1, 2, and 3. Under Condition 3,
which  employed   surfactant  addition  and  pH  and
temperature adjustment, an average of 95 percent of the
PAHs were removed. This removal efficiency achieves the
       -        ,   , Concentration of contaminant in feed - concentration of contaminant in -washed soil^
       % removal=  [	—.——-	:	:—.  ,	J
                                         concentration of contaminant in feed

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 Table 4. PCP Reductions from Feed Soil to Washed Soil
         (%, dry weight basis)
 Table 6. Washed Soil Residual Contaminant Concentrations
         (ppin, dry weight basis)

Condition 1
Condition 2
Condition 3
Average
76
92
97
Range
69-81
91-93
97-98
                                                                             PCP
                        Total Creosote
                            PAHs
                      Carcinogenic
                     Creosote PAHs
 project  objective of  demonstrating  that  trie  unit is
 capable of removing an average of 90 percent of the
 PAHs from the bulk of the feed soil.  Average PAH
 removals  of only 70  percent and 83  percent were
 obtained for Conditions 1 and 2, respectively.   These
 data, which illustrate the impact of surfactant addition
 and pH and temperature adjustment on PAH removal
 efficiencies, are listed  in Table 5.   PAH  removal
 efficiency is clearly dependent on surfactant addition and
 pH and temperature adjustment.


 Table 5. PAH Reductions from Feed Soil to Washed Soil
        (%, dry weight basis)

Condition 1
Condition 2
Condition 3
Average
76
92
97
Range
69 to 81
91 to 93
97 to 98
EPA has established target cleanup levels for the soil at
the Escambia Wood Treating Company Superfund Site.
Although meeting these cleanup  criteria  was  not a
project objective for this demonstration, they can be used
for comparison purposes. The target cleanup levels are
30 ppm  PCP, 50  ppm carcinogenic creosote,  and 100
ppm   total   creosote;  the  concentrations  of  these
contaminants in the washed soil on a dry weight basis
are presented in Table 6.

For all three conditions, the average concentration of
PCP in the washed soil was below the target cleanup
level of 30 ppm. This target was, however, exceeded for
Run 3 of Condition 1.  The cleanup criteria for total
creosote was easily met during Condition 3 but was not
met during  Condition 1  or  Condition 2.   The  target
cleanup level for carcinogenic creosote was  met by the
washed soil produced during all three conditions.
  Condition 1

    Runl

    Run 2

    Run 3



  Condition 2

    Runl

    Run 2

    Run3
28

36

43
15

13

14
  Condition 3

    Run 1          2.4

    Run 2          3.5
240

310

350
180

160

130
           44

           46
18

19

29
14

12

11
               3.5

               3.3
333    Washed Soils Recovery

As soil travels through the VRU system, the sand and
gravel fraction of  the  soil  are  separated from the
contaminated fines (i.e.,  fine clay and  silt particles).
The relatively nonhazardous sand and gravel fraction exits
the system as washed soil. By comparing the mass of dry
solids in the feed soil with the mass of dry solids in the
washed soil, average solids  recoveries of 96, 95, and 81
percent were calculated for soils treated under Conditions
1 through 3.  Also calculated were normalized recoveries,
which were determined by dividing the mass of dry solids
in the washed soil by the total mass of dry solids exiting
the system (in the  washed  soil and fines slurry).   The
recoveries shown in Table 7 achieve the project objective
of demonstrating that an average of at least 80 percent of
the solids present in the feed soil would be returned to the
site as washed soil.

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Table 7. Feed Soil Recovered as Washed SoH (dry weight basis)

                                       % Recovered,
                        % Recovered    normalized basis

 Condition 1
  Average                   95              90
  Range                   85 -114          89 - 90
                                   Table 8. Average Mass Balance Closures (%)
 Condition 2
  Average
  Range


 Condition 3
  Average
  Range
  95
86 - 103
  82
69-94
  88
85-90
  86
85-87
33.4    Mass Balances

Mass balances are  prepared by  comparing  the mass
entering a system to the mass exiting the system.  Mass
balance closure (or recovery) is calculated as follows:
     ..   „ ,     -,,       r Mass Exiting System,   1ftn
     Mass Balance Closure = [	——	] x 100
                         Mass Entering System
The mass balance  closures calculated for the VRU
demonstration are summarized in Table 8. Recoveries
were calculated for all materials present (total material
balance) and for specific materials (dry solids, PCP, and
creosote-fraction PAHs). For the total material balance,
the recovery is the percentage of the material entering
the  system  as feed soil and wash  water  that  was
recovered from the  system as washed soil  and fines
slurry.  The total material balances  conducted for  the
demonstration yielded average recoveries of 104 percent
for Condition 1, 113 percent for Condition 2, and 98
percent for Condition 3. The  project objective for  the
total material balances was average closures of between
90 and 110 percent.  Except for high recovery obtained
for  Condition 2,  average closures for total material
balances met the project objectives. During Condition 2,
the operating procedure for mass flow measurement of
fines slurry was modified and may have inflated  the
measurement.  During Condition 3,  the procedure was
readjusted to its original form, and the balance closures
returned  to the acceptable range.   This observation
indicates  that measurement of the fines slurry generated
a high bias in the total materials balance for  Condition
2.

Condition 1
Condition 2
Condition 3
Total
material
104
113
98
Dry solids
106
108
94
PCP
101
19
13
PAHs
87
28
13
 Total dry solids recoveries during the VRU demonstration
 ranged from 94 to 109 percent, meeting project objectives
'of recoveries  between 85  and  115  percent.   Under
 Condition 1, the average mass balance closures for PCP
 and PAHs were  101 and 87 percent, respectively.  These
 closures met the  project objectives of PCP and PAH mass
 balance closures between 80 and 175 percent. The average
 PCP and PAH recoveries for Conditions 2 and 3 were well
 below project  objectives and indicate  the presence  of a
 substantial negative bias. A closer inspection of the data,
 including laboratory QA indicators, reveals that fines slurry
 data are a likely source of negative  bias.  A possible
 explanation for  the poor data in Conditions  2 and 3 is
 surfactant addition.   During sample  preparation,  it is
 possible that competition between the surfactant (which
 tries to keep pollutants in  solution)  and the extraction
 solvent (which tries to remove pollutants from solution for
 analysis) may  have had a detrimental effect. The fines
 slurry samples were difficult to filter. As a result, a large
 number of particles were included in the liquid portion of
 the  sample,   which  probably  retained  significant
 concentrations of PCP  and PAHs.  The liquid samples,
 with a significant mass of particulates, were extracted by
 liquid extraction procedures, which are less rigorous for
 particulates.   Since PCP  and  PAHs  were not  well
 accounted for, these data were of limited use.
                                   33.5    Particle Size and Fines Distribution

                                   The VRU system's effectiveness is based on its ability to
                                   separate soil fines (particles that will pass through a 100-
                                   mesh screen) from the coarser gravel/sand fraction of the
                                   soil (particles  that  will not pass  through a  100-mesh
                                   screen). Significant contaminant concentration reductions
                                   can be realized by the VRU, provided the majority of the
                                   contaminants present in the feed soil concentrate within
                                   the fines.   By analyzing the dry solids mass balance data
                                   and particle size distribution, the disposition of fines and
                                   coarse gravel/sand can be calculated.   Table 9 indicates
                                   the percentage of the  soil fines and coarser gravel/sand
                                   fraction from the feed stream that were recovered in the
                                   washed soil and in the fines slurry. The data indicate that
                                   the majority of the small particles were  partitioned to the
                                   fines slurry.

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Table 9. Distribution of Fines and Coarse Gravel and Sand
        (%, dry weight basis)
  Condition
  Soil Fines

123
                                 Coarser Gravel/Sand
                                      Fraction
  Washed Soil    31     41     54      104     102    82

  Fines Slurry    75     83    110     1       22

  Closure      106   124   164     105     104    84
The partitioning of the coarser gravel/sand fraction to
the washed soil stream was excellent.   Only  1 to  2
percent of the coarser gravel/sand particles from the
feed stream were detected  in the fines slurry.  The
partitioning of the soil fines to the fines  slurry was less
complete, although the majority of these small particles
did partition to the fines slurry. As shown in Table 8, 31
to 54 percent of the soil fines from the feed stream were
recovered  in the washed  soil.    A more complete
partitioning of the soil fines to the fines slurry would,
theoretically, lead to increased contaminant removals
from the washed soil.
33.5    Water Treatment Effectiveness

Pollutants were removed from the fines slurry stream by
a  water  treatment sequence  consisting of  settling,
flocculation, filtration, and carbon adsorption. Following
treatment in the Corrugated Plate Interceptor (CPI),
where the fines were separated by gravity, the overflow
was pumped to a flocculation/clarification system for
additional fines  partitioning.  Table 10 lists ranges of
PCP   and  PAH  concentrations  in  the  CPI  and
floc/clarifier solids on a dry weight basis.  As previously
discussed in Subsection 3.3.4, these samples were difficult
to filter and the analytical methods were inadequate,
which resulted in questionable data.
Clarified water was then pumped from the floe overflow
tank through cartridge polishing filters operated in parallel
to remove soil fines that would not pass through a 4 x 10"4
inch (10-micron) screen. Water exiting these filters then
passed through activated carbon drums for hydrocarbon
removal.   The  clarified water was  analyzed for total
organic carbon (TOC) and total residue (TR), which is the
sum of total suspended solids (TSS)  and total dissolved
solids (TDS).  Table 10 lists the TOC and TR levels from
the floe tank overflow, effluent from the filters, activated
carbon, and wash water into the VRU.

The TR  reduction from the  filter  unit was minimal,
indicating that a finer-sized filter is needed.  The TOC
reduction decreased  significantly  when surfactant was
introduced into  the system during Conditions 2 and 3.
The efficiency  was  affected  because surfactant was
adsorbed  on the carbon along with the contaminants.
TOC efficiency  could  be improved  by removing  the
surfactant before it enters  the carbon canisters  or  by
utilizing another TOC removal technology.

The VRU was designed with the ability to recycle water
treatment subsystem  effluent to the  mini-washer. This
option was  not evaluated during the  demonstration
because the developer chose to operate the system without
recycling.  Because water quality criteria for recycling have
not been defined, it is not possible to determine whether
the treated water produced during the demonstration was
appropriate for recycling. Based on the data presented in
Table  11, the  levels of both TOC  and TR  during
Condition 1  were  potentially  low  enough  to  permit
recycling;  however,  much higher levels  were detected in
Conditions 2 and 3.  During these conditions, additional
treatment may have been necessary to recycle the effluent
from the carbon canisters.
Table 10. Average PCP and PAH Concentrations in CPI Underflow Solids and Floc/CIarifier Solids (dry weight basis)
Condition
CPI underflow' solids
Floc/clarifier solids
1
51-69
92-6,500
PCP (ppml
2
46-85
190-1,300
3
*
83-150
1
1300-1,800
58-2,000
PAHs (ppm)
2
370-1,100
910-1,800
3
*
940-1,200
    Unacceptable analysis resulted in questionable data.
                                                      10

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Table 11. Water Treatment Subsystem Effluent Qualify (ppm)

Wash water
Floe-tank Overflow
Filter Effluent
Activated Carbon Effluent
TOC
1 2
<1.0 <15
115 1,045
11 1,075
<1.0 283

3
<1.02
825
6975
305

1
70
260
2475
115
TR
2
73
2,200
2,025
5575

3
62
6,075
5,075
2550
3.4    Range of Site Characteristics Suitable
        for the Technology

3.4.1   Site Selection

The VRU is  a mobile research unit mounted on two
heavy-duty tractor trailers. The VRU is composed of a
number of subsystems (e.g., screening, gravity separation,
flocculation/   clarification,   filtration,   and   carbon
adsorption).  It is designed  to  be flexible, so that the
combination of subsystems  and wash  water additives
used can be  modified to achieve cleanup  goals cost-
effectively, based on site requirements.  The system can
be assembled within the contaminated soil area or placed
offsite so that soil can be transported to the unit.  The
treatment unit can be placed inside either a permanent
or a temporary building or it  can be  operated in the
open.  The pilot-scale unit can be barge mounted.The
VRU  can be scaled to  a  full-scale unit for site
remediation.  For purposes of this document, a full-scale
unit is based on a processing rate of 10 tons per hour
 (tph) of soil or sediment. Larger processing rates for a
 full-scale unit could be used. Additional details on the
 scale-up  factors   used   and  assumptions   made for
 economic analyses are provided in Section 4.
 3.42    Load, Surface, and Subsurface Requirements

 A level, graded area that is capable of supporting  able
 to support the weight of the unit, which was determined
 by the developer to be 3,500 pounds per square inch
 (psi) for both the pilot- and full-scale units.  Additional
 road construction may be necessary to support oversize
 and heavy equipment.
 Subsurface  preparation is not required since all unit
 processes occur above the ground.  If the soil is to be
 excavated and treated onsite,  however, all subsurface
 obstacles (underground  cables, piping,  etc.)  must be
 removed prior to excavation.
3.43    Clearance and Site Area Requirements

The site must be cleared to allow the unit to be assembled
and operated. The extent of clearing is dependent upon
the operational configuration selected. Cleared areas for
stockpiling, storage, and loading/unloading activities are
required.      Clearing,  other  than  for  excavation of
contaminated  soil, is  not an issue  if treatment is to be
conducted offsite.

