United States
Environmental Protection
Agency
Solid Waste
Emergency Response
(5102W)
EPA 542-N-95-001
March 1995
Issue No. 19
&ER&
urn
The Applied Technologies Journal for Superfund Removals & Remedial Actions & RCRA Corrective Actions
COLD CLIMATE SOIL BIOVENTING
A field demonstration of soil vapor
extraction (SVE) and bioventing to
remove hydrocarbons from above the
ground water table at Gulf Canada
ResomcesJjmited's_S_trachan Gas., „. .
Plant represents the first documented
evidence in Canada of the practicality
of using these technologies in colder
climates. The results show that the
addition of bioventing to conven-
tional SVE enhances remediation and
reduces costs by as much as 50% over
conventional SVE. Bioventing uses
lower air flow rates than conventional
SVE; as a result, blower and operating
costs are reduced compared to SVE,
with little or no off-gas treatment re-
quired. The SVE/bioventing demon-
strations are part of a series of field
demonstrations of remedial technolo-
gies applicable to the unique prob-
lems encountered in the natural gas
processing industry. The project is a
joint project of the Canadian Associa-
tion of Petroleum Producers (CAPP),
ALERT-URGENT
This maybe your last issae of
TECH tBBM>$ if you 4o aot
immediately let as know thai yoa
waftt to srjay Oft the Jfcsifing JSst,
The same message applies for
To stay oa tfee xnaalsjg lists for
these pabJ katlops,. send a PAX
013-891 -&5B5) or mail z«m«st
toNCEPI, 11829 Kenwood
Road* Bxoldl iae- $s. Ctatfeijatij,
OM 45242. Or, If y0a still have
the lm bus of TECH TEBH0S,
you caa use the cosvenkaat jfoim.
insetted the«ia<
the Government of Canada and the
U.S. Department of Energy.
The site, located in Alberta,
Canada, is contaminated by a
complex mixture of natural gas con-
densate liquids, polyaromatic hydro-
carbons (PAHs), dissolved volatile or-
ganic compounds (including the
BTEX compounds of benzene, tolu-
ene, ethylbenzene and xylene) and
gas-processing chemicals such as
amines and amine degradation prod-
ucts. There is free-phase natural gas
condensate in addition to a dissolved
hydrocarbon plume in glaciofluvial
sands and gravels and fractured bed-
rock. In the hydrocarbon plume,
BTEX concentrations average about
10 to 20 milligrams per liter. The
SVE/bioventing demonstrations fo-
cus on removing hydrocarbons from
above the ground water table. The
first phase of work was not optimized
for removal by SVE and bioventing.
After the first month of conven-
tional SVE operation, the system was
shut down for one month to allow
subsurface conditions to equilibrate
and to allow an extended respiration
test to be performed. This type of
test involved determining whether
aerobic biodegradation was occurring
in the subsurface by measuring
changes in the oxygen (O2) and car-
bon dioxide (CC^) concentrations in
the soil gas over time. Biodegrada-
tion can be indirectly monitored by
observing changes in O and CO2
over time. Oxygen levels in the soil
were seen to decrease over this pe-
riod, from approximately 21% (at-
mospheric concentration) to less than
3%, while CO2 concentrations in-
creased from less than 1% to ap-
proximately 8-12%. Based on these
Hydrocarbons
SVE, bioventing
Soils
calculations, it was estimated that
about 450 kilograms (kg) of hydro-
carbons were biodegraded.
The next step in the project was to
examine the effects of bioventing
(Phase I bioventing). Data collected
over the next four-month period
spanning the relatively warm late
summer to rnid-winter 1994 indi-
cated that about 3,500 kg of con-
taminant were degraded through
bioventing. Air extraction rates be-
low 50 liters per second were insuffi-
cient to maintain rapid biodegrada-
tion. A series of additional respira-
tion tests were then run over the
winter months, during which time
the subsurface temperatures dropped
from 9 degrees Celsius (C) in Octo-
ber to around 4 degrees C by March.
The data showed that biological deg-
radation continued to occur at sig-
nificant rates. The oxygen concen-
tration dropped substantially from
atmospheric levels (21%). The cor-
responding rise in CO2 concentra-
tions indicated that the changes were
due to bioactivity.
Continuing cold climate testing
from December 1994 to the present
show that the biodegradation rates
remain very high, averaging approxi-
mately 200 kg of hydrocarbon bio-
degraded per day during the winter.
During this period surface tempera-
tures dropped as low as -35 degrees
C, although subsurface temperatures
ranged from a high of a 10 degrees in
the fall to a low of 5 degrees C in the
spring.
