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A newsletter about soil, sediment, and ground-water characterization and remediation technologies
Issue 9
December 2003
Innovative Methods Used to Integrate Soil
and Ground-Water Remediation
The Hastings Ground-Water Contamination
Site consists of six industrial subsites used
for coal gas production, grain storage,
manufacturing, and landfilling within the city
of Hastings, NE. This Superfund site also
encompasses the former Naval
Ammunition Depot (NAD) subsite, which
is located on 48,000 acres outside the city.
Over the past 11 years, soil and ground-
water remediation activities have begun or
been completed at each of the seven
subsites. "Lessons learned" at individual
subsites have led to site-wide cleanup plans
that are better equipped to maximize use
of technologies shown effective within the
site's hydrogeologic setting. In addition,
updated cleanup plans now reflect a
streamlined sequencing of treatment
technologies and an increased use of
technologies that integrate treatment for
both ground water and soil.
Ground water within the upper aquifer at
the site is contaminated with a range of
volatile organic compounds (VOCs) to
depths as great as 165 ft below ground
surface (bgs). The upper aquifer consists
of Pleistocene-aged sand, silt, and gravel
units extending from a depth of about 120
to 225 ft bgs, the top of the Niobrara
Formation. Ground-water flow rates in the
upper aquifer are estimated to be 0.5-1.5
ft/day
Due to the vast size and complexity of the
Hastings site, cleanup activities are
managed in three primary treatment areas:
the Central Industrial Area, the Commercial
Area and City Landfill, and the East
Industrial Park and Former NAD.
Treatment technologies used or planned
for soil and/or ground-water remediation
atone or more of the subsites include soil
vapor extraction (SVE), ground-water
extraction with ex-situ air stripping, in-well
aeration (IWA), in-situ chemical oxidation,
clay caps, traditional pump and treat
systems, soil excavation/incineration, and
in-situ air sparging.
Central Industrial Area
The U.S. EPA's Region 7 and Robert S.
Kerr Environmental Research Center
conducted a pilot study on the use of SVE
for removing carbon tetrachloride (CC14)
from soil adjacent to aformer grain storage
facility at a subsite known as "Well #3."
With support from the Nebraska
Department of Environmental Quality
(NDEQ), Region 7 initiated a full-scale
SVE system at the subsite in 1992. The
SVE wells were designed to withdraw air
from discrete depths within the vadose
zone. Soil gas extracted through the wells
was treated with activated carbon prior to
discharge. After one year of treatment,
laboratory analyses indicated that SVE had
reduced CC14 concentrations by 99.8%.
Contaminant extraction rates during that
time decreased from 0.6 Ibs/hr to less than
O.OOllbs/hr.
Based on the success of SVE for removing
CC14 from soil, two ground-water
extraction systems were installed, one of
which utilized a former municipal supply
well. Extracted ground water was treated
through an air stripping process. Within six
[continued on page 2]
Contents
Innovative Methods Used to
Integrate Soil and Ground-
Water Remediation page 1
SVE and ISCO Used After
Pump and Treatfor Multimedia
Removal of VOCs page 3
Video Viewing on TIP's
CLU-IN page 4
Technology Innovation
Program Formed in OSWER
Reorganization page 5
Project Planning Resources
Made Available for
Brownfields Cleanup page 6
FRTR Plans Conference
on Long-Term
Remediation
On June 15-17, 2004, the Federal
Remediation Technologies Roundtable
will sponsor a new conference, Ac-
celerating Site Closeout, Improving
Performance, and Reducing Costs
through Optimization, in Dallas, TX. The
conference aims to help remediation
program managers, system operators,
regulators, and vendors by:
> Outlining long-term remediation
liabilities and optimization needs,
> Disseminating optimization strate-
gies and tools,
> Communicating lessons learned,
and
> Discussing the use of remedial op-
timization in site-wide and multi-site
management plans.
More information is available on the
Technology Innovation Program's
CLU-IN website at
http://cluin.org/siteop1/siteopt.htm.
Recycled/Recyclable
Printed with Soy/Carola Ink on paper that
contains at least 50% recyded fiber
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[continued from page 1]
years of treatment, the maximum
contaminant level (MCL) for CC14 in
ground water (5 ^g/L) was reached.
