PB95-182929
EPA-542-R-95-003
March 1995
Remediation Case Studies:
Ground water Treatment
Federal
Remediation
Technologies
Roundtable
Prepared by the
Member Agencies of the
Federal Remediation Technologies Roundtable
REPRODUCED BY:
U.S. Department of Commerce1
National Technical Information Service
Springfield, Virginia 221(1
Recycled/Recyclable
I Printed with Soy/Canola Ink on paper that
contains at least 50% recycled fiber
-------
NOTICE
This report and the individual case studies were prepared by Agencies of the United States Government. Neither the United States
Government nor any Agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or
responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its
use would not infringe privately-owned rights. Reference herein to any specific commercial product, process, or service by trade name,
trademark, manufacturer, or otherwise does not imply its endorsement, recommendation, or favoring by the United States Government or any
Agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States
Government or any Agency thereof.
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Remediation Case Studies:
Groundwater Treatment
\
Prepared by Member Agencies of the
Federal Remediation Technologies Roundtable
Environmental Protection Agency
Department of Defense
U.S. Air Force
U.S. Army
U.S. Navy
Department of Energy
Department of Interior
National Aeronautics and Space Administration
Tennessee Valley Authority
Coast Guard
March 1995
U.S. Environmental Protection Agency
Region 5, Library (PL. 12J)
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FOREWORD
This report is a collection of eleven case studies of groundwater treatment
projects prepared by Federal agencies. The case studies, collected under the auspices of the
Federal Remediation Technologies Roundtable, were undertaken to document the results and
lessons learned from early technology applications. They will help establish benchmark data
on cost and performance which should lead to greater confidence in the selection and use of
cleanup technologies.
The Roundtable was created to exchange information on site remediation
technologies, and to consider cooperative efforts that could lead to a greater application of
innovative technologies. Roundtable member agencies, including the U.S. Environmental
Protection Agency, U.S. Department of Defense, and U.S. Department of Energy, expect to
complete many site remediation projects in the near future. These agencies recognize the
importance of documenting the results of these efforts, and the benefits to be realized from
greater coordination.
There are four case study reports, organized by technology, in this series. In
the future, the set will grow through periodic supplements tracking additional progress with
site remediation. In addition to this report on groundwater treatment projects, the following
volumes are available:
Remediation Case Studies: Bioremediation;
Remediation Case Studies: Soil Vapor Extraction; and
Remediation Case Studies: Thermal Desorption, Soil Washing, and In Situ
Vitrification.
Ordering information for these and other Roundtable documents is on the following page.
Walter W. Kovalick, Jr., Ph.D. '
Chairman
Federal Remediation Technologies Roundtable
11
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Ordering Instructions
The following documents are available free-of-charge from the U.S. EPA/National Center for Environmental Publications and
Information (NCEPI). To order, mail or fax the completed form below to: U.S. EPA/National Center for Environmental Publications
and Information, P.O. Box 42419, Cincinnati, OH 45242, or FAX requests to (513) 489-8695.
Title
Abstracts of Remediation Case Studies [106pp]
Guide to Documenting Cost and Performance for Remediation Projects [64pp]
Number Price
EPA-542-R-95-001 Free
EPA-542-B-95-002 Free
Please Send
Name.
.Date.
Organization.
Address
City/State/Zip.
. Telephone.
Internet Address
The following documents are available by calling the National Technical Information Service (NTIS) at 703-487-4650 or writing
them at: National Technical Information Service (NTIS), 5285 Port Royal Road, Springfield, VA 22161
Title
Remediation Case Studies: Bioremediation
Remediation Case Studies: Groundwater Treatment
Remediation Case Studies: Soil Vapor Extraction
Remediation Case Studies: Thermal Desorption, Soil Washing,
and In Situ Vitrification
Remediation Case Studies: Four Document Set
Number
PB95-182911
PB95-182929
PB95-182937
PB95-182945
PB95-182903
Price*
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$17.50
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Other Federal Remediation Technology Roundtable (FRTR) documents available from NTIS:
Title Number Price*
Accessing Federal Databases for Contaminated Site Clean-Up Technologies (3rd Edition) PB94-144540 $17.50
Federal Publications on Alternative and Innovative Treatment Technologies for
Corrective Action and Site Remediation (3rd Edition) PB94-144557 $17.50
Synopses of Federal Demonstrations of Innovative Site Remediation Technologies
(3rd Edition) PB94-144565 $44.50
Remediation Technologies Screening Matrix and Reference Guide (2nd Edition) PB95-104782 $45.00
* Additional fee for shipping and handling; next day delivery also available. Major credit cards accepted.
Ill
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TABLE OF CONTENTS
Page
FOREWORD ii
ORDERING INSTRUCTIONS iii
INTRODUCTION 1
GROUNDWATER TREATMENT REMEDIATION CASE
STUDIES 6
Density-Driven Groundwater Sparging at Amcor
Precast Ogden, Utah 7
Petroleum Product Recovery and Contaminated
Groundwater Remediation Amoco Petroleum
Pipeline Constantine, Michigan 27
Pump and Treatment System at Commencement Bay, South
Tacoma Channel (Well 12A), Phase 2, Tacoma, Washington 44
Recovery of Free Petroleum Product Fort Drum,
Fuel Dispensing Area 1595 Watertown, New York . 59
Pump & Treat of Contaminated Groundwater at
Langley Air Force Base Virginia 75
Dynamic Underground Stripping Demonstrated at
Lawrence Livermore National Laboratory Gasoline
Spill Site, Livermore, California 90
Pump & Treat of Contaminated Groundwater at
Operable Unit B/C McClellan Air Force Base
California 125
Pump & Treat of Contaminated Groundwater at
Twin Cities Army Ammunition Plant, New
Brighton, Minnesota 140
IV
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Pump and Treat of Contaminated Groundwater at
U.S. Department of Energy Kansas City Plant
Kansas City, Missouri 155
Pump and Treat of Contaminated Groundwater at
U.S. Department of Energy Savannah River Site,
Aiken, South Carolina 171
In Situ Air Stripping of Contaminated
Groundwater at U.S. Department of Energy
Savannah River Site Aiken, South Carolina 186
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INTRODUCTION
The purpose of this report is to provide case studies of groundwater treatment
site cleanup projects. This report is one of four volumes which are the first in a series of
studies that will be prepared by Federal agencies to improve future remedy selection at
contaminated sites. For projects that are ongoing, interim findings will be updated in future
publications as additional data become available.
The case studies were developed by the U.S. Environmental Protection Agency
(EPA), the U.S. Department of Defense (DoD), and the U.S. Department of Energy (DOE).
They present cost and performance information for full-scale remediation efforts and several
large-scale demonstration projects and were prepared retrospectively, based on available
information and interviews with project personnel. The case studies are meant to serve as
primary reference sources, and contain information on the site; contaminants and media
treated; technology and vendor; cost and performance; and points of contact for the
technology application. The studies contain varying levels of detail, reflecting the differences
in the availability of data and information. Full-scale cleanup efforts are not conducted
primarily for the purpose of technology evaluation, and data collection is often limited to
establishing compliance with contractual requirements or regulatory levels.
This volume contains reports on eleven projects, eight of which are still
ongoing. Most of the projects address petroleum hydrocarbons and chlorinated aliphatics,
such as trichloroethylene (TCE). The eight ongoing projects are using pump-and-treat
technologies, while two of the three completed efforts utilized air sparging. One report in this
volume describes a project that used in situ steam injection/electrical heating of subsurface
soils (referred to as dynamic underground stripping).
Table 1 provides a project summary including information on technology used,
contaminants and media treated, and project duration. The table also notes highlights of the
technology applications.
Table 2 summarizes cost data, including information on quantity of media
treated and contaminant removed. In addition, Table 2 shows a calculated unit cost for some
projects, and identifies key factors potentially affecting project cost. While a summary of
project costs is useful, it is difficult to compare costs for different projects because of site-
specific factors and differences in level of detail.
Cost data are shown on Table 2 as reported in the case studies, and have not
been adjusted for inflation to a common year basis. The dollar values shown in Table 2
should be assumed to be dollars for the time period that the project was in progress (shown
on Table 1 as project duration).
The project costs shown in the second column of the table were compiled
consistently. However, the case studies themselves vary in terms of the level of detail and
format of the available cost data. Where possible, project costs were categorized according to
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an interagency Work Breakdown Structure (WBS).1 The WBS specifies costs as 1) before-
treatment costs, 2) after-treatment costs, or 3) treatment costs. (Table 2 provides some
additional information on activities falling under each category.) In many cases, however, the
available information was not sufficiently detailed to be broken down in this way.
The column showing the calculated treatment cost provides a dollar value per
unit of soil or groundwater treated and, if possible, per pound of contaminant removed. Note
that comparisons using the information in this column are complicated by the fact that
calculated costs may only be available on a per cubic yard or per ton basis, and cannot be
converted back-and-forth due to limited availability of soil bulk density data.
Key factors that potentially affect project costs include economies of scale,
concentration levels in contaminated media, required cleanup levels, completion schedules,
and hydrogeological conditions. It is important to note that several projects in the case study
series represent early applications, and the costs of these technologies are likely to decrease in
the future as firms gain experience with design and operation.
Abstracts and On-Line Access
The case studies have been summarized in abstracts which precede each study
and provide key project information in a consistent format. The abstracts are based on
recommended terminology and procedures from the Guide to Documenting Cost and
Performance for Remediation Projects.
The case study abstracts are also available on-line through EPA's Cleanup
Information Bulletin Board System (CLU-IN). To access CLU-IN by modem, call (301) 589-
8366, or to contact the CLU-IN help desk, call (301) 589-8368. CLU-IN is available on the
Internet; the telnet address is clu-in.epa.gov or 134.67.99.13.
'Additional information on the contents of the Work Breakdown Structure and on whom to contact for WBS
and related information is presented in the Guide to Documenting Cost and Performance for Remediation
Projects - see ordering instructions on page iii.
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GROUNDWATER TREATMENT
CASE STUDIES
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Density-Driven Groundwater Sparging at
Amcor Precast
Ogden, Utah
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Case Study Abstract
Density-Driven Groundwater Sparging at
Amcor Precast, Ogden, Utah
Site Name:
Amcor Precast
Location:
Ogden, Utah
Contaminants:
Benzene, Toluene, Ethylbenzene, Total Xylenes (BTEX), Naphthalene,
and Total Petroleum Hydrocarbons (TPH)
Groundwater
- Average groundwater concentrations (mg/L) in plume area/site
maximum - TPH (51/190), benzene (1.3/4.7), toluene (2.4/9.4),
ethylbenzene (0.78/2.7), total xylenes (2.5/8.0), naphthalene (0.18/0.63)
Soil
- Average soil concentrations (mg/kg) in plume area/site maximum -
TPH (555/1,600), benzene (2.0/7.8), toluene (1.4/2.5), ethylbenzene
(5.7/19), total xylenes (37/110)
Period of Operation:
March 1992 to
September 1993
Cleanup Type:
Full-scale cleanup
Vendor:
Todd Schrauf
Wasatch Env., Inc.
225 IB West California
Ave.
Salt Lake City, UT
84104
(801) 972-8400
SIC Code:
Not Available
Technology:
In situ Density-Driven Groundwater Sparging and Soil Vapor Extraction
- System consists of three main components - groundwater sparging
system; groundwater recirculation system; and soil vapor extraction
system
- Groundwater sparging was principal method of remediation; SVE was
used locally
Sparging System
- Density-driven groundwater sparging - removed petroleum
hydrocarbons using (1) aerobic degradation and (2) in situ air stripping;
water inside the wellbore was aerated directly by injecting air at the
base of the wellbore
- 12 groundwater sparging wells instilled to a depth of 18 feet
Groundwater Recirculation
- 3 downgradient extraction (pumping) wells installed to a depth of 20
feet and 1 upgradient injection galley (former tank excavation
backfilled with pea gravel)
SVE
- 3 vertical extraction wells located adjacent to the pumping wells
- Vapor discharged to atmosphere
Cleanup Authority:
State: Utah
Department of
Environmental
Quality, Division of
Response and
Remediation (DERR)
Point of Contact:
Shelly Quick
Utah DERR
Waste Source:
Underground Storage
Tanks
Type/Quantity of Media Treated:
Groundwater and Soil
- Site stratigraphy - interbedded silty sand and poorly graded fine gravel underlain by a silty clay
aquitard at a depth of approximately 18 feet below ground surface
- Depth to groundwater - 5 to 11 feet; aquifer thickness (7-13 feet)
- Porosity (20-35%), hydraulic conductivity (190 ft/day)
- Aerial extent of the plume - approximately 30,000 ft2; vertical extent of contamination -
contaminants concentrated in vertical zone from approximately 5 to 11 feet below ground surface
- Estimated volume of contaminated soil - 7,000 yd3
Purpose/Significance of Application:
Full-scale remediation of groundwater contaminated with diesel and gasoline fuels using in situ density-driven groundwater
sparging and soil vapor extraction.
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Case Study Abstract
Density-Driven Groundwater Sparging at
Amcor Precast, Ogden, Utah (Continued)
Regulatory Requirements/Cleanup Goals:
- Soil - DEQ Recommended Cleanup Levels (RCLs) - TPH - 30 mg/kg; Benzene - 0.2 mg/kg; Toluene - 100 mg/kg;
Ethylbenzene - 70 mg/kg; Xylenes - 1,000 mg/kg; Naphthalene - 2.0 mg/kg
- Groundwater - BTEX and naphthalene to below MCLs; no cleanup goal for TPH in groundwater
- Air - no air discharge permit was required because air emissions were below de minimis standards of the Utah Division of
Air Quality
Results:
- The cleanup goals were achieved for all contaminants of concern in both soil and groundwater
Cost Factors:
- Total Capital Cost: $156,950 (including drill/install wells and sparging system, start-up, project management)
- Total Annual Operating Cost: $62,750 (including electricity, maintenance, monitoring)
Description:
Amcor Precast in Ogden, Utah, stored gasoline and diesel fuel in three underground storage tanks. A release was discovered
in 1990. An investigation in 1991 indicated that the areal extent of groundwater contamination was approximately 30,000 ft2
and that an estimated 6,700-7,000 yd3 of soil had been contaminated. The primary contaminants of concern were benzene,
toluene, ethylbenzene, and xylenes (BTEX), naphthalene, and total petroleum hydrocarbons (TPH). A density-driven
groundwater sparging system and soil vapor extraction (SVE) system were installed in January/February 1992 and operated
from March 1992 to September 1993. The sparging system was used as the primary remediation technology. SVE was used
locally to treat volatilized hydrocarbons, created by the air stripping process, and prevent contaminants from migrating to
nearby office buildings.
With the density-driven groundwater sparging system at Amcor, water inside the wellbore was aerated by injecting air into the
base of the wellbore (rather than injected under pressure) with the resulting injection air bubbles stripping contaminants from
the water while increasing the dissolved oxygen content. In addition, the aeration process acted to create groundwater
circulation and transport. Therefore, with this system, petroleum hydrocarbons were removed from the subsurface by (1)
aerobic biodegradation resulting from the supply of oxygen to the saturated zone; and (2) in situ air stripping. The air
stripped vapors are transferred to the vadose zone and are biodegraded in place. The application of density-driven
groundwater sparging and SVE achieved the specified cleanup goals for both soil and groundwater. The cleanup goals for
soil and for all contaminants except naphthalene in groundwater were achieved within 11 months of system operation. The
cleanup goal for naphthalene in groundwater was achieved within 18 months.
The total capital cost for this application was about $157,000 and total annual operating costs were $62,750. Air sparging is
limited to contaminants that can be degraded by indigenous bacteria under aerobic conditions. Maximum sparging well air
flow and groundwater wellbore circulation rates are dependent on well diameter, depth to groundwater, and the hydraulic
conductivity of the formation. Therefore, longer remediation times or a greater number of sparging wells may be required in
lower permeability formations.
-------
TECHNOLOGY APPLICATION ANALYSIS
LIZSITE
Pago 1 of 17
CZTECHNOLOGY APPLICATION:
Name:
Amcor Precast
Location: Ogden,
Utah (directly adjacent
and south of Ogden
Defense Depot)
.AMCOR PRECAST
OMEN
UTAH
This summary addresses the field application of
density-driven groundwater sparging for the in situ
remediation of an underground storage tank
release of diesel and gasoline fuels. The system
was started up in March, 1992 and remediation
completed in September, 1993.
CUSITE CHARACTERISTICS
•S/te History/Release Characteristics
Amcor Precast operated three underground storage tanks at the site, used for the storage of unleaded gasoline,
leaded gasoline, and diesel fuel, respectively.
The release was discovered when the underground storage tanks were removed for permanent closure in
December, 1990. The volume of the release is unknown. The exact cause of the release is also unknown,
although laboratory analysis of contaminated soils from the tank excavation indicated the release consisted pri-
marily of gasoline, with minor amounts of diesel.
At the time of discovery and investigation (1991), the spill had an area! extent of approximately 30,000 ft2 and had
impacted an estimated soil volume of 6,700 yd3.
The remedial system was installed in January and February of 1992. The system was placed in to operation in
March of 1992. The remediation was completed in September of 1993.
• Contaminants of Concern
• The contaminants of concern were the aromatic hydrocarbons: benzene, toluene, ethylbenzene, total xylenes,
and naphthalene as well as total petroleum hydrocarbons (TPH)
U.S. Air Force
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Amcor Precatt 2 of 17
TABLE1:CONTAMINANTPROPERTIES II
Property
Empirical Formula
Density 9 20°C
Melting Point
Boiling Point
Vapor Pressure
(25
Organic Carbon
Partition Coefficient
<*oc>
lonizatnn Potential
Molecular
Units
gm/cm
€
°C
mm Hg
g/L
atm-
m3/mol
mg/1
ml.gn
eV
gmt
Benzene
C6H6
0 88
55
80 1
95
3 19
5.4 x 10'3
1696 to 1860
(avg. 1770)
36 to 141
(avg. 110)
49 to 100
(avg. 81)
9.25. 956
78.11
Ethylbenzene
C8H10
0 87
-95
136.2
10
4 34
0 0064 to
0 0087
(avg. 0 0072)
131 to 206
(avg 1741
1120 to 1410
(avg 1290)
95.257
3.76. 9.12
106.17
Toluene
C7H8
087
-95
110 6
31
3 77
0 0067
492 to 627
(avg, 545)
129 to 631
(avg. 417)
114,151
8.82
92.14
o.m.p-Xylene
Wo
0 86 to 0 88
-47,9 to 13,3
138.3 to 1444
6.6 to 8.8
4 34
00050 to
0,0071
156 to 204
589 to 1580
129 to 1580
8.44 to 8 58
106.17
Naphthalene j
C10H8
1 16
80 5
217.9
023, 0.87
0.00036 to
0 0012
(avg. 000061)
20.3 to 40 0
(avg 31 0)
1020 to 50,100
(avg. 2560)
550 to 3310
(avg. 1550)
8.14. 8.26
128.18
MO584171D
i Nature and Extent of Contamination
Site investigations were conducted during the first eight months of 1991 to define the extent of soil and
groundwater contamination. These investigations included soil gas surveys, drilling and sampling of soil bor-
ings, and monitor well installation and sampling. Sampling locations and plume extent are shown in Figure 1.
The maximum and average concentrations of the contaminants of concern are identified in Table 2 for both
soil and groundwater. Average groundwater concentrations are based on samples collected from wells MW-
3, MW-4, MW-5, and MW-7, all located along the centerline of the contaminant plume. Average soil concen-
trations are based on samples collected from BH-3, BH-13, BH-14, and MW-5, also all located within the cen-
ter of the plume. The aerial extent of the plume was approximately 30,000 ft2. The volume of contaminated
soil was estimated at 7,000 yd3.
TABLE 2 SUMMARY OF PRE-REMEDIIATION CONTAMINANT CONCENTRATIONS
Contaminant
of Concern
TPH
Benzene
Toluene
Ethylbenzene
Total Xylenea
Naphthalene
Soil Concentration* (mg/kg)
Site
Maxmum
1600
78
2 5
19
110
Not Measured
Average n
Plume Area
555
2 0
1 4
57
37
Not Measured
Cleanup
Goal (RCL's)
30
02
100
70
1000
20
Groundwatar Concentrations (mg/l)
Site
Maxmum
190
47
94
27
80
063
Average in
Plume Area
51
1 3
24
0 78
25
0 18
Cleanup
Goal
(MCL'l)
Not
Established
0005
1 0
07
10
0020
U.S. Air Force
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Ameor Practat 3 of 17
12th Street
'MW11
'MW6
APPROXIMATE EXTENT OF
PETROLEUM HYDROCARBON
CONTAMINATION
OFFICE BUILDING
LEGEND
Growndwater monitoring well
Exploratory soil boring (Jan,1991)
Exploratory soil boring (Feb. 1993)
Soil-gas survey point
MW8
BH11
AMCOR
SHOP BUILDING
| BIOREMEDIATION
/TREATMENT SYSTEM
TRAILER
BH1
MW1
BH9 EMISSION PIPING
EMISSION STACK
BH8
APPROXIMATE SCALE
•^••e
30 60
120
M0594173
FIGURE 1. SAMPLING LOCATIONS AND PLUME EXTENT, AMCOR PRECAST
U.S. Air Force
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Amcor PracMt 4 of 17
* Contaminant Locations and Geologic Profiles
The distribution of dissolved groundwater contamination is presented in Figure 1. Contaminants were con-
centrated within a vertical zone from about 5 to 11 feet below ground surface. The site stratigraphy consisted
of interbedded silty sands (SM) and poorly graded fine gravel (GP) underlain by a silty clay (CL) aquitard at a
depth of about 18 feet below ground surface.
i Site Conditions
The area has an arid climate with an average ambient temperature of 58°F. The average minimum temperature is
22°F, and the average maximum temperature is 85°F.
Precipitation averages approximately 20 inches per year, most of which occurs during the winter months.
The direction of shallow groundwater flow is to the north-northwest.
The elevation of the site is approximately 4260 feet above mean sea level. The site topography is flat.
i Key Soil or Key Aquifer Characteristics
Key soil and groundwater parameters are presented in Table 3.
TABLE 3: KEY SOIL AND GROUNDWATER PARAMETERS
Parameter
Units
Range or Value
Comments
Soil Parameters (Prior to System Startup)
Porosity
Particle Density
Soil Bulk Density
Aquifer Thickness
Hydraulic Conductivity
Total Heterotrophic
Bacteria
Total Hydrocarbon
Degrading Bacteria
%
g/cm3
g/cm3
It
ft/day
ctu/gm
ctu/gm
20 to 35
2.6 to 2.7
17 to 2.1
7 to 13
190
9,300 to 3,000,000
<100 to 53,000
Estimated
Estimated
Estimated
Growndwater Parameters (Prior to System Startup)
Depth to Groundwater
Dissolved Oxygen
Biological Oxygen
Demand
Chemical Oxygen Demand
NOg
Total P04
TKN
TDS
Total Heterotrophic
Bacteria
Total Hydrocarbon
Degrading Bacteria
ft
mg/l
mg/l
mg/l
mg/l
mg/l
mg/l
mg/l
clu/ml
cfu/ml
5 to 11
0.03 to 1.7
5.8 to 90
9 to 300
<0.001
0.18 to 1.3
0.52 to 1,9
660 to 700
750 to 37,000
<100 to 7,500
Highest water table In
July lowest in January
Background
Proportional to
contaminant level
Proportional to
contaminant level
MO694171B
U.S. Air Force
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Amcor Pncatt 6 of 17
LZTREATMENT SYSTEM
The overall process schematic, as well as a plan view of the remedial system is presented in Figure 2 below.
c
TrwchUm.^ s™
EW1B
Offlc* Building
IEW1A
•EW2A
• Groundwttvr •xtrMtwn w*H
A Spwgng w*U
• Soil wpor wtraetun
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Amcor Pncatt 6 of 17
FLOW METER
CONTROL VALVE
COMPRESSOR
ROUT SEAL
GRAVEL PACK
CONTAMINATED
WATER
INFLOW
FIGURE 3. DIAGRAM OF DENSITY DRIVEN SPARGING WELL CONSTRUCTION
i System Description \
The system consists of three principal components: 1 ) a groundwater sparging system; 2) a groundwater
^circulation (pumping) system; and 3) a soil vapor extraction system
• In general, groundwater sparging was the principal method of groundwater remediation employed.
• The density-driven convection system (patent pending) does not attempt to inject air into the soil pore space under
pressure like a conventional air sparging system, thereby avoiding the disadvantages of pressurized injection.
Instead, water inside the wellbore is aerated directly by injecting air at the base of the wellbore. As show in Figure 3
a grout seal prevents the air from escaping immediately into the formation. The injection air bubbles rise upward in
the wellbore, creating a turbulent frothing action. The rising air bubbles airstrip contaminants from the water and
increase dissolved oxygen content of the water (to about 10 mg/l). The aeration process also acts as a groundwater
pump, pushing aerated water upward through the wellbore and out the upper well screen and drawing resident
groundwater from the surrounding aquifer into the base of the well screen thus creating groundwater circulation and
transport. The result is a simple small-diameter installation that is virtually maintenance free.
U.S. Air Force
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7of 77 ~""
• Density-driven groundwater sparging removes petroleum hydrocarbons from the subsurface by two methods: aerobic
biodegradation and in situ air stripping.
• The technology promotes aerobic biodegradation by supplying oxygen to the saturated zone via circulation of oxy-
genated groundwater and to the unsaturated zone via circulation of air.
• The technology promotes in situ air stripping by transferring dissolved contaminants from groundwater circulated
through the wellbore to air bubbled upwards within the wellbore. Air stripped vapors are transferred to the vadose
zone where they are biodegraded in place.
• Soil vapor extraction was used locally to protect against volatilized hydrocarbons created by the air stripping process
from entering neighboring office buildings.
• Groundwater was extracted along the downgradient plume boundary and reinjected upgradient (without surface
treatment) to prevent further downgradient migration of hydrocarbons below neighboring office buildings.
• The groundwater sparging system consisted of twelve groundwater sparging wells (labeled SP in Figure 2) installed
to a depth of 18 feet and connected to a pressurized air supply source via underground lines. Each well was provided
with a separate air injection line with flow control and meter at the air supply source.
• The groundwater recirculation system consisted of three downgradient groundwater extraction or pumping wells
(labeled EWA in figure 3) installed to a depth of 20 feet and one upgradient injection gallery (former tank excavation
backfilled with pea-gravel). Pressurized air supply lines for powering the extraction pumps and water lines for con-
ducting pump discharge to the injection gallery were placed below ground. Pump controls were located at the air
supply source.
• The soil vapor extraction system consisted of three vertical vapor extraction wells (labeled EWB in Rgure 2) located
adjacent to the downgradient pumping wells. The vapor extraction wells are connected to a knock-out tank and
regenerative vacuum blower motor via underground lines. Vapors were discharged to the atmosphere via a 35-foot
high emissions stack
• Pressurized air for the sparging wells and extraction pumps was supplied by a 36 cfm air compressor. The compres-
sor, vacuum blower for vapor extraction, and associated controls were placed in a portable trailer at the site.
i System Operation
Pressurized air was introduced into the base of each sparging well via the provided air injection tube. Row rate was
controlled at the air supply source. Injected air served to create the driving force for groundwater circulation through
the well; increase dissolved oxygen content of water circulated through the well to promote biodegradation in the
saturated zone; transfer volatile constituents dissolved in the groundwater to the vadose zone soil gas; and provide
oxygen to the vadose zone to promote biodegradation in the vadose zone.
Pressurized air was also supplied via underground lines to operate the pneumatic groundwater extraction pumps.
Extracted groundwater was delivered to the Injection gallery without surface treatment. Downgradient extraction was
used to prevent further downgradient migration of dissolved hydrocarbons beneath the adjacent office building.
A vacuum draw was applied to the vapor extraction wells via underground lines attached to a vacuum blower motor.
The withdrawn vapor mass was sufficiently low that direct discharge to the atmosphere was allowed. Removal of
vapors from the downgradient extraction wells was used to prevent potential migration of product vapors into the
neighboring office building. Detectable emissions of petroleum hydrocarbons were not measured after 60 days of
system operation.
iC/oseup of Sparging Well Construction
The sparging well construction Is shown In Figure 3. Each sparging well was Installed to a depth of 18 feet
below ground surface and screened from 3 to 18 feet. The well casing consisted of schedule 40 PVC flush-
coupled well casing and 0.02-Inch slotted screen. Air was Injected at the base of the well via 3/8-inch diame-
ter plastic tubing.
U.S. Air Force
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i/Cey Design Criteria • I *MW^^^ "„ ' _
The key design criteria were as follows:
• Presence of site structures including an office building owned by the neighboring land owner requiring an in situ
remediation strategy with minimal disturbance to site occupants.
• Elimination of potential product vapor migration into neighboring office building during system operation.
• Control of further downgradient migration of dissolved hydrocarbon plume beneath adjacent office building.
• Sensitivity of neighboring land owner to potential office tenant loss.
• Cost minimization for remedial system installation and operation.
i Key Monitored Operating Parameters
System monitoring consisted of the following:
• Collection of air samples from the venting emissions stack and laboratory analysis for Total Petroleum Hydrocarbons
(TPH) and Benzene, Toluene, Ethylbenzene, Xylene, and Naphthalene (BTEXN).
• Collection and field analysis of soil gas samples from the vadose zone (plume area and background) for carbon diox-
ide and oxygen.
• Measurement of field parameters for each monitoring well including water elevation, temperature and dissolved
oxygen.
• Collection of groundwater samples from selected monitoring wells and laboratory analysis for TPH and BTEXN.
Monitoring was performed on a weekly basis for the first two months of system operation and monthly there-
after. Confirmatory soil sampling was conducted after eleven months of system operation to evaluate residual
soil concentrations.
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—^—"^—• Amcor Precmtt 9 of 17 """""
CZ PERFORMANCE I
••Performance Objectives mmmmmmmw>*xx^< _.....-• —i
• Reduce TPH and BTEXN concentrations in the site soils to below RCLs established by the Utah Department of
Environmental Quality (shown in Table 4). Soil cleanup goals were based on Division of Environmental Response and
Remediation recommended cleanup levels (RCLs) with a Level I (most sensitive) environmental sensitivity.
• Reduce TPH and BTEXN concentrations in the site groundwater to below federal MCLs (shown in Table 4). Adopted
from the Clean Water Act. No cleanup goals exist for TPH.
• Maintain control over vapor and dissolved phase petroleum product migration.
•• Treatment Plan •••••^ • -i:i::- •"" '. - . .. i
• Maintain groundwater sparging system operation to provide oxygen to promote aerobic biodegradation of petroleum
hydrocarbons.
• Maintain downgradient groundwater extraction to prevent further downgradient migration of dissolved petroleum
hydrocarbons.
• Maintain downgradient vapor extraction to prevent potential product vapor migration into neighboring office building.
• Evaluate effectiveness of biodegradation by monitoring changes in dissolved hydrocarbon contaminants and bacteri-
al activity. This activity was indicated by dissolved oxygen contents, vadose zone soil gas carbon dioxide and oxygen
contents, and bacterial plate counts in groundwater.
• Evaluate effectiveness of plume containment by monitoring downgradient concentrations of dissolved petroleum
hydrocarbons.
• Evaluate effectiveness of vapor migration containment by monitoring vapor extraction system emissions and petrole-
um vapor concentrations in neighboring office building.
• Monitor vapor emissions during system operation to verify compliance with de minimus air emissions standards
established by the Utah Division of Air Quality.
• Concentrations of all of the contaminants of concern were monitored in groundwater and soil to evaluate system per-
formance.
• The following operational performance criteria were maintained during system operation:
- Sparging well air injection rates maintained at between 60 and 100 scfh.
- Total groundwater extraction rate (combined flow from all three extraction wells) at 10 gpm .
- Total soil vapor extraction rate at 70 to 90 scfrn.
Cumulative flow was not measured or calculated for system operation.
System inspections and maintenance were conducted at weekly intervals during system operation. The
Remediation Conductor estimates that the air compressor used for sparging well and pump operation was
operational over 90 percent of the system operational life. He also estimates that the vacuum blower used for
vapor extraction was operational over 95 percent of the system operational life.
System downtime was attributed to the following factors:
• Two mechanical compressor failures resulting in two downtime periods of approximately of one week. A pressure
modulator was subsequently installed to prevent compressor cycling to reduce compressor wear and to maintain a
more constant pressure supply.
• One pneumatic pump control repair (level controls and filter replacement) resulting in downtime of approximately one
week.
• Two infiltration basin overflows (three and twelve months after system startup) due to biomass buildup within the
injection gallery backfill resulting in downtime of 2 to 3 days for each event.
• Several water knockout tank overfills triggering automated shut-off of the venting system, resulting in downtime of 2
to 3 days for each event.
U.S. Air Force
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Amcor Preca$t 10 of 17
[^TREATMENT PERFORMANCE!
i Vadose Zone Monitoring
Measured carbon dioxide and oxygen concentrations within the vadose zone remained relatively constant thoughout
the first 100 to 150 days of operation, but declined to background levels about 250 days after startup (Figure 5).
These data indicate that biological activity was present within the vadose zone through 250 days of operation.
Measured air emissions from the soil venting system declined rapidly during the initial 60 days following system start-
up (Figure 6). These data indicate that physical removal of contamination through vapor extraction was not a primary
mechanism in the remedial system operation.
0 50 100 150 200 250 300 350
TIME SINCE SYSTEM STARTUP (days)
400 450
50 100 150 200 250 300 350 400 450
TIME SINCE SYSTEM STARTUP (days)
B) CARBON DIOXIDE MO»,«E
A) OXYGEN
FIGURE 5. OXYGEN AND CARBON DIOXIDE SOIL GAS CONCENTRATIONS
250
C/3
§ 200
.
o
Q
•o
^
150
100
50
15
•4-*
,o
0 50 100 150 200 250 300 350 400
Time Since System Startup (days)
Figure 6. Emissions from Vapor Extraction System
U.S. Air Force
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AmcorPncftt 11 of 17
i Groundwater Monitoring i
« Measurements of dissolved oxygen indicate that concentrations were generally above background levels within the
immediate plume area due to the introduction of oxygen by groundwater sparging (Figure 7). These data indicate that
although dissolved oxygen initially peaked about 25 days following system startup, subsequent dissolved oxygen
concentrations fluctuated between 0.2 and 1.0 ppm through 280 days of operation. Dissolved oxygen was significant-
ly higher during the remainder of system operation, presumably as a result of significant decreases in site contamina-
tion.
UPGRADIENT
DOWNGRADIENT
•-
PLUME AREA
50 100 150 200 250 300 350 400 450
TIME SINCE SYSTEM STARTUP (days)
Figure 7. Oxygen Concentration in Groundwater
• Measurements of bacterial plate counts (both total heterotrophic and hydrocarbon degrading) initially increased sub-
stantially, but subsequently declined through the first 280 days of operation. These data indicate that bacterial
activity was increased within the saturated zone by the groundwater sparging system operation.
• Measurements of dissolved total and aromatic hydrocarbon concentrations in groundwater show long-term declines
over the life of the operating system (Figure 9). Dissolved concentrations generally exhibited the following pattern:
- Concentrations increased over the first 30 days of operation.
Concentrations declined dramatically between about 30 and 100 days of operation.
Concentrations increased, either slightly or strongly, between about 120 and 250 days of operation.
Concentrations generally decreased steadily after 250 days of operation.
U.S. Air Force
20
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Amcor Prvcatt 12 of 17
100;
100 200 300 400 500 600
TIME SINCE SYSTEM STARTUP (days)
A) TOTAL PETROLEUM HYDROCARBONS
0.001
100
200
300
400 500 600
TIME SINCE SYSTEM STARTUP (days)
D) ETHYLBENZENE
0.001
100 200 300 400 -500
TIME SINCE SYSTEM STARTUP (days)
B) BENZENE
600
0.01
0 100 200 300 400 500 600
TIME SINCE SYSTEM STARTUP (days)
E) TOTAL XYLENES
0001
100 200 300 400 500 600
TIME SINCE SYSTEM STARTUP (days)
C) TOLUENE
0.1
S0.01
o
o
0.001
z±
100
200
300
400
500
600
TIME SINCE SYSTEM STARTUP (days)
F) NAPHTHALENE
M0594165F
Figure 9. Petroleum Hydrocarbon Concentrations in Groundwater
The increase in dissolved hydrocarbon concentrations over the first 30 days is probably due to disturbance of the
subsurface equilibrium conditions caused by the sparging and pumping operations. Concentrations subsequently
declined as microbial activity and associated biodegradation rates increased.
The cause of the increase in dissolved hydrocarbon concentrations between 120 and 250 days of operation could be
the result of any combination of the following factors: increased desorption of hydrocarbons from the site soils due to
biological surfactant production and/or seasonal increase in the water table elevation; decreased microbial activity
due to a seasonal drop in groundwater temperature or increased competition from non-hydrocarbon degrading bac-
teria.
U.S. Air Force
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Amcor Pncatt 13 of 17
i Post Remedial Testing
Concentrations of the identified contaminants of concern in soil and groundwater at the completion of the
remedial system operation are presented in Table 4. Significant reductions (typically greater than 95%) were
observed for all contaminants of concern and both soil and groundwater concentrations were below the regu-
latory cleanup goals. Soil concentrations were measured 11 months after system startup. System operation
and groundwater monitoring was continued for an additional 7 months to achieve compliance with naphtha-
lene MCLs in all wells.
TABLE 4: SUMMARY OF POST REMEDIATION CONTAMINANT CONCENTRATIONS
Contaminant
of Concern
Soil Concentrations (mg/kg)
Initial
Final
%Change
Groundwater Concentrations (mg/l)
Initial
Final
%Change
Cleanup
Goal II
Soil Concentrations (mg/kg)
TPH
Benzene
Toluene
Ethylbenzene
Total Xylenes
Naphthalene
1,600
7.8
2.5
19
110
No data
6.3
<0.1
0.4
0.1
0.8
<0.1
99.6
>98.7
84.0
99.5
99.3
555
2 0
1 4
5.7
37
No data
1.6
<0.1
0.1
<0.1
0.3
<0.1
99.7
>95.0
92.9
>98.2
99.2
30
0.2
100
70
1000
2.0
Groundwater Concentrations (mg/i)
TPH
Benzene
Toluene
Ethylbenzene
Total Xylenes
Naphthalene
190
4 7
94
2.7
8 0
0.63
1 3
<0.002
0 26
0 021
0 063
0 010
99.3
>99.96
97.2
99.2
99.2
98.4
51
1.3
2.4
0 78
2.5
0.18
0.71
<0.002
0 067
0 007
0.063
0.006
98.6
>99.8
97.2
99.1
98.7
96.6
Not Est.
0.005
1 0
0.7
10
0.020
MO594171C
U.S. Air Force
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•^^——-^—•——"-^——•——^—•—»—^—• "~""^^~^^^™""^^^^^~^^^~ Amcor Pncutt Hot 17
G^COST ~IIZI===IZIIIIZZIIIZII^ZI=r=I=II^^
I Capital Costs \
Drill and Install Wells $ 16,000
3 extraction
13 sparging
6 monitor wells
Install Groundwater and Vapor Extraction System $ 40,300
Install Groundwater Sparging System $ 25,750
Electrical Connections $ 4,050
Trenching, Soil Disposal, Backfilling, Asphalting $ 26,800
Air Compressor and Control Trailer $ 26,800
Initial System Startup and Debugging $ 3,000
Project Management, Construction Oversight, Regulatory
Reporting and Coordination $ 10,000
TOTAL CAPITAL COST: $150,950
• Annual Operating Costs
Maintenance Labor and Parts $ 30,000
System Monitoring and Reporting $ 30,000
Electricity (@ $0.07/kW-hr) $ 2,750
TOTAL ANNUAL OPERATING COST: $ 02,750
CZZREGULATORY/INSTITUTIONAL ISSUES]
• The Corrective Action Plan was reviewed and approved by the Utah Department of Environmental Quality (DEQ),
Division of Environmental Response and Remediation (DERR).
• The Recommended Cleanup Levels for site soils were derived from DEQ guidelines for Level I environmental sensitivi-
ty (highest sensitivity). The environmental sensitivity of the site was evaluated according to the DEQ scoring system.
• The Maximum Contaminant Levels for site groundwater were derived from federal Clean Water Act regulations as
adopted by the Utah DERR for underground storage tank remediations
• The Utah Division of Air Quality (DAQ) was notified of the intent to discharge volatile petroleum hydrocarbons from
the vapor extraction system to the atmosphere at concentrations below de minimus standards established by DAQ
(3,000 Ibs total volatile emissions per year and 2.0 Ibs of benzene per day). Because air emissions were below
de minimus standards no air discharge permit was required.
• The Utah Division of Water Quality (DWQ) was notified of the intent to discharge contaminated groundwater to the
upgradient injection gallery. An authorization-by-rule to operate the injection gallery as a Class V injection well Was
granted upon demonstration that the injection gallery was within the zone of influence of the downgradient extraction
wells.
• Target cleanup levels (RCLs and MCLs) are presented in Table 4.
U.S. Air Force
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Amcor Pncut 15 of 17
CZSCHEDULE
Task
Tank Removal
1
Start Date
ral 12/90
lation 12/91
Yestigation 06/91
ation 09/91
'albyDERR 11/91
allation 01/92
iration 03/92
End Date
12/90
05/91
08/91
10/91
11/91
02/92
09/93
Duration
1 week
6 months
3 months
2 months
1 month
2 months
1 8 months
EARNED I
i Key Operating Parameters <
• Stimulation of biodegradation was successful by increasing oxygen supply alone. Nutrient addition was not required
at this site becouse nitrogen and phosphorous were present in the site groundwater.
• Significant air emissions associated with volatilization of contaminants by vapor extraction and air sparging was limit-
ed to the first 60 days of operation, despite the generally volatile nature of the contaminants (gasoline petroleum
hydrocarbons). This is probably attributable to promotion of in situ biodegradation in both the saturated and vadose
zones. Biodegradation appears to be the predominant mechanism for contaminant removal.
• Measurements of oxygen (soil gas and dissolved), carbon dioxide (soil gas), and bacterial plate counts (groundwater)
all proved to be reliable and consistent indicators of biological activity and time required to reach cleanup goals.
Dissolved naphthalene was an exception to these operating parameters,
• Groundwater concentrations of dissolved contaminants exhibited significant temporal fluctuations and were less reli-
able indicators of remedial progress than bioremediation parameters.
i Implementation Considerations
Discharge of air stripped volatile contaminants combined with moisture saturated air flow to the vadose zone permit-
ted in situ biodegradation of these contaminants, greatly reducing air emissions from the vapor extraction collection
points.
Sparging wells were located at the point of groundwater reinjection and along a line of wells across the direction of
groundwater flow, enhanced by the groundwater recirculation. An alternative strategy in the absence of groundwater
recirculation is to space the sparging wells evenly across the entire plume area.
I Technology Limitations
Air sparging is limited to contaminants that can be degraded by indigenous bacteria under aerobic conditions. Length
of system operation will be dependent upon the volatility and/or biodegradability of contaminants present.
Contaminants which are sufficiently volatile to be air stripped by air sparging but are not aerobically biodegradable
(chlorinated solvents for example) may be treatable by this technology with some modifications for vapor collection
and treatment.
The cost to implement air sparging is dependent upon the depth to groundwater since multiple sparging wells are
required and their installation costs increases with depth.
Maximum sparging well air flow and groundwater wellbore circulation rates are dependent upon well diameter, depth
to groundwater, and formation hydraulic conductivity. Longer remediation times or a greater number of sparging
wells may be required in lower permeability formations.
U.S. Air Force
24
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~~™""™" - - ~^^^~ ™^~~ >^~^~'~~'~ Amcor Precast 16 of 17
iFuture Technology Selection Considerations^
• Groundwater circulation and vapor extraction were utilized for groundwater plume and product vapor containment
respectively and would not generally be required as an addition to the groundwater sparging system. Subsequent
groundwater sparging remediations are being successfully implemented without these additions.
• Air compressors require more maintenance and greater power draw than alternative methods of supplying air for
groundwater sparging. Subsequent projects have utilized these alternative and more cost effective methods of air
delivery.
• The system was able to reduce contaminant concentrations below required cleanup levels including federal MCLs
and Utah RCLs. With the exception of dissolved naphthalene, all cleanup goals were achieved within 12 months of
operation, the expected operational life. Reduction of dissolved naphthalene concentrations below the federal MCL of
0.020 mg/l required an additional 6 months of system operation, although the maximum dissolved naphthalene con-
centrations were only 0.080 mg/l after 12 months of operation. This difficulty probably is attributable to the low
volatility and resistance to biodegradation of naphthalene .
CZSOURCES I
• Major Sources for Each Section
Site Characteristics: Sections: 1, 2, 3, 4, 5, 6
Treatment System: Sections: 7,11
Performance: Sections: 8, 9,10,11
Cost: Sections: 7
Regulatory/institutional Issues: Sections: 7,11
Schedule: Sections: 6, 7, 8, 9,10,11
Lessons Learned: Sections: 10,11
i Chronological List of Sources
1. Todd, David K. "Groundwater" Section 13 of Handbook of Applied Hydrology. Ven Te Chow, editor, McGraw Hill, New
York, 1964, pp. 13-4 to 13-5.
2. Spangler, M.G. and Handy, R.L. Soil Engineering. Intext Educational Publishers, New York, 1973. pg.166.
3. Montgomery, John. H. and Welkom, Linda M. Groundwater Chemicals Desk Reference. Lewis Publishers, Chelsea,
Michigan, 1990. pp. 30-31, 308-309, 398-400, 501-502, 547557.
4. Utah Division of Environmental Response and Remediation. Estimating Numeric Cleanup Levels for Petroleum-
Contaminated Soil at Underground Storage Tank Release Sites. 1990.
5. Industrial Health Incorporated. Site Investigation, Amcor Precast, April 17,1991.
6. Wasatch Environmental, Inc. Further Site Investigation, Release Site AGJX, Amcor Precast fueling Area. September
20,1991.
7. Wasatch Environmental, Inc. Amended Corrective Action Plan Proposal UST Release Site AGJX Amcor Precast.
October 10,1991.
8. Wasatch Environmental, Inc. Quarterly Monitoring Report, Amcor Precast Fueling Area, UST Release Site AGJX. June
14,1993.
9. Wasatch Environmental, Inc. Results and Recommendations for Permanent Closure, UST Release Site AGJX.
November 30,1993.
10. Schrauf, T.W., Sheehan, P.J., and Pennington, L.H. "Alternative Method of Groundwater Sparging for Petroleum
Hydrocarbon Remediation". Remediation, Vol 4, No. 3. Winter 1993/1994.
11. Wasatch Environmental, Inc. Project and master files for Amcor Precast, Project No. 1106-1 , -1 A, -1 B, -1 C.
Unpublished.
U.S. Air Force
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Amcor Precast 17 of 17
• Key Personnel/Point of Contact i
Mr. Todd W. Schrauf
Wasatch Environmental, Inc.
2251 B West California Ave.
Salt Lake City, UT 84104
(801)972-8400
[ZIANALYSIS PREPARATION
This analysis was prepared by:
Stone & Webster Environmental
Technology & Service
P.O. Box 5406
Denver, Colorado 80217-5406
Contact: Dr. Richard Carmichael 303-741-7169
EMREVIEW
Project Manager Regulatory Agency
The project manager has reviewed this report but This analysis accurately reflects the
he has postponed signing it until final closure of performance of this remediation:
the site has been accomplished.
Utah DERR
U.S. Air Force
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Petroleum Product Recovery and
Contaminated Groundwater Remediation
Amoco Petroleum Pipeline
Constantine, Michigan
(Interim Report)
27
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Case Study Abstract
Petroleum Product Recovery and Contaminated
Groundwater Remediation, Amoco Petroleum Pipeline
Constantine, Michigan
Site Name:
Amoco Petroleum Pipeline
Location:
Constantine, Michigan
Contaminants:
Benzene, Toluene, Ethylbenzene, Xylenes
(BTEX), Methyl tert butyl ether (MTBE)
- An estimated 300,000 to 2 million gallons of
gasoline, fuel oil, and kerosene released to
subsurface
- Free product present in an approximate 6-
acre area at an average apparent thickness of
2 feet
Period of Operation:
Status: Ongoing
Report covers - 10/88 to 6/94
Cleanup Type:
Full-scale cleanup (interim
results)
Vendor:
Residuals Management Technology,
Inc.
SIC Code:
4612 (crude petroleum piping)
Waste Source:
Other: Petroleum pipeline leak
Technology:
Groundwater Extraction followed by Granular
Activated Carbon (GAC); In situ Air Sparging
of saturated zone
Groundwater Extraction With GAC
- 4 extraction wells installed in two phases
(1988 and 1992); depths up to 28 feet below
ground surface (bgs) with extraction rates of
50 and 100 gpm
- Extracted water treated using two GAC
vessels in series; recovered free product sent
to storage in aboveground tanks
In-situ Air Sparging
- 30 two-inch diameter air sparging wells with
3-foot screens
- Installed to depths of 25-30 feet
- Two 300 scfm blowers
Cleanup Authority:
Other: Voluntary cleanup
Point of Contact:
Paul Ressmeyer
Remedial Project Manager
Amoco Corporation
Purpose/Significance of
Application:
Full-scale pump and treat of
petroleum contaminated-groundwater
using granular activated carbon to
recover free product and treat
groundwater. In situ air sparging
was subsequently added to treat the
saturated zone.
Type/Quantity of Media Treated:
Groundwater
- 775 million gallons of groundwater between 1988 and 1993
- Sand find gravel
- Porosity 30-40%
- Hydraulic conductivity 0.0002 - 0.0004 cm/sec
Regulatory Requirements/Cleanup Goals:
- The remediation is being performed as a voluntary action by Amoco; final cleanup criteria will be established in the future
with concurrence from the Michigan Department of Natural Resources
- Treated water required to meet SPDES permit requirements prior to discharge - benzene (5 ug/L), total BTEX (20 ug/L),
MTBE (380 pg/L), pH (6.5-9.0)
28
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Case Study Abstract
Petroleum Product Recovery and Contaminated
Groundwater Remediation, Amoco Petroleum Pipeline
Constantine, Michigan (Continued)
Results:
Groundwater Extraction with GAC
- 118,000 gallons of free product recovered (10/87-12/93); rate of free product recovery has decreased to 20 to 25 gallons
per month as of late 1993
- Free product has been hydraulically contained and observed apparent thickness of free product has been reduced to <0.01
feet
- Concentrations of BTEX in extracted groundwater have remained relatively constant; MTBE concentrations have
decreased
- Treated effluent from GAC have generally met SPDES discharge limits
In-situ Air Sparging
- Pilot testing indicated a radius of influence of 65-150 feet per single well
- No additional results were available at the time of this report
Cost Factors:
- Total Capital Costs: about $297,000 for groundwater recovery and treatment system (including well construction, pumps,
system installation, engineering); $375,000 for the air sparging system (including 3 months of initial operations, and
testing)
- Annual Operating Costs (approximate): about $475,000 for groundwater recovery and treatment system; not yet defined
for air sparging system
- An estimated total cost for completing the cleanup is not available at this time
Description:
The Amoco Corporation owns and operates a liquid petroleum product pipeline that transverses the Constantine site. As a
result of a pipeline leak, discovered in June 1987, an estimated 350,000 to 2 million gallons of gasoline, fuel oil, and
kerosene were released to the subsurface. Free product was present at an average app;irent thickness of 2 feet. Beginning in
October 1988, a groundwater pump and treat system, consisting of 4 extraction wells and granular activated carbon (GAC)
vessels, was used to recover free product and treat the contaminated groundwater. In situ air sparging of the saturated zone
was subsequently added and began operating in February 1994.
