The demonstration dye tracing investigation only showed tracer dye (eosine OJ) transport from
iniection point MW1 (1109) to recovery points STP1, STP2. STP9, MW4 (1112), and DLD. This
change in transport behavior is likely due to diversion of dye-laden groundwater around the barrier
wall. This behavioral change is apparent in the eosine OJ analytical data for recoverv point MW4
(1112), where the highest concentration detected during the investigation did not occur until 2 week:
prior to the end of the technology demonstration (Cambrian 1998). Figures 2-9 through 2-13 plot tk

concentration of eosine OJ against days relative to dye injection for dye recovered at each location.

Results from the 1996 dye tracing investigation also showed tracer dye transport to the furthest
recovery points (from monitoring well MW1 [1109]) along the tributary (SBC and $3 through S7)
sooner than the closest locations (STP2, W898, W674, and DLD) (EPA 1996). Tracer dye appeare:
bypass the upgradient recovery points and discharge directly into the tributary, indicating that a
preferential pathway may exist on the north side of the former pond. Tracer dye transport from
injection point MW1 (1109) to the tributary was not observed during the demonstration dye tracing
investigation, indicating that horizontal groundwater flow may have been impeded or retarded as a
result of the barrier wall. Table 2-2 compares the results of the 1996 investigation with the
demonstration investigation from tracer dye injection point MW1 (1109).

2.1.4 Groundwater Elevation Results

Information on water level results discussed in this section is based on data gathered by DOE and
presented in a report entitled “HRE-Pond Cryogenic Barrier Technology Demonstration: Pre- and Post-
Barrier Hydrologic Assessment” prepared by Dr. Gerilynn Moline, ORNL Environmental Sciences
Division. Hydrographs plotting average water table elevations before, during, and after emplacement
of the barrier wall for standpipes 12 and STP10 and monitoring well MW2 (1110) are included in
Figures 2-14 through 2-16. The following sections describe the groundwater conditions encountered
before and after establishment of the barrier wall in the former pond area.

39



Analytical Results for

Eosine OJ and Phioxine B
(ppb)

Location Description Phase| Sample Type | Sample Date Eosine OJ Phioxine B
STSS Trivelpiece Spring BKG cs 216/98 ND ND
‘wes piezometer BKG GS 2/6/98 ND ND

BKG. NSC 2/7198
BKG NSC 2/8/98
DLD Dale's Little Dipper Spring | BKG Gs 2/9/98 1,30E-03 ND
12 standpipe BKG GS 2/9/98 ND ND.
MW1 (1109) monitoring well BKG GS 2/9/98 ND ND
MW2 (1110) monitoring well BKG GS 2/9/98 ND ND
MW2 (1110) monitoring well BKG c 219/98 ND ND
MWS (1111) Thonitoring well BKG GS 215198 ND ND
MWS (1111) monitoring well BKG Cc 2/9/98 ND ND
MW4 (1112) monitoring well BKG GS 2/9/98 4.30E-03 1.30E-03
S1 small tributary _ BKG GS 2/9/98 ND ND
$1 small tributary _ BKG c 2/9/98 ND ND
$2 small tributary BKG GS 2/9/98 ND ND
$2 small tributary BKG c 2/9/98 ND ND
s7 small tributary BKG GS 2/9/98 ND ND
S7 ‘small tributary BKG Cc 2/9/98 ND. ND
SBC stream below culvert BKG c 2/9/98 ND ND
STP10 standpipe BKG GS 2/9/98 ND 1.30E-03
STP2 standpipe BKG Gs 2/9/98 3.79E-02 4.30E-03
STP9 standpipe BKG GS 2/9/98 4.90E-02 1.30E-03
STSS Trivelpiece Spring _ BKG Gs 2/9/98 ND ND
STSS Trivelpiece Spring BEG] - C 2/9/98 ND ND
Wws98 piezometer BKG c 2/9/98 ND ND
BKG NSC 2/10/98
BKG NSC 2/11/98
MW2 (1110) monitoring well BKG GS 2/12/98 ND ND
MW4 (1112) monitoring well BKG GS 2/12/98 5.14E-02 ND
AFIP piezometer BKG GS 2/13/98 ND 1.30E-03
DLD Dale's Little Dipper Spring | BKG Gs 2/13/98 4.30E-03 ND
12 standpipe BKG GS 2/13/98 ND ND
MW1 (1109) monitoring well BKG -GS 2/13/98 ND ND
MW2 (1110) monitoring well BKG c 2/13/98 ND ND
MWS (1111) monitoring well BKG Gs 2/13/98 ND ND
MwW4 (1112) monitoring well BKG c 2/3/98 1.30E-03 1.30E-03
Si small tributary BKG GS 2/13/98 ND ND
$2 small tributary BKG GS 2/13/98 ND ND
s7 small tributary BKG GS 2/13/98 ND ND

A3



REFRIGERATION UNITS .

INSTRUMENTATION
AND SYSTEM
CONTROL SHELTER

NOT TO SCALE

azar

ZZ WATERPROOFING MEMBRANE
LIMITS OF ASPHALT CAP
FORMER TOP OF POND
------ FORMER POND BOTTOM

° ‘THERMOPROBE

CO) TEMPERATURE MONITORING POINTS

‘MW = Monitoring Well
ast 1 = Standpips
-4W = Plezometer

ARCTIC FOUNDATIONS, INC. - HRE POND SITE
OAK RIDGE NATIONAL LABORATORY
OAK RIDGE, TENNESSEE

FIGURE 1-1
SITE DEMONSTRATION SYSTEM
LAYOUT AT _HRE POND

las Tetra Tech EM Inc.

SOURCE: MODIFIED FROM EPA QAPP_ 1908.





APPENDIX
SUMMARY OF ANALYTICAL DATA FROM THE
DEMONSTRATION OF THE FREEZE BARRIER TECHNOLOGY:
JANUARY 1998 - JULY 1998

(15 Pages)


98661 SOG -eounos

- 3/28/98

3/1/97
3/15/97
3/29/97
AN2/97
4/26/97
5/10/97
5/24/97

6/7197
6/21/97

US/91
TN9IST 4

8/2/97
8/16/97
8/30/97
9/13/97
9/27/97

10/11/97 4
10/25/97
11/8/97
11/22/97
12/6/97

12/20/97 4

1/3/98
1/17/98
1/31/98
2/14/98

21/8 §

3/14/98

4/11/98
4/25/98
5/9/98
5/23/98
6/6/98
6/20/98
114/98
7118/98

8/1/98 &

0@

Precipitation
ia

Lo

(mm)

f OOT

f OZT

Ort

8661 Aine YSnozy) L661 HABA
woay BEG UONEpIdIe1g eSpPRI HO

LTT ons,



to indicate whether penetration of a barrier had occurred; therefore, the most important issue was
whether detections of dye could be differentiated from background fluorescence. The review of overall
data quality indicates that the fluorescent dye data are useful for the purpose of evaluating the

technology.

All samples collected at the demonstration site were hand-delivered from the field to the laboratory in
good condition. Chain-of-custody protocols were followed for all samples delivered to the laboratory.
Samples for analysis of dyes were analyzed or prepared within 2 weeks of sample collection, as
specified in the QAPP.

Instrument Performance Check

Instrument performance checks were performed on an as-needed basis or whenever the
spectrofluorophotometer was moved, serviced, or its components (for example, xenon lamps) were
changed or serviced. Standard and blank results were used to assess instrument performance on a day-
to-day basis. No anomalous results were documented during the daily analyses of the standards and
blanks.

Initial and Continuing Calibrations

All calibration curves were linear with regression coefficients typically near 0.999. Calibration curves
were constructed and plotted when standards were prepared and after all the samples were analyzed.
For the C.I. Acid Red 92 (Phloxine B) dye, calibration data were produced for that specific batch of
dye (in water saniples), The calibration curve was plotted and included in each data package. No
calibration was performed for charcoal eluant analyses, since these data are qualitative.

Blanks

The spectrofluorophotometer is capable of consistently detecting the dyes used in this investigation at
concentrations of 0.0065 ppb. No tracers were reported in any of the laboratory planks, indicating no

39


For the SITE Program demonstration, a ground freezing system was constructed around the former
pond to determine the effectiveness of the technology in impeding groundwater flow into and out of the
former pond. The system incorporated an array of thermoprobes that were installed in oversized drill
holes, spaced about 6 feet apart, to form a 75 foot by 80 foot box-like structure around the former
pond. The thermoprobes were installed vertically to a depth of 30 feet below ground surface and
anchored in bedrock.

The thermoprobe is an innovative closed, two-phase system that can be used in both an active and
passive mode. This active-passive system, called a “hybrid thermosyphon,” is commonly used in
temperate locations where reliance on low ambient temperatures (the passive mode application) is not
feasible. The hybrid thermosyphon system consists of multiple thermoprobes, an active powered
refrigeration unit, a two-phase active/passive refrigerant, a piping system, and a control system. Once
installed, the thermoprobes were connected to the refrigeration unit, where the working fluid was
circulated within the closed system to remove heat from the thermoprobe. For the demonstration,
R-744 (carbon dioxide) was used as the passive refrigerant and R-404A (carbon dioxide) was used as
the active refrigerant in the system. To monitor progress of the freeze barrier wall, a series of
subsurface temperature monitoring points were installed at strategic locations.

The primary objective of the SITE demonstration was as follows:

. Determine the effectiveness of the freeze barrier wall in preventing horizontal groundwater
flow beyond the limits of the frozen soil barrier through the performance of a groundwater
tracing investigation using a fluorescent dye

The secondary objectives of the demonstration were as follows:

. Verify whether flow pathways outside the former pond are still open after placement of the
frozen soil barrier

. Evaluate hydrogeologic isolation of the enclosed area before and after placement of the frozen
soil barrier

° Monitor development of the frozen soil barrier
° Document installation and operating parameters of the freeze barrier wall

ES-3


Analytical Results for

Eosine OJ and Phioxine B
(ppb)
Location Description Phase} Sample Type | Sample Date Eosine OJ Phioxine B
MW4 (1112) monitoring well TR GS 3/9/98 ND ND
Wags piezometer TR GS 3/9/98 ND ND
SBC stream below culvert TR Gs 3/9/98 ND ND
sScs Steel Cylinder Spring TR GS 3/9/98 ND ND
wes piezometer TM GS 3/9/98 ND ND
‘wsgs plezometer TR Gs 3/10/98 ND ND
SBC stream below culvert TR GS 3/10/98 ND ND
MW2 (1110) monitoring well T GS 3/11/98 ND ND
MW4 (1112) Monitoring well TR GS 3/11/98 ND ND.
‘ws98 piezometer TR GS 3/11/98 ND ND
SBC stream below culvert TR GS 3/11/98 ND ND
STP2 standpipe To Gs 3/11/98 4.74E-02 1.30E-03
AFIP. piezometer TR GS 3/12/98 ND 1.30E-03
MWS (1111) monitoring welt TR GS 3/12/98 ND ND
W898 piezometer TR GS 3/12/98 ND ND
Si ‘small tributary TR GS 3/12/98 ND ND
S2 ‘small tributary TR GS 3/12/98 ND ND
s7 small tributary TR GS 3/12/98 ND ND.
SBC stream below culvert T GS 3/12/98 ND ND
STP10 standpipe T Gs 3/12/98 ND 3.07E-02
STP2 standpipe TR GS 3/12/98 1.82E-01 1.30E-03
STP9 standpipe TR GS 3/12/98 2.64E-02 1.30E-03
STSS Trivelpiece Spring TR GS 3/12/98 ND ND
MW2 (1110) monitoring well TR GS 3/13/98 ND ND
MW4 (1112) monitoring well TR GS 3/13/98 1.30E-03 1.30E-03
W898 piezometer TR GS 3/13/98 ND ND
SBC stream below culvert TR Gs. 3/13/98 ND ND
weg piezometer TR GS 3/14/98 ND ND
SBC stream below culvert TR GS 3/14/98 ND ND
MW2 (1110) monitoring welt TR GS 3/15/98 ND ND
MW4 (1112) monitoring well TR GS 3/15/98 1,30E-03 1.30E-03
ws98 piezometer TR GS 3/15/98 ND ND
SBC stream below culvert TR GS 3/15/98 ND ND
‘W898 piezometer TR GS 3/16/98 ND ND
SBC stream below culvert TR GS 3/16/98 ND ND
MW2 (1110) monitoring well TR GS 3/17/98 ND ND
MW4 (1112) monitoring well TM GS 3/17/98 1,30E-03 1.30E-03
W898 piezometer TM GS 3/17/98 ND ND
SBC stream below culvert TR GS 3/17/98 ND ND

A8



Analytical Results for

Eosine OJ and Phioxine B
(ppb)
Location Description Phase] Sample Type Sample Date Eosine OJ Phioxine B
W898 piezometer TR Ss 6/8/98 ND ND
SBC stream below culvert TR GS 6/8/98 ND ND
TM NSC 6/9/98
MW3 (1111) monitoring well TR GS 6/10/98 ND ND
STP10 standpipe TM Gs 6/10/98 ND 1.30E-03
STP5S Standpipe TR GS 6/10/98 ND ND
STP6 standpipe TR GS 6/10/98 ND ND
STPO standpipe TR GS 6/10/98 1.90E-02 1.30E-03
MW4 (1112) monitoring well T GS 6/11/98 1.30E-03 1,30E-03
MW2 (41110) monitoring well TR GS 6/12/98 ND ND
MW4 (1112) monitoring well TR Gs 6/12/98 1.30E-03 1.30E-03
‘we98 piezometer TR GS 6/12/98 ND ND
SBC stream below culvert TR GS 6/12/98 ND ND
TR NSC 6/13/98
TR NSC 6/14/98
MW2 (1110) monitoring well To GS 6/15/98 ND ND
W898 piezometer TR GS 6/15/98 ND ND
SBC stream below culvert T GS 6/15/98 ND ND
MW4 (1112) monitoring weil TR GS 6/16/98 1,30E-03 1,30E-03
: TR NSC 6/17/98
ia NSC 6/18/98
MW2 (1110) monitoring well TR GS 6/19/98 ‘ND ND
MW4 (1112) monitoring well TR GS 6/19/98 1.30E-03 1.30E-03
ws98 piezometer TR GS 6/19/98 ND ND
SBC stream below culvert TR GS 6/19/98 ND ND
TR NSC 6/20/98
T NSC 6/21/98
Mw (1110) monitoring well TR GS 6/22/98 ND ND
‘W898 piezometer TM Gs 6/22/98 ND ND
SBC stream below culvert T GS 6/22/98 ND ND
MW4 (1112) monitoring well TM Gs 6/23/98 1.30E-03 1.30E-03
FS Frank's Spring TR GS 6/24/98 ND ND
MH manhole south of pond T GS 6/24/98 ND ND
MW3 (1111) monitoring well TR GS 6/24/98 ND ND
STP5 standpipe TR GS 6/24/98 ND ND
STP6 standpipe T GS 6/24/98 ND ND
STP8 standpipe TR GS 6/24/98 ND ND
STP9 standpipe T GS 6/24/98 1.30E-03 9.40E-03
STSS Trivelpiece Spring TR GS 6/24/98 ND ND

A-14



z8 88

Temperature
Degrees F

cosa@SRyseeseseseasagsasaeee

Figure 2-21
Subsurface Temperature Data Over Time for T-6

- = oO
3 3 3 2 =
° ir
2
—#—Top of Ground —m— 25f BGS —t— 75% BGS —x— 125 ft BGS
—*— 17.5% BGS —e— 225 BGS —+— 30%BGS eee Freeze Line

July



responsiveness to rainfall and storm events, The average depth to groundwater is about 6 to 10 feet bgs
in the site vicinity (DOE 1986; EPA 1998).

1.4.4 System Construction

Prior to system construction, an electromagnetic geophysical survey of the former pond was conducted
to identify objects that could potentially disrupt drilling and installation activities. The survey identified
three anomalies, one of which extended through the northwest portion of the former pond that was
consistent with a subsurface pipe, as shown in Figure 1-2. The two other anomalies were interpreted as
possible buried scrap metal in the northwest and southeast corners of the former pond (DOE 1996;
1998b)._AFI’s ground freezing system was constructed from May through September 1997. The system
was constructed around the top of the former pond, just southeast of the HRE building (building 7500).

A categorical exclusion was granted under the National Environmental Policy Act for construction of the
freeze barrier system, indicating that the project would not significantly affect the surrounding
environment. .

A total of 58 boreholes were drilled vertically, using solid-stem auger and air rotary drilling methods, to
a depth of about 30 feet bgs into the underlying bedrock (DOE 1998a). Fifty thermoprobes, spaced
about 6 feet apart, were installed into the boreholes with the base of each thermoprobe anchored in
bedrock. The annular space around each thermoprobe was then filled with quartz sand. AFI also
installed a piezometer, identified as AFIP on Figure 1-5, at a depth of about 7 feet bgs within the
confines of the barrier wall, just southeast of standpipe 12. Figure 1-5 shows the system configuration in
plan view and a profile view of AFI’s thermoprobe.

Eight temperature monitoring points (T-1 through T-8) were installed in the remaining eight boreholes.
using the same general procedures used to install the thermoprobes. The temperature monitoring points
were placed at strategic locations to monitor development of the frozen barrier wall (see Figure 1-5).
Temperature monitoring points were set inside protective casings to protect the instruments and allow

12


The site has 10 monitoring wells at an average depth of 30 feet bgs that were installed during
previous site characterization work. The wells are located within and downgradient of the
containment area and will be used as dye injection/sampling points for a groundwater tracing
investigation to monitor barrier wall integrity. No other potential sampling points such as
springs or nearby streams exist within the site vicinity

The site is located in a rural area, but is easily accessible to heavy equipment

The site has no on-site structures requiring demolition and does not require extensive clearing.
No utilities exist on site that require relocation or that restrict operation of heavy equipment

Electricity for the site is readily available at a cost of $0.05 per kWh

Contaminated water is located in a shallow aquifer that overlies a bedrock unit at a depth of 30
feet bgs

The aquifer is a moderately permeable silty clay mixed with fill material in the site area.
Locally, groundwater is found at an average depth of 10 feet bgs

Assumptions regarding system design and operating parameters for Case 2 include the following:

The thermoprobes, using carbon dioxide as the two-phase working fluid, will be installed
vertically to a depth of about 30 feet bgs and anchored in the underlying bedrock

A series of eight temperature monitoring points will be placed within and outside the barrier
wall so AFI can assess whether the system is operating as expected and to make adjustments to
the system, if required

Four 30-horsepower refrigeration units operating in cycles, similar to the units used for Case 1,
will be required for system operation

AFI will provide a representative as an on-site consultant for key phases of the construction

Downtime for routine maintenance is assumed to be minimal and is not considered in this
estimate. AFI has also indicated that downtime for maintenance would not affect system.
performance because ice thaws slowly

After construction, the ground freezing system operates without the constant attention of an
operator. Routine labor requirements consist of monthly sampling and inspection of the
thermoprobes, temperature monitoring points, refrigeration units and associated piping, and the
surface seal

This estimate assumes that the freeze barrier wall will be effective in containing groundwater
contamination and therefore, effluent treatment and disposal costs will not be incurred

83


thodamine WT was detected at times ranging between 39 and 50 days following dye injection (EPA
1996). Figure 1-6 shows the locations where rhodamine WT was recovered. Table 1-1 presents
elapsed time data for rhodamine WT at each recovery point and the initial concentration.

Eosine OJ tracer was detected at times ranging from 15 to 22 days following dye injection at recovery
points MW2 (1110), MW3 (1111), and MW4 (1112). Thirty-nine to 50 days following dye injection,
transport of eosine OJ was also evident at recovery points STP2, STP9, STP10, SBC, W898, and
W674. At recovery points S3, $5, and DLD, eosine OJ arrived at times ranging from 50 to 56 days
following dye injection (EPA 1996). Figure 1-6 shows the locations where eosine OJ was recovered.
Table 1-2 presents elapsed time data for eosine OJ at each recovery point and the initial concentration.
Days to peak concentration and the peak concentration value also are provided. The eosine OJ results
suggested that a preferential pathway may exist on the north side of the former pond because eosine OJ
was detected in water samples collected from the small tributary sooner then the recovery points closest
to the eosine OJ injection point, MW1 (1109).. The eosine OJ bypassed on-site monitoring wells,
standpipes, and piezometers and discharged directly into the tributary within 2 to 4 days following
injection. The 1996 groundwater tracing investigation also showed that groundwater transport out of
the former pond occurs in a radially distributed pattern and that the pond is hydraulically connected to
the surrounding soils.

DOE Helium Gas Tracing Investigations

Following EPA’s groundwater tracing investigation, DOE conducted two independent gas tracing
investigations using helium in the summer of 1996 and winter of 1997. The results of DOE’s
investigations confirmed that transport out of the former pond occurs in a radially distributed pattern.
DOE also reported that transport out of the former pond occurs under ambient conditions and not just
under forced-gradient conditions (water injection) as was the case with the groundwater tracing

19


820

819

814

813

812

Figure 2-14
Hydrograph for Standpipe [2

TM

—— Recorded by data logger
© Manual water level

T t T a
Jan-97 Mar-97 = May-97 Jul-97 Sep-97 Nov-97 Jan-98
Time

Source: DOE 1998b

Mar-98

May-98

t
Jul-98



September 1997 and the frozen soil barrier reachea its design thickness of 12 feet about 18 weeks
following system startup.

1.4.5 SITE Demonstration Objectives

SPA established primary and secondary objectives for the SITE demonstration of ine freeze barrier
technology. The objectives were based on EPA's understanding of the freeze barrier technology, SITE
demonstration program goals, and input from AFI. The objectives were selected to provide overlapping
evaluation capacity and to provide potential users of the freeze barrier technology with technical
information to determine if the technology is applicable to other contaminated sites. The SITE
demonstration was designed to address one primary objective and four secondary objectives for
evaluation of the freeze barrier technology.

Primary Objective
The following was the primary (P) objective of the technology demonstration:

* Pi - Determine the effectiveness of the freeze barrier technology in preventing horizontal
groundwater flow beyond the limits of the frozen soil barrier through the performance of a
groundwater tracing investigation using a fluorescent dye

The primary objective was established to evaluate the frozen soil barrier’s ability to control
hydrogeologic conditions in the former pond. The barrier wall was evaluated through the performance
of a groundwater tracing investigation that included injecting a fluorescent dye into standpipe I2, located
in the center of the former pond, and monitoring for the dye at groundwater and surface water recovery
points located within and outside the former pond.

Secondary Objectives
The following were the secondary (S) objectives of the demonstration:

© §1 - Verify whether flow pathways outside the former pond were still open after placement of the
freeze barrier wall

© §2- Evaluate the hydrogeologic isolation of the enclosed former pond area before and after
placement of the freeze barrier wall

15


ater Ci

Water level data collected from monitoring locations 12, STP10, and MW2 (1110) compared to
precipitation data presented in Figure 2-17 indicates that all three monitoring points were responsive to
storm events prior to establishment of the frozen soil barrier. The data also show that all three
monitoring locations exhibited similar water level fluctuations during storm events. The rapid rise in
groundwater elevations at standpipe 12 during some storm events also suggests that the water table may
intersect the gravel layer beneath the asphalt cap, thereby providing a pathway for migration of
contaminants out of the former pond through this high permeable layer. This Telationship can be seen
in the hydrograph for standpipe 12, where the elevation from the top of the asphalt cap at standpipe 12
is 818.5 feet above MSL and the groundwater elevation at standpipe I2 frequently exceeded 817 feet
above MSL during storm events. The cap is assumed to be 1 foot thick (OE 1998b). Groundwater
elevation data also show a hydraulic gradient in the direction of the tributary, located just east of the
former pond, indicating that there is potential for contaminants to be transported through the shallow
groundwater system, eventually discharging into the tributary.

The 1996 groundwater tracing investigation conducted »y EPA, discussed in more detail in Section
1.4.6, also shows that groundwater within the former pond is hydraulically active and connected to the
surrounding soils, as evidenced by the transport of tracers from within the pond to areas outside the
pond. The dye eosine OJ, injected into center standpipe I2 under forced-gradient conditions during
water injection, was transported radially throughout the area surrounding the former pond. The
thodamine WT dye injected into monitoring well MW1 (1109) showed that a preferential pathway may
exist on the north side of the former pond between monitoring well MW1 (1109) and the tributary
located just east of the pond. Rhodamine WT was transported directly to the tributary and bypassed on
site recovery points directly in line with the tributary. DOE’s study using helium gas demonstrated that
transport out of the former pond also occurs under ambient conditions and is more frequent during the
winter months when water levels are highest (DOE 1998b).

47


. The freeze barrier technology is not expected to generate residual wastes. Soil from drilling
activities will require management as a hazardous waste

° Periodic maintenance of system Components will be required for worn parts and refrigerant
leaks associated with the refrigeration units and piping

° All system materials, including the thermoprobes, will be fabricated at AFI’s location in
Anchorage, Alaska and transported to the site

e The number of samples to be collected for barrier Performance monitoring is not expected to be
as high as for Case 1, due to a decrease in the-number of potential recovery points. For the
background study, an estimated 120 samples will be collected from the 10 on-site monitoring
wells. An estimated 600 samples per year will be collected during the groundwater tracing
investigation over a 10-year period. Additional groundwater samples may be also required to
monitor for the contaminants of concern in groundwater outside the containment area, but were
not included in this estimate. Number of samples are based on information collected during the
freeze barrier technology demonstration and may vary considerably from this estimate

. Labor costs for all 12 cost categories are presented as 1998 dollars (Means 1998)

e Salvage values on equipment were considered negligible after 10 years of operation and were
therefore not included in this estimate

4.3, COST CATEGORIES

Table 4-1 presents cost breakdowns for each of the 12 cost categories for the freeze barrier containment
technology. Data have been presented for the following cost categories: (1) site preparation,

(2) permitting and regulatory, (3) mobilization and startup, (4) capital equipment, (5) labor,

(6) supplies, (7) utilities, (8) effluent treatment and disposal, (9) residual waste shipping and handling,
(10) analytical services, (11) equipment maintenance, and (12) site demobilization. Each of the 12 cost
categories are discussed in the following sections.

