EPA
United States
Environmental Protection
Agency
Office of
Research and Development
Cincinnati, OH 45268
EPA/540/R-99/001a
March 1999
SITE Technology Capsule
Multi-Vendor Bioremediation
Demonstration Project:
Environmental Laboratories/
SBP Technologies' UVB
Vacuum Vaporization Well
Process
Abstract
The UVB process was developed by IEG Technologie
GmbH of Germany and licensed in the eastern U.S. by
Environmental Laboratories, Inc. (ELI) and SBP
Technologies, Inc. (SBP). A modified microbial system
employing an in-well biofilterwas demonstrated underthe
SITE Program at the Sweden-3 Chapman landfill in
Sweden, New York, along with the ENSR/Larsen Biovault
technology and the R. E. Wright Environmental, Inc. In
Situ Bioventing System, as part of a Multi-Vendor
Bioremediation Demonstration.
A single wide bore UVB-400 well (Vacuum Vaporization
Well) equipped with a biofilter was used in the
demonstration. Groundwaterwas circulated through the
well and is returned, presumably with an increased
microbial population, to the saturated zone for further in
situ biod eg radation of volatile organic compounds (VOCs).
An aboveground blower assists circulation of air, provides
oxygen for biodegradation, and strips volatiles from the
vadose zone. Extracted volatiles were treated by an ex
situ vapor phase biofilter followed by activated carbon.
The developers estimated that the single well would
influence a soil volume of approximately 1000 yd3.
A primary objective of the demonstration was to determine
the effectiveness of the UVB Process in reducing the
concentrations of six target VOCs in the vadose zone soil
to below New York State Department of Environmental
Conservation (NYSDEC) Soil Cleanup Criteria (acetone:
0.2 ppm, methyl ethyl ketone: 0.6 ppm, 4-methyl-2-
pentanone: 2 ppm, cis-1,2-dichloroethene: 0.6 ppm,
trichloroethene: 1.5 ppm, and tetrachloroethene: 2.5 ppm).
ELI/SBP expected that 90% of the soil samples collected
from the vadose zone of the 50 ft x 50 ft test area would
meet the NYSDEC Criteria for the six target contaminants
after six months (one season) of treatment. A second
primary objective was to evaluate the developers' claim
that biodegradation would be the dominant mechanism of
contaminant removal, but all participants agreed that this
claim could only be evaluated qualitatively because of
limitations in the sampling procedures. Assessing the
effectiveness of the process in reducing groundwater
contamination by VOCs was a secondary objective of the
study.
Because of the time required to establish the convection
loop coupled with operational and site problems, the
investigation was extended from 5.5 months to 14 months.
After 5.5 months, only 65% of approximately 50 soil
SUPERFUND INNOVATIVE
TECHNOLOGY EVALUATION
-------
samples from both vadose and saturated zones met the
NYSDEC Criteria, and only 70% met the Criteria after 14
months. Nevertheless, significant removal of the ketones
appeared to take place over the 14-month study.
Analytical results and other observations suggest that both
biodegradation and stripping were important mechanisms
for VOC removal from the soil. Groundwater
concentrations of VOCs also decreased over time, but
neitherthe extent of removal northe removal mechanism
could be ascertained from the demonstration data.
Introduction
In 1980, the U.S. Congress passed the Comprehensive
Environmental Response, Compensation, and Liability Act
(CERCLA), also known as Superfund. The Act is
committed to protecting human health and the
environment from uncontrolled hazardous waste 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 emphasizes the use of permanent solutions,
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 over 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, site
remediation technologies, and related issues. These
capsules are designed to help EPA remedial project
managers and on-scene coordinators, contractors, and
othersite cleanup managers understand the types of data
and site characteristics needed to effectively evaluate a
technology's applicability for cleaning up Superfund sites.
