&EPA
                            United States
                            Environmental Protection
                            Agency
                           office of
                           Research and Development
                           Cincinnati, OH 45268
EPA 540/R-94/520a
November 1994
SITE  Technology Capsule
Geosafe Corporation
In  Situ  Vitrification Technology
Abstract

   The Geosafe In Situ Vitrification (ISV) Technology Is
designed to treat soils, sludges, sediments, and mine
tailings contaminated with organic, inorganic, and ra-
dioactive compounds. The organic compounds are py-
rolyzed and reduced to simple gases which are collected
under a treatment hood and processed prior to  their
emission to the  atmosphere.  Inorganic and  radioactive
contaminants are incorporated into the molten soil which
solidifies to a vitrified mass similar to volcanic obsidian.

   This mobile technology was evaluated under the
SITE Program on approximately 330 yd3 of contaminated
soil at the Parsons site. Demonstration results indicate
that the cleanup levels specified by EPA Region Vwere
met and that  the vitrified soil  did not exhibit leachability
characteristics in excess of regulatory guidelines. Process
emissions were also within regulatory  limits.

   The Geosafe ISV Technology was evaluated based
on seven criteria used for decision-making in the Super-
fund  Feasibility Study (FS) process. Results of  the evalua-
tion are summarized  In Table  1.

introduction

   This Capsule provides information on the Geosafe
ISV Technology, a process designed to treat contami-
nated media by using an electrical current to heat and
vitrify the subject material. The Geosafe ISV Technology
was  investigated under the Environmental Protection
Agency (EPA) Super-fund Innovative Technology Evalua-
tion (SITE) Program during March and April 1994 at the
former site of Parsons Chemical Works, Inc. (Parsons). The
Parsons site Is  a Super-fund site located in Grand Ledge,
Ml and currently undergoing a removal action under the
supervision of the EPA Region V. Soils at the Parsons site
were previously  contaminated by normal facility opera-
                         tions including the mixing, manufacturing, and packag-
                         ing of agricultural chemicals. The technology was evalu-
                         ated on these soils which were contaminated with
                         pesticides (primarily chlordane, dieldrin, and 4,4'-
                         DDT),metals (especially mercury), and low levels of dlox-
                         ins/furans.  A total  of  approximately  3,000  yd3 of
                         contaminated soil  was treated In nine pre-staged treat-
                         ment settings. The Demonstratton Test evaluated the
                         system performance on one of these settings.

                             Information in this Capsule emphasizes specific site
                         characteristics and results of the SITE Demonstration at
                         the  Parsons site. This Capsule presents the following infor-
                         mation:

                             . Technology  Description
                             • Technology  Applicability
                             . Technology Limitations
                             • Site Requirements
                             • Process Residuals
                             . Performance Data
                             • Economic Analysis
                             • Technology Status
                             • SITE Program Description
                             • Sources of Further  Information

                         Technology  Description

                             The ISV Technology demonstrated by Geosafe Cor-
                         poration (Richland,  WA) operates by means of four
                         graphite electrodes,  arranged in a square and inserted
                         a short  distance into the soil to be treated. A  schematic
                         of the Geosafe process is presented in Figure 1.

                             ISV uses electrical current to heat (melt) and vitrify
                         the  treatment material in place. A pattern of electrically
                         conductive graphite containing glass frit Is placed on
                         the  soil  In paths between the electrodes. When power is
                         fed to  the electrodes, the graphite and glass frit con-
                                     SVPERFWD   INNOVATIVE
                                     TECHNOLOGY  EVALUATION
                                                                                Printed on Recycled Paper

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            Table 1. Criteria Evaluation for the Geosafe In Situ Vitrification Technology
                                                                                                              Criteria
            Overall Protection of
            Human Health and the
                Environment
                            Compliance with ARARs      Long-Term  Effectiveness
                                                                                        Short- Term Effectiveness
                                                                                               Reduction of Toxicity,
                                                                                                Mobility, or Volume
                                                                                                through Treatment
                                                                                                    Implementability
                                                                                                                                                                                               Cost
K>
Provides both short- and
long-term protection  by
destroying organic con-
taminants and immobil-
izing inorganic material.

Remediation can be
performed in situ, there-
by reducing the need
for excavation.

Requires  off-gas  treat-
ment system to control
airborne  emissbns. Sys-
tem can be specifically
designed to handle emis-
sions generated by the
contaminants  in the
media being treated.

Technology can simul-
taneously treat a mixture
of waste types (e.g., organ-
ic and inorganic wastes).
Requires  compliance with
RCRA  treatment, storage,
and land  disposal
regulatbns (for a hazardous
waste). Successfully treated
solid waste may be de-
listed or handled as non-
hazardous waste.