Through December 1993, groundwater extraction with GAC had recovered an estimated 118,000 Ibs of free product and
reduced the observed apparent thickness of the free product layer to <0.01 feet. MTBE concentrations were reduced;
however, BTEX concentrations near the source of contamination remained relatively constant. No full-scale performance
data were available for the air sparging system at the time of this report.
The groundwater extraction with GAC system operated > 95% of the time through December 1993. Periodic shutdowns of
1 to 3 days were required for carbon changeout and extraction well rehabilitation. Leasing the activated carbon system and
carbon provided flexibility to modify the treatment system in response to changing operating conditions. However, GAC
proved to be inefficient in removing MTBE when compared to BTEX.
29
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1HCHNOL0G Y APPLICATION ANAWl
•> V- A S • . >.» 1 .JWX4U^V£&.£j»
SITE
I Page lot 14 =
I TECHNOLOGY APPLICATION
Amoco Petroleum Pipeline
A Voluntary Cleanup
Constantine, Michigan
(Constantine Site)
This analysis covers an effort to hydraullcally contain
and recover free product as well as pump and treat
groundwater using granular activated carbon (GAC)
at a site contaminated with petroleum products.
Recovery and treatment began in 1988 and is ongoing.
In-situ air sparging was initiated in February 1994 to
enhance groundwater restoration.
SITE CHARACTERISTICS
Site History/Release Characteristics
• A liquid petroleum product pipeline owned and operated by Amoco Corporation transverses the Constantine site
from northeast to southwest. A leaking gasket associated with a central valve station for the pipeline was discovered in
June 1987. Approximately 350,000 to 2 million gallons of gasoline, fuel oil and/or kerosene were released to the
subsurface as a result of the leak.
• The leak was immediately repaired. Subsurface investigations to define the nature and extent of free product and
groundwater contamination were initiated in July 1987. Manual recovery of free product from monitoring wells was
initiated in November 1987.
• An interim free product and ground-water recovery and treatment system commenced operation in October 1988. The
interim system was still in operation as of May 1994. In-situ air sparging of the saturated zone began in February 1994.
• Contaminants of Concern
Contaminants of Concern used to track the
progress of groundwater remediation are:
Benzene -v
Toluene ( (known as
Ethylbenzene f BTEX)
Xylenes }
Methyl ten butyl ether (MTBE)
Free petroleum product, the source of
the contaminants identified above, was
also present.
•• Contaminant Properties
Properties of contaminants focused upon during remediation are:
Properties* Units
Chemical Formula
Specific Gravity
Vapor Pressure mm Hg
Water Solubility mg/l
Octanol -Water
Partition
Coefficient: KQW
Organic Carbon
Partition
Coefficient: KQC
•Properties at 20 °C.
B
C6H6
0.88
352
1,750
132
83
T
CeHgCH:
0.87
28.1
535
537
300
E
CsHsCaH
0.87
7
152
1,100
1,410
X
5 CeH^CHjte
0.86-0.88
10
198
1.830
240
MTBE
05*120
0.74
246
48.000
1.05
.
I Nature & Extent of Contamination
• Characterization of the nature and extent of contamination at the Constantine site focused on free petroleum product and
petroleum hydrocarbons dissolved in groundwater. The initial characterization (completed in October 1987) indicated free
product was present over an approximate 6 acre area in the vicinity of the valve station, at an average apparent thickness
of 2 feet.
• Petroleum hydrocarbons dissolved in groundwater were detected in the vicinity of the free product and to the west and
southwest (downgradient) in October 1987. In the spring of 1991, quarterly monitoring data indicated that some dissolved
BTEX and MTBE had migrated downgradient beyond the influence of the interim recovery well network, and were entering
a drainage ditch.
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> Cans&rrtine - Page 2 of 14 -^—
Contam/nant Locations and Geologic Profiles
Remedial investigation field activities
at the site have included:
• Borings and subsurface sampling
• Monitoring well installation and
groundwater sampling
• Groundwatar level measurements
• Apparent product thickness
measurements
• HydropunehTU groundwater sampling
• WeV permeability and pump tasting
• Surface water sampling and water level
measurements
Data from some of these efforts have
been included here to provide a
conceptual understanding of site
conditions.
Initial Extent of Free Petroleum Product fPtan View!
Data from October 1937
Extent of Free Product and Dissolved BTEX in'Groundwater (Cross-Section)
Groundwater monitoring data from 1990 along cross-section A-A' shown in plan view.
A
West
Groundwater
Tabla
Ditch
Apparent rroe
Product
(Thickness Exaggerated)
Constansne Road
Centra! Valva^
-800
-790
-780
O
o soon
Vertical exaggeration > 20X
Extent of Free Product
(Plan View)
Groundwater monitoring data troml 990.
Extent of Dissolved BTEX in
Groundwater (Plan View)
Groundwater monitoring data froml 990.
Extent of Dissolved MBTE
in Groundwater (Plan View)
Groundwater monitoring data froml 990.
Amoco
Free Product
Maximum Thickness . 1.08 ft
Amoco
,- _ Central Pioaline
Extraction val«« rlpa"nB
Wall
Amoco
Pipeline
r— Legend
all concentrations
in ppb
Cj10-100ppb
i. 000-1 0.000 ppb
>10,000ppb
Free Product
U.S. Air Force
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' Constanftn* - Pago 3 of 14 —
I Contaminant Locations and Geologic Profiles (Continued) \
Geologic Profile
View To North (along cross section A-A' shown in plan view)
, Ditch
West
Van* Station
Constants* Hd.
A'
ast r—BOO
— 790
780
^770
;*
z
— Legend
Topsoil - Silt Some Sand [23 Gravel with Some Sand
Sand and Silt [XI Silty Clay (Glacial Till)
Sand with Some Gravel Y Groundwater Elevation (Nan-pumping)
200 400 600 ft.
Site Conditions
• Topography of the Constantino site is relatively flat, ranging from - 800 ft. N.G.V.O. near the pipeline's central valve
station to - 788 ft. N.G.V.D. at the St. Joseph River, located - 3,000 ft. west of the central valve station.
• Ground water flow from the site is generally to the west and southwest, discharging to drainage ditches, a pond, and
ultimately the St. Joseph River. The water table in the shallow sand and gravel unit is 2 to 10 ft. below ground surface.
• Site stratigraphy is relatively straight forward. Approximately 10 to 29 ft. of interbedded sand and gravel overlies a silty
clay glacial till unit. Cobble-size sediments and sandy silt deposits were also occasionally encountered.
Key Aquifer Characteristics
Aquifer parameters for the shallow sand and gravel unit at the Constantino site have been estimated as:
Property Units Range Property Units
Range
Soil Porosity
Particle Density
Bulk Density
Particle Diameter
Organic Content
Permeability
Hydraulic Conductivity
Static Hydraulic
Gradient
Groundwater Flow
Velocity (Avg.)
Rainfall Infiltration
Microbial Plate Counts
%
g/cm3
g/cm3
mm
%
cm2
cm/s
ft/ft
ft/yr
cm/day
CFU/g
30- 40
2.65 - 2.70
1 8 - 2.2
0.9 - 4.5
0.8
2E-9104E-9
2E-4I04E-4
0.0018
500
0.07
2.2E4to4.1E5
Dissolved Oj (in plume)
Dissolved Oj (background)
Total Phosphorous
Nitrate-N
Nitrite-N
Kjeldahl-N
Ammonia-N
Calcium
Total Alkalinity
Hardness (as CaCC>3)
pH
Iron
Manganese
Magnesium
mg/l
mg/l
mg/l
mg/l
mg/l
mg/l
mg/l
mg/l
mg/l
mg/l
.
mg/l
mg/l
mg/l
0.8
7.8
0.029-2.15
3.6 - 13
0.001 - 0.005
0.28-1.1
<0.02 - 0.08
30-46
139-154
150-450
6.96 - 7.08
<0.02 - 0.82
<0.01
5.68-10.4
• Unconfined groundwater conditions exist at the Constantino site.
• The presence of a substantial number hydrocarbon-degrading micro-organisms within the dissolved hydrocarbon
plume, the difference in dissolved 02 concentrations in groundwater outside versus within the dissolved hydrocarbon
plume, and the sharp decrease in BTEX concentrations at the downgradient edge of the dissolved hydrocarbon plume
indicate that natural (intrinsic) bioremediation of the BTEX dissolved in groundwater is occurring.
U.S. Air Force
32
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REMEDIATION SYSTEM
Overall Process Schematic
Extraction Weil Network
Four extraction wells
installed in two phases
(RW-1, HW-2, andRW-3
in 1988, and RW-4m 1992)
Extracted Water
1 Constantino - Page 4 of 14 —•
" " • '
Treatment System
Discharge to Surface Water
Recovered Free Product
Treated Water
(Via Tributary)
jjjir St Joseph River
2 liquid-phase
GAC vessels in series
Management of Recovered
Free Product
Recovered free product
temporarily stored on site in
2 aboveground steel tanks
Free product transported to refinery
for reprocessing and reuse
Extract/on Well Network
Recovered
Product
Storage
Tanks
- Legend
• Extraction well
= Screened portion of
= groundwater
= extraction well (all
E wells screened within
= 5 ft of ground surface)
Extraction
well
designation
— RW-1 100
RW-2 100
- RW-3 50
RW-4 100
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' Constantino - Page S of 14 —
Extraction Well Detail
reatment System Schematic
Typical Extraction Well
Pump Control Box
and Pedestal (all controls
are explosion proof)
_ Heated Insulated
Pumphouse
Pressure Gauge
Check Valve
Gate
.Mounded Soil
lf for Freeze
Protection
To
>>• Treatment
V. System
4 inch Discharge Line
(buried with conduit
for electrical and flow
sensor lines and with product
recovery discharge hose)
Well Screen: 14-tnch I.D.,
1 Stainless Steel V-shaped
Continuous Slot,
#20 Slot (0.02 in)
.Groundwater Extraction Pump:
Electric Submersible, Capacity
150 GPM, 3-inch NPT Discharge
Notes: Extraction well RW-4 not equipped
with product recovery pump.
All extraction wells developed by
surging and pumping.
lischarge Treated
Effluent to Surface Water
2 Skid-Mounted
20.000-Pound GAC
Vessels in Series
Backwash
Effluent
10.000-Gallon
Backwash
Effluent Tank
Up to 350 GPM Decanted
Groundwater Backwash
from 4 water
Extraction
Wells
Notes:
10.000 - Gallon
Backwash
Supply Tank
1 ) Piping configured to allow use of either
carbon vessel as primary absorber and
backwashing of both carbon vessels.
2 ) Free product piped from extraction wells
to 2-5,000 gallon storage tanks located remote
from treatment system building.
• Key Design Criteria
• Hydraulic containment of free product and dissolved-
phase contamination.
• Recovery of water and free product using two-pump
system to avoid emulsifying water/oil.
• Handle range of flow rates to allow for operational
flexibility.
• Maximize efficiency of activated carbon to remove
BTEX from extracted groundwater.
• Automated treatment system monitoring and
shutdown.
Key Monitored Operating Parameters
— (to assess system operation)
• Water flows
• Pump discharge pressures
• Carbon bed pressures
• Automated processes
• Groundwater levels
(to assess capture zone)
' Contaminant concentrations in treatment system influent &
effluent
(to assess treatment system effectiveness)
• Apparent free product thickness and contaminant
concentrations in groundwater
(to assess remediation progress)
U.S. Air Force
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Constantino - Page 6 of 14 —
In-s/tu Sparging System
• The in-situ sparging system consists of 30 two-inch diameter air sparging wells within a 3-foot long screened section
installed into a depth of approximately 25 to 30 feet, two 300 scfm blowers housed within the groundwater treatment
shed, and buried manifold connecting the blowers and sparging wells.
• Sparging will be performed at an air flow rate of between -10 and 30 scfm and a pressure of 12 pounds per square
inch at each well.
Typical Soareine Well
Manway
Air Supplied by
Com press or
2" Dia PVC (Schedule 40)
Flush Joint Threaded Pipe
Bentorme Pellets
Fine Silica Sand
Silica Sand (as Appropriate)
Schedule 40 PVC
Well Screen with 0 020* Slot Size
Bottom Cap
8.251 Drawing not to sea/*
Sparging Wefts Layout
i— Legend
O Air Sparging
Well
• Groundwater
Extraction Well
tN
HW-3
Sparging Bloww
Housed in E>Ming
TraMmw*
System Building
Consttntirw
,Ro*d
Drawing not to »ca/»
U.S. Air Force
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' Constannne - Page 7 of 14
PERFORMANCE
Performance Objectives
• Prevent migration of free petroleum product and petroleum constituents dissolved in groundwater.
• Recover free petroleum product.
• Reduce concentrations of petroleum hydrocarbons dissolved in groundwater.
Remedial Action Plan •••••••••••••••••••BBnBliS
Remediation at the Constantino site is being implemented in a phased manner:
1987/1988 Installation and operation of interim free product and groundwater recovery and treatment system
based on results of preliminary investigation.
1988 -1992 Subsequent extraction and treatment system modifications/enhancements based on
comprehensive investigation results.
Initiated 1994 In-situ saturated zone air sparging to enhance natural volatilization and bioremediation.
Overall Performance Summary
Conclusions drawn after 5 (plus) years of operating the interim free product and groundwater recovery and treatment
system are summarized below:
• Successful hydraulic containment and substantial recovery of observed free-phase petroleum product was achieved.
• Substantial hydraulic containment of petroleum constituents dissolved in groundwater was achieved near the release source.
• A portion of the dissolved phase contamination migrated beyond the capture zone of 3 extraction wells. A fourth extraction well
installed in 1992 was apparently effective in limiting additional migration of dissolved-phase constituents from near the source
area.
• The concentration of BTEX in extracted groundwater did not decrease substantially due to continued solubilization of
hydrocarbons from free product and residual soil contamination. Substantial decreases of MTBE in extracted groundwater
occurred during the same period.
• Concentrations of petroleum constituents in treated effluent have met State Pollution Discharge Elimination System (SPDES)
discharge limits with minor exceptions.
Operational Performance
,- Volume and Rate of Water Pumped
• From Oct. 1988 through Dec. 1993 approximately 800
million gallons of groundwater was pumped from 3 to 4
extraction wells; average daily flows were maintained below
the SPDES permit limit of 350 GPM.
• During this penod, suspended solids loading on the GAC
system limited flow rates to a (project) average rate of
approximately 315 GPM.
r System Downtime
• The treatment system has operated 95% (plus) of the
time between Oct. 1988 through Dec. 1993. Periodic
shutdowns of 1 to 3 days occur for carbon changeput
and extraction well rehabilitation. Additional downtime
was experienced for equipment modification and
replacement.
• A 10
-------
Constanttne - Page 8 of 14 —
Hydrodynamic Performance
• The capture zone created by the extraction
well network provides for substantial
hydraulic containment of petroleum
constituents dissolved in groundwater.
• The capture zone does not allow for
recovery of dissolved petroleum constituents
near the surface ditches. This downgradient
contamination probably resulted from periodic
decreased pumping rates caused by plugging
of extraction wells with biomass and oxidized
inorganics.
Remediation System Performance
• Effect on Free Product
Groundwater Elevations and Zone of Capture
Data from October, 1993.
Railroad
Amoco
Pipeline
Central
Valva
Capture Zone
• The recovery system has hydraulically contained free petroleum product and has reduced the observed apparent
product thickness to a sheen (<0.01 feet).
• Product recovery rates plateaued in late 1990. Free product recovery rates had decreased to approximately
20-25 gallons/month by October 1993.
Apparent Free Product Thickness
Data from October, 1993.
Railroad
Product Recovery Per Month
.Spill Response Actions Begin
Startup of Interim Free Product Recovery System
U.S. Air Force
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[Remediation System Performance (Continued)
Effects on Dissolved Constituents in Groundwater —
Constantino - Page 9 of 14 —
• Concentrations of BTEX in groundwater within the capture zone have remained relatively constant since initiating
remediation. Increasing concentrations of BTEX in groundwater was observed downgradient from the capture zone in
1990.
• Concentrations of MTBE in groundwater decreased more rapidly than BTEX in the capture zone area. MBTE also
migrated downgradient of the capture zone more rapidly than BTEX .
BTEX in Groundwater
Data from October, 1993.
MTBE Groundwater
Data from October, 1993.
Railroa
Amoco
Central
Extraction Valve Amoco
Well ^Jr~*. \ Pipeline
[—Legend
•II concentrations ni°-«>°PPl> • 1.000-1 o.oooppb
mppo fU 100-1,000 ppb H>10,000ppb
(Treatment Equipment Performance
• The treatment system was modified late in 1991 because of operational limitations caused by
suspended solids clogging of bag filters and carbon vessels. Two parallel sets of 10,000 - pound
carbon vessels were replaced with one pair of 20,000 - pound carbon vessels (in series). A manual
water and air backwash system was also installed to extend carbon life and allow ground-water
extraction rates to be maintained. The bag filters were eliminated in late 1992.
• Except for occasional excursions of discharge limits caused by operator error and delivery of
contaminated carbon during the initial stages of remediation, the GAG treatment system has
achieved a 99% (plus) removal rate for BTEX. Removal efficiencies for MTBE have been highly
variable, depending on the frequency of carbon replacement. MTBE influent and effluent
concentrations have remained well below the discharge limit since being instituted in 1993.
Sparging Wells Performance
• Pilot testing indicated a radius of influence of 65 to 150 feet for single sparging wells based on
measured rise in groundwater levels and initial dissolved oxygen increases in groundwater up to
25 feet from the sparging wells. Close monitoring of the sparging system is planned to determine
actual remedial performance and ensure continued hydraulic containment of petroleum
hydrocarbons dissolved in groundwater using the existing groundwater extraction system.
U.S. Air Force
38
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Constantino - Page 10 of 14 <
COST
• The interim free product and groundwater recovery and treatment system was designed and
constructed in 1987-1988. The treatment system was modified and an additional extraction well
was put into service in 1992. Leasing of the activated carbon vessels and activated carbon (with
purchase option) provided the flexibility to adjust to changing operating conditions, resulting in
increased operating efficiency and cost effectiveness. Approximate capital and operating costs are
provided below.
• During 1988 -1993, the average volume of water treated by the interim groundwater pump and
treat system was approximately 155 million gallons per year. The total cost of operation and
maintenance is ~ $0.003 per 1,000 gallons treated.
• Capital Costs
Construction of Wells (4 extraction) $ 32,000
Groundwater and Product Recovery Pumps 30,000
Trenches/Piping and Well Houses 10,000
Treatment Sysxem Installation 40,000
Treatment System Controls 10,000
Buildi ng, H VAC, Utility Service 53,000
Access Road 2,000
Recovered Product Storage Tanks, Diked 20,000
Engineering (excluding site characterization 100,000
& other studies)
Total Capital Cost ~$ 297,000
•i Annual Operating Costs
The total annual operation and maintenance
cost (excluding laboratory analysis of
groundwater samples) is ~$475,000. This
cost includes:
• Carbon System Rental
• Carbon Changeout, Transport & Regeneration
• Electrical Power
• Equipment, Repair and Replacement
• Laboratory Analysis for Influent/Effluent
• Transport of Recovered Product
• O&M Labor
• Engmeenng Support
An In-sltu sparging system was installed in late 1993/early 1994 to further reduce the
concentration of saturated zone petroleum hydrocarbons. The total capital cost for the
sparging system was $375,000, including 3 months of initial operations and testing.
Operating costs sparging system have not yet been defined.
Notes: All costs presented are approximate. Costs for Amoco project management are not included.
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1 Constantino - Page 11 of 14 —
REGULATORY/INSTITUTIONAL ISSUES
• The Constantine site remediation is being performed as a voluntary action by Amoco. Final cleanup criteria for
the site will be established in the future with the concurrence from the Michigan Department of Natural Resources
(MDNR).
• The interim product and groundwater recovery and treatment system was designed in 1987 but was not installed
until 1988 due to administrative delays in obtaining the SPDES permit.
- Treated water is discharged under the authority of a SPDES permit issued by the MDNR. The initial SPDES
permit was issued in 1987 and modified in 1989. The current SPDES permit was issued in in 1993. Discharge
limits are summarized below:
1987/1989 Permit
1993 Permit
Monthly Average Daily Maximum Monthly Maximum
Compounds
Benzene 51 • 5
Toluene 100
Ethylbenzene 62
Xylenes 40
Total BTX - 20
Total BTEX - - 20
MTBE - - 380
pH - - 6.5-9.0
Note: All units in ug/l (except pH).
• Air permits were not required by the MDNR for the air sparging system.
• Petroleum constituents in groundwater led to the installation of point-of-use drinking water treatment systems for
two residences. A positive pressure ventilation system was installed to prevent petroleum vapors from entenng the
basement of one of the residences.
• New water supply wells were installed for a nearby farmer. The wells replaced the pond downgradient of the
Constantine site as a source for agricultural irrigation water.
J
Major Milestones
1987
1988
1989
1990
1901
1992
1993
1994 —
4
Continued Operation of
Intsnm Recovery/Treatment
and
In-Situ Sparging
Remediation System*
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•Constantme - Page 12 of 14 —
LESSONS LEARNED
Implementation Considerations
• An understanding of the extent of contamination at this site evolved over a period of 5 years of investigation,
monitoring, and remediation. Defining the extent of contamination was focused on determining the need for
remediation in specific areas of the site, selecting and designing remedies, and evaluating the effectiveness of
implemented actions.
• Initiating an interim remedial action provided for hydraulic containment and recovery of free-phase petroleum
product and containment of a substantial portion of petroleum constituents dissolved in groundwater while the full
extent of contamination and supplemental remedial actions were defined.
• Although the interim system operated a high percentage of the time, downtime and low flow rates caused by
operating problems resulted in a partial loss of full hydraulic containment of the dissolved - phase contamination.
• Leasing the activated carbon system and carbon provided the flexibility to modify the treatment system in
response to changing operating conditions and supplier performance.
Technology Limitations
• Regular treatment of recovery wells to remove solids buildup on intake screens and pump intakes
(redevelopment and chemical treatment) is required to maintain adequate capture zone(s) at the Constantme site.
• Olephyllic/hydrophobic filter-skimmers were initially used to recover free product. Frequent maintenance was
required due to solids buildup, and they were eventually replaced with free product recovery pumps.
• Paddle wheel-type flow sensors are less than ideal for this site due to in-line solids buildup.
• Carbon system operation is hydraulically limited by solids build-up. Laboratory analysis indicated the
reddish/brown solids causing the fouling was mainly biomass (primarily aerobic iron and slime forming bacteria)
bound with inorganic matter (iron, silica, sulfur, aluminum and calcium). Daily backwashing of the carbon vessels is
required to maintain flow adequate for sustaining hydraulic containment.
• Activated carbon efficiency is limited by suspended solids buildup. Bag filters have only been partially successful
in controlling the suspended solids loading to the carbon adsorbers. New methods to control influent solids are
regularly evaluated.
• Granular activated carbon is inefficient in removing MTBE as compared to BTEX. An engineering analysis
performed subsequent to installing the interim remediation system indicated that air stripping followed by aqueous
phase activated carbon may be a more cost-effective technique for treating water with elevated MTBE
concentrations.
• BTEX concentrations in groundwater near the source of contamination did not decrease substantially over a 5
(plus) year period. Pump and treat systems appear limited in their ability to restore groundwater quality due to
ongoing solubilization of constituents from free product and residual contamination in saturated zone soils.
Future Technology Selection Considerations
• A phased approach to investigation and remediation at this site was beneficial. Early action to control
contaminant migration in groundwater, when properly designed and implemented, can reduce the extent, duration
and cost of clean up.
• The Constantino site SPDES permit restricted the volume of groundwater that could be extracted and treated,
limiting the ability to modify system operation to expand the capture zone. Discharge permits for groundwater
treatment systems should provide for sufficient capacity to accommodate modest increases in flow to achieve
remediation objectives.
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Constant** - Pag* 13 of 14 —
LESSONS LEARNED (Continued)
Future Technology Selection Cons/derations
• Substantial attention is paid to the design and construction of groundwater pump and treat systems. Greater
attention should be paid to operation and maintenance, including periodic evaluation of the performance of
subsurface and above ground system components (e.g., capture zone analyses, contaminant transport evaluation,
treatment system removal efficiency, etc.), to ensure project objectives are met.
• The potential impact of solids buildup due to biomass growth and oxidation of inorganics should be addressed in
the design of groundwater pump and treat systems.
• Ultrasonic flow meters should be considered for use in groundwater pump and treat systems where solids buildup
is of concern.
• Alternative treatment systems (i.e., air stripping followed by aqueous-phase activated carbon polishing) should be
considered for sites where efficient removal of MTBE is required prior to discharge.
ANALYSIS PREPARATION
This analysis was prepared by:
Stone & Webster Environmental A
Technology & Services
245 Summer Street
Boston, MA 02210
Contact: Bruno BrodMd (617) 580-2767
CERTIFICATION
This analysis accurately reflects the performance and costs of the remediation:
Paul F.
Remedial Project Manager
Amoco Corporation
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Constantme - Page 14 of 14
SOURCES
Major Sources For Each Section
Sit* Characteristic*: Source #s (from list below) 1,5,7, and 23
Remediation System: Source #s 1, 2. 3, 5, 7, 9, 17, 18, 20, 21, and 23
Performance: Source #s 5, 6, 7,10, 12,14, 16,17, 19, and 23
Cost: Source #s 11, 13, 22, and 23
Regulatory/Institutional Issues: Source #s 4, 5, 7, 8,15, and 23
Schedule: Source #s 5, 7, 19, 22, and 23
Lessons Learned: Source #s 5, 6, 7,10, 12,14, 17, and 23
Chronological List of Sources and Additional References
1 Design Basis for Constantme Remediation System, prepared by Groundwater Technology, Inc., Undated.
2. Plans and Specifications for Interim Remediation System, prepared by Groundwater Technology, Inc., Undated.
3. Operational and Maintenance Information for the Intenm Groundwater Remediation and Hydrocarbon Treatment System -
Amoco, Florence Township near Constantme, Michigan, prepared by Groundwater Technology, Inc., March 6,1988
4 NPDES Permit No. MI00461S9 - AMOCO Oil Co. - Constantme, Michigan, Water Resources Commission, issued September
30,1987, modified September 21,1989.
5. Data Package, prepared by J. W. Aiken and D. A. Schumacher, ENSR Consulting and Engineering, June 17,1992.
6. August 1991 Quarterly Monitoring Report • Constantino, Michigan Site, Document 0350-020-400, prepared for AMOCO
Corporation, prepared by ENSR Consulting and Engineering, May 1992.
7. Remediation Plan for Constantme, Michigan, Document Number 0350-024-141, prepared by ENSR, January 1992.
8. MERA Operational Memorandum *8 - Type B Criteria, Rules 299.5709, 299.5711(2), 299.5711(5) and 299.5713, Interoffice
Memorandum, prepared by Alan J. Howard, Michigan Department of Natural Resources, January 8, 1992.
9. Summary of Recovery Well Installations at Constantino, Letter to Mr. Paul Ressmeyer, Amoco Corporation, prepared by Mr.
David A. Schumacher, ENSR Consulting and Engineering, March 26,1992.
10. November 1991 and February 1992 Quarterly Monitoring Report - Constantino, Michigan Site Document No. 0350-020-110,
prepared by ENSR Consulting and Engineering, May 1992.
1 1. Irrigation Well Drilling at Constantino, Letter to Mr. Paul Ressmeyer, Amoco Corporation, prepared by Messrs. Joseph W.
Aiken and David A. Schumacher, ENSR Consulting and Engineering, June 17,1992.
12. Spent Granular Activated Carbon: Foulant Analysis, Constantino Site, Michigan; Project 2112-21-D703, Internal
Memorandum to P.P. Ressmeyer, Amoco Corporation, prepared by V.E. Berkhetser, July 20,1992.
13. Calgon Carbon Service Agreement, Letter to Paul Ressmeyer, Amoco Corporation, prepared by M.C. Reiser, January, 1993.
14 Semi -Annual Monitoring Report, Constantme Michigan, Period of Apnl 1993 through October 1993, prepared by Amoco
Corporation, January 30, 1993.
15. NPD£S Permit No. MI0046159. - Amoco Pipeline Company, 63638; Constantino Road, Constantino, Michigan, Water
Resources Commission, March 18, 1993.
16. Semi-Annual Monitoring Report - Constantino, Michigan, 9/93 to 3/93, prepared by Amoco Corporation, June 8, 1993.
17. AMOCO Constantino Site, Presentation Handout prepared by Calgon Carbon, June 22,1993.
18. Work Plan for Remedial Design/Remedial Action - Constantme, Mil Residuals Management Technology, Inc., August 1993.
19. AMOCO, Constantino, Michigan - Results of Air Sparging Pilot Test, Letter to Ms. Lolita M. Anderson, Supertund Coordinator,
Amoco Corporation, prepared by Residuals Management Technology, Inc., September?, 1993.
20. Project Manual for Amoco Corporation Air Sparging System, Final Design - Phase 1 Constantino, Michigan, prepared by
Residuals Management Technology, Inc., October 1993.
21. Specifications for AMOCO Corporation Air Sparging System,
Residuals Management Technology, Inc., October 1993.
Final Design - Phase 2, Constantino, Michigan, prepared by
22. Constantino Michigan Air Sparging System - Project Summary, Letter to Ms. Lolita Anderson, Superfund Coordinator, Amoco
Corporation, prepared by Residuals Management Technology, Inc., January 5,1994.
23. Personal Communications with Mr. Paul F. Ressmeyer, Superfund Coordinator, Amoco Corporation, March through June
1994.
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Pump and Treatment System at Commencement Bay,
South Tacoma Channel (Well 12A),
Phase 2, Tacoma, Washington
(Interim Report)
44
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Case Study Abstract
Pump & Treatment System at Commencement Bay,
South Tacoma Channel (Well 12A)
Phase 2, Tacoma, Washington
Site Name:
Commencement Bay, South Tacoma
Channel (Well 12A) Superfund Site
Location:
Tacoma, Washington
Contaminants:
Chlorinated Aliphatics
- trans-1,2-Dichloroethene (DCE), 1,1,2,2-
Tetrachloroethane (PCA), 1,1,2,2-
Tetrachloroethane (PCE), Trichloroethene
(TCE)
- PCA contamination plume measured at levels
greater than 10,000 ug/L in July 1983
- Free phase estimates of contamination are
PCE - 3734 Ibs, TCE - 126,112 Ibs, and
PCA -209,115 Ibs
- Remedial investigation showed DCE up to
100 ppb; PCA up to 300 ppb; PCE up to 5.4
ppb; and TCE up to 130 ppb in Well 12A
Period of Operation:
Status: Ongoing
Report covers - 1988 to 2/94
Cleanup Type:
Full-scale cleanup (interim
results)
Vendor:
Not Available
SIC Code:
2851 (Paints, Varnishes, Lacquers,
Enamels, and Allied Products)
Technology:
Groundwater Extraction followed by Granular
Activated Carbon (GAC)
- 7 groundwater extraction wells with a 500
gpm design flow rate
- Designed to have drawn-down sufficient to
create a cone of depression and to reduce
further migration of contaminants out of the
source area
- 2 liquid-phase GAC containers operated in
parallel
- Treated water discharged to a storm drain
system
- Soil vapor extraction used in a related
application to remove volatile contaminants
from the soil matrix
Cleanup Authority:
CERCLA; Local Requirements
- ROD Date: 3/85
Point of Contact:
Kevin Rochlin
Remedial Project Manager
U.S. EPA Region 10
Seattle, Washington
Waste Source:
Storage - Drums; Other: Pour off
from Processing Tanks
Purpose/Significance of
Application:
Application of groundwater extraction
followed by granular activated carbon
treatment of extracted groundwater.
Project completed in conjunction with
an ongoing soil vapor extraction
system.
Type/Quantity of Media Treated:
Groundwater
- Upper aquifer (50 ft thickness) consists of unconfined sand and gravel
- Depth to water table approximately 36 feet
- Lower aquifer not contaminated
- Separate liquid phases of VOCs in soil and groundwater suspected
- Area suspected of groundwater contamination covers approximately 100 acres
45
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Case Study Abstract
Pump & Treatment System at Commencement Bay
South Tacoma Channel (Well 12A),
Phase 2, Tacoma, Washington
Regulatory Requirements/Cleanup Goals:
- Cleanup goals identified for Well 12A (City of Tacoma production well) based on ARARs for RCRA, CAA, and CWA:
if Well 12A is used for drinking water - 10'6 risk level for contaminants present
if not, groundwater corrective action required until the concentration of hazardous constituents meets one of the
following: MCLs, ACLs, or background
- Prior to discharge to storm sewer, extracted water required to meet EPA standards for "Fish Consumption Only", including
DCE at 1.85 ug/L; PCA at 10.7 ug/L; PCE at 8.85 ug/L; TCE at 80.7 ug/L; discharge rate of 500 gallons per minute;
pH of 6 to 9; TSS < 500 mg/L, and total VOAs of < Img/L
Results:
As of February 1994:
- 281,700,000 gallons of groundwater have been pumped and treated
- An estimated 10,361 pounds of VOCs have been removed by the GAC system
- Specific VOCs in GAC system influent ranged from 13 ug/L to 2,000 ug/L
- Specific VOCs in GAC system effluent ranged from <1 ug/L to 13 ug/L
Cost Factors:
- Total Capital Costs (contract amount) - $1,343,701 (as of 7/25/88)
- No information provided on operating costs, cost sensitivities, or breakdown of capital costs
Description:
The Commencement Bay site was used from 1927 to 1964 for waste oil recycling, paint and lacquer thinner manufacturing,
and solvent reclamation. Hundreds of drums of material were stored at this site. Leaks from these drums, as well as the
dumping of wastes directly on the ground and overflows from the solvent and waste oil recycling tanks, resulted in
contamination of the soil and groundwater at the site. The primary contaminants of concern at the site included DCE (trans-
1,2-dichloroethene), PCA (1,1,2,2-tetrachloroethane), PCE (1,1,2,2-tetrachloroethene), and TCE (trichloroethene). A PCA
groundwater contamination plume was measured at levels greater than 10,000 ug/L and a separate liquid phase of
contamination was suspected in both the soil and groundwater. In addition, chlorinated hydrocarbons were detected in a City
of Tacoma production well (Well 12A) in 1981. The site was placed on the National Priorities List (NPL) and a Record of
Decision was signed in 1985.
A groundwater extraction system using granular activated carbon (GAC) for treatment of extracted groundwater was installed
and began operating at the site in 1988. This system includes 7 groundwater extraction wells and a 500 gpm design flow
rate, and was designed to have a draw-down sufficient to create a cone of depression and to reduce further migration of
contaminants out of the source area. Treated water is discharged into a storm drain system. The groundwater remediation
was ongoing at the time of this report.
As of February 1994, approximately 282,000,000 gallons of groundwater had been extracted, and an estimated 10,631
pounds of VOCs removed by the GAC. Specific VOCs in the GAC system influent ranged from 13 ug/L to 2,000 ug/L,
and, in the effluent, from <1 ug/L to 13 ug/L. The contract amount for total capital cost was identified as $1,343,701, as of
July, 1988.
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P»go t on 2 "S
ITECHNOLOGY APPLICATION
This analysis covers the field application of sys-
tem to pump & treat the groundwater in a carbon
adsorption system in an above ground plant. This
began in late 1988 and Phase II is ongoing.
The contaminated soil matrix at this site is being
remediated through in situ soil vapor extraction
(SVE) which is not included in this analysis.
dSITE CHARACTERISTICS!
i Site History/Release Characteristics
During the period from 1927 to 1964 this site was used by National Oil and Paint for waste oil recycling,
paint and lacquer thinner manufacturing, and solvent reclamation. The site was purchased by the Time Oil
Company in 1964.
The pre-1964 operations appear to have contributed to the site VOC contamination in several ways. First,
the site was used to store hundreds of drum of potentially "useful" materials. Some of the stored drums
leaked. Non-useable materials were dumped directly onto the ground. Second, during the recycling
process for waste oil, solvents contained in the oil floated to the top of the processing tank and were
poured off. Periodically, the tank holding the solvents overflowed onto the site.
In 1981 chlorinated hydrocarbons were detected in groundwater samples from the City of Tacoma pro-
duction well 12A.
This site is in the City of Tacoma, Washington, and includes industrial, commercial, and residential areas
that surround the site. Well 12A is one of 13 wells used by the city to meet peak summer and emergency
water demands.
In 1983 a five tower air stripping system was built to treat well 12A water. In 1988 a pump and treatment
system was installed near the contamination source to intercept and treat the groundwater plume.
In accordance with the Record of Decision (ROD), signed in 1985, soils and solid waste materials were
disposed of in an offsite Resource Conservation and Recovery Act (RCRA) approved facility. This waste
material was contaminated with heavy metals (primarily lead).
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Tacoma 2 of 12
i Contaminants of Concern i
The VOCs of greatest concern in the soil and groundwater are the following chlorinated hydrocarbons:
DCE (trans-1,2-dichloroe thy lene)
PCA (1,1,2,2-tetrachloroethane)
PCE (1,1,2,2-tetrachloroethylene)
TCE (trichloroethylene)
Properties of contaminants focused upon during remediation are:
Property at 1 atm
Empirical Formula
Density
Melting Point
Vapor Pressure @ 25°C
Henry's Law Constant
Water Solubility
Log Octanol-Water
Partition Coefficient;
Organic Carbon Partition
Coefficient; Koc,
Site Specific Extraction
Efficiency, %
hire & Extent of Conta
Units
g/cm3
°C
mm Hg
(atm)(m3)
mole
mg/l
log Kow
L/kg
mination
DCE
C2H2CI2
1.257
-50
331
5.32X10-3
@25°C
600
@20°C
1.48
118
7
^9&SSSS3g&g£3^£%$£@£?&&
PCA
C2*'2 4
1.586
-43.8
419
3.81 X10-4
@20°C
2,900
@20°C
2.39
364
2
PCE
C2CI4
1.6311
-22.4
77
2.87X10-2
@25°C
150
@25°C
2.53
126
2
IGE
C2HCI3
1.462
-84.8
1.17X10-2
@25°C
1,100
®25°C
2.53
About 20% of the contamination is in the top 32.5 feet, and the remaining 80% is in the 32.5 to 40 feet depth interval.
The volume of contaminated soil is (66,287 ft2 X 40 ft deep ~) 2,651,480 ft3.
For the VOCs, there may be separate liquid phases of these compounds or miscible solutions between them in both
the soil and groundwater.
Free phase estimates are 3,734 pounds of PCE; 126,112 pounds of TCE; and 209,115 pounds of PCA.
Total semi-volitile organic compounds (SVOCs) for the site is roughly 420 pounds.
Gas chromatography limitations resulted in the PCA concentrations reported actually being PCA and/or PCE.
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Tacoma 3 of 12
i Contaminant Locations and Geologic Profiles •
Remedial investigation (Rl) field activities at the site found the following concentrations:
Contaminant
DCE
PGA
PCE
TCE
* PCA and/or PCE
Spatial Distribution of the Contaminants of Concern
Figure 2
Water from Well 12A
Concentration, ppb
30 to 100
17 to 300
1.6 to 5.4
54 to 130
Railroad Spur Fill soil
Concentration, mg/kg
3.92
*1,030
*1,030
160
LEGEND
• Monitoring Wells From Previous Investigation
• City of Tacoma Wells
PCA Contamination Plume
July 1983
Note: All concentration values are
micrograms per liter (|ig/l).
• All of the contaminants of concern have a solubility in water of 150 mg/l (PCE) or more (up to 2,900 mg/l for PCA).
• Groundwater underlying the Time Oil Company property and adjacent properties to the south appears to be the most
contaminated.
Hydrogeologic Units
• The upper aquifer (unconfined sand and gravel) is 50 feet thick (depth to the water table is about 36 feet).
• The upper aquifer is separated from the lower aquifer by a 40 foot thick dense glacial till aquitard.
• The lower aquifer is not contaminated.
• The area suspected of groundwater contamination is in the upper aquifer and covers about 100 acres and is bounded
by the city water well field on the south, the Burlington Northern Railroad on the north, and Interstate 5 on the East.
• Figure 2 shows the contamination plume for PCA which is typical for the VOC groundwater contamnation at this site.
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Tacoma 4 of 12
iS/fe Conditions
38'F (Jan.) to 65°F (July)
Average Air Temperature
Precipitation
- Annual Average 38. in.
- December Average 6.3 in.
- July Average 0.8 in.
Snowfall, Annual Average 14. in.
Relative Humidity, Average 65% to 85%
Wind Speed, Average 10 mph
Project site elevation is 270 feet.
The vadose zone thickness (depth to groundwater) varies from 33 to 40 feet.
The groundwater gradient is about 0.05%, falling to-the north-northeast.
iKey So/1 or Key Aquifer Characteristics
Property
Porosity
Particle density
Soil bulk density
Surface soil permeability
Depth to groundwater
Aquifer thickness
Water Saturated thickness
Units
%
g/cm3
g/cm3
cm/sec
ft
feet
feet
Range or value
30
2.65
1.86
2.8103.6X10-3
36
50
10 to 17
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Tacoma 5 of 12
ESTREATMENT SYSTEM
The selected remedial action includes:
• Groundwater treatment by a liquid phase granulated activated carbon (GAC) adsorption system (predicted >98%
removal), discussed in this report.
• Treated water is disposed of in the storm drain system .
• Monitor groundwater for VOCs and, after 2 years of operation, evaluate the effectiveness of the groundwater extrac-
tion and treatment system.
• Prohibit withdrawal of groundwater by private parties where the hazard > 10-6.
• Use soil vapor extraction (vacuum applied via extraction wells that extend to the groundwater), described in a sepa-
rate report to remove volatile contaminants in the soil matrix.
i Overall Process Schematic ••
Figure 3
WjJ) Strainer
L-CX-H-
Groundwater
Extraction
Well Pump
£
<
:
>
*SP
r~v_
Adsorber
-^-feO-r
nxj-r-j ] "^ » Overflow
? Carbon ^6 Effluent
>»-SP Adsorber FllteS| Tank ^l To Slab SumP
~1 ™1 **
-iXM- 2^A
^"SP f A Treated
/}. ^ L ' btnuentto
N^ 1 A Storm Drain
*SP
Slab] ^
Sumo — L
HXK SP spl
S^ Recycle
ouiup— - KUmp M06W182C
Pump <|>
SP Sampling Port
1/1 One-way Valve
M Valve
Stream Flow
Process Flow Diagram for Groundwater
Extraction and Treatment System
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Tacom* 6 of 12
i System C/oseup
Figure 4
ri o«nanl Ana of Excav«tion,
VEB InHlllitlom. «M P»ng
LOCATION OF EXCAVATION AREA AND TREATMENT SYSTEMS
Figure 5
Mr vacuum rMtaf valv*
,ChMkvalv«
PTMWT* nvfteh
8" IhtcK flntoMd ooncrat« pad
Groundwater Extraction Well
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" Tacornn 7 of 12
i/fey Design Criteria • ••• ' i•iBiK---«mB^^ >- ••• •>••*•* •••••••••-
• The extraction system is designed to have sufficient draw-down to create a cone of depression to reduce further
migration of contaminants out of the source area.
• A pumping rate of 200 gpm is estimated to induce a 0.75 foot draw down at a radius of influence of 200 feet, and a
pumping rate of 500 gpm is estimated to induce 1.9 feet of draw down at a radius of influence of 200 feet. 500 gpm
was selected as the design flow rate.
• A radius of influence of 200 feet is expected to largely prevent further contamination from leaving the source area.
• The adsorption capacity of granular activated carbon for PGA is given by the equation
mg PCA adsorbed/g GAC = l2.8(mg/L of PGA in water)0.613
EXPECTED FLOW/RATES AND CONCENTRATIONS OF
CONTAMINANTS FOR THE TREATMENT SYSTEM
Stream Number* 1 2345
Maximum Flowrate (gpm) 500 500 500 20 200
Concentration of Volatile Organic Compounds, mo/1
1,1,2,2-Tetrachloroethane(PCA) 2-35 0.3 0.3 — —
Trans-1,2-Dichloroethylene(DCE) 0.2-3.5 0.03 0.03 — —
Trichloroethylene (TCE) 0.4-6.5 0.06 0.06 — —
Tetrachloroethylene (PCE) 0.4-0.7 .01 .01 — —
"Stream number explanation (see also figure 3):
1. Groundwater from extraction well.
2. Treated groundwater leaving GAC adsorbers.
3. Effluent to storm drain.
4. Slab sump pump to strainer and GAC adsorbers.
5. recirculating water to GAC adsorbers.
i Key Monitored Operating Parameters
• Groundwater monitoring wells located in the vicinity of the Time Oil Company will be used to observe the effective-
ness of the extraction system in creating a capture zone that will effectively reduce contaminant concentration out-
side the source area.
• The groundwater treatment plant discharge shall meet the EPA standards for the storm water discharge, maximum
permitted concentrations (for "Fish Consumption Only"):
Compound Permitted Concentration,
DCE 1.85
PCA 10.7
PCE 8.85
TCE 80.7
Other limitations include:
maximum discharge rate 500 gallons/minute,
pH 6 to 9,
total suspended solids < 500 mg/L
total VOAs <1 mg/L
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Tacoma 6 of 12
i Performance Objectives i
Create a cone of depression that would reduce further migration of contaminants out of the source area.
Treat the contaminated groundwater to reduce volatile organic compounds to meet the EPA standards for the storm
water discharge.
i Treatment Plan
Contaminated groundwater is being treated to remove VOCs by pumping contaminated groundwater out of the
source area through a GAC adsorption system.
The groundwater treatment plant discharge is meeting water quality criteria for protection of human health at a 10-*
cancer risk for human ingestion of aquatic organisms (45 FR 79318, November 28,1980), as follows:
Compound Permitted Concentration, ug/L
Vinyl chloride 525
PCA 10.7
TCE 80.7
Other permit limitations include:
pH 6 to 9
i Operational Performance
Volume of Water Pumped
• As of 23 Feb. 1994, 281,700,000 gallon of groundwater have been pumped and treated by the GAC treatment system.
System Downtime
• No down time was reported for the period January 1994 through February 1994.
• The EPA has provided no other Activities Reports for this project. (Figure 6 suggests a period of downtime from early
to middle 1990.)
• Treatment Performance •"""•" Mnmm\[\»Mmmmmmmmm^^^ ; :: i
Effects on Plume
• A pumping rate of 500 gpm was estimated to induce 1.9 feet of draw down at a radius of influence of 200 feet.
• The EPA has provided no documents or data relative to the cone of influence resulting from pumping of the groundwater.
Contaminants versus Time at the Treatment Plant Influent
• Figure 6 shows the total VOC concentration for the period 1989 through February 1994.
Influent versus Effluent
• The following table gives the results of the groundwater GAC treatment for the period 11 January 1994 through 23
February 1994
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facoma 9 of 12
Figure 6
Total VOC Influent Concentrations, 1989 Through Currrent
10000
1989
1989 1989
1989 1989 1989
Date
VOCs IN GAC TREATMENT SYSTEM INFLUENT AND EFFLUENT
Concentration of VOCs. uo/l
GAG System Influent
Vinyl Chloride
Trans-1,2-Dichloroethylene
Cis-1,2-Dichloroethylene
Trichloroethylene
1,1,2-Trichloroethylene
Tetrachloroethylene
1,1,2,2-Tetrachloroethane
GAG System Effluent
Vinyl Chloride
Trans-1,2-Dichloroethylene
Cis-1,2-Dichloroethylene
Trichloroethylene
1,1,2-Trichloroethylene
Tetrachloroethylene
1,1,2,2-Tetrachloroethane
Total Pounds Contaminants Removed
1/11/94
21
290
240
1,200
15
46
3,000
1/26/94
16
270
210
1,000
10
43
2,400
2/8/94
32
280
200
1,200
15
57
3,300
Date
2/23/94
29
270
200
920
13
45
2,000
3.2
5.9
9.6
13
8.4
8.1
11
6.9
3.9
8.5
2.2
As of 23 Feb. 1994, an estimated 10,361 pounds of VOCs have been removed by treatment by the GAC treatment
system. This estimates is based on the average loading rate of the GAC as calculated by periodic sampling.
U.S. Air Force
55
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Tacoimi JO of J2
The U.S. EPA Region 10, Hazardous Waste Division declined to provide a breakdown of the capital estimate
or the operating cost estimate. It also declined to provide cost data for the period since the remediation
phase of the project started and access to the remediation contractor.
i Capital Costs i
Original (4/5/88) Current (7/25/88>
Contract Amount $987,789 $1,343,701
(reference 7)
i Operating Costs
NONE PROVIDED.
\CostSensitivtttes
NONE PROVIDED.
U.S. Air Force
56
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Tacoma 11 of12
[REGULATORY/INSTITUTIONAL ISSUES:
Highly contaminated surface soils were transported to a RCRA approved landfill facility for treatment/disposal
ARARs include RCRA, Clean Air Act regulations (for emissions of VOCs), the Clean Water Act, and the Safe Drinking
Water Act (there are no drinking water standards for the contaminants present in Well 12A).
If groundwater from Well 12A is to be used for drinking water, then it must be treated to the 10-6 risk level for the
contaminants present. Otherwise, in order to be consistent with 40 CFR 264, Subpart F, groundwater corrective
action is required until the concentration of hazardous constituents complies with one of the following: MCLs (where
designated for particular substances), ACLs (that provide adequate protection of public health and the environment),
or background.
NPL site.