4.3.1 Site Preparation

Site preparation costs include those for administration, engineering design, and preparation of the

installation area, which includes costs associated with installing the thermoprobes and subsurface

temperature monitoring points and sealing the surface of the containment area. Administrative costs

include those for legal searches, contracting, and general project planning activities. Administrative

costs for Case 1 were $10,000, or about 100 hours of technical staff labor at a rate of $50 per hour and
84


Analytical Results for

Eosine.OJ and Phioxine B
(ppb)

Location Description Phase| Sample Type Sample Date Eosine OJ Phioxine B
MW2 (1110) monitoring welt T GS 2/25/98 ND ND
MWS3 (1141) monitoring well TR GS 2/25/98 ND ND
MW4 (1112) monitoring well TR GS 2/25/98 1,30E-03 1.30E-03

Si ‘small tributary TR GS 2/25/98 ND ND
$2 ‘small tributary TR GS 2/25/98 ND ND
s7 small tributary TR GS 2/25/98 ND ND
SBC stream below culvert To GS 2/25/98 ND ND
STP10 standpipe TR GS 2/25/98 ND. 1,30E-03
STP2 standpipe TM GS 2/25/98 5.20E-03 1.30E-03
STP9 standpipe TR GS 2/25/98 7.60E-03 1,30E-03
STSS Trivelpiece Spring TR GS 2/25/98 ND ND
Wass piezometer TR GS 2/25/98 ND ND
MW2 (1110) monitoring well TR GS 2/26/98 ND ND
MW4 (1112) monitoring well TR GS 2/26/98 1.30E-03 1.30E-03
SBC stream below culvert TR GS 2/26/98 ND ND
W898 piezometer TR Gs 2/26/98 ND ND
AFIP piezometer TR GS 2/27/98 ND 1.30E-03
KL Keller's Leak TM GS 2/27/98 ND ND
MW2 (1170) Monitoring well TR Gs 2/27/98 ND ND
MW3 (1111) monitoring well TR GS 2/27/98 ND ND
MW4 (1112) monitoring well TR GS 2/27/98 1.30E-03 1,30E-03
$1 ‘small tributary TR GS 2/27198 ND ND
S2 smail tributary TR GS 2/27/98 ND ND
s7 ‘smal tributary TM GS 2/27/98 ND ND
SBC stream below culvert TR GS 2/27/98 ND ND
SBC stream below culvert TR Cc 2/27/98 ND ND
Scs Steel Cylinder Spring TR GS 2/27/98 ND ND
STP10 ‘standpipe TR GS. 2/27/98 ND 1.30E-03
STP9 standpipe TR GS 2/27/98 1.30E-03 1.30E-03
STSS Trivelpiece Spring To GS 2/27/98 ND ND
‘ws98 plezometer TR GS 2/27/98 ND ND
MW2 (1110) monitoring well T GS 2/28/98 ND ND
MW4 (1112) monitoring well TR GS 2/28/98 1.30E-03 1,30E-03
scs Steel Cylinder Spring” TR GS 2/28/98 ND. ND
‘we98 piezometer T GS 2/28/98 ND ND.
MW2 (1110) monitoring well T GS 3/1/98 ND ND
MW4 (1112) monitoring well TR GS 3/1/98 1.30E-03 1,30E-03
scs Steel Cylinder Spring TR GS 3/1/98 ND ND
W898 piezometer TM GS 3/1/98 ND ND

AS



In addition to samples collected for dye tracer analyses, water level data were supposed to be collected
from standpipe 12 located in the center of the former pond, monitoring well MW1 (1109) located
upgradient of the pond, and monitoring well MW2 (1110) located downgradient of the former pond, as
specified in the QAPP. Due to complications with DOE’s data logging equipment, however, pre-
barrier water level data from upgradient well MW1 (1109) were not available; therefore, water level
data from upgradient standpipe STP10 located directly adjacent to MW1 (1109) were used. Water
level data were collected by DOE personnel using either a manual water level indicator or a field data
logger in combination with a series of pressure transducers positioned belcw the water in each well or
standpipe, as specified in the QAPP (EPA 1998).

Continuous subsurface temperature data were collected from a series of temperature monitoring points
positioned at strategic locations to track the development of the barrier wall. AFI installed these points
for operational monitoring purposes and, as such, set up the dataloggers and frequency of monitoring to
best suit their objectives. Of particular interest to the SITE Program was the array installed near the
southeast corner of the barrier (T-3 through T-8), which provided information on development of the
barrier wall. Development of the freeze barrier wall is discussed further in Section 2.1.2.

1.5 KEY CONTACTS

Additional information on the freeze barrier technology, AFI, the SITE Program, and the DOE
demonstration site is available from the following sources:

The Freeze Barrier Technology

Ed Yarmak

Chief Engineer

Arctic Foundations, Inc.
5621 Arctic Boulevard
Anchorage, Alaska 99518
(907) 562-2741


3.5 TECHNOLOGY LIMITATIONS

Potential users of this technology must consider the possibility that formation of a soil barrier in arid
conditions may require a suitable method of adding and retaining moisture in soils to achieve saturated
conditions. AFI claims, however, that it is rarely necessary to add moisture to soils because the in situ
moisture will migrate and concentrate in the frozen soil and create an impervious wall. The

effectiveness of this technology for containment of contaminants in arid soils will require assessment.

The practicality of implementing this technology at some sites may be limited. As for most in situ
containment systems, the need for intrusive construction activities requires a significant amount of open
surface space, possibly precluding the use of this technology at certain sites. AFI claims, however, that
the open surface area required to construct a frozen soil barrier is significantly less than any other
barrier technology.

3.6 POTENTIAL REGULATORY REQUIREMENTS

This section discusses regulatory requirements pertinent to using the freeze barrier technology at
Superfund, Resource Conservation and Recovery (RCRA) corrective action, and other cleanup sites.
The regulations pertaining to applications of this technology depend on site-specific conditions;
therefore, this section presents a general overview of the types of federal regulations that may apply
under various conditions. State and local requirements also should be considered. Because these
requirements vary, they are not presented in detail in this section. Table 3-1 summarizes the
environmental laws and associated regulations discussed in this section.

3.6.1 Comprehensive Environmental Response, Compensation, and Liability Act

The Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), as
amended by SARA, authorizes the federal government to respond to releases of hazardous substances,
pollutants, or contaminants that may present an imminent and substantial danger to public health or
welfare. CERCLA pertains to the freeze barrier system by governing the selection and application of
remedial technologies at Superfund sites. Remedial alternatives that significantly reduce the volume,
toxicity, or mobility of hazardoiis substances and provide long-term protection are preferred. Selected

67


AFI

bgs

CAA
CERCLA
CFR

Cs

DOE
EPA

HVAC
ITER
kWh
MCL
MCLG
Means
ng/kg
Mrad/hour
MSE
MSL
NPDES

NRC

O&M
ORD

Acronyms, Abbreviations and Symbols

Applicable or relevant and appropriate requirement
Atomic Energy Act

Arctic Foundations, Inc.

Below ground surface

Clean Air Act

Comprehensive Envuonmental Response, Compensation, and Liability Act
Code of Federal Regulations

Cesium

Clean Water Act

U.S. Department of Energy

U.S. Environmental Protection Agency
Homogeneous reactor experiment

Heaung, ventilation, and air conditioning
Innovative Technology Evaluation Report
Kilowatt-hour

Maximum contaminant level

Maximum contaminant level goal

R.S. Means Company, Inc.

Milligrams per kilogran

Milliradian per hour

MSE Technology Applications, Inc.

Mean sea level

National Pollutant Discharge Elimination System
Net Present Value

Nuclear Regulatory Commission

National Risk Management Research Laboratory
Operation and maintenance

U.S. PA Office of Research and Development


Foreword

The U.S. Environmental Protection Agency (EPA) is charged by Congress with protecting the Nation’s
land, air, and water resources. Under a mandate of national environmental laws, the Agency strives to
formulate and implement actions leading to a compatible balance between human activities and the
ability of natural systems to nurture life. To meet this mandate, EPA’s research program is providing
data and technical support for solving environmental problems today and building a science knowledge
base necessary'to manage our ecological resources wisely, understand how pollutants affect our health,
and prevent or reduce environmental risks in the future.

The National Risk Management Research Laboratory is the Agency’s center for investigation of
technological and management approaches for reducing risks from threats to human health and the
environment. The focus of the Laboratory’s research program is on methods for the prevention and
control of pollution to air, land, water and subsurface resources; protection of water quality in public -
water systems; remediation of contaminated sites and groundwater; and prevention and control of
indoor air pollution. The goal of this research effort is to catalyze development and implementation of
innovative, cost-effective environmental technologies; develop scientific and engineering information
needed by EPA to support regulatory and policy decisions; and provide technical support and
information transfer to ensure effective implementation of environmental regulations and strategies.

This publication has been produced as part of the Laboratory’s strategic long-term research plan. It is
published and made available by EPA’s Office of Research and Development to assist the user
community and to link researchers with their clients.

Larry Rieter, Acting Director
National Risk Management Research Laboratory

iii


investigation (DOE 1998b). Based on available information, including the geology ot the former pond
area, the construction of the former pond, and the subsequent backfilling and capping of the former
pond, it appears that multiple groundwater transport pathways from the former pond may exist. These
transport pathways include transport from the bottom of the former pond through shallow fractured
bedrock; transport through the fill material (clay and shale fragments) and gravel layer overlying the
former pond; and transport through the walls of the former pond, by abandoned influent/effluent pipes
(DOE 19982).

1.4.7 Demonstration Activities at the HRE Pond

The effectiveness of AFI’s freeze barrier technology was evaluated over an 11-month period by collecting
independent data. In general, three types of data were obtained: (1) analytical tracer data from
groundwater, surface water, and charcoal packet samples collected within and outside the freeze barrier
wall; (2) water level data from on-site monitoring wells, standpipes, and piezometers; and (3) subsurface
temperature data from eight temperature monitoring points. Data collection procedures for the
demonstration were specified in (1) the EPA-approved quality assurance project plan (QAPP) written
specifically for the freeze barrier technology demonstration, and (2) EPA’s guidance for applying dye
tracing techniques (EPA 1988c; 1998).

This SITE project incorporated the assistance and expertise of SITE Program individuals and participants
outside the normal SITE Program umbrella. These participants included DOE and DOE’s subcontractor,
AFI, Cambrian Groundwater Company, and the Tennessee Department of Environment and Conservation
(IDEC).

Demonstration Background Study

In January 1998, a demonstration background study was conducted to identify (1) detectable
concentrations of residual dyes remaining in the groundwater system from EPA’s initial groundwater
tracing investigation conducted in 1996, and (2) natural background fluorescence that might interfere
with the demonstration groundwater tracing investigation. During the demonstration background study,
groundwater, surface water, and charcoal packet samples were collected from locations within and

22


es

Figure 2-20
Subsurface Temperature Data Over Time for T-5

Degrees F

eaosaBR Ses FSRsRSABRBR

Temperature

mber

January:
February
. 4

April

June

—?—Top of Ground

—*— 17.5 ft. BGS

—#— 25fR%BGS |
—e— 22.5ft BGS

July



Refrigeration technology has been used for freezing soils on large-scale construction engineering
projects for over 100 years. Companies that employ this technology claim that barriers can be
established to depths of 1,000 feet bgs. AFI recently prepared a quote on the installation of a frozen
soil barrier to a depth of 450 feet.bgs with a length of 3.5 kilometers for groundwater control at a
mining site. However, another contractor was selected to install the frozen soil barrier. Deeper
applications of this technology have not been conducted at contaminated sites. The effectiveness of
facilitating deeper applications of this technology may require adaitional research.

3.2.2. Engineered Structures

Prior to barrier placement, geophysical measurements of the source area should be conducted to
determine soil characteristics and to determine if subsurface structures exist. Based on observations
during the SITE Program demonstration at the HRE pond site, subsurface structures may provide a
conduit for movement of groundwater outside the barrier wall. The proximity of surface structures
such as roads, foundations, and tanks also should be taken into account prior to placement of a frozen
soil barrier due to the potential for frost heave effects.

3.2.3 Diffusion Characteristics

Prior to applying the freeze barrier technology, laboratory diffusion studies should be conducted on
site-related contaminants to assess diffusion characteristics. Previous laboratory-scale diffusion studies
have shown that a frozen soil barrier with a hydraulic permeability of less than 4x10E” centimeters per
second can be formed effectively in saturated soils with a chromate concentration of 4,000 milligrams
per kilogram (mg/kg) and a trichloroethylene concentration of 6,000 mg/kg. Tests using Cs also
reportedly showed no detectable diffusion through a barrier with the same permeability; however, the
immobility of Cs may have been partially attributable to sorption onto soil grains (DOE 1995)
Laboratory diffusion studies using various contaminants of differing concentrations are required to
determine the effects, if any, on barrier wall integrity.

62


SEPA ero 540R03508
Arctic Foundations, Inc.
Freeze Barrier Technology

Innovative Technology
Evaluation Report

SUPERFUND INNOVATIVE
TECHNOLOGY EVALUATION



assemble and start up the system, which included a Pressure test to determine if there were any leaks or
blockages in the system.

The total mobilization and transportation costs for the Case 2 site were scaled up using a factor of 2.3
times the cost for the Case 1 site. This factor was determined based on the differences between the
estimated volume of barrier required for each site. The increase in barrier volume for the Case 2 site
will increase the amount of equipment (thermoprobes and refrigeration units) that will have to be
transported to the site, which increases transportation costs. Using a factor of 2.3, the total estimated
cost for mobilization and transportation of equipment to the Case 2 site are assumed to be $17,700.

The total assembly and startup costs for the Case 2 site, which was also scaled up from the Case 1
Costs, are assumed to be about $221,000. This cost assumes an average labor rate of $75 per hour for
field technicians to work an estimated 2,950 hours to assemble and start up the system. All field
technicians are assumed to be trained in hazardous waste site health and safety procedures, so health
and safety training costs are not included as a direct startup cost.

The total estimated mobilization and startup costs for Case 1 are $103,700; for Case 2, costs are
assumed to be about $238,700.

4.3.4 Capital Equipment

Capital equipment for the ground freezing system consists of thermoprobes, temperature monitoring
points, refrigeration units and associated copper piping, an instrumentation and control system, and
miscellaneous materials. For this estimate, salvage values on equipment were considered negligible
and were therefore not included in this estimate. Costs for the surface seal were previously discussed
in Section 4.3.1, Site Preparation, and are not considered capital equipment costs for this estimate.

For the Case 1 site, the 30-horsepower barrier required 50 thermoprobes at a cost of $1,500 each, for a
total cost of $75,000. Two 30-horsepower refrigeration units at a cost of $42,000 each, for a total cost
of $84,000, were used for Case 1. Other capital equipment such as copper piping, the instrumentation
and control system, eight temperature monitoring points, and miscellaneous materials were Teported as

88


Analytical Results for

Eosine OJ and Phioxine B
(ppb)
Location Description Phase] Sample Type | Sample Date Eosine OJ Phioxine B
TR NSC 4/6/98
SBC stream below culvert TR Gs 417198 ND ND
TR NSC 418/98
TR NSC 4/9/98
SBC stream below culvert TR Gs 4/10/98 ND ND
TR NSC 4/11/98
TR NSC 4/12/98
TR NSC 4/13/98
SBC stream below culvert TR GS 4114/98 ND ND
AFIP. piezometer TR Gs 4/15/98 ND 1.30E-03
OF283 Overflow 283 TR GS 4/15/98 ND ND
STP10 standpipe TR GS 4/15/98 ND 1.30E-03
TCP terra cotta pipe TR GS 4/15/98 ND ND
T NSC 4/16/98
SBC stream below culvert TR. GS 4/17/98 ND ND
TR NSC 4/18/98
TR NSC 4/19/98
TR NSC 4/20/98
SBC stream below culvert To Gs 4121198 ND ND
T NSC 4/22/98
TR NSC. 4/23/98
SBC stream below culvert TR Gs 4124198 ND ND
TM NSC 4/25/98
TR NSC 4/26/98
MW2 (1110) monitoring well TR GS 4127198 ND ND
AFIP piezometer TR GS 4/28/98 ND 7.99E-01
SBC stream below culvert TR GS 4/28/98 ND ND
STP1 standpipe TR GS 4/28/98 1,30E-03 1.30E-03
STP10 standpipe TR GS 4/28/98 ND 2.35E-01
STP2 standpipe TR GS 4128/98 ND 1.30E-03
MW4 (1112) monitoring well TR GS 4/29/98 1.30E-03 7.A0E-03
TR NSC 4/30/98
MW2 (1110) monitoring well TR Gs 5/1/98 ND ND
SBC stream below culvert TR GS 5/1/98 ND ND
‘ws98 piezometer T Gs 5/1/98 ND ND
T NSC 5/2/98
SBC stream below culvert TR GS 5/3/98 ND ND
MW2 (1110) monitoring well T GS 5/4/98 ND ND
MW4 (1112) monitoring well TR Gs 5/4/98 1.30E-03 1,30E-03

A141



Notice

‘The imrormation in this document has been tunded by the U.S. Environmental Protection Agency under
Contract No. 68-C5-0037 to Tetra Tech EM Inc. It has been subjected to the Agency's peer and
administrative reviews and has been approved for publication as.an EPA document. Mention of trade
names or.commercial products does not constitute an endorsement or recommendation for use.


a combined cost, for a total of $261,000. The total estimated costs for capital equipment for Case 1 are
$420,000.

Based on the size of the containment area for Case 2, the barrier is estimated to require 115
thermoprobes at an assumed cost of $1,500 each, for a total cost of $172,500. Four 30-horsepower
refrigeration units are estimated to be required for the initial freeze down and maintenance of the
barrier for Case 2. At a cost of $42,000 per unit, a total cost of $168,000 would be incurred for the
refrigeration units. To estimate the cost of piping, instrumentation and controls, temperature
monitoring points, and miscellaneous materials, it was necessary to scale up the reported costs from
Case 1 using a factor of 2.3. As stated in Section 4.3.3, this factor is based on the differences between
the estimated volume of barrier required for each site. Using this scale-up factor, the remaining capital
equipment required for Case 2 would cost an estimated $600,000. For Case 2, the total estimated
capital equipment costs are $940,500.

4.3.5 Labor

Once the system is functioning, it can essentially operate unattended and requires only limited
monitoring and sampling activities. System monitoring activities include (1) periodic inspection of the
system to ensure that it is operating properly, and (2) inspection of the surface seal for tears or uplifted
edges. For Case 1, these activities require about 4 hours per month by an AFI-trained person at an
estimated labor rate of $50 per hour, resulting in a monthly cost of $200. Personnel are also required
for sampling activities associated with a background study and groundwater tracing investigation using
fluorescence dyes to monitor barrier wall integrity. Groundwater and surface water sampling activities
at the Case 1 site would require an estimated 16 hours per month at a labor rate of about $35 per hour,
for a total cost of $560 per month. The total monthly labor cost would be about $760 per month, or
$9,100 per year. Over the 5-year life of the project, the total estimated labor costs would be $45,500
for Case 1.

Because the containment area for the Case 2 site is larger, an estimated 6 hours per month is assumed
to be required for monitoring the system, at a labor rate of about $50 per hour, for a monthly cost of

$300. Because there are less recovery points (ten monitoring wells) for Case 2 to conduct a

8y


1.4.2 Site Topography and Geology

The site is located in Melton Valley about 2,000 feet southeast of the Copper Creek fault. The HRE
pond was excavated in clay and weathered sedimentary rock of the Conasauga Group. Figure 1-4
(cross-section line A-A’ from Figure 1-3) shows that the former pond is situated on a fairly steep slope.
The weathered sedimentary rock is underlain by bedrock units of the Conasauga Group at an elevation
about 790 feet above MSL. The two units include the Rogersville shale and the underlying Friendship
formation. The Rogersville shale consists of interbedded mudstones and calcareous and noncalcareous
siltstones. The Friendship formation is characterized by interbedded limestone and shale. Regional
strike in the area is 45 to 60 degrees east of north. Bedding dips locally from 30 to 40 degrees to the
southeast (DOE 1986; 1998b).

The thickness of the overlying soil ranges from less then 1 foot to 9 feet and includes clayey soil mixed
with shale fragments introduced by backfill material. Beneath the soil is a leached saprolitic zone that
extends down to the water table in the site vicinity. A generalized geologic cross-section of the HRE
pond is presented in Figure 1-4.

1.4.3 Site Hydrogeology

The hydraulic gradient in the vicinity of the HRE pond trends south to southeast toward the on-site
tributary that flows to Melton Branch. However, available information indicates that bedrock is
fractured and that fractures in part control groundwater flow in the former pond area (DOE 1998b).
Past studies at ORNL also indicate that the direction of groundwater movement is affected by the
intrinsic permeability of the strata in bedrock. The Conasauga Group is reportedly anisotropic with
respect to hydraulic conductivity. Therefore, groundwater flow is expected to occur at some acute
angle to the hydraulic gradient and strongly affected by bedding planes and joint orientations. Past
studies at other ORNL sites suggest that groundwater flow in the overlying saprolite is also controlled
in part by fractures. DOE has reported that groundwater flow may be controlled by the gravel layer
underlying the asphalt cap that covers the former pond during periods of high groundwater elevation.
The groundwater transport zones are also reportedly in hydraulic communication. Other anthropogenic
conditions may also affect groundwater flow on site. Water level data collected from on-site
standpipes, piezometers, and monitoring wells indicate that groundwater at the site exhibits significant

10


remedies must also be cost-effective, protective of human health and the environment, and must comply
with environmental regulations to protect human health and the environment during and after
remediation.

CERCLA requires identification and consideration of environmental requirements that are Applicable
or Relevant and Appropriate Requirements (ARAR) for site remediation before implementation of a
remedial technology at a Superfund site. Subject to specific conditions, EPA allows ARARs to be
waived in accordance with Section 121 of CERCLA. The conditions under which an ARAR may be
waived are (1) an activity that does not achieve compliance with an ARAR, but is part of a total
remedial action that will achieve compliance (such as a removal action), (2) an equivalent standard of
performance can be achieved without complying with an ARAR, (3) compliance with an ARAR will
result in a greater risk to health and the environment than will noncompliance, (4) compliance with an
ARAR is technically impracticable, (5) the situation involves a state ARAR that has not been applied
consistently, and (6) for fund-lead remedial actions, compliance with the ARAR will result in
expenditures that are not justifiable in terms of protecting public health or welfare, given the needs for
funds at other sites. The justification for a waiver must be clearly demonstrated (EPA 1988a). Off-site
remediations are not eligible for ARAR waivers, and all applicable substantive and administrative
requirements must be met. CERCLA requires on-site discharges to meet all substantive state and
federal ARARs, such as effluent standards. However, the freeze barrier wall is a containment
technology and does not typically result in off-site discharges.

3.6.2 Resource Conservation and Recovery Act

RCRA, as amended by the Hazardous and Solid Waste Amendments of 1984, regulates management
and disposal of municipal and industrial solid wastes. EPA and the states implement and enforce
RCRA and state regulations. Some of the RCRA Subtitle C (hazardous waste) requirements under 40
CFR parts 264 and 265 may apply at CERCLA sites because remedial actions generally involve
treatment, storage, or disposal of hazardous waste. However, RCRA requirements may be waived for
CERCLA remediation sites, providea equivalent or more stringent ARARs are followed

69


Where drilling is used as the installation technique, soil from drill cuttings at contaminated sites may
require management as a potentially hazardous or radioactive waste. For this reason, roll-off boxes or
55-gallon drums to store the soil, and sufficient space near, but outside of the construction area for
staging, should be available. During drilling activities at the HRE pond site, radiation levels in soil
cuttings were continuously monitored and were classified as Category 1 (<1 milliradian [mRad]/hour),
Category 2 (>1 mRad/hour), or Category 3 (>5 mRad/hour) to facilitate proper management of the
waste (DOE 1998a). A portable tank or tanker truck should also be available for thermoprobe
installation to temporarily store water generated during drilling activities. Where soil type and site
conditions are appropriate, thermoprobes also may be installed by pile driving methods. This method
eliminates handling drill cuttings and minimizes environmental disturbance. A building or shed also
may be necessary to house the system control module and instrumentation wiring, as well as for use by
workers during routine operation and maintenance (O&M) activities.

3.3.2 Climate Requirements

The thermoprobes used in the system design can operate in an “active” or “passive” mode and are used
in temperate locations where reliance on low ambient temperatures (the passive mode application) is not
feasible. For this reason, the system can be installed and operated in any climate. For applications in
regions with high ambient temperatures, such as Oak Ridge, proper ground insulation is required to
ensure that surficial soil (1 to 2 feet bgs) is adequately frozen.

3.3.3 Utility and Supply Requirements

The installation at Oak Ridge required water during construction for a safety shower, personnel
decontamination, and equipment washing. Temporary arrangements were made during construction to
supply a minimal quantity of water to the site. If water is unavailable, engineered controls must be
made to minimize water requirements and temporary facilities arranged to deliver, store, and pump
water during construction of the system.

Electricity is required to power the refrigeration units, instrumentation, and control system that
regulates the temperature of the thermoprobes. Electrical power for the ground freezing system can be
provided by portable generators or any standard electrical service. Based on information collected

64




Figure 2-6
Concentrations of Phloxine B Versus Time

8.00B-02 for Location STP9
7.00E-02
é 6.00E-02
= 5.00B-02
_ 4,00E-02
j 3.00E-02
2.00E-02
1.00E-02 o
0.00B+00 / : —_*. 44,
-25 0 25 50 75 100 125 150
Days Relative to Dye Injection at Zero
Figure 2-7
Concentrations of Phloxine B Versus Time
for Location MW4 (1112)
3.00E-02
é 2.00E-02
--}
i 1.00E-02 +
od
0.00E+00 {900006 Gam eee 00-40 00-000-00000-000000¢ |
25 0 25 50 75 100 125 150

Days Relative to Dye Injection at Zero

34


TABLE 41
ESTIMATED COSTS ASSOCIATED WITH THE FREEZE BARRIER TECHNOLOGY

Cost Category Case 1 Case 2
Barrier Volume 134,000 fe 300,000 fe
Isolated Volume 180,000 fe $vte* 900,000 fe $/fe*
Fixed Costs
Site Preparation Costs
Administrative $10,000 $0.06 $10,000 $0.01
System design 150,000 0.83 75,000 0.08
Drilling/placement 127,500 0.71 270,400 0.30
Soil disposal 3,900 0.02 8,000 0.009
Surface seal 94,500 0.53 275,000 0.31
Total Site Preparation Costs $385,900 $2.15 $638,400 $0.71
Total Permitting and Regulatory Costs $0 $0 $0 $0
Mobilization and Startup Costs
Mobilize and transport equipment $7,700 $0.04 $17,700 $0.02
System installation and startup 96,000 0.53 221,000 0.25
Total Mobilization and Startup Costs $103,700 $0.58 $238,700 $0.27
Capital Equipment Costs
Thermoprobes $75,000 $0.42 $172,500 $0.19
Refrigeration units 84,000 0.47 168,000 0.19
Piping, instrumentation, control system, 261,000 1.45 600,000 0.67
temperature monitoring point materials, and
Total Capital Equipment Costs $420,000 $2.33 $940,500 $1.05
Utility Costs
Initial freeze down $3,600 $0.02 $8,300 $0.009
Total Utility Costs $3,600 $0.02 $8,300 $0.009
Total Effluent Treatment and Disposal Costs $0 $0 $0 $0

76



Temperature

Degrees F

BRERBRBRSHSRER

coos ase

Figure 2-22
Subsurface Temperature Data Over Time for T-7

. ry e = > o 2
BP fF ¢€ € F F § EF EF '§ 3
3 é 3 i 8 £
=z
—+¢— Top of Ground —m 25f BGS —*— 7.5 ft. BGS —*— 12.5 ft BGS

—*— 17.5 ft. BGS —@— 22.5 ft BGS —t+— 309% BGS —------' Freeze Line



¢ $3 - Monitor development of the freeze barrier wall

© $4 - Document installation and operating parameters of the freeze barrier wall

Secondary objective $1 was evaluated through the performance of a second groundwater tracing
investigation that included adding a second fluorescent dye to upgradient monitoring well MW1 (1109)
and monitoring for its presence at groundwater and surface water recovery points within and outside the
barrier wall. Objective $2 was evaluated through a comparison of water level data obtained from
standpipe 12 and monitoring wells MW1 (1109) and MW2 (1110). Objective $3 was evaluated by
collecting subsurface temperature data from a series of temperature monitoring points located within and
outside the barrier wall in the southeast corner of the containment area. Objective $4 was established to
provide data for estimating costs associated with use of the freeze barrier technology, and was based on
observations made during the demonstration, demonstration data, and data provided by AFI.

1.4.6 Predemonstration Activities at the HRE Pond

Predemonstration activities at the HRE pond site, which included a groundwater tracing investigation
conducted by EPA in 1996 and two helium gas tracer studies conducted by DOE in 1996 and 1997, are
discussed below.

