EPA/540/R-94/510
                                                   JULY 1995
            Hughes Environmental Systems, Inc.


   INNOVATIVE TECHNOLOGY EVALUATION REPORT
NATIONAL RISK MANAGEMENT RESEARCH 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 in this document has been prepared for the U.S. Environmental Protection Agency
(EPA) Superfund Innovative Technology Evaluation (SITE) Program under Contract No. 68-CO-
0048. This document has been subjected to EPA's peer and administrative reviews and  has been
approved for publication as an EPA document. Mention of trade names or commercial products does
not constitute an endorsement or recommendation for use.

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                                     FOREWORD

       The U.S. Environmental Protection Agency is charged by Congress with protecting the
Nation's land, air, and water resources. Under a mandate of national environmental laws, the Agency
strives to formulate and implement actions leading to a compatible balance between human activities
and the ability of natural systems to support and nurture life.  To meet these mandates, EPA's
research program is providing data and technical support for solving environmental problems today
and building a  science knowledge  base necessary to manage our ecological  resources wisely,
understand how pollutants affect our health, and prevent or reduce environmental risks in the future.

       The National Risk Management Research Laboratory is the Agency's center for investigation
of technological and management approaches for reducing risks from threats to human health and the
environment.  The focus of the Laboratory's research program is on methods for the prevention and
control of pollution to air, land, water and subsurface resources; protection of water quality in public
water systems ; remediation of contaminated sites and groundwater; and prevention and control of
indoor air pollution. The goal of this research effort is to catalyze development and implementation
of innovative,  cost-effective environmental  technologies;  develop  scientific and  engineering
information needed by EPA to support regulatory and policy decisions; and provide technical support
and information transfer to ensure effective implementation of environmental regulations and
strategies.

       This publication has been produced as part of the Laboratory's strategic long-term research
plan. It is published and made available by EPA's Office of Research and Development to assist the
user community and to link researchers with their clients.
                                                E. Timothy Oppelt, Director
                                                National RiskManagement Research Laboratory
                                            in

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                          TABLE OF CONTENTS
Section
Page
NOTICE	ii
FOREWORD  	 iii
LIST OF TABLES  	vii
LIST OF FIGURES	 viii
LIST OF ACRONYMS AND ABBREVIATIONS  	 ix
ENGLISH TO METRIC CONVERSION FACTORS	 xi
ACKNOWLEDGEMENTS	xii

EXECUTIVE SUMMARY	1

SECTION 1  INTRODUCTION	5

      1.1    Background	5
      1.2    Brief Description of Program and Reports  	6
      1.3    Purpose of the Innovative Technology Evaluation Report	9
      1.4    Technology Description	9
      1.5    Key Contacts 	15

SECTION 2  TECHNOLOGY APPLICATIONS ANALYSIS  	17

      2.1    Objectives—Performance versus ARARs	17
      2.2    Operability of the Technology	26
      2.3    Applicable Wastes  	29
      2.4    Key Features  	30
      2.5    Availability/Transportability 	31
      2.6    Materials Handling Requirements	32
      2.7    Site Support Requirements	33
      2.8    Ranges of Suitable  Site Characteristics	34
      2.9    Limitations of the Technology  	35

SECTION 3  ECONOMIC ANALYSIS 	37

      3.1    Conclusions of the  Economic Analysis  	37
      3.2    Basis of the Economic Analysis 	40
      3.3    Issues and Assumptions 	42
      3.4    Results of the Economic Analysis	45

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                 TABLE OF CONTENTS (CONTINUED)

Section                                                                 Page

SECTION 4  TREATMENT EFFECTIVENESS  	64

      4.1    Background 	64
      4.2    Testing Methodology	67
      4.3    Performance Data	70
      4.4    Residuals 	87

SECTION 5  OTHER TECHNOLOGY REQUIREMENTS 	90

      5.1    Environmental Regulation Requirements	90
      5.2    Personnel Issues	91
      5.3    Community Acceptance 	92

SECTION 6  TECHNOLOGY STATUS	94

      6.1    Previous/Other Experience	94
      6.2    Scaling Capabilities	94
      6.3    Other Information	95

REFERENCES	96

APPENDIX A     Case Study: Dynamic Underground Stripping Process at
                 Lawrence Livermore National Laboratory	97
                                     VI

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                               LIST OF TABLES




Table                                                                          Page




Table ES-1    Evaluation Criteria Results for In Situ SERP at the Rainbow Disposal Site	4




Table 2-1     Federal and State ARARs for the Steam Enhanced Recovery Process	19




Table 3-1     Summary of Results of the Economic Analysis	38




Table 3-2     Details of the Economic Analysis 	46




Table 4-1     TPH and TRPH Results for Post-Treatment Soil   	71




Table 4-2     Results of Triplicate Analyses for TPH and TRPH 	72




Table 4-3     Percent Removal from Borehole Pairs	75




Table A-l     Post-Treatment Analytical Results for Borehole #105	100




Table A-2     Post-Treatment Analytical Results for Borehole #106	100
                                        vn

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                               LIST OF FIGURES

Figure                                                                          Page

Figure 1-1    The Layout of Injection and Extraction Wells at the Rainbow Disposal Site   .12

Figure 1-2    Aboveground SERF Treatment Train	14

Figure 3-1    Approximate Actual Cost per Cubic Yard for Rainbow Disposal  	39

Figure 4-1    Pre- and Post-Treatment Sampling Locations at the Rainbow Disposal Site ...  65

Figure 4-2    Histogram of Pre- and Post-Treatment TPH Concentration Data  	76

Figure 4-3    Temperature Monitoring Well Locations 	78

Figure 4-4    Soil Temperature Plot for Well Location 15  	79

Figure 4-5    Soil Temperature Plot for Well Location 23  	79

Figure 4-6    Soil Temperature Plot for Well Location 24	80

Figure 4-7    Soil Temperature Plot for Well Location 27	81

Figure 4-8    Soil Temperature Plot for Well Location 30	82

Figure 4-9    Soil Temperature Plot for Well Location 33  	83

Figure 4-10   Soil Temperature Plot for Well Location 20	84

Figure 4-11   Well Water Usage and Diesel Recovered at the Rainbow Disposal Site  	85

Figure A-l    Approximate Locations of Process Wells and Sampling Boreholes
             at the LLNL Site 	98
                                         vin

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               LIST OF ACRONYMS AND ABBREVIATIONS
ARAR       applicable or relevant and appropriate requirement
BTEX       benzene, toluene, ethylbenzene and xylenes
BTU        British thermal unit
CAA        Clean Air Act
CERCLA    Comprehensive Environment Response, Conservation and Liability Act of 1980
CERI        Center for Environmental Research Information
CFR         Code of Federal Regulations
CWA        Clean Water Act
DNAPL      dense non-aqueous phase liquids
FID         flame ionization detector
GC          gas chromatography
GPM        gallons per minute
in situ        in place
LEL         lower explosive limit
LLNL        Lawrence Livermore National Laboratory
LUFT        Leaking Underground Fuel Tank
MCL        maximum contaminant level
MCLG       maximum contaminant level goal
MS          matrix spike
MSD        matrix spike duplicate
NAAQS      National Ambient Air Quality Standards
NIOSH       National Institute for Occupational Safety and Health
NPDES       National Pollutant Discharge Elimination System
NPL         National Priority List
ORD        Office of Research and Development
OSHA       Occupational Safety and Health Administration
OSWER      Office of Solid Waste and Emergency Response
PEL         permissible exposure limit
POTW       publicly-owned treatment works
ppb          parts per billion
PPE         personnel protective equipment
ppm         parts per million
psi           pounds per square inch
QA          quality assurance
QAPP        Quality Assurance Project Plan
QC          quality control
RCRA       Resource Conservation and Recovery Act
RREL        Risk Reduction Engineering Laboratory
RWQCB      Regional Water Quality Control Board
                                         IX

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     LIST OF ACRONYMS AND ABBREVIATIONS (CONTINUED)
SAIC        Science Applications International Corporation
SARA       Superfund Amendments and Reauthorization Act
SCAQMD   South Coast Air Quality Management District
SCFM       standard cubic fset per minute
SDWA      Safe Drinking Water Act
SERF       Steam Enhanced Recovery Process
SITE        Superfimd Innovative Technology Evaluation
SVOCs      semivolatile organic compounds
TDS        total dissolved solids
TOU        thermal oxidation unit
TPH        total petroleum hydrocarbons
TRPH       total recoverable petroleum hydrocarbons
USEPA      United States Environmental Protection Agency
VOCs       volatile organic compounds

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            ENGLISH TO METRIC CONVERSION FACTORS

 To Obtain (metric unit)	Multiply (English unit) by	Conversion
meters                          feet                                  0.305
liters                            gallons                               3.79
cubic meters (m3)                 cubic yards (yd3)                       0.764
dollars per cubic meter ($/m3)       dollars per cubic yard ($/yd3)             1.31
kilograms                        pounds (mass)                         0.454

Note:  To convert °F to °C use °C = (°F-32)(0.56)
                                       XI

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                           ACKNOWLEDGEMENTS

This project was directed and coordinated by Mr. Paul de Percin, the EPA SITE Technical Project
Manager in the Risk Reduction Engineering Laboratory (RREL) in Cincinnati, Ohio. It was prepared
for the EPA SITE Program under the direction  of Mr.  Kyle Cook of Science Applications
International Corporation (SAIC) under Contract No. 68-CO-0048. Major contributors from SAIC
were Ms. Ruth Alfasso, Mr. Raymond Martrano, Ms. Maria Marquez, Ms. Julie Poust, Mr. Jonathan
Rochez, and Ms. Jamie Winkelrnan. Dr. Trevor Jackson, Dr Victor Engleman, and Mr. Joseph Evans
of SAIC provided technical review.

EPA-RREL  reviewers for this report were Ms. Michelle Simon and Ms. Naomi Barkley. Their
assistance in the preparation of this final  report is greatly appreciated.

The cooperation and participation of Mr. W. Ron Van Sickle of Hughes Environmental Systems, Inc.
throughout the course of the project and in review of this report is gratefully acknowledged. Special
thanks are also offered to Mr. John F. Dablow III, formerly of Hydro-Fluent, Inc., and Mr. Richard
Timm of the Rainbow Disposal Company
                                          xn

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                            EXECUTIVE SUMMARY


This report summarizes the findings of an evaluation of the in situ Steam Enhanced Recovery

Process (SERF). This technology was operated by Hughes Environmental Systems, Inc. at the

Rainbow Disposal site in Huntington Beach, California. The Rainbow Disposal site is an active
municipal trash transfer facility that was contaminated by a spill of diesel fuel from a crushed

underground  pipeline. The  evaluation  of this technology was  conducted under the U.S.

Environmental Protection Agency (EPA) Superfund Innovative Technology Evaluation (SITE)

Program in conjunction with a full-scale remediation using SERP at the Rainbow Disposal site.


The  EPA  SITE  Program evaluated the SERP  technology  to  develop full-scale  process

performance and cost data. The critical objectives for the Demonstration of the SERP technology
were: (1) to evaluate the ability of the technology to meet the cleanup requirement set by the

Regional Water Quality Control Board for the site soil,  based on soil sampling results, and (2)

to perform a detailed economic analysis of this full-scale application of the technology.


Conclusions from the SITE Demonstration


Based on the SITE Demonstration, the following conclusions can be drawn about the in situ
SERP technology as applied to the  Rainbow Disposal site remediation:


       •     The Demonstration results showed that the removal of contamination by the SERP
             technology was  less  complete than expected. Forty-five percent of the post-
             treatment soil sample results  inside  the treatment area were above the  cleanup
             criterion (1,000 mg/kg [ppm] of total petroleum hydrocarbons, or TPH). Seven
             percent of the soil samples had TPH levels in excess of 10,000 mg/kg.

       •     A geostatistical analysis of the post-treatment soil data was conducted  using a
             computerized model to assess the spatial variability of soil contamination and to
             determine a weighted average concentration of the soil sample results. From the
             geostatistical model,  a post-treatment weighted average soil concentration of
             2,290 mg/kg of TPH  with standard error of 784 mg/kg was derived. Based on an
             approximate normal  distribution  for  the  weighted average,  the 90  percent
             confidence interval for TPH concentration is 996 mg/kg to 3,570 mg/kg. This

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large interval is attributed to the variability of site soil sampling results due to the
heterogeneity of the in situ soil contamination; analytical variability was within
established quality control limits and contributed little to overall data variability.
According to this analysis, at 90 percent confidence, the true average is probably
higher than the cleanup criterion of 1,000 mg/kg.

The geostatistical analysis results  for total recoverable petroleum hydrocarbons
(TRPH) yielded a weighted average post-treatment soil concentration of 1,680
mg/kg with a standard error of 608 mg/kg. The 90 percent confidence  interval
for the weighted average for TRPH is 676 mg/kg to 2,680 mg/kg. No  cleanup
criteria were  set for TRPH. The TRPH analysis provides information similar to
TPH but is performed using an EPA-approved method; the TPH method is widely
used but is not  an EPA-approved  method.

BTEX compounds were detected at low mg/kg levels hi a few pre-treatment soil
samples and were found at levels below the detection limit (6 Mg/kg) in all post-
treatment  samples.  Based  on these results,  the SERP  technology  may have
effected removal of  BTEX  compounds  from the in situ  soil, but  this is
inconclusive  due to the lack  of positive  BTEX results and the heterogeneous
nature of in situ soil contamination at the site.

Based on the weighted averages for the  pre- and post-treatment soil data sets
determined from geostatistical analysis, the technology may have removed 40
percent of the contamination from the  site soil. Due to the high site soil
contamination variability,  at 90 percent confidence, the actual percent removal
may have been significantly higher or lower. Calculation of percent removal was
a secondary objective  of the  technology  evaluation because pre-treatment data
were  collected by  the developer before the initiation of a SITE Program
Demonstration Quality Assurance Project Plan (QAPP).

Process data collected during treatment support the finding of a low to moderate
removal efficiency. Approximately 700 gallons of diesel were collected in liquid
form during treatment, while approximately 15,400 gallons were oxidized in the
system's  vapor  treatment  equipment.   Therefore,  a   combined  total  of
approximately  16,000  gallons of diesel  were removed during  treatment with
SERP. Compared to the estimated  initial diesel spill volume of 70,000 to 135,000
gallons, this  represents a reduction of approximately 12  to 24 percent. This
estimated removal is within the percent removal confidence interval for the soil
data.

The technology experienced significant amounts of downtime during treatment.
All major equipment systems experienced problems during treatment.  An on-line
factor of 50 percent was experienced at this site for the technology application
over the two years of treatment. Reliability  in subsequent applications of the

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              technology is expected to be higher since this was the first full-scale application
              of the technology.

       •      Based on soil temperature profiles from several areas of the site, heating of the
              soil took much longer than originally anticipated and high soil temperatures were
              not  maintained in many areas. This may have been due to  the way the process
              was operated initially  (16 hours  per day,  5  days per  week) and  to excessive
              operational downtime. The heating rate improved later in the application when the
              process" operation went to a 24-hour per  day,  6-day  per week cycle.  These
              operational factors may have contributed to the failure  of the SERF technology
              to achieve the cleanup criterion for the site.  More constant process operation and
              monitoring should improve  the performance of this technology in subsequent
              applications.

       •      The costs for use of the technology at this site were relatively low; however, site
              remediation did not achieve the cleanup criterion.  Actual costs at the Rainbow
              Disposal site were estimated to be approximately $46/cubic yard. A 50 percent
              on-line factor was determined for this case. Under idealized conditions at this
              site, which assumes a 100 percent on-line factor, the technology could have cost
              as little as $29/cubic yard. For a site similar to the Rainbow Disposal site, under
              typical operating  conditions  (on-line  factor of 75 percent), the cost for use of
              SERF was  estimated to be $36/cubic yard.  The large amount of soil  treated by
              the technology at  the Rainbow Disposal  site contributed to a relatively low cost
              per  cubic  yard. The  cost for use of the technology is most sensitive to the
              duration of remediation, and start-up and utilities costs.

The in situ SERF technology was evaluated based on the nine criteria used for decision-making

in the Superfund Feasibility Study process. Table ES-1 presents the results of the evaluation.
Another  in  situ  steam technology,  the Dynamic  Underground  Stripping  Process,  was

demonstrated and evaluated by the Lawrence Livermore National Laboratory in conjunction with

the University of California at Berkeley, College of Engineering. The results of this evaluation

are presented in a case study in Appendix A of this report. The EPA SITE Program had limited

participation in the evaluation of this in situ steam technology, which is similar to the in situ

SERP discussed in this ITER.

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Table ES-1. EVALUATION CRITERIA RESULTS FOR IN SITU SERF AT THE RAINBOW DISPOSAL SITE












CO
5
E>
C/5














CRITERIA
Overall

Protection of
Human Health
and the
Environment
Reduced soil
concentrations
without excava-
tion

May reduce the
mobility of
contamination
into groundwater
after treatment

Did not appear to
cause lateral or
downward
migration of
contaminants











Compliance
with ARARs

Did not meet
soil cleanup
criterion, on the
average, in this
application

Less soil is
excavated, thus
less soil requires
disposal

Permits for
drilling,
operating, and
air and water
discharges are
required










Long-term
Effectiveness
and Permanence

A portion of
contaminants are
permanently
removed from
the soil

Removed
contaminants
can be
incinerated or
recycled

Residual
contamination
presents reduced
risk










Reduction of
Toxicity, Mobility
or Volume Through
Treatment
Treated soil had
lower concentra-
tions overall, some
areas were cleaned
to well below the
cleanup criterion

Remaining
contaminants may-
be less mobile

Lower soil
concentrations are
amenable to natural
or enhanced
biodegradation

Technology
residuals are not of
large volume as
compared to the
treated soil volume





Short-term
Effectiveness

Soil is treated
below ground so
potential air
emissions are
minimized

Other activity can
continue at
surface of
treatment area
with minor
disruption

Drilling and
treatment may
cause emissions,
noise and dust
which can be
mitigated








Implementability

Technology uses widely
available construction
and process equipment

Most regulatory permits
are common and are
readily acquired for
fuel-related cleanups -
Treatment of sites with
other contaminating
chemicals may require
additional permitting
requirements

Operational problems
can occur that may
delay the
remediation

The technology may not
be able to meet stringent
cleanup requirements,
necessitating post-
processing such as
assisted biodegradation


Cost

Ranged from
$29 "to $46
per cubic
yard for a
large site

Capital
equipment,
start-up, and
utilities costs
are high

Remediation
time is the
major factor
in the costs

Because the
process
operates in
situ, off-site
disposal costs
are minimized




State
Acceptance

Minimizes
excavation of
and exposure to
contaminated
soil

Potential exists
for off-site
subsurface
migration of
steam and
contaminants

Air emission
permit may be
required

Wastewater
discharge
permits may be
required






Community
Acceptance

Site
disturbance
can be
minimized

Does not
require major
interruptions
of existing
operations

May recover
product for re-
use or
recycling

May exceed
noise limits in
some areas







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                                     SECTION 1
                                 INTRODUCTION

 This section provides background information about the SITE Program, discusses the purpose
 of this Innovative Technology Evaluation Report (ITER), and describes  the in situ Steam
 Enhanced Recovery Process (SERF) technology that was evaluated. For additional information
 about the SITE Program, the technology, and the Demonstration site, key contacts are listed at
 the end of this section.

 1.1    BACKGROUND

 In August of 1991, a site remediation using the in situ SERF process was started at the Rainbow
 Disposal site,  an active municipal trash transfer facility in Huntington Beach, California. The
 site had been contaminated by a leak of diesel fuel from an underground pipeline used to supply
 fuel for trash  trucks and other vehicles. SERP was selected by Rainbow Disposal, Inc.  as a
 cleanup remedy for the contaminated soil based on a site-specific feasibility study. SERP was
 selected over other technologies since it required less excavation of soil,  could be  conducted
 during continuing operations on the site, and could be used beneath existing structures.

 The full-scale  remediation at the Rainbow Disposal site was seen by the SITE Program as an
 excellent chance to test the performance of the technology and to develop operating costs.  The
 SITE Program became involved with the technology at the Rainbow Disposal site when it was
 being developed by  Hydro-Fluent, Inc.  Hydro-Fluent, Inc. ceased business operations in
 September  of 1991. Hughes Environmental Systems, Inc. took over the contract and continued
 to operate the  technology until the remediation was stopped in August 1993.

Pre-treatment sampling and analysis of the soil at the Rainbow Disposal site was conducted in
September  1991 by the technology  operator with oversight from the EPA SITE Program, but
prior to full SITE Program involvement with the project. Post-treatment sampling and analysis

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was  conducted in August and September of 1993 by the SITE Program using  full quality
assurance procedures.

SERF operates on contaminated soil in situ through wells constructed in the ground. Steam is
injected into the soil through injection wells which are screened hi the contaminated depth or
depths.  Extraction  wells  are  operated  using  a vacuum to draw the steam,  water,  and
contaminants from the soil and into an aboveground  treatment system. Contaminant  removal
occurs below the soil surface,  and,  as was true at Rainbow Disposal, operations on the site
surface can continue with minimal interruption.

SERF is similar in concept to several other in situ technologies including vacuum extraction and
soil flushing. SERF  differs from conventional in situ technologies in that it uses  both steam
injection and extraction of vapor and liquids under vacuum.  The added heat from the steam is
expected to increase  the speed of remediation and make the technology more applicable to higher
boiling point (less mobile) compounds that cannot be removed by other in situ technologies such
as vacuum extraction or  soil flushing

Another steam injection technology is the Dynamic Underground Stripping process used at the
Lawrence Livermore National Laboratory (LLNL), which uses electrical heating hi addition to
steam injection/vacuum extraction to increase removals of contaminants from low-permeability
soils. This technology was recently demonstrated and evaluated by LLNL in conjunction with
the University of California at Berkeley,  College of Engineering. Appendix A to this ITER
presents a case study of the Dynamic Underground Stripping process. The EPA SITE Program
had a minor role in  the evaluation of this technology.

1.2   BRIEF DESCRIPTION OF PROGRAM AND REPORTS

The  SITE Program  is a formal program established by EPA's Office  of Solid Waste  and
Emergency Response (OSWER) and Office of Research and Development (ORD)  in response
to the Superfund Amendments  and Reauthorization Act of 1986 (SARA). The  SITE Program

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 promotes the development, demonstration, and use of new or innovative technologies to clean
 up Superfund sites across the country.

 The SITE Program's primary  purpose is  to  maximize  the  use  of alternatives in cleaning
 hazardous waste sites by encouraging the development  and demonstration of new,  innovative
 treatment and monitoring technologies. It consists of four major elements discussed below.

 The objective of the Demonstration Program is to develop reliable performance and cost data
 on innovative technologies so that potential users may assess the technology's site-specific
 applicability. Technologies evaluated are either currently available or close to being available
 for remediation of Superfund sites. SITE Demonstrations are conducted on hazardous waste sites
 under  conditions  that closely  simulate full-scale remediation conditions,  thus assuring the
 usefulness and  reliability  of information  collected.  Data  collected  are used to assess  the
 performance of the technology, the potential need for pre- and post-treatment processing of
 wastes, potential operating problems, and the approximate costs. The Demonstrations also allow
 for evaluation of long-term risks and operating and maintenance costs.

 The Emerging Technology Program focuses on successfully proven bench-scale technologies that
 are in  an early  stage of development involving pilot- or laboratory-scale testing. Successful
 technologies  are encouraged to advance to the Demonstration Program.

 Existing technologies which improve field monitoring and site characterizations are identified
 in the  Monitoring and Measurement Technologies Program.  New technologies that provide
 faster,  more cost-effective contamination and site-assessment data are supported by this Program.
 The Monitoring and  Measurement Technologies Program also formulates the protocols and
 standard operating procedures for demonstrating methods and equipment.

The Technology  Transfer  Program  disseminates  technical  information about  innovative
technologies  in the Demonstration, Emerging Technology, and Monitoring and Measurements
Technologies Programs through various activities. These activities  increase the awareness and

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promote the use of innovative technologies for assessment and remediation at Superfund sites.
The goal of technology transfer  activities is to develop  interactive communication among
individuals requiring up-to-date technical information.

Technologies are selected for the  SITE Demonstration Program through annual requests for
proposals.  ORD  staff-review the  proposals to determine which technologies show-the most
promise for use at Superfund sites.  Technologies chosen must be at the pilot- or full-scale stage,
must be innovative,  and  must have some advantage  over  existing technologies.  Mobile
technologies are of particular interest.

Once EPA has accepted a proposal, a cooperative agreement between EPA and the developer
establishes responsibilities for conducting the Demonstrations and evaluating the technology. The
developer is responsible for demonstrating the technology at the selected site and is expected to
pay any costs for transport, operations, and removal of the equipment. EPA is responsible for
project planning, sampling and analysis, quality assurance and quality control, preparing reports,
disseminating information,  and transporting and disposing of treated waste materials.

The  results  of the  SERP Demonstration are  published  in  two  basic documents: the SITE
Technology  Capsule and this Innovative Technology Evaluation Report (ITER). The SITE
Technology  Capsule provides relevant information about  the technology,  emphasizing key
features of the results of the SITE field Demonstration. Both the SITE Technology Capsule and
the ITER are intended for use: by remedial project managers making a detailed evaluation of the
technology  for a specific site and waste.  A companion document to the ITER, called  the
Technical Evaluation Report (TER) is published in limited quantities in unbound form. The TER
contains raw data from the testing and evaluation, and other information on which the ITER is
based. The TER is primarily designed to  allow a quality assurance evaluation of the ITER.

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 1.3    PURPOSE OF THE INNOVATIVE TECHNOLOGY EVALUATION REPORT

 This ITER provides information  about  the SERF  technology and  includes a comprehensive
 description of the SERF Demonstration and its results. It is intended for use by EPA remedial
 project managers, EPA on-scene  coordinators,  contractors,  and other decision-makers  for
 implementing specific-remedial actions. The ITER is designed to aid decision-makers in further
 evaluating specific technologies for further consideration as an applicable option in a particular
 cleanup  operation.   This  report   represents   a  critical  step  in  the  development  and
 commercialization of a treatment technology.

 To encourage the general use of demonstrated technologies, EPA provides information regarding
 the applicability and performance  of each technology to specific sites and wastes. This ITER
 includes information on cost and  site-specific characteristics.  It also discusses  advantages,
 disadvantages, and limitations of the technology.

 Each SITE Demonstration evaluates the performance of a technology in treating a specific waste.
 The waste characteristics of other sites may differ from the characteristics of the treated waste.
 Therefore, successful field demonstration of a technology at one site does not necessarily ensure
 that it  will be applicable  at  other sites.  Data from the field  Demonstration  may  require
 extrapolation  for  estimating the operating ranges  for which the  technology  will  perform
 satisfactorily.  Only limited conclusions can be drawn  from a single field Demonstration.

 1.4    TECHNOLOGY DESCRIPTION

 SERP is an in situ process designed to remove volatile and semivolatile organic contamination
using steam to provide heat:  and  pressure.  The process is applicable to the treatment of
contaminated soils and groundwater.

The process works by injecting high quality steam through wells (injection wells) constructed
to a depth at or  below the contamination at a site.  Additional wells (extraction wells) are

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 operated under vacuum to create a pressure gradient in the soil to draw the liquids, vapor, and
 contaminants through the soil. Liquid and vapor streams  removed by the extraction wells are
 directed to an aboveground liquid and vapor treatment system.

 The geology of the site is influential in determining whether SERF will be applicable. There are
 several site requirements for. effective operation:

        •     The contamination must consist of volatile and/or semivolatile compounds, such
              as those found hi spilled fuel contamination.
        •     The soil must: have moderate to high permeability.
        •     The subsurface  geology must provide a confining  layer below the depth of
              contamination. This layer can take three forms: (1) a continuous low permeability
              layer such as a clay layer;  (2) a water table,  for compounds with liquid phases
              lighter than water and low solubility; or (3) a continuous high permeability strata
              filled with steam prior to treatment of the contaminated depth, for compounds
              with boiling points lower than that of water [1].
        •      A low  permeability surface layer may be  needed to prevent steam breakthrough
              for shallow treatment applications.

The removal of volatile  and semivolatile contamination from the soil by SERF is effected by
several mechanisms. The high-quality, high-temperature steam (at approximately 250°F) heats
the soil mass to the steam temperature in a pattern radiating from the injection wells toward the
extraction wells,  following  the  pressure  gradients  applied to  the  soil. As the  soil heats,
contaminants which have boiling points lower than that of water will vaporize. The vapor will
then be pushed ahead of the steam front by the difference in pressure.  Since the steam front
moves through the soil faster than heat can be conducted, the temperature gradient just ahead
of the steam front is steep. The vaporized contaminants move into the cooler soil and condense
until the steam front  arrives. This results in a band of liquid contaminant that is formed just
ahead of the advancing steam. When the steam  front reaches an extraction  well, the vapor,
liquid, and contaminants are removed.
                                           10

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 Compounds with boiling points higher than that of water will not totally vaporize ahead of the
 steam front. However,  the introduction of steam and heat onto the soil matrix enhances the
 vaporization and removal of these compounds due to the increased vapor pressure  along  with
 the increase hi temperature.

 Organic contaminants- in  soil will  collect on the surface  of the  mineral particles due  to
 intermolecular forces. The energy derived from the condensation of the steam onto the soil  may
 be sufficient to release these adsorbed contaminants and allow them to be removed by the flow
 of steam and liquids.

 The Rainbow Disposal  site was contaminated by a spill  of diesel fuel, which is primarily
 composed  of longer  chain  hydrocarbon compounds  (8  or more carbon atoms). Diesel
 compounds, although less  dense than water, are heavier than those  in most other petroleum-
 based fuels (e.g., gasoline or jet fuel) and are consequently less volatile and more viscous. These
 properties make diesel a more difficult contaminant to remove from the soil than most other
 petroleum-based fuels.

 SERF  was applied to a treatment area at the Rainbow Disposal site covering a lateral area of
 approximately 2.3 acres. The developer designed  the system of process wells to treat the entire
 area concurrently. Thirty-five (35) steam injection wells and 38 vapor/liquid extraction wells
 were constructed in the  treatment area. The  wells were  placed in a repeating pattern of four
 injection wells surrounding each extraction well. The well configuration at the  Rainbow Disposal
 site is  shown in  Figure 1-1.

The distance between adjacent injection well/extraction well pairs on this site was approximately
45 feet; between adjacent wells of the same type, the spacing was approximately 60  feet. Well
spacing for a site is determined based on the permeability of the soil  in the treatment area, the
size of the area,  and the depth and concentration  of the contaminants.
                                           11

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                                                    ^     ^( —""•-— J.J •'-"•" - J-T .   '   ^      J[     "- j^ '  ""I
                                                    ^    i—m                     1
Figure 1-1. Layout of Injection and Extraction Wells at the Rainbow Disposal Site

The injection wells were constructed to a depth of 40 feet and slotted over the lower ten feet.
The extraction wells were screened from the bottom of the shallowest clay layer (approximately
ten feet below the soil surface) to two feet into the B aquitard (a total depth of approximately
35 feet). Piping was used to conduct the steam flow to the injection wells  and to extract  the
liquids and vapors from the wells. Well heads and pipe on the active portion of the Rainbow
Disposal site were installed in trenches below the ground surface.  The trenches were backfilled
and metal plates were used to cover the piping and backfill to protect the pipes from pressure
                                           12

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 caused by truck traffic on the surface. Some of the process wells were installed beneath the
 concrete floor of the service shop building.