The Multi-Vendor Bioremediation Demonstration was a
unique SITE project in that it was a cooperative effort
between the USEPA, NYSDEC, the New York State
Center for Hazardous Waste Management, and three
developers. This demonstration evaluated three
bioremediation technologies: 1) UVB Vacuum-Vaporized
Well System - Environmental Laboratories/SBP
Technologies, Inc.; 2) In situ Bioventing System - R.E.
Wright Environmental, Inc., and 3) Biovault Treatment
Process - ENSR/Larsen. A more detailed Innovative
Technology Evaluation Report (ITER) will be available for
each of the three studies.
This capsule contains information on the ELI/SBP UVB
Treatment Process, a system designed to provide
bioremediation for groundwater and permeable soils
(saturated and vadose) contaminated with VOCs. The
technology was evaluated under EPA's SITE program
from July 1994 to September 1995. The pilot-scale
demonstration was conducted at the Sweden-3 Chapman
landfill site in Sweden, New York where soils and
groundwater were found to be contaminated with
trichloroethene (TCE), tetrachloroethene (PCE), cis-1,2-
dichloroethene (cis-DCE), acetone, 2-butanone (MEK), 4-
methyl-2-pentanone (MIBK), toluene, and other aromatic
compounds.
Information in this Capsule emphasizes specific site
characteristics and results of the SITE field demonstration
of the ELI/SBP UVB Treatment Process at the Sweden-3
Chapman site. This capsule presents the following
information:
• Abstract
• Technology description
• Technology applicability
• Technology limitations
• Process residuals
• Site requirements
• Performance data
• Technology status
• Sources of further information
Technology Description
According to the developers, the Unterdruck Verdampfer
Brunnen (German for Vacuum Vaporization Well) or UVB
technology combines air stripping and biodegradation in
both the soil formation and a well to remove VOCs from
soils. The system used at the site (Figure 1) consisted of
an aboveground blower connected to a specially adapted
wide bore groundwater well. The system in the well
included a negative-pressure stripping reactor, located
above the expected seasonal high water table, on top of
an integrated bioreactor (fixed film activated carbon
bioreactorwith slow-release inorganic nutrients). To allow
for fluctuations in the water table, a submersible pump
was included to insure a constant supply of groundwater
to the bioreactor. Groundwater flow is controlled by
screening the well casing in two areas; near the expected
water table surface and near the bedrock, and by placing
a submersible pump near the base. A packer separates
the lower screened portion from the upper portion and
forces groundwater to pass through the biofilter.
In operation, the aboveg round blower induces a suction in
the stripper, drawing in ambient air through a centrally
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-------
located pipe as well as from the surrounding vadose zone
while raising the level of water already present in the well.
The ambient air infiltrating the surrounding soil formation
captures VOCs that may volatilize. Infiltration also
increases the oxygen concentration of the
groundwater/soil matrix and stimulates indigenous
microbes to enhance the biodegradation of contaminants.
The ambient air also bubbles through the raised
groundwater, sparging or stripping VOCs in the process.
The VOC-laden air is then exhausted through a
combination of ex situ, vapor-phase bioreactors and
activated carbon filters on the positive pressure side of the
blower to minimize VOC emissions to the atmosphere.
After treatment in the stripper reactor, the elevated
groundwater is discharged into the upper soil stratum and
percolates back to its natural level, again picking up
contaminants from the soil matrix. Thus, a groundwater
circulation loop is established. This circulation cell
constantly transports contaminants, nutrients, oxygen and
indigenous bacteria through the affected soil. The
contribution of the physical "stripping" effect as compared
to the biological effect varies according to site specific
conditions (e.g., water table depth, air and water
permeability, indigenous microbe characteristics, etc.).
According to ELI/SBP, dewatering is not essential for
efficient operation of this system. Treatment of the
phreatic and capillary fringe zones also occurs
simultaneously. The system can be operated in either a
standard mode as described above and used for the
demonstration, or in a reverse-flow circulation mode by
the addition of a pump; flow modes can be readily
converted in the field.