Recognizing the large volume of
wastewater produced by air stripping,
Region 7 installed a park irrigation
system in 1997 to beneficially reuse the
extracted water. More information on
the irrigation system is available in the
EPA SITE program report entitled
Sprinkler Irrigation as a VOC
Separation and Disposal Method
(EPA/540/R-98/502) available at http://
www.epa.gov/ORD/SITE/reports/
r98502.html.
EPA released its final record of decision
fertile subsite in May 200 1. detennining
that continued operation of the
converted municipal supply well was
needed to address another contaminant
plume migrating from a local
manufacturing plant but containing
trichloroethene (TCE), dichloroethene
(DCE), andperchloroethene (PCE). To
date, concentrations of TCE. DCE, and
PCE in ground water have decreased
99%). 99%, and 98%> respectively, as a
result of treatment. The system will
continue to operate until MCLs for
ground water are met — likely within 1 5
years.
An SVE system also was installed in
1996 at the Central Industrial Area's
"Colorado Avenue" subsite. Field staff
retained by the potentially responsible
parry (PRP) used computer modeling
results compiled earlier by the Ken-
laboratory for the Well # 3 pilot study.
The system's "Phase I" SVE wells are
Figure 1: Although significant
increases occurred after treatment
J
was suspended for 12 months,
contaminant concentrations in ground
water extracted by the combined efforts
ofSlTL-plus and pump-and-treat
technology dropped by almost one-half
after five years.
designed to remove TCE, 1,1,1- 2001
is expected to decrease the overall
tricliloroethane, 1 , 1 - DCE, PCE, and other time required for remediation . Long-term
chlorinated VOCs in deep and cleanup actions are needed, however, to
intennediate zones of approximately address a benzene plume that continues
800,000 yd3 of soil, to migrate downgradient of die treatment
area. While ground-water extraction and
In addition, in-well aeration treatment • • . r]iemirnl nx;Hatinn were selected
. . . . 1I1~S1LU CllClIllCdl OXlUculUll We 1C SClCCLCCl
systems inj ect air into the Colorado Avenue . ti f i H ' H H ' t ' 1
subsurface through seven IWAtreatment ^ologfes are «dlf ijStigai<»fef
wells located in more concentrated areas enhancmg natural biodegradation of
of the contaminant plume. SVE and die Q]gamc ^^^ in uie ^
in-well aeration svstem together have
^ O
achieved order-of-magnitude contaminant Commercial Area and City Landfill
reductions in ground water near the
O T* J_£T11
contaminant source "Phase IT SVE wells Two municlPal landfills operated at the
willbeinstalledin2004toremediateareas Sltemthe 1960sand 1970s to dispose of
not addressed by the Phase I wells, but municipal and mdustr^ wastes. Following
additionalground-watertreatmentwillbe tlie detection of elevated concentrations
necessary to contain the plume and of TCE. PCE. and vinyl chlonde in soil, a
minimizefi^diercontammantmigration. cla>' caP was mstalled over one of the
landfills in 1999 as a source control
At die "Second Street" subsite, SVE and measure. The record of decision for the
in-situ air stripping technologies have been second landfill selected a cap followed
employed since 1997 to remove benzene by monitored natural attenuation.
from soil and ground water. The SVE
EPA
svstem was constructed using shallow,
detennined that the two closed
intennediate, and deep wells in a design landfills and the FAR-MAR-CO subsite.
similar to that of the Colorado Avenue where ^f^f1 products had been
subsite.Resultsofrecentsamplingindicate stored and handled for over 30 >'ears'
thatbenzeneconcentrationsintiiesoilgas were the sources of ground-water
have decreased significantly, but contamination throughout the area.
concentrations in apumping welfremain Mhou§h commingling of contaminated
above the removal action target level Sround water from one landfl11 and me
C100 O-/T 1 FAR-MAR-CO subsite occurred.
ground-water sampling revealed
An IWA ground-water treatment system
installed at die Second Street subsite in
[continued on page 3]
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[continued from page 2]
commercial grain fumigants (primarily
CC14 and ethylene dibromide [EDB])
were emanating from the FAR-MAR-
CO subsite. An SYE pilot study
conducted in 1990 successfully removed
more than 1,200 Ibs of CC14 and EDB.
