IDX ELEC RESISTANCE INFO-OCR

*5831HSSF1065*
1111111111111111111111111111
DocumentlD NONCD0001814
Site Name HAMILTON BEACH/PROCTOR SILEX
oocumentType Remedial Pilot Study {PIL)
RptSegment 1
DocDate
DocRcvd
Box
Access Level
Division
Section
Program
DocCat
8/30/2002
2/20/2007
SF1065
PUBLIC
WASTE MANAGEMENT
SUPERFUND
IHS {IHS)
FACILITY
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URS
August 30, 2002
Michelle Volosin
NCDENR-Washington Regional Office
943 Washington Square Mall
Washington, NC 27889
: ! -o) ~ ® ~ a W ~ 1~11 ll~)~ 2002 J~J
I \'/ASHINGTOtl REGiOrilloFFICE
01'/Q -..,._" ____ . ____ ..., _____ _
RE: Electrical Resistance Heating Background Information,
Preparation for the Forthcoming Corrective Action Plan
Hamilton BeachOProctor-Silex (HBPS)
Washington, North Carolina
Dear Michelle:
On behalf of Hamilton BeachOProctor-Silex (HBPS), URS Corporation -North Carolina (URS)
is pleased to submit this letter and subsequent attachments providing background information on
Electrical Resistance Heating (ERB). As you are aware, in October 2002, we will be submitting
the Corrective Action Plan (CAP) for full-scale remediation at the HBPS Washington, NC site.
In this CAP, ERB in combination with soil vapor extraction (SVE) was selected as the remedial
technology to be utilized in the source area. Since this remedial technology has not been utilized
previously in the State of North Carolina, we thought it would be prudent to provide you with
some general information on the technology and the history of its use at sites across the country.
ERB is an in-situ remediation technology utilized to remediate soil and/or groundwater. ERB,
sometimes referred to as "six-phase" or "three-phase" heating, is typically used in conjunction
with SVE. An electrical current is applied through electrodes installed in the subsurface to heat
the soil and groundwater to above 100° Celsius in order to create an in-situ source of steam and
strip off VOCs. The SVE system then removes the contaminated vapor stream. Subsequently,
this vapor stream is vented to the atmosphere. ERB has been proven effective at numerous
contaminated sites across the country similar to the HBPS Washington, NC site. ERR will
remediate both soil and groundwater within the source area in a relatively short time-span.
Our technology provider, Thermal Remediation Services (TRS), has utilized this technology at
approximately 20 sites in 13 states within the past five years (see Attachment 1). URS has been
directly involved with the application of this technology at four of these sites. Historically,
regulators have been quick to recognize the remedial advantages provided by this technology and
have been very supportive of its use. The key remedial advantages include; a short time-span for
remediation, effectiveness in low permeability soils, and high % reductions in contaminants of
concern.
URS Corporation
P.O. Box 13000
Research Triangle Park, NC 27709
1600 Perimeter Park Drive
Morrisville, NC 27560
Tel: [phone]
Fax: [phone]
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URS
Michelle Volosin
August 30, 2002
Page2
Because ERR applies voltages directly to the subsurface, numerous measures are taken to ensure
the safety of an ERR application. These measures include the following:
• All above grade electrical connections are insulated.
• All monitoring wells located within 20 feet of the treatment volume are locked shut and
included in a danger tag-out system to prevent workers from attempting to sample the
wells with the ERR power on.
• For surface objects, the safe limit for step-and-touch exposure to personnel is 50 Vas
described by OSHA 29 CFR 1926.403. However, during ERR an operating limit below
50 Vis applied to provide a margin-of-safety. Step-and-touch surveys are conducted
upon system startup and re-checked whenever the applied electrode voltage is increased
or every two weeks at a minimum.
• ERR Power Control Units (PCUs) use isolation transformers to increase safety and to
eliminate interference with other electrical systems and electrical grounding systems. All
current that is introduced to the electrodes can only flow to other electrodes, it cannot
flow to a distant system or electrical sink.
I have also enclosed two Cost and Performance Reports as Attachment 2 for your review. The
USEP A and the U.S. Army Corps of Engineers generated these two reports, respectively.
Current TRS personnel and current and/or former URS personnel worked on both of the sites
described in these reports.
We look forward to providing you with the complete CAP in October. We would be happy to
meet with you at that time to review the CAP, present more details, and answer any questions
that you may have. Please call me (919-461-1290) or Jim Narkunas (919-461-1270) with any
questions or concerns.