The developers suggest several means of enhancing the
biodegradation. The fixed film indigenous microflora used
by the bioreactor can be augmented with other types of
contaminant-degrading microbes, depending on site
conditions and contaminants. Degradation also can be
stimulated by the addition of either liquid or gaseous
inorganic nutrients and/or alternative electron acceptors.
Finally, injection of heated air can enhance both VOC
desorption and the rate of biodegradation of organic
contaminants. This would be particularly useful in regions
normally subject to cold winter climates. These concepts
were not evaluated during this demonstration.
Technology Applicability
The UVB Microbial Treatment Process was evaluated
based on the nine criteria used for decision making as
part of the Superfund Feasibility Study (FS) process.
Results of the evaluation are summarized in Table 1.
The ELI/SBP UVB system is designed to treat vadose and
saturated zone soils and groundwater contaminated with
VOCs and semivolatiles. 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, according to the developers.
Technology Limitations
According to ELI/SBP, the UVB system is most
appropriate for treatment of sites with good hydraulic
conductivity in the saturated zone and high air
permeability in the vadose zone. Good hydraulic
conductivity in the saturated zone accelerates the
establishment of a circulation cell for faster and more
effective cleanup. High air permeability in the vadose
zone increases the volatilization of contaminants,
improves the supply of oxygen to indigenous microbes for
enhanced biological degradation, and increases the air
supply to the in situ stripper reactor for better performance
while reducing the size of the blower required and
lowering overall remediation costs.
The effectiveness of the technology may be limited for
soils contaminated with high concentrations of heavy
metals that could be toxic or could inhibit biological
performance. Types and concentrations of metals present
as well as any other compounds that may be toxic to the
indigenous soil microbes need to be assessed at each site
under consideration.
In areas with very shallow groundwater (less than 5 ft), it
may be difficult to establish contact between the gas and
aqueous phases long enough to remove contaminants.
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 well system.
In addition, the thickness of the saturated zone affects the
radius of the circulation cell; the smaller the aquifer
thickness, the smallerthe radius of the circulation cell and
consequently the larger the number of wells required.
The majority of the water being drawn from the aquifer
into the lower screened section is treated water
reinfiltrating from the upper section. As the UVB system
continues to operate, the circulation cell expands until a
steady state is reached. As the circulation cell grows, the
amount of recirculated water increases, causing a
significant decrease in contaminant concentrations in the
water being treated by the system. This can potentially
have an adverse effect on the performance of both the
bioreactor and stripper, since their performance is
concentration dependent.
Conversely, high concentrations of volatile compounds
may require multiple passes through the system to
achieve remediation goals. This may be a problem since
a portion of the treated water is not captured by the
system and continues to leave the circulation cell in the
downgradient direction. However, once the UVB
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Table 1. FS Criteria Evaluation for UVB In Situ Bioremediation Treatment Process
Criteria
UVB Performance
Overall Protection of
Human Health and the
Environment
Compliance with Federal
ARARs
Long-term Effectiveness
and Performance
Reduction of Toxicity,
Mobility, or Volume
through Treatment
Short-term Effectiveness
Implementability
Cost
Community Acceptance
State Acceptance
Provides both short- and long-term protection by eliminating organic
contaminants in soil. Prevents further groundwater contamination and
minimizes off-site migration. Minimal emissions and discharges during
installation and operation.
Requires compliance with RCRA treatment, storage, and land disposal
regulations (of a hazardous waste) particularly during installation. Installation
and operation require compliance with location-specific ARARs. Emission
controls may be needed to ensure compliance with air quality standards if
VOCs are present.
Has the potential to effectively remove contamination source. May involve
some residuals treatment and disposal (e.g., extracted air, well cuttings).
Significantly reduces toxicity and mass of soil contaminants by treatment. May
distribute organic contaminants through zone of influence.
Presents minor short-term risks to workers from air releases during installation
of UVB well.
Involves few administrative difficulties, other than those associated with well
installation. Wells and aboveground system can be constructed in less than 2
weeks. Requires heavy equipment, such as crane, to install and position UVB
system.
