Large-Scale
Physical Models of Thermal Remediation of DNAPL Source
Zones in Aquifers
Ralph
S. Baker, TerraTherm, Inc., 356 Broad Street, Fitchburg,
MA 01420, Tel: 978-343-0300, Fax: 978-343-2727, Email: rbaker@terratherm.com
Uwe Hiester, University of Stuttgart, Research Facility
for Subsurface Remediation (VEGAS), Pfaffenwaldring 61,
D-70550 Stuttgart, Germany, Tel: 49(0)711-685-4745, Fax:
49(0)711-685-7020, Email: uwe.hiester@iws.uni-stuttgart.de
Gorm Heron, TerraTherm, Inc., 10554 Round Mountain Road,
Bakersfield, CA 93308, Tel. and Fax: (661) 387-0610,
Email: gheron@terratherm.com
John C. LaChance, TerraTherm, Inc., 356 Broad
Street, Fitchburg, MA 01420, Tel: 978-343-0300, Fax:
978-343-2727, Email: jlachance@terratherm.com
Myron Kuhlman, MK Tech Solutions, Inc., 12843
Covey Lane, Houston, TX 77099, Tel: 281-564-8851, Fax:
281-564-8821, Email: mikuhlman@sbcglobal.net
Arne M. Färber, University of Stuttgart,
Research Facility for Subsurface Remediation (VEGAS),
Pfaffenwaldring 61, D-70550 Stuttgart, Germany, Tel:
49(0)711-685-4720, Fax: 49(0)711-685-7020, Email: arne.faerber@iws.uni-stuttgart.de
Hans-Peter Koschitzky, University of Stuttgart,
Research Facility for Subsurface Remediation (VEGAS),
Pfaffenwaldring 61, D-70550 Stuttgart, Germany, Tel:
49(0)711-685-4717, Fax: 49(0)711-685-7020, Email: hans-peter.koschitzky@
iws.uni-stuttgart.de
Oliver Trötschler, University of Stuttgart,
Research Facility for Subsurface Remediation (VEGAS),
Pfaffenwaldring 61, D-70550 Stuttgart, Germany, Tel:
49(0)711-685-7021, Fax: 49(0)711-685-7020, Email: oliver.troetschler@iws.uni-stuttgart.de
In-situ
thermal remediation (ISTR) technologies are receiving
increasing attention for remediation of dense non-aqueous
phase liquid (DNAPL) source zones in soil and groundwater. A clear understanding of the mechanisms of ISTR is crucial in
selection of appropriate sites and effective ISTR
technologies for DNAPL source zone remediation.
Large-scale physical model experiments have proven
indispensable for incorporating thermal interactions
between soil layers of different permeability.
In this Strategic Environmental Research and
Development Program (SERDP)-funded project, large-scale
physical models will be used to address several essential
research questions, including: (a) the relative
significance of various contaminant removal mechanisms
below the water table (e.g., steam stripping,
volatilization, in-situ destruction); (b) the percentage
of DNAPL source removal and accompanying change in water
saturation at various treatment temperatures/durations
through boiling; and (c) the potential for DNAPL
mobilization through volatilization and recondensation
and/or pool mobilization outside the target treatment zone
during heating. Thermal
conductive heating (TCH) is an ISTR method that takes
advantage of the invariance of thermal conductivity across
a wide range of soil types to effect treatment of DNAPL in
lower-permeability and heterogeneous formations.
TCH can complement steam-enhanced extraction, which
is generally more applicable to higher-permeability
formations. TCH
accompanied by vacuum extraction will be employed in
large-scale (containers 3 x 6 x 4.5m, and 6 x 6 x 4.5m)
[width, length, height] controlled-release, closed mass
balance experiments with geologically-relevant layering.
In parallel, non-isothermal numerical modeling will
simulate the controlling mechanisms and processes of the
experiments. This
research will answer key questions associated with the
effectiveness of ISTR and lead to improvements in
screening, selection, evaluation and design of field-scale
ISTR systems.
Economic
Basis and Application of Thermally-Enhanced Soil Vapor
Extraction
John
M. Bierschenk, TerraTherm, Inc., 356 Broad Street,
Fitchburg, MA 01420, Tel: 978-343-0300, Fax: 978-343-2727,
Email:jbierschenk@terratherm.com
Ralph S. Baker, TerraTherm, Inc., 356 Broad
Street, Fitchburg, MA 01420, Tel: 978-343-0300, Fax:
978-343-2727, Email:rbaker@terratherm.com
Uwe Hiester, Reconsite
TTI GmbH, Pfaffenwaldring 61, D-70550 Stuttgart, Germany,
Tel: +49(0)711-685-4745, Fax: +49(0)711-685-7020, Email: uwe.hiester@reconsite.com
Gorm Heron, TerraTherm, Inc., 10554 Round Mountain Road,
Bakersfield, CA 93308, Tel. and Fax: (661) 387-0610,
Email: gheron@terratherm.com
The
use of thermally enhanced soil vapor extraction (TESVE)
has been shown to be more cost effective than unheated
soil vapor extraction (SVE) for the remediation of sites
contaminated with volatile organic compounds (VOCs). In
comparison with “cold” SVE, TESVE increases the vapor
pressure of the VOCs due to higher soil temperatures and
thus allows much higher contaminant extraction rates to
occur, which results in a significant reduction in the
time required to complete a site remediation project.
In fact, at many operating SVE sites, completion of
the remediation would require that soil VOC concentrations
be reduced to a specific numeric cleanup standard that may
be unachievable due to limitations of the cold SVE
technology to treat heterogeneous, layered and/or
low-permeability soil.
Experiments
from laboratory studies along with field data from 3 sites
have been used by VEGAS, the Research Facility for
Subsurface Remediation at the University of Stuttgart,
Germany, to conduct Life Cycle Assessments (LCA) where
TESVE and cold SVE were compared for the purpose of
estimating the secondary environmental impacts of such
techniques. The results indicate that energy consumption
and environmental impacts are favored for TESVE as
compared to SVE. These
results are discussed as a method to evaluate the cost
benefit of TESVE.