(continued on page 4)
Recycled/Recyclable
' Printed with Soy/Canola Ink on paper
that contains at least 50% recycled fiber
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Field Portable Monitors
FIELD PORTABLE MONITOR FOR PAHS
By William H. Engelmann,
EPA's Environmental Monitoring System Laboratory, Las Vegas
PAH'S
Monitor
Liquids/Soil
The Field-Portable Scanning Spec-
trofluorometer (FPSS) has tackled
the difficult task of providing
immediate in situ screening For
polyaromatic hydrocarbons (PAHs)
in complex mixtures such as oils,
creosotes and tars. The FPSS, devel-
oped by Tuan Vo-Dinh and co-
workers at Oak Ridge National
Laboratory for EPA s Environmental
Monitoring Systems LaboratoryJia_,=
Las Vegas, Nevada (EMSL-LV), has
overcome the challenge presented by
the high molecular weight of these
compounds since spectrofluorometry
can readily measure their relatively
high luminescence yields. Hereto-
fore these heavy compounds have
been troublesome to analyze with
traditional gas chromatography.
Additionally, the FPSS can provide
measurements into the low part-per-
billion (ppb) range, or even lower,
for not only PAHs but also oils,
polychlorinated biphenjds, phenols,
dioxins and most pesticides.
The FPSS performs in either emis-
sion or synchronous wavelength scan
modes. The latter mode scans both
excitation and emission monochro-
mators simultaneously with a small,
constant wavelength offset. There-
suit is a simplified synchronous spec-
trum with more spectral resolution.
Advantages of the synchronous
mode include: (1) spectral peaks are
simplified and sharpened; (2) mixed
PAHs with differing numbers of fused
rings are spaced out spectrally with no
overlap, auowing unambiguous as-
signment to individual PAHs; and
(3) die relative amounts of the various
PAHs in a mkture are easily esti-
• -mated.-The=ernission-mode.has=a
slighdy higher sensitivity and is useful
for determining the total PAHs in a
mixture, or in identifying spectral
classes of PAHs, oils or tars. In the
synchronous scanning mode, it can
detect anthracene —a typical PAH —
at about 3.5 ng/mL (nanograms per
milliliter). In die emission mode, an-
thracene can be detected at about 0.5
ng/mL.
The FPSS consists of three parts: a
small suitcase-sized instrument diat
houses the optics and electronics; a
battery pack; and a laptop computer
used for instrument control, data stor-
age and analysis? The spectral cover-
age of the instrument is 210 to 650
nanometers. The instrument param-
eters are chosen by the operator
through computer control.
The FPSS can be operated two
ways: using a standard fluorescence
cuvette cell or a bifurcated optical fi-
ber. The cuvette can be used widi
liquid samples or extracts of soils.
The optical fiber attachment allows
direct screening of water samples.
The prototype of the FPSS has
been demonstrated at Region 4's
American Creosote "Works Superfund
site near Jackson, Tennessee. These
results have been so promising that
_they_havejaeritedjdie4Jresentation^t_
two recent technical symposia; diese
findings are being published in the
Proceedings. The FPSS will be fur-
ther demonstrated at sites in Regions
6 and 8. The prototype FPSS cur-
rently is available for performance
comparison at sites by Remedial
Project Managers and On Scene Co-
ordinators. If you think that your site
may be a candidate, contact Ken
Brown at EMSL-LV at 702-798-
2270.
The prototype is ready for com-
mercial manufacturing; and, EMSL-
LV and Oak Ridge National Labora-
tory will transfer the technology to a
commercial manufacturer.
For more information, call Bill En-
gelmann at EMSL-LV at 702-798-
2664 by phone or at 702-798-2107
by FAX.
;sr
ese
Chlorinated
Gases
Monitor
Soil
SITE SEARCH TO EVALUATE SO1U-GAS-MON1TOR
The EPA is adapting the U.S.
Army's hand-held chemical agent
monitor (CAM) to the area of envi-
ronmental risk assessment analysis.
The monitor is now ready for a field
demonstration and evaluation; and,
EPA's Environmental Monitoring
Systems Laboratory at Las Vegas
(EMSL-LV) is searching for a site to
field evaluate this innovative technol-
ogy. EMSL-LV, together with
Washington State University, built
the prototype field monitor that
couples gas chromatography with a
Fourier transform ion mobility spec-
trometer (GC-FTIMS). The moni-
tor is a good candidate for on-site
detection of vinyl chloride, other
chlorinated gases and many chlori-
nated solvents that are regulated at
concentrations near the one partp<
billion level in soils and water. Th<
compounds are frequendy trapped in
the soE-gas spaces and are difficult to alternative to 100% laboratory analy-
analyze because of the physical prob- ^ Of samples. The GC-FTIMS has
lems of obtaining and preserving the been tested in the laboratory and has
sample as well as the challenges inher- turned out good results.
ent in the subsequent analysis. The If you think your site is a good candi-
GC-FTIMS is particularly well suited date for afield evaluation of the moni-
for this type of analysis because it _ tor> ca,HKen Broum at the EMSL-LV
merges the separation power of capil- Technology Support Center at 702-
lary gas chromatography with the sen-
sitivity of ion mobility spectrometry
and incorporates a Fourier transform
to achieve ruggedness for in situ
analysis. The GC-FTIMS offers an
798-2270.