$149/yd3 based on successful removal of VOCs from 12,800 yd3 over 14
months. Actual costs of remedial technology are site-specific and dependent
on factors such as the cleanup level, contaminant concentrations, soil
characteristics, and volume of soil treated.
Presents minimal short term risk to community. Public familiar with and
comfortable with biotreatment as in wastewater treatment. Some minor,
controllable noise from blowers.
State permits may be required if remediation is part of RCRA corrective action.
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 from the system.
The relative sizes of the circulation cell and the
contaminant source area will determine the number of
wells needed for remediation of a particular site.
As with other biological processes, the ELI/SBP
technology could be impacted by low temperatures, which
are known to slow biodegradation processes. Extended
periods of below freezing temperatures could seriously
affect treatment performance. As such, the technology
may be better suited to areas with moderate winters, may
require a heated enclosure for protection against extreme
cold weather conditions, may require the ambient airto be
heated, or may be operated on a seasonal basis.
Process Residuals
The materials handling requirements for the UVB system
include managing spent activated carbon or residues from
other offgas treatment, drilling wastes, purge water, and
decontamination wastes generated during installation,
operation, and monitoring of the system. Spent carbon
generated by offgas treatment can either be disposed of
or regenerated by the carbon vendor. Drilling wastes
produced during installation of the system well and
monitoring wells can be managed either in 55-gallon
drums or in roll-off debris bins, depending on quantity and
characteristics. Disposal options forthis waste depend on
state and local requirements and on the presence or
absence of contaminants. The options may range from
on-site disposal to disposal in a hazardous waste landfill.
Purge water generated during development and sampling
of groundwater monitoring wells usually can be stored in
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55-gallon drums. Disposal options again depend on state
and local restrictions and on the presence or absence of
contaminants. Options include surface discharge through
a National Pollutant Discharge Elimination System
(NPDES) outfall, disposal through a Publicly Owned
Treatment Works (POTW), and treatment and disposal at
a permitted hazardous waste facility, all with or without on-
site pretreatment.
Decontamination wastes generated during installation,
decommissioning, and sampling activities include
decontamination water. A decontamination pad may be
required for the drill rig. Solid decontamination wastes
can be managed in roll-off type debris boxes and 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 microbial treatment system consists of several
major components: a dual-screened well, stripping
reactor, biofilter, well packer, submersible pump, blower,
aboveground vapor phase bioreactors, and carbon
adsorption units. A drill rig is required to install and
remove the well casing and to install the equipment within
the well itself.
The site support requirements needed forthe UVB system
are potable water, electricity, and space to set up the ex-
situ bioreactors and off-gas treatment system. The blower
requires standard 440 volts (200 amperes). An electrical
pole, a 460-volt 3-phase converter for the operating
system, and electrical hookup between the supply lines,
pole, and the UVB treatment system are necessary to
supply power. The space requirements for the
aboveground components of the UVB system, including
the UVB system well, off-gas treatment units, blower, and
piping used during the SITE demonstration, were
approximately 250 square feet. Other requirements for
installation and routine monitoring of the system may
include access roads for equipment transport, security
fencing, and decontamination water and/or steam for
drilling and sampling.
The site should be relatively level and clear of
obstructions to facilitate well and equipment placement.
As noted earlier, vadose and saturated zones should be
well defined and should be reasonably consistent from
season to season.
Performance Data
Pilot-scale testing of the UVB-400 in situ process was
conducted in a 50 ft x 50 ft plot at the Sweden-3 Chapman
landfill in Sweden, New York as part of the Multi-Vendor
Demonstration.
