&EPA
                      United States
                      Environmental Protection
                      Agency
                       Office of
                       Research and Development
                       Cincinnati, OH 45268
EPA/540/R-95/500a
July 1995
 SITE Technology Capsule
Unterdruck-Verdampfer- Brunnen
Technology (UVB)
Vacuum Vaporizing Well
Introduction

In 1980, the U.S. Congress passed tie Comprehensive
Environmental Response, Compensation, and Liability Act
(CERCLA), also known as Superfund, committed to
protecting human health and the environment from
uncontrolled hazardous wastes sites.  CERCLA was
amended  by  the  Superfund  Amendments  and
Reauthorization Act (SARA) in 1986 - amendments that
emphasize the achievement of long term effectiveness
and permanence of remedies at Superfund sites. SARA
mandates implementing permanent solutions and using
alternative treatment technologies or resource recovery
technologies, to the maximum extent possible, to clean
up hazardous waste sites.

State and federal agencies, as well as private parties,
are now exploring a growing number of innovative
technologies for treating hazardous wastes. The sites on
the National Priorities List total more than 1,200 and
comprise a  broad spectrum of physical, chemical, and
environmental  conditions requiring varying types of
remediation. The U.S. Environmental Protection Agency
(EPA) has focused on policy, technical, and informational
issues related to exploring and applying new remediation
technologies applicable to Superfund sites. One such
initiative is EPA's Superfund  Innovative Technology
Evaluation (SITE) program, which was established to
accelerate  development, demonstration,  and  use of
innovative technologies for site cleanups.  EPA SITE
Technology Capsules summarize the latest information
                         available on selected innovative treatment and site
                         remediation technologies and related issues.  These
                         capsules are designed to help EPA remedial  project
                         managers, EPA on-scene coordinators, contractors, and
                         other site cleanup managers understand the types of data
                         needed to effectively evaluate a technology's applicability
                         for cleaning up Superfund sites.

                         This capsule provides information on the Unterdruck-
                         Verdampfer-Brunnen (UVB)  in situ groundwater
                         remediation technology, a technology developed to remove
                         volatile organic compounds (VOCs) from groundwater. The
                         UVB system is a patented technology.  The developer
                         and patent holder is IEG mbH of Germany, and the United
                         States license holder is IEG™ Technologies Corporation
                         (IEG). The UVB process was evaluated under EPA's SITE
                         program between April 1993 and May 1994 at Site 31,
                         March Air Force Base (AFB) California, where groundwater
                         was   contaminated with  solvents,  including
                         trichloroethylene  (TCE).  Information in this capsule
                         emphasizes specific site characteristics and results of
                         the SITE field demonstration at March AFB.  Results
                         obtained independently by the developer at other sites in
                         the United States and Germany are summarized in the
                         Technology Status section. This capsule presents the
                         following information:

                            •  Abstract

                            •  Technology description

                            •  Technology applicability
                                  SUPERFUND INNOVATIVE
                                  TECHNOLOGY EVALUATION

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    •   Technology limitations

    •   Process residuals

    •   Site requirements

    •   Performance data

    •   Technology status

        Sources of further information

Abstract

The UVB technology is an in situ groundwater remediation
technology for aquifers contaminated with compounds
amenable to air stripping, and is an alternative method to
pump-and-treat remediation of groundwater. The UVB
technology is designed to remove VOCs from groundwater
by transferring the contaminants from the aqueous phase
to the gaseous phase and subsequently treating the
resulting air stream through carbon adsorption units.

The developer and patent holder is IEG mbH of Germany,
the U.S. license holder is IEG® Technologies Corporation.
The UVB system  consists of a single well  with two
hydraulically separated screened intervals installed within
a single permeable zone.  Pumping  in the lower section
followed by in situ  air stripping and reinfiltration in the
upper section creates a recirculation pattern of groundwater
in the surrounding aquifer. The continuous flushing of the
saturated zone with recirculated treated water facilitates
the partitioning of adsorbed, absorbed, and free liquid
contaminants to the dissolved phase through increased
dissolution, diffusion, and desorption.   Increased
partitioning through these processes is driven by increased
groundwater flow rates within the  system's radius of
circulation cell and increased concentration gradient
established by the reinfiltration and recircuiation of treated
water in the aquifer.

