United States
Environmental Protection
Agency
. Office of Research
and Development
Washington DC 20460
EPA/600/R-97/019
February 1997
&EPA
The Site Characterization
and Analysis Penetrometer
System (SCAPS) Laser-
Induced Fluorescence (LIF)
Sensor and Support System
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Internet Address (URL) • http://www.epa.gov
Recycled/Recyclable • Printed with Vegetable Oil Based Inks on Recycled Paper (20% Postconsumer)
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The Site Characterization and
Analysis Penetrometer System (SCAPS)
Laser-Induced Fluorescence (LIF) Sensor
and Support System
Innovative Technology
Verification Report
by
Grace Bujewski
Brian Rutherford
Sandia National Laboratories
Albuquerque, New Mexico
National Exposure Research Laboratory
Characterization Research Division
U.S. Environmental Protection Agency
Las Vegas, Nevada 89193
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Notice
The U.S. Environmental Protection Agency (EPA), through its Office of Research and Development
(ORD), partially funded and managed the extramural research described here. It has been peer reviewed
by the Agency and approved as an EPA publication. Mention of trade names or commercial products
does not constitute endorsement or recommendation by EPA for use.
11
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF RESEARCH AND DEVELOPMENT
Washington, D.C. 20460
ENVIRONMENTAL TECHNOLOGY
VERIFICATION PROGRAM
ENVIRONMENTAL TECHNOLOGY VERIFICATION PROGRAM
VERIFICATION STATEMENT
TECHNOLOGY TYPE:
APPLICATION:
TECHNOLOGY NAME:
COMPANY:
ADDRESS:
PHONE:
CONE PENETROMETER-DEPLOYED SENSOR
IN-SITU DETECTION OF PETROLEUM HYDROCARBONS
SITE CHARACTERIZATION AND ANALYSIS PENETROMETER
SYSTEM (SCAPS)
U. S. NAVY, NAVAL COMMAND, CONTROL, AND OCEAN
SURVEILLANCE CENTER, RESEARCH, DEVELOPMENT, TEST AND
EVALUATION DIVISION
MATT. CODE 3604
SAN DIEGO, CALIFORNIA 92152-5000
619/553-1172
The U. S. Environmental Protection Agency (EPA) has created a program to facilitate the deployment of
innovative technologies through performance verification and information dissemination. The goal of the
Environmental Technology Verification (ETV) Program is to further environmental protection by
substantially accelerating the acceptance and use of improved and more cost effective technologies. The ETV
Program is intended to assist and inform those involved in the design, distribution, permitting, and purchase of
environmental technologies. This document summarizes the results of a demonstration of the Site
Characterization and Analysis Penetrometer System (SCAPS) developed by the RDT&E Division of the
Naval Command, Control and Ocean Surveillance Center (NCCOSC), in collaboration with the U.S. Army
and U. S. Air Force.
PROGRAM OPERATION
The EPA, in partnership with recognized testing organizations, objectively and systematically evaluates the
performance of innovative technologies. Together, with the full participation of the technology developer,
they develop plans, conduct tests, collect and analyze data, and report findings. The evaluations are
conducted according to a rigorous demonstration plan and established protocols. EPA's National Exposure
Research Laboratory which conducts demonstrations of field characterization and monitoring technologies,
selected the U. S. Department of Energy's Sandia National Laboratories as a testing organization.
DEMONSTRATION DESCRIPTION
In May and October, 1995, two cone penetrometer-deployed sensor systems were demonstrated to evaluate
how well they could measure subsurface petroleum hydrocarbon contamination. The performance of each
system was evaluated by comparing field analysis results to those obtained using conventional sampling and
analytical methods. These methods included using a hollow stem auger in conjunction with a split spoon
EPA-VS-SCM-02
The accompanying notice is an integral part of this verification statement
iii
February 1997
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sampler and subsequent analysis of the collected sample by a reference laboratory using EPA Method 418.1
for total recoverable petroleum hydrocarbons (TRPH) and California Department of Health Services Method
8015-Modified for total petroleum hydrocarbons.
The primary objectives of the demonstration were to (1) verify technology performance, (2) determine how
well the developer's field instrument performs in comparison to conventional laboratory methods, (3)
determine the logistical and economic resources needed to operate the instrument, and (4) produce a verified
data set for use in considering the technology for future use in hazardous waste investigations.
Field demonstrations were conducted at two geologically and climatologically different sites: (1) the
Hydrocarbon National Test Site located at Naval Construction Battalion Center (NCBC) Port Hueneme,
California, in May 1995, and (2) the Steam Plant Tank Farm at Sandia National Laboratories (SNL),
Albuquerque, New Mexico, in November 1995. The conditions at each of these sites represent what are
considered typical conditions under which the technology would be expected to operate, but it is not
considered all inclusive. Details of the demonstration, including a data summary and a discussion of results
may be found in the report entitled "The Site Characterization and Analysis Penetrometer System (SCAPS)
Laser-Induced Fluorescence (LIF) Sensor and Support System.'The EPA document number for this report is
EPA/600/R-97/019.
TECHNOLOGY DESCRIPTION
The SCAPS LIF system uses a pulsed nitrogen laser coupled with an optical detector to measure fluorescence
via optical fibers. The measurement is made through a sapphire window on a probe that is pushed into the
ground with a truck-mounted cone penetrometer testing (CPT) platform. The LIF method provides data on the
in situ distribution of petroleum hydrocarbons based on the fluorescence response induced in the polycyclic
aromatic hydrocarbon (PAH) compounds that are components of petroleum hydrocarbons. The method
provides a "detect/nondetect" field screening capability relative to a detection limit derived for a specific fuel
product on a site-specific soil matrix.
The SCAPS LIF technique does not provide species-specific quantitation but can be used as a field screening,
qualitative method which can also produce semi-quantitative results at concentrations within two orders of
magnitude of its detection limit for fluorescent fuel hydrocarbons. The estimated cost of using the SCAPS LIF
system varies between $12 and $20 per foot depending upon whether the operators provide a turnkey
operation or the customer provides field deployment assistance. Under normal condition, 200 feet of pushes
can be advanced per day.
VERIFICATION OF PERFORMANCE
The findings of the demonstration for each of the performance claims is as follows:
4 Push rate was 3ft/min. Data was collected every 0.2 ft or less if the cone was slowed or
stopped.
4 Average percent agreement with conventional analysis for both sites was 94 percent correct
with 1 percent false positives and 5 percent false negatives.
4 Good agreement with the pattern of contamination was derived from an analysis of the
subsurface soil samples. ^^
EPA-VS-SCM-02
The accompanying notice is an integral part of this verification statement
iv
February 1997
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+ All spectral data was stored and easily retrieved in real time.
4 Real time sensor data acquisition was achieved during both demonstrations.
The results of the demonstrations satisfy the requirements set forth in the demonstration plan for the SCAPS
LIF system. The system located the plume accurately with higher matching percentage than the developer
claimed The false negative rate for the combined demonstrations was 4.9 percent, nearly identical to the five
percent claimed by the developer. Disagreements with the laboratory results were primarily confined to
regions where contaminant concentration levels were close to the detection threshold. A portion of these
discrepancies could be the result of variability in laboratory results where random errors are estimated to be in
the range of 10 to 15 percent. The SCAPS rods and umbilical allow a maximum push of 150 ft without signal
loss. The SCAPS technology worked well in both the saturated and unsaturated zones. This may be an
important feature at sites where it is necessary to delineate the continuity of the contamination across the
interface.
The main savings attributable to the SCAPS LIF system is that it can substantially reduce the number of wells-
drilled at a site In a general site characterization effort, it can provide site characterization data in less time
and far less expensively than conventional drilling and sampling. Investigation-derived wastes are minimal.
This technology can provide useful, cost-effective data for environmental problem-solving and decision-
making Undoubtedly, it will be employed in a variety of applications, ranging from serving as a complement
to data generated in a fixed analytical laboratory to generating data that will stand alone in the decision
making process.
The SCAPS LIF system is an emerging technology worthy^? pursuit in site investigations where petroleum
hydrocarbons are suspected. The technology offers a number of advantages over conventional drilling and
sampling technologies for the purpose of screening a site for the nature and extent of contamination. It does
not entirely take the place of a conventional sampling program, but adds significant benefits in terms of
resolution of the nature and extent of contamination. This information, when used properly, could provide a
more complete picture of the contamination, and also could be used to predict future sampling locations.
Gary J. Fbfc&.Ph.D.
Director
National Exposure Research Laboratory
NOTICE: EPA verifications are based on an evaluation of technology performance under specific, V™***™™*™*™™,
appropriate quality assurance procedures. EPA makes no expressed or implied warranties as to the performance of fe technology and
does not certify that a technology will always, under circumstances other than those tested, operate at the levels verified. The end user
is solely responsible for complying with any .and all applicable Federal, State and Local requirements.
EPA-VS-SCM-02
The accompanying notice is an integral part of this verification statement
February 1997
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Foreword
The U.S. Environmental Protection Agency is charged by Congress with protecting the Nation's land, air,
and water resources. Under a mandate of national environmental laws, the Agency strives to formulate
and implement actions leading to a compatible balance between human activities and the ability of
natural systems to support and nurture life. To meet this mandate, EPA's Office of Research and
Development (ORD) provides data and science support that can be used to solve environmental problems
and to build the scientific knowledge base needed to manage our ecological resources wisely, to
understand how pollutants affect our health, and to prevent or reduce environmental risks.
The National Exposure Research Laboratory (NERL), ORD, is the Agency's center for the investigation
of technical and management approaches for identifying and quantifying risks to human heath and the
environment. One focus of the Laboratory's research program is to develop and evaluate technologies
for the characterization and monitoring of air, soil, water and subsurface resources. This in turn, will
provide the scientific information needed by EPA to support regulatory and policy decisions; and to
provide the science support needed to ensure effective implementation of environmental regulations and
strategies.
Effective measurement and monitoring technologies are needed to assess the degree of contamination at a
site, to provide data which may be used to determine the risk to public health or the environment, to
supply the necessary cost and performance data to select the most appropriate technology, and to monitor
the success or failure of a remediation process.
Candidate technologies can originate from within the federal government or from the private sector.
Through this program, developers are given the opportunity to conduct a rigorous demonstration of their
technology's performance under realistic field conditions. By completing the evaluation and distributing
the results, the Agency establishes a baseline for acceptance and use of these technologies. The
Characterization and Monitoring portion of this program is administered by NERL's Characterization
Research Division in Las Vegas, Nevada.
Gary J. Foley, Ph.D.
Director
National Exposure Research Laboratory
VI
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Table of Contents
Section
Notice ;**
Verification Statement "f
Foreword vl
List of Figures x
List of Tables x
List of Abbreviations and Acronyms xi
Acknowledgment xiu
Executive Summary.. 1
Technology Description 1
Demonstration Objectives and Approach 2
Demonstration Results and Performance Evaluation 2
Cost Evaluation *
Introduction • 4
The Site Characterization Technology Challenge 4
Technology Demonstration Process 4
Technology Selection 4
Technology Demonstration 5
Technology Performance Assessment, Evaluation, and Verification 5
Information Distribution "
The CPT-LIF Sensor Demonstrations 6
SCAPS LIF Technology Description 7
LIF Sensing Technologies 7
The Cone Penetrometer Platform 7
Cone Penetrometer LIF Probe 8
Laser Source "
Detection System 9
Noise, Background, and Sensitivity 9
Calculated Fluorescence Threshold and Detection Threshold 10
Dynamic Range H
Technology Applications H
Advantages of the Technology H
Limits of the Technology H
Truck-Mounted Cone Penetrometer Access Limits 12
Cone Penetrometer Advancement Limits 12
Response to Different Petroleum Hydrocarbons 12
Matrix Effects • 12
Spectral Interferences • 13
Technology Deployment and Costs 14
vn
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Reference Laboratory Results and Evaluation .........15
Selection of Reference Laboratory and Methods 15
Assessment of Laboratory Data Quality .'. 16
Audits (-i6
Sample Holding Times 16
Sample Preparation 16
Sample Analysis 16
Detection Limits 17
Quality Control Procedures 17
Accuracy, Precision, and Completeness 17
Use of Qualified Data for Statistical Analysis 19
Demonstration Design and Description .• ».........................................20
Evaluation of SCAPS LIF Sensor Performance 20
Evaluation of SCAPS CPT Platform Performance 20
Description of Demonstration Sites .....20
Port Hueneme Site Description 21
Demonstration Sampling Operations, Port Hueneme 23
Port Hueneme Sampling Locations 25
SNL Tank Farm Site Description 26
Demonstration Sampling Operations, SNL Tank Farm 28
Calibration Procedures, Quality Control Checks, and Corrective Action 29
SCAPS LIF Initial Calibration Procedures 30
SCAPS LIF Continuing Calibration Procedures 30
Method Blanks 31
Spike Samples 4 31
Instrument Check Standards 31
Performance Evaluation Materials 31
Duplicate Samples 31
Equipment Rinsate Samples 31
Data Reporting, Reduction, and Verification Steps 31
Data Reporting 32
Data Reduction and Verification Steps for the SCAPS LIF Data 32
Changes to the Demonstration Plan /. 33
Technology Results and Evaluation 34
Developer Claims Presented 34
Technology Data Quality Assessment 35
Accuracy 35
Precision 38
Completeness 38
Port Hueneme Site Data Presentation and Results 38
Port Hueneme Detection Limit 39
Downhole Results for Port Hueneme 40
Port Hueneme Subsurface Contaminant Mapping 40
SNL Tank Farm Site Data Presentation and Results 45
SNL Tank Farm Detection Limit 45
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Downhole Results for SNL Tank Farm •- 48
. SNL Tank Farm Subsurface Contaminant Mapping 51
Geotechnical Data Assessment 52
Overall Performance Evaluation • 52
Cost Evaluation • 52
Applications Assessment 56
Advantages of the Technology 56
Real-Time Analysis 56
Continuous LIF Data Output 56
Continuous Lithological Logging 56
Cost Advantages 57
Enhanced Operator Safety • • 57
Performance Advantages 57
Limitations of the Technology 58
Applicability 58
Quantisation and Speciation 58
Push Limitations 59
Interferences 59
Conclusions 59
Developer Forum **0
Xenon Chloride Laser • 60
Microchip Laser 60
Video Microscope 60
Time Domain Reflectometry 61
Raman Spectroscopy 61
Laser-Induced Breakdown Spectroscopy 61
Other Applied Research 61
Previous Field Trials • 62
References ,. • "^
Appendices ""
Appendix A: Reference Laboratory Data 66
Appendix B: SCAPS LIF Field Data Logs 73
Appendix C: SCAPS LIF Draft EMMC Method 74
IX
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List of Figures
Figure
3-1 Schematic diagram of SCAPS LIF System
5-1 Site vicinity map, Port Hueneme
5-2 Demonstration site and sampling locations, Port Hueneme
5-3 Site vicinity map, SNL Tank Farm
5-4 Demonstration site and sampling locations, SNL Tank Farm
6-1 Schematic of the four possible LIF and TRPH/TPH data categories
6-2 Plot of results of comparison of Port Hueneme LIF data with laboratory data.
6-3 Downhole results for Port Hueneme
6-4 Adjusted downhole results for Port Hueneme
6-5 Cross-sectional map of transect near Tank 5114 at Port Hueneme
6-6 Plot of results of comparison of SNL LIF data with laboratory data
6-7 Normalized spectra showing two distinct clusters
6-8 Downhole results for SNL Tank Farm
6-9 Subsurface contaminant map for SNL Tank Farm
....8
.22
.24
.27
.27
.37
.39
.41
.43
.45
.46
.49
.50
.51
List of Tables
Table
4-1
4-2
5-1
5-2
6-1
6-2
6-3
6-4
6-5
6-6
7-1
Quality Control Results for TPH
Quality Control Results for TRPH
Port Hueneme Boring and Push Summary Table
SNL Tank Farm Boring and Push Summary Table
Summary of comparison of results for Port Hueneme Demonstration
Summary of comparison of unadjusted results for SNL Demonstration.
Summary of comparison of adjusted results for SNL Demonstration
LIF sensor claims evaluation
SCAPS CPT claims evaluation
Relative costs for the SCAPS LIF system
Performance statistics
.18
.18
.26
.29
.37
.47
.47
.53
.54
.55
.58
x
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List of Abbreviations and Acronyms
AEC
ASTM
ATI
bbl
bgs
cm
CAS
CPT
CSCT
DFM
DHS
DoD
DOE
DOT
DQO
EDM
EMMC
EPA
ETI
ETV
ft
FVD
GC/FID
HASP
HNTS
HSA
Hz
IDW
IR
IRP
ITVR
LBF
m
m/min
mg/kg
mg/L
Army Environmental Center
American Society for Testing and Materials
Analytical Technologies, Inc.
Barrel (Equivalent to 42 U.S. Gallons)
Below Ground Surface
Centimeter
Chemical Abstracts Service
Cone Penetrometer Testing
Consortium for Site Characterization Technology
Diesel Fuel Marine
Department of Health Services (California)
Department of Defense
Department of Energy
Department of Transportation
Data Quality Objective
Engineering Development Model
Environmental Monitoring Management Council
U. S. Environmental Protection Agency
Environmental Technology Initiative
Environmental Technology Verification Program
Feet
Fluorescence Versus Depth
Gas Chromatograph/Flame lonization Detector
Health and Safety Plan
Hydrocarbon National Test Site
Hollow Stem Auger
Hertz
Investigation Derived Waste
Infrared
Installation Restoration Program
Innovative Technology Verification Report
Laser-Induced Fluorescence
Meter
Meters per Minute
Micrometer
Milligrams per Kilogram
Milligrams per Liter
XI
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List of Abbreviations and Acronyms (Continued)
ml
mL
mm
MS
MSD
ms
msl
NCBC
NCCOSC RDT&E
NERL-CRD
nm
NRaD
ns
PAH
PDA
PE
PPE
ppm
PRC
QA
QAPP
R
RI/FS
RPD
SCAPS
SNL
SOP
SPT
TER
TPH
TRPH
TSF
U.S.
uses
UV
WES
Millijoules
Milliliter
Millimeter
Matrix Spike
Matrix Spike Duplicate
Millisecond
Mean Sea Level
Naval Construction Battalion Center
Naval Command, Control, and Ocean Surveillance Center Research,
Development, Test, and Evaluation (Division)
National Exposure Research Laboratory-Characterization Research
Division
Nanometer
Unofficial Shorthand Abbreviation for NCCOSC RDT&E Division
Nanosecond
Polycyclic Aromatic Hydrocarbons
Photodiode Array
Performance Evaluation
Personal Protective Equipment
Parts per Million
PRC Environmental Management, Inc.
Quality Assurance
Quality Assurance Project Plan
Quality Control
Correlation Coefficient
Remedial Investigation/Feasibility Studies
Relative Percent Difference
Site Characterization and Analysis Penetrometer System
Sandia National Laboratories (Department of Energy)
Standard Operating Procedure
Standard Penetrometer Testing
Technology Evaluation Report
Total Petroleum Hydrocarbons
Total Recoverable Petroleum Hydrocarbons
Ton/ft2
United States
Unified Soil Classification System
Ultraviolet
Waterways Experimental Station (Army Corps of Engineers)
Xll
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Acknowledgment
We wish to acknowledge the support of all those who helped plan and conduct the demonstrations,
interpret data, and prepare this report. In particular, for demonstration site access and relevant back-
ground information, Stephan McCarel and Ernest Lory (Naval Facilities Engineering Service Center),
and David Miller (SNL); for implementation of the demonstration plan and data evaluation, Grace
Bujewski, Brian Rutherford, Dr. Robert Knowlton, and Robert Helgesen (SNL) and Peter Stang (PRC);
for logistical and health and safety support, Michael Skelly (Roy F. Weston, Inc.) and Michael
Strosinsky (SNL); for editorial and publication support, Merlyn Liberty (Tech Reps, Inc.); for peer and
technical reviews, Jerry Peace (SNL), Dr. Bruce LaBelle (State of California Environmental Protection
Agency, Department of Toxic Substances Control), and Dr. Robert Lien (U.S. EPA); and for U.S. EPA
project management, Dr. Stephen Billets and Dr. Robert Lien (U.S. EPA). In addition, we gratefully
acknowledge the participation of the SCAPS LIF technology developers, Dr. Stephen Lieberman,
Dr. David Knowles, and Mr. Thames Hampton (U.S. Navy NCCOSC RDT&E Division) and Mr. George
Robitaille (Tri-Services SCAPS Program of the U.S. Army Environmental Center), (619) 553-1172 and
(410) 612-6865, respectively.
xm
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Section 1
Executive Summary
The Consortium for Site Characterization Technology (CSCT) has established a formal program to
accelerate acceptance and application of innovative monitoring and site characterization technologies
that improve the way the nation manages its environmental problems. The CSCT is a partnership
program involving the U.S. Environmental Protection Agency (EPA), the Department of Defense (DoD),
and the Department of Energy (DOE). Its mission is to support the demonstration and verify the
performance of new and emerging technologies.
In 1995 the CSCT conducted a demonstration of two in situ laser-induced fluorescence-based
technologies using the Site Characterization and Analysis Penetrometer System (SCAPS) cone
penetrometer testing (CPT) platform. The two technologies were the SCAPS LIF, developed through a
collaborative effort of the Army, Navy, and Air Force under the Tri-Services SCAPS program and by the
Naval Command, Control, and Ocean Surveillance Center, Research, Development Test, and Evaluation
(NCCOSC RDT&E) Division, and the Rapid Optical Screening Tool™ developed by Loral Corporation
and Dakota Technologies, Inc. These technologies were designed to provide rapid sampling and real
time, relatively low cost analysis of the physical and chemical characteristics of subsurface soil to
distinguish contaminated and noncontaminated areas. Results for the Rapid Optical Screening Tool
technology are presented in a separate report.
The purpose of this Innovative Technology Verification Report (ITVR) is to document the demonstration
activities, present and evaluate the demonstration data in order to verify the performance of the SCAPS
LIF sensing technology relative to developer claims.
Technology Description
The SCAPS LIF system uses a pulsed laser coupled with an optical detector to measure fluorescence via
optical fibers. The measurement is made through a sapphire window on a probe that is pushed into the
ground with a truck-mounted cone penetrometer. The CPT platform and standard penetrometer testing
(SPT) have been widely used in the geotechnical industry for determining soil strength and soil type from
measurements of tip resistance and sleeve friction on an instrumented probe. The LIF technology
demonstrated was a nitrogen laser-based LIF sensor and support system currently being used in the Navy,
Army, and DOE (developed by the Navy's NCCOSC RDT&E Division in collaboration with the Army's
Waterways Experimental Station and Army Environmental Center [AEC]), using the SCAPS CPT
platform.
The LIF method provides data on the in situ distribution of petroleum hydrocarbons based on the
fluorescence response induced in the polycyclic aromatic hydrocarbon (PAH) compounds that are
components of petroleum hydrocarbons. PAHs in petroleum products are induced to fluoresce by
excitation with UV light. The method provides a "detect/nondetect" field screening capability relative to
a detection limit derived for a specific fuel product on a site-specific soil matrix. The SCAPS LIF is
primarily used as a field screening, qualitative method but can be semi-quantitative at concentrations
within two orders of magnitude of its detection limit for fluorescent petroleum hydrocarbons.
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Demonstration Objectives and Approach
The primary objectives of the field demonstrations were to evaluate the SCAPS LIF technology in the
following areas: (1) its performance compared to conventional sampling and analytical methods; (2) the
logistical resources necessary to operate the technology; (3) the quality of the LIF data; (4) the applica-
tions of the technology as determined by its performance in the CSCT demonstrations; and (5) its
performance relative to developer claims. Performance of the SCAPS LIF was evaluated to determine
the agreement between LIF "detect/nondetect" data and laboratory analyses for both total recoverable
petroleum hydrocarbons by EPA Method 418.1 and total petroleum hydrocarbons by California
Department of Health Services Method 8015-modified. A secondary objective for this demonstration was
to evaluate the LIF technology for cost, range of usefulness, and ease of operation.
In the approved demonstration plan, the developers presented several performance claims against which
they were evaluated. These claims may be separated into two groups: claims for the LIF sensor and
claims for the SCAPS CPT platform. The claims regarding the capabilities and performance of the
sensor included the percentage agreement between LIF detect/nondetect data and laboratory reference
method results, sample collection rates, ability to produce a site-specific detection threshold in concen-
tration units, ability to store spectral signatures, ability to distinguish different classes of hydrocarbon
products, ability to assist in real-time decision making as part of a field sampling event, and ability to
detect hydrocarbons in the vadose zone, capillary fringe, and saturated zones. The claims regarding the
capabilities and performance of the SCAPS CPT platform included push rates, ability to collect
simultaneous continuous geotechnical and stratigraphic information, ability to minimize contaminating or
altering soil samples, ability to measure depth more accurately than with conventional methods of
drilling and sampling, and the production of minimal amounts of investigation-derived waste.
The demonstration was designed to evaluate the LIF technology as a field screening method by com-
paring LIF data to data produced by conventional sampling and analytical methods. For both demon-
strations, conventional sampling and analysis consisted of boring with a hollow stem auger, collecting
split spoon samples as closely as possible to the push cavity, and analyzing discrete samples at an off-site
commercial laboratory for petroleum hydrocarbons by EPA Method 418.1 and California Department of
Health Services Method 8015-modified. The demonstrations were conducted at two geologically and
climatologically different sites: (1) the Hydrocarbon National Test Site located at Naval Construction
Batallion Center (NCBC), Port Hueneme, California, in May 1995, and (2) the Steam Plant Tank Farm at
Sandia National Laboratories (SNL), Albuquerque, New Mexico, in November 1995.