The surface  area required for the VRU soil washing
equipment is approximately 40 x 60 feet for the pilot-scale
unit and 300 x 400 feet for the full-scale unit. The vertical
height of the system is based on the height of the settling
tank as erected; 13.5 feet for the pilot-scale or 23 feet for
the full-scale unit.  The  system configuration will dictate
whether or not a concrete pad is required to support the
equipment.    Additionally, separate  areas   should be
provided for storage for both feed materials and any waste
generated during the treatment process. The shape of the
site should allow convenient access to the equipment.
 3.4.4    Climate Characteristics

 The critical climate requirements for the operation of this
 system include  temperature range and wind conditions.
 Low ambient temperatures will either adversely  affect
 treatment efficiency (if the wash water is not heated) or
 increase  energy costs (if  the  wash water is heated).
 Temperatures below freezing would hinder the operating
 capabilities of the soil washing system because the system
 uses a  significant amount  of  water in  the  treatment
 process.  Also, the slurries created  from the treatment
 process are adversely affected by freezing temperatures.
 Windy conditions may affect the excavation, transport, and
 feed of dry soils. Hazardous operating conditions  would
 also exist in severe storm conditions.
                                                       11

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To diminish the effects of climate, the system may be
erected in an enclosure.  For the pilot-scale unit, this
may be a fixed structure or a tent covering the system.
The full-scale unit requires a fixed structure.
3.4.5    Geological and Topographical Characteristics

Except for soil-bearing capacity requirements applicable
to any heavy machinery, there are no geologic character-
istics that restrict the implementation of this technology.
The treatment  unit must be  flat, level,  and stable.
Currently the unit has been used at land-based facilities
only.
3.4.6    Utility Requirements

Electricity and water are required to operate the VRU
soil washing system. The pilot-scale system is equipped
to operate using a generator to supply electrical power.
Otherwise a 3-phase power supply from the local electric
company is required.  The full-scale system will require
a 3-phase electrical system  to operate. The pilot-scale
system uses approximately 3.3 kilowatt hours (kWh) per
ton of soil processed during operation.  This requirement
increases to 6.6 kWh/ton for the full-scale system.

Water required to operate the  pilot-scale system  is
approximately 80 gallons per hour (gph).  This assumes
a recycle rate of 0 percent and an operational rate of 100
Ibs/h process  feed material.   The  full-scale system
requires 1,600 gph. This  assumes a 90 percent recycle
rate and a process throughput of 10 tph of process feed
material.  An abundant water  supply must be readily
available and accessible to operate the system.  It is not
required that the water be potable, but it must be free of
debris. Water sources with debris  may be used provided
the water is filtered prior to its use hi the system. Water
need not be obtained from the local utility but could be
from sources such as rivers, streams, lakes,  or wells. If
the  unit  is  operated  with  elevated  wash  water
temperatures, a water heater is required.  Propane was
used to heat water in the pilot-scale  unit;  natural gas
could be used for  a full-scale unit.  The full scale unit
would require approximately 120 cubic feet per minute
(cfm) of natural gas.

Other utilities required include diesel fuel to operate the
generator and natural gas or fuel oil for the steam boiler.
The steam is required for the removal of volatile organic
compounds (VOCs) from the feed material prior to soil
washing. In this process, the steam is used to heat the
screw   conveyor   jacket,  thereby  increasing   the
temperature to a point at which the volatile organics are
released from  the soil.  These are then collected and
treated by air stripping or some other treatment process.
The amount of steam required for the pilot-scale unit is
600 Ibs/h at of 50 psi, which requires approximately 10
cfm of natural  gas or 4 gph of No. 2 fuel oil.  Since no
substantial quantity of VOCs was present, the steam jacket
was not used during the demonstration.
3.4.7    Size of Operation

The capacity of the pilot-scale system  used during the
demonstration test was 100 Ibs/h.  The processing rate for
the full-scale system is assumed to be 10 tph. Currently,
the VRU Soil Washing System has only been tested as a
pilot-scale unit. No full-scale units exist at this tune.
3.5    Applicable Wastes

This technology may be used to treat soil contaminated
primarily with volatile and semivolatile organic compounds.
When the system is used  to  treat soils  with volatile
organics,  steam stripping and  vapor phase adsorption
equipment is used.  The unit  has not been tested on
sediments, though it is potentially capable of treating them.

The contaminated soil or sediment should contain no more
than  30 to  40 percent fines, and maximum  particle
diameter  should be  no more than Vz inch.   However,
during the demonstration the pilot-scale was fed material
^-inch or less. The process is also less cost effective when
the surfactant concentration is  high.  A high surfactant
concentration also causes a foam problem that can inhibit
the ability of the unit to remove the contaminants from the
soil effectively.

The VRU soil washing system can be effectively used to
treat  organic compounds such  as PAHs,  PCP,  and
pesticides.    In general,  a  wide variety  of chemical
contaminants can be removed or concentrated through soil
washing applications. It has been shown that soil washing
is effective on coarse sand and gravel contaminated with
a wide range  of organic and  inorganic contaminants.
Based  on   other  soil  washing   systems,  potential
contaminants that may be suitable for soil washing include
petroleum and fuel residues and cyanides.
3.6    Regulatory Requirements

Operation of the VRU for treatment of contaminated soil
requires compliance with certain Federal, State, and local
regulatory standards and guidelines.  Section 121 of the
                                                     12

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ComprehensiveEnvironmentalResponse, Compensation,
and Liability Act  of  1980 (CERCIA) requires that,
subject to specified exceptions, remedial actions must be
undertaken in compliance with ARARs, Federal laws,
and more stringent promulgated State laws (in response
to release or threats of release of hazardous substances,
pollutants,  or contaminants)  as  necessary  to protect
human health and the environment.

The ARARs  that  must be  followed in treating
contaminated media onsite are outlined in the Interim
Guidance on Compliance with ARARs, Federal Register,
Vol. 52, pp. 32496 et seq [2]. These are:

•  Performance,  Design,   or   Action-Specific
   Requirements.      Examples   include   Resource
   Conservation and Recovery Act (RCRA) incineration
   standards and Clean Water Act (CWA) pretreatment
   standards for discharge to publicly-owned treatment
   works (POTWs). These requirements are triggered
   by the particular remedial activity selected to clean a
   site.

•  Ambient/Chemical-Specific Requirements. These set
   health-risk-based  concentration  limits  based  on
   pollutants and contaminants, e.g., emission limits and
   ambient air quality  standards.  The most stringent
                       ARAR must be met.

•  Locational Requirements.  These set restrictions on
   activities because of site locations and environs.
 Deployment of the VRU will be affected by three main
 levels of regulation:

 •   Federal EPA air, water, and solid/hazardous waste
    regulations

 •   State  air,   water,   and  solid/hazardous  waste
    regulations             t

 •   Local   regulations,   particularly  Air   Quality
    Management District requirements

 These   regulations  govern  the  operation   of   all
 technologies. Other Federal, State, and local regulations
 are discussed in detail in the following subsections as
 they apply to the performance, emissions, and residues
 evaluated   from  measurements  taken  during  the
 demonstration test.
3.6.1    Federal Regulations

3.6.1.1  Clean Air Act (CAA)

The CAA establishes primary and secondary ambient air
quality standards for the protection of public health and
emission limitations for certain hazardous air pollutants.
Permitting requirements under the CAA are administered
by each state as part of the State Implementation Plans
developed to bring each state into compliance with the
National Ambient Air Quality Standards (NAAQS). The
ambient air quality standards listed for specific pollutants
may be applicable to operation of the VRU due  to
potential emissions when processing volatile compounds.
When volatile compounds  are present in the feed,  an air
pollution control device maybe required.  Other regulated
emissions may be produced, depending on the waste feed.
The allowable emissions will be established on a case-by-
case basis depending on whether the  site is located in an
area that is in attainment with the NAAQS.
3.6.1.2 CERCLA

CERCLA, as amended by the Superfund Amendments and
Reauthorization Act (SARA) of 1986, provides for Federal
funding to respond to releases of hazardous substances to
air,  water, and land.  Section 121 of SARA,  Cleanup
Standards, states  a strong  statutory  preference  for
remedies that are highly reliable  and provide long-term
protection. It strongly recommends that remedial action
use  onsite treatment that "...permanently and significantly
reduces  the  volume, toxicity,  or  mobility of hazardous
substances."  In addition, general factors that must be ad-
dressed by CERCLA remedial actions include:

•  Overall   protection  of  human  health  and   the
   environment

•  Compliance with ARARs

•  Long-term effectiveness and permanence

•  Reduction of toxicity, mobility, or volume

•  Short-term effectiveness

•  Implementability

•  Cost

•  State acceptance

•  Community acceptance.
                                                     13

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 The  ability of the VRU  to  concentrate the organic
 contaminants originally present in the feed,  as demon-
 strated by removal efficiencies of 90 percent or greater
 for PCP and PAH contaminants, indicates the VRU is
 capable   of  significantly  reducing the  quantity  of
 contaminated waste requiring subsequent treatment or
 disposal.
3.6.1.3 RCRA

The RCRA is the primary Federal legislation governing
hazardous waste activities. Although a RCRA permit is
not required for  onsite remedial actions at Superfund
sites,  the VRU  must  meet  all  of  its  substantive
requirements. Administrative RCRA requirements such
as  reporting  and  recordkeeping,  however, are  not
applicable for onsite  action.  Subtitle  C  of  RCRA
contains  requirements   for   generation,   transport,
treatment, storage, and  disposal of hazardous waste.
Compliance with these requirements is mandatory for
CERCLA sites producing hazardous waste onsite.  In
order  to  maintain compliance with RCRA,  sites
employing the VRU must obtain an  EPA generator
identification number and observe storage requirements
stipulated under 40 Code of Federal Regulations (CFR)
262.  Alternatively, a Part B Treatment, Storage, and
Disposal  (TSD)  permit  of interim  status may be
obtained.  Invariably, a hazardous waste manifest must
accompany offsite shipment of waste, and transport must
comply with Federal  Department  of Transportation
hazardous waste  transportation regulations.  Without
exception, the receiving TSD facility must be permitted
and  in  compliance  with RCRA  standards.    The
technology or treatment  standards applicable  to  the
media produced by the VRU will be determined by the
characteristics of the material  treated and the waste
generated.  The RCRA  land disposal  restrictions  (40
CFR 268) preclude the land disposal of hazardous wastes
which  fail to meet the stipulated treatment standards.
Wastes which do not meet these standards must receive
additional treatment to bring the wastes  into  compliance
with the  standards prior to land  disposal, unless a
variance is granted.
3.6.1.4 CWA

The CWA regulates direct discharges to surface water
through the National Pollutant Discharge Elimination
System (NPDES) regulations. These regulations require
point-source discharges of wastewater to  meet estab-
lished  water  quality standards.   The discharge  of
wastewater to  the  sanitary sewer requires a discharge
permit or, at least, concurrence from State and local
 regulatory authorities that the wastewater is in compliance
 with regulatory limits.

 If the treated water cannot be reused as wash water, then
 it must be disposed. Disposal options include discharge to
 a local POTW,  discharge to surface water,  or onsite
 treatment.  Discharge to a POTW will  typically  be
 regulated  according  to  the   industrial  wastewater
 pretreatment standards of the POTW.  These standards
 are specified in the CFR for certain industries. Depending
 on the site, the treated wash water may fall into one of the
 specific  industrial  categories.    If  it does  not, the
 pretreatment  standards  for  the wash  water will  be
 determined by the POTW and  depend on site-specific
 parameters such as the flow rate of the wash water, the
 contaminants  present,  and the  design of the POTW.
 Alternatively,  the wash  water  can be treated onsite.
 Pursuant  to  the   National  Contingency Plan,  the
 administrative and permitting requirements  of RCRA do
 not apply.  However, substantive requirements of RCRA
 do apply to onsite treatment facilities.
3.6.1.5 Safe Drinking Water Act (SDWA)

SDWA  establishes  primary  and  secondary  national
drinking water standards.   CERCLA  refers to these
standards, and Section 121(d)(2) explicitly mentions two of
these  standards  for  surface  water or groundwater:
Maximum Contaminant Levels (MCLs) and Federal Water
Quality Criteria. Alternate Concentration Limits may be
used when conditions of Section 121 (d)(2)(B) are met and
cleanup  to  MCLs or  other  protective levels  is  not
practicable.  Included in these sections is guidance on how
these requirements may be applied to Superfund remedial
actions.   The guidance,  which  is  based   on  Federal
requirements and policies,  may be superseded by more
stringent promulgated State requirements, resulting in the
application of even stricter standards than those specified
in Federal regulations.
3.6.1.6 Toxic Substances Control Act (TSCA)

TSCA grants EPA the authority to prohibit or control the
manufacturing, importing, processing, use, and disposal of
any chemical substance that presents an unreasonable risk
of injury to human health or the  environment.  These
regulations may be found in 40 CFR 761. With respect to
hazardous waste regulation, TSCA focuses on the use,
management,  disposal, and cleanup of polychlorinated
biphenyls (PCBs). Materials with less than 50 ppm PCB
are classified as non-PCB; those with PCB concentrations
between 50  and  500  ppm  are   classified  as  PCB-
contaminated; and those with PCB concentrations greater
                                                     14

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than or equal to 500 ppm are classified as PCBs. State
PCB regulations may be more stringent than TSCA.

