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                        /A newsletter about soil, sediment, and ground-water characterization and remediation technologies
                                                                                                                   May 2004
        Issue 12
           Active Capping Demonstrated on Anacostia River
The Hazardous Substance Research Center/
South and Southwest (HSRC/S&SW), a U.S.
EPA-funded, university research consortium led
by Louisiana State University, is demonstrating
an active capping process to remediate portions
of the Anacostia River in Washington, DC. The
HSRC/S&SW is collaborating with EPA's SITE
program, members of the Anacostia Watershed
Toxics Alliance, the EPA/Industry  Sediment
Remediation Technology Development Forum,
and the District of Columbia government.
Conventional sand caps  are designed to reduce
contaminant  release  from sediments by
physically isolating  contaminants   from
organisms and the water column. The  active
capping process  underway at the Anacostia,
however, involves covering contaminants with
layers  of alternative  materials that offer
treatment    and/or    sequestration    of
contaminants.

Large  amounts  of  sediment wash, excess
nutrients,  industrial  waste, and urban runoff
have severely degraded water quality  of the
Anacostia. As a  result, the river contains
extremely  low levels of dissolved oxygen and
high levels of bacteria that detrimentally affect
aquatic life and use of the river. Demonstration
of active capping is occurring on  a grid of
capping cells located on several acres along
the river west of the  Washington Navy Yard.

Extensive site assessment was conducted in
2002 to identify the sediment contaminants and
their distribution and to characterize the site's
hydrological and geotechnical properties. PCB
concentrations in the demonstration sediment
were found to reach 6-12 ppm, and total
polycyclic aromatic hydrocarbons reached 30
ppm. In addition, elevated concentrations of
target metals exist in the sediment:  cadmium
(3-6 ppm), chromium (120-155  ppm), copper
                             (127-207 ppm), lead (351-409 ppm), mercury
                             (1.2-1.4 ppm) and zinc (512-587 ppm). Although
                             the flow velocity of the river is relatively low
                             (less than 1 ft/s), the area is subject to 1-ft tidal
                             variations and tidal influence seepage. Soft
                             sediments  with  a surficial  strength  of
                             approximately 10 lb/ft2 underlay much of the
                             area.

                             Following two years of laboratory treatability
                             studies, HSRC/S&SW selected four alternative
                             cap technologies for the demonstration:
                             > AquaBlok™: a  permeability control agent
                               tested in conjunction with the SITE program
                             > Apatite: a phosphate  mineral with ability to
                               scavenge metals
                             > Coke: a high carbon-content material capable
                               of sorbing organic contaminants, and
                             > Laminated mat: synthetic materials emplaced
                               under controlled conditions, with coke for
                               added weight.
                             Other capping materials such as  activated
                             carbon, zero  valent iron, and commercial
                             sorbents were excluded due to cost, lack of
                             effectiveness under the conditions of the
                             Anacostia, or potential problems with placement
                             or long-term performance.

                             The demonstration  is taking place in five 100-
                             by  100-ft  study cells, each  containing one of
                             the four  capping  materials  as well  as  a
                             conventional sand control. Two- to six-inch
                             layers of capping materials were placed and
                             verified   using    underwater   surveying
                             techniques.  Conventional clamshell buckets
                             introduced the cap  materials in thin lifts. This
                             technique reduced loading on underlying
                             sediment and minimized intrusion to the water
                             column above, while safeguarding future use
                             of the waterway  and providing  adequate
                             contaminant  isolation.  Use of  a global
                                                [continued on page 2]
                                                                                    Contents
Active Capping
Demonstrated on
Anacostia River

NRMRL Evaluates Active
and Semi-Passive
Technologies for Treating
Acid Mine Drainage