EPA conducted a groundwater tracing investigation at the HRE pond site between June 6 and August
16, 1996. The investigation was conducted to validate (1) the suitability of the two injection points
(monitoring well MW1 [1109] and standpipe 12) proposed for use during the demonstration groundwater
tracing investigation; (2) the functionality of the dyes prior to establishment of the barrier wall;.and @)
to identify viable groundwater and surface water sampling locations for the demonstration groundwater
tracing investigation. The investigation was also used as a baseline for comparing dye transport patterns
to those observed during the demonstration groundwater tracing investigation after the barrier wall was
in place.

16


water samples from potential dye recovery points. The potential dye recovery points were located
downgradient and cross gradient from the two dye injection points (standpipe I2 and monitoring well
MW1 [1109}). Charcoal packets were suspended in water at each recovery point using nylon cord and
an anchor, so as to expose them to as much water as possible. Grab samples of water were collected
using one of three techniques, depending on location: (1) decontaminated bailers, (2) ISCO” automatic
water samplers, or (3) by lowering a clean sample vial into the well using nylon fishing line. The
samples were collected in accordance with the methods required by the Freeze Barrier Technology
Demonstration QAPP (EPA 1998).

The demonstration background study was conducted over a 21-day period in January 1998 after the
frozen soil barrier reached its design thickness of 12 feet. A total of 22 charcoal packets and 114 grab
samples of water were collected from the recovery points over the 21-day period. The samples were
analyzed using a spectrofluorophotometer for any residual dyes from the 1996 groundwater tracing
investigation or natural background fluorescence.

The demonstration groundwater tracing phase of the demonstration was conducted over a 5-month
period after the background study was completed.. Phloxine B and eosine OJ were injected at locations
12 and MWI (1109), respectively. As before, each dye recovery point was monitored using activated
charcoal packets and by collecting and analyzing frequent grab samples of groundwater and surface
water. A total of 15 charcoal packets and 359 grab samples of water were collected from the recovery
points, using the same general sample collection procedures as described above. As stated in Section
1.4.7, charcoal packets were initially used, but later discontinued because water samples provided more
teliable fluorescence data. The frequency of sample collection at each recovery point for both phases
of the SITE demonstration are included in the appendix.

The samples were analyzed for the two dyes phloxine B and eosine OJ,-using a
spectrofluorophotometer. The laboratory method, which used a synchronous scanning
spectrofluorophotometer, enabled the evaluation of both excitation and emission spectra for the dyes.
Each sample was placed in the cuvette or sample compartment; the appropriate wavelengths were
selected; and the sample was scanned in the synchronous mode. Calculations comparing the emission
spectra for the sample to known standard emission spectra were performed to identify the source of the

28


6.0 | REFERENCES

Arctic Foundations, Inc. (AFI). 1998. “The Frozen Soil Barrier Demonstration Project.” Report
prepared for U.S. Department of Energy (DOE).

Evans, G. 1990. “Estimating Innovative Treatment Technology Costs for the SITE Program.” Journal
of Air and Waste Management Association. Volume 40, Number 7. July.

Means, R.S. Company, Inc. 1998. Environmental Restoration Assemblies Cost Book. R.S. Means
Company, Inc., Kingston, Massachusetts.

MSE Technology Applications, Inc. 1998. Facsimile Regarding Costs Associated with the Freeze
Barrier Technology. From Mike Harper, Bechtel-Jacobs, to Stan Lynn, Tetra Tech EM Inc.
(Tetra Tech). October.

Tennessee Department of Environmental Conservation. 1998. “Gross Beta Flux Sample Results
Collected From Weir Box.” November 13

DOE. 1986. “Characterization of the Homogeneous Reactor Experiment (HRE) No. 2 Impoundment.”
Environmental Sciences Division. July.

DOE. 1988. Radioactive Waste Management Order. DOE Order 5820.2A. September.

DOE. 1995. “Frozen Soil Barrier Technology Innovative Technology Summary Report.” Office of
Technology Development. April.

DOE. 1996. Internal Memorandum Regarding Electromagnetic Conductivity Survey of the HRE Pond.
From Ron Kaufmann, Environmental Sciences Division. To Mike Harper, Lockheed Martin
Energy Research Corporation. April 8.

DOE. 1998a. “HRE Pond Cryogenic Barrier Technology Demonstration: Pre-Barrier Subsurface
Hydrology and Contaminant Transport Investigation.” Environmental Sciences Division.
March.

DOE. 1998b. “HRE Pond Cryogenic Barrier Technology Demonstration: Pre- and Post-Barrier
Hydrologic Assessment.” Environmental Sciences Nivision. December.

U.S. Environmental Protection Agency (EPA). 1988a. Protocol for a Chemical Treatment
Demonstration Plan. Hazardous Waste Engineering Research Laboratory. Cincinnati, Ohio.
April.

EPA. 1988b. CERCLA Compliance with Other Environmental Laws: Interim Final. Office of Solid
Waste and Emergency Response (OSWER). EPA/540/G-89/006. August.

EPA. 1988c. Application of Dye Tracing Techniques For Determining Solute-Transport Characteristics
of Groundwater in Karst Terranes. EPA/904/6-88-001. October.

97


Figure 2-4
Concentrations of Phloxine B Versus Time

150

for Location STP1
3.00E-02
ze
2.00802 4 °
a
i 1,00E-02
0.00E+00 : ro @
25 0 25 50 75 100 125
Days Relative to Dye Injection at Zero
Figure 2-5
Concentrations of Phloxine B Versus Time
for Location STP2
3.00E-01
5 2.00801
a
j 1,00E-01
o
0.00E+00 — ¢ r T
25 i) 25 50 7S 100 125 150

Days Relative to Dye Injection at Zero

33




fluorescence and determine sample concentrations. Dilutions were made as necessary to keep sample
measurements within the range of the standards. All samples and standards were analyzed at room
temperature with all other conditions being the same for all analyses performed.

2.1.2 Results of the Demonstration Background Study

Results of analysis of samples collected during the background study indicated the presence of residual
concentrations of the dyes eosine OJ and rhodamine WT at the same recovery points where the two
dyes were detected during the 1996 groundwater tracing investigation (see Section 1.4.6). According
to the analytical laboratory, a green compound, which is a common derivative of rhodamine WT, was
identified in samples collected from recovery points STP2, STP9, DLD, KL, and MW1 (1109).
Analytical results also indicated that uranine was present in water samples collected from recovery
points 12, SBC, STP9, AFIP, MW4 (1112), S1, and $2. Uranine also was present in samples collected
from the same recovery points during the 1996 groundwater tracing investigation.

The highest concentration of fluorescence in background samples in the range of the emission spectra
for phloxine B and eosine OJ was 1.30e-03 parts per billion (ppb). This background concentration for
phloxine B and eosine OJ was used as a baseline for comparison to demonstration groundwater tracing
investigation results. Therefore, phloxine B and eosine OJ detected above the highest background
concentration was considered a detection at any recovery point.

During the demonstration background study, field personnel interviewed Mr. Marlin Ritchey, a
Lockheed Martin Energy Systems, Inc., engineer in charge of sump pumps in the basement of the HRE
building (7561), located northwest (upgradient) of the former pond. Mr. Ritchey was interviewed in an
attempt to identify a source for the uranine. Mr. Ritchey stated that he had conducted a number of dye
tracing experiments from the basement of the HRE building, using the dye uranine, during the period
between the 1996 groundwater tracing investigation and the demonstration background study. After
discovering a potential source for the uranine, it was unclear how uranine migrated from the HRE
building to standpipe 12 and piezometer AFIP located within the containment area. Available
information indicates that a number of pipes connected to the HRE building entered the former pond
from the northwest and may have been left in place after the pond closed. A report of a geophysical

29


categories, and a breakdown of these costs under the 12 cost categories is presented in Table 4-1 and
Figure 4-1.

2.1.7 Data Quality

A data quality review and assessment was conducted to remove unusable values from the investigation
data set, to evaluate the field and laboratory QC sample results, and to assess the overall data quality.
All project data specified in the project QAPP that were collected to directly support demonstration
objectives were reviewed, including those data relating to physical measurements.

The only critical measurement (measurement required to support:a primary objective) was the
fluorescent dye data concentration in groundwater and in the eluant from charcoal packet samples. A
detailed review of the analytical data for these dyes was therefore conducted. Data from field ec
samples and laboratory QC samples were reviewed to estimate the precision of the results and to
demonstrate that measurements were not affected by cross-contamination. The QC data were evaluated
against the QA objectives defined in the Freeze Barrier Technology Demonstration QAPP (EPA 1998).
Accuracy was not an issue, since only relative values were of interest. For this reason, a QA objective
and QC samples to evaluate accuracy were not required. The QC samples included laboratory blanks
and sample duplicates. Initial and continuing calibrations were also reviewed to assure that proper
procedures were implemented.

The following specific items were evaluated during the data review:

¢ Sample chain of custody, condition, and holding times
¢ Instrument performance checks

¢ Initial and continuing calibrations

¢ Blanks

* Sample/sample duplicate precision

The following subsections discuss the results of quality control activities that were implemented in
relation to the fluorescent dye measurements and summarize any limitations of the analytical data based
on the evaluation of QC sample results. It should be recognized that the fluorescent dye data was used

58


Note:

TABLE 3-1

SUMMARY OF ENVIRONMENTAL REGULATIONS

Act/Authority

Applicability

Application to the Freeze Barrier Technology

Citation

CERCLA

Superfund sites

This program authorizes and regulates the cleanup of
Teleases of hazardous substances. It applies to all
CERCLA site cleanups and requires that other
environmental laws be considered as appropriate to
protect human health and the environment.

40 CER part 300

RCRA

Superfund and RCRA

sites

RCRA regulates the transportation, treatment,
storage, and disposal of hazardous wastes. RCRA
also regulates corrective actions at treatment,
storage, and disposal facilities.

40 CFR parts 260 to 270

Discharges to surface
water bodies

NPDES requirements of the CWA apply to both
Superfund and RCRA sites where treated water is
discharged to surface water bodies. Pretreatment
standards apply to discharges to POTWs. These
Tegulations do not typically apply to containment
technologies.

40 CFR parts 122 to
125, part 403

SDWA

Water discharges,
water reinjection, and
sole-source aquifer
and wellhead
protection

Maximum contaminant levels and contaminant level
goals should be considered when setting water
‘cleanup levels at RCRA corrective action and
Superfund sites. Sole sources and protected wellhead
water sources would be subject to their respective
control programs. These regulations do not typically
apply to the freeze barrier technology unless used in
conjunction with a remediation program.

Regulations governing underground injection may
apply at sites requiring addition of soil moisture to

40 CFR parts 141 to 149

CAA

Air emissions from
stationary and mobile
sources

The technology may be used to limit migration of
contaminant plumes, and therefore may help reduce
the potential for exposure to airborne VOCs
emanating from contaminated groundwater. If VOC
emissions occur or hazardous air pollutants are of
‘concern, these standards may be ARARs for a site
cleanup. However, this technology uses benign
Tefrigerants, produces no air emissions, and does not
degrade air quality. For these reasons, the CAA will
not apply to this technology in most cases. State air
program requirements also should be considered,

40 CFR parts 50, 60,
61, and 70

AEA and RCRA

‘Mixed wastes

AEA and RCRA requirements apply to the treatment,
Storage, and disposal of mixed waste containing both
hazardous and radioactive components. OSWER and
DOE directives provide guidance for addressing
mixed waste.

AEA (10 CFR part 60)
land RCRA (see above)

OSHA

All remedial actions

OSHA regulates on-site construction activities and
the health and safety of workers at hazardous waste
sites. Personnel working on installation and
operation of the freeze barrier technology at
Superfund or RCRA cleanup sites must meet OSHA.
requirements.

29 CFR parts 1900
to 1926

NRC

All remedial actions

‘These regulations include radiation protection

standards for NRC-licensed activities.

10 CER part 20

Acronyms used in this table are defined in the “List of Acronyms and Abbreviations,” (pages x through xi).

68



outside the barrier wall over a period of 21 days, as specified in the QAPP. The samples were
analyzed for residual dyes and background fluorescence by spectrofluorophotometric analysis. The
background sampling began after the barrier wall reached its design thickness of about 12 feet.

Based on the demonstration background study results (see Section 2.1.1) two dyes, phloxine B and
eosine OJ, were selected for use during the demonstration groundwater tracing investigation. The two
dye injection points, standpipe 12 and monitoring well MW1 (1109), that were used during EPA’s 1996
groundwater tracing investigation were retained for this investigation. The purpose of injecting dye
into standpipe I2 was to evaluate the effectiveness of the barrier wall in controlling the horizontal flow
of groundwater in the containment area. The purpose of injecting dye into monitoring well MW)
(1109) was to evaluate the effect of the barrier wall on the groundwater system outside the containment
area by comparing the results to the 1996 groundwater tracing investigation data obtained prior to
establishment of the barrier wall.

On February 20, 1998, field personnel injected about 1,800 grams of eosine OJ into monitoring well
Mw! (1109) and about 450 grams of phloxine B into standpipe 2. Next, about 130 gallons of potable
water was flushed into each injection point over a 5-day period to assist in mobilizing the two dyes.
Dye was monitored by collecting groundwater and surface water samples and by sorption of dye onto
particles of activated charcoal packets suspended in the flow of water, as specified in the QAPP.
Charcoal packets were initially used, but later discontinued because water samples yielded more
reliable fluorescence data. Table 1-3 describes each recovery point and the sampling method used at

each location.

Field personnel collected samples from five additional locations identified as MH, KL, OF283, TCP,
and FS in Table 1-3. The additional locations are also identified on Figure 2-1 in Section 2.1.3. When
weather conditions warranted, the frequency of sample collection was sometimes modified to ensure
that a slug of dye did not pass recovery points undetected. QA/QC samples were also prepared and
submitted for analyses, as specified in the EPA-approved QAPP (EPA 1998). Samples were delivered
to a local laboratory for spectrofluorophotometric analysis.

23


Analytical Results for

Eosine OJ and Phioxine B
(ppb)
Location Description Phase| Sample Type| Sample Date Eosine OJ Phioxine B
AFIP. piezometer. TR GS 3/18/98 ND ND
DLD Dale's Little Dipper Spring |_TR GS 3/18/98 1.83E+01 ND
Wws898 a T GS 3/18/98 ND ND
OF283 Overflow 283 TR GS 3/18/98 ND ND
SBC stream below culvert TR GS 3/18/98 ND ND
SCS Steel Cylinder Spring | TR Gs 3/18/98 ND ND
STP10 standpipe TR Gs 3/18/98 ND ND
STP2 standpipe TR Gs 3/18/98 6.79E-02 ND
STP9 standpipe T Gs 3/18/98 1.30E-03 1.30E-03
MW2 (1110) monitoring well TR GS 3/19/98 ND ND
MW4 (1112) monitoring well TR GS 3/19/98 1,30E-03 1.30E-03
Wess "piezometer TR Gs 3/19/98 ND ND
SBC stream below culvert T Gs 3/19/98 ND ND
DOLD Dale's Little Dipper Spring |_ TR GS 3/20/98 9.10E+01 ND
W898 _. plezometer TR GS 3/20/98 ND ND -
SBC stream below culvert T GS 3/20/98 ND ND
STP1 standpipe TR GS 3/20/98 4.30E-03 1.30E-03
STP10, ‘standpipe TR Gs 3720/98 ND 1.30E-03
STP2 standpipe TR GS 3/20/98 ND 1,30E-03
STP9 standpipe TR Gs 3/20/98 4.15E-02 1.30E-03
MW2 (11410) monitoring well TR GS 3/21/98 ND. ND
MW4 (1112) monitoring well T GS 3/21/98 1,30E-03 1.30E-03
W898 plezometer TM GS 3/21/98 ND ND
SBC stream below culvert TR GS 3/21/98 ND ND
‘W898 piezometer TR GS 3/22/98 ND ND
SBC stream below culvert TR GS 3/22/98 ND ND
AFIP plezometer TR GS 3/23/98 ND 1,30E-03
DLD Dale's Little Dipper Spring | TR GS 3/23/98 4.19E+02 ND
MW2 (1110) monitoring well To GS 3/23/98 ND ND
MW4 (1112) monitoring well TR GS 3/23/98 ND» ND
‘we98 piezometer TR GS 3/23/98 ND ND
S7 small tributary _ TR GS 3/23/98 ND ND
SBC stream below culvert TR GS 3/23/98 ND ND
STP1 standpipe TR GS 3/23/98 1.30E-03 1.30E-03
STP10 standpipe T GS 3/23/98 ND 1,59E-02
STP2 standpipe TR GS 3/23/98 2.28E-02 1.30E-03
STP9 standpipe TR GS 3/23/98 2.09E-02 1,30E-03
Wws98 piezometer TR GS 3/24/98 ND ND
SBC stream below culvert TR GS 3/24/98 NO ND

Ag



QA/QC samples will be analyzed at no additional cost. This cost estimate includes only those samples
associated with a groundwater tracing investigation for system performance monitoring. Additional
groundwater samples may be also required to monitor for the contaminants of concern in groundwater
outside the containment area, resulting in additional costs. The total estirnated costs for analytical
services over the 10-year life of the project are $90,000 for Case 2. Therefore, the total analytical
costs from the background study and monthly sampling are estimated to be $91,800.

4.3.11 Equipment Maintenance

Periodic maintenance of the ground freezing system components includes repairing refrigerant leaks,
recharging tefrigerant, and replacing worn equipment. Actual costs associated with maintenance
activities for the demonstration were not provided; therefore, maintenance costs for Case 1 were
estimated to be about 3 percent of capital equipment costs (excluding labor), for a total of $12,600 per
year. Most maintenance activities associated with the refrigeration units and piping can be completed
by an HVAC technician; however, maintenance of thermoprobes requires the attention of an AFI
technician. Total routine maintenance labor is estimated to require about 4 hours per month, at an
average labor rate of $35 per hour, for an annual cost of $1,700. The total annual maintenance cost for
Case 1 is estimated to be $14,300, which corresponds to $71,500 over the 5-year life of the project.

For Case 2, the same annual estimate of 3 percent of capital costs is assumed to be required for routine
maintenance activities, excluding labor, resulting in a cost of about $28,200. The labor required for
routine maintenance of equipment for the Case 2 site was scaled up using a factor of 2.3 times the cost
for the Case 1 site. The Case 2 site will have more equipment requiring maintenance which will
increase the number of labor hours. Based on a factor of 2.3, about 9 hours of labor per month is
estimated to be required to maintain the equipment, at a labor rate of $35 per hour or $3,800 annually.
Based on these estimates, annual equipment maintenance for Case 2 would cost about $32,000, which
corresponds to $320,000 over the 10-year life of the project.


Analytical Results for

Eosine OJ and Phioxine B
(ppb)
Location Description Phase| Sample Type | Sample Date Eosine OJ Phioxine B
SBC stream below culvert BKG GS 2/1/98 ND ND
Wws98 piezometer BKG GS 2/1198 ND ND
DLD Dale's Little Dipper Spring [ BKG GS 2/2/98 1.30E-03 ND
KL Keller's Leak BKG GS 2/2/98 ND ND.
MW3 (1111) monitoring well BKG GS 2/2/98 ND ND
MWS (1111) monitoring well BKG c 2/2/98 ND ND
Si ‘small tributary BKG GS 2/2/98 ND ND
Si small tributary BKG Cc 2/2/98 ND ND
82 small tributary BKG GS 2/2/98 ND ND
$2 ‘small tributary BKG Cc 2/2/98 ND ND
s7 small tributary BKG GS 2/2/98 ND ND
s7 small tributary BKG Cc 2/2/98 ND ND
SBC stream below culvert BKG GS 2/2/98 ND ND
STP10 standpipe BKG Gs 2/2/98 ND 1.30E-03
STP10 standpipe BKG c 2/2/98 ND ND
STP2 standpipe BKG Gs 2/2/98 2.47E-02 1.30E-03
STP9 standpipe BKG GS 2/2/98 1.33E-02 1.30E-03
STP5S standpipe BKG GS 2/2/98 ND ND
STP5 standpipe BKG Cc 2/2/98 ND ND
W898 piezometer BKG Gs 2/2/98 ND ND.
MW2 (1110) monitoring well BKG GS 2/3/98 ND ND
MW4 (1112) monitoring well BKG GS 2/3/98 4.30E-03 1.30E-03
SBC stream below culvert BKG GS 2/3/98 ND ND
Wwe98 piezometer BKG GS 2/3/98 ND ND
SBC stream below culvert BKG GS 2/4/98 ND ND
‘wsg8 piezometer BKG GS 2/4/98 ND ND
SBC stream below culvert BKG Gs 2/5/98 ND ND
W898 piezometer BKG GS 2/5/98 ND ND
DLD Dale's Little Dipper Spring | BKG Gs 2/6/98 4.30E-03 ND
MW2 (1110) monitoring well BKG GS 2/6/98 ND ND
MW3 (1111) monitoring well BKG GS 2/6/98 ND ND
MW4 (1112) monitoring well BKG GS 2/6/98 1.30E-03 1.30E-03
Si ‘small tributary BKG Gs 2/6/98 ND ND
$2 ‘small tributary BKG GS 2/6/98 ND ND
S7 small tributary BKG GS 2/6/98 ND ND
SBC stream below culvert BKG GS 2/6/98 ND ND
STP10 standpipe BKG Gs 2/6/98 ND 1.30E-03
STP2 standpipe BKG GS 2/6/98 2.85E-02 1.30E-03
STP9 standpipe BKG GS 2/6/98 1.30E-03 1.30E-03



Analytical Results for

Eosine OJ and Phioxine B
(ppb)

Location Description Phase| Sample Type| Sample Date Eosine OJ Phloxine B
MW2 (1110) monitoring well TR GS 3/2/98 ND ND
MW4 (1112) monitoring well TR GS 3/2/98 1,30E-03 1.30E-03

scs Steel Cylinder Spring TR GS 3/2/98 ND ND
‘W898 plezometer TR Gs 3/2/98 ND ND
MW2 (1110) monitoring well T Gs 3/3/98 ND ND
MW4 (1112) monitoring well TR. GS 33/3/98 1.30E-03 1,30E-03
scs Steel Cylinder Spring TR Gs 3/3/98 ND ND
W898 piezometer TR Gs 3/3/98 ND ND
MW2 (1110) monitoring well TR GS 3/4/98 ND ND
MW4 (1112) monitoring well T GS 3/4/98 1.30E-03 1.30E-03
scs Steel Cylinder Spring TR GS 3/4/98 ND ND
Wws98 piezometer TR GS 3/4/98 ND ND
MW2 (1110) Tonitoring well TR GS 3/5/98 ND. ND
MW4 (1112) monitoring well TR GS 3/5/98 1.30E-03 1.30E-03
SCS Steel Cylinder Spring | TR GS 3/5/98 ND ND
‘W898 piezometer TR GS 3/5/98 ND ND
AFIP. piezometer TR GS 3/6/98 ND 1.30E-03
MW2 (1110) monitoring well TR GS 3/6/98 ND ND
Mws (1111) monitoring well TR GS 3/6/98 ND. ND
MW4 (1112) monitoring well TR GS 3/6/98 1.30E-03 1.30E-03
$1 ‘small tributary TR GS 3/6/98 ND ND
S2 ‘small tributary TR GS 3/6/98 ND ND
$7 ‘small tributary T Gs 3/6/98 ND ND
SCS Steel Cylinder Spring TR GS 3/6/98 ND ND
STP10 standpipe TR GS 3/6/98 ND 3.20E-01
STP2 standpipe TR __GS 3/6/98 3.04E-02 4.30E-03
STP9 standpipe TR GS 3/6/98 1.51E-02 1.30E-03
STSs Trivelpiece Spring TR GS 316/98 ND ND
Wws898 _piezometer TR Gs 3/6/98 ND ND
MW2 (1110) monitoring well TR GS 3/7/98 ND ND
MW4 (1112) monitoring well TR GS 3/7/98 ND ND
SCS Steel Cylinder Sprin: TR GS 3/7198 ND ND
Ws98 piezometer TR GS 3/7/98 ND ND
MW2 (1110) monitoring well TR GS 3/8/98 ND ND
MW4 (1112) monitoring well TR GS 3/8/98 ND ND
scs Steel Cylinder Spring TTM Gs 3/8/98 ND ND
‘W898 piezometer TR GS 3/8/98 ND ND
DLD Dale's Little Dipper Spring |_ TR GS 3/9/98 3.66E+02 ND
MW2 (1110) monitoring well TR GS 3/9/98 ND ND

A?



EPA/S40/R-03/508
September 2004

Arctic Foundations, Inc.
Freeze Barrier Technology

Innovative Technology Evaluation Report

National Risk Management Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268

CRY, Fie vegetable based ink on

paper that containe a minimum of
post-consumer fiber content
processed chlorine free.


and an estimated eight temperature monitoring points. A total of 123 10-inch-diameter borings would
be drilled to a depth of 30 feet bgs using the same drilling methods used for Case 1. Based on drilling
costs from the demonstration (Case 1), the total cost for drilling including mobilization, demobilization,
miscellaneous materials, and installation of thermoprobes and temperature monitoring points was
$270,400, or $73.28 per foot drilled. Auger cuttings generated from drilling activities may require
management as a hazardous waste. This cost estimate assumes that the soil will be stored on site in
55-gallon drums pending characterization, and shipped off site and disposed of as a hazardous waste.
The volume of soil estimated to be displaced and Tequiring disposal is about 54 cubic yards. The total
estimated cost for waste disposal is about $8,000, which includes a loading and transport cost of
$2,700, a hazardous waste tipping cost of $4,500, and a washout and manifesting cost of $800 (Means
1998). Actual costs for waste disposal are highly Site-specific, and may vary substantially from this
estimate, particularly if the soil requires incineration. Where site geologic conditions are appropriate,
thermoprobes and temperature monitoring points may also be installed by pile-driving methods,
eliminating the need for drilling and waste handling.

Following drilling activities for Case 1, an extruded polystyrene insulation is placed over the
containment area to ensure that surficial soil was adequately frozen. A waterproofing membrane is
then placed over the insulation to prevent rainfall infiltration. In high traffic areas, a surfacing layer
will be added for skid and wear resistance. The total cost for surface seal materials, including labor for
installation, was estimated at $94,500. Assuming the same type of surface seal is used at the Case 2
site and based on costs provided by AFI, the surface seal is estimated to cost about $275,000.
According to AFI, larger areas can be efficiently sealed using pre-manufactured sheets of surface seal
at half the cost of the spray applied system used at the HRE pond site.