Operation of on-site  treat
ment unit  may require
compliance with
location-specific ARARs.

Emission  controls may be
needed to ensure com-
pliance with air quality
standards depending upon
local ARARs  and test
soil components.

Scrubber  water  will
likely require secondary
treatment before discharge
to POTW or surface  bodies.
Disposal requires compli-
ance with  Clean Water
Act regulatbns.
Effectively  destroys
organic contamination
and immobilizes in-
organic material

Reduces the likelihood
of contaminants leaching
from treated soil.  ISV
glass  is thought to have
a stability similar to
volcanic obsidian. The vit-
rified product is conserv-
atively estimated to re-
main physically and chem-
ically stable for approx-
imately 7,000,000 years.

May allow re-use of prop-
erty after remediation.
Effectively destroys
organic contamination and
immobilizes inorganic material.

 Vitrification of a single
 15-ftdeep treatment
setting may be accom-
plished in  approximately
ten days.  Treatment times
will vary with actual treat-
ment depth and site-
specific conditions.

Presents potential short-term
exposure  risks to workers
operating  process equipment.
 Temperature and electric
hazards exist.

Some short-term risks
associated with air emissions
are dependent upon test
material composition and
off-gas treatment system
design.

Staging, if required, involves
excavation and construction
of treatment areas. A potential
for fugitive emissions and ex-
posure exists during  excavat-
ion and construction.
Significantly reduces toxicity
and mobility of soil con-
taminants through treatment.

 Volume reductions of 20 to
50% are typical after
treatment.

Some inorganic  con-
taminants, especially
volatile metals, may escape
the vitrifbatbn process and
require subsequent  treat-
ment by the off-gass treatment
system.

Some treatment residues
(e.g., filters, personal
protective  equipment) may
themselves be treated
during subsequent
vitrificatbn settings.
Res/dues from the final
setting,  including
expended or contaminated
processing equipment may
require special disposal
requirements.

 Volume of scrubber water
generated is highly
dependent upon soil
moisture content, ambbnt
air humidity, and soil
particulate levels in the
off-gas.
A suitable source of
electric power is required
to utilize this technology.

Equipment is transportable
and can be brought to a
site using conventional
shipping  methods. Weight
restrictions on
tractors/trailers may vary
from state to state.

Necessary support
equipment includes earth-
moving equipment for
staging treatment areas (if
required)  and covering
treated areas with clean
soil. A crane is required
for  off-gas hoodplacement
and movement.

The staging of treatment
areas is recommended for
areas where the
contamination is limited to
shalbw depths  (less than
eight feet).

The soil oxide composition
must provide sufficient
electrical  conductivity in
the molten state and
adequate quantites of
glass formers to produce a
vitrified product. Oxides
can be added to soil to
corrected for deficiencies.

Groundwater should be
diverted away from
treatment area to improve
economic viability.
 The estimated cost for
 treatment when the soil is
 staged into nine 15-ft
 deep cells is  approximately
$780/y(f ($430/ton). This
 cost is based on data
gathered from the Parsons
site. Costs are highly site-
specific and will vary with
 on-site conditions.

 Treatment is  most
 economical when treating
large sites to  maximum
depths.

 Electric power is a major
 element of when associated
 with ISV processing.
 Other important factors (in
order of significance)
include labor costs; startup
and fixed costs;  equipment
costs; and facility
modifications  and
maintenance  costs.

Moisture  content of the
media being treated
directly influences the cost
of treatment since electric
energy must be used to
 vaporize  water before soil
melting occurs.

Sites that require staging
and extensive site
preparation will have
higher overall costs.

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                                         Off-gas hood
                                                                                            Backup
                                                                                            off-gas
                                                                                            treatment
                                                                                            system
           Utility or
            diese'l
          generated
           power
Figure 1. Geosafe in situ vitrification process
                                                                                         treatment system
                                                                                      To atmosphere
                                                                (if necessary)
ducts the current through the soil, heating the surround-
ing  area and melting directly adjacent soil.

    Molten soils are electrically conductive and can con-
tinue to carry the current which heats and melts soil
downward and  outward. The electrodes are allowed to
progress down into the soil as it becomes molten, con-
tinuing the  melting process to the desired treatment depth.
One setting of four electrodes is referred to as a "melt."
Performance of each melt occurs at an  average rate of
approximately  three to  four tons/hr.