Thermal
Conduction Heating (TCH) is a method to heat the
subsurface at low incremental cost.
It is being applied to sites for the purpose of
performing thermal enhancement of conventional remediation
methods, such as SVE and free-product recovery.
One site will be reviewed as a case study.
This southern California site has been undergoing
high vacuum vapor extraction remediation for a period of
more than 6 years. During
the years of cold SVE operation the source zone
concentrations of VOCs in the saturated clay rich zone, at
a depth of 20 to 35 feet below ground surface, have not
been reduced. A
TESVE system was installed in the spring of 2004, and heat
was applied over a period of 12 months.
The concept, cost and results from this site will
be presented to demonstrate the comparative economics of
TESVE and SVE.
Successful
Remediation at Contaminated Sites with a Very Tight Soil
Matrix
Richard
T. Cartwright P.E., CHMM, MECX, LLC, 8096
Clarherst Drive, East Amherst, NY 14051, Tel:
713-412-9697, Fax: 713-585-7049, Email: richard.cartwright@mecx.net
R. Thomas Numbers P.E., MECX, LLC,
3005 Margaret Jones Lane, Williamsburg, VA 23185, Tel:
757-220-6666, Fax: 757-220-3396, Email: thomas.numbers@mecx.net
An
innovative three step remediation approach has been
developed to successfully treat contaminants at sites with
a very tight soil matrix. The first step is to
pre-condition low permeability soils using both chemical
and mechanical means. The second step is to apply an
optimized enhancement of the Traditional Fenton’s
Reagent chemical oxidation process. Unlike previous
applications of Traditional Fenton’s Reagent, the new
emphasis is on optimization of the “Free Radical Fate
and Transport Process and Total Contaminant Mass
Desorption”. The third step is a bioremediation
polishing step applied to treat the remaining desorbed
contaminant mass. This break through approach avoids
Traditional Fenton’s free radical chemical oxidation
fate and transport limitations. Fenton’s free radicals
are typically not applied in very tight soils since they
are limited to a shelf life of seconds and minutes.
Bench
scale studies have indicated that use of high temperature
(greater than 180oF) chemical oxidant
applications in the saturated zone negatively impacts the
subsequent bioremediation polishing step (third
remediation stage). Use of low temperature (less than 100oF)
chemical oxidant applications in the saturated zone have
resulted in dissolved phase rebound problems. When the
saturated zone temperature is optimally maintained
consistently between 140oF and 170oF,
contaminants are still effectively desorbed from the tight
soil matrix through a mass transfer partitioning process
without overly stressing the indigenous biological species
needed for subsequent bioremediation while avoiding
subsequent dissolved phase rebound problems.
The
second chemical-oxidation/desorption-extraction step
facilitates the third treatment step used
to reduce total contaminant mass transferred from the soil
matrix into the dissolved phase within the saturated zone.
The final treatment step is an
aerobic and/or anaerobic
biostimulation process, which cost-effectively
completes the innovative
sequence of complementary treatment technologies needed to
optimize the reduction of total contaminant mass in a very
tight soil matrix.
Sorption/Desorption
of Polychlorinated Dibenzo-p-Dioxins and Polychlorinated
Dibenzo Furans (PCDDs/PCDFs) in the Presence Of
Cyclodextrins
Shamil
J. Cathum, SAIC Canada, 335 River Road, Ottawa, Ontario
K1A 0H3, Canada, Tel: 613-990-6879, Fax 613-991-1673,
Email: shamil.cathum@saiccanada.com
Andre Dumouchel, SAIC Canada, 335 River Road, Ottawa,
Ontario K1A 0H3, Canada, Tel: 613-998-7903, Fax
613-991-1673. Email: andre.dumouchel@saiccanada.com
Monique M. Punt, SAIC Canada, 335 River Road, Ottawa,
Ontario K1A 0H3, Canada, Tel: 613- 991-2737, Fax
613-991-1673, Email: monique.punt@saiccanada.com
Carl E. Brown, Environmental Technology Centre,
Environment Canada, Ottawa, Ontario K1A 0H3, Canada, Tel:
613- 991-1118, Fax 613- 991-9485, Email: Carl.Brown@ec.gc.ca
The
goal of this study was to investigate the usefulness of
cyclodextrins in the remediation of polychlorinated
dibenzo-p-dioxins and polychlorinated dibenzo furans (PCDDs/PCDFs)
in soil and water. Five
cyclodextrins having different molecular cavities and
active functional groups were selected and evaluated for
their ability to include (trap) PCDDs/PCDFs. The inclusion
of PCDDs/PCDFs was performed in soil and water.
For the soil experiments, cyclodextrins were added
to the soil on day one and the concentrations of unbound
PCDDs/PCDFs were monitored over a 28-day period.
Control experiments were conducted parallel to the
testing experiments to assist in the process performance
evaluation. The
ability of cyclodextrins to remove PCDDs/PCDFs from the
contaminated soil was dependent upon the type of
cyclodextrin used and constituents of PCDDs/PCDFs.
Among the five cyclodextrins investigated,
hydroxypropyl-b-cyclodextrin
gave the highest removal efficiency for all components of
PCDDs/PCDFs. The removal efficiency was 81% at the start
(one day after application of cyclodextrins) and then
increased to 96% after 28 days. The congeners removal
efficiencies ranged from 69% to 96% for 2,3,7,8-TCDD and
1,2,3-TCDD, respectively.
The a-cyclodextrin
and b-cyclodextrin
removed only 45% and 50% of the total PCDDs/PCDFs after 28
days, respectively, whereas hydroxypropyl-b-cyclodextrin
and hydroxypropyl-g-cyclodextrin
removed 73% and 80% of the total PCDDs/PCDFs from the
contaminated soil, respectively.