Where applicable, the UVB technology provides an
effective long-term solution to aquifer remediation by
removing contaminants in  the saturated zone without
extracting groundwater, lowering the groundwater table,
and generating wastewater typical  of  pump and treat
systems. Additionally, once the UVB treatment system
is installed and balanced, it requires minimal support from
on-site personnel.  The UVB technology was evaluated
under the SITE program at Site 31,  March AFB, where
groundwater was contaminated with solvents  including
TCE.

The demonstration evaluated the reduction  of TCE
concentrations in the groundwater discharged from the
 treatment system, the radius of circulation cell of the
 system, and the reduction of TCE concentrations in the
 groundwater within the system's radius of circulation cell.
 The study results showed that the UVB system removed
 TCE from the groundwater by an average of greater than
 94 percent.  The mean TCE concentration in water
 discharged from the  system  was approximately 3
 micrograms per liter (/L/g/L) with the 95 percent upper
 confidence limit calculated to be approximately 6 /L/g/L.
 The study also indicated that the radius of circulation cell
 was 40 feet in the downgradient direction and may extend
 as far as 83  feet based on modeling of the radius of
 circulation cell in the alluvial aquifer at March AFB by the
 developer.  The  radius of circulation  cell is  largely
 controlled by the  hydrogeologic characteristics of the
 aquifer and, to a lesser extent, UVB system design. TCE
 concentrations within the aquifer were reduced laterally
 by approximately 52 percent in the radius  of circulation
 cell during the 12-month pilot study.

 Technology Description

 One of the UVB technology designs is an  in situ
 groundwater remediation technology that combines air-
 lift pumping and air stripping to remove VOCs from
 groundwater.  A properly installed UVB system consists
 of a single well with two hydraulically separated screened
 intervals installed  within a single permeable zone
 (Figures  1, 2 and 3).  The air-lift pumping occurs in
 response to negative pressure introduced at the wellhead
 by a blower. This blower creates a vacuum that draws
 water into the well through the lower screened portion of
 the well. Simultaneously, air stripping occurs as ambient
 air (also flowing in response to the vacuum)  is introduced
 through a sieve plate located within the upper screened
 section of the well, causing air bubbles to form in the
 water pulled into the  well.  The rising air bubbles provide
the air-lift pump effect that moves water toward the top of
the well and draws water into the lower screened section
 of the well. This pumping effect is supplemented by a
 submersible pump that ensures that water flows from
 bottom to top in the well. As the air bubbles rise through
the water column, volatile compounds are transferred from
the aqueous to the gaseous phase. The rising air transports
 volatile compounds to the top of the well casing, where
they are removed by the blower. The blower effluent is
treated before discharge using a carbon adsorption unit.

The transfer of volatile compounds is further enhanced
 by a stripping reactor located immediately above the sieve
 plate.  The stripping reactor consists of a fluted and
 channelized column that facilitates the transfer of volatile
 compounds to the gas phase by increasing the contact
time between the two  phases and by minimizing the
 coalescence of air bubbles. The overall stripping zone of
the UVB system extends from the sieve plate to the top

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   Carbon Adsorption Units
                          Blower
     Well
   Centerline
       K-

Monitoring Well
  Ambient Air
                                                                        40 Feet-X
                             60 Feet-X
Monitoring Well
                                                                            Inner Cluster
                                                                           Monitoring Wells
                                                      Vapor Monitoring Well
85 Feet-X
                                                      Outer Cluster
                                                     Monitoring Wells
                                          Groundwater
                                             Intake
                                                                                           Groundwater
                                                                                              Table
                                                                                           	T	
                   Saturated Zone
                                                                  CONCEPTUAL DIAGRAM
     —». Groundwater flow
     NOT TO SCALE
Figure 1:  The Unterdruck-Verdampfer-Brunnen  Well