Pilot and  Full-Scale
ISCO Using  Sodium
Permanganate in
Fractured Bedrock

Bioaugmentation Tested
on DNAPL Sources
page 1
page 2
page 4
page 5
    CLU-IN Resources
 The U.S. EPA and Army Corps of
 Engineers jointly compiled the
 Field Analytic Technologies
 Encyclopedia (FATE) to provide
 an information  resource about
 field technologies used for
 characterizing contaminated
 media, monitoring remedial
 progress, and confirming site-
 closeout sampling and analysis.
 In addition to describing specific
 field technologies, guidelines for
 systematic planning, and site-
 specific summaries, this on-line
 resource  includes capabilities to
 "ask an expert" and participate in
 training modules. FATE is
 available at http://fate.clu-in.org.
                                                                                                        Recycled/Recyclable
                                                                                                        Printed with Soy/Canola Ink on paper that
                                                                                                        contains at least 50% recycted fiber

-------
 [continued from page 1]
 positioning system to guide the buckets
 ensured uniform placement of individual
 loads.

 Field efforts began in March 2004 with
 placement of a sand cap, followed by the
 alternative cap materials. Preliminary results
 indicate that the simple technique of clamshell
 distribution can effectively lay the thin lifts
 of cap material required over soft  sediment.
 Some variation in material thickness due to
 intermixing with  soft sediment and to
 placement variations has been noted, but no
 areas of inadequate  cap coverage have been
 detected. Final analysis of the cap placement
 effectiveness is expected in late spring.
Monitoring of the  caps is underway  to
evaluate changes in chemical isolation,
physical stability, and fate processes. Long-
term monitoring  of the site will continue to
track  sediment  recovery  and   overall
improvements to the Anacostia watershed.
Preliminary performance of the  capping
materials will be evaluated in 2004 with
monitoring continuing through at least 2005.
Webcam viewing of the demonstration and
project updates are available at http://
www.hsrc-ssw.org/anacostia/.

Contributed by Danny Reible, Ph.D.,
Louisiana State University (225-578-6770
or reible(a)lsu.edu)

                                                         Figure 1. Demonstration
                                                         of the active capping
                                                         process is taking place in
                                                         study cells located on the
                                                         Anacostia River in
                                                         southern Washington,
                                                         DC.
  NRMRL Evaluates Active and Semi-Passive Technologies for Treating Acid Mine Drainage
The U.S. EPA National Risk Management
Research Laboratory (NRMRL) cooperated
with EPA/Region 9, the State  of California,
and Atlantic Richfield Corporation over the
past three years  in evaluating technologies
for treating acid  mine drainage (AMD) and
acid rock drainage (ARD).  Evaluations
focused on three technologies used to treat
drainage from mine workings and seeps at
the Leviathan mine in Alpine County, CA: 1)
active biphasic (two-step) lime treatment; 2)
semi-passive settling in an alkaline (lime)
treatment lagoon; and 3) passive compost-
free bioreactors (Figure 2). Biphasic and
lagoon treatment technologies enhance
conventional alkaline-based technologies,
which typically capture,  store, and batch or
continuously treat water through the
addition of lime to neutralize  water acidity
and  precipitate metals. In contrast, the
compost-free   bioreactor  technology
nurtures sulfate-reducing bacteria that
generate sulfides capable of scavenging
dissolved metals to form metal  sulfide
precipitates.

AMD is caused by sulfur and sulfide mineral
oxidation occurring when oxygen and water
contact waste rock and mineralized rock in mine
workings. The acid generated through  the
mixing of water and sulfide minerals dissolves
metals such as aluminum, arsenic, copper, iron,
and nickel. The metals in solution create toxic
conditions for fish and insects. Since the mid-
18608, intermittent extraction of copper sulfate,
copper, and sulfur minerals from the abandoned
Leviathan mine resulted in extensive AMD and
ARD. When converting underground workings
into an open pit mine during the 1950s, workers
removed approximately 22 million tons of
overburden  and waste rock from the open pit
mine and distributed them across the 253-acre
site. Placement of overburden and waste rock in
local creeks led to ARD, which when combined
with AMD from the mine workings resulted in
fish and insect kills in local creeks and the  east
fork of the Carson River.