Surfactant
Injection for the Remediation of Light Non-Aqueous Liquids
(LNAPL)
Richard
P. Cerbone, P.G., Sovereign Consulting Inc. 111-A North
Gold Drive, Robbinsville, N.J. 08691, Tel. 609-259-8200,
Fax 609-259-8288, Email:
rcerbone@sovcon.com
Ronald Traver, Sovereign Consulting Inc. 111-A North Gold
Drive, Robbinsville, N.J. 08691, Tel. 609-259-8200, Fax
609-259-8288, Email:
rtraver@sovcon.com
Darren Scillieri, Sovereign Consulting Inc. 111-A North
Gold Drive, Robbinsville, N.J. 08691, Tel. 609-259-8200,
Fax 609-259-8288, Email:
dscillieri@sovcon.com
Sovereign
Consulting Inc. (Sovereign) completed a surfactant
injection pilot test to remove residual light non-aqueous
phase liquid (LNAPL) at an operating retail service
station in south-central New Jersey.
Sovereign utilized a biodegradable, EPA registered
oil spill response chemical surfactant, BIOSOLVE®,
produced by Westford Chemical Corporation.
The surfactant was mixed on site as a dilute 2%
solution, and injected into the area straddling the water
table through a grid of 78 closely-spaced GeoprobeTM
injections. Prior
to the pilot test, a baseline ground-water sampling
episode was completed, including the analyses of methylene
blue active substances (MBAS).
Anionic detergents or surfactants react with
methylene blue to form a blue colored complex.
The concentration of MBAS in ground water is
therefore a measure of the concentration of anionic
detergents or surfactants.
MBAS was analyzed during the recovery process and
during post injection ground-water monitoring.
A total of 1,950 gallons (approximately 25 gallons
per boring) of surfactant was injected at a rate of 1-3
gallons per minute (gpm).
Vacuum recovery of ground water in the area of the
surfactant injection, via existing monitoring wells, was
the method of control and recovery of injection fluids and
solubilized hydrocarbons from the aquifer matrix. Four days after injection was completed, ground-water
monitoring in the injection area identified one monitoring
well with approximately 0.49 feet of LNAPL or free
product. Lab
analyses of ground water extracted during a recovery
episode found a significant decrease in dissolved
petroleum hydrocarbon concentrations compared to historic
concentrations observed in the well nearest the injection.
Particularly, a benzene concentration of 186 ug/l is the
lowest concentration historically detected in that well,
and xylenes were the lowest concentration observed in over
4 years.
HRC®
Remediation of a PCE Impacted Till Aquifer and
Underlying Shallow Bedrock Aquifer
Jonathan
K. Child, Fuss & O’Neill, Inc., 78 Interstate Drive,
West Springfield, MA
01089, Tel: 413-452-0445
x4414, Email: jchild@fando.com
Timothy J. St. Germain, Fuss & O’Neill, Inc., 78
Interstate Drive, West Springfield, MA
01089, Tel:
413-452-0445 x4412, Email: tgermain@fando.com
John B. Hankins, Fuss & O’Neill, Inc., 146 Hartford
Road, Manchester, CT
06040, Tel: 860-646-2469 x5245, Email: jhankins@fando.com
A
release of tetrachlorethene (PCE) has been documented in a
dense, fine grained till aquifer over an approximate
10,000 square foot area.
PCE groundwater concentrations in the
unconsolidated aquifer have been detected above 10,000
micrograms per liter (ug/L) with maximum soil impacts
located near the bedrock surface.
PCE concentrations in the underlying shallow
bedrock aquifer (sandstone) exceeded 50,000 ug/L.
In
2001, a bedrock groundwater pump and treat system was
installed as a source area control measure to reduce
potential off-site migration of PCE and related
chlorinated volatile organic compounds (CVOCs) such as
trichloroethene (TCE) and cis-1,2-dichloroethene
(cis-1,2-DCE). Operation
of the system produced only limited influence on
groundwater flow potentials and contaminant
concentrations.
Supplemental
source area remediation was initiated in 2003 using
Hydrogen Release Compound (HRC®) to enhance
in-situ rates of reductive dechlorination within the
unconsolidated aquifer.
HRC® was injected by Geoprobe®
from the water table to the bedrock surface at rates of 4
to10 pounds per vertical foot.
Within four months, reductions in PCE
concentrations were observed throughout the unconsolidated
aquifer in conjunction with increasing TCE and cis-1,2-DCE
concentrations. Six
to nine months following HRC® injections,
significant reductions in PCE concentrations were observed
within the shallow bedrock aquifer.
Concurrent iron-fouling issues that were associated
with the enhanced bioremediation program resulted in
shutdown of the bedrock pump and treat system while the
HRC® remediation program continued.
A
second HRC® injection was performed
approximately one year following the original injection.
Within 14 months of initiating the HRC® groundwater
remediation program, unconsolidated aquifer PCE
concentrations had decreased from >10,000 ug/L to below
50 ug/L and PCE concentrations in the shallow bedrock
aquifer had declined from >50,000 ug/L to less than
1,000 ug/L.
Results
of the Hydraulic Testing of the Fuel Spill-1 Remedial
System Design at Massachusetts Military Reservation
Ronald
J. Citterman, CH2M HILL, 318 E. Inner Road, Otis ANGB, MA
02542, Tel: 508-968-4670 x5631, Fax: 508-968-4490, Email: Ron.Citterman@ch2m.com
Frank Lewis, CH2M HILL, 9193 S. Jamaica Street,
Englewood, CO 80112, Tel: 720-286-5410, Fax: 720-286-9894,
Email: Frank.Lewis@ch2m.com
John Glass, CH2M HILL, 1321 Park Center Road,
Suite 600, Herndon, VA 20171, Tel: 703-471-1441, Fax:
703-471-1508, Email: John.Glass@ch2m.com
John Schoolfield, Air Force Center for
Environmental Excellence, 322 E. Inner Road, Otis ANGB, MA
02542, Tel: 508-968-4670 x5601, Fax: 508-968-4673, Email: John.Schoolfield@brooks.af.mil
As
a result of historic fuel spills dating back to the 1950s
at the Massachusetts Military Reservation (MMR), a plume
of ethylene dibromide (EDB)-contaminated groundwater
extends over a mile in length southeast of MMR.
This plume, designated Fuel Spill-1 (FS-1), is
detached from its source area and is currently migrating
in a southerly direction terminating at the Quashnet River
and surrounding cranberry bogs.