While  the soil  used  for  the demonstration  did not
contain PCBs, it is reasonable to assume that the full-
scale VRU could be utilized to clean soils  that may
contain PCBs.  The separation process could  result in
elevated PCB concentrations in some output streams. If
the concentrations of PCBs in an output stream are too
high, the  output stream will need to be handled as a
TSCA-regulated waste.
3.6.2    State and Local Regulations

Compliance with ARARs  may require meeting State
standards that are more stringent than Federal standards
or that are the controlling standards in the case of non-
CERCLA treatment activities. Several types of State and
local regulations that may affect operation of the VRU
include:

•  Permitting requirements for
   construction/operation

•  Limitations on emission levels

•  Nuisance rules
 3.7    Personnel Issues

 3.7.1   Training

 Since  selected personnel  involved  with sampling or
 working close to the VRU (especially the grizzly screen
 and feed  hopper) are  required  to wear  respiratory
 protection, 40 hours of Occupational Safety and Health
 Act (OSHA)  training  covering  personal  protective
 equipment (PPE) application, safety and health, emer-
 gency response procedures, and quality assurance/quality
 control are required.  Additional training addressing the
 site activities, procedures, monitoring,  and equipment
 associated with the technology is also recommended.
 Personnel should  also be briefed when new operations
 are planned, work practices change, or if the site or
 environmental conditions change.
procedures.   Health and  safety training  covering the
potential hazards and provisions for exposure, monitoring,
and the use and care of PPE should be required.  When
appropriate, workers should have medical exams. Health
and  safety monitoring and incident reports should be
routinely filed and records of occupational illnesses and
injuries  (OSHA Forms 102 and 200) should be main-
tained.  Audits ensuring compliance with the health and
safety plan should be carried out.

Proper PPE should be available and properly utilized by
all  onsite personnel.   Different levels  of  personal
protection will be required based on the potential hazard
associated with the site and the work activities.

Site monitoring should be conducted to identify the extent
of hazards and to document exposures at the site.  The
monitoring results should be maintained and posted.
3.73    Emergency Response

In the event of an accident, illness, explosion, hazardous
situation at the site, or intentional acts of harm, assistance
should be immediately sought from the local emergency
response teams and first aid or decontamination should be
employed when appropriate. To ensure a timely response
in the case  of an emergency, workers should review the
evacuation plan, firefighting procedures, cardiopuhnonary
resuscitation  (CPR)  techniques,   emergency   decon-
tamination procedures, and routes to local hospitals before
operating the system.  Fire extinguishers, spill cleanup kits,
emergency eye washes, alarms, evacuation vehicles, and an
extensive 'first aid kit should be onsite at all times.
3.8    References

1.      Federal Technology Transfer Act of 1986.   15
        USC 3702-3714.

2.      Interim Guidance on Compliance with ARARs -
        Federal Register, 52: pp.32496 et. seq.
 3.7.2    Health and Safety

 Personnel should be instructed on the potential hazards
 associated with the operation of the VRU, recommended
 safe work practices, and standard emergency plans and
                                                      15

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                                                 Section 4

                                          Economic Analysis
 4.1    Introduction

 The primary purpose of this economic analysis is  to
 estimate costs (not including profits) for a commercial
 treatment system utilizing the mobile VRU. This analysis
 is based on the results of a SITE demonstration which
 utilized a pilot-scale soil washing system. The pilot-scale
 unit operated at a feed rate of 100 Ibs/h of contaminated
 soil. It is projected the commercial unit will be capable of
 treating approximately 10 tph of contaminated soil.
4.2    Conclusions

The commercial-scale VRU proposed by EPA appears to
be suited to the remediation of soils and other solid wastes
contaminated with organic compounds.  Treatment costs
appear to be competitive with other available technologies.
The cost to remediate 20,000 tons of contaminated soil
using a 10-tph VRU is estimated at $137 per  ton if the
system is on-line 90 percent of the time. Treatment costs
increase as the percent on-line factor decreases.  Projected
unit costs for a smaller site (10,000 tons of contaminated
soil) arc $171 per ton; projected unit costs for a larger site
(200,000 tons) are $106 per ton.
4.3    Issues and Assumptions

Because the VRU appears  to be capable of effectively
treating soils contaminated with organics, it is considered
potentially applicable to the remediation of Superfund
sites.   In the following  economic analysis, the  costs
associated with this technology are calculated based on the
treatment of a small-to-medium hazardous waste site that
has approximately 20,000 tons of contaminated soil suitable
for treatment by  soil washing.   Approximately  3,600
pounds of contaminated soil were treated during the  SITE
demonstration. While the pilot-scale VRU was designed
for the treatment of VOCs,  the SITE demonstration did
not involve the treatment of VOCs. It is assumed that the
 10-tph VRU will have and use equipment designed for the
 treatment of VOCs.

 Costs  that  are assumed to be  the obligation of the
 responsible  party or site owner have been omitted from
 this cost estimate and are indicated by a line (—)  hi all
 tables.

 Important assumptions regarding operating conditions and
 task responsibilities that could significantly affect the cost
 estimates are presented in the following subsections.
43.1    Costs Excluded from Estimate

The cost  estimates presented are representative  of the
charges typically assessed to the client by the vendor but
do not include profit.

Many other actual or potential costs were not included as
part of this estimate.  These costs were omitted because
site-specific engineering designs are beyond the scope of
this SITE project.  Certain functions were assumed to be
the obligation of the responsible party or site owner and
were not included in this estimate.

Costs  such as preliminary  site  preparation, permits,
regulatory requirements, initiation of monitoring programs,
waste disposal, sampling and analyses, and post-treatment
site cleanup and restoration are considered to be the re-
sponsible party's (or site owner's)  obligation and are not
included.  These costs tend to be site-specific and it is left
to the reader to  perform calculations relevant to each
specific case.  Whenever possible,  applicable information
is provided on  these topics so the reader may perform
calculations to obtain relevant economic data.
433    Utilities

To support the operation of the 10-tph VRU, a site must
have clean  water available at a flow rate of at least 24
                                                     16

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gpm, assuming recycling with 10 percent blowdown. This
water will be used in the miniwasher and the floe clarifier.
Other uses of the water include cooling and miscellaneous
onsite applications such as cleaning and rinsing.

A natural gas source  and the required piping must be
available  and  accessible to accommodate a natural gas
usage  of approximately  7,800  cubic  feet  per hour  at
standard  conditions (60° F and 30 inches of mercury).
Alternatively, provisions may be made for the use of oil as
a supplemental  fuel.  The pilot-scale unit used for the
demonstration utilized propane as a fuel source for the
water heater.   The steam boiler was not utilized since
VOCs were not present in the feed soil.

Electrical power is required  for the operation  of the
pumps, mixers, vibrating screens, and many smaller pieces
of equipment.  The pilot-scale unit utilized an electrical
generator, but for the full-scale unit it is  anticipated that
electrical power will be supplied from offsite source. It is
assumed that the cost of connecting the full-scale VRU to
an outside electrical source, including the transformer, is
the responsibility of the site owner. Maximum electrical
power consumption is estimated to be 66 kWh per ton of
contaminated soil treated.

For these cost  calculations,  it is assumed  the site will
support all of these requirements.  The cost of preparing
a site to meet these requirements can be high and is not
included in this analysis.
 433    Operating Times

 It is assumed the treatment operations will be conducted
 24 hours per day, 5 days per week.  It is further assumed
 that site preparation will be conducted 8 hours per day, 5
 days per week.  Assembly and disassembly are assumed to
 be carried out 8 hours per day, 7 days per week.  Startup
 and testing will be accomplished in one shift working 8
 hours  per day,  5  days  per  week.   Training  will be
 concurrent with startup activities and be conducted 8 hours
 per day  for  3  days.   Excavation activities  for site
 preparation will be concurrent with treatment (and may be
 concurrent with assembly and  shakedown and testing as
 well).   Assembly and disassembly are  both assumed to
 require 3 weeks.  Shakedown, testing, and training are
 expected to take 1 week.  Except where noted, these
 calculations are based on the treatment of a total of 20,000
 tons of waste using a 10-tph system.
43.4    Labor Requirements

Treatment operations for a typical shift are assumed to
require five  workers.   These workers include  a shift
supervisor, a maintenance person, a nonlocal operator, and
two local operators.  With 3 shifts, there will be 24 hours
of coverage for those  directly involved in operating the
system. In addition, a project manager, safety officer, and
local administrative person will each work a standard 40-
hour schedule at the site.  When the safety officer is off-
duty,  the shift  supervisors  will  assume  all  safety
responsibilities.
43.5   Capital Costs

The purchased equipment cost consists of the VRU and
additional equipment such as VOC  treatment system,
water heater, steam generator, and trailers.  The fixed
capital investment  (i.e.,  capital costs)  consists  of  the
purchased equipment cost and other fixed costs such as
freight,   sales   tax,   installation,   piping,   electrical,
instrumentation,  engineering, and  supervision.   The
percentage of these major cost components are presented
in Table 12.  Assumed proportions are based on ranges of
estimates given by Peters and Timmerhaus [1].  Since the
total  equaled less than  100 percent  the items were
normalized.    Once  the  purchased  equipment costs
 (including freight and sales tax) are known, the total fixed
 capital investment can be determined.  Freight and sales
 tax are  estimated  as  percentages  of the  purchased
 equipment cost, while the other fixed costs are  estimated
 as percentages of the total fixed capital investment.
 Table 12. Proportional Costs of Major Fixed Capital Investment
         Components
                            Assumed %
                             of Total
         Normalized %
            of Total
  Equipment (Including
  Freight & Sales Tax)

  Equipment
  Installation

  Instrumentation
  (Installed)

  Piping (Installed)

  Electrical (Installed)

  Engineering &
  Supervision

  Total
                                40
13

5

12


85
                                              47
              11
15

 6

14


100
                                                        17

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 43t6    Equipment and Fixed Costs

 Annualizcd equipment costs and other fixed costs have
 been prorated for the duration of time that the equipment
 is onsitc. The costs for equipment, contingency, insurance,
 and taxes accrue during assembly, shakedown and testing,
 treatment, and disassembly; scheduled maintenance costs
 accrue during treatment only.
 4.4    Basis of Economic Analysis

 The cost analysis was prepared by breaking down the
 overall cost into 12 categories.  The cost categories, some
 o£ which do not have costs associated with them for this
 particular technology, are:
      Site preparation
      Permitting and regulatory
      Equipment
      Startup and fixed
      Labor
      Supplies
      Consumables
      Effluent treatment and disposal
      Residuals  and  waste  shipping,  handling,   and
      transport
      Analytical
      Facility modification, repair, and replacement
      Site demobilization
The 12 cost factors as they apply to the VRU and the as-
sumptions employed  are described in  the following
subsections.
4.4.1    Site Preparation Costs

It is assumed that preliminary site  preparation will be
performed by the responsible party (or site owner).  The
amount of preliminary site preparation will depend on the
site. Site preparation responsibilities include site design
and layout, surveys and site logistics, legal searches, access
rights   and  roads,  preparations  for  support  and
decontamination facilities, utility connections, and auxiliary
buildings. Since these costs are site-specific, they are not
included as part of the site preparation costs in this cost
estimate.