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                                           Fresh Air Intake
                                   To  Blower    -L.
           Ground  Surface
                 inch
     Monitoring Weils (W2  &  W3)
     with Stainless  Steei Screen
          (40  ft to 55 ft)

         1 PVC  2 inch Deep
         Monitoring Weil (W1)
     with Stainless Steel Screen
         (69.7  ft to 79.7  ft)
               Unsaturcted
                   Zone
                  \   Vacuum
             .   .   \Extraction
      Approximate   X,
   Groundwater Level  %>>
   3  Double—cosed Screens
   and  1  Bridge-Slot Screen
       (41.2  ft to 55  ft) ^<
      Saturated
         Zone
      Steel Casing
  (55 ft  to  69.7 ft)


       3 Bridge-Slot Screens
        (69.7 ft to 81.7 ft)
               Sump
        (81.7  ft to  83.7 ft)
                                           24 In. Diameter
Figure 2:  The As-Built Unterdruck-Verdampter-Bmnnen Configuration
                                                                           NOT TO SCALE

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                                       Frash Air  Intake
                              To Blower     '
    Internal  Cantrailzers
        Double-Wai!
      Stripper  Reactor

       Pinhoie Plate
           Pump
          Packer
       Water Intake
HOPE - High Density Polyethylene
                                                                         NOT TO SCALE
Figure 3:  The As-Built Unterdruck-Vardampfer-Brunnen Internal Components

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of the water column.  To maximize volatilization in the
stripping zone, the sieve plate and stripping reactor are
positioned at a depth that optimizes the reach of the
stripping zone and the volume of air flow into the system.
The down-well components of the UVB system have been
designed with leveling ballast that allows the system to
be free floating.  This feature allows the system to
compensate for fluctuations in groundwater  elevation
during operation and,  thereby, maintain maximum
volatilization.

Once the upward stream of  water leaves the stripping
reactor, the water falls back through the well casing and
returns to the aquifer through the upper well screen. This
return flow to the aquifer, coupled with inflow at the well
bottom, circulates groundwater around the UVB well. The
extent of the circulation pattern is known as the radius of
circulation cell,  which determines the volume of water
affected by the UVB system.

The radius of circulation cell and the shape of the circulation
pattern are directly related to the properties of the aquifer.
The  circulation pattern is further modified by  natural
groundwater flow that skews the  pattern  in the
downgradient direction. Numerical simulations of the UVB
operation indicates that the radius of circulation cell is
largely controlled by anisotropy (horizontal [Kh] and vertical
[Kv]  hydraulic  conductivity),  heterogeneity, aquifer
thickness and, to a lesser extent, well design. In general,
changes that favor horizontal flow over vertical flow such
as a small  ratio of screen length to aquifer thickness,
anisotropy, horizontal heterogeneities such  as low
permeability layers,  or increased aquifer thickness will
increase the radius of circulation cell. As a general rule,
the developer estimates the system's radius of circulation
cell to be approximately 2.5 times the distance between
the upper and lower screen intervals.

Groundwater within the radius of circulation cell includes
both treated and untreated water. A portion of the treated
water discharged to the upper screen is recaptured within
the circulation cell.  Treated  water not captured by the
system leaves the circulation cell in the downgradient
direction. The percentage of treated water recycled within
the UVB system (IEG estimates that it can be up to 90
percent) is related to the radius of circulation cell and is a
function of the ratio  of Kh/Kv.  The larger the radius of
circulation cell and the larger the Kh to Kv ratio  values,
the smaller the percentage of recycled water for  a given
aquifer.  The recycled treated water dilutes influent
contaminant concentrations.