The EPA standard for "Fish Consumption Only" was used for the storm water discharge maximum permitted concen-
trations:
Compound Permitted Concentration, ug/L
DCE 1.85
PCA 10.7
PCE 8.85
TCE 80.7
Other limitations include:
maximum discharge rate 500 gallons/minute,
pH 6 to 9,
total suspended solids < 500 mg/L
total VOAs <1 mg/L
CZSCHEDULE
None provided.
dSLESSONS LEARNED
The project is not complete as yet.
An operational analysis from which Lessons Learned could be derived has not been provided by the Region 10 of the
U.S. EPA
U.S. Air Force 57
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^^^—•—-^"—^^——^^^ ^™"~~ - ~~~~~^~~~~"""~"^"^™ Tacom* 12 of 12
ISOURCES
i Major Sources For Each Section
Site Characteristics: 2 and 9
Treatment System: 2 and 3
Performance: 4
Cost: 4 and 7
Regulatory/Institutional Issues: 1,2,5 and 6
Schedule: None
Lessons Learned: None
iChronological List of Sources and Additional References'*
1. EPA Superfund Record of Decision: South Tacoma Channel-Well 12A, WA, EPA/ROD/R10-85/OO4, May, 1985.
2. Revised Remedial Design Report, South Tacoma Channel Well 12A, by Woodward-Clyde Consultants for U.S. Army
Corps of Engineers, Superfund Branch, Kansas City, Missouri District, April 17,1987.
3. Letter from Philip N. Stoa, EPA Coordinator, Construction Division, Construction Services Branch, Seattle District,
Corps of Engineers, December 15,1993.
4. Fax from Kevin Rochlin, Region 10 U.S. EPA, Hazardous Waste Division, dated 18 May 1994.
5. RREL Treatability Data Base, Version 4.0, EPA, November 15,1991.
6. Climates of the States, by the National Oceanic and Atmospheric Administration, US Department of Commerce, pub-
lished by the Water Information Center, 1974.
7. Fax from Bill Brooker, Fort Lewis Area Office, Corps of Engineers, 10 May 1994.
QSANALYSIS PREPARATION -^^^^^^
This analysis was prepared by:
Stone & Webster Environmental
Technology & Service
P.O. Box 5406
Denver, Colorado 80217-5406
Contact: Dr. Richard Carmichael 303-741-7169
EREVIEW
Support and review for the preparation of this report was provided by
Kevin Rochlin
Project Manager
U.S. EPA, Region 10
Seattle, Washington
U.S. Air Force
58
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Recovery of Free Petroleum Product
Fort Drum, Fuel Dispensing Area 1595
Watertown, New York
(Interim Report)
59
-------
Case Study Abstract
Recovery of Free Petroleum Product
Fort Drum, Fuel Dispensing Area 1595, Watertown, New York
Site Name:
Fort Drum Fuel Dispensing Area 1595
Location:
Watertown, New York
Contaminants:
Benzene, Toluene, Ethylbenzene, and Xylenes
(BTEX)
- Gasoline and #2 fuel oil
- Free product measured in two wells in 1990
and 1994
- Full extent of contamination not yet defined
Period of Operation:
Status: Ongoing
Report covers - 2/92 to 4/94
Cleanup Type:
Full-scale cleanup (interim
results)
Vendor:
Not Available
SIC Code:
9711 (National Security)
Technology:
Groundwater Extraction followed by Air
Stripping and Granular Activated Carbon
- 2 recovery wells - approximately 25 ft.
below ground surface; average rate of 5-6
gpm
- Oil/water separator - 575 gallon capacity
- Air stripper - 750 cfm
- GAC - 4 55-gallon steel drums; 200 Ib
GAC per drum; operated 2 in series
Cleanup Authority:
DoD
Point of Contact:
Remedial Project Manager
Fort Drum Environmental
Division
Watertown, NY
Waste Source:
Underground Storage Tank
Purpose/Significance of Application:
Full-scale remediation to recover free-
phase petroleum product using
groundwater extraction and air stripping
and granular activated carbon (GAC).
Type/Quantity of Media Treated:
Groundwater and Free Product
- Hydraulic conductivity of aquifer 0.11 to 0.0012 cm/sec
- Transmissivity 11,787 to 32,518 using Jacob method
Regulatory Requirements/Cleanup Goals:
- Final cleanup criteria have not been established at this time; the project is being conducted as a Rapid Response Interim
Remediation
- Treated water discharged to the POTW must meet the following criteria - benzene (3 ug/L), toluene (35 ug/L), xylenes
(190 ug/L), ethylbenzene (8 ug/L)
Results:
- Information on the total quantity of free product recovered is not available at this time
- The effluent from the treatment system met all discharge criteria
Cost Factors:
- Total Capital Costs - $958,780 (including system design and construction including site work, equipment, and
mobilization/demobilization)
- Total Annual Operating Costs - $129,440 (including carbon changeout/regeneration, maintenance, laboratory analysis, and
project management)
- An estimated cost for completion of the cleanup is not available at this time
60
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Case Study Abstract
Recovery of Free Petroleum Product, Fort Drum,
Fuel Dispensing Area 1595, Watertown, New York (Continued)
Description:
Fort Drum in Watertown, New York, established in 1906, serves as a combat skills training area and operations headquarters
for light infantry troops. Motor vehicle and aircraft refueling activities are conducted in Area 1595 of the facility. Area 1595
includes an underground storage tank (UST) and 10 dispensing units for gasoline, diesel fuel, and jet fuel. In 1982, free
petroleum product was observed in a spring near this area. Suspected contaminant sources include leaking USTs and
wastewaters from vehicle washing operations located adjacent to Area 1595. The primary contaminants of concern are BTEX
(benzene, toluene, ethylbenzene, and xylenes) and free petroleum product. The full extent of the contamination had not been
defined at the time of this report. The site remediation is being performed as a Rapid Response Interim Remediation and
final cleanup criteria have not been established at this time.
A pump and treat recovery, consisting of two recovery wells, an oil/water separator, an air stripper, and granular activated
carbon vessels, was operated from March 1992 to mid-1993. The system was restarted in February 1994 and was operational
at the time of this report. The first year of operation focused on troubleshooting and little data were collected during that
time. As such, no information is available at this time on the total quantity of free product recovered or the rate of recovery.
Data from the air stripper/GAC system indicated that the concentrations of contaminants in the effluent meet the POTW
discharge criteria for BTEX. An air emissions certificate was issued by the State in October 1992; however, information on
specific emission limits was not available at the time of this report.
The total capital costs for this remediation are $958,780 and the estimated total annual operating costs are $129,440. Based
on operations to date, it has been observed that free product recovery pumps require frequent maintenance and that activated
carbon efficiency was limited because of fouling by iron and biomass.
61
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CHWOLOG Y APPL/CATfON
, Page f of f 3 =S
I SITE
I TECH NO LOGY APPLICATION
Fort Drum, Fuel Dispensing
Area 1595
Watertown, NY
• Motor vehicles and aircraft refueling at Fort Drum took place at nine dispensing facilities located along a 2-mile strip of land known
as "Gasoline Alley." Fuel Dispensing Area 1595 (Area 1595), the subject of this report, is located along a portion of Gasoline Alley
• Area 1595 consists of an underground storage tank (UST) area approximately 150 feet in length, and a dispensing area
with 10 dispensing units spread over a distance of approximately 400 feet.
• In 1982, free petroleum product was observed discharging from a natural spring located 550 feet northwest of the underground
storage tanks (USTs) which supplied gasoline, diesel fuel and jet fuel to the Area 1595 dispensers.
• The precise source of the tree product could not be found. A 1' diameter hole was discovered in an UST removed in 1975. All of
the USTs were reported to have been replaced by 1985. The tanks on site passed a leak test in March 1991, but the system piping
was determined to have a leak rate of 0.05 gallons/hour. The current status of the USTs is unknown.
• Several former washracks located next to Area 1595 may also have been a source of oil and other materials discharged to the
subsurface. The washracks were used to clean wheeled arid track vehicles.
• An earthen dike was constructed immediately downstream of the spring to facilitate the surface collection and skimming of free
petroleum product. The interim groundwater pump and treat system addressed in this report was constructed in 1991 to recover
free product from the subsurface.
J
This analysis covers an effort to recover free phase
petroleum product using an interim groundwater
pump and treat system. Air stripping and granular
activated carbon (GAC) have been used in series to
treat recovered groundwater. Interim remediation was
first initiated in February 1992. This analysis covers
performance through April 1994.
I Site History/Release Characteristics ••••••••••IMMHBBHEEZZZ
• Fort Drum, a U.S. Armed Forces Command installation, was originally established in 1906 as a National Guard training
area and has served as a combat skills training area and operations headquarters tor light infantry troops.
[ Contaminants of Concern
Contaminants of concern focused on during the
groundwater remediation are:
Benzene
Toluene
Ethylbenzene
Xylene-m (1
Xylene-o (1
4
1,3) f
-2) }
BTEX
Free petroleum product, a source of the
contaminants identified above, was also
of concern.
Contaminant Properties
Property at STP* Units
Empirical Formula
Density g/cnr*
Vapor Pressure mmHg
Henry's Law atn*rrAmal
Constant
Water Solubility mo/L
pctanot-Water
Organic Carbon
B T
CfHf CeHjCHj
0.87 0.87
75 29
e 5.6E-3 6.5E-3
1,780 534
132 490
50 339
E
CsHjCHj
0.87
7
8.4E-3
161
1,413
565
X*"
C$H4(CH3)2m
-0.87
10
2.5E-1
178
1,830
255
'STP m Standard Temperatun and Pressure; 1 arm, 25 °C
" Properties at 20PC '"Uixtun of m.o and p-xyionos
I Nature & Extent of Contamination
• Laboratory analytical results have indicated that the detected petroleum contamination is gasoline and #2 fuel oil. The free product
and the petroleum-contaminated soil and groundwater in Area 1595 appears to be located in a narrow zone hydraulically
downgradient and downstream from the fuel dispensing area.
• Petroleum hydrocarbons and lead have been detected in surface water and sediment samples collected from the stream at
locations downstream from the dike.
• The full extent of contamination has not yet been defined.
• A preliminary human health risk assessment indicated that petroleum contamination poses an increased lifetime cancer risk of > 1x10-6.
U.S. Air Force
62
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Fort Drum • Page 2 of 13 —
Contaminant Locations and Geologic Profiles
Remedial investigation field activities at the site have included a shallow soil vapor survey; the excavation of shallow test
pits, soil borings and groundwater monitoring wells; free product gauging; water level elevation measurements; and the
collection and laboratory analysis of surface water, sediment, soil, and groundwater samples. Some of the data is
summarized in this report to provide a conceptual understanding of site conditions.
Site Lavout and Surface Water/Sediment Contamination (Plan View)
Benzene, toluene, xylenes, total
volatile aromatic hydrocarbons
and lead were detected in
surface water. Toluene, xylenes
and total volatile aromatic
hydrocarbons were detected in
sediment samples.
Arm 1595
rLegend
^—— Surface Water Route
2\ Sample Location
Total Volatile Aromatic
Hydrocarbons
(EPA method 503.1)
I S*d«n*nt ConcwinMn mpfeg
Surtac* Wafer Concentration ma/i.
\
BDL - Below Detection Limit
All Results: December 1989
Paved
Roads
N
Unpaved
Roads
soon
Soil Contamination (Plan View!
Evidence of subsurface soil
contamination associated with
petroleum was found in soil
samples collected from
shallow test pits and soil
borings in December 1989.
Fuel USTs
Fuel Dispensing Area
i—Legend
All Values IndicateTotal
Volatile Hydrocarbons
(EPA Method 503.1)
Q Soil Test Pit Location
j^j Soil Boring Location
11.000 [Concentration in Soil (moykfl)
BDL m Below Detection Limit
AH results: December 1989
N
300ft
U.S. Air Force
63
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Contaminant Locations and Geologic Profiles (Continued)
Free Floating Product and Groundwater Contamination (Plan View)
Fort Drum • Page 3 of 13 —
Free product was measured in two of the
Area 1595 monitoring wells in 1990.
Benzene, toluene, etnylbenzene, xytones,
total volatile hydrocarbons and lead were
detected in groundwater samples during late
1989/early 1990.
All of the monitoring wells were again
gauged for free product on April 4,1994;
two of the wells within 150 ft of the former
fuel USTs contained free product- one with
7.25 inches, and the other with 3.5 feet
Fuel USTs Fuel Oispenttne Area
— Legend
All Values Indicate
Total Volatile
Aromatic Hydrocarbons
Q Groundwater Sample
Location
A A' Cross Section
Location
~^~\ Grouno*«t»r Concentration
"T. Fn» Product Truekrwu. 2/90
BDL - Below
Detection Limit
(-) indicates no
free product measured
Profile A-A'
NW
650 T
640f
I
ff 630f
N
Groundwater Monitoring
Wells
/ Ground
Area 1595 Surface.
Fuel USTs
SE
Fine
Sand TR •
«— "* "" ™" i
Free
Product
300ft
350ft
60C4-
Vertical Exaggeration »15X
Note: Extent of free product and soil and groundwater contamination not fully defined.
U.S. Air Force
64
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I Contaminant Locations and Geologic Profiles (Continued)
Fort Drum • Page 4 of 13 —
LHhology of Area 1595
Conceptual Site Model: This
model was constructed
based on limited site geology
information. The model is
intended to provide a general
pictorial representation of the
site based on available
information, but may not fully
represent actual site
conditions.
DriwdArea
.Fuel USTi
D»ltnc deposit
of (in* sand
The unconsolidated material observed in the study area is primarily fine-grained, well-sorted sand.
iet below ground surface (BGS). It is thi
surface near the stream channel located downgradient of the
• The unsaturated zone ranges from approximately 6 to 15 feet below ground surface (BGS). It is thickest upgradient of
the diked area (south). Groundwater is closest to the ground '
diked area
• Bedrock surface elevations at Area 1595 are unknown
Site Conditions
• The regional average annual temperature is 45.1 ° F. The regional monthly average rainfall is 3.28 inches. The
monthly average snowfall is 9.51 inches.
• Ground surface elevations within Fort Drum range from approximately 450 to 900 feet above mean sea-level (MSL).
The immediate vicinity of Area 1595 is relatively flat and is between 640 and 650 feet (MSL). The ground surface slopes
toward the spring and diked area where it decreases to 610 to 620 feet (MSL). The surface elevation decreases from the
diked area to approximately 510 feet (MSL) at the pond (approximately 3,000 feet away).
• Surface drainage from Area 1595 flows to the north, and into the unnamed stream, which leads to into Remington Pond.
• Groundwater flow direction within the unconsolidated deposits is primarily to the northwest, from the Area 1595 fuel
dispensing area towards the spring and stream.
• The site is unpaved; infiltrating precipitation affects contaminants mobilization and migration.
Key Soil and Aquifer Characteristics \
— Groundwater Parameters
1993 pump fast data, using 8 wells, unless noted:
Property
Transmissivity
Storage coefficient
Groundwater velocity (ft/day)*
Hydraulic conductivity (cm/s)'
Groundwater gradient (ft/foot)*
Range
11,787-32,518
2.01 E -3 to 2.25 E -2
3.7
1.1 E-1 to 1.2 E-3
0.027
Percolation rate (in/yr) 15
* Data i» from a 1990 rtudy of Area 1S9S.
Comment
Jacob method
Jacob method
At location approximately 150 ft northwest
of fuel dispensing area
At location approximately 150 ft northwest
of fuel dispensing area
Based on water balance
Gasoline Alley data, not specific to Area 1595:
Property
Sand Laver M9 borings)
Moisture content
Plasticity index
Clav Layar (2 borings)
Liquid limit(%)
Plastic limit(%)
Plasticity index
Range
2.5 - 26.0
characteristic
not exhibited
222, 26.0
182, 19.1
6.9, 8.3
• Twelve Fort Drum water supply wells and five residential supply
wells are located within a one to four mile radius upgradient of Area
1595. Nine of the twelve wells, are completed in bedrock, and three
are screened within the unconsolidated deposits.
• The primary source of groundwater for Fort Drum is a confined
bedrock aquifer; the secondary source is a water table aquifer located
within the unconsolidated deposits.
U.S. Air Force
65
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• Fort Drum • Page 5 of 13 _
• TREATMENT SYSTEM
The pump and treat recovery system operated from March 1992 to early/mid 1993, and was restarted in February 1994.
During the first year of operation, efforts were focused on troubleshooting. Very little data was collected during this time
period. Analytical data presented in this report was recorded during the most recent period (1994) of operation.
•• Overall Process Schematic
Recovery Wells Oil/Water Separator
Air Stripper
Granular Activated Carbon Vessels Discharge
10
^
^
| f \04C1\ -+LOAC2\
•I
I
'--*• (aAC3 J -*/C4C4 )
Di*ch*rg»
toPOTW
n
Influent
Vault
Vault
Effluent Vault
Free petroleum product accumulating in the recovery wells is pumped into a product storage tank. Water from
the wells is pumped into the oil/water separator to remove residual free product and is treated by air stripping
and granular activated carbon (GAC) to remove dissolved hydrocarbons. Treated water is then discharged to a
publicly-owned treatment works (POTW).
Recovery Well Network
The recovery wells are
approximately 25 feet below
the surface. Each well has a
screened interval from
approximately 5 to 20 feet
BGS, and produces an
average of 5 to 6 gallons per
minute (GPM).
N
300ft
Fuel USTs Fuel Dispensing Area
Treatment
Facility
Recovery Well-1
Product Storage
Tank
Diked Area
Recovery Well-2
U.S. Air Force
66
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"Fort Drum - Page 6 of 13 —
Extraction Well Detail
1 t
11
1
4'*
(£>•
I
L
"t
I
M
1-
—
~
..
I
Ground Surface
Protective
. .Pped to Product Storage Tank
- • Piped to Trettment System
•* Wet Screen and Casing
— Product Recovery
Pump
— Transducer
Pump
• Key Monitored Operating Parameters
• Fluid levels in recovery wells
• Product storage tank volumes
• Influent flow rates
• Air stripper: Inlet flow rate and pressure, and blower
pressure
• Granular activated carbon units: inlet flow rates and
pressure
• Total effluent flow
• Contaminant concentrations in air stripper influent, air
stripper effluent, and the GAC effluent
Operator can manually adjust the elevation of the product
recovery pump intake based on the observed floating
product thickness and water level in the wells.
•1 Air Stripping/Carbon Adsorption System Schematic
AirStripp»r
18 in Diameter, 20 Ft.
750 CFM Blower, Delta
Pa* PVCFilm Packing
Material
Qnnular Activated Carbon Unite
£5 gallon steel drums, 200 to GAC
per drum. Two an connected in
series, and two are on standby.
Oil/Water Separator
575 gallon capacity
Discharge
toPOTW
U.S. Air Force
67
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PERFORMANCE
Performance Objectives
•Fort Drum - Page 7 of 13 —
"""•"* '
Recover free petroleum product from the water table as an interim measure.
Operations/ History
Initiated operations m March 1992. Operational difficulties prevented continuous operations.
System shut down in early/mid 1993.
Contractor retained to provide O&M and troubleshooting support. Reinitiated operations
in February 1994.
Treatment Approach
Completed Activities
Preliminary assessment of the nature and extent of contamination through Initial Site Investigations
Implementation of diked area skimming
Design, construction, and operation of interim free product
recovery (pump and"treat) system
Future Activities
Continue operating interim ayatem to recover free floating petroleum product
Conduct Phaae II Remedial Investigation to fully define the extent of auoaurfaee
contamination aaaoeiated with Gaaoline Alley
Develop and implement a comprehensive remediation program for Gaaoline Alley (including Area 1505)
U.S. Air Force
68
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Operational/Treatment Performance
Fort Drum- Page 8 of 13 —
— Free Product Recovery
Information on the total quantity of free product recovered and
the rate of free product recovery over time was not available.
r System Throughput
Information on the volumes of water treated was not available.
Parameter
Total hardness
Total Alkalinity
Iron
Manganese
Concentration
120mg/L
121 mg/L
17.3mg/L
1.6 mg/L
System Downtime
The system did not operate continously during
its periods of operation. The actual percentage
of downtime is not known due to lack of
operating records. The causes for the downtime
are described below:
• The oil/water separator and the GAC units,
fouled with inorganics and/or biomass.
• Seals in fuel recovery pumps deteriorated.
• Recovery well #2 was not recovering free
product and was significantly contributing to
the iron precipitation problem This well was
shutdown sometime in 1993.
• The system was not operated and
maintained by trained personnel, and the
monitoring conducted was infrequent.
•aiumming irum uinea Area ~
Complete quantitative
performance data on the
effectiveness of efforts to skim
free product from water
collected in the diked area was
not available.
Insufficient data is available to determine if VOCs and target contaminants have
been consistently treated below discharge levels. The data presented below
data represents the second treatment period.
Air Stripper
Air Stripper Effluent /GAC
Compound Influent Influent GAC EFfluent
Benzene 86 2.5 <0.20
Toluene 130 4.3 <0.20
Ethylbenzene • 120 2.9 <0.20
m-Xylene 320 9.7 <0.20
o-Xylene 86 3.8 <0.20
p-Xylene <0.20 <0.20 <0.20
All concentrations in mg/L
Hydrodynamic Performance •
The capture zone for the interim system has not been defined.
U.S. Air Force
69
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•Fort Drum - Page 9 ot 13 —
COST
Detailed cost data for the interim product recovery system construction and operation are not available. The cost
breakdown below provides an estimate of costs for some components of the treatment system. Information was
derived from projected costs, not actual cost data.
Capital Costs
System Design a
Labor $349,810
Direct Costs 12,420
Laboratory 3,490
Construction Costs b
Site Work 102,350
Equipment 137,750
Mechanical 48,560
Structural and Architectural 121,770
Electrical 167,630
Mobilization/Demobilization 15,000
Total Capital Costs $ 958,780
Operating Costs
Carbon Changeout, Transport, and Regeneration $
Electrical Power (@ $. /kwh)
Equipment, Repair, and Replacement
Laboratory Analysis
O&M Labor (@ $ /hr)
Engineering Support
Project Management
Total Annual Operating Costs c $129,440
• These costs ware taken from a contractor's 95 percent design estimate prepared in 1991. They are
included to provide a representation of the probable breakdown of actual total costs among the various
cost elements.
b These figures are based on a contractors' cost proposal dated March 1991.
c Final operating costs are based on a contractor's scope of work for operation and maintenance of
the interim pump and treat system, dated September 1993.
U.S. Air Force
70
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REGULATORY/INSTITUTIONAL ISSUES
' Fort Drum - Page 10 of 13 —
D
• The Fort Drum Area 1595 site remediation is being performed as a Rapid Response Interim Remediation.
Final cleanup criteria will be established for the site in the future.
• Treated water is discharged under the authority of a POTW dishcharge interim permit. The permit was
issued in December 1992. As an interim, the design effluent discharge limits for the air stripper are used.
Discharge limits are summarized below:
Compound
Benzene
Toluene
Xylenes
Ethylbenzene
Maximum Air Stripper Effluent Concentration (uoTT)
3
35
190
8
• An air emission certificate was issued by the New York Department of Environmental Conservation in
October 1992. Information on specific emission limits was not available.
SCHEDULE
Major Milestones
1975 1979 1982 I???? I 1985
U.S. Air Force
71
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Fort Drum - Page 11 of 13 —
LESSONS LEARNED
Implementation Considerations
• Initiating an interim remedial action provided for recovery of free-phase petroleum product and
petroleum constituents in groundwater while the full extent of contamination and supplemental remedial
actions were planned. Earlier action could have further limited contaminant migration.
• The effectiveness of damming the dike to contain contamination was not addressed. During the
winter of 1989, the surface of the diked area froze over. The skimming device froze below the ice, and
free product migrated on top of the ice and past the dike. Free product was observed migrating below
the absorbent pads.
• High iron concentrations (> 17 mg/L) were present in the Area 1595 groundwater. The presence of
iron concentrations and potential precipitation problems should have been addressed in designing the
interim system.
• The capture zone was not defined for the interim system. Consequently, the success or failure of the
interim recovery system in capturing and limiting further migration of free product at this site is
unknown. Defining the capture zone is an important part of evaluating the system's performance in
capturing contaminants and stopping plume migration.
Technology Limitations
• The free product recovery pumps required frequent maintenance. Information was not available on whether
alternative equipment would have been more appropriate.
• Activated carbon efficiency was limited in this instance by fouling caused by iron and/or biomass.
• No additional information was available on the full range of design and implementation experience gained
from this technology application.
Future Technology Selection Considerations
• Application of the interim pump and treat system with above ground air stripping at Area 1595 of Fort
Drum has not provided sufficient data to date to allow generalized conclusions to be made concerning
the suitability of the technology at Fort Drum. Experience has been obtained, however, on design and
implementation issues involved in assuring continuous system operation. Operational difficulties have
only recently been overcome at Fort Drum and future performance data should provide a better
understanding of the effectiveness of the interim product recovery system.
U.S. Air Force
72
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1 Fort Drum • Page 12 of 13 —
ANALYSIS PREPARATION
This analysis was prepared by:
Stone & Webster Environmental A
Technology & Services
245 Summer Street
Boston, MA 02210
Contact: Bruno BrodfeW (617) 589-2767
CERTIFICATION
The Fort Drum Environmental Division has indicated that, due to staffing
limitations, they are unable to provide additional information necessary to
complete this analysis or to review its contents.
U.S. Air Force
73
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SOURCES
Major Sources For Each Section
1 Fort Drum -Page 13 of 13 —
1
Site Characteristics:
Treatment System:
Performance:
Cost:
Regulatory/Institutional Issues:
Schedule:
Lessons Learned:
Source #s (from list below) 1,2,3,5, and personal communications with
Brian Roberts of the U.S. Corps of Engineers (COE), Kansas City District.
Source #s 4,5, and personal communications with Dan Gelb of Radian
Corporation
Source # 6, and personal communications with Dan Gelb and James Baxter
of Radian Corporation
Source # 6
Source # 4
Source #s 1,2,3,6
Source # 6, and personal communications with Dan Gelb and James Baxter
of Radian Corporation
Chronological List of Sources and Additional References
1. Remedial Investigation Fuel Dispensing Area 1595 Fort Drum, New York; prepared for U.S. Army Corps of
Engineers, Kansas City, Missouri (COE, Kansas City); prepared by O'Brien & Gere Engineers, Inc., February 1990.
2. Report of Findings - Corrective Measure Study Gasoline Alley, prepared for COE, Kansas City; prepared by
CDM Federal Programs Corporation, September 1991.
3. Remdial Investigation of Fort Drum, New York, AMXTH-AS-CR-85054, prepared for U.S. Army Toxic and
Hazardous Materials Agency (USATHAMA); prepared by Dames & Moore, August 1992..
4. Data Package provided by Dan Gelb of Radian Corporation, February 1994.
5. Area 1595 Map provided by James Baxter of Radian Corporation, April 1994.
6. Data Package provided by Brian Roberts of the US COE Kansas City District, April 1994.
U.S. Air Force
74
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Pump & Treat of Contaminated Groundwater at
Langley Air Force Base
Virginia
(Interim Report)
75
-------
Case Study Abstract
Pump & Treat of Contaminated Groundwater at Langley Air Force Base
Virginia
Site Name:
Langley Air Force Base, IRP Site 4
Location:
Langley, Virginia
Contaminants:
Benzene, Toluene, Ethylbenzene, Xylenes
(BTEX) and Total Petroleum Hydrocarbons
(TPH)
- Primary constituents of JP-4 fuel are
alkanes, cycloalkanes, alkylbenzenes,
indans/tetralins, naphthalenes
- Total Recoverable Petroleum Hydrocarbons
- 25 to 4,100 ppb in groundwater; >100
ppm in soil
- Free product floating on groundwater has
exceeded 1 ft. in thickness
Period of Operation:
Status: Ongoing
Report covers - 7/92 to 1/94
Cleanup Type:
Full-scale cleanup (interim
results)
Vendor:
Not Available
SIC Code:
9711 (National Security)
Waste Source:
Underground Storage Tanks
Technology:
Groundwater Extraction using a Vacuum
Assisted Well Point Extraction System and
Aboveground Air Stripping
Extraction - 16 vacuum extraction wells
connected by a header pipe to a central
vacuum system; wells extend to
approximately 14 ft. below ground surface
Extraction network has an average flow rate
of 32 gpm (2 gpm per well); vacuum pump
provides 24-25 in of Hg
- Separation - initial oil/water separation
occurs in a vacuum decanter followed by a
high efficiency oil/water separator; oil
phase is sent to a storage tank
Treatment of aqueous phase - 2 air
stripping columns - Column 1 - air/water
ratio of 180 and air flow of 1,440 cfm at 60
gpm; Column 2 - air/water ratio of 100 and
air flow of 800 cfm at 60 gpm
Cleanup Authority:
UST Corrective Action and
State: Virginia
Point of Contact:
Vern Bartels
Remedial Project Manager
Langley AFB
Purpose/Significance of Application:
Full-scale remediation of groundwater
contaminated with fuel oil using a
vacuum assisted well point extraction
system and aboveground air stripping.
Type/Quantity of Media Treated:
Groundwater and Free Product
- Area of free product - about 600 ft. x 300 ft.; estimated volume of free product
is 12,000 to 31,000 gallons
- Area of groundwater contamination - about 1,000 ft. x 2,000 ft.
- Properties of aquifer include pH (6.4 - 7.2), hydraulic conductivity (0.00099 -
0.002 ft/day), transmissivity (0.99 - 2.2 ft2/day)
Regulatory Requirements/Cleanup Goals:
- Groundwater: BTEX - Benzene (1.4 ppb), Toluene (2 ppb), Ethylbenzene (1 ppb), Total Xylenes (3 ppb)
- Air Stripper Criteria for discharge: BTEX - Benzene (7 ppb), Toluene (50 ppb), Ethylbenzene (4.3 ppb), Total Xylenes (13
ppb), Lead (5.6 ppb) and TPH (1,000 ppb)
- Cleanup conducted under Virginia State Regulations and Federal Underground Storage Tank Regulations
76
-------
Case Study Abstract
Pump & Treat of Contaminated Groundwater at
Langley Air Force Base, Virginia (Continued)
Results:
As of 1/94:
- Floating product - appears to be largely unaffected at this time; no estimates of the amount of free product recovered are
available at this time
- Air Stripper - average concentrations from air stripper are below discharge criteria
Cost Factors:
- Total Capital Costs - $569,739 (1992) (including demolition and excavation, system installation, startup, mobilization and
site preparation)
- Annual Operating Costs - $216,561 (1993), $143,047 (1994) (including labor, materials, and equipment)
- An estimated total cost for completing the cleanup is not available at this time
Description:
Langley AFB has operated since 1916 as an aviation research and development facility. JP-4 fuel was stored in underground
storage tanks and, in 1981, twenty-four 25,000-gallon underground fuel tanks and a fuel pipeline located at IRP Site 4 were
determined to be leaking. In 1987, the tanks were abandoned by cleaning and sand-cement backfilling. Subsequent remedial
investigation activities detected fuel contamination in soil and groundwater, including free product floating on the groundwater
table at up to 1 foot in thickness. Primary contaminants of concern at the site are BTEX (benzene, toluene, ethylbenzene, and
xylenes) and total petroleum hydrocarbons (TPH).
A groundwater pump and treat system consisting of a vacuum assisted well point extraction system, oil/water separators, and
air strippers, began operating in July 1992 and was operational at the time of this report. Results to date indicate that, on
average, the effluent concentration of BTEX, TRPH, and lead from the air stripper are below the discharge criteria. However,
the layer of free product floating on the groundwater appears to be largely unaffected at this time. In addition, an estimate of
free product recovered to date cannot be made since a sample port was not installed because of vacuum inlet conditions. It
was noted that such sampling points are necessary to allow quantification of system performance.
The total capital costs for this application were about $569,700 and the annual operating costs for years 1993 and 1994 were
about $216,600 and $143,000, respectively. Operational difficulties including problems with scaling, oil/water separator icing,
and delays in acquiring spare parts have caused the system to be down about 51% of the time. In early 1994, adjustments to
the system were made, including the use of chemical additives to prevent fouling of the system. It was noted that a roof over
the treatment plant would have prevented weather-related damage and downtime (i.e., icing of oil/water separator).
77
-------
TECHNOLOGY APPLICATION AWAttf
Langley Air Force Base
IRP Site 4
Langley AFB, Virginia
Page 1 of 12 =
TECHNOLOGY APPLICATION
This analysis covers an effort to pump and treat
groundwater contaminated with JP-4 jet fuel using a
vacuum assisted well point extraction system and
above ground air stripping. The treatment began in
July 1992 and is currently ongoing. This analysis
covers performance through January 1994.
m SITE CHARACTERISTICS
•i Site History/Release Characteristics
• Langley AFB has been an aviation research and development establishment since 1916 and is the oldest continually
active air force base in the U.S.
• IRP Site 4 contains twenty-four 25,000 gallon underground fuel tanks and a 6 inch JP-4 jet fuel pipeline. The tanKs
and pipeline were sources of leaks and were abandoned in 1987 by cleaning and sand-cement backfilling.
• Releases were first noted in 1981 and site characterization activities began in 1985. This technology application
analysis presents data through January 1994 from ongoing treatment which began in July 1992.
• Contaminants of Concern
The primary contaminant is JP-4 jet fuel whose
principal constituents are:
61%
29%
8%
1.1%
Alkanes
Cycloalkanes
Alkylbenzenes
Indans/tetralins
Napthalanes
Indicator contaminants for the fuel mix are:
Benzene (B)
Toluene (T)
Ethylbenzene
Xylene
Site characterization also involved measurement
of Total Recoverable Petroleum Hydrocarbons
(TRPH) by EPA Method 418.1.
•• Contaminant Properties
Properties of contaminants focused upon during remediation are:
Property at STP*
Empmcal Formula
Density
Vapor Pressure
Henry's Law
Constant
Water Solubility
Qctanol-Water
Coefficient; KQW
Organic Carbon
Partfoon
Coefficient; KOC
Units
g/crrft
mmHg
ahi'rrftm:
mg/L
•
JP-4" B
0.75 0.87
91 95
&10E-4U10 5.6E-3
300 1750
1E3W1E7 132
SE-610240 83
T
06H5CH3
0.86
28
6.4E-3
535
537
300
X*"
-0.87
10
7.0E-3
198
1830
240
*STP . Standard Temperature and Pressure; 1 atm. 25 °C
" Properties at 20°C "'Mixture ot m,o and p-xylenes
i Nature & Extent of Contamination
• Fuels contamination is present in soil, as free product atop the groundwater table and dissolved in groundwater.
• Soil contamination appears to be limited to the area above the floating product and has exceeded 100 ppm TRPH in
only one instance.
• Floating product has exceeded 1 foot in thickness in some locations. An oily sheen has been found in nearby estuaries.
• Significant groundwater contamination (25 to 4100 ppb TRPH) appears to be limited to locations directly beneath areas
having a thick floating product layer.
• The lack of a significant groundwater gradient has minimized the potential for migration, however, underground utilities
and original fuel containment facilities may have created preferential pathways for transport.
U.S. Air Force
78
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Langtoy-Page2ot12 —
Contaminant Locations and Geologic Profiles
Remedial investigation field activities at the site have included soil and groundwater sampling and analysis, soil vapor analysis,
geotechnical analyses and hydraulic conductivity measurements. Some of this data is included here to provide a general
conceptual understanding of site conditions.
Soil Contamination & Site Layout
I—Legend
all concentrations
inppm
TRPH
Concentration
bd =. below
detection
limit
soil
boring
location
* ^
of ;
JP-4 Fuel
Pipeline
Estimated area of
TRPH contamination
greater than detection
limits; Volume of soil
estimated at 12,300 yd3
assuming a 5 ft depth of
contamination. ~
Floating Product Contamination
I—Legend
all values in feet
of floating product
*0da«a
0.37- »~~ Qec .go data
*
nd » none
detected
nm - not
measured
groundwater
monitoring
well
Estimated area of
floating fuel.
Volume has been
estimated between
12,000 to 31,000
gallons
Groundwater Contamination
I— Legend
all concentrations
inppb
' Benzene data
-TRPH data
groundwater
monitoring
well
Location of
abandoned
underground fuel
tanks (5 to 7 ft
below surface)
U.S. Air Force
79
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• Contaminant Locations and Geologic Profiles (Continued)
Hvdrogeologic Units
1 Langley - Page 3 of 12 —
t
2-2.5 ft
sand
I sana
Surface
• y Water table
• Loose sitty sand interbedded with sandy clay & some clayey deposits
Geology characterized down to ~ 11ft through field investigations
Site Conditions
• The topography of the base is very flat, showing little of no relief and ranging in elevation between 5 and 8 ft above MSL.
• Regional geology is that of an outer coastal plain characterized by a series of flat plains and intervening marine terraces.
• Land use in the nearby city of Hampton is primarily residential with 5% used by heavy or light industry. The base borders
the highly environmentally sensitive Chesapeake Bay area.
Key Aquifer Characteristics
Soil Parameters (data taken from depths between 2 and 12 ft from six hand augend wells)
Property Range
Size distributions (% passing #200 sieve) 17-28%
Liquid limits 35-39%
Plasticity index 7-11%
Water content 23.8-362
Groundwater Parameters (data taken during the development of six monitoring wells)
Property Range Comment
Specific conductance
Temperature
PH
Hydraulic conductivity
Transmissivity
600-700 umhos/cm
20-24°C
6.4-7.2
0.00099-0.002
0.99-2.2
"VBased on slug in/slug out Bouwer & Rice method tests
-" performed with two wells (slug out data shown).
• The groundwater occurs in three aquifer systems (water table, upper artesian and principal artesian) within the
coastal plain sediments.
• The water table aquifer, beginning at 4-6 ft below the surface, occurs within the fine sand, silts and shell beds of
Pleistocene age and surficial sands of recent Holocene age.
• The upper and principal artesian aquifers begin at depths of approximately 400 and 700 ft respectively. These
aquifers are assumed to be free of contamination and are not considered further in this analysis.
• Due to high chloride concentrations from salt-water intrusion, none of the aquifers beneath the base are used for
drinking water supply. The water table aquifer, however, is an important source of domestic water supply for locations
west of the base.
U.S. Air Force
80
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Langby - Page 4 of 12 —
mi TREATMENT SYSTEM
•• Overall Process Schematic
Vacuum Extraction
Separation
Treatment & Discharge
16 vacuum extraction wells are
connected by a header pipe to a
central vacuum system; initial
separation occurs in a vacuum
decanter
[detailed below and on next page]
A high efficiency oil/water
separator provides a second
level of oil removal
[detailed on next page]
• Oil phase - tank storage
• Aqueous phase - air stopping
for a final level of VOC removal
and permitted storm sewer
discharge of treated effluent
{detailed on next page]
Vacuum Extraction Well Network
storm sewer
discharge point
recovery system
vacuum extraction wells;
each of the 16 vacuum extraction wells
extends approximately 14 ft below the surface
and draws an average of 2 GPM
100ft
See p. 2 for site layout and
contamination location
descriptions
U.S. Air Force
81
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Extraction Weil Close-Up
Typical Vacuum Extraction Well
Key Design Criteria
-Surface
Cement mortar
Brick and mortar
Shut off valve
Flow meter
Throttling valve
Shut off valve
Cement mortar
Bentonita pallets
3/4' Copper tube
(with adjustable
depth)
3' Well screen
• Each well head flow rale
can be adjusted based upon
data from 22 observation
well* and 5 piezometers to
ensure necessary flow rate
and hydrodynamc control
M
"1
• Maximum overlap of zones of influence of individual
extraction wells within contaminated area
• Ability to create significantly increased oxygen levels in the
vadose zone to enhance volatilization and biodegradation of
residual soil contamination
• Ability to be installed without disturbing a complex network
of existing underground utilities
• Treatment to satisfy Virginia Instream Values to aUow for
permitted storm sewer discharge (<5 ppb benzene from an
influent of approximately 4700 ppb)
• Maximum flow of 60 GPM; Average flow of 32 GPM
• Series arrangement of air strippers for unobtrusive siting of
treatment plant within air base facilities
• Key Monitored Operating Parameters
• Extraction well flow rates
• Extraction weU drawdown depths
• Monitoring well and piezometer location drawdown depths
• Flow to storm sewer
• Vacuum decanter vacuum pressure
• Recovered fuel tank level
• Contaminant concentrations in air stripper influent, air
stripper effluent, between air stripper columns and in oil/water
separator feed
Vacuum Extraction/Air Stripping Systems Schematic
<.014UhrVOC
to atmosphere
Air Stripping Column »1
36 in diameter: 16 ft tall
10.5 ft of polypropylene packing
air/water ratio of 180
air flow of 1440 cfm at 60 GPM
<0.003/b/hr VOC
to atmosphere
Air Stripping Column «2
30 in diameter 16 ft tall
10 ft of polypropylene packing
air/water ratio of 100
air flow of 800 cfm at 60 GPM
Air Stripper Feed Tank
700 gallon capacity
aqueous phase
< 10 ppm unOtssotved JP-4
Oil Water Separator
high efficiency coalescer type
6 ft diameter; 24 ft long
to Storm Sewer
<5 ppb De/ifene
*" (permanent 7,500 gallon effluent
storage tank and temporary activated
carbon adsorption system installed
during first year of operation)
Recovered Fuel Tank
1500 gallon capacity
5 ft diameter; 10 ft tall
Vacuum Pump
provides 24-25 in of Hg vacuum
Vaouum Decanter'
400 gallon capacity
4 ft diameter
provides 10 min residence time
supplied by 6 GPM sealing water inflow
supplied by 140 cfm air compressor
32 GPM How rate from Extraction Well Network
Drawing not to scale
U.S. Air Force
82
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Langtoy - Page 6 of 12 —
PERFORMANCE
Performance Objectives
• Remove floating product atop groundwater to prevent further dissolution of contaminants (other
criteria detailed in the Regulatory/Institutional section).
• Create a zone of capture that envelopes the floating product layer and prevents further migration.
Operational History
Initial operations in July 1992 resulted in discharge to the storm sewer of insufficiently treated
contaminated groundwater. A notice of regulatory violation was imposed.
An effluent storage tank and carbon adsorption unit was procured to prevent future
contaminated discharges.
Operational difficulties prevented sufficient continuous pumping to create an effective zone of
capture. These difficulties are detailed below under System Downtime.
In early 1994, system adjustments permit continuous operation. These adjustments include
the use of chemical additives to prevent system fouling. To date, performance data is
insufficient to assess potential system effectiveness.
Operational Performance
I— System Throughput
500-
400-
300-
200-
100-
0 J
Total throughput:
3,310,000 gallons
JASONDJFMAMJJASONDJ
1992
1003
1904
r- System Downtime
During the period July 1992 through January
1994 the treatment system did not operate
due to scheduled or forced downtime on 292
day* (51% of all days). Causes of
downtime included:
• Scaling deposits destroyed impellers, couplings
and connectors on pumps. Pipe diameters have
been reduced (rom buildup of deposits. The
system mis flushed and cleaned to remove iron,
calcium silicate and bacterial slime buildup. A
chemical additive (Betz Ente-320) was applied to
recovery wells and proved effective at preventing
further fouling.
• Oil/water separator icing during shut downs.
• Delays in acquiring spare pumps.
• Regulatory requirements calling for sampling of
recovery wells mandated system shut down and
disassembly of well extraction equipment
U.S. Air Force
83
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Langley - Page 7 of 12 —
Hydrodynamic Performance
Quarterly prepared potentiometric maps of the surficial aquifer fail to indicate the influence of the treatment system
to create a drawdown zone surrounding the contaminated region. Insufficient pumping duration appears to be the
cause.
Treatment Performance
— Effects on Boating Product Layer
Plots of floating product thickness over time at various wells containing the largest amount
of fuel do not reveal overall trends. The floating layer appears largely unaffected to date.
Jul92 Jan93
Jan94
Jan94
— Mir ompper imiueiu a
• All VOCs and targeted
iiu cmuem
pollutants have
been consistently
treated below discharge criteria.
Compound
Benzene
Toluene
Ethylbenzene
Xylenes
TRPH
Lead
Influent
t2 Avs
<5
<5
<5
<5
<5
<5
<5
<5
dl
82
12
150
54
La.
<5
<5
<5
<5
Effluent
Aye
<5
<5
<5
<5
<500 <500
-
-
-
<1
<5
M
<5
24
<5
19
1030
19
all concentrations in ppb
new rruuuia necuvereu
• Currently there is no means to
sample influent to the treatment
system. No sample port was
installed due to the vacuum inlet
conditions.
• Negligible amounts of fuel have
been observed in the recovered
fuel tank.
U.S. Air Force
84
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Langl0y • Page 8 of 12 •—•
COST
J
The U.S. Army Corps of Engineers Omaha District prepared a detailed cost estimate and
specification for the treatment plant prior to procurement. That cost breakdown was pro-
rated against the selected contractor's bottom-line price for system installation and start-up
to arrive at the capital costs indicated below. Long-term operations and maintenance was
procured via a lump-sum task order contracting mechanism. Initially estimated, contracted
and final actual operating costs for the first few years of operation are presented below.
Capital Costs
Direct Costs
Demolition & Excavation $7,604
Horizontal Boring 5,661
Asphalt & Concrete 9,609
Screen Walls 33,560
Recovery Wells 49,403
Piezometers 8,674
Paint 593
Piping 54,537
Tanks/Equipment 111,961
Instrumentation 11,935
Electrical (Power, lighting and grounding) 24,377
Subtotal 317,914
Indirect Costs
Mobilization & Site Preparation
Field Overhead
Other Overhead
Subtotal
Start-up (Rrst 90 days O&M)
21,748
162,029
34,048
217,826
34,000
Total $569,739
Operating Costs
Labor
Materials
Equipment
Travel & Living Expenses
Overhead
Profit
Total
Change Orders
Grand Total
Year 1 (ending March 93) Year 2 (ending March 94) Year 3 (ending March 95)
Budget3
43,232
23,639
38,535
15,553
46,916
9,851
177,726
Actual
.
-
-
-
-
-
187,293b
Budget8
34,740
22,448
2,268
7,188
34,881
7,339
108,864
Actual
.
-
-
-
.
112,112b
Budget*
35,248
23,570
2,365
6,033
34,965
7,452
109,633
Actual
.
.
.
.
.
.
113,324b
0 29,268C 0 30,935d 0 Pending
$177,726 $216,561 $108,864 $143,047 $109,633 Pending
a - These initial budgeted amounts are taken from an Army Corps of Engineers estimate prepared in 1991
and are merely included to illustrate the probable breakdown of actual total costs among various cost
elements.
b - The actual amounts are fixed priced task order sums taken agreed to by the O&M contractor
c • Necessary change orders in Year 1 included addition of an effluent storage tank and carbon adsorption
unit to handle insufficiently treated flows during initial operation; system troubleshooting and optimization
efforts; and laboratory analysis of effluent.
d - Necessary change orders in Year 2 included chemical flushing to remove iron, calcium and bacterial
slime buildup throughout the system; analytical work; pump replacement; and oil water separator repairs.
U.S. Air Force
85
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Langley - Page a of 12 —•
REGULATORY/INSTITUTIONAL ISSUES
• The Corrective Action Plan was not approved by all necessary parties until well into the construction period of the
system. Significant difficulties could have arisen if last minute objections were made.
• State approval of work plans significantly impacted the project schedule. Review periods over a year in duration
occurred in some instances.
• To facilitate regulatory approval and maintain a project schedule, it was necessary to actively request face-to-face
meetings to discuss work plans and treatment system design issues with approving agencies.
• Regulatory relief was successfully sought from the burden of sampling recovery wells in addition to monitoring
wells and piezometers. Such sampling required dismantling and reassembly of recovery well apparatus.
• The treatment system was specially configured behind walls in a secure area to minimally impact operations and
aesthetics at the active air base.
• Many specified materials were of foreign manufacture. Coordination with the Buy Amencan Act was an issue.
• Cleanup was principally governed by Virginia State Regulations and Federal Underground Storage Tank
Regulations 40CFR280.
—Cleanup Criteria
• Concentrations of Total Petroleum Hydrocarbons in soil must be below 100 ppm in accordance with
State of Virginia standards.
• Groundwater values must not rise above mean levels identified during site characterization efforts
completed in 1991 of:
Compound Criteria Level foobJ Compound Criteria Level fpobl
Benzene 1.4 Ethylbenzene 1
Toluene 2 Total Xylenes 3
• Virginia Instream Values were used as criteria for discharge of air stripper effluent:
Compound Criteria Level fppbJ
Benzene 7
Toluene 50
Ethylbenzene 4.3
Compound Criteria Level foobl
Total Xylenes 13
Lead 5.6
Petroleum Hydrocarbons 1000
SCHEDULE
Major Milestones
**...-..\.**^_ \. jv.^ v"> ="'
4
*
1985
1986
1987
[1988 |
1989
1990
1991
1992
1 [1
993
1994
U.S. Air Force
86
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• Langley - Page 10 of 12 —
LESSONS LEARNED
Design Considerations mff^ff^MHffffffffHfHffffHHIW^-'^msis^
• Suction/vacuum pumps were designed to close to their limits at Langley to be dependable. These pumps
experienced fouling and had to be replaced. Replacement parts were not readily available and spares should be
specified for future systems.
• Heat tracing was inadequate and incomplete in the original design. The oil water separator experienced icing
problems during periodic maintenance related shut downs.
• Sampling ports must be located at treatment plant influent to enable quantification of system performance.
• Controls must be readily accessible. At Langley, controls were located in a nearby secure area which made
access more difficult.
• Operating contractor's offices must be adequately planned especially in instance where field analytical equipment
requires special housing.
• The exhaust pipe on the oil water separator deflected excessively and allowed gases to be released. Adequate
height and stability must be addressed in future design^ for this element.
• A roof over the treatment plant would have prevented weather related damage and downtime.
• Recovery wells should be designed to allow cleaning and other maintenance without complete disassembly.
fmpfementatfon Cons/derations •••••••••••••••BBHU^^^^
• The Corrective Action Plan for the site must be approved by all necessary parties, in writing, in a timely manner
before significant construction and design efforts are underway. Lengthy reviews of work plans impacted project
schedules at Langley.
• Butt fusion welding proved to be highly expensive. An alternative method should be specified to address added
connections or other system design changes in the field.
• Significant attention must be payed to early identification and prevention of conditions which may cause system
fouling. Scaling of calcium silicate, iron and bacterial slime destroyed pump internals and reduced interior
diameters of pipes. System flush outs and chemical additives to recovery wells were used to combat the problem.
• Recovery wells need to be periodically redeveloped.
Technology Limitations
• In this instance, a continuing series of operation problems prevented long term operation sufficient to create a
zone of influence to capture and treat floating product atop the groundwater.
• Assessment of system performance was further complicated by inadequate ability to sample treatment plant
influent.