    When all  of the soil within a treatment setting be-
comes molten, the power to the electrodes is  discontin-
ued and the molten  mass begins to  cool. The electrodes
are cut near the surface and allowed to settle into the
molten soil to  become part of the melt. Inorganic  con-
taminants in the soil are generally incorporated into the
molten soil which solidifies Into a monolithic vitrified mass
similar in characteristics to volcanic obsidian. The vitrified
soil  is dense and hard, and significantly reduces the possi-
bility of leaching from the mass over  the long term.

    The organic  contaminants in the soil undergoing treat-
ment are  pyrolyzed (heated to decomposition tempera-
ture without oxygen)  and are generally reduced  to simple
gases. The gases move  to the surface  through the dry
zone immediately adjacent to the melt, and through the
melt itself. Gases at the surface are collected under a
stainless steel hood placed over the treatment area and
then treated in an off-gas treatment system. The off-gas
treatment system comprises  a quencher, a scrubber, a
demister, high efficiency particulate air (HEPA) filters, and
activated carbon adsorption to process the offgas  be
fore re|easing  the cleaned gas through a stack. A ther-
mal  oxidizer can be used following the off-gas treatment
system to polish the offgas before release to the atmo-
sphere. A thermal oxidizer was utilized during the SITE
Demonstration at the Parsons site.

Technology  Applicability

    The Geosafe ISV Technology is  a stand-alone pro-
cess that can be used to treat a wide variety of media
including soils, sludges,  sediments,  and mine tailings. It is
a mobile system with  process equipment permanently
mounted on three trailers. The hood and remaining equip-
ment are  transported on two additional trailers.

    The soil type treated during the Demonstration was a
clay-like soil with some sand and gravel present. Con-
taminants  suitable  for remediation by this technology
may be organic or inorganic. The technology has also
been  successfully demonstrated on radioactive and

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mixed  (hazardous and radioactive)  wastes by Battelle
Memorial Institute for the U.S. Department of Energy, but
supporting data for this claim was not gathered as part
of the Demonstration Test. Testing to  date does not indi-
cate an upper limit of contamination restricting success-
ful remediation if the composition of the material is suitable
for treatment (see Technology Limitations). The technol-
ogy is also being developed for burled waste, under-
ground tank, and barrier wall applications.

   The technology can remediate contaminated  mate-
rials in situ. Alternatively, contaminated materials may be
excavated,  consolidated, and  staged in  prepared  treat-
ment settings when the contamination zones are shallow
(less than eight ft) or scattered. Other processing con-
figurations are under development for unique applica-
tions.

Technology  Limitations

   The technology has the capability of treating large
areas  In multiple treatment  settings. The size of each
treatment setting is dependent on the electrode spacing
appropriate for remediation. At the Parsons site, each
treatment setting covered a 27-ft by 27-ft  ground surface
area. Adjacent settings can be melted until the entire
contaminated area Is treated. Melt  settings are config-
ured such that each area melts and fuses into the previ-
ous setting,  leaving one large  vitrified  block after
treatment. This overlap ensures treatment  of the material
between settings.

   The maximum acceptable treatment depth with  the
current equipment is 20 ft below land surface  (BLS): how-
ever, full-scale tests at Geosafe's  testing facilities In
Richland, WA have  demonstrated that  the technology
can successfully reach a depth of approximately 22  ft
BLS. Treatment at the Parsons site typically  reached depths
of 15to 19 ft BLS.

   The presence of large amounts of water in the treat-
ment media may hinder the rate of  successful applica-
tion of the Geosafe technology since  electrical energy  is
initially  used to vaporize this water instead of melting  the
contaminated soil. Ihe resulting water vapors must also
be handled  by the  off-gas treatment system. Treatment
times  are thus prolonged and  costs increased when  ex-
cess water Is present.

    The overall oxide composition of the test soil deter-
mines  properties such as fusion and melting tempera-
tures, and melt viscosity. Soil to be treated must contain
sufficient quantities of conductive cations (K, Li and Na)
to carry the current within the molten mass. Additionally,
the soil should contain acceptable amounts of glass form-
ers (Al and Si). Most soils worldwide have  an acceptable
composition for  ISV treatment  without composition modi-
fication. Geosafe determines  the oxides present in the
soil prior to treatment. A computer-based model is then
used to determine the applicability of the site for vitrifica-
tion. The model can also identify oxide composition  levels
that  require modification before treatment.

    The type  of contamination present on-site  affects the
off-gas treatment system more dramatically than it af-
fects the rest of the ISV system.  For this reason, the off-gas
treatment system is modular in  configuration, allowing
treatment of the off-gases to be site-specific. The extent
of modularity Is expected to increase with future units.