Sincerely,
URS CORPORATION -NORTH CAROLINA
8~~
Brett Berra
Attachments
cc: Mario Kuhar, HBPS
Brad De Vore, Womble Carlyle Sandridge and Rice
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--------- --- - - -----
Electrical Resistance Heating -Project Experience (1997-2002)
-SJteName :rr~·-' ' ,-,Initial ----operations ~~19.W/l-lydfOlogy-_!lnd ' ' Cleanup goals: ·.' ~ '~'~~71,~f ~~~~fl~, l': : , , , , , , ~-~-----9,ll~l]t 1~~f11re~~ .-' Regulators , I ·---t '
-': 'O l ·: ,' ·' ' co0ce11lra,~r;ins of :':.=:"'.i.'/:.,1·: ,: ~''.: :'. ::"' "" '' . ·,1 ···1 ' ,' ··' ... Pe.~·/", ; : l?,lz~' o~, T~ea.~nt >V~~ ,'' :·:' ' " " ' ... -'._~,~,:''" ':i ' ·.i " -' " --,' i:··, ,":''.:·/:.Ii:'.,•, ,·.~,'.' .~ ~-.i ':,, .. '1;1 . " ·,' '''I ','1,1 ',. ·--cont8minants'ot' '.: ' ~ '«·~· 1 • ., .. ,,.: " (yds3>·", __ ,, "-" "' 11• ,, r 1 :, >, 111
1
, I ' I I '" " . concern· ! >. -,, -· .-• --~ ---_ " ' '.' ---: _;--. -. ' --~· ,_ ' f ----•• --·-·..:· ---' '}, ' '. '.,.,. ----' .. ~_/ " -· "··' --,_ _, --'• ,.; n ----=.-·:.._ -; -! -Na~QrgaoJii!tiQ!'I __ -Telept)one, !;mail , --· -' -,-! ~ .::-;. .. -. -' --·-" . -
---· " ·--=---·--" ..... -...:---·--· " " ; -.-_ , , · Address " -' .--:.-
Fort pilot test PCE, 1997-1998 dense, low permeability, no defined remedial Avg. 99.3% TetCA reduction (hydrolysis); Mr. Scott Kendall, 907-753-5661 AK
Richardson, followed by full Tetrachloroethane heterogeneous glacial till goals Avg. 93.2 % PCE reduction; Avg. 93.1 % U.S. Army Corps of [e-mail]
Anchorage, AK scale 1,000 mg/kg TCE reduction (hydrolysis product of Engineers, .army.mil
remediation 47,000 ug/I TetCA) Anchorage, AK
99503
Fort pilot test Benzene, gasoline 1998 sandy gravel, depth to no defined remedial 98% benzene reduction, 95% gasoline Mr. Rich Hom, 907-276-6833 ext 287 AK
Wainwright, and diesel water 17 feet bgs goals reduction CH2MHill, 301 W. [e-mail]
Fairbanks, AK Northern Lights
Blvd., suite 601,
Anchorage, AK
99503
Naval Air pilot test TCEDNAPL Designed Sands and silty sands as 95% Reduction in Thermal completed the design of the pilot Mr. Rudy Millan, IT 925-288-2229 CA
Station, 1,2-DCA performed fill material underlain by TCE test. Corporation, 4005 [e-mail]
Alameda, CA 2001 native silty clay or bay Port Chicago
mud. Groundwater depth Highway, Concord,
6 ft bgs. CA 94520-1120
Lowry Landfill, two full scale PCE, xylene 3/28/02-Hazardous waste landfill mass removal to Operations are on-going. Mr. Bill Plaehn, 303-764-8729 CO and US
Denver, CO sites {DNAPL) materials including buried the maximum Parsons Engineering [e-mail] EPA
55 gall. drums. extent practical, Science, 1700
Groundwater depth 17 ft about90% Broadway Suite 900,
bgs -33,700 yds3 Denver, CO 80290
DOD, Dover Air pilot test TCEandPCE 1997 Sandy aquifer 99% Removed tracers to ND levels DEand US
Force Base, mimicking tracers EPA
Dover, DE
Launch pilot test TCEDNAPL; 08118/1999 Fine sand with shells. 90% reduction in Overall TCE reduction 90%, DNAPL Mr. Steve Antonioli, 406-494-7343 Fland US
Complex34, 4,500 mg/kg, 07/12/00 Depth to groundwater from DNAPLwas reduction 97% MSE Technology [e-mail] EPA
Cape 1, 100,000 ug/L surface to 6 feet bgs. desired goal. Applications, 200
Can~veral, FL technology way,
Butte, MT 59701
Former full scale TCEandTCA 06/04/1998 Heterogeneous silty sands IL EPA Tier Ill Exceeded goals on schedule. By Dec. Mr. Val Jurka, 973-606-2848 312-697-IL
Electronics DNAPL. 04/30/1999 with clay lenses to 18 feet goals were TCE 1998 (six months of operation), Illinois Tier Lucerat Technologies 7211
Manufacturing Degradation bgs (hydraulic conductivity (17.5 mg/L); TCA Ill cleanup goals were achieved for TCE, and [e-mail]
Facility, Skokie, products: cis-and 10-4 to 10-5 cm/sec); (98.85 mg/L); and TCA, and DCE in all wells In the initial Mr. Greg Smith,
IL trans-1,2-DCE, 1,1 underlain by dense clay till DCE (35.5 mg/L). area of contamination. The site is now URS Corporation, 1
DCE, 1,1-DCA, aqultard (hydraulic closed and all groundwater monitoring Continental Towers,
and vinyl chloride. conductivity 10-8 cm/sec). wells have been abandoned. 1701 golf rd., suite
Groundwater depth 3-7 1000, Rolling
feet bgs -33,000 yds3 Meadows, IL 60008
Former full scale Methylene 12/08/1999 Glacial till with silty clay. 99% reduction of Exceeded goals on schedule, 99.8% Mr. Wayne 508-422-3187 IL
Consumer chloride; 42,000 11/09/00 Perched water at various MeCL as measured average reduction, 99.9% reduction in Wirtanen, Avery wayne_wlrtanen@averyden
Products mg/kg depths. by95% UCL 95%UCL Dennison Office nison.com
Manufacturer, Products, 409
Waukegan, IL Fortune Blvd., suite
#201, Milford, MA .. ,,.
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ATTACHMENT 2
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U.S. Environmental Protection Agency
Six-Phase Heating™ (SPH) at a
Former Manufacturing Facility
Skokie, Illinois
October 1999
Office of Solid Waste and Emergency Response
Technology Innovation Office
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---------------------Former Manufacturing Facility, Skokie, Illinois
Technology System Vendor:
David Fleming, Corporate Development Leader
Current Environmental Solutions
P.O. Box 50387
Bellevue, WA 98015
425-603-9036
425-643-7590 FAX
[e-mail]
PRP Oversight Contractor:
Gregory Smith 1
ENSR
27755 Diehl Rd.
Warrenville, IL 60555
630-836-1700
State Regulator:
Stan Komperda
Illinois EPA
Bureau of Land, No. 24
1021 East North Grand Avenue
Springfield, IL 62794-9276
217-782-5504
[e-mail]
MATRIX IDENTIFICATION
MATRIX DESCRIPTION
Type of Media Treated With Technology System: Soil and groundwater
CONTAMINANT CHARACTERIZATION [3,4, 7, 13)
Primary Contaminant Groups and Concentrations Measured During Site Investigation: The
primary contaminants at the site were TCE and TCA. Degradation products included cis-and trans-1,2-
dichloroethene, 1, 1-dichloroethene, 1, 1-dichloroethane, vinyl chloride and chloroethane.
At the initiation of SPH, aqueous phase concentrations and concentration trends indicated the presence
of DNAPL. Sampling indicated that DNAPL resided in proof-rolled clays at depths of 5 to 8 feet bgs, and
in the soil pores from the water table (7 feet bgs) to depths of 18 to 20 feet bgs. Concentrations in
groundwater at the initiation of SPH for cis-1,2-dichloroethene (DCE) were as high as 160 mg/L, for TCE
as high as 130 mg/L, and for TCA as high as 150 mg/L. Groundwater samples were obtained from
seven monitoring wells (see Figure 1 ).
