United States
Environmental Protection
Agency
Office of Research and
Development
Washington DC 20460
EPA/600/R-98/096
August 1998
<&EPA Environmental Technology
Verification Report
Soil Gas Sampling Technology
Quadrel Services, Inc.
EM FLUX Soil Gas System
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EPA/600/R-98/096
August 1998
Environmental Technology
Verification Report
Soil Gas Sampler
Quadrel Services, Inc.
EMFLUX® Soil Gas Investigation System
Prepared by
Tetra Tech EM Inc.
591 Camino De La Reina, Suite 640
San Diego, California 92108
Contract No. 68-C5-0037
Dr. Stephen Billets
Characterization and Monitoring Branch
Environmental Sciences Division
Las Vegas, Nevada 89193-3478
National Exposure Research Laboratory
Office of Research and Development
U.S. Environmental Protection
ET
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Notice
This document was prepared for the U.S. Environmental Protection Agency s (EPA) Superfund
Innovative Technology Evaluation Program under contract 68-C5-0037. The work detailed in this
document was administered by the National Exposure Research Laboratory—Environmental Sciences
Division in Las Vegas, Nevada. The document has been subjected to EPA s peer and administrative
reviews, and has been approved for publication as an EPA document. Mention of corporation
names, trade names, or commercial products does not constitute endorsement or recommendation for
use of specific products.
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
Office of Research and Development
Washington, D.C. 20460
ENVIRONMENTAL TECHNOLOGY VERIFICATION PROGRAM
VERIFICATION STATEMENT
TECHNOLOGY TYPE: PASSIVE SOIL GAS SAMPLER
APPLICATION: SUBSURFACE SOIL GAS SAMPLING
TECHNOLOGY NAME: EMFLUX® SOIL GAS INVESTIGATION SYSTEM
COMPANY: QUADREL SERVICES, INC.
ADDRESS: 1896 URBANA PIKE, SUITE 20
CLARKSBURG, MD 20871
PHONE: (800) 878-5510
S^AvSw^iS^&wX^v^^^
ETV PROGRAM DESCRIPTION
The U.S. Environmental Protection Agency (EPA) created the Environmental Technology Verification (ETV)
Program to facilitate the deployment of innovative technologies through performance verification and information
dissemination. The goal of the ETV Program is to further environmental protection by substantially accelerating the
acceptance and use of improved and 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 Quadrel Services, Inc., EMFLUX® Soil Gas Investigation System.
PROGRAM OPERATION
Under the ETV Program and with the full participation of the technology developer, the EPA evaluates the
performance of innovative technologies by developing demonstration plans, conducting field tests, collecting and
analyzing demonstration data, and preparing reports. The technologies are evaluated under rigorous quality
assurance (QA) protocols to ensure that data of known and adequate quality are generated and that the demonstration
results are defensible. The EPA's National Exposure Research Laboratory, which demonstrates field characterization
and monitoring technologies, selected Tetra Tech EM Inc. as the verification organization to assist in field testing
various soil and soil gas sampling technologies. This demonstration was conducted under EPA's Superfund
Innovative Technology Evaluation Program.
DEMONSTRATION DESCRIPTION
In May and June 1997, the EPA conducted a field test of the EMFLUX® system along with one other soil gas and
four soil sampling technologies. This verification statement focuses on the EMFLUX® system; similar statements
have been prepared for each of the other technologies. The performance of the EMFLUX® system was compared
to the reference sampling method, active soil gas sampling, which provides a snapshot of the soil gas environment
at the time the sample is collected. The comparison addressed three parameters: (1) volatile organic compound
(VOC) detection and quantitation, (2) sample retrieval time, and (3) cost. Data quality indicators for precision,
accuracy, representativeness, completeness, and comparability were also assessed against project-specific QA
objectives to ensure the usefulness of the data.
The EMFLUX® system was demonstrated at two sites: the Small Business Administration (SBA) site in Albert City,
Iowa, and the Chemical Sales Company (CSC) site in Denver, Colorado. These sites were chosen because each site
exhibited a wide range of VOC concentrations and a distinct soil type. The VOCs detected at the sites include vinyl
EPA-VS-SCM-22 The accompanying notice is an integral part of this verification statement August 1998
iii
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chloride; cis-l,2-dichloroethene (cis-l,2-DCE); 1,1-dichloroethane (1,1-DCA); 1,1,1-trichloroethane (1,1,1-TCA);
trichloroethene (TCE); and tetrachloroethene (PCE). The SBA site is composed primarily of clay soil, and the CSC
site is composed primarily of medium- to fine-grained sandy soil. A complete description of the demonstration,
including a data summary and discussion of results, is available in the report titled Environmental Technology
Verification Report: Passive Soil Gas Sampler, Quadrel Services, Inc. (Quadrel), EMFLUX®, EPA/600/R-98/096).