State actions in 1984  significantly reduced the
metals and acidity in AMD and ARD from the
Leviathan mine. Actions included  storm water
controls, separation of Leviathan Creek from the
waste rock, and construction of five ponds to
prevent discharge of AMD. The Leviathan mine
was added to the NPL in May 2000 to address
AMD/ARD discharge to surface water. Cleanup
has been hampered  by the site's alpine
environment, which limits site access and
operations each  year from November through
May.

The  biphasic  lime treatment used at the
Leviathan mine  employs two-step addition of
lime to neutralize  acidity and precipitate
dissolved metals from the AMD at an inflow of
50-185 gpm. During the first step, the pH of
AMD is raised from 2.8 to 3.2 by mixing it with
lime slurry in a 10,000-gallon tank to precipitate
iron as ferric hydroxide. Arsenic co-precipitates
by adsorbing to the ferric hydroxide.  The
precipitate is flocculated and allowed to  settle
in a 10,000-gallon clarifier to form a small volume
of arsenic-rich hazardous sludge. The sludge
is dewatered through use of a filter press and
shipped offsite  for disposal. Water extracted
       from the sludge is  recycled into the
       treatment system. In the second step,

                   [continued on page 3]

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[continued from page 2]
the pH of the partially-treated AMD is raised to
approximately 8.0-8.4 in a second, 10,000-gallon
tank, and the remaining metals are precipitated
in an 800,000-gallon lagoon. The final precipitate
forms a larger quantity of non-hazardous
sludge that may be  used onsite as soil
amendment, pending the results of additional
studies on sludge stability over time. The
NRMRL  study found that biphasic lime
treatment results in metal removal efficiencies
exceeding 99% (Figure 3).

The alkaline treatment lagoon system  at the
Leviathan site is  a simplified version of the
biphasic treatment system employing a low-
flow (12-30  gpm) ARD source containing low
levels of arsenic. Single-step addition of lime
combined with vigorous aeration in a series of
three 1,000-gallon tanks neutralizes  the ARD
acidity (from pH 4.5 to pH 8) and precipitates
dissolved metals. A series of 15- by 15-foot bag
filters captures large flocc particles, and  a 1.4-
million gallon, multi-cell settling lagoon allows
extended contact  of ARD with the  lime and
additional time for fine particles to settle. The
effluent is discharged to surface water. Tests
showed that effluent discharge  standards for
all targeted metals typically are met following
treatment in the lagoon system.

In late 2003,  NRMRL  began long-term
evaluation  of a  compost-free bioreactor
developed by researchers at the  University of
Nevada-Reno. The reactor relies on sulfate-
reducing  microbial  organisms   such  as
Desulfovibrio sp.  to neutralize acidity and to
precipitate metal sulfides from the ARD year-
round at flow rates ranging from 8 to 30 gpm.
Unlike compost bioreactors, this technology
uses a liquid carbon source and a rock matrix
(rather than  a conventional compost or wood
chip matrix) that is consumed by bacteria and
collapses over time. Benefits of this technology
include better control of biological activity and
 Figure 3. NRMRL examined the influent,
 effluent, and removal efficiencies of three
 different technologies used to treat AMD
 and ARD at the Leviathan mine.
improved hydraulic conductivity and precipitate
flushing.

The bioreactor treatment begins with  the
introduction of ARD to a pretreatment pond
where sodium hydroxide is added to increase
the pH from 3.1 to 4.0. Alcohols also are added
to serve as a carbon source for the microbes.
ARD flows from the pretreatment pond to an
upstream, 12,500-ft3 bioreactor for biological
reduction of sulfate to sulfide. Excess sulfide
and partially treated ARD next pass to a second,
7,000-ft3 downstream bioreactor for additional
metals removal. Both bioreactors contain 6- to
24-inch river rock aggregate that serves as a
substrate for sulfate-reducing  bacterial growth.
Each bioreactor has three influent distribution
lines and three effluent collection  lines located
at different elevations to allow variable flow
operations.