Certain site  preparation  activities,  such  as  excavating
hazardous waste from  the contaminated  site, will be
required at all sites  and are therefore included in  this
 estimate. Cost estimates for site preparation are based on
 rental costs for operated heavy equipment, labor charges,
 and equipment fuel costs. An excavation rate of 27 tph is
 assumed for all cleanup scenarios using the 10-tph VRU.
 It is assumed that the minimum rental equipment required
 to achieve  an excavation rate of approximately  27 tph
 includes nine excavators, three box dump trucks, and three
 backhoes.  The operation of this equipment will consume
 approximately 42 gph of diesel fuel.  It is also assumed
 that excavation activities will  be  conducted 8 hours per
 day, 5 days per week.  Excavation costs are  itemized in
 Table 13.
 Table 13. Excavation Costs
Item
Excavator
Box dump truck
Backhoe
Supervisor
Excavator operator
Dump truck operator
Backhoe operator
Diesel fuel
Cost
$l,260/week
$525/week
$585/week
$40/hour
$30/hour
$30/hour
$30/hour
Si/gallon
4.42    Permitting and Regulatory Costs

Permitting and regulatory costs are generally the obligation
of the responsible party or site owner. These costs may
include   actual   permit  costs,   system   monitoring
requirements, or  the  development  of  monitoring and
analytical protocols.  Permitting and regulatory costs can
vary greatly because they are site- and waste-specific. No
permitting or regulatory costs are included hi this analysis.
Depending on the treatment site however, this may be a
significant factor  since permitting activities can be both
expensive and time consuming.
4.43    Equipment Costs

The commercial-scale VRU will be capable of treating 10
tph of contaminated soil. System accessories will include
a steam generator for stripping volatile organics from the
feed  soil,  off-gas  treatment system,  and waste-water
treatment system. Major pieces of equipment include:
                                                     18

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    Heated soil conveyor
    Trommel screen miniwasher
    Water heater
    Floc-clarifier
    Steam boiler
    Membrane filter press
    VOC treatment system
Miscellaneous equipment such as screens, pumps, mixers,
and tanks are included in equipment costs.

The developer supplied equipment and utility costs for the
pilot-scale and  the 10-tph  system.   Total  purchased
equipment cost for the 10-tph unit was  estimated to be
$1,240,000; the total fixed capital investment (including
freight and sales tax, installation, instrumentation, piping,
electrical,  and   engineering   and  supervision  during
construction) was projected to be $3,110,000.

It is  assumed that no rental equipment  or purchased
support equipment will be required for operation (with the
exception of trailers).  Support equipment  refers to
purchased equipment  necessary for operation but not
integral to the system.

The total equipment  cost is  calculated and  annualized
using the following formula:
                 A = C
where: A  =
        C  =
        i   =
        n  =
          (1 +  0" - 1

annualized cost, $
capitalized cost, $
interest rate, %
useful life, years
 The annualized cost (rather than depreciation) is used to
 calculate equipment costs incurred by a site. It is assumed
 that the interest rate will be 10 percent.  For the 10-tph
 unit, a useful life of 10 years is assumed.  The annualized
 equipment cost is prorated to the actual  time the unit is
 commissioned to  treat a hazardous  waste  (including
 assembly,   shakedown  and  testing,  treatment,  and
 disassembly).  The prorated annualized cost is estimated
 to be $271,000.   The prorated cost is then normalized
 relative to the tons of soil  treated.
 4.4.4    Startup and Fixed Costs

 Mobilization includes both transportation and assembly.
 Transportation activities include moving the system and
 the workers to and from the site.  As a rough estimate, it
 is  assumed that five oversize  and one legal load size
tractor  trailers  will  be  required  to  transport  the
commercial-scale soil washing system.  In addition,  one
legal  load  size  tractor  trailer  will  be  required  for
miscellaneous equipment  and spare parts.  Travel costs
were developed based on 1,300 road miles at  a rate of
$1.65 per mile  per  legal load and $3.30  per  mile  per
oversized load (including  drivers).  Transportation costs
for the 11 nonlocal onsite  workers are based on two $220
one-way airfares per person.  Two one-way airfares were
used instead of a round-trip airfare due to the restrictions
of a round-trip ticket and the  difficulties in predicting
when the project would end.

Assembly consists of unloading the system from the trucks
and trailers and reassembling the VRU. It is assumed that
unloading the equipment  will require the use of a 50-ton
crane and operator  for 3 weeks at a cost of $6,360 per
week.   Assembly is assumed to require  10 people (8
construction workers and 2 shift supervisors) working 8
hours per day, 7 days per week, for 3 weeks.  Table 14
lists fully burdened salaries for  all onsite personnel
involved with assembly as well  as other  phases of the
project (e.g., startup and testing, training, treatment, and
disassembly). Labor charges  during assembly  consist of
wages and living expenses for nonlocal personnel (refer to
Subsection 4.4.5) including two rental cars.

This cost estimate assumes that 1 week of shakedown and
testing  will  be required after assembly and prior to the
commencement of treatment. During this time, the system
components are tested individually. It is  estimated  that
eight workers will be required for 8 hours per day, 5 days
per week during shakedown and testing.  The 8 workers
include a project manager, shift supervisor, safety officer,
maintenance  worker, operator,  administrator,  and  two
local operators. In addition, the four local operators will
be trained for 3 days during this week. Labor costs consist
of wages and living expenses for nonlocal personnel (refer
to subsection 4.4.5) including two rental cars.

Working capital consists of the amount of money currently
invested in supplies,  energy, spare parts, and labor kept on
hand [1]. The working capital for this system is based on
maintaining a 1-month inventory of these items. For the
calculation of working capital, 1 month is defined as  one-
twelfth of 1 year, or approximately 21.8 working days.

For the purposes of this estimate, insurance is assumed to
be 6 percent of the total purchased  equipment costs;
property taxes are assumed to be 3 percent of the  total
fixed capital investment [1].  These costs are annual and
have been prorated to  the actual time the  VRU  is
 commissioned  to treat  contaminated  waste  on  a site
 (including assembly, shakedown and testing, treatment, and
 disassembly).
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 Table 14.  FWfy Burdened Salaries for Onsite Personnel Using
          10-tpli VRU

                                             Salary
Title
Project Manager
Shift Supervisor
Safety Officer
Non-local Operator
Maintenance Worker
Local Operator
Construction Worker
Administrative Personnel
Local
No
No
No
No
No
Yes
Yes
Yes
(S/h)
50
40
35
30
20
20
20
12
 The cost for the initiation of monitoring programs has not
 been included in this estimate.  Depending on the site,
 local  authorities may  impose  specific guidelines  for
 monitoring programs.  The stringency and frequency of
 monitoring required may have a significant impact on the
 project costs.

 An annual contingency  cost  of  10  percent  of  the
 annualizcd equipment capital costs is allowed to  cover
 additional costs  caused  by unforeseen or unpredictable
 events, such as strikes, storms, floods, and price variations
 II]. The annual contingency cost has been prorated to the
 actual time the  10-tph  VRU is commissioned to treat
 hazardous  waste (including  assembly,  shakedown and
 testing, treatment, and disassembly).
4.4.5   Labor Costs

Labor  costs  consist  of  wages  and  living  expenses.
Personnel requirements are discussed in Subsection 4.3.4.
Fully burdened rates are given in Table 14.

Living expenses depend on several factors:  the duration of
the project, the number of local workers hired, and the
geographical location of the project. Living expenses for
all personnel who are not local hires consist of per diem
and rental cars, both charged at 7 days per  week for the
duration of the treatment.  Per diem varies by location,
but for the purposes of this report, it is assumed to be $70
per day per person.  Four rental cars are required for 24-
hour operation and are available for $30 per day per car.
Depending on the length of the project, it may be more
practical to hire only local personnel and train them in the
operation of the unit, eliminating living expenses.
 4.4.6    Supplies Costs

 For this estimate, supplies consist of chemicals and spare
 parts.   Surfactant,  alkali  (sodium  carbonate),  alum,
 polyelectrolyte (flocculent), and sulfuric acid requirements
 for the VRU are estimated to cost approximately $420,000
 for the entire  project.  Annual spare parts costs  are
 estimated  to  be  5  percent  of the total purchased
 equipment cost or approximately $22,000 for the entire
 project. Expenses for personal protective equipment are
 included in spare parts costs.
 4.4.7    Consumables Costs

 In order to heat wash water and steam strip VOCs from
 the feed, the VRU  consumes natural gas at a rate of
 approximately 7.7 million Btu/h. The cost of natural gas
 is estimated as $4.00 per million Btu with no monthly fee,
 yielding a fuel cost of approximately $13,400 per month or
 $31 per hour of operation.

 The electricity requirement for the screw conveyor, pumps,
 and mixers is approximately 66 kWh  per ton of soil
 treated. The estimated cost of electricity is $25,000 per
 month or $48 per hour of operation.  The  cost estimate
 assumes that electricity can be obtained for a flat rate of
 $0.08 per kWh with no monthly charge.

 The VRU has an estimated water requirement of 1,420
 gallons per ton of soil treated.  It is assumed that 90
 percent of the water can be recovered  and treated for
 reuse (i.e., only about 24 gpm of makeup is needed).  The
 other 10 percent is discarded as blowdown or lost with
 clean solids during separation processes.  Water costs are
 estimated at $2 per 1,000 gallons. One month's supply of
 water (667,000 gallons) costs about $1,330,  and the  cost
 per hour of operation is $2.56.
4.4.8    Effluent Treatment and Disposal Costs

The clean solids generated during the SITE demonstration
remained onsite.  It is assumed that clean solids from a
full-scale cleanup will be used as fill material if found to
be nonhazardous. The fines will require further processing
by another technology. Recovery of at least 80 percent of
the solids present in the feed as washed soil is one of the
project objectives. The remainder (less than 20 percent)
is incorporated into the fines slurry.
                                                     20

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Most of the water from the water treatment system should
be suitable for recycling as wash water in the mini-washer.
A fraction of this water will be removed as blowdown and
require disposal or treatment. The responsible party or site
owner should obtain a discharge permit from the  local
municipality if possible.  If no sewer service is available,
the site owner or responsible party must obtain a direct
discharge permit or arrange for disposal by other means.
It should not  be necessary to treat the blowdown water
prior to discharge, but this must be determined on a site-
specific basis.

Onsite treatment and disposal costs are restricted to onsite
storage of the blowdown water (if necessary) and are
assumed to  be  the obligation  of  the site  owner or
responsible party.  Offsite treatment and disposal  costs
consist of wastewater disposal fees and  are assumed  to be
the obligation of the responsible party (or site owner).
These costs may significantly add to the total cleanup cost.
The cost of additional treatment of the fines is assumed to
be the obligation of the responsible party (or site owner).
4.4.9   Residuals and Waste  Shipping, Handling, and
        Transport Costs

It is assumed that the residuals generated by this process
will include the clean solids, fines, filters, spent carbon
canisters, and spent PPE. Residuals will also be generated
when the unit is decontaminated. Potential waste disposal
costs include storage, transportation, and treatment costs
and are assumed to  be the obligation of the responsible
party (or site owner).  These costs could significantly add
to the total cleanup cost.
 4.4.10  Analytical Costs

 No  analytical costs are included in this cost estimate.
 Standard operating procedures do require sampling and
 analytical activities to determine when breakthrough has
 occurred in equipment such as aqueous or vapor-phase
 carbon  absorption, reverse osmosis,  or  ultrafiltration
 systems. The client may elect or may be required by local
 authorities to initiate a sampling and analytical program at
 their own expense.  If specific sampling and monitoring
 criteria are imposed by local authorities, these analytical
 requirements could contribute significantly to the cost of
 the project.
4.4.11   Facility Modification, Repair, and Replacement
        Costs

Maintenance labor and material costs vary with the nature
of the waste and the performance of the equipment. For
estimating purposes, total annual maintenance costs (labor
and materials)  are assumed to be 10 percent of annual
equipment costs. Maintenance labor typically accounts for
two-thirds of the total maintenance costs and has been
discussed in Subsection 4.4.5.  Maintenance material costs
are estimated at one-thkd of the total maintenance cost
and are prorated to the entire period of treatment. Costs
for  design  adjustments,  facility   modifications,  and
equipment replacements are included in the maintenance
costs.
4.4.12   Site Demobilization Costs

Demobilization  costs are limited to disassembly costs;
transportation  costs  are included under mobilization.
Disassembly consists of taking the VRU apart and loading
it onto trailers for transportation. It requires the use of a
50-ton crane with operator, available at $6,360 per week,
for 3 weeks.   Additionally,  disassembly  requires a 10-
person   crew  (8  construction  workers  and  2  shift
supervisors) working 8 hours per day, 7 days per week, for
3 weeks. Labor costs consist of wages (see Table 14) and
living expenses (refer to Subsection 4.4.5)  including 2
rental cars.