1Now at: Radian International, One Continental Towers, 1701 Golf Road, Suite 1000,
Rolling Meadows, IL 60008, [e-mail]
A U.S. Environmental Protection Agency
~EPA Office of Solid Waste and Emergency Response
"' Technology Innovation Office
3
October 1999
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---------------------Former Manufacturing Facility, Skokie, Illinois
COST OF THE TECHNOLOGY SYSTEM
PROCUREMENT PROCESS [3,7,13)
The client was interested in finding a new technology that could enhance or accelerate the remediation of
the remaining regions of the site that were determined to be difficult to clean-up with steam injection. The
client's consultant, ENSR, performed an evaluation of several technologies for remediating the site and
recommended alternatives, including subsurface heating via thermal conductivity from resistive heating
elements and SPH.
COST DATA [5, 7)
According to the vendor, at the request of the site owner, the total cost of remediation efforts to date could
not be disclosed. However, on a per unit basis, the full-scale SPH remediation was completed at a total
price of $32 per cubic yard of treatment area as of November 1998. This cost included the installation and
operation of the SPH power system and electrodes as well as vapor extraction and condensate treatment.
The costs also included project permitting, preparation of work plans, electrical use, waste disposal,
interim sampling, and progress reporting. As of November 20, 1998, a total of 1,775 MW-hr of electrical
energy had been consumed by the SPH system. At full operation the electrical usage cost was $14,000
per month plus $40 per MW-hr. Over the course of the remediation, cumulative electrical costs totaled
$148,000. This corresponded to $6.40 per cubic yard of treatment volume or 20% of the total cost of $32
per cubic yard. The only costs not included in this total were final equipment demobilization, as these
activities have not been completed.
The unit cost for this technology of $32 per cubic yard is based on a calculated treatment volume of 23, 100
cubic yards of soil and groundwater, or a treatment area of 26,000 square ft and a depth of 24 ft bgs.
The unit cost for the treatment from December 1998 through May 1999 also was $32 per cubic yard,
based on a calculated treatment volume of 11,500 cubic yards. [12]
REGULATORY/INSTITUTIONAL ISSUES
CES has an exclusive license to market the SPH technology in North America and specific markets in
Europe and Asia. SPH was developed by Battelle Northwest Laboratories for the U.S. Department of
Energy.
OBSERVATIONS AND LESSONS LEARNED
COST OBSERYeJIONS ANQ LESSONS LEARNEQ
The unit cost of SPH at the Skokie site was $32 per cubic yard of soil treated, including installation and
operation over a 1-year period. Electricity costs accounted for 20% of the total unit cost for this
application. This unit cost was the same for both the initial and additional treatment areas.
PERFORMANCE OBSERVATIONS AND LESSONS LEARNED
The SPH system used at the Skokie, Illinois site achieved the established Tier Ill cleanup goals for the
remediation of the initial estimated 23,000 cubic yards of remaining contamination at the site in about six
months and for the remediation of the additional 11,500 cubic yards of contamination at the site in about five
months. In addition, the concentrations of constituents in a number of wells had been reduced to the more
stringent Tier 1 standards.
& U.S. Environmental Protection Agency
EPA Office of Solid Waste and Emergency Response
Technology Innovation Office
15
October 1999
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---------------------------Ft. Richardson PRDA OU-B
TREATMENT SYSTEM DESCRIPTION
PRIMARY TREATMENT TECHNOLOGY (1\
Soil In Situ -Soil Vapor Extraction
-In Situ Heating (Six-Phase Soil Heating)
SUPPLEMENTARY TREATMENT TECHNOLOGIES C1l
Post-treatment (Air) -Condenser
Post-treatment (Air) -Catalytic Oxidation (only used during the beginning of the study)
Post-treatment (Water) -Air Stripping
TREATMENT SYSTEM SCHEMATIC AND TECHNOLOGY DESCRIPTION AND OPERATION
Figure 3 shows a process flow diagram for the SPSH SVE system used to treat in-situ soil at OU-8.
Initial Activities (2,8)
The contractor mobilized to the site in June 1997. Pre-treatment soil samples were collected from the areas
covered by each array. Three arrays were constructed and operated at the OU-8 site. The array 1 SPSH
and SVE system was installed in June 1997. System shakedown at array 1 occurred from July 1 through
July 10, 1997. The array 2 SPSH and SVE system was installed in August 1997. The array 2 shakedown
period lasted approximately two weeks due to grounding problems that prevented effective soil heating. The
array 3 SPSH and SVE system was installed in October 1997. Only two days were needed for shakedown
at array 3.
Technology Description and Operation (1,2)
General Description of SVE Enhanced by Six-Phase Soil Heating
SPSH is a patented, multi-phase electrical technique that utilizes common power line frequency (60 Hz) to
resistively heat soil. SPSH can tum groundwater into steam that will strip volatile and semivolatile
contaminants from the soil. The steam stripping facilitates movement of contaminants from low permeability
zones into more permeable zones where the contaminants are removed by the SVE system. In situ heating
also allows the contaminants to volatize more readily.
Electrical power is delivered throughout the area being treated by steel electrodes inserted vertically into the
soil. The electrodes are placed in a circular array consisting of six electrodes on the periphery and one
electrode in the center. Each periphery electrode is connected to one of the six single-phase transformer
wires. Six conventional single-phase transformers convert standard three-phase electricity into six-phase
electricity at the desired voltage. Each electrode is operated at a different voltage phase, so the electricity
conducts with all the other electrodes in proportion to the voltage differences. The electrode spacing and the
connected electrical phases are both 60 degrees apart, resulting in a uniform ratio of voltage difference to
physical distance between all electrodes in the array. The result is a relatively even heating pattern. The
seventh neutral electrode is located at the center of the array. Each electrode also serves as an SVE vent.
•
Prepared by:
U.S. Anny Corps of Engineers
Hazardous, Toxic, Radioactive Waste
Center of Expertise
Final
October 22, 1999
Page9
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Ft. Richardson PRDA OU-B
electrodes of approximately 400 kW. Higher voltages were required to maintain the desired power input as
the soil dried and the soil conductivity decreased. The computer that monitored the six-phase transformer
calculated the phase resistance at each electrode. The water flow rate was increased to electrodes that
had higher resistances.