Future Technology Selection Considerations
• Application of vacuum assisted pump and treat with above ground air stripping at Langley has not provided
sufficient data to date to allow generalized conclusions to be made concerning the suitability of the technology at
Langley or other potential locations. Much experienced has been obtained, however, on design and
implementation issues involved in assuring continuous system operation. Operational difficulties have only recently
been overcome at Langley and future performance data should provide a better understanding of its remediation
effectiveness.
U.S. Air Force
87
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ANALYSIS PREPARATION
This analysis was prepared by:
Stone & Webster Environmental A
Technology & Services
245 Summer Street
Boston, MA 02210
Contact Bruno Brodfeld (617)589-2767
Pagt 11 of 12 —
CERTIFICATION
This analysis accurately reflects the performance and costs of the remediation:
Vern Bartels
Remedial Project Manager
LangleyAFB
U.S. Air Force
88
-------
Langley - Page 12 of 12 •—
SOURCES
Major Sources For Each Section
Site Characteriatic*:
Treatment System:
Performance:
Coat:
Source #s (from list below) 2, 3 and 6
Source #s 1,4, 5 and 7
Source #s 1 and 2
Source #s 1 and 3
Regulatory/lnatitutional laauea: Source #s 1,3 and 6
Schedule: Source #s 1, 2, 3 and 6
Leaaona Learned: Source #s 1, 3 and personal communications with Eric Anthony Amdt, Deputy
Area Engineer, Langley Resident Office, Norfolk District Army Corps of Engineers
(804) 764-2941
Chronological List of Sources and Additional References
1. Data package provided by Eric Anthony Arndt Deputy Area Engineer, Langley Resident Office, Norfolk District Army Corps of
Engineers, March 28,1994.
2. Data package provided by Eric Anthony Arndt Deputy Area Engineer, Langley Resident Office, Norfolk District Army Corps of
Engineers, February 8,1994.
3. Data package provided by S.L Carlock, Chief, Environmental Branch, Engineering Division and Paul Dappen, Technical
Manager, Army Corps of Engineers, Omaha District, November 16,1993.
4. Operations and Maintenance Manual (Pre-Final), for Installation Restoration Program - Site No. 4 Langley Air Force Base,
Virginia, prepared for U.S. Army Corps of Engineers, Omaha District August 1991.
5. Final Specifications, for Installation Restoration Program - Site No. 4 Langley Air Force Base, Virginia, prepared for U.S. Army
Corps of Engineers, Omaha District August 1991.
6. Final Corrective Action Plan for IRP Site 4, Langley Air Force Base, Virginia, prepared by Law Environmental, prepared for
U.S. Army Corps of Engineers, Omaha District, February 1991.
7. Specifications (For Construction Contract) Solicitation No. DACA4S 90 B 0088, Installation Restoration Wont, IRP SHe 4,
Langley AFB, Virginia, U.S. Army Corps of Engineers, Omaha District, July 1990.
U.S. Air Force
89
-------
Dynamic Underground Stripping
Demonstrated at Lawrence Livermore National Laboratory
Gasoline Spill Site, Livermore, California
90
-------
Case Study Abstract
Dynamic Underground Stripping
Demonstrated at Lawrence Livermore National Laboratory
Gasoline Spill Site, Livermore, California
Site Name:
Lawrence Livermore National
Laboratory, Gasoline Spill Site
Location:
Livermore, California
Contaminants:
Benzene, Toluene, Ethylbenzene, Total Xylenes
(BTEX)
- Concentrations of fuel hydrocarbons (FHC)
in saturated sediments indicates likely
presence of free-phase gasoline
- Benzene levels in groundwater greater than 1
ppb found within 300 feet of release point
- Benzene levels in soil greater than 50 ppm
Period of Operation:
November 1992 - December
1993
Cleanup Type:
Field demonstration
(commercial-scale)
Technical Information:
Roger Aines, Principal Investigator,
LLNL (510) 423-7184
Robin Newmark, LLNL
(510)423-3644
Kent Udell, UC Berkeley
(510) 642-2928
SIC Code:
5541 (Gasoline service station)
Waste Source:
Underground Storage Tanks
Technology:
Dynamic Underground Stripping (DUS)
- Combination of three technologies: steam
injection at periphery of contaminated area to
drive contaminants to centrally-located
vacuum extraction locations; electrical
heating of less permeable soils; and
underground imaging to delineate heated
areas
- Six steam injection/electrical heating wells
approximately 145 feet deep, 4-inch
diameter, screened in upper and lower steam
zones
- Three electrical heating wells approximately
120 feet deep, 2-inch diameter
- Three groundwater and vapor extraction
wells, approximately 155 feet deep, 8-inch
diameter
- Extracted water processed through an air-
cooled heat exchanger, oil/water separators,
filters, UV/H2O2 treatment unit, air stripping,
and GAC
- Extracted vapors processed through heat
exchanger, demister, and internal combustion
(1C) engines
Cleanup Authority:
CERCLA and Other: Bay Area
Air Quality Management District
Licensing Information:
Kathy Willis
University of California Office
of Tech Transfer
1320 Harbor Bay Parkway,
Suite 150
Alameda, CA 94501
(510) 748-6595
Kathy Kaufman
Tech. Transfer Init. Program,
L-795
University of California
Lawrence Livermore Nat'l.
Laboratory
7000 East Avenue
P.O. Box 808
Livermore, CA 94550.
(510)422-2646
Purpose/Significance of Application:
Commercial-scale demonstration of dynamic underground stripping. Results compared to pump and treat, and pump and
treat with vacuum extraction technologies.
91
-------
Case Study Abstract
Dynamic Underground Stripping
Demonstrated at Lawrence Livermore National Laboratory
Gasoline Spill Site, Livermore, California (Continued)
Type/Quantity of Media Treated:
Soil and Groundwater
- 100,000 cubic yards heated to at least 200°F
- 4 hydrogeologic units and 7 hydrostratigraphic layers identified near gas pad
- Hydraulic conductivity ranged from <5 gpd/ft2 (low permeability) to 1,070 gpd/ft2 (very high to high permeability)
- Low groundwater velocities kept contamination confined to a relatively small area
Regulatory Requirements/Cleanup Goals:
- Groundwater cleanup levels established based on California MCLs: benzene 1 ppb; ethylbenzene 680 ppb; and xylenes
1,750 ppb
- Remediation was required until soil contaminant concentrations were identified as not adversely impacting groundwater
- Air permits were issued by the BAAQMD for the air stripper, GAC, 1C engine, and for site-wide benzene
Results:
- Over 7,600 gallons of gasoline removed during demonstration effort
- Most of the gasoline was recovered in the vapor stream and not from extracted groundwater
Cost Factors:
- Overall program costs for the field demonstration, including all research and development costs, were $1,700,000 for
before-treatment costs (project management, characterization and compliance monitoring), and $8,740,000 for treatment
activities (process monitoring, subsurface wells, steam generation and electrical heating surface equipment, aboveground
treatment systems, utilities, and labor and material costs)
Description:
The 800-acre Lawrence Livermore National Laboratory (LLNL) site was used as a flight training base and aircraft assembly
and repair facility by the Navy beginning in 1942. In 1951, the Atomic Energy Commission converted the site into a
weapons design and basic physics research laboratory. Initial releases of hazardous materials occurred in the mid- to late-
1940s. Between 1952 and 1979, up to 17,000 gallons of leaded gasoline were released from underground storage tanks
beneath a gasoline filling station in an area now designated as the Gasoline Spill Area (GSA). Soil and groundwater in the
GSA were found to be contaminated with BTEX (benzene, toluene, ethylbenzene, and xylenes) and fuel hydrocarbons.
A commercial-scale field demonstration of Dynamic Underground Stripping (DUS) was completed at the GSA from
November 1992 to December 1993. DUS is a combination of three technologies: steam injection at the periphery of a
contaminated area to drive contaminants to a centrally-located vacuum extraction location; electrical heating of less
permeable soils; and underground imaging (primarily Electrical Resistance Tomography) to delineate heated areas. The DUS
system used at the GSA employed 6 steam injection/electrical heating wells, 3 electrical heating wells, and 3 vacuum
extraction wells, as well as above ground water and vapor treatment equipment.
Over 7,600 gallons of gasoline were removed by the DUS system in the demonstration effort. Most of the gasoline was
recovered in the vapor stream and not from the extracted groundwater. Potential cost savings of $4,000,000 were identified
for applying DUS at the same site in the future (taking into account the benefits of the lessons learned and without research-
oriented activities).
92
-------
SECTION 1
SUMMARY
D
Technology Description
Dynamic Underground Stripping (DUS) is a combination of several technologies targeted to remediate soil and ground
water contaminated with organic compounds. DUS is effective both above and below the water table and is especially
well suited for sites with interbedded sand and clay layers. The main technologies which comprise DUS are:
• steam injection at the periphery of a contaminated area to heat permeable subsurface areas, vaporize
volatile compounds bound to the soil, and drive contaminants to centrally located vacuum extraction wells;
• electrical heating of less permeable clays and fine-grained sediments to vaporize contaminants and drive
them into the steam zone; and
• underground imaging, primarily Electrical Resistance Tomography (ERT), which delineates heated areas to
ensure total cleanup and process control.
Electrical
heating
wells
9
Steam injection/
electrical heating
•- -\wells
\
^Vacuum \
extraction i
wells
Contaminated
Q, area
Plan View
Steam
Vacuum extracted vapor and
ground water to aboveground
treatment
Steam
Electrodes
I
Contaminated
area
Electrically
u-_^ - heated
—Si /impermeable
zones
^Permeable
layers
Cross-Sectional View
Technology Status
A full-scale demonstration was conducted at:
Lawrence Livermore
National Laboratory (LLNL)
Gasoline Spill Site: GSA
Livermore, California
November 1992 through December 1993
Before application of DUS, the site contained an estimated 6,500 gallons of fuel hydrocarbons (FHCs) both above and
below the water table at depths up to 150 ft. The site is underlain by complexly interbedded high and low permeability
sediments.
Key results Included:
• The system removed over 7,000 gallons of gasoline (more than the original estimate of contamination) during
10 weeks of operation conducted in phases over a 1-year period. The maximum extraction rate was 250 gallons
per day.
• DUS removed the localized underground spill at LLNL more rapidly and cost-effectively than the estimated
effectiveness of competing baseline technologies of pump-and-treat or pump-and-treat with vacuum extraction.
• DUS is projected to cost between $11 and $37 per cu yd of contaminated soil and is projected to remediate a
site in six to nine months as opposed to thirty years for the baseline technology of pump and treat.
Page 1
U.S. Department of Energy
93
-------
SUMMARY
continued
Technology Status (continued)
D
Over a dozen patents covering the major aspects of DUS are either pending or have already been granted to DOE and
the University of California. DUS is licensable from the University of California Office of Technology Transfer, and
licensing discussions are currently in progress. The results of the LLNL demonstration illustrating the effectiveness of
subsurface heating are corroborated by the results of field-scale demonstrations of other in situ thermal treatment
processes conducted through other EPA, DOD, and DOE programs. Conceptual designs, cost estimates, and detailed
designs have been prepared for applying DUS at other sites. Future development efforts will focus upon applying the
technology at sites contaminated with dense nonaqueous phase liquids (DNAPLs) and at sites with fractured subsurface
media.
Contacts
Technical
Roger Aines, Principal Investigator, LLNL, (510) 423-7184
Robin Newmark, LLNL, (510) 423-3644
Kent Udell, UC Berkeley, (510) 642-2928
Management
John Mathur, DOE Program Manager, (301) 903-7922
Jim Wright, DOE Plumes Focus Area Implementation Team Manager, (803) 725-7289
Licensing Information
Kathy Kaufman, Technology Transfer Initiative Program, Lawrence Livermore National Laboratory,
(510)422-2646
Kathy Willis, University of California Office of Tech Transfer, (510) 748-6595
Page 2
U.S. Department of Energy 94
-------
SECTION 2
TECHNOLOGY DESCRIPTION
Overall Process Schematic
DUS combines steam injection, electrical resistance heating, and underground imaging and monitoring techniques to
mobilize and recover contaminants from the subsurface. The figure below is a conceptual illustration of the process
for relatively simple subsurface conditions. Appendix B provides detailed information about the process including
close-ups of subsurface wells and descriptions of surface treatment equipment.
Vacuum
extraction
Tomography wells
monitor steam movement
Steam
injection
Ground water is
displaced by steam
Impermeabli
clay zones
Steam zone
is dry
Electrodes
electrically
heat clays
Volatiles driven
into steam
Well-to-well stripping - 1 to3 months
Extraction well in center §0 to WO feet
of treatment zone
Major elements of the technology are:
Steam Infection and Vacuum Extraction - Injection wells drilled around an area of concentrated contamination
supply steam and electric current. Vacuum extraction wells in the center of the contaminated area remove
contaminants. A steam front develops in the subsurface as permeable soils are heated to the boiling point of
water and volatile organic contaminants are vaporized from the hot soil. The steam moves from the injection to
the extraction wells.
Electrical Resistance Heating - Electric current is used to heat impermeable soils. Water and contaminants
trapped in these relatively conductive regions are vaporized and forced into the steam zone for vacuum
extraction.
Underground Imaging and Monitoring - Several geophysical techniques used to monitor the underground
movement of steam and the progress of heating include temperature measurements (taken from monitoring wells
throughout the treatment area), ERT (which relates measurement of electrical conductivity to the progress of the
steam front in the heated zone, and tiltmeters (which detect small subsurface pressure changes created by the
movement of the steam front).
Page3
U.S. Department of Energy
95
-------
SECTION 3
PERFORMANCE
Generalized Treatment Plan
A generalized approach to implementing DUS developed as a result of the demonstration includes:
Electrically heat impermeable clay zones
Inject steam into peripheral wells;
extract ground water and vapor from central wells
Prepare plots of subsurface steam Monitor in situ ground water Monitor subsurface temperatures
influence from ERT, piezometer, and contaminant levels from thermocouple data
tiltmeter data
Monitor aboveground flow,
concentration and
temperature data
Adjust flow rates to optimized growth of steam fronts
Operate steam intermittently to flash off contaminants
in pore spaces
Operate until rate of contaminant removal diminishes
significantly or cleanup objectives are satisfied
Demonstration Operations and Results Overview
DUS activities at LLNL occurred in a series of demonstration efforts:
PHASE OBJECTIVES/APPROACH
Clean Site Demonstration
DUS Demonstration
Electrical Heating Phase
DUS Demonstration
1st Pass Steaming Phase
DUS Demonstration
2nd Pass Steaming Phase
Accelerated Removal &
Validation (ARV) Project
To field test the DUS process on an uncontaminated
site with well-characterized geology
To heat less permeable contaminated clay zones
Continuous steam injection over a 5-week period to
vaporize and remove gasoline
Intermittent steam injection and vacuum extraction
over a 6-week period
Continuous operation to remove residual
contamination; additional electrical heating
Test of process modifications such as altering
injection/extraction locations and air sparging
Installation of fiber-optic transmission system to allow
for simultaneous electrical heating and process
monitoring
KEY RESULTS
Steam injections, electric heating, and
monitoring well design improvements were
identified
Identification of improved operating strategy
of electric heating before steaming
Temperature of clay layers raised from 70°F
to 160°F
Over 1700 gal of gasoline removed
Over 4900 gal of gasoline removed
Temperature of most soils within treatment
zone exceeds 212°F; residual contamination
(estimated at 750 gal) and an unsteamed
area ("cold spot") remained
Over 1000 gal of gasoline removed
Improved understanding of electrical heating
process developed
Sparging tests demonstrated value of
modeling and use of tracer gases to better
understand subsurface gas flow
Fiber-optics successfully installed
Page 4
U.S. Department of Energy
96
-------
PERFORMANCE
continued
Treatment Performance
i- Reductions In Plume Concentratlons-
600
560
520
Estimated Total Fuel Hydrocarbon concentrations before and after the second steam pass of DUS are shown below:
.f*'Elevation, ft MSL Ground surface M I 1 . . .„
On i •aimii tuna I 11 i'"i-' _M > , •, (^ •<• «y*ja»" '1U!M ""1 I i"l I "^'.'....i1.1.1;.-! 1 I " ' >••••••' ' I I 1 tO 10 PPIT1
110 to 100 ppm
1100 to 1,000 ppm
| > 1,000 ppm
water table
P^rS-— ^pr rf_ --- --cpj| I • |
480J
• No spreading observed; contamination drawn to extraction wells.
• Continued operation during the ARV phase removed an additional 1000 gallons.
• The ability of DUS to remove contaminants sorbed to soils was illustrated by a marked rise in benzene and total
gasoline concentrations in ground water during DUS. At one ground water monitoring well in the treatment zone,
concentrations of C6 to C12 hydrocarbons had been below 30 ppm since 1987, but during DUS these
concentrations rose to nearly 150 ppm before dropping to levels below those found before DUS.
coma/
300
f
3 200
o>
1
1 100
2/1
ninant Mass Hem
1st steam i
• pass 1
i f
oval
/ Cumulative
/2nd steam ARV phase J
/ pass
\ ,~,~
/93 3/23/93 5/12/93 7/1/93 8/20/93 10/9/93 11/28/93 1/1
8000 • During the DUS 1st steam pass,
1 74% of approximately 1 700 gallons
eooo 1 removed was collected by the vapor
"Jj stream GAG unit. An additional 17%
J condensed in the vapor stream and
4000 3 the remaining 9% was dissolved in
> ground water.
3
2000 1 • During the 2nd steam pass, 77% of
" the 4900 gallons removed was burned
0 by the internal combustion engines,
?/94 21 % was condensed, and 1 % was
dissolved.
-flume containment ~ ~ —
BTEX [mg/kg] BTEX [mg/kg]
t Tha ("5QA U/QC an iHaal cnnt fnr Hnmnnctratinn nf ni 1C riv —1-0 ^0 „ 100 300
because of its low ground water velocities, which kept
contamination confined to a relatively small area. The E so-
plots at right illustrate that BTEX concentrations in soils f
at the periphery of the treatment zone declined during Q 100-
the demonstration. This phenomenon was determined
to be indicative of the DUS process limiting further 150-
! . •*•
gso-
0100-
migration Of contamination. Before DUS at a typical After 2nd *teampai3 of
well at the edge of the DUS at the same well
treatment zone
Pages
U.S. Department of Energy
97
-------
PERFORMANCE
continued
Operational Performance
Aboveground Treatment Plan Performance
• The majority of contaminants removed from the subsurface was in the vapor phase.
• Surface treatment consisted of (1) a UV/peroxide unit to treat ground water and condensed vapors during both
phases of the demonstration, (2) a GAG unit to treat vapors removed during phase I, and (3) an ICE unit to treat the
vapors removed during phase II.
• The volume of contaminated vapors removed from the subsurface was initially underestimated. Thus the GAC
unit selected for offgas treatment was undersized. It was replaced by an ICE unit during phase II. The ICE unit
could also have been larger but nevertheless performed successfully. Dilution of air was necessary since the
hydrocarbon concentrations were above the explosive limit.
• Destruction efficiencies of the UV peroxide liquid treatment unit during the last half of the first steam pass were
less than 40%, but adjustments maintained an efficiency over 90% during the last half of the second steam pass.
• Free gasoline product was found in the UV peroxide unit after the first steam pass.
* GAC = granular activated carbon; ICE = internal combustion engine
I In Situ Heating Performance b^BnmHo^BB^BBHBMMBHMHHHHHHHHM
A total of 100,000 yds of soil were heated at least to 200°F (boiling point at applied vacuum).
The growth of the hot zone was monitored by ERT and a network of temperature probes and tiltmeters.
A variety of data was used to prepare multiple representations of heating effects:
— Electrical Resistance Tomography Imaging
Below are images illustrating resistivity change over time between two monitoring wells approximately 50 ft apart in
the central part of the treatment zone.
50-,
70-
90-
110-
130-
150-1
Day 1
Day 4
Day 16
Day 36
I
_YWater.
table
- lithology of ERT
monitoring well
on north side of
cross-section
(lithology profile
at left is for
opposite side of
cross-section)
dark
represents
impermeable
clays
K "9ht
IN represents
permeable
gravel
Resistivity Change:
[ohm m]
\>0
\ JQlo-S
• -5 to -10 Resistivity change is strongly correlated to temperature;
^* more negative resistivity change (darker regions) indicate
*pl 1 n tn 15 higher temperatures (note - all values are approximations
2™ based upon more detailed computer-generated images)
ERT images provide a continuous representation of steam passage between two electrode-equipped boreholes.
The process allows identification of "cold spots" and provides data to support efforts to provide uniform heating.
PageB
U.S. Department of Energy
98
-------
PERFORMANCE
continued
I In Situ Heating Performance (continued)
- Temperature Profiles Along Individual Wells
electric heating
1st steam pass
,2nd steam pass
"TIJO"150"
Temperature [°F]
I
• typical
lithology in
treatment
zone
• dark
represents
impermeable
clays
I light
!t represents
permeable
gravel
212
More permeable layers heat first.
Heating ultimately effective throughout treatment zone.
r— Tiltmeter Plots
injection
well
tiltmeter
steam growth
plots from
consecutive days
100ft
• Tiltmeter data allow generation of vector-based
representations of steam front growth on a given day
from two injection wells.
• Data are useful for tracking any steam heading outside
the treatment zone.
-Time Versus Temperature Plot
• Impermeable layers
maintained temperature
increases.
• Permeable layers were
cooled by ground water
pumping especially at
peripheral wells because of
infiltration of ground water
from outside the treatment
zone.
Profile taken at
treatment zone
center in clay-rich
impermeable layer
Profile taken at
periphery of
treatment zone in
a permeable layer
Page?
U.S. Department of Energy
99
-------
SECTION 4
TECHNOLOGY APPLICABILITY & ALTERNATIVES
Technology Applicability
• DUS has been successfully demonstrated to remediate fuel hydrocarbons. Laboratory tests have been successful
for a variety of volatile and semi volatile compounds including diesel fuel and both light nonaqeuous phase liquids
(LNAPLs) and dense nonaqueous phase liquids (DNAPLs).
• DUS is effective in the presence of free-phase and dissolved-phase contaminant liquids. It is extremely effective in
the absence of liquids (vadose zone) but is usually not cost effective versus alternative technologies in these
instances. It would be better applied at sites with contamination both above and below the water table.
• The minimum depth for application of DUS is approximately 5 feet. At greater depths, the steam injection pressure
can be increased, producing higher efficiencies and extracting more work from each well.
• DUS becomes more cost-effective the larger the application site.
• A key competitive advantage of DUS is the speed of cleanup relative to conventional technologies. This order-of-
magnitude superiority reduces overall cost, reduces risk to nearby populations and the environment, and frees land
for beneficial reuse.
• DUS has a potential market at sites where conventional technologies have failed to produce acceptable results.
The GSA site at LLNL is an example; soil vapor extraction had been previously applied and its performance
predicted a cleanup time of greater than one hundred years.
• DUS is best suited to treat NAPLs and strongly sorbed contaminants in heterogenous or fractured formations.
Unlike most competing technologies, it can directly address contamination in complexly mterbedded sands and
clays. Further information on the applicability of DUS is in Appendix D.
El
Competing Technologies
• DUS competes with conventional baseline technologies of pump-and-treat and pump-and-treat combined with soil
vapor extraction. LLNL researchers estimated the effectiveness of these technologies at the GSA and compared the
estimates with the results of the DUS demonstration, as shown below:
6000
4000
2000
Dynamic Underground Stripping
Time
6 months
• A variety of In situ thermal treatment technologies have been either demonstrated or developed through
DOE, DOD, and EPA programs. The aggregate experience with these programs enhances confidence In the
fundamentals of DUS. Full-scale demonstrations of these related technologies include those shown in the
table on page 9.
Page 8 —•
U.S. Department of Energy
100
-------
TECHNOLOGY APPLICATIONS & ALTERNATIVES
continued
Competing Technologies (continued)
^i^M^':-^
'"",, ^fism$tp&: '•'.
, - i-*™f3&&Mt,.aia*1*f4.t±t£ji *'
• yMmw^v^fWHilmf -^ -J » \
DOE
T
Six-Phase Soil
Heating
2
Thermal Enhanced
Vapor Extraction
3
Radio Frequency
Heating
Pacific Northwest
Laboratory (PNL)
Sandia National
Laboratories (SNL)
KAI Technologies,
Inc.
Combines electrical heating
with soil vapor extraction
(six-phase distributes energy
better)
Combines soil vapor
extraction with powerline
frequency (ohmic/electrical)
and radio-frequency soil
heating
Radio frequency heating of
soils combined with soil
vapor extraction
Full-scale demonstration at DOE
Savannah River as part of the VOC in
Non-Arid Soils and Ground Water
Integrated Demonstration in 1993;
partnering/licensing discussions ongoing
Full-scale demonstration planned in 1 994
at SNL chemical waste landfill in part of
the Mixed Waste Landfill Integrated
Demonstration; builds upon previous
demonstrations at Volk Field, Wl, Rocky
Mountain Arsenal, CO, and Kelly AFB, TX
(see EPA projects)
Field demonstrated on VOC
contaminated soils using a horizontal well
at the DOE Savannah River Site as part
of the VOC in Non-Arid Soils and Ground
Water Integrated Demonstrationin 1993
EPA/DOD
1
Contained Recovery
of Oily Wastes
(CROWTM)
2 HRUBOUTR
Process
3
In Situ Steam and
Air Stripping
4 In Situ Steam
Enhanced
Extraction Process
In Situ Steam
Enhanced
Extraction Process
6
Radio Frequency
Heating
7
Steam Enhanced
Recovery System
Western Research
Institute
Hrubetz
Environmental
Services, Inc.
Novaterra, Inc.
(formerly Toxic
Treatments USA, Inc.)
Praxis Environmental
Technologies, Inc.
Udell Technologies,
Inc.
Illinois Institute of
Technology Research
Institute/Halliburton
NUS
Hughes Environmental
Systems, Inc.
Steam or hot water
displacement guides
contamination to extraction
wells
Hot air injection combined
with a surface exhaust
collection system
Portable steam and air
injection device (Detoxifier ™)
used in soils
Steam injection/vacuum
extraction (same as 5 and 7)
Steam injection/vacuum
extraction (same as 4 and 7)
Radio frequency heating of
soils combined with soil
vapor extraction
Steam injection/vacuum
extraction (same as 4 and 5)
EPA SITE field demonstration underway
at the Pennsylvania Power & Light
Brodhead Creek Superfund site, PA;
pilot-scale demonstrations completed at
a wood treatment site in Minnesota
EPA SITE field demonstration on JP-4
contaminated soils completed at Kelly
AFB, TX, in 1993
EPA SITE field demonstration conducted
on VOC and SVOC contaminated soils at
the Annex Terminal, San Pedro, CA, in
1989
Field demonstrations underway at Hill
AFB, UT, and McClellan AFB, CA
Field demonstrations underway at Naval
Air Stations Lemoore and Alameda in
California; Udell technologies no longer
in existence
EPA SITE field demonstration completed
at Kelly AFB, TX, in 1993; earlier
demonstrations occurred at Rocky
Mountain Arsenal, CO, and Volk Field,
Wl; demonstration cofunded by DOE
EPA SITE field demonstration completed at
the Rainbow Disposal Site in Huntington
Beach, CA, from 1991 to 1993; Hughes no
longer offering technology
Further information on these full-scale applications is available in references 16 (DOE programs) and 5 (DOD/EPA
programs). In addition EPA's Vendor Information System for Innovative Treatment Technologies (VISITT) electronic
database lists additional suppliers of equipment and services related to in situ thermally enhanced recovery of
contaminants. These include:
Bio-Electrics, Inc., Kansas City, MO
EM&C Engineering Associates, Costa Mesa, CA
SIVE Services, Dixon, CA
Thermatrix, Inc., San Jose, CA
Page 9
U.S. Department of Energy
101
-------
SECTION 5
COST
Cost Estimate for Future Applications
LLNL researchers have developed projected costs for applying DUS to other sites based upon demonstration results
(actual costs for demonstration at LLNL are presented in Appendix E). An estimate was prepared for remediating a
shallow (less than 50 ft in depth) chlorinated solvent spill. The proposed implementation approach involved successive
application of DUS to 10,000 yd3 cells by relocating equipment to various locations at the site. Key results of the cost
estimate were as follows:
• Cleanup of the entire site (an estimated volume of 20,000 to 40,000 yd3) would cost approximately $28/yd3.
• A pilot treatability study using full-scale equipment would cost $37/yd3. Economics improve as the area to be
remediated increases; LLNL researchers believe that larger sites could be engineered to cost $11-15/yd3.
• The total cost for DUS implementation was estimated to be less than the first-year cost of constructing and
operating a conventional groundwater pump-and-treat facility.
The following table details the equipment and labor costs associated with the treatability demonstration, full-scale
operation for the first two 10,000 yd3 treatment cells, and subsequent pairs of 10,000 yd3 treatment cells.
•^•^•^^•^^^^^^^^^^^^H Treatabilitv Demonstration Full-Scale Remediation \
Per Site Per Site
A/on- Monthy
Eauioment Costs ^ES@!^^^E^2&^1
Steam Equipment
Boiler rental
Boiler manifold
Steamhose (200 ft)
2 ea wellhead fittings
6-in black pipe (wells)
Compressor for pumps and boiler control
2 ea 6-in x 20 ft stainless steel (ss) well screens
Surface coolings/confinement barriers.
Extraction Well Equipment
8 ea downhole pumps
8 ea 6 in x 20 ft SS screens
6-in black pipe
Wellhead fittings and Instrumentation
ERT/Monitoring Equipment
2-in fiberglass pipe (40 ft/well)
2-in fittings for fiberglass pipe
Electrical wire and electrodes
Computer equipment
Thermocouple wire
Thermocouple monitoring system
Surface Treatment Equipment
Air stripper (water treatment)
Vacuum pump for extraction wells
Fiberglass extraction piping
4-in fiberglass pipe fittings
Cyclone cylinder
Condenser
Cooling tower
Product/water separator
25,000 gal treated water storage tanks
Storage tanks for separated product
Incidental Surface Equipment
Forklift rental ($2000/month)
Crane rental ($100/day)
Barricades, fencing, etc.
Miscellaneous small equipment
$15,000
$600
$2,400
$5,000
$50,000
$9,500
$1,200
$6,300
$4,000
$3,990
$4,000
$3,000
$1,000
Per Site
Reusable
$2,000
$2500
$4,000
$15,000
$16,000
$15,000
$4,000
7
$15,000
$3,000
$5,000
7
$2,000
$500
$1,000
$5,000
Incremental Cost
for Next Two
Treatment Cells
$15,000
$300
$1,200
$3,200
$400
$400
$267
$266
Average Cost
for Additional Pairs
of Treatment Cells
$15,000
$150
$600
$3,200
$400
$400
$267
$266
$2,000
$500
$1,000
$1,000
$200
$500
$800
$500
Page 10
U.S. Department of Energy
102
-------
COST
continued
Cost Estimate for Future Applications (continued)
^^^^^^^^^^^^^^^^^^^^^^H Treatabilitv Demonstrator! Full-Scale Remediation
I Total
Eauioment Costs (continued) ^^^^^^ES^^^^^^M
Replacement costs for consumable equipment
Non-reusable equipment total (demonstation only)
Reusable equipment total (demonstration only)
Shipping (10% of equipment costs)
Total rental costs for 6 months onsite
Equipment contingency (15% of equipment costs)
Procurement cost-LLNL (estimated at 19.78%)
Total equipment costs
Labor Costs
Engineering/Scientific Labor from
LLNL/UC/Commercial Partners
Planning/design/consultation (4 FTEs for 3 months)
Characterization/Installation (6 FTEs for 2 months)
Operation (2 FTEs for 6 mosnths)
Evaluation/reporting (4 FTEs for 1 month)
LLNUUC Technical Labor
ERT electrode preparation
Pressure testing wellheads
ERT installation (1 FTE for 1 month)
Monitoring system operation
Commercial Partner Technical Labor
Wellhead pump installation (4 FTEs for 1 month)
Regulatory compliance monitoring (1/2 FTE, 6 months)
Health and safety monitoring (1 FTE for 6 months)
Operation (1 FTE for 6 months)
Boiler operator (1 FTE, 24 hr/day, 5 months @ $75/h)
Treated water disposal costs (based on LLNL rates)
Analytical process chemistry
Installation Expenses
1 0 ea extraction/injection wells
10 ea monitoring/ERT wells with chemist
Treatment system hookup/lasting (4 FTEs for 1 month)
Miscellaneous/Travel/Overhead
Travel (40 person trips @ $1500/trip)
Miscellaneous supplies and expenses
Overhead/etc, nonwage nonprocurement at 64.89%
Labor subtotal
Labor contingency (25%)
Total labor costs
$31,790
$171,600
$20,089
$135,000
$33,884
$77,609
$469,972
$230,000
$230,000
$230,000
$75,000
$10,000
$10,000
$10,000
$40,000
$40,000
$57,500
$118,000
$116,000
$270,000
?
$50,000
$20,000
$45,000
$40,000
$60,000
$20,000
$51,912
$2,189,384
$547,346
$2,737,000
Incremental Cost
for Next Two
Treatment Cells
$8,580
$7,782
542,895
Average Cost
for Additional Pairs
of Treatment Cells
$17,160
$6,945
$46,268
$23,000
$23,000
$23,000
$7,500
$23,000
$23,000
$23,000
$2,000
$2,000
$2,000
$20,000
$57,500
$25,000
$10,000
$15,000
$20,000
$15,000
$43,125
$12,500
$4,000
$11,250
$20,000
$10,000
$4,000
$9,085
$295,978
$73,995
$390,000
$221,163
$55,291
$278,000
NOTE: All costs are preliminary approximations for work within the DOE environment (overhead, travel, and
procurement charges may be less for other applications). Costs not specified in this estimate include costs for
disposal of boiler blowdown (if any) and equipment for offgas treatment (see Appendix E for vapor phase
equipment costs during demonstration).
Page 11
U.S. Department of Energy
103
-------
COST
continued
Cost Savings Versus Alternative Technologies
LLNL researchers compared DUS costs and remediation times with estimated costs and cleanup times of applying
alternative technologies at the GSA:
[-Time for Cleanup
50-|
30 yrs
DUS DUS Soil Pump-and-
New Excavation Treat with
SVE
f- Cost of Cleanup
50-1
o
DUS DUS Soil Pump-and-
New Excavation Treat with
SVE
Notes: DUS New = cost of commercial application of DUS at the GSA; assumes 40% reduction from
demonstration costs due to use of lessons learned and elimination of research-oriented
activities; detailed in Appendix E
DUS = cost of demonstration program for DUS
Soil Excavation includes relocation of underground utilities
SVE = soil vapor extraction
Page 12
U.S. Department of Energy
104
-------
SECTION 6
REGULATORY/POLICY REQUIREMENTS & ISSUES
Regulatory Considerations
Permit requirements for future applications of DUS are expected to include:
• air permits for operation of steam generation equipment and discharge from surface treatment equipment (i.e., air
stripper, GAC units, or internal combustion engine)
• liquid effluent discharge permits from aboveground treatment systems (discharge criteria are likely to be related to
ground water cleanup levels)
For applications in some states, underground injection permits may be required for system application.
Permitting requirements and regulatory considerations arising from the demonstration at LLNL and relevant to future
applications elsewhere are detailed below.
Water
• Ground water cleanup levels have been established for the major contaminants at the GSA:
COMPOUND
Benzene
Toluene
Ethyl benzene
Xylenes (total)
Total VOCs
FEDERAL
MCL (ppb)
5
1,000
700
10,000
CALIFORNIA
MCL (ppb)
1
680
1,750
NPDES
LIMIT (ppb)
0.7
5
5
5
5
NOTE: MCL = Maximum Contaminant Level; NPDES = National Pollutant Discharge Elimination System
• Remediation will continue until in situ soil concentrations are deemed not to adversely impact groundwater.
Those levels are determined through monitoring and modeling efforts as well by using the criteria listed above.
Air
• The timetable for the DUS demonstration was dictated by the air permits issued for the project. The system was
shut down while it was still removing 50 gal/day of gasoline, and an unheated region remained because the air
discharge allowances had been consumed.
• The boiler for steam generation utilized Best Available Control Technology (BACT) consisting of a low NOx
burner design and flue gas recirculation to control NOx emission to 40 ppm. The Bay Area Air Quality
Management District (BAAQMD) granted a research exemption for the project instead of requiring LLNL to
purchase an emission allotment of 2,200 Ibs (1.6 Ibs/hr) of NOx.
• The BAAQMD issued permits for the following:
DISCHARGE
Air stripper
GAC
1C engine
Sitewide benzene
COMPOUND
Total hydrocarbons
Total hydrocarbons
Total hydrocarbons
Benzene
SAMPLING
FREQUENCY
5/wk
5/wk
5/wk
Monthly
DISCHARGE
LIMIT
10 ppm
10 ppm
Destruction > 98.5%
1.815lbs/day
• The LLNL DUS demonstration project incurred one violation from the BAAQMD because of higher than
anticipated concentrations of VOCs in extracted vapor streams exceeding the capacity of surface treatment
systems.
Page 13
U.S. Department of Energy
105
-------
REGULATORY/POLICY REQUIREMENTS & ISSUES
continued
Regulatory Considerations (continued)
Other Considerations
• Waste forms generated by DUS include the air and liquid discharges (effluent limitations listed above) as well
as spent activated carbon. The carbon can be either regenerated or landfilled and poses no unusual regulatory
or permitting burden.
• As dictated in the LLNL sitewide Record of Decision and Remedial Implementation Plan, project milestones for
site cleanup specify dates for designing and starting various treatment facilities to satisfy overall objectives of
protecting human health and the environment in the shortest time possible. DUS represents the most rapid
alternative identified during feasibility studies for achieving these objectives.
• No anticipated regulatory developments are expected to change the ability of DUS to comply with relevant
requirements. Use of the technology at sites other than LLNL is not expected to be conducted under more
stringent requirements. In some cases, permitting of airborne discharges may be easier.
Safety, Risks, Benefits, and Community Reaction hM^M^H^Bi^HBHMHMH
Worker Safety
• Operational Safety Procedures were developed to address DUS-specific safety issues not covered by
existing LLNL procedures. Areas of concern included hazards posed by the steam generating equipment,
electrical hazards from the large currents utilized, proper handling of pressurized steam injection wells, and
hazards posed by implementation of ERT.
• Although large amounts of contaminants are more quickly extracted from the ground with DUS than with
conventional technologies, safety measures for handling extracted liquid and vapor streams are similar to
those for the conventional technologies. One exception, however, is that in some instances the contaminant
concentrations of extracted vapors exceeded the upper explosive limits for the mixture.
• Level D personnel protection was used during installation and operation of DUS.
Community Safety
• Although DUS involves handling extracted vapor and liquid streams with higher concentrations of
contaminants than conventional technologies, the dramatically increased speed of cleanup reduces long-term
risks to nearby populations.
• DUS employs real-time monitoring controls, which greatly reduces the likelihood of accidents or offsite
migration of contaminants.
Environmental Impacts
• DUS speeds cleanup relative to conventional technologies freeing land for beneficial reuse. Contaminants
are either destroyed or are concentrated, transferred to other media, and disposed of offsite depending upon
the configuration of surface treatment equipment.
Socioeconomic Impacts and Community Perception
• Unlike some other long-term remedial alternatives, DUS will require a staff only for a limited period of time.
Selection of DUS can reduce the amount of time an environmental restoration work force is needed at some
installations.
• DUS has received positive support from the general public at the LLNL Community Work Group Meetings.
The basic principles of the technology have been readily understood by both technical and nontechnical
audiences.
Page 14
U.S. Department of Energy 106
-------
SECTION 7
LESSONS LEARNED
Design Issues
• The DUS demonstration made use of an existing groundwater treatment facility designed to treat gasoline and low
levels of chlorinated solvents for the design life of 30 years. The facility utilized oil/water separation, UV/H2O2, and
GAG for the liquid phase and GAG for the vapor phase. This design was not optimal for DUS conditions. The large
vapor flows loaded with fuel hydrocarbons required installation of an internal combustion engine to replace the GAG.
The high temperature process created conditions unfavorable to UV treatment (increased carbonates and silicates in
the extracted liquids would come out of solution when cooled in the ilV unit). Packed tower air stripping may be more
appropriate for similar applications in the future.
• The success of the D'JS process is dependent upon boiling the subsurface environment. The process must be
designed not only to bring soil and groundwater to steam temperature but to impart a large amount of energy to
create a complete steam zone. Sufficient steam must be injected to counter the cooling effects of inflow of ground
water into the treatment zone.
• Aboveground treatment systems must be sized to handle anticipated peak extraction rates and the expected
distribution of VOCs in extracted vapor and liquid streams. During demonstration, the majority of extracted VOCs
were in the vapor stream. Initially, the vapor treatment system was undersized to handle this stream.
• Aboveground treatment systems must be located so as not to interfere with access to the subsurface treatment zone.
This is necessary to avoid situations in which additional injection, extraction, heating, or monitoring wells need to be
installed in a spot occupied by surface equipment.
Implementation Considerations
• Effective removal of contaminants from the subsurface requires repeated creation of the steam zone by
successive phases of steam injection and continuous vacuum extraction. The pressure changes created by this
oscillatory approach distill contaminants from pore spaces in both saturated and unsaturated sediments.
• Operational difficulties encountered included biofouling from microorganisms destroyed by steaming, scaling and
deposits on sensors, and clogging from fines brought to the surface. Maintenance plans must address these
situations in future applications by scheduling for routine cleaning of equipment.
• Extraction rates can vary greatly depending upon the amount of steam injected, the total vacuum applied, and
cycle times.
• Permitting of air discharges from both aboveground treatment units and equipment used to supply steam energy
is an issue requiring early attention.
• DUS is a labor intensive process requiring significant field expertise to implement.
• ERT proved to be the most effective method for monitoring the DUS process in real time. Alternative
geophysical techniques could be used for other applications.
B
Technology Limitations/Needs for Future Development
• Data on long-term routine operating experience with DUS are not yet available but are needed to better plan future
applications.
• Treated soils can remain at elevated temperatures for months and even years after cleanup. This could impact site
reuse plans. Soil venting can greatly accelerate the cooling process.
• Future development needs currently identified for DUS include demonstrating the process for removing chlorinated
solvents including DNAPLs, mixed wastes, and sites with fractured subsurface media, automating monitoring
techniques, and further refining system design and operating techniques.
Page 15 —
U.S. Department of Energy 107
-------
LESSONS LEARNED
continued
Technology Limitations/Needs for Future Development (continued)
• OUS is effective in th-> presence of free-phase and dissolved-phase contaminant liquids. It is extremely effective
in the absence of liquiOo (vadose zone), but is usually not cost effective versus alternative technologies in these
instances.
• DUS is not applicable at depths less than five feet. At greater depths, the steam injection pressure can be
increased which produces higher efficiences and extracts more work from each well. (More Information on
technology applicability is located in Section 4 and Appendix D.)
Technology Selection Considerations
• DUS was effective at quickly removing concentrated free-product contaminants, including materials sorbed to
saturated sediments, without mobilizing contaminants outside the treatment zone.
• Steam injection is effective at heating permeable zones, and repeated steam passes, when combined with electric
heating, can heat adjacent impermeable areas.
• Electrical heating is effective on clay zones; however, power requirements increase when extracting hot fluids
from the treatment zone.
• Future applications of DUS will be designed to focus on mobile/temporary aboveground treatment and steam
injection systems that can treat plumes on a cell by cell basis.
• DUS is compatible with long-term efforts to bioremediate residual contamination following steam injection. After
application of DUS at LLNL, viable microbial populations continued to degrade gasoline at the site at
temperatures above 158°F. Although microbial populations present after application of DUS were different from
those present before treatment; the treatment zone was not sterilized.
• DUS can compare favorably in terms of speed, effectiveness and cost with alternative technologies for deep
subsurface plumes. At LLNL, significant cost savings were realized from DUS as opposed to installation of soil
vapor extraction/pump-and-treat systems or excavation of contaminated areas. Further reductions in DUS cost are
anticipated as experience is gained that will optimize subsequent applications.
B
Page 16
U.S. Department of Energy 108
-------
APPENDIX A
DEMONSTRATION SITE CHARACTERISTICS
Site History/Background
• The 800-acre LLNL site was converted from agricultural use into a flight training base and aircraft assembly and
repair facility by the Navy in 1942. In 1951, the Atomic Energy Commission converted the site into a weapons
design and basic physics research laboratory. Later site missions have included programs in biomedicine, energy,
lasers, magnetic fusion energy, and environmental science.
• Initial releases of hazardous materials occurred in the mid to late 1940s. There is also evidence that
subsequent localized spills, leaking tanks and impoundments, process cooling water, and landfills released VOCs,
FHCs, lead, chromium, and tritium to sediments and groundwater primarily from 14 major source areas of
contamination.
• Between 1952 and 1979, based upon inventory records, as much as 17,000 gallons of leaded gasoline was
released from underground storage tanks (USTs) beneath a gasoline filling station in an area now designated the
GSA. The GSA occupies an approximately 1.25-acre level area at the southern edge of LLNL and is the site of the
DUS application.
• Land north and south of the site is zoned for industrial use, high-density urban areas are west of the site, and the
east side is primarily agricultural. Immediately south of the GSA are facilities owned and operated by Sandia
National Laboratories. The climate is semiarid with annual precipitation of around 14 inches/year.
• Corrective actions taken since 1988 at the GSA have included the removal and sand filling of four USTs,
installation of a gas skimmer which removed 100-150 gal of gasoline, soil vapor extraction of about 1900 gal, and
intermittent use of a groundwater pump-and-treat system using UV/H2O2 treatment. A large subsurface
microbiological population indicates that indigenous microbes have metabolized additional gasoline constituents.
Contaminants of Concern
Contaminants of concern focused on during the
remediation are:
• benzene,
• toluene,
• ethylbenzene,
• xylene (mixture of m, o, and p-xylenes), and
• 1,2-dichloroethane.
Low levels of other chlorinated solvents are also
present in the GSA but were not specifically
targeted by DUS remediation efforts.
i Nature and Extent of Contamination
Property at STP* Units
Empirical Formula
Density g/cm3
Vapor Pressure mmHg
Water Solubility mg/L
Octanol-Water
Partition
Coefficient; Kow
Organic Carbon
Partition
Coefficient; Koc
B
0.87
75
1.780
132
50
'STP = Standard Temperature and Pressure;
T E
C6H5C2H5 C6H5CH3
0.87 0.87
29 7
534 161
490 1,413
339 565
1atm,2S°C
X
-0.87
10
178
1,830
255
• The volume of FHC as gasoline before any remediation efforts was estimated based on soil and ground water
sampling to be approximately 16,000-17,000 gal: 6,000 in the vadose zone, 10,000-11,000 in saturated sediments,
and 100 dissolved in ground water. Mass volume estimates made immediately before application of DUS identified
approximately 6,500 gal of gasoline within the treatment zone.
• High concentrations of gasoline in saturated sediments indicated the likelihood of free phase gasoline. The free
phase was trapped within low-permeability sediments below a ground water table that has risen 10 to 30 ft since
the time of the main portion of the release (1979) because of the cessation of agricultural pumping.
• FHC concentrations exceed 10 ppm only in the immediate vicinity of the release point with concentrations
decreasing to 1 ppm and 100 ppb at 35-40 ft and 40-45 ft, respectively. Benzene levels above 1 ppb [California
MCL is now 0.5 ppb] are found within 300 ft. FHCs were not found below a depth of 150 ft.
PageAl
U.S. Department of Energy
109
-------
DEMONSTRATION SITE CHARACTERISTICS
continued
Contaminant Locations and Hydrogeologic Profiles
Site Layout (Plan
view;
Truck Scale
Gate
The GSA has been extensively
studied since 1984. Over 70
subsurface borings and
monitoring wells revealing the
area's geologic, physical, and
chemical characteristics have
been completed. Short- and long-
term drawdown, injection, and
extraction tests were conducted to
assess hydraulic properties.
Pneumatic data derived from soil
vapor extraction efforts have also
been collected.
Cross-Sectional
View
Four hydrogeologic units and seven hydrostratigraphic layers have been identified along cross-section B-B' shown in
the plan view above. An FHC concentration profile along this cross-section is providedmSection 3. ._. ,
K r a Hydrostratigraphic Layers with
Location of
/' the gas pad
' at LLNL
640'
480
Legend: BIUnit1 •• Unit 2 I I Unit 3 | | Unit 4
Well sorted Moderately Channel & Overbank/
channel well sorted debris flow interchannel
Water
table
Estimated Gasoline Volumes Prior
to PUS
1 none
2 311 gal
3 642 gal
4 Upper Steam Zone (USZ) -
31 53 gal
5 1963 gal
6 Lower Steam Zone (LSZ) -
480 gal
none
Note: Steam zones bounded by
bold lines
deposits
channel
deposits
deposits deposits
Hydrogeologic Unit Characterization Hydrostratigraphic Layer Characterization
Hydraulic
Conductivity Interpreted
# Range [gpd/ftz] Permeability
1 15 to 1070
2 13 to 1000
3 16 to 170
4 <5to18
Very high to high
(mean=280)
High to moderate
(mean=154)
Moderate to low
(mean=116)
Low
(mean=11)
1 5-15-ft-thick interval of coarse-grained high-permeability sandy gravels and gravelly
sands
2 30-ft-thick, laterally continuous interval of clayey silts to silty clays
3 very heterogeneous zone of elongated lenses of channel sands and gravels
interbedded with intervals of silty clays and clayey silts from 50 to 80 ft depth; forms
aquitard over USZ
4 partially saturated water-bearing zone composed of a heterogenous mix of high to
low permeability sandy to clayey gravels and gravelly to silty sands, 80 to 100 ft depth
5 low-permeability silty clays and clayey silts; forms barrier between the USZ and LSZ
6 high-permeability laterally continuous gravelly sands and sandy gravels; average
thickness of 11 ft
7 laterally continuous sequence of silty clays to clayey silts at least 15 ft below base
of LSZ
NOTE: The two steam zones appear to be hydraulically isolated from adjacent aquifers,
are relatively permeable, and contain the most elevated FHC concentrations.
• The site is underlain by several hundred feet of complexly interbedded alluvial and lacustrine sediments.
• Depth to ground water in the GSA is approximately 100 to 120 ft.
• Regional ground water flow is generally westward, locally stratified, and primarily horizontal.