Demonstration Results and Performance Evaluation
The LIF technology demonstrated using the SCAPS CPT platform provided real-time field screening of
the physical characteristics of soil and chemical characteristics of petroleum hydrocarbon contamination
at both demonstration locations. The system was able to quickly distinguish contaminated and uncon-
taminated areas when compared to conventional sampling and analysis technologies.
The results of the demonstration indicate that the performance claims of the SCAPS LIF sensing
technology were met. Specifically, at both sites the SCAPS LIF technology produced comparable results
to the reference methods, with better than 90 percent agreement with discrete soil sample analytical
results. During the field tests the SCAPS cone penetrometer encountered some difficulties in pushing
through gravel and cobble lithologies at both sites. In addition, the LIF technology produced a
significant number of positive responses at the SNL Tank Farm site due to fluorescing minerals in the
soil. However, these nonhydrocarbon fluorescent minerals were easily identified in the field and
confirmed in post-demonstration processing of the LIF data. Based on this evaluation, the SCAPS LIF
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technology appears to be capable of rapidly and reliably mapping the relative magnitude of the vertical
and horizontal extent of subsurface fluorescent petroleum hydrocarbon contaminant plumes in soil and
groundwater.
Cost Evaluation
The SCAPS technology is designed to be operated by trained technicians from the AEC, U.S. Navy, or
other licensees. It is not available for use by private citizens or corporations, but is available to state and
federal agencies. The estimated cost of sampling using the SCAPS LIF system varies between $12 and
$20 per foot depending upon whether the operators provide a turnkey operation or the customer provides
field deployment assistance such as permitting, site management, and development of work and health
and safety plans. Under normal conditions, 200 feet of pushes can be advanced per day. Concrete
coring, grouting, permit fees, and distant travel costs or mobilization/demobilization costs vary with each
deployment and thus are not included. This compares to conventional drilling costs, which range
between $15 and $20 per foot for drilling and installation of monitoring wells and between $50 and $100
per foot for drilling and sampling for site characterization. In addition, laboratory analysis costs, which
range from $90 to $150 per sample for TPH or TRPH, must also be considered.
The main savings attributable to the SCAPS LIF system is that it can substantially reduce the number of
monitoring wells drilled at a site. In a general site characterization effort, it can provide data in less time
and far less expensively than conventional drilling and sampling. Investigation-derived wastes are
minimal, and worker exposure to contaminants is reduced when using in situ technologies rather than
conventional drilling and sampling methods.
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Section 2
Introduction
The Site Characterization Technology Challenge
Rapid, reliable and cost effective field screening technologies are needed to assist in the complex task of
characterizing and monitoring of hazardous and chemical waste sites. However, some environmental
regulators and remediation site managers may be reluctant to use new site characterization technologies
that have not been validated in an EPA-sanctioned testing program, since data from them may not be
admissible in potential legal proceedings associated with a site or its cleanup. Until characterization
technology claims can be verified through an unbiased evaluation, the user community will remain
skeptical of innovative technologies, despite their promise of better, less expensive and faster
environmental analyses.
The Consortium for Site Characterization Technology was established as a component of the
Environmental Technology Innovation, Commercialization and Enhancement Program as outlined in
1993 in President Clinton's Environmental Technology Initiative to specifically address these concerns.
The CSCT is a partnership between the EPA, the Department of Energy, and the Department of Defense.
As a partnership, the CSCT offers valuable expertise to support the demonstration of new and emerging
technologies. Through its organizational structure, it provides a formal mechanism for independent
third-party assessment, evaluation, and verification of emerging site characterization technologies.
The mission of the CSCT is to identify, demonstrate, assess, and disseminate information about
innovative and alternative environmental monitoring, measurement, and characterization technologies to
developers, remediation site managers, and regulators. The Consortium is intended to be a principal
source of information and support with respect to the availability, maturity, and performance of
innovative environmental monitoring, measurement, and characterization technologies.
Technology Demonstration Process
The CSCT provides technology developers a clearly defined performance assessment, evaluation and
verification pathway. The pathway is outlined in the following four components:
• technology selection;
• technology demonstration;
• technology performance assessment, evaluation, and verification, and
• information distribution.
These are discussed in more detail in the following paragraphs.
Technology Selection
The first step in the overall demonstration process is one of technology selection. The selection process
comprises two components. Beyond the initial identification of potential technologies, a critical aspect
of technology selection is an assessment of its field deployment readiness. Only pre-production and
production instrumentation with a history of successful laboratory or field operation are accepted into the
program. Early, unproven prototype instrumentation systems requiring extensive testing and modifi-
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cation prior to field deployment are not acceptable demonstration candidates. The candidate technology
must meet minimum technology maturity criteria in order to participate in a demonstration. The degree
of technology maturity may be described by one of three levels:
Level 1
Technology has been demonstrated in a laboratory environment and ready for initial field
trials.
Level 2
Technology has been demonstrated in a laboratory environment and in field trials.
Level 3
Technology has been demonstrated extensively both in the laboratory and in field trials and is
commercially available.
A second aspect of the technology selection process involves a determination of technology/field
requirements match. Because of limited resources, the Consortium must determine a technology's
suitability for demonstration in light of the current needs of the environmental characterization and
monitoring community. A technology may be given priority for demonstration and evaluation based on
its environmental and fiscal impact and the likelihood that its demonstration will fill information gaps
which currently impede cost effective and efficient environmental problem solving. The CSCT conducts
surveys of EPA, DOE, DoD, state, local, tribal and industry agencies to assist in determining the degree
of match between the candidate technology and the needs of the environmental restoration community.
Technology Demonstration
A technology demonstration plan is developed by the technology verification entity, according to
document preparation guidance provided by the Consortium for Site Characterization Technology
(CSCT). The demonstration plan includes a technology description, the experimental design, sampling
and analysis plan, methods for evaluating the technology, a quality assurance project plan, and a health
and safety plan. After approval by the EPA and technology developers, the demonstration plan is
implemented at an appropriate field location. The CSCT provides technical support to the technology
developer during demonstration plan preparation and execution and also audits the demonstration and
data collection processes.
Technology Performance Assessment, Evaluation, and Verification
In this important component of the demonstration process, an objective comparison of demonstration
technology data is carried out against a reference data set generated using conventional analysis
methodologies. The principal product of this phase of the project is the ITVR, prepared by an
independent third party. The report documents the demonstration technology data along with an
assessment of the technology's performance in light of the reference data. The degree of data analysis in
the technology report is determined by the level of maturity of the technology under evaluation, with the
more mature technologies receiving more thorough analysis. The CSCT provides Level 1 technologies
with a fielding opportunity in which the system can be tested. Evaluation of the system performance and
comparison of field data with reference laboratory data are the developer's responsibility. In the case of
Level 2 technologies, the performance evaluation is performed by the CSCT. The most extensive
evaluation is done for the Level 3 technologies since these are considered market-ready. As part of the
demonstration objectives, the CSCT evaluates the developer claims regarding the capabilities of the
Level 3 technology and prepares a technology evaluation report containing an assessment of the
technology's performance.
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Information Distribution
Evaluation reports for Level 2 technologies are distributed to the developers, CSCT partners and the
general public. In addition, Level 3 technology performance verification statements are distributed to the
developers for their subsequent use in seeking additional funding or marketing.
Reports for Level 1 technologies contain the field results and laboratory reference data. No evaluation or
verification is conducted. The developer or reader may reach their own conclusions as to the
performance of the technology.
The CPT-LIF Sensor Demonstrations
The developer of the SCAPS LIF technology is the NCCOSC RDT&E Division. The NCCOSC RDT&E
Division and its contractor, PRC Environmental Management Inc. (PRC) prepared the demonstration
plan and conducted the predemonstration and demonstration field efforts, coordinated the analyses of the
soil samples, and provided the raw data to Sandia National Laboratories-New Mexico (SNL), a DOE-
owned laboratory operated by Lockheed Martin Corporation. SNL, as the EPA's verification entity,
reviewed and approved the demonstration plan and amendments and reduced and analyzed the data
generated during the two field demonstrations.
The SCAPS LIF is a CSCT Level 3 technology. For these demonstrations, the CSCT worked with the
State of California Environmental Protection Agency Department of Toxic Substances Control (Cal
EPA-DTSC), to evaluate the SCAPS LIF technology as a field screening tool for detection of petroleum
hydrocarbons in the subsurface. Representatives of the Consortium, Cal EPA-DTSC, and developers
selected the demonstration sites, participated in the demonstration planning process, and jointly and
separately evaluated the data generated during both demonstrations.
This report describes how the demonstration participants collected and analyzed samples, provides the
results of the demonstration, and describes how the performance of the SCAPS LIF technology was
verified. Section 3 discusses the experimental design for the demonstration. Section 4 presents the
reference laboratory results and evaluation. Section 5 describes the SCAPS LIF technology. Section 6
presents the SCAPS LIF demonstration results and evaluation. Section 7 is an assessment of
•recommended applications of the technology. Section 8 is a forum wherein the developer has the
opportunity to discuss the technology results and comment on the evaluation and future developments.
Section 9 is a presentation of previous field trials of the SCAPS LIF technology. In addition, there are
appendices containing the reference laboratory data, SCAPS LIF data, and proposed SCAPS LIF method.
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Section 3
SCAPS LIF Technology Description
The description of the SCAPS LIF technology and verification of its performance has been divided into
two sections, Section 3 and Section 6. Because this is an innovative technology, evaluating its
performance and comparing it to conventional laboratory methods with well-established procedures is
not as simple as the evaluation of the laboratory methods as presented hi the preceding section. Section 3
describes the SCAPS LIF sensor technology developed by NCCOSC RDT&E Division and includes
background information and a description of the equipment. General operating procedures, training and
maintenance requirements, and some preliminary information regarding the costs associated with the
technologies are also discussed. Much of this information was provided by the technology developer and
presented in the demonstration plan. Any claims made in this section may or may not have been verified
during this demonstration. Specifically, the subsections regarding technology applications and limitations
and advantages of the technology were provided by the developer and may not have been verified. The
verification of technology performance at the two demonstration sites and evaluation of developer claims
for this program are presented in detail in Section 6.
LIF Sensing Technologies
The SCAPS CPT is the platform for a family of new rapid field screening technologies for surficial and
subsurface contaminants. The LIF technology demonstrated is the nitrogen laser-based LIF sensor and
support system currently being used by the Navy and Army (developed and provided by NCCOSC
RDT&E Division and Army WES) and supported by the SCAPS CPT platform. The LIF system uses a
pulsed laser coupled with an optical detector to make fluorescence measurements via optical fibers. The
measurement is made through a sapphire window on a probe that is pushed into the ground with a truck-
mounted cone penetrometer. Figure 3-1 is a schematic drawing of the SCAPS LIF system.
The Cone Penetrometer Platform
CPT and standard penetrometer testing have been widely used in the geotechnical industry for
determining soil strength and soil type from measurements of tip resistance and sleeve friction on an
instrumented probe. The SCAPS uses a truck-mounted CPT platform to advance its chemical and
geotechnical sensing probe. The CPT platform provides a 20-ton static reaction force associated with the
weight of the truck. The forward portion of the truck-mounted laboratory is the push room. It contains
the rods, hydraulic rams, and associated system controllers. Underneath the SCAPS CPT push room is
the steam manifold for the rod and probe decontamination system. The rear portion of the truck-mounted
laboratory is the isolatable data collection room in which components of the LIF system and onboard
computers are located. The combination of reaction mass and hydraulics can advance a 1-meter long by
3.57-cm diameter threaded-end rod into the ground at a rate of 1 m/min in accordance with ASTM
Method D3441, the standard for CPT. The rods, sensing probes, and sampling tools can be advanced to
depths in excess of 50 meters in soil. As the rods are withdrawn, grout can be injected through 1/4-inch
diameter tubing within the interior of the SCAPS LIF umbilical, hydraulically sealing the push hole. The
platform is fitted with a self-contained decontamination system that allows the rods and probe to be
steam cleaned as they are withdrawn from the push hole, through the steam cleaning manifold, and back
into the CPT push room.
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Figure 3-1. Schematic diagram of SCAPS LIF System.
In addition to chemical sensors, a number of additional sensors provide valuable information relevant to
subsurface characteristics. Groundwater, soil, and soil-gas sampling tools can be used with the CPT.
Groundwater sampling tools can vary from a slotted well-point design to a retractable well screen. Soil
sampling is accomplished with core-type samplers. Soil-gas sampling is typically accomplished by
allowing subsurface vapors to equilibrate in Teflon tubing within the rods. The soil gas is then either
collected for delivery to an off-site laboratory or analyzed by an on-board gas chromatograph. These
tools were not used in the EPA CSCT demonstrations. Existing CPT systems do not allow in situ
sampling tools and subsurface sensors to be used concurrently.
Cone Penetrometer LIF Probe
The lead probe rod can be fitted with various types of sampling tools and sensors. The CPT LIF systems
use a steel probe containing the LIF sapphire optical window and cone and sleeve strain gauges. The
excitation and emission optical fibers are isolated from the soil system by a 6.35 millimeter (mm)
diameter sapphire window located 60 cm from the probe tip, mounted flush with the outside of the probe.
The SCAPS LIF fibers are 500 fim in diameter and up to 100 m in length.
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Laser Source
The SCAPS LIF pulsed laser fiber optic-based system uses 337-nm ultraviolet light from a pulsed
nitrogen laser with a 0.8-ns pulse width and a pulse energy of 1.4 mJ. The nitrogen laser is coupled to a
silica-clad ultraviolet/visible light transmitting optical fiber. This fiber and the collection fiber are
integrated with the geotechnical probe and umbilical of a standard truck-mounted CPT system.
Detection System
The SCAPS LIF system uses a pulsed laser fiberoptic-based sensor. As the pulse from the laser is
launched into the excitation fiber, a photodiode is triggered which generates a synchronization pulse that
is fed into a pulse delay generator. The pulse from this apparatus is used to gate a photodiode array
(PDA) detector. Fluorescence stimulated in the in situ soil "sample" by the laser is collected by the
emission fiber and returned to a spectrograph, where it is dispersed spectrally on the PDA. This
arrangement allows for the rapid acquisition of spectral data. Readout of a fluorescence emission
spectrum, performed by an EG&G PARC Model 1460 optical multichannel analyzer, requires
approximately 16 ms. For a laser firing at a rate of 20 Hz, an entire fluorescence emission spectrum
measurement, composed of the average of responses from 20 laser firings, can be collected in
approximately 1 second.
Under normal operating conditions, fluorescence emission spectra are collected once per second as the
penetrometer probe is pushed into the ground at a rate of approximately 1 m/min. This yields a
measurement with a vertical spatial resolution of approximately 0.2 feet. A host computer equipped with
custom software controls the fiber optic fluorometer sensor system and stores fluorescence emission
spectra and conventional CPT sleeve friction and tip resistance data. The host computer is also used to
generate real-time depth plots of fluorescent intensity at the spectral peak, wavelength of spectral peak,
sleeve friction and tip resistance, and soil type characteristics as interpreted from the strain gauge data.
The fluorescent intensity in the spectral window is plotted as a function of depth in real time as the probe
is pushed into the soil. The entire fluorescent emission spectrum is stored on a fixed hard disk to
facilitate post-processing of the data. Data logs from both field demonstrations are presented in
Appendix B.
Noise, Background, and Sensitivity
Three quantities are needed to determine the fluorescence threshold and the detection limit for a specific
site: noise, background, and sensitivity. For normal field operations, these quantities are determined
using the calibration samples prepared immediately prior to the site visit using soil from the site and
standard analytical techniques.
The fluorescence intensity for each calibration sample is measured in triplicate daily at the start of
operations. The three measurements are averaged to provide a single measured intensity for each
concentration. A regression analysis is performed wherein the slope and intercept for this restricted
range of operations are estimated. The estimates are:
intercept = b = estimated fluorescence intensity for a 0 mg/kg calibration sample; and
slope = m = estimated increase in fluorescence intensity per increase in contaminant concentration
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This procedure is carried out using only the lower concentration calibration standards. For example,
when using diesel fuel marine (DFM) as the target fuel, the standards will typically consist of samples
with concentrations of 0 mg/kg, 500 mg/kg, 1000 mg/kg, 1500 mg/kg and 2000 mg/kg. Experiments
have shown that for the full range of calibration standards (up to 100,000 mg/kg), the calibration data
does not lend itself well to a linear regression. By restricting the data set to low concentration samples,
the data appear to be adequately represented using linear regression.
For the calibration soil samples, xt is given by the concentration of the target fuel, while yt is the
measured fluorescence intensity of the sample, adjusted by the normalization factor described in
Section 5. The linear model provides an estimated fluorescence value y for any given concentration x,
calculated as y =b + mx.
The residuals are the difference between the data and the fit (y/ -(b
The residual variance s2 in the regression is estimated by:
ii-2
where n is the number of measurements and the standard deviation s of the fit is estimated by the square
root of this quantity.
The sensitivity and background are defined as follows:
sensitivity- slope of fitted data = m;
background = intercept of fitted data = b; and
noise = standard deviation of the fit = s.
Calculated Fluorescence Threshold and Detection Threshold
The quantities needed to calculate the SCAPS LIF fluorescence threshold and the detection threshold are
estimated using quantities described in the previous paragraphs.
fluorescence threshold =
detection threshold =
background + noise
b-i-s
noise / sensitivity
s/m
The fluorescence threshold is the quantitative limit that the fluorescence intensity must exceed in order to
qualify as a "detect." If the fluorescence intensity is less than the fluorescence threshold, the sensor
indicates "nondetect." The detection threshold is the amount of contaminant (based on the calibration
performed with the target fuel) that corresponds to the fluorescence threshold. This is the practical
detection level in mg/kg as determined from the calibration standards for a given site and on a given day.
If the laboratory results indicate contamination levels lower than the LIF detection threshold, the result is
classified as a nondetect.
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Based on the results calculated for the sites up to this time, the SCAPS LIF detection threshold will vary
somewhat from site to site and day to day, but is approximately 100 to 300 mg/kg as TRPH by EPA
Method 418.1.
Dynamic Range
The linear dynamic range of the LIF detector depends on the specific hydrocarbon analyte as well as the
particular matrix. Generally, for in situ measurements, it has been found that the linear portion of the
response curves extends well beyond three orders of magnitude. Nonlinearity tends to occur at
concentrations greater than 10,000 mg/kg. In sandy soils, the non-linearity occurs at lower
concentrations than in clay rich soils, possibly due to self absorption or saturation. The linear dynamic
range of the LIF sensor also depends on operator-controlled instrumental parameters. For example, the
linear dynamic range may be extended to higher concentrations by adjusting the slit width of the detector,
but this results in decreased sensitivity at lower concentrations.
Technology Applications
The NCCOSC RDT&E Division SCAPS LIF system was developed in response to the need for real-time
in situ measurements of subsurface contamination at hazardous waste sites. The LIF system performs
rapid field screening to determine either the presence or absence of petroleum hydrocarbon contaminants
within the subsurface of the site. The site can be further characterized with limited numbers of carefully
placed borings or wells. In addition, remediation efforts can be directed on an expedited basis as a result
of the immediate availability of the LIF and soil matrix data.
Advantages of the Technology
The LIF sensing technology is an in situ field screening technique for characterizing the subsurface
distribution of petroleum hydrocarbon contamination before installing groundwater monitoring wells or
soil borings. The method is not intended to be a complete replacement for traditional soil borings and
monitoring wells, but is a means of more accurately placing a reduced number of borings and monitoring
wells in order to achieve an adequate site characterization at a reduced cost.
The current configuration is designed to quickly and cost-effectively distinguish petroleum hydrocarbon-
contaminated areas from uncontaminated areas. This capability allows further investigation and
remediation decisions to be made more efficiently and reduces the number of samples that must be
submitted to laboratories for costly analysis. In addition, the SCAPS CPT platform allows for the
characterization of contaminated sites with minimal exposure of site personnel and the community to
toxic contaminants, and minimizes the volume of investigation derived waste (BDW) generated during
typical site characterization activities.
Limits of the Technology
This section discusses the limitations of the SCAPS LIF technology as they are currently understood.
These limitations are not restricted to possible accuracy limitations when compared to the reference
methods but include differences that might be compared to an ideal contaminant detection instrument.
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Truck-Mounted Cone Penetrometer Access Limits
The SCAPS CPT support platform is a 20-ton Freightliner all-wheel-drive diesel powered truck. The
dimensions of the truck require a minimum access width of 10 feet and a height clearance of 15 feet.
Some sites, or certain areas of sites, might not be accessible to a vehicle the size of the SCAPS CPT
truck. The access limits for the SCAPS CPT vehicle are similar to those for conventional drill rigs and
heavy excavation equipment.
Cone Penetrometer Advancement Limits
The CPT sensors and sampling tools may be difficult to advance in subsurface lithologies containing
cemented sands and clays, buried debris, gravel units, cobbles, boulders, and shallow bedrock. As with
all intrusive site characterization methods, it is extremely important that all underground utilities and
structures be located using reliable geophysical equipment operated by trained professionals before
undertaking activities at a site. Local utility companies should be contacted for the appropriate
information and approval.
Response to Different Petroleum Hydrocarbons
The relative response of the SCAPS LIF sensor depends on the specific analyte being measured. The
instrument's sensitivity to different hydrocarbon compounds can vary by as much as two orders of
magnitude. These variations in sensitivity are primarily a reflection of the variations in the PAH
distribution of fossil fuel. Other contributing factors such as optical density, self absorption, and
quenching are less important. As mentioned previously, the SCAPS LIF sensor responds only to PAHs
that fluoresce when excited at 337 nm. This wavelength will excite aromatic compounds with three or
more rings as well as some two-ring compounds. Aliphatic species, single-ring aromatics, and most two-
ring PAHs do not contribute to the SCAPS LIF signal. The total observable fluorescence produced by
any given petroleum hydrocarbon sample depends on the mole fraction of fluorescing PAHs along with
the relative quantum efficiency of each of the fluorescing species. The fluorescence properties of a
hydrocarbon mixture may also change after long-term exposure to and interaction with the environment.
A contaminant that has been in the ground for any period of time will undergo changes in chemical
composition due to weathering, biodegradation, and volatilization. In terms of degradation and transport,
the lighter PAHs tend to volatilize and biodegrade first, leaving the heavier PAHs as time progresses.
These are the PAHs that are preferentially excited by the 337-nm laser source used in the SCAPS LIF
sensor.
Matrix Effects
The in situ fluorescence response of the LIF sensor to hydrocarbon compounds is also sensitive to
variations in the soil matrix. Matrix properties that affect LIF sensitivity include soil grain size,
mineralogy, moisture content, and surface area. Each of these factors influences the relative amount of
analyte that is adsorbed on or absorbed into the soil. Only the relative fraction of analyte that is optically
accessible at the window of the probe can contribute to the fluorescence signal. Of the four influencing
factors mentioned above, the dominant variable appears to be soil surface. LIF sensitivity to petroleum
hydrocarbons on soil has been shown to be inversely proportional to the available surface area of the soil
substrate. Sandy soils tend to have a much lower total available surface area than clay soils. A specific
concentration of petroleum hydrocarbon compounds in sandy soils generally yields a correspondingly
higher fluorescence response than an equivalent concentration in clay rich soils. In one study, soil
samples were prepared as a series of sand/clay (illite) mixtures with progressively increasing clay
content. The relative LIF response to PFM in each soil is essentially identical once the response curves
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were normalized to the available surface area of each of the soils. The moisture content of the soil matrix
is another influencing factor. The LIF sensitivity to petroleum hydrocarbons generally increases with
greater soil moisture content, although in some natural soils the effect appears to be small. LIF response
curves representing the results of fluorescence measurements on a soil with varying water content have
also been generated. These results suggest that the response is fairly insensitive to changes in moisture
content. In another study it was demonstrated that increasing the amount of water in a soil tends to
narrow the sensitivity difference between sandy and clay soils. It is thought that water physically
displaces the hydrocarbons from within the pore spaces of the matrix, effectively reducing the surface
area available to contaminants. The effects of soil grain size has also been examined in laboratory
studies. LIF sensitivity generally increases with increased grain size. The measured fluorescence was
shown to be substantially greater in the coarser mesh sizes.
Spectral Interferences
The SCAPS LIF sensor is sensitive to any material that fluoresces when excited with ultraviolet
wavelengths of light. Although intended to specifically target petroleum hydrocarbons, the excitation
energy produced by the LIF system's laser may cause other naturally occurring substances to fluoresce as
well. At some investigation sites, it is possible that LIF sensors could respond to fluorescence
originating from nonhydrocarbon sources. Many common fluorescent minerals can produce a
measurable LIF signal. Other nonhydrocarbon fluorescent material introduced through human activity
may be found in the subsurface environment. De-icing agents, antifreeze additives, and many detergent
products are all known to fluoresce very strongly. The potential presence of fluorescence emission from
nontarget (nonhydrocarbon) analytes within the soil matrix must be considered when assessing LIF field
screening data. In some instances, the inability to discriminate between hydrocarbon fluorescence and
nonhydrocarbon fluorescence can lead to false positives for the presence of hydrocarbons. Nonhydro-
carbon fluorescence can mask the presence of hydrocarbon fluorescence, leading to reduced sensitivity or
erroneous estimation of the relative amount of hydrocarbon present. In the worst case, spectral
interference can lead to a false positive or false negative report of findings. Because the LIF sensor
collects full spectral information, however, it is almost always possible to discriminate between
hydrocarbon and non-hydrocarbon fluorescence by analyzing the spectral features associated with the
data.