    Heat removal limitations of the  current equipment
dictate  that the organic content of the treatment media
be less than 7 to 10% by weight. To minimize pooling of
treated metals  at the bottom of a melt, which may result
in electrical short-circuiting, metals content must be  less
than 15% by weight. The volume of inorganic debris is
limited to 20% or less.

    Previous experience has indicated that safe, effec-
tive treatment cannot be assured when pockets of vapor
or buried drums exist beneath the soil surface. The gases
released  may cause bubbling  and splattering of molten
material,  resulting in a  potential safety hazard.  For  this
reason, extensive site characterization is recommended
prior to treatment if  buried drums are suspected. Com-
bustible materials generally do not  present processing
difficulties  since they decompose relatively slowly as  the
melt front approaches.  Full-scale demonstrations have
been successfully conducted  on sites containing signifi-
cant quantities of combustibles  such as wooden timbers.
automobile tires, personal protective  equipment, and plas-
tic sheeting.

Site Requirements

    The site requirements for the Geosafe ISV technology
are a function of the size of the equipment used. The  site
requirements are also determined, in part, by whether
the soil is  excavated and staged prior to treatment. Ad-
equate area is required to accommodate staging, if
employed, and to support the off-gas treatment system
and the power conditioning system which feeds the elec-
trodes.  Space for maneuvering  a crane is also necessary
to allow placement and removal of the off-gas contain-
ment hood and toassist In the placement of the elec-
trodes.

    At the Parsons site, the original soil contamination
was relatively shallow, five ft or less, and located in three
main areas. To increase the economic viability of treat-
ment at this site, the contaminated soil was excavated
and consolidated into a series  of nine treatment cells.
The cell walls were built using concrete, cobble, and
particle board  as shown In Figures 2 and 3. The cells were
constructed by trenching an area of the site,  installing
particle board and concrete forms, and pouring con-
crete into the forms to create the nine cell settings. A
one-ft layer of cobble was placed in the bottom of each
cell, and approximately two ft of cobble was used to
surround the exterior of the cell forms. The use of cobble
at the  sides was intended as a means to retard melting
out into  adjacent clean soil. The bottom cobble was
used to provide a drainage pathway for water that was
known to be present on-site; the resultant flow of water
was directed  to a drainage trench. After construction,
the cells were filled with contaminated soil from the site,
and topped with a layer of clean soil.

    During the treatment of the first few cells, problems
with the cell design were observed. The intense  heat that
was melting the soil was also thermally decomposing the
particle board  forms. Analysis of water samples collected
from the diversion system surrounding the cells identified
volatiles (benzene), phenollcs, and epoxies that were

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                                                                                                    Eloctroda
        Clean fill (soil)
                                                                                                               Concrete wall
Figure 2. Side view of typical treatment cell.
                                Initially planned location of
             2' Cobble fill        12' dia. electrode (typical)

             1    *              I
                          o/\o
                                            oo
                             >r
??'
                               *» J   Ce// 8   '
                                demonstration
                              .?*  test area
                  IT
                                                                                     v                v
                                                                                   O     O           O     O
                                                                                   0      O
                                                                                     XV
                                                        O     O
                                                           /\
        , Clean fill surrounds cobble.
 Figure 3. Plan view of treatment cells.

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released by this decomposition, The cobble outside of
the cells created porous paths In the vicinity of treatment,
thereby increasing the likelihood of vapors escaping the
area outside the hood and causing  irregular melt shapes.

    Geosafe responded by excavating the area outside
of the remaining treatment cells and removing the par-
ticle board forms.  A refractory ceramic material with insu-
lating and reflective properties was  placed adjacent to
the exterior of the concrete cell walls. This helped to
control the melt shape, limit fugitive vapor emissions, and
restrict the melt  energy  inside  the cell boundaries.  Based
upon the experience Geosafe gained at the Parsons site.
the design and construction  of staged  treatment cells will
be modified for future projects,  it should be noted that
the use of cobble in treatment cell construction was
unique to the Parsons site where the configuration and
flow of the on-site groundwater dictated Its application.

    Utility requirements for this technology include elec-
tricity, natural gas (If a thermal oxidizer  Is used), and
water. As expected, electricity is a  major consideration
when implementing ISV. Total power to the electrodes
during treatment is approximately three  MW; the voltage
applied to each of the two phases during steady state
processing averages around 600 volts while the current
for each phase  averages approximately 2,500 amps. Dur-
ing treatment of the Demonstration Test cell (Cell 8).
energy  to the electrodes totalled  613 MW/h. Energy de-
mands for other cells at the Parsons site differed-prima-
rily because of variations in  the soil moisture content.