A primary objective of the demonstration was to determine
the effectiveness of the technology in reducing VOC
contamination in the soil sufficiently to meet NYSDEC Soil
Cleanup Criteria. As a remediation goal to evaluate this
objective, the developers expected that 90% of the soil
samples collected from the anticipated vadose zone in the
plot after 5.5 months (nominally one warm season) of
operation would be below NYSDEC Cleanup Criteria for
six target VOCs (acetone: 0.2 ppm, MEK: 0.6 ppm, MIBK:
2.0 ppm, cis-DCE: 0.6 ppm, TCE: 1.5 ppm, and PCE: 2.5
ppm). In addition, the developers claimed that
biodegradation would be the dominant mechanism of
contaminant removal from the formation. The developers
also expected that groundwater would exhibit significant
reductions in VOC concentrations as a result of the
recirculation cell through the in situ biofilter. Finally, as an
adjunct to the project, the developers also sought to
evaluate the effectiveness of ex situ biofilters in removing
VOCs from the air extracted from the formation.
To evaluate the primary and secondary objectives,
samples from the soil, groundwater, and extracted air
streams were collected at intervals starting in July 1994
and continuing to the termination of the project in
September 1995. To assure that a maximum number of
the soil samples would contain detectable concentrations
of the critical VOCs, the plot was first divided into a 3 x 3
grid. Soil borings (2-inch split spoon) from the expected
vadose zone (~9 to 15 ft below ground surface, bgs) were
first scanned by a field photoionization detector (PID). On
the basis of this screening, sixteen additional boring
locations were selected to maximize the detection of
contamination. It quickly became clear that the vadose
and saturated zones were not clearly defined and that the
vadose zone was usually much narrower than the
anticipated 9 - 15 ft bgs. To overcome some of these
unanticipated problems, samples were designated as
"vadose" or "saturated" and were analyzed separately. In
addition, again to assure maximum contamination, the
sample from each 2-foot split spoon section was selected
based on a "hot spot" reading by the PID. Consequently,
the resulting ~50 samples from the 25 borings obtained
during each sampling event cannot be considered to be
representative of the site, and may not even be
representative of an individual core. Samples were
analyzed for VOCs, other contaminants, microbiological
activity, and nutrients to assess performance and
effectiveness of the system.
When preliminary results indicated that little decrease in
soil VOC concentrations was occurring during the first
growing season, due to bad weather and operational
difficulties or the unique characteristics of the UVB
system, the EPA and the NYSDEC agreed to continue the
evaluation through a second warm season. Operation of
the in situ system was continued through the winter and
was assumed, for evaluation purposes, to be continuous
forthe 14-month test period. Modifications to the system
also were made in the Spring of 1995 to accommodate
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large, unanticipated variations in the water table and to
assure that the exhausted air passed through the ex situ
vapor phase biofilters.
The primary objective (achievement of the NYSDEC Soil
Cleanup Criteria) was evaluated by measuring the
residual concentrations of the selected VOCs in grab
samples from cores obtained from twenty five locations
within the test plot at the completion of the first season
(~5.5 months) and at the end of the 14-month test period.
Although the original intent was to evaluate the
effectiveness of the technology for the vadose zone only,
a high and variable water table left only a very shallow
vadose zone and made it prudent to evaluate changes in
both the vadose and the saturated zone.
The second objective, estimating the contribution of
biodegradation to overall removal, was assessed by
several biological and chemical measurements over the
course of the demonstration. In addition to VOC mass
removal, other measurements used to assess the extent
of biodegradation included: changes in CO2, O2, cis-DCE
and vinyl chloride concentrations, and changes in total
heterotroph and TCE-degrading microbial growth in the
soil and groundwater. The mass removal of VOCs in the
groundwater could not readily be estimated because of
factors such as flushing and migration.
Based on the analytical results (Table 2), the developers
were not successful in meeting the 90% cleanup
objective, even after 14 months. Only 65% of the usable
soil samples collected in the plot after 5.5 months and
70% of the samples collected after 14 months met the
NYSDEC Cleanup Criteria. (At the outset of the
demonstration the calculated compliance was 67%).
As indicated in Table 2, some of the analytical data,
primarily for acetone and MEK, could not be utilized
because detection limits were higher than the NYSDEC
criterion for that contaminant and it could, consequently,
not be determined whether these samples met the
Criteria. Higher-than-anticipated concentrations of
aromatic VOCs (compared to predemonstration data)
were a major contributing factor in the high detection limits
for the critical analytes.