 Figure 1-2 is a schematic of the aboveground treatment system for steam generation and liquid
 and vapor treatment. Water from a nearby deep well was pumped to a water softening system
 for  conditioning. The. softened water was directed through a heat recovery heat exchanger
 designed  to  pre-heat the boiler  feedwater while also  cooling the  liquids  removed from the
 extraction wells. Two chemical additives, a polymer dispersant and an oxygen scavenger, were
 mixed with the feedwater to protect the boilers from scaling and corrosion. The pre-heated water
 was then  fed to one of two boilers on the site (only one boiler was used at a time). Steam at
 approximately 15 pounds per square inch (psi) was produced by the boiler and injected into the
 soil  through  the injection wells.

 The liquid and vapor were removed from the extraction  wells using pumps and compressors.
 The liquid was pumped back through the heat recovery heat exchanger to be cooled by the boiler
 feedwater. Vapor from the extraction wells was directed to  a knock-out pot which removed
 entrained  particles and liquid. The liquid from the knock-out pot was then  combined with the
 liquid from the extraction wells in an oil/water  separator. A condenser, fabricated of copper
 piping placed in a large water bath,  was constructed during the remediation to cool the liquid
 from the knock-out  pot and  enhance the  operation of the oil/water separator. The oil/water
 separator  was designed  to remove the diesel  compounds from the water by  gravimetric
 separation. The water phase discharged from the separator was treated by filtration and carbon
 adsorption before being discharged to a storm sewer. The diesel phase (recovered product) was
 collected in a 4,000-gallon tank for recycling or  disposal  off-site.

 The  vapor from the knock-out pot was  directed to the thermal  oxidizing unit (TOU).  The TOU
 is a self-contained regenerative vapor incineration system that used electric power and ceramic
rods to heat a bed of gravel-sized rocks to destroy the organic compounds in the vapor stream.
The  TOU  was designed to effect greater than 99.99 percent destruction and removal efficiency
of the organic compounds in the gas stream. The gas  exiting the TOU  was exhausted to the
                                           13

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Water
ifteners

i

Softened Water /• 	 tal 	

Heat Recovery
Heat Exchangers
WeU Water Stack
TlAir Cooled
OHeat Exchanger
^\
r \
1
P^-^l n ' 	 ' n *H~
Natural Gas
From City



O
""i^n

D
High Quality
n*om

Boiler Feed Tank 	 '
Steam Boiler
ned Vapor
A

Vacuum
Blower
Thermal Oxidizer Unit ' * "T
Zondensate
Micron
Filters
Knock-Out ^—
urum ^*
V


Contaminant Vapor
Treated Water
"T-^To Storm Drain
Oil/Water 4,000 gallon Tank Holding Tank Carbon
Separator (Recovered Diesel) (Separated Water) Filters
Deep
Water
Well

-j
LEGEND b
Vapor Stream •
^^^^^^^^^1 Well

Oily Water
(Hot)
T
Injection
Well

Figure 1-2. Aboveground SERF Treatment Train
atmosphere.  A Ratfisch flame ionization detector and  a  lower explosive  limit meter were
connected to the  inlet of the: TOU to measure the concentration of total hydrocarbons being
burned and to ensure that safe operating conditions were maintained hi the unit.

The aqueous  phase from the oil/water separator was discharged to the water  treatment system,
which used  5-micron filters and activated carbon beds  to remove residual  organics  to meet
NPDES permit requirements for discharge to the storm sewer. The spent carbon and filters were
containerized in appropriate drums and sent  off-site for  disposal when spent.  Other residuals
from the process  included excess soil from boreholes drilled for wells or sampling, and used
disposable clothing and equipment.
                                          14

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 1.5    KEY CONTACTS


 Additional information on in situ steam technologies and the SITE Program can be obtained from
 the following sources:


 Potential Contractor for Thermal Enhanced Soil and Groundwater Remediation

 John F. Dablow III
 Groundwater Technology, Inc.
 741 East Ball Road
 Suite  103
 Anaheim, CA 92805
 (714)991-7112
 FAX: (714) 991-8805
Hughes Environmental Systems, Inc. is no longer vending the SERP technology for use at other
sites.
Information on the  Dynamic  Underground Stripping Process at Lawrence  Livermore
National Laboratory

Dr. Roger Aines
Earth Sciences Department
Lawrence Livermore National Laboratory
7000 East Avenue, Mail Stop 219
Livermore,  CA 94550
(510) 423-7184
FAX: (510) 422-0208

The SITE Program

Robert Olexsey
Director, Superfund Technology Demonstration Division
U.S. Environmental Protection Agency
26 West Martin Luther King Dr.
Cincinnati, OH 45268
513-569-7861
FAX: 513-569-7620
                                        15

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Paul de Percin
EPA SITE Project Manager
U.S. Environmental Protection Agency
26 West Martin Luther King Dr.
Cincinnati, OH 45268
513-569-7797
FAX: 513-569-7620
Information on the SITE Program is also available through the following on-line information

clearinghouses:

       •      The Alternative Treatment Technology Information Center  (ATTIC)  System
              (operator:  301-670-6294) is a comprehensive, automated information retrieval
              system  that integrates data on hazardous waste treatment  technologies into a
              centralized, searchable source. This database provides summarized information
              on innovative treatment technologies.

       •      The Vendor Information System for Innovative Treatment Technologies (VISITT)
              (hotline: 800-245-4505) database contains information on 154 technologies offered
              by 97 developers.

       •      The OSWER CLU-IN electronic bulletin board contains information on the status
              of SITE technology Demonstrations. The system operator can be reached at 301-
              585-8368.

Technical reports may be obtained  by  contacting the  Center for Environmental Research

Information (CERI), 26  West Martin Luther King Drive in Cincinnati, Ohio, 45268. The
telephone number is 513-569-7562.
                                          16

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                                   SECTION 2
                TECHNOLOGY APPLICATIONS ANALYSIS

This section  of the report  addresses the general applicability  of the SERF  technology to
contaminated sites. The analysis is based primarily on the SITE Program SERF Demonstration
results. Additional data from bench-scale and pilot-scale studies of the process have been used
where applicable.

2.1    OBJECTIVES-PERFORMANCE VERSUS ARARS

Under  the  Comprehensive  Environmental  Response,  Compensation,  and  Liability  Act
(CERCLA),  as  amended by  the  Superfund  Amendments and  Reauthorization  Act  of
1986(SARA), remedial actions undertaken at Superfund sites must comply with federal and state
(if more  stringent) environmental laws that are  determined to be applicable or relevant and
appropriate requirements  (ARARs). ARARs are determined on  a site-specific  basis by the
remedial project manager. They are used as a tool to guide the remedial project manager toward
the  most environmentally safe way to  manage remediation activities.  The remedial project
manager reviews each federal environmental law and determines  if it is applicable. If the law
is not  applicable, then the  determination must be made  whether the law  is  relevant  and
appropriate. For example, a requirement under the Resource Conservation and Recovery Act
(RCRA) is to provide secondary containment for hazardous waste storage tanks. In the process
of treating fuel-contaminated soil using SERP, liquid product is extracted.  The extracted fuel
product must be stored in a tank. The storage tank would not be considered a hazardous waste
storage tank,  as  defined by RCRA,  since fuel is  not hazardous waste. However, RCRA's
secondary containment requirements for hazardous waste storage tanks may be  relevant and
appropriate.
                                        17

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 A discussion of the federal  and state environmental laws that are applicable or relevant and
 appropriate to SERF follows. A table of ARARs as they relate to the process activities conducted
 at the Rainbow Disposal site for the SERF technology is presented in Table 2-1.

 2.1.1  Comprehensive Environmental Response,  Compensation,  and Liability Act

 CERCLA authorizes the EPA to provide liability, compensation, cleanup, and  emergency
 response  for hazardous substances  released into the environment and the cleanup  of inactive
 hazardous waste disposal sites. Facilities become "Superfund sites" when they have been listed
 on the National Priorities List.

 SARA directed the EPA to use remedial alternatives that permanently and significantly reduce
 the  volume,  toxicity, or mobility of the  contamination; select remedial actions that are
 protective, cost-effective, and involve alternative treatment technologies to the maximum extent
 possible;  and  avoid off-site transport and disposal of untreated hazardous  substances.

 The Rainbow  Disposal site is not a Superfund site; however, CERCLA/SARA is relevant and
 appropriate for the treatment technology occurring on-site. Using the SERP technology at the
 Rainbow Disposal site met all of the SARA criteria. It was an in situ treatment technology, thus
 the treatment process occurred in place and the removal of the contamination was permanent and
 protective to human health arid the environment; the  volume and mobility of the waste diesel in
 the soil was reduced; SERP was cost-effective and an alternative treatment technology; and, as
 stated above,  untreated waste  was  not transported  off-site for disposal. Also  the extracted
contaminants could potentially be concentrated and reused on-site  as a  fuel supplement  or
transported off-site for fuel recovery. Unfortunately, the treatment technology did not meet the
cleanup standard imposed by the California Regional Water Quality Control  Board  (1,000 mg/kg
total petroleum hydrocarbons as diesel).
                                          18

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Table 2-1. FEDERAL AND STATE ARARS FOR THE SERF TECHNOLOGY
Process Activity
Waste characterization
of untreated waste
Drilling activities
related to well
installation
1 	 1 —
Waste processing using
SERF technology



Cleanup standards are
established

ARAR
RCRA: 40 CFR 261
OSHA: 29 CFR
1910.120
RCRA: 40 CFR 264
Subpart J and 270 (or
State Equivalent;
RCRA: 40 CFR 266
Subparts D or E. and
H
CAA: 40 CFR 50, and
52 (Subpart F)
SDWA: 40 CFR 144
and 146 Subpart F
SARA Section
121(d)(2)(A)(ii);
SDWA: 40 CFR 141;
H&SC Chapter 6.75
LUFT
Description
Untreated waste should be characterized to determine if it is a
hazardous waste, and if so, if it is a RCRA-listed waste.
Personnel need to be protected from volatile emissions and
airborne particulates during soil boring activities. Personnel need
to be provided with protective equipment and be involved in a
medical monitoring program.
Treatment of a RCRA hazardous waste requires a permit. If
non-RCRA waste, then a permit or a variance from the State
hazardous waste agency may be required.
Hazardous waste and oil burned for energy recovery must meet
the reporting and record keeping requirements. Permits arc
required for hazardous waste burned in boilers and industrial
furnaces.
Emissions from vapor treatment system must be monitored to
meet NAAQS; air permit may be necessary.
Injection of steam requires a Class V permit.
Remedial actions of surface and groundwater are required to
meet MCLGs (or MCLs) established under SDWA. Corrective
actions of leaking underground fuel tanks in California must be
consistent with waste discharge requirements.
California Regional Water Quality Control Board establishes
clean up standards for fuel-contaminated soil and water using a
decision matrix found in the LUFT.
Comment
Applicable
Provide air monitoring
equipment during drilling;
Use a fan to keep
personnel upwind of
vapors.
If activity is conducted
within one year on
remediation wastes, full
RCRA permit may not be
required.
Applicable
Applicable
Applicable
Applicable for surface and
groundwater; Relevant and
appropriate if drinking
water source could be
affected.
Applicable, relevant and
appropriate.

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                                                            Table 2-1. (Continued)
           Process Activity
       ARAR
                        Description
        Comment
        Storage of waste
RCRA: 40 CFR Part
264 Subpart  J (or  State
Equivalent)
Storage tanks for recovered liquid waste (i.e.,  recovered diesel)
must be placarded appropriately,  have secondary containment,
and be inspected daily.
If storing non-RCRA
wastes, RCRA
requirements are still
relevant and appropriate.
                                 RCRA: 40 CFR Part
                                 264 Subpart I (or State
                                 Equivalent)
                        Containers of contaminated soil from soil borings and process
                        stream residuals (separator sludge, filters) need to be labeled as
                        a hazardous waste, the storage area needs to be in good
                        condition, weekly inspections should be conducted, and storage
                        should not exceed 90 days unless a storage permit  is acquired.
                                                              Applicable for RCRA
                                                              wastes; relevant and
                                                              appropriate for non-RCRA
                                                              wastes.
        Waste Disposal
K)
O
RCRA:  40 CFR Part
262
Generators of hazardous waste must dispose of the waste at a
facility permitted to handle the waste. Wastes  generated include
soil cuttings  and recovered product. Generators must obtain an
EPA ID No. prior to waste disposal.
Applicable
                                 CWA: 40 CFR Parts
                                 403 and/or 122 and
                                 125
                        Discharge of wastewaters to a POTW must meet pre-treatment
                        standards; discharges to a navigable water must be permitted
                        under NPDES.
                                                              Applicable
                                 RCRA: 40 CFR Part
                                 263; HWCA: H&SC
                                 Chapter 13
                        Hazardous wastes transported off-site for treatment or disposal
                        must be accompanied  by a hazardous waste manifest. Hazardous
                        waste haulers operating  in California must be registered with the
                        State and  inspected by the California Highway Patrol.
                                                              Applicable
                                 RCRA: 40 CFR Part
                                 268
                        Hazardous wastes must meet specific treatment standards prior
                        to land disposal, or must be treated using specific technologies.
                                                              Applicable

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 2.1.2  Resource Conservation and Recovery Act

 As opposed  to CERCLA, RCRA regulates solid and hazardous wastes managed (generated,
 treated, stored, and disposed of) at operating facilities to minimize the need for corrective action
 in  the future. Wastes are defined as RCRA  hazardous  wastes if they meet  one of the
 characteristics (toxic, ignitable, corrosive,  or reactive) as discussed in 40 CFRPart 261 Subpart
 C,  or if they  are listed in 40 CFR Part 261  Subpart D. RCRA contains  specific requirements for
 any unit managing hazardous wastes including proper labeling, condition of containers, and
 secondary containment. In addition, RCRA contains specific requirements for personnel handling
 hazardous waste  including training,  inspections, medical monitoring, and record  keeping. In
 1984,  RCRA was  amended by the Hazardous  and Solid  Waste Amendments which  added
 requirements for corrective action and  restrictions  on land disposal.

 The SERF technology can treat RCRA-listed wastes containing volatile and semivolatile organics
 in soil. After treatment, the extracted liquid waste must meet specific treatment standards prior
 to being land disposed. The waste would need to be transported off-site to a permitted treatment
 facility or treated on-site.  If treated on-site,  the facility would require a RCRA permit. Under
 the  corrective action regulations,  a treatment unit used to treat "remediation wastes" may not
 require a full RCRA permit if that treatment activity occurred in one year or less. RCRA wastes
 generated during  SERF   treatment may  include  extracted   waste,  contaminated filters,
 contaminated activated carbon,  and wastewater; these must  be  transported  off-site for further
 treatment and disposal. In some cases, the recovered product could be used as a fuel for the
 steam generation system. In this case, the standards applicable to units burning hazardous waste,
 or oil, for energy recovery apply,  40 CFR 266, Subparts D or E.

 The Rainbow Disposal site is not a RCRA facility in that it does not manage RCRA wastes.  In
 addition, the released diesel product and the waste streams generated during the SERF treatment
process are not RCRA wastes since 40  CFR 261.4 exempts releases from underground storage
tanks undergoing corrective action from the RCRA regulations. Thus, the diesel waste would
                                          21

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not be required to be disposed of at a RCRA hazardous waste facility. However, RCRA is an
appropriate  and relevant requirement. The  4,000-gallon diesel tank should have secondary
containment. Drums of soil cuttings should be leak-free and marked with the contents and the
date of accumulation.

2.1.3  Clean Air Act

The Clean Air Act establishes national primary and secondary ambient air quality standards for
sulfur oxides, particulate matter, carbon monoxide, ozone, nitrogen dioxide, and lead. It also
limits the emissions  of hazardous air pollutants, including vinyl chloride, arsenic, asbestos, and
benzene. States are responsible for enforcing the Clean Air Act. In so doing, Air Quality Control
Regions were established. If necessary, and for purposes of efficiency and effectiveness, an Air
Quality Control Region may be broken up  into Air Quality Management Districts. The Air
Quality Control Region establishes allowable  emissions, on a site-specific basis, depending upon
whether or not the site is locaited within an air basin in attainment with the National Ambient Air
Quality Standards (NAAQS).

The SERF technology extracts volatile and semivolatile organics from soil in both liquid and
gaseous forms. NAAQS for nitrogen oxides and carbon monoxide and emission standards for
benzene may  be applicable to the SERF technology's vapor treatment  system and  steam
generation system; thus, an air permit from  the Air Quality Control Region may be required.
In addition,  any unit that may emit a pollutant to the air during normal operations requires an
Authority  to Construct permit. In order  to operate the unit,  a Permit to Operate must be
obtained.

The Rainbow Disposal site is located within  the South Coast Air Quality Management District
(SCAQMD) hi Orange County, California.  Orange County is in non-attainment  status for all
primary and secondary  air quality standards except sulfur dioxide. Emission standards  were
established by the SCAQMD for the thermal oxidizer unit: benzene in the exhaust stream (0.041
                                           22

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pounds per day); volatile organic compounds in the inlet stream (4,200 ppmv); and hydrocarbon
vapors in the outlet stream (5 percent of the inlet stream).

2.1.4  Clean Water Act

The  objective of the Clean Water Act is  to restore and maintain the chemical, physical, and
biological integrity of the nation's waters.  To achieve this objective, effluent limitations of toxic
pollutants from point sources were established. Publicly-owned treatment works (POTW) can
accept wastewaters with toxic pollutants from facilities; however, pre-treatment standards must
be met and a discharge permit may  be required.  A facility desiring to discharge water to a
navigable waterway must apply for a permit under the National Pollutant Discharge Elimination
System (NPDES).  When a NPDES permit is  issued, it includes waste discharge requirements.

Since water is extracted along with the organic contamination using SERP, waste water must be
properly  managed. Depending on the type  of  contaminant and the facility at which the
technology  is being employed, three options are open for water disposal: off-site disposal at a
RCRA treatment facility; discharge through a sanitary sewer under an industrial pre-treatment
permit; and discharge to the waterways of the United States under a NPDES permit. Wastewater
generated at the Rainbow Disposal site using the SERP technology was first polished  in an
activated carbon system and then discharged  to the storm sewer system under  NPDES permit
number CA 8000176.

2.1.5  Safe Drinking Water Act

The  Safe Drinking Water Act establishes primary and  secondary national  drinking water
standards to protect human health and the public welfare. The drinking water standards are
expressed as the maximum contaminant levels for the various constituents. Under SARA Section
121(d)(2)(A)(ii), remedial  actions of groundwater and surface water are required to  at least meet
the standards of the maximum contaminant  level goals (MCLGs) if they  are relevant and
appropriate. MCLGs have been established for several organic, inorganic, and  microbiological
                                          23

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 contaminants. Some MCLGs for organic compounds capable of being remediated by SERF
 include toluene (1 mg/L), xylene (10 mg/L), and ethylbenzene (0.7 mg/L).  For contaminants
 with MCLGs set at 0 mg/L,, the maximum contaminant level (MCL) for that constituent must
 be attained when groundwater or surface water is remediated. MCLs for contaminants capable
 of being remediated by SERF include vinyl chloride (0.002 mg/L), benzene (0.005 mg/L, and
 trichloroethylene  (0.005 mg/L).  Since some contamination  may  remain  in  the soil after
 remediation with SERF which may reach groundwater, a regulatory agency may require that
 MCLGs or MCLs, as appropriate, be used as standards for determining if the remedial action
 met its pre-specified cleanup criteria.

 Although groundwater treatment was not evaluated at the Rainbow Disposal site, MCLGs may
 be appropriate and relevant action levels for  ascertaining a successful remediation of the site,
 should contaminants remain hi the soil that could potentially leach to the groundwater. Benzene,
 toluene, xylene, and ethylbenzene (BTEX) were constituents of interest at the Rainbow Disposal
 site. During pre-treatment soil sampling, toluene and xylene were detected at low concentrations.
 Post-treatment soil samples  had  non-detectable concentrations.

 The Safe Drinking Water Act also contains requirements for the Underground Injection Control
 Program. Any operator injecting water underground must first obtain approval from  the
 authorized State agency.  No underground injection authorization can be granted if it results in
 any of the following: a fluid containing any contaminant moves into underground sources  of
 drinking water, a contaminant causes a violation of the primary drinking water standards, or a
 contaminant adversely affects human health. Underground injection wells are divided into five
 classes. Class V wells are those not covered by Classes I through IV and include injection wells
 used in experimental technologies.  Criteria and standards applicable to Class V injection wells
 can be found in 40 CFR  Part 146,  Subpart F.

The SERP technology injects steam,  thus the wells used for this purpose would fall under the
requirements  of the Underground  Injection Control Program. Steam injection wells  would
                                          24

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 require a Class V permit. The primary drinking water standard that would have to be monitored
 is total dissolved solids (must be less than 10,000 mg/kg).

 2.1.6  Occupational Safety and Health Act

 CERCLA remedial actions.and  RCRA corrective actions must be conducted  within  the
 requirements of the Occupational Safety and Health Act. Personnel working at a hazardous waste
 site are required to complete a 40-hour initial training,  3-day on-site supervised training, and
 annual 8-hour refresher courses. Personnel must also be in a medical monitoring program that
 first establishes a medical baseline. Annual monitoring is performed to determine if an individual
 was exposed  to  hazardous  substances or conditions.  Requirements are also established  for
 confined space entry, trenching and shoring, and personnel protective equipment such as steel-
 toed boots, hard  hats, and hearing protection.

 2.1.7  California Hazardous Waste Control Act

 California's Hazardous  Waste Control Act,  included hi the Health and Safety Code,  Sections
 25000 et.  seq., is comparable to RCRA in many ways. California's hazardous waste regulations
 are promulgated  in Title 22, California  Code of Regulations. The similarities  include waste
 management requirements, handling requirements, training, inspections, and emergency planning
 requirements.  However, there are differences which make the Hazardous Waste Control Act
 more stringent.  One difference  is how  California regulations define a waste as hazardous.
 Certain wastes are hazardous hi  California and not considered hazardous under RCRA. These
 include waste oil, asbestos, PCBs, and waste fuels (including diesel). Treatment of these wastes
 would be  considered a hazardous waste treatment requiring a hazardous waste facility  permit.
Also, tank systems holding more than 5,000 gallons of a hazardous waste are defined as storage
tanks and require a hazardous  waste  storage permit.  California  offers variances from the
permitting requirements if  a facility is treating a  non-RCRA waste  and meets  specific
requirements.
                                          25

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 The SERF technology treats hazardous waste in that it removes the hazardous constituents from
 the soil and concentrates them. A hazardous waste permit may be required unless the treatment
 occurs as part of a CERCLA remediation activity or a RCRA corrective action (lasting less than
 one year).

 2.1.8  California Petroleum Underground Storage Tank Cleanup Act

 Chapter 6.75 of the Health and Safety Code, Petroleum Underground  Storage Tank Cleanup,
 was added in 1989 to address corrective action pertaining to leaking underground fuel tanks. The
 statute requires corrective actions to be consistent with applicable waste discharge requirements
 or other applicable state policies for water quality control.

 2.1.9  California Leaking Underground Fuel Tank Field Manual

 The Leaking Underground Fuel Tank (LUFT) field manual was prepared by a multiagency task
 force involving personnel from the  California Department of Toxic  Substances  Control,
 California Department of Health Services,, California State Water Resources Control Board,
 California Regional Water Quality Control Boards, and various County Health Departments. The
 LUFT field manual was created to provide  guidance for regulatory agencies responsible  for
 dealing with leaking fuel tank problems. The primary jurisdiction for overseeing cleanups of fuel
 from underground tanks lies with the California State Water Resources Control Board. Using
 this  manual, the California Regional Water Quality Control Boards set cleanup standards  for
petroleum-contaminated soil and  water. The Regional Water Quality Control Board established
a 1,000 mg/kg cleanup limit for diesel (total petroleum hydrocarbons) hi soil and 100 mg/L limit
for diesel in groundwater for the Rainbow Disposal site.

2.2    OPERABBLITY OF THE TECHNOLOGY

Because SERP operates on contaminated soil in situ, the use of the technology is site-specific.
The  size of the site, the type of contamination and its extent, the geology,  and the geographical
                                          26

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 location all influence the suitability of the technology, the way the technology is implemented,
 and the effectiveness of the technology on treating the waste. The Rainbow Disposal site had
 several features which determined  the method by which the technology was implemented.  A
 discussion of some of those characteristics and their effects follow.

 The site is approximately 2.1 acres in size, which posed logistical challenges during installation
 and operation. The size of the site required a large number of injection and extraction wells (73
 total)  for complete coverage, at a well spacing of 45 feet between each injection well and the
 nearest extraction wells. Well installation and maintenance was more difficult because most of
 the well heads in the active area were installed below grade and under metal plates. While this
 configuration allowed operation of the transfer facility to continue without major interruption,
 downtime for SERF was increased when problems could not be detected or repaired as quickly
 as they might be otherwise.

 The underground conditions influenced design requirements. This included the depth and interval
 of contamination. Process wells (injection and extraction) were constructed to 40 feet deep. The
 injection wells were screened in the contaminated sand zone between approximately 35 and 40
 feet. Extraction wells had 25-foot screens. The site geology was not constant over the  entire
 treatment  area. The same  alternating layers of  sand  and  clay which directed  the flow  of
 contamination in the site soil also influenced the treatment process. Removal of contamination
 trapped in the  less permeable clay layers was  difficult because the steam and heat could not
 penetrate  these areas easily and flow patterns could have been developed which bypassed less
 permeable areas altogether.

 Underground utilities and other objects were present in the treatment area. While the technology
 was capable of treating around the obstructions,  some of them posed specific challenges.  Early
 in the treatment process,  steam became channeled into a gravel conduit for the phone cables on
the site, leading to steam breakthrough hi an on-site utility shed. The treatment process  was shut
down while the damage  was repaired and the water was removed. Several underground fuel
tanks were present  in the middle of the treatment area. Because these tanks  contained residual
                                           27

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fuel, the technology operator had to be careful not to expose them to excessive heat. Extra
temperature monitoring probes were placed near the tanks, and the injection wells nearby were
kept turned off until late in the treatment process, The result was that the area either reached the
steam temperature late in the process or not at all; therefore, those areas were probably not
effectively treated.

No vapor condensation system was designed and included in the aboveground treatment system.
Most of the contamination removed from the site by the SERF technology remained in the vapor
phase during treatment in the aboveground treatment process. Only about 4,700 gallons of diesel
were collected in the aboveground storage tank during treatment  according  to measurements
taken by the developer. About 4,000 gallons  of this was free product that was removed from
some of the wells before treatment with SERF commenced. It is estimated that at least 15,400
gallons of removed diesel were oxidized in the TOU  during treatment with SERF.

Although the treatment system was initially designed to operate for only eight months, treatment
operations occurred for a period of two years. Several factors were responsible for the large
increase  in operating time. Knowledge of the  process was limited prior to remediation at the
Rainbow Disposal site,  and no application of this size had been designed or attempted. For
example, the operators learned from the process that more time would be needed to heat and
remediate the site. Major and minor operational problems that stopped or slowed operation were
also quite common during treatment. Both boilers experienced frequent and sometimes lengthy
breakdowns. The TOU required frequent service and could take more than a day to return to
operating temperature after repair. During the winter of 1991-1992, both boilers were shut down
for a period of more than two months due to operational  and structural  problems. This long
shutdown probably allowed the site to cool considerably and, therefore, delayed the treatment
even further. Process operation changed in October 1992, from a 16-hour per day, five days per
week cycle to a 24-hour per day, six days per week cycle. Operational efficiency for heating the
soil seemed to increase  after this change, and  more constant operation was  felt to be less
stressful  on the boilers and other components as well.
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 Although some of the diesel contamination was removed from the soil, the process did not meet
 the cleanup level of 1,000 mg/kg total petroleum hydrocarbons. This may be due to the factors
 mentioned  above. In the initial plan for treatment of the site, it was known that the technology
 was not capable of removing all of the contamination from the site. It was believed, however,
 that the cleanup level could be obtained  rapidly, and the residual contamination would be low
 enough for natural biodegradation to become effective.

 2.3    APPLICABLE WASTES

 According to the developer and operators of SERF,  the technology can be applied to many in
 situ contaminant situations. The contamination must consist  of volatile and/or  semivolatile
 organic compounds. Because of the addition of heat  (steam) to the  soil, SERF  is applicable to
 compounds that are  less  volatile than  those which would be  removed solely  by vacuum
 extraction. Wastes containing a mixture of compounds of varying boiling points potentially can
 be treated with this technology. For contaminants whose liquid phases have densities greater than
 water  (dense non-aqueous phase liquids or DNAPLS), too high an initial concentration could
 result  in downward migration of contamination when the liquid is concentrated in situ by the
 process. The suggested upper concentration limit depends on the specific compound and ranges
 from 200 to 1,000 mg/kg [1].

 The primary contaminated matrix must be composed of soil; fractured rock or semisolid matrices
 cannot be treated by this technology. Highly impermeable clay materials also may not be suitable
 for SERP treatment. The technology is capable of treating soil  with underground obstructions
 such as buried tanks, utility lines, and buried rocks or debris. The location of such obstructions
 should be determined to the greatest extent practical before treatment. Applying heat around
underground objects such as utility lines could cause damage. Contaminated groundwater can
be treated by the technology concurrently with the soil, or the treatment area may be dewatered
before  treatment.
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The depth to the bottom of the treatment zone is not a significant limiting factor. The technology
has been used at a depth of over 100 feet at another site (see Appendix A for more information).
Applications of the technology in deeper soils  may realize  a  significant cost advantage over
excavation,  due to the difficulty in removing soils at greater depths.

Applicable waste requirements for this in situ technology also include requirements for the site
geology and geography. As described in Section 1.4, the site  must have a lower confining layer
and may need an upper confining layer to control the steam and contaminant flow. Sites with
channels of permeable material (e.g., sand, utility trenches,  loose debris) in a less permeable
matrix may cause channeling of the steam  and limit treatment of other areas. A minimum
volume of contiguous waste is required for cost-effective operation. In general, this technology
is not economical for areas smaller than 1,000 square feet or those with contamination extending
to no more than 10 feet below the soil surface.

2.4    KEY FEATURES

The most obvious advantage to an in situ technology, such as SERF, is  that little excavation is
required  to treat the soil. Since the soil is treated  in place, the  waste is  not subject to any land
disposal restrictions that might  be applicable if excavation were required. This can reduce the
costs of cleanup by reducing the need for transportation  and  disposal of hazardous substances.
Additionally, because the soils are treated in place,  the waste problem is  not simply moved  to
another location.

The developer  claims that SERF offers advantages over other in  situ technologies such  as
vacuum extraction or  soil flushing. High energy steam is used to treat the  soil so that treatment
can be much faster and more complete than with just air or cold water.  Higher boiling point
compounds can also be removed more readily using steam. Although the perched groundwater
table at the Rainbow Disposal site was depressed during free product recovery prior to treatment
with SERF, the developer clamed that contaminated groundwater could be treated concurrently
with the soils in the treatment area. This claim was not evaluated.
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 The developer also claimed that SERF can effectively treat operating sites with minimal impact
 to site operations. At the Rainbow Disposal site, the ability to treat soils under and around
 existing structures was especially important to the site owners. On the active portion of the site,
 process and monitoring wells were installed below grade under metal plates so that truck traffic
 could continue unimpeded. Had large-scale excavation been required, the commercial activities
 on the site would have been suspended,  which was  not acceptable  to the site owners or the
 serviced community.

 2.5    AVAILABILITY/TRANSPORTABILITY

 An expert in the field of SERF technology is required to design the system so that treatment
 theory can be properly applied to subsurface characteristics.  Most of the process can then be
 constructed from  off-the-shelf  items. This allows the operator of the technology to estimate
 construction costs accurately. Some of the aboveground treatment processes (e.g., condensers
 and separators) must be sized and fabricated for the specific application. Temperature monitoring
 probes and accessories may also require custom fabrication.