Here's how it works. Reactive ions
are formed from air or carrier gas
molecules by using either a nickel-63
(continued on page 3 )
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SITE Subjects
PCB SOIL, SOLVENT EXTRACTION
By Mark Meckes, EPA Risk Reduction Engineering Laboratory
The EPA Superfund Innovative
Technology Evaluation Program
(SITE Program) has successfully
demonstrated the Terra-Kleen sol-
vent extraction system's ability to re-
duce polychlorinated biphenyl (PCB)
concentration in soils to less than 2
milligrams per kilogram (mg/kg).
This is equivalent to the Toxic Sub-
stance Control Act's (TSCA) incin-
eration performance guidance level.
The Terra-Kleen solvent extraction
system has overcome many of the soil
handling, contaminant removal and
regulatory restrictions that have made
it difficult to implement a cost-effec-
tive PCB soil treatment system.
The Terra-Kleen system is a batch
process that operates at ambient
temperatures and removes organic
contaminants from soils using propri-
etary solvents. After soils are washed
with solvent, contaminated solvent
passes through a solvent recovery
unit, where contaminants are sepa-
rated from the solvent and concen-
trated, reducing the contaminant vol-
ume for disposal. Terra-Kleen maxi-
mizes its waste reduction potential
by: (1) recycling the extraction sol-
vent as part of the routine system op-
erations; (2) maintaining a closed-
loop process to reduce volatile emis-
sions; and (3) concentrating organic
contaminants.
For the initial treatability studies
portion of the demonstration, the
SITE Program obtained 1-ton
batches of soil from each of three
PCB-contaminated sites and shipped
the soil to Terra-Kleen's testing facil-
ity in Okmulgee, Oklahoma. Soils
were also obtained from Sites 4 and 6
at the Naval Air Station North Island
(NASNI) near San Diego, California
and from a third site in Anchorage,
Alaska. Analyses of all demonstra-
tion soils revealed that Aroclor 1260
was the only PCB mixture present.
PCB concentrations in untreated
soils ranged from 17 to 640 mg/kg.
Following treatment, PCB removal
efficiencies ranged from 95 to 99%.
Successful removal of PCBs during
the treatability study led to a pilot-
scale demonstration at NANSI in
June 1994. Treated soil concentra-
tions for the NASNI Site 4 pilot-
scale demonstration were consistently
below 2mg/kg. Untreated PCB con-
centrations in the soil had ranged
from 129 to 168 mg/kg; removal ef-
ficiency rates ranged from 98.7 to
98.9%. Completion of the pilot-
scale demonstration at NASNI has
encouraged the U.S. Navy to select
Terra-Kleen to implement full-scale
remediation at three NANSI PCB-
contaminated sites, totalling about
5,000 cubic yards of soil.
PCB
Solvent
Extraction
Soil
Additionally, as a result of the PCB
pilot-scale results at NANSI, the
Navy has chosen TERRA-Kleen to
implement a full-scale system to
remediate 500 tons of pesticide
contaminated soils at NCS-Stockton.
There, analytical results of samples
collected from idle first 20-cubic-yard
container of treated soil showed 98%
removal for dichlorodiphenyldichlo-
roethane (12.2 mg/kg in untreated
soil); 99.4% removal for dichlo-
rodiphenyldichloroethene (1.5 mg/
kg in untreated soil); and 98.9% re-
moval of dichlcirodiphenyltrichlo-
roethane (80.5 mg/kg in untreated
soil). Full-scale: remediation began in
July 1994.
In addition to PCBs and the pesti-
cides discussed above, the Terra-
Kleen system is designed to remove
petroleum hydrocarbons, chlorinated
hydrocarbons, polynuclear aromatic
hydrocarbons, polychlorinated
dibenzo-p-dioxins and polychlori-
nated dibenzofurans from soils, slud-
ges and sediments.
For more information and to get
on the mailing list for reports, call
Mark Meckes at EPA's Risk Reduc-
tion Engineering Laboratory at 513-
569-7348 by phone or at 513-569-
7 67 6 by FAX.
(continued, from page 2)
beta source or a photoionization
source. These ions then react with
analyte molecules, after having been
separated by GC, to form ion clus-
ters which are then measured by at-
mospheric pressure time of flight
(IMS). The ions enter a drift region
where they move through an applied
field toward a collector electrode.
The electrode current is monitored
continuously, allowing a mobility
spectrum to be measured. The
specificity is imparted by the ioniza-
tion preferences of analytes and the
mobility differences of the ion clus-
ters. Separations are a function of
ion size.