Process  Residuals

    The primary  residual generated by  the Geosafe  ISV
technology is the vitrified soil product. This  material is
generally left Intact and In place at the conclusion of
treatment. The treated volume may take one to two
years to cool completely.

    A number of  secondary process waste streams are
generated by the Geosafe  technology.  These  include air
emissions, scrubber liquor, decontamination liquid, car-
bon filters, scrub solution bag filters, HEPA filters, used
hood panels, and personal protective equipment (PPE).
Gaseous emissions which meet regulatory requirements
are discharged directly to the atmosphere following treat-
ment. The amount of scrubber liquor and filter  waste
generated depends on the nature of the treatment me-
dia. Factors such  as high off-gas particulate loading and
high soil moisture content may result In large quantities of
these materials. The number of used hood panels requir-
ing disposal depends on the type and extent of contami-
nation  at the site, the corrosiveness of the off-gases
generated during treatment (as well  as the corrosion-
resistance of the hood panels), and the  duration of treat-
ment.

    Some process residuals  (e.g., used scrub solution bag
filters, HEPA filters, and  PPE) can be disposed in  subse-
quent melt settings to reduce  the volume of these  materi-
als requiring ultimate disposal off-site. Scrubber water
generated  during treatment may require special  han-
dling depending  upon the type and level of contami-
nants being treated.
Performance  Data

   The Geosafe ISV technology was evaluated to deter-
mine its effectiveness in treating soil contaminated with
pesticides and metals. Cell 8 was selected for the Dem-
onstration Test since it exhibited the highest levels of con-
tamination whereby demonstration objectives could be
evaluated. The critical objective for this project was to
determine if final soil cleanup  levels set by the EPA  Region
V could be achieved. These specified cleanup levels
included  1,000  ng/kg for chlordane. 4,000 (xg/kgfor 4,4'-
DDT, 80 ^g/kg for dleldrln, and 12,000 ng/kg for mercury.
Non-crlttcal objectives for this project were:

    • to evaluate the leachability characteristics of chlor-
     dane, 4,4'-DDT, dieldrin, and mercury in the pre-
     treatment  soil using the toxicity  characteristic
     leachability procedure (TCLP)and determine whether
     the leachability characterlsttcs  of these compounds
     in the vitrified residue meet the regulatory limits speci-
     fied  In 40 CFR 261.24.  (Note: only chlordane and
     mercury are listed.);

    • to determine  the approximate levels of dioxins/furans,
     pesticides (specifically chlordane, 4,4'-DDT, and di-
     eldrin), mercury, and moisture in the pretreatment
     soil;

    • to characterize the liquid residues (scrubber water)  of
     the process with respect to pesticide and mercury
     concentrations:

    • to evaluate emissions from the process;

    • to identify the operational parameters of the  technol-
     ogy:

    • to develop operating costs and  assess the reliability
     of the  equipment: and

    . to examine  potential  impediments to the use of the
     technology including technical, institutional, opera-
     tional,  and safety impediments.

    Approximately 3,000 yd' (5,400 tons) of contaminated
soil  was  excavated and staged into  nine treatment cells.
Prior to treatment, three primary soil cores were obtained
from Cell 8  to  characterize  the concentrations of pesti-
cides, dioxins/furans, and metals. Samples were also col-
lected to determine the  leachability characteristics  of
pesticides and  mercury before treatment. In addition,
samples were taken for the analysis of grain size, moisture,
density, and  permeability. Prior to treatment, potable wa-
ter was charged to the scrubber system, and then sampled
and analyzed for volatile and semivolatile organic com-
pounds, pesticides, dioxins/furans, and metals. The scrub-
ber water was again sampled and analyzed for these
parameters during treatment.

    Samples of the stack gas were collected during treat-
ment. The samples  were  analyzed  for  volatiles.
semivolatiles, pesticides, dioxins/furans metals,  hydrogen
chloride, and particulates.  The stack gas was also moni-
tored for oxygen, carbon monoxide, and total hydrocar-
bons using continuous emission monitors.

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    System parameters including, but not limited to, volt-
age and amperage applied to  the  molten soil,  hood
vacuum,  and off-gas treatment train operational  attributes,
were monitored  during  treatment.  Measurements were
taken  every  minute and recorded by computer. Addi-
tional  parameters such as  hood  skin  and  plenum  tem-
peratures, scrubber pH  and volume, and  differential
pressures  across the scrubber system and filters were manu-
ally recorded  regularly.