The SCAPS LIF sensor system uses a multichannel detection scheme to capture a complete fluorescence
emission spectrum at each point along the push. An advantage of this approach is that spectral features
are obtained that can be used to associate the signal with a specific petroleum class, mineral substance, or
other material. The spectral patterns collected in situ provide the means to uniquely distinguish hydro-
carbon fluorescence from potential interferents. The SCAPS LEF's ability to recognize nonhydrocarbon
fluorescence has been tested in several laboratory experiments. In one study, the spectra of eight
fluorescent minerals and five fluorescent chemicals were obtained with the LIF sensor. These spectra
were compared with the LIF spectra obtained from multiple samples of jet fuel, gasoline, diesel fuel, and
lube oil. In all cases, the hydrocarbon spectra could easily be recognized (by both computer algorithm
and human analysts) as being different from the nonhydrocarbon spectra. The specific substances used
in the experiment were chosen because they fluoresced in the same spectral region as the fuel products.
Many other fluorescent chemicals and minerals fluoresce in a spectral region far removed from the
hydrocarbon spectra. The materials used included calcium carbonate, resinous coal, Tide® surfactant,
norbergite, aragonite, Prestone® antifreeze, fluorite, fossil algae, Simple Green® detergent, scapolite,
turritella agate, and quinine sulfate.
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In addition, the organic component of some soils contains humus. This naturally occurring residue of
plant decay often contains some small amount of fluorescent PAHs. Laboratory tests have demonstrated
that humics do not interfere with SCAPS LIF detection of hydrocarbon on soil. This is because humic
fluorescence is minimal at concentrations found in even the most organic-rich soils.
Technology Deployment and Costs
The SCAPS CPT and LIF technology are designed to be operated by trained technicians from the AEC,
U.S. Navy, and other licensees. It is not available for use by private citizens or corporations, but is
available to state and federal agencies. The SCAPS truck is typically dispatched for three weeks to
perform field screening and sensor validation at a site. Prior to the actual deployment of the system, the
site is visited to determine location of obstructions such as buildings, cement platforms, fencelines, etc.,
as well as underground obstructions such as pipes and existing storage tanks. At this time, information
on possible contaminants and prior efforts at characterization and/or remediation is also collected. Soil
samples will be obtained for preparation of calibration samples.
The truck is typically deployed with a three-person crew and a geologist. Two people are needed to
handle the push rods and operate the hydraulic press, and the third person operates the sensor, including
measurements of the calibration and control standards, monitoring the actual real time push data, and
measurement of the response from soil samples collected during the validation phase of the operation.
Under typical conditions, up to 200 feet of pushes can be reasonably advanced in one day.
Following the site deployment, a field report is prepared for the site owner and applicable permitting or
regulatory agencies that includes the raw data from the SCAPS pushes, the field borelogs, the analytical
data, and a short summary describing the results of operations. This summary report is intended to be
followed by a more thorough analysis, with in-depth discussion of site detection limits, the plume
boundaries, and contaminant identification.
Cost estimates provided by the NCCOSC RDT&E Division indicate that the SCAPS CPT and LIF system
can be deployed in two ways: as a turnkey operation or a more limited service.
For a turnkey operation, the daily cost is approximately $4000.00 (assuming 200 feet per day), with an
estimated per foot cost of $20.00. The services include the CPT platform and LIF system; pre-
deployment site survey; development of work plan, health and safety plan, and permit preparation; utility
screening; field crew and supervising geologist; data analysis and review; and report preparation. On-site
investigation-derived waste (IDW) handling is included, but does not include waste characterization or
disposal. Additionally, the cost assumes local travel only (no per diem or distant travel costs), no
mobilization/demobilization costs, no concrete coring, no permit fees, and gravity/surface grouting and
restoration only.
The general SCAPS deployment with limited services costs approximately $2500.00 per day (assuming
200 feet per day), with an estimated per foot cost of $12.50. This option includes the CPT platform, the
LIF system, and the field crew (crew chief, technician, and data analyst) and the supervising geologist.
The customer would be responsible for utility locating; development of work plans and health and safety
plans; all permitting; providing a site manager to identify push locations and site documentation; and
drums for containment of IDW. The end product for this option would be the SCAPS LIF and
geotechnical profiles for all pushes. Again, under normal conditions, 200 feet of pushes can be advanced
daily. Concrete coring, grouting, permit fees, and distant travel costs or mobilization/demobilization
costs are not included.
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Section 4
Reference Laboratory Results and Evaluation
The purpose of this section is to address issues related to the reference laboratory used for these
demonstrations. Section 4 is divided into four subsections. The first subsection provides details
concerning the selection of ATI as the reference laboratory and the reference methods performed on the
soil samples at ATI for the purpose of comparison with results from the LIF technology. The second
subsection provides an assessment of data quality for the laboratory and gives a description of the quality
control procedures for TRPH (total recoverable petroleum hydrocarbons by DR. spectrophotometry) by
EPA Method 418.1 and California DHS Method 8015-modified for TPH (total petroleum hydrocarbons
by GC-FID). These methods will be referred to as TRPH and TPH throughout the remainder of this
report. In the third subsection, the methods used to estimate accuracy, precision, and completeness are
discussed and results provided. The final subsection provides a summary of the laboratory data quality
evaluation and a brief discussion of how the laboratory results will be used for comparison with the
results of the LIF technology.
Selection of Reference Laboratory and Methods
To assess the performance of the LIF technology as a field screening tool for petroleum hydrocarbons in
the subsurface, the data generated using the LIF technology was compared to data obtained using
conventional sample collection and analytical methods. The analytical laboratory selected to provide
reference analytical services, ATI, is certified in the state of California. The laboratory is located in San
Diego, California.
ATI was selected because of its experience with QA procedures, analytical result reporting requirements,
data quality parameters, and previous involvement with the SCAPS LIF program. ATI is not affiliated
with NCCOSC RDT&E Division or any of the demonstration team members. ATI provided copies of the
analytical results directly to SNL in order to maintain independence of the data. Copies of all QA and
analytical procedures were provided to SNL for review prior to the demonstration and were included in
the approved demonstration plan.
After discussion between representatives of State of California EPA, SNL, and the U.S. EPA, EPA
Method 418.1 for TRPH and California DHS Method 8015-Modified for TPH were selected as the
reference methods for the LIF technologies. The TRPH and TPH methods were chosen because of their
widespread and generally accepted use in delineating the extent of petroleum hydrocarbon contamina-
tion. The TRPH and TPH methods are currently used as indicators of petroleum contamination in
leaking underground and aboveground fuel tank investigations; as such they are the most comparable
analytical methods corresponding to the objective of demonstrating rapid field screening using LIF.
EPA Method 418.1 for total recoverable petroleum hydrocarbons (TRPH) is used for the measurement of
Freon-113-extractable petroleum hydrocarbons from surface and saline waters, soil, and industrial and
domestic wastes. The sample is acidified to a low pH (<2) and serially extracted with Freon-113 in a
separatory funnel. Interferences from polar animal oils and greases are removed with silica gel
adsorbent. Infrared analysis of the extract is performed, and its absorption is directly compared to that
measured on a standard mixture of hydrocarbons. This method is not recommended for more volatile
hydrocarbons (C5 to C7) due to loss of volatiles.
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California Department of Health Services (DBS) Method 8015-modified for total petroleum
hydrocarbons (TPH) is based on EPA SW-846 Method 8015 for determination of ketones, modified for
determination of petroleum hydrocarbons in soil. It is used for the determination of gasoline and diesel
in contaminated groundwater, sludges, and soil. After solvent extraction, a sample is injected into a gas
chromatograph where compounds are separated. Compounds in the GC effluent are identified and
quantified using a flame ionization detector. The chromatogram produced by this analysis covers the
carbon range from C7 to C36 and can help to identify the product type using the n-alkane pattern
distribution, pristane: phytane ratios, and the width of the unresolved complex mixture.
Assessment of Laboratory Data Quality
Audits
As part of the cooperative agreement between the U.S. EPA and the State of California EPA Department
of Toxic Substances Control, a representative of the California EPA audited the ATI laboratory in April
1995 and provided audit results to SNL. The audit found no irregularities and verified the procedures
used to homogenize and analyze the discrete soil samples. SNL reviewed the ATI Quality Assurance
Manual and all related procedures prior to the demonstrations (ATI, 1995).
Sample Holding Times
The holding tune specification for EPA Method 418.1 is 28 days from the sampling date. The holding
time specification for California DHS Method 8015-modified is extraction within 14 days of sampling
date. The required holding times per ATI SOP 105 from the date of sample receipt to the date of
extraction and analysis were met for the samples from both sites. However, for the SNL samples, two
samples (SNLDB11-5 and SNLDB11-10) were misplaced prior to homogenization and were left un-
refrigerated in a sealed container for five days before being located. They were homogenized, extracted
and analyzed per both methods within 14 days of the sampling date (CEIMIC, 1996). The results are
shown in Table A-2. These samples had large concentrations (> 10,000 mg/kg) of hydrocarbons that
exceeded the LIF detection limit. For this verification study, the total concentration of the petroleum
hydrocarbons in the sample was unimportant for the comparison; the fact that both samples showed
contamination well above the LIF detection limit (qualifying the samples as "detect") was important for
the purpose of comparison to the LIF method. For this reason, they were not excluded from the data set.
Sample Preparation
All soils were homogenized for five minutes prior to extraction and analysis per ATI SOP 421.
Preparation of soils for TPH analysis was performed per ATI SOP 400 by diluting in methylene chloride.
Preparation of soils for TRPH analysis was performed by extraction with Freon-113 for 45 minutes prior
to analysis per ATI SOP 803.
Sample Analysis
TRPH was determined by EPA Method 418.1 by calculating the linear regression of absorbance versus
concentration. The concentration thus derived tells only the concentration of oils in the Freon-113
extract. This was then related back to the original sample. TPH was quantified by DHS Method 8015-
modified by sample peak area using the mean response factor of the curve. The concentration was
calculated using the response factor and the mean calibration factor obtained from prepared diesel fuel
standards and adjusting for volume and dilution factors. FID was used for compound detection.
16
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Detection Limits
The ATI method detection limit for TRPH is 1.0 mg/kg for soil. The method detection limit for TPH is
5.0 mg/kg for soil.
Quality Control Procedures
For TPH,. quality control procedures included preparation of a calibration curve for instrument
calibration using NIST-traceable standards, A reagent blank is extracted each time a batch of no more
than 20 samples is extracted. An additional reagent blank is extracted for each batch of 20 samples in
any given day. A blank spike is extracted with each batch of no more than 20 samples. Surrogates are
run with each soil sample and quality control sample. Matrix spikes and matrix spike duplicates are also
prepared and associated to no more than 20 samples of a similar matrix to check for precision and
accuracy. Spiking is done directly into the sample prior to extraction. Spiking levels for fuel
hydrocarbons are 100 mg/kg for soils.
For TRPH, a reagent blank, blank spike, matrix spike, and matrix spike duplicate were analyzed for each
batch of 10 samples. Spiking level for petroleum hydrocarbons is 130 mg/kg for soils. A laboratory
control sample was analyzed to verify the working curve, and a midrange check standard was run every
tenth scan. The working calibration curve was prepared once per day.
Calibration standards were run at least every 10 samples to verify the calibration curve. In addition, a
laboratory control sample (a midrange reference standard) was run at least once during each instrument
run to verify the calibration curves. ATI did not provide written results of calibrations but reported
verbally that all calibration and control standards were within acceptance limits or the procedures would
have been repeated.
Accuracy, Precision, and Completeness
This section discusses the accuracy, precision, and completeness of the reference method data. Tables 4-
1 and 4-2 display the results of the quality control samples used to estimate accuracy and precision of the
methods. The data from the reference laboratory was internally reviewed by ATI QC personnel before
the data were delivered to SNL and NCCOSC RDT&E Division. SNL reviewed the raw data and quality
control sample results and verified all calculations.
Accuracy
Accuracy and matrix bias of the reference methods were assessed using laboratory spiked samples and, in
the case of DHS Method 8015-modified, surrogate additions. Results of past PE audits of ATI were also
reviewed to verify laboratory performance for accuracy and precision.
To estimate accuracy, the percent recovery is calculated using the following equation:
% Recovery =
Spiked sample result - Unspiked sample result
Spike concentration
x 100%
Diesel fuel standard was the spiking compound for the TPH method, and the surrogate is bis-2-
ethylhexylphthalate. Surrogate recoveries were all well within laboratory acceptance limits (69-132%
recovery). Blanks were prepared using sterilized silica sand as the "soil." The spiking compound for
17
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TRPH was a prepared mixture of fuel hydrocarbons containing hexadecane, isooctane, and benzene.
Blanks for both methods were prepared using sterilized silica sand as the "soil."
The percent recoveries for the laboratory measurements of matrix spikes, blank spikes, and duplicate
spikes for both methods are presented in Tables 4-1 and 4-2.
Cal EPA-DTSC also obtained splits of samples to independently verify ATI's results at the State of
California Hazardous Materials Laboratory. There was excellent agreement between both laboratories
for TPH and TRPH.
Table 4-1. Quality Control Results for TPH (total petroleum hydrocarbons by GC/FID,
California DHS Method 8015-modified).
QC Sample
Matrix Spike % Recovery
MS Duplicate % Recovery
MS Duplicate RPD
Surrogate Spikes
Blank Spike
Reagent Blanks
ATI Acceptance Limits
63-1 19% Recovery
63-1 19% Recovery
18%
69-132% Recovery
61-125% Recovery
<5.0 mq/kg
Port Hueneme Demo
Average Result
88 (range 80-100)
86 (range 77-100)
3 (range 0-8)
104 (range 97-126)
96 (range 90-100)
all < 5.0 mg/kg
SNL Demo Average Result
100 (one sample)
110 (one sample)
4 (range 0-10)
110 (range 100-126)
108 (range 100-1 10)
all < 5.0 mg/kg
Table 4-2. Quality Control Results for TRPH (petroleum hydrocarbons by IR
spectrophotometry, EPA Method 418.1).
QC Parameter
Matrix Spike % Recovery
MS Duplicates RPD
Blank Spike
Reagent Blank
ATI Acceptance Limits
74-126% Recovery
20%
88-1 18% Recovery
< 1.0 mg/kg
Port Hueneme Demo
Average Result
104 (range 79-1 18)
3 (range 0-20)
102 (range 90-118)
all< 1.0 mg/kg
SNL Demo Average Result
104 (range 98-1 06)
4 (range 0-13)
104 (range 100-1 10)
all< 1.0 mg/kg
Precision
Precision of the reference method results can be estimated using the field duplicates by comparing the
relative percent differences (RPD) for sample results and their respective field duplicates, or results of a
laboratory spiked sample prepared and analyzed in duplicate, using the following equation:
I Sample result - Duplicate result I
RPD = • x 100%
Average result
Field duplicate samples were analyzed by both reference methods. After the soil samples were
homogenized, nine of the samples from the Port Hueneme site and one of the samples (SNLDB11-40)
from the SNL site were analyzed hi duplicate (see Table A-l). This subset was selected randomly by the
SNL verification entity in the field during the Port Hueneme demonstration, based on a visual assessment
of the contamination of the sample; only the samples containing visually detectable hydrocarbon
contamination were analyzed .in duplicate. The sample for the SNL demonstration was selected after the
demonstration based on inspection of the LEF results. The mean precision estimate (RPD) for the 10 total
field duplicates was 10.7% for TPH and 16.5% for TRPH. Overall, this data shows good agreement
between the samples and their respective field duplicates, indicating a high degree of precision by the
reference laboratory.
IS
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The precision for the laboratory duplicates (Table 4-1,4-2) was estimated by comparing the results of 14
pairs of matrix spike/matrix spike duplicates for TPH and 23 pairs of matrix spike/matrix spike
duplicates for TRPH. Overall, these data show good agreement between the laboratory matrix spikes and
their duplicates for both methods.
Completeness
Percent completeness is defined as follows for all measurements:
where
%C = 100% x
V= number of sample measurements judged to be valid
T = total number of discrete sample measurements
Results were obtained for all of the soil samples. A total of 130 analytical soil sample results plus nine
field duplicate results using both TPH and TRPH methods were available from Port Hueneme. A total of
92 soil sample results for both TPH and TRPH plus one field duplicate sample result were available from
the SNL Tank Farm demonstration data set. As mentioned earlier, two samples from SNL that were left
unrefrigerated for 5 days at the laboratory were included in the data set because their suitability for
comparison to the LIF measurements did not appear to be compromised. Based on these results, the
completeness of the data set was 100 percent.
Use of Qualified Data for Statistical Analysis
As noted above, 100 percent of the reference laboratory results from Port Hueneme and SNL samples
were reported and fell within laboratory acceptance limits. The data review indicated that all data were
acceptable for meeting the demonstration objectives. The results of these analyses are presented in
tabular form in Appendix A, Tables A-l and A-2, and graphically in Section 6.
Although the two analytical methods are quite different, the TRPH and TPH measurements for both
demonstrations were generally quite close, and using one or the other in determinations of agreement had
little bearing on the results. Therefore, the laboratory measurements used for the comparisons required
for this evaluation are based on the average result from these two analytical methods performed on a split
sample at the laboratory.
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Section 5
Demonstration Design and Description
Evaluation ofSCAPS LIF Sensor Performance
The performance of the SCAPS LIF sensor was evaluated to determine the percentage agreement
between LIF "detect/nondetect" data and both TPH and TKPH results. Conventional sampling and
analysis consisted of boring adjacent to the push holes with a hollow stem auger, collecting split spoon
samples as close as possible to the push cavity, and analyzing the discrete samples at the reference
laboratory. The data from the laboratory analysis of soil samples which showed TRPH or TPH
contamination above the LIF detection limit were considered to show a "detect." Similarly, if in situ LIF
readings registered above the LIF site detection limit, they would also indicate a "detect." The number of
matches (detect/detect plus nondetect/nondetect) were tallied and reported as percentage agreement. The
misses were indicated as LIF "false positives" or "false negatives." Because of natural interferences and
fluorescent subsurface minerals, a greater number of false positives than false negatives was expected
during the operation of the LIF technologies. Because the false positive data could be investigated with
additional LIF spectral analysis, the primary goal was to keep the number of false negatives to no more
than 5 percent.
Other sensor attributes evaluated included the ability to obtain near continuous measurements (at 0.2 foot
intervals); the ability to provide detailed mapping of the distribution of subsurface petroleum
contamination; the ability to provide a daily site detection limit in fluorescence and concentration based
units; the ability to show good qualitative agreement with the pattern of contamination obtained from
analytical measurements of semicontinuous soil samples; the ability to store and retrieve the entire
fluorescence spectra for each push; the ability to use spectral data to distinguish hydrocarbon from
nonhydrocarbon fluorophores; the ability to obtain sensor data in real time during each push; the ability
to decide location of future pushes in real time; and the ability to detect the presence of hydrocarbons in
the vadose zone, capillary fringe, and saturated zones. These sensor attributes were evaluated by
observing them in the field during the demonstration.
Performance audits were conducted in the field to verify that the SCAPS LIF system was operated
according to the procedures outlined in the demonstration plan.
Evaluation of SCAPS CPT Platform Performance
The SCAPS CPT platform was evaluated by measuring or observing the following in the field:
collection rate, maximum push depth, ability to achieve better depth measurement estimates than
conventional drilling and sampling techniques, the ability to collect simultaneous geotechnical
information to aid in interpreting contaminant distributions, and the amount of investigation-derived
waste generated.
Description of Demonstration Sites
Field demonstrations were conducted at two sites: (1) the Hydrocarbon National Test Site located at
Naval Construction Battalion Center (NCBC) Port Hueneme, California, in May 1995, and (2) the Steam
Plant Tank Farm at Sandia National Laboratories (SNL), Albuquerque, New Mexico, in November 1995.
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Port Hueneme Site Description
The NCBC Port Hueneme site encompasses approximately 4,000 acres on the Pacific coast in Ventura
County, California. NCBC Port Hueneme is approximately 60 miles northwest of Los Angeles and is
located immediately to the west and northwest of the City of Port Hueneme (Figure 5-1). NCBC Port
Hueneme is an active naval facility where remedial investigation/feasibility studies (RI/FS) under the
Navy's Installation Restoration Program (IRP) are currently in progress. The demonstration area is
located at Site 22, the aboveground fuel farm. Site 22 is located in the southwestern portion of NCBC
Port Hueneme, approximately 1,000 feet west of Hueneme Harbor and approximately 2,000 feet north of
the Pacific Ocean.
Port Hueneme Site History
Site 22 includes five decommissioned aboveground fuel storage tanks numbered 5021, 5022, 5025, 5113,
and 5114. The tanks are surrounded by a series of asphalt-paved earthen berms that restrict surface
runoff and which were designed to contain the contents of each tank in the event of failure. Based on
investigative findings during remedial investigation/feasibility studies activities, it appears that leakage
has occurred from all five tanks or their associated piping.
Based on the contaminant type and distribution in the vicinity of Tank 5114, this area was selected for
the demonstration. Tank 5114, a 10,500-barrel capacity tank, was constructed in 1969 and used to store
diesel fuel marine (DFM).
Port Hueneme Site Geology and Hydrogeology
The uppermost 1 to 2 feet of soil at Site 22 typically consist of orange-brown silty sand or silt. Below
this interval is a layer consisting of predominantly medium-grained sand, tan in color, with some coarse
and fine-grained sand. This sand layer is approximately 18 feet thick. Site 22 has been built up several
feet higher than the surrounding region; the elevation of the ground inside the berms averages about 17
feet above mean sea level (msl). A dark gray silt layer is present below the sand layer corresponding
approximately to 18.5 feet below ground surface (bgs). Recent measurements of groundwater elevations
in monitoring wells at Site 22 indicate a groundwater flow direction to the south-southeast. Depth to
groundwater is 11 to 13.5 feet bgs.
Port Hueneme Site Contaminants and Distribution
The soils and groundwater hi the area around Tank No. 5114 have been contaminated by petroleum
hydrocarbons. The full extent of the contamination has not been assessed; however, previous site
investigations have indicated TPH levels exceeding 70,000 mg/kg to a depth of 20 feet bgs. Pre-
demonstration sampling as part of this effort indicated TPH contamination at 24,000 mg/kg at a depth of
16 feet bgs. Laboratory analysis confirmed that DFM is present in the soil. Contaminants appear to
have migrated vertically and reached their greatest concentration near the water table.
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Channel Islands Boulevard
Naval Facilities Engineering
Service Center (NFESC)
N
0 1000 2000 feet
I I I
Figure 5-1. Site vicinity map, Port Hueneme; NCBC Port Hueneme area is delineated by
the dashed perimeter.
22
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Predemonstration Sampling and Analysis
A predemonstration sampling and analysis event was performed in accordance with the demonstration
plan to evaluate the demonstration site and the standard analytical methods for verifying the LIF
technologies. NCCOSC RDT&E Division conducted predemonstration sampling between April 4 and
12,1995. Representatives of SNL and State of California EPA Department of Toxic Substances Control
(Cal EPA-DTSC) were present during the predemonstration event. During the sampling activities, a
number of individual SCATS LIF pushes were advanced at the site. Following select pushes, a borehole
was advanced adjacent to the penetrometer hole using a hollow stem auger with split spoon sampler, and
discrete soil samples were collected. The soil samples were shipped to Analytical Technologies, Inc.,
(ATI) for confirmatory analyses. Representatives of Cal EPA-DTSC collected duplicates for analysis at
the State of California Hazardous Materials Laboratory for verification of contaminants.
In addition to the soil samples submitted to ATI and the State of California Hazardous Materials
Laboratory for chemical analysis, one to two soil samples per boring were submitted to the Law/Crandall
geotechnical laboratory in San Diego, California. These samples were subjected to mechanical soil
analysis for grain size estimation using ASTM Method 422 and for moisture and density analysis using
ASTM Method 2937.
The results of the predemonstration sampling and analysis were used by the NCCOSC RDT&E Division
to assess matrix effects or interferences, revise operating procedures where necessary, and finalize their
performance claims. The developers and representatives of Cal EPA-DTSC, SNL, and U.S. EPA
determined that the site and the contaminant type and distribution were acceptable for the purposes of
this demonstration.
Demonstration Sampling Operations, Port Hueneme
The objective of the sampling design at Port Hueneme was to collect in situ LIF and conventional
laboratory analytical data concurrently to demonstrate the LIF technology's capability to delineate the
boundary (field screening) of a petroleum hydrocarbon plume. To accomplish this, a series of eight
iterative pushes and comparison borings were advanced between Tank 5114 and the expected plume
boundary. After each push, a boring was drilled adjacent to the push hole and sampled. The push and
boring locations are depicted hi Figure 5-2.
According to the demonstration plan, the SCAPS CPT platform alternatively pushed the SCAPS LIF
probe and ROST LIF probe, producing a pair of pushes located approximately 8 niches apart, prior to the
advancement of the comparison boring between the two push holes.
For the SCAPS LIF pushes, the SCAPS CPT platform was used to push the SCAPS LIF probe and
acquire fluorescence data to a total depth of 16 to 20 feet bgs. Following the pair of pushes, the rig was
moved completely away from the location and a hollow stem auger (HSA) drill rig was positioned with
its stem center approximately 4 inches from the push hole. The HSA rig drilled a hole using an 8-in
diameter hollow stem auger such that the internal diameter of the auger was parallel to, and
approximately 2 inch offset from, the LIF probe cavity. Operating within this drilling geometry, the
advancing auger flights destroyed the LIF probe's push hole while allowing for the collection of split
spoon soil samples within approximately 3 inches (horizontally) of the push cavity. Soil samples were
collected with a split spoon sampler lined with 6-inches long, 2.5-inches in diameter stainless steel tubes.
The sampler was driven in advance of the lead auger using a 140-pound slide hammer falling over a 30-
inch distance, in accordance with the ASTM 1586 Standard Penetration Test.