• Pumping tests and the distribution of contaminants at LLNL indicate a high degree of horizontal subsurface
communication. Minimal observed communication in the vertical direction and the layered alluvium restricts downward
migration of contaminants.
i i PageA2 —
U.S. Department of Energy
110
-------
DEMONSTRATION SITE CHARACTERISTICS
continued
Contaminant Locations and Hydrogeologic Profiles (continued)'
Areal Extent of Benzene ContgminatiiieftYe application of DUS)
Soil
Ground Water
Upper
Steam
Zone
so'tolDOtt
depth
Lower
Steam
Zone
isz
110To~f20ft
depth
L _Y /
Legend'
40ft
soil concentrations in ppm
[~] 0.5 to 5 ppm H > 50 ppm
H 5 to 50 ppm
ground water concentrations in ppb
CD 1 to 10 ppb H > 10 ppb
Page A3
U.S. Department of Energy
111
-------
APPENDIX B
TECHNOLOGY DESCRIPTION DETAIL
System Configuration
a
Effluent
storage
tanks
Granular
Steam activated
boiler internal carbon
combustion (GAC)
engine system
Truck scale
Blowers
GAC _A
unit
DDDODD
Aeration
tanks
a
UV/H2O2 Cooling /
|X unit / towers /
** o/rj
Gasoline
storage
3
Transformers
Ground water
heat exchanger
/
Oil/water
separators
- Fence
NOTE: 21 tltmeters (not shown) were also utilized. Additional subsurface borings and ground water
monitoring wells are present from initial and ongoing characterization activities
Legena
ffyfo Extraction
^f} Well
/Tk Injection
Vfj Well i
A Electrical
3i Heating Well
Geophysical
A Monitoring Well
^B(ERT, thermocouple,
and piezometer)
40ft
Operational Requirements
• Typical staffing requirements for future applications of DUS, at sites of size similar to that of LLNL, are
anticipated to include:
one project engineer,
one or two geophysicists to handle ERT and temperature monitoring and data interpretation,
four certified boiler operators (one operator needed 24 hours/day),
four effluent treatment technicians/sampling technicians (one technician needed 24 hours/day),
one chemical data analyst, and
one electrician available for periodic maintenance.
• DUS consumes significant quantities of electricity, water, and, for some applications, natural gas.
These requirements can be handled via hookups to existing facilities or can be stored or generated
onsite for more remote applications.
Page B1
U.S. Department of Energy
112
-------
TECHNOLOGY DESCRIPTION DETAIL
continued
Well Close-Ups
Thermal Enhancement
Extraction
Steam Injection/
Electrical Heating
4* Schedule 40
pipe
18* Casing
Electrical Heating
Stainless steel A
injection screen/
for upper and '
lower steam
zones
2" Schedule 40
pipe*
Stainless steel
electrode
heating screen
11" Casing
Approx. 145ft
depth
Various layers
of sand, gravel,
and anode
material
Approx. 120 ft
depth
Sand and gravel
layers; approx.
60ft \
8" Ground water
and vapor
extraction well
Grout
Benlonite
Stainless
steel
sump
Approx. 155 ft
depth
Monitoring
Geophysical Monitoring
, 2" Fiberglass pipe
if
11" Casing
Grout layers
Approx. 165fl
depth
Bentonite
Electrodes (10)
2 spaced
aproximately 10ft
apart, grouted in
place
Tiltmeter
Data logger
8" Casing
Grout
Tiltmeter
(electromagnetic
bubble accurate to
1 nanoradian)
Sand
Approx. 21 ft
depth
Thermocouples (not shown) are present in the
monitoring, steam injection, and electric heating wells
All drawings not to scale
Page B2
U.S. Department of Energy
113
-------
TECHNOLOGY DESCRIPTION DETAIL
continued
Surface System Schematics
Steam Injection Surface
Equipment
Injection pressures at wellheads limited to 45 psi
for shallow intervals and 55 psi for deep intervals.
Pressures also kept below 0.5 psi/ft of overburden
to prevent fracturing of the formation
Natural gas fired
32,000,000 BTU/h skid
mounted boiler with low
NOx burners and flue gas
recirculation
Pressure regulated
manifolds using schedule
40 welded black steel pipe
and steam hose rated at
250 psi and 400°F at
wellheads
Wellheads
Electrical Heating Surface Equipment
13.8kVlinefromtheLU
utility grid
15 kV load 13.8 kV/1500 kVA mam circuit breaker
interrupter switch 3 phase rated at 4000 Amps
transformer @ 600 VAC
up to 300 to 400 amps per
subsurface electrode; up
to 800 kW total used to
heat the subsurface
4000 amp, 600 VAC
switch panel
Extracted Liquid and Vapor Treatment Equipment
Flat plate heat 5
-------
TECHNOLOGY DESCRIPTION DETAIL
continued
Waste Generation/Process Influents and Effluents
Atmospheric discharge
containing low-level NOx
Atmospheric
discharge
from internal
combustion
engine (ICE)
Atmospheric
discharge
from GAC
Process
water
Extracted vapor
and ground water
Aboveground
treatment systems
Treated liquid
Spent GAC forpffsite
landfill or regeneration/recycle
Page 84 —
U.S. Department of Energy
115
-------
APPENDIX C
PERFORMANCE DETAIL
Operational Performance
- Maintainability and Reliability
• A significant percentage of the field activities
occurred in a shakedown mode where various
processes were debugged and optimized. In
addition, distinct demonstration phases used
different equipment configurations; therefore,
long-term routine maintenance and reliability
data are not available.
• Operational difficulties encountered included
biofouling (especially from microorganisms
destroyed by steaming), scaling and deposits on
sensors, clogging from fines brought to the surface,
and difficulties in maintaining the cycling, pressure
varying, high-temperature process.
r— Operational Simplicity
• DUS requires real-time in-the-field expertise to
interpret monitoring data and appropriately adjust
injection and extraction flow rates. Staffing
requirements are presented on page B1.
• Routine implementation practices have not yet
been developed for all aspects of DUS. Future
development efforts will include consideration of
automating certain process monitoring activities.
Schedule
Major Phases of the Demonstration Program
1991 / /1992 1993
1994
JUL
AUGl /NOV
DEC
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
JAN
FEB
MAR
w Clean Site Demonstration
]* » DUS Electric Heating
J DUS 1st Pass Steam
DUS 2nd Pass Steam
-J ARV Electric Heating
ARV Extraction
Performance Validation
• The EPA Superfund Innovative Technology Evaluation (SITE) program installed two soil borings for analysis of
post-treatment conditions during the DUS demonstration. The results corroborated the data on pre- and post-
treatment soil conditions developed by LLNL researchers.
• Although DUS has not been applied at any other sites, the principle of in situ thermal treatment has been
demonstrated and validated through other DOE, DOD and EPA sponsored projects which are discussed in
Section 4.
Page C1
U.S. Department of Energy
116
-------
PERFORMANCE DETAIL
continued
Sampling, Analytical, and QA/QC Issues ^••••••••••BiHBBnBHBHBB
p Sampling and Analysis Objectives
• Obtain concentrations for calculating daily contaminant removal from vapor and liquid streams.
• Characterize the contamination removed.
• Measure destruction efficiencies of the surface treatment systems for regulatory compliance.
• Compare results with on-line monitoring instrumentation.
Sampling Locations/Procedures
To
atmosphere
Oil/water / sampled / Filters
separatoi
Discharge
Heat exchanger
\
Extraction Wells
Gasoline storage
h^Og storage
6 Air stripping tanks
- Legend-
Vapor flow
Liquid flow
Vapor
Liquid
vapor w uquiu
sampling I sampling
port port
• Aqueous samples were collected in 40-ml volatile organic analysis (VOA) vials after three line volumes
passed through each port unsampled.
• Free product samples were collected from the megators and placed into 40-ml VOA vials.
• All liquid phase samples were cooled to 4°C until analysis.
• Evacuated 500-ml stainless steel spheres of Tedlar bags were plumbed in-line with sampling ports
for collection of vapor samples.
.Page C2
U.S. Department of Energy
117
-------
PERFORMANCE DETAIL
continued
Sampling, Analytical, and QA/QC Issues (continued)
Analytical Methods
• Aqueous samples were analyzed onsite according to EPA methods 601/602 and 8015 [total
petroleum hydrocarbons (TPH)].
• Sudan IV was used as a petroleum indicator to visually determine the presence of gasoline in
aqueous samples. These experiments were conducted on surplus sample volumes subsequent to gas
chromatography (GC) analysis
• GC/mass spectroscopy (GC/MS) analyses of recovered free product were performed offsite to
determine composition changes with time.
• Vapor samples were analyzed onsite in accordance with EPA method T014.
• Results of onsite analyses were available within 24 hours of sampling to implement necessary
changes in extraction rates and treatment facility operations.
Equipment
• TPH analyses were performed using an autosampler and purge-and-trap concentrator coupled to a
Hewlett Packard (HP) 5890 Series II GC equipped with a flame ionization detector.
• EPA 601/602 and TOM analyses were performed using an HP 5890 Series II GC outfitted with an
autosampler, photoionization detector, electrolytic conductivity detector, purge and tap concentrator,
and low dead volume injector port.
• An HP Chemstation, an automated GC systems control and data acquisition workstation was used to
gather, process, and archive GC data.
QA/QC Issues
— Liquid Phase
• Quality control limits were set for
surrogate recoveries, field spike
recoveries, and precision and accuracy.
• The Internal Standard method was
used for data calculation and reporting.
• Limits of detection were set using
American Chemical Society
recommendations.
• Three-point calculation checks were run
daily.
• Instrument calibration was performed at
least quarterly or as needed (determined
by daily checks).
• Method blanks were run every 3 to 4
unknown samples.
— Vapor Phase
• Quality control limits were set for
precision and limits of detection. Vapor
samples were not spiked; therefore,
accuracy was not calculated.
• Stainless steel spheres were cleaned,
pressure-checked, and analyzed for EPA
601/602 compounds before use.
• Two-point calibration checks were run
daily.
• Instrument calibration was performed
quarterly or as needed (determined by
daily checks).
Page C3
U.S. Department of Energy
118
-------
COMMERCIALIZATION/INTELLECTUAL PROPERTY
continued
Intellectual Property Rights (continued)
Existing/Pending Patents
• Twelve patent applications have been filed for different processes and designs.
• To date, two patents have been issued:
- Patent 5,018,576 "Process for In Situ Decontamination of Subsurface Soil and Groundwater,"
K.S. Udell, N. Sitar, J.R. Hunt, and L.D. Stewart assignors to The Regents of the University of
California and
- Patent 5,325,918, "Optimal Joule Heating of the Subsurface," J. Berryman and W.D Daily,
assignors to the United States of America as represented by the DOE.
Licensing Information
• DUS technology is commercially available through UC Berkeley/LLNL, who are currently negotiating nonexclusive
licenses with several government and private parties (see Contacts section below for further information).
• LLNL has received hundreds of inquiries from site owners concerning the potential applicability of DUS to their
sites. This level of interest combined with the attention focused upon other in situ thermal treatment technologies
attests to the broad market for DUS. Specific commercialization activities already initiated by LLNL include:
- performing a feasibility and cost analysis to remediate a chlorinated solvent-contaminated site at the DOE
Pinedas facility,
- the design of a system to remediate shallow underground hydrocarbons at a U.S. Navy facility in California,
- the conceptual design to remediate a large shallow fuel-contaminated U.S. Army Corps of Engineer
managed site in Alaska, and
- other private sector projects.
These efforts are part of LLNL efforts to transfer DUS know-how to new licensees of the technology.
.Page 02
U.S. Department of Energy
119
-------
APPENDIX E
COST DETAIL
Demonstration Costs
• DUS costs were obtained from a variety of sources at LLNL. The costs of demonstration were
based upon overall funding received from the Department of Energy, program management planning
documents, capital costs for individual equipment components, and actual operating costs incurred
during the second steam pass (which is most representative of operating costs for future
applications).
• LLNL has prepared an estimate of potential cost savings if DUS were applied at the same site in
the future with the benefit of lessons learned and without research-oriented activities. Resultant
total savings would be approximately $4,000,000 or a 40% reduction versus demonstration
costs.
Overall Program Costs
Construction through 1st Steam Pass
2nd Steam Pass
ARV Phase
$7.240M
2.200M
1 .OOOM
Total $10.440M
Note: Costs include all research and development costs associated with the demonstration
— laemmea uosr ^omponenis
The following program elements
Project Management
Management
Analysis and report writing
Safety plan writing and review
Permitting
Equipment design
were taken from planning documents.
$225,000
335,000
70,000
65,000
200.000
$895,000
Process Monitoring
Design
ERT and thermal
Tiltmeter
Hydraulic testing
Characterization and Compliance
Drilling-phase sampling
Pre-electrical heating sampling
Pre-steam sampling
Post-steam sampling (4 new weiis)
Compliance monitoring
Sampling during experiment
$50,000
270,000
70,000
55.000
$445,000
Monitoring
$315,000
35,000
20,000
50,000
10,000
25.000
$455,000
Page E1
U.S. Department of Energy
120
-------
COST DETAIL
continued
Demonstration Costs (continued)
- Identified Cost Components (continued)
The following capital cost items include overlaps with the program cost elements shown previously:
Subsurface Wells
Note: Costs do not include design and installation labor
Steam injection/vapor extraction (a weiis at
approx. $32,000 each with average depth of 145 ft) $256,000
ERT-Temperature monitoring (11 weiis at
approx. $10,000 each with average depth of 165 ft) $110,000
Electrical heating (3 weiis at approx.
$10,000 each with average depth of 120 ft) $30,000
Electrical Heating Surface Equipment
Note: Costs do not include design and engineering
Installation labor $129,000
Transformer 50,000
Circuit breaker/switch panel 40,000
Cable 18,000
Miscellaneous materials 67,000
Other direct costs 63.000
$367,000
Steam Generation Surface Equipment
Note: Boiler leased for $17,300/month; design costs not included
Installation labor $174,000
Boiler utility set-up 100,000
Miscellaneous materials 42,000
Other direct costs 79.000
$395,000
Extracted Ground Water and Vapor Surface
Treatment Systems - Treatment Facility F
Note: Costs do not include design and engineering; facility originally
designed for 30-year pump-and-treat mission
Piping and power
Process equipment
Vapor modifications for DUS
Discharge pipeline
Activation
Other direct costs
$1,512,000
400,000
160,000
87,000
80,000
291.000
$2,530,000
uperaung ocsrs
Utility Consumption
Boiler natural gas (3 8E10 ft3 ©$0.39/100,000 ft3) $149,000 ~] $1.50/yd3
Boiler water (3 6E6 gal @ $1.25/100 ft3) $6,000 -treated
Boiler electricity (40,000 kWh @ $o.oe/kwh) $2,400 J
Electricity for electrical heating (200,000 kWh @ $o.oe/kWh) $12,000
Labor and Material Costs for 2nd Steam Pass (all values in thousands of dollars)
Note: Costs represent 6 weeks of 24-hr operations and continuously monitored experimental conditions
Phase 1: Planning
Phase 2: Maintenance and Modification
Phase 3: Operations
Steam Injection Operations
Periods of steam injection
Periods of no steam injection
ERT Monitoring
Additional DC Berkeley support
Effluent Treatment Operations
Effluent treatment
Sampling and analysis
Phase 4: Post Steaming Characterization
Sampling
Soil Analysis
Drill Rig
Phase 5: Reporting and Technology Transfer
Phase 6: Dismantling (conservative estimate)
Contingencies
Scientists and External
Engineers Technicians Analysis Materials
44
2 31 - 27
-'''
27 51 - 167
14 5
13 22
50
35 203 - 91
50 17 18
41 36 - -
83
26 - 9
400
TOTALS
44
60
245
19
35
50
329
85
77
83
35
400
181
228
Grand Total $1,871
Page E2
U.S. Department of Energy
121
-------
COST
continued
I Cost Considerations for Future Applications
Cost Savings for Commercial Applications
• LLNL has prepared an estimate of potential cost savings if DUS were applied at the same site in the future with the
benefit of lessons learned and without research-oriented activities. The estimated savings would be derived from:
reduction in design effort by over 50% (-$206K)
elimination of discharge lines & transformer
modifications (-855K)
use of temporary steam generation equipment
(-355K)
reduced site characterization (-21 OK)
replacement of UV unit with air stripper (-500K)
- elimination of modification designs for 2nd pass
steam and ARV phases (-604K)
- reduced management effort (-100K)
- reduced science & engineering staff
requirements (-166K)
- reduced operations staff requirements (-505K)
- reduced reporting and safety documentation
preparation (-470K)
Resultant total savings would be approximately $4,000,000 or a 40% reduction versus
demonstration costs
Cost Estimates Completed for Additional Applications
• LLNL researchers prepared a cost estimate for applying DUS to a shallow chlorinated solvent spill at the DOE
Pinellas facility. Key results of that cost estimate were:
- average cleanup costs of approximately $65/yd3 which was based upon a fixed cost of
approximately $1.5 M and a variable cost of $20/yd3 indicated the increased cost-
effectiveness of the technology at larger sites
- a total cost for DUS implementation was estimated as less that the first year cost of
constructing and operating a conventional groundwater pump and treat facility
Cost Savings Versus Alternative Technologies
DUS costs and remediation times were compared, by LLNL researchers, to estimated costs and cleanup times of
applying alternative technologies at the GSA:
—Time for Cleanup
50-1
40-
-------
APPENDIX F
REFERENCES
Major References for Each Section
Demonstration Site Characteristics: Source (from list below) 1 and 17
Technology Description: Source 1, 4, 6, 7, 8, 9,10 and 11
Performance: Source 1, 2, 4, 6, 7, 8, 9, 10,11,13,14,15 and 18
Cost: Source 1,3 and 18
Regulatory/Policy Issues: Source 1, 6, 8, 9, 14 and 15
Lessons Learned: Source 1, 2, 6, 7, 8, 9,10,11,1-3,14,15, and 18
Commercialization: Source 1, 5, 8,12 and 16
Chronological List of References and Additional Sources
1. Personal communications with Roger Aines, Lawrence Livermore National Laboratory, (510) 423-7184,
November 1994-January 1995.
2. Personal communications with Marina Jovanovich, Lawrence Livermore National Laboratory, (510) 422-2144,
January 1995.
3. Memorandum from Roger Aines, LLNL to Jesse Yow, LLNL, "Summary of Dynamic Underground Stripping
Funding," December 19,1994.
4. Personal communications with Robin Newmark, LLNL, (510) 423-3644, November 1994.
5. U.S. Environmental Protection Agency, Superfund Innovative Technology Evaluation Program: Technology
Profiles Seventh Edition, EPA/540/R-94/526, November 1994.
6. Design, Construction and Operation of the Dynamic Underground Stripping Facility at Lawrence Livermore
National Laboratory, draft, Lawrence Livermore National Laboratory, Livermore, CA, 1994.
7. Aines, Roger, William Siegel, and Everett Sorenson, Gasoline Removal During Dynamic Underground Stripping:
Mass Balance Calculations and Issues, draft, Lawrence Livermore National Laboratory, Livermore, CA, 1994.
8. Aines, Roger, Robin Newmark, John Ziagos, Alan Copeland, and Kent Udell, Cleaning Up Underground
Contaminants: Summary of the Dynamic Underground Stripping Demonstration, LLNL Gasoline Spill Site,
Lawrence Livermore National Laboratory, Livermore, CA, [UCRL-ID-118187], September 1994.
9. Siegel, William H., and Everett Sorenson, Treatment Facility F, internal document, Lawrence Livermore
National Laboratory, Livermore, CA, 1994.
10. Yow, Jess L, Roger D. Aines, Robin L. Newmark, Kent S. Udell, and John P. Ziagos, Dynamic Underground
Stripping: In Situ Steam Sweeping and Electrical Heating to Remediate a Deep Hydrocarbon Spill, draft, Lawrence
Livermore National Laboratory, Livermore, CA, 1994.
11. Newmark, Robin L., and the DUS Project Gasoline Spill Site Monitoring Team, Using Geophysical Techniques
to Control In Situ Thermal Remediation, draft, Lawrence Livermore National Laboratory, Livermore, CA, 1994.
12. MacDonald, J.A., and M.C. Kavanaugh, "Restoring Contaminated Groundwater: An Achievable Goal?",
Environmental Science & Technology, Vol. 28, No. 8, August 1994.
Page G1
U.S. Department of Energy 123
-------
REFERENCES
continued
Chronological List of References and Additional Sources (continued)
13. Jovanovich, Marina C., Roger E. Martinelly, Michael J. Dibley, and Kenneth L. Carroll, Process
Monitoring of Organics, revised draft, Lawrence Livermore National Laboratory, Livermore, CA,
August 1994.
14. Sweeney, Jerry J., and Alan B. Copeland [eds.], Treatment Facility F, Accelerated Removal and
Validation Project, draft, Lawrence Livermore National Laboratory, Livermore, CA, April 1994.
15. Demonstration of Dynamic Underground Stripping at the LLNL Gasoline Spill Site: Summary of
Results 3/94, draft, Lawrence Livermore National Laboratory, Livermore, CA., March 1994.
16. U.S. Department of Energy, Office of Environmental Management, Office of Technology
Development, Technology Catalogue, First Edition, February 1994.
17. Bishop, D.J. [ed.], Dynamic Underground Stripping Characterization Report, draft, Lawrence Livermore National
Laboratory, Livermore, CA, January 1994.
18. Brown, Mike, Roger Liddle, Alan Copeland, and John Ziagos, "Headquarters Dynamic Underground Stripping
Briefing," presentation materials, October 1993.
This summary was prepared by.
CKY incorporated
Environmental Services
140E Division Rd Suite C-3
Oak Ridge, Tennessee, 37830
Contact. Kenneth Shepard (615)483-4376
in conjunction with:
Stone & Webster Environmental A
Technology & Services Afv\
245 Summer Street
Boston, MA 02210
Contact: Bruno Brodfeld (617) 589-2767
Assistance was provided by the
LAWRENCE LIVERMORE NATIONAL LABORATORY
ENVIRONMENTAL TECHNOLOGY PROGRAM
EARTH SCIENCES DIVISION
which supplied key information and reviewed report drafts
Final editing and production was provided by the
Colorado Center for Environmental Management
999 18th Street Suite 2750
Denver CO 80202
(303)297-0180
HAZARDOUS WASTE REMEDIAL ACTIONS PROGRAM
Environmental Managment and Ennchment Facilities
Oak Ridge, Tennessee 37831-7606
managed by
MARTIN MARIETTA ENERGY SYSTEMS
for the
U.S. Department of Energy
under Contract DE-AC05-840R-21400
950R-7400-001-008
Page G2
U.S. Department of Energy
-------
Pump & Treat of Contaminated Groundwater
at Operable Unit B/C
McClellan Air Force Base
California
(Interim Report)
125
-------
Case Study Abstract
Pump & Treat of Contaminated Groundwater
at Operable Unit B/C
McClellan Air Force Base, California
Site Name:
McClellan Air Force Base, Operable
Unit (OU) B/C
Location:
Sacramento, California
Contaminants:
Chlorinated Aliphatics
- Trichloroethene (TCE), cis-1,2-
Dichloroethene (cis-1,2-DCE),
Tetrachloroethene (PCE), 1,2-
Dichloroethane (1,2-DCA)
- In an area of 7,800 million cubic feet, there
is an estimated 33,000 kg of VOCs; percent
of total mass for individual constituents is
TCE (82.7%), cis-l,2-DCE (0.5%), PCE
(16.7%), 1,2-DCA (0.1%)
Period of Operation:
Status: Ongoing
Report covers - 1988 to 1993
Cleanup Type:
Full-scale cleanup (interim
results)
Vendor:
Not Available
SIC Code:
9711 (National Security)
Technology:
Groundwater Extraction followed by
Aboveground Air Stripping
- 7 extraction wells pump to a main treatment
plant
- Air stripper - design capacity of 1,000 gpm;
average flow rate of 250 gpm
- Supplemental Treatment - thermal oxidizer
and caustic scrubber for offgases; two GAC
units in series to polish liquid phase prior to
discharge
Cleanup Authority:
DoD
Point of Contact:
Remedial Project Manager
McClellan AFB
Sacramento, CA
Waste Source:
Landfill; Underground Storage Tank;
Disposal Pit; Open Burn Area
Purpose/Significance of Application:
Full-scale remediation of groundwater
contaminated with VOCs using
groundwater extraction and
aboveground air stripping.
Type/Quantity of Media Treated:
Groundwater
- As of 1/94: Over 660 million gallons of groundwater treated since startup in
March 1987
- Groundwater subsurface consists of 5 distinct monitoring zones (A through E);
evidence points to hydraulic link among 5 zones
- Hydraulic conductivity ranges from 2.8 to 30.7 ft/day
- Transmissivity ranges from 100-2,000 ft2/day
Regulatory Requirements/Cleanup Goals:
Final cleanup criteria have not been established at this time
- Current target is <0.55 ug/L VOCs for groundwater
- NPDES permit - acetone, MEK, and MIK to <1 mg/L and VOCs to <0.5 ug/L
126
-------
Case Study Abstract
Pump & Treat of Contaminated Groundwater
at Operable Unit B/C
McClellan Air Force Base, California (Continued)
Results:
- Influent VOC concentrations have decreased from about 60 ppm in 1987 to about 4 ppm in 1993
- The effluent from the treatment system has been below the permitted discharge levels since operation began
- As of 3/94, approximately 44,000 Ibs of VOCs have been removed since startup
Cost Factors:
- Total Capital Cost in 1987 - $4,000,000 (including over $1,700,000 for the incinerator, air stripper, scrubber, wells, and
GAC tanks, and about $1,000,000 for heat exchangers, blowers, pumps, and compressors; control center)
- Total Annual Operating Costs - $1,240,000 (including contractor operations, utilities, sampling and analysis, project
management)
- An estimated total cost for completing the cleanup is not available at this time
Description:
The McClellan Air Force Base in Sacramento, California was established in 1937. Operations at the 3,000-acre facility
include aircraft, electronics, and communications equipment maintenance and repair, and a wide variety of hazardous materials
have been used at the site. The site was added to the National Priorities List in 1987. Areas of contamination at the site
include Operable Unit B (OU B) and Operable Unit C (OU C). Releases from OU B resulted from disposal/release Of
hazardous substances from landfills, underground storage tanks, storage lots, burial and burn pits. Releases from OU C were
attributed to waste disposal activities. Extensive VOC contamination has been identified at the facility. The primary
constituents of concern are TCE, cis-l,2-DCE, PCE, and 1,2-DCA.
A groundwater extraction and treatment system including air stripping was installed with operations beginning in 1988.
Offgases from the air stripper are treated by thermal oxidation and caustic scrubbing. The effluent from the air stripper is
treated using GAC prior to a NPDES-permitted discharge. The 1993 data on the influent to the air stripper show that the
VOC concentrations have decreased to about 4 ppm from concentrations of 60 ppm (1987). An estimated 44,000 pounds of
VOCs have been removed as of March 1994. The remediation was ongoing at the time of this report and final performance
data are not yet available. In addition, the treatment system has been effective in treating groundwater to below the NPDES
discharge limits.
The total capital costs for this system are $4,000,000 and the total annual operating costs are $1,240,000. The system has
been on line 98% of the time. Problems of scaling and deposition in the air stripper from calcium and magnesium salt
precipitation were remedied by changing to 2-inch packing from 1-inch packing in the air stripper. Corrosion was minimized
through material changes to nickel-based commercial alloys and change in physical layout to improve flow.
127
-------
C '^ffffVf)y ----fYffry > " \ -*"-*"yyX -rmrrm^r^rf'-fr^nyt
^[QtpGYAPPLICATION! AJN^^
! Pags / of 12 r=
McClellan Air Force Base
Groundwater Operable Unit (OU) B/C
Sacramento, California
HI TECHNOLOGY APPLICATION
This analysis covers an effort to pump and treat
groundwater contaminated with volatile organic
compounds (VOCs) by above ground air stripping.
The treatment began in 1988, was expanded in 1990
and is ongoing. This analysis covers performance
through 1993.
i SITE CHARACTERISTICS
• Site History/Release Characteristics
• McClellan Air Force Base (AFB), an Air Force Command Logistics Center, was established in 1937. Operations
have included the management and repair of aircraft, electronics and communications equipment. These activities
have involved the use, storage and disposal of a wide variety of hazardous materials such as petrochemical solvents,
cleaners, electroplating chemicals, heavy metals, polychlorinated biphenyls (PCBs), low-level radioactive wastes and
fuel oils and lubricants.
• In 1987, the base was placed on the National Priorities List as the highest priority U.S. Air Force Installation.
• Investigations of groundwater contamination beginning in 1979 have identified three areas containing VOC plumes
onbase and offbase. Overall contamination at 254 confirmed and potential sites have been grouped within 11 OUs.
• Base operations within OU B resulted in the disposal or environmental release of a wide variety of hazardous
materials at landfills, underground storage tanks, storage lots, burial pits and burn pits. The primary nature of base
activities within OU C was waste disposal. The Industrial Waste Line (IWL) conveyed wastes from numerous facilities to
OU B and C and is itself a major source of contaminant releases.
I Contaminants of Concern
The primary contaminants of concern
(listed in order of frequency of detection)
are:.
Trichloroethene (TCE)
cis-1,2-Dichloroethene (cis-1,2-DCE)
Tetrachloroethene (PCE)
1,2-Dichloroethane (1,2-DCA)
Contaminant Properties
Property at STP*
Empirical Formula
Density
Vapor Pressure
Henry's Law
Constant
Water Solubility
Octanol-Water
Partition
Coefficient; Kow
Organic Carbon
Partition
Coefficient; K^.
Units
.
c/cm3
mniHg
. .-i.
iUlfnr'ffTX
mg/L
-
-
TCE
CICH-CCI2
1.46
59
to 8.9E-3
1,000
240
126
ds-1 ,2-DCE
CHCI-CHCI
-
200
7.5E-3
asoo
s
32
PCE
C!2C-CCI2
1.62
14
2.3E-2
150
398
661
1.2-DCA
C2H4CI2
126@15°C
64
1.1 E-3
8,690
3
14
'STP - Standard Temperature and Pressure; 1 aim. 25 °C
Nature & Extent of Contamination
• Contaminants in groundwater have been found to exist in 3 separate phases at McClellan: sorbed to the soil matrix,
solubized in porewater, or as free product. Contamination is additionally present dissolved in soil gas in the vadose zone.
• A drop in groundwater levels of 60 feet over the past 50 years has created a smear zone of contamination above the
declining water table.
• In general, the concentrations of VOCs of concern in groundwater has decreased with time while the number of
monitoring wells detecting the contaminants has increased.
U.S. Air Force
128
-------
> McClellan OU 8/C • Page 2 of 12—-
Contaminant Locations and Geologic Profiles
Over 300 monitoring wells
and 14 extraction wells
have been installed
basewide. In 1986, an
extensive monitoring
program was initiated to
assess levels of volatilss,
semivolatiles, metals,
pesticides and dioxins.
A small portion of this
hydrogeologic and
contaminant location data
has been included here to
provide a general
understanding of site
conditions.
TCE Plume
Site Layout
Operable Unit locations
Groundwater Levels & Flow Directions
Data from groundwater monitoring Zone A (sea p. 3 for
explanation of monitoring zones) in January, 1903.
Values in ft below surface.
influence of OUD
QfOUndWatef
extraction system
-46
-Influence ofb«se water
supply well
Data from groundwater monitoring Zone A in 1993.
Estimated TCE plume locations
• TCE concentrations are highest near confirmed
source areas; horizontal movement of
contamination is limited, and is in a southwest
direction.
• TCE concentrations are much higher in the A
monitoring zone than the B,C,D or t zones which
suggest that downward migration has been
slowed by operation of the pump and treat
system.
• Locations of other VOCs of concern are
generally similar to TCE locations.
• Overall amounts of VOCs of concern present in
groundwater ar McClellan has been estimated at
33,000 kg occupying over 7800 million ft 3 with
the following breakdown:
Contaminant
of Concern
Monitoring Zone
Mo
%A
%B %C % of Total Mas*
„ .
all concentrations
inug/L
Monitoring or
Extraction Wall
Unbound Contour
0.1-1 ug/L
1-10 ug/L
10-20 ug/L
20-100 uo/L
100-1000 ug/L
>1000 uo/L
TCE
eis-1,2-DCE
PCE
1,2-DCA
38
44
40
92
42
29
60
8
20
27
0
82.7
0.5
16.7
0.1
U.S. Air Force
129
-------
Contam/nant Locations and Geologic Profiles (Continued)
McClallan OU B/C - Page 3 of 12 —
Hvdrogeologic Profile
• Soils and geology at the base are
a complex series of alluvial and
fluvial deposits which were
deposited, eroded and redeposited.
• Deposits of any one lithology are
limited in horizontal and vertical
extent; units rarely extend laterally
for more than 50 ft.
• Extensive subsurface
characterization has been performed
to depths over 400 ft. below the
surface which has aided
understanding of the relative
permeabilities of subsurface
materials beneath each operable unit
and within each monitoring well
zone.
Soil boring data taken from a north-
south cross section illustrates typical
conditions beneath source area
waste pits and the industrial waste
IWL Wet Well
— Legend
Fill-Gravelly Sands
Pit - Silty sands and
sandy silts with oily material,
wire, wood debris
Fine Sand
(Includes Sand w/Silt)
Combination of Silty /Clayey
Sand. Sandy SHVCby, with
Lenses of Silt and Clay
Asphalt
Water Level
14Q_
ft below"
surface
Site Conditions
• McClellan Air Force Base occupies nearly 3,000 acres and is located approximately 7 miles northeast of downtown
Sacramento. Land use immediately adjacent to the base includes residential areas supplied by private well water for
nonpotable uses. (Connection of residences west of the base to municipal rather than private water supplies was a
remedial action initiated by the base in the late 1980s.)
• Topography is generally flat and sloping gently from the east side at 75 ft mean sea level (MSI) to the west side at 50 feet
MSL.
• Climate is characterized by hot, dry summers and cool, moist winters with average annual temperature of 60° F and
precipitation of 17 inches.
• Regional groundwater levels have dropped over 60 ft in the last 50 years, including a drop rate of 1.5 to 2 ft/yr for the past
10 years, due to pumping for agricultural irrigation, domestic use and base use.
Key Aquifer Characteristics
• The groundwater subsurface has been divided into five distinct monitoring zones (A, B, C, D and E) layered atop one
another. However, there is strong evidence that the units are hydraulically linked. Each of the highly heterogenous zones
have similar water levels, flow directions, vertical gradients and concentrations of inorganic species.
• Groundwater quality is characterized as a calcium-sodium-bicarbonate type excellent for irrigation and domestic use.
• Flow direction is mainly south in OU B/C in the A, B and C zones and is significantly influenced by a base water supply
well in OU B. The supply well draws water at a rate of 1200 GPM from several screened depths up to 400 ft.
• Other key aquifer parameters have been estimated as
Zone A B C
Transmissivity (ft2/day)
Hydraulic Conductivity (ft/day)
Zone Thickness (ft)
100-900
2.8-25.7
35
250-500
3.8-7.7
65
500-2,000
7.7-30.7
65
Other physical characteristics of the aquifer materials were measured during a series of basewide remedial investigations:
Parameter Range
Organic carbon content, foe:
Moisture content, wet percent:
Porosity:
Bulk density, g/cm3:
0.001 to 0.003
0.25 to 0.25
0.35 to 0.45
1.2 to 1.3
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McCtellan OU B/C - Page 4 of 12 —
I TREATMENT SYSTEM
l Overall Process Schematic
Extraction Well Network
7 extraction wells within OU B/C
pump water to a centralized
treatment plant
2 wells pump water to a small
treatment unit within OU B
Extraction Well Network
Treatment Plant and Permitted Discharge
Vapor Phase
Air
Stripper
Aqueous Phase
The main treatment plant with a
capacity of 1000 GPM treats an
average flow rate of 250 GPM by
air stripping
Caustic
Scrubber
GAG GAG
Offgases are thermally treated and
scrubbed before release to the atmosphere.
Liquid effluent is polished by granular
activated carbon (GAG) before discharge
to a nearby stream.
300 LJ
Extraction
Wed
Screened Interval
of Monitoring Well
in Feet Below
Surface
EW
Extraction Well Identification Number
- Groundwater Monitoring Zone
Screened by Well
*?JK— Typical Extraction Rate in GPM
(based on Dec. 1993 data)
U.S. Air Force
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Extract/on Well Detail
4' Steel Protective
'Gating with Locking Cap
M M
Cheek Valve Gate Valvo
•tToGroundwater
Holding Tank
4'-4' Concrete Apron
Mild Stool Conductor Gating
2' PVC Sounding Tuba
Gravel Cating Support
V-4' Steel Discharge Pipe
6-5/8'Mild Steal Casing
2* to 21/2* Annular Grout Seal
Bantonita Seal
6-5/8' Stainless Steal Casing
•fl 1 - Clean Sand Pack
6-5/8' Slotted Screen
Submersible Pump
Stainless Steal Bottom Cap
Design Evolution
< McClallan OU B/C - Page 5ol12 —
The GWTP has undergone several significant redesigns. The
current configuration presented below reflects changes made to
minimize scaling problems in the configuration of heat exchangers
as well as to accommodate lower influent flow rates and VOC
concentrations. The configuration shown has been used for all but
few months of the GWTP operation. Specific design changes
have included:
• Introduction of recycle loops to allow air shipper operation at
lower than originally anticipated flow rates. The original design
was based upon an influent stream of 1000 GPM while actual rates
have ranged from 100 to 250 GPM.
• Reduction in maximum system water temperature from 188°F to
120°F as a result of improved internal recycling of aqueous
streams.
• Replacement of carbon steel air-water heat exchanger with
nickel-based commercial alloy equipment to decrease
susceptibility to corrosion from acid gas condensation.
• Rearrangement of heat exchange network to reduce
susceptibility of scaling from precipitation of calcium and
magnesium salts.
• Replacement of air stripping packing material to a medium with
larger void space to reduce susceptibility of fouling from scaling
buildup.
• Elimination of activated sludge treatment process for kerosene
removal, which followed the granular activated carbon (GAG)
treatment, once influent ketone concentrations fell below detection
limits.
I Treatment System Schematic
u
Incinerator
(natural gas fired,
1800°F operating temperature.
2 second residence time,
7* diameter, 14'length)
From
Extraction
Wall '
Network
Influent Storage
Tank
Primary Water/Water
Heat Exchangers
(4 In parallel)
Air/Water
CHeat
ixch anger
High Temperature
- AirStnpper
,25:1 air water
rate ratio.
Secondary Water/Water
Haat Exchanger
. Caustic Scrubber
for Hydrochloric Acid
Gas Removal
(371 tall, 16'of packing)
GAC Treatment Unite
(each hold* 20,000 IDS
ol carbon,
10'diameter, 10'height
carbon usage rate ol
0.4 lb/1000 gal of water
Magpie Creak
NPOES Permitted
Discharge
• The plant operates 24 hours/day, 365 days/year and is staffed by 4 full time employees working two 12 hour shifts and 1
part time secretary. At least one operator is on duty at all times.
• The plant has full spare backup pumps and blowers and backup GAC and heat exchange capacity at low flow rates.
• GWTP II which operates within OU B is a simple arrangement of two groundwater extraction wells pumping approximately 2
GPM each through a double-contained pipeline equipped with a leak detection system to a holding tank. The groundwater is
then pumped through a bag filter and treated by two GAC adsorption units in series.
U.S. Air Force
132
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• McClellan OU BfC - Pag* 6 of 12 —
I PERFORMANCE
• Performance Objectives
A primary objective of the GWTP and its associated extraction well network within OU B/C is to limit
the offbase subsurface migration of contamination plumes beneath the OU.
Additional groundwater operable unit priorities include:
• Control of concentrated areas of contamination or hot spots.
• Remediation of contamination between the hot spots and plume boundary.
The remediation strategy for OU B/C includes:
Ongoing
Pumping and treatment of groundwater to prevent further migration of pollutants. This effort is the
focus of this analysis.
Future
• Continued implementation of existing technologies and possible upgrade to accommodate
higher flow rates of contaminated groundwater from other areas on the west side of the base.
A similar treatment plant is proposed as a remedial alternative for the east side.
• Incorporation of innovative technologies within current efforts particularly to address hot spot
(>500 ug/L VOCs) areas. These technologies include in situ anaerobic biodegradation, soil vapor
extraction with air-sparging, cometabolic treatment, and dual-phase extraction.
Operational Performance
As of January 1994 the GTWP had treated over 660 million gallons of groundwater since startup
in March 1987.
During 1993 the GWTP:
• Treated over 73 million gallons of groundwater
• Was online 98% of all available time
• Experienced 2 major repairs
• Experienced 9 minor repairs
• Consumed 2.2 million ft3 of natural gas, 200,000 kwhrs of electricity, approximately 650 gallons
of sodium hypochlorite, and over 50 gallons of sodium hydroxide
GWTP II had processed a total of 7.9 million of groundwater as of January 1994 and had only one
minor repair during 1993 which allowed for a 98% total system uptime percentage.
U.S. Air Force 133
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Hydrodynamic Performance
• Within OU B the five existing extraction wells
pump water either to the GWTP or the local carbon
treatment unit (GWTP II). In addition, a base water
supply well is located within OU B and creates a
radius of influence of approximately 500 to 700 ft in
the A and B zones and a slightly higher influence in
the C zone due to a larger screened interval.
• The four extraction wells in OU C capture
approximately 90 GPM from the A, B and C zones
but do not contain the known groundwater
contamination areas.
• McClellan OU B/C • Page 7 of 12 —
Capture Zones
Estimated from 1993
monitoring well data
Extent of Capture in the
B-Monitonng Zone
Extent of Capture in the
C-Monitonng Zone "
Base Water Supply Well (EW-18)
• The concentrations of contaminants in the GWTP influent
has varied over short time periods but has exhibited a
significant downward trend since startup.
• Influent VOC concentrations wore approximately 60 ppm in
1987 and have decreased to approximately 4 ppm.
• The GWTP has consistently removed VOCs to below
established discharge criteria for primary contaminants since
startup.
• Over 44,000 Its of VOCs have been removed since startup.
\
Concentration Ippm]
9 9 $ $ $ 9 §
I
1
H*v~_
987 19'88 19'89 1990 1991 1992 1993
r Effects on Plume
Close-up of OU B/C area identified on page 2.
• A comparison of individual monitoring well data from
1986 to 1993 was performed to determine trends in
VOC concentrations.
• Monitoring Zone A: Most wells exhibited static
trends. There is no observable overall trend for OU B
wells. More wells within OU C than OU B exhibit
increasing trends which may indicate continued
contaminant release from the vadose zone to OU C.
• Monitoring Zones B through D: Most data is static
which may suggest that groundwater impacts within the
deeper zones are equilibrated. OU B data within the B
and 0 zones presents much uncertainty. Zone C
shows more increasing wells which, in the case of OU
C, may represent preferential migration from other OUs.
i— Legend
Wells with constant risk values
Wells with increasing risk values
Wells with fluctuating risk values
Wells with decreasing risk values
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McClellan OU SC - Page 8 of 12 —
COST
• The groundwater extraction and treatment system at McCleilan was built in several phases from
the late 1980's to early 1990s. The data below was provided by McClallan personnel based upon
available records. Pump and treat efforts have removed over 42,000 pounds of VOCs at the base
as of March 1994. This corresponds to dollars per pound removal rates of approximately $80/lb
VOC based on operating costs alone (based upon an analysis done with first year operation data)
and approximately $150/lb VOC including treatment system direct costs. Cost bases and
assumptions are detailed below:
• Capital Costs
Direct Coats
Incinerator $300.000
Air Stripper 400,000
Scrubber 300,000
Water to Water Heat Exchanger 200,000
Gas to Water Heat Exchanger 50,000
Gas to Gas Heat Exchanger 50,000
Electric Motors (6) 180,000
Blowers (2) 40,000
Pumps (6) 180,000
GAC Tanks (4) 360,000
Water Holding Tank 40,000
Berm and Foundation 150,000
Air Compressors (2) 60,000
Water Pipes to Plant 300,000
Wells and Pumps (10) (a) 300,000
Control Center and Trailer 80,000
Control Center External 60.000
Subtotal Direct Costs 3,090,000
Indirect Costs 910,000
Total Capital Cost In 1987 (b) $4,000,000
Operating Costs
Contractor Operations
Labor $300,000
Operation Support 350,000
Reimbursables 200,000
Other Direct Costs 150,000
Utilities
Electricity for Extraction Wells 30,000
Electricity for Treatment Plant 50,000
Natural Gas 40,000
Sampling and Analysis 40,000
McClellan Staff Labor 80.000
Total Annual Operating Costs $1,240,000
(a) Three additional extraction wells were added within the OU B in 1990. McClellan estimates the cost of developing and
extraction well at the site to be approximately $100,000.
(b) The small treatment plant within OU B was constructed in 1991 for a total cost of approximately $1,000,000 broken
down as follows (Numbers taken from an estimate prepared while construction was ongoing and all values rounded to the
neared multiple of $5,000):
Dlnct Costs
Extraction/Monitoring Wells
Piping and Fittings
Pumps
Holding Tank
GAC Treatment Units
Discharge Piping and Fittings
Contaminated Soil Disposal
Site Work (@25%)
Piping/Valving (@5%)
Instrumentation (@5%)
Controls (@5%)
Electrical (@15%)
$145,000
55,000
10,000
15,000
60,000
5,000
95,000
100,000
20,000
20,000
20,000
60,000
Indirect Costs
Contingency (@5%) 30,000
Fees (@ 15) 90.000
Construction Management (@15%) 90,000
Startup (@ 10%) 60,000
Sampling (@ 10%) 61,000
The yearly operating costs of the system is approximately $70,000 and is largely for GAC replacement
U.S. Air Force
135
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' McClellan OU fiHC - Page 9 of 12 —
REGULATORY/INSTITUTIONAL ISSUES
• The GWTP currently has a National Pollution Discharge Elimination System (NPDES) which permits a
0.36 MOD discharge with a total allowable discharge of 1.45 MGO (30-day average) from additional
groundwater extraction systems.
• The NPDES permit for the GTWP sets forth sampling requirements and limitations for discharge into
Magpie Creek, an onbase stream. The primary treatment requirements are that the plant remove
acetone, methyl ethyl ketone and methyl isobutyl ketone to less than 1 mg/L, and remove all other VOCs
to less than 0.5 ug/L.
• Air permits from the Sacramento Metropolitan Air Quality Management District require sampling and
specify certain operation conditions and procedures. A risk assessment of the facility was performed as
part of the permitting process
• McClellan AFB has developed positive working relationships with federal and state environmental
regulators which has facilitated planning and implementation of remedial measures.
• McClellan AFB has extensive ongoing public involvement programs which have been instrumental in
overcoming initial apprehensions about the GWTP.
I— Cleanup Criteria
• While final cleanup criteria have yet to be determined for groundwater beneath
Operable Units B and C, treatment requirements mandate removal of the principle VOCs
of concern to less than 0.55 ug/L. The base and regulators are currently evaluating
cleanup scenarios based upon remediation to Maximum Contaminant Levels (MCLs),
lifetime individual cancer risk levels less than 1E-6 (more stringent), or background levels
(most stringent).
SCHEDULE
Major Milestones
1986
1987
1986
1989
1990
1991
1992
1993
1994
U.S. Air Force
136
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> McClellan OU B/C - page 10 of 12 —
LESSONS LEARNED
Design and Implementation Considerations
• Major changes in the quantity of extracted groundwater and changes in VOC influent concentrations havo
necessitated changes in GWTP design/and operation. Currently the plant has excess treatment capacity requiring
internal recycle of groundwater to sustain efficient treatment which raises operating costs. These and other process
changes have optimized performance at lower flow rates.
• Existing extraction systems at McClellan capture a small portion of the groundwater contamination present at
the site. The system must be significantly expanded to create a zone of capture encompassing other known
areas of contamination. The success of the existing design has established it as a candidate system of choice
for future remediation efforts.
• Scaling and deposition within the air stipper from precipitation of calcium and magnesium salts affected initial
operation. The problem was minimized by substituting 2 inch packing for 1 inch packing in the air stripper.
• Corrosion was observed in the hot vapor train due to condensation of acid gases. The problem was minimized
through both substitution of materials of construction from carbon steel to nickel-based commercial alloys and
changes in physical layout which reduced turbulence, improved laminar flow and eliminated stagnant regions.
Technology Limitations
• Influent concentrations to the treatment plant have shown a significant downward trend since startup, however,
that trend has stabilized in recent years. Groundwater monitoring data largely exhibits static trends in VOC
concentrations despite the removal of over 40,000 Ibs of VOCs from OUs B/C and OU D.
• Among the organic compounds being treated, acetone is the only compound that the air stripper has had difficulty
removing because of its solubility in water. Biological treatment was initially required but has been discontinued
after acetone was no longer encountered in the GWTP influent.
• Pump and treat efforts at McClellan must be augmented with vadose zone source area remediation efforts so that
continued seepage of contamination into groundwater does not require indefinite pump and treat operation.
Future Technology Selection Considerations
• Pump and treat efforts have been successful at containing further migration of contamination. Only low
concentrations of VOCs are anticipated to migrate beyond the established zones of control.
• The above ground treatment system has been effective at consistently reducing VOC levels below discharge
criteria.
• The air stripper/incinerator/scrubber treatment train has proven to both efficient and effective.
• Although incineration has proved to effectively treat VOCs from the air stripper off gas, feasibility studies for future
treatment capacity at McClellan consider catalytic oxidation and vapor-phase granular activated carbon as
additional options for handling air stripper offgas. Vapor-phase granular activated carbon is considered to
generate less community acceptance problems and would reduce permitting complexity.
• The use of activated charcoal is cost effective for treatment of low water flow rates in the range of 2 to 10 GPM
which generally corresponds to a carbon replacement occurring every three years. For relatively high flow rates,
such as 200 GPM, and VOC contamination in excess of 10 ppm, charcoal alone is not cost effective due to the
high frequency of carbon replacement.
• Ongoing feasibility studies at McClellan have identified air stripping and liquid granular activated carbon as the
preferred groundwater treatment technologies for the east side of the base. These would be implemented along
with demonstration and evaluation of innovate technologies primarily targeting hot spots.
U.S. Air Force 137
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' McClellan OU B/C - Page 11 of 12 —
ANALYSIS PREPARATION
This analysts was prepared by:
Stone & Webster Environmental A
Technology & Services Arv\
245 Summer Street
Boston, MA 02210
Contact Bruno Brodfeld (617) 589-2767
for:
US Army Corps of Engineers
Omaha District
This analysis was funded by:
U.S. Air Force
Headquarters USAF/CEVR
CERTIFICATION
This analysis was prepared in cooperation with and was reviewed by McClellan personnel.
Critical assistance was provided by Badrul Hoda and Alec Elgal.