Precipitates from the  second bioreactor settle in
a 16,400-ft3, continuous-flow pond. The effluent
then flows to a rock-lined aeration channel  that
promotes degassing of residual hydrogen sulfide
prior to discharge. Precipitate slurry is flushed
periodically from the bioreactors to prevent
plugging of the river rock matrix, and settled in
an  18,000-ft3 flushing pond.  Solids generated
by this technology are non-hazardous and may
be used (pending additional studies) as  soil
amendments during future reclamation of the
site. Preliminary results indicate that this
bioreactor system is achieving a metal removal
efficiency of 91-99%.

NRMRL found that each technology promotes
AMD/ARD   neutralization   and   metal
precipitation while meeting site discharge
standards. The field studies suggest that active
biphasic lime treatment may be more effective
in applications involving a high rate of flow
and a short treatment season, while the semi-
passive alkaline treatment lagoon favors a
lower flow rate and extended treatment season.
The passive, compost-free bioreactor, however,
is not constrained by seasonal conditions and
can be scaled to treat the low to moderate flows
common at AMD and ARD sites. In addition,
both the biphasic and alkaline treatment lagoon
technologies generated larger quantities of
sludge than the bioreactor.

NRMRL will publish additional information
such as implementation costs, benefits, and
limitations of the two lime-based technologies
in an ITER (innovative technology evaluation
report) and demonstration bulletin later this
summer. Documentation of the bioreactor
evaluation will be available in mid 2005.

Contributed by Ed Bates, NRMRL  (513-
569-7774 or bates. edward(a),epa.gov) and
Matt Udell, Tetra Tech EM Inc. (916-853-
4516 or matt, udellfdittemi. com)
Concentration (mg/L)

Aluminum
Arsenic
Copper
Iron
Nickel
Biphasic Lime System
Influent
Effluent
Removal Efficiency
486
1.09
99.86%
4.05
0.0101
99.75%
2.99
0.0101
99.66%
653
0.0038
99.99%
8.77
0.0389
99.56%
Alkaline Lagoon
Influent
Effluent
Removal Efficiency
31.6
0.21
99.34%
0.533
0.0032
99.40%
0.0161
0.0041
74.53%
378
0.32
99.92%
1.61
0.0204
98.73%
Bioreactor
Influent
Effluent
Removal Efficiency
^ Discharge Standard
38.1
0.0798
99.79%
2.0
<0.005
0.0125
NotCalculated
0.15
0.701
0.0045
99.36%
0.016
121
4.03
96.67%
1.0
0.484
0.0417
91.38%
0.094


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           Pilot and Full-Scale  ISCO Using Sodium  Permanganate in Fractured Bedrock
Two-phase pilot testing of in-situ chemical
oxidation (ISCO) using sodium permanganate
(NaMnO4) was conducted in 2000-2001 at the
Tenneco Automotive site in Hartwell, GA, to
remediate a dissolved-phase trichloroethene
(TCE) plume in a fractured bedrock aquifer.
The ISCO pilot was initiated to identify an
alternative to ground-water pumping  and
treatment in the off-facility plume, which was
used for 12 years without significant success
(but at significant cost). Difficulties in ground-
water remediation  at  this  site  were
compounded by off-facility migration of the
plume through connective fractures to 52
adjacent residential and commercial properties.
Pilot test results demonstrated that ISCO can
effectively remediate chlorinated volatile
organic compounds (CVOCs) in a fractured
bedrock aquifer due to the geologic setting's
low demand  by natural organic  matter for
oxidant material. The pilot test also highlighted
the need for using an effective hydrogeologic
conceptual model in this type of project. Pilot
test   results  led  to  ISCO   full-scale
implementation during 2003.