 Since the process  operates in place, each  application uses a different configuration tailored to
 the site size, geography, contaminant type, and other local factors. Key equipment includes well
 casings and materials, water conditioning  equipment,  boilers, vacuum pumps, and wastewater
 treatment equipment. The same aboveground equipment can be used to treat several  sites in
 succession; however, transportability depends on the size of the equipment. Well materials and
 other below ground equipment such as temperature probes, however, are often not reusable once
 they have been installed.

 One developer of a technology similar to SERF is designing a transportable system to be used
 with the technology. The transportable system will  provide all  the aboveground treatment
processes required for application  of the technology (steam generation, wastewater treatment,
and vapor treatment). The size and other specifications of this  transportable unit are not known
at this time. Portable  systems employing steam injection to treat shallow fuel contamination have
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been used  in the Netherlands since 1985 [2]. These systems include re-usable  steam lances
instead of constructed injection wells.

2.6    MATERIALS HANDLING REQUIREMENTS

For  SERF, materials handling equipment includes a variety of equipment required to install the
wells and other process equipment; handle water conditioning chemicals, maintenance materials,
and  process wastes; and transport liquids and gases through the treatment system.

Boreholes  for wells and for collecting soil samples are installed  using a  drill  rig.  Drilling
services are generally subcontracted to a company which has both the required equipment (e.g.,
drill rigs, augers, samplers) and personnel trained in drilling operations and well construction.
Drilling  services are required at different times during  the project, including pre-treatment
sampling, process installation, and post-treatment sampling.

A forklift was used at the Rainbow Disposal site for transporting bags of salt or other chemicals
to the water softeners; transporting drums containing drill cuttings, spent carbon or other wastes;
and transporting equipment, such as piping, during process installation. Depending on site size
and configuration, hand-powered equipment may be used exclusively or in addition to a forklift.

Pumps are used to transport the vapors  and liquids away from the wells. Other pumps are used
within the system to convey well water and water treatment chemicals to the boilers and to drive
the wastewater through the treatment  system.  These  pumps, especially the extraction well
pumps, must be able to perform under harsh conditions,  including  elevated  temperature, high
solids content, and variable chemical concentrations. These factors should be taken into account
during  the selection of pumps and ancillary equipment, such as hoses and fittings.
                                           32

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 2.7    SITE SUPPORT REQUIREMENTS

 Access to utilities is required to use SERF on a site. Water is needed for producing steam. This
 water must be of high quality, containing no contaminants that might further contaminate the
 soil.  Injectable  water quality may  be  further  determined  by  injection well  permits.
 Approximately  20,000 gallons of water per day were required at the Rainbow Disposal site.
 Water usage is determined primarily  by site size and volume of soil to be treated. SERF
 operators at the Rainbow Disposal site were able to discharge the treated wastewater directly to
 a storm  sewer. Without a sewer connection, wastewater might need to be transported or piped
 to another location for disposal.

 Electricity is required to run pumps,  other process equipment, lights, monitoring equipment, and
 office equipment.  At the Rainbow Disposal site, the boilers for steam production were fired by
 natural gas.  A  high capacity  natural gas line was brought to the  site.  If a gas  line is not
 available, other fuel may be substituted, depending on availability and air quality requirements.

 Other support facilities for use of the technology would include concrete pads to support the
 boilers and other process equipment, a building or trailer for use as office  space, and a storage
 building or trailer to store tools and equipment. A maintenance shop or area is also required.
 Outdoor lighting may be necessary for 24-hour operations.

 A relatively accessible site with good roads is required to bring in process equipment and other
 heavy equipment, such as drill rigs and transport trucks. In addition, personnel must also be able
 to get to and from the  site  readily  for daily process monitoring and control.  The entire site,
 including all process wells, must be secured to prevent damage to the equipment and to minimize
hazards to unknowing  trespassers or visitors.  A  fence  and a locked gate were used  at the
Rainbow Disposal site  for  security  purposes.  The  Rainbow  Disposal site also  had  24-hour
security to protect the  active commercial facility, and this assisted in protecting  the  SERF
equipment. Other  sites  may require a  24-hour  guard  depending on the application and site
location.
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2.8    RANGES OF SUITABLE SITE CHARACTERISTICS

Site characteristics which have not been included in Section 2.3, Applicable Waste, are discussed
below. SERF is suitable for operation in moderate climates. It may be suitable for use in cold
climates, but utilities or fuel consumption may be greater.  Arid areas may also be prohibitive
unless there is a large, amount of water available for steam generation. System equipment can
be designed or modified to use available fuels, and also to  operate in colder climates by using
insulation and shelter.

SERF is generally suitable for use in industrial areas  and in areas with little habitation (such as
military bases). While the technology can be operated with a low profile, the potentially long
duration of treatment may not be acceptable in a  residential  setting since the process equipment
may be noisy and unsightly. Investment in equipment  which minimizes noise and other nuisance
problems may allow use of this technology in almost any setting, although costs may be higher.

Because SERP is an in situ treatment technology,  it may not be suitable for locations where there
are fragile geological structures or ecosystems. Permits for constructing and operating injection
wells may be  difficult to obtain if there is any potential for negatively impacting usable water
bodies above or below the soil surface. It may not be desirable to operate the technology at sites
with certain toxic contaminants,  such as dioxins, because of the chance  of mobilizing these
contaminants and the difficulty or cost of disposing of the wastewater and residuals generated
from the process.

To  treat shallow soils,  an upper confining layer may be required so that steam does not  exit
through the surface.  If an adequate layer does not already exist on the site, a temporary cap of
asphalt could be placed  on the site until treatment was completed.
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 2.9    LIMITATIONS OF THE TECHNOLOGY

 The main limitation of the SERF technology, as shown by this full-scale Demonstration, is that
 it can be difficult to predict both how long the technology will need to be operated and how
 complete the treatment will be. An initial treatment time of eight months was planned for the
 Rainbow Disposal site, but the system was operated for two years (see Section 2.2, Operability).
 During  treatment with SERF,  the operators  monitored  certain  operational  parameters to
 determine the progress of treatment including soil and extraction well temperatures, and vapor
 stream contaminant concentrations. According to these indicators,  the rate of  removal of
 contamination from the soil was slow,  thus extending the treatment time. The rate of removal
 of contamination might  have been much greater  if the process had been operated more
 continuously over the entire site.

 Because  the entire site is treated at once and in place, it  is more difficult to test and adjust the
 technology while it is operating, unlike a flow-through process where the impact of operational
 changes  can be determined more  immediately. Additionally, plots of soil are generally not
 homogeneous in either contamination or geology. Some areas of a site may be completely treated
 while others are not, making it difficult to judge remediation progress. Proper monitoring of the
 treatment is crucial to the application and success of the technology.  Even when treatment is
 effective, a certain amount of residual contamination is likely to remain in the soil.

 The  SERF equipment has  a high  capital cost. Some of the equipment is  site-specific; it is
 difficult to reuse wells and temperature probes purchased to remediate a site. Operation of SERF
 requires  trained personnel for  operation of the boilers and for service  and maintenance of the
 equipment. Labor costs were determined to be the most significant of the twelve cost categories
 investigated in the Economic Analysis found in Section 3 of this  document.

After treatment  with SERF is  complete,  the soil will remain at  elevated temperatures for an
extended period of time. Soil is an excellent thermal  insulator,  and a large mass of moist soil
has a high  capacity to retain heat. Data from  models and from the application of SERF and
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similar technologies suggest that several years of cooling are required to bring the soil back to
ambient temperatures.  High soil temperatures can pose a hazard during digging or construction
activities on the site and may delay any beneficial use of the site. The temperature of the soil
may also inhibit natural biodegradation of the residual  contamination.  Continued  vacuum
extraction of  the  site long  after the  application  of steam can potentially reduce the  soil
temperature much more rapidly than conductive cooling alone.
                                            36

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                                     SECTION 3
                              ECONOMIC ANALYSIS

 3.1    CONCLUSIONS OF THE ECONOMIC ANALYSIS

 The results of the economic analysis are  summarized in Table 3-1. The approximate total cost
 for use of the full-scale SERF  technology at the Rainbow Disposal site was about $4,401,120
 over the two-year period of operation. This results in a cost of approximately $46 per cubic yard
 for a site  with 95,000 cubic yards of  contaminated  soil  (see  Section  3.3,  Issues  and
 Assumptions). Figure 3-1 is a graphical representation of the costs per cubic yard, broken out
 by cost category, for the actual case. Under ideal operating conditions, the  remediation with
 SERF at the Rainbow Disposal site might  have cost about $2,789,910, or approximately $29 per
 cubic yard. Based on available information, costs  were also calculated for use of SERF at a
 similar site of the same size and contamination profile under what might be considered "typical"
 operating conditions. These costs were estimated to be about $3,375,910, or approximately $36
 per cubic yard.

 Labor is the largest cost for use of SERF, accounting for about one third of the total cost. Since
 labor costs are directly proportional to the  duration of remediation, factors which would increase
 the remediation time would increase total costs the most significantly. Start-up costs and utilities
 are also significant for use of SERF, together accounting for another third of the total costs. The
 cost for natural  gas accounted for  more than ten percent of the total remediation costs. Cost
 details are discussed  further in the  following sections.

 As discussed in the Executive Summary,  and in more detail in Section 4 of this report, SERF
 did not meet the cleanup objectives set for the Rainbow Disposal site. At the time remediation
 at the site was stopped, the operator believed that the process had gone nearly  to completion
under the circumstances, and mat little additional removal would have occurred if treatment had
been continued. Continuing treatment would have increased the total cost and the cost per cubic
yard for the site, but it is impossible to determine what these costs would  have  been. It is
                                          37

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          Table 3-1. SUMMARY OF RESULTS OF THE ECONOMIC ANALYSIS

rime to Remediate {Days)
Assumed On-Lifle Factor
Site $&e (yd1)
Site Preparation Costs
Permitting and Regulatory Costs
Non-Depreciable Equipment Costs
Startup and Fixed Costs
Labor Costs
Consumables and Supplies Costs
Utilities Costs
Effluent Treatment and Disposal Costs
Residuals and Waste Handling and
Disposal Costs
Sampling and Analytical Costs
Facility Modification, Repair, and
Replacement Costs
Site Demobilization Costs
TOTAL COSTS
Approx. Actual Costs for
Rainbow Disposal
Total ($)
$/yds"
746
50%

$ 338,230
$ 16,100
$ 522,990
$ 758,800
$ 1,362,000
$ 43,430
$ 631,470
$ 71,100
$ 67,200
$ 299,900
$ 150,700
$ 139,200
$ 4,401,120
$ 3.56
$ 0.17
$ 5.51
$ 7.99
$ 14.34
$ 0.46
$ 6.65
$ 0.75
$ 0.71
$ 3.16
$ 1.59
$ 1.47
$ 46.33
Estimated Ideal Cost for
Rainbow Disposal
Total ($)
$/yd3**
373
100%
$5,000
$ 325,960
$ 11,100
$ 522,490
$ 413,500
$ 775,600
$ 24,320
$ 280,190
$ 35,600
$ 49,250
$ 195,900
$ 57,500
$ 98,500
$ 2,789,910
$ 3.43
$ 0.12
$ 5.50
$ 4.35
$ 8.16
$ 0.26
$ 2.95
$ 0.37
$ 0.52
$ 2.06
$ 0.61
$ 1.04
$ 29.37
Estimated Cost for a Typical
Site of the Same Size
Total <$)
S/yd3**
497
75*

$ 336,200
$ 14,100
$ 524,070
$ 435,700
$ 1,033,600
$ 32,420
$ 493,020
$ 47,400
$ 61,400
$ 221,900
$ 77,600
$ 98,500
$ 3,375,910
$ 3.54
$ 0.15
$ 5.52
$ 4.59
$ 10.88
$ 0.34
$ 5.19
$ 0.50
$ 0.65
$ 2.34
$ 0.82
$ 1.04
$ 35.54
*  This table presents a summary of the detailed costs itemized in Table 3-2.
** For each cost category, costs per cubic yard are reported to the nearest cent.
                                               38

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                         ED Facility Modification,
                               Repair, and
                            Replacement Costs
                                 ($1.58)
    Residuals and Waste
   Handling and Disposal
       Costs ($0 71)
Site Demobilization
   Costs ($1.47)
                       Sampling and Analytical
                            Costs ($3.15)
    Effluent Treatment and
    Disposal Costs ($0.75)
  Utilities Costs ($6.65)
   D   Consumables and
     Supplies Costs ($0.45)
           HI Site Preparation Costs
                    ($3.55)
 Permitting and
Regulatory Costs
    ($0.17)
     Non-Depreciable
     Equipment Costs
          ($5.50)
                                                                                              D Startup and Fixed
                                                                                                  Costs ($8.00)
                                           H Labor Costs ($14.34)
                                                                                All costs in U.S. Dollars.
                                                                                Total cost per cubic yard: $46.32
Figure 3-1. Cost Per Cubic Yard Treated During SITE Demonstration

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 possible that, had treatment been conducted with less downtime, the site would have been more
 completely remediated in less time.

 3.2    BASIS  OF THE ECONOMIC ANALYSIS

 This economic  analysis is designed to conform with the specifications for an order-of-magnitude
 estimate. This is a level of precision established by the American Association of Cost Engineers
 (AACE) for  estimates having; an expected accuracy within +50 percent and -30 percent.  In the
 AACE definition, these estimates are generated without detailed engineering data. Suggested uses
 of these estimates are in feasibility studies or as aids in the selection of alternative processes [3].
 Because the costs for use of SERP were  derived from a post-mortem analysis of the treatment
 over  the two-year  period,  the costs are probably more accurate than  these specifications,
 especially for some cost categories. However, the applicability of these costs to  other uses of
 SERP at other sites is limited by the highly site-specific nature of the process and the associated
 costs.  Therefore, labeling these cost figures as  "order-of-magnitude" estimates is appropriate.

 3.2.1  Factors Affecting the Estimated Costs

 The costs derived from the Rainbow Disposal SERP Demonstration are specific to this site only.
 A detailed cost estimate of SERP for another site1 would involve designing a treatment system
 to apply to that site, which is beyond the scope of this analysis.

 Factors affecting the estimated costs include site soil type, site contamination characteristics, site
 location, and volume and area of the contaminated soil. The impact of any of these factors on
the cost for using the technology can only be estimated based on available data. Soil type affects
how quickly the steam can penetrate the soil and how rapidly the contamination can be removed.
Less permeable soils, or areas of lower permeability within a more permeable matrix, can
require longer treatment times and consequently exhibit higher costs. Different contaminant types
or concentrations can influence the required treatment time; less volatile compounds are expected
to require longer treatment for removal. The type of contamination may also influence the types
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 and  amounts  of waste products generated,  types  of effluent  treatment required, and waste
 disposal costs. Site location can affect the costs for labor, construction, utilities, and materials.
 Climate can also affect the costs, both in the energy required to heat the soil and the design of
 the necessary process and  ancillary equipment.  From  examining costs  for  construction and
 operation,  it appears that more cost-effective operation can be achieved when the volume of
 contaminated  soil extends in depth as opposed to extending in surface  area, since  fewer wells
 would be required.

 3.2.2  Cost Data Categories

 Cost data  associated with SERF have  been assigned to the following 12 categories: (1)  site
 preparation; (2) permitting and regulatory requirements;  (3) capital equipment; (4) start-up  and
 fixed costs; (5) labor; (6) consumables and supplies; (7) utilities; (8) effluent treatment  and
 disposal; (9) residual waste shipping, handling, and disposal costs; (10) sampling and analytical
 services; (11)  maintenance and modifications; and (12) demobilization.

 3.2.3  Cost Sources

 Cost data for this economic analysis were derived from several sources. The technology operator
 provided costs for equipment, labor, permitting, and demobilization. Other costs were derived
 from  vendors  of supplies  and  equipment and  from utility companies.  During  operation,
 information on the use of utilities and supplies was collected, and operational logs were updated
 daily. These data were used to calculate and estimate the costs for supplies and maintenance as
 well as the on-line  factor for the process.  Costs for  start-up, sampling and analysis,  and
demobilization were  derived from process diagrams and construction drawings as well  as
information gathered  by SAIC while conducting post-treatment sampling and analysis.
                                           41

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3.3    ISSUES AND ASSUMPTIONS

3.3.1  Type of Cost Analyses Performed

An economic analysis for the SERF technology was performed for three cases. The first case
represents  actual costs  incurred at  the Rainbow Disposal site  over the two-year period  of
remediation. The second case examined potential costs for idealized conditions at the same site,
while the third presents costs that could be expected at a site of the same size and contamination
profile under "typical" operating conditions.

The first cost analysis, termed the actual case, represents the approximate actual costs incurred
during the two-year remediation period (September 1991  to August 1993, a total of 746 calendar
days) at the Rainbow Disposal site. This case uses actual cost data from the operator whenever
available, utility rates and other cost information valid for Southern California during the period
of remediation, and estimated costs where necessary.  Significant equipment downtime occurred
at the  Rainbow Disposal site during remediation.  For the actual case, an on-line factor  of
approximately 50 percent was calculated  based on operational  logs and observations of the
process.  For this cost case,  monthly charges were based on a total of 25 months of operation,
and weekly charges were based on a total  of  107 weeks.

The second cost analysis, termed the ideal case, is a study of the costs of the technology at the
Rainbow Disposal site for idealized conditions. These costs were based on use of the technology
without major operational problems or equipment failures, and therefore assume an on-line factor
of 100 percent. A remediation time of 373 (calendar) days was used for this cost case, half  of
the actual case, based on the assumption that the treatment rate is proportional to the total days
of remediation  only. This simplifying  assumption was made  although it is likely  that, with a
complex  in  situ  process such as this one, there is not a proportional relationship  between the
percent of days  that the equipment is in operation and the necessary duration of remediation.
Further examination of the required length of treatment is beyond the scope of this investigation.
The ideal case used the same cost rates as those  incurred for the actual case at the Rainbow
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  Disposal site,  and costs associated with Southern  California utilities,  labor rates,  and other
  business factors. For this cost case, monthly charges  were based on a total of 12 months of
  operation, and weekly charges were based on a total of 53 weeks. Because this case is based on
  the potentially  unrealistic assumption that operation could occur without operational downtime,
  it represents the lowest cost, or "best case"  that could be achieved for the technology at the
  Rainbow Disposal site and should therefore be considered a lower bound on the potential costs.

  The third case  suggests what costs would be  incurred by using the technology at a site of the
  same size and similar contamination profile at a non-specified location. This typical case includes
  some equipment or process downtime, which might be expected during typical operations. This
 case assumed an on-line factor of 75 percent and therefore an operational time of approximately
 75 percent of the duration of the actual case (for a total duration of 497 calendar days). This on-
 line factor was  estimated based on knowledge of the process  components and on lessons learned
 during operation that will prevent or minimize  the impact of some potential operating problems.
 For this cost case, monthly charges were based on a total of 17 months of operation, and weekly
 charges were based on a total of 71  weeks.

 The typical case differs from the actual and  the ideal  case in that calculations use  rates for
 utilities, labor,  and other cost factors that are based on a composite of those found in a  selection
 of metropolitan areas around the country, (e.g., gas and water rates were derived from those
 currently charged in Boston, Massachusetts; Dallas, Texas; Miami, Florida; St. Louis, Missouri;
 and Seattle, Washington) instead of those for Southern California. Although this cost case is not
 directly  comparable to the actual and the ideal cases, the application of the typical cost case
 allows discussion of the effect of site location and other factors on the total costs for SERF.
 Because the typical case utilized an on-line factor midway between those for the actual and ideal
 cases, it represents a likely set of costs  for the technology application. The application of this
 case is explained more fully in subsections of  Section 3.4.

Both the ideal case and the typical case assumed 24-hours-per-day operation, six days per week
during operation. The actual operation began with a 16-hours-per-day operation for the first year
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of treatment.  When 24-hours-per-day operation was  started,  system efficiency appeared  to
increase dramatically, with only moderate increases in costs. Less frequent shutdowns (weekly
rather than daily) are also believed to reduce wear on boilers and other equipment due to cycling
and thermal shock and to minimize blockage of process wells.

The three cost cases presented bracket a range of costs for similar sites over the expected range
of on-line factors. The actual case is  seen as a "worst case" for costs due to the large amount
of operational downtime. Lessons  learned from  this application  will assist  in  preventing
excessive downtime in subsequent applications. Since the technology is extremely site-specific,
actual costs will vary from these estimates. The effect of site size or contamination on the costs
for SERF are not considered due to  the complexity of the process, although both  factors are
expected to be important in both treatment effectiveness and total costs.

3.3.2  Other Assumptions

In addition to the assumptions  described above, other general assumptions were used for each
of the cost cases:

       •     Legal fees, legal searches, and access  rights and roads are the responsibility of
              the site owner and are not included in remediation costs.
       •     Costs do  not include profit.
       •     Extensive site characterization data, including the delineation of the size of the
              contamination plume, types of contaminants, and basic site geology (for all cases)
              were already available prior to the selection of SERF as the remedy. This limits
              the need for technology-specific site characterization.
        •     The site  size  for all cost cases is the same. The  treatment  zone is 2.3  acres
              (100,000 square feet)  in area and encompasses  a depth between 20  feet and 40
              feet below the soil surface for a total volume of approximately 95,000 cubic yards
               (2,565,000 cubic feet). This volume is used to calculate the cost per cubic yard
               of soil treated.
        •      Costs  for labor include wages,  fringe  benefits,  and overhead  charges.
                                            44

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        •     All personnel required for the remediation, except the project manager and any
               parent-company administration, are hired locally.
        •     High quality water is available for use with the technology.
        •     Clean drill cuttings from soil borings can be redeposited on the site rather than
               disposed of off-site.
        •     The  level of health and  safety protection needed is minimal (level D) during
               normal operations because the process occurs beneath the surface. Modified or
               full  level C protection  may  only  be needed  during  drilling  and  sampling
               operations. Higher levels of protection are not needed.

 3.4    RESULTS OF THE ECONOMIC ANALYSIS

 The  detailed results of the economic  analysis are shown in Table 3-2. Details  on specific
 subcategories of costs and the derivation of costs for each category are found in the following
 text.
 3.4.1  Site Preparation Costs

 For use of an in situ technology such as SERF, a large proportion of the costs are incurred at
 the start with the planning and preparation of the site and equipment. A SERF process well
 system is built into the soil  to be treated. Therefore, site preparation costs are a significant factor
 in the  total treatment costs.

 Site preparation costs include the costs for designing the system (site design and layout), as well
 as the  aboveground systems to be installed. This was estimated, based on information supplied
 by  the operator,  as  requiring 2,500  hours  of engineering time at  $100 per hour  plus
 miscellaneous labor and other expenses ($20,000) for a total of $270,000. This cost was used
 for all  three cases. It can be assumed that treatment systems for smaller sites, or those with less
complex geology than at the Rainbow Disposal site, would be less costly to design.
                                           45

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Table 3-2. DETAILS OF THE ECONOMIC ANALYSIS


Time to Remediate (Days)
Assumed Oa-Liae Factor
Site size (yd3)
SITE PREPARATION COSTS
Site Design and Layout
Site Survey and Investigation
Legal Searches
Access Rights and Roads
Preparation for Support Facilities
Auxiliary Buildings
Technology-Specific Requirements
Total Site Preparation Costs
PERMITTING AND REGULATORY COSTS
NPDES and Other Permits
Development of Monitoring Protocols

Total Permitting and Regulatory Costs
EQUIPMENT COSTS
Major Equipment2
Minor Equipment
Equipment Rental
Total Equipment Costs7
Total Non-Depreciable Equipment Costs
STARTUP AND FIXED COSTS
Equipment Installation
Shakedown
Working Capital
Depreciation
Insurance and Taxes
Initiation of Monitoring Program
Contingency
To^S^ajc^u£ ai^JwedjDpsts 	
Approximate
Actual Costs for
Rainbow Disposal
Total ($)
746
50%


$ 270,000
$ 39,100


$ 3,700
$ 8,930
$ 16,500
$ . 338,230

$ 10,000
$ 6,100
$•** «fuv
lO,l(JU

$ 402,000
$ 519,000
$ 3,990
$ 924,990
$ 522,990

$ 249,000
$ 52,800
$ 30,000
$ 362,000
$ 50,000
$ 5,000
$ 10,000
758,800.00
Estimated
Ideal Cost for
Rainbow Disposal
Total {$)
373
100%
95,000

$ 270,000
$ 39,100
Not applicable1
Not applicable1
$ 3,700
$ 4,660
$ 8,500
$ 325,960

$ 5,000
$ 6,100
$11 1AA
IJLfJLUv

$ 402,000
$ 519,000
$ 3,490
$ 924,490
$ 522,490

$ 249,000
$ 52,800
$ 30,000
$ 41,700
$ 25,000
$ 5,000
$ 10,000
413,500.00
Estimated Cost for
a Typical Site
of the Same Size
Total <$>
497
75%


$ 270,000
$ 39,100


$ 3,700
$ 14,900-
$ 8,500'
$ 336,200

$ 8,000
$ 6,100
$14 1AA
J.4,1UU

$ 402,000
$ 519,000
$ 5,070
$ 926,070
$ 524,070

$ 249,000
$ 52,800
$ 30.000
$ 55.6U)
$ 33.300
$ 5.000
$ 10.001)
435,700.00
                    46

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Table 3-2. (Continued)


Time to Remediate (Days)
Assumed On-Line Factor
Site size (yd3)
LABOR COSTS
Project Direction
Administration
Engineering/Technical
Maintenance
Clerical Support
Fetal Labor Costs
CONSUMABLES AND SUPPLIES COSTS
Water Softening Chemicals
Filters and Activated Carbon
Maint and Cleaning Materials
Monitoring Supplies
Health and Safety Supplies
Paper/Office Supplies
Total Consumables and Supplies Costs
UTILITIES COSTS
Natural Gas
Well Water
Electricity
Phone
Sewer
Total Utilities Cost$
EFFLUENT TREATMENT AND DISPOSAL COSTS
Treatment Equipment (See Equipment)
Filter & Carbon Replacement (See Supplies)
Sewer Discharge Costs (See Utilities)
Monitoring and Reporting Requirements
Total Effluent Treatirient and Disposal Costs
Approximate
Aciual Costs for
Rainbow Disposal
Total ($)
746
50%


$ 107,000
$ 38,100
$ 1,030,000
$ 79,900
$ 107,000
$ 1,362,000

$ 21,200
$ 8,600
$ 3,380
$ 2,250
$ 4,000
$ 4,000
$ 43,430

$ 527,000
$
$ 99,500
$ 4,970
$
$ 631,470

—
—
—
$ 71,100
$ 71,100
Estimated
Ideal Cost for
Rainbow Disposal
Total {$)
373
100%
95,000

$ 53,300
$ 16,000
$ 613,000
$ 40,000
$ 53,300
$ 775,600

$ 13,200
$ 4,300
$ 1,690
$ 1,130
$ 2,000
$ 2,000
$ 24,320

$ 228,000
$
$ 49,700
$ 2,490
$
$ 280,190

—
—
—
$ 35,600
$ 35,600
Estimated Cost for
a Typical Site
of the Same Size
Total {$)
497
75%


$ 71,000
$ 21,300
$ 817,000
$ 53,300
$ 71,000
$ 1,033,600

$ 17,600
$ 5,730
$ 2,250
$ 1,500
$ 2,670
$ 2,670
$ 32,420

$ 269,000
$ 21.400
$ 66.300
$ 3.320
$ 133.000
$ 493,020




$ 47.4OO
$ 47,400
         47

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                                       Table 3-2.  (Continued)

rime to Remediate (Days)
Assumed Oa-Line Factor
Site size (yd1)
Approximate
Actual Costs for
Rainbow Disposal
Total {$)
746
50%
Estimated
Ideal Cost for
Rainbow Disposal
Total {$)
573
100%
Estimated Cost for
a Typical Site
of the Same Size
Total ($)
497
75%
95,000
RESIDUALS AND WASTE HANDLING AND DISPOSAL COSTS
Drill Cuttings
Liquid Wastes (product, sludge)
Other Wastes
total Residuals and Waste Handling and Disposal Costs
SAMPLING AND ANALYTICAL COSTS
Operational Analyses (see Effluent Treatment)
Environmental Monitoring, initial
Environmental Monitoring, periodic
Environmental Monitoring, confirmation
Total Sampling and Analytical Costs
$ 42,600
$ 7,500
$ 17,100
$ 67,200
$ 33,200
$ 7,500
$ 8,550
$ 49,250
$ 36,300
$ 7,500
$ 17,600
$ 61,400

—
$ 31,800
$ 209,000
$ 59,100
$ 299,900
—
$ 31,800
$ 105,000
$ 59,100
$ 195,900
—
$ 31,800
$ 131,000
$ 59,100
$ 221,900
FACILITY MODIFICATION, REPAIR, AND REPLACEMENT COSTS
Design Adjustments
Scheduled Maintenance
Equipment Replacement
Total Facility Modification, Repair, and Replacement Costs
$ 56,500
$
$ 94,200
$ 150,700
$ 20,600
$
$ 36,900
$ 57,500
$ 27,400
$
$ 50,200
$ 77,600
SITE DEMOBILIZATION COSTS
Site Restoration
Shutdown
Closure Permitting Costs
Removal of Equipment
Total Site Demobilization Costs
TOTAL COSTS
$ 92,000
$ 47,200
$ 92,000
$ 3,500
Not Applicable1
$
$ 139,200
$ 4,401,120
$ 3,000
$ 98,500
$ 2,789,910
$ 92,000
$ 3,500

$ 3,000
$ 98,500
$ 5,375,910
Not applicable: This cost is the responsibility of the site owner and is not included in this analysis.
Major Equipment costs are taken into account under depreciation and are used to estimate factors such as repair and modification
costs. They are not direct costs and are therefore excluded from the totals.
No direct maintenance costs have been used in this analysis. Costs for regular maintenance tasks are considered under labor
and supplies.
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 Site surveying and investigation must be conducted to complete the design of the technology and
 to assist in designing the environmental monitoring program. The scope of these activities is very
 site-specific.  The investigation at the Rainbow Disposal  site  included borehole drilling  and
 logging, sample analysis,  and data interpretation.  Since preliminary site  investigation  and
 characterization occurred before the selection of SERF as a treatment technology, the cost for
 site surveying and investigation included drilling  costs for only ten boreholes. It was assumed
 that thirty (30) soil and 30 groundwater samples from these boreholes were analyzed.  Soil gas
 probes  were  also utilized to complete the plume  delineation.  The  total  site surveying  and
 investigation costs were calculated to be approximately $39,100. Total costs for site design and
 layout,  as well as site surveying and investigation,  were assumed to be the same for all three
 cost cases.

 Preparation for support  facilities included grading, location of underground  utility lines,
 connections for gas, electric, and water/sewer lines,  and installation of auxiliary buildings. The
 total cost for these activities was calculated to be $3,700 for all cost  cases. Construction of a
 concrete pad for the  major equipment and associated grading  requirements were considered
 technology-specific requirements and cost about $8,500. An additional concrete pad was built
 due to an error in specifications,  which contributed an additional cost  of $8,000 (for a total of
 $16,500) for the actual case that would not be incurred in the ideal or the typical cases.