23
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Borm
Berm
B21
B23
B25
B26 B27
• • • •B24
B28
B22
Berm
S22-W3
• B09SCAPS/Borlng Location
£ S22-W3 Existing Monitoring Well
°L
20
40ft
Figure 5-2. Demonstration site and sampling locations, Port Hueneme. B21-B28 are the
locations of the HSA borings associated with the CRT pushes. For example, B21 is the boring associated with
PHDP21, the initial SCAPS push.
Soil samples were collected from every 1 to 1.5 feet of boring starting at a depth of approximately 2 feet
below ground surface. The sampler was overdrilled approximately 6 inches prior to retrieval to reduce
the amount of slough soils typically in the bottom of the borehole. Only tubes containing sample soils
that appeared relatively undisturbed were used.
The depth from which samples were collected was measured by lowering a weighted tape before and
after sample retrieval. This permitted identification of the depth from which the samples were collected
in the vadose zone to within approximately 3 inches. In the water saturated zone, however, sloughing
and hydraulic soil movement (flowing or heaving sand conditions) were encountered which resulted in
much greater uncertainty in identifying sample depth.
After each split spoon sampler was retrieved and the individual soil sample collection tubes were visually
inspected, each soil sample was handled as follows:
• The soil sample tube was sealed with Teflon swatches and plastic end caps. The tube was labeled
with the sample identification information.
• The end caps of the sealed, labeled soil sample tube were duct-taped in place, and placed into an
insulated cooler with ice, recorded onto the chain-of-custody form, and held for shipment to ATI for
analysis. The PRC sample custodian and SNL representative verified the accuracy and completeness
of the soil sample chain-of-custody form and placed a custody seal on the cooler. Original field
sheets and chain-of-custody forms accompanied all samples shipped to the reference laboratory.
• In addition to those soil samples submitted to ATI for chemical analysis, one to two soil samples per
boring were submitted to Law/Crandall's geotechnical laboratory in San Diego, California. These
24
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samples were subjected to mechanical soil analysis to determine grain size distribution using ASTM
Method 422 and for moisture and density analysis using ASTM Method 2937. Those samples
determined by grain size analysis to contain a substantial portion (>25 percent) of fine-grained
material (defined as that passing through a #200 sieve) were subjected to hydrometer testing by
ASTM Method 422. Although not part of the verification process, Law/Crandall Inc. performed the
geotechnical laboratory analyses on selected soil samples to confirm the visual logging of the borings
in the field.
• Rinsate samples of the split spoon sampler were collected to check for cross-contamination after
decontamination of the sampler. The rinsate samples were submitted to ATI for analysis.
Ultimately, the data collected from the demonstration were used to compare in situ LEF results with
conventional TPH and TRPH results.
Port Hueneme Sampling Locations
The sampling locations were in a line running west to east located south of Tank 5114 (Figure 5-2). The
first SCAPS LEF push was located in what was estimated to be an area within the plume and identified as
PHDP21, at 6 feet east of the 0 foot location (Table 5-1). The first boring was advanced and sampled
immediately after the probe was retrieved and the SCAPS CPT was moved away. A second push,
designated as PHDP22, was then advanced in an area estimated to be outside of the plume boundary.
The second boring was advanced and sampled immediately after the probe was retrieved and the SCAPS
CPT was moved away. The strategy was to advance the first two pushes in locations that would bound
the edge of the plume and then locate subsequent pushes, PHDP23-PHDP28, in an effort to close in on
the horizontal extent of the plume. The distance between each successive push decreased until the edge
of the subsurface hydrocarbon plume had been defined within 9 feet, for a total of 8 borings. The
number of sampling locations was based on past use of the SCAPS LD? to define hydrocarbon plume
boundaries at other sites and on demonstration budget constraints.
Each boring using the HSA and split spoon sampler was identified with a unique number assigned in the
field. For example, PHDB21 identified the boring (B21) that was collocated with the initial SCAPS
(PHDP21) push. Individual samples collected from each boring were sequentially numbered as they
were logged; for example, PHDB21-5 identified the fifth soil sample collected from boring B21. Each
sample was submitted for analysis accompanied by the chain-of-custody documentation.
Note that PHDP26A represents the second SCAPS push attempted at the location indicated in Figure 5-2.
The first push was refused due to an impenetrable gravel/cobble layer within 6 feet of the surface.
PHDP26A was offset 8" to the west of PHDP26 and was advanced without difficulty. PHDP27B was the
third attempt to advance a SCAPS push at the location indicated hi Figure 5-2. The third attempt was
successful only after a pilot hole was advanced using an uninstrumented (dummy) probe. After removal
of the dummy probe, the CPT and LDF probe was advanced through the pilot hole and LIF measurements
were collected throughout the push.
25
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Table 5-1. Port Hueneme Boring and Push Summary Table. The PHDP prefix denotes a SCAPS
push at the Port Hueneme Demonstration. The PHDB prefix denotes the hollow stem auger boring.
Push or Boring
Identification
PHDP21
PHDB21
PHDP22
PHDB22
PHDP23
PHDB23
PHDP24
PHDB24
PHDP25
PHDB25
PHDP26A
PHDB26
PHDP27B
PHDB27
PHDP28
PHDB28
Date
5-17-95
5-17-95
5-18-95
5-18-95
5-19-95
5-19-95
5-22-95
5-22-95
Comments
P21 located 6 feet east of zero point; B21 located 8 inches east of P21 . Total
of 15 samples collected; max depth 19 feet.
P22 located 200 feet 8 inches east of zero point; B22 located 4 inches west of
P22. Total of 17 samples collected; max depth 19.5 feet.
P23 located 53 feet east of zero point; B23 located 4 inches east of P23. Total
of 16 samples collected; max depth 19 feet.
P24 located 162 feet 8 inches east of zero point; B24 located 4 inches west of
P24. Total of 21 samples collected; max depth 19.5 feet.
P25 located 81 feet east of zero point; B25 located 4 inches east of P25. Total
of 16 samples collected; max depth 20 feet.
P26A located 141 feet 4 inches east of zero point; B26 located 4 inches east
of P26. Total of 17 samples collected; max depth 20 feet.
P27B advanced through pilot hole of approximately 6 feet bgs. P27B located
157 feet east of zero point. B27 located 4 inches west of P27B. Note that
pushes P27 and P27A were refused or excessively inclined in upper 5 feet due
to gravel and cobble. Total of 19 samples collected; max depth 19.5 feet.
P28 advanced through 6-foot pilot hole 148 feet 8 inches east of zero point.
B28 located 4 inches west of P28. Total of 17 samples collected; max depth
18.5 feet.
SNL Tank Farm Site Description
The location for the second LIF demonstration was an active fuel tank farm for the Steam Plant at Sandia
National Laboratories, Albuquerque, New Mexico (Figure 5-3). This site was selected because it
represented a different climate, geology, and contaminant distribution than the Port Hueneme demon-
stration site. The Tank Farm site is an SNL Environmental Restoration Site that is currently being
characterized and will begin a remediation feasibility investigation beginning in 1998. It is located in the
southwest portion of Technical Area I on the northeast corner of the intersection of Hardin and Wyoming
Boulevards (Figure 5-4). The 3-acre site is L-shaped and contains five tanks. The area west and north of
Tank 5 was the area for this demonstration.
Site History, SNL Tank Farm
The Steam Plant Tank Farm was constructed in the 1940s. All tanks contained #2 diesel fuel to be used
as a backup supply system for the Steam Plant when the primary fuel supply (natural gas) was
unavailable. The backup supply system has never been used and the fuel currently in the tanks is the
original product delivered. One documented release of fuel occurred in June 1991, when the main valve
of Tank 5 was left open and more than 5,000 gal of fuel was discharged into a holding tank at the Steam
Plant (approximately one-half mile north of the tank farm). During transfer operations from the holding
tank to another storage tank south of Hardin Boulevard, a leaking pipe was discovered. The pipe was
then cut and capped, and the impacted soils in the area were scheduled for excavation. A few weeks later
during excavation operations, it became evident that the fuel release was much greater than previously
thought. Although the full horizontal and vertical extent of the plume was not determined, the 50 feet by
35 feet by 15 feet deep excavation pit was backfilled with the original fuel-contaminated soil. Recent
site investigations using a Geoprobe® identified petroleum contamination down to at least 30 feet bgs in
the area of the excavation.
26
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1-25
1-40
Albuquerque
Gibson Blvd
Sandia National Laboratories
HardinBlvd
Kirtland Air Force Base
Figure 5-3. Site vicinity map, SNL Tank Farm.
1
Tank 1
Tank 2
TankS
Tank 4
o
o
o
.NLDP10/B10
DP11/B11
f J Tank 5
APPROXIMATE
LOCATION OF
LEAKING FUEL
TRANSFER LINE
10O SO O
Hardin Boulevard
100
SCALE 1" = 1OO'
Figure 5-4. Demonstration site and sampling locations, SNL Tank Farm.
27
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SNL Tank Farm Site Geology/Hydrogeology
SNL is located near the east-central ridge of the Albuquerque Basin. The basin is a rifted graben within
the Rio Grande Rift that is bounded on the east and west by north-south trending faults. SNL lies on a
partially dissected bajada formed by coalescing alluvial complexes. The deposits on the surface are
composed of alluvial fan deposits shed from the eastern uplifts that interfinger with valley alluvium and
consist of clayey to silly sands, with lesser amounts of silt, clay, and sand. Surficial deposits are
underlain by a thick sequence (greater than 5,000 feet) of basin-fill deposits of interbedded gravels,
sands, silts, and clays. Depth to groundwater is approximately 500 feet, with the potential for perched
water at shallower depths. During the exploratory and informal predemonstration investigations, the
SCAPS CPT consistently met with refusal near 52-57 feet, due to a consolidated gravel/caliche layer at
this depth.
SNL Tank Farm Site Contaminants and Distribution
The SNL Geoprobe® investigations and the preliminary SCAPS investigations indicated diesel
contamination greater than 1000 mg/kg in the vadose zone down to 56 feet. The area that was excavated
down to approximately 15 feet and subsequently backfilled with the contaminated soil contains a
somewhat homogenized mixture of diesel contaminated soil and uncontaminated soil. A high
concentration of subsurface fluorescing minerals, most likely calcium carbonate, was identified prior to
the demonstration. Calcium carbonate is present to some degree throughout the vadose zone in this area;
it is more concentrated near the surface.
SNL Tank Farm Predemonstration Sampling
A formal predemonstration event was not conducted at the SNL Tank Farm site. The site was evaluated
for its suitability as a demonstration site during a site exploratory tour by the NCCOSC RDT&E Division
in August 1995. Two other arid locations were evaluated at this time and determined to be unsuitable for
this demonstration. Immediately prior to the field demonstration in November, the NCCOSC RDT&E
Division performed an informal sampling event to determine sampling locations for the demonstration.
Earthen berms had been removed to allow access to contaminated areas. Following select pushes, stab
samples (discrete soil samples collected using the cone penetrometer soil sampling apparatus) were
collected and shipped to ATI for overnight confirmatory TPH and TRPH analysis. Laboratory analysis
of the stab samples indicated TRPH of 3380 mg/kg and TPH of 3300 mg/kg (as diesel) at a depth of 25
feet Nine SCAPS LIF pushes indicated fluorescence from the surface to 15 feet bgs, from 16 to 22 feet
bgs, and from 39 to 56 feet bgs on several of the pushes. Carbonate was observed in all the discrete soil
samples in varying concentrations by the professional geologist and confirmed by applying hydrochloric
acid, causing release of carbon dioxide, to a few representative samples.
Demonstration Sampling Operations, SNL Tank Farm
The sampling operations at the SNL Tank Farm were similar to the operations at Port Hueneme Site 22,
with the following changes.
Because the horizontal extent of the plume at Port Hueneme Site 22 had been delineated to within 9 feet
with 8 pushes during the field demonstration, this capability of the SCAPS LIF technology was not the
primary focus of the second demonstration. For the SNL Tank Farm demonstration, the developers and
representatives of SNL and U.S. EPA determined that it would be preferable to collect more samples
from areas expected to be contaminated to compare the LIF technology with the results from the
reference laboratory analysis of discrete soil samples. The addendum to the demonstration plan reflected
this change to the sampling strategy. For the demonstration, three SCAPS LIF pushes were advanced,
28
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followed by three overborings. Based on the results of the informal predemonstration, the first push and
boring were located in an area that had contamination throughout the push, the second push and boring
were advanced in an area that had contamination from approximately the 40 to 50 feet depth, and the
third push and boring were advanced in an area expected to be uncontaminated.
During the Port Hueneme demonstration, samples were collected throughout the contaminated and
uncontaniinated areas at intervals of every 1 to 1.5 feet. The experimental design called for several
pushes to be located in clean areas hi order to delineate the horizontal extent of the plume. This resulted
in a large quantity of clean samples in the data set (114 nondetects of 130 total samples as determined by
the reference laboratory). For the demonstration at the SNL Tank Farm, the experimental design was
modified to focus discrete sampling in the impacted areas and limit the number of samples in areas
expected to be unimpacted. This conserved resources and allowed for more comparisons of
hydrocarbon-impacted samples (68 detects of 92 total samples as determined by the reference
laboratory).
During drilling operations, discrete soil samples for reference laboratory analysis were collected using a
California modified split-spoon sampler lined with 2.5-in diameter by 3-in stainless steel tubes. The
smaller size of the sample tube was selected to allow for a greater number of discrete samples to be
collected during a single 24-inch sample drive and would also permit finer scale resolution of the
comparison of the LIF response to the reference laboratory analytical results. In addition, fewer samples
were collected in the unimpacted boring. A total of 92 soil samples were collected during this
demonstration, compared to 130 for the Port Hueneme demonstration.
All demonstration samples were collected and documented as previously described. Each SCAPS CPT
push was identified with a unique number assigned in the field. For example, the tenth SCAPS LIF push
was identified as SNLDP10 (SNL Demonstration, Push 10). Each boring was uniquely identified, such
as SNLB10 for the boring (B) that was collocated with the initial SCAPS (SNLDP10) push. Individual
samples collected from each boring were sequentially numbered as they were logged; for example,
SNLDB10-5 identified the fifth soil sample collected from the tenth boring.
Table 5-2. SNL Tank Farm Boring and Push Summary Table. SNLDP represents the SCAPS
push at the SNL Tank Farm Demonstration. SNLDB represents the hollow stem auger boring.
Push or Boring
Identification
SNLDP10
SNLDB10
SNLDP11
SNLDB11
SNLDP12
SNLDB12
Date
11-6-95
11-7-95
11-8-95
Comments
P10 located 2 feet east of fuel transfer line. B10 located 4 in offset from P10.
Total of 53 samples collected; max depth 56.25 feet.
P1 1 located 9 feet west of fuel transfer line. B1 1 located 4 inches offset from
P1 1 . Total of 28 samples collected; max depth 55.25 feet.
P12 located 50 feet north and east of P10. B12 located 4 inches offset from
P12. Total of 20 samples collected; max depth 49.5 feet.
Calibration Procedures, Quality Control Checks, and Corrective Action
Calibration procedures, method-specific QC requirements, and corrective action associated with
nonconformance QC for the LIF technology are described in the following paragraphs.
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SCAPS LIF Initial Calibration Procedures
Initial system setup requires calibration of a number of components in the SCAPS LIF system. A time-
delay calibration was performed because the detector setup was gated for the duration of fluorescence
emission return at the detector. An automated software procedure was run to determine the optimal time
delay between laser firing and enabling the detector. A plot of intensity versus time delay was acquired
and determined the optimal delay. The time delay varied solely as a function of the optical path length
between the laser and the detector, which changed only with the length of fiber in the probe umbilical.
A wavelength calibration was also performed for the SCAPS LIF system to determine the parameters AO
and Al, which are the intercept and slope of the line converting detector pixel number into wavelength.
A micrometer on the spectrograph was adjusted to center 500 nm on the center of the detector. The
center 700 pixels of the 1024 in the detector were intensified; therefore, the starting pixel was set to 162,
and the pixels-to-read parameter was set to 700. A mercury lamp was used to provide known
wavelengths for calibration. A helium-neon (HeNe) laser was used to verify the calibration. This
procedure was required after the spectrograph, the fiber input to the spectrograph, or the detector was
changed. Recalibration was also required when the wavelength of the fluorescent standard was greater
than 5 nm from the standard value.
Strain gauge calibration was performed hi accordance with ASTM standard D3441. A load cell device
and an automated software procedure was used to determine the scale and offset converting strain gauge
output in millivolts to tons per square foot, for both the sleeve and cone tip strain gauges. This procedure
was required each time a different probe assembly is used or when strain gauge zero checks (performed
after each push) differ from zero by more than 1 ton per square foot (TSF) for the sleeve and 10 TSF for
the cone tip.
The concentration calibration procedure was performed using a set of calibration standards (DFM-spiked
site-specific soil samples) prepared by the serial addition method. The calibration standards were run in
triplicate at the beginning of each day and again when equipment was changed. These samples were
sequentially presented to the sapphire window for measurement. After measurement, the average and
standard deviation was computed for each sample. If the standard deviation exceeded 20 percent for
replicate analyses of any single sample, that sample was rerun. If deviation remained excessive, the
system check standard was measured. If the check standard was out of compliance, system checkout and
debugging was required. A calibration curve was generated by plotting the average of maximum
fluorescence peak intensity versus the concentration of fuel product added to the calibration soil sample.
A linear fit is performed yielding slope, intercept, and correlation coefficient, R2. If the R2 did not exceed
0.90, the calibration curve was regenerated.
SCAPS LIF Continuing Calibration Procedures
A fluorescent standard 10 mg/L quinine sulfate solution) was analyzed before and after each push. This
measurement is a check of system performance and provides a means for normalizing measurements. If
the fluorescent intensity changed by more than 20 percent of the initial value determined during pre-push
calibration, system trouble shooting procedures were initiated.
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Method Blanks
A clean sand blank was measured pre- and post-push as part of the standard data collection procedure. If
the clean sand blank LIF measurement varied beyond 50 percent of its pre-push calibration value,
troubleshooting procedures were initiated.
Spike Samples
Spiked samples were not used for monitoring the performance of the SCAPS LIF system. In situ
measurement precludes the presentation of spiked samples to the LIF measurement system.
Instrument Check Standards
A system check using a fluorescent standard (quinine sulfate, wavelength = 458 ± 2 nm) was performed
before and after SCAPS LIF data collection operations (concentration calibration and pushes). Both
wavelength and intensity of the standard were monitored. If the wavelength differed by greater than 5
nm from the known value, a wavelength calibration was performed. If the intensity changed by more
than 20 percent, system trouble shooting was required.
Performance Evaluation Materials
Performance evaluation (PE) samples were not used for this demonstration. Because the LIF
technologies are in situ measurement techniques, PE samples cannot be inserted into these dynamic
measurement processes.
Duplicate Samples
Due to the nature of the in situ measurement, duplicate samples cannot be measured by LIF. Soil
heterogeneity and variation in contaminant distribution can be significant over short distances both
horizontally and vertically. For purposes of this study, samples were taken from adjacent holes, drilled
no more than six inches apart.
Equipment Rinsate Samples
To assess whether cross contamination was being introduced during equipment decontamination, an
equipment rinsate sample was collected daily. The source of the water for the equipment rinsate sample
was the deionized water used for the final rinse step of the equipment decontamination process.
Deionized water was poured over the sampler and into vials equipped with Teflon seals in a manner so
that headspace was minimized. The equipment rinsate samples were sealed, labeled, and placed into an
insulated cooler, logged on the chain-of-custody form, and submitted to ATI for analysis of TRPH and
TPH using the reference analysis methods previously described.
Data Reporting, Reduction, and Verification Steps
To maintain good data quality, specific procedures were followed by the developer and the SNL
verification entity during data reduction and validation, and reporting. These procedures are detailed
below.
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Data Reporting
The following data were reported to SNL:
1. Field data plots from all pushes, including SCAPS fluorescence intensity, cone pressure, sleeve
friction, and soil classification, each with respect to depth. Also provided were the field plots of
peak fluorescence wavelength versus depth, and all push data displaying the raw fluorescence
spectrum collected during the pushes.
2. System check and calibration sample concentrations; tabulated raw system check and calibration
sample fluorescence data; average system check intensity and system check ratio for each push;
background, noise, and sensitivity calculated from calibration data.
3. Borehole logs indicating soil sample collection information, including sample numbers, depth of
samples, location of water table, and other relevant information concerning the collection of the
soil samples; chain-of-custody documentation associated with soil samples.
4. Laboratory results for TPH and TRPH measurements of soil samples, including the standard
analytical results and quality control data.
Data Reduction and Verification Steps for the SCAPS LIF Data
The LIF sensor records fluorescence intensity as a function of depth as the probe is pushed into the
ground. In addition to this raw data, a system check standard was measured before and after each push,
and a series of calibration samples were measured on a daily basis during the site operations. The raw
data and daily calibration procedures were used to make decisions in the field. Following the conclusion
of site operations, the raw fluorescence measurements were adjusted by a normalization factor, and the
daily thresholds were averaged (after normalization) to provide site fluorescence and detection
thresholds. This procedure is detailed below.
1. A site-average quinine sulfate value was calculated by averaging all the pre-push measurements of
the quinine sulfate standard. For each push, and for the daily calibration measurement, a
normalization factor QS, equal to the pre-push quinine sulfate measurement divided by the site
average quinine sulfate value, was calculated. The LIF data from each push were normalized by
dividing the fluorescence intensity by QS. The fluorescence intensity values for the calibration
samples were also normalized by dividing by QS.
2. The fluorescence threshold and detection threshold values for each day were normalized by dividing
them by QS, which is equivalent to regressing the normalized calibration data. The normalized
threshold values were averaged to provide an overall site fluorescence threshold and detection
threshold. These average threshold values were used to determine detects and nondetects for the
verification phase of the demonstration.
3. To compare the in situ data with the soil sample analysis results, the normalized fluorescence
intensity measurements taken at the depths from which the soil samples were gathered were
tabulated. Because the sampling spacing for LIF data points is approximately 2.4 inches, the
fluorescence data from all points corresponding to the 6-inch interval of soil sample from Port
Hueneme were averaged to produce a single fluorescence intensity for a given sample. For the SNL
demo, the sample interval was modified to 3 inches. Therefore, the fluorescence data from all points
corresponding to the 3-inch interval of soil sample were averaged to produce a single fluorescence
intensity for a given sample.
4. Fluorescence data were reduced to a detect or nondetect reading using the fluorescence threshold and
associated detection limit as determined from the calibration samples. The average fluorescence
reading corresponding to each soil sample was compared to the fluorescence threshold. Those
32
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exceeding the threshold were recorded as detects; those falling below the threshold were recorded as
nondetects.
5. Results from the reference laboratory were also reduced to a detect or nondetect reading. The
laboratory result (TPH and TRPH) for each soil sample was compared to the site detection threshold.
Those exceeding the threshold were recorded as detects; those falling below the threshold were
recorded as nondetects.
6. Field notes and photographs were reviewed to verify that procedures outlined in the demonstration
plan were followed.
7. On-site system audits for field operations and procedural quality assurance audits were conducted by
SNL while the demonstration was being conducted. Audit results are reported in Section 6.
Specifically, the SCAPS LIF system and operators were audited for compliance with the draft LIF
method provided in Appendix C.
Changes to the Demonstration Plan
Because of the depth discrepancy between discrete samples collected using the hollow stem auger and
the in situ LIF measurements that was noted after predemonstration sampling, the developers performed
ex situ measurements of the discrete samples (called single-point tests or SPTs) after the demonstration.
SPTs are measurements taken by placing a homogenized portion of a discrete sample (after laboratory
analysis is complete) on the LIF probe window and recording the fluorescence intensity. This intensity
can be compared to the reported laboratory result for the original sample and to the in situ fluorescence
intensity. After the Port Hueneme demonstration, SPTs were performed by the NCCOSC RDT&E
Division as an optional procedure to determine if there was a depth discrepancy between the LIF in situ
readings and the discrete sample locations. Although SPTs were performed for both demonstrations,
results of SPT measurements affected only the data evaluation for the Port Hueneme demonstration.
Because the saturated zone was not encountered at the SNL Tank Farm, there was no depth discrepancy
noted at this site. Results of SPTs for the Port Hueneme demonstration are reported in Section 6.
For both demonstrations, calibration standards were prepared using site-specific soil. The standards were
measured daily at the start of operations. During the SNL Tank Farm demonstration it was determined
that the soil collected at the surface for preparation of the standards was not representative of the
nonimpacted soil at the site. The soil down to a depth of 10-15 feet had been excavated near the leaking
fuel transfer line in order to repair the line, and then had been returned without remediation. In addition,
the soil near the surface had a large concentration of calcium carbonate, which fluoresces quite strongly
under UV light. It was determined that the calibration standards prepared prior to the demonstration
were unusable. It was agreed by all parties that a revised set of calibration standards would be prepared
using soil more representative of the subsurface environment. This soil was collected at a depth of 36
feet bgs using the split spoon sampler during advancement of boring SNLDB12, the nonimpacted
location. New calibration standards were prepared after the demonstration at the NCCOSC RDT&E
Division laboratory, and a new calibration curve was prepared. The revised calibration data were used to
prepare the site fluorescence and contamination thresholds.
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Section 6
Technology Results and Evaluation
The purpose of this section is to present and evaluate the SCAPS LIF results from the two
demonstrations performed as part of this program. First, the developer claims are presented. Second, the
accuracy, precision, and completeness of the SCAPS LIF data set are provided. Third, the SCAPS LIF
results are compared to the laboratory results, and the performance of the technology is evaluated against
the developer claims. Finally, a summary of the performance evaluation is given at the end of this
section.