Site cleanup and restoration are limited to the removal of
all equipment  from  the site.   These  costs have  been
previously  incorporated  in  the  disassembly  costs.
Requirements   regarding  the   filling,   grading,   or
recompaction of the soil will vary depending on the future
use of the site and are assumed to be the obligation of the
responsible party (or site owner).
 4,5    Results of Economic Analysis

 The costs associated with the operation of the VRU, as
 presented in this economic analysis, are defined by 12 cost
 categories  that   reflect   typical   cleanup  activities
 encountered on Superfund sites.  Each of these  cleanup
 activities is defined and discussed; together they form the
 basis for  the  cost analysis presented in Table 15.  The
 percentage of the total cost contributed by each of the 12
 cost categories is shown in Table 16.
                                                      21

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Table 15. Treatment Costs for 10-tph VRU Treating 20,000 Tons of
         Contaminated Soil
                                   Cost CS/tonl
                            70%       80%      90%
 Item                      oa-line      on-line    on-line
Site preparation
Permitting end regulatory
Equipment
Startup and fixed
Labor
Supplies
Consumables
Effluent treatment
and disposal
Residuals and waste
shipping, handling,
and transport
Analytical
Facility modification,
repair, and replacement
Site demobilization
Total operating costs
34.61
—
16.13
29.91
32.04
21.33
8.65
—

—
0.54
3.18
14639
34.61
—
14.68
30.03
28.03
21.15
8.65
—

—
0.49
3.18
140.82
34.61
—
1356
30.29
24.92
21.01
8.65
—

—
0.45
3.18
136.67
Table 16.  Treatment Costs as Percentages of Total Costs for 10-tph
         VRU Treating 20,000 Tons of Contaminated Soil
                                Cost fas % of total cost")
 Item
 70%
on-line
 80%
on-line
 90%
on-line
 Site preparation                 23.6      24.6       25.3
 Permitting and regulatory          —        —       —
 Equipment                    11.0       10.4       9.9
 Startup and fixed               20.4       21.3       22.2
 Labor                        21.9       19.9       18.2
 Supplies                       14.6       15.0       15.4
 Consumables                    5.9        6.1       6.3
 Effluent treatment and            —        —       —
 disposal
 Residuals and waste              —        —       —
 shipping, handling,
 and transport
 Analytical                      —        —       —
 Facility modification,              0.4        0.3       0.3
 repair, and replacement
 Site demobilization               2.2        2.3       2.3
 Total operating costs             100       100       100
The developer claims that the VRU can operate with an
on-line factor of over 90 percent.  On-line factors of 90,
80, and 70 percent were used in the cost  calculations in
order to determine the impact of this parameter.  The on-
line factor is used to adjust the unit treatment  cost to
compensate  for the  fact that the system  is not  on-line
constantly   because  of  maintenance   requirements,
breakdowns, and unforeseeable delays. Through the use of
the on-line factor, costs incurred while the system is not
operating are incorporated in the unit cost.

The VRU  is  believed  to  be capable  of  operating
continuously (24  hours  per  day, 7  days  per  week) for
extended periods of time; however, it was assumed that it
will be operated only 5 days per week.  If  the VRU is to
be to operated continuously, adjustments must be made to
prorated cost estimates.

The feed rate during the SITE  Demonstration Test was
approximately  100  Ib/h  and  the  pilot-scale  system
consumed approximately 66 kWh per ton  and 71 gph of
water (no recycling). The pilot-scale unit used propane to
heat the wash water; no steam was required since VOCs
were not present in the feed soil. Based on the pilot-scale
system, chemical usage rates per ton of soil for surfactant,
alkali,  alum, and polyelectrolyte were 24, 12, and 18 and
0.18 Ibs, respectively.

The developer provided cost and capacity information for
both the pilot- and full-scale (10-tph)  VRU units.  All
costs are for 1993. It is assumed the commercial-scale unit
will have a feed  rate  of  10 tph and will  require
approximately 24 gpm  of water  (assuming 90 percent
recycling), 66 kWh/ton of electricity, and 7.7 million Btu/h
of natural gas.  For this  feed  rate, the  results  of the
analysis  show a unit cost ranging from $137 per  ton to
$147 per ton for 90 and 70 percent on-line conditions,
respectively.

Based on the information provided by the developer, the
estimated purchased equipment cost for a larger (100 tph)
VRU unit was calculated using the following formula:

                      F = P(R)n

where:  F = Full-scale cost
         P = Pilot-scale cost
         R = Scale-up ratio (full-scale capacity/pilot-scale
              capacity)
         n = Scale-up factor
                                                        22

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This formula represents a typical cost verses capacity curve
[2]. Knowing the cost and capacity of the pilot and 10-tph
equipment, the scale-up factors were determined. These
values ranged from 0.32 to 0.97, but were typically between
0.4 and 0.7.  Using the same factors and estimated scale-
up ratios, equipment costs for the 100-tph VRU unit were
calculated.

These costs are considered order-of-magnitude estimates
as defined by the American Association of Cost Engineers.
The actual cost is expected to fall between 70  and 150
percent of the estimated cost when scaling-up from a full-
scale unit to a larger full-scale unit.  Since these costs were
estimated from scaling-up a pilot-scale unit to a full-scale
unit, the range may actually be wider.

Table 17 compares estimated unit treatment costs for sites
containing   10,000,  20,000,   and  200,000   tons   of
contaminated soil; Table  18 shows the percentage of the
treatment  costs  contributed  by  each  of the  12  cost
categories.   All  variables  except  total amount  of
contaminated soil are held constant.  In  particular,  all
three estimates utilize a 10-tph VRU and a 90 percent on-
line factor. If the 10-tph VRU is used to remediate a site
containing less than 20,000  tons of contaminated soil (all
other variables remaining constant), the startup and fixed
costs will become more of a factor.  Unit costs derived
from startup, demobilization, and from fixed expenses will
be higher, but unit costs derived from operating expenses
will remain approximately the same.

For example, if this system is applied to a site containing
 10,000 tons of contaminated soil, the unit treatment costs
 (using a 90 percent on-line factor) are estimated at $171
 per ton  of soil.   If the 10-tph VRU is used  at  a site
 containing over 20,000 tons  of contaminated soil (all other
 variables remaining constant), the startup, demobilization,
 and fixed costs will become less of a factor.  Unit costs
 derived from startup, demobilization, and fixed expenses
 will be  lower,  but  unit costs  derived from operating
 expenses will remain approximately the same.

 If this system is applied  to the  remediation  of  a site
 containing  200,000 tons of contaminated soil, the unit
 treatment costs  (using a 90  percent on-line factor)  are
 estimated at $106 per ton of  soil.

 It will take nearly 4 years  to remediate a  site containing
 200,000 tons of contaminated soil  with the 10-tph system.
 For this volume of soil, one or more larger units would be
 more  appropriate.   In order to  make a  comparison, a
 preliminary cost estimate was prepared for  a system
 capable of treating 100 tph of contaminated soil.
Table 17.  Treatment Costs for 10-tph VRU Operating with a 90%
         On-line Factor
                                   Cost (S/ton)
Item
Site preparation
Permitting and
regulatory
Equipment
Startup and fixed
Labor
Supplies
Consumables
10,000
tons
34.61
— -
18.12
56.70
24.92
21.01
8.65
20,000
tons
34.61
—
13.56
30.29
24.92
21.01
8.65
200,000
tons
34.61
_
9.45
6.52
24.92
21.01
8.65
  Effluent treatment
  and disposal
  Residuals and waste
  shipping, handling,
  and transport
  Analytical
  Facility modification,
  repair, and replacement
  Site demobilization
  Total operating costs
 0.60

 6.36
170.97
 0.45

 3.18
136.67
 0.31

 0.32
105.79
 Table 18. Treatment Costs as % of Total Costs for 10-tph VRU
         Operating With a 90% On-line Factor