    Three primary post-treatment vitrified soil samples were
collected from the surface  of Cell 8. Analysis of the sur-
face samples  was intended to  provide immediate  infor-
mation regarding the condition of the soil  until  samples
more representative of the center of the treatment area
can be safely obtained. Additional sampling is scheduled
to be  performed after the molten  mass has sufficiently
cooled (in approximately one  yr).  The  surface  samples
collected immediately after treatment were analyzed for
pesticides, dioxins/furans, and metals.  The TCLP was also
performed on these samples to  determine the leachabil-
ity of the treated soil.  Post-treatment samples were  col-
lected from the scrubber water and analyzed for volatile%
semivolatlles, pesticides,  dioxins/furans, and metals.

    Table 2 summarizes the range of selected analytical
results  from samples collected during the Demonstration.
Because  of the  limited  number  of samples collected,
ranges are presented rather than  average  values. The
data presented  in  this table are  limited to analytes  that
were of concern  during the Demonstration and important
in evaluating  test objectives. Concentrations below the
                            respective  reporting detection limits are indicated by a
                            less than' symbol (i.e., <).

                                Evaluation of the data  suggests the following results
                            and conclusions:

                               • The  technology successfully treated  the soil, com-
                                 pleting the test cell melt in ten days with only minor
                                 operational problems. During this time, approximately
                                 330 yd3 (approximately 600 tons)  of contaminated
                                 soil was vitrified, according to Geosafe melt summa-
                                 ries.  Approximately 613 MWh of energy was applied
                                 to the total soil volume (estimated to be 475 yd3)
                                 during vitrification of Cell 8; energy applied to  the
                                 actual contaminated soil volume could not be inde-
                                 pendently measured because clean fill  and surround-
                                 ing uncontaminated soil are vitrified as part of each
                                 melt. System operation was occasionally interrupted
                                 briefly for routine  maintenance such  as  electrode
                                 system addition and adjustment.

                                • The treated (vitrified) soil met the EPA Region V cleanup
                                 criteria for pesticides and mercury. Target pesticides
                                 were reduced to levels below their analytical report-
                                 ing detection  limits (<80ng/kg for chlordane, <16  ng/
                                 kg for 4,4'-DDT and dieldrin) in the treated soil. Mer-
                                 cury, analyzed  by standard SW-846  Method 7471
                                 procedures, was reduced to less than 40 fig/kg in the
                                 treated soil. Although the concentration of pesticides
                                 and mercury were below the cleanup criteria in some
                                 samples, significant contaminant reductions were
                                 achieved. Chlordane was not detected In any of the
 Table 2. Selected Data Summary Results
Pesticides
Pre-Treatment Soil fog/kg)
Post-Treatment Soil fag/fy)
Pre-Treatment TCLP (pg/L)
Post-Treatment TCLP (fig/L)
Stack Emissions (pg/rri3)
Stack Emissions (Ib/hr)
Chlordane !
<80
<80
O.5
O.5
<1.38
<1. 1 xJO-5
4,4' DDT
2,400- 23, 100
0.120-0.171
CO.f
<0,28
<2.2 x 10*
Dieldrin
1,210 - 8,330
6.5 - 10.2

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     SITE Demonstration samples, but were detected in
     samples collected by EPA Region V.

    • The solid vitrified material collected was subjected to
     TCLP for pesticidesand mercury. No target pesticides
     were detected in the leachate: the average leach-
     able mercury wasapproximately 0.2ng/L, well below
     the regulatory limit of 200 ng/L (40 CFR Part 261.24).

    • Stack gas samples were collected during the Dem-
     onstration Test to characterize process emissions. There
     were no target pesticides detected In the stack gas
     samples. During the Demonstration  Test, mercury
     emissions averaged 16 ng/m3 (1.1 xlCP" Ib/hr). The
     emissions were below the regulatory requirement of
     88 ng/m3 (5.93 x 1 O"4 Ib/hr).  Other metal emissions in
     the stack gas (specifically arsenic, chromium, and
     lead) were monitored and found to meet regulatory
     standards during testing. Stack gas  dispersion model-
     ing by Region V Indicated that metal  emlssionsdurlng
     treatment were not a human health risk.

    • Emissions of total hydrocarbons and carbon monox-
     ide were regulated at 100  ppmV  (as propane) and
      ISOppmV,  respectively. Throughout the Demonstra-
     tion Test, vapor emissions of these gases (measured
     downstream from the  thermal oxidizer) were  each
     consistently below 10 ppmV-well below the regula-
     tory guidelines.

    • Scrubber water generated  during the Demonstration
     Test contained volatile organlcs, partially oxidized
     semivolatile organics (phenolics),  mercury, and other
     metals. The scrubber water underwent secondary
     treatment off-site before ultimate disposal and data
     suggest that secondary treatment of  this waste stream
     is likely In most cases.