TECHNOLOGY DESCRIPTION
The EMFLUX® system is a passive soil gas sampling technology designed for use in shallow deployment to identify
and quantify a broad range of VOCs and semivolatile organic compounds (SVOC), including halogenated compounds,
petroleum hydrocarbons, polynuclear aromatic hydrocarbons, and other compounds present at depths to more than
200 feet. For this ETV demonstration, the EMFLUX® system consisted of the EMFLUX® sample cartridge, sample
insertion tools, and developer-provided sample analysis. The EMFLUX cartridge consists of 100 milligrams of
sorbent sealed in a fine-mesh screen, which is placed in a glass vial; the vial and cartridge make up the EMFLUX®
field collector. This assembly is inserted into the soil, but only the cartridge is thermally desorbed and analyzed in
the laboratory. The EMFLUX field collector is installed by creating a three to four-inch deep pilot hole using a
manual hammer and a stake, and inserting the sampler manually. The sampler is then covered to reduce the potential
for sorption of airborne contaminants. The cartridge is retrieved by hand and, for this demonstration, was analyzed
by the developer. The EMFLUX® system also includes computer modeling by Quadrel using a proprietary model
to predict periods of maximum soil gas emission for geographic locations and optimize sampling efficiency. However,
the performance of the model was not evaluated during the demonstration.
VERIFICATION OF PERFORMANCE
The demonstration data indicate the following performance characteristics for the EMFLUX system:
VOC Detection and Quantitation: Soil gas samples collected using the EMFLUX® system and the reference soil gas
sampling method at nine grids at both the sites were analyzed for six target VOCs. Analysis of EMFLUX samples
yielded results in total nanograms per sample, which Quadrel converted to mass per unit volume of air (nanograms
per liter [ng/L]). The reference method also produced results in mass per unit volume of air (ng/L). A comparison
of the mean VOC concentrations calculated for each sampling method at each grid indicates that the EMFLUX system
identified the presence of all of the VOC compounds detected by the reference soil gas sampling method in 24 of 25
cases. In addition, in 7 of 31 cases, the EMFLUX system also reported VOCs that the reference method did not
detect but were identified as present during previous soil and groundwater investigations at the demonstration sites.
This performance characteristic suggests that the EMFLUX® system can detect the presence of lower concentrations
of VOCs in soil gas than the reference soil gas sampling method. In addition, the sample locations where the
EMFLUX® system reported high VOC concentrations generally corresponded to the sample locations where the
reference method also reported high VOC concentrations. However, the values in the two data sets do not appear to
exhibit any direct or consistent proportional relationship, and the mean concentrations of VOCs calculated using the
reference method data were typically one to four orders of magnitude higher than those calculated using the
EMFLUX system for samples from the same grid. Because the EMFLUX system relies on diffusion of soil gas
from subsurface sources such as contaminated soil or groundwater, the performance range for the EMFLUX system
may be controlled by factors such as depth to the contaminant source, contaminant concentrations and diffusion rates,
soil type and organic content, the detection limits of the methods used to analyze the samples, and possibly other
factors. However, during the demonstration, the system was evaluated at locations with relatively shallow subsurface
contamination, and was only evaluated with regard to its ability to detect certain targeted VOCs. For these reasons,
the performance range of the EMFLUX system was not fully established by the demonstration data. It should be
noted that the EMFLUX® system and reference method are field screening techniques that provide only an estimate
of the actual concentration of contaminants in soil gas. Because the EMFLUX system and reference method use
different techniques to collect soil gas samples, it is not expected that the two methods will provide the same response
and that the data will be directly comparable. Because the mean VOC concentrations for the data sets differ by several
orders of magnitude in most instances, a statistical analysis of the data was not performed and interpretation of the
chemical concentration data for this demonstration is limited to qualitative observations.