The in situ LIF results from both demonstrations are presented in Appendix B. The raw LIF data have
been analyzed by SNL and presented in this section in a variety of formats to compare them with the
reference laboratory results and to determine if the developer claims were met. The graphical depictions
of the SCAPS LIF data were developed from the original data set.
Developer Claims Presented
As stated in Section 5, the purpose of the demonstration was to generate appropriate field data to verify
the performance of the technology as a field screening tool for identifying petroleum hydrocarbons in the
subsurface. To accomplish this, two different sites were selected for demonstration locations: a shallow,
coastal site and a deep, arid site. The LIF data were evaluated to determine the technology's per-
formance relative to developer claims made in the demonstration plan. The LIF sensor data were
compared to the data from laboratory soil analyses and the SCAPS CPT platform was compared to
conventional sampling methods.
Specific claims for the SCAPS LIF sensor presented in the demonstration plan were:
1. Near continuous measurements generated by the sensor provide detailed mapping of the distribution
of subsurface petroleum contamination. At standard push rates of 1 m/min, fluorescence data are
typically collected at intervals of 0.2 feet.
2. The distribution of contamination provided by the LIF push data shows good qualitative agreement
with the pattern of contamination derived from analytical measurements (EPA Method 418.1 and
DHS Method 8015-Modified) of semicontinuous soil samples.
3. Calibration procedures have been developed to provide a site detection threshold based on a
specified fuel product in a site specific soil matrix. This procedure is used to report the detection
capability of the LIF sensor (specified hi both fluorescence counts and in concentration units
common to traditional analytical methods) on a daily basis. This procedure allows the detection
capability of the LIF sensor to be specified in concentration units common to traditional analytical
methods.
4. Direct comparisons of sensor data with samples collected using a split spoon sampler by overboring
the push hole with a conventional auger, using the "detect/non-detect" criteria, show good agreement
with conventional laboratory methods (EPA Method 418.1 and DHS Method 8015-Modified).
Historically, agreement between the LIF sensor and the analytic soil measurements has exceeded 80
percent, and the "correlation" (percentage agreement with the reference lab results) for this
demonstration will exceed 80 percent. False positives reported as a percentage of total analyses will
be no more than 5 percent.
34
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5. The SCAPS LIF sensor uses a detector system comprised of a spectrograph coupled to a linear
photodiode array detector to collect the spectral signature of the induced fluorescence emission
response. The entire fluorescence spectrum is collected and stored throughout the push.
6. Qualitative use of spectral data provides a means of distinguishing different classes of hydrocarbon
products, and can also be used to minimize potential false positives from non-POL fluorophores.
Different contaminants often have a different PAH distribution, resulting in a distinctive fluorescence
spectrum for each class of contaminants. When dissimilar spectra are encountered during a site
characterization, this can be indicative of more than one contaminant. Differences in spectral
signatures can also be used to discriminate non-hydrocarbon fluorophores present in the soil.
7. Data from the LIF sensor are available in real time as the sensor is advanced into the ground. This
allows real time decisions on how deep to sample the site.
8. The location of future pushes can also be decided in real time at the site using the information
available from all previous pushes. This can greatly speed location of the edge of the contamination
plume.
9. The LIF method can detect the presence of hydrocarbons in the bulk soil matrix throughout the
vadose, capillary fringe and saturated zones.
10. Measurements can be made to depths up to 150 feet, when the LIF sensor is used in conjunction with
an industry-standard 20 ton penetrometer push vehicle.
11. Geotechnical sensors (cone pressure, sleeve friction) are integrated with the LIF sensor to provide
simultaneous continuous geotechnical and stratigraphic information to aide in interpreting
contaminant distributions.
12. The in situ nature of the LIF sensor minimizes possibilities for contaminating or altering soil samples
that are inherent with traditional collection, transport and analysis procedures.
13. The LIF sensor provides more accurate measurement of the depth of the contaminant, especially for
sites where the contaminant is found in the saturated zone, because the LIF sensor does not suffer
from the sampling difficulties encountered by other common methods such as soil boring/split spoon
sampling. During typical operations, the uncertainty in depth with the SCAPS LIF sensor is
approximately 3 inches.
14. The LIF sensor produces minimal IDW. A typical 20-foot push with the SCAPS LIF sensor produces
approximately 10 gal of water EDW (used to clean the push rods). A typical 20-foot boring produces
55-75 gal of soil IDW as well as 20 gal of water used to clean the augers. Furthermore, the
penetrometer rods are steam cleaned directly upon removal from the ground, reducing potential
contamination hazards to site personnel.
These claims were evaluated individually and collectively throughout the demonstration and in post-
demonstration data analysis. Results are summarized at the end of Section 6.
Technology Data Quality Assessment
Data generated by the SCAPS LIF technology were compared to the data generated from analysis of soil
samples using the two analytical methods. The quality of the reference laboratory data has been
previously discussed, and all laboratory data were determined to be acceptable for comparison to the LIF
technology data. The following LIF data quality indicators were closely examined to determine if the
technology data were of sufficient quality to be compared to the reference laboratory data. The indicators
evaluated for the SCAPS LIF technology were accuracy, and precision, and completeness.
Accuracy
Accuracy refers to the degree of agreement of a measurement to the true value. For an in situ field
screening measurement technique such as LIF, determining the accuracy of the technique presents a
35
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particular challenge. This is because it is not a simple matter to confidently assign a "true" value to a
subsurface contaminant distribution. When compared to conventional laboratory-based measurements,
the accuracy of the method is a function of both the sampling errors and errors associated with the
measurement method.
Because there is no independent measure of the subsurface value of contaminant concentration, the
accuracy of the in situ measurement was assessed by comparing it to results from conventional laboratory
measurements. The percent agreement between TRPH (or TPH) and fluorescence data and percent false
negatives was calculated using the equations that follow.
%Agreement =
X~
x 100%
XT
Where:
x..=
XT =
Number of samples where fluorescence is less than the detection threshold and the
corresponding lab result is also less than the corresponding detection limit;
Number of samples where fluorescence is greater than the detection threshold and the
corresponding lab result is also greater than the corresponding detection limit; and
Total number of samples collected for comparison.
% False Negatives = — x 100%
XT-
Where:
xu-= Number of samples where fluorescence is less than the detection threshold and the
corresponding lab result is greater than the corresponding detection limit.
The average of the SCAPS LIF measurements corresponding to a 6-inch interval (Port Hueneme) or a 3-
inch interval (SNL Tank Farm) were compared to TRPH and TPH results for a discrete sample collected
at the same depth. Possible results for each comparison are shown schematically in Figure 6-1.
Although results from two separate analytical methods were compared to the LIF data, the difference
between the results in terms of detecl/nondetect agreement was minimal, so an average result of the two
methods was used for the graphical presentations in this section. Separate results for TRPH and TPH are
included in Table 6-1. The average laboratory result from each homogenized soil sample was compared
to the corresponding concentration detection threshold. If the laboratory result was above the
concentration detection threshold and the average LIF data from the push at the corresponding depth
exceeded the LIF fluorescence threshold, the result was a "detect/detect" (field B on Figure 6-1). If the
average LIF data were below the threshold and the corresponding analytical data were above the
corresponding detection threshold, the result was a "false negative" (field D). If the average LIF data
were above the threshold and the laboratory results were below the corresponding concentration
detection threshold, the result was a "false positive" (field A). If the average LIF data and laboratory
results were below the threshold and corresponding detection limit, the result was "nondetect/nondetect"
agreement (field C). This process was performed on each sample for both demonstrations. The results
were used to determine the claims of 1) field screening capability, 2) at least 80 percent agreement, and
3) no more than 5 percent false negatives.
36
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+
Detect
TRPH or TPH
Concentration
Nondetect
Detect
LIF
Fluorescence
Nondetect
LIF Detect
and TRPH or TPH
Nondetect
"False Positive"
'
A
C
LIF Detect
and TRPH or TPH
Nondetection
Agreement
LIF and TRPH or TPH
Detection Agreement
B
D
TRPH or TPH
and LIF Nondetect
"False Negative"
LIF Method
Detection
Threshold
in Fluorescent
Intensity
(Relative)
Determined in
Field Based
on Site-specific
Conditions
TRPH or TPH
Concentration (in mg/kg)
Corresponding to
LIF Detection Threshold
(Determined in the Field
During Pre-Push Calibration)
Figure 6-1. Schematic of the four possible LIF and TRPH/TPH data categories. This
schematic indicates the four possible outcomes of the data comparison for each sample analyzed by the laboratory.
The two lines crossing in the center indicate the LIF thresholds in fluorescent intensity and in concentration units. In
order for either the laboratory or the LIF system to show a "detect," the sample result had to be above the LIF
threshold. Quadrant A indicates false positives (the SCAPS LIF had a "detect" but the laboratory did not), Quadrant
D indicates false negatives (the SCAPS LIF had a "nondetect" and the laboratory had a "detect"), and Quadrants B
and C indicate agreement between the SCAPS LIF data and the laboratory data.
Table 6-1. Summary of comparison of results for Port Hueneme Demonstration.
Category
LIF/Lab
Nondetect/Nondetect Match
Detect/Detect Match
Nondetect/Detect Miss ("FN")
Detect/Nondetect Miss ("FP")
Total Samples
Percent ND/ND of Total
Percent D/D of Total
Percent Matches of Total
Percent ND/D Misses f FN1) of Total
Percent D/ND Misses ("FP") of Total
Compared to
TRPH result
111
11
5
3
130
85.4%
8.5%
93.9%
3.8%
2.3%
Compared to
TPH result
112
12
4
2
130
86.1%
9.2%
95.3%
3.1%
1.5%
Compared to
TRPH/TPH mean
111
12
5
2
130
85.4%
9.2%
94.6%
3.8%
1.5%
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Precision
Precision refers to the reproducibility of measurements of the same characteristic, usually under a given
set of conditions. Unfortunately, the conditions can vary in environmental data to an extent that leaves
the term ambiguous. Differences from site to site, sample to sample within a site, and differences in
results from repeated measurements from a single sample provide examples. Because the SCAPS LIF
sensor's primary utility is for in situ sensing as the probe is pushed into the ground, it was not possible to
obtain precision data for the sensor under conditions that exactly duplicated the manner in which in situ
measurements are made in the subsurface.
During the Port Hueneme demonstration, an estimate of the instrumental precision was obtained by
placing a standard cuvette containing a 10 ppm concentration of quinine sulfate dissolved in 0.1 N
EfeSCu) in front of the sapphire window and measuring the sample 20 times (20 laser shots for each
analysis). This is the same as the system check procedure used before and after each push. Because the
system check standard is in solution, it was considered to be homogenous. This procedure provided an
estimate of the precision of the instrument. The standard deviation of the 20 measurements was less than
1 percent of the mean count.
Completeness
Completeness refers to the amount of data collected from a measurement process compared to the
amount that could be obtained under ideal conditions. For this demonstration, completeness refers to the
proportion of valid, acceptable data generated using each method. It was anticipated that less than 100
percent completeness of both the LIF data and discrete sample analysis results would occur. For LIF data
collection, a push that was refused due to contact with cobbles or other obstructions was disqualified. A
substitute push was advanced in these cases, within 8 inches horizontally of the disqualified push. This
occurred on pushes 26 and 27 at Port Hueneme. At this site, the refusals occurred near the surface, so the
subsequent push allowed for LIF data to be collected near the same location. As long as the substitute
push was located within 8 niches, the disqualified push was not counted against the completeness goal.
Therefore, the completeness was 100 percent for Port Hueneme. At SNL, preliminary pushes had
indicated an impenetrable gravel/caliche layer at approximately 50-58 feet bgs. While this was able to be
penetrated by the HSA rig, the cone penetrometer was not advanced past this depth. The pushes were
considered to be complete at the point of refusal. Therefore, the LIF data set was considered 100 percent
complete for the SNL site.
Based on the evaluation of these data quality parameters, the SCAPS LIF data set was considered to be of
sufficient quality to complete the verification process.
Port Hueneme Site Data Presentation and Results
The data presented in this section are used to assess of the ability of the SCAPS LIF to provide field
screening and mapping of subsurface contaminants in a shallow, coastal site with contamination in the
vadose zone, capillary fringe, and saturated zone. The percentage agreement with the laboratory results
of soil samples from the Port Hueneme demonstration site is reported in this section.
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Port Hueneme Detection Limit
As described in.Section 5, the detection limit was determined on a daily basis in the field during the
demonstration, and a composite site detection limit was used for determination of agreement. For the Port
Hueneme site, the average detection thresholds were 3370 LIF counts (the daily threshold ranged from
2306 to 5433 counts) and 105 mg/kg (daily threshold ranged from 56.4 to 198.7 mg/kg) using DFM as
the calibrant fuel. The reference method data were considered to show a detect when the value exceeded
the Port Hueneme LIF site detection limit of 105 mg/kg. Because the soil samples were 6 inches long,
the fluorescence for the 6-inch interval associated with each sample was averaged, and this average was
compared to the detection limit. When the average in situ fluorescence result exceeded the average site
detection threshold, this was designated a "detect."
A chart showing possible "detect" versus "nondetect" results from comparing the LIF results to the
laboratory data is shown in Figure 6-1. A corresponding plot of the data for the Port Hueneme
demonstration is provided hi Figure 6-2. A summary of results for the Port Hueneme demonstration are
presented in Table 6-1.
Results from the Port Hueneme
Demonstration
1000000
100000
10000
1000
100
L'S!
;.
,-EU
10 100 1000 10000 100000
Laboratory Concentration Measurement (mg/kg)
Figure 6-2. Plot of results of comparison of Port Hueneme LIF data with laboratory data.
The average site thresholds described above are indicated by the heavy vertical and horizontal lines. The Port Hueneme site
LIF detection threshold is 3370 counts. The concentration detection threshold is 105 mg/kg. The concentration measurements
plotted are the average of TPH and TRPH results.
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Downhole Results for Port Hueneme
The LIF results obtained during five contaminated pushes at Port Hueneme have been plotted in Figure
6-3. These five plots indicate the pushes and associated borings along the transect near Tank 5114. The
corresponding soil sample collection locations and results are also indicated. The square symbols
indicate the locations and results of the single point tests. As discussed in Section 5, during the
predemonstration event there was a depth discrepancy observed with the hollow stem auger and split
spoon sampling operation, believed to be due to sloughing of sands in the saturated zone. This was also
observed during the demonstration. The reference laboratory provided splits of the homogenized
samples from the demonstration to the developer to perform single point tests (SPTs) at the developer's
facility after the demonstration. The developer placed portions of the homogenates on the LIF probe
window, and the fluorescent intensity was measured. SPT results were compared to the in situ
measurements obtained during the demonstration.
On review of the SPT measurements and in situ measurements for both LIF technologies, SNL
determined that on two holes, a slight offset was apparent that affected the results of the laboratory
measurements that were compared to the data from both technologies. Field notes were reviewed to
determine where sloughing of soils was most prominent. SNL determined that for holes 23 and 28, a
depth adjustment of 4-6 inches for the laboratory samples collected in the saturated zone was appropriate.
This adjustment supported (i.e., unproved) the percentage agreement results from both LIF technologies.
All downhole results, including the adjusted data for holes 23 and 28, are presented in Figure 6-4.
Port Hueneme Subsurface Contaminant Mapping
The test areas at Port Hueneme and the transect along which LIF pushes and hollow stem auger borings
were advanced to collect data for the performance evaluation are illustrated in Figure 6-5. Each symbol
along a hole indicates where a soil sample was collected. The result of each data point was compared to
the LIF measurement at the corresponding depth interval. The area of the plume was estimated based on
the laboratory measurements. This figure illustrates several points:
• the contaminant plume was narrow, and the false positives and false negatives, in general, were
located at the plume boundaries,
• the LIF field screening technology was able to determine the horizontal extent of the plume within 9
feet, based on the results of 8 pushes, and
• soil samples were collected at 1-1.5 foot intervals and often missed the boundaries of the plume.
40
-------
HOLE 21
°o
•OH-
560000
o
H
10 15
Depth (ft)
20 3 25
HOLE 23
1
«
C
a>
20000 --
10000 -.
777500
I
10 15
Depth (ft)
20
M 25
PH
HOLE 25
250200
5 10 15
Depth (ft)
Figure 6-3. Downhole results for Port Hueneme. Results from the five drilling locations where single
point tests were evaluated at NCCOSC RDT&E Division are illustrated above. The laboratory measurements are
indicated by the circles, the single-point test measurements are indicated with the square symbols, and the LIF
results are indicated by the continuous solid line. The horizontal axis is indexed by both concentration in mg/kg as
measured by the average of the analytical methods and in counts measured by the SCAPS LIF technology. Note:
It is inappropriate to compare the relative magnitudes of the laboratory concentration to the LIF peak as the LIF
results are not linear at higher concentrations.
41
-------
HOLE 26
20200
5 10 15
Depth (ft)
HOLE 28
.2
2500 T
2000 I
1500.-
1000 --
608:i
-o—co-oo—oo+oo-o
5 10 15
Depth (ft)
20
77600
8
g-1
5 25
Figure 6-3. Downhole results for Port Hueneme. (Continued)
42
-------
g 20000
'i -53 15000
1 Us 1000°
1 |j, 5000
6 o
HOLE 21
T O
0
0 5 10 15 20
Depth (ft)
560000
|
1
25
120 -r-
1 <-* 8°--
S oB
J-& 40-
|S 0-s
0 .40 i
HOLE 22
/I
IA^^^/IA-
/ r^Af 10000
3s" o
HOLE 23
o
o
yu^^^
0 5 10 15 20
Depth (ft)
777500
1
1
£ '
25
100 ,
§ 80-
g -aS 60 -
1 *3) 4^ "
§ ^ 0 -
U -20 J
HOLE 24
o
A fXv
/ N/^v \
" /AvjV^AvA^^A^C^'V3!?/>/°P ^ "^
) 5 10 15 , 20
Depth (ft)
3170
8
8
§
§
SI
25
Figure 6-4. Adjusted downhole results for Port Hueneme. This figure provides a summary of all
downhole results after adjustment for depth measurement inaccuracies due to sloughing that appears to have affected the
measurements in the saturated zone at boring locations 23 and 28. Note that the vertical axes for the holes beyond the plume
boundary, holes 22,24, and 27, have a smaller scale than holes 21,23,25,26, and 28, where contamination was detected.
43
-------
HOLE 25
250200
S 15000 T
• S
1 ^ 10000 -
1 J 5000-
<§ 0-
O
8
a
S
0 5 10 15 20
Depth (ft)
25
HOLE 26
J 8000.
I g 6000-
'1 "5 4000 -
1 & 2000.
.9 0 -
o
0 5 10 15 20
Depth (ft)
202000
S
a
3
I
25
HOLE 27
3200
10 15
Depth (ft)
20
25
HOLE 28
77600
10
15
20
25
Depth (ft)
Figure 6-4. Adjusted downhole results for Port Hueneme. (Continued)
44
-------
LIF/Lab Result
o Nondetect/Nondetect
• Detect/Detect
>fc. Detect/Nondetect
Nondatect/Detect
Figure 6-5. Cross-sectional map of transect near Tank 5114 at Port Hueneme. A contour view
of the results shown in Table 6-1, comparing the average ATI results to those of the SCAPS LIF system. The results are based
on the adjusted downhole data shown in Figure 6-4.
SNL Tank Farm Site Data Presentation and Results
As described in the addendum to the demonstration plan, the purpose of the SNL Tank Farm
demonstration was to demonstrate the capabilities of the LIF technology in an arid site with a deeper
hydrocarbon plume. Again, the percentage agreement of the LIF technology data set with the laboratory
analytical results of soil samples from the SNL Tank farm site provides the basis for evaluation.
SNL Tank Farm Detection Limit
As described hi Section 5, the detection limit was determined on a daily basis hi the field during the
demonstration, and a composite site detection limit was used for determination of agreement. For the
SNL Tank Farm site, the detection limit determined in the field was 13317 LIF counts or 929 mg/kg
DFM. During the demonstration, it was realized that the site-specific background soil to be used for
preparation of calibration soils had been collected from the area that had been previously excavated.
This soil had a high concentration of fluorescent minerals. A second set of calibration soils was
collected at 36 feet bgs from boring 12 (the uncontaminated push/boring). This second set showed a
more typical background fluorescent response (based on previous field deployments). It was agreed by
SNL, Cal EPA-DTSC, and the developers that this soil would be used to prepare a second set of
calibration standards after the demonstration. The site detection limit using this second set of calibration
standards was 1094 counts or 89 mg/kg. During data analysis, when the average in situ fluorescence
result exceeded the fluorescence threshold of 1094 counts, this was designated a detect. Because the soil
samples were 3 inches long, the fluorescence responses for the 3-inch interval associated with each
sample were averaged, and this average was compared to the detection limit. The TRPH and TPH
45
-------
measurements were considered to show a detect when the value exceeded the SNL Tank Farm site
detection limit of 89mg/kg.
A chart showing possible "detect" versus "nondetect" results comparing the reference methods and the
LIF fluorescence data is shown in Figure 6-1. A corresponding plot of the data for the SNL Tank Farm
demonstration is provided in Figure 6-6. This plot provides an illustration of how well and where
SCAPS LEF qualitative results (detect/nondetect) matched those of the laboratory methods. The figure
indicates similar results to those of the Port Hueneme demonstration, in terms of match and miss
percentages. The discrepancies are in regions that are impacted at levels close to the SCAPS LIF
detection limit and in the areas where high carbonate fluorescence was observed. In the case of
boring/push 10, the regions are separated from the plume because of the excavation, which redistributed
hydrocarbon contamination near the surface. The actual percentage agreement is given in Table 6-2
(unadjusted results).
Results from the SNL Tank Farm
Demonstration
J5
tu
IX
CJ
a
CO
o
v*
CO
>-.
o
1000000
100000
10000
1000
100
. x
1 10 100 1000 10000 100000
Laboratory Concentration Measurement (mg/kg)
Figure 6-6. Plot of results of comparison of SNL LIF data with laboratory data. This scatter
diagram illustrates the fluorescence counts and average laboratory measurements recorded for the SNL Tank Farm
Demonstration. The different symbols represent different groupings of spectral shapes provided by the SCAPS LIF
system In the field. V indicates samples with an obvious petroleum hydrocarbon spectral shape. "A" indicates
samples with spectra intermediate between the background spectral shape and the hydrocarbon spectral shape.
The primary source of fluorescence in results, "•" was determined to be from carbonate materials occurring
naturally in the soil at this site. For this reason, the matching percentages presented in Table 6-3 were computed
as if all square symbols (17 false positives and 5 detect/detects) were nondetects for the LIF SCAPS technology.
Table 6-2 shows that without this adjustment for carbonates, developer's claims were still met with 82 percent
agreement and 18 percent detect/nondetect ("false positives").
46
-------
Table 6-2. Summary of comparison of unadjusted results for SNL Demonstration. The
results indicate that carbonates in the soil led to a large percentage (18%) of SCAPS LIF false positives but no false
negatives.
Category
LIF/Lab
Nondetect/Nondetect Match
Detect/Detect Match
Nondetect/Detect Miss ("FN")
Detect/Nondetect Miss ("FP")
Total Samples
Percent ND/ND of Total
Percent D/D of Total
Percent Matches of Total
Percent ND/D Misses ("FN") of
Total
Percent D/ND Misses ("FP") of
Total
Compared to
TRPH result
7
68
0
17
92
8%
74%
82%
0
18%
Compared to
TPH result
7
68
0
17
92
8%
74%
82%
0
18%
Compared to
TRPH/TPHmean
7
68
0
17
92
8%
74%
82%
0
18%
Table 6-3. Summary of comparison of adjusted results for the SNL Demonstration.
Several samples with high fluorescence were reclassified as nondetects based on their spectral shape and field
observation of soil samples.
Category
LIF/Lab
Nondetect/Nondetect Match
Detect/Detect Match
Nondetect/Detect Miss ("FN")
Detect/Nondetect Miss ("FP")
Total Samples
Percent ND/ND of Total
Percent D/D of Total
Percent Matches of Total
Percent ND/D Misses ("FN") of
Total
Percent D/ND Misses ("FP") of
Total
Compared to
TRPH result
24
63
5
0
92
26.1%
68.5%
94.6%
5.4%
0
Compared to
TPH result
24
63
5
0
92
26.1%
68.5%
94.6%
5.4%
0
Compared to
TRPH/TPH mean
24
63
5
0
92
26.1%
68.5%
94.6%
5.4%
0
47
-------
Unlike results established at the Port Hueneme site, detects in the Sandia Tank Farm demonstration could
not be identified simply by comparing fluorescence counts to a threshold. Naturally occurring
fluorescent minerals in the soil (i.e., carbonates) caused a high level of nonhydrocarbon fluorescent
detects and false positive results. Although carbonates occur naturally throughout the vadose zone in
desert environments and were observed in soil samples at all depths, they were especially concentrated
within 14 feet of the ground surface.
As a standard practice, in order to distinguish between hydrocarbon and nonhydrocarbon fluorescing
materials, the SCAPS LIF operators evaluate the shape of the spectral signature from the fluorescent
response and, if possible, examine discrete samples collected from the same location and depth. The
discrete samples may be collected with the SCAPS stab sampler or, in the case of this demonstration,
with the hollow stem auger and split spoon sampler. The carbonates can be distinguished from
nonfluorescent soil by examining the soil sample (carbonate-based minerals appear as white crystalline
material) and confirmed by pouring hydrochloric acid on the soil and observing release of a gas believed
to be carbon dioxide.