In 1995, PRPs for the landfills and
industrial property began working
together to plan remediation of the
commingled plume. Joint field efforts
began in 1997, when a full-scale SVE
system was implemented to remediate
soil on the industrial property. After 2.5
years of operation, remediation goals for
chloroform (138 (jg/L), CC14 (7.54 |jg/L),
and EDB (0.0016 (jg/L) in soil were
reached.
Operational periods were extended again
in 2000 to allow treatment to advance to
the phase of "SVE-plus," wherein SVE
treatment reaches beyond typical soil
remediation goals and begins to influence
ground-water conditions. Operation of
the system for two additional years
provided an opportunity to address vadose-
zone water that was determined to be the
contaminant source. Soil vapor samples
collected in November 2002 indicated that
no contaminant rebounding has occurred.
contaminants and incinerating soils with
high concentrations of explosives and
PAHs. SVE systems also were installed
to remove volatile contaminants from soil
at three portions of the East Industrial
Park and former NAD area.
A pump and treat system has operated Cleanup Planning and Review
since 1997 to address the CC14 and EDB
ground-water plume migrating from the
industrial property (Figure 1). Region 7
estimates that restoration of the aquifer to
maximum contaminant levels for these
contaminants will be achieved in 2012.
East Industrial Park and Former NAD
Contaminants of concern at the former
NAD include VOCs, heavy metals,
polycyclic aromatic hydrocarbons (PAHs),
and explosives. In 1995, the U.S. Army
Corps of Engineers began remediating
VOC-contaminated soil and ground water
at the NAD by installing a full-scale air
sparging system employing both horizontal
and vertical wells. Remedy construction
involved excavating soil with low levels of
Region 7 and the NDEQ established an
integrated action plan in 2001 to address
ground-water contamination across the
six industrial subsites. The plan specifies
institutional controls, alternate drinking
water supplies, well inventories, and
extensive ground-water monitoring. In
July 2002, EPA completed its second
five-year review of cleanup progress at
the entire Hastings site. The final report
is available at www.epa.gov/region07/
superfund.
Contributed by Diane Easley. EPA
Region 7 (913-551-7797 or
easlev. diane(aieya. sov)
SVE and ISCO Used After Pump and Treat for Multimedia Removal of VOCs
EPA Region 1 recently completed its first
five-year review of cleanup progress at
the Union Chemical Company Superfund
site near South Hope, ME. The 1990
record of decision (ROD) selected
conventional technologies, including soil
excavation with low-temperature aeration
and ground-water pump and treat.
Cleanup plans have since been modified
to incorporate more innovative
technologies for removing VOCs. In
1996, SVE augmented with hot air
injection was implemented to enhance
contaminant volatilization. Monitoring
confirmed that by late 1998, two years
Figure 2: Contaminant concentrations in
ground water at the Union Chemical site
decreased 47-97% following injections of
potassium/sodium permanganate solution.
after SVE treatment had begun, the soil
had met project cleanup goals.
Once the soil was clean, the ground-water
extraction system was enhanced with in-
situ chemical oxidation (ISCO). Potassium
and sodium permanganate were injected
into the subsurface each summer for
three years, resulting in substantial
decreases of contaminant concentrat-
ions (Figure 2). After recognizing that
the peak effectiveness ofthese injectants
[continued on page 4]
• Jan 1996
I Nov 1999
1,1-DCA
47%
N.N-DMF
80%
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[continued from page 3]
had likely been reached, but cleanup
goals had not yet been achieved, EPA
agreed to incorporate enhanced
bioremediation as a final step for ground-
water remediation. Molasses and sodium
lactate were injected between 2001 and
2002 to serve as carbon sources capable
of creating reductive dechlorination
conditions in an anaerobic environment.
From 1967 to 1984. Union Chemical used
the 12-acre site to manufacture solvents
and recover petrochemical-based
solvents. Spills from an onsite boiler,
disposal of wastewater into an adjacent
stream and wetlands, and leakage from
storage containers contributed to
extensive contamination of the area's soil
and ground water. Primary contaminants
include TCE. PCE. and 1,1-dichloro-
ethene (DCE) in concentrations
reaching 84.000 |jg/L, 73.000 ng/L, and
2,700 |lg/L, respectively.