Technology Applicability

The UVB technology's applicability was evaluated based
on the nine criteria  used for  decision making in the
Superfund  feasibility study  process.   Results of the
evaluation are summarized in Table 1. In general, the UVB
technology is applicable for treatment of dissolved phase
volatile compounds in groundwater. The developer claims
that other UVB system configurations allow for treatment
of semi- and non-volatile contaminants and nitrates. In
addition, the chemical and physical dynamics established
by the recirculation of treated water make this technology
suited for remediation of contaminant source areas.  The
technology employs readily available equipment  and
materials and the material handling requirements and site
support requirements are minimal.

The UVB system demonstrated for the SITE program was
designed to remove VOCs from the groundwater, in
particular TCE and  1,1-dichloroethene (DCE).   The
developer claims that the technology can also clean up
aquifers contaminated with other organic compounds,
including volatile and  semivolatile hydrocarbons.
According to the developer, the UVB technology in some
cases is also capable of simultaneous recovery  of soil
gas from the vadose zone and treatment of contaminated
groundwater from the aquifer as a result of the  in situ
vacuum. For soil gas recovery, the upper screened portion
of the UVB well is completed from below the water table
to above the capillary zone. Although the developer claims
that the UVB technology reduces VOCs from soil gas in
the vadose zone, the technology was evaluated only for
its effects in the saturated zone.

Technology Limitations

The UVB technology has limitations in areas with very
shallow groundwater (less than 5 ft.).  In such  areas, it
may be difficult to establish a stripping zone long enough
to remove contaminants from the aqueous phase.  The
technology has further limitations in thin aquifers (less
than 10 ft.); the saturated zone must be of sufficient
thickness to allow proper installation of the system. In
addition, the thickness of the saturated zone affects the
radius of circulation cell; the smaller the  aquifer
thicknesses, the smaller the radius of circulation cell.

The majority of water being drawn from the aquifer into
the lower screen section is treated water reinf iltrated from
the upper section.  This recirculation of cleaned water
significantly decreases the contaminant levels in the water
treated by the system. As the UVB system continues to
operate, the circulation cell grows until a steady state is
reached.  As the circulation cell grows, the amount of
recirculated water increases causing a further decrease
of contaminant levels in the water treated by the system.

High concentrations of volatile compounds may require
more than one pass through the system to  achieve
remediation goals.  This may initially be a problem since
a portion of the treated water is not captured by the system
and leaves the circulation cell in the downgradient direction.

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Table 1:  Feasibility Study Evaluation Criteria for the UVB Technology
         CRITERION
                   UVB TECHNOLOGY PERFORMANCE
        Overall Protection of   The technology eliminates contaminants in groundwater and prevents further
        Human Health and the  migration of those contaminants with minimal exposure to on-site workers and
        Environment          the community. Air emissions are reduced by using carbon adsorption units.
        Compliance with
        Federal ARARs
        Long-Term
        Effectiveness and
        Permanence

        Reduction of Toxicity,
        Mobility, or Volume
        Through Treatment
Compliance  with  chemical-,  location-, and  action-specific ARARs  must be
determined on a site-specific basis. Compliance with chemical-specific ARARs
depends  on  (1)  treatment  efficiency of  the UVB  system,  (2)  influent
contaminant  concentrations,  and  (3)  the amount of  treated groundwater
recirculated within the system.

Contaminants are permanently removed  from  the groundwater.  Treatment
residuals (for example, activated carbon) require proper off-site treatment and
disposal.

Contaminant  mobility  is  initially  increased, which  facilitates  the  long-term
remediation of the groundwater within  the system's  radius of influence.  The
movement  of contaminants  toward the  UVB system  within  the  system's
capture zone prevents further migration of those contaminants  and ultimately
reduces the volume of contaminants in the  groundwater.
   5    Short-Term
        Effectiveness
   6    Implementability
During site preparation and installation of the treatment system, no adverse
impacts to the  community, workers,  or the environment  are anticipated.
Short-term  risks  to  workers,  the community,  and the  environment  are
presented by increased mobility of contaminants during  the  initial start-up
phase of the system and from the system's air stream. Adverse impacts from
the air stream  are  mitigated  by passing  the  emissions  through carbon
adsorption units before discharge to the ambient air. The time requirements for
treatment using the UVB system depends on site conditions and may require
several years.