Degreasing fluids containing CVOCs were
released at the facility between 1956 and 1981.
TCE  was  detected in ground  water at
concentrations reaching 240 ug/L in an onsite
well and 330 ug/L in an off-facility commercial
well. The pilot test site is situated in Piedmont
metamorphic and granite rocks that have
weathered into a 20- to 50-ft layer of residual
soil (saprolite) near ground surface. Hydraulic
conductivity of the saprolite is approximately
IxlO'4 cm/s. A more permeable transition zone
of partially weathered rock (PWR)  exists
beneath the saprolite and above unweathered
bedrock, at a  typical depth of 50-60 ft below
ground surface.

Impacted ground water  at the site  exists
primarily in the PWR, which has an average
hydraulic conductivity  of IxlO'2 cm/s  (30 ft/
day), with an  average ground-water flow rate
of 100 ft/yr in the off-facility plume area. A
bifurcated TCE plume in the unconfined PWR
aquifer extends approximately 1,800 feet west
beneath the facility and nearly 1,700 feet north
into  adjacent,   off-facility   properties.
Development of an effective conceptual model,
which cost nearly $1 million, involved geologic
and hydrogeologic  characterization using
remote   sensing   techniques,   downhole
geophysics, hydraulic testing, and ground-
water modeling.

Early bench-scale testing on ground-water and
soil samples collected from the site indicated
that TCE degradation in the field would depend
on  both residence  time  and  NaMnO4
concentration. Within  six hours, a NaMnO4
concentration of 50 mg/L completely degraded
1,000 ug/L of TCE in ground water collected
from an on-facility area of the plume (with higher
overall concentrations). Laboratory tests also
demonstrated that the oxidant demand from
factors such as natural organic material, TCE
concentration, and ionic composition would not
limit TCE degradation in ground water.  Pre-
injection activities included bromide tracer tests
to calculate the concentration of NaMnO4
injectant needed  to  achieve  the  target
concentration of 50 mg/L within the primary
injection well.

The Phase I pilot test was conducted on-facility
using an existing pumping recovery well and a
monitoring well located approximately 30 ft from
the recovery well. The initial field injection
employed one gallon of a 40% NaMnO4 solution
that was  injected into the subsurface  through
the monitoring  well. ISCO monitoring included
sampling for TCE and degradation products
such as chloride and vinyl chloride in ground
water extracted from the recovery well. Water
quality parameters such as pH, temperature,
dissolved oxygen, and oxidation reduction
potential also were measured.

Phase I results indicated that the lowest TCE
concentration corresponded to the highest
measurement in oxidation reduction potential,
indicating that TCE oxidation by the NaMnO4
had  occurred.  An  increased chloride
concentration also corresponded to the
lowest TCE concentration, at an approximate
ratio of 3:1.  Contrary to bench-scale testing,
complete TCE degradation in ground water
did not occur due to continued contribution
of TCE from radial flow of impacted ground
water into the pumping well.

Phase II pilot testing was conducted using
an existing off-facility monitoring well
screened  in the PWR and located  on
commercial property with the highest off-
facility TCE concentration in ground water.
Four additional PWR monitoring wells were
installed upgradient of the existing well at
20-ft intervals. A total  of 7,780 gallons with
an average NaMnO4 concentration of 210
mg/L was  injected  into a  single  well
(MW-112A) during four events in May 2001.
Within two months, three additional injections
occurred in the same well using significantly
higher NaMnO4 concentrations averaging
5,600 mg/L. In addition, the  individual
injection volume was lowered from 1,750 to
500 gallons in order to eliminate potential
displacement of impacted ground water. The
final injection occurred one month later in an
                  [continued on page  5]
                                                - MW-112B
                                                -MW-112C
                                                 MW-112
                                                 MW-112D
                                                 MW-112A
       2/28   4/19   6/8   7/28   9/16    11/5
                   Date (2001)
        Note: dashed line denotes injection date
                Figure 4. To address
                TCE concentrations
                in ground water at
                the Tenneco
                Automotive site,
                seven ISCO injections
                using sodium
                permanganate were
                conducted during
                four months of pilot-
                scale  operations.