 Rental of the  office trailer cost $342 per month, based on actual invoices. For the actual case
 (25 months of operation), office rental costs totaled $8,930 including delivery charges. A roll-off
 bin, borrowed at no cost from the Rainbow Disposal site, was used as  an auxiliary storage and
 maintenance trailer. Costs  for the buildings for the ideal case also included rental for the office
 trailer at a total cost of about $4,660 for 12 months of rental including delivery. A cost of about
 $14,900 for rental of both an office and a storage/maintenance trailer was calculated  for the
 typical case based on a rental cost of $500 per month. Office and storage space requirements are
 site-specific and depend on climate, geographical location, and available space and buildings on
the treatment site.
                                            49

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3.4.2  Permitting and Regulatory Costs

Several types of permits are required for installing and operating the SERF technology. Costs
incurred include permit application fees and permit compliance fees. Costs were included for the
following permits: permit to construct (SCAQMD), permit to operate (SCAQMD); NPDES
permit for effluent discharge; well drilling permit (may not be required when less than 40 feet
deep and  no aquifers penetrated); and air permits for process equipment and the TOU.  The
NPDES permit was estimated to have cost $2,000 per year (for a total of $4,000 in the actual
case).  The cost for  the remaining permits were  estimated at $6,000 over the course of the
project, for  a total of $10,000. For the ideal case, a permitting cost of half the actual case was
assumed ($5,000), since most permits are issued on an annual basis.

Also  included  in this category  are  costs for development and  initiation of an appropriate
environmental monitoring plan. These costs include engineering costs, reporting, and project
management time to  discuss these  issues  with  the  regulators.  The cost  for initiating the
environmental monitoring program was estimated to be approximately $6,100. Regardless  of
how long the cleanup takes, this cost is incurred at the start of a project; therefore, this amount
is the same  for the actual and the ideal cases.

Permit costs are dependent  on the local and regional conditions and environmental laws.
California has rigorous environmental policies, and permit costs for this  state are expected to
be higher than the national average. Permit requirements  and associated  permitting costs can
change rapidly, even over the course of a two-year project. For the typical case, permitting
costs,  including development of a monitoring program, were estimated to be about $14,100.
However, depending on site-specific conditions,  contaminants, and other factors (geological,
ecological, and political),  these costs could fluctuate significantly.
                                           50

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 3.4.3  Equipment Costs

 Costs  for major and some minor equipment were received from the technology operator and
 based  on actual invoice figures in 1991 dollars. The major  equipment components  are: two
 boilers,  the thermal  oxidizing unit, the ion exchange water softening unit,  and the effluent
 treatment system (tanks and filters). The total cost for the major equipment was about $402,000.
 This cost was used to calculate the depreciation cost for use of the technology for all three cost
 cases (see Section 3.4.4). The items were sold at the end of remediation for $100,000 and were
 removed from the site by the purchaser.

 Minor equipment includes items such as the following: tanks, well water collection systems, heat
 exchangers, an oil/water separator, well materials and headers,  casings,  well pumps, piping,
 metal trench plates, and miscellaneous monitoring equipment. This  equipment was assumed to
 have been exempt from depreciation; the  total cost for this equipment is included in the cost
 totals.  The  total  cost for minor equipment, calculated from  information received  from the
 operator along with catalog pricing information [4,5], is about $519,000. Some of the  minor
 equipment and associated materials may have salvage value  at  the end of the project. Well
 casings and in situ instrumentation were assumed to be non-reusable;  however, they may have
 scrap value. If the costs for removing the materials  is higher than the potential scrap value, and
 removal is not necessary for  site restoration, these materials may be abandoned in place.

 Rental  equipment was used during the start-up phase of the project to assist in installation of
 process equipment. A forklift was rented for  ten days at a daily cost of $45. A crane (with
 operator) was  required to set  up the boilers and other heavy equipment at a cost of $190/hour.
 The crane was assumed to have been rented for two eight-hour days.  A forklift was borrowed
 from the site owners during  treatment,  so  rental was not necessary.  A pump was rented for
 approximately 10 days (at $50/day) to help clear some wells after heavy rains, but pumps were
 not assumed to be required for the ideal case or the typical case. For the typical cost case,  where
a forklift might not be readily available, use of a forklift for a total of 35  days (one day every
two weeks) was added to the  rental equipment costs.
                                          51

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3.4.4  Start-up and Fixed Costs

Start-up costs include installation of the process equipment, equipment shakedown, initiation of
the monitoring  program,  working capital, depreciation, insurance, and contingency costs.
Installation  of the equipment for this in situ process included  well drilling and  installation
($191,000) and installing the aboveground process equipment and piping ($58,000). Well drilling
costs were the same for all cases of this cost estimate and were based on available drilling rates
and known time to drill and construct wells.

Shakedown  costs  were  incurred  over  the two-week period when the system was tested.
Treatment was initiated on a small  area of the treatment zone  to test  the wells and all  the
aboveground equipment. Shakedown costs include the labor and  materials for the shakedown.
Eight-hour work days were assumed. The total costs for shakedown were the same for all cases
of this cost estimate  and were estimated to be  about $52,800.

In this cost estimate,  working capital was assumed to be the cash required to run the process  for
a period of one month.  This figure included approximate costs for monthly utilities, supplies,
rentals, and monthly monitoring requirements. Because Hughes Environmental Systems had a
parent company  responsible for direct payment of the employees involved during treatment at
the Rainbow Disposal site, this cost did not include labor. Working capital was calculated to be
$30,000.

Depreciation is the cost for use of all the major equipment over the course of the project.  For
the actual  case, this included two years (746 days) worth of equipment use and also accounted
for the resale value received for the equipment at the end of the project ($100,000). Therefore,
an equipment life of two years was used to calculate the depreciation costs for the actual case.

The ideal  and the typical cases either assume that a selling cost close to the book value could
be achieved  or  that the teclmology operator had another use  for the  equipment after  the
                                           52

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 remediation. Depreciation was calculated using a straight-line method with a ten-year equipment
 service  life  and the number of years (or fractions of years) of remediation.

 Costs for insurance and taxes were estimated  as approximately 2.5 percent of the total cost of
 the equipment per year. These factors were estimated to be approximately $50,000, $25,000,
 and $33,300 for the actual case, the ideal case, and the typical case, respectively.

 Initiation of the monitoring program was also included in the start-up cost category. These costs
 typically include operator training required  and collection  of the first site or process samples
 used to establish a baseline for operations. The total cost for  initiation of the monitoring program
 was estimated to be $5,000 for all cases.

 Contingency represents the amount of money the operating company has available for unexpected
 needs. This  was estimated to be  $10,000 for all cost cases.

 3.4.5 Labor Costs

 The labor costs for the actual case were based on hourly wage figures  and  weekly schedules
 supplied by the technology operator. For approximately the first year of operation (61 weeks),
 the process was operated for 16 hours per day,  5 days per week. Full-time workers during two-
 shift-per-day operation included a site supervisor ($60/hour), site engineer ($75/hour), and two
 technicians/boiler  operators ($40/hour each). The project director charged an average of ten
 hours each week to the project at $100/hour, and an administrative secretary ($40/hour) was
 employed  for approximately  30  hours  each week.  Additional labor  in the form  of off-site
 company administration (ten hours per week at  $50/hour) and additional maintenance personnel
 (15 hours per week, $50/hour) were assumed to have been required. The total weekly cost for
 two-shift-per-day operation was calculated to be $11,500.

When the 24-hours-per-day, six-day s-per-week  cycle of operation was started, labor costs were
 increased with the addition of another full-time technician. The secretarial position was split with
                                           53

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another job, so only 25 hours per week were devoted to the SERF project. The total weekly
costs for the three-shift per day operation were about $14,500 for over 45 weeks.

The weekly cost for the three-shift-per-day operation was also used to calculate the cost for the
ideal case.  The same weekly schedule was used for the typical case. Southern California labor
rates are approximately 127% of the national average, so weekly labor costs used for the typical
case have been adjusted. This figure was determined based on average regional labor cost data
[3]. In the  Northeast,  labor rates are similar to those in Southern California, while other areas
of the country have rates that average two-thirds  of the Southern California rates.

In this cost estimate,  the total labor costs calculated for the actual case were $1,362,000, of
which 75 percent was  for technical and engineering functions. The total costs calculated for the
ideal and typical cases were approximately  $775,600 and $1,033,600, respectively.

3.4.6   Consumables  and Supplies Costs

The major  consumables used during treatment with SERF were water softening  salt and two
water treatment chemicals used to protect the boilers  from scaling and fouling. The  water
treatment chemicals were  purchased from Blackhawk Engineering Company. Blackhawk 625
(BH625) is an oxygen scavenger used to control corrosion, while Blackhawk 689 (BH689)  is a
polymeric dispersant used to control boiler scale. A total of 30  tons of salt were used during
treatment at a cost of $0.11 per pound. A total of 3,000 pounds of BH625 (at $2.05 per pound),
and 650 gallons of BH689 (at $12.50 per gallon) were used. The total cost for these consumables
was about $21,200.

For the ideal and typical cases,  the amount  of salt and chemicals used was calculated based on
the average daily use  of these chemicals during 24-hour-per-day-operation (100 pounds salt, 5
pounds  BH625, and 1.1 gallons BH689), and the total assumed  number of days of treatment.
Costs for the ideal case were estimated to be approximately $13,200; costs for the typical case
were estimated to be  approximately  $17,600. Costs  for water softening  and treatment are
                                          54

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 influenced by  the  quality of the water available, but this factor was not  considered  in the
 analysis.

 Other supplies  used during the project included filters and carbon for the water treatment system;
 maintenance and cleaning materials such as oil, detergent, and fuses; monitoring supplies such
 as strip chart paper and calibration gas; health and safety supplies such as disposable gloves; and
 office supplies. The rate of use of these supplies was based on operator log entries for the actual
 case and was assumed  to be basically proportional to the number of days  in operation for the
 ideal and typical cases.  One full set of carbon and filters was included with the treatment system
 as installed. Supplies were calculated to cost a total of $22,230 for the actual case, $11,120 for
 the ideal case, and $14,820 for the typical case. The total cost for consumables and supplies was
 calculated for the actual, ideal, and typical cases to  be approximately  $43,430, $24,320 and
 $32,420, respectively.

 3.4.7  Utilities Costs

 The major utility required for treating the Rainbow Disposal site with SERF was the natural gas
 needed to fire the steam boilers. A total of approximately 800,000 therms (1 therm = 100,000
 BTUs) of natural gas were used over the course of the project at a cost of $0.611/therm for the
 summer months (April through November) and $0.754/therm for the winter months,  for a total
 cost of approximately $527,000. Based on this  cost estimate,  natural gas  use alone  was more
 than 10 percent of the total cost for use of SERF.

 For the ideal case, the following factors were used to calculate the natural gas used: the average
 monthly natural gas usage during 24-hour operation (33,000 therms/month),  twelve months of
 operation, and  an average natural gas  cost/therm of $0.654.  The total natural  gas cost was
 approximately $228,000.

 For the  typical  cost case, the average monthly usage  of 33,000 therms was used to determine
the monthly gas costs using the monthly charges and gas rates for the cities investigated. Because
                                            55

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different utility companies charge for natural gas using different combinations of monthly and
usage charges, a monthly cost for gas was calculated for each locale and then the monthly costs
were averaged. The average monthly charge for the natural gas was calculated to be $15,800,
for a total of approximately $269,000. Natural gas rates vary by season and by region; the rates
investigated for this analysis ranged from $10,000 to $20,000 for a month. In some locations,
higher costs for natural gas and less stringent air quality regulations may make alternate fuels,
such as diesel  or gasoline, more attractive  although this has not  been figured into the cost
calculations.

A large quantity of water, at least 12 million gallons, was used over the course  of the project.
At the Rainbow Disposal site, water was supplied  by an on-site deep water well, formerly used
by an  ice company, and was available  at no cost. Therefore, for the actual case,  the cost for
water  was $0. The cost of the water used for the  ideal case was also assumed to be $0. Costs
for water discharged to the storm sewer were assessed only through the NPDES permit, with
no additional charges based on actual gallons discharged. The same is assumed for the  ideal
case.
The totalizing meter used to record the amount of well water used in the process was calibrated
at the conclusion of treatment according to procedures specified in the QAPP. At that time, the
meter was found to be inaccurate at the  typical flow rates used during treatment. Based on the
field calibration and further calibration and testing performed  by the meter manufacturer at the
conclusion of the Demonstration, actual total flow was estimated to have been 110 to 130 percent
of total meter reading. Since no charges  were incurred for using water at the Rainbow Disposal
site, this did not affect the costs for the actual or ideal cases. However, a correction factor of
1.2 was applied to the amount of water  used  presented here.  This corrected value was used to
calculate the cost of water for the typical case. Costs  for water represent a small portion, less
than one percent, of the total cost for use of SERF, so a small discrepancy in the actual amount
of water used  is negligible in the total  calculated costs at the level of precision of these cost
estimates.
                                            56

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  For the typical case, an average cost for high-grade industrial or potable water was used in the
  calculation ($2/1,000 gallons), and water was assumed to be used at the same daily rate as the
  average  during 24-hours-per-day operation at the Rainbow Disposal  site (24,000 gallons,
  corrected).  The total  cost  for  process water  for  the  typical  case  was  calculated  to be
  approximately $21,400. Sewer charges for the typical case were assumed to be charged on a per-
  gallon basis  (at $0.10/gallon), based  on the  average daily water discharge for the  actual
  remediation (2,500 gallons), and the  number of days assumed for the typical case. This cost was
  estimated to be  about $133,000. Sewer charges are expected to be highly site-specific.

 Electricity service  costs were based on an average  monthly cost of $4,000 reported from
 invoices.  Electricity use stayed fairly constant  over the course of the project.  A total  cost of
 about $99,500 was calculated for the actual case, about $49,700 for the ideal case, and $66,300
 for the typical case.

 Phone service was  calculated based  on a monthly  rate of $200, which  included a three-line
 business  system and a reasonable  number of toll calls. The total  cost for  phone service was
 estimated  to be  about  $4,970; $2,490; and  $3,320 for the actual, ideal,  and typical  cases,
 respectively.

 3.4.8 Effluent  Treatment and Disposal Costs

 The liquid effluent from the SERF process is composed mostly of oily water removed from the
 extraction wells.  During the Demonstration, this water was treated in the aboveground system
 and released to the  storm sewer.  Costs for the treatment equipment were included with the
 equipment costs (Section 3.4.3), and  the cost for filters and carbon was included with supplies
 and consumables costs (Section 3.4.6).  Calculated sewer discharge costs (for the typical case)
 were included in the utilities category of this cost estimate (Section 3.4.7).  Other costs for the
 disposal of the treated water were  incurred during monitoring and reporting for the NPDES
permit requirements. The monitoring  included sample containers, analytical  services,  data
interpretation, and report generation for the regulatory authorities.  Samples  were collected
                                           57

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weekly during treatment and analyzed  for total petroleum hydrocarbons (TPH) and benzene,
toluene, ethylbenzene, and xylenes (BTEX).  Calculated costs  were based on collecting four
samples per month for two parameters  each with an approximate analytical cost of $1,760 per
month, handling cost of $100 per month, and reporting cost of $1,000 per month. The total costs
for the actual case were calculated to be about $71,100. Costs for the ideal and typical cases
were based on the same frequency of monitoring over the  shorter  durations of treatment,  and
total approximately $35,600 and $47,400,  respectively.

In some cases, discharge to a storm sewer would not be appropriate due to waste constituents
or local water conditions. In these situations, wastewater would need to be handled in some other
manner, such as secondary on-site treatment, discharge to a POTW, or off-site hazardous waste
disposal. Costs for these other disposal options would probably be much higher than for NPDES
discharge to a storm sewer.

3.4.9  Residual and Waste Handling and Disposal Costs

Several types of wastes are generated during treatment with the SERF process. These include
drill cuttings from well installation and sampling boreholes, collected fuel product from the
oil/water separator, spent carbon from  the wastewater treatment system, oily sludge (bottoms)
from the oil/water separator, and used  disposable tools and protective  clothing.

During  the  Demonstration,  drill  cuttings were placed  into  55-gallon drums  which were
segregated by borehole number and drilling depth. Drums were purchased for approximately $30
each.  Drill cuttings,  which were determined to be uncontaminated based on analytical results,
were redeposited on the site as fill at  a negligible cost (about half of these drums could be
reused). Approximately 137 drums of drill cuttings (out of approximately 460 drums collected)
required off-site disposal at a certified landfill at a disposal cost  per drum of $250. For this cost
estimate, the ideal and typical case costs for drill cutting disposal were calculated based on the
sum of the  actual number of boreholes drilled before and after  treatment and an estimated
number of boreholes that would be required during interim sampling.  Since interim sampling
                                          58

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 was performed quarterly,  the number of interim sampling events was estimated based on the
 assumed  treatment time for the ideal  and typical cases.  Two drums  of drill  cuttings  were
 normally generated per borehole drilled. It was assumed that a total of 108 (out of 360), and 115
 (out of 385) drums required disposal for  the ideal and typical cases, respectively.

 During the Demonstration, the contaminated activated carbon from the water treatment system
 was changed once during operation and once at the end of treatment. This generated 38 drums
 of contaminated carbon for disposal at a cost of $450 per drum. The same cost was assumed for
 the typical  case. For the ideal case, only one change of carbon was assumed to be required,
 resulting  in approximately 19  drums of  spent carbon requiring  disposal.  Approximately ten
 drums of sludge from the oil/water separator were disposed of at a cost of $280 per drum; this
 cost included drum purchase price and was used for all cases.

 Less liquid diesel was recovered during treatment with SERF than originally anticipated because
 most of the contamination  was  extracted in the vapor  phase and could not  be condensed to the
 liquid phase by the process. A total of approximately 4,700 gallons was collected over the course
 of the remediation, most of which was pumped from the extraction wells as free product on the
 water table. Recovered diesel can be recycled or disposed  of, with a cost  involved for either
 option.  A cost of $l/gallon, or approximately $4,700, was calculated  for disposal of the
 recovered diesel based on quotes from fuel blending and disposal companies. This same disposal
 cost was used for all three cases of this cost estimate.

 Additional wastes requiring disposal included disposable equipment and other solid wastes. Since
 contact with the diesel only occurred during sampling activities, most  of the disposable clothing
 and materials were disposed of with other solid wastes.  Rainbow Disposal personnel collected
 non-hazardous  solid wastes from the site  during their normal operations,  and no  costs were
 incurred for this service. For the typical case,  trash disposal might require a tipping fee which
 was estimated to be $500 total for the project. Well casings and other materials removed during
demobilization  also required cleaning, handling, and disposal, incurring an additional cost.
                                           59

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3.4.10       Sampling and Analytical Costs

Sampling and analytical services were required for soil, groundwater, and process liquid streams
during the project. The cost for operational analysis for the wastewater treatment system was
previously included under effluent treatment and disposal. Soil sampling was conducted at the
beginning of the project,  at quarterly intervals during treatment, and at the end of the project.
Groundwater was sampled monthly  during treatment.

The cost for analytical services was based on the number of samples collected, the analyses
performed, and the reporting requirements for each analytical event. For pre-treatment sampling,
30 soil samples and 40 groundwater samples were collected and analyzed for BTEX, TPH, and
semivolatile organic compounds  (not all  samples  were analyzed for all parameters).  Eight
boreholes were directly  attributed to pre-treatment sampling; other boreholes sampled  were
included as a part of process well installation. The cost of pre-treatment sampling used in this
economic analysis was estimated to be approximately $31,800. This cost was used for the actual,
ideal, and typical case.

Interim  sampling for the actual case was estimated to have cost approximately $209,000 over
the course of the project. This is based on the drilling of about 12 boreholes and collection of
30 groundwater  and 30  soil samples per quarter  for analysis  for TPH and BTEX  (actual
quarterly sampling schemes and numbers of samples varied for each instance). Costs for interim
sampling for the ideal and typical cases were based on the same sampling frequency over the
shorter duration of treatment. Costs for interim sampling for the ideal and  typical cases were
estimated to be about $105,000 and $131,000,  respectively.

 Confirmation analyses for the Rainbow  Disposal site, including drilling and sampling, were
 performed by the SITE Program. The confirmation analyses cost presented for the actual case
 was estimated  based on the costs  incurred by the SITE Program for these analyses,  adjusted for
 the smaller number of samples that probably would have been collected if the operator conducted
 the confirmation sampling. Some sampling and analysis  is required to determine  whether the
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 cleanup criteria have been met. The costs were based on drilling 20 boreholes and collecting and
 analyzing 50 samples for BTEX and TPH and include sampling, handling, and reporting costs.
 The total cost for confirmation sampling was estimated to be about $59,100 for all cost cases.

 3.4.11        Maintenance, Repair, and Modification  Costs

 Maintenance and  modification  of the  SERF  system occurred almost  continuously  during
 treatment. Normal maintenance costs were  included under  the labor costs category (Section
 3.4.5) and the consumables and  supplies costs category (Section 3.4.6). Labor for repairs and
 modifications was  also included in the labor rates described  for labor costs. Maintenance and
 modification costs included in this section include costs for outside contracting for repairs, repair
 materials, and replacement parts. Specific design adjustments and modifications made  during
 treatment included adding and abandoning injection and extraction wells (five  were added  during
 treatment); fabricating a condenser; hard piping the extraction wells after the hoses had started
 to deteriorate; and modifying parts of the TOU to resist  corrosion.  Design adjustments were
 estimated to have  cost approximately $56,500 over the  course  of the project; the  cost for
 replacement  and repair was approximately $94,200.

 The rate  of both repair and modifications were assumed  to  increase  as the  process operates,
 since parts wear out. If the treatment at the Rainbow Disposal  site had taken only the anticipated
 eight months,  items  such as  well  headers  and extraction  hoses would not have required
 replacement. Design adjustment and modification costs were assumed to be five percent  of the
 major equipment cost (per year and fractions) for both the ideal and typical cases, estimated as
 approximately  $20,600, and  $27,400,  respectively.  Replacement  costs were based  on  a
 percentage of the total equipment costs. Four percent of the total equipment cost (per year and
 fractions) was used to estimate the cost for replacement for the ideal and typical case, for costs
of approximately $36,900, and $50,200, respectively. These costs are estimates only and depend
on site and equipment-specific factors. Because the application  of SERF at the Rainbow Disposal
site was the first  full-scale application of the technology,  lessons were learned about  process
                                           61

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equipment requirements which can  be used  to  reduce modification and  repair  costs for
subsequent applications.

3.4.12        Demobilization Costs

Demobilization of in situ SERF is as site-specific as the installation and start-up. Depending on
the site, demobilization might include removal of the aboveground process equipment, removal
or  abandonment of the process  wells,  site restoration,  continued monitoring,  or further
treatment. At the  Rainbow Disposal  site, the process equipment (major equipment and some
minor equipment) was purchased by an outside company for a total of $100,000. In return, the
purchaser removed the equipment from the site. This resale figure was used in the calculations
for depreciation over the life of the operation. It is likely that Rainbow Disposal realized some
salvage value on items of equipment that could not be sold, since recycling and reclamation is
part of its business. This savings is probably negligible,  considering the extra labor that would
be  involved in preparing  the equipment for salvage, and has not been  included  in the cost
calculation.

The process wells were removed from the site according to Regional Water Quality Control
Board specifications and well holes were filled with new grouting. Piping was  removed from the
trenches along with the gravel, and the trenches were filled with soil. The entire site was then
covered with concrete, including the formerly  bare  "dirt lot" area as a  part of the Rainbow
Disposal  operational  expansion.  The total  cost for technology-specific removal and site
restoration was estimated,  based on information supplied by the operator,  to be $92,000 for the
actual case. This  cost was also used for the ideal and typical cases  because  these costs  are so
site-specific. Since the Rainbow Disposal site is  in an  area zoned for industrial use and will
remain covered by a concrete cap and in operation for at least the next seven  years (the interval
of the current disposal contract), little other site  restoration was required. Costs at a site that
requires  restoration to a  near-native state  could  be much higher  due to additional costs for
removal  of concrete or asphalt capping, site grading and capping, and other requirements.
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 Other demobilization costs incurred at the Rainbow Disposal site included severance pay for laid-
 off workers  ($43,700), excess inventory that had not been used by the end of the treatment
 ($1,000), return of rental offices and other equipment ($1,000), and miscellaneous  expenses
 ($1,500). These are much higher in the actual case than would be expected for any subsequent
 application due to the sudden decision to stop work on the site. Severance pay was not included
 in the ideal or typical cost case estimates.

 Because the SERF technology did not meet the regulatory cleanup criterion,  Rainbow  Disposal
 proposed performing groundwater monitoring on a frequent and regular basis  to confirm that the
 potential for off-site migration of the contamination has been mitigated. Since  the  site will
 remain  in operation and covered by concrete, there is no hazard to workers or the public from
 any contact with contaminated soils  The costs for long-term monitoring are the responsibility
 of the site owner and were not included  in the cost estimates presented here.

The total estimated cost for demobilization at the Rainbow Disposal  site was estimated  to be
about $139,200.  Costs  for the ideal and the typical case costs  were estimated  to  be about
$98,500 for both cases.
                                           63

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                                    SECTION 4
                       TREATMENT EFFECTIVENESS

4.1    BACKGROUND

4.1.1  Site and Contamination

The  Rainbow Disposal site is an active municipal trash transfer facility. Six days per week,
trucks collect and deliver municipal trash to this site,  where the trash is sorted and placed into
other trucks  for  recycling or disposal. Rainbow Disposal currently is the sole company
responsible for waste pickup from five cities in the Orange County, California area.

The site became contaminated in 1984 when an underground diesel fuel pipeline, used to supply
fuel  to the trucks, was punctured during digging operations.  The leaking  pipeline was not
discovered for approximately 22 months, during which time a large quantity of diesel had leaked
into  the surrounding  soil. Preliminary investigations  showed that the soil under the Rainbow
Disposal site had  several distinct layers composed of alternating bands of permeable sand and
low permeability clay. The layers influenced how the fuel became distributed in the soil. The
fuel flowed downward under gravity through each sand layer. At each sand/clay  interface, the
fuel  was  forced to flow horizontally until breaks  in the underlying  clay allowed further
downward flow. A perched aquifer located in a sand layer between 25 and 40 feet below the soil
surface (known as the B-sand) prevented the fuel from flowing further downward while allowing
for wide lateral spread. The contamination distribution that resulted included  elevated levels of
fuel compounds at all depths at the point of the spill and a zone of contamination, which extends
for more  than two acres laterally, in the sand layer between approximately 25 and 35 feet.
Beneath the B-sand layer was a thick clay layer that protected a confined aquifer  beneath from
contamination. A  perimeter designating where soil concentrations were above 1,000 mg/kg of
total petroleum  hydrocarbons (TPH)  was drawn after further site investigation, as shown in
Figure 4-1. This perimeter  was used as the treatment area for SERF.
                                          64

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     Figure 4-1. Pre- and Post-Treatment Sampling Locations at the Rainbow Disposal Site
     It was originally estimated that between 70,000 and  135,000 gallons of No. 2 diesel were
     released  into the site [7,8]. Free product was present in most monitoring wells screened above
     40 feet in the zone of contamination. Approximately 4,000 gallons of free product were pumped
     from these wells, along with the ground water from the perched aquifer, during well installation
     [7,8].  The perched  aquifer remained drawn down throughout treatment with SERF.

     Because the services provided by Rainbow Disposal were indispensable in the community,  and
     operations  could not be resumed at a different location, Rainbow Disposal required a remedial
     technique that could clean up the site without completely disrupting the ongoing operations. In
     situ SERF  was selected because of the developer's claims that major excavation of soil would
     not be  required and that the technology could be installed and operated below the soil  surface.
                                                65

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The SITE Program  became  involved  with the Rainbow Disposal site  after most of the
preliminary investigation had occurred and the remedy had been selected for the cleanup. The
SITE Program was involved with an evaluation of steam injection technology at another site, and
saw the concurrent evaluation of the  full-scale SERP technology during the Rainbow Disposal
site  remediation as  an excellent opportunity to gain additional knowledge of steam injection
technology.

4.1.2  Treatment Objectives

The objectives for the cleanup at the Rainbow Disposal site were driven by the requirements of
the lead  regulatory  agency, the Regional  Water Quality Control Board (RWQCB). The soil
cleanup level for the site was determined based on risk assessment, and was set at 1,000 mg/kg
(ppm) of TPH as determined by the  diesel fraction analysis of the California  LUFT method.
Additionally, the  RWQCB  required that the technology should not cause further spread of the
diesel fuel  into otherwise unimpacted areas adjacent to or below the contaminated strata.

There were two critical objectives for the SITE Program Demonstration of the SERP technology:
(1) to evaluate the ability of the technology to meet the cleanup requirement set by the RWQCB
for the site soil, based on soil sampling results; and (2) to perform a detailed economic analysis
of this full-scale application of the technology.

Comparison of pre- and post-treatment soil  data was performed only for informational purposes.
The  determination of contaminant removal efficiencies could not be designated as  a critical
objective because the SITE  Program  was not  involved with  the Rainbow Disposal site
remediation at the beginning. Pre-treatment sampling was conducted at the site by the developer
prior to the completion of a  SITE Program Quality Assurance Project Plan (QAPP) for the
Demonstration.
                                          66

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 4.1.3  Treatment Approach

 The technology was configured to treat the entire contaminated area (2.3 acres to a depth of
 approximately 40 feet) simultaneously. Since it was known that some portions of the site were
 much more contaminated than others, the technology could be and was adapted during treatment
 to try  to focus  the action of the steam and vacuum on portions  of the site which required
 additional  treatment,  while  shutting down the process in portions  of the site presumed to be
 clean.  Quarterly soil sampling and analysis was conducted by the operator and helped to guide
 the operation.

 4.2    TESTING METHODOLOGY

 The pre-treatment soil sampling borehole locations were selected and sampled by the technology
 developer  with  input from the SITE Program.  Twelve  boreholes  were drilled within  the
 treatment area. These are marked on Figure 4-1 as boreholes  1 through 12. Several sample
 borehole locations were selected in the area of the spill zone. Other borehole locations were
 selected  based on the known distribution  of site contamination and  the  configuration of  the
 technology such as in areas that might be expected to have greater or  lesser cleanup efficiency
 based on the anticipated steam  flow pattern. Vertical sampling locations within each borehole
 were selected during sampling based on lithology and readings from a hand-held organic vapor
 analyzer; one to four samples  were  collected from  each borehole  for  laboratory  analysis.
 Samples  were collected at discrete  depths  up to 40 feet  below ground surface.  One  of the
designated pre-treatment sample borehole  locations  was not sampled due to underground
obstructions.

A total of 24 soil samples were collected during pre-treatment sampling. The soil samples for
laboratory analysis were collected in brass tubes six inches in length and two inches in diameter.
Pre-treatment  soil samples  were analyzed  for total  petroleum hydrocarbons (TPH—diesel
fraction)  and BTEX. A small number of samples were also analyzed for  semivolatile organic
                                          67

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compounds (SVOCs) to check for the presence of polynuclear aromatic compounds typically
found in diesel.

The  sampling and analysis plan for post-treatment soil sampling was designed based on pre-
treatment soil sampling data and other site characterization information. The number of borehole
locations and samples were determined based on a geostatistical analysis of pre-treatment data.
Geostatistical methods were also used to evaluate post-treatment soil sample data. A total of 72
samples  from 24 boreholes were collected  after treatment. Twelve of these boreholes were
located adjacent to the 12 pre-treatment borehole locations, including the borehole location that
was not sampled. These paired boreholes were within three to four  feet of each other. Samples
from the paired post-treatment boreholes were collected from the same depths as those for pre-
treatment, and also  from  additional  depths. Within the perimeter  of contamination, primary
samples were collected at two to four discrete depths up to 40 feet below ground surface.