The total estimated site preparation costs for Case 1 are $385,900, and for Case 2 are $638,400.
4.3.2 Permitting and Regulatory

In applications of the freeze barrier technology as part of a remediation program, permitting and
regulatory costs will vary depending on whether remediation is performed at a Superfund or RCRA

corrective action site. Superfund site remedial actions must be consistent with ARARs of

86


Figure 2-16
Hydrograph for Monitoring Well MW2 (1110)

v Recorded by date logger
Manual water level

ao [--} ao
3 3 8 8

Groundwater Elevation Feet Above MSL

g

Dec96  Feb97 Apro?  Jun‘97, «= Aug 67 Octb7  Dec-97 ——Feb-98
Time

DOE 1998b


Figure 2-2
Concentrations of Phloxine B Versus Time
for Location STP10

a

° ° ry
0.00E+00 OOO 1 T—o—-

-25 0 25 50 75 100 125 150.
Days Relative to Dye Injection at Zero

Figure 2-3
Concentrations of Phloxine B Versus Time
for Location AFIP
9.00E-01

8.00B-01 +
= 7.00B-01
# 6.00E-01
® 5.00E-01
i 4.00B-01
3.00E-01
2.008-01 °
1.00B-01
0.00E+00 , . 2 ,
25 0 25 50 5 100 «125-150
Days Relative to Dye Injection at Zero

32


Assumptions regarding site- and waste-related factors for Case 1 include the following:

. The site is a former surface impoundment known as the HRE pond at DOE’s ORNL facility in
Oak Ridge, Tennessee. The HRE pond received radioactive liquid wastes, which consisted
primarily of Cs and Sr. The site has been well-characterized in terms of hydrogeology and

type and extent of contamination

. The estimated total volume of material within the HRE pond that would require containment is
about 180,000 cubic feet

. The system would continue to be used as an interim containment measure to limit off-site

migration of wastes to a nearby tributary

. The site has a series of monitoring wells, piezometers, and standpipes installed at depths
ranging from 10 to 40 feet bgs that were used during previous site characterization work. The
wells are located within, upgradient, and downgradient of the impoundment and would
continue to be used as part of the groundwater tracing investigation to monitor barrier wall
integrity. The site also has some nearby springs and a tributary that would continue to be used
as recovery points during the investigation

. The site has existing electrical lines and an access road

. The site has no on-site structures that require demolition and did not require extensive clearing
during construction activities. No utilities were on site that required relocation or that
restricted operation of heavy equipment

. Electricity for the site is readily available at a cost of $0.05 per kWh

e Contaminated water is located in a shallow aquifer that overlies a shale bedrock unit at a depth
of about 30 feet bgs

. The aquifer is a moderately permeable clay mixed with shale fragments introduced from
backfill material after the impoundment was closed. Groundwater is found at an average depth
of 6 to 10 feet bgs.

Assumptions regarding system design and operating parameters for Case 1 include the following:

. The thermoprobes, using carbon dioxide as the two-phase working fluid, are installed vertically
to a depth of about 30 feet bgs and anchored in the underlying shale bedrock unit

. A series of eight temperature monitoring points are placed at strategic locations in the
northwest and southeast corners of the barrier wall to monitor the barrier wall

. Two 30-horsepower refrigeration units operating in cycles are required for system operation

81


refrigeration unit through a copper piping network cools and condenses the carbon dioxide vapor back
to its liquid phase. The liquid carbon dioxide flows down the inside walls of the thermoprobes,
drawing heat energy from the surrounding soil, again vaporizing the liquid, and the cycle repeats.
Thermal expansion valves at each thermoprobe modulate to allow flow of carbon dioxide from the
refrigeration unit, through the heat exchanger coil. Each expansion valve is controlled by a pressurized
bulb attached to the suction side of its respective heat exchanger coil, opening whenever the suction
side temperature is above -32 °C. There are no other moving components in the thermoprobe
structure.

Each refrigeration unit consists of two motor/compressors in parallel and two fan coils in parallel.
During the initial freeze-down, both units operated simultaneously to increase heat removal from the
soil surrounding the thermoprobes. Once the frozen soil barrier reached an average thickness of 12
feet, the units were set up to operate for alternating periods of 24 hours each, sufficient to maintain
barrier design thickness.

1.4 OVERVIEW AND OBJECTIVES OF THE SITE DEMONSTRATION

This section provides site background, site topography and geology, hydrogeology, system
construction, SITE Program demonstration objectives, and predemonstration and demonstration

activities.
1.4.1 HIRE Pond Site Background

The SITE Program demonstration of the freeze barrier technology was conducted over a 5-month
period from February to July 1998. The technology was demonstrated at DOE’s ORNL Waste Area
Grouping 9 area in Oak Ridge, Tennessee. A former unlined surface impoundment known as the HRE
pond was the specific location for the technology demonstration. When it was operational, the HRE
pond’s surface measured about 75 feet by 80 feet, with sides sloping to a bottom measuring 45 feet by
50 feet (EPA 1998). The bottom of the HRE pond was reportedly about 15 feet below ground surface
(bgs) (EPA 1998). Figure 1-2 shows the original engineering diagram for the HRE pond.


specific site cleanup. To produce useful and reliable data, demonstrations are conducted at hazardous
waste sites or under conditions that closely simulate actual waste site conditions. The program’s
rigorous quality assurance/quality control (QA/QC) procedures provide for objective and carefully
controlled testing of field-ready technologies. Innovative technologies chosen for a ‘SITE demonstration
must be pilot- or full-scale applications and must offer some advantage over existing technologies.

Implementation of the SITE Program is a significant, ongoing effort involving ORD, OSWER, various
EPA regions, and private business concerns, including technology developers and parties responsible
for site remediation. Cooperative agreements between EPA and the innovative technology developer
establish responsibilities for conducting the demonstrations and evaluating the technology. The
developer is typically responsible for demonstrating the technology at the selected site and is eapected
to pay any costs for the transport, operation, and removal of related equipment. EPA is typically
responsible for project planning, site preparation, technical assistance support, sampling and analysis,
QA/QC, report preparation, information dissemination, and transport and disposal of treated waste
materials.

1.1.2 Ducumentation of SITE Demonstration Results

The results of each SITE demonstration are reported in an ITER.’ Information presented in the ITER is
intended to assist Superfund decision-makers in evaluating specific technologies for a particular clean-
up situation. The ITER represents a critical step in the development and commercialization of a
technology. The ITER discusses the effectiveness and applicability of the technology, summarizes the
overall data quality, and analyzes costs associated with its application. The technology's effectiveness
is evaluated based on data collected during the SITE demonstration and from other case studies. The
applicability of the technology is discussed in terms of waste and site characteristics that could affect
technology performance, material handling requirements, technology limitations, and other factors for
application of the technology.


200 hours of administrative staff labor at a rate of $25 per hour (Means 1998). Based on costs from
the demonstration, the administrative costs for Case 2 were assumed to also be about $10,000.
However. administrative costs are highly site-specific and may vary significantly from this estimate.

After a site assessment, AFI assists in designing an optimal system configuration for the site. The total
system design cost for Case 1 was estimated to be $150,000. Design costs include engineering designs
for thermoprobes and temperature monitoring points, including placement and construction, site layout,
electrical power supply and piping configuration, and any other necessary engineering services.
Itemized costs for each design component were not provided; therefore this estimate assumes that 2,000
hours at an average labor rate of $75 per hour were required for system design services (Means 1998).
Based on AFI’s experience with Case 1 and similar conditions assumed for Case 2, AFI’s design costs
are expected to be minimal because the same ground freezing system configuration for Case 1 would be
applied to the Case 2 site therefore, design costs for Case 2 were assumed to be considerably less at a
cost of about $75,000.

For Case 1, 58 30-foot-deep, 10-inch-diameter borings were drilled for placement of 50 thermoprobes
and 8 temperature monitoring points using solid-stem auger and air rotary drilling methods. The total
cost for drilling including mobilization, demobilization, miscellaneous materials, and installation of
thermoprobes and temperature monitoring points was estimated to be $127,500, or $73.28 per foot
drilled. Auger cuttings were categorized and managed off site by DOE personnel and therefore, costs
for waste disposal were not incurred during the demonstration. For comparison of costs to Case 2,
however, an estimated 26 cubic yards of soil was assumed to have been removed during installation of
Thermoprobes and temperature monitoring points. For Case 1, the total estimated cost for waste
disposal is about $3,900, which includes a loading and transport cost of $1,300, a hazardous waste
tipping cost of $2,200, and a washout and manifesting cost of $400 (Means 1998). Costs for
Thermoprobes and temperature monitoring points are discussed in Section 4.3.4, Capital Equipment.

Similar types of costs associated with preparing the site were assumed to be incurred for Case 2,
although the site is much larger and overall site preparation costs would therefore increase accordingly.
This estimate assumes that the barrier will require about 115 thermoprobes, and based on information
collected from the freeze barrier technology demonstration would use a 6-foot spacing configuration

85


replacement without having to redrill. The temperature sensors used for the temperature monitoring
points are thermistors, which are reportedly stable resistance thermometers commonly used for soil
temperature monitoring. Temperature monitoring points T-1 through T-4 have eight sensors each and
are positioned to collect temperature readings at the top and bottom of the insulation material. Points
T-1 through T-4 were installed following installation of the thermoprobes and have sensors positioned to
collect temperature readings at 2.5, 7.5, 12.5, 17.5, 22.5, and 30.0 feet bgs. Temperature monitoring
points T-5 through T-8 have seven sensors each, positioned to collect temperature readings at ground
surface, 2.5, 7.5, 12.5, 17.5, 22.5, and 30.0 feet bgs.

Additional‘subsurface temperature data were collected from platinum resistance temperature detectors
(RTD) that were installed on the external surface about midway down (15 feet bgs) each thermoprobe.
The RTDs provide an indication of the operating temperature of each thermoprobe, and thus provided a
means for AFI to evaluate thermoprobe performance. AFI then wired each thermistor and RTD to a
datalogger for continuous collection of subsurface temperature data. The stored data were accessed
either remotely by modem or were downloaded with a portable computer. Subsurface temperature data
are.discussed in detail in Section 2.1.4.

Following placement of thermoprobes and temperature monitoring points, cracks and voids in the asphalt
cap were filled with an asphalt patching material. An extruded polystyrene insulation material was then
placed over the asphalt surface extending 10 feet on each side of the centerline of the thermoprobes, and
cut to fit securely around the thermoprobes and temperature monitoring points. A waterproofing
membrane was placed over the insulation to prevent infiltration of rain or surface water. Concrete
pavers were placed along the perimeter of the membrane and on other centralized locations to prevent
uplift from wind. Once the waterproof membrane cured, the two refrigeration units, an abovegrade
copper piping network, and the electrical connection were installed.

The two refrigeration units, each connected to 25 thermoprobes, were configured so that every other
thermoprobe in the array surrounding the former pond was plumbed to the same refrigeration unit.
Before the system was charged with two-phase refrigerant, the system underwent pressure testing to
ensure that there were no leaks or blockages. The ground freezing system was activated in mid-

14


1, other important cost categories included mobilization and startup (9.0 percent), equipment
maintenance (6.0 percent), analytical services (6.0 percent), labor (4.0 percent), demobilization (3.0
percent), and utilities (3.0 percent). All other cost categories (permitting, supplies, effluent treatment,
and residual shipping) accounted for less than 1 percent of the total costs. Figure 4-1 shows the
distribution of total costs for Case 1.

For Case 1, extending the use of the barrier wall at the HRE pond site over a 5-year period resulted in
total estimated fixed and total annual costs of about $1,165,400. This figure corresponds to a unit cost
of $8.30 per cubic foot of frozen soil, or $6.50 per cubic foot of isolated volume. Fixed costs
represent 82 percent and annual costs represent 18 percent of the total costs for the Case 1 estimate.

For the Case 2 estimate (see Figure 4-2), capital equipment (37.1 percent) and site preparation (25.2
percent) account for the majority of costs. . Significant costs were accrued in the following categories:
equipment maintenance (12.6 percent), mobilization and startup (9.4 percent), utilities (5.3 percent),
analytical services (3.6 percent), labor (3.4 percent), and demobilization (3.0 percent). The costs for
permitting, supplies, effluent treatment, and residual shipping accounted for less than 1 percent of the
total costs for Case 2.

The total estimated cost for applying the freeze barrier technology to the Case 2 site over a 10-year
period is approximately $2,535,700. Unit costs of $8.50 per cubic foot of frozen soil, or $2.80 per
cubic foot of isolated volume, were calculated based on this estimate.. About 75 percent of the total
costs were for fixed costs, with the remaining 25 percent associated with annual costs. The annual
costs for Case 2 are a larger fraction of the total costs than for Case 1, primarily due to the longer
duration of the barrier application for this estimate.

95




‘Figure 2-8
_Gross Beta Activity in Surface Water Samples
Collected From Weir Box

1000

x # yet & s x - e ee - e s cl *

Date

38



4.3.10 Analytical Services

Analytical services include costs for laboratory analyses, data reduction, and QA/QC. Sampling
frequencies and number of samples are highly site-specific and are based on rainfall frequency, size of
the containment area, and distance between the containment area and sampling points (nearby surface
water bodies, springs, or monitoring wells).

During the background study at the Case 1 site, about 150 samples were collected over a 25-day period
and analyzed for natural background fluorescence and dyes used during. previous investigations, at a
cost of about $15 per sample, for a total of $2,300. During the groundwater tracing investigation for
Case 1, an average of 70 samples per month was collected over a 6-month period and analyzed at a
cost of $15 per sample, for a total cost of about $6,300. Continued sampling at the same frequency as
the demonstration period for Case 1 would require an estimated 840 samples per year, for a total
analytical services cost of $12,600 annually. This estimate includes analytical services costs for
standard QA/QC samples. This cost estimate includes only those samples associated with a
groundwater tracing investigation for system performance monitoring. Additional groundwater
samples may be also required to monitor for the contaminants of concern in groundwater outside the
containment area, resulting in additional costs. The total estimated costs for analytical services uver te
5-year life of the project are $63,000 for Case 1. Thus, the total analytical costs for the background
study and monthly sampling are estimated to be $65,300.

Fewer groundwater samples are assumed for Case 2 because there are only 10 potential recovery points
(monitoring wells) and no nearby springs or streams exist on site. For the purposes of this estimate, it
is assumed that the cost for sample analysis is also $15 per sample. For the Case 2 background study,
an estimated average of 120 groundwater samples will be collected from on-site monitoring wells over
a 3- to 4-week period. The analytical services cost for the Case 2 background study is estimated to be
about $1,800.

Because there are fewer potential recovery points for the Case 2 groundwater tracing investigation, an
estimated average of 50 samples per month, or 600 samples per year, will be collected from on-site

monitoring wells, for an analytical services cost of $9,000 annually. Case 2 assumes that standard

92


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From 1958 through 1961, the HRE pond served as a retention/settling basin for low-level radioactive
liquid wastes with a radioactivity level equal to or Jess then 1,000 counts per minute (cpm). High
levels of fission products from a chemical processing system and shield water containing about 340
curies (Ci) of beta-gamma activities were generated in a reactor tank in the HRB Building (7561); an
influent line carrying these wastes reportedly entered the northwest corner of the HRE pond (DOE
1984). Contaminants from these waste streams were flocculated in the HRE pond, and treated water
from the pond was piped and discharged to a weir box located about 40 feet southeast of the pond, The
water was then released from the weir box to a small nearby tributary. A series of drainage ditches
were also located on the north, south, and west sides of the HRE pond to contain any overflow from
the waste streams (DOE 1998a; EPA 1998). In 1970, the HRE pond was (1) closed and backfilled with
off-site soil containing shale fragments, (2) combined with sodium borate, and (3) capped with 8 inches
of crushed limestone followed by an asphalt cap (EPA 1998). Figure 1-2 shows the influent and
effluent lines along with the drainage ditches, which are identified as troughs.

In 1986, DOE conducted a soil and groundwater characterization study in and around the former pond
to determine the concentrations of radiological contaminants (DOE 1986). As part of these activities,
six soil borings were advanced and a series of monitoring wells, piezometers, and standpipes were
installed (see Figure 1-3). The monitoring wells, piezometers, and standpipes were installed at depths
ranging from 10 to 40 feet bgs. The standpipes are 3-inch-diameter steel pipes with 1-inch-diameter
holes drilled along the length of the pipe. Analytical data from the-soil borings indicated that the
primary radiological contaminants detected in the former pond were cesium” (Cs) and strontiumTM (Sr).
A soil boring installed in the northwest corner of the former pond yielded the highest radiological level,
with a portion of the core reading about 100 millirems at a depth near the top of the former pond (DOE
1998a). Similar soil patterns were encountered in each borehole installed within the former pond. The
stratification of each borehole consisted of about 4 inches of asphalt at the surface, about 1 foot of
crushed limestone below the asphalt cap, followed by 13 feet of clay and shale fragments mixed with
fill material down to an elevation of 803 feet above mean sea level (MSL), which is consistent with the
bottom of the former pond (DOE 1998b). A plan view of the HRE pond showing site topography and
on-site monitoring wells, standpipes, and piezometers is shown in Figure 1-3.


4.0 | ECONOMIC ANALYSIS

This economic analysis presents two cost estimates for applying the freeze barrier technology to
prevent off-site migration of contaminants. The estimates are based on data compiled during the SITE
demonstration and from additional information obtained from AFI, DOE, current construction cost
estimating guidance, and SITE Program experience. Past studies by AFI have indicated that the costs
for this technology are highly variable, and depend on the site hydrogeology, climate, regulatory
requirements, and other site- and waste-specific factors. The following containment volumes and time

frames presented for both cases represent typical applications for the freeze barrier technology
anticipated by the vendor.

Two estimates have been performed in this analysis to determine costs for applying the freeze barrier
technology. The first estimate (Case 1) Presents a cost estimate that is based on costs incurred during
the demonstration for operating the barrier wall at the HRE pond site at ORNL extrapolated over a
5-year period. The isolated area at the HRE pond site is about 75 feet by 80 feet (6,000 square feet),
and the estimated isolated volume (to a depth of 30 feet bgs) is 180,000 cubic feet. The volume of soil
frozen is estimated to be about 134,000 cubic feet, based on the perimeter length (310 feet), an
assumed maximum frozen depth of 36 feet (estimated by AFI), and thickness of the barrier wall (12
feet).

The second estimate (Case 2) is for containment over a 10-year period for a site with conditions similar
to the HRE pond site, but a larger containment area (see Section 4.2). The cost estimate for Case 2 is
based on extrapolation of data from the HRE pond SITE demonstration costs over a 10-year period.
For Case 2, the dimensions of the isolated area are assumed to be 150 feet by 200 feet, with an
assumed aquitard depth of 30 feet bgs. The total isolated area is assumed to be 30,000 square feet,
with a volume of 900,000 cubic feet. The volume of soil frozen is about 300,000 cubic feet, based on
a perimeter of 700 feet, frozen depth of 36 feet bgs, and a thickness of 12 feet.

For sites with no aquitard, the barrier wall would be installed in a “V” or “U” configuration to
Promote complete isolation of a waste source. However, the SITE Program demonstration involved a
vertical syscem, and cost data tor other configurations were not collected. For these reasons, both

scenarios assume vertical systems.

74


Acronyms, Abbreviations and Symbols (Cont’d.)

ORNL Oak Ridge National Laboratory

OSHA Occupational Safety and Health Act

OSWER Office of Solid Waste and Emergency Response
POTW Publicly owned treatment works

ppb parts per billion

PPE Personal protective equipment

QAPP Quality assurance project plan

QA/QC Ouality assurance/quality control

RCRA Resource Conservation and Recovery Act

RTD Resistance temperature detector

SARA Superfund Amendments and Reauthorization Act
SITE Superfund Innovative Technology Evaluation

Sr Strontium

TDEC Tennessee Nepartment of Environmental Conservation
UIC Underground injection control

voc volatile organic compound


Once the design thickness was achieved, the maintenance freezing phase began and the refrigeration.
units operated on a 24-hour alternating run schedule to minimize power consumption. Maintenance
freezing required significantly less energy then the initial freezedown. According to AFI, the barrier
wall thickness remained fairly constant during this phase and will be maintained at the HRE pond site
through fiscal year 2002 for DOE. The total volume of soil frozen was estimated to be about 134,000
cubic feet and the total volume of soil contained was estimated to be about 180,000 cubic feet (AFI
1998).

In late September 1998, AFI simulated a power outage at the HRE pond site. The refrigerant feed to
the array of Thermoprobes was shut down for a period of 8 days while subsurface temperature data
were continuously collected. AFI reported that ambient air temperatures during this period averaged
between 32° C and 24° C. The barrier reportedly lost less than 2 percent of its design thickness during
this period, with the maximum loss at the top of the barrier, just beneath the insulation. However,-
subsurface temperature data collected from T-3 showed that the centerline of the barrier from the
bottom of the insulation to 30 feet bgs remained frozen throughout the 8-day testing period (AFI 1998).

2.1.6 Installation and Operating Costs

The cost to implement the freeze barrier technology at the HRE pond site was determined by assessing
the following 12 cost categories.

Site preparation

Permitting and regulatory requirements
Capital equipment

Mobilization and startup

Labor

Supplies

Utilities

Effluent treatment and disposal

. Residual waste shipping and handling
10. Analytical services

11. Equipment maintenance

12. Site demobilization

Po2NAWP YN

The actual costs associated with the implementation of the freeze barrier technology at the HRE pond
site are presented and analyzed in Section 4.0. The demonstration costs are grouped into 12 cost

37


3.3 SITE CHARACTERISTICS AND SUPPORT REQUIREMENTS

Site-specific factors can affect the application of the freeze barrier technology, and these factors should
be considered before selecting the technology for use at a specific site. Site-specitic ractors addressed
in this section are site area and preparation requirements; climate; wulities and supplies; maintenance;
support systems; and personnel requirements. The support requirements for the ground freezing
system may vary depending on the size of the containment area. This section presents support
requirements based on information collected during the SITE demnstration at ORNL.

3.3.1 Site Area ana Preparation Requirements

In auaition to the hydrogeologic conditions that determine the technology’s applicability and design,
other site characteristics affect implementation of this technology. The amount of space required for a
ground freezing system depends on the thickness of the barrier wall and size of the containment area.
For the HRE pond demonstration, the array of thermoprobes encompassed an area of about 75 feet by
80 feet, with an average frozen soil barrier wall thickness of 12 feet. Thermoprobes may be installed
ina “V” or “U” configuration to promote complete encapsulation and isolation of the waste source. At
the HRE pond site, the thermoprobes were installed in a vertical position, with the bottom of each
thermoprobe anchored in bedrock, to inhibit horizontal groundwater movement into and out of the
waste source area.

The site must be accessible and have sufficient operating and storage space for heavy construction
equipment. Access for a drill rig or pile driver to install the thermoprobes and temperature monitoring
Points for system operation is required. A crane may also be necessary to install the thermoprobes and
to subsequently remove the thermoprobes from the containment area following remediation activities.
Access for tractor trailers (for delivery of thermoprobes, refrigeration units and associated piping,
construction supplies, and equipment) is preferable. Underground utilities crossing the path of the
proposed system may require relocation if present, and overhead space should be clear of utility lines to
allow installation equipment to operate. Construction around existing surface structures may also be
required.

63


4.0 ECONOMIC ANALYSIS .. 2... ec eee eee nt ee ee 74
4.1. FACTORS AFFECTING COSTS. .......-- 20 eee eee eee eens
4.2. ASSUMPTIONS OF THE ECONOMIC ANALYSIS
43 COST CATEGORIES ..... 0... cece ete eee terete nee tees 84
4.3.1 Site Preparation ©... 6.6... eee eee ee eee ee .
4.3.2 Permitting and Regulatory . :
4.3.3. Mobilization and Startup .........--.---

4.3.4 Capital Equipment ...........--.-+06-
43.5 Labor ..: 0... cece ee bet ee

4.3.6 Supplies ..... 0.6.0.0. e cece eee
43.7 Utilities ...... 00...
4.3.8 Effluent Treatment and Disposal . . .
4.3.9 Residual Waste Shipping and Handling .

4.3.10 Analytical Services ....-...- 66... eee eee
4.3.11 Equipment Maintenance wee oe
4.3.12 Site Demobilization ©. 6.0... 66 reece te eee te wees
44 ECONOMIC ANALYSIS SUMMARY .... 6.2... eee eee eee eee eee 94
5.0 TECHNOLOGY STATUS AND IMPLEMENTATION .......--+---- beeen ee 96
6.0 REFERENCES ......... 0.0 cece cece eee tee teeta 97

Appendix

A SUMMARY OF ANALYTICAL DATA FROM THE DEMONSTRATION OF THE FREEZE
BARRIER TECHNOLOGY: JANUARY 1998 - JULY 1998

Attachment

A VENDOR’S CLAIMS FOR THE TECHNOLOGY

vii


Maintaining the freeze barrier for Case 1 requires about 300 kWh per day, or $15 per day at $0.05 per
kWh rates, for an annual cost of $5,500. However, when outdoor temperatures are below freezing and
heat load on the system is low, the entire system shuts down, thereby decreasing utility costs. The total
estimated utility costs to maintain the barrier over the, 5-year life of the project after the initial freeze
down is about $27,500 for Case 1. Therefore, the total utility costs, including the initial freeze down
and maintenance of the barrier over a 5-year period, are $31,100.

Electrical costs for Case 2 have been scaled up from Case 1, using a factor of 2.3, based on the larger
frozen soil volume required for containment. Electricity costs may vary considerably depending on the
geographic location of the site and local utility rates. As with Case 1, a utility rate of $0.05 per kWh
was assumed for this estimate. The initial freeze down is estimated to cost about $8,300 (165,600
kWh), with annual utility requirements estimated to be about 251,900 kWh at a cost of $12,600. The
total estimated utility costs to maintain the barrier over the 10-year life of the project after the initial
freeze down are about $126,000 for Case 1. Therefore, the total utility costs, including the initial
freeze down and barrier maintenance over a 10-year period, are $134,300 for Case 2.

Water is required for personnel and equipment decontamination during construction of the ground .
freezing system, but is not vital for system operation. Telephone service is required for remote
monitoring of system performance and detection of system malfunction. Water and telephone costs are
insignificant compared to electricity costs and are therefore not included in this estimate.

4.3.8 Effluent Treatment and Disposal

This estimate assumes that groundwater contamination will be effectively contained on site by the
freeze barrier wall. For this reason, effluent treatment and disposal costs will not be incurred.

4.3.9 Residual Waste Shipping and Handling
The ground freezing system generates no residual wastes. However, soil from drilling activities during
installation of the system may require handling as a hazardous waste and is discussed in Section 4.3.1,

Site Preparation.

91


3.0 | TECHNOLOGY APPLICATIONS ANALYSIS

This section discusses the following topics regarding the applicability of the freeze barrier technology:
applicable waste, factors affecting technology performance, site characteristics and support
requirements, material handling requirements, technology limitations, potential regulatory
requirements, and state and community acceptance. Information in this section is based on the results
of the site demonstration at ORNL and additional information provided by AFI and other sources.

3.1 APPLICABLE WASTE

According to AFI, the frozen soil barrier can provide subsurface containment for most biological,
chemical, and radioactive contaminants transportable in groundwater. At the HRE pond site, the SITE
Program demonstration primarily examined the technology’s ability to contain the radioactive
contaminants Cs'”” and Sr. A contaminant’s effects on barrier wall integrity should be evaluated prior
to implementing this technology at any contaminated site.

3.2 FACTORS AFFECTING TECHNOLOGY PERFORMANCE

Factors potentially affecting the performance of the freeze barrier technology include site
hydrogeologic characteristics, engineered structures, and diffusion characteristics.

3.2.1 Hydrogeologic Characteristics

The technology’s implementability is affected by the depth to and saturated thickness of the aquifer.
The technology is most effective when it can be installed to completely contain groundwater over the
entire saturated thickness of the aquifer. The base of the thermoprobes should be keyed into an
underlying aquitard to prevent groundwater from flowing beneath the barrier wall. For sites with no
underlying aquitard, the thermoprobes may be installed in a “V” or “U” configuration to promote
complete isolation of the waste source. Near-surface refrigerant piping and proper ground insulation
should be used to ensure complete isolation of the shallower portion of the aquifer.

61


environmental laws, ordinances, regulations, and statutes, including federal, state, and local standards
and criteria. Remediation at RCRA corrective action sites requires additional monitoring and

recordkeeping, which can increase the base regulatory costs.