While the test was running, several parameters were monitored to help estimate the performance of the
system. Some parameters were monitored by electrical sensors and automatically recorded by the on-site
computer. These parameters included:
• Condenser off-gas pressure, flow, and temperature;
• Soil temperature from thermocouples placed at locations within each array that would be the last to
heat;
• Transformer voltages, amperages, and total power; and
• Soil resistivity.
Other parameters were observed and manually recorded from various gauges. These parameters included:
• Generator amperage;
• Fuel levels;
• Vacuum at SVE knockout tanks;
• Off-gas photoionization detector levels; and
• Effluent water tank levels.
Post-Operation (1,2,8)
Treatment system shutdown and demobilization occurred in December 1997. Post-treatment soil samples
were collected in January 1998. After operation of the treatment system, no additional restoration activities
(e.g., final grading, landscaping) were necessary at the site.
Personnel Requirements (8)
Operation of the treatment system normally required one person on-site 8 hours per day, 5 days per week,
and several hours each weekend day. An off-site project manager spent several hours each day managing
the project (e.g., calling the client, locating parts, working with subcontractors, etc.) .
Health and Safety Requirements (4,8)
For the RI, initial drilling operations were performed in Level B personal protective equipment (PPE), which
included supplied breathing air and chemical resistant clothing, boots, and gloves. Approximately halfway
through the field irtvestigation, the health and safety requirements were reviewed and approval was granted
by the USACE to downgrade to Level D PPE. The downgrade was requested because no chemical warfare
materials had been detected in the area most likely to be contaminated.
All work related to the treatment system was performed in Level D PPE. During drilling operations, fans
were used to dissipate solvent vapors.
OPERATING PARAMETERS AFFECTING TREATMENT COST OR PERFORMANCE l1 2 3 8\
The following table lists values for parameters associated with operation of the SVE system at PRDA OU-8.
The parameters were selected for this report based on USACE guidance.
• Prepared by:
U.S. Anny Corps of Engineers
Hazardous, Toxic, Radioactive Waste
Center of Expertise
Final
October 22, 1999
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Ft. Richardson PRDA OU-B
a e 1peratmQ T bl 3 0 p arameters
" n ~' ~&'' ••. Par~metel'.· ·--" ',f,:': '. -1' . - . Dj!sign~ _. :· ',.i,: .. :1. ·;'~· .· A¢tµai:. :>,, . ' ... :
Soil pH Not Annlicable 6.08-7.26
Soil Temperature 100°c 40 -100°C after 2 weeks
Electrical Power Input 455 kW (Arrays 1 and 2) 400 kW (Arrays 1 and 2)
1,200 kW (Arrav 3) 200 -800 kW (Arrav 3)
Air Flow Rate of the SVE System Not Available 200 -260 acfm
(20°C and 1 O -11 psia)
Operating PressureNacuum of the Not Available 100 -150 inches water
SVESystem
Condenser Flow Rate Not Available 600 Qal/day
Condenser Temperature Not Available 140°C-Inlet
Ambient -Outlet
TIMELINE (1 2\
!' •' 'oafe·>. ;· _,. : · .. .. .-.-~:·-),·::.~~ r~ .. : --: ~-:· ... · Activttvr'.c,'.", _,;_:, ',::-;,-::'":·•'··'·· '.:· «" . ,-_ .. ,., ~.-,. ., ' -. ..
1990 The OU-B site was identified
1990-1992 Preliminarv investigations conducted at the site
1993-1994 Removal action conducted at the site
June 1994 Fort Richardson added to the NPL
December 1994 FFA signed by the Army, ADEC and EPA
AuQust-September 1995 Remedial investiQation conducted
September 1996 Human and ecoloQical risk assessment completed
January 1997 Feasibility study completed
August 8, 1997 ROD signed by U.S. EPA Reaion X Administrator
June 1997 Site mobilization, system set-up, and collection of pre-treatment soil
samples
Julv 1-10, 1997 Svstem shakedown
July 11 -AUQUSt 22, 1997 Treatment conducted at Arrav 1
August 24 -October 9, 1997 Treatment conducted at Array 2
November 6 -December 18, Treatment conducted at Array 3
1997
December 1997 -Januarv 1998 Demobilization and collection of post-treatment soil samoles
TREATMENT SYSTEM PERFORMANCE
PERFORMANCE OBJECTIVES (1 2\
System performance was evaluated against three primary criteria:
• The ability of each six-phase heating array to heat soil in-situ;
• Demonstrated removal of contaminants, as measured in the condenser off-gas and condensate; and
• Demonstrated reduction of soil contamination, as measured by the pre-and post-treatment soil
sampling results.
The air stripper was operated so that the effluent concentrations were below Alaska's maximum
contaminant levels (MCLs} for drinking water. Table 4 presents the MCLs for contaminants of concern at the
site.
' • Prepared by:
U.S. Anny Corps of Engineers
Hazardous, Toxic, Radioactive Waste
Center of Expertise
Final
October 22, 1999
Page 13
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Ft Richardson PRDA OU·B
Table 4. Alaska Maximum Contaminant Levels (3)
" 1<'.:HeriUcaN ': ·' · . .. . . . •. : .. Alask~MCL:'.(11/L)( .. ·~ :_·::>: .... · . ~· -. ·-.. .-=· . ' ~ : .. ..
Benzene 5
Carbon Tetrachloride 5
Chlorobenzene Not Established
Chloroform 100
1,4-Dichlorobenzene Not Established
1,2-Dichloroethane Not Established
1, 1-Dichloroethene 7
cis-1,2-Dichloroethene 70
trans-1,2-Dichloroethene 100
Hexachloroethane Not Established
TCA Not Established
PCE 5
Toluene 1,000
1, 1,2-Trichloroethane 5
TCE 5
TREATMENT PERFORMANCE DATA (1 2l
Figure 4 presents temperature profiles for each of the three arrays. Each thermocouple boring provided
temperature readings at three depths within the arrays.