Seven of the post-treatment boreholes (numbered 12 through 18 on Figure 4-1) were located
outside of the established  perimeter of contamination in areas that  were known to be clean or
had levels of contamination less than 200 mg/kg of TPH. Two samples with depths between 25
and 40 feet were collected from each of these boreholes  in order to detect any lateral off-site
migration of contaminants during treatment.

The  remaining five post-treatment borehole locations  were in areas of the site  that were
determined to be under-represented in the pre-treatment  sampling.  The locations of the post-
treatment boreholes  in relation to landmarks on the site  and the contamination perimeter are
shown in Figure 4-1. On the scale of this  drawing, the pre-treatment boreholes correspond
directly to those for post-treatment with the  same numbers.

Because  in-place soil contamination can be highly variable, triplicate sampling was performed
to assess the contaminant variability  over short distances.  To accomplish this, duplicate and
triplicate samples were collected at six primary sample  locations.  The specific locations for
triplicate sampling  were selected randomly prior  to treatment. The  triplicate samples  were
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 collected vertically within an 18-inch split spoon sampler in separate brass sleeves. Six three-
 inch-long sleeves  were  used in the split  spoon to collect the soil. The first, third, and fifth
 sleeves were used for TPH and TRPH analysis, while  the remaining sleeves were used for
 BTEX analysis. Each sample was analyzed separately to allow the variability inherent in the soil
 matrix to be statistically determined.

 Samples collected  after treatment were analyzed  for TPH,  total  recoverable  petroleum
 hydrocarbons (TRPH), and BTEX.  The analysis of TRPH was conducted in addition to TPH
 because TRPH is an approved EPA method, while TPH, though widely used, is a California
 state method and is not an approved EPA method. The TPH method (modified SW-846 Method
 8015) analyzed extractable  petroleum hydrocarbons by  Gas Chromatograph/Flame lonization
 Detector. Methylene chloride is used in this method to extract the sample. The TRPH method
 (EPA  Method  418.1)  used an  infrared instrument to analyze petroleum  hydrocarbons.
 Fluorocarbon-113  is used in this  method to extract  the  sample. The  analysis of BTEX was
 required by the RWQCB even though BTEX compounds were only present in a few of the pre-
 treatment soil samples.

 SVOCs were not positively identified in the pre-treatment samples due to their low levels in the
 soil and to matrix interferences from the  high levels of TPH. Therefore, analysis for SVOCs was
 not performed for post-treatment samples,  and no conclusions can be drawn about their removal
 by the technology.

 Quality assurance and quality control samples, including equipment blanks  and trip blanks were
 also collected and analyzed during the post-treatment sampling event to ensure that the data was
 of good and known quality.  Matrix spike and matrix spike duplicate samples were analyzed for
 all three analytical parameters. Quality  control standards  were also analyzed.

Groundwater conditions  were beyond  the scope of the SITE Program SERP  technology
evaluation,  and groundwater samples were not collected for this purpose. Due to regulatory
requirements, the technology operator performed routine monitoring of the confined groundwater
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aquifer.  According  to  the operator,  this  routine monitoring  detected  no degradation of
groundwater quality  during use of the SERF technology.

4.3    PERFORMANCE DATA

4.3.1  Soil  Sample Analyses

Table 4-1 presents the  post-treatment soil sampling results for TPH and TRPH. Based on
analysis of the post-treatment  TPH and TRPH data, removal of contamination by the SERP
technology was less complete than expected. Forty-five percent of the post-treatment soil sample
results inside the treatment area were above the cleanup criterion of 1,000 mg/kg TPH. Seven
percent of soil samples had TPH concentrations in excess of 10,000 mg/kg.

No BTEX was detected in any  of the post-treatment samples. The analytical detection limit was
6 /xg/kg.  This  may be an indication that the SERP technology was effective in removing these
compounds because BTEX compounds were found at low mg/kg levels in a few pre-treatment
soil samples. However, this finding is not conclusive. There were no cleanup criteria established
for BTEX compounds in soil.

Results  of the analysis  of triplicate samples  were highly variable, showing that  the  site
contamination was heterogeneous even over small vertical distances (approximately three inches).
Table 4-2 presents the triplicate sample results and associated statistics.

A geostatistical analysis of the post-treatment soil data was conducted using a "nearest neighbor"
approach on a  computerized model to assess  the spatial variability of soil contamination and to
determine a  weighted average of the soil results. The use of this geostatistical approach results
in the calculation of a more "unbiased" estimate of the true average level of contamination for
the site as a  whole. This is particularly true when there is no pattern of spatial correlation such
as low spatial variability at short distances and high spatial variability at longer distances for soil
contamination, as was determined to be the case at the Rainbow Disposal  site [9]. Based on the
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      Table 4-1. TPH AND TRPH RESULTS FOR POST-TREATMENT SOIL
Boring
1
1
1
1
1A
1A
1A
1A
2
2
3
3
4
4
5
5
5
6
6
7
7
8
8
9B
9B
9B
10
10
10
11
11
Depth (ft)
16.5
26.5
30
35
15
25
30
35
32
35
32
38
30
38
30
35
38
32
40
25
35
31
43
25
32
37
30
37
40
30
35
TPH (mg/kg)
21
31,800
5,640
3,500
4.3
344
6,090
2,270
670"
960
392
4.2
6,800"
1,800
11
5,160
7,910
1,080
1,700*
3.3
9,330
3,360
15
2.6
3.4
8.5
69"
1,360
3,260
1,880
807
TRPH
(mg/kg)
60
12,500
1,430
1,100
<24
108
5,570
4,570
187"
376
190
<27
2,000"
604
<26
113
8,110
542
1,400"
<22
12,900
2,000
164
43
<20
<20
<55"
762
592
348
141
Boring
19
19
19
20
20
20
21
21
21
22
22
22
23
23
23
Depth (ft)
28
32
38
30
34
41
30
35
40
31
37
42
20
30
38
TPH (mg/kg)
41
351
232
1,880
21,600
2.8
10,900
9,080
1,020
14
177
628
5.5
6,100"
438
TRPH
(mg/kg)
214
686
232
1,610
1,690
307
25,400
9,740
952
151
96
291
<20
6,100"
770
Outside Treatment Area
12
12
13
13
14
14
15
15
16
16
17
17
18
18

33
39
32
38
30
40
31
36
35
39
31
36
30
35

3.6
4.2
7.8"
4.8
4.2
4.4
35
369
6.3*
4.3
3.2
3.3
4.1
6.2

<20
82
<40*
<20
<20
<20
<20
228
<42"
<20
<20
<20
<20
74

Average of Triplicate Results
< Not detected at detection limit shown
                                    71

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      Table 4-2. RESULTS OF TRIPLICATE ANALYSES FOR TPH AND TRPH
Borehole
Number
2
4
6
10
13
16
23
Depth (ft)
and
designation
32 primary
duplicate
triplicate
30 primary
duplicate
triplicate
40 primary
duplicate
triplicate
30 primary
duplicate
triplicate
32 primary
duplicate
triplicate
35 primary
duplicate
triplicate
30 primary
duplicate
triplicate
TPH Results
(mg/kg)
674
120
312
12,400
239
7,710
590
3,680
863
82
5.6
118
3.3
14
5.9
5.3
9.2
4.5
5,090
5,320
8,010
TRPH Results
(mg/kg)
80
161
321
1,450
259
5,820
1,150
2,460
638
<20
<20
127
<20
81
20
<20
85
<20
5,830
6,230
6,230
Standard
Deviation of
TPH Results
(mg/kg)
230
5,000
1,400
47
4.6
2.1
1,300
Standard
Deviation of
TRPH Results
(mg/kg)
100
2,400
770
>50*
>29*
>30'
190
<     Not detected at the detection limit shown
*     Calculated using non-detect results at the detection limit. Actual standard deviations may be slightly
      higher.
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 geostatistical analysis, the post-treatment weighted average soil  TPH concentration is 2,290
 mg/kg, with a  standard error of 784 mg/kg. Based on an approximate normal distribution for
 the weighted average, the 90 percent confidence interval for TPH concentration is 996 mg/kg
 to 3,570 mg/kg. This large interval is because of the variability of site soil sampling results due
 to the heterogeneity  of the  in situ soil; analytical variability was within  established  quality
 control limits and contributed little to overall data variability. According to  this analysis, at 90
 percent confidence, the true  average may be below the cleanup criterion of 1,000 mg/kg, but
 this  represents  a small probability. Therefore, with almost 90 percent confidence, the average
 concentration of the site soil after treatment with SERP is above the cleanup criterion.

 The  geostatistical analysis results for TRPH yielded a weighted average concentration of 1,680
 mg/kg, with a standard error of 608 mg/kg. The 90 percent confidence interval for the weighted
 average  for TRPH  is 676  mg/kg to 2,680 mg/kg.  The calculated  weighted average and
 confidence interval for TRPH are lower in magnitude than for TPH. No TRPH cleanup criteria
 were set for the Rainbow  Disposal site.

 Samples collected from areas  outside the perimeter of contamination (those numbered 12 through
 18) were analyzed for TPH, TRPH, and BTEX. Only one of the 12 samples  collected had TPH
 levels  higher than 200 mg/kg,  the  limit used to determine  whether lateral  migration of
 contamination due to  treatment with SERP had occurred. Since this one sample was less than
 twice the limit,  and the variability found in samples from the site was so great, this result is not
 felt to indicate that any significant lateral migration had occurred. Additionally, of the remaining
perimeter samples, only two  contained greater than 10  mg/kg TPH and many contained levels
 less than 5 mg/kg, which was the achieved detection limit during the original  site survey.  TRPH
results for samples collected outside the perimeter of contamination were similar to TPH results.
BTEX  compounds were not detected above the 6 /zg/kg detection  limit.
                                           73

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 4.3.2  Comparison of Pre- and Post-Treatment Conditions

 A secondary (non-critical) objective of the Demonstration was to determine a removal efficiency
 (or  percent  removal)  by comparing pre- and post-treatment sample analysis data. Percent
 removal was calculated for TPH only, since no pre-treatment TRPH data exists, and only three
 of the pre-treatment samples contained detectable amounts of BTEX. Percent removals calculated
 for each set of paired boreholes are shown in Table 4-3. Percent removal was calculated as:
            Pre-treatment Concentration - Post-treatment Concentration    ,„„
            	—	—  x 100
                           Pre -Treatment Concentration
Direct comparison of the paired borehole sample TPH results shows great variability for the data
set.  This pairing analysis is of limited value because of the high spatial variability associated
with the in situ soil contamination. Samples from paired boreholes were located within three to
four feet of each other laterally and at the same depth; however, triplicate sample results over
much shorter distances (18-inches) showed variability as high as those between the pre- and post-
treatment paired boreholes.  Some  areas seem to  show  good  or  moderate  reduction  in
contamination, while other areas  show increases in contamination, some of them rather  large.
These results are supported by Figure 4-2 which presents the pre- and post-treatment data sets
in a  histogram showing the percent of samples in incremental concentration ranges.

Due  to  the high spatial variability of the  in situ soil  contamination at this site, a  more valid
approach to determine a removal efficiency  is to pool pre- and post-treatment data sets  for
comparison. To accomplish this, weighted average concentrations of TPH in the soil before and
after treatment were compared.  A weighted average TPH concentration  in the  soil before
treatment was calculated using geostatistical modeling (nearest neighbor approach) as was done
for the post-treatment data. The weighted average pre-treatment concentration was calculated to
be 3,790 mg/kg with a standard error of 2,340 mg/kg. Since the distribution of the pre-treatment
weighted average did not conform  to a normal distribution, the confidence interval  on this

                                           74

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              Table 4-3. PERCENT REMOVAL FROM BOREHOLE PAIRS
Borehole
1
1
1
2
3
4
5
5
5
6
7
7
8
10
10
10
11
11
1A
1A
1A
1A
AVERAGES
Depth (ft)
15
25
30
35
32
30
30
35
38
32
25
35
43
30
37
40
30
35
15
25
30
35

Pre-Treatment TPH
Concentration (mg/kg)
3,480
11,300
4,870
1.3
728
3,860
2,240
325
312
2,800
10.6
39,100
469
472
3.2
72
165
810
1.2
4,180
4,160
1,380
3,670
Post-Treatment TPH
Concentration (mg/kg)
20.5*
31,800b
5,640
3,500
392
6,800C
11.4
5,160
7,910
1,080
8.3
9,330
12.3
69C
1,360
3,260
1,880
807
4.3
344
6,090
2,270
3,190d
Percent Removal
(%)
99
0
0
0
46
0
99
0
0
61
22
76
97
85
0
0
0
0
0
92
0
0
13
a Post-treatment sample was collected at 16.5 feet
b Post-treatment sample was collected at 26.5 feet
c Average of triplicate sample results
d Average for post-treatment was calculated using all the post-treatment data in the treatment
area, including data  from boreholes which were not sampled before treatment.
                                               75

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    Percent of Results
    40%
    30%
    20%
    10%
    0%
            <5              10-50           100-500         1,000-5,000         > 10,000
                    5-10            50-100          500-1,000        5,000-10,000
                                   Concentration Ranges (ppm)
            Pre-treatment
                        Post-treatment
Figure 4-2. Histogram of Pre- and Post-Treatment TPH Concentration Data

average was calculated using a computerized  "resampling" technique. This technique is often
used to more accurately estimate confidence intervals for statistics with non-standard and non-
normal distributions [10]. At 90 percent confidence, the calculated interval on this weighted
average is 1,390 mg/kg to 7,290 mg/kg. This large range is due to the smaller number of pre-
treatment samples collected and to the variability in the data set.

Comparing the pre-treatment soil TPH weighted average to the post-treatment soil TPH weighted
average,  the overall  removal efficiency was calculated  to  be about 40 percent. Using  the
resampling technique to calculate the confidence interval, at 90 percent confidence, the percent
removal could be significantly higher or lower. This large uncertainty about the exact removal
efficiency is due primarily to the lack of sufficient pre-treatment sample measurements, and the
resultant  data set variability. (Pre-treatment data were  collected by the developer before the
preparation of the SITE Program QAPP.) According to process data, however,  it is known that
some diesel contamination was removed from the soil during treatment.
                                           76

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The amount of diesel recovered in the storage tank during treatment was measured and totaled
approximately 700 gallons  at the end  of the  project.  This is  much less than the amount
anticipated to be collected when the system was designed and installed. Partly, this was due to
the poor effectiveness of the process  at treating the site soil. However, this was also due to
design factors of the technology application including inadequate vapor stream condenser design.
More diesel was removed through the vapor treatment system and oxidized in the TOU than was
collected in the storage tank. Vapor concentration measurements taken at the inlet of the TOU
over the course of treatment by the flame ionization detector (and the LEL meter before the  FID
was on line), along with  the flow  rate and inlet temperature,  were used to estimate the amount
of diesel which was removed in vapor form.

Based on these data,  it was calculated that approximately 15,400 gallons of diesel were treated
by the TOU.  Therefore, a  combined total of  approximately 16,000 gallons of diesel were
removed during  treatment with SERF. This volume, compared with the initial estimate of the
amount of fuel released (70,000 to 135,000 gallons [7,8]), less 4,000 gallons recovered prior
to treatment with SERF,  suggests that between  12 and 24 percent of the original spill volume
was removed from the soil and treated above ground. This removal efficiency, based on diesel
recovered and treated, although lower than the removal efficiency based on the soil data, is
within the percent removal confidence interval for the soil data. It should be noted  that vapor
stream system measurements were not critical measurements for this  Demonstration.

4.3.3 Soil Temperature Data

Twenty temperature monitoring wells in and around the treatment area were used to measure the
soil temperature, determine the progress  of the steam through the soil within the treatment area,
and ensure  that the steam flow stayed within the treatment area. The locations of all these wells
are shown in Figure 4-3. Plots of the temperatures over time in selected wells are presented with
a discussion of what  these temperature plots may indicate about the operation of the process in
different locations of the site.
                                           77

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— *
>
*
O INJECTION WELL
D EXTRACTION WELL
A TEMPERATURE
MONITORING WELL
	 PERIMETER OF
CONTAMINATION
T STORAGE TANKS
r**-~
1 \
\
OFFICE
— *— •
•^>
— i
                            a
                                    D
                                                   a.
                                                          D
TRANSFER BUILDING
7=3 -^
a u







7A








                                                            A6
Figure 4-3. Temperature Monitoring Well Locations
                                                                         A5
Figure 4-4 is a plot of the temperature versus time at Well 15. This figure shows little heating
of this area of the site at all depths. Since this well was close to underground tanks on the site,
the injection and extraction wells in this area were not turned on until late in the remediation,
at which time the area began to heat. Only the 30-foot depth appears to have reached the steam
temperature, and only for a period of a few weeks. However, temperatures recorded at 20- and
40-foot depths were increasing during this time.

Figure 4-5 is a plot of the temperature versus time at  Well 23, and Figure 4-6 is a plot of the
temperature versus time at Well 24. As can be seen on the site map (Figure 4-3), Wells 23 and
24 are in a line between an injection well and an extraction well, with Well 23 being closer to
the  injection well. As would be expected from the process, the two figures seem to  indicate a
steam or heat front moving from the injection well towards the extraction well, since Well 23
heated up sooner than Well 24. No heating was seen  at Well 23 until April 1992, which was

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      200 -
         08-01-91   10-21-91   01-13-92   04-06-92   06-29-92   09-21-92   12-14-92   03-08-93   05-31-93
                                                Date
                                10'       20'        30'        40'
     Figure 4-4.  Soil Temperature Plot for Well Location  15
          3-01-91   10-21-91   01-13-92  04-06-92   06-29-92   09-21-92   12-14-92   03-08-93   05-31-93
                                                Date
                                10'       20'        30'        40'
Figure 4-5. Soil Temperature Plot for Well Location 23
                                                79

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             08-01-91  10-21-91   01-13-92  04-06-92   06-29-92  09-21-92   12-14-92   03-08-93  05-31-93
                                              Date
                                10'
                                        20'
                                                 301
                                                         40'
Figure 4-6. Soil Temperature Plot for Well Location 24

after the boilers  had been recommissioned after lengthy downtime; Well 24 began heating in
June 1992. In both these wells, as in many  of the other monitoring wells, the 30-foot depth
heated more effectively than the 20-foot depth or other depths. This indicates that the expected
steam flow pattern  was established, from the injection interval (30 to 40 feet) to the higher
extraction  interval (10 to 35 feet). Slower and more gradual heating at the 40-foot depth may
be due to the  upward flow pattern developed, the influence  of the cooler soil below, or to the
change in soil type near the bottom of the treatment zone.
Figure 4-7  shows the temperature  profile for Well 27. Temperature probes  were placed at
different depths in this well than in many of the other wells, showing more detail in the middle
depths. This graph shows a similar  pattern of heating to that of Well 23,  indicating that many
parts of the site started heating to steam temperature at the  same time (April 1992). The  steam
front reached this location at the same time for depths between 15 and 27 feet and slightly later

                                            80

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            200 -
               5-01-91  10-21-91   01-13-92  04-06-92   06-29-92  09-21-92   12-14-92  03-08-93   05-31-93
                                               Date
                             15'
                                                      32'
                                                              40'
Figure 4-7. Soil Temperature Plot for Well Location 27

for the 32-foot depth. The shallower depth of the initial steam front shown in this well could
have been caused by many factors, including soil types. Another reason for a different flow path
at this location is that this temperature well is located between pairs of the same type of process
well,  rather than between an injection/extraction well pair as was the case for Wells 23 and 24.
Figure 4-8 is a temperature plot of Well 30, which is located further away from the spill zone
than the wells discussed previously.  This plot shows a slightly different pattern of heating. In
October 1991, this location had nearly reached the steam temperature for  all but the  10-foot
depth. Then the soil began to cool off, coinciding with the extended boiler problems experienced
in the winter of 1991/1992. Reheating in this location began in April 1992. However, the second
time the soil was heated, the temperature increased less rapidly.  It is possible that the initial
steam front changed the soil (e.g.,  porosity or moisture content) which then retarded reheating
of the soil. If this is true of treatment with SERF, then intermittent operation could be very

                                            81

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           200  —
             08-01-91   10-21-91   01-13-92  04-06-92  06-29-92   09-21-92  12-14-92  03-08-93  05-31-93
                                               Date
                                 10'
                                         20'
                                                 30'
                                                         40'
Figure 4-8. Soil Temperature Plot for Well Location 30

inefficient, and reduction of downtime critical to effective operation. However, this area of the
site did stay heated after the steam temperature was reached again.

Figure 4-9 is a plot of the temperature at Well 33, which is near Well 15 and the location of the
initial diesel spill. The heating in this area was slow initially, and then intermittent for the rest
of treatment. A significant increase  in temperature in this location was not seen until late June
1992. Well 33 is near two extraction wells,  and began heating about the same time as well 24
which was also near an extraction well. This again seems to demonstrate the movement of a
steam front from injection to extraction well areas. The temperature fluctuated in Well 33 until
the fall of 1992 when it reached the steam temperature. The fluctuating temperature pattern may
have occurred because a nearby injection well was turned off for much of the treatment time to
protect the underground tanks. Also, since this temperature well is near two extraction wells,
the operation of the vacuum may have caused the soil  to  cool. The poor heating of this area,

                                            82

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         200 -
           08-01-91   10-21-91   01-13-92  0406-92  06-29-92   09-21-92   12-14-92  03-08-93  05-31-93
                                             Date
                               10'
                                       20'       30'
                                                       40'
Figure 4-9. Soil Temperature Plot for Well Location 33

especially at the lower and higher depths (10 feet and 40 feet) may have led to poor treatment;
two nearby sample  locations (S-1A  and  S-23)  showed high levels of contamination  after
treatment. However, the variability in soil  concentration data limits this conclusion.
The last temperature graph shown here, Figure 4-10, is the temperature profile for Well 20. This
plot is also representative of Wells 17, 18,  19, 25 and 26 since they are located close together.
These wells  were installed in a test plot used during shakedown testing  of the process and
equipment. The wells in this location reached high temperatures sooner than other wells because
this area was treated much earlier and more intensely than the rest of the treatment area. The
temperatures recorded  at  Well 20, especially at the 20- and 30-foot  depths, approximately
parallel to the  operation of the process. Major downtime,  which occurred over the winter of
1991/1992 and in the fall  of  1992,  is seen on the plot where the soil starts to cool.  Injection
wells  near this  location were shut off in early  1993 to focus the operation elsewhere, which can
also be seen  in the cooling of the soil near the end of treatment.
                                            83

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          200  -
             08-01-91   10-21-91   01-13-92   04-06-92  06-29-92   09-21-92  12-14-92   03-08-93   05-31-93
                                              Date
                                10'
                                        20'
                                                301
                                                        40'
Figure 4-10. Soil Temperature Plot for Well Location 20
From the examination of the soil temperature profiles, several general conclusions can be drawn
about the operation of SERF at the Rainbow Disposal site. Heating of the soil took much longer
than originally anticipated, and high soil temperatures needed to effect contaminant removal were
not maintained in many areas. This may have been due to the way the process was operated
initially and to excessive  operational downtime. The steam flow patterns expected to occur in
the soil did seem to occur,  including  the development of a steam front which moved  from
injection wells  to extraction wells and from the injection depth upward towards the extraction
depth. Inspection  of the temperature data collected also suggests  that additional temperature
monitoring wells  over  the entire  treatment  area  would have  been useful in  monitoring and
operating the process, which could have improved the remediation overall.
                                            84

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 4.3.4 Additional Process Data

 Figure 4-11 is a graph of the monthly water use, based on flow totalizer readings, and monthly
 diesel extracted from the soil in the vapor phase, calculated from FID and LEL readings of the
 inlet vapor to the TOU.  FID readings are only available from June 1992;  LEL readings were
 used for months before that. These two process measurements help to describe the operation of
 the process. For example, the water used in a month indicates the amount of time the boilers
 were operating that month and is therefore representative of the energy input to the soil in the
 form of steam. Major equipment downtime occurred in the winter of 1991/1992, and in the
 spring of 1993,  which is shown by decreases in water use in this graph.

 The calculated volumes of diesel recovered show the removal of hydrocarbons from the soil by
 the technology,  since most of the contaminant removed remained in the vapor  phase.  The
 volume of diesel removed per month was dependent on several  process factors including the
 temperature of the treated  soil, the amount of vacuum drawn  on the soil,  the number of
 extraction  wells in operation, and  the number of hours in operation. It can be seen from the
Gallons
1,500
1,000
 500
         11!
1
                             I Well Water
                           , ,,f (gal/1000)
I                              Diesel Recovered
                              (gal)

II
     1991 July  Sept   Nov  1992 Jan  Mar   May   July    Sept   Nov   1993 Jan  Mar   May    July
                                         Date
 Figure 4-11. Well Water Usage and Diesel Recovered at the Rainbow Disposal Site
                                          85

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graph  that a rapid increase in the diesel recovery occurred in  April of  1992.  Temperature
monitoring well graphs showed that the site was near or at steam temperature at this time after
the lengthy process downtime. Diesel recovery is lower after May of 1992, probably due in part
to intermittent TOU problems. Another reason for the decrease in removal may be because an
initial front of easily mobilized contaminant had been removed in April and May, leaving more
tightly bound contamination in the soil.

In October and November 1992, shortly after process operation was changed to a  24-hour per
day cycle, another peak hydrocarbon removal was reached. The removal remained high for
several months.  When the removal dropped off, the operator  felt this indicated that parts of the
site were becoming clean, and therefore started to turn off some of the injection wells in order
to concentrate the treatment on areas known to be more contaminated.

Each time a group of wells were shut off, this resulted in a small increase (peak)  in removals
due to  the effect of concentrating the steam and vacuum on a  smaller, more contaminated area.
These smaller peaks, which cannot be distinguished on the monthly diesel recovery graph, taper
off more quickly than the original  peak in October.

4.3.5  Reliability

The SERF system experienced many operational problems during the two-year treatment period.
The actual on-line efficiency during this period was determined to be about 50 percent based on
operational logs. Both of the boilers had operational downtime, frequently simultaneously, which
delayed the heating of the soil. The boiler downtime was due to structural, mechanical,  and
electrical problems, and in approximately a half-dozen instances resulted in downtime of several
weeks or more during repairs. Intermittent operation of the boilers probably contributed to these
problems. The change from 16-hour- to 24-hour-per-day operation lessened the thermal shock
on the boilers from frequent starting and stopping and helped to prevent further problems. Some
boiler problems  could be traced to emission reduction devices required by regional air quality
regulations. These devices may not need to be used on sites  in other areas.
                                           86

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The TOU also experienced several operational failures and significant amounts of downtime over
the course of the project.  Because of the high operating temperatures inside the unit, several
days were required to cool the unit before repair work could be performed, and then at least 24
hours of heating were required to bring it up to operating temperature. Internal components of
the TOU  failed in part  due to the high humidity in the vapor stream being oxidized. A more
effective vapor condensing system in front of the TOU might have helped to prevent or minimize
these problems. Alternately, a vapor treatment technology less sensitive to moisture could have
been selected for use with the technology.

Other reliability and maintenance problems occurred over the course of the project,  including
breakage or malfunction of well headers, hoses, and valves. At the Rainbow Disposal site, two
factors were significant in increasing the amount of system maintenance and repair required. The
installation of all the process wells below grade  on the active portion of the facility made it more
difficult to locate problems until they had become significant. Also, the remediation took almost
three times as  long as originally planned, so many of the parts had reached the end of their
useful service life before the end of the project.

Because  this was  the first full-scale application of the  technology, it  is  believed that  more
operational problems occurred here than would occur after additional experience has been gained
with the technology. Lessons  learned  from this  application will also assist  in minimizing
equipment and operational problems with subsequent systems.

4.4    RESIDUALS

Residuals from the SERF treatment  which required disposal or further handling are described
in this section.  Drill cuttings were produced every time a borehole was drilled for installation
of process wells or for a sampling event. On the average, two 55-gallon drums of drill cuttings
were generated for each 40-foot borehole drilled  using  an eight-inch auger.  Some  sampling
events  were  conducted with smaller augers,  generating fewer  drill cuttings.  Samples  were
collected from each borehole to determine whether the drill cuttings contained detectable levels

-------
 of diesel fuel. Uncontaminated drill cuttings were redeposited on the site as fill. Approximately
 230 drums of drill cuttings were generated during the technology mobilization, treatment, and
 post-treatment sampling.  An  estimated  40 percent of these drums (92) were considered
 contaminated and required off-site disposal.

 The effluent from the process  wastewater treatment system can also be considered a residual
 from the process. Approximately 1.6 million gallons of water were treated by the wastewater
 treatment system and discharged to the storm sewer. At a site with some highly regulated or
 difficult to  treat contaminants, the  use of a storm sewer for the discharge of the process
 wastewater might not be appropriate. For this case, discharge to a POTW might be an option.
 More rigorous on-site treatment, or off-site disposal, might also be necessary for disposing of
 the wastewater effluent.

 The SERF wastewater treatment system at the Rainbow  Disposal site included  5-micron filters
 and activated carbon beds, which needed to be replaced when blinded or exhausted. The filters
 and carbon were another source of residuals from the system.  One change of the carbon beds
 was required during treatment, and another at the end of treatment. A total of nineteen 55-gallon
 drums of spent carbon were generated from the beds when they were replaced. The used carbon
 was sent off-site to be regenerated or landfilled.  Regeneration might be the more economical
 option, depending on the amount and types of contaminants that the carbon had been removing
 from the water. The 5-micron filters were mostly used to remove particulates and colloids from
 the water.  Depending on the  composition of the waste,  these  filters may  or  may not be
 considered a hazardous waste. The filters would then be disposed of accordingly in a municipal
 or hazardous waste landfill.

The SERF technology is designed to remove the contaminants from the soil and concentrate them
for more efficient treatment or disposal.  The effluent treatment system includes a gravimetric
oil/water separator to remove most of the diesel from the extraction well liquids. The diesel was
then collected in a storage tank. For this treatment about 4,700 gallons of diesel were collected.
The  recovered  diesel was  sent off-site  for disposal  or  recycling.  At  other  sites, the type of
                                           88

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 contamination present in the soil would determine the disposal options for the recovered liquid,
 which in some cases could be burned on-site as fuel. The recovered diesel could not be burned
 as a fuel at the Rainbow Disposal site due to air regulation requirements.

 The oil/water separator also produced small amounts of sludge. This material was periodically
 removed, placed into 55-gallon drums, and sent off-site for disposal. Approximately ten drums
 of this material  were generated during treatment.

 The contaminated vapor from the extraction wells was oxidized in the TOU, which was designed
 to effect at least 99.99 percent destruction of the organic compounds. The  resultant gas stream
 contained water vapor and carbon dioxide. This gas was released to the atmosphere through a
 stack. A site contaminated with other compounds, especially those containing sulfur or chlorine,
 might require further gas treatment.

 Solid waste residuals  produced from SERF treatment  include  used  protective clothing and
 disposable tools. Depending on the contact these items have had with the waste materials, they
 can be disposed of as non-hazardous trash, decontaminated, or packaged in drums and sent to
 a hazardous waste landfill. At the Rainbow Disposal site, non-hazardous trash could be readily
 disposed of by the site owners. Potentially hazardous trash could be disposed of in the same
 manner as the contaminated drill cuttings.  If it is necessary to remove well casings  from the
ground,  these materials  may also be disposed of as  non-hazardous waste if they can be
decontaminated, or as  hazardous waste if they cannot be decontaminated.
                                           89

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                                    SECTION 5
                 OTHER TECHNOLOGY REQUIREMENTS

5.1    ENVIRONMENTAL REGULATION REQUIREMENTS

Federal,  state, and local regulatory agencies may require permits  prior to construction and
operation of the SERF technology. Most federal permits will be issued by the authorized state
agency. Federal  and state  requirements may include obtaining a hazardous  waste treatment
permit or modifying an existing permit. Air emission permits may be required for any unit that
could emit a hazardous substance. The Air Quality Control Region may also have restrictions
on the types of process units and fuels that would be used. Local agencies may have permitting
requirements for grading, well installation and abandonment, and health and safety. In addition,
if wastewater is  disposed of to  the sanitary sewer, then the local water district  would have
effluent limitations and sampling  requirements. Finally, state or local regulatory agencies may
also establish cleanup standards for the remediation.