The flow of the Quashnet River increases two to
three times as a direct result of groundwater discharge to
the river and surrounding bog ditches. Groundwater fate and transport modeling was used in the
design of groundwater remedial system for the FS-1 plume. Subsequent hydraulic testing of the remedial system has been
performed to verify the effectiveness of the system design
at meeting the remedial objectives.
During hydraulic testing, changes in the
groundwater and surface water levels in response to
various pumping stresses were monitored.
The resulting data provide insights regarding
aquifer hydraulic properties, the spatial influence of the
remedial pumping, and the nature of groundwater and
surface water interactions.
The testing data were also used in conjunction with
the groundwater fate and transport model to delineate the
capture zones of the remedial system’s extraction wells,
and to compare actual conditions with the predicted
conditions of the original wellfield design.
Additionally, the hydraulic data were used to
optimize the operation of the remedial system and the
effectiveness and efficiency of the hydraulic and chemical
monitoring network. In
this way, the groundwater restoration timeframe is
minimized and potential impacts to local ecosystems (i.e.,
excessive drawdown of groundwater discharging to wetlands)
are eliminated.
Remedial
Action Optimization, Marine Corps Mountain Warfare
Training Center, Bridgeport, California
Christopher
Corey, R.G., Shaw Environmental, Inc, 3347 Michelson
Drive, Suite 200, Irvine, California, 92612, Tel:
949-660-5387, Fax: 949-474-8309, E-Mail: Chris.Corey@Shawgrp.com
Christopher S. Seipel, R.G., Shaw
Environmental, Inc., 3347 Michelson Drive, Suite 200,
Irvine, California, 92612, Tel: 949-660-5495, Fax:
949-474-8309, E-Mail: Scott.Seipel@Shawgrp.com
Kathie Beverly, P.E., Naval Facilities
Engineering Command, Southwest Division, 1220 Pacific
Highway, San Diego, California, 92132, Tel: 619-532-4819,
Fax: 619-532-4160, E-Mail: Kathie.Beverly@navy.mil
The
U.S. Marine Corps’ Mountain Warfare Training Center (MCMWTC),
located near the town of Bridgeport, California is a
year-round facility located in the eastern Sierra Nevada.
The facility supports U.S. Marines Corps mountain warfare
and survival training for fleet Marines and reserve
troops. MCMWTC
has relied on stored fuel products for heating,
transportation, heavy equipment, training operations, and
emergency generators.
Historic releases of these petroleum hydrocarbons
have impacted soil and groundwater and are the primary
environmental issue at the base.
In
1988, the U.S. Department of the Navy (DON) implemented a
comprehensive environmental program at MCMWTC to identify,
assess, and implement appropriate remedial actions.
The highest priority site on MCMWTC (Installation
Restoration Program Site 4) encompasses the base gas
station with groundwater impacts into a nearby alpine
wetland meadow. Petroleum
hydrocarbons were detected in soil and groundwater at
concentrations great enough to require active remediation
to mitigate the site.
In 1998, an active remediation system was installed
at the site and has been in continuous operation.
Collaborative
efforts have been ongoing between the DON and Shaw
Environmental, Inc. to develop and implement appropriate
exit strategies for all sites at MCMWTC.
In 2004, a Remedial Action Optimization (RAO)
Report for IR Program Site 4 was prepared for the DON
following the Naval Facilities Engineering Service
Center’s 2001 interim final guidance document Guidance
for Optimizing Remedial Action Operation.
The purpose of the RAO report was to review the
conceptual site model used to design and implement the
remediation processes, review system and cost performance,
and make recommendations for future activities at the
site. A
review of the CSM, operations and cost data, and remedial
alternatives identified that significant cost saving could
be made at IR Site 4 by modifying the current remediation
configuration. The
DON has agreed with the results of the evaluation and
recommendations given in the report, and has embraced an
aggressive approach to move to long-term monitored natural
attenuation as the preferred next remedial technology.
The DON plans to implement the recommended actions
in 2004/2005 to accelerate site closure.
Developing
an Exit Strategy for Remediation, DFSP Yorktown Fuel Farm,
Virginia
Jennifer
Davis, NAVFAC Mid-Atlantic, Code EV3, 9742 Maryland
Avenue, Bldg N-26, Room 3208, Norfolk, VA 23511-3095, Tel:
757-322-4775, Fax: 757-322-4805, Email: Jennifer.j.Davis@navy.mil
William Hughes, Shaw Environmental, Inc., 5700 Thurston
Avenue, Suite 116, Virginia Beach, VA, 23455, Tel:
757-318-5140, Fax: 757-363-7222, Email:
Bill.Hughes@Shawgrp.com
P. Taylor Sword, Shaw Environmental, Inc., 5700 Thurston
Avenue, Suite 116, Virginia Beach, VA, 23455, Tel:
757-318-5142, Fax: 757-363-7222, Email: Taylor.Sword@Shawgrp.com
Recently
the focus in accelerating the remediation process at
contaminated site is to optimize the process to the reduce
cost. There
are times when the technology employed to remediate the
site is not the most effective in reaching the site
closure in the shortest period of time.
An exit strategy is a plan to recognize when a
change in conditions requires a reevaluation of the
remedial technology employed to meet the clean up goals.
Conditions that may indicate a change is necessary
include decreases in contaminant removal, continuing
rebound of contaminant concentrations or free product
thicknesses, development of new technologies that would
accelerate the rate of contaminant removal or destruction.
Approximately 3 million gallons of Naval Special
Fuel Oil (NSFO) is present as a free-product plume at the
Yorktown Fuel Farm. The
NSFO is a very viscous fuel that is present in thicknesses
up to 13-feet on the water table.
An innovative heat-enhanced recovery system is used
to heat the NSFO in the subsurface using horizontal steam
circulation wells. The
mobilized NSFO is recovered using recovery trenches.
Approximately 215,000 gallons of NSFO has been
recovered at the site.