Typical spectral shapes for fluorescence responses (recorded at depths corresponding to the depths where
discrete samples were collected) are depicted in Figure 6-7. Clearly there are at least two spectral
groupings, one group peaking at 420 nm (typical for diesel) and one group peaking at 460-550 nm, and
some spectra that appear to indicate intermediate results. The spectra have been normalized to give the
same magnitude fluorescence at their peak wavelength so that differences in shape can be more easily
identified. Further, statistical analysis indicated three fairly distinct groupings.
The SCAPS LIF operators, relying on the evaluation of spectral shapes and examination of the collocated
soil samples, were able to reevaluate and reclassify areas of high fluorescent response. All percentages
for agreement, false positives, and false negatives have been adjusted in Table 6-3 to reflect the
additional information obtained from spectral interpretation. The SCAPS LIF is deployed with trained
operators and geologists familiar with interpreting spectral information and identifying soil composition.
In order to evaluate their procedures, the verification entity evaluated the spectral shapes independently
to see if there was any difference in results. Using principal component analysis, and corroborated with
field notes, SNL produced similar matching results.
Downhole Results for SNL Tank Farm
Figure 6-8 shows the downhole fluorescence measurements for pushes 10,11, and 12 with different line
patterns corresponding to the different spectral groupings and some of the relevant soil description
comments from the field notes. The soil descriptions indicate that both the spectral group on the left in
Figure 6-7 and the "intermediate results" group were contaminated with hydrocarbons. Both these
groups fluoresce at a similar peak wavelength in the 420 nm range, as did the hydrocarbon-impacted
areas in the Port Hueneme demonstration. This is a typical peak wavelength for polycyclic aromatic
hydrocarbon spectra. Peak wavelength is monitored continuously in the standard operating procedure of
the SCAPS LIF system and can also be used to suggest nonhydrocarbon fiuorophores in the subsurface.
The area with the heavy solid lines indicate the areas where carbonate was identified in the field notes
and evaluation of spectral shape indicated the high fluorescence was due to the subsurface minerals and
not due to hydrocarbon impact, particularly in areas that had been excavated. These mineral fluorescence
"detects" were reclassified as nondetects hi the final evaluation of results by the developer. Because
some of these carbonate-rich samples also had some hydrocarbon impact, the reclassified samples did not
always match the laboratory results, resulting in a higher number of false negatives but no false positives
in the final tally.
48
-------
1
350
'X'VtJ?* A Intermediate Results
liisSri \
Carbonate Cluster
400
450
500
Wavele5n5gih (nm)
600
650
700
750
Figure 6-7. Normalized spectra showing two distinct clusters. The spectra plotted here are the
normalized spectra obtained by the SCAPS LIF sensor at depths where soil samples were collected and analyzed
by ATI. Most of the spectra appear to fall into one of two clusters, one peaking at 420 nm (hydrocarbons) and the
other in the 460 to 550 nm range (background with carbonate fluorescence). The third intermediate group indicates
there is hydrocarbon contamination and some influence from carbonate fluorescence. The heavy solid lines indicate
the median values of the three groups.
49
-------
40000-r
•I •£ 20000-..
3 .8.
HOLE 10
0 -p"*
-------
SNL Tank Farm Subsurface Contaminant Mapping
The test area at the SNL Tank Farm and the three collocated SCAPS LIF pushes and hollow stem auger
borings are shown in Figure 6-9. Each symbol along a hole indicates where a soil sample was collected.
The result of each sample was compared to the LIF measurement at the corresponding depth interval.
The horizontal boundary of the plume cannot be estimated from the information obtained from the three
pushes and borings; however, the areas of strong carbonate fluorescence and hydrocarbon contamination
are evident based on the LIF and laboratory results. This figure shows several points:
• the contaminant plume was thick and migrated downward rather than laterally;
• the false negatives were confined to areas where the strong carbonate fluorescence signal masked the
hydrocarbon fluorescence signal; and
• the point of refusal for the CPT pushes was the gravel/caliche layer at 50-57 feet bgs.
Push/Boring Location
#12
Area of Excavation
and Backfill
(Homogenized
Impacted Soils)
Carbonate
Rich
Region
LIF/Lab Result
o Nondetect/Nondetect
Nondetect/Detect
• Detect/Detect
Plan View
Figure 6-9. Subsurface contaminant map for SNL Tank Farm. Cross-section view of the results
shown in Table 6-3, comparing the ATI results to those of the SCAPS LIF. The results are based on the adjusted downhole data
shown in Figure 6-8.
51
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Geotechnical Data Assessment
The SCAPS CPT provides CPT sleeve friction and tip resistance data as the probe is pushed into the
ground at a rate of 1 m/min. The spatial resolution for geotechnical data is 1 sample/cm. The host
computer stores sleeve friction, tip resistance, and soil characteristics as interpreted from the strain gauge
data.
All discrete samples were visually logged and classified by the on-site geologist of the SCAPS CPT
crew. Soil classifications were determined to be sand, silt and admixtures of both. In addition, 14
samples from five boreholes at Port Hueneme and seven samples from three boreholes at SNL Tank Farm
were submitted to a geotechnical laboratory for grain size analysis to verify the field observations. The
visual observations and the geotechnical laboratory grain size analysis were in general agreement and
also agreed with the strain gauge data which provided soil classification information. Soil classification
was determined from the tip pressure and sleeve friction data according to the procedure described in
Robertson (1986).
Depth measurements were determined to be accurate by comparing the depth data recorded on the host
computer to manual measurements made by the verification entity during rod additions for actual pushes
in the field. Depths of sampling intervals for the HSA were measured in the field by lowering a weighted
tape in the open borehole. Depth measurements were off by as much as 6 inches from sampling interval
to sampling interval, especially in the saturated zone and capillary fringe.
Overall Performance Evaluation
In summary, the results of the demonstrations satisfy the requirements set forth in the demonstration plan
and addendum for the SCAPS LIF system. The system located the plume accurately with higher match-
ing percentage than the developer claimed. The false negative rate for the combined demonstrations was
4.9 percent, nearly identical to the five percent claimed by the developer. Disagreements with the labora-
tory results were primarily confined to regions where contaminant concentration levels were close to the
detection threshold. A portion of these discrepancies could be partially the result of variability in
laboratory results where random errors are estimated to be in the range of 10 to 15 percent.
As stated earlier, the performance of the SCAPS LIF was evaluated against the developer claims made in
the demonstration plan. Evaluation of the developer claims for the LIF sensor is presented in Table 6-3,
and evaluation of claims for the SCAPS CPT platform is presented in Tables 6-4 and 6-5.
Cost Evaluation
The SCAPS technology is designed to be operated by trained technicians from the AEC, U.S. Navy, or
other licensees. It is not available for use by private citizens or corporations, but is available to state and
federal agencies. The estimated cost of sampling using the SCAPS LIF system varies between $12.00
and $20.00 per foot depending upon whether the operators provide a turnkey operation or the customer
provides field deployment assistance such as permitting, site management, and development of work and
health and safety plans. Under normal conditions, 200 feet of pushes can be advanced per day. Concrete
coring, grouting, permit fees, and distant travel costs or mobilization/demobilization costs vary with each
deployment and thus are not included.
52
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Table 6-4. LIF sensor claims evaluation.
LIF Sensor Claim
Near continuous measurements provide
detailed mapping of the distribution of
subsurface contamination. Push rate 1 m/min,
data collected at 0.2 foot intervals.
Better than 80 percent agreement with
conventional laboratory analysis of samples,
with no more than 5 percent false negatives.
Distribution of contamination shows good
qualitative agreement with pattern of
contamination derived from analytical
measurements of semicontinuous soil samples.
Site-specific and contaminant specific
thresholds reported daily.
Entire fluorescence spectrum for each push is
collected and stored.
Qualitative use of spectral data can be used to
1) distinguish different classes of hydrocarbon
compounds and 2) minimize false positives
from nonhydrocarbon fluorophores.
Sensor data are available in real time as sensor
is advanced into the ground.
Location of future pushes can be decided in
real time.
Can detect the presence of hydrocarbons in the
vadose zone, capillary fringe, and saturated
zones.
Result
Push rate was 1 m/min. Data were collected
every 0.2 feet or less if cone slowed or
stopped.
Average for both sites: 94 percent correct
1 percent false positives, 5 percent false
negatives.
Good agreement with pattern of contamination
derived from results of semicontinuous soil
samples.
Thresholds were reported daily and used for
determination of next push at Port Hueneme.
Thresholds were averaged for site-specific
thresholds for data verification.
All spectral data were stored and easily
retrieved.
1) Only one class of hydrocarbon was
available at each site; therefore, first claim
not evaluated.
2) Spectral information was used to reclassify
carbonate detects (false positives) .to
nondetects at SNL site.
Real time sensor data acquisition was
observed during both demonstrations.
Location of next push was determined in the
field at the Port Hueneme site based on
fluorescence results from the previous push.
Hydrocarbons detected in the vadose zone at
SNL; in saturated and capillary fringe zones at
Port Hueneme.
Evaluation
Met
Met
Met
Met
Met
1) Not
evaluated
2) Met
Met
Met
Met
The main savings attributable to the SCAPS LIF system is that it can substantially reduce the number of
wells drilled at a site. In a general site characterization effort, it can provide site characterization data in
less time and far less expensively than conventional drilling and sampling. Investigation-derived wastes
are minimal. Three times as much decontamination water per push was produced by the HSA, which
required hazardous waste characterization prior to disposal. In addition, the SCAPS CPT does not
generate soil cuttings.
Table 6-6 provides a comparison of deployment costs for the SCAPS LIF system and conventional
drilling and sampling with a hollow stem auger drilling rig outfitted with a split spoon sampler, and off-
site analysis for petroleum hydrocarbons.
53
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Table 6-5. SOAPS CPT claims evaluation.
SCAPS System Claim
Measurements can be made to 150 foot
depths.
More accurate depth measurements
than HSA.
Production of minimal Investigation-
derived waste.
Integrated geotechnical sensors provide
simultaneous geotechnical and
stratigraphic information to aid in
interpreting contaminant distributions.
Result
150 foot depth claim not evaluated at either
site; max push depth was 57.6 feet at SNL
Review of previous deployments indicate
maximum push of 101 feet at Guadalupe Oil
Field. SCAPS CPT rods and fiberoptic
umbilical allow a maximum push of 150 feet.
Depth uncertainty with HSA was observed to be
3-6 inches on comparison of exs/tuand in situ
LIF measurements. Depth uncertainty with
SCAPS was measured to be less than 1 inch
(Port Hueneme).
SCAPS system produced 8 gal/22 foot push.
Decon water for HSA was 20 gal/22 foot
borehole plus 12 gal/hole for decon of samplers
(Port Hueneme).
Geotechnical and stratigraphic information was
used to determine soil classification in real
time. Strain gauge information was used at
both sites to determine point of refusal of cone.
Evaluation
Not
evaluated
Met
Met
Met
54
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Table 6-6. Relative costs for the SCAPS LIF system. Costs do not include per diem, permitting,
interpretive report preparation, utility location, location surveying, or work plan preparation. These costs would be
necessary in some circumstances but would be approximately the same for each.
SCAPS LIF In Situ Measurement
10 pushes
Depth of each push 30 feet
Semi-continuous LIF
samples plus geotechnical
data
2 days field time @
4000/day
Sample semi-continuously
at 1 sample/2 inches for
LIF response, total of 1800
samples for 300 linear feet
Sample continuously at 1
sample/cm for
geotechnical data
Cost of Drums for waste, 4
drums @ $40/drum
Decon water
characterization
No waste soil
characterization
No waste soil produced
Decon water disposal
4drums@$100/drum
4 man crew included
4 man crew included
TOTAL
Per hole sample costs
Cost
8000
Data included in above cost
Data included in above cost
160
1000
0
0
400
0
0
9560
$956/hole
Conventional drilling with HSA, sampling with split
spoon sampler, and off-site analysis
10 borings
Depth of each boring 30 feet
60 soil samples
300 linear feet of borehole
Analysis per DHS Method 8015
Drilling cost @ $50/ft x 300 linear
feet
Lab cost @ $80/sample x 60
samples, TPH
Lab cost @ $100/sample x 5
samples, geotechnical (grain
size, moisture, density)
Cost of Drums for waste, 28
drums @$40/drum
Decon water characterization
Waste soil characterization
Waste soil disposal 20 drums x
$100/drum
Decon water disposal 8 drums x
$100/drum
Geologist/Engineer 40 hrs x
$60/hr
Technician 40 hrs x $40/hr
TOTAL
Per hole sample costs
Cost
15000
4800
500
1120
1000
3000
2000
800
2400
1600
32,220
$3222/hole
55
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Section 7
Applications Assessment
The SCAPS LIF technology is emerging as a supplement to and possible replacement for conventional
drilling and sampling methods. As demonstrated, the SCAPS system and the LIF technology have
advantages and limitations. These advantages and limitations are described in the following sections.
Advantages of the Technology
Real-Time Analysis
Through the use of a cone penetrometer system, the SCAPS LIF provides real-time analysis of site
conditions. This approach is faster than any competitive technology, and therefore quite useful for real-
time decision making in the field. This is especially important in guiding soil sampling activities. For
conventional field characterization, soil samples are collected using a standard drill rig and sent to a
commercial laboratory for analysis. It can take weeks, and sometimes months, to get results. When the
results are reviewed, a return trip to the field for further drilling and sampling may be indicated. Real-
time sampling and data analysis often eliminates the expense and time delays of laboratory analysis and
return trips to the field.
Continuous LIF Data Output
The SCAPS LIF has an advantage over conventional drilling and sampling methods in its ability to
provide nearly continuous spatial data. It is common practice in environmental investigations to select a
sampling interval (e.g., 5 feet) to collect samples and ship to a laboratory for analysis. Characterization
of the contaminant zone may be severely impaired when the data density is sparse as it commonly is with
conventional drilling and sampling approaches due to budget constraints. Areas of contamination may go
wholly unnoticed in extreme cases. The LIF system allows a continuous record of possible contaminant
locations and a more complete delineation of the area of contamination. In addition, some drilling and
sampling operations can be hindered by an inability to produce core samples, due to flowing sands or
limited cohesiveness of the soils to be sampled, whereas the SCAPS LIF could potentially retrieve
readings from these horizons.
Continuous Lithological Logging
The SCAPS system affords continuous logging of the subsurface lithology, with on-board sensors used in
conjunction with the LIF sensor. This allows a user to target stratigraphy of interest, which may
influence contaminant flow and transport or have potential interfering influences on the LIF readings. A
conventional drilling and sampling program would require continuous core collection and a dedicated
geologist to get the same level of detail. The geologist may be able to define finer scale attributes of the
media, but only through a much more labor intensive effort. Compared to the conventional approach of
sampling at regular intervals (e.g., every 5 feet), the SCAPS CPT offers much greater resolution.
56
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Cost Advantages
When considered on a price per volume of characterization data, the SCAPS LIF provides a significant
advantage over conventional drilling and sampling. Most importantly, the SCAPS provides nearly
continuous data at a fraction of the cost of discrete sampling and analysis of the same area. The cost
effectiveness of the SCAPS (without LIF) compared to conventional drilling and sampling techniques has
been evaluated independently (LANL, 1991). They concluded that the SCAPS technology has a 30 to 50
percent cost savings for various scenarios analyzed. Cost information provided by the NCCOSC
RDT&E Division indicates that per sample costs can differ by an order of magnitude.
Enhanced Operator Safety
The SCAPS LIF system is safer than a conventional drilling and sampling program. There is little
chance of contacting contaminated soils, because soil samples are only occasionally brought to the
surface and the sensor is driven into the subsurface to take measurements. SCAPS workers are located in
the SCAPS truck, and not hi contact with the soil at the site. The cone penetrometer push rods are steam
cleaned to minimize any residual contamination along the sidewalls of the device when retrieving the
string. Grouting of the push hole can be done to minimize any potential cross-contamination of geologic
units in the subsurface. With drilling and sampling methods, the soil cuttings are brought to the surface
and potentially come in contact with workers and also must be disposed of as investigation-derived
waste. The samples are handled by multiple individuals for packaging and transport, and for subsequent
laboratory analysis, again providing an opportunity for exposure. Decontamination of the sampling and
drilling equipment is most often done manually by drilling personnel rather than automated. The SCAPS
system offers a clear advantage over conventional drilling and sampling in the area of health and safety
of the crew.
Performance Advantages
The SCAPS LIF technology works well in both the unsaturated and saturated zone. This may be
important at sites with a relatively shallow water table or perched zone to delineate the continuity of the
contamination across the interface.
The developer's performance claims were generally met in these demonstrations. Table 7-1 summarizes
the performance statistics for the technology relative to the ability of the LIF to locate the presence of
hydrocarbons. The developer claimed an overall detect/nondetect success rate of 80 percent. In other
words, the laboratory and LIF data should be in agreement on detect or nondetect designations for the
presence of hydrocarbons for 80 percent of the samples. The developer met this claim in all instances.
The developer also claimed a false negative rate of no more than 5 percent. In other words, the developer
expects that when the laboratory data indicate that hydrocarbons are present, but the LIF data signify a
nondetect, the percentage of samples that fall into this category should be no more than 5 percent. In
reality they met this claim with one exception, when the data were adjusted for carbonate influences at
the SNL Tank Farm demonstration and the percent of false negatives was 5.4 percent. A probable reason
for these false negative findings is that the appreciable carbonate fluorescence appears to mask the
presence of hydrocarbons on spectral analysis. These statistics are quite positive given that the SCAPS
LIF system is a field screening tool.
57
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Table 7-1. Performance statistics.
Demonstration
Site
Port Hueneme
SNL adjusted*
SNLnonadjusted
Overall Detect & Nondetect Agreement
Percentage Claim (>80%)
94.6
94.6
82.0
False Positive Percentage
(implicit claim <20%)
1.5
0
18.0
False Negative Percentage
(claim <5%)
3.8
5.4
0
detects reclassified as nondetects due to carbonate fluorescence, as determined from spectral analysis
The SCAPS LIF system should meet the expectations of regulators or site owners interested in
compliance with EPA sampling guidance (USEPA, 1989b). In designing sampling strategies the EPA
has acknowledged the concepts of uncertainty and potential errors in analysis. They have incorporated
these expectations in their guidance on allowable false positive and negative rates when comparing con-
firmatory sampling data to screening data. The EPA guidance on statistical sampling typically accepts a
5 to 10 percent false negative rate, which is within the range of the SCAPS LIF based on the results of
these demonstrations. In addition, they allow a higher percentage of false positives, typically up to 20
percent. The SCAPS LIF system appears to be capable of meeting EPA's guidance of performance
criteria for comparison of laboratory versus screening data.
Limitations of the Technology
Applicability
The applicability of the SCAPS LIF system is limited to detection of petroleum products containing
polycyclic aromatic hydrocarbons (e.g., diesel fuel) that fluoresce when exposed to 337 run wavelength
UV light. The strongest response occurs if the compound contains three or more aromatic rings.
Detection of other common contaminants such as light petroleum products (e.g., BTEX), chlorinated
hydrocarbons, and inorganics would require additional sensors. Therefore, the class of problems which
this technology can detect is restricted, and mixtures of contaminants (e.g., gasoline mixed with diesel
fuel) may not be readily identified.
Quantitation and Speciation
The SCAPS LIF does not allow direct quantitation of particular constituents of the petroleum cont-
aminants. The regulatory requirements for deciding cleanup requirements for RCRA or CERCLA sites
are established on the basis of individual constituent concentrations (e.g., naphthalene concentrations)
through comparisons with background, or established through the use of risk assessment techniques.
The LIF system is has been calibrated to TPH, which is appropriate for underground storage tank regu-
latory cutoff criteria, but may not be appropriate for RCRA or CERCLA investigations as a screening
measure. Again, the RCRA and CERCLA requirements are formulated" around contaminant-specific
concentration thresholds, and not aggregate measures of a total class of products, such as TPH. TPH is
affected by many things and is not readily correlated to individual constituents. Also, the LIF system is
calibrated to TPH for the purpose of defining detects versus nondetects of petroleum hydrocarbons (with
a cutoff threshold) and not intended to provide relative concentration measurements of TPH. For
underground fuel tank applications, typically an action level of 100 ppm TPH is used for delineation of
areas of potential concern. The LIF detection limits determined using the developer's calibration
procedure for detect/nondetect site evaluations are often higher than 100 ppm TPH and may result in an
area of concern not being defined to a regulator's satisfaction.
58
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On the other hand, an analysis of the data from the first demonstration at Port Hueneme showed that a
certain amount of conservatism was built into the procedure for establishing detection thresholds. The
data from Port Hueneme would have essentially the same detect/nondetect statistics if the cutoff were 40
mg/kg or greater, 2 to 3 times less than the detection limit of 105 mg/kg. A relaxation of the error
allowance in the calibration procedure would likely allow a 100 mg/kg or lower detection threshold to be
achieved in most circumstances. Additional testing would be required to adequately test this hypothesis.
Push Limitations
A cone penetrometer system is limited in its ability to hydraulically push through certain stratigraphies
(e.g., boulders, cobbles, caliche). The maximum depth is governed by site-specific stratigraphy and the
method is limited to sites where the cone penetrometer can be pushed to the depth of concern through
primarily unconsolidated sedimentary deposits or formations. This can limit the applicability of the
SCAPS LIF deployment to sites which have less severe geotechnical characteristics. It should also be
noted that the sensor location for the LIF is some distance above the cone tip (i.e., 60 cm), and when
refusal occurs due to a stratigraphy change the sensor does not actually get to that depth horizon. This
can be problematic if the stratigraphic layer is also an impedance to flow and transport of the
contaminants, thereby offering an opportunity for the contaminant to become concentrated at the
interface boundary. In this case the LIF sensor would not be able to address the issue unless the
constituent concentrations were elevated 60 cm above the interface or refusal depth.
Interferences
The LIF system is subject to interferences which can make data reduction complicated, and limit the real-
time nature of data analysis and decision making. Moisture in the soil and fluorescing compounds or
minerals (e.g., carbonates) are examples of naturally occurring constituents which affect the LIF readings
and influence performance statistics.
Conclusions
The SCAPS LIF system is an emerging technology worthy of pursuit in site investigations where
polycyclic aromatic hydrocarbons (e.g., petroleum, oils, and lubricants) are suspected. The technology
offers a number of advantages over conventional drilling and sampling technologies for the purpose of
screening a site for the nature and extent of contamination. It does not entirely take the place of a
conventional sampling program, but adds significant benefits in terms of resolution of the nature and
extent of contamination. This information, when used properly, could provide a more complete picture
of the contamination, and also could be used to predict future sampling locations. As noted above, there
are some disadvantages of which a prospective user should be aware when designing an environmental
investigation. Stratigraphy and fluorescent interferences appear to be the major issues that may prevent
the sole use of a SCAPS LIF system. In addition, the technology is not presently applicable for other
classes of contaminants. Further, the technology does not provide species-specific quantitation, and
therefore cannot be used in lieu of conventional sampling and analysis if risk assessment needs or
cleanup criteria must be met. As a screening technology to identify the extent of POL contamination,
this technology has many advantages over conventional techniques. Site-specific considerations will
determine whether the technology adds significant value to an investigation.
59
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Section 8
Developer Forum
NCCOSC RDT&E Division agrees that the CSCT's findings are objectively correct; however, inordinate
attention to limitations in Section 7 and elsewhere in this report detracts from the many advantages in
situ field screening with this technology offers. The in-depth evaluation performed concurrently by the
California EPA DTSC for their certification program establishes guidelines for usage that emphasize the
many advantages this technology offers without excessive reference to limitations (Cal EPA DTSC,
1996).
NCCOSC RDT&E Division has developed or is in the process of developing additional sensors for use
with the SCAPS CPT platform. These sensors are in various stages of development as of the date of this
report. Some of these new sensors are LIF-based, utilizing wavelengths other than the nitrogen LIF
system's 337-nm excitation source. As with the nitrogen LIF system, the detectors are designed to detect
petroleum hydrocarbon contamination. Other sensors have been designed to measure soil moisture by
time domain reflectometry; visually observe soil properties, including grain size, with the CPT-deployed
video microscope; detect chlorinated hydrocarbons (solvents) using Raman spectroscopy; and detect
metals using laser-induced breakdown spectroscopy. These sensors are further described below.
Xenon Chloride Laser
The xenon chloride laser uses a laser source that emits 308-nm ultraviolet light rather than the 337 nm
light used by the nitrogen laser system. The detector system and all other components of the LIF system
using the xenon chloride laser are identical to the nitrogen system. The laser is contained in the SCAPS
push vehicle, and the excitation and emission signals are transmitted by optical fibers. The use of a
wavelength slightly deeper into the ultraviolet region of light is designed to cause stronger fluorescent
response of the two-ringed PAHS. This should permit enhanced detection capabilities for lighter (more
refined) petroleum distillates without compromising the detection capabilities of the heavier petroleum
products. The xenon chloride laser has been field tested at three sites through May 1996.
Microchip Laser
The microchip laser delivers ultraviolet light at 266-nm in order to induce fluorescence. Light at this
wavelength is very poorly transmitted by available optical fibers, so the laser has been incorporated
directly into the probe itself. The excitation light is emitted directly out of the optical window without
the use of optical fibers. The induced fluorescence is coupled into an optical fiber and transmitted up
into the SCAPS instrument room for detection and signal processing. Ultraviolet light at 266 nm has
been shown in research studies to induce fluorescence in single-ring aromatic compounds.