U.S. Air Force
138
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McCleltan OU B/C - Page 12 of 12 —
SOURCES
Major Sources For Each Section
Site Characteristic*:
Treatment System:
Performance:
Cost:
Source #s (from list below) 1, 4, 5, 6 and 7
Source #s 1,3. 4, 5, 6, 7and8
Source #s 1, 2, 3. 4,6 and 7
Source #s 1 and 7
Regulatory/Institutional Issues: Source #s 4 and 8
Schedule:
Lessons Learned:
Source *s 1, 3, 4, 5, 6and7
Source #s 2, 4 and personal communications with Alec Elgal, McClellan AFB (916) 643-0627
Chronological List of Sources and Additional References
1. Data Package provided by Alec Elgal, Environmental Restoration Division, Environmental Management Directorate, McClellan
Air Force Base, February - April, 1994.
2. Personal Communications with Alec Elgal, Environmental Restoration Division, Environmental Management Directorate,
McClellan Air Force Base, May-June, 1994.
3. GWTP Weekly Reports, prepared by Mefcalf and Eddy Services for McClellan Air Force Base, through 10 January 1994.
4. Draft Copy. Groundwater Operable Unit Remedial Investigation/Feasibility Study Report, prepared by CH2M Hill for McClellan
Air Force Base, November 1993.
5. Basewide Groundwater Operable Unit, Groundwater Well Specific Data Report, prepared by CH2M Hill for McClellan Air Force
Base, 1993.
6. Preliminary Groundwater Operable Unit Remedial Investigation (PGOURI), prepared by Radian Corporation for McClellan Air
Force Base, September 1992.
7. Operable UnitB, Engineering Evaluation/Cost Analysis, prepared by Radian Corporation for McClellan Air Force Base,
October 1990.
8. Operation and Maintenance Manual, McClellan Air Force Base Groundwater Treatment Facility, prepared by Metcatf and Eddy
for McClellan Air Force Base, Undated.
U.S. Air Force
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Pump & Treat of Contaminated Groundwater at
Twin Cities Army Ammunition Plant,
New Brighton, Minnesota
(Interim Report)
140
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Case Study Abstract
Pump & Treat of Contaminated Ground water at
Twin Cities Army Ammunition Plant, New Brighton, Minnesota
Site Name:
Twin Cities Army Ammunition Plant
(TCAAP)
Location:
New Brighton, Minnesota
Contaminants:
Chlorinated Aliphatics
- Contaminants of greatest concern in the
groundwater are: 1,1-DCE, 1,1-DCA, 1,2-
DCE, chloroform, 1,1,1-TCA, TCE, and PCE
- TCE is the most prevalent VOC on site, with
concentrations greater than 10,000 ppb in
groundwater
Period of Operation:
Status: Ongoing
Report covers - 10/87 to 9/92
Cleanup Type:
Full-scale cleanup (interim
results)
Vendor:
Not Available
SIC Code:
9711 (National Security)
Technology:
Groundwater Extraction followed by Air
Stripping
- 12 boundary recovery wells and 5 source
area recovery wells
- Air stripping plant designed to treat 2,900
gal/min; 4 towers - 2 @ 7 feet diameter and
2 @ 8 feet diameter; all 36 feet tall with
propylene packing
- Treated water discharged to a sand and
gravel pit, or, alternately to an elevated tank
- Designed for an operating life of 30 years
Cleanup Authority:
CERCLA
- ROD Date: 10/88
Point of Contact:
Remedial Project Manager
Twin Cities Army Ammunition
Plant
New Brighton, MN
Waste Source:
Other: Variety of Waste Disposal
Practices, including Discharges to
Sewer, Dumping, and Burning
Purpose/Significance of
Application:
Pump and treat of large-volume of
groundwater contaminated with
VOCs.
Type/Quantity of Media Treated:
Groundwater
- Over 1.4 billion gallons of water pumped from 10/91 to 9/92
- Complex hydrogeology and heterogeneities in a multilayer aquifer system
- Fractured bedrock and discontinuous sand, clay, and till layers
- Hydraulic conductivity 0.001 to 137 ft/day; transmissivity 3,160 to 28,724 ftVday
Regulatory Requirements/Cleanup Goals:
- Several RODs apply to overall TCAAP remedial program, including a ROD for groundwater remediation
- Target cleanup criteria focus on residual levels of contamination in groundwater and containment of existing plume
- Target cleanup levels in groundwater include: TCE - 5 ppb; PCE - 6.9 ppb; 1,2-DCE - 70 ppb; and 1,1,1-TCA - 200 ppb
141
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Case Study Abstract
Pump & Treat of Contaminated Groundwater at
Twin Cities Army Ammunition Plant,
New Brighton, Minnesota (Continued)
Results:
- Boundary Groundwater Recovery System (BGRS) recovered an average of 23 pounds of VOCs per day
- TCAAP Groundwater Recovery System (TGRS) recovered 19,510 pounds of VOCs in one year of operation
- Historical total of 92,700 pounds of VOCs recovered in 6 years of operation (BGRS and TGRS)
- Plume containment successful at site
- VOC plumes changed little after several years of treatment; estimate of remediation time increased to achieve a
concentration of 17 ppb TCE in 50 to 70 years
Cost Factors:
- Capital costs - $8,034,454 (including construction of treatment plant, wells, force main and pump houses, startup,
engineering, and project management)
- Annual operating costs - $588,599 (including power, labor, maintenance, laboratory charges, and replacement of tower
packing)
- Total Life Cycle Costing estimated as $0.30 per 1,000 gallons of water treated
- Total cost of operation and maintenance calculated as $0.12 per 1,000 gallons of water treated
Description:
The Twin Cities Army Ammunition Plant, established in 1941, has been used for the production and storage of munitions.
The site includes 7 major production buildings and over 300 auxiliary buildings. A series of hydrogeological investigations
beginning in 1981 revealed elevated levels of VOCs in groundwater; 14 separate source areas have been identified at the
site. Trichloroethene (TCE) has been measured at concentrations over 10,000 ppb in the groundwater. Target groundwater
cleanup levels were established for four constituents - TCE, PCE, 1,2-DCE, and 1,1,1-TCA.
Groundwater extraction followed by air stripping has been used at this site since October 1987 to treat contaminated
groundwater. The groundwater extraction system includes 12 boundary recovery wells and 5 source area recovery wells.
Extracted groundwater is treated using four 36-feet tall air stripping towers. An estimated 92,700 pounds of VOCs have
been recovered in 6 years of system operation. Although plume containment has been successful at the site, the plumes have
changed little after several years of treatment.
An estimate of the time required for remediation has been revised from 30 years to 50 to 70 years, based on a review of
data collected to date. Capital costs for this application were $8,034,454, and annual operating costs are $588,599.
142
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TECHNOLOGY APPLICATION ANALYSIS
Page 1 of 12 =
• TECHNOLOGY APPLICATION
Twin Cities Army Ammunition
Plant (TCAAP)
ACERCLA Site
New Brighton, Minnesota
This analysis covers an effort to pump and treat
groundwater contaminated with volatile organic
compounds (VOCs) by above ground air stripping.
The treatment began in October 1987 and is currently
ongoing. This analysis covers performance through
September 1992.
• SITE CHARACTERISTICS
•• Site History/Release Characteristics
• TCAAP is an approximately 4 square mile facility established in 1941 which primarily produced and stored munitions
during the periods of 1941 to 1957 and 1966 to 1976. The site includes 7 major production buildings and over 300 auxiliary
buildings. Most of the site is now in caretaker status, however, current lessees manufacture ammunition and other products.
• A series of hydrogeological investigations which began in 1981 revealed elevated levels of VOCs in groundwater.
Fourteen separate source areas have been the focus of detailed site characterization and various remediation efforts.
• Contamination resulted from a variety of past waste disposal practices such as sewer disposal, dumping and
burning which released process wastes, oil and grease, heavy metals and solvents to the environment.
• In October 1987 a Boundary Groundwater Recovery System (BGRS) started operation. An expanded system, the
TCAAP Groundwater Recovery System (TGRS), began operation in January 1989. Additional smaller scale groundwater
remediation efforts were implemented at the plant. Remedial actions were also conducted outside of the plant boundaries.
This analysis will focus upon the performance of the BGRS and TGRS up through September 1992,
Contaminants of Concern
Contaminants of greatest concern in the
groundwater are:
1,1 -dichloroethylene
1,1-dichloroethane
cis-1,2-dichloroethylene (1,2-DCE)
chloroform
1,1,1-trichloroethane(1,1,1-TCE)
trichloroethylene (TRCLE)
tetrachloroethylene (TCLEE)
TRCLE, the most prevalent VOC on site, is the
target compound used to measure system
performance.
•i Contaminant Properties
Properties of contaminants focused upon during remediation are:
Property at STP*
Empirical Formula
Density
Vapor Pressure
Henry's Law
Constant
Water Solubility
Octanol-Water
Partition
Coefficient; KQW
Organic Carbon
Partition
Coefficient; KOC
Units
g/cm3
mmHg
TRCLE
cotca
1.46
73
atn'nV/tTDle 9.9E-3
mg/L
1000-1470
195
66
*S7P= Standard Temperature and Pressure;
TCLEE
2 02C=CCl2
1.62
19
2.9E-3
15&485
126
209
1atm.2S°C
12OCE
CHCfed-fct
208
-
3500
5
•
1,1,1-TCE
1.31
124
1.6E-2
300-1334
148
105
! Nature & Extent of Contamination
• Characterization of the nature and extent of contamination at TCAAP slowly evolved over several years of monitoring
and treatment. In the mid 1980s it was known that a plume beneath the site had TRCLE concentrations as high as 3600
ppb (later analyses revealed levels over 10,000 ppb) as well as 1,2-DCE and 1,1,1 -TCE levels of 160 and 950 ppb respectively. After
installation of the BGRS, TGRS and associated monitoring wells more detailed plume delineation became possible.
• A plume extends over six miles downgradient (southwest) of the site; no contamination has been detected immediately
upgradient of the site.
• Contaminants have been found to be fairly mobile in most geologic strata.
US Army
Environmental Center
143
-------
• Contaminant Locations and Geologic Profiles ••••
Remedial investigation field activities at the site have included:
• soil gas surveys
• surface soil sampling
• soil trenching and sampling
• soil boring installation and sampling
• groundwater well installation and sampling
• geophysical investigations (electromagnetic induction and
ground penetrating radar)
Data from hundreds of soil borings and groundwater monitoring wells has
allowed the development of numerous two-dimensional contour diagrams
illustrating the upper and lower surface areas, groundwater elevations, and
contaminant concentration profiles for various geologic units. Portions of
some of these diagrams have been included here to provide a general
conceptual understanding of site conditions.
Recent (1992) data is used in these diagrams. Earlier plume delineation
efforts were based upon less complete data sets. It is currently assumed that
the plume outline has not changed significantly over the past several years.
TRCLE Plume fSide View)
Groundwater monitoring data from Spring 1992 along cross-section A-A' shown in top view
1 Twin Cities - Page 2 of 12 •
TRCLE Plume (TOO view)
Groundwater
monitoring data
from Spring 1992
(upper Unit 4
hydrogeologic until
- TCAAP Boundary
10,000ft
Vertical exaggeration - 25X
r-1000
-900
-800
III
s
^-700 \
o
-600
-500
I— Legend ——
„ . . UM I Screened portion of EU1-10Pf* H100-1,000 ppb
•"conception. TVE Lowell Q10-100 PpbBB 1^00-10,000 ppb
Concentration I •>10,000ppb
Hydrogeologic Units
Four distinct hydrogeologic units have been identified beneath TCAAP and
the surrounding regions:
Unit 1 New Brighton & Discontinuous recent alluvium and lacustrine
Fridley Formations deposits; discontinuous local water table aquifer;
0-50 ft thick
Unit 2 Twin Cities
Formation
Unit 3 Hillside Sand
Discontinuous glacial till; acts as aquitard with some
water bearing sand and gravel lenses;
0-150 ft thick
Overlain by Arsenal sand which forms kame in center
of TCAAP; aquifer arbitrarily subdivided into upper
middle and lower parts for monitoring;
25-450 ft thick
Unit 4 Prairie du Chien & Dolomite bedrock aquifer; 0-250 ft thick •
Jordan Sandstone Sandstone bedrock aquifer; 0-100 ft thick
,-TCAdP Boundary
US Army
Environmental Center
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Twin Cities - Page 3of12 >
Site Conditions
• Surrounding region characterized by a continental climate with average yearly temperature of 44°F, rainfall of
25 inches, and snowfall of 40 inches.
• Topography at TCAAP ranges from 880 ft MSL at Rice Creek on the western edge to 1,000 ft MSL at the kame in the
center of the site.
• Groundwater flow is generally to the west and southwest.
• The site possesses a complex hydrogeology arising from heterogeneities in the multilayer aquifer system, fractured
bedrock, and discontinuous sand, clay and till layers.
Key Aquifer Characteristics
Aquifer parameters along the southwest TCAAP boundary have been estimated as:
Unit
Approximate Hydraulic Transmissjvity
Thickness Conductivity _
M
Flow Direction
Unit? New Brighton and 10 0.007-22
Ridley Formations
Unit 2 Twin Cities Formation 63 0.001-0.01
Unit 3 Hillside Sand 156 137 21,424
Unit 4 Prairie du Chien 37 85 3,160
Unit 4 Jordan Sandstone 90 46 4,140
Bulk Flow for Units 3 and 4 283 - 28,724
Recent alluvium. Reflects surface topography
Low conductivity aquitard; groundwater moves slowly
downward to Unit 3
Generally horizontal and directed southwest and west;
vertical gradient is downward and is <0.005
Generally horizontal and directed southwest and west
Generally horizontal and directed southwest and west
• A wide range of values has been used to describe regional aquifer characteristics. Uncertainties stem from
difficulties in aquifer testing and interpretation methods applied to the hydrogeological complexities noted above
under Site Conditions.
• Groundwater along the southwest TCAAP boundary is unconfined but becomes confined to the west and north.
The confining boundary may change throughout the year due to seasonal groundwater table fluctuations.
US Army
Environmental Center
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• TREATMENT SYSTEM
' Twin Cities - Page 4 of 12 <
Overall Process Schematic
Extraction Well Network
12 Boundary recovery wells and 5
source area recovery wells
installed in two stages (first BGRS,
then TORS)
[detailed below]
Extraction Well Network
Treatment Plant
Air stripping plant treating
2900 GPM
[detailed on next page]
Forcemain & Discharge
w
Sand & Gravel
Pit
Elevated Tank
16" cement lined 150 psi
pressure tested ductile iron pipe
buried 7-10 ft below grade.
Primary discharge point is a
sand and gravel pit having
extensive erosion protection.
Alternate discharge to an
elevated tank.
Air Stripping
Treatment Plant
B12 160
7CAAP
* -^ _ - Discharge
to Sand &
Gravel Pit
Piping
Forcemain
^
I
*V3
P
II
5 E
.*_!
i \
1 .
1 1 Mile
1 Vertical exaggeration - 1 3X
i< SC3 100
\< SC245
SC4 45
SC5 100
SC1 40
= Screened
= portion of
= groundwater
= monitonng well
= in Umt3
=
6 Screened
B1200
6 portion of Jf ^L
X groundwater s N
Z rnonitonng well We|( Extraction
gin Unit 4 Designation Rate in
4
O BGRS Extraction Well
[B*Boundary GPM
SO*Source Control]
^ TGRS Extraction Well
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> Twin Cities - Page 5 of 12 —
Extraction Well Close-Up
Key Design Criteria
Typical Unit 3 Extraction Well
(Well Shown is B1)
Depth
ro
•25
•50
•75
-100
-125
-150
175
Lockable
Cap
Surface
14'Surface
Casing
Bentonite
Cement
Bentonite
Pellets
Groundwater
Table
14* Borehole
8* Stainless
Steel Screen
Natural Pack
Operating life of 30 years (estimated remediation time).
Handle maximum flow rates throughout system.
Discharge to multiple points.
Handle changes in flow rates.
Operate with portions of system shut down.
Minimal operating labor requirements.
Key Monitored Operating Parameters
— (to assess system operation)
Water flows
Airflows
Pump discharge pressures
Automated processes —'
Groundwater levels
(to assess zone of capture)
Contaminant concentrations in treatment plant influent & effluent
(to assess treatment effectiveness)
Contaminant concentrations in groundwater
(to assess achievement of remediation goals)
• Each well equipped with
pumphouse and originally
developed through air lifting
and water jetting.
i Mr Stripper System Schematic
From
Extraction
Wells
To
atmosphere
To To To
atmosphere atmosphere atmosphere
7 ft diameter
3/16* stainless
steel tower
(Towers 344
are 8 ft dia.)
To
2900gpmf-»» Discharge
Points
• Tower 4 was added for the TGRS arrangement. Previously, the BGRS system split 1200 gpm
between Towers 1 and 2 with discharge from both going to Tower 3.
• Air compressor ratings represent minimum operating levels.
• Drawing not to scale.
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Environmental Center
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Twin Cities • Page 6 of 12 •
PERFORMANCE
Performance Objectives
• Achieve cleanup goals including TRCLE concentrations of 5 ppb in groundwater (other criteria
detailed within Regulatory/Institutional section).
• Prevent migration of contaminants off the TCAAP site.
• Design and operate treatment system such that its zone of capture contains the plume within the
TCAAP boundary.
Treatment Plan
BGRS Startup
A phased approach was utilized to implement an overall TCAAP groundwater remediation program:
• Installation of BGRS
• Execution of a Performance Assessment Review (PAR) evaluating the
first 90 days of BGRS operation.
• Recommendations from the PAR used to develop criteria for the TGRS.
• Installation of the TGRS.
90-Day Review
1-Year Review
• Further modifications to the system identified through yearly monitoring
and performance assessment reports.
. TGRS Startup
Initial Process Optimization Efforts
BRGS Performance Assessment
Conclusions drawn after 90 days of BGRS operation and confirmed
by 1 year of operating experience included:
• A substantial portion of Unit 3 & 4 groundwater and VOC plumes were
captured based upon observed drawdowns.
• The treatment system processed an average of 23 Ibs of VOCs/day
(range of 17 to 29 Ibs/day).
• VOC plumes showed little variation during treatment.
• Treated effluent satisfied contaminant specific requirements established
in the Record of Decision (ROD) for interim measures.
• Air emissions met ROD requirements and were not detected upwind or
downwind of the BGRS.
• The TGRS expansion should include four Unit 4 and two Unit 3 boundary
extraction wells and four Unit 3 source control extraction wells and
corresponding increases in flow handling and treatment facility capacities.
Annual Reviews &
System Modifications
r-TGRS Performance Assessment -
Conclusions drawn after 1 year of
TGRS operation included:
• Hydraulic capture extended beyond the
5 ppb TRCLE contour at the TCAAP
boundary in both Units 3 & 4.
• The TGRS extracted and treated
19,510 Ibs of VOCs.
• VOC plumes showed little variation
during treatment.
* Treated effluent satisfied contaminant
specific requirements established in the
ROD for interim measures.
Operational Performance
— Volume of Water Pumped
• From Oct 1991 through Sept 1992 over 1.4
billion gallons of water were pumped from the
17 different extraction wells; monthly flow
rates ranged from 112 to 123 million gallons.
• During this period 112% more water was
pumped than was previously determined to
be necessary to maintain a capture zone
encompassing the VOC plume.
r System Downtime
• The TGRS was operational 98% of
the year ending Sept '92; this
performance represented a slight
improvement over '90 and '91 and a
significant improvement over '89.
• A preventive maintenance program
was instrumental in reducing system
downtime.
pauses of downtime 10/91 to 9/92:
Repair to pumphouse 1.0 day
Repair to treatment plant 0.9
Preventive maintenance 0.1
TCAAP power system failures 4.2
Total 5-2 day*
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Environmental Center
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' Twin Cities - Page 7 of 12 >
Hydrodynamic Performance
' The zone of capture created by the TGRS extends
beyond the 5 ppb TRCLE contour along the entire
southwest TCAAP boundary. There is some ongoing
debate among parties at TCAAP concerning the extent to
which any part of the onsite contaminant plume may be
breaking through the system of boundary extraction wells.
• The horizontal extent of capture is nearly identical
throughout Units 3 & 4.
• Groundwater contours were manually constructed due
to the complexities of the flow field and were based upon
elevation measurements, pumping test analyses,
drawdown analyses and vertical gradient analyses.
-Lvyeiiu
O Extraction well
QMOppb |
[£]]10-100 ppb |
1 100- 1,000 ppb
g>1,000ppb
850
Groundwater^
elevation
contour line
Treatment Performance
r Effects on Plume
• VOC levels appear to have been
reduced near source areas. Interim
measures on soil may be the cause.
• Overall, VOC plumes have changed
little. The plume configurations identified
in 1992 are similar to those identified
earlier. Original estimates of a 30 year
remediation time have been revised and
project achievement of 17 ppm TERCLE
concentrations in 50 to 70 years.
r TRCLE vs Time at Influent-
• The concentration of TRCLE in groundwater extracted from each
well and sent as influent to the air stripping plant:
has decreased over time for wells Bt, 82, 87, 610, 812, SCI, SC2
and SC3
has increased over time for wells B5, SC4 and SC5
has shown no clear trend for wells B3, B4, B6, 88, B9 and B11
• The trends may indicate plume redistribution and may also
represent a decline in plume strength.
• There has been no clear reduction in overall contaminant
concentrations sent to the treatment plant.
r- Influent vs Effluent
• Average TRCLE removal efficiency of 99.9%
• All VOCs, priority pollutants and metals treated
below ROD discharge criteria.
Influent
Lo Ave Hi
1200 16371900
bd bd 3
Compound
TRCLE
TCLEE
1,2-DCE
1,1,1-TCE 210 407 560
bd - below detection
Effluent
Lo Ave Hi
bd 0.62 1.3
bd bd bd
bd bd bd
bd bd bd
Total Pounds VOCs Removed
26700
24500
Historical
Total:
92,700lbs
BGRS BGRS TGRS TGRS TGRS TGRS
1987 1968 1989 1990 1991 FY 1992
• Wells located near the center of the plume (B1,84. BS, 66,
SC2 and scs) accounted for 95% of VOC mass removed.
• The five source control wells (SC1-5) removed 41% of
the VOCs while pumping only 12% of the groundwater.
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Environmental Center
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' Twin Cities - Page 8 of 12 <
COST
An economic evaluation of the TCAAP air stripping facility was performed in 1990. The evaluation
focused on determining (1) total capital cost, (2) operating costs and (3) significant cost elements.
In addition, the installed cost of the TCAAP facility was compared to two other groundwater air
stripping facilities using total life cycle costing (TLCC) analysis based upon treatment of 1,000
gallons of water over the life of each plant. The TCAAP facility compared favorably based on the
TLCC approach, however, theTCAAP system handled flow rates one order of magnitude larger than
the other facilities. The TLCC at TCAAP was estimated to be $0.30 per 1,000 gallons of water
treated. The total cost of operation and maintenance was calculated to be $0.12 per 1,000
gallons.
Other results of the evaluation are summarized below in 1990 dollars.
• Capital Costs
Construction of Treatment Plant
Construction of Wells (16 extraction, 48 monitoring
and 17 return wells)
Construction of Forcemain & Pumphouses
(17,600 ft buried pipe, 16 pumphouses)
Startup
Health & Safety (Medical monitoring of employees)
Engineering '
Project Management
Overhead & Profit
$774,757
1,026,406
2,386,712
358,220
110,125
1,575,710
928,267
874,257
•• Operating Costs
Power (@ $o.04/Kwhr) $148,846
Operating Labor 219,502
Maintenance Labor & Parts 150,054
Laboratory Charges 25,175
Other O&M Charges 39,518
Replacement of Tower Packing 5,504
($20,865 occurring every 5 years,
annualized at 10% interest)
Total Annual Operating Cost $588,599
Total $8,034,454
Cost Sensitivities
Significant cost elements were:
Capital
• Pumphouses (16) $775,964
• Extraction, monitoring & return well drilling (81) 399,633
• Stripping towers 296,821
• Extraction, monitoring & return well casings (81) 241,095
• Wet wells at base of stripping towers (3) 142,740
Operating
Operating Labor $219,502
Maintenance labor & parts 150,054
Electricity 148,846
US Army
Environmental Center
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• Twin Cities • Page 9 of 12
REGULATORY/INSTITUTIONAL ISSUES
_J
• BGRS construction was completed in April 1987 but startup was delayed until October 1987 due to administrative
delays in obtaining regulatory approval to operate.
• Extraction well B1 was relocated from the original design since access to private property adjacent to TCAAP was
denied.
• Groundwater in the New Brighton/Arden Hills area near TCAAP has led to abandonment of some municipal water
supplies and private wells and necessitated the provision of bottled water in some instances. Municipal wells near
TCAAP have added granular activated carbon treatment to meet water supply and remediation objectives.
• It is likely that the contaminant plume emanating from TCAAP has mixed offsite with plumes from other sources
complicating allocation of responsibility and coordination of remedial response plans. More evaluation is needed.
• Various responsible parties at TCAAP have hired different consultants to manage aspects of the remedial response.
In some cases, parties and their consultants have disagreed in their interpretations of environmental conditions and
the performace of treatment systems. Responsible parties are bound by past lawsuits by the City of New Brighton, the
City of St. Anthony, and 96 other plaintiffs.
• Regulatory oversight requires reporting any shutdowns or operational problems over 24 hours in duration and rapid
development of accompanying plans for correction.
~ Cleanup Criteria
Several Records of Decision (RODs) apply to the overall TCAAP remedial program. Target cleanup
criteria applicable to the BGRS and TGRS systems focus upon 1) residual levels of contamination in
the groundwater and 2) containment of existing plumes.
Applicable target cleanup levels for major contaminants indude:
Compound Criteria Level food! Compound
Criteria Level fpobl
TRCLE
TCLEE
5
6.9
1,2-DCE
1,1,1-TCE
70
200
SCHEDULE
BGRS & TGRS Installation History
1986 1987
1988
OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY
-H BGRS Extraction Well Installation
[« »(BGRS Return Well Installation
-*J BGRS Monitoring Well Installation
^ ROD for Groundwater Remediation Signed
+ BGRS Startup
|* »j 90-Day BGRS Study
90-Day Study Report Issued
1989
1990
JUN JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DECljAN
TGRS Startup
BGRS First Year Assessment Report Issued
1991
FEB
MAR
APR
MAY JUN JUL
AUG
SEP OCT
NOV DEC
JAN
FEB
MAR APR
TGRS First Year Assessment Report Issued
Continued TGRS Operation
'& Annual Report Issuance
4 Remedial Investigation Report Issued
US Army
Environmental Center
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i Twin Cities - Page 10 of 12 •
LESSONS LEARNED
Key Operating Parameters
Implementation Considerations
• An understanding of the nature and extent of contamination at the site evolved over several years of monitoring
and treatment. Phased design of the treatment system helped insure its proper sizing and effectiveness.
• Extensive efforts to quantify and model aquifer properties were of limited utility due to the presence of many
hydrogeological complexities.
• A preventive maintenance program was instrumental in increasing the operational performance of the
treatment facility.
Technology Limitations
• Original estimates of a 30 year treatment period have been extended. Minimum concentrations of target
contaminants are projected to be achieved after 50-70 years of treatment. Perpetual operation of the system
will be necessary to ensure continued containment of the VOC plume.
• As anticipated earlier, the technology is not expected to achieve the 5 ppb target cleanup level for TRCLE.
It is projected that levels of 17 ppb may be achieved after 50 to 70 years of operation. No alternative
technology or system enhancements have been identified to improve upon this performance to date.
• While plume containment appears to be successful, overall VOC plumes appear to have changed little after
several years of treatment. Influent concentrations of contaminants to the the treatment plant have exhibited no
clear downward trend. Extraction wells have experienced both increases and decreases in TRCLE
concentrations from extracted groundwater. However, only Interim measures have been taken thus far to
clean up source areas. Permanent solutions are scheduled to be implemented in the 1995-1997 time frame.
Future Technology Selection Considerations
• The zone of capture created by the treatment system encompasses the entire contaminant plume of
concern. There is some ongoing debate among parties at TCAAP concerning the extent to which any part of
the onsite contaminant plume may be breaking through the system of boundary extraction wells.
• Operation of the treatment system in conjunction with surface remediation of soils has been effective at
reducing VOC plume strengths near source areas.
• Bioremediation is being considered by regulators as a viable long-term solution to restore the aquifer to
i 5 ppb TRCLE. While selection of bioremediation is not currently anticipated, some technology must be
implemented over the next 20-50 years to go below 17 ppb TRCLE.
• The above ground air stripping system has been effective at removing all VOCs, priority pollutants and
metals to concentrations below discharge criteria. However, the air strippers simply transfer contaminants
from the groundwater to the air. Granular activated carbon or other emission control technology may be
needed in 1995 when new Clean Air Act requirements take effect.
• Groundwater treated by the air stripping systems is used as drinking water at TCAAP following post-
treatment by granular activated carbon. Identification of long-term drinking water used for treated
effluent will be part of future planning efforts.
• The system has been effective at containing further migration of the VOC plume off of the TCAAP site
while treatment of groundwater within subsurface aquifers to drinking water levels has not and is not
expected to be achieved.
US Army
Environmental Center
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• Twin Cities - Page 11 of 12'
•I ANALYSIS PREPARATION
This analysis was prepared by:
Stone & Webster Environmental
Technology & Services
245 Summer Street
Boston, MA 02210
Contact: Bruno Brodfeld (617)589-2767
US Army
Environmental Center
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• Twin Cities - Page 12 of 12 •
SOURCES
Major Sources For Each Section
Site Characteristics:
Treatment System:
Performance:
Cost:
Source #s (from list below) 1, 3 and 8
Source #s 5 ,7 and 8
Source #s 1, 4, 6 and 8
Source # 2
Regulatory/Institutional Issues: Source #s 1,2, 3, 4,5, 6 and 8
Schedule: Source #s 1,3,5 and 7
Lessons Learned: Source #s 1,2, 3, 4, 6,8 and personal communications with Marty McCleary, Project
Manager, TCAAP (612) 633-2301 ext. 651.
Chronological List of Sources and Additional References
1. Fiscal Year 1992 Annual Monitoring Report; Installation Restoration Program Twin Cities Army Ammunition Plant, prepared for
Commander of Twin Cities Army Ammunition Plant and Commander of U.S. Army Toxic and Hazardous Materials Agency,
prepared by Federal Cartridge Company, Wenck Associates, Inc., Alliant Techsystems, Inc., and Conestoga-Rovers &
Associates, Ltd., July 1993.
2. Technical and Economic Evaluation of Air Stripping for Volatile Organic Compound (VOC) Removal from Contaminated
Groundwater at Selected Army Sites, CETHA-TE-91023, prepared for U.S. Army Toxic and Hazardous Materials Agency,
prepared by Tennessee Valley Authority National Fertilizer and Environmental Research Center, July 1991.
3. Installation Restoration Program: Remedial Investigation Report for the Twin Cities Army Ammunition Plant, (4 volumes),
prepared for the U.S. Army Toxic and Hazardous Materials Agency (USATHAMA), prepared by the Environmental Assessment
and Information Sciences Division, Argonne National Laboratory, April 1991.
4. IRA-TGRS 1990 Annual Monitoring Report Installation Restoration Program Twin Cities Army Ammunition Plant, (2 volumes),
prepared for Commander of Twin Cities Army Ammunition Plant and Commander of U.S. Army Toxic and Hazardous Materials
Agency, prepared by Alliant Techsystems, Inc., and Conestoga-Rovers & Associates, Ltd., February 1991.
5. Final Engineering Report: Boundary Groundwater Recovery System (BGRS), prepared by Conestoga-Rovers & Associates,
January 1991.
6. IRA-TGRS 1989 Annual Monitoring Report Installation Restoration Program Twin Cities Army Ammunition Plant, (2 volumes),
prepared for Commander of Twin Cities Army Ammunition Plant and Commander of U.S. Army Toxic and Hazardous Materials
Agency, prepared by Honeywell, Inc., and Conestoga-Rovers & Associates, Ltd., May 1990.
7. TGRS Operations and Maintenance Manual; Installation Restoration Program Twin Cities Army Ammunition Plant, (5
volumes), prepared for Commander of Twin Cities Army Ammunition Plant and Commander of U.S. Army Toxic and Hazardous
Materials Agency, prepared by Honeywell, Inc., and Conestoga-Rovers & Associates, Ltd., October 1989.
8. SMCTC-EV Review Comments on the Technology Application Analysis Draft Report, prepared by U.S. Army Environmental
Center, September 1993.
US Army
Environmental Center
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Pump and Treat of Contaminated Groundwater at
U.S. Department of Energy, Kansas City Plant
Kansas City, Missouri
(Interim Report)
155
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Case Study Abstract
Pump and Treat of Contaminated Groundwater at
U.S. Department of Energy, Kansas City Plant
Kansas City, Missouri
Site Name:
U.S. Department of Energy (DOE)
Kansas City Plant
Location:
Kansas City, Missouri
Contaminants:
Chlorinated Aliphatics; includes
Tetrachloroethene (PCE), Trichloroethene
(TCE), 1,2-Dichloroethenes (1,2-DCEs), and
Vinyl Chloride
PCBs, Petroleum Hydrocarbons, and Metals
- TCE concentrations of > 10,000 ug/L in
groundwater
- Presence of DNAPLs suspected
Period of Operation:
Status: Ongoing
Report covers - 5/88 to 2/94
Cleanup Type:
Full-scale cleanup (interim
results)
Vendor:
Allied Signal, Inc.
SIC Code:
9711 (National Security)
3724 (aircraft-engine manufacturing)
Technology:
Groundwater Extraction with Advanced
Oxidation Processes (AOPs)
14 extraction wells and one trench;
screened intervals of wells ranged from 27
feet to approximately 47 feet below ground
surface; flow rates ranged from 0.9 to 5
gallons per minute (gpm) based on a design
flow rate of 2 gpm
- Interceptor trench of 250 ft. in length;
ranged in depth from about 22 ft. to 31 ft.
- Treatment system - acidification to
solubilize inorganic metals, bag filtration,
UV/peroxide oxidation, and neutralization
- Initial AOP - UV/Ozone/Peroxide system
replaced in May 1993 with a high intensity
UV/Peroxide system
Cleanup Authority:
RCRA Corrective Action and
Other: Kansas City Water and
Pollution Control Department
Point of Contact:
G.P. Keary
Environmental Restoration
Program Manager
DOE Kansas City Plant
Kansas City, MO
Waste Source:
Manufacturing Process
Type/Quantity of Media Treated:
Groundwater
- 11.2 million gallons treated (1993)
- Horizontal/Vertical distribution of VOCs in groundwater - up to 4,000 ft.
horizontal and over 40 ft. vertical
- Alluvial deposits underlain by bedrock consisting of sandstone and shale
- Shale is relatively impermeable
- Porosity of aquifer is 20%
- Horizontal Hydraulic Conductivity of aquifer is 1.1 to 2.3 ft/day; sandstone is
0.04 to 0.005 ft/day; underlying shale is impermeable in water
Purpose/Significance of Application:
Full scale remediation of groundwater contaminated with VOCs using advanced oxidation processes (UV/peroxide).
Regulatory Requirements/Cleanup Goals:
- Final cleanup goals for site have not been established at time of report; will be set subsequent to RFI/CMS activities
- Treated groundwater discharged to municipal sewer system must meet requirements of permit issued by the Kansas City
Water and Pollution Control Department; for organics - total organic halogen 0.16 mg/L; metals - 0.69 to 100 mg/L
156
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Case Study Abstract
Pump and Treat of Contaminated Groundwater at
U.S. Department of Energy, Kansas City Plant
Kansas City, Missouri (Continued)
Results:
As of February 1994:
- Influent VOC concentrations to UV/Peroxide treatment system were 10.6 mg/L with an average influent concentration of 25
mg/L; effluent concentrations were 0.01 mg/L
- The UV/peroxide system destroyed > 99.95% VOCs
- PCBs were detected at levels up to 0.3 ug/L in influent to UV/peroxide unit; not detected in effluent
- VOC contaminant plume appears to be contained
- No significant change in VOC groundwater concentrations at this time
Cost Factors:
- Total Capital Costs: $1,383,400 (including equipment, site preparation, construction/engineering, startup)
- Annual Operating Costs: $355,200 (including maintenance, project management, laboratory analysis, supplies)
- An estimated total cost for completing the cleanup is not available at this time.
Description:
The U.S. Department of Energy (DOE) Kansas City Plant, constructed in 1942, has been used for aircraft engine
manufacturing, production of nuclear weapons components, and defense-related research and manufacturing operations.
During the 1980s, hydrogeologic investigations identified soil and groundwater contamination at the site which had resulted
from releases from the research and manufacturing operations. The primary contaminants detected included chlorinated
VOCs, aromatic VOCs, PCBs, and metals. DNAPLs are suspected in the groundwater, but have not been detected at this
time. Final cleanup goals have not been established at this time. Treated water from the system is discharged to the
municipal sanitary sewer system under the provisions of a Kansas City Water and Pollution Control Department wastewater
discharge permit (2/88).
Operation of a groundwater pump and treat system, which includes an Advanced Oxidation Process (AOP), began in May
1988 under RCRA corrective action. The initial system included 14 extraction wells followed by a low intensity Ultraviolet
(UV)/Ozone/Peroxide treatment system. This system was replaced in May 1993 by a high intensity UV/Peroxide system to
provide additional 30 GPM treatment capacity for groundwater and to correct operational problems with the initial unit
(equipment malfunctions and downtime). While the cleanup is ongoing at this time and final performance data are not yet
available, interim results indicate that the extraction system appears to be containing the VOC contaminant plume. However,
the concentrations of VOC in the groundwater have not changed significantly.
The total capital costs for this application were $1,383,400 and the annual operating costs were $355,200. With respect to the
AOP, the replacement of the low intensity UV/ozone/peroxide system with the high intensity UV/peroxide system resulted in
both increased treatment capacity and cost savings while meeting the discharge limits for the treated water. The high intensity
UV/peroxide system eliminated the need for GAC polishing and treatment of air emissions and reduced operation and
maintenance costs. Although more expensive than alternatives such as air stripping, AOP was selected because it destroys the
contaminants rather than transferring contaminants to other media.
157
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TECHNOLOGY APPLICATION ANALYSIS
Page 1 of 13 sr
SITE
TECHNOLOGY APPLICATION
This analysis covers an effort to pump and treat
groundwater contaminated with volatile organic
compounds (VOCs) by above ground advanced
oxidation processes (AOPs). The treatment began in
May 1988 and is currently ongoing. This analysis covers
performance through February 1994.
U.S. Department of Energy
Kansas City Plant (KCP)
A RCRA Corrective Action Site
Kansas City, Missouri
M SfTE CHARACTERISTICS
• Site History/Release Characteristics •••••••••[(^•Bi^^^^^SEZZ:
• The KCP is located within the Bannister Federal Complex approximately 13 miles south of downtown Kansas City,
Missouri. The complex is bordered on the east by the Blue River and on the south by Indian Creek.
• Constructed in 1942 as an aircraft engine manufacturing facility, the KCP is part of the U.S. Department of Energy's
(DOE) Albuquerque Operations Office. The Atomic Energy Commission, predecessor to the DOE, began production of
components for nuclear weapons at the KCP in 1949. Subsequent defense related research and manufacturing operations
resulted in the release of contaminants to the subsurface.
• A series of hydrogeologic investigations initiated in the early/mid 1980s revealed elevated contaminant concentrations
(primarily chlorinated VOCs) in soil and groundwater.
• A groundwater pump and treat system, the subject of this report, started operation in May 1988. That system was
designed as an interim remedial measure to prevent further migration of VOC-contaminated groundwater while additional
RCRA Facility Investigation (RFI) and Corrective Measures Study (CMS) efforts to define final site remedial measures
were being performed. A low intensity Ultraviolet (UV)/Ozone (O3)/Hydrogen Peroxide (H2O2) treatment system operated
until May 1993 when it was replaced by a high intensity UV/H2O2 system. The initial system was a demonstration of
first-generation AOP technology; the replacement system is considered second-generation technology.
• Contaminants of Concern BEES •• Contaminant Properties ••BBBHSB^K^EE
Contaminants identified as being of greatest Properties of contaminants focused upon during remediation are:
concern in groundwater at the KCP are:
Tetrachloroethene
Trichjoroethene
1,2-dichloroethenes
Vinyl chloride
(PCE)
(TCE)
1,2-DCEs)
Other contaminants detected in soil or
groundwater include aromatic and halogenated
VOCs, petroleum hydrocarbons, PCBs and
selected metals.
Arsenic, present at concentrations higher than
drinking water standards, was determined to be
the result of natural geochemical processes.
• Nature & Extent of Contamination
Properties* Units
Density
Vapor Pressure mmHg
Henry's Law atrmrrP/mole
Constant
Water Solubility mg/l
Octanol -Water
Partition
Coefficient KQW
Organic Carbon -
Partition
Coefficient; K^
'Properties at 20 °C.
PCE
1.62
952
0.0259
150
398
364
TCE
1.46
2ai
0.0091
1,100
240
126
1 ,2-DCEs"
1.25/1.27
7
0.0066/
0.0076
2,250/3,3500
3/5
49/59
Vinyl
Chloneto
0.91
245
0.0144
2,670
24
57
" Data presented for both cis and trans-tsomers.
• Characterization of the nature and extent of contamination at the KCP evolved over a number of years of investigation
and interim remediation. Thirty-seven solid waste management units were found to have contributed to three primary
areas of groundwater contamination known as: the TCE Still Area, the Underground Tank Farm Area, and the Northeast
Area/Outfall 001 Area.
• Groundwater contamination is largely confined within the KCP limits. However, chlorinated VOCs have migrated with
groundwater along a backfilled stream channel to the Blue River northeast of the KCP.
• The vertical distribution and concentrations of VOCs in soil and groundwater suggest the potential presence of dense
non-aqueous phase liquid (DNAPL) in several areas which contribute to groundwater contamination.
• The presence of numerous subsurface utilities/utility trenches, including building footing tile drains, have a significant
impact on contaminant migration at the KCP site. These utilities act as sources of recharge water, preferential migration
pathways, and collectors for contaminated groundwater.
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Kansas City Plant - Page 2 of 13 —
Contaminant Locations and Geologic Profiles
Site Layout /Plan View)
Remedial investigation field activities
at the site have included:
• Borings and subsurface soil sampling
• Monitoring well installation and
groundwater sampling
• Groundwater elevation measurements
• Geophysical testing
• Water source/sink assessment
- Hydraulic tests
• Borehole packer testing
• Surface water sampling and elevation
measurements
• Groundwater modeling
Data from ~200 soil borings and ~ 190
monitoring/extraction wells were used to
develop an understanding of subsurface
conditions, including contaminant
migration. Selected data from site studies
have been used in this report to depict
site conditions.
Horizontal Distribution of VOCs in Groundwater -
Generalized Representation (Plan View!
Flood Wall
A A' 0 750 1.500
Cross Section scale in Feet
Location
Flood Wall
i—Legend
I Release Sites
I Groundwater Plume
> 1,000 uo/1
Total VOCs
I Groundwater Plume
> 5 ugrl Total VOCs
Scale in Feet
750 1,500
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• Contaminant Locations and Geologic Profiles (Continued)
Vertical Distribution of VOCs in
Groundwater
• In general, concentrations of prime
contaminants of concern in groundwater
increase with depth in overburden soils at
the KCP site. Dense non-aqueous -phase
liquid(s) (DNAPL) may be present in some
areas. The figure below, illustrating TCE
concentrations in groundwater at one of the
3 primary contamination areas (the TCE Still
Area), is representative of the vertical
distribution of chlorinated VOCs at the KCP
site.
TCE Still Area
Surface
• Alluvial deposits at the KCP site are under
lain by bedrock consisting of alternating
layers of sandstone and shale. A thin layer
of sandstone (< 10 feet thick) immediately
beneath the alluvium pinches out beneath
the site. Packer testing performed on the
shale indicated it was relatively
impermeable. No bedrock migration of
VOCs has been observed.
• Because the bedrock surface dips in the
opposite direction as alluvial groundwater
flow, additional monitoring wells were
completed within the shallow sandstone at
the request of EPA to monitor for the
potential migration of VOCs. No VOCs or
dissolved-phase contamination have been
detected in these wells. Additionally,
contaminant transport modeling predicted
that VOCs (if present) would migrate at an
average rate of < 1 foot per year under
worst-case conditions in the sandstone.
Upper
Completion
Zone Approximately 20 feet below ground surface (bgs)
Lower
Completion
Zone Approximately 40 feet bgs
[Legend
TCE Concentrations in Groundwater (July 1993)
Oto10ug/l Bl 1,000 to 10,000 ug^
Schematic Cross-Section of Bedrock and Alluvium at KCP
A
_^on
- Limestone
-Shale Main Manufacturing
/ Building
Ground Surface
A'
Blue Rivw and
Indian Crack Alluvium
Pteasanton
Group
Shale
Black Shale
Helper Sandstone
Shale
Notes: Cross section is not to scale.
Cross section location shown on site map (page 2).
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Kansas City Plant - Page 4 of 13 —
Location of Old Blue River Channel /Plan View]
The former Blue River channel, now filled,
has a hydraulic conductivity an order of
magnitude greater than the surrounding
soil. This former river channel is serving
as a preferential pathway for migration of
contaminated groundwater from the
Northeast Area/001 Outfall to the current
location of the Blue River.
Pr«-1967 Blue
River Channel
r Groundwater Sinks and Sources
Several site structures (in addition to the extraction wells and interceptor trench) serve as sinks/collectors for groundwater on
the KCP site and impact contaminant migration. Groundwater drains include: the 001 Outfall Interceptor system [ -6,000
gallons per day (GPD)], which is a collection system to prevent groundwater infiltration into an NPDES storm sewer, a sump
for the building southwest of the former South Lagoon, building footer drains, and possibly the plant sewer lines. Building
drains control the surface of the water table in the vicinity of the Main Manufacturing Building.
In addition to recharge due to infiltrating precipitation, it is believed that leaking underground water and steam lines could
be serving as a source of water to the subsurface. The KCP has initiated a study to quantify artificial sinks and sources
of water in the subsurface at the KCP site.
Site Conditions
• The KCP is situated in the Blue River Valley about 800 feet above Mean Sea Level (MSL) and is in the 100-year flood
plain of the both the Blue River and Indian Creek. However, a 500 year event floodwall protects the site.
• Approximately 46% of the site is covered by grass or gravel and is available for recharge. The site receives ~ 34 inches
of precipitation per year.
• The topography of the complex is flat-lying except where it drops - 30 feet along the Blue River and Indian Creek and
where it rises ~ 50 feet north of the KCP site.
• The Pennsylvanian bedrock (shales) in the vicinity of the KCP is noted for its uniformity. There are no structural features
such as faults, that affect the KCP site. No fractures were observed in bedrock (shale) cores performed at the KCP site.
• The surface of the bedrock at the KCP site slopes to the east, reflecting surface topography. However, the slope or dip
of individual layers (sandstones and shales) is to the west. Site lithologic logs indicate the presence of ~1 to 3 feet
variation in the elevation of the bedrock surface.
• Groundwater flow at the KCP site is primarily to the east and discharges to the Blue River and Indian Creek. A portion of
the KCP site groundwater flow is to the south.
Aquifer parameters for the alluvial deposits at the KCP site have been estimated as:
Propefty
Porosity
Hydraulic Gradient
Horizontal Hydraulic Conductivity*
Groundwater Velocity
Storage Coefficient"
Units
%
ft/ft
ft/day
ft/yr
-
Tank Farm
20
0.002
2.3
8.4
0.002
South Lagoon
20
0.008
1.1
16
0.0005
Northeast Area
20
0.007 to 0.02
1.5
19 to 55
0.002
* Based on pumping test data. Conductivities calculated from bail and slug test data were ~ one order of magnitude lower.
" Low values are reflective of the fine-grained nature of the aquifer materials.
The horizontal hydraulic conductivity of the shallow (knobtown) sandstone is 0.04 to 0.005 ft/day. The underlying shale is
impermeable to water.
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REMEDIATION SYSTEM
Overaff Process Schematic
Extraction Well Network
and Trench
Replacement Treatment System
Tranch(nottoic*l*)
r-0-
Acidification
(Dn
Kansas City Plant - Page S of 13 —
Neutralization
Filtration
UV/Ptroxide
Oxidation
Discharge to Sanitary
Sewer
Municipal
tVastowator
Treatment
Plant
Fourteen extraction wells and
one trench installed in three
phases (1987,1988, and
1989).
I Extraction Well Network
Acidification to solubilize inorganic metals, bag
filtration, (UV/peroxide) oxidation of organic
contaminants in one of two reactors, and
subsequent neutralization.
Discharge treated water
to municipal wastewater
treatment plant.
KC89-11146.5 2.0
KC89-62 39 1.3
Qroundwator
Treatment
Building
KC89-€3 39
KC88-9041 1.1
KC88-91 42.5 1.4
KC88-87 40 0.9
KC88-86 42 f.O
KC88-89 42.2 1.1
£~y~%3r
.,*-* :--•- ,
KC8B-11246.7 7.5
'rench (width not to *cale)
KC89-108275.0
KC89-11046.5 0
KC89-10945.2 1.0
KC87-61 40 1.6
KC88-88 40.5 1.4
KC88-92 40.5 1.3
Legend
Extraction Well
Well Identification
Number
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Kansas City Plant - Page 6 of 13 —
I Extraction Well Detail
Typical extraction well (KCB&-112)
Interceptor Trench Schematic
Ground Surface
•To Treatment System
11/4- Stainless Steel
Conductor Pipe
1:6 Ben ton ite Grout
KC89-108
6* Stainless Steel Casing
Production Well
10' Screen from Bedrock
10 1/4
in
1/4* Bentonite Pellets
Six inch Stainless Steel Casing
Welded «f 21 ft. Joints)
Black Iron Casing Centralizers
Welded to Casings (16 It and 34 ft BGS)
0.010 inch Continuous Wire-Wound
Stainless Steel Screen
«20 Frac Sand Pack
Welded Bottom Cap
Bedrock
0 25 50 75 100 125 150 175 200 225 250
Distance in Feet
I Key Design Criteria ••••••fP^* •
• Hydraulic containment of VOC-contaminated
groundwater
• Handle range of flow rates to allow for operational
flexibility
• Destruction of organic contaminants in extracted
groundwater rather than transfer to another media
• Redundant treatment capability to maintain hydraulic
containment in the event of unanticipated breakdown, and
to provide for treating increased flow rates during future-
final site remediation
NOTES: 1.) Some extraction wells completed with subsurface vaults
2.) Submersible pumps with stainless steel impellers in
each well
I Key Monitored Operating Parameters
• Groundwater elevations —,
• Groundwater VOC
concentrations
(to assess
containment system
performance)
Water flow rates
Temperature, pressure, and pH
UV and H2O2 dosage
Filter pressures
Influent/effluent contaminant concentrations —'
(to assess treatment
— system operation and
effectiveness
Treatment System Schematic
UV/Peroxide Treatment Units
(100 GPM_ jg KW each)
Cone.