The clean up goals for the site are to reduce the
NSFO thickness to less than 0.01-feet or the asymptotic
decline in recovery and 25,000 ppm total petroleum
hydrocarbons concentration in soil.
Refinement of the exit strategy for this site is
predicated upon developing an estimate of the recoverable
volume of NSFO at the site using the existing technology.
Reviews of available and emerging remedial
technologies are conducted to determine if another method
can be employed to achieve the established clean-up goals
more quickly and economically.
Prior to the application of a new technology, it
must be first approved by the regulatory agency.
Ex
Situ Treatment of MTBE-Containing Groundwater by an
UV/Peroxide System
Ijaz S. Jamall, Ph.D., Risk-Based Decisions, Inc., 2033 Howe
Avenue, Suite 240, Sacramento, California 95825, Tel:
916-923-0570, Fax: 916-923-0611, Email:
ijamall@riskbaseddecisions.com
Tex Lu, Ph.D., Risk-Based Decisions, Inc., 2033 Howe
Avenue, Suite 240, Sacramento, California 95825, Tel:
916-923-0570, Fax: 916-923-0611, Email: texlu@riskbaseddecisions.com
Ian Brown, Risk-Based Decisions, Inc., 2033 Howe Avenue,
Suite 240, Sacramento, California 95825, Tel:
916-923-0570, Fax: 916-923-0611, Email:
ianbrown@riskbaseddecisions.com
James C. Powers, M.S., Risk-Based Decisions, Inc., 2033
Howe Avenue, Suite 240, Sacramento, California 95825, Tel:
916-923-0570, Fax: 916-923-0611, Email: jpowers@riskbaseddecisions.com
This paper describes the design, implementation and operating
results for an ex situ ultra-violet/hydrogen peroxide (UVP)
system to treat MTBE in extracted groundwater.
The UVP system is a third stage treatment to reduce
the operating and maintenance costs of an existing
groundwater pump and treat treatment system that relies on
air stripping with a boiler to boost the water
temperature, and carbon adsorption.
The UVP system is relatively inexpensive and can
easily be scaled to cope with different groundwater
extraction rates up to 80 gpm by adding UV lamps in series
or in parallel at the higher groundwater extraction rates. At an extraction rate of approximately 18-20 gallons per
minute (68.4 to 76.0 liters per minute), we were able to
achieve 75-85 percent destruction efficiency for MTBE with
60 second exposure to 30 watt UV lamps.
The absolute MTBE concentrations in the effluent
from the UVP system decreased from an average of 590 µg/L
initially to less than 5 µg/L on average currently.
Incorporation of this UVP system as a second stage
treatment to our groundwater pump and treat/soil vapor
extraction system after the air stripper and prior to the
carbon polishing vessels significantly increased the
usable life of the carbon, requiring no carbon change out
in 450 days as compared to carbon change outs every 50
days prior to installation of the UVP system.
The UVP system completely resolved the issue of
frequent MTBE breakthrough of the carbon that had plagued
the remediation system since its inception.
Steam
Injection Expedites Removal of Viscous NAPL at a
Manufacturing Complex
Tim
Kemper, PE, LSP, Shaw Environmental, 88C Elm St.,
Hopkinton, MA 01748, Tel: 508-497-6162, Fax: 508-435-9641,
Email: tim.kemper@shawgrp.com
Eric Vining, Shaw Environmental, 88C Elm St., Hopkinton,
MA 01748, Tel: 508-497-6142, Fax: 508-435-9641, Email:
eric.vining@shawgrp.com
Barbara Riley, LSP, GE Transportation, Email:
barbara.riley@ae.ge.com
This
presentation will review an innovative remedial approach
to remove viscous Non-Aqueous Phase Liquid (NAPL) from the
subsurface below a former manufacturing building complex.
This innovative approach injects steam into the vadose and
saturated zones within the impacted area to reduce the
viscosity of heavy NAPL and expedite its removal through a
network of recovery wells. Previous remediation efforts at
this location to recover the heavy NAPL using conventional
technologies at ambient temperatures were less successful
in reducing thicknesses to meet the state’s regulatory
standards (i.e. less than ˝ inch of NAPL measured in
monitoring wells). Recent NAPL recovery efforts using
steam injection, groundwater depression and down-well NAPL
pumps have significantly increased NAPL recovery rates.
The steam enhanced NAPL recovery system has recovered
2,500 gallons of NAPL in the first twelve months of system
operation and is anticipated to reach the state’s
regulatory standards for site closure in the future.
Technical
aspects of this project that will be presented include:
- Site
background and release history
- Remedial
objectives and regulatory drivers
- Various
remedial alternatives evaluated
- Design
considerations for the selected remedy - steam
enhanced NAPL recovery system with groundwater
depression and treatment, steam migration control and
vapor treatment
- Subsurface
heat-up time and measurement, including 3-dimensional
thermal depictions of site-specific thermocouple data
- NAPL
recovery rates and other Critical-to-Quality data
- Lessons
learned and key factors for success
Remediation
and Restoration of a Sensitive Wetland Located in Western
Massachusetts
Corey
B. King,
AMEC Earth and Environmental, 239 Littleton Road, Suite
1B, Westford, MA 01886,
Tel: 978-692-9090,
Fax: 978-692-6633,
Email: corey.king@amec.com
Celeste M. Hunt, P.E., AMEC Earth and
Environmental, 239 Littleton Road, Suite 1B, Westford, MA
01886, Tel: 978-692-9090,
Fax: 978-692-6633,
Email: celeste.hunt@amec.com
Matt Adkins, CSX Transportation, Inc., 351
Thornton Road, Suite 125, Lithia Springs, GA 30122, Tel:
770-819-2849, Fax: 904-245-2273, Email: matt_adkins@csx.com
A
pile of railroad ties, ballast, and debris was identified
within the boundaries of a delineated wetland on a
property located in Washington, Massachusetts (Site).
Additionally, the property was located within an
area of critical environmental concern as determined by
the Massachusetts Department of Environmental Protection (MADEP).
Environmental investigations at the Site indicated
elevated concentrations of polycyclic aromatic
hydrocarbons (PAHs) within shallow soil in close proximity
to the pile. The
mound of railroad ties, ballast, and debris was excavated
from the Site in September 2003.