Table 3 compares initial and final (14 month) calculated
masses for the six critical VOCs and toluene, using the
Practical Quantitation Limits (PQLs) for "ND" value, and
also indicates the relative contribution to VOC removal in
the exhausted air. Ketone removals from the soil appear
to be more extensive than removal of chlorinated
hydrocarbons; cis-DCE results may be ambiguous due to
production of this compound by degradation of TCE
and/or PCE.
Because of apparent elevated masses of VOCs after 5.5
months, the contribution of biodegradation (if any) to
removal could not be estimated. Using calculated values
Table 2. UVB Compliance with NYSDEC Cleanup Criteria
VOC
Criterion
(PPb)
Usable Data Points
Data Meeting
Points Criterion
(#) (#) (%)
RESULTS AFTER 5.5
Acetone
MEK
MIBK
DCE
TCE
PCE
Total
200
600
2000
600
1500
2500
11
12
23
32
31
31
140
RESULTS AFTER 14
Acetone
MEK
MIBK
DCE
TCE
PCE
Total
200
600
2000
600
1500
2500
19
25
46
46
46
46
229
MONTHS
0
0
21
14
27
29
91
MONTHS
0
4
45
22
45
44
160
0
0
91
44
87
94
65
0
16
98
48
98
96
70
Note: (*) Data reported as non-detectable were not utilized
in the evaluation if the detection limit was above the NYSDEC
Criterion.
Developers "credited" with any samples that were
uncontaminated initially.
for the masses of each VOC at the 14-month event and
the masses of each contaminant removed in the extracted
air stream and in the knockout water (very small), rough
estimates of removal (61-70%) and the potential
contribution of biodegradation (94-98%) could be
calculated for the ketones, but not for the chlorinated
VOCs. The effects of extraction, biodegradation, or
flushing by groundwater on any of the contaminants are
not included. Degradation of TCE and/or PCE to cis-DCE
is another factor that may be affecting the observed
values for cis-DCE.
Other data expected to support numerical data do not
clarify the interpretation of the results of this
demonstration. Oxygen and carbon dioxide
concentrations in the extracted air remained essentially
unchanged, as expected, because of the intake of
ambient air. TCE-degrading microbial populations in the
soil and the groundwater were small and decreased over
the course of the demonstration, providing little support for
biodegradation of the chlorinated VOCs. On the other
hand, average total heterotroph populations for the soil
samples, with approximately a 7-fold increase over the
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Table 3. VOC Removals by UVB System after 14 Months
VOC
Acetone
MEK
MIBK
cis-DCE
TCE
PCE
Toluene
Mass in
Initial
3700
6300
2200
1900
1500
380
58000
Soil (gm)
Final
960
2100
440
1200
3200
350
7400
Mass
Removed in
Air& Water
(gm)
120
58
69
2200
510
120
1900
Overall Percent
Removal
74
67
80
37
—
8
87
Percent Potentially
Biodegraded
71
66
77
—
-
84
course of the demonstration, were more indicative of
biodegradation; however, total heterotroph populations in
groundwater samples decreased over the course of the
demonstration. These observations, the high removal
efficiency for the ketones, and the apparent production of
cis-1,2-dichloroethene would suggest that some
biodegradation is underway, although the evidence is not
strong. The detection of significant concentrations of vinyl
chloride (VC) in the exhausted air and in groundwater (but
not in soil samples) suggests that biodegradation is
occurring, but that anaerobic mechanisms ratherthan the
expected aerobic mechanisms may be operative.
Analyses of groundwatersamples, particularly those from
wells upgradient of the UVB well, indicate significant but
variable reductions in VOC contamination overthe course
of the demonstration, particularly in wells closer to the
UVB well. Groundwater well data initially and for each
sampling event also indicated that concentrations of all
contaminants increased downgradient from the UVB well.