Condenser off-gas and condensate were sampled to determine concentrations of contaminants extracted by
the system. Off-gas and condensate were collected from the condenser approximately every other day
during operation. The off-gas samples were collected in summa canisters and sent to an analyti<;:al
laboratory for volatile organic chemical (VOC) analysis by EPA Method T0-14. Water samples were
analyzed for voes by EPA Method 8260A.
Table 5 presents the condenser off-gas sample results for arrays 1, 2, and 3. Condensate results from the
three arrays are provided in Table 6. These results were used to calculate the mass of contaminants
removed in the off-gas and condensate, respectively. While data was collected for a standard list of voes,
only results for TCA, TCE and PCE are presented in these tables.
Air stripper effluent results for TCA, TCE, and PCE are also provided in Table 6 for comparison to influent
concentrations. Sampling of the effluent was terminated once the air stripper demonstrated the ability to
comply with the Alaska MCLs.
Soil samples were collected to determine pre-and post-treatment soil concentrations. Pre-treatment soil
samples were collected during drilling for the thermocouple borings, and post-treatment soil samples were
collected by drilling a boring adjacent to the thermocouple boring. Sampling at array 1 included two borings
within the array and two outside the array. Sampling at arrays 2 and 3 each included one boring within the
array and one outside the array. Sample locations are shown on Figure 2. Soil samples were analyzed for
voes by EPA Method 8260A.
Table 7 presents a comparison of soil samples taken pre-and post-treatment. Results for the principal
contaminants of concern at OU-B (TCE, PCE and TCA) are shown in the table. Detection limits were used
to calculate removal efficiencies for samples where contaminants were not detected.
• Prepared by:
U.S. Army Corps of Engineers
Hazardous, Toxic, Radioactive Waste
Center of Expertise
Final
October 22, 1999
Page 14
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'" , Arrav:· ·.
1
2
3
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Ft. Richardson PROA OU-8
Table 5. Contaminant Concentrations in Condenser Off-Gas Coomv)
., 'i ... Samole·Date· . . . . '~ ~::" TCA,-. ..
7/15/97 20
7/19/97 50
7/21/97 58
7/24/97 condenser 2.3
7/24/97 catox 5
7/29/97 9.4
7/31/97 130
8/2/97 46
8/4/97 18
8/6/97 4.7
8/8/97 5.8
8/12/97 4.5
8/16/97 1.4
8/18/97 4.8
8/26/97 5
8/29/97 5.9
9/5/97 5.3
9/10/97 5.5
9/20/97 3.3
9/23/97 5.4
9/25/97 6.7
9/27/97 4.4
9/29/97 2.4
10/1/97 2.4
10/4/97 8.1
11/18/97 2
11/20/97 0.38
11/22/97 0.73
11/24/97 0.38
11/26/97 0.63
11/28/97 1.3
11/30/97 0.46
12/2/97 0.6
12/4/97 1
12/6/97 0.18
12/8/97 1.3
12/10/97 2.3
12/12/97 1.6
12/14/97 1.5
12/16/97 1.1
12/18/97 1.5
Prepared by:
U.S. Army Corps of Engineers
Hazardous, Toxic, Radioactive Waste
Center of Expertise
' :. ~ TCE-. -. · :'.1rj'
93
200
180
53
9.4
140
340
190
120
120
73
64
100
82
140
120
50
52
85
110
100
130
55
30
36
49
18
42
56
26
38
20
23
27
17
31
30
32
27
21
20
i"·"·:··»1',-;'PCE.·
2.1
6
4.2
1.3
0.38
3.5
11
7.4
3.6
4.1
2.4
2
2.8
2.4
3.8
3.5
1.6
1.5
3.2
4.1
3.6
4.7
1.8
0.98
1.2
1.7
0.56
1.3
1.7
0.81
1.2
0.66
0.76
1.1
0.66
1.3
1.2
1.2
1
1.5
0.94
Final
October 22, 1999
Page 16
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Table 9 • Averai:ie Removal Efficiencies for Soil Remediation
.-;,:': ,:\:';·~·:.;~: .. :.,:! ':',< ?;" :;"';~·-::-1~> -.·: .A':'l;_:«tc~: .. ~ .. ·~:::·.i;. ~ .. '/ /,: .1';;\ ;::::
<. Ar:rav: <..:, .: < ,;_1nskl&,:.:< .. :~''. ~~:\·:121:outs1de;.,.,.,.
<:, < «,«' Pee:,:«< <'<:'•,:<":/':;" c: :! .;:,:<!;;~Y::::;'::::":•<"< .. rcE·~·:'.'' <,, ',' .>"
Inside_< »-_-.,!·OutsKfe/:·<· :,:;,;;i::·lnslde:~ ,<. · .::'. <OUt&ide:'<,,. ..
100% 96% 00% 00% Mo/o ~%
2 100% 99% 96% 84% 99% 85%
3 100% -198% 82% -332% 89% -49%
Soil sample results from areas outside arrays 1 and 2 indicate that contaminant removal is significant but
less efficient than inside the arrays. This may be due to the zone of heated soil not extending as far outside
of the arrays as the radius of influence for the SVE system. The SPSH zone extended at least to the
outside sampling point for arrays 1 and 2 (approximately 40% of the array radius, or 5 feet, beyond the array
boundary); the SPSH zone did not extend as far (percentage wise) beyond the array-boundary for array 3.
The pre-and post-treatment soil sampling results indicated that the contaminant concentrations in several
locations actually increased during the treatment period. Several negative removal rates were calculated.
This is most likely a result of sampling variability and not an actual increase in the concentration of
contaminants.
Performance of the SPSH-SVE system was compared with performance of the SVE-only system, which
was tested at OU-Bin November 1996. This test involved extracting soil gas vapors from MW-14, located
directly adjacent to array 1 (shown on Figure 2). Table 10 presents the range of total VOC concentrations in
the condenser off-gas under test conditions with and without SPSH. The tests were conducted at similar
vacuum flow rates.
The concentration of total voes in extracted soil gas was significantly higher in samples collected during
the SPSH study. This increase in voe concentrations is attributed to the increased soil temperatures
induced by the SPSH system.