Video Microscope
NCCOSC RDT&E Division has developed and tested an in situ video microscope using the SCAPS CPT
platform. A small video camera has been placed in the probe and optical fibers are used to transmit
visible light for illumination from a source in the truck. The video microscope has the capability to
resolve soil grains less than 10 um in diameter, and various magnifications are presently being evaluated
for field use. The video signal is recorded with a standard VCR and is viewed in real time. Applications
for the technology include grain size analysis, visual confirmation of strain gauge data, and visual
identification of geologic contacts. Additionally, identification of pore size and the presence of cavities,
60
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vertical structures, and other contaminant transport conduits are possible applications. The video
microscope has been field deployed at three sites.
Time Domain Reflectometry
The time domain reflectometry (TDK) probe measures the bulk dielectric constant of the media (soil
and/or water) with which it is in contact during a push. This data permits the estimation of the moisture
content of the soil in the vadose as well as the saturated zone. Applications of this technology include
identification of vadose zone and capillary zone thicknesses, identification of perched water zones, and
as a secondary feature, changes in salinity of the pore water for identification of separate water bodies
and salt water intrusion in coastal aquifers. NCCOSC RDT&E Division has field tested the TDR at two
sites and is currently upgrading the probe design based on the initial results.
Raman Spectroscopy
NCCOSC PDT&E Division has developed a prototype Raman spectroscopy probe for detection of
chlorinated solvents. Initial, bench-scale studies have indicated that the technology is feasible for
DNAPL levels of contamination. Initial field tests have been conducted, and the data are currently under
review.
Laser-Induced Breakdown Spectroscopy
NCCOSC RDT&E Division has developed a metals sensor for deployment with the SCAPS CPT
platform based on a spectroscopic technique known as laser-induced breakdown spectroscopy (LIBS).
Laser energy is transmitted from the platform via optical fibers and focused on soil particles immediately
adjacent to the optical window of the probe. The focused energy vaporizes the soil and creates a micro
plasma. The spectral emissions from the plasma are transmitted via optical fibers to a detector, which
quantitatively measures the intensity of specific wavelengths from the plasma associated with different
metals that may be present in the soil. The sensor has been field tested at three sites through May 1996.
Applications include detection and delineation in real time, with fine-scale resolution, of metal impacted
soil and groundwater.
Other Applied Research
The nitrogen LIF system and the sensors described above are being consolidated into a field screening
and monitoring system to provide a broad spectrum of rapid site characterization capabilities. NCCOSC
RDT&E Division is also working with Lawrence Livermore National Laboratory (LLNL) and California
State Water Resources Control Board (SWRCB) officials to incorporate SCAPS in a series of
demonstrations at military bases throughout California. The purpose of these demonstrations is to apply
the ASTM Risk Based Corrective Action (RBCA) approach at petroleum contaminated sites. The
SCAPS LIF and other sensors will be used at these sites to complete delineation, establish an existing
baseline condition at the sites, and subsequently, monitor plume conditions to establish hydrocarbon
plume stability and natural attenuation.
61
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Section 9
Previous Field Trials
The following information was compiled from data provided by the NCCOSC RDT&E Division. All
data sets from these field trials received a limited review by the verification entity, SNL, for the purpose
of determining confidence bounds for the developer's claims. These field trials took place from 1993 to
1995 using one of three NCCOSC RDT&E Division-operated CPT platforms.
Naval Station San Diego Fire Fighting Training Facility, January and February 1994. A total of 22
pushes and 3 boreholes were advanced at the site, located in San Diego, California. Maximum push
depth was 16.4 feet bgs. The target contaminant was dieselfuel marine. A total of 12 discrete soil
samples were collected from the 3 borings and submitted to ATI for TPH and TRPH analysis. Site
detection threshold was 106 mg/kg.
Naval Amphibious Base Coronado, Abandoned Fuel Farm Site, February and March, 1994. A total
of 22 pushes and 3 hand auger borings were advanced at the site, located in Coronado, California.
Maximum push depth was 15 feet bgs. The target contaminants were dieselfuel and gasoline. A total of
9 discrete soil samples were collected from the 3 hand auger borings and submitted to ATI for TPH and
TRPH analysis. Site detection threshold was 285 mg/kg.
Naval Air Station Alameda Site 13, Old Refinery Site, March and April 1994. A total of 45 pushes
and 8 boreholes were advanced at the site, located in Alameda, California. Maximum push depth was 22
feet bgs. The target contaminants were gasoline, JP-5, and refinery -waste. A total of 49 samples were
collected from the 8 borings and submitted to ATI for TPH and TPRH analysis and secondary
classification. Site detection threshold was 137 mg/kg.
Marine Corps Air Station Yuma, CERCLA AOC7 Site, June 1994. A total of 29 pushes and 4
boreholes were advanced at the site, located in Yuma, Arizona. Maximum push depth was 72 feet bgs.
The target contaminants were JP-5, dieselfuel, and gasoline. Site detection threshold was 898 mg/kg.
The detection threshold was high, reportedly due to errors in the calibration procedure. The site also
contained significant calcium carbonate layers, The calcium carbonate strongly fluoresced at 337 nm,
the SCAPS LIF excitation wavelength, but during post-processing of the data it was possible to screen
out the calcium carbonate fluorescence response from PAH fluorescent response by examining
fluorescence spectra.
Marine Corps Air Station Camp Pendleton, Ground Control Approach Facility, June and July
1994. A total of 25 pushes and 4 boreholes were advanced at the site located in Camp Pendleton,
California. Maximum push depth was 17.7 feet bgs. The target contaminant was dieselfuel from a
surface spill. The Marine Corps had excavated visually impacted soil and wanted confirmation that all
contaminant had been removed. The SCAPS LIF found no contamination. A total of 14 discrete soil
samples were collected and submitted to ATI for confirmatory analysis. ATI found no contamination
above 10 mg/kg. Site detection threshold was 745 mg/kg.
Naval Air Station North Island, Underground Storage Tank 489 Site, July and August 1994. A total
of 25 pushes and 4 boreholes were advanced at the site, located in San Diego County. Maximum push
depth was 30.8 feet bgs. The target contaminant was dieselfuel. A total of 26 discrete samples were
collected from the 4 HSA borings and submitted to ATI for TPH and TRPH analysis. Site detection
62
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threshold was 286 mg/kg. At this site, the wrong calibrant fuel was used and fluorescing minerals were
present in the background.
Guadalupe Oil Field, August 1994. A total of 36 pushes and 4 boreholes were advanced at the
UNOCAL Guadalupe Oil Field located in San Luis Obispo County, California. Maximum push depth
was 101 feet bgs. The target contaminant was oilfield diluent, a light nonaqueous phase liquid, that had
been released throughout the oil field. Soils encounted during pushes were dune sands and silty sands.
A total of 23 discrete soil samples were collected from the 4 borings and submitted to ATI for TPH and
TRPH analysis. Site detection threshold was 90 mg/kg.
Naval Training Center San Diego, Former Auto Hobby Shop, November 1994. A total of 16 pushes
and 3 boreholes were advanced at the site located in San Diego, California. Maximum push depth was
18.8 feet bgs. The target contaminant was used motor oil from a leaking underground storage tank. A
total of 19 discrete soil samples were collected and submitted to ATI for TPH and TRPH analysis. Site
detection threshold was 1141 mg/kg. From the notes it appears the wrong calibrant was used to
determine the site detection threshold.
63
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Section 10
References
Analytical Technologies, Inc. (ATT). 1995. ATI-SD SOP 605. Hydrocarbon Characterization /Fuel
Fingerprint Analysis by GC-FID Standard Operating Procedure. Revision 6.0. Revised March
1995.
ATI. 1994. ATI Quality Assurance Manual. Revision 5.0. Revised November 1994.
ATI. 1993a. ATI-SD SOP 421. Sub-Sampling and Compositing Soil Samples for VOA and Non-
VOA Analyses Standard Operating Procedure. Revisions. Revised June 1993.
ATI. 1993b. ATI-SD SOP 803. Determination of Total Recoverable Petroleum Hydrocarbons by
Infrared Spectrophotometry Standard Operating Procedure. Revision 1. Revised September
1993.
California Environmental Protection Agency Department of Toxic Substances Control. 1996. Draft
Hazardous Waste Technology Certification Program Evaluation Report, Site Characterization
and Analysis Penetrometer System with Laser-Induced Fluoremetry as an In-situ Field Screening
Technology for the Detection of PNA-containing Petroleum Hydrocarbons. May 1996.
CEIMIC. 1996. Letter to Stang, PRC Environmental Management, Inc., re: two samples lost at ATI-
SD. From Leslie Getman, CEIMIC (formerly ATI-SD). February 28,1996.
Los Alamos National Laboratory (LANL), 1991. Schroeder, J.D., Booth, S.R., and Trocki, L.K.,
"Cost Effectiveness of the Site Characterization and Analysis Penetrometer System." Los
Alamos National Laboratory Report LA-UR-91-4016, submitted to Department of Energy.
December 1991.
PRC Environmental Management, Inc. (PRC). 1994. "Draft Site Inspection Report for Installation
Restoration Program Site 22 - Aboveground Fuel Farm," NCBC Port Hueneme. July 1,1994.
PRC. 1995a. Laser Induced Fluorometry/Cone Penetrometer Technology Demonstration Plan at the
Hydrocarbon National Test Site, Naval Construction Battalion Center Port Hueneme, California.
Prepared for U.S. Environmental Protection Agency, Office of Research and Development,
Environmental Systems Monitoring Laboratory-Las Vegas, Consortium for Site Characterization
Technology. May 1995.
PRC. 1995b. LIF/CPT Technology Predemonstration and Demonstration Summary Report, NCBC
Port Hueneme Fuel Farm-County of Ventura Boring Permit E-575, Contract N66001-94-D0141,
Delivery Order 0003. July 10,1995.
PRC. 1995c. Addendum to the Laser Induced Fluorometry/Cone Penetrometer Technology
Demonstration Plan at the Arid Demonstration Site, Sandia National Laboratories Steam Plant
Tank Farm, Albuquerque, New Mexico. Prepared for U.S. Environmental Protection Agency,
Office of Research and Development, National Exposure Research Laboratory, Characterization
Research Division-Las Vegas, Consortium for Site Characterization Technology. October 1995.
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PRC. 1995d. LIF/CPT Technology Predemonstration and Demonstration Summary Report, Arid
Demonstration Site, Sandia National Laboratories Above Ground Fuel Farm, Contract N66001-
94-D0141, Delivery Order 0006. December 20, 1995.
Robertson, P.K, 1986. In situ Testing and Its Application to Foundation Engineering, 1985 Canadian
Geotechnical Colloquium. Canadian Technical Journal, Vol. 23, No. 23, pp 573-594.
U.S. Environmental Protection Agency (EPA). 1995. Test Methods for Evaluating Solid Waste,
Physical/Chemical Methods (SW-846). Revision 3. January 1995.
EPA. 1994. "Guidance Manual for the Preparation of Site Characterization Technology
Demonstration Plans-Protocol I." Version 3.0. December 25, 1994.
EPA. 1989a. "Preparing Perfect Project Plans." Risk Reduction Engineering Laboratory, Office of
Research and Development. Cincinnati, Ohio. EPA/600/9-89/087. October 1989.
USEPA. 1989b. "Methods for the Attainment of Cleanup Standards, Volume 1: Soils and Solid
Media." Office of Policy, Planning, and Evaluation, EPA 220/02-89-042. October 1989.
65
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Appendix A
Reference Laboratory Data
66
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Table A-1
Reference Laboratory Results of Soil Samples
NCBC Port Hueneme
Sample
Number
PHDB21-1
PHDB21-2
PHDB21-3
PHDB21-4
PHDB21-5
PHDB21-6
PHDB21-7
PHDB21-8
PHDB21-9
PHDB21-10
PHDB21-11
PHDB21-12
PHDB21-13
PHDB21-14
PHDB21-15
PHDB22-1
PHDB22-2
PHDB22-3
PHDB22-4
• PHDB22-5
PHDB22-6
PHDB22-7
PHDB22-8
PHDB22-9
PHDB22-10
PHDB22-11
PHDB22-12
PHDB22-13
PHDB22-14
PHDB22-15
PHDB22-16
PHDB22-17
PHDB23-1
PHDB23-2
PHDB23-3
PHDB23-4
PHDB23-5
PHDB23-6
PHDB23-7
PHDB23-8
PHDB23-9
PHDB23-10
PHDB23-11
PHDB23-12
PHDB23-13
Depth
2.5-3.0'
3.0-3.5'
4.5-5.0' .
5.0-5.5'
6.5-7.0'
7.0-7.5'
8.5-9.0'
9.0-9.5'
10.5-11.0'
11.0-11.5'
12.5-13.0'
13.0-13.5'
15.5-16.0'
16.0-16.5'
18.5-19'
2.5-3.0'
3.0-3.5'
4.5-5.0'
5.0-5.5'
7.0-7.5'
7.5-8.0'
8.5-9.0'
9.0-9.5
10.5-11.0'
11.0-11.5'
12.5-13.0'
13.0-13.5'
14.5-15.0'
15.0-15.5'
16.5-17.0'
17.0-17.5'
19.0-19.5'
2.5-3.0'
3.0-3.5'
4.5-5.0'
6.5-7.0'
7.0-7.5'
8.5-9.0'
9.0-9.5'
10.5-11.0'
11.0-11.5'
12.5-13.0'
13.0-13.5'
14.0-14.5'
14.5-15.0'
Date
5-17-95
5-17-95
5-17-95
5-17-95
5-17-95
5-17-95
5-17-95
5-17-95
5-17-95
5-17-95
5-17-95
5-17-95
5-17-95
5-17-95
5-17-95
5-17-95
5-17-95
5-17-95
5-17-95
5-17-95
5-17-95
5-17-95
5-17-95
5-17-95
5-17-95
5-17-95
5-17-95
5-17-95
5-17-95
5-17-95
5-17-95
5-17-95
5-18-95
5-18-95
5-18-95
5-18-95
5-18-95
5-18-95
5-18-95
5-18-95
5-18-95
5-18-95
5-18-95
5-18-95
5-18-95
TRPH Concentration
(mg/kg)
<1
4
<1
<1
4
<1
<1
2
2
2
21 900 (Duo 22500)
18500 (Duo 17400)
28
18
11
<1
<1
<1
<1
<1
<1
<1
<1
<1
<1
4
<1
<1
<1
<1
<1
6
<1
<1
14
<1
<1
<1
<1
53
<1
1 6200 ( DUD 18300)
24200 (Duo 26500)
6460 (Duo 6160)
22
TPH Concentration
(mg/kg)
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
1 8000 (Duo 18000)
1 5000 (Duo 4000)
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
9.6
<5.0
1 6000 (Duo 16000)
1 9000 (Duo 23000)
7000 (Duo 5800)
29
LIF/Lab
Result
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
D/ND
DID
DID
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
D/D"
DID"
DID"
D/NDd
indicates samples for which single point test measurements were used to determine the depth discrepancy between discrete
soil samples and in situ LIF measurements. Depth of discrete samples was adjusted 6 in to correlate with in situ LIF
measurements.
67
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Table A-1 (continued)
Reference Laboratory Results of Soil Samples
NCBC Port Hueneme
Sample
Number
PHDB23-14
PHDB23-15
PHDB23-16
PHDB24-1
PHDB24-2
PHDB24-4
PHDB24-5
PHDB24-7
PHDB24-8
PHDB24-9
PHDB24-10
PHDB24-12
PHDB24-13
PHOB24-14
PHDB24-15
PHDB24-17
PHDB24-18
PHDB24-19
PHDB24-20
PHDB24-21
PHDB25-1
PHDB25-2
PHDB25-3
PHDB25-4
PHDB25-5
PHDB25-6
PHDB25-7
PHDB25-8
PHDB25-9
PHDB25-10
PHDB25-11
PHDB25-12
PHDB25-13
PHDB25-14
PHDB25-15
PHDB25-16
PHDB26-1
PHDB26-2
PHDB26-3
PHDB264
PHDB26-5
PHDB26-6
PHDB26-7
PHDB26-8
PHDB26-9
PHDB26-10
PHDB26-11
PHDB26-12
Depth
17.0-17.5'
17.5-18.01
18.5-19.0'
2.5-3.0'
3.0-3.5'
4.5-5.0'
5.0-5.5'
6.5-7.0'
7.0-7.5'
8.5-9.0'
9.0-9.5'
10.5-11.0'
11.0-11.5'
12.5-13.01
13.0-13.5'
14.5-15.0'
15.0-15.5'
16.0-16.5'
16.5-17.0'
19.0-19.5'
3.0-3.5'
3.5-4.0'
4.5-5.0'
5.0-5.5'
6.5-7.01
7.0-7.5'
8.5-9.0'
9.0-9.5'
11.0-11.5'
12.5-13.0'
13.0-13.5'
14.5-15.0'
15.0-15.5'
17.0-17.5'
17.5-18.0'
19.5-20.0'
2.5-3.0'
4.5-5.0'
5.0-5.5'
6.5-7.0'
7.0-7.51
8.5-9.0'
9.0-9.5'
10.5-11.0'
11.0-11.5'
12.5-13.0'
13.0-13.5'
15.0-15.5'
Date
5-18-95
5-18-95
5-18-95
5-18-95
5-18-95
5-18-95
5-18-95
5-18-95
5-18-95
5-18-95
5-18-95
5-18-95
5-18-95
5-18-95
5-18-95
5-18-95
5-18-95
5-18-95
5-18-95
5-18-95
5-19-95
5-19-95
5-19-95
5-19-95
5-19-95
5-19-95
5-19-95
5-19-95
5-19-95
5-19-95
5-19-95
5-19-95
5-19-95
5-19-95
5-19-95
5-19-95
5-19-95
5-19-95
5-19-95
5-19-95
5-19-95
5-19-95
• 5-19-95
5-19-95
5-19-95
5-19-95
5-19-95
5-19-95
TRPH Concentration
(mg/kg)
224
2
5
81
<1
<1
<1
<1
<1
<1
<1
<1
<1
<1
<1
17
<1
<1
11
<1
<1
<1
<1
<1
<1
<1
<1
<1
25
748
5620
9340 (Duo 13600)
172 (DUD 264)
28
1
9
31
<1
<1
<1
<1
<1
<1
<1
<1
<1
36
8600
TPH Concentration
(mg/kg)
89
<5.0
<5.0
77
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
51
1100
6400
16000 (Dim 15000)
150(Duo190)
16
11
<5.0
11
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
41
7900
LIF/Lab
Result
ND/D
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/D
ND/D
DID
DID
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
DID
68
-------
Table A-1 (continued)
Reference Laboratory Results of Soil Samples
NCBC Port Hueneme
Sample
Number
PHDB26-13
PHDB26-14
PHDB26-15
PHDB26-16
PHDB26-17
PHDB27-1
PHDB27-2
PHDB27-3
PHDB27-4
PHDB27-5
PHDB27-6
PHDB27-7
PHDB27-8
PHDB27-10
PHDB27-11
PHDB27-12
PHDB27-13
PHDB27-15
PHDB27-16
PHDB27-17
PHDB27-19
PHDB28-1
PHDB28-2
PHDB28-3
PHDB28-4
PHDB28-5
PHDB28-6
PHDB28-7
PHDB28-8
PHDB28-9
PHDB28-11
PHDB28-12
PHDB28-13
PHDB28-14
PHDB28-15
PHDB28-16
PHDB28-17
Depth
15.5-16.0'
17.0-17.5'
17.5-18.0'
19.0-19.5'
19.5-20.0'
2.5-3.0'
3.0-3.5'
4.5-5.0'
5.0-5.5'
6.5-7.0'
7.0-7.5'
8.5-9.0'
9.0-9.5'
10.5-1 1.01
11.0-11.5'
1 2.5-1 3.01
13.0-13.5'
14.5-1 5.01
15.0-15.5'
16.5-17.0'
19.0-19.5'
2.5-3.0'
4.5-5.0'
5.0-5.5'
6.5-7.0'
7.0-7.5'
8.5-9.0'
9.0-9.5'
10.5-11.0'
11.0-11.5'
12.5-13.0'
13.0-13.5'
14.5-15.0'
15.0-15.5'
15.5-16.0'
17.5-18.0'
18.0-18.5'
Date
5-19-95
5-19-95
5-19-95
5-19-95
5-19-95
5-22-95
5-22-95
5-22-95
5-22-95
5-22-95
5-22-95
5-22-95
5-22-95
5-22-95
5-22-95
5-22-95
5-22-95
5-22-95
5-22-95
5-22-95
5-22-95
5-22-95
5-22-95
5-22-95
5-22-95
5-22-95
5-22-95
5-22-95
5-22-95
5-22-95
5-22-95
5-22-95
5-22-95
5-22-95
5-22-95
5-22-95
5-22-95
TRPH Concentration
(mg/kg)
3540
229
145
<1
<1
2
2
<1
<1
4
9
<1
1
<1
<1
<1
<1
<1
3
1
2
34
2
2
3
4
3
3
5
<1
2
<1
1100(Duo800)
1800(Duo2100)
100
13
9
TPH Concentration
(mg/kg)
2800
250
170
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
9.8
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
780(Duo920)
2900 (Duo 3400)
250
<5.0
<5.0
LIF/Lab
Result
DID
ND/D
ND/D
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/D
ND/Dd
D/D"
D/Dd
ND/ND
ND/ND
Notes:
1.
2.
3.
4.
5.
6.
TRPH indicates total recoverable petroleum hydrocarbons, analyzed by EPA method 418.1.
TPH indicates total petroleum hydrocarbons, analyzed by the California Department of Health
Services method 8015-modified.
mg/kg = milligrams per kilogram.
Dup indicates duplicate analysis performed by separate analysis of split sample following
homogenization.
Accuracy in depth is estimated to be within 3 inches in the vadose zone, and 6 inches in the saturated
zone.
d indicates samples for which single point test measurement results were used to determine depth
discrepancy between discrete soil samples and in situ measurements. Depth of discrete samples was
adjusted 4 in to correlate with in situ LIF measurements.
69
-------
Table A-2
Reference Laboratory Results of Soil Samples
SNL Tank Farm
Sample
Number
SNLDB10-1
SNLDB1Q-2
SNLDB10-3
SNLDB10-4
SNLDB10-5
SNLDB10-6
SNLDB10-7
SNLDB10-8
SNLDB10-9
SNLDB10-10
SNLDB10-11
SNLDB10-12
SNLDB10-13
SNLDB10-14
SNLDB10-15
SNLDB10-16
SNLDB10-17
SNLDB10-18
SNLDB10-19
SNLDB10-20
SNLDB10-21
SNLDB10-22
SNLDB10-23
SNLDB10-24
SNLDB10-25
SNLDB10-26
SNLDB10-27
SNLDB10-28
SNLDB10-29
SNLDB10-30
SNLDB10-31
SNLDB10-32
SNLDB10-33
SNLDB10-34
SNLDB10-35
SNLDB10-36
SNLDB10-37
Depth
(bgs)
2.75-3.0'
3.25-3.5'
4.75-5.0'
5.25-5.5'
6.75-7.0'
7.25-7.5'
8.75-9.0'
9.25-9.5'
10.75-11.0'
11.25-11.5'
12.75-13.0'
13.25-13.5'
14.75-15.0'
15.25-15.5'
16.75-17.0'
17.25-17.5'
18.75-19.0'
19.25-19.5'
20.75-21.0'
21.25-21.5'
22.75-23.0'
23.25-23.5'
24.75-25.0'
25.25-25.5'
26.75-27.0'
28.75-29.0'
29.25-29.5'
30.75-31.0'
31.25-31.5'
32.75-33.0'
33.25-33.5'
34.75-35.0'
35.25-35.5'
36.75-37.0'
37.25-37.5'
38.75-39.0'
39.25-39.5'
Date
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
TRPH Concentration
(mg/kg)
60
25
89
42
71
162
17
11
27
22
206
1.470
4.870
7.600
14,300
8.500
25,600
25,800
14,700
5.790
6.530
8.560
5.100
5.400
11,200
20,400
24.900
7.330
3.520
1.340
28.400
25,600
18,200
9,620
26.200
32.200
21,700
TPH Concentration
(mg/kg)
23
<5
99
54
70
150
<5
14
24
27
270
1.500
5.000
6.600
21,000
13,000
26,000
28,000
14,000
6,300
6.900
9,100
4.200
4.500
9.800
20,000
23.000
6,600
3.100
1.400
35.000
24.000
18,000
10,000
21,000
28.000
21,000
LIF/Lab
Result
ND/ND8
ND/ND8
ND/D8
ND/ND5
ND/ND8
ND/D8
ND/ND8
ND/ND8
ND/ND8
ND/ND5
ND/D5
ND/D8
DID
DID
DID
DID
DID
DID
DID
DID
DID
DID
DID
DID
DID
DID
DID
DID
DID
DID
DID
DID
DID
DID
DID
DID
DID
8 indicates LIF result was changed from detect (D) to nondetect (ND) based on review of spectrum which
indicated strong carbonate fluorescence. In some cases, the strong carbonate fluorescence signal
masked any hydrocarbon presence, resulting in a false negative (ND/D).