For Case 1, a NEPA categorical exclusion was granted for the construction of the ground freezing
system. A UIP was also issued by the TDEC for injection of dyes and potable water into groundwater
conducted as part of the groundwater tracing investigations. No other regulatory permits were required
for Case 1. However, information regarding regulatory costs was not available for Case 1 and
therefore permitting and regulatory costs are not included in this estimate.

Because permitting and regulatory requirements are highly variable, the costs were not included for
Case 2.

4.3.3. Mobilization and Startup

Mobilization costs consist of mobilizing the construction equipment and transporting materials to the
site. Startup activities include installation of the piping network, refrigeration units, instrumentation,
remote system controls. and electrical power supply hookup.

For Case 1, equipment and materials were transported from Anchorage, Alaska to Knoxville,
Tennessee at an estimated cost of $5,000. Two semi-trailer trucks were necessary to haul the
equipment to the site in Oak Ridge, Tennessee at an estimated ground transportation cost of $17.00 per
mile or $2,000, for a total transportation cost of $7,000. Two workers at an estimated labor rate of
$15 per hour worked about three 8-hour days to unload the equipment from the trucks, for a total cost
of about $700. The total cost of mobilization and transportation for Case 1 was estimated to be $7,700.

The cost for connecting the piping system to the refrigeration units and thermoprobes, and installing
and making electrical connections to the temperature monitoring points, control system, and
instrumentation for Case 1, was reported by AFI to be about $96,000. This cost consisted of about
1,300 hours of labor at an estimated rate of $75 ve- *~ur for OSHA-trained field technicians to

87


condensate and heat. This technology also uses benign refrigerants and does not produce air emissions
so the technology would not be subject to CAA regulations.

3.6.6 Mixed Waste Regulations

Use of the freeze barrier technology at sites with radioactive contamination, such as the HRE pond site,
might involve containment of mixed waste. As defined by the Atomic Energy Act (AEA) and RCRA,
mixed waste contains both radioactive and hazardous waste components. Such waste is subject to the
requirements of both acts. However, when application of both AEA and RCRA regulations results in a
situation that is inconsistent with the AEA (for example, an increased likelihood of radioactive
exposure), AEA requirements supersede RCRA requirements (EPA 1988a). OSWER, in conjunction
with the NRC, has issued several directives to assist in identification, treatment, and disposal of low-
level radioactive mixed waste. Various OSWER directives include guidance on defining, identifying,
and disposing of commercial, mixed, low-level radioactive, and hazardous waste (EPA 1988b). If the
freeze barrier technology is used to contain low-level mixed waste, these directives should be
considered, especially regarding contaminated soils removed during installation. If the technology is
used to provide containment for high-level mixed waste or transuranic mixed waste during any
remediation program, internal DOE orders should be considered when developing a protective remedy
(DOE 1988). The SDWA and CWA also contain standards for maximum allowable radioactivity levels
in water supplies.

3.6.7 Occupational Safety and Health Act

OSHA regulations in 29 CFR parts 1900 through 1926 are designed to protect worker health and
safety. Both Superfund and RCRA corrective actions must meet OSHA requirements, particularly
§1910.120, Hazardous Waste Operations and Emergency Response. Part 1926, Safety and Health
Regulations for Construction, applies to any on-site construction activities. For example, drilling of
boreholes for placement of thermoprobes and temperature monitoring points during the demonstration
was required to comply with regulations in 29 CFR part 1926, subpart N. Any more stringent state or
local requirements must also be met. In addition, health and safety plans for site remediation projects


Figure 2-9
Concentrations of Eosine OJ Versus Time

4,00E-02 for Location STP1
Z 3.00602 °
&
3 2006-02
2
8 1.00E-02
0.00E+00 os +. 2%.
25 ti) 25 50 75 100 125 150
Days Relative to Dye Injection at Zero
Figure 2-10
Concentrations of Eosine OJ Versus Time
3.00E-01 for Location STP2
= >
2
& 2.00E-01 .
§ 1,00E-01
a ?* . o °
4 o °
o¢ ¢
omoevo 1#* 9% *  ¢ ¢
B75) 0 a 50 7S 100 125 150
Days Relative to Dye injection at Zero


the former pond, were designed to contain any pond overflow and prevent release into the surrounding
groundwater system. The ditches are also reportedly below the water table at an elevation of about 804
feet above MSL (DOE 1998a). The ditch locations and flow directions, based on information provided
by DOE, are shown on Figure 2-1. The drainage ditches may have provided a preferential pathway to
transport the phloxine B from STP10 to recovery points STP1, STP2, STP9, and MW4 (1112) which
were located downgradient of STP10.

As previously discussed, the dye tracing investigation conducted in 1996 demonstrated that
groundwater within the former pond is hydraulically active and connected to the surrounding soil. The
tracer dye eosine OJ injected into center standpipe 12 was transported radially throughout the
surrounding area to recovery points MW2 (1110), MW3 (1111), MW4 (1112), W674, STP10, W898,
STP2, SBC, STP9, S3, S5, and DLD. This was not the case during the demonstration investigation
using phloxine B as shown in Figure 2-1. Table 2-1 compares the results of the 1996 investigation with
the demonstration investigation from tracer dye injection point standpipe 12.

During the technology demonstration, TDEC state regulators also collected surface water samples from
the weir box located in the outfall about 40 feet southeast of the former pond, to compare radionuclide
levels during and after development of the barrier wall. Surface water sampling results from July
through September 1998 showed slightly lower levels of gross beta activity. However, sampling results
should be qualified until long-term results are made available because the samples were collected
during the dry season when gross beta activity is generally lower (TDEC 1998). See Figure 2-8 for
surface water sampling results.

Eosine OJ Results

The tracer dye transport behavior of eosine OJ, injected into monitoring well MW1 (1109), observed
during the demonstration dye tracing investigation differed from the dye tracing investigation conducted
by EPA in 1996, suggesting that the barrier wall had an effect on horizontal groundwater flow in the
former pond area. The 1996 investigation showed rhodamine WT dye tracer transport from injection
point MW1 (1109) to most of the downgradient recovery points including DLD, SBC, MW2 (1110),
MW3 (1111), MW4 (1112), STSS, STP2, STP9, STP10, W674, W898, and S3 through S7 (EPA
1996).

36


TABLE ES-1

SUPERFUND FEASIBILITY STUDY EVALUATION CRITERIA *
FOR THE FREEZE BARRIER TECHNOLOGY

Criterion

Discussion

{Overall Protection of Human
Health and the Environment

(Compliance with Applicable or
Relevant and Appropriate
(Requirements (ARAR)

(Long-Term Effectiveness and
[Permanence

|Reduction of Toxicity,
IMobility, or Volume Through
\Treatment

Short-Term Effectiveness

Implementability

The technology is expected to protect human health and the
environment by preventing the further spread of waterborne
contaminants until appropriate remediation techniques can be
applied.

Requires measures to protect workers during drilling and
installation activities.

Requires compliance with RCRA storage and disposal
regulations for hazardous waste and pertinent Atomic Energy
Act, DOE, and Nuclear Regulatory Commission requirements
for radioactive or mixed waste.

Drilling, construction, and operation of a ground freezing
system may require compliance with location-specific ARARs.
The treatment provides containment of wastes for as long as
freezing conditions are maintained or until remediation
techniques can be applied.

Periodic review of ground freezing system performance is
needed because application of this technology to hazardous
waste sites with contaminated groundwater is relatively recent.
A properly installed frozen soil barrier can isolate. a
contaminant source area without excavation, decreasing the
potential for waste mobilization.

The speed of development of the barrier wall may vary
depending on site hydrogeology, topography, soil moisture
content, soil type, and climate.

Hydrogeologic conditions should be well-defined prior to
implementing this technology. The technology is most easily
implemented at shallow depths; however, companies that
employ this technology claim that barriers can be established
to depths of 1,000 feet or more and can be used in both vadosel
and saturated zones,

The site must be accessible to standard drilling and other
heavy equipment and delivery vehicles.

The actual space requirements depend on the size of the
containment area and thickness of the barrier wall.



2.0 TECHNOLOGY EFFECTIVENESS ANALYSIS

This section addresses the effectiveness of the freeze barrier technology in preventing groundwater flow
beyond the limits of the frozen soil barrier. The effectiveness of the freeze barrier technology in
controlling the horizontal flow of groundwater through the former pond was the primary objective of
the SITE demonstration. Some characteristics of the HRE pond site, such as shallow depth to
groundwater, waste properties, and site topography and drainage appeared favorable for demonstrating
the freeze barrier technology. Prior to the demonstration, participants identified several unconfirmed
features, such as groundwater flow in fractured bedrock and subsurface features (pipes) in the former
pond area with the potential to affect dye migration. For this reason, the SITE Program demonstration
included objectives based on factors such as piezometric data ana suosurtace soil temperature data, in
addition to the tracer studies, to evaluate system performance. The analysis of the technology’s
effectiveness presented in this section is based on the results of the SITE demonstration at the HRE
pond site.

Tables summarizing the laboratory analytical data for groundwater and surface water samples collected
during the demonstration are included in the appendix. AFI's claims regarding the effectiveness of the
freeze barrier technology are presented in the attachmefit.

2.1 SITE DEMONSTRATION RESULTS

This section summarizes the methods and procedures used to collect and analyze samples for the
critical parameters during the SITE demonstration, the results of the SITE demonstration, including the
demonstration background study, the demonstration groundwater tracing investigations, water level
measurements, subsurface soil temperature, installation and operating parameters, and quality control
results.

2.1.1 Methods

Both the demonstration background study and groundwater tracing investigation employed the use of
activated charcoal packets and grab sampling techniques for the collection of groundwater and surface

27


EOSINE OJ
INJECTION POINT—|~

a = a
Orcr (1109) | W6740
F283! 1109) sTPt \
” esr ) #0
° Z Ort ~ anil
ay eogecoeeeeeeee
oe! .
ore7s
STPS
~ REFROCRRATION UNITS,
oe:
LEGEND

FORMER TOP OF POND
so FORMER POND BOTTOM
UMITS OF ASPHALT CAP

———_~~t——_ DRAINAGE DITCH CONFIGURATION

a
GROUND SURFACE Oun 7
WATER _WATER
° RECOVERY POINT 7 y a
° PHLOXINE B DETECTIONS a Y
© EOSINE OJ DETECTIONS at
e EOSINE OJ AND Sol ARCTIC FOUNDATIONS, INC. — HRE POND SITE
PHLOXINE B DETECTIONS wi OAK RIDGE NATIONAL LABORATORY
© THERMOPROBE a OAK RIDGE, —
© TEMPERATURE FIGURE
MONITORING POINTS iy ts ag_ | RECOVERY OF PHLOXINE B AND EOSINE
lod DURING DEMONSTRATION INVESTIGATION
SOURCE: EPA 1998; DOE 19984 SCALE: 1° = 30 re Tetra Tech EM Inc.

31


laboratory contamination or interferences. Each laboratory blank was Prepared in a clean, new test
tube using either distilled water or Oak Ridge tap water. Oak Ridge tap water is representative as a
blank, since it has background fluorescence but does not contain any dye. Eluant blanks were prepared
from each new batch of eluant, and rinsed in one of the containers that would be used for preparation.
If dye had been detected in a blank, the batch of eluant would have been discarded.and a new batch
prepared from new reagents; however, this was not necessary during analysis of the demonstration
samples.

Sample/Sample Duplicate Precisio

A comparison of sample and sample duplicate results indicates that most of the field duplicate results
were within the QA objective of +25 percent relative percent difference (RPD). Out of 32 sample
duplicates that were processed, only four had RPDs of greater than 25 percent. Overall, precision of
the data appeared adequate.

The reason for the higher RPD percentages in the four duplicate samples that were outside of the QA
objective is thought to be related to varying levels of flocculant and associated fluorescence of Fe(OH),
in the sample as compared to the duplicate. Variation in the amount of flocculant present between
samples and their duplicates was observed on at least one occasion due to imperfect decanting of the
supernatant.


new science to be used in the future without being hamstrung by technology that may be outdated. The
frozen soil barrier also offers the following advantages over conventional containment systems:

. Ice does not degrade or weaken over time

. The system does not create unwanted reactions and by-products in the subsurface

° It provides a means to fully contain wastes, including a bottom, without excavation
. Maintenance costs are extremely low, allowing continued use for extended periods
. The barrier uses benign refrigerants and does not have any lasting effects

Attachment-4


Analytical Results for

Eosine OJ and Phioxine B
(ppb)
Location Description Phase| Sample Type | Sample Date Eosine OJ Phioxine B
TR NSC 6/25/98
MW4 (1112) monitoring well TR Gs 6/26/98 1.30E-03 1.30E-03
‘wase __piezometer TR GS 6/26/98 ND ND
SBC. stream below culvert TR Gs 6/26/98 ND ND
TR NSC. 6/27/98
TR NSC 6/28/98
MW2 (1110) monitoring well TR Gs 6/29/98 ND ND
‘W898 piezometer TR Gs 6/29/98 ND ND
SBC stream below culvert TR GS 6/29/98 ND ND
MW4 (1112) monitoring well TR. GS 6/30/98 1.30E-03 1.30E-03
T NSC THI98
MW2.(1110) monitoring well TR Gs 712/98. ND ND
MW4 (1112) monitoring well TR GS 7/3/98 2.70E-03 1.30E-03
ws98 r T GS 713/98 ND ND
SBC stream below culvert TR GS 7/3/98 ND ND
TR NSC 7/4198.
TR NSC 7H5I98
We898 piezometer TR GS 7/6/98 ND ND
SBC stream below culvert TR GS 76/98 ND ND
MW4 (1112) monitoring well TR GS TITI98 1.30E-03 4.30E-03
TR NSC 718/98
TR NSC 7/9/98
MW4 (1112) monitoring well TR GS 7H0/98 1,30E-03 1.30E-03
TR NSC TA198
TR NSC 72/98
MW2 (1110) monitoring well TR GS 73/98 ND ND
MW4 (1112) monitoring well TR GS 7A4I98 1,30E-03 1.30E-03
Notes:
BKG = background
TR = tracer
GS = grab sample
C = charcoal
ND = none detected
ppb = parts per billion
NSC = no samples collected

A158,



EXECUTIVE SUMMARY

Arctic Foundations, Inc. (AFI), originally developed the freeze barrier technology to give load-bearing
strength to soils during excavation activities and construction of subsurface structures. The technology
of freezing soils has just recently been considered for use as a containment technology to isolate a
contaminant source area. AFI’s freeze barrier technology was demonstrated under the U.S.
Environmental Protection Agency’s (EPA) Superfund Innovative Technology Evaluation (SITE)
Program from September 1997 to July 1998 at the U.S. Department of Energy’s (DOE) Oak Ridge
National Laboratory (ORNL) in O°" Ridge. Tennessee.

The purpose of this Innovative Technology Evaluation Report (ITER) is to present information that will
assist Superfund decision-makers in evaluating the freeze barrier technology for application at a
particular hazardous waste site. The report provides an introduction to the SITE Program and the
freeze barrier technology and discusses the demonstration objectives and activities (Section 1);
evaluates the technology's effectiveness (Section 2); analyzes key factors pertaining to application of
this technology (Section 3); analyzes the costs of using the technology to impede waterborne
contaminants (Section 4); summarizes the techn~!ogy's current status (Section 5); and presents a list of
references (Section 6). Analytical data for groundwater-and surface water samples collected during the
demonstration are included in the appendix. Vendor's claims are included in the attachment.

This executive summary briefly summarizes the information discussed in the ITER and evaluates the
technology with respect to the nine criteria used in Superfund feasibility studies.

Technology Description

The use of frozen barrier technology as a hazardous waste control/containment technology typically
involves the installation of an array of freeze pipes (thermoprobes) around and often beneath a
contaminant source area in an effort to seal off a hazardous waste area, thereby preventing further
migration of contaminants. Thermoprobes are typically installed in a “V” or “U” configuration to
ensure complete encapsulation and isolation of a waste source. This type of installation is accomplished
by placing the thermoprobes within closely spaced, directional boreholes. Standard drilling techniques

ES-1


ATTACHMENT A

VENDOR’S CLAIMS FOR THE TECHNOLOGY

(Note: All information in this appendix was provided by the vendor, Arctic Foundations, Inc. [AFT].
Inclusion of any information is at the discretion of AFT, and does not necessarily constitute U.S.
Environmental Protection Agency concurrence or endorsement.)


Although this is not the exact location for the inlet pipes shown in Figure 1-2, there are no as-built
diagrams available to confirm the exact location of the pipes. Drilling activities associated with
installation of the ground freezing system revealed the highest concentration of radionuclides in auger
cuttings collected in the northwest corner of the former pond, close to where the geophysical anomaly
was identified. This high concentration is most likely associated with either a leak in the influent pipe
that extends from the HRE building to the former pond or where the pipe emptied into the pond (DOE
1998a).

Water level data collected from standpipes 12 and STP10, during water injection to mobilize the
phloxine B dye, revealed that the groundwater elevation in standpipe 12 was higher compared to that in
standpipe STP10 (DOE 1998b). The hydrograph for standpipe 12 shows a rapid water level increase
and subsequent decrease during water injection to mobilize the phloxine B dye. According to DOE,
this fluctuation was caused by groundwater mounding following water injection at standpipe 12. The
water level data collected within and outside the area surrounded by the barrier wall also showed that
the barrier wall inhibited groundwater recharge into the former pond area. . This factor along with
water injection at standpipe 12 likely created a temporary gradient reversal in the direction of STP10.
This gradient reversal may have transported the phloxine B-laden groundwater laterally through the
subsurface pipe to the area near standpipe STP10. Although the exact depth of the subsurface pipe is
unknown, the pipe is assumed to be located close to where the highest concentrations of radionuclides
were detected during installation of the freeze barrier system. The highest concentration of
radionuclides were detected in the northwest corner of the former pond at depths ranging from 10 feet
to 14 feet bgs, consistent with the water table which is found at an average depth of 6 to 10 feet bgs in
the former pond area (DOE 1998a).

Phloxine B also was detected at concentrations above background at recovery points STP1, STP2,
MW4 (1112), and STP9 between 69 and 126 days following dye injection, which was much later than
the detection at STP10. Based on the timing of the recoveries and decreased concentrations with
distance from recovery point STP10, it does not appear that phloxine B migrated directly to any other
location. Available information also indicates that recovery points STP10, STP1, STP2, STP9, and
MW4 (1112) may be located within the drainage ditches on the north and west sides of the former
pond, outside the containment area. The drainage ditches, which are located around the perimeter of

35


Abstract

Arctic Foundations, Inc. (AFI), of Anchorage, Alaska has developed a freeze barrier technology
designed to prevent the migration of contaminants in groundwater by completely isolating contaminant
source areas until appropriate remediation techniques can be applied. With this technology,
contaminants are contained in situ with frozen native soils serving as the containment medium. The
U.S, Environmental Protection Agency’s (EPA) Superfund Innovative Technology Evaluation (SITE)
Program evaluated the technology at the U.S. Department of Energy’s (DOE) Oak Ridge National
Laboratory facility in Oak Ridge, Tennessee from September 1997 to July 1998.

For the evaluation, an array of freeze pipes called “thermoprobes” were installed in a box-like
structure around a former waste collection pond. The thermoprobes were installed vertically to a depth
of 32 feet below ground surface and anchored in bedrock. The thermoprobes were connected to a
refrigeration system by a piping network. A cooled refrigerant (R404A) was circulated through the
system to remove heat from the soil. When the soil matrix next to the pipes reached 0 °C, soil
particles bonded together as the soil moisture froze. Cooling continued until an impermeable frozen
soil barrier was formed.

After the barrier wall reached its design thickness of 12 feet, the groundwater level within the former
pond dropped, indicating that the barrier wall was effective in impeding recharge into the former pond.
Further, water levels collected from within the former pond did not respond to storm events compared
to water levels collected from locations outside the containment area, indicating that the barrier wall
was effective in impeding horizontal groundwater flow through the former pond. Finally, a 1996
groundwater tracing investigation showed groundwater transport from the former pond area in a radial
pattern which was not the case during the demonstration groundwater tracing investigation.

iv




|SOURCE: MODIFIED FROM DOE 19980

ARCTIC FOUNDATIONS, INC. — HRE POND SITE
OAK RIDGE NATIONAL LABORATORY
OAK RIOGE, TENNESSEE

FIGURE 1-2
ENGINEERING DRAWING OF HRE POND
SHOWING INFLUENT AND EFFLUENT
PIPES AND DRAINAGE DITCHES

@ Tetra Tech EM inc.



2.1.5 Subsurface Soil Temperature Results

Continuous subsurface temperature data were collected from eight temperature monitoring points at
various locations and distances from the Thermoprobes to monitor the development of the frozen soil
barrier wall (see Figure 1-5). Six temperature monitoring points (T-3 through T-8) installed in the
southeast corner of the containment area were used to monitor development of the barrier wall. Each
temperature monitoring point was equipped with eight temperature sensors installed at various depths to
provide a vertical profile of temperature conditions at each location. Figures 2-18 through 2-23 plot
temperature at each sensor interval against time for temperature monitoring points T-3 through T-8 to
show a vertical profile of temperature response with distance from the barrier. Temperature data from
each sensor interval were averaged for each month to facilitate presentation of data in Figures 2-18
through 2-23.

The ground freezing system operated in three phases: initial freeze-down, freezing to design thickness,
and maintenance freezing. During the freeze-down phase, which began in mid-September 1997, the
two refrigeration units operated simultaneously, driving the 50 thermoprobes at temperatures below

0° C. Gradually, the soil temperature was reduced until the soil moisture around each thermoprobe
was frozen and began coalescing, which occurred about mid-October 1997. According to AFI, this
Process was continued until the frozen soil region around each thermoprobe reached about 3 feet in
thickness radially and completely joined at the surface of the asphalt pavement, which occurred around
the first week of November 1997 (see Figure 2-18) (AFI 1998). This process, which is referred to as
“freezing to closure,” occurred about 7 weeks following system start-up.

Following closure, AFI reported that freezing was continued until the frozen soil wall reached the
design thickness of 12 feet, which occurred in mid-January 1998, or about 18 weeks following system
startup (AFI 1998). According to AFI, the design thickness was selected based on AFI’s past
experience using the thermoprobe placement configuration similar to that applied to the HRE pond site.
As shown in Figure 2-18, subsurface temperatures at T-3 (located directly on the centerline of the
barrier) from the bottom of the insulation to 30 feet bgs remained well below 0° C, from mid-January
through mid-July 1998. According to AFI, the frozen soil barrier probably extended to a depth of
about 36 feet bgs, into the bedrock. However, this claim cannot be confirmed because the deepest
temperature sensors are set at about 30 feet bgs along the length of the temperature monitoring points.


COMPARISON OF ANALYTICAL RESULTS FROM THE 1996

TABLE 2-2

INVESTIGATION WITH THE RESULTS OF THE DEMONSTRATION DYE
TRACING INVESTIGATIONS FOR MONITORING WELL MW1 (1109)

1996 Investigation Using Rhodamine WT
Initial
Recovery Detection Initial Concentration Peak Detection Peak
Point (days) (ppb) (days)* Concentration
(ppb)

SBC 2 1.20e-05 8 3.27e-01

S7 4 1.00e-01 71 2.15e+01

S6 4 1.06e-01 15 7.86e+-00

S5 4 1.12e-01 15 5.41e+00

$3 4 2.95e-01 15 1,24e+01

S4 4 1.16e-01 15 9.09e+00
DLD 3 3.70e+01 8 8.36+01
MWz2 (1110) 15 2.83e-01 15 2.83e-01
MW3 (1111) 15 6.48e-03 7 1.76e-02
MW4 (1112) 15 8.81e-03 36 1.20e-02
STSS 22 9.606-04 28 5.50e-03
STP10 39-43 Not Determined ° 43 4.90e-02
W674 43 8.45e-02 64 2.91e-01
‘W898 43 1.78e-01 64 3.38e-01
STP2 43 1.20e-05 36 1,59e-02
STP9 50 1.20e-07 56 3.63e-02

Demonstration Investigation Using Eosine OJ
STP1 97 3.07e-02 97 3.07e-02
STP2 3 2.75e-02 25 1,82e-01
STP9 2 1,52e-02 27 4,15e-02
MW4 (1112) 137 2.70e-03 137 2.70e-03
DLD 2 1.09+03 2 1,09+03
Notes:

* number of days following tracer dye injection

ppb parts per billion

® initial concentration could not be determined due to the sampling frequency

43





Prior to the investigation, EPA initiated a background study to determine if the fluorescent dyes under
consideration for the groundwater tracing investigation already occurred at detectable concentrations in
the vicinity of the former pond. Dyes exhibiting characteristics similar to natural background
fluorescence, or commercial dyes detected in the groundwater system would not be used for the
groundwater tracing investigation. A background study was initiated on May 17, 1996, and included
collection of water and charcoal samples at 20 surface water and monitoring well recovery points in the
vicinity of the HRE pond. Figure 1-6 shows the specific groundwater and surface water recovery points
selected for the study. The background study took place over a 3-week period so that three samples
were collected from each location. After collection, the samples were analyzed for detectable
concentrations of frequently used fluorescent dyes and natural background fluorescence. The dye
uranine was detected at the following recovery points: $1,.S3, S4, S5, S6, and S7 (EPA 1996).

Two dyes, rhodamine WT and eosine OJ, were selected for use during the groundwater tracing
investigation because the dyes were not detected in samples collected during the background study. On
Tune 7, 1996, 9.01 X 10° grams of rhodamine WT dye was injected into monitoring well MW1 (1109)
located in the northwest corner of the pond, and 9.89 X 10? grams of eosine OJ dye was injected into
standpipe [2 located near the center of the asphalt cap covering the former pond (see Figure 1-6). Both
dyes were flushed into the surrounding aquifer by a slow injection of deionized water over a 5-day
period. A few days after dye injection, Oak Ridge received several inches of rain, which also helped to
mobilize the dyes (EPA 1996).

During the groundwater tracing investigation, charcoal packets and water samples were collected from
the same locations used during the background study. Rhodamine WT was detected at 16 recovery
points and eosine OJ was detected at 12 recovery points (EPA 1996). Recovery points DLD, SBC, S3,
S4, S5, S6, and S7 showed detectable concentrations of rhodamine WT tracer between 2 and 5 days
following dye injection. Transport of rhodamine WT was also evident at locations MW2 (1110), MW3
(1111), and MW4 (1112) 15 days following dye injection. Rhodamine WT was detected at recovery
point STSS 22 days after dye injection. At recovery points STP2, STP9, STP10, W898, and W674,

17


TABLE 2-1

COMPARISON OF ANALYTICAL RESULTS FROM THE
1996 INVESTIGATION WITH THE RESULTS OF THE
DEMONSTRATION DYE TRACING INVESTIGATION

FOR STANDPIPE 12
1996 Investigation Using Eosine OJ
Recovery Initial Initial Concentration Peak Detection Peak
Point Detection (ppb) (days)* Concentration
ale (opb)

MW2 (1110) 15 1.10e-02 43 6.71¢-02
MW4 (1112) 22 5.29e-03 36 2.68e+00

MW3 (1111) 22 4.046-02 43 1.32e-01
W674 39-43 Not Determined? 43 1.25e+00

STP10 39-43 Not Determined? 43 1.79e-01
W898 39-43 Not Determined” 43 4.98e+00
STP2 43 1.10e-05 64 2.03e+00

SBC 43-50 Not Determined” 50 4.19e-01

STP9 50 1.10e-05 64 2.85e-02
_S5 50-56 Not Determined” 55 5.67e+00

83 50-56 Not Determined? 55 1.65e-01
DLD 56 1,.64+01 71 4.29e+01

Demonstration Investigation Using Phloxine B

STP10 16 3.20e-01 16 3.20e-01

AFIP 69 7.99e-01 69 7.99e-01

MW4 (1112) 70 7.10e-03 70 7.10e-03
STP2 79 2.03e-02 100 2.24e-02
STP1 100 2.03e-02 100 2.03e-02

STP9 126 9.40e-03 126 9.40e-03

Notes:

* number of days following tracer dye injection

ppb parts per billion

» initial concentration could not be determined due to the sampling frequency

37



1.2 OVERVIEW AND APPLICATION OF FROZEN SOD. BARRIERS

Artificially frozen soil barriers have been used for over 100 years in the mining and construction
industries (AFI 1998). The technology has been used in a variety of settings, including dam, tunnel,
and highway construction. The process has recently been considered as a control and containment
technology in the hazardous waste remediation industry. With this type of application, contaminants
are contained in situ with native soils serving as a subsurface barrier. In theory, a frozen soil barrier is
impermeable to aqueous phase waste and can thus provide subsurface containment for a variety of sites,
including underground tanks, nuclear waste sites, groundwater plumes, burial trenches, in situ waste
treatment areas, and ponds. Each application is site-specific and must take into account a number of
factors that include, but are not limited to, waste type, topography, overall site hydrogeology, soil
moisture content, subsurface structures, soil types, and thermal conductivity.