At the Rainbow Disposal site, federal and state permits included  an ah* permit obtained from the
South Coast Air Quality Management District for the construction and operation of the thermal
oxidation system. The South Coast Air Quality Management District also placed restrictions on
the model of boiler used for steam generation and the type  of fuel allowed (natural gas). A
NPDES  permit  was obtained  from the Santa Ana RWQCB  for discharge of the  treated
groundwater to the storm  sewer system,  and a  Class  V Underground  Injection permit  was
obtained from the USEPA for injection of the steam. No hazardous waste treatment permit was
required  since the remediation  involved  spilled  diesel product  which  is not considered a
hazardous waste.

Local permits included various construction and operation permits from the Huntington Beach
Department  of Building and Safety, and  permission  to operate granted  by the local Fire
Department. The Orange County Health Care Agency required permits for the construction and
                                         90

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 abandonment of the groundwater monitoring, extraction, and injection wells. They also requested
 to be kept informed about the operations during the remediation activities.

 5.2    PERSONNEL ISSUES

 Full-scale application of a SERF system will probably necessitate 24-hour per day operation. At
 the Rainbow Disposal  site, three technicians, a full-time site engineer, and a full-time site
 supervisor were required  each week during 24-hour per day operation. At least one technician
 must be on hand at all times during operation to supervise the function of the boilers and other
 equipment. These technicians must be certified in boiler operation by the state in which they are
 operating.  The technicians and other personnel must also be skilled in maintenance of machinery
 (such as pumps and blowers).  Training in duties  specific to the operation of SERF,  such as
 collecting temperature data, will need to be  performed during process operation.

 A part-time secretary was required to order supplies, produce required reports,  and handle other
 secretarial  and administrative tasks. For SERF,  Hughes Environmental had a parent company
 to which  certain administrative duties  were directed, and  from which came administrative
 requirements for items like tirnecards and purchasing;  additional administrative staff may have
 otherwise been needed.

 During sampling events, a geologist and a sampling assistant were required to direct the drilling,
 collect the samples, and log the boreholes.  Personnel present during drilling on a hazardous
 waste site must have current OSHA health and safety certification. Other personnel working on
the site may also need this training, depending on  the job description, site layout, and type of
contamination. Personnel who work with hazardous substances or waste must also be enrolled
in a medical monitoring program hi accordance with OSHA regulations.

At the Rainbow Disposal  site, the contamination was present below the soil  surface.  During
typical operations, no  contact was made with the  contaminated material. Personal protective
equipment  for normal  work functions included a hard hat and  work boots for any personnel
                                           91

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required to enter the equipment area or the active portion of the Rainbow Disposal site (required
by Rainbow Disposal's Health, and Safety policies). During drilling, digging, residuals handling,
or other  activities where  contaminated or  hazardous materials might be  encountered, other
equipment such as chemical resistant gloves and disposable coveralls were sometimes required.
For other sites, the  type  and use  of protective clothing  would depend  on job function,  and
contaminant characteristics and toxicity.

5.3    COMMUNITY ACCEPTANCE

A Visitor's Day meeting was held in March 1992 to distribute information to the public on the
remediation project and on the SITE Program Demonstration of the SERF technology.  The
meeting included presentations by the developer and the EPA SITE project manager, and a brief
tour of the site and technology. Participants in the Visitor's Day included regulatory personnel,
remediation contractors, and members of the public.  The turnout at the Visitor's Day was high,
indicating strong interest  in  the SERP technology and its application for remediation at the
Rainbow Disposal site.

The SERP technology works mainly underground, and contaminated soil excavation activities
are minimized. This  process limits the potential for human exposure to the contaminants in the
soil, which may make the  technology more  acceptable to the local community. If the process is
designed and applied properly, the contaminants will be kept within the treatment zone and will
not migrate off-site or vaporize to the atmosphere. The technology is designed to operate more
rapidly than  other in situ technologies,  thus limiting the duration of the  disturbance to site
neighbors. The ability to operate a commercial facility aboveground  while the process  is
operating belowground can be very important, as  was the case at the Rainbow Disposal site.

The process equipment used for SERP, including boilers and compressors,  has the potential to
be  noisy. This  can  be somewhat mitigated  through choices of equipment and appropriate
installation. Drilling  activities required  for soil  sampling  and process well installation can
                                           92

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produce both noise and dust.  These disturbances are for a short duration and can be mitigated
as appropriate to the situation.

Increases  in traffic in the area are temporary and would include mobilization and demobilization
of heavy equipment at the start and end of the project, and periodic mobilization of drill rigs.
The technology  requires a small crew of personnel for operation,  so increases in daily traffic
would be  minimal.  At the Rainbow Disposal site, the increases  in traffic, dust, and noise were
all negligible in comparison with the ongoing trash transfer activities at the site.
                                           93

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                                    SECTION 6
                            TECHNOLOGY STATUS

6.1    PREVIOUS/OTHER EXPERIENCE

Technologies similar to in  situ SERP have been investigated  on a field-scale level at other
contaminated sites. Most notably, a portion of a site  contaminated by gasoline to a depth of
about 135 feet was recently remediated with Dynamic Underground (steam) Stripping at the
Lawrence Livermore  National Laboratory  in Livermore, California. The technology was
successful in removing and recovering a significant portion of the gasoline contamination from
more permeable unsaturated and saturated soil  in the test area. Innovative techniques were
applied to monitor the steam zone and control the process. Appendix A to this ITER presents
a case study of the Dynamic Underground Stripping Process.

Since 1985, several small gasoline and diesel  spill sites hi the Netherlands  have been treated
using similar steam stripping methods [2]. Due to the shallow groundwater in that area, portable
systems utilizing steam lances were used instead of permanent process wells.

At this tune, other tests of steam injection technology are planned at sites contaminated with
dense  non-aqueous phase liquids such as  trichloroethene. The  ability of the technology to
remediate  sites  contaminated with  these denser-than-water  compounds,   without causing
downward or off-site migration, will be a key evaluation objective for these tests.

6.2    SCALING CAPABILITIES

The  SERP technology can be designed, within engineering constraints, to treat a large area to
significant depths. Based on results  from the full-scale application of SERP technology at the
Rainbow Disposal site, the critical factor hi scale-up from pilot- or field-scale to full-scale site
remediation seems to be maintaining control of the  in situ process. Insufficient subsurface
                                          94

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 temperature monitoring  capability over the large treatment area (2.3 acres) and excessive
 equipment downtime contributed to inadequate process control and operation and  incomplete
 remediation at the Rainbow Disposal site. To reduce downtime, major process equipment must
 be sized correctly for the full-scale application and must be designed to withstand the corrosion
 and wear  from long-term treatment.

 6.3    OTHER INFORMATION

 Hughes Environmental Systems, Inc. operated the SERF technology  at the Rainbow Disposal
 site;  however, they are not vending the technology for use at other sites because they are no
 longer in the environmental remediation business. Since SERF uses commonly available process
 equipment, the technology can be designed and operated by other consultants knowledgeable in
design and operation of  the process.  Similar in situ steam technologies may have patented
process or monitoring equipment available only through the developers.
                                         95

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                                 REFERENCES


1.   Udell Technologies, Inc. Field Design  for In Situ  Recovery of Hazardous Wastes by
    Combined Steam Injection and Vacuum Extraction, Final Report,  Contract No. DAAL03-
    86-D-001. January, 1991.

2.   Dablow, John F., III.  Steam Injection to Enhance Removal of Diesel Fuel from Soil and
    Ground Water. Hazmacon 91.

3.   Peters, Max S. and Klaus D. Timmerhaus. Plant Design and Economics for Chemical
    Engineers. McGraw-Hill, Inc., San Francisco, 1991.

4.   McMaster-Carr Supply Company Catalog No. 96. Atlanta, GA.

5.   Lab Safety Supply Inc, 1994 General Catalog: Fall/Winter Edition. Janesville, WI. 1993.

6.   Evans, G., Estimating Innovative Technology Costs for the SITE  Program. Journal of Air
    and Waste Management Association, 40:7, pages 1047-1051. 1990.

7.   Converse  Environmental Consultants California. Site Characterization,  Conducted for
    Rainbow Disposal, 17121 Nichols Street, Huntingdon Beach,  California. Costa Mesa, CA,
    August 11, 1988

8.  Telephone communication with John F. Dablow III, formerly of Hydro-Fluent, Inc. January
    26, 1994.

9.  Isaaks, E.H. &  Srivastava,  R.M. An Introduction to Applied Geostatistics. New York:
    Oxford University Press, 1989.

 10. Efron, B. & Tibshirani, R. Bootstrap methods for standard errors,  confidence intervals, and
    other measures of statistical  accuracy, Statistical Science, Volume 1, 1986,  pp. 54-76.
                                          96

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                             APPENDIX A: Case Study
                         Dynamic Underground Stripping Process
                       at Lawrence Livermore National Laboratory

  The Dynamic Underground Stripping process, similar to the Steam Enhanced Recovery Process
  (SERF), was developed and operated by Lawrence Livermore National Laboratory (LLNL) in
  conjunction with the College of Engineering at the University of California, Berkeley. This
  process was used to recover gasoline contamination from an underground spill at LLNL. The
  process uses steam injection, vacuum  extraction, and electrical heating to effect contaminant
  removal from soil and groundwater. In addition, underground imaging is used to monitor  the
  process.

 This case study  is included here because it presents another application of a technology similar
 to SERF with different contamination and geologic conditions. The Demonstration of Dynamic
 Underground Stripping at LLNL was conducted and evaluated by LLNL personnel, with limited
 participation by  the EPA SITE Program. Therefore, this study is only included in this report as
 an appendix.

 The test site at LLNL was contaminated  with leaded gasoline. Gasoline, being more volatile than
 diesel,  is more  readily  removed by  vapor extraction.  Gasoline contamination existed in the
 vadose and saturated zones, and in permeable and low permeability  soils, at the LLNL site. The
 geology of the LLNL test site is alluvial, and  is highly variable from location to location.

 A full-scale  Dynamic Underground  Stripping process  was used at LLNL.  Treatment  was
 conducted with six injection wells encircling three extraction wells. These wells along with the
 EPA SITE Program post-treatment sampling borehole locations are shown in Figure A-l. An
 area  of  roughly  2,000 yd2 down to approximately 135 feet was treated by the process.  The
 treatment area was significantly  smaller than at the Rainbow Disposal site, but the depth of
treatment was much greater. Electrical heating was used to enhance the removal of contaminants
from low permeability zones.
                                         97

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          0'
20'
                         TEP-GP-106,
                           (EPA 2)  '
                           HW-GP-105
                            (EPA 1)
                                 A
                                A
                                    A
              Fence
                                                Truck Scale
                                         Building 406
                           Concrete

                             Pad
                                                                         Gate
Figure A-l. Locations of Ptocess Wells and Sampling Boreholes at the LLNL Site


The  maximum total concentration of benzene, toluene, ethylbenzene, and xylenes (BTEX)

recorded in the unsaturated zone before  treatment was 4,800 ppm. The volume of soil with

contamination in excess of one ppm of BTEX existed in an approximate cylinder,  60 feet in

diameter, extending down to almost 135 feet.
                                         98

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 Tables A-l and A-2 present the results for the soil samples collected and analyzed by the EPA
 SITE Program after treatment with steam and electrical heating was completed. Soil  samples
 from borehole #105 showed BTEX and Total Petroleum Hydrocarbons  (TPH) contamination
 below the water table (100 feet). This borehole was located near the original spill point.
 Additional contamination was  removed by vapor extraction after this sampling episode. Soil
 samples from borehole #106 had non-detectable values for BTEX and TPH. This borehole was
 located further from the original spill point.

 The following document,  "Summary of the LLNL  Gasoline Spill Demonstration—Dynamic
 Underground Stripping Project" presents the LLNL results of the study. These results  indicate
 that Dynamic Underground  Stripping was very effective in removing gasoline contamination
 from groundwater and soil in the test zone. As indicated by the EPA SITE Program data above,
 this report shows that the process mobilized the contamination toward the center of the  test site
 and significantly reduced the concentrations of contaminants overall.

 There were several reasons  why Dynamic Underground  Stripping was more  successful than
 SERP: the contamination had more  volatile components, LLNL enhanced the treatment with
electrical heating, LLNL used improved operational procedures, and LLNL used more effective
monitoring of the steam zone for operational control.
                                         99

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  Table A-l. POST-TREATMENT ANALYTICAL RESULTS FOR BOREHOLE #105
Depth (ft)
76.25
82.00
84.25
91.75
96.10
101.55
104.65
109.35
112.05
116.95
122.30
125.30
130.75
135.00
TPH (mg/kg)
ND
ND
ND
ND
ND
ND
ND
21
120
1,400
23
9
ND
ND
Benzene
(mg/kg)
ND
ND
ND
ND
ND
ND
ND
0.8
2.8
13
1.4
0.27
ND
ND
Toluene
(mg/kg)
ND
ND
ND
ND
ND
ND
ND
2.9
12
81
4.2
0.92
0.015
ND
Ethylbenzene
(njg/kg)
ND
ND
ND
ND
ND
ND
ND
0.34
2.3
24
ND
0.18
ND
ND
Xylenes
(mg/kg)
ND
ND
NDX
NDX
NDX
NDX
NDX
2.3X
13X
140X
3.2X
0.91X
0.014X
0.028X
ND - Not detected at or above detection limit.
Detection Limits: TPH-1.0 mg/kg; Benzene-0.0005 mg/kg; Toluene-0.0005 mg/kg; Ethylbenzene-0.0005 mg/kg; Xylenes-0.0010 mg/kg.
X - Estimated value; Continuing calibration values for xylenes failed QC criteria.


  Table A-2. POST-TREATMENT ANALYTICAL RESULTS FOR BOREHOLE #106
Depth (ft)
76.25
81.75
87.30
93.85
95.85
100.25
103.80
106.75
109.35
115.35
128.80
130.75
135.00
TPH (mg/kg)
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
Benzene
(mg/kg)
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
Toluene
(mg/kg)
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
Ethylbenzene
(mg/kg)
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
Xylenes
(mg/kg)
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND - Not detected at or above detection limit.
Detection Limits: TPH-1.0 mg/kg; Benzene-0.0005 mg/kg; Toluene-0.0005 mg/kg; Ethylbenzene-0.0005 mg/kg; Xylenes-0.0010 mg/kg.
X - Estimated value; Continuing calibration values for xylenes failed QC criteria.
                                              100

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                                                                               UCRL-ID-120416
                     Summary of the LLNL Gasoline Spill Demonstration-
                             Dynamic Underground Stripping Project
                                      R. L. Newmark and R. D. Aines
                                                April 3,1995
This is an informal report intended primarily for internal or limited external
distribution. The opinions and conclusions stated are those of the author and may
or may not be those of the Laboratory.
Work performed under the auspices of the U.S. Department of Energy by the
Lawrence Livermore National Laboratory under Contract W-7405-Eng-48.

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                                               DISCLAIMER

This document was prepared as; an account of work sponsored by an agency of the United States Government. Neither
the United States Government nor the University of California nor any of their employees, makes any warranty, express
or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any
information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned
rights. Reference herein to any specific commercial product,  process, or service by  trade name, trademark,
manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by
the United States Government or the University of California. The views and opinions of authors expressed herein do
not necessarily state or reflect those of the United States Government or the University of California, and shall not be
used for advertising or product endorsement purposes.


                                       This report has been reproduced
                                    directly from the best available copy.

                               Available to DOE and DOE contractors from the
                                 Office of Scientific and Technical Information
                                      P.O. Box 62, Oak Ridge, TN 37831
                               Prices available from (615) 576-8401, FTS 626-8401

                                       Available to the public from the
                                    National Technical Information Service
                                       VS. Department of Commerce
                                            5285 Port Royal RcL,
                                           Springfield, VA 22161

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Li
Lawrence Livermore
National Laboratory
 University of California
Berkeley Environmental
Restoration Center
         Summary of the LLNL Gasoline Spill Demonstration
                Dynamic Underground Stripping Project
                       R. L. Newmark and R. D. Aines
                    Environmental Technologies Program
                             UCRL-ID-120416

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                                            Preface

     This report summarizes the four volumes of Dynamic Underground Stripping Project: LLNL Gasoline Spill
 Demonstration Report (Newmark, 1994a), which compiles the final reports for all the component activities of
 the Dynamic Underground Stripping demonstration at the LLNL gasoline spill site. The demonstration
 and cleanup efforts at that site from 1992 to early 1994 were funded jointly by the Department of Energy's
 Office of Technology Development and Office of Environmental Restoration. The full report combines
 those efforts into sections that reflect the major technical aspects of the project: Summary, Characterization,
 Operations, Monitoring, Predictive Modeling, and the Accelerated Removal and Validation (ARV) Project.'

     The Dynamic Underground Stripping demonstration at the LLNL gasoline spill site was extremely
 successful, and all of the project goals were met or exceeded. All aspects of this project reflect the inte-
 gration of complementary technologies and process engineering. Some applications are obvious, such  as
 the use of electrical heating and  steam injection to heat the whole range of soil types.  Others are not so
 obvious, such as the need to electrically isolate diagnostic and monitoring systems from the tremendous
 currents intentionally applied to the ground. The technical challenges in merely fielding these methods
 in a safe and effective manner at an operating industrial site were great. Safety in operation was a prime
 design parameter; our excellent safety record is one of the most satisfying accomplishments of this pro-
 ject. The combined achievements are greater  than the sum of each individual component; this satisfies
 the requirements of true integration of method and application.
                                    Acknowledgments

    The full report, like the demonstration project itself, represents collaboration among investigators
 from many organizations, both between LLNL and other agencies and between organizations within
 LLNL. In particular, we acknowledge the contributions of Professor Kent Udell and the team members
 from the Environmental Restoration Center of the University of California at Berkeley, and the close col-
 laboration between these individuals and LLNL researchers. The success of this project was largely due
 to the unique field-scale collaboration that utilized the complementary interests and research abilities of
 University and Laboratory researchers.

    The successful demonstration of Dynamic Underground Stripping at the LLNL gasoline spill site
 was made possible through the combined efforts of a great many people, with a broad range of exper-
 tise. We acknowledge the efforts of the mechanical and environmental technicians, procurement, con-
 struction and plant engineering personnel, and other staff without whose contributions (often in difficult
 conditions and inclement weather) this project would not have been possible. Students from the
 Environmental Center at University of California-Berkeley also provided essential support.

    We gratefully acknowledge the support of the U.S. Department of Energy's Office of Environmental
 Management for this demonstration. The demonstration of innovative technologies requires that both
 experimental and compliance-driven cleanup operations needs be addressed. The efforts of the U.S.
 Department of Energy's representatives to reconcile often conflicting requirements made this project
 possible. In particular, we acknowledge the efforts of Clyde Frank, Pat Whitfield, Tom Crandall, Tom
 Anderson, Katie Hain, John Mathur, Kathy Angleberger, John Lehr, J. T Davis, Richard Scott, Mike
 Brown and Bill Holman. Over its three-year history, this project utilized the resources of mariy, if not
 most, of the organizations at LLNL. In particular, we acknowledge the support of Jesse Yow, John
 Ziagos, Lee Younker, Bob Schock, J. I. Davis, Ann Heywood, Jay C. Davis, Alan Levy, Walt Sooy, Dennis
 Fisher, Harry Galles, Jens Mahler, and Bill McConachie.

    This work was performed under the auspices of the U.S. Department of Energy by Lawrence
Livermore National Laboratory under contract W-7405-Eng-48. The UC-Berkeley effort was  funded in
part by the National Insrutue of Environmental Health Sciences under grant 3P42E504705.0251.
                                               1 11

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    The following is a list of contributing authors and their organizational affiliations.

                               Lawrence Livermore National Laboratory

    Earth Sciences Division, Environmental Programs Directorate,-Lawrence Livermore National Laboratory,
Livermore, CA 94550
        Roger D. Aines
        O. Sierra Boyd
        Charles R. Carrigan
        Kevin C. Knauss
        Kenrick H. Lee
        Robin L. Newmark
        John J. Nitao
        Abelardo L.  Ramirez
        Jerry J. Sweeney

    Defense Sciences Engineering Division, Electronics Engineering Department, Engineering Directorate,
Lawrence Livermore National Laboratory, Livermore, CA 94550
        Maurice A. Hernandez
        Ray M. McNairy

    Engineering Research Division of Electronics Engineering Department, Lawrence Livermore National
Laboratory, Livermore, CA 94550
        Jane Beatty
        H. Michael Buettner
        William Daily
        Michael Wilt

    Environmental Restoration Division, Environmental Protection Department, Lawrence Livermore National
Laboratory, Livermore, CA 94550
        Dorothy J. Bishop
        Kenneth L. Carroll
        C. Suzanne Chamberlain
        Alan B. Copeland
        Michael J. Dibley
        Paula  Krauter
        J.  C. Nelson-Lee
        Maureen N. Ridley

    Health and Ecological Assessment Division, Environmental Programs Directorate, Lawrence Livermore
National Laboratory, Livermore, CA 94550
        Marina C. Jovanovich
        Thomas J. Kulp
        Kevin C. Langry
        Roger E. Martinelli

    Isotope Sciences Division, Chemistry and Material Sciences Directorate, Lawrence Livermore National
Laboratory, Livermore, CA 94550
        G. Bryant Hudson

    New Technologies Engineering Division, Mechanical Engineering Department, Lawrence Livermore National
Laboratory, Livermore, CA 94550
        William H. Siegel
                                                 IV

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    Nuclear Test Engineering Division, Mechanical Engineering Department, Lawrence Livermore National
Laboratory, Livermore, CA 94550
        John Carbine

    Technical Support and Policy Development Division, Hazards Control Department, Lawrence Livermore
National Laboratory, Livermore, CA 94550
        James Martin
                                  University of California at Berkeley

    Department of Mechanical Engineering, University of California at Berkeley, 6165 Etcheverry Hall, Berkeley,
CA 94720
        Ron Goldman
        Kent M. Kenneally
        Kent S. Udell

    Materials Science and Mineral Engineering Department, University of California at Berkeley, Berkeley, CA
94720
        A. E. Adenekan
        T. W. Patzek
                                    Oak Ridge National Laboratory

    Health Sciences Research Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6113
       Tye E. Barber
       Walter G. Fisher
       Eric A. Wachter
                                           Weiss Associates
    Weiss Associates, Inc., Emeryville, CA
       Charles Noyes
       Everett A. Sorensen
                                       Infraseismic Systems, Inc.

   Infraseismic Systems, Inc., 4630 Eastern Drive Suite 5, Bakersfield, CA 93309
       Roger J. Hunter
       Richard F. Reinke

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                                         Contents
Preface 	
                          	  111
Acknowledgments	       —
Introduction 	    1
  Results of First Full-Scale Test	       3.
  Based on Three Technologies	       2
    Steam Injection	        2
    Electrical Heating	          ^
    Underground Imaging	         ^
The LLNL Gasoline Spill Site	"."!!!!"Z"Z.".".'.'."!!  6
Cleanup Operations	          9
  Goals of the Experiment	       9
  Experimental Operations	        9
Cleanup Results	       26
  Free-Product Removal	           26
  Ground-water Cleanup	         27
  Ongoing Bioremediation	      33
Conclusions from the Gasoline Spill Site Demonstration	 34
References	      34
                                            VI l

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  Summary of the LLNL Gasoline Spill Demonstration—
              Dynamic Underground  Stripping Project
                                      Introduction
     Underground spills of volatile hydrocarbons
 (solvents or fuels) can be difficult to clean up
 when the hydrocarbons are present both above
 and below the water table and are found in rela-
 tively impermeable clays (Figure 1).  Years of
 ground water pumping may not completely
 remove the contamination. Researchers at
 Lawrence Livermore National Laboratory (LLNL)
 and the College of Engineering at the University
 of California at Berkeley (UCB) have collaborated
 to develop a technique called Dynamic Under-
 ground Stripping to remove localized under-
 ground spills in a relatively short time. The U.S.
 Department of Energy's Office of Environmental
 Restoration and Waste Management has spon-
 sored a full-scale demonstration of this technique
 at the LLNL gasoline spill site.
    Although it has been known for years that
 accumulations of separate-phase organics repre-
 sent the most serious cause of groundwater pollu-
 tion (National Research Council, 1994; MacDonald
 and Kavanaugh, 1994), their very low solubility
 in water has made them very hard to remove by
 the classic method of pumping out groundwater
 and treating it at the surface. Similarly the prin-
 cipal natural mechanism for groundwater restora-
 tion, biological metabolism of the contaminant,
 usually will not work in very concentrated conta-
 minant because of the toxic nature of the organic.
 (Bacteria typically metabolize organics dissolved
 in water, not free organic liquids.)
    When highly concentrated contamination is
 found above the standing water table, vacuum
 extraction has been very effective at both remov-
 ing the contaminant and enhancing biological
 remediation through the addition of oxygen.
 Below the water table, however, these advantages
 cannot be obtained. For such sites where the con-
 tamination is too deep for excavation, there are
 currently no widely applicable cleanup methods.
    Dynamic Underground Stripping removes
 separate-phase organic contaminants below the
 water table by heating the subsurface above the
boiling point of water, and then removing both
contaminant and water by vacuum extraction.
The high temperatures both convert the organic
 to vapor and enhance other removal paths by
 increasing diffusion and eliminating sorption.
 Because this method uses rapid, high-energy
 techniques in cleaning the soil, it requires an inte-
 grated system of underground monitoring and
 imaging methods to control and evaluate the
 process in real time.
 Results of First Full-Scale Test

    We conducted the initial testing of the
 combined thermal and monitoring/imaging
 methods of Dynamic Underground Stripping
 at the site of a gasoline spill at the Lawrence
 Livermore National Laboratory. This site was
 chosen because several thousand gallons of gaso-
 line were trapped up to 30 feet below the water
 table (Figure 2), mimicking the behavior of heavy
 solvents such as trichloroethylene (TCE).
    This first full-scale test of Dynamic
 Underground Stripping at the LLNL  gasoline site
 was extremely successful. Results completed in
 December 1993 indicate that the process is more
 than 60 times as effective as the conventional
 pump-and-treat process now being used at 300
 designated Superfund Sites to treat contamination
 below the water table, and is 15 times as effective
 as vacuum extraction in the vadose zone (above
 the water table) (Figure 3). The LLNL site was
 previously under treatment by vacuum extraction
 from a central extraction well (Nicholls et al.,
 1988; Thorpe et al., 1990; Cook et al., 1991).
 From August 1988 to December 1991, more than
 1900 gallons of gasoline were removed from the
 vadose zone. However, the extraction rate had
 dropped to about 2 gallons per day by 1991. No
 large groundwater removal actions were under-
 taken at that point; but because of the low solu-
bility of gasoline in water (about 10,000-ppb total
hydrocarbons were observed in the groundwa-
ter), a pumping rate of 50 gallons/minute would
have only removed about 0.5 gallon of gasoline
per day To continue the cleanup, the vacuum
venting operation was halted, and replaced by
the Dynamic Underground Stripping  technique.

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            Leaking
                  fuel
                 tank
                                                       Fuel trapped
                                                       in  silty layer
Figure 1. A plume of organic liquid forming beneath a leaking underground storage tank.  This behavior is typ-
ical of a heavy organic solvent such as trichloroethylene (TCE). Some of the liquid may be trapped in layers of
low-permeability soil above the water table. The remainder will form a pool below the water table, as shown
here. Lighter contaminants such as gasoline can be trapped below water by movement of the water table.
    During the 21 weeks of operation over the
course of one year, Dynamic Underground
Stripping removed more than 7600 gallons of
gasoline trapped in soil (significantly more than
the 6200 gallons estimated to be present), both
above and below the water table, with separate-
phase contamination extending to >120 ft deep.
The maximum removal rate was 250 gallons of
gasoline a day. The process was limited only by
the ability to treat the contaminated substance
at the surface. Actual field experience  indicates
that the process costs $60-$70 a cubic yard.
Approximately 100,000 yd3 were cleaned.
Based on Three Technologies

    Dynamic Underground Stripping relies on
three integrated technologies; steam injection,
electrical heating, and underground imaging
(Figure 4).

Steam Injection
    Steam is pumped into injection wells, heating
the contaminated earth to 100°C. Steam drives
contaminated water toward the extraction wells
where it is pumped to the surface. When the
steam front encounters contamination, volatile
organic compounds are distilled from the hot
soil and are moved to the steam/ground water
interface, where they condense. Vacuum extrac-
tion after full steaming of the contaminated zone
continues to remove residual contaminants.  The
steam injection/vacuum  extraction technique was
developed at UCB (Udell and Stewart, 1989, 1990;
Udell et al., 1991; UdeU, 1994d).  The steam system
and operational design used here are described
in Siegel (1994) and Udell (1994c).  Predictive

-------
   160
              1-10 ppm
              10-100ppm
              100-1,000  ppm
              >1,000 ppm
Upper steam zone
Lower steam zone
Water table

Screened interval

Sample point
20
                                                        0
                                                         0     10
                                                        Scale : Feet
Figure 2. Cross section showing an approximation of the gasoline contamination at the treatment site before Dynamic Underground Stripping
began. The darker areas represent higher concentrations; the darkest indicates free-product gasoline. The dashed line denotes the level of the
water table. (From Bishop et al., 1994).

-------
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-------
                                               i- Steam
                                              /  injection
                                             {S^t
  Typical pattern
                       Y Vacuum
                        \extraction
                                           Tomography monitors steam movement
                               Vacuum
                               removes
                               vapor
 Condensate
sweeps waste
Tomography images
    cleaned areas
     Water
     table
                            ^	    Well to well stripping -1 to 3 months   	^
                                                           60 to 100 feet

Figure 4. The Dynamic Underground Stripping process. Steam drives contaminated groundwater toward extraction wells and then heats the soil to distill
organics. Electrical heating dries and distills impermeable clays that the steam cannot readily penetrate.  Geophysical techniques monitor the process.
The process operates both above and below the water table (dashed line) and is particularly economically attractive for free-product removal (solid green).

-------
calculations of the operational characteristics and
recovery efficiency of steam injection as applied
at the LLNL gasoline spill site are given by Udell
(1994b), Kenneally (1994), Adenekan and Patzek
(1994), and Lee (1994).