70
-------
Table A-2 (continued)
Reference Laboratory Results of Soil Samples
SNL Tank Farm
Sample Number
SNLDB10-38
SNLDB10-39
SNLDB10-40
SNLDB10-41
SNLDB10-42
SNLDB10-43
SNLDB10-44
SNLDB10-45
SNLDB10-46
SNLDB1047
SNLDB10-48
SNLDB10-49
SNLDB10-50
SNLDB10-51
SNLDB11-1
SNLDB11-2
, SNLDB11-3
SNLDB11-4
SNLDB11-5
SNLDB11-6
SNLDB11-7
SNLDB11-8
SNLDB11-9
SNLDB11-10
SNLDB11-11
SNLDB11-12
SNLDB11-13
SNLDB11-14
SNLDB11-15
SNLDB11-16
SNLDB11-17
SNLDB11-18
SNLDB11-19
SNLDB11-20
SNLDB11-21
SNLDB11-22
SNLDB11-23
SNLDB11-24
SNLDB11-25
SNLDB11-26
SNLDB11-27
SNLDB11-28
Depth
(bgs)
40.75-41.0'
41.25-41.5'
42.75-43.0'
43.25-43.5'
44.75-45.0'
45.25-45.5'
46.7547.0'
47.25-47.5'
48.75-49.0'
49.25-49.5'
50.75-51.0
51.25-51.5'
52.75-53.0'
53.25-53.5'
6.0-6.25'
10.75-11.0'
11.25-11.5'
16.0-16.25'
20.75-21.0'
21.25-21.5'
25.75-26.0'
26.25-26.5'
30.75-31.0'
33.25-33.5'
35.75-36.0'
36.25-36.5'
40.75-41.0'
41.25-41.5'
42.75-43.0'
43.25-43.5'
44.75-45.0'
45.25-45.5'
46.75-47.0'
47.25-47.5'
48.25-48.5'
48.75-49.0'
49.25-49.5'
50.75-51.0'
51.25-51.5'
52.75-53.0'
53.25-53.5'
55.0-55.25'
Date
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-6-95
11-7-95
11-7-95
11-7-95
11-7-95
11-7-95
11-7-95
11-7-95
11-7-95
11-7-95
11-7-95
11-7-95
11-7-95
11-7-95
11-7-95
11-7-95
11-7-95
11-7-95
11-7-95
11-7-95
11-7-95
11-7-95
11-7-95
11-7-95
11-7-95
11-7-95
11-7-95
11-7-95
11-7-95
TRPH Concentration
(mg/kg)
15,800
8.440
9.500 (Dup 9,160)
15.000
7,500
11,000
13,000
19,000
26,000
8,200
13,000
15,000
17,000
5,500
9.7
9.0
<1
3,470
13,000
15,200
12,000
22.300
18,200
31,000
19,800
22,200
26,200
5.160
20,600
18,300
7,030
6,240
11,900
25,400
17,200
44,600
7,340
14,700
23,600
16,100
13,600
21,400
TPH Concentration
(mg/kg)
14,000
9.700
12,000 (Duo 12.000)
18.000
12.000
9.900
15,000
23,000
32.000
14,000
14,000
27,000
12,000
8.500
19
<5
<5
2.700
11,000
21,000
10,000
21,000
17,000
21.000
19,000
21,000
24,000
4,200
22,000
22.000
14,000
10,000
13,000
29,000
29,000
39.000
8.900
14.000
25.000
16.000
13,000
20,000
LIF/Lab
Result
DID
DID
DID
DID
DID
DID
DID
DID
DID
DID
DID
DID
DID
DID
ND/ND5
ND/ND"
ND/NDS
ND/D
DID
DID
DID
DID
DID
DID
DID
DID
DID
DID
DID
DID
DID
DID
DID
DID
DID
DID
DID
DID
DID
DID
DID
DID
s indicates LIF result was changed from detect (D) to nondetect (ND) based on review of spectrum which
indicated strong carbonate fluorescence.
71
-------
Table A-2 (continued)
Reference Laboratory Results of Soil Samples
SNL Tank Farm
Sample Number
SNLDB12-1
SNLDB12-2
SNLDB12-3
SNLDB12-5
SNLDB12-7
SNLDB12-9
SNLDB12-11
SNLDB12-12
SNLDB12-13
SNLDB12-15
SNLDB12-17
SNLDB12-19
SNLDB12-20
Depth
(bos)
2.75-3.0'
3.25-3.5'
6.0-6.25
11.25-11.5'
16.0-16.25'
21.0-21.25'
26.25-26.5'
26.75-27.0'
31.0-31.25'
36.5-36.75'
41.041.25'
43.0-43.25'
49.049.5'
Date
11-8-95
11-8-95
11-8-95
11-8-95
11-8-95
11-8-95
11-8-95
11-8-95
11-8-95
11-8-95
11-8-95
11-8-95
11-8-95
TRPH Concentration
(mg/kg)
3
2
<1
<1
<1
2
2
<1
<1
<1
<1
<1
<1
TPH Concentration
(mg/kg)
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
LIF/Lab
Result
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
ND/ND
1 . TRPH indicates total recoverable petroleum hydrocarbons, analyzed by EPA method 418.1.
2. TPH indicates total petroleum hydrocarbons, analyzed by the California Department of Health
Services method 8015-modified.
3. mg/kg = milligrams per kilogram.
4. Dup indicates duplicate analysis performed by separate analysis of split sample following
homogenization.
72
-------
Appendix B
SCAPS LIF Field Data Logs
73
-------
Depth (feet)
« O j
^ s s
-------
Depth (feet)
m
tr
a.
O
a
§
en
OJ.M
C CO
_O 0)
00.
>~*
q
d-
tn
in
q
8
CM
Si UJ 5
D_ DQ O
Q O 2
X CC LL-
Q. O. Q
III
999
goo
co w «
CD CD CQ
odd
i:
O3 O3
lJ- T-
\. I
CO Is*
T— O
I
IJ
Q i2
-------
Depth (feet)
IS
o
c>
S3
m
Q O 5
I CC U.
5 I i
111
999
333
o o o
Jz o if
-------
Depth (feet)
CD
o
•^ ®
5 o
CO CO
CC 2
o
LL
q
o
Q O 5
X CC U.
Hi
£$$
999
C (3
.0) .2
-------
Depth (feet)
5 o ®
04 UJ in
o_ m o
Q O 2
I CC U-
999
CO CO 03
< < <
S3 9 9
666
i: oj c
oj ja o
o
0-
•
2
.£}
3
in
01
-------
Depth (feet)
-£- QT -jj
W OL §
£§§
CM S g
Q. CO o
Q O 5
X EC U.
9> 9= 9
999
co w en
< < <
g m m
006
-C 0) C
03 J3 O
3 O '^3
o
in
en
co
-------
-------
-------
J- • -I- I V. , -r-4 - • -J ' • r --. * - - • •
-------
Depth (feet)
X <
S. 3
ESI
Q Q. ^
999
S3 9 9
066
0>
-8
CO
O
in
en
oo
o
-------
-------
Appendix C
SCAPS LIF Draft EMMC Method
74
-------
-------
DRAFT METHOD
IN SITU FIELD SCREENING OF PETROLEUM HYDROCARBONS
IN SOIL AND GROUNDWATER
USING A PENETROMETER-DEPLOYED FLUOROMETRIC SENSOR
1.0 SCOPE AND APPLICATION
1.1 This field screening method is used to rapidly determine the location and relative
extent of subsurface petroleum hydrocarbon contamination in soil and groundwater. The
method can be used to detect contaminants throughout the vadose, capillary fringe, and
saturated zones to depths of up to 50 meters. No physical sampling is required by this
method. Analytical measurements are collected in situ. A partial list of the analytes for
which this method is appropriate includes:
mineral oil
kerosene
fuel oil
gasoline
diesel fuel
lubricating
oil
tar
asphaltum
hydraulic
oil
jet fuel
aviation fuel
petroleum
distillates
1.2 Method sensitivity can vary from the low parts-per-million (ppm) range to parts-per-
thousand depending on a number of critical factors including soil matrix, choice of excitation
source, optical collection efficiency, and the specific analyte targeted.
1.3 The method yields qualitative and semiquantitative results, making it appropriate for
preliminary assessments of contaminant distribution as in environmental field screening
applications.
2.0 SUMMARY OF METHOD
2.1 This method provides an overview and guidelines for the use of an integrated Laser
Induced Fluorescence sensor/cone penetrometer testing (LIF/CPT) to obtain in situ
measurements of hydrocarbon contamination in soil. Optional procedures for calibration and
data analysis are also provided.
2.2 A LIF sensor is used to detect petroleum products by measuring the fluorescence
energy emitted when aromatic or polycyclic aromatic constituents are excited by intense
ultraviolet radiation. The truck-mounted penetrometer system provides a mobile platform
from which the LIF sensor is deployed as a means of performing remote spectroscopy in soil.
The sensor is coupled to the penetrometer through a set of optical fibers that transmit the
excitation energy to a sapphire window located near the penetrometer tip, and collect and
transmit the return signal back to the surface for analysis.
2.3 Fluorescence measurements can be obtained at subsurface depths of up to 50 meters
when the sensor is used in conjunction with a standard 20-ton penetrometer vehicle.
Typically, data are collected at a rate of one fluorescence spectrum every 2 seconds. This rate
75
-------
provides a vertical spatial resolution of less than 4 cm when the penetrometer is driven at a
standard rate of 1 m/min.
2.4 Geotechnical sensors are normally integrated with the DDF sensor probe to facilitate
hydrogeological and stratigraphic analyses of the soil matrix.
3.0 DEFINITIONS
3.1 LIF: laser-induced fluorescence
3.2
3.3
3.4
Penetrometer: an instrument in the form of a cylindrical rod that is hydraulically
pressed into soil to acquire subsurface measurements of penetration resistance. Used
for cone penetrometer testing (CPT). Also called cone penetrometer, friction-cone
penetrometer.
POL: petroleum, oil, lubricant. Used in reference to any petroleum product or
derivative.
Push rods: cylindrical rods with threaded tips that are joined to advance the
penetrometer probe into the ground.
3.5 UV: ultraviolet
4.0 SPECTRAL BVTERFERENCES
4.1 The LIF sensor is sensitive to any materials that fluoresce when excited by the laser
light source. Although the method is intended to specifically target petroleum hydrocarbons,
the excitation energy produced by the laser excitation source may cause other substances to
fluoresce as well. It is possible that the sensor could respond to fluorescence originating from
non-POL sources. For example, many common fluorescent minerals can produce a
measurable LIF signal. In rare instances, non-POL fluorescence may also originate in
naturally occurring organic material. Other non-POL fluorescers may be found in the
subsurface environment as a result of human activity. De-icing agents, antifreeze additives,
and many detergent products are all known to fluoresce strongly.
4.2 The potential presence of fluorescence emission from nontarget (non-POL) analytes
within the soil matrix must be considered when assessing data generated by this method. In
some instances, the inability to discriminate between POL fluorescence and non-POL
fluorescence could lead to a false positive determination of the presence of POL
contaminants.
4.3 By analysis of the fluorescence emission spectral information, it is often possible to
discriminate between POL and non-POL fluorescence. The LIF sensor system uses a
multichannel detection scheme to capture a complete fluorescence emission spectrum at
selected (or all) points along the push. The spectral features associated with a particular data
set can be used to uniquely distinguish POL fluorescence from potential interferents. The
advantage of this approach over methods that rely on single-channel measurements of
fluorescence intensity is that spectral features are obtained that can be used to associate the
signal with a specific petroleum class, mineral substance, or other material.
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5.0 SAFETY
This section describes the safety concerns for staff operating the Site Characterization and
Penetrometer System (SCAPS) cone penetrometer testing (CPT) technology that go beyond the scope
of routine laboratory practices. It is divided into subsections corresponding with the four separate
tune periods that typically occur during a routine day of SCAPS CPT operations. The last subsection
deals with less frequent operations.
5.1 Each morning, the crew chief must enter the cab and power up the CPT vehicle. The
steps and handles leading to the cab are usually wet with dew and present a slip and fall
hazard. The crew is generally busy loading supplies for the day onto the CPT itself as well as
the support vehicle. The supplies consist of bags of cement and bentonite, 55-gallon drums,
5-gallon buckets of water, and nitrogen cylinders. All of these present the potential to injure
the crew's backs and joints. Possible injuries from dropping or tripping while carrying any of
these heavy items is also a concern.
5.2 While stationing the vehicle for a push, it is necessary for a crew member to direct the
crew chief as he maneuvers the rig into position. Both the crew chief and the person directing
him must be acutely aware of their relative positions to avoid mishaps. Obstacles, including
an uneven ground surface, can present a trip hazard. After the CPT truck is positioned over
the push location, the push room access ladder is typically deployed. Some crew members
use the ladder at least twice during each push to enter and exit the CPT. General ladder safety
practices to avoid slips, twists, and falls must be followed. The support vehicle is then
brought alongside with the grout supplies and equipment. The crew member parking the
vehicle must approach slowly and position the truck carefully in relation to the ladder.
The crew member handling the CPT rods in the push room faces a foot injury hazard that
would result from dropping one of the rods. Steel-toed safety shoes are a requirement for all
crew members. Hard hats and safety glasses must be worn at all tunes except for when
working in the data collection room. The technician (and any other crew members working in
the data collection room) must follow standard laser operation safety procedures which
typically involve wearing ultraviolet (UV) protective safety glasses. The quinine sulfate
standard and other cuvettes used during the method are cleaned by the technician and the
crew chief using paper wipes and ethanol. Since the flooring of the SCAPS CPT is steel, the
ethanol is kept in a plastic, squeeze-dispensing container to avoid breakage if dropped.
A pinch or crushing hazard is presented by the platform located on the outside rear of the
SCAPS CPT which holds the steam cleaner, wastewater drum, and nitrogen cylinders. This
platform must be operated twice during each push. The space between the platform and the
SCAPS CPT is at a height conducive to pinching fingers or arms. Special care must be taken
by crew members operating the platform to keep feet clear of the heavy steel ramp that comes
to rest on the ground.
A similar finger pinching hazard exists in association with the operation of the hydraulic
grout pump tray. The grout for the abandonment of the push hole is mixed in a plastic
container using a compressed air-powered tool. The grout pumping line in the CPT umbilical
is purged using compressed air. Standard safety practices regarding the use of compressed air
must be followed, chief among these being the protection of eyes during connection to and
disconnection from the compressor. Protection is accomplished by the SCAPS CPT crew by
holding the two quick connectors at waist level. While the grout is pumped, special care must
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be taken to keep fingers and hands well away from the pump's impellers located below the
base of the funnel. A constant awareness of the status and condition of the various hydraulic
pressure lines during each push is important. Checking to make sure that lines are not
pressurized before disconnection is required to avoid the hazard of being sprayed (especially
in the face) with hydraulic fluid. The hoses are checked regularly for signs of wear that could
lead to rupture.
5.3 After a push is complete, the SCAPS CPT truck and support vehicle must be
repositioned to the next location. Repositioning can involve backing up, which presents
hazards associated with limited visibility. The drivers of the SCAPS CPT and its support
vehicle must not feel rushed during the operations. As the vehicles move to the next push, the
technician in the data collection room uses metal picks, paper wipes, and ethanol to clean the
probe, which has been placed hi a bracket on the work bench. Since the vehicle is in motion
at this time, the technician should take care not to puncture a finger with the pick or spill the
ethanol as the probe is cleaned for the next push.
5.4 It is periodically necessary to change out the steam cleaning wastewater drum located
on the rear platform either when it becomes full at a point in between pushes or at the end of a
day in the field. In addition to the hazards associated with operation of the electric platform
discussed in Subsection 5.2 above, a 55-gallon drum of wastewater weighs well in excess of
400 pounds and thereby presents several safety concerns. The changeout operation is best
performed by two crew members working carefully together to avoid crushing a foot or hand
by the drum during handling. The support vehicle is equipped with a hydraulic lift gate that
presents a pinching hazard, but the lift gate can be used to minimize the distance over which
the waste drum must be handled, both to be removed from the CPT and to be placed in the
HDW storage area. The same safety parameters also apply to change out of the nitrogen gas
cylinder.
6.0 EQUIPMENT AND SUPPLIES
6.1 LASER INDUCED FLUORESCENCE (LIF) SENSOR
The LIF sensor system consists of the following basic elements:
1. A laser excitation source operating in the UV range at one or more discrete
wavelengths between 250 and 360 nm.
2. Optical fibers for carrying the excitation light to the optical window built into the
penetrometer probe and for transmitting the resulting fluorescence emission back to
the surface for detection and analysis.
3. A spectrograph or other dispersive element for performing spectral analysis on the
emission signal.
4. An optical detector for quantifying the emission signal.
5. A data system for analyzing and storing spectral data.
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6.2 TRUCK MOUNTED CONE PENETROMETER
6.2.1 An industry standard system employs a hydraulic ram mounted to a truck chassis so
that a series of attached threaded rods can be pressed into the ground through an opening in
the floor of the vehicle.
6.3 PENETROMETER WITH SPECTROSCOPIC VIEW PORT AND FIBER OPTIC
INTERFACE
6.3.1 This is a standard penetrometer modified with a sapphire view port mounted on the
side of the shaft. A set of optical fibers is fixed near the inside surface of the view port.
7.0 REAGENTS AND STANDARDS
7.1 Reagent-grade chemicals shall be used in all tests. Unless otherwise indicated, it is
intended that all reagents shall conform to the specifications of the Committee on Analytical
Reagents of the American Chemical Society, where such specifications are available. Other
grades may be used, provided it is first ascertained that the reagent is of sufficient high purity
to permit its use without lessening the accuracy of the determination.
7.2 QA STANDARDS
7.2.1 Choice of the check standard will depend on the specific excitation wavelength and
target analyte. The check standard should fluoresce in the same wavelength range as the
target analytes. A dilute solution of quinine sulfate is often a good choice because it has a
high quantum efficiency, is chemically stable, preparation is reproducible, and it exhibits
minimal photodegradation. The appropriate concentration of the check standard will depend
on system sensitivity.
7.2.2 A 100 milliliter (ml) solution containing 1,000 ppm quinine sulfate is prepared as a
primary standard as follows. Using an analytical balance that is accurate to +/- 0.0001 grams,
weigh out 0. 10 grams of quinine sulfate dehydrate (Chemical Abstract Service [CAS] no.
6119-70-6). Transfer to a 100 ml volumetric flask. Add 0.1 normal sulfuric acid to make 100
ml. This solution may be diluted to create solutions of lower concentration. The solution
must be stored in amber-colored bottles and checked frequently for signs of degradation or
evaporation.
7.2.3 A method blank may be prepared from a sample of clean dry soil. Fine to medium-
grain sea sand is appropriate.
7.4 CALIBRATION STANDARDS
7.4.1 When calibration standards are used, they are prepared as a series of standard
additions to soil samples representative of the analyte matrix. The added material should
match the target POL analyte as closely as possible. One of the difficulties in establishing the
target POL analyte is that often many different petroleum products are present at a particular
site. The actual contaminant may represent a combination of POL products. In addition, the
contaminant will have weathered from long-term exposure at the site. Many other
quantifying analytical methods also encounter this problem.
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7.4.2 To prepare the standards, a soil sample is collected from the specific site to be
characterized. The soil is gathered from below the surface at a depth of 1-2 feet, to reduce
hydrocarbon contamination from aerosols and other airborne particulates. A set of standards
is prepared by inoculating the soil samples with a series of increasing amounts of the target
analyte. Added concentrations may range from 0 ppm to 50,000 ppm. The spiked samples
are rumbled for 24-48 hours to ensure uniform distribution of the fuel.
8.0 SAMPLE COLLECTION
This is an in situ method. Spectroscopic measurements are obtained directly without physical
sampling. Sample collection is not a part of the normal method procedure.
9.0 QUALITY CONTROL
9.1 Three replicate measurements of a check standard (quinine sulfate) and method blank
(clean sand) are taken before and after each set of calibration runs and before and after each
penetrometer push. Normal variation of the check standard intensity is 5 percent for one set
of replicates. The check standard data may vary up to 20 percent over sets of replicates
obtained during multiple pushes. The method blank may vary up to 25 percent for multiple
pushes. If variations fall outside of these specified ranges, the probe window and sample
cuvette should be cleaned and the measurements of the QA standards repeated. If compliance
cannot be achieved, the system operator should begin troubleshooting procedures as per the
system's maintenance manual.
10.0 CALIBRATION AND STANDARDIZATION
10.1 At present, there is no standard procedure for calibrating the LIF sensor. Depending
on data objectives, fluorescence intensity alone may be reported as a relative indicator of POL
presence.
10.2 When called for, a calibration curve is generated to establish the LIF sensor response,
dynamic range, and limit of detection. Three replicate measurements of each of the prepared
calibration standards are run at the beginning of each day and again the equipment is changed.
The calibration standards (most typically diesel fuel marine) may vary up to 20 percent for
one data point with a given probe and set of test conditions. If a point falls outside of these
specified ranges, the probe window and sample cuvette should be cleaned and the test of the
standards repeated. If compliance cannot be achieved, the operator should begin
troubleshooting procedures as per the system's maintenance manual and the standards
reevaluated until compliance is met.
10.3 If simultaneous geotechnical measurements are to be obtained, the penetrometer strain
gauges are calibrated in accordance with ASTM D3441.
11.0 PROCEDURE
11.1 Before the LIF/CPT system is deployed, the site is visited to determine location of
obstructions that would limit access by the CPT truck. These obstructions may include
buildings, cement platforms, and fence lines. The site is also surveyed for possible
underground obstructions such as utilities, pipelines, and existing storage tanks. At this time,
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information on possible contaminants and prior efforts at characterization or remediation is
also obtained. Soil samples can be collected to prepare of calibration standards.
1 1 .2 The truck is deployed with a four-person field crew, including a professional geologist.
Two people are needed handle the push rods and operate the hydraulic press. A third person
operates the LIF sensor, taking measurements of the calibration and control standards, and
monitoring the actual real-time push data. The truck is positioned over the location to be
pushed and then elevated and leveled on hydraulic jacks. Following a short series of
measurements to establish quality control, the sensor is pushed into the ground at a rate of 1
meter/minute. The push rods are 1 meter in length, and rods are added approximately once a
minute as the sensor is advanced. A 30-meter push will typically require about 40 minutes to
reach full depth. Generally, the hole will be grouted with a cement mixture as the probe is
removed, through a tube connected through the probe to an expendable probe tip. Five to six
pushes a day, or approximately 200 feet, can be accomplished in a routine day's operation.
1 1 .3 The fluorescence spectra from the spiked samples are measured at the start of each day
of field operations. As with the check standard, 20 shots are averaged to provide a single
measurement. At present, a single aliquot from each standard concentration is measured three
tunes, with the aliquot being stirred between measurements. The standard deviation of the
calibration standards will reflect both the internal noise as well as the variations due to
inhomogeneities in the soil, and can be compared to that of the check standard (quinine
sulfate) to assess the inhomogeneity of the soil at the site.
12.0 DATA ANALYSIS AND CALCULATIONS
12. 1 When using a calibration curve for analysis, the fluorescence intensity for each
calibration sample is regressed to establish a slope and intercept. For each regression, a
record of the goodness of the fit (r2) and the uncertainty in the slope and intercept values are
calculated:
where I is the measured fluorescence intensity in counts, C is the concentration of the target
analyte in mg/kg, Io is the intercept in fluorescent counts, a is the slope, and
= uncertainty hi intercept
Act = uncertainty in slope
determined from the goodness of the fit.
This regression shall be carried out using only the lower concentration calibration standards.
Log-log plots shall be used for analysis of the complete set. The fluorescence threshold and
the detection limit shall be determined as follows:
threshold limit =
detection limit =
ot
The fluorescence threshold limit is that number of fluorescent counts above which will be
considered a detect, below which will be considered nondetect for the test.
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13.0 METHOD PERFORMANCE
13.1 The detection limit, accuracy, and precision obtained through use of this method are
highly dependent on the soil matrix, target analyte, and choice of laser wavelength.
14.0 POLLUTION PREVENTION
The reference analytical methods require that discrete soil samples be obtained from the subsurface
using & hand or power auger, drill rig, or soil trenching equipment. These methods generate waste
contaminated soils that must be treated or landfilled. The SCATS CPT does not generate any waste
soils. The reference methods require that soil samples be submitted to the laboratory for extraction
and analysis. In order to achieve this, the samples must be kept chilled, usually with ice, in an
insulated cooler. Each sample is kept in the cooler in an individual container. The sample containers
come in cardboard boxes that must be transported to the site and then either be discarded or recycled.
Once the necessary aliquot of soil has been removed from the containers by the laboratory in order to
perform the reference methods, the containers and remaining soil must be either stored under
refrigeration, disposed of, or decontaminated for reuse. The SCAPS CPT does not require the
acquisition of soil samples in jars or tubes, or any refrigerated storage.
The SCAPS CPT generates wastewater in steam cleaning the rods and probe after each push. The
amount of wastewater generated is small in comparison to the amount necessary to decontaminate a
similar footage of augers and samplers necessary hi order to obtain soil samples for the reference
method.
Since the crew are isolated from all but the surface chemical hazards at the site, the amount of
personal protective equipment (PPE) typically used is minimal. Drilling or trenching, on the other
hand, could expose personnel to the subsurface contaminants they are trying to assess. As a
consequence, the drilling or trenching necessary to obtain soil samples for the reference method will
result in the use of a greater amount of PPE, which must then be either decontaminated (creating more
wastewater) for reuse or discarded at an appropriate landfill depending on the degree to which it is
contaminated.
15.0 WASTE MANAGEMENT
The wastewater generated by the steam cleaning system is vacuumed into and stored in 55-gallon
drums in a designated area of the site being characterized. Each drum is labeled with the site name,
date, contents, and corresponding pushes during which the wastewater was generated. After
operations at the site are complete, an appropriate subgroup of the drums (usually representing the
anticipated worst case) is randomly selected for sampling. Based on the results of the analysis of the
wastewater samples, an appropriate disposal method is selected. This method is often discharge to the
sewer following review of the analyses results by the publicly owned treatment works (POTW).
16.0 REFERENCES
References are to be provided by NCCOSC RDT&E Division.
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17.0 SYSTEM SCHEMATIC
A schematic of the SCATS LIF system is provided.
Umbilical Cable
and Probe
(II
V.M.
II
\ /
^^^1
p
Quinine Sulfate
System Standard
robe Calibration Assembly
Nitrogen Bottle
gbl.ppt
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