Surficial geology at the site consists of a
glacial and marine till. The till thickens
from less than 25 ft to the west
(upgradient) of the site to about 80 ft in
the vicinity of Quiggle Brook to the east.
The hydraulic conductivity of the till is
estimated to be 1x10° cm/s; the ground-
water velocity under non-pumping
conditions is approximately 15 ft/yr. A
schist/gneiss bedrock containing granitic
intrusions underlies the till. The upper 10
feet of the bedrock is weathered and
has an estimated hydraulic conductivity
of 8x 10"5 cm/s. Seepage velocity through
the bedrock fractures is approximately
300 ft/day. Contaminants were found in
both the till and the weathered bedrock.
Conventional Technologies
The pump and treat system operated
from 1996 through 1999. and on a limited
basis for six months during 2000. to
ensure permanganate containment and
prevent it from contaminating Quiggle
Brook. The system consisted of 28
extraction wells fully screened through
Video Viewing on TIP'S CLU-IN
The Technology Innovation Program's CLU-IN Internet "studio" hosts
streaming videos on a range of topics concerning innovative site
characterization and cleanup, such as:
> Introduction to Environmental Geophysics.
> Superfund Redevelopment: Realizing Possibilities
> The Clean Green-Phytoremediation.
> Biosolids Recycling: Restore, Reclaim. Remediate,
> Dynamic Workplans & Field Analytics: The Keys to Cost-Effective Site
Cleanup.
The studio is accessible at http://cluin.org/stiidio/video.cfin.
the till and 109 monitoring wells. Above-
ground treatment of the extracted ground
water involved the removal of metals
through precipitation and the removal of
organic contaminants through air stripping.
granular activated carbon absorption, and
ultraviolet oxidation (to destroy
dimethylformamide [N. N-DMF]). As of
2000, approximately 8.35 million gallons of
ground water were treated. A total of
approximately 950 pounds of VOCs.
including 350 pounds of non-chlorinated
VOCs. such as BTEX and ketones, were
removed.
SVE Application
The SVE system consisted of 91 hot air
injection points and 33 25-foot vapor
extraction wells over an area of 1.5 acres.
Before the injections began, dewatering
took place in order to increase the volume
of soil to be treated. Hot air was
continuously injected to depths of 6-20
feet from February 1996 to March 1998.
except for brief periods of system
maintenance and repair. Vapors from both
the SVE system and ground-water
treatment units were destroyed by a
propane-fired thermal oxidizer pnor to
atmospheric discharge. Soil sampling data
collected at the end of August 1998
indicated that concentrations of TCE,
1,1 -DCE, and PCE had decreased to
below the site-specific target level of
0.1 mg/kg. SVE treatment of 48,000
yards3 of soil resulted in the removal of
nearly 9.000 pounds of VOCs.
ISCO Applications
Following the drop-off of contaminant
removal via the ground-water extraction
system, an ISCO pilot-scale test was
performed in late 1997. Based on
successful test results, a full-scale
system began operating in 1998.
Treatment involved the injection of a
solution containing either potassium
permanganate (2%) or sodium
permanganate (20-40%). Injections
were performed in both monitoring and
extraction wells screened throughout the
till and weathered bedrock. Over three
summers, approximately 36.000 pounds
of potassium permanganate and 7.300
pounds of sodium permanganate were
injected. An application rate of 10 times
the minimum amount estimated to
oxidize the contaminants at each
injection point was used across the site.
[continued on page 5]
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[continued from page 4]
Initial post-application data indicated
VOC reductions of 30-99% in individual
wells. Combined with the ground-water
extraction system, the average
concentrations of VOCs following
permanganate injections in the till
decreased from 620-8.050 jig/Lto 7-875
Hg/L. Similarly, average concentrations
of VOCs in the weathered bedrock
decreased from 55-725 ng/L to 6-420
|.lg/L. Ethene contaminants generally
responded to the permanganate more
readily than the ethane compounds.
although some rebounding of TCE and
DCE concentrations has occurred.
In August 2001. with DCA as the major
remaining contaminant, the system was
converted to an anaerobic environment
in order to increase the rate of reductive
dechlorination. Food-grade molasses and
sodium lactate were injected as carbon
sources into two separate areas of the site.