T bl 10 C a e . omparison 0 fVOC R em ova 1w· h dW"th tt an I out SPSH
'',;, ' >.:': : < ,:Test'': >:1·:;:,:'::··.'.:" ., .,,, : < "~; : .,< ,• .. -:·T~t81:vocconceritrat10n'toomv}:· · :-. ',.;, -<,, ~ . '
SVE treatabilitv study (without SPSH) 15-70
Array 1 (SVE with SPSH) 50-499
Arrav 2 (SVE with SPSH) 36-161
Array 3 (SVE with SPSH) 20-60
PERFORMANCE DATA QUALITY (4\
The following QNQe requirements were followed during the RI performed at OU-B:
• Applicable EPA sampling and analysis methods were used. Where EPA methods were not available,
standard industry methods were used.
• Laboratory data packages included complete raw data deliverables and documentation sufficient to
perform a USAGE Level Ill data validation.
• QC samples and procedures were utilized by the off-site laboratory.
• A Level Ill data validation was performed on the off-site laboratory data. Guidelines recommended in
EPA's Laboratory Data Validation Functional Guidelines for Evaluating Organic or Inorganic Analyses
were followed .
•
Prepared by:
U.S. Army Corps of Engineers
Hazardous, Toxic, Radioactive Waste
Center of Expertise
Final
October 22, 1999
Page21
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• Duplicate samples were collected at a frequency of 10% and sent to the USACE Quality Assurance
Laboratory for analysis.
• For generation of field screening data, applicable organic methods were used in the field laboratory and
QC samples and procedures were utilized by the field lab.
• Rinsate blanks, field duplicates, and trip blanks were collected and submitted to the off-site laboratory
for analysis to provide a means for assessing field QC.
TREATMENT SYSTEM COST
PROCUREMENT PROCESS f1 8)
The SPSH study was implemented as a delivery order to a pre-placed indefinite delivery type architect-
engineer (IDT-AE) contract. As such, the scope of work for each array was defined by the government and
negotiated with the contractor. The result of the negotiation was a firm-fixed price contract for
accomplishment of the work described in the defined scope.
Woodward-Clyde Federal Services was selected as the contractor to perform the SPSH study. Woodward-
Clyde subcontracted with the following companies to perform the listed project tasks:
Subcontractor/Equipment Vendor
Current Environmental Solutions
Tester Drilling
Treatment system vendor, monitoring the on-site computer
Drilling operations
Multichem
Pye-Per Fuels
Craig Taylor Rental
NC Machinery
H20il
TREATMENT SYSTEM COST (1 8\
Analytical laboratory
Diesel fuel delivery
Rental of 455 kW generator
Rental of 1200 kW generator
Rental of blower and air stripper
The total budgeted cost for this project was $967 ,822. Costs for each array includes installation of the
electrode wells, thermocouple wells, and all ancillary equipment for operation of the system (generator,
blowers, piping, etc.) All sampling, testing, and monitoring costs are also included. Table 11 summarizes
the budgeted costs for the SPSH study. The contractor indicated that these costs were fairly close to the
actual costs incurred.
The contract price for the first array included costs for mobilization of the SPSH transformer equipment, a
catalytic oxidizer for treatment of off-gas, and other startup and operational troubleshooting costs not
included in subsequent arrays.
Unit costs were calculated using the sum of the budgeted capital and operation and maintenance (O&M)
costs. These unit costs are shown in Table 11. The soil treatment costs calculated for the treatability
study at OU-B ranged from $189 to $288 per CY of soil treated or $103 to $158 per ton of soil treated. On
a contaminant basis, the soil treatment costs ranged from $726 to $2,552 per pound of contaminant
removed.
• .
Prepared by:
U.S. Army Corps of Engineers
Hazardous, Toxic, Radioactive Waste
Center of Expertise
Final
October 22, 1999
Page22
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For cost comparison purposes, the cost of treating the same soil (soil excavated from areas A-3 and A-4) in
ex-situ static piles by heat enhanced SVE was $150 per CY not including excavation, sampling, and testing
costs. The supplier of the technology reported that costs can be reduced to a range from $30 to $85 per CY
of treated soil for easily accessible sites where commercial power is available. The cost of off-site disposal
at the Defense Reutilization and Marketing Office is approximately $2,400 per CY, not including excavation
or packaging'.
COST SENSITIVITIES (1)
A significant portion of the operating cost of the treatment system came from the large power requirements
of the treatment equipment. Because the site was in a remote location, power was provided by mobile,
diesel fuel-powered electric generators. Because of this, fuel consumption and rental of the generators and
storage tanks added a significant cost to the project that would not be incurred at sites where commercial
electrical power is available.
REGULA TORY/INSTITUTIONAL ISSUES
Because this project was performed under CERCLA regulations, it was not necessary to obtain permits from
local regulatory authorities for on-site activities. It was necessary, however, to meet the substantive
requirements of potentially applicable regulations.
The following table lists the remedial action objectives for soil treated at OU-B. These objectives were
established in the ROD.
Table 12. Treated Soil Objectives (2)
· ··~ ·.· · ,,. · .;'··.i;,::ch~ml~1 ... ':t.-·: ,., : : ·1 ••• :.~ :·::!·~~s:fp~arice·ckt~erta',(rrfg'li(g~,;~.:,.1··':'·:+·'''.).!:::·
TCA 0.1
PCE 4.0
TCE None Provided
The remedial objective for groundwater at OU-B is to reduce contamination to comply with Alaska's MCLs
for drinking water. The applicable MCLs are provided in Table 4.
TECHNOLOGY APPLICABILITY AND ALTERNATIVES
APPLICABILITY OF THE TECHNOLOGY <2 3 Zl
The media of concern for evaluation in the FS at OU~B were the perched, shallow and intermediate
groundwater intervals, and "hot spor soil, all potential sources of continuing contamination to the deep
aquifer at the site. The FS evaluation focused on contaminated soil and groundwater to a depth of 60 feet
bgs. The depth of 60 feet bgs was chosen because it was deeper than the most highly contaminated
groundwater, modeling showed that treatment to this depth would be sufficient to capture contaminants, and
it is the depth below which specialized and overly expensive equipment would be necessary for trenching.