The excavation resulted in the removal of nearly
1,400 cubic yards of railroad ties, soil, ballast, and
debris contained within the pile.
Confirmatory soil samples were collected for risk
assessment purposes prior to regrading and restoration
activities. The
restoration plan was approved by the Washington
Conservation Commission.
Clean topsoil/peat was imported to the Site and
regraded to closely correspond with surrounding land
surface configurations.
A minimum of six inches of topsoil/peat was
imported and regraded over the excavated area.
After regrading
was complete, Site restoration included the planting of
the following wetland species: Red Maple, Highbush
Blueberry, and Southern Arrowwood.
Upon completion of planting, hydroseed was
applied to the topsoil/peat to promote vegetative growth.
Two different hydroseed mixtures identified as
wetland and upland mixtures were applied to the
appropriate locations of the regraded area.
A Method 3 risk characterization determined that No
Significant Risk of harm to human health, safety, public
welfare, or the environment existed.
This determination was based on the evaluation of
the soil, groundwater, surface water, and sediment data
collected at the Site and the potential exposure of human
and ecological receptors at the Site.
The excavation and associated risk assessment
resulted in regulatory closure of the Site.
Multiple
Technologies Optimize Remediation of Tetrachloroethylene
(PCE) At Former
Drycleaning Site in a
Residential Neighborhood
Clifford
R. Lippitt, S. W. COLE ENGINEERING, INC., 37 Liberty
Drive, Bangor, Maine, 04401-5784, Tel: 207-848-5714, Fax:
207-848-2403, Email: CLippitt@swcole.com
Amyjean Lussier, U. S. Environmental Protection Agency,
Office of Site Remediation and Restoration, 1 Congress
Street, Suite 1100, Boston, MA 02114, Tel: 617-918-1248,
Fax: 617-918-1291, Email: lussier.amyjean@epa.gov
Gary J. Creaser, S. W. COLE ENGINEERING, INC.,
37 Liberty Drive, Bangor, Maine, 04401-5784, Tel:
207-848-5714, Fax: 207-848-2403, Email: GCreaser@swcole.com
The
assessment, remediation, and environmental closure of a
tetrachloroethylene (PCE) contaminated area associated
with a former dry cleaning site located in a residential
area in Bangor, Maine was performed using multiple
technologies for assessment and remediation. S. W. COLE
ENGINEERING, INC. coordinated with adjacent property
owners, the Environmental Protection Agency, the Maine
Department of Environmental Protection, the City of Bangor
and other consultants to implement a site evaluation plan
consisting of geophysics, trenching and direct push and
conventional drilling.
Soil, soil vapor, groundwater and ambient air
samples were analyzed by the EPA Mobile Laboratory.
Analytical results were evaluated in combination
with geological and hydrogeological data and information
from previous EPA investigations and investigations by
others. Approximately
800 cubic yards of soil were identified to be above the
Maine Remedial Action Guidelines.
Confirmation
of the conceptual model of unsaturated, contaminated fill,
confined by low permeability glacial till resulted in a
remediation plan addressing immediate and long term
exposure concerns. In
situ treatment of saturated contaminated soils was
performed by HRC® injection. Subslab
ventilation systems provided initial and continuing
mitigation of household PCE vapor exposures. The
unsaturated soils were excavated for off-site disposal
(100 to 5,000 mg/kg PCE); segregated for on-site treatment
(30 to 100 mg/kg PCE); or treated in-situ using SVE
(greater than 1mg/kg PCE).
PCE
levels have declined predictably from the initial vapor
system concentration level of more than 300,000 µg/m3
to less than 28,000 µg/m3 after 3 months of
operation. These reductions are consistent with initial projections to
meet the soil clean-up guidelines of 3000 µg/kg.
Soil clean-up verification sampling in April 2005
will confirm progress toward the closure goal of August
2005.
Case
Study: Full-Scale Application of Innovative and Standard
Remediation Technologies at a Chlorinated Solvent/DNAPL
Site
Craig
W. MacPhee, P.E., ENSR International, 2 Technology Park
Road, Westford, MA, 01886, Tel: 978-589-3064, Fax:
978-589-3282
Larry Hogan, LSP, ENSR International, 2 Technology Park
Road, Westford, MA, 01886, Tel: 978-589-3000, Fax:
978-589-3282
Remediation
of sites contaminated with high levels of chlorinated
volatile organics (CVOCs) in soil and groundwater can be
extremely difficult.
Achieving remediation goals for soil, groundwater,
and indoor air is often complicated by the presence of
non-aqueous phase liquids, especially dense non-aqueous
phase liquids (DNAPL).
For this case study, these common problems were
further compounded by the presence of organic silts and
peat and the presence of CVOCs near and underneath an
occupied building. The
subject site is a former manufacturing facility that is
now in commercial use.
CVOCs were present in soil at concentrations above
5,000 parts per million (ppm) and in groundwater above 100
ppm. DNAPL was found to be present.
ENSR developed a pragmatic overall approach and
then selected specific technologies to meet the project
objectives. ENSR’s
overall approach to remediation of the site included
aggressive treatment of source areas and installation of
vapor barriers. Because
no single method would work in all areas, ENSR used a
variety of remedial technologies. To address the primary
source areas, ENSR used excavation, dewatering, and
backfilling with zero valent iron.
Excavated soil was treated on-site using thermally
enhanced vapor extraction. In a secondary source area where soil conditions were more
favorable, sparge and vent was used to reduce CVOC levels.
Systematic inspection of the floors, sealing of
floors, installation of passive vents, and indoor air
sampling were used to address potential indoor air issues.
Performance and lessons learned from implementation
of these technologies will be presented.