HySO^
(300
Gallons)
J__
50%
NaOH
(300
Gallons)
J5
4 —
Up to 33 GPM Groundwater
From Interceptor Trench
and Extraction Wells
Discharge Treated Water
to Sanitary Sewer
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Kansas City Plant - Page 7 of 13 —
PERFORMANCE
Performance Objectives
• Prevent further migration of VOC-contaminated groundwater from 3 areas of identified contamination
• Design and operate treatment system to decrease VOC concentrations in extracted groundwater to below sewer
discharge limits
• Remedial Action HJstory/WanHHHBBBHHHHBBBBBH^^^^^^^K
Remediation at the KCP site is being implemented in a phased manner. The following groundwater-related interim
remedial actions have been performed to date:
1986 Initiated pumping of groundwater (6 GPM) from Underground Tank Farm Area and treatment with
UV/OyH2O2 system as interim measure and to demonstrate treatment technology
1880 Treatment of additional 14 GPM from TCE Still Area and 13 GPM from Northeast Area/001 Outfall using
the same treatment system with additional Aqueous-Phase Granular Activated Carbon (GAC) polishing
1993/1994 Second-generation \JVM2®2 treatment system installed to provide capacity for treating an
additional 30 GPM (approximate) of groundwater from the 001 Outfall Area, and to provide additional
operational and environmental benefits
• Overall Performance Summary ••••••••••••^^
Conclusions drawn after 5 (plus) years of operating the interim pump and treat system are summarized below:
• The extraction system appears to have been effective in substantially containing VOC-contaminated groundwater
emanating from the KCP site. The KCP expects to begin extracting up to an additional 30 GPM of VOC-contaminated
groundwater to prevent its infiltration into the 001 Outfall storm sewer line during 1994.
• The concentrations of VOCs in groundwater and the extent of contamination has not changed considerably in the TCE
Still Area, Underground Tank Farm Area or the Northeast Area/001 Outfall since initiating the Interim Remedial Action.
• While the initial AOP treatment system met discharge limits, ozone leaks, the need to treat air emissions and significant
downtime required for maintenance contributed to the decision to change to the high-intensity UV/H2O2 AOP. The new
AOP system has also operated within discharge limits.
Operational Performance
Volume and Rate of Water Pumped/Treated
• During 1993, a total of approximately 11.2 million gallons of groundwatar water was extracted
and treated by the interim system. Of this total, -2.2 million gallons was extracted from the
Underground Tank Farm Area -4.5 million gallons from the TCE Still Area and -4.5 million gallons
from the Northeast Area/001 Outfall.
• The average daily flow rate for the entire interim system in 1993 varied from a high of 32 GPM in
January to < 2 GPM in July, during treatment unit replacement.
System Downtime
• Numerous equipment malfunctions and a significant amount of downtime occurred during the first 15 months (May 1988 - July
1989) of continuous operation of th UV/Oj/H2O2 system. The system operated > 65%of the time in 1988 except during
September when it was shut down for equipment modifications. The interim system operated 61 % of the time in 1989 except
during June when it was down for servicing modifications by the manufacturer. Except during downtime periods for construction,
equipment, modifications and frozen pipes, and the UV/Oj/H2O2 system operated > 90% of the time from 1990 until May 1993
when it was replaced by the high intensity UV7H2O2 system.
• The replacement UV/HjOj system commenced continuous operation in August/September 1993. This treatment system has
operated > 95% of the time. Much of the maintenance that required the prior treatment system to be shut down can now be
performed while the replacement system remains operational.
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• Kansas City Plant - Pago 8 of 13"
Hydrodynam/c Performance
• A modeling evaluation performed in May
1992 concluded that the extraction system
was substantially containing the three
primary groundwater VOC plumes at the
KCP site. The planned addition of
supplemental extraction wells near Outfall
001 is intended to decrease infiltration of
contaminated groundwater into storm sewer
lines to comply with NPDES permit effluent
standards.
! Effect on In Situ Contaminant Concentrations
While the pump and treat system has removed a substantial mass of VOCs from the subsurface, statistically significant
changes of in situ groundwater VOC concentrations have not occurred.
Treatment System Performance
• The original UV/CyH2O2 treatment system was replaced with the high intensity UV/H2O2 in May 1993 to provide
capacity to treat an additional 30 GPM from the 001 Outfall Area. Despite the on-going maintenance problems, the
UV/Oa/H2O2 treatment system routinely met permit discharge limits at a flow rate - 6 GPM from 1988 until 1990. The
sewer discharge limit for total organic halogens was exceeded on 2 occasions in 1990 as a result of the adding of - 27
QPM of groundwater extracted from the TCE Still Area and the Outfall 001 /Northeast Area. The original system was
designed to handle only 25 GPM of water containing VOCs at concentrations higher than predicted by an Interim
Corrective Measure Study. Aqueous-phase granular activated carbon (GAG) polishing of the UVYOj/H20 Unit effluent
was added in the late 1990 to remove residual organics prior to discharge. An in-line filter was installed and backwashing
instituted to extend the life of the GAC by removing iron and manganese that precipitated following oxidation in the AOP
reactor.
• Following successful completion of a rigorous acceptance testing program of the replacement UV/H2O2 system during
late 1992, the system was placed into operation during May 1993 . As illustrated in the following graph, total VOC
concentrations in the replacement system effluent have been well below the sewer discharge limit. The on-going
maintenance problems experienced with the initial system have been eliminated .
UV/Peroxlde Treatment System Performance
January/February 1994
100,000
10,000
1,000
100
10
0
Date
PERMIT LIM IT 160 ug/ITOX
1/5
1/12
1/19
1/26
2/2
2/9
2/16
2/23
Influent 23,500 30,400 31,000 19,600 21.000 23.500 26,410 10,600
Effluent 9 25 67 27 32 9 28 10
Method Detection Limit« 5 ug/l All results ug/l total VOCs
• The initial UV/Oj/H2O2 system destroyed -
94.6% VOCs; -37% were emitted to ambient
air and - 1.7% were discharged to the sanitary
sewer system. The replacement UV/H2O2
system destroyed > 99.95% VOCs; ~< 0.05%
are discharged to the sanitary sewer system
and there are no emissions.
• The system is designed to treat up to 30,000
ug/1. Influent averaged approximately 25,000
ug/l.
• Up to 0.3 ug/l PCBs have been detected in
the UV/H2O2 treatment system influent. PCBs
have not been detected in the treated
groundwater discharged to the sanitary sewer.
C Legend
- Influent VOC Concentration -*-Effluent VOC Concentration
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Kansas City Plant • Page 9 of 13 —
COST
• Although advanced oxidation was more expensive then other alternatives such as air stripping/GAC, it was
selected because of its waste minimization benefits. With advanced oxidation the contaminants are destroyed,
and not transferred to another media.
• The selection of the high intensity UV/H2O2 treatment to replace the UV/H2O2 was due in part to cost savings
associated with: eliminating GAC polishing, eliminating the need to treat air emissions, and reduced operation
and maintenance labor and expenses.
• Capital and operating costs for the replacement UV/H2O2 system is presented below. Operating costs for
treatment (including replacement parts, laboratory analysis, utilities, labor, and raw materials) calculated by
Oak Ridge National Laboratory were $15.51/1,000 gallons for the first-generation UWOj/H2O2 demonstration
unit and are projected to be $13.80/1,000 gallons for the second-generation UV/H2O2 replacement units once
the additional 001 Outfall extraction system commences operation. The costs presented below are based on
actual costs spent from fiscal years 1987 to 1994; the cost figures are not in constant dollars.
Capital Costs
Extraction Wells, Vaults, Pumps, Piping, Trenching, Electrical Conduit, & Utilities $1,213,900
Bag Filter Units (2) 4,500
Tanks (3) 1,700
Treatment Buildings (site preparation, construction, and engineering), 3 original extraction wells 126,000
Control Systems 2,300
Equipment Installation 20,000
Startup (including acceptance testing) 15,000
Total Capital Cost $ 1,383,400
Operating Costs
Electrical Power $ 25,300
Maintenance
Labor 52,200
Equipment Repair and Replacements3 3,300
Engineering Support and Project Management 44,200
Laboratory Analysis (Influent/Effluent) 78,000
Monitoring Well Analysis 110,000
Consumables
Hydrogen Peroxide 3,600 gallons/year @ $4.00/gallon 14,400
Sulfuric Acid 3,600 gallons/year @ $1.09/gallon 3,900
Caustic 7,200 gallons/year @ $1.91 /gallon 13,800
Bag Filters 700
Extraction Pump and Motor Assembly Replacement (2/year) 1,200
Transport and Disposal of Spent Filters and Personal Protective Equipment 500
Extraction Well Rehabilitations
Chemical Treatment 5,300
Redevelopment 2,400
Total Annual Operating Cost $ 355,200
a Average annual cost of equipment repair and replacement costs from 1983 to 1994, including costs associated with system
start-up and the purchase of spare parts.
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Kansas City Plant - Page 10 of 13 —
REGULATORY/INSTITUTIONAL ISSUES
• The KCP Site investigation is being performed in accordance with a U.S. Environmental Protection Agency
RCRA 3008 (h) Administrative Consent Order in 1989. Initial investigation efforts, and the extraction and treatment of
groundwater from the Underground Tank Farm Area were performed as voluntary actions in 1988 with EPA cognizance.
• Treatment of extracted groundwater using UV/Oj/H2O2 was initiated in 1988 as a demonstration of one of the first full-
scale operating AOP systems. A rigorous program of pilot testing and long term performance monitoring was
implemented to assure regulators of the effectiveness of this treatment technique and to develop data on long-term
reliability and operation and maintenance costs. The second generation UV/H2O2 that replace the UV/OyH2O2 system in
1992 also underwent rigorous prove-in testing in accordance with a Startup Plan approved by EPA and the City of Kansas
City, MO.
• Treated water is discharged to the municipal sanitary sewer system under the provisions of a wastewater discharge
permit issued by the Kansas City Water and Pollution Control Department in February 1988. Discharge limits are
summarized below:
Parameter
Cadmium
Chromium
Copper
Lead
Nickel
Zinc
Iron
Manganese
Boron
Concentration (mo/Ll
0.69
2.77
3.38
0.69
3.98
2.61
100.00
20.00
1.00
Parameter
Concentration (mo/Ll
Arsenic 0.250
Total Organic Halogen 0.16
Sulfides 10.0
Oil and Grease 100
Total Cyanide 2.0
• Final cleanup goals have not yet been established for the site. Cleanup goals will be set subsequent to completing
RFI/CMS activities.
SCHEDULE
Major Milestones
Completed Activities
Future Activities
• Extraction and treatment of groundwater from near the 001 Outfall will be initiated following NEPA review and obtaining
approval from a railroad to a pipe groundwater beneath an active rail line that crosses the KCP site.
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Kansas City Plant - Page 11 of 13 -
LESSONS LEARNED
Implementation Cons/derations
• An understanding of the extent of contamination at this site has evolved over a decade of investigation, monitoring, and
remediation. Defining the extent of contamination has focused on determining the need for remediation in specific areas
of the site, selecting and designing remedies, and evaluating the effectiveness of implemented remedial actions.
• Monitoring data and modeling results suggest that predicting the rate of aquifer restoration my be complicated due to
hydrogeologic variability caused by leaking underground utilities, building footing tile drains and other anthropogenic
factors and the likely presence of ONAPL(s) in a a number of areas of the site.
• Initiating an interim remedial action provided for hydraulic containment of VOCs dissolved in groundwater while the full
extent of contamination and supplemental remedial actions are defined.
• Extraction flow rates must be manually adjusted at the individual well heads. The ability to control flows from the
central treatment system building would eliminate difficulty in performing this task.
• Substantial and frequent fouling of the extraction system wells with bacterial slime and oxides of naturally-occurring iron
and manganese have resulted in the need for frequent chemical treatment and redevelopment of wells, and
repair/replacement pumps, pump motors and water level probes.
• Vaults and pipe conduits allow oxygenated rainwater to drain into extraction wells through vent tubes, contributing to the
growth of bacterial slime and need for more frequent well treatment/redevelopment. Modifications made to minimize this
concern have included installation of berms and drainage systems around selected well vaults. Measures to epoxy seal
openings in the piping conduit are being investigated.
• The initial UV/Oj/H2O2 treatment system was not designed to adequately handle the flow rate and VOC concentrations
realized with the interim containment system. The replacement UV/H2O2 treatment system was designed to handle a
wider range of flow rates and concentrations to provide operational flexibility.
• The initial UV/Oj/H2O2 treatment system experienced significant downtime for acid cleaning of filters, ozone sparger
tubes and UV lamp sheathes, and GAC backwashing/changeout. The replacement system provides for pH adjustment
prior to UV/H2O2 treatment to minimize fouling caused in part by oxidation of inorganics.
Technology Limitations
• The initial UV/O^HjOj treatment system was a first-generation AOP technology installed and operated at the KCP for
demonstration purposes. The second-generation (replacement) AOP treatment system, operational since May 1993, has
performed well at a lower cost and without the on-going maintenance problems experienced with the initial demonstration
system.
• The saturated hydrocarbons present at the KCP site were readily treated by both the initial UV/OyHgO, and the second-
generation/replacement UV/H2O2 systems. AOP manufacturers' literature indicates that treatment efficiencies for
unsaturated hydrocarbons are much lower.
• UV/H2O2 was selected instead of a second-generation UV/O^HjOj AOP to replace the initial treatment system because
systems that employ ozone: require more maintenance (e.g., the ozone generator and delivery system), residual ozone in
the headspace of the reaction chamber is corrosive to the chamber, and catalytic oxidation is required to destroy ozone in
the air discharge.
Future Technology Selection Considerations
• Greater attention should be paid to the design of extraction well systems that minimize operation and maintenance
problems.
• AOP systems can destroy saturated hydrocarbons in extracted groundwater. However, designs must consider the
potential for fouling with oxidized inorganics and the implementation of pretreatment measures when appropriate to ensure
satisfactory performance and manageable maintenance.
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Kansas C/fy Plant - Page 12 of 13 -
ANALYSIS PREPARATION
This analysis was prepared by:
Stone & Webster Environmental ,A
Technology & Services ^^
245 Summer Street
Boston, MA 02210
Contact: Bruno BrodfeW (617) 589-2767
Assistance was provided by the
ALUEDSIGNALINC.
which supplied key information and reviewed report drafts.
HAZARDOUS WASTE REMEDIAL ACTIONS PROGRAM
Environmental Restoration and Waste Management Programs
Oak Ridge, Tennessee 37831-7606
managed by
MARTIN MARIETTA ENERGY SYSTEMS
for the
U.S. Department of Energy
under Contract DE-AC05-84OR-21400
This analysis was funded by:
U.S. Air Force
Headquarters USAP/CEVR
CERTIFICATION
This analysis accurately reflects the performance and costs of the remediation:
G.P.KSafy
DOE Kansas City Plant
Environmental Restoration Program Manager
U.S. Air Force
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Kansas City Plant - Page 13 of 13 —
SOURCES
Major Sources For Each Section
Site Characteristics:
Remediation System:
Performance:
Coat:
Ragulatory/lnstltutlonal Issues:
Schedule:
Lessons Learned:
Source #s (from list below) 3,4, 6, 7, 8,9, and 10
Source #s 1, 2, 3, 4,5,7, 8,9, and 10
Source #s 1.2. 3,4, 6,7, 8, 9,10, and 11
Source #s 1,2, 8, and 11
Source #s 1,3,4, 5,6,9, and 11
Source #s 1,2,4,5,6,7, and 10
Source #s 1,2,4, 6,7,10, and 11
Chronological List of Sources and Additional References
1. Kansas City Plant Groundwater Treatment System Overview, prepared by AlliedSignal, Inc., Undated.
2. Kansas City Plant Ultraviolet/Ozone/Hydrogen Peroxide Groundwater Treatment System Overview, prepared by
M.E. Stites, Environment, Safety and Health Department AlliedSignal, Inc., and R.F. Hughes, Energy and
Environmental Systems Division, Oak Ridge Associated Universities, Undated.
3. Tank Farm Interceptor System Evaluation and Treatment Unit Corrective Action Plan - Rev 1, April 1991.
4. Groundwater Interceptor System Evaluation, Kansas City Plant, prepared by Department of Energy,
Albuquerque Operations Office, Environmental and Health Division, Environmental Programs Branch, May 1992.
5. Groundwater Treatment System Interim Measures Plan, U.S. DOE Kansas City Plant, revised August 1993.
6. TCE Still Area RCRA Facility Investigation Report • Draft, Kansas City Plant, prepared by Department of
Energy, Albuquerque Operations Office, Environmental and Health Division, Environmental Programs Branch,
Environmental Restoration Program, September 1993.
7. Kansas City Plant Groundwater Remediation, prepared by AlliedSignal, Inc., October 15,1993.
8. Northeast Area/001 Outfall Corrective Measure Study - Draft, Kansas City Plant, prepared by Department of
Energy, January 1994.
9. Annual Groundwater Monitoring Report for Calender Year 1993, Kansas City Plant, prepared by Department of
Energy, Albuquerque Operations Office, Environmental Programs Branch, Environmental Restoration Program,
March 1994.
10. Data Package Supplied by Mr. Michael E. Stites, AlliedSignal, Inc., April 25,1994.
11. Personal Communications with Michael E. Stites and Joseph L Baker, AlliedSignal, Inc. May and June 1994.
U.S. Air Force
170
-------
Pump and Treat of Contaminated Groundwater
at U.S. Department of Energy Savannah River Site,
Aiken, South Carolina
(Interim Report)
171
-------
Case Study Abstract
Pump and Treat of Contaminated Groundwater at
U.S. Department of Energy Savannah River Site, Aiken, South Carolina
Site Name:
U.S. Department of Energy (DOE)
Savannah River Site A/M Area
Location:
Aiken, South Carolina
Contaminants:
Chlorinated Aliphatics
- Trichloroethene (TCE), Tetrachloroethene
(PCE), and 1,1,1-Trichloroethane (TCA)
- Concentrations of volatile organic
compounds (VOCs) in groundwater reported
as high as 500 ppm
- Groundwater TCE concentrations over 48
ppm
- Groundwater contains 260,000-450,000
pounds of dissolved organic solvents in
concentrations greater than 0.01 ppm,
estimated to be 75% TCE
- Soil TCE concentrations over 10 ppm
- Dense nonaqueous phase liquids (DNAPLs)
are present in groundwater
Period of Operation:
Status: Ongoing
Report covers - 9/85 to 12/93
Cleanup Type:
Full-scale cleanup (interim
results)
Vendor:
C.L. Bergen
Westinghouse Savannah River
Company
Aiken, SC
SIC Code:
9711 (National Security)
3355 (Aluminum forming)
3471 (Metal finishing)
Technology:
Groundwater Extraction Wells followed by Air
Stripping
- 11 recovery wells at depths to over 200 feet
below ground surface
- Production air stripper has a design capacity
of 610 gpm; operated at 510 gpm
- 1993 average flow rate was 479 gpm;
average air flow rate was 2,489 cfm
- In 1993, 19,500 Ibs of VOCs removed;
average air emission rate of 2 Ibs/hr
Cleanup Authority:
RCRA Corrective Action and
State: South Carolina Bureau of
Air Quality Control
Point of Contact:
G.E. Turner, DOE
Savannah River Oper. Office
Environmental Restoration Div.
Aiken, SC
Waste Source:
Surface Impoundment
Purpose/Significance of
Application:
Full-scale pump and treat remediation
of groundwater contaminated with
VOCs using aboveground air
stripping.
Type/Quantity of Media Treated:
Groundwater
- VOC contaminated groundwater has an approximate thickness of 150 ft and
covers about 1,200 acres
- Complex hydrogeology arising from heterogeneities in a multilayer aquifer
system with discontinuous sand and clay layers
- Hydraulic conductivity 9 - 73 ft/day
- Transmissivity 175 - 12,500 gpd/day
172
-------
Case Study Abstract
Pump and Treat of Contaminated Groundwater at
U.S. Department of Energy Savannah River Site,
Aiken, South Carolina (Continued)
Regulatory Requirements/Cleanup Goals:
Groundwater:
TCE - 5 ppb; PCE - 5 ppb; TCA - 200 ppb
- Adopted in 1990, based on EPA MCLs
- During initial remediation efforts in 1985, the cleanup goal was 99% removal of VOCs over a 30-year period
Air:
34 tons/yr VOCs or 7.9 Ibs/hr
- Based on South Carolina Bureau of Air Quality Control permit
Results:
As of 1993:
- Influent concentrations to air stripper decreased for TCE (from 25,000 ppb to about 6,000 ppb) and PCE (from 12,000 ppb
to 4,000 ppb)
- The total quantity of VOCs removed from 1985 to 1993 is 273,300 Ibs
- Average VOC removal efficiency for air stripper >99.9%
Cost Factors:
- Total Capital Costs (1990 dollars) - $4,103,000 (including design, construction and installation, engineering, site
development)
- Total Annual Operating Costs (1990 dollars) - $149,200 (for years 1985 to 1990) (including electricity, maintenance,
operation, well sampling and analysis)
- Total cost of operation and maintenance is $0.75 per 1,000 gallons treated (198 million gallons per year treated)
- An estimated total cost for completing the cleanup is not available at this time
Description:
At the U.S. Department of Energy Savannah River Site, administrative buildings are located within the "A" area and
aluminum forming and metal finishing operations have been performed within the "M" area. An estimated 3.5 million
pounds of solvents were discharged from these operations between 1958 and 1985, with over 2 million pounds sent to an
unlined settling basin. Groundwater contamination beneath the settling basin was discovered in 1981. The primary
contaminants were volatile organic compounds (VOCs) at concentrations up to 500 ppm. A pilot groundwater remediation
system was operated in 1983, with the full-scale groundwater treatment begun on September 1985. The full-scale
technology included groundwater extraction wells and a production air stripper. The design of the production air stripper
was based on pilot and prototype air strippers.
While the remediation was ongoing at the time of this report, reductions in concentrations of both TCE and PCE to the air
stripper have been noted and the estimated total historical (1985 to 1993) removal of VOCs is over 273,000 Ibs. In addition,
the average VOC removal efficiency of the air stripper is greater than 99.9%. Contaminated groundwater in the source areas
and the areas of the highest VOC concentrations appears to be contained at this time. However, the areas at the fringes of
the plume are not as well contained, due to hydraulic factors.
The total capital cost for this application is $4,103,000 and the total annual operating costs are $149,200. DNAPLs were
discovered in the groundwater in 1991 and pose a significant limitation to the long-term use of pump and treat, since pump
and treat is effective for plume restoration only where DNAPL source areas have been contained or removed. A need for
supplemental site characterization to fully define the DNAPL contamination and to redirect ongoing remediation activities
has been identified.
173
-------
TECHNOLOGY APPLICATION ANALYSIS
Page 1o(12 =
U.S. Department of Energy
Savannah River Site
A/M Area
Aiken, South Carolina
mi SITE CHARACTERISTICS
• TECHNOLOGY APPLICATION
This analysis covers an effort to pump and treat
groundwater contaminated with volatile organic
compounds (VOCs) by above ground air stripping.
Full scale treatment began in September 1985 and is
one component of an ongoing environmental
restoration program. This analysis covers performance
through December 1993.
• Site H/story/Refease Characteristics ••••••^••^^
• The Savannah River Site's historical mission has been to support national defense efforts through the production of
nuclear materials. Production and associated research activities have resulted in the generation of hazardous waste
byproducts now managed as 266 waste management units located throughout the 300 square mile facility.
• The A and M areas at Savannah River have been the site of administrative buildings and manufacturing operations
respectively. The Savannah River Laboratory is also located within the A area. Specific manufacturing operations
within the M area include aluminum forming and metal finishing.
• The M area operations resulted in the release of process wastewater containing an estimated 3.5 million pounds
of solvents. From 1958 to 1985, 2.1 million pounds was sent to an unlined settling basin which is the main feature of
the M-Area Hazardous Waste Management Facility (HWMF). The remaining 1.3 million pounds was discharged to
Tims Branch, a nearby stream, during the years 1954 to 1982.
• Discovery of contamination beneath the settling basin in 1981 initiated a site assessment effort eventually involving
approximately 250 monitoring wells over a broad area. A pilot groundwater remediation system began operation in
February 1983. Full-scale groundwater treatment began in September 1985.
• Contaminants of Concern
Contaminants of greatest concern in the
groundwater are:
1,1,2-trichloroethylene (TCE)
tetrachloroethylene (PCE)
1,1,1 -trichloroethane (TCA)
•1 Contaminant Properties
Properties of contaminants focused upon during remediation are:
Property at STP* Units TCE PCE TCA
pycm3
mmHg 73
atrfm3*noto9.9E-3
OCH-Ca2
1.46 1.62
19
2.9E-3
Empirical Formula
Density
Vapor Pressure
Henry's Law
Constant
Water Solubility
Qctanol-Water
Coefficient; Kow
'STP « Standard Temperature and Pressure; 1 aim, 25 °C
mg/L
1000-1470 150-485
195 126
CHjCOg
1.31
124
1.6E-2
300-1334
148
Nature & Extent of Contamination
• Approximately 71 % of the total mass of VOCs released to both the settling basin and Tims Branch was PCE, 28% was
TCE and 1% was TCA.
• The dissolved organic solvents are estimated to be 75% TCE. A continued source for dissolved phaseVOCs is
contaminants sorbed to solids in the saturated zone or in the vadose zone.
• The area of VOC contaminated groundwater has an approximate thickness of 150 feet, covers about 1200 acres and
contains contaminant concentrations as high as 223 ppm.
• Dense nonaqueous phase liquids (DNAPLs) were found in 1991 and present complications to long term remediation
efforts.
U.S. Department of Energy
174
-------
Contaminant Locations and Geologic Profiles
' Savannah River • Page 2 of 12 —•
Data from hundreds of
soil borings, groundwater
monitoring wells and a
variety of other
investigative techniques
has allowed the
development of a three
dimensional conceptual
model of the site including
groundwater behavior and
contaminant
concentration profiles for
various geologic units.
The following diagrams
have been included here
to provide a general
understanding of site
conditions. Data from the
third quarter of 1985 is
presented.
Site Layout
Savannah River
Laboratory
TCE Plume (Upper Lost Lake Aquifer TOP View)
10-100 ppb
CD 100-1000 ppb
IP 1,000-10,000 ppb
10,000-100,000 ppb
>100,000 ppb
TCE Plume (Side View)
Groundwater monitoring data from the third quarter of 1985 along cross-section B-B' shown in top view
Aquifer
Estimated
Total VOC Mass
Water Table
Unit 179,600 IDS
Lost Lake
Aquifer
282,900 Ibs
Middle Sand
Crouch Branch
Confining Unit 1,800 Ibs
Crouch Branch
Aquifer Not calculated
— Legend
Surface
M-Area Settling Basin
VOC contamination appears to generally be located
near the surface in the vadose zone in
concentrations up to 500 ppm beneath source areas.
r-400
-300
-100
2000ft
Vertical exaggeration > 40X |_0
CO
-200
all concentrations r^
'nppo TCE IFnomtonngwell
Concentration I
I Screened portoon of d 10-100 ppb £31,00-10,000 ppb
| groundwater Q 100-1,000 ppb ffl 10,000-100,000 ppb
B >100.000 ppb
U.S. Department of Energy
175
-------
• Contaminant Locations and Geologic Profiles (Continued)
Hvdrogeologic Units
' Savannah River- Page3 of 12 •—
Aquifer
Subunit Description
Thickness
Upland
Tobacco
Road
Drv Branch
Poorly sorted mix of sand, cobbles, silt A clay.
Moderate to well sorted, fine to medium sand
containing some pebbles; 13% silt & day.
Moderately to wall cortad radium land- 1814 citt
-57ft -i
0-97 ft
an.5i< ft-
s
Water Table Unit
aclay.
Moderate to well sorted fine sand with some
calcareous zones; 25% silt & clay; 14% silt and
day beds.
Upper
Lost Lake Aquifer
Well sorted fine to medium sand; 16% silt & clay;
7% silt & clay beds.
Discontinuous day beds containing 70% siH & day
Lower
.Crouch Branch
Confining Unit
Crouch Branch Aquifer
Moderate to well sorted medium sand; 17% silt &
day; 7% silt & day beds.
Clay, clayey silt and poorly sorted fine to coarse,
clayey sand; 62% silt 7 clay; contains 2 major
clay layers the lower of which is 10-56 ft thick and
is the principal confining unit for the Black Creek
Formation.
Very poorly to well sorted, medium to coarse
sands; 5% sand & clay beds; an important
production zone for water supply wells in the M-
Area.
152-180
Site Conditions
• The A/M-Area is approximately one mile inward from the northeast boundary of the 300 square mile Savannah
River Site. Adjacent to the site boundary are rural and farming communities.
• The Savannah River Site includes a complex hydrogeology arising from heterogeneities in the multilayer aquifer
system and discontinuous sand & clay layers.
Key Aquifer Characteristics
Aquifer parameters beneath the A/M-Area have been estimated as:
Unit
Water Table Unit
Lost Lake
Aquifer
Middle Sand
Crouch Branch
Confining Unit
Crouch Branch
Aquifer
Hydraulic
Conductivity
[ft/day]
9
Avg. 40
29
73
Transmissivity
[gpd/day]
175
Avg. 1750
1600
12,500
Flow Direction
Row in the unconfined water table unit within the McBean
Formation is complex but radial flow is expected outward from a
plateau (at 244 MSI) surrounding most of the A/M-Area.
Ranged from southwest to northeast near the A/M-Area in the
Upper Lost Lake. Mainly east and south in the Lower Lost Lake
during 1985-86.
Mainly southeast during 1985-86.
Mainly southeast during 1985-86.
• A wide range of values has been used to describe regional aquifer characteristics. Uncertainties stem from
difficulties in aquifer testing and interpretating methods applied to the hydrogeological complexities noted above
under Site Conditions.
• A moderate downward gradient appears to exist beneath the M-Area. Vertical flow rates have been estimated
to be from 2 to 8 feet per year.
• Radial flow outward from a groundwater plateau surrounding most of the A/M-Area within the water table unit and
Upper Lost Lake aquifer is approximately 15 to 100 ft/year.
U.S. Department of Energy
176
-------
Savannah River- Page4 of 12 —
I TREATMENT SYSTEM
I Overall Process Schematic
Groundwater
Extraction Well Network
11 recovery wells each containing
four 10 ft screened intervals and
extending to depths over 200 ft
[detailed below]
J
Air Stripper
Treatment Plant
Production air stripper
treating Avg. 500 GPM
[detailed on next page]
Treated
Groundwater Outfall
Treated effluent discharge to
outfall A-014 feeding tributary to
Tims Branch
Extract/on Well Network
See p.2 for site
layout description
545
225
740
Screened
g portion of
groundwatar
recovery wall
(10 ft length)
125
sj XL
Wall Extraction
Number Rate in
GPM
U.S. Department of Energy
177
-------
Savannah River - Page 5 of 12 —
Mr Stripper System Schematic
• In 1988, the original pall ring
packing was replaced with
cascade mini-rings to provide
more surface area and less
pressure drop across the system.
• In 1990, system in flow was
upgraded from 400 gpm to 510
gpm.
• Drawing not to scale.
To
atmosphere
Groundwater
From
Extraction
Wells
Demister
4.5 ft diameter
304ctainless
steel tower
T
•>j
3
1
Propytene
Packing
(3000 cfrrKlesign)
Treated
Groundwater
To
Outfall
A-014
Extraction We/I Close-Up
Key Monitored Operating Parameters
Typical Extraction Well
(Well Shown is #4)
Depth
ro
>-40
•80
•120
160
•200
Surface
Concrete
Pad
Surface
Neat
Cement
Grout
1 V4- PVC
Riser Pipe
2- Stainleu
Steel Pipe
Fine Sand
Cap
8" Steel
Casing
15' Borehole
8" Stainless
Steel Screen
5 HP Stainless Steel
Submersible
Pump
Graded Gravel
Pack
Stainless
Steel Sump
(to assess system operation)
• Water flows
• Airflows
• Pump discharge pressures
• Groundwater levels
(to assess zone of capture)
• Contaminant concentrations in treatment plant influent
& effluent
(to assess treatment effectiveness)
• Contaminant concentrations in groundwatar
(to assess achievement of remediation goals)
U.S. Department of Energy
178
-------
> Savannah River - Page 6 of 12 —
PERFORMANCE
Performance Objectives
• Achievement of Groundwater Protection Standards (GWPS) established as part of a RCRA
permit for the M-Area. The GWPS are based on EPA's Maximum Contaminant Levels (MCLs) of
5 ppb for TCE and PCE and 200 ppb for TCA.
• Prevent migration of contaminated groundwater toward the Savannah River Site boundary and
downward into the confined aquifer (Black Creek Formation).
• Achieve cleanup goals within 30 years.
The overall long-term environmental restoration strategy for the A/M-Areas involves an integrated
approach containing three major elements. Only the larger A/M air stripping effort is fully detailed in
this analysis:
h^
• Operation of pump-and-treat systems to hydraulically contain contaminant plumes and remove
contaminant mass from groundwater.
One 600 GPM capacity air stripper treats an average water flow of 510 GPM drawn from 11 extraction wells
throughout the A/M area; a second stripper treating an average of 55 GPM from 1 extraction well near the
Savannah River Laboratory in the A-Area.
• Further characterization of nature and extent of contamination with increasing focus on dense
nonaqueous phase liquid (DNAPL) contamination.
The use of minimally invasive techniques, such as the cone penetrometer and geophysical techniques, are
currently recommended for future use to fully characterize the extent of DNAPL contamination.
• Development, demonstration and implementation of technologies to supplement pump-and-
treat efforts with increasing focus on source area, DNAPL and vadose zone remediation.
So/7 vapor extraction, in situ air stripping, in situ heating, and surfactant flushing techniques are in various stages
of implementation or demonstration.
Initial Process Optimization Efforts
Air stripper viability was tested through a succession of field programs:
Pilot Air Stripper
Constructed and operated for
24 months beginning in 1983;
34 ft high; 20 GPM capacity;
removed 16,100 IDS VOCs.
Prototype Air Stripper
Stainless steel construction;
operated for 14 months; 46 ft
high; 50 GPM capacity;
removed 15,800 Ibs of VOCs.
Full Scale
Production Air Stripper
Stainless steel construction;
70 ft high, 610 GPM design
capacity; removed 270,000 IDS of
VOCs since startup in 0/85.
Operational Performance •
|— System Throughput
• For 1993,243 million gallons of groundwater were
pumped from 11 recovery wells to the production air
stripper.
• Average water flow rate was 479 GPM and average air
flow rate was 2,489 cfm through the air stripper during
1993.
• 19,500 Ibs of VOCs were removed in 1993 which
produced an average air emission rate of 2 fbs/hr.
r- System Downtime
• Average utility for 1993 was 96.4%. Cumulative average
utility since 1985 is 95.3%.
• 1993 experienced 316 hours of downtime.
• Causes of downtime included scheduled maintenance,
operator training, power outages, and equipment repair.
U.S. Department of Energy
179
-------
' Savannah River - Page 7 of 12 —
Hydrodynam/c Performance
• Current estimates of the 30 year zone of capture of the pump and treat system have determined that portions of
the existing plume will not be effectively controlled. Contaminated groundwater beneath the Savannah River
Laboratory and southeast of the settling basin are beyond the anticipated capture zone. However, contaminated
groundwater in the source areas and areas of highest VOC concentration is contained.
• The downward gradient across the Crouch Branch Confining Unit, and consequently the driving force for downward
contaminant migration to the confined aquifer in the Crouch Branch Aquifer, has been reduced due to pumping
effects.
• The groundwater recovery wells are screened in the more permeable areas of the shallow aquifer which increase
hydraulic control yet limits access to silt and clay layers where retention of contaminants may be strongest.
Treatment Performance
r- Effects on Plume •
• Reductions in contaminant plume size and concentration as a result of remediation are evident (the >100,000 ppb
contaminant concentration zone has disappeared) but are generally limited to areas near recovery wells.
• Significant progress is evident in the Lost Lake Aquifer where initial contaminant concentration and hydraulic
conductivity are highest.
• Downward migration of VOCs to the Crouch Branch Aquifer beneath the settling basin and north of the M-Area is
evident. VOC concentrations have increased slightly in the confined aquifer since 1985.
- iv,e b rt.c vb nine di iiinuuiii
• The concentration of TCE in extracted groundwater x<:ao
has varied widely over short (one year) time frames 5"
for individual wells. Some wells have shown short •= """"•
term increases in contaminant concentration, some J 20000
decreases and others no clear trend. £ 15000
• The trends may indicate plume redistribution and g 1000°
may also represent a decline in plume strength. o sooo
• There has been a clear reduction in overall ^^* \
contaminant concentrations sent to the air stripper. "^
Influent Concentrations to Air Stripper
I
i
— -|
^
1
s
- — <
1
^
^=H
1 1
— H
L
^-H
— =^
1 1
I=J
^-1
=5
15 'SB "67 '88 '89 90 91 92 'K
Year
Legend
-»TCE
-*-PCE
J
- Air Stripper Influent vs Effluent
• Average VOC removal efficiency >99.9%
• All VOCs treated below discharge criteria.
Average Concentration'[ppb]
Compound Influent Effluent
TCE
PCE
Total
15,006
6,705
21,711
'data from September 1985-1993
•Total Pounds VOCs Removed
50-1
•ST 40-
=• 30-
£ 20-
Historical
Total*:
273,300 IDS
•85 «6 "87 "88 '89 90 91 '92 *93
'based on data from Sept 1985 through end of 1993
U.S. Department of Energy
180
-------
Savannah River - Page 8 of 12 —
COST
J
• The production air stripper was designed and constructed in 1984-1985. The major capital
cost elements associated are provided below. Annual operating costs based upon data from
1985 through 1990 are also listed. All information is based on an analysis performed in 1990
and all costs are in 1990 dollars.
• During 1985 to 1990, the average volume of water treated by the air stripper was 198 million
gallons per year. Using the operating costs detailed below (in 1990 dollars), the total cost of
operation and maintenance is $0.75 per 1000 gallons treated.
• An assessment of total cost and duration of operation for the pump and treat system to
complete the cleanup is not possible due to the multi-phased approach to environmental
restoration of the A/M Area. As detailed on page 6, the overall treatment plan for the site
includes future identification and implementation of technologies to achieve cleanup goals. The
extent to which the pump and treat system will be part of that effort has not yet been
determined therefore projected costs to cleanup can not be estimated.
Capital Costs
Design $420,000
Contracts (permitting, modeling, etc.) 368,000
Site Development 28,000
QA Engineering 18,000
Control Building 211,000
Electrical 877,000
Instrumentation 466,000
Piping/Construction 925,000
Tower Installation 132,000
Control System 230,000
Erect/Test Tower 428,000
Total $4,103,000
• Operating Costs
Electrical Power (@ $0.052/kwh) $26,000
Maintenance
Labor (@ $35/hr) 13,500
Equipment repair & replacement 13,000
Operation
Operation & daily inspections 45,700
Well sampling & lab analysis 15,000
Engineering support 36,000
Total Annual Operating Cost $149,200
U.S. Department of Energy
181
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' Savannah River - Page 9 of 12 —
REGULATORY/INSTITUTIONAL ISSUES
• The production air stripper is part of the M-Area Hazardous Waste Management Facility which is permitted under
the Resource Conservation and Recovery Act (RCRA). The air stripper unit is permitted as a waste water
treatment facility requiring South Carolina certified Class-D physical/chemical operators. The air stripper unit is not
regulated as a RCRA treatment, storage, disposal (TSD) facility.
• The air stripper has a South Carolina Bureau of Air Quality Control permit allowing the release of 34 tons/year (or
7.9 Ibs/hr) of VOCs to the atmosphere.
• Recent Clean Air Act requirements mandate that industrial off gas systems be retrofitted with an off-gas treatment
system. Catalytic oxidation has been demonstrated as an effective off-gas treatment and the M-Area air stripper is
being retrofitted. The system will be installed by 1995, even though regulations for mitigation will not require retrofit
until 2000.
• Treated water effluent from the stripper is released through an National Pollution Discharge Elimination System
(NPDES) permitted outfall. The EPA Maximum Contaminant Levels (MCLs) listed under "Cleanup Criteria" below
apply to this discharge.
• The facility's RCRA Part B permit requires periodic sampling at the recovery wells, air stripper and NPDES outfall.
• Eight production wells drawing from the Crouch Branch Confined Aquifer currently supply process and drinking
water for A/M-Area Site operations.
— Cleanup Criteria
• During initial remediation efforts in 1985, a cleanup goal of removal of 99% of VOCs over a 30 year
period was used. A CERCLA baseline risk assessment was not developed or required.
• In 1990, groundwater protection standards based upon EPA MCLs were adopted during
modifications of the facility's RCRA permit. The standards are:
Compound
TCE
PCE
TCA
Criteria Level foobl
5
5
200
SCHEDULE
A/M-Area Remediation Milestones
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
J
U.S. Department of Energy
182
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—•—•—. I. . i Savannah River - Page 10 of 12 —
LESSONS LEARNED HBHKHgs&sragiSJg^B^j^piii^"^ '" i
Implementation Considerations
• An integrated treatment program consisting of pump and treat for hydraulic control and dissolved
plume mass removal combined with source/DNAPL targeted technologies has been determined to be
the most effective long term remedial solution for the M-Area VOC plume at Savannah River.
• Technologies to supplement the pump and treat systems are in various stages of development,
demonstration or implementation. These technologies focus on either the source area, DNAPL or
vadose zone contamination and include soil vapor extraction, in situ air stripping, in situ bioremediation,
in situ heating and surfactant flushing.
• There is a recognized need for supplemental site characterization efforts to redirect ongoing
remediation activities at the site. Further characterization will focus on ONAPL contamination and will
involve minimally invasive methods such as the cone penetrometer and geophysical techniques.
• Significant volumes of VOC-contaminated purge water are generated from sampling the extensive
network of over 250 monitoring and compliance wells. Modifications to the air stripping system were
implemented to treat this groundwater. The system changes include addition of a 10,000 gallon carbon
steel receiving tank and associated piping.
Technology Limitations
• The presence of DNAPLs represents a significant long-term limitation to pump and treat due to
residual DNAPL above and below the water table combined with mass removal limitations.
• Hydraulic factors, combined with the nature of contaminants, has inhibited the pump and treat
system's ability to affect the fringes of the plume. However, the contaminated groundwater in the
source areas and areas of highest VOC concentration is contained.
• Pump and treat is effective for plume restoration only where DNAPL source areas have been
contained or removed.
Future Technology Selection Considerations
• Early M-Area remediation efforts did not address the long term prospect of removing residual levels of
contamination. Future cleanups at sites with chlorinated solvents must carefully look for DNAPL during
site characterization and address DNAPL and residual contamination removal as part of an overall
remediation plan.
• The original aim of the pump and treat system in the M-area was for broad plume containment and
destruction of 99% of the VOCs. This goal was later changed to achievement of EPA MCL based
groundwater protection standards. Future pump and treat systems should consider the actual
environmental and human risks, be highly designed, and address realistic elements of overall cleanup
goafs.
• Pump and treat for containment of dissolved contaminants is a viable tool for dissolved phase VOC
removal and can be an element of presumptive remedies for such sites.
• A phased approach to site assessment and remediation is beneficial. Early actions to control plume
migration and remove contaminant sources, when properly designed and implemented, can reduce
risks posed by contaminated groundwater.
U.S. Department of Energy
183
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> Savannah River- Page 11 of 12 m
ANALYSIS PREPARATION
This analysis was prepared by:
Stone & Webster Environmental
Technology & Services
245 Summer Street
Boston, MA 02210
Contact: Bruno Brodfeld (617)589-2767
Assistance was provided by the
WESTINGHOUSE SAVANNAH RIVER COMPANY
which supplied key information and reviewed report drafts.
HAZARDOUS WASTE REMEDIAL ACTIONS PROGRAM
Environmental Restoration and Waste Management Programs
Oak Ridge, Tennessee 37831-7606
managed by
MARTIN MARIETTA ENERGY SYSTEMS
for the
U.S. Department of Energy
under Contract DE-AC05-84OR-21400
This analysis was funded by:
U.S. Air Force
Headquarters USAF/CEVR
CERTIFICATION
This analysis accurately reflects the performance and costs of the remediation:
CX. Bergren
Westinghouse Savannah River Company
Environmental Restoration Department
Manager Northern Ground Water Facilities
G.E. Turner
Department of Energy
Savannah River Operations Office
Environmental Restoration Division
Environmental Specialist
U.S. Department of Energy
184
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Savannah River - Page 12 of 12~
SOURCES
Major Sources For Each Section
Site Characteristics:
Treatment System:
Performance:
Cost:
Source #s (from list below) 5,7.8 and 9
Source #s 5,6 and 7
Source #s 1,2,3,5 and 7
Source #5
Regulatory/Institutional Issues: Source # 5
Schedule: Source #s 1,5, and 7
Lessons Learned: Source #s 1,3, and 4.
Chronological List of Sources and Additional References
1. Personal communications with J.E. Jordan, Westinghouse Savannah River Company, April 1994.
2. Corrective Action System Operation and Performance (Draft), Fourth Quarter 1993 and 1993 Summary, WSRC-RP-93-67-4,
February 1994.
3. Savannah River Site DNAPL Technical Program Plan, J.E. Jordan, et.al., Westinghouse Savannah River Company, February
1994.
4. Guidance for Evaluating the Technical Impracticability of Ground-Water Restoration, Interim Final, U.S. EPA, September 1993.
5. McWIlip, ST., K.L Sibley and J.G. Horvath, Air Stripping of Volatile Organics Chlorocarbons: System Development,
Performance, and Lessons Learned, Proceedings of Waste Managment '90, Roy Post, editor, 1990.
6. Well logs for recovery wells (undated).
7. Evaluation of Ground-water Extraction Remedies: Phase II EPA Publication 9355.4-05A, February 1992.
8. Evaluation of Ground-water Extraction Remedies, EPA/540/2-89-054, September 1989.
9. Preliminary Technical Data Summary M-Area Groundwater Cleanup Facility, DuPont - Savannah River Laboratory, October
U.S. Department of Energy
185
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In Situ Air Stripping of Contaminated Groundwater at
U.S. Department of Energy, Savannah River Site
Aiken, South Carolina
186
-------
Case Study Abstract
In Situ Air Stripping of Contaminated Groundwater at
U.S. Department of Energy, Savannah River Site
Aiken, South Carolina
Site Name:
U.S. Department of Energy (DOE),
Savannah River Site M Area, Process
Sewer/Integrated Demonstration Site
Location:
Aiken, South Carolina
Contaminants:
Chlorinated Aliphatics
- Trichloroethene (TCE), Tetrachloroethene
(PCE), 1,1,1-Trichloroethane (TCA)
- Concentrations of volatile organic
compounds (VOCs) in groundwater reported
as high as 1800 ug/L
- Groundwater TCE concentrations over
48 ppm
- Groundwater contains 260,000-450,000
pounds of dissolved organic solvents in
concentrations greater than 0.01 ppm,
estimated to be 75% TCE
- Soil TCE concentrations over 10,000 ug/L
(1991)
- Dense nonaqueous phase liquids (DNAPLs)
are present in groundwater
Period of Operation:
July 1990 to September 1993
Cleanup Type:
Field Demonstration
Technical Information:
Brian Looney, Principal Investigator,
Westinghouse Savannah River
Company (WSRC), (803) 725-3692
Carol A. Eddy Dilek, WSRC (803)
725-2418
Kurt Gerdes, DOE EM-50, (301)
903-7289
Dawn Kaback, Colorado Center for
Environmental Management, (303)
297-0180, ext. Ill
SIC Code:
9711 (National Security)
3355 (Aluminum forming)
3471 (Metal finishing)
Technology:
In Situ Air Stripping
- 7 horizontal wells installed; only 2 wells
used in field demonstration
- Demonstration wells: 1 installed in saturated
zone; 1 installed in vadose zone; targeted
contaminated sands
- Air injected through lower horizontal well,
below the water table
- Demonstration focused on supplementing
pump and treat efforts
- Demonstration did not include offgas
treatment
Cleanup Authority:
RCRA Corrective Action and
State: South Carolina Dept. of
Health and Environmental
Control, Air Quality Control, and
Underground Injection Control
Licensing Information:
Caroline Teelon
Tech Transfer Office, WSRC
P.O. Box 616, Building 77341A
Aiken, SC 29803
(803) 725-5540
Waste Source:
Surface Impoundment
Type/Quantity of Media Treated:
Groundwater and Soil
- Area of VOC-contaminated groundwater has an approximate thickness of 150 feet
and covers about 1,200 acres
- Aquifer units characterized to 180 feet below ground surface (9 separate units),
showing complex hydrogeology and discontinuous sand and clay layers
Purpose/Significance of Application:
Field demonstration of in situ air stripping using horizontal wells to supplement groundwater pump and treat technology.
187
-------
Case Study Abstract
In Situ Air Stripping of Contaminated Groundwater at
U.S. Department of Energy, Savannah River Site
Aiken, South Carolina (Continued)
Regulatory Requirements/Cleanup Goals:
- RCRA permit for M Area includes the following Groundwater Protection Standards: TCE 5 ppb, PCE 5 ppb, and TCA
200 ppb
- Demonstrations permitted by the South Carolina Department of Health and Environmental Control (SCDHEC) Air Quality
Control (AQC) and Underground Injection Control (UIC)
Results:
- Substantial changes in groundwater VOC concentrations measured during demonstration
- Increased microbial numbers and metabolic activity exhibited during air injection period
- 139 day demonstration (July-December 1990) removed nearly 16,000 pounds of VOCs
- Vacuum extraction removed an estimated 109 Ibs VOC/day while air injection resulted in an additional 20 Ibs/day VOC
removal
Cost Factors:
- Costs for conducting field demonstration not provided
Cost study for in situ air stripping provided the following projected costs:
- Total equipment costs - $253,525 (including design and engineering, well installation, air injection and extraction system,
piping, and electrical)
- Site costs - $5,000 (setup and level area)
- Total Annual Labor Costs - $62,620 (including mobilization/demobilization, monitoring, and maintenance)
- Total Annual Consumable Costs $157,761 (including carbon recharge, fuel, and chemical additives)
Description:
At the U.S. Department of Energy Savannah River Site, aluminum forming and metal finishing operations have been
performed within the "M" area. An estimated 3.5 million pounds of solvents were discharged from these operations between
1958 and 1985, with over 2 million pounds sent to an unlined settling basin. Groundwater contamination beneath the
settling basin was discovered in 1981. A pump and treat program has been ongoing since 1985 for removal of VOCs from
the groundwater.