•
Prepared by:
U.S. Anny Corps of Engineers
Hazardous, Toxic, Radioactive Waste
Center of Expertise
Final
October 22, 1999
Page24
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Ft. Richardson PRDA OU-B
A treatability study was performed that included pilot testing of SVE and air sparging. The SVE system
was run for 5 days with the air sparging test conducted on the last day. Samples of extracted soil gas
showed that SVE was effective at removing TCA and TCE, the designated indicator chemicals. With the air
sparge blower on, TCE concentrations were increased in the SVE off-gas but TCA concentrations were not
significantly affected. Although the SVE test was considered successful, the FS recommended that SVE
treatment enhanced with in situ soil heating could be used at the site as a means for completing treatment
more rapidly.
USACE requested an analysis of heat enhancement methods. After a comparison of several different
methods to heat the subsurface soil, electrical resistance (e.g., SPSH) was selected for evaluation at OU-
B over radio frequency heating because it more efficiently delivers energy to the fine-grained soil found on
site. This is important because, with either technology, electrical costs represent a significant portion of the
total cost of remediation.
SPSH simultaneously heats and ventilates soil in situ to remove volatile and semivolatile organic
contaminants. SPSH is applicable for treatment of contaminated subsurface environments (soil, sludge, or
sediments) in which contamination may be sorbed onto soil particles, dissolved in groundwater, or in the
vapor phase. These media may be either fully or partially saturated with water. The process has been
proven greater than 99% effective at removing voes in the vadose zone.
COMPETING TECHNOLOGIES (2,7\
The SPSH technology has many advantages over currently available and comparable technologies. There
are several different accepted methods for heating subsurface soil. These include steam injection, use of
radio frequency, and use of electrical resistance (e.g., SPSH). Steam injection is typically effective in more
permeable and heterogeneous soil. High soil permeability is necessary to allow the steam to move through
the soil. Steam injection was rejected as a potential heating technology at OU-B because contamination at
OU-B is predominantly found in finer-grained soil.
Radio frequency and electrical resistance heating methods work well with moist, fine-grained, low-
permeability soil. Soil heterogeneity is not necessary since steam is generated within the soil matrix. Both
technologies require large amounts of electrical power, however electrical resistance heating is more
efficient in delivering energy to the soil. Approximately 55% of the energy supplied by an electrical source is
delivered to the soil by the radio frequency method compared to nearly 100% energy delivery by the
electrical resistance method. In contrast to electrical resistance heating, radio frequency heating does not
require the presence of water to carry electrical current. As a result, radio frequency heating can increase
soil temperatures above 100°C, the limiting temperature for electrical resistance heating. In addition, SPSH
uses standard power frequency systems which are more robust and less expensive than higher frequency
systems. At the time of this report, a treatability study was being conducted at Fort Wainwright, near
Fairbanks, Alaska· to compare the performance characteristics of radio frequency and SPSH,
The SPSH process results in accelerated and more complete removal of target contaminants from soil when
compared to conventional SVE treatment and does not require excavation. Compared to pump-and-treat
systems, SPSH provides an increased rate and extent of remediation, reduced O&M costs due to shorter
time on site, and is applicable to low-permeability, heterogeneous, and LNAPUDNAPL-contaminated soil. In
addition, SPSH has several advantages over excavation and ex-situ treatment. SPSH provides lower risk of
contaminant exposure to humans and the environment, lower cost (20% to 30% of the cost of excavation
and on-site treatment), and is applicable to sites with deep contamination (excavation is difficult below the
water table).
• '
'
Prepared by:
U.S. Anny Corps of Engineers
Hazardous, Toxic, Radioactive Waste
Center of Expertise
Final
October 22, 1999
Page25
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SPSH has the following disadvantages compared to alternate technologies. However, some of these
disadvantages are common to several alternate technologies. SPSH:
• Is limited to heating soil to 100°C;
• Does not address non-volatile organics, metals, and other inorganics;
• Requires treatment of contaminants above ground in the off-gas treatment system;
• Requires access roads for equipment, materials, and system transport;
• Requires site mobilization, operation, and demobilization of equipment;
• Is emerging on the commercial market, so demonstration experience is limited;
• Excludes people from the treatment zone; and
• Requires a relatively large source of electrical power.
SPSH is a patented technology available through Battelle or Battelle's industrial partners working in a
collaborative relationship. Batelle created Current Environmental Solutions (CES) for the purpose of
commercializing the SPSH technology.
MATURITY OF THE TECHNOLOGY C1.7l
Development of SPSH began at Battelle in 1989. Before 1996, SPSH used on saturated soil had only been
tested at the bench scale although SPSH had been successfully demonstrated and was commercially
available for removing contaminants from the vadose zone. In 1996, Battelle performed a technology
demonstration of saturated soil at the National Test Site at Dover Air Force Base. Since then, CES has
conducted pilot-scale studies in Alaska and full-scale remediation of DNAPL in the saturated zone at sites
in Chicago, Seattle and Niagara Falls.
OBSERVATIONS AND LESSONS LEARNED
COST OBSERVATIONS AND LESSONS LEARNED C2 8 10,11\
The most critical factor in controlling energy costs is the volume of soil treated. The amount of electricity
that needs to be applied to a site increases in proportion to the volume of soil treated. Other treatment
system costs such as blowers, air strippers, sampling and labor to operate the system do not increase as
quickly, Other factors that affect energy costs include the cost of electricity, soil type, moisture content,
and the length of time needed to reach remediation goals, which depends on initial contaminant
concentrations, physical/chemical properties of the contaminants, and the remediation goals,
Energy consumption can be estimated for a site by calculating the energy required to heat a known volume
of water to a certain temperature, which, in the case of SPSH, is typically 100°C. The volume of water to be
heated is calculated based on the dimensions of the soil to be treated and the moisture content of the soil.
Larger arrays require larger generators. For example, array 3 used a 1200 kW generator while arrays 1 and
2 used a 455 kW generator. A large generator can potentially use several thousand gallons of fuel each
day. The fuel requirement can significantly impact operating costs and can, therefore, restrict the size of a
cost-effective array.