Electrical Heating
    This technique heats clay and fine-grained
sediments and causes water and contaminants
trapped within the soils to vaporize and be forced
into the steam-swept zones, where vacuum
extraction removes them. Electrical heating is
ideally suited for tight, clay-rich soil and/or near-
surface (less than 20 feet) cleanups. It is an effec-
tive complement to steam injection, because it
cleans the thick, less permeable zones that the
steam does not penetrate well.
    Electrical heating has been used in a number
of configurations in enhanced petroleum recovery
(e.g., Chute et al, 1987; Chute and. Vermeulen,
1988); the three-phase system used here was
designed at LLNL (Buettner and Daily, 1994a;
McGee et al., 1994). Details of the electrical
heating construction  and  operational design used
here are given by Siegel (1994), arid the results of
the preheat phase are found in Buettner and
Daily (1994b).  Our predictive and diagnostic
modeling capability for electrical heating is pre-
sented by Carrigan and Nitao (1994). Sweeney
et al. (1994) give details of the post-steam electrical
heating process conducted during this experiment

Underground Imaging
    To monitor the Dynamic Underground Strip-
ping process, we used geophysical imaging meth-
ods to map the boundary between the heated
zones and the cooler surrounding areas. Electrical
resistance tomography (ERT) has proven to be the
best imaging technique for near-real-time images
of the heated zones (Newmark, 1992, 1994c;
Ramirez et al., 1993; Vaughn et al., 1993).  This
technique is necessary for controlling the thermal
process and for monitoring the water movement.
Details of the use of ERT at the gasoline spill site
are given by Newmark (1994b), and Ramirez et
al. (1994). Tiltmeters provided additional infor-
mation regarding the shape of the steamed zone
(Hunter and Reinke, 1994),  while detailed temper-
ature and geophysical logs  provided extremely
accurate assessments of the degree of penetration
and the complex heating of the numerous hetero-
geneous formation layers (Newmark, 1994b;
Goldman and Udell, 1994; Boyd  et al., 1994).
                            The LLNL Gasoline Spill Site
    We conducted an experimental application of
the Dynamic Underground Stripping technique
during 1993 at the LLNL gasoline spill site. This
is the former site of the Laboratory's filling sta-
tion; fueling operations at this location date back
to the 1940s, when the LLNL site was a U.S.
Naval air station.  It is located in the center of an
industrial area—the Laboratory's shipping and
receiving yard.  A county road runs along the
south side,  and major underground utility lines
run through the site.
    Previous characterization results were com-
bined with  an extensive set of measurements
taken during the installation of 22. process and
monitoring boreholes at the site. Details of the
site characterization are given in Bishop et al.
(1994). This characterization showed that an
estimated 6200 gallons of gasoline  were present
within our  target treatment area (both above
and below the water table) (Figure 2). Gasoline
was trapped up to 30 ft below the water table
because of a rise in the water table after the spill
occurred, with the gasoline held below water by
capillary forces in the soil.  The soils at the site are
alluvial, ranging from very fine silt/clay layers to
extremely coarse gravels, with unit permeabilities
ranging over several orders of magnitude. There
are two principal permeable zones, one above
and one below the water table, which is located at
100 ft. In between the permeable zones, straddling
the water table, is a 10-15-ft-thick silty/clay layer
of low permeability, which was also heavily cont-
aminated (Nelson-Lee, 1994).
   The targeted volume was intended to include
all of the free-phase gasoline at the site, and was a
distorted cylinder about 120 ft in diameter and 80 ft
high, extending from a depth of 60 ft to a depth of
140 ft (Figure 5).  Later results indicated that two
small areas of gasoline probably  existed outside
the treatment area, possibly from separate spills.
   Six steam injection/electric-heating wells
were placed to surround the free product in an
irregular circle determined by the shape of the
free product; three additional electric heating
wells were placed near the center of the spill.
These were not part of the original design, but

-------
Figure 5. Aerial view of the LLNL gasoline spill area, showing regions of known or suspected free-product gasoline contamination (circled). The area is
within the LLNL shipping and receiving yard. East Avenue, a county road, is seen on the south edge of the photograph. Injection wells were sited to
encircle the central plume of free product to ensure that the gasoline would be moved toward the extraction well cluster at the center.

-------
were required when the free-product zone was
discovered to be larger than anticipated during
the drilling of the injection wells.  Each injection
well was initially center-punched  with a small-
diameter hole for characterization. The discovery
of unexpected free product in two of them had
minimal impact; the holes were completed as
monitoring locations, and new injection wells
were drilled farther from the spill center.  We
placed eleven monitoring/imaging wells within
and outside the target area to provide control of
the heating processes (Figure 6).
N
• TEPS •
Perimeter Fence -»
• TEP4 <•> \ *

Well Legend
• Monitcring/Imaging Well
• Steam Injection Well
•f Electrical Heating Well
A Extraction Well
x Soil Sample Well
O Water Monitoring Well
 Tiltmeter
OGSW-208
* <•> 1 \ | v-'TEPe*
GIW-818B\ y
TEP-CP-106, \GS^80T \
XX \GEW-710 \ BGIW-820
/ +HW\ \ +HW1
'.TEP9 \ x-SSSSJrf
HW-OP-105 X ^( TEp 10 1^ Liquid Phase
. »r * \ Gasoline
OW-819B/ GEW-808A "GSW-1S l Q ®|
• TEP80:'» ^GSW-16 \ GSW-T1
HW-GP-104 X A i GSB-2 \GIW-«15B
1 GEW -«16 \^ Q •
^ C5W-« O V csz_4 GSW-IA 1
• TFP'J \ TEP 8 M x -tHW3 OGSW-2
" A *-^ -' • * ^V _ -rr-p 7
0 . TEP-GP-103 \ «lhi 7 GSW 216
 
OGSW-*

Scale
Metere 10 20 30
ill 1
1 1 1 1 | 1 1 1 |
Feet 50 100
GSW-7O
<•>
 Figure 6. Map of the LLNL gasoline spill site, showing the location of wells referred to in this summary.
 The location of cross section B-B' (Figure 2) is shown. (Not all pre-Dynamic Underground Stripping well
 and boring locations are shown.) This map shows a slightly larger area than Figure 5.

-------
                                  Cleanup Operations
Goals of the Experiment

    Dynamic Underground Stripping was origi-
nally designed for the removal of separate-phase
organic liquids from highly contaminated areas
both above and particularly below the water
table. The goals of the first application of the
method were:
    1. To determine the effectiveness of the
process in removing free product.
    2. To evaluate the effectiveness of the moni-
toring methods for controlling heat input and
mapping heated zones.
    3. To examine whether any deleterious effects
(such as dispersal of contaminant) might occur.
    4. To demonstrate the necessary engineering
and operational practices required for effective
and safe operation of this high-energy technique.
    All goals were met and the site and process
were turned over to the Laboratory's site remedi-
ation team (funded by DOE's EM 40) for final site
cleanup (Sweeney et al., 1994).
Experimental Operations

    Operations at the site were conducted in four
distinct phases:
(1) Electric Preheating: November and December
1992
(2) First Steam Pass: February 1993
(3) Second Steam Pass: May-July 1993 (drill-back
characterization followed)
(4) Polishing Operations (accelerated removal
and validation): October-December 1993
Table 1 summarizes the project history.
    The electrical preheat of the site began in
November 1992, before the treatment facility was
completed. No extraction data are therefore
available from this phase. The electrical preheat
phase is described in detail by Buettner and Daily
(1994b). The 1-MW electrical system operated at
a maximum power output of about 800 kW. The
chief monitoring methods used during the electri-
cal preheating were temperature' measurements
and ERT. Temperatures were measured using
both fixed thermocouples in individual boreholes
and, for continuous logs, an infrared-sensor sys-
tem in the 11 2-in.-diameter fiberglass monitoring/
imaging wells (Newmark, 1994b; Goldman and
UdeU, 1994).
    The goal of an average 20°C temperature
rise in the clay zones was achieved; some of the
clay layers were heated to a maximum of 70 °C
(Figure 7). The effects of this phase on the
extraction of gasoline were not tested, but several
of the groundwater monitoring wells on the site
showed increases in the concentration of gasoline
components, indicating that free-phase gasoline
was being mobilized in the vicinity (Figure 8).
Gasoline concentrations in these wells had been
decreasing previously, apparently due to local-
ized bioremediation or venting resulting from the
increased air circulation to the borehole area.
    Steam injection began in early February 1993
into the lower of two steam zones (permeable
layers) using a 24,000 Ib/hr (50 gallons water/
minute, energy approximately 8 MW) natural-
gas-fired, skid-mounted boiler (Figure 9). Siegel
(1994) describes the steam operations in detail.
Steam injection rapidly heated the permeable
zones to above the boiling point of water, and ini-
tial steam breakthrough to the extraction wells
occurred in 12 days (Figure 10). During  the first
steam pass, it was learned that, although a bank
of cold, free-product gasoline may precede the
steam front to the extraction wells, it contains
only a small fraction of the recovered gasoline
(Jovanovich et al., 1994; Aines et al., 1994)
(Figure 11). None of the 1700 gallons recovered
during the first steam pass could unambiguously
be associated with the liquid front ahead of  the
steam. The great majority of the gasoline came
out after a steam zone was fully established, and
the extraction continued without further steam
injection. The reduced vapor pressure forces
residual pore fluids and contaminants to boil.
At this point, the forced boiling generated large
amounts of water and  gasoline in the vapor
stream, and our potential removal rates greatly
exceeded our dual-bed activated-carbon  trailer's
design limit of about 25 gallons/day. During the
planned shutdown following the first steam pass,
the vapor treatment system was redesigned to
increase capacity (Sorensen and Siegel, 1994).
    The monitoring and imaging systems utilized
at the gasoline  spill site provided excellent control
of the steam injection process (Newmark, 1994b;
Goldman and UdeU, 1994; Ramirez et al., 1994;
Boyd et al., 1994). Initial steam breakthrough to
the extraction wells occurred in only 12 days;
each subsequent breakthrough occurred  sooner as

-------
Table 1.  Project history of the Dynamic Underground Stripping project LLNL gasoline spill site cleanup.
        Phase
  Dates
Objectives
Accomplishments
 Vacuum Extraction,
 Vadose Zone
 EM 40 Operations
9/88 to     > Extract vadose gasoline
12/91          contamination.
           > Evaluate extraction
               effectiveness.
                    > Pilot Test permitting received.
                    > 2000 gallons removed
                    > Biological activity confirmed
 Clean Site
 Engineering Test


 EM 50
2/91 to     > Demonstrate
9/91           establishment of steam
               zone below water table.
           > Evaluate and optimize
               monitoring, imaging
               systems.
           > Optimize resistance
               heating electrode
               design.
           > Evaluate personnel and
               environmental safety.
                    > 10,000 yd-3 steam zone
                        established below water table
                        with no steam rise.
                    > ERT, thermal logging, and
                        tiltmeters demonstrated, chosen
                        for gas pad use.
                    > Individual electrode capacity
                        raised from 20 kW to 200 kW.
                    > Safe procedures established  for
                        personnel; no detrimental
                        environmental effects  .
 Electrical Pre-Heat


 EM50 operations,
 EM 40 Treatment
 Facility F
 construction
11/92 to    > Raise temperature of
1/93           clay/silt layers 20°C so
               conductivity always
               above steam-
               temperature gravel
               zones.
           > Test electrical safety at
               high current in
               industrial area.
           > Optimize electrical
               heating methods.
                    > Clay pre-heating accomplished.
                    > Maximum heating to 70°C in
                        clay layer.
                    > Safety measures and procedures
                        adequate.
                    > 850 kW continuous power
                        achieved.
                    > Nighttime operations with
                        daylight  construction of
                        treatment facility.
 1st Steam Pass


 Joint EM40/EM50
 operations
2/93 to    > Heat target zones to steam
3/93           temperature.
          > Optimize
               monitoring/control
               methods.
          > Evaluate treatment
               procedures and facility.
          > Quantify possible
               deleterious effects
               (such as contaminant
               spreading).
          > Demonstrate safe
               handling of steam and
               hot gasoline effluent.
                   > Upper and Lower steam zones
                        heated to boiling point.
                   > ERT established as control system
                        with 12 hr turnaround on 10
                        planes/day.
                   > Non-contact thermal logger
                        demonstrated with no
                        hysteresis, 100°C/2 ft
                        gradients.
                   > Gasoline found to be mainly
                        recovered in vapor phase,
                        greatly exceeding capacity. No
                        liquid  phase free-product
                        recovered.
                   > No spreading of contaminant to
                        outer monitoring wells/
                   > Safe handling of steam and hot
                        gasoline.
                   > 1700 gallons gasoline removed.
                                            10

-------
Table 1.  (Continued.)
 2nd Steam Pass


 Joint EM40/EM50
 operations
5/93 to    > Operate re-designed vapor
7/93           treatment system witn
               lOx capacity of first
               pass.
           > Optimize
               steaming/recovery
               technique to maximize
               vacuum recovery.
           > Heat zones which were
               insufficiently heated in
               first pass.
           > Accurately measure
               gasoline flux in vapor
               and condensate paths,
               reduce  uncertainty in
               total recovery rate,
               continuously monitor
               gasoline flux.
                            > 100,000 yd3 heated to boiling
                                point.
                            > Recovery rates in excess of 250
                                gal/day achieved.
                            > Tiltmeters used for imaging of
                                horizontal extent of steam
                                zones from individual wells.
                            > Most cool zones from 1st pass
                                fully heated to steam
                                temperature (one "cold spot"
                                remained at SO°C).
                            > Fluxes measured to ± 10 %
                                accuracy, continuous
                                monitoring systems
                                demonstrated.
                            > 4600 gallons gasoline removed.
 Post-Test Drill-Back
 Characterization
 EM 50
7/93 to     > Measure soil
9/93           concentration changes
               along six-hole cross-
               section
           > Ascertain from soil
               concentrations whether
               spreading had occurred
               (outside original
               contamination)
           > Evaluate process
               effectiveness.
           > Examine possible changes
               to soil.
           > Examine effects on
               existing  microbial
               gasoline-degrading
               ecosystem.
                           > Soil concentrations reduced
                               dramatically.
                           > No spreading of contaminant;
                               only inward motion seen.
                           > Vadose zone completely clean
                               ( Saturated zone contaminant
                               remained around extraction
                               cluster only.
                           > No significant soil changes.
                           > Active microbial ecosystems at all
                               locations and soil temperatures
                               up to 90°C, makeup varies by
                               soil temperature.
 Accelerated
 Recovery and
 Validation (ARV)


 EM 40 Operations
10/93 to
1/94
> Remove remaining free
    product, especially in
    cool zone.
> Make use of existing heat
    and high extraction
    rates to continue
    removal.
> Electrically heat clay/silt
    zones to enhance
    removal.
> Test sparging, injection
    well extraction.
> Remaining free-product gasoline
    removed (1000 gallons).
> Ground water concentrations of 5
    of 6 regulated compounds
    reduced to MCL.
> Benzene down to 100 ppb in
    ground water.
> Sparging monitored with noble -
    gas tracers.
> Electrical heating maintained site
    soil temperatures during
    extraction.
                                             11

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                                 Well TEP- 007
               0      20
                    Temperature (C)

                    40      60     80     100   120  Lithology
           40..
           50  -I-
Electrical Heating
(1/11/93)


First Steam Pass
(3/11/93)
                                                          Second  Steam Pass
                                                                (6/28/93)
                                                          xxxxxxx>
                                                          xxxxxxx>
                                                          XXXXXXX
                                                          XXXXXXX
                                                          xxxxxxx>
                                                          XXXXXXX'
                                                          XXXXXXX'
Clay  *+
                                                                          Gravel
       Figure 7. Temperature logs from a monitoring well inside the ring of injection wells, along
       with the lithology. These logs show electrical heating of the clay-rich layers during the elec-
       trical preheat, steam passing through the most permeable layers during the first steam
       pass, and conductive heating of and later penetration by steam into less permeable layers
       during the second steam pass.  (From Newmark, 1994b).
the formation gained heat. This made the day-to-
day process monitoring critical in order to ensure
that the correct amount of steam was injected to
drive contaminant to the center without adding
excessive amounts of steam outside the pattern.
Each of the twelve injection ports (two  each in six
wells) would inject a different cimount of steam at
a given pressure, ranging from 600 Ib/hr to one
                                      well that would apparently have taken the entire
                                      output of the boiler had we so permitted. This
                                      range is expected in such a heterogeneous site,
                                      but it requires that the location and size of the
                                      steam zones be measured in situ, not merely cal-
                                      culated from injection volumes.
                                          Temperature measurements made both with
                                      fixed thermocouples in the field and with the
                                              12

-------
          200000
   c
   o
   CO
   o
   o
          150000
          100000
   o
   H
           50000
                 0
       After heating
                                      Before electrical heating
I
                                            GSW-006



                                            GSW-001A



                                            GEW-710
                                    Electrical

                                 / heating

                                    interval
                                      1/1/89     1/1/90     1/1/91  ^-1/1/92    1/1/93


                                               	Time
HMB/LLNL/ll-l-93


Figure 8. Chemical signatures of groundwater in monitoring wells in the central gasoline spill area. Before electrical heating, total fuel hydrocarbon

concentrations (TFH) were below 50,000 ppb and generally decreasing, most probably due to localized enhanced bioremediation in the vicinity of the

boreholes. After electrical heating, high TFH concentrations were found, indicating contact with free-product gasoline (Buettner and Daily, 1994b).

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Figure 9. Portable steam plant used for the Dynamic Underground Stripping demonstration at the LLNL gasoline spill area. The 24,000 -Ib/hr boiler is skid-mounted;
this particular unit was leased by the month. A steam injection/electrical heating well can be seen in the foreground.  Steam is distributed to the injection wells via
flexible rubber hoses.  The boiler is fired by natural gas and fed by Laboratory drinking water, both from Laboratory utility lines. An injection well is seen in the fore-
ground, with two injection lines (one for each steam zone). Steam is piped to the wells using flexible reinforced-rubber steam lines.

-------
                           10
                                 15
                Day* (1st Pats)
                       20
                                                          25
                                                                 30
                                                      35
                                                                                          40
   1004-
    80
60
 I
 «
    40  •
    20 -
              Calculated
              Boiling Point
         Pumped
         Water
         Temperature
                                                   Well 808 Vapor
                                                   Temperature
                                                      Temperature At
                                                      Recovery Wells
     2/3/93
           2/8/93
2/13/93
2/18/93
2/23/93
                                                         2/28/93
3/5/93
                                                                           3/10/93
                                             Date
Figure 10. Extraction well temperatures during the first steam pass. Steam breakthrough to the extraction
wells occurred about 12 days after steam injection began in the lower steam zone. Calculated boiling point
based on the vacuum applied to the well. (After Aines et al., 1994).
continuous temperature loggers showed a rapid
temperature rise in the more permeable zones
(Figures 6 and 12). The temperature logs
revealed thermal gradients of up to 100°C over
just a few feet depth during initial steam injec-
tion, and provided the most accurate measure-
ments of the vertical distribution of the steam at
the 11 locations (Newmark, 1994b; Kenneally,
1994).
    Between the wells, ERT proved to be a rapid
and accurate way to map steam progress at 1-2-m,
resolution, providing actual images of the heated
zones by comparing the electrical resistance dis-
tribution before heating to that afterwards
                                             (Ramirez et al., 1994) (Figure 13). Daily ERT
                                             images showed the vertical extent of the steam
                                             zones and the lateral movement between imaging
                                             wells. They revealed a number of areas where
                                             steam was moving vertically in the formation that
                                             were not detected by the temperature logs in
                                             individual wells. The total cycle time to obtain
                                             and process the data for each image was about
                                             an hour. This made ERT the principal control
                                             method, and decisions on steam injection rates
                                             made at the morning operations meetings were
                                             based principally on ERT images from the previ-
                                             ous day. Coupled with the temperature profiles
                                             from the continuous temperature loggers, steam
                                              15

-------
S.
                                                                                   total
                                                                                 carbon trailer
                                                                                liquid megaton-
                                                                               aqueous
        2/3/93
                                                                   3/10/93
Figure 11. Daily average gasoline recovery rates during the first steam pass. (From Udell, 1994a,c).
progression through the formation was seen to
occur in multiple horizontal pe:rmeable zones,
with significant vertical motion occurring in some
areas. The combined ERT/temperature 2-in.
fiberglass wells were placed to allow optimal
monitoring of the interior of the treated zone
(extending about 30 ft outside the ring defined by
the steam injection wells) and lower-resolution
monitoring of the surrounding area. Induction
logs run in the monitoring wells revealed the
changes in the electrical properties of the heated
soils in detail. These results were used to calcu-
late fluid saturation in the steamed zones (Boyd
et alv 1994) (Figure 14).
    An array of tiltmeters was installed near-
surface in a double ring surrounding the site to
monitor the lateral extent of the steam zone out-
side the treated area (Hunter and Reinke, 1994).
The array was used in two modes: passive  and
active.
    In the passive mode, tiltmeters measure the
small deformations in the ground surface that
result from a subsurface pressure transient  in
terms of tilt.  As the steam front moving in  the
subsurface approaches a tiltme ter, it produces a
pressure transient and causes the ground to
deform.  If the signal is sufficiently large, the tilt-
meter will detect the slight tilt resulting from that
pressure transient. Using this method, we
mapped the outer extent of the steamed region
during steam injection.
    In a more active mode, the tiltmeter array
was used to measure the slight deformation in the
ground surface resulting from a pressure tran-
sient induced into the steam zone by shutting off
an injection well for a fixed time. Maps of the
areal extent of the steam zone emanating from
each well could then be obtained, particularly for
the lower steam zone (located below the pre-
steam water table). This technique was extremely
effective in mapping the lateral spread of steam
and the development of any preferential steam
pathways.
   During the first steam pass, tiltmeters were
primarily relied upon to delineate the outer
extent of the steam front. We tested and validat-
ed the processing technique whereby the individ-
ual steam zones could be mapped during this
pass, where the subsurface monitoring network
of temperature measurements and ERT image
planes could provide ground truth.
   The second steam pass was begun after a
3-month hiatus to redesign the  effluent treatment
capacity, establish better analytical control on the
effluent stream based on our new knowledge of
the comparative flows in vapor and water, and
evaluate the cost-effectiveness of the process.  In
this pass, we optimized the amount of time the
formation was kept under vacuum (no steam
injection) and greatly increased the extraction
rate, hitting a contaminant recovery peak of more
than 250 gallons/day and routinely removing
more than 100 gallons/day (Figures 15 and 3).
   The focus of the various monitoring activities
was somewhat different during this pass, where
steam was being injected into previously heated
soil.  Although the ERT images continued to pro-
vide valuable information, interpretation was
                                               16

-------
    CJ
     CD
       120
       TOO
         80
         60
     Q.
     E
     0)
         20
          0
                        First Steam Pass
                                          Second Steam Pass
                                                                  ARV Phase
                                      Ground water pumping
  " Electrical Preheat
                                                                 Electrical Heating
       O   ^r*   ""C*

     >Jy    eP    ^»


-50      0     50
                                                                        V 
-------
                                                 TEP8
                                                                    TEP9
00
                            silts & clays

                            inter bedded
                            sands, silts
                            fit gravels
                            silts & clays
                            permeable
                            sands,
                            silts & clays
              Absolute Image
            Resistivity {log ohm rn)
                                                                                                                             \
                                                                       Iniectlon wells
                                                                                                            1.7
                                  ft    m
                                           TEP8
                                                    Day 1
Day 2
Day 4
Day 12
                                                                                                                      uay  ID
Day 36
                                                                                                                                                  TEP9
                                                                             Resistivity change (ohm m)
                                                                   -30.0
         Figure 13. Electrical Resistance Tomography (ERT) images. Top: ERT absolute images reveal the continuity of soil units across image planes. The resistive units correspond to the more
         permeable sand and gravel zones; the conductive units correspond to the clay-rich intervals. (The apparent pinching-out of units in the center of the image is due to the increase in resolu-
         tion radius toward the center of each image). Bottom: ERT difference images show the progress of the steam fronts across the image plane, starting from the first day of steam injection.
         This image plane (between wells TEP 8 and TEF 9) is  located approximately 6 m from the nearest injection well, and is oriented nearly perpendicular to a line linking it and the extraction
         wells.  Small decreases in electrical resistivity are observed within hours of the start of steam injection. Although steam was initially injected into only the lower steam zone (centered at
         about  35-in depth), steam leaked into the upper steam zone (centered at about 25-ni depth) through the well completion in the nearby injection weil; this is evidenced by the resistivity
         decreases in both zones in these images. By the end of the first steam pass (Day 36), both the upper and lower steam zones were at or near steam temperature, with conductive heating
         occurring in the neighboring day-rail units.  The preferential steam paths closely follow the more resistive units seen in the absolute images. (Frout Newuiark, 1994b).

-------
         o  ••
   •s
   Q.
   &
        10
        15 •
        20
        25'
        30'
        35  '
        40-
       45 '
               Lithology
W////.
               XXXXXXXXXXXX*.
               XXXXXNXXXXXX>
               N\\\\\\N
               \X\\\S\\\\X\\
              . 1>N\\S\SN\\\\>
              I\\N\\\\\\N\\>
              |XN\\\\\\NNNN>
                                  5  "
                  10 '
                  15 •
                  20 '
                  25 '
                  30
                 35 '
                  40-
                 45
                                          TEP  5
                                Resistivity   (ohm-meters)
                            5      10     15    20    25     30
                                                                            0
                                                                         0  -
                                                                         5  •
                                           10 •
                                           15
                                           20  -
                                           25
                                           30
                                                                November 4, 1992

^   \      ^July  19,  1993       40
           February  24,  1993
                                          45  -
                                                                                       50
                                                        Temperature   (degrees  C)
                                                      20     40      60      80     100
                                                                  —I	1—
                                                                                                J
                                                                                                   k
                                                                                                                   July  19,  1993
                                                                                                      February 24, 1993  2
                                                                                                       r
Figure 14. Induction logs such as these obtained in well TEP 5 reveal the changes in soil electrical properties in detail. In the baseline log (11/4/92, solid curve), the permeable zones
have high resistivity. During the first steam pass (2/24/93, dashed), the narrow heated zone at about 35 m displays lowered resistivity. After the second steam pass (7/19/93, dotted),
a broad zone from about 15-40 m exhibits both elevated temperatures and diminished resistivity. The narrow aquifer at 35 m has experienced groundwater recharge; hence, its
resistivity is  indicative of heated saturated conditions compared to the hot, dryer conditions existing during the first steam pass. (From Boyd et al., 1994; New mark, 1994b).

-------
                                                                                            condensed
                                                                                           aqueous
         5/24/93
                    5/31/93
                                6/7/93
                                           6/14/93
                                                       6/21/93
                                                                  6/28/93
                                                                              7/5/93
                                               Date
Figure 15. Daily average gasoline recovery rates during the second steam pass. (From Udell, 1994a,c).
                           N
A Injection well
0 Extraction well
© Tiltmeter
                                      June 2,1993
Figure 16.  Tiltmeter maps show the growth of the team fronts emanating from two injections wells on con-
secutive days. At this time, steam was being injected into only two wells, below the water table. Steam
broke through to the extraction wells  the third day. (From Hunter and Reinke, 1994).
                                                  20

-------
and "sweep" the steam across the remaining cool
areas.  The pulsed mode of operation, alternating
steam and vacuum-only on a 5-6-day cycle, was
very effective at maximizing contaminant
removal.  We terminated this phase on schedule
on July 9,1993, while the extraction rates still
ranged between 50 and 100 gallons/day.
    Evaluation of the gasoline concentration in
the effluent from the extraction \vell proved diffi-
cult in the first pass, but was significantly
improved in the second pass (Jovanovich et al.,
1994; Aines et al., 1994).  Most of the gasoline was
removed in the vapor phase, and much of that
was condensed along with a large amount of
water in the heat exchanger (Ain.es et al., 1994).
The second-pass addition of an oil-water separa-
tor on this part of the effluent stream allowed an
accurate determination of the condensed part
of the flux by simple volume measurement
(Sorensen and Siegel, 1994). The remaining dried,
cooled vapor was burned in two internal combus-
tion engines; the flux of gasoline in this stream
was highly variable, as a function of the amount
of steam in the injection wells, total vacuum
applied, and time of day (temperature of the heat
exchanger).
    Because of the cost and hazards associated
with sampling and analysis, off-line vapor sam-
ples were collected only once or twice daily.  This;
sampling frequency provides somewhat limited
insight into the Dynamic Underground Stripping
process, and cannot provide sufficient data for
detecting short-term fluctuations in system per-
formance or for real-time optimization and
control of the system.
    We employed a series of continuous in-line
chemical sensing systems to measure this flux
and to allow the same level of control for the
chemical extraction rate as was obtained for the
thermal injection systems. These included a stan-
dard Fourier-transform-infrared (FT-IR) spec-
trometer equipped with a gas sample cell, an
automated gas chromatograph (with photoioniza-
tion detector), and the experimental Differential
Ultraviolet Absorption Spectroscopy (DUVAS)
system. The trends indicated by the in-line sen-
sors were  in agreement with standard off-line lab-
oratory analyses, and were obtained continuously
in near or real-time (Figure 17a).
    Continuous monitoring allowed transient
events and mid- to  long-term trends in the
extraction process to be measured.  For example,
the DUVAS data showed significant diurnal
fluctuations in the absorption of total aromatic
compounds; these fluctuations corresponded with
recorded variations in ambient temperature and
changes in the pressure and flow rates within the
vapor extraction system (Barber et al., 1994a,b)
(Figure 17b).  The correlation between ambient
temperature and sensor response led to an
analysis of the vapor system's efficiency. The
fluctuations appear to be caused by changes in
condensation efficiency resulting from variations
in ambient temperatures (higher condensation
rates during the cooler nighttime temperatures.)
This explanation also resolved the apparent scat-
ter between the contaminant concentrations
measured in the morning and afternoon vapor
samples. (The morning values showed signifi-
cantly lower concentrations than the afternoon
samples.)  Thus, the in-line sensors, due to their
high sample frequency, revealed trends that
occurred between samples and provided a
context in which to interpret the analytical
results.
    During the second steam pass, about 5000
gallons of gasoline were recovered. Extraction
rates were extraordinarily high at the beginning
of the second pass because of the 3-month heat
soak of the formation and the accompanying
release and volatilization of gasoline (Aines et al.,
1994).
    By the end of the two steam injection phases,
most of the soil within the treatment volume was
heated to the boiling point of water.  Only the
thick clay layer at 95 to 110 ft in depth did not
reach  this value, in places reaching only 80°C.  It
was within this "cold spot" that the largest con-
centrations of gasoline remained (Figure 18).
    Drill-back characterization utilizing six bore-
holes in a line across the spill site after these first
two phases indicated that, as expected, there was
still free-product gasoline in the vicinity of the
extraction wells but that it was now restricted to a
small  area just below the water table (Figure 19).
Based on the observed soil concentrations, it was
estimated that about 750 gallons remained in the
clay unit.  Gasoline had been substantially
removed from the edges of the spill and from the
vadose zone.
    Of significant importance to this experimental
application of Dynamic Underground Stripping
was the finding that gasoline concentrations were
not increased in the soil outside the treatment
volume. However, groundwater and vapor gaso-
line concentrations were still very high.
    At this point, operational control of cleanup
activities at the gasoline spill site was transferred
                                              21

-------
    OH
    D-
    CQ
    d
       600
       500-
       400-
       30CH
       200-
       100-
                                                   Laboratory
         14 '  16  '  18  '  20  '  22   24262830323436384042444648
                                         Total Days of Operation
                                                                      Total Aromatics
          14
24    26   28    30    32    34   36
       Total Days of Operation
                                                                    38
                                                                         40
                                                                              42
                                                                                   44
                                                                                       46   48
Figure 17. (a) Comparison of the benzene concentration measured by DUVAS and off-line laboratory analy-
ses, (b) Observed variations of relative total aromatic concentration from DUVAS, extraction line vacuum,
and vapor temperature. (From Barber et al., 1994a).
                                                 22

-------
N>
CO
                         ft   m
                      50-T1 5  20
                      70 ~
                                       TEP  8
                                                                                                      TEP 2
                                            Data for 3/11/93, end of first steam pass
                                                     resistivity   change   ohm   m
                                        -30.0
0.0   5.0
                   Figure 18. ERT and temperature surveys detected a "cold spot" after the first steam pass.  Data from March 11,1993,
                   at the end of the first steam pass, reveal a zone between about 32 m and 37 m where temperatures have not risen much
                   above ambient. The ERT images indicate the lateral continuity of this zone between wells in which temperatures can be
                   measured.