Design
and Implementation of a Remedial Action at the Pownal
Tannery Superfund Site
Neil
Thurber, Metcalf & Eddy, 701 Edgewater Drive,
Wakefield, MA, 01880, Tel: 781-224-6352, Fax:
781-224-6548, Email: neil.thurber@m-e.com
Greg Mischel, TRC Environmental
Corporation, 100 Foot of John Street, Lowell, MA 01852,
Tel: (978) 970-5600, Fax: 978-453-1995, Email:
gmischel@trcsolutions.com
Leslie McVickar, U.S. EPA Region 1, One Congress
Street, Suite 1100, Boston, MA 02114-2023, Tel: (617)
918-1374, Fax: (617) 918-0101, Email:
mcvickar.leslie@epa.gov
Don Dwight, Metcalf
& Eddy, 701 Edgewater Drive, Wakefield, MA, 01880,
Tel: 781-224-6286, Fax: 781-224-6548, Email: don.dwight@m-e.com
Dale Weiss,
TRC Environmental
Corporation, 100 Foot of John Street, Lowell, MA 01852,
Tel: (978) 970-5600, Fax: 978-453-1995, Email: dweiss@ix.netcom.com
The
former Pownal Tannery site consists of a 28-acre set of
parcels located along the Hoosic River in the village of
North Pownal. It
was once used as hide tanning and finishing facility which
discharged wastes, including solvents, lubricating oils,
and tanning wastes to a sludge lagoon complex. M&E and TRC Environmental conducted a remedial
investigation and feasibility study to support EPA in
developing a record of decision for the site and to serve
as the basis of design.
The selected remedy that was designed for the
10-acre lagoon complex includes the stabilization and
excavation of 55,000 cubic yards of contaminated sludge
materials from two of the most hazardous lagoons,
consolidation of the sludge over two other lagoons, and
capping of the consolidated sludge with a 5.5-acre
multi-layer engineered landfill cover system to eliminate
multiple human health and environmental risks.
Development of the appropriate conceptual design
required evaluation of various factors including the
volume of material to be landfilled, impacts on the
adjacent Hoosic River, and the intended future use of the
landfill area. Challenges
also included protecting workers and the public from
hazardous gases and noxious odors emanating from the
contaminated lagoons and constructing the landfill cap in
a 100-year flood plain over the stabilized waste.
The remediation effort was tailored to restore the
natural beauty of the site and open the area for potential
reuse as a wastewater treatment facility and for
recreational use by the community.
The project was completed under a tight schedule
and under budget by more than $1 million.
High-Temperature
Burning of Oil Sludges and Oil Contaminated Soils
V.О.
Nekuchaev, Ukhta State University, Departament of Physics,
Pervomayskaja 13, 169300 Ukhta, Komi, Russia, Tel: 82 147
36749 Email: nekouch@uii.sever.ru
Е.I.
Krapivsky and A.E. Beljaev, Ukhta State University,
Departament of Physics, Pervomayskaja 13, 169300 Ukhta,
Komi, Russia
А.D.
Charnetsky, Sankt-Peterburg, ZAO “TD Turmalin”, Russia
The
present work is devoted to the solution of quite urgent
ecological problem of our days — remediation of oil
sludges and oil contaminated soils.
At
oil production, transportation and processing the
significant amount of oil sludges and contaminated soils,
representing serious danger for environment is formed. In
Russia about 50-100 mln. tons of oil sludges and oil
contaminated soils is formed per one year. The absence of
modern technologies of liquidation and utilization of
sludges has transformed significant quantity of oil sludge
storehouses from means of an environment prevention from
petroleum pollution into threat of large-scale
contamination of soils, underground and surface waters.
The complexity of effective utilization and liquidation of
oil sludge wastes is determined by their structure: by
petroleum, water, emulsions, mechanical impurities in
various proportions. Low average temperature of soils in
northern areas of Russia makes biological cleaning low
effective application. In the present work the technology
of high-temperature burning of oil sludges and oil
contaminated soils has been developed. At that technology
water, contained in wastes evaporates and the organic
substances are decomposed and oxidized, forming nontoxic
gaseous products of complete combustion.
The
advantages of installations developed on the basis of the
given technology:
practically
complete absence of toxic emissions; safety of servicing;
economical operation; quite low cost; reliability and
operating longerity of the equipment.
The
petroleum contaminated soils are local frequently, and the
sites of pollution are considerably removed from each
other. Therefore we also made mobile installation for
remediation oil sludges, placed in three 20-foot
containers with productivity about 100 kg per out.
Design
Considerations for Electrical Safety of Remediation
Equipment.
Dennis
Rentschler, ENSR International, 2 Technology Park Drive,
Westford, MA, 01886, Tel: 978-589-3701, Fax: 978-589-3100,
Email: drentschler@ensr.com
Operation
and maintenance (O&M) issues, particularly electrical
safety requirements, need to be carefully considered when
designing remediation systems. The technical
backgrounds of individuals, who monitor, troubleshoot and
repair remote remediation equipment, differ greatly. Site
visits at remediation systems are often staffed by
geologists, engineers or environmental scientists and
rarely by a licensed electrician. OSHA and NFPA NEC
(National Electrical Code) specify electrical work to be
performed by a “Qualified Person”. A “Qualified
Person” is an individual with not only appropriate
technical training and experiences, but also safety
training on the hazards involved. Often remediation
control designs include display elements and control
operators within the same enclosure as the power
distribution. This can expose remediation staff to
electrical hazards beyond their qualifications. In this
case, a qualified electrician would be required to perform
simple monitoring, control adjustments or troubleshooting.
Alternatively, an electrical design and application
which isolates the distributed electrical power from a low
voltage controls center can greatly reduce the electrical
hazards to all and allow qualified remediation staff to
safely perform larger scopes of monitoring or
troubleshooting of the control system. Implementing a
low-voltage control scheme to a new remediation system
should not significantly increase the capital cost. It
will be important to specify a low-voltage control scheme
in the early stages of the design process and ensure that
remediation equipment bids and submittals meet the
presented specifications.