Since the treatability study was completed, the Army installed a buried electric line to OU-B from an access
point one mile away. The installation cost was approximately $108,000. Any additional SPSH remedial
actions at OU-B will have lower costs since generator rental and fuel purchase costs will be eliminated,
•
Prepared by:
U.S. Army Corps of Engineers
Hazardous, Toxic, Radioactive Waste
Center of Expertise
Final
October 22, 1999
Page26
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PERFORMANCE OBSERVATIONS ANO LESSONS LEARNED (1 2\
There may be limitations to the size of the array that can effectively treat soil at a particular site. The size of
the array is limited by the resistivity of the soil and power requirements. In array 3, voltage could not be
effectively transferred to the soil throughout the array due to the increased resistivity of the volume to be
treated. The result was decreased heating. It is recommended that arrays should not be constructed
greater than 30 feet in diameter at OU-B unless electrode construction and water delivery systems are
improved.
Soil temperatures can be maintained near 100°C in areas where soil moisture can be replaced.
Lower initial contaminant concentrations in array 3 reduced the treatment efficiency. As can be expected
with many treatment systems, it is more difficult to remove contaminants at low concentrations.
Preferential flow pathways due to discontinuities in the soil may cause increased contaminant
concentrations in some areas. Several concentration increases were measured, particularly in array 3 in
which incomplete heating reduced removal effibiencies.
While TCE was present at lower concentrations than TCA in the soil prior to treatment, TCE was measured
at an order of magnitude higher than TCA in the condenser off-gas. This is to be expected because TCE is
much more volatile than TCA, and TCA has been shown to hydrolyze to TCE in the presence of water.
Elevated temperatures may increase the rate of hydrolysis.
Effluent water from the condenser must be heated prior to treatment in an air stripper. The water leaving the
condenser was sufficiently cold that the treatment efficiency of the air stripper was diminished. As a result,
the air stripper did not meet treatment objectives initially. Pre-heating of the water leaving the condenser
solved this problem.
OTHER OBSERVATIONS AND LESSONS LEARNED (1 2 8)
Use of a hollow stem auger caused problems during installation of the electrodes. The 6-inch auger casing
barely allowed sufficient space for installation of the 4-inch electrode, the drip tubes, and the granular
graphite. The drillers had problems reaching the desired depths with the augers because large cobbles were
present at the site. Other problems occurred because of water that moved into and remained in the augers
while drilling below the water table. The granular graphite often bridged at the water table interface, forcing
the drillers to remove the electrode materials and start over. Future electrode installations that extend below
the water table should be made with an air rotary drill rig. The air rotary drill rig provides a larger inside
diameter workspace and allows easy removal of water within the casing.
The voltages induced by the SPSH in the soil can cause problems with site safety and the operation of
sensitive electrical equipment. Significant grounding problems were encountered during operation of arrays
1 and 2. Electrical equipment used during operation of arrays 1 and 2 was located, in some cases, as
close as 25 feet from the nearest electrode. Despite the fact that each piece of equipment was equipped
with an individual grounding rod, problems with proper grounding still occurred. These problems were avoided
during operation of array 3, by moving the equipment farther from the array. The equipment was placed 70
to 80 feet from the nearest electrode while heating array 3. In addition, a properly sized grounding mat was
used and the problems were mitigated. For future applications, it is recommended that equipment not be
sited closer than 80 feet from any electrode. An experienced electrical engineer should design the
grounding system.
•
Prepared by: • U.S. Anny Corps of Engineers
Hazardous, Toxic, Radioactive Waste
Center of Expertise
Final
October 22, 1999
Page27
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Use of SPSH has been a limitation at some sites where there are electrically conductive utilities.
Modifications to the desigQ_ and installation of the SPSH system allowed its use at a site in Seattle with
buried utilities for sewer, electrical, water, and natural gas; similar modifications may be possible at other
sites.
Consideration should be given to the substantive regulatory requirements that may be triggered by using on-
site generators at remote locations. The air emissions from the generators are more likely to be regulated
than are the relatively low emissions from the treatment system. Depending on the estimated potential air
emissions, New Source Review/Prevention of Significant Deterioration and other Clean Air Act requirements
may be applicable. Potential emissions must be calculated assuming year-round operation of the system
(8, 760 hours per year).
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)
11)
REFERENCES
Gagnon, Bernard T. and Kendall, Scott, "Treatment of Solvent Contaminated Soil and Groundwater
Using Six-Phase Heating Combined with Soil Vapor Extraction", unpublished.
Draft Desjgn Verification Study, Operable Unit B, Poleline Road Disposal Area, Fort Richardson,
Alaska, Woodward-Clyde Federal Services, February 6, 1998.
Final Feasibility Study Report, Operable Unit B, Poleline Road Disposal Area, Fort Richardson,
Alaska, Woodward-Clyde, January 1997.
Final Remedial Investigation Reoort, Operable Unit B, Poleline Road Disposal Area, Fort
Richardson, Alaska, Woodward-Clyde, September 1996.
Verschueren, Karel, Handbook of Environmental Data of Oraanic Chemicals, zict Edition, Van
Nostrand Renhold Company: New York, 1983.
Montgomery, John H. and Welkom, Linda M., Groundwater Chemicals Desk Reference, Lewis
Publishers, Inc., 1990.
Test Plan: Six-Phase Soil Heating of the Saturated Zone. Dover Air Force Base. Delaware, Pacific
Northwest National Laboratory and Battelle Columbus Operations, August 1996.
Response to Memorandum "Questions on the Six-Phase Soil Heating Enhanced Soil Vapor
Extraction System at the Poleline Road Disposal Area at Ft. Richardson", received June 2, 1999,
from Scott Kendall of URS Corporation.
Six Phase HeatingTM Application Report, "DNAPL Remediation in the Saturated Zone, Ft.
Richardson, Anchorage, Alaska", Current Environmental Solutions, unpublished.
Phone conversation between Kristin Andreae of Radian International and David Fleming of Current
Environmental Solutions, July 14, 1999.
Phone conversation between Kristin Andreae of Radian International and Kevin Gardner of the U.S.
Army, July 14, 1999.
' Ill Prepared by:
U.S. Anny Corps of Engineers
Hazardous, Toxic, Radioactive Waste
Center of Expertise
Final
October 22, 1999
Page28
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ACKNOWLEDGEMENTS
This report was prepared for the U.S. Army Corps of Engineers under USAGE Contract No. DACA45-96-D-
0016, Deliver:y Order No. 12.
•
Prepared by:
U.S. Anny Corps of Engineers
Hazardous, Toxic, Radioactive Waste
Center of Expertise
Final
October 22, 1999
Page29