                               Cost fas % of total cost)
Item
Site preparation
Permitting and
regulatory
Equipment
Startup and fixed
Labor
Supplies
Consumables
10,000
tons
20.2
~
10.6
33.2
14.6
12.3
5.1
20,000
tons
25.3
_
9.9
22.2
18.2
15.4
6.3
200,000
tons
32.7
~~~
8.9
6.2
23.6
19.9
8.2
   Effluent treatment
   and disposal
   Residuals and waste
   shipping, handling,
   and transport

   Analytical costs
   Facility modification,
   repair, and replacement
   Site demobilization

   Total operating costs
 0.4

 3.7
 100
  0.3

  2.3
  100
  0.3

  0.3
  100
                                                          23

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Table 19 compares estimated unit treatment costs for the
use of 10-tph and 100-tph systems at a site containing
200,000 tons of contaminated soil; Table 20 shows the
percentage of the treatment costs contributed by each of
the 12 cost categories.  All process variables except feed
rate are held constant. In particular, both estimates utilize
a  90 percent on-line factor.  This preliminary  analysis
indicates that it will  cost $72 per ton to remediate a site
containing 200,000 tons of contaminated soil using the 100-
tph system (assuming a 90 percent on-line factor). When
the larger  system  is  used,   the treatment  time  is
approximately 0.4 years and the equipment is onsite for
approximately 054 years.    Transportation  and onsite
assembly  of the  larger unit,  however,  could  present
difficulties.  More trailers and labor will be required for
mobilization and demobilization. It was assumed that one
extra local operator would be required per shift to operate
the larger unit.   Scale-up  to 100  tph from  10 tph was
accomplished by either increasing the scale-up ratio or the
number of units or a combination of both.

Table 19. Treatment Costs for the Remediation of 200,000 Tons of
         Contaminated Soil Using the VRU Operating With a 90%
         On-line Factor
                                     Cost CS/tonl
 Item
10-tph
System
100-tph
System
 Site preparation                   34.61          25.26
 Permitting and rcgulatoiy            —            —
 Equipment                        9.45           2.35
 Startup and fixed                   652          11.90
 Labor                           24.92           2.71
 Supplies                          21.01          20.40
 Consumables                       8.65           8.65
 Effluent treatment                  —            —
 and disposal
 Residuals and waste shipping,         —            —
 handling, and transport
 Analytical                         —            —
 Facility modification,                0.31           0.08
 repair, and replacement
 Site demobilization                  0.32           0.64
 To«al operating costs              105.79          71.99
                                Table 20.  Treatment Costs as Percentages of Total Costs for VRU
                                         Treating 200,000 Tons of Contaminated Soil

                                                                 Cost fas % of total cost")
                                 Item
                                                                  10-tph
                                                                 System
                                                                100-tph
                                                                System
                                 Site preparation                    32.7         35.1

                                 Permitting and regulatory             —           —

                                 Equipment                         8.9           3.3

                                 Startup and fixed                    6.2          16.5

                                 Labor                            23.6          3.8

                                 Supplies                          19.9         28.3

                                 Consumables                       8.2         12.0
                                 Effluent treatment and disposal         —           —

                                 Residuals and waste shipping,           —           —
                                 handling, and transport

                                 Analytical costs                      —           —

                                 Facility modification, repair, and        0.3           0.1
                                 replacement

                                 Site demobilization                   0.3           0.9

                                , Total operating costs                100          100
The costs excluded from this cost analysis are described in
Subsections 4.3 and 4.4.   This analysis does not include
values for 4 of the 12 cost categories, so the actual cleanup
costs incurred by the site owner or responsible party may
be significantly higher than the costs shown in this analysis.
While the volume of waste treated can be significantly
reduced,   the  contaminants   are  not  destroyed  or
immobilized,  so another treatment  technology will  be
required to treat the fines removed from the VRU.
                               4.6     References

                               1.       Peters, M.S. and Timmerhaus, K.D. Plant Design
                                        and Economics for Chemical Engineers; Third
                                        Edition; McGraw-Hill, Inc., New York, 1980.

                               2.       Baasel, W. D.  Preliminary Chemical Engineering
                                        Plant  Design; Elsevier Science Publishing  Co.,
                                        Inc., New York, 1976.
                                                        24

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                                              Appendix A
                                         Process Description
A.I    Introduction

Section 121(b) of CERC1A  mandates 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 "permanently and significantly
reduces the volume,  toxicity,  or  mobility of hazardous
substances, pollutants, and contaminants as a principal
element."   The  VRU was  developed to  meet those
objectives, as well as the objectives listed below:

•    To make available to  members  of the  research
     community and the commercial sector the results of
     government research on a flexible, multi-step, mobile,
     pilot-scale soil washer capable of running treatability
     studies on a wide variety of soils

•    To demonstrate the capabilities of soil washing

•    To  provide  data  that  facilitate  scale-up   to
     commercial-size equipment

The VRU is a mobile, pilot-scale soil washing system for
stand-alone field  use in cleaning soil  contaminated with
hazardous substances. Removal efficiencies depend on the
contaminant as well as the type of soil. In  general, soil
washing  is   effective  on   coarse  sand   and  gravel
contaminated with a wide range of organic and inorganic
contaminants.
A.2 Process Description

The VRU is  a  mobile research unit developed  for
treatability studies on  soils  contaminated with a wide
variety of contaminants.  It was designed to be extremely
flexible in terms of equipment and wash water additives
used.  It was not designed to be a commercial treatment
unit.
Soil  washing  is  a  water-based ex  situ  process for
mechanically scrubbing  soils  to  remove  undesirable
contaminants.  The process removes contaminants from
soils by either dissolving or suspending them in the wash
solution (which is later treated by conventional wastewater
treatment methods) or by  concentrating them into  a
smaller volume of  soil through  simple particle  size
separation techniques.  The  concept of reducing soil
contamination through the use of particle size separation
is based on the finding that most organic and inorganic
contaminants tend  to bind  to fine-sized clay and silt
particles primarily by physical processes [1].  Washing
processes that separate fine clay and silt particles from the
coarser sand and gravel soil particles effectively separate
and concentrate the contaminants into a smaller volume of
soil that can be further treated. The clean larger fraction
can be returned to the site for continued use.  This set of
assumptions forms the  basis  for the volume-reduction
concept upon which the VRU has been developed.

The VRU  is designed  to  decontaminate  certain soil
fractions using state-of-the-art washing equipment.

The total system consists of process  equipment and
support utility systems mounted on two heavy-duty tractor
trailers. The design capacity of the VRU is 100 Ibs/h.
The  basic  VRU  system  consists  of the  following
subsystems:

•    Soil handling and conveying (grizzly)
•    Soil washing and coarse  screening trommel screen
     (miniwasher and vibrating screens)
•    Fines/floatables gravity separation (CPI tank)
•    Fines  flocculation/water  clarification  and  solids
     disposal (floe clarifier)
•    Water  treatment   (filter,   carbon   drums,
     blowdown tank, and makeup water tank)
•    Utilities (electric generator, steam boiler, water heater
     and air compressor)
                                                      25

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  The  electric  generator,  air compressor,  water heater,
  filters/carbon drums, water recycling pump, and blowdown
  tank are located on  the utility trailer. All remaining
  equipment is located on the process trailer.  Figure A-l is
  a diagram of the typical VRU operational setup.  (The
  VRU setup  at  the Escambia Treating Company site
  demonstration was  modified  slightly from this typical
  setup.) The VRU system is controlled and monitored by
  conventional  industrial  process  instrumentation  and
  hardware including safety interlocks, alarms, and shutdown
  features.

  During the demonstration,  feed  soil was  taken  from
  prepared test  piles and manually processed through a V*-
  inch  screen.  After screening,  the  demonstration was
  conducted in accordance with the standard VRU operating
  procedure, a description of which follows.

  The screened soil is collected in a bucket for transfer to
  the  feed surge bin, and oversized soil is returned to the
site. From the feed surge bin, the soil less than V* inch is
conveyed through a screw conveyor to the miniwasher. The
conveyor flow is adjusted by a speed  controller on the
conveyor motor.  The  solids  pass through a  motor-
operated rotary valve (which prevents air infiltration), and
then into the feed hopper of the miniwasher.

Soil is fed  to  the miniwasher  at a controlled rate  of
approximately 100 Ibs/h by the screw conveyor.  Filtered
wash water  is added to the soil in the feed hopper and
also sprayed onto an internal slotted trommel screen [with
a  10-mesh  (2-mm)  slot opening]  miniwasher.   Five
manually controlled levers can adjust the flow up to  an
approximately 13 to  1 overall water-to-soil ratio.  Two
vibrating screens continuously segregate soil into various
size fractions.  The screens can be set at a variety of mesh
sizes. For the demonstration, 10-mesh (2-mm) and 100-
mesh (0.150-mm) screens were used.
                                                  Makeup Water Tank
                              Blowdown Tank
                                                                         Water Heater

                                                                              Screw Conveyor
              Carbon Drums
                                 Trommel Screen
                                 Mini-Washer

                                       Steam Boiler
     Air Compressor
Electric Generator
                                                                                                        Grizzly
                                                                            Screened Soil Fractions
                                  Figure A-l. Typical VRU Operational Setup.

                                                      26

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Miniwasher overflow (the stream exiting the top of the
washer), which contains the coarser solids, falls onto the
first 10-mesh (2-mm) vibrascreen.  The first vibrascreen
overflow (less than 14 inch, greater than 10-mesh) solids
flow by gravity down to a recovery drum. The underflow
(the stream exiting the bottom) is pumped at a controlled
rate to the second 100-mesh (0.150-mm) vibrascreen where
it is joined by the miniwasher underflow.

The overflow from the second vibrascreen [less than 10-
mesh (2-mm), greater than  100-mesh (0.150-mm)] is
gravity fed to the same recovery drum containing the other
miniwashed coarse soil fraction.  The second vibrascreen
underflow (a fines slurry) drains into a tank with a mixer.

Slurry from the 100-mesh (0.150-mm) screen (fines slurry)
tank is pumped to the  CPI. Materials lighter than water
(floatables such as oil) flow over an internal weir, collect
in a compartment within the CPI, and drain by gravity to
a drum for disposal.  CPI-settled solids [particles which
will pass  through a 100-mesh (0.150-mm) screen] are
discharged by the bottom auger to a recovery drum.

An   aqueous   slurry,   containing   fines   less   than
approximately 400 mesh (38 fim), overflows the CPI and
gravity feeds into a tank with a mixer. The slurry is then
pumped to a static mixer located upstream of the floe
clarifier's mix tank. Flocculating chemicals, such as liquid
alum and aqueous polyelectrolyte solutions, are metered
into the static mixer  tank to neutralize  the  repulsive
electrostatic charges on colloidal particles (clay/humus)
and promote  coagulation.  The slurry is then discharged
into the floe chamber, which has a variable-speed agitator
for controlled floe growth (sweep flocculation).  Sweep
flocculation refers to the adsorption of fine particles onto
the floe (colloid  capture) and continuing floe growth to
promote  rapid settling of the floe.   The floe slurry
overflows into the clarifier (another corrugated plate unit).
Bottom solids are augured to  a drum for disposal.
Clarified water is polished with the objective of reducing
suspended solids and organics to low levels that permit
recycling of spent wash water. Water is pumped from the
floe  settler overflow tank at a controlled rate through
cartridge-type polishing filters  operating  in  parallel  in
order to remove soil fines greater than 4 x 10"4 inch (10
^m).  Water leaving the cartridge filter  flows through
activated carbon drums for removal of hydrocarbons. The
carbon drums may be operated either in series or parallel.
Hydrocarbon breakthrough is  monitored by sampling;
drums are replaced when breakthrough has been detected.

In order to recycle water and maintain suitable dissolved
solids and organic levels, aqueous bleed (blowdown) to the
boiler blowdown tank may be initiated at a controlled rate.
A.3    References

1.  Ballard,  R.B.,  BJ.  Losack,  and  T.M.  Murphy.
    Treatment of Hydrocarbon and Lead Contamination
    by Soil Washing at a Pipe Inspection Facility, Prudhoe
    Bay, Alaska. Presented at the 86th Annual Meeting
    of the Air & Waste Management Association, June
    13-18, 1993.
                                                      27

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                                              Appendix B
                                          Developer Claims
B.I    Introduction

The VRU is a mobile, pilot-scale soil washing system. It
was designed to be a research platform to evaluate the
effectiveness of soil washing as a technology to remove
volatile organics, semivolatile organics, and metals from
soils,  sludges,  and sediments.  Soil washing is a water-
based process which  extracts  and concentrates the
hazardous constituents into a smaller volume of soil and
sludge using chemical extraction and physical separation
methods.

The VRU is composed  of two 40-foot trailers, a process
trailer, and a utilities trailer. The unit has a flexible design
to  enable the formulation of wash fluids composed of
different combinations of water, surfactants, caustic,  acids,
and chelating agents.   In addition to  soil washing and
physical separation, there is an onboard steam generator
and a jacketed screw conveyor to  enable the evaluation
and use of steam  stripping or low temperature thermal