-------
    20
    40
    60
£   80
Q.
0)

0



   100
   120
   140
   160 L
                                    in
                                    o
                                    OCN,

                                    if
    9
    I
                         CO
                         o
                                                                                 Ground surface
               1-10 ppm


               10-100ppm


               100-1,000 ppm


               >1,000 ppm
Upper steam zone

Lower steam zone
Water table



Screened interval


Sample point
20
                                                             0      10

                                                            Scale: Feet
 Figure 19. Approximate cross section of the treatment site from the characterization drill-back after the two steam passes (compare with Figure 2). The area

 of gasoline contamination has contracted greatly, and there are no indications of free product remaining in the treated area outside the volume immediately

 around the extraction wells. No gasoline has been dispersed outside the treated volume. (From Bishop et al., 1994).

-------
 from the more experimental Dynamic Under-
 ground Stripping demonstration team to the
 LLNL site cleanup organization. Subsequent
 activities focused on the final cleanup of the site.
    Extraction of groundwater and vapor
 resumed as part of the Accelerated Recovery and
 Validation (ARV) project (Sweeney et al., 1994) in
 October 1993; the spike in initial extraction rates
 was smaller than observed after the first pass
 (Figures 20 and 3). Electric heating was applied
 to the system in November.  Approximately 1000
 gallons were removed during this phase, with the
 concentrations and extraction rates falling dra-
 matically. Electric heating raised the overaD
 temperature of the treated zone only slightly,
 apparently because the extraction systems were
 removing large amounts of heat (50 to 100 kW) at
 the high temperatures prevailing at the time.
    When the extraction systems; were turned off,
 temperatures in the clay zones began rising
 (Figure 21). The electric heating was terminated
 on December 16, and the system was shut down
 for the holidays. At this point, at least 7600 gal-
 lons of gasoline had been removed from the site.
 The discrepancy between this and the 6200 gal-
 lons estimated to be present is not surprising
 due to the extreme heterogeneity of the site
 and the difficulty in characterizing gasoline
 trapped in soil capillaries.  Historically, very few
measurements of total hydrocarbons were made
at the site, since measurements of BTEX (benzene,
toluene, ethylbenzene, and xylenes) were suffi-
cient to delineate the contamination and quantify
the regulated contaminants (Dresen et al., 1986).
The error in converting the BTEX measurements
to total gasoline is therefore fairly large, and the
estimated total volume of gasoline subject to an
error of several thousand gallons (Devaney, 1994;
Aines et al., 1994).
    In January 1994, groundwater pumping and
vapor extraction resumed.  During the 1-month
shutdown during the 1993-1994 year-end-break,
concentrations in the vapor increased only slightly,
and water concentrations decreased.  Benzene
concentrations in the extraction wells continued
their downward  trend, now at less than 200 ppb
from a peak of 7000 ppb before the start of steam
injection. At a groundwater monitoring well
within the pattern, benzene concentrations have
decreased dramatically, from several  thousand
parts per billion before Dynamic Underground
Stripping to less than 30 ppb in January 1994.
Other wells show similar decreases. These factors
indicate that there is no significant free-phase
gasoline remaining in the treatment volume,
although significant contamination may still lie
outside the treatment volume.
                                                             W000000000000000000ff0i
                                                   11/15/93 11/22/93 11/29/93
                                      total
                                     burned
                                    condensed
                                   aqueous
        10/4/93  10/11/93 10/18/93  10/25/93
                                                                         12/6/93
Figure 20. Daily average gasoline recovery rates during the ARV phase. (From Udell, 1994a,c).
                                              25

-------
 o>
 CO
I
 0>
 t
 o>
H-
              100

                90

                80

                70

                60

                50

                40

                30

                20
   Tc 2 (33.5 m, gravel)
  •s i lm  n
   ^^^^^^^^F"^^^^_.^^^M_ai^^fc


   Tc 3 (29 m, sand)
               Tc 4 (24.4m, silt)
               Tc 1 (39.6 m, sand)
Pumps    Pumps
.off/.../on
 320

Heating begins
fi 111 ft.i 1111111^
 330 /     3AGT
    /  Pumps/
ins '    Off
Z                                             Heating ends

                                             .1.........1
                                                    350
                                       360
                                                                   370
                                          Julian day
Figure 21. Fixed thermocouples in well TEP 2 show different responses to electrical heating during the ARV
phase. Slight temperature rises occur hi sandy or silty zones, even while the extraction systems were remov-
ing heat from the system. The two lower thermocouples (Tc 1 and 2, open symbols) are located below the
standing water table.  The two thermocouples above the water table (Tc 3 and 4, dosed symbols) show tem-
perature rise throughout electrical heating. (After Sweeney et al., 1994).
                                   Cleanup Results
Free-Product Removal
    Free-product gasoline has been removed from
the treated area at the LLNL gasoline spill site,
thus accomplishing the goal of Dynamic
Underground Stripping; approximately 7600 gal-
lons of gasoline were removed from above and
below the water table. This conclusion deserves
careful scrutiny because of the previous great dif-
ficulty in accomplishing this goal experienced by
other cleanup methods.
    The bases for this conclusion are:
    1. 6200 gallons of gasoline were estimated to
be in the treatment zone, and 7600 have been
                       removed. After the August 1993 drill-back, soil
                       concentrations indicated that 750 gallons
                       remained (if the distribution was symmetric).
                       Over 1000 gallons have since been removed.
                       Extraction rates fell to nearly zero (11 gallons per
                       month) in January 1994 and have remained low.
                          2. Groundwater concentrations in the extrac-
                       tion wells and in the two available monitoring
                       wells inside the pattern (GEW 710 and GSW 1A)
                       are lower than the apparent solubility of the most
                       recently extracted gasoline. Although the solubil-
                       ity of gasoline can vary greatly depending on its
                       composition, by measuring the concentration in
                       the water in the oil-water separator where raw
                                            26

-------
 gasoline is known to be in contaict with ground-
 water (Jovanovich et alv 1994; Sweeney et al.,
 1994), an accurate estimate under site conditions
 can be obtained. The equilibrium concentrations
 currently are >35,000 ppb at 20°C; groundwater
 samples from the extraction and monitoring wells
 are less than 10,000 ppb at elevated temperatures
 (>50°C). These are well below the initially
 observed values for water in contact with free
 product when wells were drilled (40,000-70,000
 ppb), and an order of magnitude? below the
 values observed in the monitoring wells after
 electrical heating mobilized gasoline (120,000—
 180,0000 ppb).
    3. Vapor and liquid concentrations did not
 rise significantly after the December 1993-January
 1994 shutdown period.  Previous shutdowns with
 hot ground resulted in large increases in concen-
 tration when the treatment system was turned on
 again. Presumably, this was due to the mobiliza-
 tion and/or vaporization of free-product gaso-
 line. The  absence of such a pulse after ARV indi-
 cates that there was no free product remaining.
    4.  Groundwater concentrations of BTEX at
 the central extractors are at lower values than the
 initial groundwater concentrations just outside
 the injection ring (e.g., GSW 2, 3,13), and are at
 comparable concentrations to many of the distal
 wells (see below).
    The limitations to the conclusion that we
 have removed all the free product are:
    1.  Our ability to resolve the  presence of free-
 product pockets  by chemical means is limited by
 the degree of contact with flowing air or water.
 This is difficult to quantify.
       At the start of ARV, the remaining gasoline
 left a chemical signature of 20,00(3 ppb total petro-
 leum hydrocarbons (TPH) in groundwater, which
 dropped to 10,000 ppb by the end of the ARV
 phase (Sweeney  et al., 1994). During ARV, about
 1000 gallons of gasoline were removed. This
 places an upper limit on the free product remain-
 ing in the treated area today, based on ground-
 water analysis alone of 1000 gallons.
      There are  approximately 1 million gallons
 of groundwater in the near vicinity of the extrac-
 tion wells. Given the observed concentrations of
 TPH during the ARV phase, this places a lower
 limit of 10-20 gallons (dissolved in groundwater).
 This indicates that there are much less than 1000,
but possibly on the order of tens, of gallons of
 gasoline remaining (99.9% removal would cor-
respond to about 10 gallons remaining).  Any
pocket of free product near the extraction wells
 would have to be extremely well isolated from the
 permeable parts of the formation to have survived.
     2. Free product may remain in the area out-
 side and east of the treated area (e.g., near GSW
 216). The vapor concentrations in the eastern-
 most injection well (GIW 815) are still fairly high
 (Sweeney et al., 1994). This may be due to either
 free product in the area or from the vapor being
 pulled in from the area to the east.  It is more like-
 ly that this results from vapor being pulled in
 from the east; if there were free products in the
 area, we would have seen this in the GSW-001A
 results.  In addition, there was a pocket of free
 product under the receiving yard to the north of
 the treatment area before Dynamic  Underground
 Stripping was begun. This was sampled during
 the drilling of TEP 5 (Bishop et al., 1994).
 Groundwater Cleanup

    Cleanup of groundwater is the goal of any
 remediation effort, so the results of the LLNL
 demonstration must be measured principally in
 terms of the resulting contaminant concentrations
 in the water beneath the site even though the
 goals of the project were strictly limited to free-
 product removal.  The regulated contaminants 1,2
 dichloroethane (DCA), xylene, and toluene are at
 or near their allowed Maximum Contaminant
 Limit (MCL) in the groundwater of the treated
 area. Benzene has been reduced dramatically,
 although it is still  well above the MCL (Table 2,
 Figure 22).
    Table 2 gives average values for the major
 regulated contaminants in the central region of
 the gas pad; this requires the use of data from
 several wells, as noted.  Dynamic Underground
 Stripping went far beyond free-product removal;
 it lowered the benzene concentrations inside the
 central region to levels below those observed out-
 side the treated area (the so-called bathtub ring of
 untreated but slightly contaminated water)
 (Figure 23).
    Concentrations of 1,2 DCA have dropped to
 below detection limits in the treated area, and are
 significantly reduced in the surrounding region.
    Xylene concentrations are diminished in the
 treated area. The increase in xylene concentration
 in GSW 216 (east of the treated area) probably
 reflects the local mobilization of gasoline compo-
nents through increased solubility and decreased
sorption due to heating (Figure  8).
                                              27

-------
          Table 2.  Average level of contaminant in central extractors.
Data iBanzana 1.0 ppb

1987
1999
1990
1992 (Pr«-OU3)
1999(Av«rag«DUS)
12/99 (Poat-DU8)
1/94
i/94
9/94
9/94
9/1A1994
Av*rag* of w«4la
outolda treated araa,
ppb
6400
4600
1705
3646
2081
286
170
125
157
172
200
385
1992*
ratio to md -1
0399
4599
1704
3645
2080
285
169
124
156
171
208
384

iToluaiM 100 ppb IXytanaa (1750 ppb)
ppb
4900
4220
1500
2187
4143
804
683
150
257
177
189
3

ratio to md -1
46.0
412
14.0
20.9
40.4
7.0
5.8
0.5
1.6
0.8
0.9
•1.0

PPb
2800
2940
1643
2935
3810
1725
1866
846
327
530
448
6

ratio to md -1
0.6
0.7
•0.1
0.7
1.2
0.0
0.1
•0.5
-08
•0.7
•0.7
•1.0

11.2 OCA (1.0 ppb) |EttivlbanzafM(680ppb) 1
ppb
200
118
188
117
0
0
0
0
0
0
0
72

ratio to md -1
399
235
375
233
-1
-1
•1
•1
•1
-1
•1
143

ppb
360
360
305
838
684
88
36
7.7
26
2
6
5

ratio to md -1
-0.5
-0.5
-0.6
0.2
0.0
•0.9
•0.9
-1.0
-1.0
-1.0
•1.0
-1.0

                •Notes: 1987 GSW 15 value from 12/15/87

K>
0°                     1988 average of values from GSW-015 in 1988
                       1990 average of tests of GSW 16 11/6 -12/14/90


                       Data for GSW 001A for DCA only, 1990


                       1992 Avenge of GEW 816 tests, about 8/15/92


                       1993 Average of all values observed at SEPI port during second pass operations (from Jovanovich et al., 1994)


                       12/93 LLNL Lab data sampled 12/6/93 , GO-018. UVI port (although SEPI is consistently about 20% higher)


                       1/94 Data from LLNL ERD GM-071 sampled 1/19/94, data from UVI port (uncorrected for SEPIAJVI differences if any)


                       3/94 LLNL lab data GO-091 sampled 3/10/94, UVI port


                       6/94 LLNL data GP-037 sampled 6/14/94, UVI port. After about 1 month at total shut down.


                       8/94 LLNL data OP-096 sampled 8/1/94, UVI port


                       LLNL data GP-125 sampled 9/1/94, UVI port


                       Outside wells: Average of 1992 values for GSW 8,10,208,216 (wells well outside the treated area that had gasoline contaminant)

-------
               6399
                                                                               399
                               Benzene
                               MCL=1.0  ppb
                                    6/94
,7000
1,2  DCA
MCL=1.0 ppb
                                                               400
                                                                                                                    300
                                                                                                                   h200
                                                                   o
                                                                   15
                                                                   _j
                                                                   O
                                                                                                                   100
                                                                                           3/94
                                                                                                6/94
                                                 Non Detect
                                                 C'<>e---	Ho

                                                             i
                                                               50
                 48.0
                                   Toluene
                                   MCL=100ppb    50°
                          0.6
                                                                                                                      5.0
   Xylenes
   MCL=1750  ppb  f40
Figure 22. Dissolved groundwater contaminants at the gasoline spill site through June 1994. MCL ratio is expressed as [(contaminant concentration (ppb))/
(MCL (ppb))] - 1. The ratio is zero when the MCL is reached, and drops to negative values (as shown for xylene) when the MCL is exceeded.  Values are given
for the central extraction wells (GSW 15,16 and GEW 808,816). Starting and ending ratios are noted. In June, 1,2 DCA and total xylenes were below MCL,
as were ethylbenzene and ethylene dibromide (not shown). Toluene was at 1.6 above its MCL, and benzene was 156 times its MCL. Data from Table 2.

-------
Figure 23  Comparison of MCL ratios observed at seven monitoring or extraction wells before Dynamic Underground Stripping (1992 average values) and after the
ARV phase (January 1994). Clockwise from the central extraction wells (GEW 808 and 816) are GEW 710, GSW 208, GSW 216, GSW 7, GSW 8, and GSW 1 (at
center of photo) (Figure 6).  Free-product gasoline was observed in GSW 216 when it was drilled in 1986 (Dresen et aL, 1986). (a) Benzene.

-------
                                                      u
                                                      Q
31

-------

    Ratio of ground Waier
    concentration io;$jpj^*|t*
    MCL before and after Sf
    Dynamic Stripping

                                          After

(c) Total xyienes.

-------
    Concentrations in GSW 1 appear higher in
 the treated area; this value roughly matches the
 levels seen in the extraction wells, and reflects the
 same mobilization mechanisms. Ethylbenzene
 and ethylene dibromide are below the MCL as
 well.
    Contaminant concentrations in the central
 extraction wells appear to approach the outside
 well values, indicating that water in the treated
 area is equilibrating with the untreated water as
 the extraction system draws water in.
    The ability of Dynamic Underground
 Stripping to remove contaminants to such low
 levels in groundwater is probably indicative of
 the boil-off distillation mechanism described by
 Udell (1994a).  Because volatile components are
 generally removed from boiling; water at a mass-
 removal rate exceeding that of the water, boiling
 of a small percentage of the pore water can dra-
 matically reduce aqueous concentrations.
    Udell examines the effect as a function of
 boiling rate, solubility, and Henry's law constants;
 unfortunately, solubility and Heinry's law con-
 stants are not known at high temperatures for
 most groundwater contaminants (see data for
 xylene obtained as part of the ARV activities,
 Sweeney et al., 1994). This mechanism may be
 responsible for the almost instantaneous removal
 of 1,2 DCA from the gasoline spill site ground-
 water by Dynamic Underground Stripping and
 the dramatic decrease seen in benzene relative to
 xylene.
Ongoing Bioremediation

    Before Dynamic Underground Stripping
treatment of the gasoline spill area, a wide variety
of microorganisms were actively degrading  the
BTEX components of the gasoline. These organ-
isms included the dominant genus Pseudomonas
originally, and after a campaign of vacuum vent-
ing in 1990-92, the genus Flavobactor was domi-
nant.  The largest populations otisted in areas
where gasoline was present at low concentra-
 tions.  In the capillary fringe zone (up to 5 ft
 above the water table) where gasoline concentra-
 tions were highest, there were low numbers of
 culturable organisms. In the central area of the
 spill, below the water table, oxygen concentra-
 tions were very low, and microbial activity was
 effectively zero.
    Extensive characterization of the microbial
 population was conducted before heating the
 area, with the expectation that the soils would be
 sterilized and the population rebound of microor-
 ganisms in the area could be studied.  Post-test
 drill-back in August 1993 included collection of
 extensive soil samples that were cultured for
 microorganisms both at room temperature and at
 50°C.
    Although the gram-negative bacteria that had
 been the dominant BTEX degraders were gone,
 extensive microbial communities were flourishing
 in all samples, including those in which the soil
 was collected at temperatures greater than 90°C
 The dominant species were no longer bacteria,
 but yeasts and related organisms (Rhodotorula,
 Streptomyces], which had been observed in  small
 numbers before heating.  Thermophiles previous-
 ly identified from environments such as the hot
 springs at Yellowstone National Park are impor-
 tant members of the new community, as well as a
 number of other organisms apparently represent-
 ing previously unidentified species.
    The rates at which this new biological com-
 munity are degrading gasoline components has
 not yet been quantified, but it is clear that BTEX
 degraders (e.g., Rhodotorula) have survived and
 can rapidly undertake the final removal of  conta-
minants from the groundwater.  At this point, the
addition of trace nutrients to the  system is being
considered to enhance this activity. It is hoped
that final reduction of benzene levels to below the
MCL of 1.0 ppb can be accomplished through a
combination of continued intermittent operation
of the groundwater and vapor extraction systems
to provide oxygen, and proper encouragement of
the microbial ecosystem.
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          Conclusions from the Gasoline Spill Site Demonstration
    •  Separate-phase gasoline has been removed
from the treated area.
    •  A stable steam zone can be established
below the water table.
    •  Steam injection is effective for heating per-
meable zones, and repeated steeim passes can
effectively heat small impermeable layers
between.
    •  Dynamic Underground Stripping can
reduce groundwater contamination to very low
levels.
    •  Electrical heating is effective for heating
clay zones, but higher power levels are required
when extraction of hot fluids is removing heat
from the formation.
    •  Establishing a complete steam zone in very
permeable materials requires large amounts of
steam; the more the better.
    • Electrical resistance tomography is
extremely sensitive to heating of soil and gives
rapid images of steam movement between wells.
    • Tiltmeters accurately mapped the outer
extent of the steam fronts both above and below
the water table, and the footprint of steam zones
emanating from individual injectors in the lower
steam zone.
    • Steam did not displace much liquid conta-
minant in a piston flow.
    • Vapor recovery is the major contaminant
removal mechanism.
    • Gasoline is locally mobilized in heated
areas and may show higher groundwater concen-
trations outside the treatment area even though it
is not being transported.
    • Treatment systems must be robust to han-
dle the large peak extraction rates and the rapid
changes in rate.
                                       References

Adenekan, A. E., and T. W. Patziek, (1994), "Cleanup of the Gasoline Spill Area with Steam:
     Compositional Simulations," Dynamic Underground Stripping Project: LLNL Gasoline Spill
     Demonstration Report, Lawrence Livermore National Laboratory, Livermore, CA, UCRL-ID-116964,
     Section 5, p. 143.
Aines, R., W. Siegel, E. Sorenson, and M. Jovanovich (1994), "Gasoline Removal During Dynamic
     Underground Stripping: Mass Balance Calculations and Issues; Chemical Fractionation," Dynamic
     Underground Stripping Project: LLNL Gasoline Spill Demonstration Report, Lawrence Livermore
     National Laboratory, Liverrnore, CA, UCRL-ID-116964, Section 3, p. 447.
Barber, T. E., W. G. Fisher, and E. A. Wachter (1994a), "Characterization of the Vapor Stream at the
     Lawrence Livermore Dynamic Stripping Site by  Differential Ultraviolet Absorption Spectroscopy,"
     Dynamic Underground Stripping Project: LLNL Gasoline Spill Demonstration Report, Lawrence
     Livermore National Laboratory, Livermore, CA,  UCRL-ID-116964, Section 3, p. 397.
Barber, T. E., W. G. Fisher, and E. A. Wachter (1994b), "On-Line Monitoring of Aromatic Hydrocarbons
     Using a Near Ultraviolet Fiberoptic Absorption Sensor," Environmental Science and Technology (in
     preparation).
Bishop, D. J., et al. (1994),  "Dynamic Underground Stripping Characterization Report," Dynamic
     Underground Stripping Project: LLNL Gasoline Spill Demonstration Report, Lawrence Livermore
     National Laboratory, Livennore, CA, UCRL-ID-116964, Section 2, p. 3.
Boyd, S., R. Newmark, and M. Wilt (1994), "Borehole Induction Logging for the Dynamic Underground
     Stripping Project, LLNL Gasoline Spill Site," Dynamic Underground Stripping Project: LLNL Gasoline
     Spill Demonstration Report, Lawrence Livermore National Laboratory, Livermore, CA, UCRL-ID-
     116964, Section 4, p.  165.
Buetmer, H. M., and W. D. Daily (1994a), "Cleaning Contaminated Soil Using Electrical Heating and Air
     Stripping," Journal of Environmental Engineering (in press).
Buetmer, H. M., and W. D. Daily (1994b), "The Electrical Soil Heating Preheat Phase of Dynamic
     Underground Stripping," Dynamic Underground  Stripping Project: LLNL Gasoline Spill Demonstration
     Report, Lawrence Livermore National Laboratory, Livermore, CA, UCRL-ID-116964, Section 3, p. 137.
                                             34

-------
 Carrigan, C. Rv and J. J. Nitao (:L994), "Development of a Predictive and Diagnostic Modeling Capability
      for Joule Heating/' Dynamic Underground Stripping Project: LLNL Gasoline Spill Demonstration Report,
      Lawrence Livermore National Laboratory, Livermore, CA, UCRL-ID-116964, Section 5, p. 197.
 Chute, R S., R E. Vermeulen, and L. G. Stevens (1987), "A Study of the Technical and Economic
      Feasibility of an Electric Preheat Process for In Situ Recovery from Athabasca Sands," AOSTRA
      Journal of Research 3 (3).
 Chute, R S., and R E.  Vermeulen (1988), "Present and Potential Applications of Electromagnetic Heating
      in the In Situ Recovery of Oil," AOSTRA Journal of Research 4 (1).
 Cook, G. E., J. A. Oberdorfer, and S. P. Orloff (1991), Remediation of a gasoline spill by vapor extraction,
      Lawrence Livermore National Laboratory, Livermore, CA, UCRL-JC-108064.
 Devaney, R. (1994), "Gasoline Volume Estimation," Dynamic Underground Stripping Project: LLNL Gasoline
      Spill Demonstration Report, Lawrence Livermore National Laboratory, Livermore, CA, UCRL-ID-
      116964, Section 2, p. 223.
 Dresen, M.  D., R Hoffman, and S. Lovejoy (1986), Subsurface Distribution of Hydrocarbons in the Building
      403 Area at LLNL, Lawrence Livermore National Laboratory, Livermore, CA, UCID-20787.
 Goldman, R., and K. S. Udell (1994), "Design and Development of a Temperature Measurement System
      to Monitor Subsurface Thermal Processes," Dynamic Underground Stripping Project: LLNL Gasoline
      Spill Demonstration Report, Lawrence Livermore National Laboratory, Livermore, CA, UCRL-ID-
      116964, Section 4, p. 23.
 Hunter, R. J., and R. R Reinke (1994), "Tiltmeter Mapping of Steam Zones During Steam Injection,
      February-June 1993," Dynamic Underground Striding Project: LLNL Gasoline Spill Demonstration
      Report, Lawrence Livermore National Laboratory, Livermore, CA, UCRL-ID-116964  Section 4
      p. 185.
 Jovanovich, M. C., R. E. Martinem, M. E. Dibley, and K. L. Carroll  (1994), "Process Monitoring of
      Organics During Dynamic Underground Stripping," Dynamic Underground Stripping Project: LLNL
      Gasoline Spill Demonstration Report, Lawrence Livermore National Laboratory, Livermore, CA,
      UCRL-ID-116964, Section 3, p. 187.
 Kenneally, K. M. (1994), "Modeling Steam Locations During a Steam Injection Process for  Subsurface
      Gasoline Spill," Dynamic Underground Stripping Project: LLNL Gasoline Spill Demonstration Report,
      Lawrence Livermore National Laboratory, Livermore,  CA, UCRL-ID-116964, Section 5, p. 57.
 Lee, K. H. (1994), "Predictive Modeling Using the STARS Code," Dynamic Underground Stripping Project:
      LLNL Gasoline Spill Demonstration Report, Lawrence Livermore National Laboratory, Livermore, CA,
      UCRL-ID-116964, Section 5, p. 169.
 MacDonald, J. A., and M. C. Kavanaugh (1994), "Restoring Contaminated Groundwater: An Achievable
      Goal? Environmental Science and Technology 28 (8), 362A-368A.
 McGee, B. C. W., R Vermeulen, S  Schute, and H. M. Buettner (1994), "Mathematical Solution of
      Electromagnetic,  Conductive, and Convective Transient Heat Transfer for In Situ Decontamination
      of Soil with Variable Electrical Properties," (in preparation).
 National Research Council (1994), Alternatives for Groundwater Cleanup, National Academy Press,
     Washington, DC.
 Nelson-Lee, J. C. (1994), "Sediment Physical and Chemical Characterization," Dynamic Underground
     Stripping Project: LLNL Gasoline Spill Demonstration Report, Lawrence Livermore National
     Laboratory, Livermore, CA, UCRL-ID-116964, Section 2, p. 47.
 Newmark, R. L. (1992), Dynamic Underground Striding Demonstration Project, Interim Engineering Report,
     Lawrence Livermore National  Laboratory, Livermore, CA, UCRL-ID-110064.
Newmark, R. L., ed. (1994a), Dynamic Underground Stripping Project: LLNL Gasoline Spill Demonstration
     Report, Lawrence Livermore National Laboratory Livermore,  CA, UCRL-ID-116964.
Newmark, R. L. (1994b), "Using Geophysical Techniques to Control In Situ Thermal Remediation,"
     Dynamic Underground Stripping Project: LLNL Gasoline Spill Demonstration Report, Lawrence
     Livermore National Laboratory, Livermore, CA, UCRL-ID-116964, Section 4, p. 3.
Newmark, R. L. (1994c), "Using Geophysical Techniques to Control In Situ Thermal Remediation," Proc.
     Symp. on Application of Geophysics tc Engineering and Environmental Problems, Boston, MA, March
     27-31,1994.
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Nicholls, E. M, M. D. Dresen, and J. E. Field (1988), Proposal for Pilot Study at LLNL Building 403 Gasoline
     Station Area, Lawrence Livermore National Laboratory, Livermore, CA, UCAR-10248.
Ramirez, A., W. D. Daily, D. LaBreque, E. Owen, and D. Chesnut (1993), "Monitoring an Underground
     Steam Injection Process Using Electrical Resistance Tomography," Water Resources Research 29,
     73-87.
Ramirez, A., J. Beatty, J. Carbine, W. Daily, and R. Newmark (1994), "Monitoring Thermal Treatment
     Processes Using Electrical Resistance Tomography," Dynamic Underground Stripping Project: LLNL
     Gasoline Spill Demonstration Report, Lawrence Livermore National Laboratory, Livermore, CA,
     UCRL-ID-116964, Section 4, p. 69.
Siegel, W. H. (1994), "Design, Construction, and Operation of Dynamic Underground Stripping Facilities
     at Lawrence Livermore National Laboratory" Dynamic Underground Stripping Project: LLNL Gasoline
     Spill Demonstration Report, Lawrence Livermore National Laboratory, Livermore, CA, UCRL-ID-
     116964, Section 3, p. 3.
Sorenson, E., and W. H. Siegel (1994), 'Treatment Facility F," Dynamic Underground Stripping Project:
     LLNL Gasoline Spill Demonstration Report, Lawrence Livermore National Laboratory, Livermore, CA,
     UCRL-ID-116964, Section 3, p. 123.
Sweeney, J. J., M. H. Buettner, C. R. Carrigan, C. S. Chamberlain, A. B. Copeland, M. A. Hernandez, G. B.
     Hudson, M. C. Jovanovich, K. C. Knauss, R. M. McNairy, W. H. Siegal, and E. A. Sorenson (1994),
     "Treatment Facility F: Accelerated Removal and Validation Project," Dynamic  Underground
     Stripping Project: LLNL Gasoline Spill Demonstration Report, Lawrence Livermore National
     Laboratory, Livennore, CA, UCRL-ID-116964, Section 6, p. 3.
Thorpe, R. K., W. F. Isherwood, M. D. Dresen, and P. Webster-Scholten, eds. (1990), CERCLA Remedial
     Investigations Report for the LLNL Livermore Site, Lawrence Livermore National Laboratory,
     Livermore, CA, UCAR-10299.
UdeU, K. S. (1994a), "Heat and Mass Transfer in Cleanup of Toxic Waste," Advances  in Heat Transfer
     Research, C. L. Tien, ed., Environmental and Engineering Geophysical Society, Englewood, CO,
     pp. 195-211.
Udell, K. S. (1994b), "Predictions of Recovery of Gasoline from the LLNL Gasoline Spill Site with
     Dynamic Underground Stripping," Dynamic Underground Stripping Project: LLNL Gasoline Spill
     Demonstration Report, Lawrence Livermore National Laboratory, Livermore, CA, UCRL-ID-116964,
     Section 5, p. 45.
Udell, K. S. (1994c), "Thermally Enhanced Removal of Liquid Hydrocarbon Contaminants from Soils
     and Groundwater," Dynamic Underground Stripping Project: LLNL Gasoline Spill Demonstration
     Report, Lawrence Livermore National Laboratory, Livermore, CA, UCRL-ID-116964, Section 5, p. 5.
Udell, K. S. (1994d), "Thermally Enhanced Removal of Non-Aqueous-Phase Liquid Contaminants from
     Soils and Groundwater," 'Subsurface Restoration, C. H. Ward, ed. (in press).
UdeU, K. S., and L. D. Stewart (1989), "Mechanisms of In Situ Remediation of Soil and Groundwater
     Contamination by Combined Steam Injection and Vacuum Extraction," Symp. on Thermal Treatment
     of Radioactive and Hazardous Waste, AIChE .Annual Meeting, November 6, San Francisco, CA.
UdeU, K. S. and L. D. Stewart (1990), "Combined Steam Injection and Vacuum Extraction for Aquifer
     Cleanup," Con/, of the International Association of Hydrogeologists, April  18-20, Calgary, Alberta,
     Canada.
UdeU, K. S., N. Sitar, J. R. Hunt,  and L. D. Stewart (1991), Process for In Situ  Decontamination of Subsurface
     Soil and  Groundwater, United States Patent 5,018,576.
Vaughn, P. J., K. S. UdeU, and M. J. Wilt (1993), "The Effects of Steam Injection on the Electrical
     Conductivity of an Uncorisolidated Sand  Saturated with a Salt Solution," /. Geophysical Research 98
      (Bl), 509-518.
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