EPA-VS-SCM-22 The accompanying notice is an integral part of this verification statement August 1998
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Sample Retrieval Time: Installation of the EMFLUX® system averaged 3.0 minutes per sample at the SBA site and
4.0 minutes per sample at the CSC site. For the demonstration, the samplers were left in place for approximately 4
days at each site. Collection of the samplers required an average of 2.3 minutes per sample at the SBA site and 3.2
minutes at the CSC site. Overall, installation and collection of 35 samples at the SBA site required 187 minutes, an
average of 5.3 minutes per sample, and installation and collection of 28 samples at the CSC site required 201 minutes,
an average of 7.2 minutes per sample. The analysis and reporting by the technology developer required an additional
12 days for the SBA site data and 16 days for the CSC site data from the time samples were collected until the
laboratory report was delivered. The reference soil gas method required 458 minutes to collect 35 samples at the SBA
site, an average of 13.1 minutes per sample, and 183 minutes to collect 28 samples at the CSC site, an average of 6.5
minutes per sample. One day was required per site to analyze the samples and report the results. Based on the
demonstration results, the average sample retrieval times for the EMFLUX system were quicker than those of the
reference soil gas sampling method in the clay soils at the SBA site and slower than those of the reference sampling
method in the sandy soils at the CSC site. During sample collection using the reference soil gas sampler, the clay soil
at the SBA site caused the system to hold its vacuum at several sampling locations; therefore, soil gas was not
completely drawn into the system for sampling. In these cases, the rod was withdrawn in additional 6-inch increments
until the vacuum was broken and the system s pressure reached equilibrium with atmospheric pressure. The vacuum
problem was not encountered in the sandy soil at the CSC site. At both sites, one person collected soil gas samples
with the EMFLUX® system, and a three-person sampling crew collected and analyzed soil samples using the reference
sampling method.
Cost. Based on the demonstration results, the EMFLUX system costs $85 to $195 per sample plus equipment costs
of $25 to $90 per day and mobilization/demobilization costs of $200 to $600 per day. Operating costs for the
EMFLUX® system ranged from $660 to $1,390 at the clay soil site and $710 and $1,440 at the sandy soil site. For
this demonstration, the active soil gas sampling method was procured at a lump sum of $4,700 for each site. The
oversight costs for the active soil gas sampling method ranged from $680 to $1,260 at the clay soil site and $480 to
$910 at the sandy soil site. A site-specific cost and performance analysis is recommended when selecting a subsurface
soil gas sampling method.
A qualitative performance assessment of the EMFLUX system indicated that (1) the samplers are reliable in that 100
percent of the required samples were collected without sample losses; (2) the samplers are easy to use and require
minimal training (a 16-minute training video is available from the developer); (3) logistical requirements for the
EMFLUX system differ from those of the reference sampling method because the EMFLUX field collectors are
installed using a hammer-driven, 6-inch steel rod, left in place for several days, retrieved by hand, and sent to the
developer for analysis; and (4) sample handling in the field was easier than the reference method because the only
requirements are that the recovered cartridges be properly packed and shipped to the developer for analysis.
The demonstration results indicate that the EMFLUX system can provide useful, cost-effective data for environmental
problem-solving. The EMFLUX^ system successfully collected soil gas samples in clay and sandy soils. The sampler
provided positive identification of target VOCs and may be able to detect lower concentrations of VOCs in the soil
gas than the reference method. The results of the demonstration did not indicate consistent proportional comparability
between the EMFLUX® data and the reference method s data. As with any technology selected, the user must
determine what is appropriate for the application and the project data quality objectives.
GaryJ. Foley, Ph.D.
Director
National Exposure Research Laboratory
Office of Research and Development
NOTICE: EPA verifications are based on an evaluation of technology performance under specific, predetermined criteria and
appropriate quality assurance procedures. EPA makes no expressed or implied warranties as to the performance of the
technology and does not certify that a technology will always operate as verified. The end user is solely responsible for
complying with any and all applicable federal, state, and local requirements.
EPA-VS-SCM-22 The accompanying notice is an integral part of this verification statement August 1998
V
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Foreword
The U.S. Environmental Protection Agency (EPA) is charged by Congress with protecting the
nation s natural resources. Under the 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, the 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) is the Agency s center for the investigation of
technical and management approaches for identifying and quantifying risks to human health and the
environment. Goals of the Laboratory s research program are to (1) develop and evaluate methods
and technologies for characterizing and monitoring air, soil, and water; (2) support regulatory and
policy decisions; and (3) provide the science support needed to ensure effective implementation of
environmental regulations and strategies.
The EPA s Superfund Innovative Technology Evaluation (SITE) Program evaluates technologies for
the characterization and remediation of contaminated Superfund and Resource Conservation and
Recovery Act sites. The SITE Program was created to provide reliable cost and performance data to
speed the acceptance and use of innovative remediation, characterization, and monitoring technologies
by the regulatory and user communities.
Effective measurement and monitoring technologies are needed to assess the degree of contamination
at a site, to provide data that can 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. One component of the EPA SITE Program,
the Monitoring and Measurement Technologies Program, demonstrates and evaluates innovative
technologies to meet these needs.
Candidate technologies can originate from within the federal government or from the private sector.
Through the SITE Program, developers are given the opportunity to conduct a rigorous
demonstration of their technology under actual field conditions. By completing the evaluation and
distributing the results, the Agency establishes a baseline for acceptance and use of these technologies.
The Monitoring and Measurement Technology Program is managed by the ORD s Environmental
Sciences Division in Las Vegas, Nevada.