-------
[continued from page 4]
alternate well (MW-112C) using the same
NaMnO,,  solution and volume. A lower
        4
injectant intake rate was noted during the final
injection, likely due to  lower hydraulic
conductivity of a less fractured area.

Phase   II  results   indicate  that  TCE
concentrations in each of the monitoring wells
decreased significantly after the NaMnO4
injections (Figure 4). The most significant
reductions in TCE concentrations occurred
after the fourth injection. Marginal increases
in TCE concentrations in downgradient wells
after the first (large) injection likely were
caused by impacted ground water flushing
from upgradient sources, or by variation in
TCE concentrations reflecting the aquifer
heterogeneity and  fracture distribution.
Downward trends in TCE concentrations
followed by  sudden increases in two of the
wells (MW-112 and MW-112D) indicate that
TCE in the wells was displaced by the initially
large injection rather than  degraded.
Overall pilot results indicated that no daughter
products had formed, oxidant demand was
minimal (less than 10  mg/L), and  TCE
concentrations were reduced to below the
maximum contaminant level (5 ug/L) in three of
the five wells. In addition, NaMnO4 was highly
persistent in the aquifer (more than one year),
no screen fouling was observed, and metal
mobilization did not occur. The results of pilot-
scale ISCO prompted refinement of the site
conceptual model, including redefinition of the
contaminant plume.

Current full-scale ISCO implementation builds
upon lessons learned during the two pilot tests,
the most important of which was the need to
use relatively small injection volumes (only a
fraction of estimated pore volume) in order to
minimize displacement of treated ground water.
Operations began with the installation of 12
new wells in the north off-facility portion of
the plume. The first series of semi-annual
injections was conducted in February 2003.
Single injections ranging from 250 to 500 gallons
in volume were accomplished through gravity
feed of a 2%  NaMnO4 solution  to  the
screened zone of eight wells. Similar injection
events were conducted in October 2003  and
April 2004.

Preliminary  results indicate  that  two
monitoring wells in the vicinity of the injection
well show TCE concentration reductions of
69 and 77%. TCE degradation in these wells
is supported by the presence of oxidant
degradation indicators such as  increased
levels of manganese dioxide and carbon
dioxide and a temporary decrease  in ground-
water pH. Semi-annual injections of NaMnO4
are scheduled to continue through the  end
of2007.

Contributed by  Carrie  Williams,
GeoSyntec Consultants
(c-williams(S)geosyntec. com or
404-236-7306), and Elizabeth Penny,
State of Georgia/Environmental
Protection Division
(elizabeth_penny(S),dnr.state.ga. us)
           Bioaugmentation Tested on DNAPL Sources
 The U.S. Navy began laboratory and field
 experiments at the Dover National Test Site
 in 2001  to  evaluate  the use  of  in-situ
 bioaugmentation in enhancing dissolution
 of   tetrachloroethene   (PCE)   dense
 nonaqueous  phase   liquid  (DNAPL).
 Bioaugmentation is an in-situ remediation
 approach in which selected microorganisms
 are injected in the presence of electron
 donors  and  nutrients   to   stimulate
 chloroethene dechlorination. Laboratory
 tests suggested that microbial cultures could
 be adapted to grow in high volatile  organic
 compound (VOC) concentrations. In the
 field, naturally-occurring, dehalorespiring
 microbial consortia were introduced into
 DNAPL source areas within the saturated
 zone to function at the solubility limits of
 chlorinated solvents. Test results indicated
 that the microbes enhanced biodegradation
 rates  at the  DNAPL  interface,  thus
 increasing the concentration gradient driving
 DNAPL   dissolution.  Increasing   the
concentration gradient resulted in more rapid
DNAPL dissolution and potential reductions
in cleanup time and costs.