In August 2002. sodium lactate was
applied again, this time in all areas with
elevated DCA concentrations. While post-
application monitoring of water quality
parameters indicated reductive conditions
remained through the fall and winter, the
April 2003 data were mixed. No
significant DCA decrease could be
attributed to the sodium lactate application,
but a gradual increase of chloroethane (a
daughter product of DCA) was observed.
It is estimated that approximately 475
pounds of the four primary contaminants
remain in the subsurface. More than
10.000 pounds have been removed using
this multiple-technology approach.
Currently, the till's low permeability is
recognized as the limiting factor in site
cleanup completion. Contaminant data
indicate that the plume footprints in the till
and weathered bedrock have reached
equilibrium and are not anticipated to
migrate beyond the site boundaries. The
installation of additional bedrock wells
for field testing is underway to confirm
these conditions. All performance
standards have been met in the western
(upgradient portion) of the site.
Total capital costs for the pump and treat
and SVE systems were $9.500.000. The
average annual operation and
maintenance costs were $600.000 for
the (combined) pump/treat and SVE
systems and $150.000 for the ISCO
system. Additional information on
cleanup activities at this and other
Region 1 sites is available online at http:/
Avvvw.epa.gov/region01/superfund/
sites.
Contributed by Terry Connelly,
EPA/Region / (617-918-1373 or
connellv, terrvCcliepa. sov)
Technology Innovation Program Formed in
OSWER Reorganization
As of June 24.2003. EPA's Technology Innovation Office (TIO) and the Office
of Emergency and Remedial Response have joined to form the new Office of
Superfund Remediation and Technology Innovation (OSRTI) within the Office
of Solid Waste and Emergency Response (OSWER). TIO has changed its
name to the Technology Innovation Program. In a second phase of the
reorganization. TIP will join with the Environmental Response Team and the
Analytical Services Branch to make up the Technology Innovation and Field
Services Division, one of three divisions within OSRTI. This phase should be
effective by January 2004.
The Technology Innovation Program or "TIP" now publishes the Technology
News and Trends newsletter and w ill continue providing an information network
for technology decision makers addressing contaminated soil and ground water.
TIP's updates and links to its extensive on-line information network. CLU-IN.
are available at http://www.epa.gov/tio.
The Agency anticipates that the organ izational change will enhance and stream line
OSWER's current activities and new initiatives. One such initiative is the One
Cleanup Program (OCP). which envisions how different cleanup programs at
all levels of government can work together to improve the coordination, speed.
and effectiveness of site cleanups. More information about OSRTI activities is
available on-line at http://www.eDa.gov/siiDerfund/Dartners/oerr.
Technology N&vs and Trends
is on the NET!
View, download, subscribe, and
unsubscribe at:
http://www.epa.gov/tio
http://cluin.org
Technology News and Trends
welcomes readers" comments
and contributions. Address
correspondence to:
Ann Eleanor
Office of Superfund Remediation
and Technology Innovation
(5102G)
U.S. Environmental Protection Agency
Ariel Rios Building
1200 Pennsylvania Ave. NW
Washington. DC 20460
Phone:703-603-7199
Fax: 703-603-9135
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532-
Technology
News and Trends
Solid Waste and
Emergency Response
(5102G)
EPA 542-N-03-006
December 2003
Issue No. 9
United States
Environmental Protection Agency
National Service Center for Environmental Publications
P.O. Box 42419
Cincinnati, OH 45242
Official Business
Penalty for Private Use $300
First Class Mail
Postage and Fees Paid
EPA
Permit No. G-35
Project Planning Resources Made Available for Brownfields Cleanup
EPA's Brownfields Technology Support Center assists project managers for local and state organizations
and EPA staff addressing the unique issues of brownfield investigations and cleanup. On-line requests can
be placed (at http://vvvwv.brownfieldstsc.org) for technical assistance in:
> Developing strategies for streamlining site assessment and cleanup.
> Identifying and understanding technology options.
> Evaluating contractor capabilities.
> Explaining technologies to communities, and
> Planning technology demonstrations.
Support is available in the form of site-specific technical assistance, traditional and on-line training seminars,
professional conferences, news updates, and technical publications. Recent decision-making tools made
available by the center include the primer. Using the Triad Approach to Streamline Brownfields Site
Assessment and Cleanup (EPA 542-B-03-002).
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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