    • Pre-treatment soil drydensityaveraged 1.48tons/yd3,
     while  post-treatment soil dry density averaged 2.10
     tons/yd3. On a dry basis, a  volume reduction of ap
     proximately 30 % was observed for the test soil.

    Key findings from the  demonstration, including  com-
plete analytical results and the economic analysis, will be
published in  an  Innovative Technology  Evaluation Report.
This report will be used  to evaluate the Geosafe ISV Tech-
nology as an altermative for cleaning up similar sites across
the country. Information will also be presented in a  SITE
Demonstration  Bulletin  and a videotape.

Economic  Analysis

    Estimates on capital and operating costs have been
determined for a treatment volume of approximately 3,200
yd* (5,700 tons). This is slightly higher than the total treat-
ment volume at the Parsons site, but it is  based on the
treatment configuration used at this site (nine treatment
cells measuring 27 ft by 27 ft by 15 ft deep with 2 ft of
clean fill on top of the contaminated soil). This information
was extrapolated to determine a treatment cost for
remediating  approximately 970  yd5 (nine treatment cells
measuring 27 ft by 27 ft by 5 ft deep with 1  ft of clean  fill)
and approximately 4,400 yd3 (nine treatment cells  mea-
suring 27 ft by 27 ft by 20 ft deep with 2 ft of clean fill).  The
cost for the  treatment of approximately 3200 yd1  (5,700
tons) of soil is based on the SITE demonstration at the
Parsons site and is estimated to be approximately $780/
yd3 ($430/ton). For lesser volumes of soil (970 yd3, as de-
scribed above), the cost becomes approximately $1,500/
yd3 ($858/ton). For  larger volumes of soil (4,400 yd3, as
described above), the cost becomes approximately $670/
yd3 ($370/ton)  The primary determinants of cost are the
local price of electricity, the depth of processing, and the
soil  moisture content. Treatment volume (and therefore
treatment time) is the key variable between the costs of
these three cases. The cost of time-dependent factors
including equipment  rental,  labor,  consumables and sup-
plies, and utilities varies directly with treatment  time.

    The primary cost categories include utilities, labor,
and startup and fixed costs,  each contributing roughly
20% to the total cost (utilities slightly higher). The contribu-
tion of utilities increases markedly with increased treat-
ment volume.  Equipment costs and facilities modifications
and maintenance costs are each responsible for roughly
10% of the total treatment  cost. Treatment is  most eco-
nomical when treating large sites to maximum depths,
particularly since time between melts is minimal com-
pared to actual treatment time.

    The cost for treatment using the Geosafe ISV technol-
ogy is based on, but  not limited to, the following assump-
tions:

    . The contaminated  soil is staged  into treatment cells
      by an independent contractor prior to  Geosafe's
      arrival on-site. Cell preparation and construction are
      site-specific  and may be different for each case,
      however, it Is assumed  that each  site is prepared in a
      manner similar to the Parsons site.

    • The depth of treatment is assumed to exceed the
      depth of contamination by at least one ft to ensure
      that the melt incorporates the floor of the cell and
      beyond.

    . Treatment takes place 24 hr/day, 7 days/wk, 52 wk/yr.
      An on-line efficiency factor of 80% has been incorpo-
      rated to account for down-time  due to  scheduled
      and unscheduled  maintenance  and other unfore-
      seen  delays.

    • Operations for a typical shift require one shift engi-
      neer and one operator. In addition,onesite manager
      and one project control specialist  are present on-site
      during the day shift. Three shifts of workers are  as-
     sumed to work eight hr/day, seven day/wk for three
      weeks. At the end of three weeks, one shift of workers
      is rotated out, and a new set replaces the former.

    • The costs presented (in dollars/cubic  yard) are calcu-
      lated based on the number of cubic yards of con-
      taminated soil treated. Because clean fill and
      surrounding uncontaminated soil are treated as part
      of each melt, the total number of cubic yards of soil
      treated is higher than  the number of cubic yards of
      contaminated  soil  treated. Costs/cubic yard  based
      on total soil treated would, therefore, be  lower than
      the costs presented in this estimate.

    If Geosafe scales its  process differently than assumed
in this analysis (a likely scenario),  then the cost  of
remediation/cubic yard of contaminated soil will change.

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    These cost estimates are representative of charges
 typically assessed to the client by the vendor and do not
 include profit. The costs presented in this economic analysis
 are based upon data gathered at the Parsons site. The
 developer claims these  costs were unusually high, and
 expects the treatment costs for future sites to be  less than
the treatment costs for the Parsons site. A detailed expla-
 nation of  these costs is included in the Innovative Tech-
 nology Evaluation Report.