Thermoprobes may be installed in a “V” or “U” configuration to ensure complete encapsulation and
isolation of a waste source (AFI 1998). This type of installation is accomplished by placing the
thermoprobes within closely spaced directional boreholes. Standard drilling techniques are normally
used to create boreholes that house the thermoprobes. In certain geological settings, where downward
migration of contaminants is limited by a very low permeability clay or bedrock unit, and when such a
unit occurs at a shallow depth, thermoprobes can be installed in a vertical position with the bottoms of
the pipes anchored in the unit, which acts as a basal bottom confining layer.

The arrangement of the thermoprobes to create a frozen barrier wall ultimately depends on the
topography and underground disposition of the waste material. For a freeze barrier wall to be
effective, the waste source must be completely surrounded by the frozen soil barrier, thereby
preventing groundwater movement into and out of the waste source. To limit hydraulic loading due to
direct infiltration of precipitation, the surface of the enclosed waste area is sealed. Once installed, the
thermoprobes are connected to a refrigeration system by a distributive manifold. A two-phase
refrigerant is circulated through the system to remove heat from the soil, with the heat being dissipated
to the air. When the soil matrix next to the pipes reaches 0 °C, soil particles are bonded together as
soil moisture freezes. Cooling is continued until the frozen region around each pipe begins to expana
and build outward, coalescing with frozen regions developed around other pipes until a continuous,


.

w

United States
Environmental Protection
Agency

Office of Research and Development

National Risk Management
Research Laboratory

Cincinnati, OH 45268

Official Business
Penalty for Private Use
$300

EPA/540/R-03/508
September 2004
Wwww.epa.gov

e

a=

%

Recycled/Recyclable

Printed with vagetable-based ink on
er that contains a minimum of
post-consumer fiber content
processed chlorine free

PRESORTED STANDARD
POSTAGE & FEES PAID
EPA
PERMIT No. G-35



Most RCRA regulations affecting conventional treatment technologies will not apply to the freeze
barrier technology because once installed, a properly designed and maintained system does not generate
any residual waste. However, the soil and groundwater removed from boreholes during drilling and
installation activities may be contaminated and classified as hazardous waste. Wastes defined as
hazardous under RCRA include characteristic and listed wastes. Criteria for identifying characteristic
wastes are included in 40 CFR part 261 subpart C. Listed wastes from specific and nonspuitic
industrial sources, off-specification products, spill cleanups, and other industria! sources are itemized in
40 CER part 261 subpart D. If soil and/or groundwater are classified as RCRA. hazardous waste, they
will require management, incluaing storage, transport, ana disposal, in accordance with Subtitle C of
RCRA. Active industrial facuities generating hazardous waste are required to have designated
hazardous waste storage areas, and operate usaer 90-day or 180-dav storage permits, depending on
generator status: A facility’s storage area could be used as a temporary storage area for contaminated
svounawater and/or soil generated during the installation of the treeze barrier technology. For
nonactive facilities, or those uot generating hazardous waste, a temporary sturage area shouid be
constructed on site following RCRA guidelines, and a temporary hazaraous waste generator
identification nuaber shoua be obtained i:um the regional or state oPA office. as appropriate.
Guidelines for hazardous waste storage are listed under 40 CFR parts 264 and 265.

Other applicable RCRA requirements may include (1) obtaining Uniform Hazardous Waste Manifests if
the soil and/or groundwater are transported as a RCRA hazardous waste, and (2) placing restrictions on
depositing the waste in land disposal units.

3.6.3 Clean Water Act

The Clean Water Act (CWA) governs discharge of pollutants to navigable surface water bodies or
publicly owned treatment works (POTW) by providing for the establishment of federal, state, and local
discharge standards. Because the freeze barrier technology does not normally result in discharge of
contaminated groundwater to surface water bodies or POTWs, the CWA would not typically apply to
the normal operation and use of this technology. According to AFI, however, if an open, water-cooled
condensing system is used, the effect of the heated water on the local environment must be evaluated.

70


TABLE 1-3
RECOVERY POINTS AND SAMPLING METHODS

Recovery Point Description Sampling Method
MWI (1109) | monitoring well/injection point water grab samples
MW2 (1110) monitoring well automatic water sampler/charcoal packet
MW3 (1111) monitoring well water grab samples
MW4 (1112) monitoring well automatic water sampler/charcoal packet
2 standpipe/injection point water grab samples
STP1 standpipe water grab samples
STP2 standpipe water grab samples/charcoal packet
STPS standpipe water grab samples
STP6 standpipe water grab samples
STP7 standpipe water grab samples
STP8 standpipe water grab samples
STP9 standpipe water grab samples/charcoal packet
STP10 standpipe water grab samples/charcoal packet
AFIP piezometer water grab samples
W898 piezometer automatic water sampler/charcoal packet
SBC stream below culvert automatic water sampler/charcoal packet
STSS Trivelpiece Spring water grab samples/charcoal packet
MH manhole south of pond water grab samples
KL Keller’s Leak water grab samples
DLD Dale’s Little Dipper Spring water grab samples
OF283 Overflow 283 water grab samples
Scs Steel Cylinder Spring water grab samples
$1 small tributary water grab samples/charcoal packet
$2 small tributary water grab samples/charcoal packet
S7 small tributary water grab samples/charcoal packet
TCP terra cotta pipe water grab samples
FS Frank’s Spring water grab samples



during the SITE demonstration and estimates provided by AFI, the electrical power required trom
system startup to establishment of a 12-foot-thick barrier wall was about 72,000 kilowatt-hours (kWh).
Once frozen, the average power consumption required to maintain the barrier wall was reportedly
about 288 kWh per day. The thermoprobes also can operate without electrical power whenever air
temperature drops below the target soil temperature. Should a power loss or other system failure
occur, an immediate breach in the barrier wall is unlikely because subsurface frozen soil thaws at a
slow rate. As discussed in Section 2.1.5, thawing was evaluated during a simulated power outage at
the HRE pond site and found to be minimal.

3.3.4 Maintenance Requirements

The system components should be inspected periodically for proper operation. Maintenance of the
ground freezing system components is required only in the event of a mechanical failure associated
with the refrigeration units and thermoprobes. Because the refrigeration units are standard unmodified
items, they are easily serviced by a qualified heating, ventilation, and air conditioning (HVAC)
technician. Maintenance of the refrigeration units includes, but is not limited to, leak repair,
refrigerant recharge, and replacement of worn equipment. Maintenance and repair of the
thermoprobes would require the attention of an AFI designer/fabricator due to the proprietary nature of

the devices.

3.3.5. Support Systems

in situ temperature sensors, such as the temperature monitoring points used during the HRE pond SITE
demonstration, may be required to monitor and track the development of the frozen soil barrier and
ensure that refrigeration equipment is operating properly.

Groundwater tracing similar to that completed during this demonstration may be required to monitor
barrier wall integrity. According to AFI, geophysical techniques such as soil resistivity that is capable
of detecting barrier infrastructure properties such as voids also can be used to monitor performance of
the barrier wall.

65


8.00E-02

Figure 2-13
Concentrations of Eosine OJ Versus Time
for Location STP9

7.00E-02 °

6.00E-02
8.00E-02
4006-02
3006-02
2.00E-02%e oo
1.006.024 *

0,00E+00 +_#

Eosine OJ (ppb)

*.
o¢ °
—%& 2% —_*—_$ _~

-25

0 25 50 75 100 125
Days Relative to Dye Injection at Zero

42

150


3.3.6 Personnel Requirements

Personnel requirements for the system are minimal. Personnel are required to periodically inspect the
ground freezing system, including the thermoprobes and refrigeration units and associated piping, for
general operating condition. A certified HVAC technician is required for routine maintenance of the
refrigeration units. Personnel also should inspect the condition of the insulation and waterproofing
membrane over the containment area and identify indications of potential problems, such as tears or
uplifted edges.

Personnel working with the system at hazardous waste sites should have completed the training
Tequirements under the Occupational Safety and Health Act (OSHA) outlined in Title 29 of the Code of
Federal Regulations (CFR) $1910.120, which covers hazardous waste operations and emergency
Tesponse. Personnel working with the system at radioactive waste sites, such as the HRE pond site,
also should have completed radiation worker training in accordance with 10 CFR Part 20, which covers
standards for protection against radiation. Personnel should also participate in a medical monitoring
program as specified under OSHA and the Nuclear Regulatory Commission (NRC).

3.4 MATERIAL HANDLING REQUIREMENTS

Material handling requirements for the freeze barrier technology include those for the soil and water
temoved during drilling activities. Groundwater removed from boreholes during thermoprobe
installation activities will probably contain site-related contaminants. Soils removed from below the
water table in the vicinity of a contaminant plume may have become contaminated by contact with
contaminated groundwater. For this reason, soil and water generated during construction activities
may require handling, storage, and management as hazardous wastes. Precautions may include
availability of lined, covered, roll-off boxes; drums; or other receptacles for the soil; storage tanks or
drums for the water; and appropriate personal protective equipment (PPE) for handling contaminated
materials. Contaminated soils should be stockpiled on site separately from soils determined to be clean,
to minimize the amount of material requiring management as potentially hazardous waste.


Analytical Results for

Eosine OJ and Phioxine B
(ppb)
Location Description Phase| Sample Type | Sample Date Eosine OJ Phloxine B
DLD Dale's Little Dipper Spring | BKG GS 1/26/98 1.30E-03 ND
12 standpipe BKG GS 1/26/98 ND ND
MW1 (1109) monitoring well BKG GS 1/26/98 ND ND
MW2 (1110) monitoring well BKG GS 1/26/98 ND ND
MWS (1111) monitoring well BKG GS 1/26/98 ND ND
- $2 small tributary BKG GS 1/26/98 ND ND
S7 small tributary BKG GS 1/26/98 ND ND
SBC stream below culvert BKG GS 1126/98 ND ND
Si small tributary BKG GS 1/26/98 ND ND
STP10 standpipe BKG GS 1/26/98 ND 1.30E-03
STP2 standpipe BKG GS 1/26/98 2.38E-01 1.30E-03
STP9 standpipe BKG GS 1/26/98 2.09E-02 1.30E-03
STP5 standpipe BKG GS 1/26/98 ND ND
‘W898 piezometer BKG GS 1/26/98 ND ND
SBC stream below culvert BKG GS 427198 ND ND
W898 piezometer BKG GS 1/27/98 ND ND
MW2 (1110) monitoring well BKG GS 1/28/98 ND ND
MW4 (1112) monitoring well BKG GS 1/28/98 1.30E-03 1,30E-03
SBC stream below culvert BKG GS 1/28/98 ND ND
‘we98 piezometer BKG GS 1/28/98 ND ND
SBC stream below culvert BKG GS 1/29/98 ND ND
‘Ws98 piezometer BKG GS 1/29/98 ND ND
OLD Dale's Little Dipper Spring | BKG GS 1/30/98 1,30E-03 ND
12 standpipe BKG GS 1/30/98 ND ND
MW1 (1109) monitoring well BKG GS 1/30/98 ND ND
MW3.(1111) monitoring well BKG GS 1/30/98 ND ND
Si small tributary BKG GS 1/30/98 ND ND
$2 small tributary BKG GS 1/30/98 ND ND
s7 small tributary BKG GS 1/30/98 ND ND
SBC stream below culvert BKG GS 1/30/98 ND ND
STP10 standpipe BKG GS 1/30/98 ND 1.30E-03
STP2 standpipe BKG GS 1/30/98 2.28E-02 1.30E-03
STP9 standpipe BKG GS 1/30/98 1.90E-02 1,30E-03
STP5 standpipe BKG GS 1/30/98 ND ND
‘wes piezometer BKG GS 1/30/98 ND ND
MW2 (1110) monitoring well BKG GS 1/31/98 ND ND
MW4 (1412) monitoring well BKG GS 1/31/98 1,30E-03 1,30E-03
SBC stream below culvert BKG GS 1/31/98 ND ND
‘we98 piezometer BKG GS 1131/98 ND ND



Analytical Results for

Eosine OJ and Phioxine B
(ppb)
Location Description Phase} Sample Type Sample Date Eosine OJ Phloxine B
SBC ‘stream below culvert BKG c 2/13/98 ND ND
STP10 standpipe: BKG GS 2/13/98 ND 1.30E-03
STP2 standpipe BKG GS 2/13/98 6.07E-02 1.30E-03
STP9 standpipe BKG GS 2/13/98 1,90E-02 1.30E-03
STSS Trivelpiece Spring BKG GS 2/13/98 ND ND
ws98 piezometer BKG c 2/13/98 ND ND
BKG NSC 2/14/98
MW2 (1110) monitoring well BKG GS 2/15/98 ND ND
MW4 (1112) monitoring well BKG GS 2/15/98 1.30E-03 1.30E-03
BKG NSC 2/16/98
DLD Dale's Little Dipper Spring | BKG GS 2/17/98 1.30E-03 ND
MW2 (1110) monitoring well BKG Cc 2/17/98 ND ND
MW3 (1111) monitoring well BKG GS 2/17/98 ND ND
MW4 (1112) monitoring well BKG Cc 27/98 ND ND
S1 ‘small tributary BKG GS 2/17/98 ND ND
$2 ‘mail tributary BKG GS 217/98 ND. ND
s7 small tributary BKG Gs 2/17/98 ND ND
SBC stream below culvert BKG GS 217198 ND ND
SBC stream below culvert BKG Cc 2/17/98 ND ND
STP10 standpipe BKG GS 2/17/98 ND 1.30E-03
STP2 standpipe BKG GS 2/17/98 1.14E-02 1.30E-03
STP9 standpipe BKG GS 2/17/98 7.17E-02 1.30E-03
STSS Trivelpiece Spring BKG GS 2/17/98 ND ND
WEEE piezometer BKG GS 2/17/98 ND ND
‘W898 piezometer BKG c 2/17/98 ND ND
BKG NSC 2/18/98
MW4 (11412) monitoring well TR GS 2/19/98 1,30E-03 1,30E-03
SBC stream below culvert T GS 2/19/98 ND ND
‘ws898 piezometer TR GS 2/19/98 ND ND
AFIP. piezometer TR Ss 2/20/98 ND 1.30E-03
DLD Dale's Little Dipper Spring [- TR GS 2/20/98 1.09E+03 ND
MW2 (1110) monitoring well TR GS 2/20/98 ND ND
MW3 (1111) monitoring well TR GS 2/20/98 ND ND
MW4 (1112) monitoring well TR GS 2/20/98 1.30E-03 1.30E-03
$1 ‘small tributary TR Gs 2/20/98 ND ND
$2 ‘small tributary TR GS 2/20/98 ND ND
s7 ‘small tributary TR GS 2/20/98 ND ND
SBC stream below culvert TR GS 2/20/98 ND ND
STP10 standpipe TR GS 2/20/98 ND 1.30E-03

A-4



I

FEET ABOVE MSL

HRE Pond

A’

az

250

On-site
Tributory

METERS ABOVE MSL

ND
=
a

| es a | ee ee oho il 1
a a a eB Fa i 240
Ee ee LEN ne Ss ae ae a aes as a oo
oe a ee I
a ee a
CN Ne ee ee eee eee eens anon ae eal T} ARCTIC FOUNDATIONS, INC. — HRE POND SITE
~~ eNOS One REO cae
IDGE,
es Welt Clay ond Geologic conditions were
0 S'= Top of Sand Pack = shale fragments extrapolated from on-site} FIGURE +4
0 Approximate 50 7 = Top of Well. Screen ERE-] Saprolitic zone boring logs: Actual GENERALIZED GEOLOGIC
Scale in Feet B = Bottom of Well Screen j conditions may vary CROSS-SECTION OF HRE POND.
8 ee Bottom Soa Level Weathered shale significantly from those
SOURCE: NODIFIED FROM DOE 1986 AND DOE 19980 [ETOH shote' bedrock _ depicted on this figure. Ee Tetra Tech EM Inc.



2-14
2-15
2-16
2-17
2-18
2-19
2-20

2-21

2-22.

223,

41

42

1-1

1-3

2-1

3-1

41

42

Figures (Cont’d.)

EOSINE OJ RESULTS FOR LOCATION STP2.........00 00. scene eee ee eee e eee 44
EOSINE OJ RESULTS FOR LUCATION DLD .... 20.00. 0c cece cece eee e eens 45
EOSINE OJ RESULTS FOR LOCATION MW4 (1112)... 00.0.0 cece veces seca ee 46
EOSINE OJ RESULTS FOR LOCATION STP9... 2.0... cece eee eens 48
SUBSURFACE TEMPERATURE DATA OVER TIME FORT-3 ........... 0-200. 51
SUBSURFACE TEMPERATURE DATA OVER TIME FOR T-4 ............ beeeeee 52
SUBSURFACE TEMPERATURE DATA OVER TIME FORT-5 .........0 00000000 53
SUBSURFACE TEMPERATURE DATA OVER TIME FOR T-6 ........... 02-000: 54
SUBSURFACE TEMPERATURE DATA OVER TIME FORT-7 ........... 000000 55
SUBSURFACE TEMPERATURE DATA OVER TIME FOR T-8 .2......... 000000 56
DISTRIBUTION OF TOTAL COSTS FOR CASE1...........0.00.0.00 0 teens 79
DISTRIBUTION OF TOTAL COSTS FOR CASE2 ..........0..0.0000000 TS 79
Tables

RESULTS OF THE 1996 GROUNDWATER TRACING INVESTIGATION FOR

RHODAMINE WT... 1... cc cece nee enn e teens 20
RESULTS OF THE 1996 GROUNDWATER TRACING INVESTIGATION

FOR EOSINE OF 00... cece eee nett eens 21
RECOVERY POINTS AND SAMPLING METHODS .................00 0008 11 24
RESULTS OF THE DEMUNSTRA1iUN GROUNDWATER TRACING INVESTIGATION
FOR PHLOXINEB .. 0... cece tee teens 35
SUMMARY OF ENVIRONMENTAL REGULATIONS ............ 0000 0e deve 68
ESTIMATED COSTS ASSOCIATED WITH THE FREEZE BARRIER

TECHNOLOGY ...,....... cece cette eee ran 16
COST DISTRIBUTION FOR THE FREEZE BARRIER TECHNOLOGY ...........°.. oc)

ix


VENDOR'S CLAIMS
A.l Background

Since 1862, ground freezing has been used to augment soil properties at civil works and mining sites to
facilitate construction. Freezing gives load-bearing strength to soils and has frequently been used for
large scale engineering projects. AFI has produced over 600 foundation and ground stabilization systems
since the early 1970s. Systems have been installed at sites including hangars, towers, antennae, schools,
houses, apartments, hospitals, power stations, maintenance facilities, pipelines, oil production facilities,
water treatment facilities, sewage treatment and containment facilities, roadways, air fields, shopping
centers, libraries, and storage tanks.

In 1962, the Atomic Energy Commission disposed of over 6,800 kilograms of radioactively contaminated
material in a burial mound at the Project Chariot site in northwestem Alaska. The naturally occurring
frozen soil at the site (permafrost) was deemed to be the perfect containment medium for the
radionuclides. Indeed, upon remediation of the site in 1995, it was found that virtually no transport of
radionuclides into the permafrost had occurred. There are several sites where the impermeability of
permafrost is used to prohibit migration of contaminants such as sewage, landfill leachate, and mining
tailings in Alaska, Canada, and Russia. The technology of freezing soil has just recently been considered
as a hazardous waste containment technology.

A.2_ Freeze Barrier Technology

Generally, soil refrigeration for ground freezing is performed using a series of concentric pipes
(thermoprobes) installed in a line to approximate the geometry of the proposed frozen barrier. Pumping
cold brine down the inside pipe and letting it flow back through the annular space between the inner and
outer pipes freezes the soil. The frozen soil grows on the outside of the concentric pipes until it connects
to the frozen cylinder formed on the adjacent pipe in the array. The typical refrigerating medium used to
chill the brine is ammonia. The brine is commonly a mixture of calcium chloride and water. Should a
leak occur in the brine system, the possibility exists that the antifreeze brine will solution-thaw the frozen
soil and cause a breach in the barrier. Likewise, groundwater contamination can occur and brine

Attachment-1


The SITE Program

Annette M. Gatchett

Assistant Director for Technology

U.S. Environmental Protection Agency

National Risk Management Research Laboratory
Land Pollution and Remediation Control Division
26 West Martin Luther King Jr. Drive

(MD 215)

Cincinnati, Ohio 45268

(513) 569-7697

Steve Rock

EPA Work Assignment Manager

U.S. Environmental Protection Agency

National Risk Management Research Laboratory
26 West Martin Luther King Jr.’ Drive
Cincinnati, Ohio 45368

(513) 569-7149

The DOE Demonstration Site

Elizabeth Phillips

ORNL Program Manager

3 Main Street

P.O. Box 2001

Oak Ridge, Tennessee 37831
(423) 241-6172


1-1
1-2

1-3

14

1-5

1-6
21
22
23

2-4

2-6
2-7

2-8

2-9
2-10
2-11

2-12

2-13

Figures

PLAN VIEW OF HRE POND SHOWING SITE TOPOGRAPHY AND ON-SITE
MONITORING WELLS, STANDPIPES, AND PIEZOMETERS............ ene

PLAN VIEW OF SYSTEM CONFIGURATION AND PROFILE VIEW OF

THERMOPROBE ..................,.

RECOVERY POINTS AND RHODAMINE WT AND EOSINE OJ DETECTS ....

INFERRED MIGRATION PATHWAY FOR PHLOXINEB ............. tee

PHLOXINE B RESULTS FOR LOCATION STP10 ......... bee ee eae

PHLOXINE B RESULTS FOR LOCATION AFIP ...................4 cred

PHLOXINE B RESULTS FOR LOCATION STP1 ..................04 soe

PHLOXINE B RESULTS FOR LOCATION STP2 ................ eee

PHLOXINE B RESULTS FOR LOCATION STP9 .... 2... eee sree

PHLOXINE B RESULTS FOR LOCATION MW4 (1112) ..............- oe

GROSS BETA ACTIVITY IN SURFACE WATER SAMPLES

COLLECTED FROM WEIR BOX ........

~u

13

31
32
32
33
33
34

34

. 38

OAK RIDGE PRECIPITATION DATA FROM MARCH

1997 THROUGH JULY 1998 ...........,

viii

. 41

++ 41

- 42


TABLE 1-1

RESULTS OF THE 1996 GROUNDWATER TRACING
INVESTIGATION FOR RHODAMINE WT

Recovery Initial Detection | Peak Detection Initial Peak
Point (days)* (days)* Concentration Concentration
(ppb) (ppb)

SBC 2 781 1.20e-05 3,27e-01

S7 4 71.00 1.00e-01 2.15e+01

S6 4 14.91 1.06e-01 7.86e+00

85 4 14.91 1.12e-01 5.41e-+00

$3 4 14.91 2.95e-01 1.24e+01

S4 4 14.91 1.16e-01 9.09e-+00
DLD 5 7.81 3.70e+01 8.36+01
MW? (1110) 15 14.91 2.83e-01 2.83e-01
MW3 (1111) 15 1 6.48e-03 1.760-02
MW4 (1112) 15 36.21 8.81¢-03 1.20e-02
STSS 22 27.52 9.60e-04 5.50e-03
STP10 39-43 42.60 Not Determined® 4.90e-02
W674. 43 63.90 8.45¢-02 2.91e-01
W898 43 63.90 1.78e-01 3.38e-01
STP2 43 56.09 1.206¢-05 1.59e-02
STP9 50 56.09 1.20e-07 3.63e-02

Notes:

ppb parts per billion
* Number of days following dye injection
Initial concentration could not be determined due to the sampling frequency

20




TABLE ES-1 (Continued)

SUPERFUND FEASIBILITY STUDY EVALUATION CRITERIA *
FOR THE FREEZE BARRIER TECHNOLOGY

Criterion Discussion
© Ice does not degrade or weaken over time and is repairable in
situ. The barrier wall is simply allowed to melt upon
completion of containment needs and thermoprobes are
removed.

¢ Subsurface structures may interfere with the formation of a
frozen soil barrier.

© The formation of a frozen soil barrier in arid conditions may
require a suitable method for adding moisture to the soils to
achieve saturated conditions prior to barrier wall development.

|Cost ¢ Fora frozen soil barrier applied to a site that is 150 feet by.
200 feet in size and operating for 10 years under some of the
same general conditions observed at the HRE pond site, total
estimated fixed costs are estimated to be about $1,903,700.
Annual operating and maintenance costs, including those for
utilities, supplies, analytical services, labor, and equipment
maintenance are estimated to be about $63,200.

{Community Acceptance © This criterion is generally addressed in the record of decision
(ROD) after community responses are received during the
public comment period. However, because communities are
not expected to be exposed to harmful levels of contaminants,
noise, or fugitive emissions, community acceptance of the
technology is expected to be high.

State Acceptance © This criterion is generally addressed in the ROD; state
acceptance of the technology will likely depend on the long-
term effectiveness of the technology.

Note:

. EPA. 1988b. CERCLA Compliance with Other Environmental Laws: Interim Final. OSWER. EPA/540/G-89/006.
August.


are normally used to create boreholes that house the thermoprobes. A “V” or “U” configuration is not
always necessary or possible. In certain geological settings, where downward migration of
contaminants is limited by a lithologic unit that is characterized by very low permeability, and when
such a unit occurs at a shallow depth, thermoprobes may be installed in a vertical position, with the
bottoms of the thermoprobes anchored in the unit. The arrangement of the thermoprobes to create a
frozen barrier wall ultimately depends on the topography and underground disposition of the waste to
be contained. For the freeze barrier wall to be effective, the waste source must be completely
surrounded by the frozen soil barrier, or a combination of the frozen barrier and other impermeable
features, limiting and perhaps preventing groundwater movement into and out of the waste source. To
limit hydraulic loading due to direct infiltration of precipitation, the surface of the enclosed waste area
is typically sealed. AFI claims that the technology can contain most known biological, chemical, and
radioactive contaminants.

Once installed, the thermoprobes are connected to a refrigeration system through a piping network. A
two-phase refrigerant is circulated through the system to remove heat from the soil, with the heat being
dissipated to the air. When the soil matrix next to the pipes reaches 0 °C, soil particles are bonded
together as soil moisture freezes. Cooling is continued until the frozen region around each
thermoprobe begins to expand and build outward, coalescing with frozen regions developed around
other thermoprobes until a continuous impermeable, frozen soil barrier is formed.