The site must be accessible to large trucks.  The entire system requires  about
100-700 square feet (average 300). Services and supplies required include a
drill rig, off-gas treatment system, laboratory analysis,  and electrical utilities.
   7    Cost
Capital costs for installation of a single unit are estimated to be $180,000, and
annual operation and maintenance costs estimated to be $72,000.
   8    Community
        Acceptance
The small risks presented to the community along with the permanent removal
of the contaminants make public acceptance of the technology likely.
   9    State Acceptance      State   acceptance   is   anticipated   because   the   UV   system   uses
                              well-documented and widely accepted processes for the  removal of VOCs
                              from groundwater and  for treatment of the process air  emissions.  State
                              regulatory agencies may require permits to operate the treatment system, for
                              air emissions,  and to store contaminated soil cuttings and  purge water for
                              greater than 90 days.
ARAR - Applicable or relevant and appropriate requirements

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 However, as the UVB circulation cell is established, the
 influent concentrations should be diluted to below levels
 requiring more than one pass, thereby limiting the potential
 migration of contaminants above target concentrations
 from the system.

 Process Residuals

 The materials handling requirements for the UVB system
 include managing spent granular activated carbon, drilling
 wastes, purge water, and decontamination wastes
 generated during installation, operation, and monitoring of
 the treatment system.  Spent carbon generated during
 treatment of the system air effluent will either be disposed
 of or regenerated by the carbon vendor. Tine drilling wastes
 are produced during installation of the system well. The
 drilling waste can be managed either in 55-gallon drums
 or in roll-off type debris bins.  Disposal options for this
 waste depend on local requirements and on the presence
 or absence of contaminants. The options may range from
 on-site disposal to disposal in a hazardous waste or
 commercial waste landfill.

 Purge water is generated during development and sampling
 of the groundwater monitoring wells.  Purge water can be
 managed in 55-gallon drums.  Disposal options  again
 depend on local restrictions and on the presence or
 absence of contaminants.  Options  range from surface
 discharge through a National Pollutant Discharge
 Elimination System (NPDES) outfall, to disposal through
 a Publicly Owned Treatment Works (POTW), to treatment
 and disposal at a permitted hazardous waste facility.

 Decontamination wastes are generated during installation
 and  sampling activities.   Decontamination  wastes
 generated during installation include decontamination water
 and may include a decontamination  pac for the drill rig.
 The solid decontamination wastes can be managed in roll-
 off type  debris  boxes, and the liquid wastes can be
 managed in 55-gallon drums. Disposal options are similar
to those for drilling wastes and purge water.

Site Requirements

A  UVB treatment system consists of several major
components: an 8,  10, 16,  or 24-inch dual screen well,
well packer, submersible  pump, sieve  plate, stripping
 reactor, blower, and carbon filter units.  A drill rig is required
to install the system  well.  Once the well has  been
completed, the treatment system can be operational within
 1 day if all necessary equipment, utilities, and supplies
are available.

The site support requirements needed for the UVB system
are space to set up  the carbon adsorption units and
 electricity.  The system requires standard 120/240 volts
 (200 amperes). An electrical pole, a 480-vott transformer,
 and electrical hookup between the supply lines, pole, and
 the UVB treatment system are necessary to supply power.
 The space requirements for the above-ground components
 of the UVB system including the UVB system well, off-
 gas treatment units, blower, and piping used during the
 SITE demonstration are approximately  500 square feet.
 Other requirements for installation and routine monitoring
 of the system include access roads for equipment
 transport, security fencing, and decontamination fluids for
 drilling and sampling.