Keeping
the Buses Moving: Remedial Design Constraints at an Active
Facility
Frank
Ricciardi, P.E., Project Manager, M.S.CE, Brian McCormack,
P.E., Senior Engineer M.S. CE, Kelley C. Race, P.G., LSP,
Associate M.S. GEO, Weston & Sampson Engineers, Inc.,
5 Centennial Drive, Peabody MA 01960, Tel: 978-532-1900,
Fax: 978-977-0110, Email: ricciarf@wseinc.com
Several
feet of floating petroleum product were discovered in
groundwater beneath a bus storage and maintenance garage
located in the Boston area. The product was found to be
migrating along utility lines and impacting nearby
structures. The
remediation system for the site needed to evaluate and
overcome several difficult site constraints in the design.
The remedial system selected for the site consisted
of a high vacuum dual-phase extraction system, LNAPL
recovery, and in-situ bioremediation.
The location of the treatment building, extraction
wells, piping, trenching, and other remedial
equipment/activities was secondary to keeping the bus
operations intact. The bus facility processes over 100 buses a day and daily
operations including maintenance, bus washing, driver
rotation, and bus inspection could not be interrupted
during the construction of the remediation system.
The
goal of the site remediation is to perform source removal
and minimize impacts to existing operations. The remedial design of the system had to overcome several
significant design constraints, including:
- Excavation
next to multiple bus bays and disturbance of bus
parking
- Multiple
petroleum product sources
- Location
of a treatment building on-site and away from the bus
traffic
- Coordination/installation
of thousands of feet of conveyance piping
- Odor
migration and dust control in the garages
- Explosion
proofing of select equipment
- Control
of LNAPL migration into a nearby pump station
- Bus
traffic and worker protection
- Protection
of existing utilities
- Recovery
well installation/trenching along multiple utilities
at various depths
- Potential
impacts to the subway system below the site and
- Small
available site footprint with no room for stockpiling
of soil or equipment
Remediation
was designed to achieve maximum contaminant removal while
providing for the least interruption to the busy bus
schedule.
A
Laboratory Pilot System for the Simulation of Thermal
Desorption of Residual Listed Wastes from the Sarex Waste
Treatment Process for the Purpose of Waste Delisting
George
M. Sawyer, Laboratory Technical Manager, Casie Protank,
Inc., Vineland, NJ, Tel: 856-696-4401
A
laboratory apparatus which conforms to a small scale pilot
system for the thermal treatment of residual solids from
listed wastes was designed to simulate the thermal
desorption process for the achievement of residential
cleanup standards or universal cleanup standards on the
treated residual solids generated by the SAREX process.
The
SAREX process treats listed wastes taken from various
facilities by state-of-the-art high speed centrifugation,
heating, and chemical treatment to achieve a separation of
the waste into three phases—oil, water, and residual
solids. The
residual solids are slated to be treated by thermal
desorption to remove contaminants down to trace levels
which conform to residential and/or universal cleanup
standards for the purposes of delisting the wastes.
Optimization
of Groundwater Remediation Systems and Long-term
Monitoring Programs – A Client’s Approach
Gregory
L. Simpson, P.E., Textron, Inc., 40 Westminster Street,
Providence, Rhode Island 02903, Tel: 401-457-2635, Fax:
401-457-6028, Email: gsimpson@textron.com
Each
year, millions of dollars are spent by responsible parties
to collect, treat and discharge/dispose of contaminated
groundwater and monitor the status of remedial activities.
Often, these activities are not subjected to
regular value-added evaluations that most other types of
projects with a similar magnitude of capital expenditure
receive.
To
evaluate and optimize its ongoing groundwater remediation
projects, Textron, Inc. launched an annual Remediation
Optimization initiative in 2002.
One of the key components of this initiative is an
annual effectiveness report that is completed for each
project by Textron’s consultants.
By completing this standardized report, the
consultant provides the Textron project manager with
valuable data regarding the effectiveness and efficiency
of the remedial system and monitoring program on a yearly
basis and allows site-to-site comparison for benchmarking
purposes.
Using
the data contained in these reports, Textron is able to
compare the effectiveness of remedial systems (including
specific system components) and identify costly, under
performing systems. Proactive
modifications to these under performing systems or
alternative approaches can subsequently be evaluated to
improve overall system performance.
As part of the initiative, Textron’s consultants
are also challenged to maintain at least a 90% runtime
rate for remedial systems.
The
reports also target the overall performance of groundwater
monitoring activities by identifying data trends and
tracking costs on a detailed basis.
Sampling programs have been optimized based on the
information provided in the reports. Detailed groundwater
monitoring cost tracked across several remediation sites
allows Textron to identify inefficient sampling programs
and corrective action to be requested.
The
Remediation Optimization initiative also challenges
consultants on an annual basis to propose more efficient
approaches to remedial activities, with performance
measured against a 5% annual savings goal.
Overall, the initiative has been a success for
Textron.
Evaluation
of the Remediation Progress of Three
Hydrocarbon-contaminated Soils using a
Simple Seedling-based
Bioassay
Jan
J. Slaski, Environmental
Technologies, Alberta Research Council Inc., Hwy 16A-75
St., Vegreville, Alberta, T9C 1T4, Canada, Tel:
780-632-8436, Fax: 780-632-8620, Email:
slaski@arc.ab.ca
Xiaomei Li, Environmental
Technologies, Alberta Research Council Inc., 250 Karl
Clark Road, Edmonton, Alberta, T6N 1E4, Canada, Tel:
780-450-5290, Fax: 780-450-5083, Email: xiaomei@arc.ab.ca
Daniel J. Archambault,
Environmental Technologies, Alberta Research Council Inc.,
Hwy. 16A-75 St., Vegreville, Alberta, T9C 1T4, Canada,
Tel: 780-632-8604, Fax: 780-632-8620, Email: archambault@arc.ab.ca
A
simple, seedling-based bioassay was used to evaluate
bioremediation progress of three hydrocarbon-contaminated
soils/wastes and to identify the main factors contributing
to toxicity. The wastes included a
crude oil and brine contaminated agricultural topsoil
(waste 1), a diesel invert mud residue (waste 2), and a
flare pit sludge (waste 3), which underwent physical,
chemical and thermal treatment in a biorector. The wastes
were subsequently placed on agricultural land for further
treatment. Three sets of experiments were conducted. The rate
of germination and shoot and root elongat |