Overview of the Freeze Barrier Technology SITE Demonstration

The SITE demonstration of the freeze barrier technology occurred between September 1997 and July
1998. The demonstration site was a former surface impoundment known as the Homogeneous Reactor
Experiment (HRE) Pond in Waste Area Grouping 9 at ORNL. The HRE pond’s surface measured
roughly 75 feet by 80 feet with sides sloping to a bottom measuring 45 feet by 50-feet. The HRE pond
served as a retention/settling basin and received low-level radioactive liquid wastes. The HRE pond
also received high levels of fission products and shield water from a chemical processing system. Past
sediment and groundwater samples collected from the HRE pond area indicate the presence of
radioactive contaminants including cesium’, strontiumTM, and tritium.


aN, Ob (©) <a ii
5 =10):4Sh''/ 0): 2D a CS iii
ABSTRACT 00... c ccc tee tenet nee ree renee nena iv
CONTENTS 0.0.0 occ eee eter t tener e nee een v
FIGURES AND TABLES ........ 000 cece tee eee net ene ne tetas viii
ACRONYMS, ABBREVIATIONS AND SYMBOLS ....... 06-2. esse eee ee eee ene x
CONVERSION FACTORS .... 06. cee tenet tent e tenes xii
ACKNOWLEDGMENTS .... 0... 0-2 e eee eens Bcc eee e eee eee e eee xiii
EXECUTIVE SUMMARY....... 00. ce cee cece eee nner tnt ES-1
1.0 INTRODUCTION ....... 0.0.0 c cece ene eee tenes viii
1.1. DESCRIPTION OF SITE PROGRAM AND REPORTS ..........-----++-5- 1
1.1.1 Purpose, History, and Goals of the SITE Program veel
1.1.2 Documentation of SITE Demonstration Results .,.....---..-000+05 2
1.2 OVERVIEW AND APPLICATION OF FROZEN SOIL BARRIERS .........- 3
1.3. API FREEZE BARRIER TECHNOLOGY ........ Lecce eee eee eae 4
1.4 OVERVIEW AND OBJECTIVES OF THE SITE DEMONSTRATION ........ 6
1.4.1 Site Background ...........--.--
1.4.2 Site Topography and Geology........
1.4.3. Site Hydrogeology ............--.
1.4.4. System Construction. ............-5
1.4.5 SITE Demonstration Objectives
1.4.6 Predemonstration Activities ............
1.4.7 Demonstration Activities ©... 6.0... eee ee ee eee
1.5 KEY CONTACTS ......... 0.0 c cece eee eee eee eens 25
2.0 | TECHNOLOGY EFFECTIVENESS ANALYSIS ........ 0-00 esse eee eens 27
2.1 SITE DEMONSTRATION RESULTS ......... 00 cee eee eee 27


Analytical Results for

Eosine OJ and Phioxine B
(ppb)
Location Description Phase| Sample Type Sample Date Eosine OJ Phioxine B
SBC stream below culvert TR GS 5/5/98 ND ND
W898 piezometer TR GS 5/5/98 ND ND
To NSC 5/6/98
MW4 (1112) monitoring well TR GS 5/7/98 1.30E-03 1.30E-03
AFIP plezometer TR GS 5/8/98 ND 2.44E-01
DLD Dale's Little Dipper Spring | TR GS 5/8/98 1,30E+00 ND
FS Frank's Spring TR GS 5/8/98 ND ND
KL Keller's Leak TR GS 5/8/98 ND. ND
MH manhole south of pond TR Gs 5/8/98 ND. ND
MW2 (1110) monitoring well T GS 5/8/98 ND ND
MWS (1111) monitoring well TR GS 5/8/98 ND ND
OF283 Overfiow 283 T GS 5/8/98 ND ND
$1 ‘small tributary TR GS 5/8/98 ND ND
S2 small tributary TR GS 5/8/98 ND ND
STP1 standpipe TR GS 5/8/98 1.30E-03 1.30E-03
STP10 standpipe TR GS 5/8/98 ND 1.30E-03
STP2 standpipe TR GS 5/8/98 4.52E-02 2.03E-02
STP5 standpipe TR GS 5/8/98 ND ND
STP6 standpipe TR GS 5/8/98 ND ND
STP7 standpipe TR GS 5/8/98 ND ND
STP9 standpipe TR GS 5/8/98 1.30E-03 1.30E-03
TCP terra cotta pipe TR GS 5/8/98 ND ND
‘W898 piezometer TR GS 5/8/98 ND ND
TR NSC 5/9/98
TM NSC 5/10/98
MW2 (1110) monitoring well TR GS 5/11/98 ND ND
MW4 (1112) monitoring well TR GS 5/11/98 1.30E-03 1,30E-03
SBC stream below culvert TR Gs 5/12/98 ND ND
W898 piezometer TR GS 5/12/98 ND ND
To NSC 5/13/98
MW4 (1112) monitoring well TR GS 5/14/98 1.30E-03 4.30E-03
MW2 (1110) monitoring well TR GS 5/15/98 ND ND
SBC stream below culvert TR GS 5/15/98 ND ND
ws98 piezometer TR GS 5/15/98 ND ND
TR NSC 5/6/98
TTM NSC 5/17/98
MW2 (1110) monitoring well TR GS 5/18/98 ND ND
MW4 (1112) monitoring well T GS 5/18/98 1.30E-03 1,30E-03
W898 biezometer TR GS 5/19/98 ND ND

A-12



background study and groundwater tracing investigation, sampling time is expected to be less then for
Case 1 and is estimated to require 12 hours Per month at a labor rate of about $35 per hour, for a total
cost of $720 per month. This monthly cost correlates to an annual cost of $8,600, and an estimated
total of $86,000 over the 10-year life of the project for Case 2.

Laboratory analytical costs are presented in Section 4.3. 10, Analytical Services. Labor requirements
associated with routine maintenance activities for thermoprobes, refrigeration units, and piping network
for both cases are discussed in Section 4,3. 11, Equipment Maintenance.

4.3.6 Supplies

The necessary supplies for sampling associated with a background study and groundwater tracing
investigation include Level D disposable PPE and miscellaneous field supplies. Disposable PPE
typically consists of latex inner gloves, nitrile outer gloves, and safety glasses. Disposable PPE is
estimated to cost about $300 per year for Case 1. Field supplies for Case 1 consisted of fluorescent
dyes, sample bottles, shipping containers, disposable bailers, and labels. Annual sampling supply costs
were estimated to be about $1,000 per year, resulting in a total annual supply cost of $1,300 for

Case 1. The total estimated costs for supplies over the 5-year life of the project is about $6,500.

Because there are fewer sampling points for a background study and groundwater tracing investigation
for Case 2, the amount of sampling supplies is expected to be less then for Case 1. Annual sampling
and PPE supply costs for Case 2 are estimated to be $1,000. The total estimated costs for supplies over
the 10-year life of the project are about $10,000 for Case 2.

4.3.7 Utilities

Electricity is used to run the refrigeration units and to power the temperature monitoring points,
instrumentation, and computer-controlled operating system. The electricity consumption rates for the
system can be broken down into the initial freeze down cost when the barrier design thickness is
reached, and an operating cost to maintain the barrier design thickness. Based on costs from the
demonstration, freeze down for Case 1 was assumed to require about 72,000 kWh at a cost of $3,600.

90


Post-Barrier Groundwater Conditions

Groundwater measurement results showed that the water level within the former pond was significantly
affected by the barrier wall. As demonstrated in the hydrograph for standpipe I2, the measured water
table elevations gradually decreased over time and did not appear to respond to storm events (compared
to locations outside the containment area) after freezing was initiated (see Figure 2-14). According to
AFI, the slow decline in water levels at standpipe 12 is a result of soil moisture being drawn to the
frozen soil barrier (AFI 1998). The slow decline also may have been a result of slow seepage through
fractured bedrock in the base of the former pond, combined with the inhibited recharge induced by the
barrier wall. The hydrograph for standpipe 12 also shows some distinct peaks just prior to the
demonstration groundwater tracing investigation that do not reflect actual water table fluctuations that
require some explanation. According to DOE, the water level monitoring system at standpipe 12 was
not maintained due to budgetary problems, which resulted in moisture buildup in the pressure
transducer. The pressure transducer was replaced just prior to initiation of the demonstration.
groundwater tracing investigation, which reportedly displaced the water level in standpipe 12, resulting
in fluctuations in the hydrograph for standpipe I2. The only other water level responses seen in the
hydrograph for standpipe 12 correspond to water injections that occurred for 5 days following dye
injection, even though there were numerous storm events during this period as seen in the precipitation
data presented in Figure 2-17 (DOE 1998b). As seen in the hydrograph for standpipe 12, there
appeared to be a slow decline in water levels at standpipe 12 following the initial increase caused by dye
and water injections.

Water table elevations downgradient of the former pond were also affected by the frozen soil barrier.
DOE reported that the water level in standpipe STP5 dropped about 6.5 feet following barrier
placement. DOE also reported that water levels at standpipe STP6 were not as responsive to storm
events following barrier placement and that only large storms produced the type of response observed
at STP6 prior to barrier placement. This effect also shows that horizontal groundwater flow through
the former pond to these downgradient locations was impeded or that flow was diverted around the
barrier wall, resulting in suppression of the water table at these locations (DOE 1998b).

49


impermeable frozen soil barrier is formed. Barrier wall thickness and temperature will vary depending
on site conditions.

13 AFI FREEZE BARRIER TECHNOLOGY

For the SITE demonstration, AFI used an innovative thermoprobe to demonstrate the capabilities of its
freeze barrier technology. A standard AFI thermoprobe removes heat from the soil by acting as a
thermosyphon. A thermosyphon removes heat passively, which means that soil can be frozen or
maintained in the frozen state without the need for an external supply of energy or power. The
thermosyphons function using a two-phase working fluid. The working fluid is contained in the
thermoprobe, which is partially buried. In cold climates, particularly in permafrost regions,
thermosyphons are used to maintain a frozen subgrade for foundation stability purposes. In these
situations, the thermosyphons operate in a passive mode. In this case, the aboveground portion is
subjected to cold ambient air, which cools and condenses the working fluid. The condensate flows by
gravity to below ground level, where it encounters a warmer regime, warms, vaporizes and rises .
upward again to repeat the cycle.

AFI used a closed two-phase system that can be used in an active-passive mode and is applicable when
the ambient air temperature is above freezing. Such active-passive systems are called “hybrid
thermosyphons” and are often used in more temperate locations where reliance on low ambient air
temperatures (passive mode application) is not feasible. AFI’s ground freezing system deployed at the
U.S. Department of Energy’s (DOE) Oak Ridge National Laboratory (ORNL) homogeneous reactor
experiment (HRE) pond site included 50 thermoprobes; two above-grade, 30-horsepower refrigeration
units; a two-phase working fluid; an interconnecting piping network; and an instrument

control system. The ground freézing system used during the SITE demonstration is shown in Figure
1-1.

For the “active/passive” operating tnermoprobes, carbon dioxide in the bottom of each thermoprobe
functions as the two-phase working fluid to move heat against gravity. As the surrounding soil warms
the thermoprobe walls, the liquid phase of the carbon dioxide boils and the vapor rises to the top of the
thermoprobe. At the top of the thermoprobe, a heat exchanger coil connected to an abovegrade




Length:

Volume:

Mass:

Energy:

Power:

Temperature:

Conversion Factors

To Convert From

inch
foot

square foot

acre

gallon

cubic foot

pound

kilowatt-hour

kilowatt

(°Fahrenheit - 32)

To

centimeter
meter
kilometer

square meter

square meter

liter

cubic meter

kilogram

megajoule

horsepower

°Celsius

Multiply By

2.54
0.305
1.61

0.0929
4,047

3.78
0.0283

0.454

3,60

1.34

0.556


barrier or as an encapsulating soil mass. The configuration of the barrier is primarily constrained by the
installation techniques that are available. The temperature of the barrier can be adjusted to ensure the
necessary liquid to solid phase change even though certain contaminants may effect a depression of the phase
change temperature to a point well below 0°C. Frozen barriers can be developed in soils that are saturated
or relatively dry. It is rarely necessary to add moisture because the in-situ moisture will migrate and
concentrate in the frozen soil and create an impervious wall. The movement of waterborne contaminants only
serves to accelerate this process.

‘The frozen barrier technology can also be used for immobilization of aqueous contaminants such as
tritium. As there is no large scale method of removing tritium from groundwater, one simple method for
treatment is to contain or immobilize tritiated water until the tritium has decayed to acceptable levels.
Typically, 2 to 3 half-lives, or about 30 years of containment is the time period considered for most tritium
treatment provided the source is eliminated. Similarly, Sr with a half-life of approximately 29 years
could be immobilized for 90 years or so to significantly reduce the contamination hazard. Immobilization
periods must correspond to contamination levels and acceptable standards or the immobilization may be
used as a stopgap measure to preclude the spread of contamination until technology can be found for
remediation. The majority of system components for a frozen soil barrier using hybrid thermosyphons
have no wear parts other than the skid-mounted condensing units so it is a relatively simple procedure to
replace worn out components. In fact, the hybrid thermosyphons are not particular on how they are
driven, so newer refrigeration technologies may provide increased efficiencies when the original
equipment mechanical systems wear out.

A.4 Advantages and Innovative Features

Although there are numerous developed and embryonic technologies, such as steel, concrete, slurry walls,
or grout curtains, that purport to contain or immobilize hazardous wastes, few can match the use of a
frozen barrier created and maintained with thermosyphons. This technology is proven to be effective
independent of climatic zone. The self-healing feature of the frozen barrier makes it attractive in locations
where ground movement may occur. The soil strengthening feature is advantageous where weak soils are
present or where the plane of the barrier may be on the slip surface of a potential slope failure. One of the
most appealing features of the frozen barrier is the reversibility feature, that is, when the barrier is no
longer needed, it is simply allowed to thaw with no lasting effect on the subgrade. Reversibility allows

Attachment-3


(1110)

LEGEND
FORMER TOP OF POND

— —— — FORMER POND BOTTOM:

UMITS OF ASPHALT CAP
—— 820——._ 10-FOOT CONTOUR LINE
————_ 2-FOOT CONTOUR LINE
smmemmonmmenn GEOLOGIC CROSS-SECTION LINE

MW = Monitoring Well
‘STP, I = Stendpipe
W = Piezometer

SCALE: 1” = 30°

ARCTIC FOUNDATIONS, INC. ~ HRE POND SITE
OAK RIDGE NATIONAL LABORATORY
OAK RIOGE, TENNESSEE

FIGURE 1-3
PLAN VIEW OF HRE POND SHOWING

SITE TOPOGRAPHY AND ON-SITE
MONITORING WELLS, STANDPIPES,
AND PIEZOMETERS

\@ Tetra Tech EM Inc.

SOURCE: MODIFIED FROM EPA 1998


TABLE 4-2

COST DISTRIBUTION FOR THE FREEZE BARRIER TECHNOLOGY

Case 1 Case 2

Cost Categories Costs % Costs Costs % Costs

' Site Preparation 385,900 33.0 638,400 25.2
Permitting and Regulatory 0 0 0 0
Mobilization and Startup 103,700 9.0} 238,700 9.4
Capital Equipment 420,000 35.5] 940,500 37.1
Labor 45,500 4.0 86,000 3.4
Supplies 6,500 0.5 10,000 0.4
Utilities 31,100 3.0 134,300 5.3
Effluent Treatment & Disposal 0 0 i) 0
Residual Shipping & Handling 0 0 0 0
Analytical Services 65,300 6.0 91,800 3.6
Equipment Maintenance 71,500 6.0} — 320,000 12.6
Site Demobilization 35,900 3.0 76,000 3.0
Total Costs $1,165,400 100 | $2,535,700 100

78



contaminated soil may have to be excavated and cleaned, depending upon the environment where the
work is taking place.

The thermosyphons or passive heat removal devices, efficiently move heat against gravity without the
need for an external energy source. They are the most widely used passive refrigeration systems for
creation, maintenance, and augmentation of permafrost. In cold region applications where the mean
annual air temperature is below freezing, they are completely self-sufficient refrigeration devices. In the
pure passive form, thermosyphons function with no moving parts. Thermosyphons operate because of a
two-phase working fluid. The working fluid is contained in a closed vessel, which is usually partially
buried. Whenever the above ground portion of the vessel is subjected to air that is cooler than the buried
portion, heat is released to the air by condensation of the vapor within the vessel. The condensate flows
via gravity to the portion of the vessel below the ground where it evaporates and the vapors return to the
top. The cycling repeats until the air temperature rises above the soil temperature. These devices are
thermodynamically similar to heat pumps; that is, they absorb heat by vaporizing a liquid, carry heat in the
vapor phase, and release heat by condensing the vapor.

Hybrid thermosyphons incorporate an integral heat exchanger to allow the units to be driven with a
standard mechanical refrigeration system. A typical system utilizing hybrid thermosyphons includes an
active (powered) refrigeration condenser, an interconnecting supply and return piping system, and system
controls. The hybrid thermosyphons will function actively without direct dependence on the ambient air
temperature. If ambient temperatures are sufficiently low enough, the hybrid units will function passively,
thereby reducing energy costs.

A3 Deployment of Freeze Barriers

Frozen barriers are well suited to control a variety of contaminants including, but not limited to,
radionuclides, DNAPLs, hydrocarbons, sewage, landfill leachate, and other hazardous chemicals. They can
be deployed at a wide variety of sites at any depth from the ground surface to several thousand feet deep. The
barrier can be continuous from the surface to a great depth or it can be restricted to a predetermined zone
below the surface. Freezing can be confined to specific subsurface target zones for more efficient energy
usage. Subsurface heat loads due to flowing groundwater, utilities, and other sources can be quantified and
accounted for in the design of the barrier. It can be used to form a vertical, horizontal, or angled impervious

Attachment-2


3.6.4 Safe Drinking Water Act

The Safe Drinking Water Act (SDWA), as amended in 1986, required EPA to establish regulations to
protect human health from contaminants in drinking water. The legislation authorized national drinking
water standards and a joint federal-state system for ensuring compliance with these standards. The
SDWA also regulates underground injection of fluids and sole-source aquifer and well head protection
programs. An underground injection control (UIC) permit was issued by TDEC for the injection of
tracer dyes and potable water used during the technology demonstration; however, the technology
would only require injection of fluids if the soil moisture content is too low to allow freezing to occur
in soil pore water voids.

The National Primary Drinking Water Standards are found in 40 CFR parts 141 through 149. These
drinking water standards are expressed as maximum contaminant levels (MCL) for some constituents,
and maximum contaminant level goals (MCLG) for others. Under CERCLA (Section 121
(d)(2)(A)(ii)), remedial actions are required to meet the standards of the MCLGs when relevant. The
freeze barrier technology is not a groundwater treatment technology, but it could improve the quality of
groundwater by containing the source of contamination until appropriate remediation techniques can be
applied. As a result, MCLGs would not apply to this technology unless used in conjunction with a
groundwater treatment technology.

3.6.5 Clean Air Act

The Clean Air Act (CAA), as amended in 1990, regulates stationary and mobile sources of air
emissions. CAA regulations are generally implemented through combined federal, state, and local
programs. The CAA includes pollutant-specific standards for major stationary sources that would not
be ARARs for the freeze barrier technology. However, state and local air programs have been
delegated significant air quality regulatory responsibilities, and some have developed programs to
regulate toxic air pollutants (EPA 1989). Therefore, state air programs should be consulted regarding
installation and use of the freeze barrier technology. The only emissions associated with operation of

the freeze barrier system, which are typical of most commercial refrigeration systems, include water

wat


Acknowledgments

This report was prepared for U.S. Environmental Protection Agency’s (EPA) Superfund Innovative
Technology Evaluation (SITE) Program by Tetra Tech EM Inc. (formerly PRC Environmental
Management, Inc.) under the direction and coordination of Mr. Steve Rock, project manager for the
SITE Program in the National Risk Management Research Laboratory, Cincinnati, Ohio.

Special acknowledgment is given to Mr. Ed Yarmak of Arctic Foundations, Inc.; Ms. Elizabeth
Phillips and Dr. Gerilynn Moline of the U.S. Department of Energy; Gareth Davies of Cambrian
Groundwater Company; and Dr. Sidney Jones and Mr. John Sebastian of the Tennessee Department of
Environmental Conservation for their cooperation and support during the SITE Program demonstration
and during the development of this report.

xiii


TABLE 4-1 (Continued)
ESTIMATED COSTS ASSOCIATED WITH THE FREEZE BARRIER TECHNOLOGY

Cost Category Case 1 Case 2
Barrier Volume 140,000 fe 300,000 ft*
Isolated Volume 180,000 ft? Sippe 900,000 ft* $/ft*

Total Waste Shipping & Handling Costs $0 $0 $0 $0
Analytical Services Costs

Background study $2,300 $0.01 $1,800 $0.02
Total Analytical Services Costs” $2,300 $0.01 $1,800  $0.002
Demobilization Costs

System disassembly $1,100 $0.006 $2,200 $0,002

Borehole abandonment 34,800 0.19 73,800 0.08
Total Demobilization Costs. $35,900 $0.20 $76,000 $0.08
Total Estimated Fixed Costs $951,400 $5.29 $1,903,700 $2.12
Annual Costs
Annual Labor Costs $9,100 $0.05 $8,600 $0.01
Annual Supply Costs $1,300 $0.07 $1,000 $0,001
Annual Utility Costs $5,500 $0.03 $12,600 $0.01
Annual Analytical Costs $12,600 $0.07 $9,000 $0.01
Annual Equipment Maintenance Costs $14,300 $0.08 $32,000 $0.04
Total Estimated Annual Costs $42,800 $0.24 $63,200 $0.07
Total Estimated Fixed & Annual Costs $1,165,400 $6.50 $2,535,700 $2.80
Cost per unit barrier volume ($/ft*) $8.30 $8.50

Notes:
* Costs per cubic foot of isolated waste.

> Based on the assumption ‘hat a groundwater tracing investigation would be performed to verify

ier integri

° Costs presented do not reflect costs associated with initial freeze down, which are listed in fixed

costs.

77



. AFI will provide a representative-as an on-site consultant during key phases of the construction

. Downtime for routine maintenance will be minimal and is therefore, not considered in this
estimate. During the demonstration, AFI simulated a power outage which showed (based on
temperature monitoring points data) that periodic downtime would not affect system.
performance because the barrier thaws slowly

. After construction, the ground freezing system operates without the constant attention of an
operator. Routine labor requirements consist of monthly sampling and inspection of the
thermoprobes, temperature monitoring points, refrigeration units and associated piping, and the
surface seal

° This estimate assumes that the freeze barrier wall will be effective in containing groundwater
contamination and therefore, effluent treatment and disposal costs will not be incurred

. The freeze barrier technology will not generate wastes other than soil from drilling activities

° Periodic maintenance of system components will be required for worn parts and refrigerant
leaks associated with the refrigeration units and piping

. All system materials, including the thermoprobes, are fabricated at AFI’s location in
Anchorage, Alaska and transported to the site in Oak Ridge, Tennessee

. About 70 groundwater and surface water samples per month, or 840 per year, would be
collected from the same recovery points and analyzed for the same dyes used during the
demonstration for 5 years. Additional groundwater samples may also be required to monitor
for the contaminants of concern in groundwater outside the containment area, but were not
included in this estimate

. Labor costs for all 12 cost categories are presented as 1998 dollars and are not adjusted for
inflation (Means 1998)

e Salvage values on equipment were considered negligible after 5 years of operation and were
therefore not included in this estimate

Assumptions regarding site- and waste-related factors for Case 2 include the following:

° The location is a Superfund site in the southeastern U.S., and the site has been well-
characterized in terms of hydrogeology and type and extent of contamination

. ‘The system will be used as an interim containment measure to limit off-site migration of a
contaminant plume. The estimated total.volume of the contaminant plume requiring
containment is about 900,000 cubic feet

. Site groundwater is assumed to be contaminated with radionuclides, including Cs and Sr

82


EPA. 1989. CERCLA Compliance with Other Laws Manual: Part Il. Clean Air Act and Other
Environmental Statutes and State Requirements. OSWER. EPA/540/G-89-006.

EPA. 1996. Initial Ground-Water Trac

ing Results. National Center For Environmental Assessment.
October 31.

EPA. 1998. “Freeze Barrier Technology Final Quality Assurance Project Plan.” Prepared by Tetra.
Tech on behalf of EPA NRMRL, Cincinnati, Ohio. J:

98


sy

Groundwater Elevation Feet Above MSL

’ Figure 2-15

623

8

8

8

818

Hydrograph for Standpipe STP10
-—— Recorded by data logger
‘© Manual water level
Dye/water
injections
2/20/98
Freezing
initiated
8/8/87
| Sa
o od ° o °
Jan-97 Mar-97 May-97 Jul-97 Sep-97 Nov-97 Jan-98 Mar-98 May-98 Jul-98
. Time

Source: DOE 1998b



bs

Figure 2-18
Subsurface Temperature Data Over Time for T-3

Temperature
Degrees F

SeooSSBUSRFSKSRBRIASRERESRZERES

September

June

July

—*— 2.5 ft BGS
—e— 17.5 ft. BGS
trtttt Freeze Line



Prior to conducting the groundwater tracing investigation, a background study was conducted to
determine if any dyes still remained in the groundwater system from previous tracer studies and to
identify natural background fluorescence. Following the background study, the dye phloxine B was
injected into a standpipe located in the center of the former pond. Groundwater and surface samples
were collected and analyzed for phloxine B from February through July 1998. Samples were also
collected and analyzed for the dye eosine OJ which was injected into an upgradient monitoring well.
Groundwater and surface water samples were collected from the same dye recovery points that were
used during a groundwater tracing investigation conducted by EPA Headquarters in 1996. These
recovery points included a series of monitoring wells, piezometers, standpipes, springs, and a nearby
tributary, Field measurements of subsurface soil temperatures and groundwater elevations were also
performed to evaluate system performance.

SITE Demonstration Results

The following items summarize the significant results of the SITE demonstration:

e The frozen soil barrier reached its design thickness of 12 feet about 18 weeks following system
startup and was maintained at an average power consumption rate of about 300 kilowatt-hours
per day. Subsurface temperature data collected from temperature monitoring points
demonstrated that the soil was frozen from the ground surface down to a depth of about 30 feet.
The total volume of soil frozen.is estimated at about 134,000 cubic feet and the total volume of
soil isolated within the area enclosed by the barrier at about 180,000 cubic feet.

. Following establishment of the frozen soil barrier, water level data collectea from within the
barrier wall showed a drop in the water table elevation and a lack of response to storm events
compared to locations outside the former pond, indicating that the barrier wall was effective in
impeding recharge into the former pond.

. Tracer data collected during the demonstration show that the barrier was effective in impeding
horizontal groundwater flow, with the exception of a breach in the northwest corner likely
attributed to a subsurface pipe left in place after the former pond was closed or fractured
bedrock."

. The barrier can be expected to maintain its integrity for several weeks following a loss of
power or refrigeration as demonstrated during the technology demonstration.

. Results of the SITE demonstration show that subsurface engineering structures may interfere
with the formation of a frozen soil barrier and preclude the use of this technology at some sites.

ES-4


Note: effluent treatment and disposal, residual shipping and handling costs, and permitting and
‘9gulatory costs are not included because costs are $0 for this estimate.