 Technology Status

    The technology was originally developed by Pacific
 Northwest Laboratory, operated  by  Battelle Memorial In-
 stitute, and has been undergoing testing and develop-
 ment since 1980. A majority of the development work was
 performed by the US. Department of Energy, however, sig
 nificant work also has been done for various private and
 other government sponsors. The technology has been
 licensed exclusively to Geosafe  Corporation  for the  pur-
 pose of commercial  applications  of hazardous and radio-
 active waste remediation. To date, the technology has
 been tested on a wide variety  of hazardous chemical.
 radioactive, and  mixed wastes. Treatability tests are typi-
 cally conducted on an engineering scale (100 to 200 Ib
 melts) to determine potential  applicability of the technol-
 ogy. Geosafe has also conducted full-scale in situ opera-
 tional acceptance tests at their facility in Rlchland, WA.
 The work performed at the Parsons site was the first com-
 mercial full-scale application  of the  ISV technology.

    The Records of Decision for five  U.S. Department of
 Defense and EPA-lead Superfund sites  (including the Par-
 sons site)  have identified ISV  technology as the  preferred
 remedy for cleanup. ISV also has been identified as an
 alternative cleanup option at two  additional sites. Cur-
 rently,  Geosafe is  scheduled to perform  full-scale
 remediation activities for other customers at sites con-
 taminated with PCBs, chlorinated organlcs, and toxic met-
 als. Treatment at each of these sites involves some amount
 of debris or otherwise foreign  materials.  In situ or staged in
 situ  configurations will  be used  for  the  planned
 remediatlons.

     Higher levels of contamination at other sites are  not
 expected to represent a significant challenge to the pro-
 cess. For these sites, it may be possible to obtain destruc-
 tion and  removal efficiencies (ORE) if contaminants are
 present at high enough  levels. DRE  calculations  were  not
 possible at the Parsons site due to the low levels of target
 organics.

     Operational parameters that affect the overall pro-
 cess performance  have  a  much  larger influence on suc-
 cessful application of ISV than  contamination levels.
 Factors such as high soil moisture, extreme depths (deep
 or shallow), the presence of  sealed  drums, and  soil com-
 position are the primary factors that  influence  remedial
 design and  operation.  With proper  management,  it  is
 anticipated  that the  process  may successfully be applied
 at other sites with higher levels of contamination.

 SITE Program  Description
  (CERCLA), also known  as Superfund. CERCLA was
  amended by the Superfund Amendments and Reautho-
  rlzatlon Act (SARA) In 1986. The SITE Program is a formal
  program established in response to SARA. The primary
  purpose of the SITE Program is to maximize the use of
  alternatives in cleaning up hazardous waste sites by en-
  couraging the development and  demonstration of new,
  innovative treatment and  monitoring technologies.  It con-
  sists of four major elements: the Demonstration Program,
  the Emerging Technology Program, the Monitoring and
  Measurement Technologies Program, and the Technol-
  ogy Transfer Program. The Geosafe ISV Technology was
  demonstrated  under  the Demonstration Program. This
  Capsule was published as part of the Technology Trans-
  fer Program.

- Disclaimer

     While the technology conclusions presented in this
  report may not change, the data  has not been reviewed
  by the Quality Assurance/Quality Control  office.

  Sources of  Further  Information

  EPA  Confacfs:

     U.S. EPA Project Manager:
     Teri Richardson
     U.S.  Environmental Protection  Agency
     Risk  Reduction Engineering Laboratory
     26 West Martin  Luther King Drive
     Cincinnati, OH 45268
     Telephone No.: 513/569-7949
     Fax No.: 513/569-7620

  Technology Developer:

     James E. Hansen
     Geosafe  Corporation
     2950 George Washington  Way
     Richland, WA 99352
     Telephone No.: 509/375-0710
     Fax No.:  509/375-7721

  References

     Hansen,  James E.  1993. 'In Situ Vitrification (ISV) for
  Remediation of Contaminated Soil Sites.' Geosafe Cor-
  poration.  Richland, WA.

     SAIC. 1993. 'Geosafe In Situ Vitrification Demonstra-
  tion Plan; Superfund Innovative Technology Evaluation,"
  Science  Applications International Corporation. San Di-
  ego,  CA.

     USEPA. 1992.  Handbook on Vitrification Technologies
  for Treatment of Hazardous and Radioactive Waste. EPA/
  625/R-92/002.  U.S.  Environmental  Protection Agency.  Of-
  fice of Research and  Development. Washington, D.C.
     In 1980, the U.S. Congress passed  the Comprehensive
 Environmental Response,  Compensation,  and Liability Act

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