 Performance Data

 The SITE demonstration  for the UVB  technology was
 designed with three primary  and seven secondary
 objectives to provide potential users of the technology
 with the necessary information to assess the applicability
 of the  UVB system at  other contaminated sites.
 Demonstration program objectives were  achieved by
 collecting groundwater and soil gas samples, as well as
 UVB system process air stream samples over a 12-month
 period.  To meet the  objectives, data were collected in
 three phases: baseline sampling, long-term sampling, and
 dye  trace sampling.  Baseline and long-term sampling
 included the collection of groundwater samples from eight
 monitoring wells, a soil gas sample from the soil vapor
 monitoring  well, and  air samples from the three UVB
 process air streams both before UVB system startup and
 monthly thereafter.  In addition, a dye trace study was
 conducted to evaluate the system's radius of circulation
 cell.  This study included the introduction of fluorescent
 dye into the groundwater and the subsequent monitoring
 of 13 groundwater wells for the presence of dye three times
 a week over a 4-month period.

 The conclusions of the UVB SITE demonstration at March
 AFB are presented below by project objective.

 Primary  Objectives:
P1     Determine the concentration to which the UVB
       technology reduces TCE and DCE in groundwater
       discharged from the treatment system.

The UVB effectively removed target compounds from the
groundwater as indicated  by the analytical  results
presented in Table 2.  During the demonstration, TCE
concentrations in samples from the influent well ranged
from 14 jL/g/L to 220 jug/L with an arithmetic mean of
approximately 56 /L/g/L.  The UVB system reduced TCE
in the groundwater discharged from the treatment system
to below 5 ug/L in nine out of the 10 monthly monitoring

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 events and on average by greater than 94 percent during
 the period in which the system operated without apparent
 maintenance problems. The mean concentration of TCE
 in  the  water  discharged from  the system  was
 approximately 3 ug/L; however, the 95 percent upper
 confidence limit for TCE in the treated groundwater was
 calculated to be approximately 6/jg/L

 The UVB system reduced DCE to  less than 1 ji/g/L. in
 groundwater discharged from the  treatment system;
 however, the system's ability to remove DCE cannot be
 meaningfully estimated due to the low (less than  4/jg/L)
 influent concentration of DCE.

 P2    Estimate the radius of circulation cell of the
       groundwater treatment system.

 The radius of circulation cell of the groundwater treatment
 system was estimated by both direct and indirect methods.
 The radius of circulation cell was directly measured by
 conducting a dye trace study.  Based on the dye trace
 study, the radius of circulation cell was measured to be at
 least 40 feet in the downgradient direction. However, no
 dye was observed in wells located 40 feet upgradient or
 cross gradient of the UVB system. The radius of circulation
 cell was indirectly evaluated  by  (1)  modeling  the
 groundwater flow, and (2) analyzing aquifer pump test data.
 Groundwater flow modeling results conducted  by the
 developer indicate a radius of circulation cell of 83  feet.
 Analysis of aquifer pump test data indicates a radius of
 circulation cell of about 60 feet for a traditioned pumping
 well near this UVB system. An attempt was made to
 indirectly evaluate the radius of  circulation eel! using
 variations  of target compound  concentrations  and
 fluctuations of dissolved oxygen in surrounding
 groundwater monitoring wells. However, these methods
 did not provide a  reliable  or conclusive estimate of the
 radius of circulation cell due to variables independent of
the UVB system.

 P3     Determine whether TCE and DCE concentrations
       have been reduced in groundwater (both vertically
       and horizontally) within the radius of circulation
       cell of the UVB system over  the course of the
       pilot study.

 Based on the demonstration results presented in Table 2,
TCE concentrations in samples from the shallow and
 intermediate zone wells were reduced both vertically and
 laterally except in the intermediate outer cluster well, which
showed an increase in concentration,  TCE concentrations
 have  been reduced laterally  by  an average of
approximately 52 percent in samples from the shallow and
 intermediate zones of the  aquifer  No reduction of TCE
was observed in samples from the deep zone, which could
be due to limited duration of monitoring in this zone.
 Secondary Objectives:

 S1     /Assess homogenization of the groundwater within
        the zone of influence.