desorption to remove volatile and semivolatile organics.
The  VRU  also  has  a  solids separation  and   water
purification system to enable the treatment and recycling
of  the wash  water and to evaluate the effectiveness of
different  water treatment  chemicals  (coagulants and
flocculants) and equipment.

Several treatability  studies  have  been  performed in
conjunction  with  EPA  Regional staff   and EPA's
Environmental Response Team  (ERT).  The VRU has
treated pentachlorophenol, creosotes, dioxin and furans at
the Escambia Wood Treating Sites and herbicides and
pesticides at  the  Sand Creek Superfund Site.   These
studies have  been  performed  primarily  to help the
Remedial  Project Managers  (RPMs)  and  On-Scene
Coordinators  (OSCs)  determine  the  feasibility of soil
washing for their particular sites. The studies also enable
RREL staff to evaluate  the effect of varying  process
parameters such as the wash fluid temperature and pH;
liquid-solid ratio, the system contact time, and screen mesh
size were varied to evaluate their effect on the extraction
efficiency of the system. Various wash formulations and
surfactant concentrations have also been explored. Work
at several other sites will be performed this year looking
at contaminants  such as  diesel fuel,  polychlorinated
biphenyls (PCBs), and heavy metals.

The VRU is designed to easily accommodate the addition
of other unit operations such as low temperature thermal
systems,  chemical extraction processes, electron beam
oxidizers, and biotreatment units.  Previous studies  have
evaluated these types of units for treating the effluent from
the soil washing operation. RREL plans to publish the
research and treatability findings  so  RPMs, OSCs, and
project managers can make informed decisions about the
effectiveness of soil washing technology on the particular
sites.
B.2    SITE Demonstration Claims

During the  spring of 1992, EPA's ERT performed site
investigations at four wood treating facilities.  These sites,
located in the southeastern U.S., were contaminated with
organic (creosote and pentachlorophenol)  and inorganic
(copper,  chromium,  and  arsenic)  wood  preservative
compounds.   Bench-scale  soil washing  studies  were
performed on the soil from two of the sites.  Aqueous
biodegradable surfactants were tested for their ability to
increase the solubility of PCP and creosote  compounds,
and 280 ppm carcinogenic creosote compounds showed
removals of greater than 99 percent, 92 percent, and 95
percent after several washes with Tergitol NP-10 surfactant
at elevated pH and temperature. Dioxin and furan levels
were also reduced more than 91 percent.

Pilot studies using the VRU were performed in July 1992
by RREL and RBC at the Escambia Wood Treating Site
in   Pensacola,  Florida.     Representative soil  was
homogenized and washed under varying pH, temperature,
and  surfactant  concentrations.    Twenty  runs  were
performed over a 2-week period.   Concentration levels
                                                     29

-------
were reduced from an initial concentration of 150 ppm
PCP, 75 ppm carcinogenic creosote, and 1,250 ppm total
creosote to 1.7 ppm PCP, 3.5 ppm carcinogenic creosote,
and 80 ppm total creosotes.  Nondetectable levels (<1
ppm, > 99 percent removal) were achieved for PCP and
carcinogenic creosote after a clean water rinse was applied
to the washed coarse samples. The total creosote residual
was reduced to less than 32 ppm, greater than 97 percent
removal.

Analysis indicated that only  1 weight percent of the feed
soil was below 115 mesh (0.125 mm).  Thus, the VRU
used  100-mesh  (0.150-mm)  screens  as the cut  point.
Theoretically, volume reductions of 97 to 98 percent could
be achieved.  Due to inefficiencies of the screening units,
the unit achieved volume reductions of approximately 90
to 93 percent.
The SITE Demonstration also took place at the Escambia
Site.  Thus, the project claims and tests conditions were
based on the results of the previous treatability studies.
The specific claims and project objectives of this study are
as follows:

•   The VRU will separate the coarse gravel and sand
    (material which will not pass through  a 100-mesh
    screen) from the finer silt and  clay particles.  A
    volume reduction  of  at least 80 percent will be
    achieved.

•   The coarse soils  exiting  the VRU  will contain
    residuals  of total creosote and  pentachlorophenol
    contaminants at least 90 percent lower than the initial
    values found in the feed soil.
                                                     30

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                                             Appendix C
                                  SITE Demonstration Results
C.I   Introduction

This appendix  summarizes  the results  of  the SITE
Demonstration  Test  of the  VRU  developed by EPA.
These results are also discussed in Sections 1 and 3 of this
report.  A more detailed account of the  demonstration
may be found in the TER.

The ability of the VRU to reduce  the concentration of
organic  contaminants in  excavated soils was evaluated.
Results   from  this   demonstration  include:   percent
reductions for PCP; percent reductions for PAHs; percent
solids returned to the site  as  washed soil; and mass
balances for total material, dry  solids, PCP, and PAHs.
VRU operating conditions were verified  and the water
treatment system effectiveness was assessed based on wash
water quality before and after  treatment by the VRU
system.

PAH-  and PCP-contaminated  soil  from  the  former
Escambia Treating Company site in Pensacola, Florida was
treated during the demonstration.  Contaminant levels in
the excavated soil from the site ranged from the low parts
per million to percent levels. For the SITE demonstration,
the  excavated  soil  was  homogenized  and manually
processed through a VS-inch screen before it was fed to the
VRU.

Average contaminant concentrations in the feed soil on a
dry weight basis are summarized  in Table  C-1.  Five
compounds from the  standard set of  creosote-fraction
PAHs were not detected in the feed soil samples. These
compounds   [naphthalene,   benzo(k)fluoranthene,
ideno(l,2,3-cd)pyrene,  dibenzo(a,h)anthracene,  and
benzo(g,h,i)perylene] were not included as PAHs for this
evaluation.
Table C-1. Average Contaminant Concentrations in the Feed Soil (dry
         weight basis)
 Contaminant
(ppm)
PAHs
Acenaphthylene
Acenaphthene
Fluoiene
Phenanthrene
Anthracene
Fluoranthene
Pyrene
Benzo(a)anthracene
Chrysene
Benzo(b)fluoranthene
Benzo(a)pyrene
PCP

3
120
130
330
59
180
110
29
27
12
8
140
C.2    Operating Conditions

The target operating conditions were  specified in the
Demonstration Plan  [1].   Three runs,  each 4 hours in
duration, were performed for each of Conditions 1 and 2.
Two runs, each 6 hours in duration, were performed under
Condition 3. Sampling was conducted in accordance with
the procedures outlined in the Demonstration Plan [1].
Surfactant concentration, and wash  water  pH  and
temperatures were monitored to determine whether the
VRU was functioning at the specified operating conditions.
                                                    31

-------
The  surfactant  concentration  was  determined  by
calculating the ratio of surfactant-to-wash water on a mass
basis.  The pH was determined by measuring the pH of
the fines slurry stream. The temperature was determined
by measuring the temperature of the wash water just
before it entered the soil washing segment of the VRU.
Table C-2 lists the operating conditions experienced during
the demonstration.

By  adding   surfactant  and  increasing  the  pH  and
temperature  of the wash  water, contaminant  removal
efficiencies can be improved significantly. Water is a polar
substance while the contaminants, PCP and  PAHs  (and
other organic contaminants) are nonpolar. Because polar
substances do not dissolve nonpolar substances well, the
addition of a nonpolar surfactant to the wash water can
improve organic  contaminant removal significantly.
Adjusting the pH and temperature of the wash water can
also increase contaminant solubilities and improve removal
efficiencies.

The  conditions established for  this  demonstration were
based on earlier treatability studies conducted by EPA at
the Escambia Treating Company site.  During these
studies, PCP and PAH removal efficiencies under varying
operating parameters (surfactant  addition,  pH  and
temperature increases) ranged from 92.6 to 98.9 percent
and 85.2  to 97.1 percent, respectively.

The  surfactant  used during the  demonstration  was
Tergitol.  In bench-scale tests conducted by EPA prior to
the demonstration, several surfactants were evaluated on
the Escambia  soils.  Tergitol was considered  to be the
most effective in removing contaminants from the soil
samples  and  was therefore  selected  for use in the
demonstration.
C3     Contaminant Removal

Table  C-3 lists the  contaminant  concentrations  and
contaminant removal efficiencies obtained during the
demonstration.  Contaminant removal efficiencies were
determined by comparing (on a dry weight basis) the mass
of the contaminant in the feed soil with the mass of the
contaminant in the washed soil. Removal efficiencies are
calculated using the following equation:
      % removal- [Concentration of contaminant in feed - concentration of contaminant in washed soil,   1QQ
                                        concentration of contaminant in feed
Table C-2. VRU SITE Demonstration Operating Conditions

Condition 1
Runl
Run 2
Run3
Condition 2
Runl
Run 2
Run3
Condition 3
Run 1
Run 2
Feed Rate
(Ib/h)

93
64
95

97
106
108

117
148
W/F Ratio

7
10
7

6
6
6

5
4
Surfactant Flow
(Ib/h)

0
0
0

13.4
13.7
14.1

11.0
11.7
Surfactant
Concentration in
pH Wash Water (%)

7.3
7.2
7.1

7.0 0.22
6.9 0.22
6.9 0.22

10.2 0.17
10.1 0.18
Water
Temperature
(°F)

60
56
55

59
60
65

145
139
                                                    32

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Table C-3. Removal Efficiencies for FCP and FAHs (dry weight basis)
Parameter
Condition 1
Runl
Run 2
Run 3
Range
Condition 2
Runl
Run 2
Run 3
Range
Condition 3
Runl
Run 2
Range

Feed Soil
(ppm)

150
170
140
130-180

170
180
160
150-210

100
110
48-190
PCP
Washed Soil
(ppm)

28
36
43
21-52

15
13
14
8-19

2.4
3.5
2-5

%
Reduction

81
78
69


91
93
91


98
97


Feed Soil
(ppm)

1,000
1,200
860
770-1,500

1,000
1,000
830
900-1,200

1,100
960
550-1,700
PAHs
Washed Soil
(ppm)

240
310
350
200-520

180
160
130
120-220

44
46
29-65

%
Reduction

77
74
59


83
84
84


96
95

PCP removal efficiencies were calculated for Conditions 1,
2, and 3.  Under Condition 3, which employed surfactant
addition and pH and temperature adjustment, the average
PCP   removal efficiency  was  97  percent.   Under
Condition 2, which employed surfactant addition only, the
average PCP removal efficiency was 92 percent.  These
removal  efficiencies achieve  the project objective  of
demonstrating that the unit is capable of removing 90
percent of the PCP from the bulk of the feed soil.  The
average PCP removal efficiency for Condition 1 was only
76 percent. These data illustrate the impact of surfactant
addition and pH adjustment on PCP removal efficiencies.
PCP removal efficiency is clearly surfactant-dependent and
also  appears to  be  slightly pH- and temperature-
dependent.

PAH removal efficiencies were calculated for Conditions
1,  2,  and  3.   Under Condition 3,  which employed
surfactant addition and pH adjustment, the average PAH
removal efficiency was 95 percent. This removal efficiency
achieves the project objective of  demonstrating that the
unit is capable of removing 90 percent of the PAHs from
the bulk  of the feed  soil.  The average PAH  removal
efficiencies for Conditions 1 and 2 were only 70 percent
and 83 percent, respectively. These results illustrate the
impact of surfactant addition and pH and temperature
adjustment on PAH removal efficiencies.
C.4    Washed Soils Recovery

The VRU system is designed to separate the sand and
gravel fraction of the soil from the contaminated fines (i.e.,
fine clay and silt particles).  The larger sand and gravel
fraction exits the system as washed soil. By comparing the
mass of dry solids in the feed soil with the mass of dry
solids in the washed soil, solids recoveries of 95,95, and 82
percent were calculated for soils treated under Conditions
1 through 3.  These recoveries were also calculated on a
normalized basis, yielding normalized recoveries of 90,88,
and 86 percent for Conditions  1, 2, and 3.   These
recoveries,  shown in Table C-4,  achieve the  project
objective of  demonstrating that at least 80 percent of the
solids present in the feed soil would be returned to the site
as washed soil.
                                                     33

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 Table C-4. Feed Son Recovered as Washed Soil (dry weight basis)

Condition 1
Runl
Run 2
Run3
Average
Condition 2
Runl
Run 2
Run 3
Average
Condition 3
Runl
Run 2
Average
Feed Soil
Ob/h)

86
62
90
—

90
101
104
-

101
132
-
Washed Soil
(Ib/h)

73
71
79
—

90
104
88
-

95
90
-
Fines Slurry
(Ib/h)

9
9
9
-

9
13
15
-

13
15
-
%
Recovery

85
114
86
95

97
103
86
95

94
69
82
Recovery
Normalized Basis

90
89
90
90

90
89
85
88

87
85
86
C.S    Mass Balances

Mass balances were  performed to assess material  and
contaminant fate  as  well  as system efficiency.   Mass
balances were conducted for total materials, dry solids,
PCP, and PAHs.  These  balances  were  obtained by
comparing the mass  of a  given substance  entering the
system  (in  all input streams) with  the mass of that
substance exiting the system (in all output streams). Mass
balance closure (or recovery) is calculated as follows:
 Mass Balance Closure = L Mass Eating System ^
                         Mass Entering System
C5.1   Total Material

The total mass of all material (feed soil and washwater)
entering the VRU was compared to the total mass of all
material (cleaned soil and fines slurry) exiting the system.
The mass balances for the total material are presented in
Table C-5.  Closures of 104,  113, and  98  percent were
obtained during  Conditions 1, 2, and  3,  respectively.
                                                             During Condition 2, it was noted  the  mass flow rate
                                                             measurement of the fines slurry may have been affected by
                                                             sampling procedures employed during the demonstration.
                                                             This resulted in inflated mass flow rates. The procedure
                                                             was modified and the  percent closures  dropped to the
                                                             acceptable range.  Except for this inflated closure of 113
                                                             percent for Condition 2, average closures for total material
                                                             balances met the project objectives of 90 to 110 percent.
                                                            C.5.2   Dry Solids

                                                            Dry solids mass balances were calculated by comparing the
                                                            total dry weight of the soh'ds entering soil washer per hour
                                                            as feed soil with the total dry weight of the solids exiting
                                                            the soil washer as washed soil and slurry fines. Except for
                                                            Run 2 of Condition 1, Run 2 of Condition 2, and Run 2 of
                                                            Condition 3, the closures obtained during the demonstra-
                                                            tion are  consistent  with  project objectives  specifying
                                                            closures of between 85 and 115 percent for solids treated
                                                            within the soil washing portion of the VRU system. Even
                                                            though  closures for individual runs were outside of  the