Figure 4-2
Distribution of Total Costs for Case 2

Analytical

(3.8%) Maintenance (12.6%) Demobiiization (3.0%)

Labor (3.4%).

are all Mobilization & Startup

(9.4%)

Note: effluent treatment and disposal, residual shipping and handling, and permitting and regulatory costs are
not included because costs are $0 for this estimate.

79


1.0 INTRODUCTION

This section describes the Superfund Innovative Technology Evaluation (SITE) Program and the
Innovative Technology Evaluation Report (ITER); provides an overview and application of frozen soil
barriers; presents background information on the Arctic Foundations, Inc. (AFI), freeze barrier
technology; provides an overview and objectives of the SITE demonstration; and lists key contacts.

11 DESCRIPTION OF SITE PROGRAM AND REPORTS

This section provides information about (1) the purpose, history, and goals of the SITE Program, and
(2) the reports used to document SITE demonstration results.

1.1.1 Purpose, History, and Goals of the SITE Program

The primary purpose of the SITE Program is to advance the development and demonstration, and
thereby establish the commercial availability, of innovative treatment technologies applicable to
Supertund and other hazardous waste sites. The SITE Program was established by the

U.S. Environmental Protection Agency (EPA) Office of Solid Waste and Emergency Response
(OSWER) and Office of Research and Development (ORD) in response to the Superfund Amendments
and Reauthorization Act of 1986 (SARA), which recognizes the need for an alternative or innovative
treatment technology research and demonstration program. The SITE Program is administered by
ORD's National Risk Management Research Laboratory (NRMRL) in Cincinnati, Ohio. The overall
goal of the SITE Program is to carry out a program of research, evaluation, testing, development, and
demonstration of alternative or innovative treatment technoldgies that can be used in response actions to
achieve more permanent protection of human health and welfare and the environment.

The SITE Program consists of four component programs: (1) the Demonstration Program, (2) the
Emerging Technology Program, (3) the Monitoring and Measurement Technologies Program, and

(4) the Technology Transfer Program. This ITER was prepared under the SITE Demonstration
Program. The objective of the Demonstration Program is to provide reliable performance and cost data
on innovative technologies so that potential users can assess a given technology's suitability for a


survey conducted prior to the demonstration refers to a subsurface pipe that extends through the
northwest wall of the former pond, inferring that a pathway could exist between the former pond and
the HRE building (DOE 1996). However, it is unknown whether this pathway was open or closed after
placement of the barrier wall.

2.1.3 Results of the Demonstration Groundwater Tracing Investigations

Tracing investigation results of the dye phloxine B injected into standpipe 12 located within the
containment area and the dye eosine OJ injected into monitoring well MW1 (1109) located outside and
northwest of the containment area are presented below. Figure 2-1 shows the recovery points where
phloxine B and eosine OJ were detected during the demonstration groundwater dye tracing
investigation.

Phloxine B Results

Phloxine B was detected in water samples collected outside the former pond at recovery points STP10,
AFIP, STP1, STP2, STP9, and MW4 (1112). Figures 2-2 through 2-7 plot the concentration of
phioxine B relative to days following dye injection for dye recovered at each recovery point. Phloxine
B was first recovered about 16 days after dye injection at recovery point STP10, which is located
upgradient of injection point I2. The concentration of phloxine B detected at recovery point STP10 was
3.20e-01 ppb, well above the highest concentration (1.30e-03 ppb) detected during the demonstration
background study. The recovery pattern at STP10 shows a rapid increase in concentration of the
emission peak for phloxine B over time, with a lower exponential decrease as shown in Figure 2-2.
The second detection of phloxine B occurred at recovery point AFIP 10 weeks after dye injection.
AFIP is located within the area surrounded by the freeze barrier wall, just southeast of injection point
12 (see Figure 2-3).

Based on the recovery of phioxine B at recovery point STP10, the probability that a series of pipes may
exist in the northwest portion of the former pond cannot be discounted. The pathway from standpipe 12
to the area near standpipe STP10 is very close to the reported location and alignment of a geophysical
anomaly, inferred to be a pipe, that was detected prior to the technology demonstration.

30


This section summarizes factors that influence costs, presents assumptions used in this analysis,
discusses estimated costs, and presents conclusions of the economic analysis. Tables 4-1 and 4-2
Present the estimated costs generated from this analysis. Costs have been distributed among 12
categories applicable to typical cleanup activities at Superfund and RCRA sites, and the distribution of
these costs is shown in Figures 4-1 and 4-2 (Evans 1990). Costs are presented in 1998 dollars, are
rounded to the nearest 100 dollars, and are considered to be -30 percent to +50 percent order-of-

4.1 FACTORS AFFECTING COSTS

Costs for implementing the freeze barrier technology are significantly affected by site-specific factors,
including site regulatory status, waste-related factors, containment duration, and site features and
geology. The regulatory status of the site typically depends on the type of waste management activities
that occurred on site, the relative risk to nearby populations and ecological receptors, the state in which
the site is located, and other factors. The site’s regulatory status affects costs by mandating ARARs
and remediation goals that may affect the system design parameters and duration of the remediation
project. Certain types of sites may have more stringent monitoring requirements than others,
depending on regulatory status. Site features and geology determine the recuired installation depth and
configuration of the freeze barrier system layout which will affect costs.

Waste-related factors affecting costs include the volume and distribution of contamination at the site,
because these factors directly affect the size and positioning of the barrier that is required for
containment. Formation of frozen soil barriers in areas where low freezing point contaminants are
present may require a different refrigeration system then what was applied at the HRE pond site, which
will affect costs. The type and concentration of contaminant will also affect disposal costs for
investigation-derived wastes. Finally, the length of time that the barrier must remain in place will
affect costs, due to ongoing electricity usage, general maintenance, and monitoring costs.

75


tas

azar

PLAN VIEW OF
SYSTEM CONFIGURATION
LEGEND NOT TO SCALE

LZ, WKTERPROOFING MEMBRANE

UMITS OF ASPHALT-CAP
FORMER TOP OF POND
-_---T- FORMER POND BOTTOM
@  THERMOPROBE
@ TEMPERATURE MONITORING POINTS
> MW = Monitoring Well
4 — SIP,I_ = Standpipe
4 — W = Piezometer

ISOURCE: MODIFIED FROM EPA 1998

NOT TO SCALE

SSNS

PROFILE VIEW OF
THERMOPROBE
NOT TO SCALE

ARCTIC FOUNDATIONS, INC. — HRE POND SITE
OAK RIDGE NATIONAL LABORATORY
OAK RIDGE, TENNESSEE

FIGURE 1-6
JPLAN VIEW OF SYSTEM CONFIGURATION
AND PROFILE VIEW _OF THERMOPROBE

Tetra Tech EM Inc.



Analytical Results for

Eosine OJ and Phioxine B
(ppb)
Location Description Phase| Sample Type | Sample Date Eosine OJ Phloxine B
TR NSC 5/20/98
MW4 (1112) monitoring well TR GS 5/21/98 1.30E-03 1,30E-03
MW2 (1110) monitoring well TR GS 5/22/98 ND ND
W898 piezometer TR GS 5/22/98 ND ND
T NSC 5/23/98
TR NSC 5/24/98
MW4 (1112) Monitoring well TR GS 5/25/98 1.30E-03 1.30E-03
W898 piezometer TR Gs 5/26/98 ND ND
TR NSC 5/27/98
MW4 (1112) monitoring well TR. GS 5/28/98 1.30E-03. 1,30E-03
AFIP. piezometer To GS 5/29/98 ND 3.30E-02
MW2 (1110) monitoring well TR GS 5/29/98 ND. ND
MW3 (1111) monitoring well TR. GS 5/29/98 ND ND
MW4 (1112) monitoring well TR GS 5/29/98 1.30E-03 1.30E-03
‘we98 piezometer TR GS 5/29/98 ND ND
STP1 standpipe TR GS 5/29/98 3.07E-02 2.03E-02
STP10 standpipe TR GS 5/29/98 ND 2.60E-02
STP2 standpipe T Gs 5/29/98 3.61E-02 2.24E-02
STPS standpipe To GS 5/29/98 ND ND
STP standpipe TR GS 5/29/98 ND. ND
STPS standpipe TR GS 5/29/98 ND ND
STP9 standpipe TR GS 5/29/98 4.30E-03 41.30E-03
TR NSC 5/30/98
TR NSC 5/31/98
MW2 (1110) monitoring well TR GS 6/1/98 ND ND
W898 piezometer TR GS 6/1/98 ND ND
SBC stream below culvert TR GS 6/1/98 ND ND
TR NSC 6/2/98
TR NSC 6/3/98
TR NSC 6/4/98
STP6 standpipe TR GS 6/5/98 ND ND
MW2 (11410) monitoring well TR _GS 6/5/98 ND ND
MW4 (1112) monitoring well TR GS 6/5/98 1.30E-03 1.30E-03
W898 piezometer TR GS 6/5/98 ND ND
SBC stream below culvert TR GS 6/5/98 ND ND
TR NSC 6/6/98
TR NSC 6/7/98
MW2 (1110) monitoring well TR. Gs 6/8/98 ND ND
MW4 (11412) monitoring well TR Ss 6/8/98 1,30E-03 1,30E-03

A-13



Economics

Using information from the SITE demonstration, AFI, and other sources, an economic analysis was
conducted that examined 12 cost categories for two different applications of the freeze barrier
technology. The first case (Case 1) presents a cost estimate for extending the use of the freeze barrier
technology at the HRE pond site over a 5-year period. The second case (Case 2) is based on applying
the treeze barrier technology to a Superfund site over a 10-year period. The cost estimate for Case 2
assumes that site conditions and contaminants were similar to those encountered at the HRE pond site,
with the exception of the size of the containment area. Case 2 assumes that the area requiring
containment is about 900,000 cubic feet. Based on these assumptions, the total cost per unit volume of
frozen soil was about $8.30 per cubic foot for Case 1 and $8.50 per cubic foot for Case 2. The cost
per unit volume of waste isolated decreased with increased size of the containment area which was
about $6.50 per cubic foot for Case 1 and $2.80 per cubic foot for Case 2. Costs for applications of
the freeze barrier technology may vary significantly from these estimates, depending on site-specific
factors.

Superfund Feasibility Study Evaluation Criteria for the Freeze Barrier Technology
Table ES-1 briefly discusses an evaluation of the freeze barrier technology with respect to the nine

evaluation criteria used for Superfund feasibility studies when considering remedial alternatives at
Superfund sites (EPA 1988b).


Figure 2-11
Concentrations of Eosine OJ Versus Time

4.206403 for Location DLD
o4
1,00E+03
 8.00e+02
3 6.00E+02 °
>
Hf 4.00E+02 « %
2.00E+02
A
0.00E+00 1 ___4- +
-25 0 25 50 75 100 126 150
Days Relative to Dye Injection at Zero
Figure 2-12
Concentrations of Eosine OJ Versus Time
3.00E-02 for Location MW4 (1112)
€
5 2.00E-02
H
i 1.00E-02
\/
900000000000 00000
0,00E+00 {2CCeee> ammmamD 40800- 2 » oe
-25 tt) 25 50 75 100 125 150
Days Relative to Dye Injection at Zero

41


Analytical Results for
Eosine OJ and Phioxine B

(ppb)
Location Description Phase| Sample Type Sample Date Eosine OJ Phioxine B
DOLD Dale's Little Dipper Spring | TR Gs 3/25/98 3.56E+02 ND
MW2 (1410) monitoring well TR GS 3/25/98 ND ND
MW4 (1112) monitoring well TR GS 3/25/98 1,30E-03 1,30E-03
‘wsg8 plezometer TR GS 3/25/98 ND ND
SBC stream below culvert TR GS 3/25/98 ND ND
STP10 standpipe TR GS 3/25/98 ND ND
STP9 standpipe TR GS 3/25/98 1.30E-03 1.30E-03
W898 piezometer TM GS 3/26/98 ND ND
SBC stream below culvert TR GS 3/26/98 ND ND
AFIP. piezometer T GS 3/27/98 ND 1,30E-03
DLD Dale's Little Dipper Sprin T GS 3/27/98 4.56E+02 ND
MW3 (1111) monitoring well T GS 3/27/98 ND ND
OF283 Overfiow 283 TR GS 3/27/98 ND ND
$1 ‘small tributary TR GS 3/27/98 ND ND
S1 Small tributary TR Cc 3/27/98 ND ND
$2 ‘small tributary TM GS 3/27/98 ND ND
$2 small tributary TR Cc 3/27/98 ND ND
s7 Small tributary TR GS 3/27/98 ND ND
s7 ‘small tributary TR Cc 3/27/98 ND ND
SBC stream below culvert TR GS 3/27/98 ND ND
SBC stream below culvert T c 3/27/98 ND ND
STP10 standpipe TR GS 3/27/98 ND 1.30E-03
STP2 standpipe TR GS 3/27/98 3.61E-02 ND
STP9 standpipe T GS 3/27/98 1.30E-03 1.30E-03
STSS Trivelpiece Spring TR GS 3/27/98 ND ND
TR NSC 3/28/98
T NSC 3/29/98
TR NSC 3/30/98
SBC stream below culvert TR GS 3/31/98 ND ND
TR NSC 4/1198
AFIP piezometer TM GS 4/2/98 ND 1.30E-03
OLD Dale's Little Dipper Spring | TR GS 412198 4.50E+00 ND
KL Keller's Leak TR GS 4/2198 ND ND
STP10 standpipe TR GS 412/98 ND 1.30E-03
STP2 standpipe T Gs 412/98 9.44E-02 ND
STP9 standpipe TR GS 4/2/98 1.30E-03 ND
SBC stream below culvert T GS 413/98 ND ND
TR NSC 4/4198
TR NSC. 4/5/98

A-10



4.3.12 Site Demobilization

After the system is shut down and allowed to thaw, the surface seal would be removed and disposed of
as nonhazardous material or scrap. Following system shutdown, a two-person crew at an estimated
labor rate of $35 per hour would work about two 8-hour days to disassemble the system for Case 1 at a
cost of $1,100. The 50 thermoprobes and eight temperature monitoring points, installed at a depth of
30 feet bgs, would then be removed and the boreholes grouted to the ground surface at an estimated
cost of $20 per foot, for a total cost of about $34,800. Thermoprobes and temperature monitoring
points may be decontaminated and salvaged, if possible. However, as stated in Section 4.3.4, salvage
values were not included in this estimate. Total site demobilization costs for Case 1 are assumed to be
about $35,900.

For Case 2, a two-person crew also earning. an estimated labor rate of $35 per hour would work about
four 8-hour days to disassemble the system at a cost of $2,200. The same cost for Case 2, $20 per
foot, is also assumed to be incurred for removal of 115 thermoprobes and eight temperature monitoring
points also installed at a depth of 30 feet bgs, and grouting boreholes, for a total cost of about $73,800.
Total site demobilization costs for Case 2 are assumed to be about $76,000.

4.4 ECONOMIC ANALYSIS SUMMARY

This analysis presents two cost estimates for installing the freeze barrier technology to prevent off-site
migration of.contaminants. Two cases are discussed: the first case (Case 1) involves a cost estimate
that is based on costs collected during the demonstration for operating the barrier wall at the HRE pond
site at ORNL over a 5-year period, and the second case (Case 2) involves applying the ground freezing .
system to a larger site having conditions similar to those encountered at the Case 1 site, over a 10-year
period. Table 4-1 shows the estimated costs associated with the 12 cost categories presented in this
analysis for both cases.

The total costs and percent distributions for the 12 cost categories in both cases are presented in Table
4-2. The predominant cost categories for Case 1 were capital equipment (35.5 percent) and site

preparation (33.0 percent), accounting for over 60 percent of the total costs for both cases. For Case

94


5.0 TECHNOLOGY STATUS AND IMPLEMENTATION

To date, this SITE demonstration represents the first full-scale application of the AFI frozen soil barrier
technology a a contaminated site. However, AFI has been developing, cesigning, fabricating, and
installing ground freezing systems for about 30 years. AFI has used the techuvicg, to seal subsurface
structures against flooding of groundwater; to stabilize soils for excavation; and for foundation and
ground stabilization purposes. While the AFI ground freezing sysiem nas been primarily used in arctic
and subarctic environments, such as Alaska, Canada, and Greenland, the system can also be used in
more temperate locations as demonstrated at the HRE pond site.

Current plans for AFI’s ground freezing at ORNL’s HRE pond site incluae maintaining the frozen soil
barrier through DOH’s fiscal year 2002 w assess long-term performance of the barrier wall.. DOE is
also considering the use of the freeze barrier technology for containment of radiologically contaminated
groundwater plumes at two other DOE facilities, including Savannah River and Hanford. The
technology also is being considered for containment of a groundwater plume contaminated with
polychlorinated biphenyls and dense nonaqueous-phase liquids at a site in Smithville, Canada.


3.0

Contents (Cont’d.)

2.1.1 Methods

FS 27
2.1.2 Results of the Demonstration Background Study 29
2.1.3 Evaluation of Objective PL... 0... ec c eee e eee 30
2.1.4 Evaluation of Objectives S-1 andS2......0....00. 00.00. e eee . 39
2.1.5 Evaluation of Objective S-3 ..... . 50
.2.1.6 Evaluation of Objective S-4 . . on -. 57
2.1.7 Data Quality 2... cece nee eee eee . 58
TECHNOLOGY APPLICATIONS ANALYSIS ............:...0.00005 . 61
3.1 APPLICABLE WASTE ....... 2.0.0... eee eee cece cece eee aae . 61
3.2 FACTORS AFFECTING TECHNOLOGY PERFORMANCE .........5... . 61
3.2.1 Hydrogeologic Characteristics... 2... eee eee eee ee . 61
3.2.2 Engineered Structures ........ . 62
3.2.3 Diffusion Characteristics .
3.3. SITE CHARACTERISTICS AND SUPPORT REQUIREMENTS .......... . 6
3.3.1 Site Area and Preparation Requirements . 6
3.3.2 Climate Requirements ............. . 64
3.3.3 Utility and Supply Requirements . . 64
3.3.4 Maintenance Requirements .............. . 65
3.3.5 Support Systems .....0......-....0.00. . 65
3.3.6 Personnel Requirements .........0.. 0.0.00 ccc eee e eee eeeee 66
3.4 MATERIAL HANDLING REQUIREMENTS .......2.....0 00000 eee ce 66
3.5 TECHNOLOGY LIMITATIONS 67
3.6 POTENTIAL REGULATORY REQUIREMENTS . 67
3.6.1 Comprehensive Environmental Response; Compensation,
: and Liability Act ©... 0... 6... eee ee eee . 67
3.6.2 Resource Conservation and Recovery Act 69
3.6.3 Clean Water Act... ...0.. ra . 70
3.6.4 Safe Drinking Water Act ...... . 71
3.6.5 Clean Air Act ............. . 71
3.6.6 Mixed Waste Regulations ...... nT
3.6.7 Occupational Safety and Health Act 7
3.7. STATE AND COMMUNITY ACCEPYANCE ............00....00e00e vk)


should address chemicals of concern and include monitoring practices to ensure that worker health and
safety are maintained.

For most on-site workers, PPE will include gloves, hard hats, steel-toed boots, and coveralls.
Depending on contaminant types and concentrations, additional PPE may be required. Noise levels
should be monitored to ensure that workers are not exposed to noise levels above a time-weighted
average of 85 decibels over an 8-hour day. Noise levels associated with the freeze barrier technology
are limited to compressor noise from the refrigeration units.

3.7 STATE AND COMMUNITY ACCEPTANCE

State regulatory agencies will likely be involved in most applications of the freeze barrier technology at
hazardous waste sites. Local community agencies and citizens’ groups are often actively involved in
decisions regarding remedial alternatives.

Because few applications of the freeze barrier technology have been completed, limited information is
available to assess long-term state and community acceptance. However, state and community
acceptance of this technology is generally expected to be high, for several reasons: (1) it provides a
means to fully contain waste, thereby preventing the further spread of contaminants; (2) the barrier is
environmentally safe, using benign working fluids; (3) the barrier wall does not have any lasting effects
and is simply allowed to melt after thermoprobes are removed; and (4) the system generates no residual
wastes requiring off-site management and does not transfer waste to other media.

TDEC oversees investigation and remedial activities at ORNL. State personnel were actively involved
in the preparation of the QAPP and field work and data gathering activities during the technology
demonstration. The state also issued a UIC permit for the groundwater tracing investigation. The role
of states in selecting and applying remedial technologies will likely increase in the future as state
environmental agencies assume many of the oversight and enforcement activities previously performed
at the EPA Regional level. For these reasons, state regulatory requirements that are sometimes more
stringent than federal requirements may take precedence for some applications. As risk-based closure
and remediation become more commonplace, site-specific cleanup goals determined by state agencies
will drive increasing numbers of remediation projects, including applications involving the freeze
barrier technology.

73


[-—_—-. N s20
RHODAMINE. WT INJECTION POINT WE74@ A
stP1
‘yt esr2 “e :
1109) Wess
stP3
i spc #
[ ~7 j
| | stss |
en | NEBr | :
| NS | Riri
I
|
LEGEND

FORMER TOP OF POND
——. ——— — FORMER POND BOTTOM
UMITS OF ASPHALT CAP

GROUND SURFACE
WATER WATER

fe} © — REcoveRY PONT

e © © RHODAMINE WT DETECTIONS

e @ = RHODAMINE WT AND
EOSINE OJ DETECTIONS

ca ARCTIC FOUNDATIONS, INC, — HRE POND SITE
OAK RIDGE NATIONAL LABORATORY
OAK RIDGE, TENNESSEE .

bad

FIGURE
1 ° s xo RHODAMINE WT. AND EOSINE OJ
TRACER RECOVERY POINTS

SAE I =30  {{ Tetra Tech EM Inc.

SOURCE: MODIFIED FROM EPA 1998

18


Analytical Results for

Eosine OJ and Phloxine B
(ppb)

Location Description Phase} Sample Type | Sample Date Eosine OJ Phioxine B
STP2 standpipe TR Gs 2/20/98 2.75E-02 1.30E-03
STP9 standpipe T Gs 2/20/98 1,.52E-02 ND
STSS Trivelpiece Spring TR GS 2/20/98 ND ND
W898: piezometer TR GS 2/20/98 ND ND

MW2 (1110) monitoring weil TR Gs 2/21/98 ND ND
MW4 (1112) monitoring well TR GS 2/21/98 1.30E-03 1,30E-03
SBC stream below culvert T GS 2/21/98 ND ND
‘we98 piezometer TR Gs 2/21/98 ND ND
W898 piezometer TR c 2/21/98 ND ND
MW4 (1112) monitoring well TR c 2/22/98 1.30E-03 1.30E-03
SBC stream below culvert TR Gs 2/22/98 ND ND
‘ws98 piezometer TR GS 2/22/98 ND ND
AFIP. piezometer. TR GS 2/23/98 ND 1.30E-03
DOLD Dale's Little Dipper Spring |_ TR GS 2/23/98 6.27E+02 ND
KL Keller's Leak TR GS 2/23/98 ND ND
MW2 (1110) monitoring well TR GS 2/23/98 ND ND
MWS (1111) monitoring well TR Gs 2/23/98 ND ND
MWS (1111) Monitoring well TR Cc 2/23/98 ND ND
MW4 (1112) monitoring well T GS 2/23/98 4.30E-03 1.30E-03
Si ‘small tributary TR GS 2/23/98 ND ND
Si small tributary TR Cc 2/23/98 ND ND.
$2 small tributary TR GS 2/23/98 ND ND
$2 small tributary TR Cc 2/23/98 ND ND
S7 ‘small tributary TR GS 2/23/98 ND ND
$7 small tributary TR Cc 2/23/98 ND ND
SBC. stream below culvert TR. GS 2/23/98 ND ND
STP10 standpipe TR cs 2/23/98 ND 1.30E-03
STP10 standpipe TR Cc 2/23/98 ND ND
STP2 standpipe TR Gs 2/23/98 7.55E-02 1.30E-03
STP9 standpipe T Cc 2/23/98 7.60E-03 1.30E-03
STSS Trivelpiece Spring TR GS 2/23/98 ND ND
STSS Trivelpiece Spring TR Cc 2123/98 ND ND
wes9s8 piezometer TR GS 2/23/98 ND ND
MWz2 (1110) Monitoring well TR GS 2/24/98 ND ND
MW4 (1112) monitoring well TR GS 2/24/98 1.30E-03 1,30E-03
SBC. stream below culvert T GS 2/24/98 ND. ND
W898 piezometer TR Gs 2/24/98 ND ND
‘W898 piezometer T Cc 2/24/98 ND ND
AFIP. piezometer TR GS 2/25/98 ND- 1.30E-03

AS



Site features affecting costs include site hydrogeology, location, and physical characteristics.
Hydrogeologic conditions are significant factors in determining the applicability and design parameters
of the barrier and should be thoroughly defined before applying this technology. The depth to
groundwater and depth to the uppermost underlying aquitard, if present, determine the depth of the
installation and the type of construction technology that will be employed. Sites with no underlying
aquitard will require thermoprobes to be installed in closely spaced, directional boreholes in a “V” or
“U” configuration. Each of these factors affect site preparation, capital, and operating costs. Site
location and physical features will affect mobilization, demobilization, and site preparation costs.
Mobilization and demobilization costs are affected by the relative distances that system materials must
travel to the site. High visibility sites in densely populated areas may require higher security and the
need to minimize obtrusive construction activities, noise, dust, and air emissions. Sites requiring
extensive surficial preparation (such as constructing access roads, clearing large trees, working around
or demolishing structures) or restoration activities will also incur higher costs. The availability of
existing electrical power and water supplies may facilitate construction activities and continuing O&M
activities for the ground freezing system. Within the U.S., significant regional variations may occur in
costs for materials, equipment, and utilities.

4.2 | ASSUMPTIONS OF THE ECONOMIC ANALYSIS

This section summarizes major assumptions regarding site-specific factors aid equipment and operating
parameters used for both cases. For Case 1, existing technology and site-specific data from the
demonstration were used to present costs for extended use of the barrier wall over a 5-year period at
the HRE pond site. Certain assumptions were made to account for variable site and waste parameters
for Case 2. Other assumptions were made to simplify cost estimation for situations that would require
complex engineering or financial functions. In general, most system operating issues and assumptions
are based on information provided by AFI, DOE, and observations made during the SITE
demonstration. Cost figures for both cases are established from information provided by AFI, DOE
(MSE Technology Applications, Inc. [MSE] 1998), current environmental restoration cost guidance
{R.S. Means Company, Inc. [Means] 1998), and SITE Program experience.


TABLE 1-2

RESULTS OF THE 1996 GROUNDWATER
TRACING INVESTIGATION FOR EOSINE OJ

Recovery Initial Detection | Peak Detection Initial Peak
Point (days)* (days)* Concentration Concentration

(ppb) (ppb)
MW2 (1110) 15 42.6 1.10e-02 6.71e-02
MW4 (1112) 22 36.21 5.29e-03 2.68e+-00
MwW3 (1111) 22 42.6 4.04e-02 1.32e-01
W674 39-43 42.6 Not Determined” 1.25e+00
STP10 39-43 42.6 Not Determined” 1.79e-01
W898 39-43 42.6 Not Determined? “4.98e-+00
STP2 43 63.9 1.10e-05 2.03e+00
SBC 43-50 49.7 Not Determined” 4.19e-01
STP9 50 63.9 1.10e-05 2.85¢-02
85 50-56 55.38 Not Determined” 5.67e+00

$3 50-56 55.38 Not Determined? 1.65e-01
DLD 56 11 1.64e+01 4.29e+01

Notes:

ppb parts per billion
» Number of days following dye injection
> Initial concentration could not be determined due to the sampling frequency

21