 A convergence and stabilization of TCE concentrations
 was observed  in samples  from the shallow and
 intermediate  zones of the aquifer,  which suggest
 homogenization  of contaminant concentrations in the
 groundwater.

 S2     Document  selected  aquifer geochemical
        characteristics that may be affected by oxygenation
        and recirculation of treated groundwater.

 No clear trends in the field parameters, general chemistry,
 or dissolved metals results were observed that would
 indicate significant precipitation of dissolved metals,
 changes in dissolved organic carbon, or the presence of
 dissolved  salts caused by the increase in  oxygen in
 groundwater.

 S3     Determine whether the treatment system induces
        a vacuum in the vadosezone that suggests vapor
        transport.

 Although the developer claims that the UVB system has
 applications to cleanup of both groundwater and soil gas,
 the system installed at Site 31 was designed  to remove
 halogenated hydrocarbons from the groundwater only. The
 VOC concentrations and vacuum measurements in the
 vapor  monitoring well indicate that transport  of
 contaminants was not significantly affected by operation
 of the UVB system as currently designed. Changes in
 system  design and operating parameters may lead  to
 significant transport of contaminants in the vadose zone.

 S4     Estimate the capital and  operating costs  of
        constructing a single treatment unit to  remediate
       groundwater contaminated with TCE and DCE.

 Costs are highly site specific. EPA estimates that one-
time capital costs for a single treatment unit are $180,000;
variable annual operation and maintenance costs for the
first year were estimated to be $72,000, and for subsequent
years, $42,000. Based on these estimates, the total cost
for operating a single UVB system for 1 year was calculated
to be $260,000. Since the time required to remediate an
aquifer is site-specific, costs have been estimated for
operation of a UVB system over a range of time for
comparison purposes. Therefore, the cost to operate a
single UVB system was calculated to be $340,000 for 3
years, $440,000 for 5 years, and $710,000 for 10 years.
Additionally, the costs for treatment per 1,000 gallons of

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Table 2:  Aquifer Trichloroethene Concentration  Summary
 Well      Description
                         Baseline      1ST       2NO       3HD
                                             Trichloroethene Concentration (upA)

                                        4™       5Tn       6™       7™       8TH
                                                                                                                    9™       10™      11™       12™
 Wl      Intermediate
          System Well
22*       57        60       220        35        31        30        22        34
                                                                                         31
                                                                                                   14
                                                                                                             26       110
 W2       Shallow         1'
          System Well
                              16       2.4
                                                                               38*
   Percent Reduction'
                           NC       >98       >98       93       93        87        >97      >95       -12        94        93        95       41
 PW1     Shallow Inner      530
          Cluster Well
         500      440       6?0       608       530       540       600       600       530       30Q       330       340
 PW2   Intermediate Inner    750
          Cluster Well
         1,000      1.900     2,000     1,100     1.200      910       800       620      340      280       240       270
 PW3  Deep Inner Cluster     100
             Well
          130      180       310       230       200       250       NA        NA        NA        NA        NA       NA
 PW4     Shallow Outer      650       760       760       680       818       980      1,100      1,600      1.400      970       300       340       290
          Cluster Well


 PW5   Intermediate Outer    120       270       310       390       330       350       450      640       360       310       230       210       210
          Cluster Well


 PW6   Deep Outer Cluster    110       130       110       130       92        140       150      NA       NA       NA       NA       NA       NA
             Well
         Concentration affected by water added during drilling and well installation.
1         Percent reduction = [[C (w-l) - C (w.2)] / C (w.t)J x  100; where C (w.t) = deep well concentration and C (w.2) = shallow well concentration
*         Concentration affected by system maintenance problems; therefore, results were not used to evaluate primary objectives.
ug/L     Micrograms per liter
<        Less  than
>        Greater than
NC      Not calculated
NA      Not analyzed

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groundwater were estimated to be $260 for 1 year, $110
for 3 years, $88 for 5 years, and $71 for 10 years.  The
cost of treatment  per 1,000 gallons refers to the amount
of groundwater pumped through the system.  Potential
users of the treatment technology should be aware that
typically 60 to 90 percent of the water pumped through
the system is recirculated water. A more detailed document,
the  Innovative Technology Evaluation  Report (ITER)
contains information on the assumption for these cost
figures.