The data also indicate that MEK, cis-DCE, toluene and
vinyl chloride were the most prominent VOCs, and that the
ketones tended to be concentrated in the shallow
groundwater while the chlorinated ethenes were
concentrated in the deep monitoring wells, as might be
anticipated. Vinyl chloride remained at significant
concentrations in all wells throughout the 14-month study,
suggesting that anaerobic biodegradation was occurring.
Analyses of influent to and effluent from the in situ biofilter
indicated that VOC removal was taking place in the
biofilter overthe course of the demonstration as well as
during the short residence time in the biofilter. It is not
possible to attribute this to biodegradation or adsorption
without more extensive testing.
Due to excessive head loss, the original single, spiral-
wound vapor phase biofilter was replaced in April 1995
with two biofilters, each containing seven carbon
cartridges. Operating in parallel, the new design produced
much lower head loss. Flow and VOC data confirmed that
the changes were successful in assuring uniform passage
of airthrough the two trains. Sampling and analysis ofthe
air stream before and after the two redesigned indicate
target VOC removals of about 60% to 75%, but the
removal mechanisms cannot be defined.
In general, various aromatic compounds were much more
prevalent than the target VOCs in all soil samples.
Toluene is included in the data compilations as an
example. High concentrations of these aromatic VOCs
adversely affected the ability to detect or quantify low
concentrations of the target VOCs, but they also may have
served as cometabolites for biodegradation - if the
concentrations were not high enough to cause toxicity to
the biological system.
For the 14-month demonstration, the estimated cost was
$347/yd3 to treat about 628 yd3 in the test plot. The cost
to remediate approximately 13,000 cubic yards of similarly
contaminated vadose zone soil over a 14 month period at
the Sweden-3 Chapman site using 22 UVB wells is
estimated at $149/yd3. Increasing the treatment time to 3
years or 5 years, as suggested by the developers,
increases the cost to $259/yd3 and $375/yd3, respectively.
Because ofthe nature ofthe technology, saturated zone
soils and groundwater within the radius of influence would
also be treated simultaneously. However, no credit was
taken forgroundwatertreatment in this economicanalysis,
which focused on vadose zone soil treatment. As the full-
scale, 14-month cost analysis was configured, the largest
cost categories are site preparation and equipment costs,
accounting for40% and 22% ofthe costs. Labor accounts
for 17% ofthe costs. As the duration ofthe remediation
increases, the contribution of site preparation costs
decreases and the labor cost increases. This technology
is typical of other bioremediation processes in that the
majority ofthe costs are in the initial site preparation and
startup phases. For this estimate no costs were assigned
for permitting and regulatory requirements or facility
modification, repair or replacement.
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Technology Status
New York State Contact:
The UVB microbial technology has been utilized at a
number of sites throughout the world, primarily for
treatment of BTEX-contaminated groundwater.
Disclaimer
The data, observations and conclusions presented in this
Capsule have been reviewed by EPA's Quality
Assurance/Quality Control Office.
Sources of Further Information
An Innovative Technology Evaluation Report will be
available for the UVB technology and for the other two
technologies that were evaluated as part of the same
investigation.
EPA Contact:
U.S. EPA Project Manager
Michelle Simon
U.S. EPA NRMRL
26 W. Martin Luther King Jr. Dr.
Cincinnati, OH 45268
(513)569-7469
Fax (513) 569-7676
email: simon.michelle@epamail.epa.gov
NYSDEC Project Manager
James Harrington, P.E.
New York State Dept. of Environmental
Conservation, Room 222
50 Wolf Road
Albany, NY 12233
(518)485-8792
Fax (518) 457-1088
NY State Center for Hazardous Waste Mgmt.
Professor Scott Weber
Jarvis Hall
SUNY at Buffalo
Buffalo, NY 14260
(716)645-2114
Fax (716) 645-3667
Technology Developers:
Environmental Laboratories, Inc.
New Haven, CT 06510
Information is now available through:
Dr. James Mueller
Dames and Moore
Chicago, IL
(847) 228-0707
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