Both microcosm and column studies were
conducted in a  laboratory using soil  and
ground water from Dover Air Force Base. In
microcosm  tests,  PCE  degradation at
solubility concentrations  was evaluated
using three different cultures. The two-
dimensional (2-D)  model aquifer column
studies compared enhanced bio stimulation
and bioaugmentation. Column samples were
analyzed for VOCs, dissolved gases, anions,
volatile fatty acids, molecular assessment,
and compound-specific isotopes. Screening
of a range of electron donors over a period
of 700 days resulted in the selection of
ethanol as an electron donor.

No significant PCE biodegradation was
observed throughout the  bio stimulation
                [continued on page 6]
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-------
                  Technology
               News and Trends
       Solid Waste and
       Emergency Response
       (5102G)
EPA 542-N-04-003
May 2004
Issue No. 12
 United States
 Environmental Protection Agency
 National Service Center for Environmental Publications
 P.O. Box 42419
 Cincinnati, OH 45242
Presorted Standard
Postage and Fees Paid
EPA  "
Permit No. G-35
 Official Business
 Penalty for Private Use $300
  [continued from page 5]
  phase of laboratory testing. Results indicated
  that indigenous dehalorespiring bacteria
  (such as Dehalococcoides) in the aquifer
  material could not actively dechlorinate PCE.
  The mass  discharge of total chlorinated
  ethenes in the bioaugmented model aquifer,
  however, was approximately 120% more than
  in the non-bioaugmented aquifer.

  Field experiments were conducted at a Dover
  test cell where 100 L of PCE had been released.
  Ground water was recirculated in the cell at a
  constant velocity throughout three phases
  of testing: baseline, bio stimulation,  and
  bioaugmentation. Extensive monitoring
  networks of conventional and multilevel
  piezometers were employed to assess  spatial
  and temporal trends in parent and daughter
  compound  concentrations   and  mass
  transport. These data were complemented
  by  microbial community analysis  using
  molecular genetic methods and compound-
  specific isotopic analysis that confirmed
dechlorination  was  occurring   through
anaerobic biodegradation.

As observed in  the laboratory  studies,
biostimulation (using ethanol and lactate) in the
field did not produce significant PCE reduction.
Bioagumentation using 50 L of a bacterial culture
(KB-1™)  resulted  in  an  increase  in
trichloroethene, c«-l,2-dichloroethene, vinyl
chloride, and  ethene.

Standard and quantitative  polymerase chain
reaction (PCR and QPCR) analyses were used
to assess bioaugmentation effects on the
microbial community. While standard PCR
estimated the intensity of microbial response
compared to known standards, QPCR estimated
the actual numbers of target microorganisms
(as gene copies/L) in each sample. PCR analysis
indicated that intensity scores in the test cell
ranged from 81 to 261% of the control samples,
which was significantly higher than  the non-
detectable  levels (<3%) estimated  prior to
bioaugmentation. QPCR analysis indicated large
increases in the numbers of Dehalococcoides
        approximately 100 days after bioaugmentation,
        with an average of 7.87 x 108 rRNA gene (16S)
        copies/L.  These  results  support  the
        increased  concentrations  of  cis-1,2-
        dichloroethene, vinyl chloride, and ethene
        that were observed throughout the test cell.

        Now that complete dechlorination to ethene
        is observed consistently in areas nearest the
        residual PCE  zones, bioaugmentation
        enhancement factors  will be calculated.
        Monitoring of the field test cell will continue
        under  the  interagency  Environmental
        Security Technology Certification Program
        (ESTCP). Updated project information is
        available on-line at http://www.estcp.org/
        documents/techdoc s.

        Contributed by Carmen LeBron,  Naval
        Facility Engineering Service Center
        (805-982-1616 or
        carmen.lebron(q)navy.mil) and Michaye
        McMaster,  GeoSyntec  Consultants
        (519-822-2230 or
        mmcmaster(a},eeosvntec.com)
EPA is publishing this newsletter as a means of disseminating useful information regarding innovative and alternative treatment techniques and
technologies. The Agency does not endorse specific technology vendors.

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