S5     Document pre- and post-treatment off-gas volatile
       organic contaminant levels.

The results from air monitoring of  the UVB treatment
system indicated that low concentrations of TCE were
removed from the groundwater.  TCE  concentrations
reduced by the UVB system correlate to trends observed
in target compound concentrations in the  inner cluster
monitoring wells (that is, increasing concentration from
the  baseline event to the third monthly monitoring event
with a subsequent decrease in concentrations).

S6     Document system operating parameters.

The temperature of the internal monitoring  ports ranged
from 18.5 to 44.7 degrees Celsius; the relative humidity
ranged from 27 to 100 percent; the vacuum  pressure
ranged from 13.81 to  15.03 pounds per  square  inch
absolute; the air flow ranged from 100 to 898 standard
cubic feet per minute; the air velocity ranged from 1,109
to 9,999 feet per minute; and the discharge through the
UVB system  was estimated by the developer to be
approximately 22 gallons per minute

S7     Evaluate the presence of aerobic biological
       activity in the saturated and vadose zones.

Carbon dioxide concentrations measured  in the vapor
monitoring well indicate that carbon dioxide has increased
by more than 2 percent since baseline monitoring. Several
fluctuations in O2 level were observed;  however, there
was no evidence of a downward trend of these
concentrations.   The minor changes in CO2  and O2
measured  suggest that  bioactivity in the  soil  and
groundwater was not significantly enhanced by operation
of the UVB system.

Additionally, CO2 concentrations measured at the UVB
system's  intake and after the blower reveal minor
fluctuations of relative CO2 concentration. These results
also suggest that bioactivity due to increased dissolved
oxygen levels in  the groundwater was not significantly
enhanced by operation of the UVB system.
Technology Status

Since its introduction in 1986, the UVB technology has
been  applied at some 80 sites in Europe.  No U.S.
installation of a UVB system has required an NPDES
permit to date. A UVB system was first installed at a
U.S. site in September 1992; currently, there are 22 UVB
systems operating in eight states.

A more detailed document,  the ITER,  contains more
information on this documentation, the developer has
provided four select case studies that document operation
of the UVB system at sites in the U.S. and Germany. Two
of the cases are from sites in Germany and involve the
remediation  of chlorinated hydrocarbons  (TCE, 1,1,1-
trichloroethane, and dichloromethane) in the groundwater.
The two cases from the U.S.  document the remediation
of groundwater contaminated with benzene, toluene,
ethylbenzene, and xylene at an underground storage tank
site  in  Troutman, North Carolina, and Weston's
interpretation of the data collected during but independent
of this SITE demonstration.

Sources of Further Information

For further information, contact:

        U.S. EPA Project Manager:
        Ms. Michelle Simon
        U.S. Environmental Protection Agency
       26 West Martin Luther King Drive
        Cincinnati, OH 45268
        513-569-7469
        FAX: 513-569-7676
Technology Developer:

       I EG Technologies Corporation
       Dr. Eric Klingel
       1833-D Cross Beam Drive
       Charlotte, NC 28217
       704-357-6090
       FAX: 704-357-6111

March AFB Demonstration Partner:

       Roy F. Weston, Inc.
       Mr. Jeff Bannon
       14724 Ventura Blvd., Suite 1000
       Sherman Oaks, CA 91403
       (818)971-4900
       Fax:  (818)971-4901
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United States
Environmental Protection Agency
National Risk Management Research Laboratory (G-72)
Cincinnati, OH 45268

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