A field demonstration using in situ air stripping with horizontal wells in the M Area was conducted from July 1990 to
September 1993. The demonstration was part of a program at Savannah River to investigate the use of several technologies
to enhance the pump and treat system. In the air stripping demonstration, air was injected into a lower horizontal well in the
saturated zone and extracted through the horizontal well in the vadose zone. The demonstration did not include treatment of
offgases. The in situ air stripping process increased VOC removal over conventional vacuum extraction from 109 pounds
per day to 129 pounds per day. Nearly 16,000 pounds of VOCs were removed during the 139 day demonstration period.
A cost analysis performed as part of this demonstration showed that in situ air stripping would reduce costs by 40% over a
conventional pump and treat with soil vapor extraction system. Installation costs for horizontal wells is greater than for
vertical wells. At depths greater than 40 to 50 ft, horizontal well installation costs are approximately $200/ft; at less than 40
to 50 ft, costs are as low as $50/ft. Several implementation concerns were identified for installing horizontal wells at
Savannah River.
188
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SECTION 1
SUMMARY
Technology Description E
In Situ Air Stripping (ISAS) technology was developed to remediate soils and ground water contaminated with volatile
organic compounds (VOCs) both above and below the water table. ISAS employs horizontal wells to inject (sparge)
air into the ground water and vacuum extract VOCs from vadose zone soils. The innovation is creation of a system
that combines two somewhat innovative technologies, air sparging and horizontal wells, with a baseline technology,
soil vapor extraction, to produce a more efficient in situ remediation system.
• The horizontal wells provide a more effective access to the subsurface contamination
• The air sparging process eliminates the need for surface ground water treatment systems and
treats the subsurface in situ, directly attacking the problem of subsurface contaminant retention.
The types of sites most likely to apply ISAS will contain permeable, relatively homogeneous sediments contaminated
With VOCs. Injection Well
., Extraction Well
Surface
(figure modified from Reference 6)
Technology Status
A full-scale demonstration was conducted as part of the Savannah River
Integrated Demonstration VOCs in Nonarid Soils and Ground Water at:
U.S. Department of Energy
Savannah River Site
M Area Process Sewer/Integrated Demonstration Site
Aiken, South Carolina
July to December 1990
The demonstration site was located at one of the source areas within the one-square mile VOC ground water plume.
Prior to application of ISAS, 1,1,2-trichloroethylene (TCE) and tetrachloroethylene (PCE) concentrations in ground
water ranged from 500 to 1800 ug/L and 85 to 184 ug/L, respectively. TCE and PCE concentrations in sediments
ranged from 1.26 to 16.32 mg/kg and 0.03 to 8.75, mg/kg, respectively. The site is underlain by a thick section of •
relatively permeable sands with thin lenses of clayey sediments. Appendix A describes the site in detail.
Key results included:
• Removal of nearly 16,000 Ibs VOCs over a 139-day period. The daily removal rate from the upper horizontal well
was equal to the eleven-well pump and treat system operating to contain the central portion of the plume that
surrounds the demonstration site.
• Final TCE and PCE concentrations in ground water ranging from 10 to 1031 ug/L and 3 to 124 ug/L
respectively. Final concentrations in sediments ranged from 0.67 to 6.29 mg/kg and 0.44 to 1.05 mg/kg,
respectively.
• Completion of a cost-benefit analysis performed by Los Alamos National Laboratory showed that ISAS could
reduce costs 40% over a baseline pump-and-treat/soil vapor extraction system.
The ISAS process is patented by the Department of Energy and has been licensed to eight commercial vendors with
eleven additional license applications under review. Licenses are available through the Westinghouse Savannah
River Company (WSRC). ISAS has been implemented at commercial sites in Minnesota, Missouri, North Carolina and
New York. Many other sites plan to implement the technology in the next year.
Page 1
U.S. Department of Energy
189
-------
SUMMARY
continued
Contacts
Technical
Brian Looney, Principal Investigator, Westinghouse Savannah River Company (WSRC), (803) 725-3692
Carol A. Eddy Dilek, Characterization, WSRC, (803) 725-2418
Dawn Kaback, Horizontal Drilling, Colorado Center for Environmental Management, (303) 297-0180, ext. 111
Management
Kurt Gerdes, DOE EM-50, DOE Integrated Demonstration Program Manager, (301)903-7289
Jim Wright, DOE Plumes Focus Area Implementation Team Manager, (803) 725-5608
Licensing Information
Caroline Teelon, Technology Transfer Office, WSRC, (803) 725-5540
D
Page 2
U.S. Department of Energy 190
-------
SECTION 2
TECHNOLOGY DESCRIPTION
Overall Process Schematic
Injection Well
Extraction Well
Surface
Contaminated
Clay Lens
Contaminated
Zone
• Air injected through lower
horizontal well, below the water table.
• Air/contaminant mixture extracted
from upper horizontal well, above
water table.
• Off-gas treatment available for
long-term remedial operation, but not
used for the demonstration
described.
(figure modified from Reference 6)
Appendix B provides detailed information about the horizontal well installations and the monitoring wells installed.
Aboveground Systems
Air Injection
Reservoir
Tank
Oil
Separator
Air-
Compressor
200 SCFM Air
Injection Manual
Control
Injection Pport for
Nnutrients and Additives
(not used in ISAS
demonstration)
• Flow Indicator
• Pressure
Sensor
Static Mixer
Pressure
Sensor
Mufti-level
Sample
System
I nji
Horij
Injection to
izontal Well
Extraction & Offgas Treatment
Dilution Air
Temperature
Pressure &
Flow Indicators
Water
Trap*
Rotary Positive
Oislacement
Blower
240 SCFM;
-iquid 0.7" Hg vacuum
Effluent
(to M-Area
Air Stripper)
Extraction from
Horizontal Wells
Discharge
to Atmosphere
Treatment
System"
Notes:
* Water trap removes debris and moisture from airstream. System includes a daytank to drain water
from separator for ultimate treatment at M-Area air stripper.
" Demonstration released VOCs directly to the atmosphere. Offgas treatment may be required for
long-term remediation.
Pages
U.S. Department of Energy
191
-------
SECTION 3
PERFORMANCE
Demonstration Plan
Performance of the technology has been assessed using information from the full-scale demonstration at SRS.
Major elements of the demonstration included:
• initial vacuum extraction of vadose zone gases;
• addition of air sparging (simultaneous air injection into the saturated zone and extraction from the vadose
zone) at low, medium, and high air injection rates;
• evaluation of temperature effects through heating of injected air;
• assessment of subsurface microbial activity; and
• assessment of the behavior of injected air through a 24-hour inert tracer (helium) test.
Key system parameters are explained on page 6. Appendix C describes the demonstration schedule, sampling and
analysis to support performance monitoring, and the overall A/M Area cleanup program.
Treatment Performance
Amount of VOCs Removed
16,000
12,000
8,000
4,000
o
139 days
50
Days
150
• Nearly 16,000 Ibs of VOCs removed during
the 139-day demonstration.
• Soil vapor extraction (without air injection)
removed contaminants at a rate of 109 Ibs/day.
• Combined injection and extraction increased
the removal rate to 130 Ibs/day.
(figure modified from Reference 11)
In Situ Air Stripping VOC Extraction Rates
I
1
8
100
100
Days
150
• Contaminant removal rate ranged between
100 and 140 Ibs/day over most of the 139 days.
• Vacuum extraction removed an estimated
109 Ibs/day (day s 1 -16 and 113-139) while air
injection removed an additional 20 Ibs/day
(days 16-113).
(figure modified from Reference 11)
Page 4
U.S. Department of Energy
192
-------
PERFORMANCE
(continued
Treatment Performance (continued)
Pre- and Post-Demonstration Ground Water Data: TCE Concentrations
Well #2
I— Legend
All concentrations
are ug/L TCE
858'
817-
453-
386'
• ug/L TCE on Day 11 - Initial conditions/vacuum only
• ug/L TCE on Day 28 - End of low air injection rate
• ug/L TCE on Day 39 - After medium injection rate for 11 days
• ug/L TCE on Day 144 - Final conditions
Ground Water Monitoring Well
na=not available
• Similar reductions in PCE concentrations were observed: initial concentrations of 85 mg/L to 184 mg/L were lowered
to3mg/Lto 124 mg/L.
• Two hypotheses are being examined to explain increases in VOC concentrations near the far ends of the horizontal
wells:
1) upward migration of contaminants caused by the injection of air below the monitoring well screen, and
2) slight pressurization of the vadose zone between the water table and a zone of clays resulting in
downward migration from the water table to the depth of the screen being measured.
Page 5 _
U.S. Department of Energy
193
-------
PERFORMANCE
continued
Treatment Performance (continued)
Pre- and Post-Demonstration Sediment Data
TCE concentrations in sediments before ISAS
200 -
"8750
site coordinates in ft
The sediment data are known to underestimate the VOCs at the demonstration site, but can be used to
develop a sense of relative amounts of contamination removed during the demonstration.
TCE concentrations in sediments after ISAS
320
280
200
Comparison of the pretest and post-test results suggest that 57% of the solvents were removed from
the modeled volume during the five-month long demonstration.
U.S. Department of Energy
194
PageB
-------
PERFORMANCE
continued
Key System Parameters
Vacuum Applied
• Vacuum extraction from Well #2 in the vadose zone ranged from 550 to 600 scfm at 10 to 11 in of Hg.
Temperature Effects
• Heating of injected air up to 147°F had no measurable effect on system performance or on the temperature of
extracted gas, which was relatively constant at 60°F.
Injection Pressure Effects
• Air injection was varied at low (65 scfm), medium
(170 scfm), and high (270 scfm) rates during the
demonstration.
• The effects of increasing injection pressure did not
produce a linear increase in extracted VOCs as shown.
Operating at lower flow rates may offer substantial cost
savings without a major impact on performance.
50
Microbial Activity
100 150 200 250
Air Injection rate (scfm)
300
» Air injection significantly increased the biomass of microbes and their metabolic activity (2 to 3 orders of
magnitude), especially at those wells where the greatest stripping effect was seen.
• Post-demonstration sediment data indicate that almost all contaminants in sediment in the vadose zone were
removed primarily by microbial activity during later phases of demontration.
Results of Helium Tracer Test
• Helium was injected into the saturated zone horizontal
well (Well #1) over a 24-hour period to determine:
• the extent injected air was reaching extraction
wells and
• the extent injected air was escaping through
monitoring wells.
• Results confirmed significant "communication" between
injection and extraction wells with approximately 45% of
injected helium recovered over nearly a 7-week period as
shown at right. Injected air appeared to disperse
throughout subsurface heterogeneities
• Losses through monitoring wells were estimated at less
than 5% of the total injected air flow.
100
90
f so
o
5 70
a.
5°
30
20
10
0
-50 5 10 15 20 25 30 35 40 45 50
Elapsed Time Following Initiation of Helium Pulse (days)
Zones of Influence
• The vacuum well in the vadose zone created a zone of influence estimated at greater than 200 ft based upon
pressure measurements.
• Electrical resistance tomography (ERT), electromagnetic tomography (EMT) and seismic tomography were
used to map a sparge zone of influence in the saturated zone approximately 40 to 60 ft wide (20 to 30 ft on either
side of Well #1).
Page 7
U.S. Department of Energy
195
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SECTION 4
TECHNOLOGY APPLICABILITY & ALTERNATIVES
Technology Applicability
• ISAS has been demonstrated to remediate soils, sediments and groundwater contaminated with VOCs
both above and below the water table.
• The geometry of horizontal well treatment conforms to typical subsurface contaminated zones, which are
often relatively thin but laterally extensive areas.
• Quantitative modeling and bench- and pilot-scale work indicate that ISAS would be effective at removing
light nonaqueous phase liquids (LNAPLs). It is not suitable for dense nonaqueous phase liquids (DNAPLs).
• ISAS is not well suited for sites with highly stratified soils with low permeability layers, fractured rock or clay
geologies. ISAS does not effectively remediate large dilute plumes but would be useful near source areas.
• Similar to pump-and-treat, ISAS may not be able to reach drinking water standards (without enhancements
such as addition of nutrients to promote biodegradation).
• Commercialization and intellectual property information is included in Appendix D.
I Competing Technologies (
• ISAS competes with conventional baseline
technologies of pump-and-treat and pump-and-treat
combined with soil vapor extraction (SVE).
Numerous other thermal, physical/chemical, and
biological technologies are also either available or
under development to treat VOC-contaminated soils
and ground water either in situ or aboveground.
• The effectiveness of ISAS was compared with
performance data from application of pump-and-treat
and SVE at SRS (Reference 9) as shown as right.
Extrapolation of these data was the basis of the Los
Alamos cost analysis discussed in Section 5.
• Vertical well air sparging and in well recirculation
technologies have been implemented at a number of
sites across the US and Europe.
T3
C
I
o
0)
-------
SECTION 5
COST
I Introduction
A cost study (Reference 9) was conducted by researchers from Los Alamos National Laboratory that
compared in situ air stripping with horizontal wells against the conventional cleanup technologies of combined
pump and treat and soil vapor extraction. Detailed capital and operating costs taken from the study for the
ISAS application are presented below. Cost breakdown analyses and comparative assessments of ISAS
cost versus those of conventional technologies are included in the sections that follow. Critical assumptions
relevant to the quality of the cost data are included within each section.
I Capital and Operating Costs
The Los Alamos study presented these costs as representative of the actual costs of demonstration (with the
exception of offgas treatment as indicated below under "Notes"):
Equipment Costs
Design and engineering (100 hrs
e $50/hr) $5,000
Mobile Equipment (pickup truck) 15,000
Capital: Well installation (subcontracted)
Air injection well (165 ft deep, 300 ft long) 93,323
Air extraction well (75 ft deep, 175 ft long) 76,762
Subtotal: Well installation 170,085
Other Equipment
Air injection system (300 cfm blower) 3,500
Air extraction system (eoo cfm blower) 5,000
Vapor air separator (1 @eoo cfm) 2,750
Carbon adsorption unit (2@eoocfm
canister) 10,000
Duct heater (2,000 btu propane fired) 3,250
Water treatment unit (12 gpn
recirculation unit) 4,000
Monitoring equipment 17,000
Temporary storage (metal shed) 1,500
Portable generator (25 kva) 3,500
Fuel Storage (fuel oil and propane) 1,500
Piping and installation (10% of
equipment cost) 5,200
Electrical (12% of equipment cost) 6,240
Subtotal: Other Equipment 63,440
Total Equipment Costs $253,525
Site Costs
Site Costs (set up and level area) $5,000
Total Site Costs $5,000
Labor Cost
Mobilize/demobilize (based on 200 hrs
set up & tear down)
Technician --2 12,000
Laborers--2 10,000
Oversight engineer --1 12,000
Per diem 3,600
Monitoring/maintenance crew (139
days @ 2 hrs/day)
Technician --1 8,340
Oversight engineer -1 16,680
Total Annual Labor Costs $62,620
Consumable Costs
Carbon recharge (2.23 ib carbon/ib voc) 101,688
Fuel oil - diesel @ 10 gph 35,362
Lubricants 6,950
Deionized water 3,336
Chemical additives 6,950
Maintenance supplies 3,475
Total Annual Consumable Costs $157,761
Notes:
1. Consumable supplies: Recycled carbon, $2.85/lb.; Diesel fuel, $1.06/gal; Lubricants, $50/day; Deionized
water, $0.10/gal; Chemical additives, $50/day; Maintenance supplies, $25/day.
2. Offgas treatment costs assume conventional carbon adsorption. Demonstration did not
include offgas treatment.
Page 9
U.S. Department of Energy
197
-------
COST
continued
I Cost Breakdown Analysis
• The Los Alamos study developed a
breakdown of ISAS costs per pound of VOC
removed during the 139 day demonstration
period by annualizing capital costs over an
estimated 10-year equipment life. Carbon
adsorption was included for offgas treatment.
However, more cost-effective offgas treatment
systems might be applicable and could reduce
annual costs substantially.
Cost/Lb of VOC Removed
28.6% Other Consumable:
Equipment
Site
Labor
Consumables
$1.51
$0.31
$3.91
$9.86
0.2% Site Costs
6.6% Well Installation
3.2% Equipment
4.6% Mobilization
,4.9% Monitoring/Maintenance
51.9% Carbon Recharge
Total $15.59
Cost Considerations for Future Applications
Cost Sensitivities
• Horizontal well installation costs are quite variable, depending upon depth of installation, site geology, site specific
institutional requirements, well design, well materials, etc.
t At depths greater than 40 to 50 ft, river crossing techniques are normally used at costs of approximately
$200/ft.
^ At depths less than 40 to 50 ft, the utility industry compaction or smaller river crossing rigs can be used at
costs as low as $50/ft.
• Horizontal well installation costs have steadily decreased in recent years due to technical improvements and
increased experience of drilling companies.
Horizontal Well Costs Versus Vertical Well Costs
• Promotional literature from horizontal well service providers show that, depending upon plume geometry and site
characteristics, one horizontal well can replace five to fifty vertical wells. One hypothetical project cost comparison
(Reference 5) illustrated that one horizontal well could accomplish the same containment/remediation objectives as
ten vertical wells at a cost savings of nearly 80%. The higher individual capital cost of a horizontal well was offset in
this case by the large number of vertical wells replaced and their larger associated costs for surface equipment,
operations and maintenance.
• A horizontal well case study at a Department of Defense site predicted one horizontal well to replace 80 vertical wells.
Page 10
U.S. Department of Energy
198
-------
COST
continued
Cost Considerations for Future Applications (continued)
Cost Savings Versus Alternative Technologies
The Los Alamos study evaluated the demonstrated cost of ISAS versus the combined cost of pump-and-treat
with soil vapor extraction. The cost and removal rates of the ISAS system were extrapolated from data from the
demonstration and compared to data from the in place baseline technology at SRS. All systems were normalized
to remediate equivalent zones of contamination. ISAS Cases 1, 2 and 3 represent different assumed VOC
extraction rates over 5 years of operation. The VOC extraction rates assumed are detailed in the table at the
bottom of the page. Costs over a 5 year life cycle were:
$3,000,000-1
3
e.
c
over 1 39 days
115
86
57
57
57
86
57
57
57
57
57
57
57
57
57
Pump-and-Treat
and SVE
Pump-and-Treat:
2700 Ibs
over 114 days
23
17
11
11
11
SVE:
7480 Ibs
over 21 days
80
60
40
40
40
* VOC extraction rates taken from the results of short-term application at SRS
** Projected VOC extraction rates for five years of operation. ISAS Cases 1, 2 and 3 represent increasingly conservative
estimates of ISAS performance over longer periods.
Page 11
U.S. Department of Energy
199
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SECTION 6
REGULATORY/POLICY REQUIREMENTS & ISSUES
Regulatory Considerations I
• Permit requirements for the demonstration conducted in 1990 were controlled by the South Carolina Department
of Health and Environmental Control (SCDHEC) and included an Air Quality Control (AQC) permit waiver and an
Underground Injection Control (DIG) permit issued by the South Carolina Board of Drinking Water Protection.
• Permit requirements for future applications of ISAS are expected to include an air permit for discharge of treated
vapor extracted from the subsurface. For applications in some states, underground injection permits may be
required for air injection. Some federal projects may also require a National Environmental Policy Act (NEPA)
review.
• Groundwater Protection Standards (GWPS) have been established as part of a RCRA permit for the M-Area. The
GWPS' are based upon EPA Maximum Contaminant Levels (MCLs). Specific goals for contaminants of greater
concern are:
Compound Concentration [ppbl
TCE
PCE
TCA
5
5
200
• For application of ISAS as a remedial activity at the M-Area HWMF, the RCRA Part B Permit must be reviewed to
determine if a permit modification is necessary. Offgas treatment is expected to be required for full-scale
remediation at SRS.
• The ISAS system experienced no regulatory compliance problems during demonstration at SRS nor are any future
regulatory changes anticipated to pose compliance obstacles. ISAS has been subsequently approved by regulators
for use at additional sites both at SRS and in other states, including New York, Minnesota, Missouri, and North
Carolina.
Safety, Risks, Benefits, & Community Reaction
Worker Safety
• Health and safety issues for the installation and operation of ISAS are essentially equivalent to those for
conventional technologies of pump-and-treat or soil vapor extraction.
• Level D personnel protection was used during installation and operation of the ISAS system.
Community Safety
• ISAS with offgas treatment does not produce any routine release of contaminants.
• No unusual or significant safety concerns are associated with the transport of equipment, samples, waste, or other
materials associated with ISAS.
Environmental Impacts
• ISAS systems require relatively little space, and use of directional drilling minimizes clearing and other activities
that would be needed to install a comparable vertical well network.
• Visual impacts are minor, but operation of the vacuum blower and compressor create moderate noise in the
immediate vicinity.
Socioeconomic Impacts and Community Perception
• ISAS has a minimal economic or labor force impact.
• The general public has limited familiarity with ISAS: however, the technology received positive support on public
visitation days at Savannah River. ISAS can be explained to the public with ease similar to that of pump-and-treat
technologies.
Page 12
U.S. Department of Energy
200
-------
SECTION 7
LESSONS LEARNED
Design Issues ^^^mmmammmi^amfmmmmtmmgmmfm^aamiam^mmfammgmmm
• The bundle-tube pressure sensors installed along horizontal wells 1 and 2 to measure injection/extraction efficiency
are inexpensive and recommended for future applications.
• The filter pack on all the horizontal wells is made up of natural formation solids, principally because of collapse
around the borehole. This may diminish well efficiencies. Well design must be tailored to the ultimate use of the well.
Prepacked screen should only be used if necessary because it adds significantly to the cost.
• A horizontal well removes water from the vadose zone that can collect in the well, reducing its effective length.
Wells must be designed to channel water away from low areas.
• Careful alignment of the injection and extraction wells is probably not necessary because the zone of influence of
the extraction well is far greater than that of the injection well and because subsurface heterogeneities strongly
influence air flow.
• The system must be designed carefully to minimize the potential for plume spreading during injection
Implementation Considerations
• Increasing injection flow rates did not result in linear increases in mass removal; operating at lower flow rates may
save on operating costs with only a modest impact on performance.
• Cycling operations may offer substantial cost savings for only a marginal performance penalty.
• Air sparging efficiency is affected by injection pressure, flow rates, permeability, and subsurface heterogeneities.
• The injection of heated air is unlikely to result in increased VOC removal based upon the results of field tests.
• Horizontal drilling methods must be tailored to specific site conditions with special considerations for the type of
drilling fluid, drilling bit, drilling methodology, casing installation, etc.
Technology Limitations/Needs for Future Development
• Clay layers, because of their low permeability, are troublesome. Heterogeneities in the subsurface, caused by
either stratigraphy or fractures, can create preferential air flow pathways, resulting in less effective contact and
remediation.
• By inducing water flow, ISAS can accelerate lateral migration of contaminants in certain geologic settings. If
clay layers or other geologic features constrict vertical flow, it may be necessary to use ISAS in conjunction with a
pump-and-treat system for hydraulic control.
• Long-term performance data from several years of operation are required to assess the need for design
improvements and to better quantify life-cycle costs.
• Simplified design and monitoring methods are required to facilitate implementation of ISAS.
• Determination of the most effective enhancements to the technology, such as addition of nutrients to promote
biodegradation, presents opportunities to significantly improve performance. Follow-on work, not discussed in this
analysis, involving methane injection to bioremediate the site has already produced positive results.
• More experience with environmental horizontal drilling under a variety of subsurface conditions will ensure better
well installations at reduced costs.
.Page 13
U.S. Department of Energy 201
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LESSONS LEARNED
continued
Technology Selection Considerations
• Directional drilling of horizontal wells was demonstrated to assess its role in improving the efficiency of a
remediation project. Remediation efficiency may be enhanced by increased surface area for reaction, similarity of
well profile and contaminant plume geometry, borehole access to areas beneath existing facilities, and drilling along
facility boundaries to control plume migration. However, each site must be assessed for the utility of horizontal
wells.
• Successful ISAS requires good contact between injected air and contaminated soils and ground water. An
optimal geologic setting would have moderate to high saturated soil permeability, a homogenous saturated zone,
and sufficient saturated thickness. Vadose zone characteristics would be high permeability and homogeneity. Air
stripping is more effective in coarse-grained soil.
• For ISAS to be effective, the contaminants of concern must be strippable, that is mobile in and between all
phases. Most light hydrocarbons and chlorinated solvents satisfy these conditions.
• Horizontal wells may provide for better contact with linearly shaped plumes. ISAS may be more effective with
relatively thin plumes of contaminants.
Page 14
U.S. Department of Energy
202
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APPENDIX A
DEMONSTRATION SITE CHARACTERISTICS
•Site History/Background |
SiteJjayoul
/
Roads
M-Area Process
Sewer/Integrated
Demonstration
Site
• The Savannah River Site's historical mission has been to
support national defense efforts through the production of nuclear
materials. Production and associated research activities have
resulted in the generation of hazardous waste by-products now
managed as 266 waste management units located throughout the
300 mile2 facility.
• The A and M Areas at Savannah River have been the site of
administrative buildings and manufacturing operations,
respectively. The A/M-Area is approximately one mile inward
from the northeast boundary of the 300 mile2 Savannah River
Site. Adjacent to the site boundary are rural and farming
communities. Specific manufacturing operations within the M-
Area included aluminum forming and metal finishing.
• The M-Area operations resulted in the release of process
wastewater containing an estimated 3.5 million Ibs of solvents.
From 1958 to 1985, 2.2 million Ibs were sent to an unlined settling
basin, which is the main feature of the M-Area Hazardous Waste
Management Facility (HWMF). The remaining 1.3 million pounds
were discharged from Outfall A-014 to Tim's Branch, a nearby
stream, primarily during the years 1954 to 1982.
• Discovery of contamination adjacent to the settling basin in 1981 initiated a site assessment effort eventually involving
approximately 250 monitoring wells over a broad area. A pilot ground water remediation system began operation in
February 1983. Full-scale ground water treatment began in September 1985.
• High levels of residual solvent are found in the soil and ground water near the original discharge locations.
Technologies to augment the pump-and-treat efforts, for example soil vapor extraction, ISAS, and bioremediation, have
been tested and are being added to the permitted corrective action.
M-Area
~ A-014 Outfall/
Tim's Branch
HWMF/Settling
Basin
I Contaminants of Concern
Contaminants of greatest concern are:
1,1,2-trichloroethylene (TCE)
tetrachloroethylene (PCE)
1,1,1-trichloroethane (TCA)
Nature and Extent of Contamination
Property at STP*
Empirical Formula
Density
Vapor Pressure
Henry's Law
Constant
Water Solubility
Octanol-Water
Partition
Coefficient; Kow
Units
g/cm3
TCE
OOtCCfe
1.46
mmHg 73
atm*rn3/rncte9.9E-3
mg/L
•
1000-1470
195
PCE
OgCtCCfe
1 62
19
2.9E-3
150-485
126
TCA
CHsCOj
1 31
124
1.6E-2
300-1334
148
*SIP = Standard Temperature and Pressure; 1 atm, 25 °C
• Approximately 71 % of the total mass of VOCs released to both the settling basin and Tim's Branch was PCE, 28%
was TCE, and 1 % was TCA.
• The estimated amount of dissolved organic solvents in ground water in concentrations greater than 10 ppb is between
260,000 and 450,000 Ibs and is estimated to be 75% TCE. This estimate does not include contaminants sorbed to
solids in the saturated zone or in the vadose zone. The area of VOC-contaminated ground water has an approximate
thickness of 150 feet, covers about 1200 acres, and contains contaminant concentrations greater than 50,000 ug/L.
• DNAPLs found in 1991 present challenges for long-term remediation efforts.
• Vadose zone contamination is mainly limited to a linear zone associated with the leaking process sewer line, solvent
storage tank area, settling basin, and the A-014 outfall at Tim's Branch. 0
^^•^^•^^•^"•^••^•^••^••"•"•^"•^•^•^^"^"^•^••••^•^••^•••••••^^••••^••••^^•••^•^^M^MMH^M^i^M tQQQAt IM
U.S. Department of Energy
203
-------
DEMONSTRATION SITE CHARACTERISTICS
continued
Contaminant Locations and Hydrogeologic Profiles
Simplified schematic diagrams show general hydrologic features of the A/M Area at SRS.
Vadose Zone and Upper Aquifer Characteristics
0'
35'
60'
' 90'
Ground Surface
130'
160'
Water Table
(figure modified from Reference 12)
~ Legend
H Water Table Q Semiconfined Aquifer
l~~l Unsaturated Zone B Confined Aquifer
• Sediments are composed of sand, clay and gravel.
• Clay layers are relatively thin and discontinuous, with the
exception of the clay layers at 160-foot depth and a thicker
zone of interbedded clay and sand found at 90-foot depth.
• The water table is approximately 135 feet below grade.
• A moderate downward gradient appears to exist beneath
the M-Area. Vertical flow rates have been estimated to be
2 to 8 ft/year.
• Radial flow outward from a groundwater plateau under most
of the A/M-Area exists. Flow is approximately 15 to 100
ft/year.
Hvdrogeoloaic Units
Aquifer
Unit
Vadose Zone
Description
Poorly sorted mix of sand, cobbles, silt and clay
Moderate to well-sorted, fine to medium sand
containing some pebbles; 13% silt and clay
Thickness
-57 ft -
0-97 ft
\
Water Table Unit
Upper
Lost Lake Aquifer
Lower
Crouch Branch
Confining Unit
Moderately to well-sorted medium sand; 18% silt 30-55 ft
and clay
Moderate to well-sorted fine sand with some
calcaneous zones; 25% silt and clay; 14% silt and
clay beds
Well-sorted fine to medium sand; 16% silt and
clay; 7% silt and clay beds.
Discontinuous clay beds containing 70% silt & clay
Moderate to well-sorted medium sand; 17% silt
and clay, 7% silt and clay beds
Clay, clayey silt, and poorly sorted fine to coarse,
clayey sand; 62% silt and clay; contains 2 major
clay layers the lower of which is 10-56 ft thick and
is the principal confining unit for lower aquifer
16-34 ft -
14-60 ft
4-44 ft
32-95 ft
Crouch Branch Aquifer Very poorly to well-sorted, medium to coarse
sands; 5% sand and clay beds; an important
production zone for water supply wells in the M-
Area
152-180 ft
Wtitcr tiibtc f Uppermost nquifer-uppor /one
f.UnDermost nauifer-lower .
U.S. Department of Energy
204
PageA2 -
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DEMONSTRATION SITE CHARACTERISTICS
continued
Contaminant Locations and Hydrogeologic Profiles (continued)
Metal-degreasing
solvent wastes were
sent to the A-014 outfall
and, via the process
sewer, to the M-Area
settling basin. Data
from hundreds of soil
borings, ground water
monitoring wells, and a
variety of other
investigative techniques
have established a well-
documented VOC
plume in both the
vadose and saturated
zones.
TCE Ground Water Plume (Top View)
Data from 15 feet below water table in
the third quarter of 1990.
2000 ft ,
8,000-16,000 ug/L
F~3 16,000-24,000 ug/L
24,000 - 32,000 ug/L
32,000 - 40,000 ug/L
40,000 -48,000 ug/L
> 48,000 ug/L
(figure modified from Reference 6)
TCE Concentrations in Soil (West-East Cross-Section)
Concentration and lithology data from 1991 along an approximately 200-ft cross-section across the
integrated demonstration site. Concentration contours of TCE in sediments are based on analysis of over
1000 sediment samples. Highest concentrations of TCE occuVin clay zones.
Borehole
Lithology
Sand
50-
100-
140-1
Clay
(figure modified from Reference 6)
— Legend
soil concentrations
in ug/kg
CD 1 00 to 1 ,000 ug/kg
Ml.OOO to 5,000 ug/kg
5,000 to 1 0,000 units ug/kg
|>10,000 ug/kg
Page A3
U.S. Department of Energy
205
-------
APPENDIX B
TECHNOLOGY DESCRIPTION DETAIL
System Configuration
• Wells 1&2 are paired wells targeting contaminated
sands. They are semiparallel in the subsurface, one
in the vadose zone and one in the saturated zone.
Legend
Horizontal Horizontal well
well surface plan view
borehole subsurface
profile
Abandoned
Process Sewer
Line
M-Area
Settling Basin
Cross-Sectional View of Well #2
Surface
"75ft
Water Table
120 ftf
Installed in Saturated zone
Screened Length =205 ft.
Diameter = 4.5 in.
rCross-Sectional View of Well #/ -,
Surface
Water Table
176ft
\ ^J
Installed in Saturated zc
Screened Length = 310
Diameter = 2.4 in.
120 ft »
me
ft.
100ft
(all data taken from Reference 6)
Horizontal Well Close-Ups
Well#1
Well #2
Ground Surface
Kick-off
point x.
at115ftSt
2 3/8 in diameter steel tubing
Top of pocket assembly at 7 ft.
Pup joints and subassembly
8 5/8 in diameter steel surface casing
t Inflatable pocker assembly
M 5 in diameter borehole
Topofwhipstockat121.8ft
8 5/8 in diameter steel surface casing
Perforated steel tubing for screen
End of screen at 450 ft
' Bottom of whipstock 121.2 ft
480 ft.
Kick-off
point
at 25 ft
Ground Surface
8 5/8 in diameter steel surface casing
Cement "baskets" 14 & 15 ft
ntralizer
Top of screen at 25.12 ft
Whipstock window at 14 ft
16 in diameter borehole
6 1/2 in diameter borehole
4 1/2 in diameter stainless steel
wirewrapped screen
(0.010 in screenings)
Bull-nose plug
caved in at 205 ft
7
Bottom of whipstock at 31.2 ft
263ft
Page B1
U.S. Department of Energy
206
-------
TECHNOLOGY DESCRIPTION DETAIL
continued
Horizontal Well Installation Techniques
The techniques used to directionally drill and install a horizontal well depend on the location and purpose of the well.
Petroleum industry technology was used to install wells 1 and 2 at the Savannah River Site; however, this technology is
no longer used. Current installation techniques include the following:
1. Pipeline/Utility River Crossing System- Based on a mud rotary system used to drive a downhole drill assembly,
including a drilling tool, a hydraulic spud jet with a 2-degree bend to provide directional drilling or a downhole motor
depending on the lithology to be drilled.
2. Utility Industry Compaction System -Down hole drill assembly consists of a wedge-shaped drilling tool and a
flexible subassembly attached to the drill string. The borehole is advanced by compaction, forcing cuttings into the
borehole wall. Reduced volumes of water are introduced to cool the drill bit; no circulation of drilling flulid is
accomplished.
3. Hybrid Petroleum Industry/Utility Industry Technology - Modified mud rotary system with bottom hole assembly
comprised of a survey tool, steerable downhole motor, and expandable-wing drill bit. Drilling fluids are used. Curve is
drilled and pipe is installed in curve before horizontal is drilled. Only one company provides this type of drilling system.
Operational Requirements
• Design and management of ISAS systems require expertise in environmental, chemical, mechanical, and civil
engineering as well as hydrogeology and environmental regulations. Operation of multiple systems of the scale
implemented at the Savannah River Site can be performed by a 1/3 full-time equivalent technician. Larger systems or
extensive monitoring activities would require additional staff.
Monitoring Systems
r- Ground Water Monitoring Well Clusters -]
• Ten boringswere completed as 4-in monitoring
well clusters in the locations shown on the following
page.
• One well from each cluster was screened in the
water table at elevations ranging from 216 to 244 ft.
• The second well in the cluster was screened in
the underlying semiconfined aquifer at elevations
ranging from 204 to 214 ft.
i— Vadose Zone Piezometer Clusters
• Five borings were cored in order to install
piezometer clusters in the vadose zone.
• Three piezometer tubes having lengths of
approximately 52 ft, 77 ft and 100 ft were installed
into each borehole.
I— Geophysical Monitoring
• Eight borings were completed for geophysical monitoring.
• Seismic tomography was performed in two borings. This technique was used to map subsurface structure and
to monitor the extent of the air-stripping process.
• ERT and EMT were performed in three borings. ERT and EMT map the behavior of subsurface fluids as they
change in response to natural or remedial processes.
• Several single-point flow sensors were placed between the injection and extraction wells (just below the water
table) to measure ground water flow in the area most affected by the ISAS process.
Page B2
U.S. Department of Energy
207
-------
TECHNOLOGY DESCRIPTION DETAIL
continued
Monitoring Systems (continued)
Sampling/Monitoring Locations
I— Legend
Well #2
HW Well Head
MW Cluster
Vadose Zone Piezometer
Cluster
Flow Sensor
Seismic Tomography Well
Electrical Resistance/
Electromagnetic Tomography Well
i— Bundle Tubes
Each horizontal well was filled
with a bundle of six tubes
encased in a perforated pipe
or well screen. Each tube
terminated at a discrete
distance from the surface for
sampling or monitoring at
different locations along the
well bore.
Cross-Sectional
View at Well Head
1/8 in Stainless steel
tube Ground Surface
22.2 ft from surface
58.5ft
179.0ft 219.2ft
75ft
, Page B3
U.S. Department of Energy
208
-------
APPENDIX C
PERFORMANCE DETAIL
Operational Performance
Maintainability and Reliability
• No functional problems encountered during
demonstration; system was operational
approximately 90% of all available time.
» Operational performance over long periods
(years) not yet available.
Demonstration Schedule
Operational Simplicity
• Monitoring performance of ISAS is more difficult
than monitoring performance of baseline pump-and-
treat technology; however, systems can be operated
and maintained in the field typically by less than 1
full-time equivalent technician. Staffing
requirements are detailed in Appendix B.
Major Milestones of the Demonstration Program
1990 July
August
September
October
November
December
•J?
Sampling, Monitoring, Analysis, and QA/QC Issues
Objectives
• Gather baseline information and fully characterize site
• Evaluate removal efficiencies with time
• Identify and evaluate zones of influence
Baseline Characterization
• Baseline characterization was performed before the demonstration to gather information on the geology,
geochemistry, hydrology, and microbiology of the site. The distribution of contaminants in soils and sediments in the
unsaturated zone and ground water was emphasized. These data were compared with data on soil collected during
and after the demonstration to evaluate the effectiveness of ISAS.
• Continuous cores were collected from monitoring well and vadose zone boreholes. Sediments for VOC analysis
were collected at 5-ft intervals and at major lithology changes. Samples for microbiological characterization were
collected every 10ft.
• Water samples were collected and analyzed for VOC content and microbial characteristics from monitoring well
clusters and at discrete depths adjacent to monitoring well clusters.
• Geologic cross-sections were prepared using gamma ray, sp, resistivity density, and neutron geophysical logs
and core logs.
Page C1
U.S. Department of Energy
209
-------
PERFORMANCE DETAIL
continued
Sampling, Monitoring,
Sampling & Monitoring
Pressure Monitoring
Vacuum Monitoring
Temperature
Monitoring
Vapor Sampling
Ground Water
Sampling
Microbiological
Sampling
Helium Tracer Test
Analysis and QA/QC Issues (continued) yBHBHHHHBHHy
Location(s)
vadose zone piezometers
injection well
extraction well
extraction well bundle tubes
vadose zone piezometers
injection well
extraction well
vadose zone piezometers
extraction well
bundle tube
monitoring well clusters
monitoring well clusters
all exit points
Frequency
3 X daily
3 X daily
weekly
3 X daily
3 X daily
3 X daily
weekly
3 X daily
weekly
weekly
biweekly
once
•• • • Technique " " '•">'
measured at surface using magnehelic or
slack-tube macrometer
measured at wellhead using pressure gauge
measured at wellhead using vacuum gauge
measured at surface
measured at surface using temperature gauge
same as above
same as above
sampled through a septum on the vacuum side
of a vacuum pump using gas-tight syringes
same as above
same as above
sampled using documented Savannah River
Site (SRS) well sampling protocols
sampled using documented SRS well
sampling protocols
sampled using 500-ml disposable syringes
and transferred to 30-ml preevacuated serum
vials
Analytical Methods and Equipment
• Vapor grab samples were analyzed in the field using both a Photo Vac field gas chromatograph (GC)
and a GC fitted with flame ionization and electron capture detectors. Analysis was performed
immediately after collection.
• Bulk water parameters, including temperature, pH, dissolved oxygen, conductivity, and oxidation
reduction potential, were measured using a Hydrolab.
• VOC analysis of water and sediment samples was performed onsite using an improved quantitative
headspace method developed by Westinghouse Savannah River Company. Analyses were performed
on an HP-5890 GC fitted with an electron capture detector and headspace sampler.
• Helium tracer samples were analyzed using a helium mass spectrometer modified to sample serum
vials at a constant rate.
QA/QC Issues
• Vapor samples were analyzed immediately after collection and GC analysis of soil and water
samples were completed less than 3 weeks after collection.
• Duplicate analysis was performed for nearly every water and sediment sample collected.
• Approximately 161 samples were analyzed offsite using standard EPA methods to corroborate
onsite testing which used the improved quantitative headspace method described earlier. Cross-
comparison showed that the quantitative headspace analysis generated equivalent to superior data.
• GC calibration checks were run daily using samples spiked with standard solutions.
Performance Validation
• Samples analyzed onsite by nonstandard EPA methods were sent offsite for confirmatory analysis
using EPA methods. Results from these analyses confirmed the findings of Savannah River efforts.
• The effectiveness of horizontal wells for environmental cleanup has been demonstrated by their use in
vapor extraction and ground water/free product recovery systems which are also discussed in Appendix D.
Page C2
U.S. Department of Energy
210
-------
APPENDIX D
COMMERCIALIZATION/INTELLECTUAL PROPERTY
Marketplace Opportunities
• A key competitive advantage of ISAS is the use of horizontal wells. Horizontal wells can be used to:
- remediate beneath buildings and other obstacles to avoid interference with aboveground activities,
- remediate linear sources of contamination such as beneath pipelines,
- prevent further migration of contamination along site boundaries, and
- provide improved access to the subsurface especially for remedial enhancement processes such as
bioremediation.
• Additional advantages of ISAS/horizontal well technology include:
- reduction in the numbers of wells required and their associated pumps and surface equipment, and
- elimination of contaminated ground water as a secondary waste stream as a result of the in situ treatment.
• The success of the ISAS demonstration has led to plans for reimplementation at the same site as well as
application at other locations at SRS.
• ISAS has a potential market at sites where conventional technologies have failed to produce acceptable results. An
application at an airport in New York is one example where a pump-and-treat system had been previously applied.
• WSRC has received hundreds of inquiries from private industrial site owners (especially oil companies) as well as
from consultants and regulators. This response has led to the creation of a WSRC Industrial Assistance Program.
Specific activities of this program have included:
- input to feasibility studies to determine potential applicability of ISAS,
- aid in determining design criteria for surface and subsurface equipment,
- technical assistance to equipment vendors and manufacturers, and
- participation in the regulatory negotiating and permit approval process.
Intellectual Property j i •
Primary Sponsor
U.S. Department of Energy, Office of Environmental Management, Office of Technology Development
Existing/Pending Patents
Several parties, including national laboratories, technology developers, and consultants, participated in the
development and implementation of the ISAS system. These participants are listed on page 26.
- Patent 4,832,122, "In Situ Remediation System and Method for Contaminated Groundwater," J.C. Corey, B.B.
Looney, and D.S. Kaback, assignors to the U.S. as represented by the U.S. DOE.
- Patent 5,186,255, "Flow Monitoring and Control System for Injection Wells," J.C. Corey, assignor to the U.S. as
represented by the U.S. DOE.
- Patent 5,263.795, "In Situ Remediation System for Groundwater and Soils," J.C. Corey, D.S. Kaback, and B.B.
Looney, assignors to the U.S. as represented by the U.S. DOE.
• Related patents include:
- Patent 4,660,639, "Removal of Volatile Contaminants from the Vadose Zone of Contaminated Ground," M.J.
Visser and J.D. Malot assignors to the Upjohn Company. WSRC paid a one-time license fee to the assignee for
the use of the process with horizontal wells.
- Patent 5,006,250, "Pulsing of Electron Donor and Electron Acceptor for Enhanced Biotransformation of
Chemicals," P.V. Roberts, G.D. Hopkins, L. Semprini, P.L. McCarty, and D.M. McKay, assignors to the Board of
Trustees of the Leland Stanford Junior University.
• There are no pending patents for ISAS.
PageD1 —
U.S. Department of Energy ^ i 1
-------
COMMERCIALIZATION/INTELLECTUAL PROPERTY
continued
Intellectual Property (continued)
Licensing Information
• ISAS is commercially available through the WSRC Technology Transfer Office
• To date, 19 licenses have been applied for and 8 licenses have been granted.
Collaborators
ISAS Demonstration Participants
COM Federal Programs Corporation
Conoco, Inc.
Eastman Christensen Company
Environmental Monitoring and Testing
Graves Well Drilling
Los Alamos National Laboratory
Lawrence Berkeley Laboratory
Lawrence Livermore National Laboratory
Martin Marietta Energy Systems, Inc., HAZWRAP
Sandia National Laboratories
Sirrine Environmental
South Carolina Department of Health and Environmental Control
Terra Vac, Inc.
University of California at Berkeley
University of South Carolina
U.S. EPA
Page D2
U.S. Department of Energy
212
-------
APPENDIX E
REFERENCES
Major Refernces for Each Section
technology Description Sources (from list below) 1 and 6
Performance Sources 1, 3, and 6
Technology Applicability and Alternatives Sources 1, 3, and 4
Cost: Sources 5 and 11
Regulatory/Policy Requirements and Issues Sources 1, 3, 4, 6, 11, and 12
Lessons Learned: Sources 2, 4, and 5
Demonstration Site Characteristics Sources 6, 8,15, and 17
Technology Description Detail Sources 1, 6, 14, 15, and 16
Performance Detail Sources 1, 3, 4, and 6
Commercialization/Intellectual Property Sources 1, 3, 4, and 7
Chronological List of Refernces and Additional Sources
1. Personal communications with Brian Looney, Westinghouse Savannah River Company, November 1994 -
January 1995.
2. Personal communications with C.A. Eddy Dilek, Westinghouse Savannah River Company, April 1994.
3. Looney, B.B., C.A. Eddy Dilek, D.S. Kaback, T.C. Hazen, and J.C. Correy, In Situ Air Stripping Using Horizontal
Wells: A Technology Summary Report (U), Westinghouse Savannah River Company, Working draft, 1994
4. Battelle Pacific Northwest Laboratories, PROTECH Technology Information Profile for In Situ Air Stripping,
PROTECH database, 1994.
5. The Hazardous Waste Consultant, Horizontal Wells Prove Effective for Remediating Groundwater and
Soil, "July/August, 1994.
6. Turnover Plan for the Integrated Demonstration Project for Cleanup of Contaminants in Soils and Groundwater
at Non-Arid Sites, SRS, Science Applications International Corporation, September 7, 1993.
7. Wilson, D.D., and D.S. Kaback, Industry Survey for Horizontal Wells, Westinghouse Savannah River Company,
July 1993
8. C.A. Eddy Dilek, et al., Post Test Evaluation of the Geology, Geochemistry, Microbiology, and Hydrogeology of
the In Situ Air Stripping Demonstration Site at the Savannah River Site," WSRC-TR-93-369 Rev 0, Westinghouse
Savannah River Company, July 1993.
9. A.L. Ramirez, and W.D. Daily, "Electrical Resistance Tomography During Gas Injection at the Savannah River
Site", UCRL-JC-114126 preprint, Lawrence Livermore National Laboratory, May 1993
10. B.B. Looney, C.A. Eddy, and W.R. Sims, "Evaluation of Headspace Method for Volatile Constituents in Soils
and Sediments", Proceedings of the National Symposium on Measuring and Interpreting VOCs in Soils: State of
the Art in Research Needs, 1993.
Page E1
U.S. Department of Energy 2 * 3
-------
REFERENCES
continued
Chronological List of References and Additional Sources
(continued)
11. J.D. Schroeder, et al., In Situ Air Stripping: Cost Effectiveness of a Remediation Technology
Field Tested at the Savannah River Integrated Demonstration Site, Los Alamos National Laboratory,
June 1992.
12. G.J. Elbring, Crosshole Shear-Wave Seismic Monitoring of an In Situ Air Stripping Waste
Remediation Process, SAND91-2742, Sandia National Laboratories, February 1992.
13. Cleanup of VOCs in Non-Arid Soils - The Savannah River Integrated Demonstration, WSRC-
MS-91-290, Rev. 1, U.S. DOE, 1991.
14. Looney, B.B., T.C. Hazen, D.S. Kaback, and C.A. Eddy, Full Scale Field Test of the In Situ Air
Stripping Process at the Savannah River Integrated Demonstration Test Site (U), WSRC-RD-91 -22,
Westinghouse Savannah River Company, June 29,1991.
15. Eddy, C.A., B.B. Looney, J.M. Dougherty, T.C. Hazen, and D.S. Kaback, Characterization of the
Geology, Geochemistry, Hydrology and Microbiology of the In-Situ Air Stripping Demonstration Site
at the Savannah River Site" (U), Westinghouse Savannah River Company, WSRC-RD-91 -21, May
1, 1991.
16. D.S. Kaback, B.B. Looney, J.C. Corey, and M.L. Wright, Well Completion Report on Installation
of Horizontal Wells for In Situ Remediation Tests (U), Westinghouse Savannah River Company,
WSRC-RP-89-784, August 1989.
13. Preliminary Technical Data Summary M-Area Groundwater Cleanup Facility, Savannah River
Laboratory, E.I. DuPont deNemours, October 1982
This summary was prepared by
CKY Incorporated
Environmental Services
140 E. Division Rd Suite C-3
Oak Ridge, Tennessee, 37830
Contact- Kenneth Shepard (615) 483-4376
in conjunction with:
Stone & Webster Environmental A
Technology & Services XA&s
245 Summer Street
Boston. MA 02210
Contact: Bruno Brodfeld (617) 589-2767
Assistance was provided by the
WESTINGHOUSE SAVANNAH RIVER COMPANY
which supplied key information and reviewed report drafts.
Final editing and production was provided by the
Colorado Center for Environmental Management
999 18th Street Suite 2750
Denver CO 80202
Contact: Dawn Kaback (303) 297-0180
HAZARDOUS WASTE REMEDIAL ACTIONS PROGRAM
Environmental Management and Enrichment Facilities
Oak Ridge, Tennessee 37831-7606
managed by
MARTIN MARIETTA ENERGY SYSTEMS
for the
U.S. Department of Energy
under Contract DE-AC05-84OR-21400
950R-7400-001-009
_______________.^______——— Page E2
2] A "U.S. GOVERNMENT PRINTING OFFICE:1995-386-541/22006
U.S. Department of Energy
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