                                                            specified range, the average closures for Conditions 1, 2,
                                                            and 3 met project objectives.  The mass balances for  dry
                                                            solids are presented in Table C-6.
                                                     34

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Table C-5.  Total Material Mass Balance
                                           Inputs
Feed Soil Wash Water
(lb/h) (lb/h)
Condition 1
Run 1 93 692
Run 2 64 662
Run 3 95 626
Average — ~
Condition 2
Runl 97 593
Run 2 116 587
Run 3 108 604
Average — —
Condition 3
Run 1 117 622
Run 2 148 635
Average — —
Table C-6. Dry Solids Mass Balances
Solid Inputs
Feed Soil
(lb/h)
Condition 1
Runl 86
Run 2 62
Run 3 90
Average —
Condition 2
Run 1 93
Run 2 101
Run 3 104
Average —
Condition 3
Run 1 101
Run 2 132
Average —
Washed Soil
(lb/h)

88
88
95
—

110
130
108
—

121
112
-

Solid
Washed Soil
(lb/h)

73
71
79
—

90
104
88
—

95
88
'
Fines Slurry
(lb/h)

697
699
666
~~

677
688
697
—

644
653
-

Outputs
Fines Slurry
(lb/h)

9
9
9
—

9
13
15
—

12
15
-
%
Closure

100
108
105
104

112
116
111
113

101
95
98

%
Closure

94
128
96
106

108
116
101
108

108
80
94
                                                               35

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 O5.3   PCP

 At Condition 1, the average mass balance closure for PCP
 was 101 percent, which meets the project objective of PCP
 mass balance closures between 80 and 175 percent. The
 average PCP closures for Conditions 2 and 3 were below
 80  percent,  and therefore did not meet  the  project
 objective.

Average PCP closures for Conditions 2 and 3 were 19
percent and 13  percent, respectively.   Because the  low
PCP closures were experienced when surfactant was added
to the wash water, it seems probable that the surfactant
interfered with the PCP analyses. The PCP mass balances
are presented in. Table C-7.
C.5.4   PAHs

Like PCP, the majority of PAHs entering the VRU within
the feed soil exited in the slurry fines. At Condition 1, the
average mass balance closure for PAHs was 87 percent,
which meets the project objective of PAH mass balance
closures between 80 and 175 percent.  The average PAH
closures for Conditions 2 and 3 were below 80 percent,
and therefore did not meet the project objective. Average
PAH closures for Conditions 2 and 3 were 28 percent and
13 percent, respectively. Like PCP the low PAH closures
were experienced when surfactant was added  to the wash
water, and it seems probable that the surfactant interfered
with the PAH analyses.  The PAH mass balances are
presented in Table C-8.
Table C-7. PCP Mass Balance

Condition 1
Runl
Run 2
Run 3
Average
Condition 2
Runl
Run 2
Run 3
Average
Condition 3
Runl
Run 2
Average
PCP Inputs
Feed Soil

13
10
12
-

13
19
16
-

10
15
-
PCP
Washed Soil
(lb/h)

2.0
2.6
3.3
-

1.5
1.4
1.3
-

0.54
0.31
-
Outputs
Fines Slurry
(lb/h)

9.0
8.4
10.0
-

1.3
2.1
1.4
-

1.3
1.3
-
% Closure

85
105
113
101

22
18
17
19

15
11
13
                                                    36

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Table C-8. PAH Mass Balance



Condition 1
Runl
Run 2
Run3
Average
PAH Inputs
Feed Soil
(Ib/h)

86
77
77
-
PAH
Washed Soil
(Ib/h)

17
22
26
-
Outputs
Fines Slurry
(Ib/h)

55
51
37
-


% Closure

82
95
85
87
 Condition 2
   Runl
   Run 2
   Run 3
   Average
82
104
88
17
18
12
8.8
9.7
9.7
31
27
25
28
 Condition 3
   Runl
   Run 2
   Average
108
130
4.6
4.2
7.7
16
11
15
13
 C.6    Particle Size and Fines Distribution

 A number of steps were employed to control the size of
 the various streams entering and exiting the soil washing
 portion of the VRU system. The feed soil was screened
 so that only particles less than *A inch hi size entered the
 unit. The washed soil was composed of particulate matter
 that  would not pass through a 100-mesh (0.150-mm)
 screen while the fines slurry contained particles that would
 pass through a 100-mesh (0.150-mm) screen. Particle size
 distribution data for the feed, washed soil, and fines slurry
 are presented in Table C-9.

 The underflows from the CPI  and flocculation tank were
 also analyzed for particle size distribution characteristics.
 The  underflow from the  CPI should primarily contain
 particles  which will pass through a 100-mesh (0.150-mm)
 screen but will not pass through a 200-mesh (0.075-mm)
 screen; the underflow from the flocculation tank should
 primarily contain particles which will pass through a 200-
 mesh screen.  Particle  size  distribution  data for the
 underflow streams from the CPI and the flocculation tank
 are presented in Table C-10.

 The VRU's effectiveness is based on its ability to separate
 soil fines that will pass through a 100-mesh  (0.150-mm)
 screen from the coarser gravel/sand fraction of the soil,
 which will not pass through a 100-mesh  (0.150-mm)
                           screen.   Dry solids  mass  balance data  defining the
                           disposition of the fines and the gravel/sand portion of the
                           feed can be found in Tables C-ll and C-12, respectively.
                           Excellent results for partitioning the coarser sand/gravel
                           fraction to the washed soil were achieved. Approximately
                           1 to 2 percent of these particles were detected in the fines
                           slurry.  While a majority of the soil fines partitioned into
                           fines slurry, the partitioning was less complete.  As shown
                           in Table C-ll, 31 to 54 percent of the soil fines recovered
                           in the output stream were located in the washed soils.  A
                           more complete partitioning of the soil fines to the fines
                           slurry would, theoretically, lead to increased contaminant
                           removals from the washed soils.
                           C.7    Water Treatment Effectiveness

                           The fines slurry  stream was  stripped of pollutants by
                           utilizing  a settling, flocculation,  filtration,  and carbon
                           adsorption treatment sequence. The solids in the CPI and
                           floe clarifier were analyzed for PCPs and PAHs.  The
                           results are presented in Tables C-13 and C-14.

                           Wash water into  the VRU and the clarified water were
                           analyzed for TOC and TR, which is the sum of TSS and
                           TDS.  The results of these analyses are summarized in
                           Tables C-15 and C-16.
                                                       37

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T*bJe C-9. Particle Size restriction wlMa the Feed Sofl, Washed Soi, snd Pines Stony (% Finer)

Feed SoU
Condition 1
Average
Range
Condition 2
Average
Range
Condition 3
Average
Range
Washed Soil
Condition 1
Average
Range
Condition 2
Average
Range
Condition 3
Average
Range
Fines Slurry
Condition 1
Average
Range
Condition 2
Average
Range
Condition 3
Average
Range
10 mesh 50 mesh
(2,000 ^m) (300 ftni)


99 28
99.1 - 100.0 23.1 - 315

99 25
98.8 - 100.0 20.4 - 30.8

99 17
98.1 - 100.0 133 - 205


100 18
99.4 - 99.9 10.7 - 245

100 17
99.3 - 99.9 13.2 - 25.6

98 15
955 - 99.6 7.4 - 54.8


100 100
100.0 - 100.0 96.8 - 99.9

100 99
100.0 - 100.0 98.2 - 100.0

100 99
100.0 - 100.0 94.8 - 99.9
100 mesh
(150 ^m)


14
12.0 - 112

12
10.4 - 17.8

9.7
8.9 - 10.9


4.6
1.9 - 16.3

5.2
1.9 - 16.7

65
0.8 - 47.3


91
65.6 - 99.1

84
54.6 - 99.2

88
643 - 98.7
200 mesh 250 mesh 400 mesh 4x10-* inch
(74 /«n) (63 /«n) (38 /mi) (10 fim)


10.0 83 65 62
8.6-13.6 7.4-9.8 5.9-75 5.7-6.7

9.0 16 5.9 5.7
7.9-14.2 6.6-10.2 45-83 4.4-7.4

75 65 5.6 5.4
6.8-8.6 5.9-7.1 4.8-6.9 4.8-6.4


3.1 2.0 1.1 0.9
0.9-15.9 1.0-7.7 0.7-1.6 0.7-1.4

3.1 2.1 0.8 0.6
0.6-15.8 1.0-7.6 0.3-15 0.3-1.1

6-0 3.1 05 03
0.3-46.9 03-21.3 0.0-1.3 0.0-0.8


63 59 52 46
47.4-89.4 37.7-70.4 26.8-66.7 9.8-61.0

68 65 60 54
33.7-945 31.1-94.9 253-95.4 21.9-82.8

66 64 60 56
395-90.8 33.1-90.8 23.6-90.8 19.2-875
2 x Iff4 inch
(Sftm)


5.7
55-6.1

5.4
4.4 - 6.6

5.0
3.8-5.9


0.8
05 - 1.4

0.6
0.1 - 1.0

0.3
0.0 - 0.8


40
3.9 - 56.6

51
21.0 - 79.8

50
14.3 - 875

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Table C-10. Particle Size Distribution within the Underflow from the CPI and Hoc Tank (% Rner)

CPI Underflow
Condition 1
Average
Range
Condition 2
Average
Range
Condition 3
Average
Range
Hoc Tank Underflow
Condition 1
Average
Range
Condition 2
Average
Range
Condition 3
Average
Range
10 mesh
(2,000 fim)


100
100.0 - 100.0

100
100.0 - 100.0

100
100.0 - 100.0


100
100.0 - 100.0

100
100.0 - 100.0

100
100.0 - 100.0
50 mesh
(300 ftm)


100
98.7 - 100.0

100
98.9 - 100.0

100
99.8 - 100.0


75
43.7 - 91.8

100
99.4 - 100.0

91
85.4 - 93.7
100 mesh 200 mesh
(150 ftm) (74ftm)


91 76
79.7 - 95.1 55.6 - 88.3

99 96
95.4 - 99.9 92.0 - 98.2

99 84
97.7 - 99.3 78.1 - 90.7


69 65
39.4 - 91.2 36.9 - 90.9

100 99
99.1 - 100.0 98.8 - 99.7

84 80
70.0 - 88.9 65.6 - 86.4
250 mesh 400 mesh 4 x 10"4 inch
(63 ftm) (38,um) (10 ftm)


73 67 59
51.2 - 87.0 42.6 - 84.1 30.6 - 80.6

95 94 88
90.0 - 98.3 85.3 - 98.6 76.9 - 96.6

80 75 69
723 - 88.7 62.1 - 87.9 585 - 80.8


64 60 50
35.2 - 90.2 32.6 - 88.6 245 - 82.7

98 94 89
93.9 - 99.6 78.6 - 99.1 70.1 - 985

77 67 56
64.1 - 81.8 56.8 - 71.4 45.2 - 62.9
2 x 10" inch
(5 ftm)


56
27.6 - 78.1

81
74.8 - 90.2

66
51.1 - 77.3


38
245 - 70.6

60
34.7 - 955

49
34.7 - 58.2

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 Table C-ll. Disposition of Fines (dry weight basis)
                          Feed Soil
                                                         Washed Soil
                                                                                               Fines Sluny
Flow Rate How Rate Recovered
Ib/h Ib/h %
Condition 1 11 3.4 31
Condition 2 12 4.9 41
Conditions 11 5.9 54
Table C-12. Disposition of Coarse Gravel and Sand (dry weight basis)
Feed Soil Washed Soil
Flow Rate How Rate Recovered
Ib/h Ib/h %
Condition 1 68 71 104
Condition 2 87 89 102
Conditions 105 86 82
Table C-13. Range of FCP Concentrations in Fines Slurry Solids (ppm)
CPI Underflow
Condition 1 51-69
Condition 2 46-85
Condition 3 *
* Unacceptable analysis resulted in questionable data.
Table C-14. PAH Concentration in Fines Slurry Solids (ppm)
CPI Underflow
Condition 1 1,300 - 1,800
Condition 2 370 - 1,100
Condition 3 *
How Rate Recovered Total %
Ib/h % Recovered
8.2 75 106
10 83 124
12 110 164
Fines Sluny
Row Rate Recovered Total %
Ib/h % Recovered
1 1 105
2 2 104
2 2 84
Hoc/Clarifier
92 - 6,500
190 - 1,300
83-150
Hoc/Clarifier
58 - 2,000
910 - 1,800
940 - 1,200
* Unacceptable analysis resulted in questionable data.
                                                                  40

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Table C-15. TOC Levds in Water Streams (ppm)

Condition 1
Condition 2
Condition 3
Wash Water
<1.0

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C,8   References

1.   Demonstration Plan for  USEPA RREL's Mobile
    Volume Reduction Unit.   Prepared by:  Science
    Applications International Corporation.
                                                42

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                                              Appendix D
                                             Case Studies
D.I    Bench- and Pilot-Scale Treatment of Soil
       from a Wood Treating Facility

Bench-scale experimental studies  were  performed on
contaminated soil samples from wood treating facilities to
determine  if  soil  washing  was  capable of removing
creosote and PCP from a soil matrix and collecting them
in a water matrix

The effectiveness of the study was based on soil cleanup
criteria set by EPA of 30 ppm PCP, 50 ppm carcinogenic
creosote  compounds,  and   100  ppm  total  creosote
compounds. Water-based biodegradable surfactants were
tested for their ability to increase the solubilization of PCP
and creosote compounds in water.  Effects of elevated
temperature and pH were also tested.

The bench-scale studies were performed on soil with initial
contamination levels of approximately 420 ppm PCP; 4,200
ppm total creosote compounds; and 280 ppm carcinogenic
creosote compounds.  During these studies, the  soil was
subjected to three washes with Tergitol NP-100 surfactant
at elevated pH and temperature. These studies achieved
PCP, total creosote, and carcinogenic creosote removals of
greater than 99, 92, and 95 percent, respectively.  Dioxin
and furan levels were also reduced more than 91 percent.

Due to the favorable results of the bench-scale studies, a
pilot-scale study was performed to test the applicability of
soil washing further.  Representative soil samples were
washed  at various  pHs, temperatures,  and surfactant
concentrations a VRU soil washer.  Twenty runs were
performed over a  2-week  period.   Under the best
conditions, PCP concentrations were reduced from 120
ppm to  less than  1  ppm (greater  than 99.1 percent
removal), total creosote concentrations were reduced from
2,280 ppm to 2 ppm (greater than 99.9 percent removal),
and  carcinogenic creosote concentrations were reduced
from 103 ppm to less than 1 ppm  (greater than 99.0
percent  removal).    Cleanup  criteria  for PCP and
carcinogenic creosote compounds were  met during all
pilot-scale  runs; cleanup  criteria  for  total  creosote
compounds were met during all but 1 of the 20 pilot-scale
runs.
D.2    Pilot-Scale Treatment of Pesticide-
        Contaminated Soil

The VRU was used to perform a pilot-scale study to
evaluate the  ability of soil washing to  remediate soils
primarily  contaminated with organochlorine pesticides
(e.g., dieldrin, heptachlor, chlordane, 4,4'-DDT), herbicide
(2,4-D), and metals (chromium and arsenic). The Record
of Decision set cleanup levels of 0.155 ppm dieldrin and
0.553 ppm heptachlor.

The pilot-scale study included 23 runs conducted under
varied conditions. Test variables included surfactant type,
surfactant concentration, pH, temperature, liquid-to-soil
ratio, soil type, and number of washes. The concentrations
of heptachlor  and dieldrin in the feed  soil  also varied
widely.    The results  of this   pilot-scale  study  are
summarized in Tables D-l and D-2.  Based  on these
results, it is not possible to determine conclusively whether
soil  washing is capable of meeting the cleanup levels.
Achieving cleanup levels may require a multistage washing
process that is more efficient than the single-stage VRU.
                                                     43

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 Table D-l.  Heptachlor Results
                                                                               Minimum
                                                                                                  Maximum
                                                                                                                     Average
Hcptachlor concentration in feed, ppm
Hcptachlor concentration in coarse treated solids, ppm
Heptachlor concentration in fine treated solids, ppm
Removal of heptachlor from feed to coarse treated solids, %
Removal of heptachlor from feed to fine treated solids, %
8
1.4
4.4
17
-107
460
50
340
99
97
159
22
88
79
34
Table D-2. Dieldrin Results
                                                                                  Minimum
                Maximum
                                                                                                                      Average
  Dieldrin concentration in feed, ppm
  Dieldrin concentration in coarse treated solids, ppm
  Dieldrin concentration in fine treated solids, ppm
  Removal of dieldrin from feed to coarse treated solids, %
  Removal of dieldrin from feed to fine treated solids, %
 2.7
 1-5'
0.93b
 -44
-131
27
6.8
37
91
86
16
3
11
71
34
*     The coarse treated solids from two other runs had dieldrin concentrations below the detection limit of 1.6 ppm.
b     The fine treated solids from one other run had a dieldrin concentration below the detection limit of 1.6 ppm.
                                                                44

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