Selectivity of IMS for various
analytes is based on the atmospheric
pressure ionization events themselves,
which relate to the proton and elec-
tron affinities of the analytes, the po-
larity of the products (i.e., positive or
negative ions) and the mobility of
those ions. Analytes with higher pro-
ton or electron affinities than other
constituents of the ambient environ-
ment are differentiated and detected
easily. Analytes with low affinities
can be measured when competing
chemicals with higher affinities are
not present. Thus, compounds such
as benzyl chloride, halogenated com-
pounds, hydrogen cyanide, nitro-
compounds (explosives), organo-
phosphorus compounds, phenols,
phosphorus trichloride, toluene
diisocyanate and vinyl chloride are
better suited to analysis by IMS than
are compounds like hexane and ben-
zene.
If your site is used to evaluate the
GC-FTIMS, you will get immediate
on-site data that will enable you to
make immediate decisions. In order
to determine the performance of the
GC-FTIMS system during field mea-
surement, a selected number of split
samples should be sent to an ap-
proved laboratory for confirmatory
analysis, using approved laboratory
methods or a gus chromatography-
mass spectrometry.
For more technical information, call
Tammy Jones atEMSL-LVat 702-
798-2270, But, call Ken Brown at
702-798-2270 if you want to discuss
field evaluation of the monitor at your
site. •
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INTERNATIONAL, SYMPOSIA AlUEJRT
GROUNDWATER AND
SOIL REMEDIATION
Canada's 5th Annual Symposium on
Groundwater and Soil Remediation
will highlight innovative technologies
for ground water and soil remedia-
tion. The symposium will be held
October 2-6,1995 in Toronto,
Ontario, Canada.
For farther information, contact Lise
Gendron, Environment Canada, by
phone, 819-953-9368; or by Fax
819-953-7253.
MANUFACTURED GAS
PLANT REMEDIATION
From September 19-21, EPA will
sponsor the International Sympo-
sium and Trade Fair on the Cleanup
of Manufactured Gas Plants in
Prague, The Czech Republic The
goals are to provide an international
Forum for discussing innovative and
state-of-the-art technology and ap-
proaches for addressing environmen-
tal restoration needs and to provide a
venue for U.S. environmental busi-
nesses interested in exporting tech-
nology and services. Worldwide par-
ticipation and business opportunities
are oeing solicited by the symposium.
Jfyou want to present papers and for
more information, call Steve James of
FJ>A at 513-569-7877 or John
Moerlins of Florida State University
(FSU) at 904-644-5524. However,
exhibitors call Gene Jones at FSU at
S>04-644-55!6
(continuedpom page 1)
In economic terms, SVEwith
bioventing removed over 17,000 kg
of contaminant for a total capital
cost for the SVE test cell system (cov-
ering aboutj. hectare^ of $150,000
andsemirt:":" •-,= "don and __
maintenant. Approximately
$15,000. This ..^resents a mass re-
moval unit cost of about $10/kg.
Compared to many other tech-
niques, SVEwith bioventing is
clearly an economical method of re-
moving volatile hydrocarbons from
subsoils. The goal of the Strachan
bioventing demonstration in the fu-
ture (Phase II bioventing) is to deter-
mine how clean bioventing can get
the soil at Strachan, and how long it
will take. In December 1993 and
October 1994 the subsurface soils
were sampled and analyzed for hy-
drocarbon concentration and compo-
sition, bacterial concentrations, nutri-
ents and soil moisture. The subsoils
will be re-sampled in the same loca-
tions after the O2 depletions rates in-
dicate that most or all of the biode-
gradable hydrocarbons have been re-
moved.
For a more detailed description of
background, range and extent of the
field demonstrations at the Strachan
Gas Plant (including the use of hori-
zontal wells), see the July 1994 issue
of "Subsurface Remedial Technolo-
gies Newsletter," published by the
Canadian Association of Petroleum
Producers Public Affairs Group in
Calgary, as well as the upcoming
April 1995 issue of the same Newslet-
ter. The information presented in
_this-article borraw£dJieavily_froirutb.e_
CAPP newsletters. To obtain a copy
of CAPP's newsletters on this project,
call Michele White at CAPP at 403-
267-1154. Also, the results will be
presented at Canada's 5di Annual
Symposium on Groundwater and
Soil Remediation in Toronto,
Canada in October (see "Interna-
tional Symposia Alert" section, p. 4 of
this issue of TECH TRENDS for
Symposium details).
For more technical information on
the project, call Alex Lye, GASReP
Manager at 905-336-6438.
MAILING L.IST/ORDER INFO
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United States
Environmental Protection
Agency
Solid Waste
Emergency Response
(5102W)
EPA 542-N-9B-001
March 1995
Issue No. 19
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