Gary Foley, Ph.D.
Director
National Exposure Research Laboratory
Office of Research and Development
VI
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Contents
Notice ii
Verification Statement iii
Foreword vi
Figures ix
Tables x
Acronyms and Abbreviations xi
Acknowledgments xii
Executive Summary xiii
Chapter 1 Introduction 1
Technology Verification Process 3
Needs Identification and Technology Selection 3
Demonstration Planning and Implementation 3
Report Preparation 4
Information Distribution 4
Demonstration Purpose 4
Chapter 2 Technology Description 5
Background 5
Components and Accessories 7
General Operating Procedures 7
Developer Contact 9
Chapter 3 Site Descriptions and Demonstration Design 10
Site Selection and Description 10
SBA Site Description 10
CSC Site Description 12
Predemonstration Sampling and Analysis 14
Demonstration Design 14
VOC Detection and Quantitation 15
Sample Retrieval Time 17
Cost 17
Deviations from the Demonstration Plan 17
Chapter 4 Description and Performance of the Reference Method 18
Background 18
Components and Accessories 18
Description of Platform 19
Demonstration Operating Procedures 19
Qualitative Performance Factors 20
Reliability and Ruggedness 20
Training Requirements and Ease of Operation 21
Logistical Requirements 21
Sample Handling 21
Vll
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Contents (Continued)
Performance Range 21
Quantitative Performance Factors 21
VOC Detection and Quantitation 22
Sample Retrieval Time 22
Data Quality 22
Chapter 5 Technology Performance 25
Qualitative Performance Factors 25
Reliability and Ruggedness 25
Training Requirements and Ease of Operation 25
Logistical Requirements 25
Sample Handling 26
Performance Range 26
Quantitative Performance Assessment 26
VOC Detection and Quantitation 26
Sample Retrieval Time 32
Data Quality 33
Chapter 6 Economic Analysis 34
Assumptions 34
EMFLUX® System 34
Reference Sampling Method 37
Chapter 7 Summary of Demonstration Results 39
Chapter 8 Technology Update 42
Empirical and Theoretical Bases for EMFLUX® System 42
The ETV Demonstrations 43
Expanding Applications 44
Chapter 9 Previous Deployment 45
References 48
Appendix
A Data Summary Tables A-1
Vlll
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Figures
2-1. EMFLUX® Collector Parts and Deployment Options 8
3-1. Small Business Administration Site 11
3-2. Chemical Sales Company Site 13
3-3. Typical Sampling Locations and Random Sampling Grid 16
5-1. Comparison of Mean 1,2-Dichloroethene Concentration in Samples Collected Using the
EMFLUX System and the Reference Soil Gas Sampling Method 30
5-2. Comparison of Mean 1,1,1-Trichloroethane Concentration in Samples Collected Using the
EMFLUX System and the Reference Soil Gas Sampling Method 30
5-3. Comparison of Mean Trichloroethene Concentration in Samples Collected Using the
EMFLUX System and the Reference Soil Gas Sampling Method 31
5-4. Comparison of Mean Tetrachloroethene Concentration in Samples Collected Using the
EMFLUX System and the Reference Soil Gas Sampling Method 31
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Tables
4-1. Volatile Organic Compound Concentrations in Samples Collected Using the
Reference Soil Gas Sampling Method 23
5-1. Volatile Organic Compound Concentrations in Samples Collected Using the EMFLUX
System 28
5-2. Mean Chemical Concentrations of EMFLUX and Reference Soil Gas Sampling
Method Data 29
5-3. Average Sample Retrieval Times for the EMFLUX System and the Reference Soil Gas
Sampling Method 32
6-1. Estimated Subsurface Soil Gas Sampling Costs for the EMFLUX System 35
6-2. Estimated Subsurface Soil Gas Sampling Costs for the Reference Sampling Method .... 37
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Acronyms and Abbreviations
bgs
cc
cis-l,2-DCE
CLP
CSC
CSCT
1,1-DCA
1,2-DCE
E&E
ELCD
EMFLUX®
EPA
ETV
ETVR
GC
GC/MS
mg
mg/kg
ml
•g/kg
NERL
ng/L
OU
PAH
PCE
QA
QC
QA/QC
Quadrel
RI/FS
SBA
SITE
SMC
SVOC
1,1,1-TCA
TCE
VOC
below ground surface
cubic centimeter
cis-1,2-dichloroethene
contract laboratory program
Chemical Sales Company
Consortium for Site Characterization Technology
1,1-dichloroethane
1,2-dichloroethene (total)
Ecology & Environment
electrolytic conductivity detector
EMFLUX Soil Gas Investigation System
U.S. Environmental Protection Agency
Environmental Technology Verification
Environmental Technology Verification Report
gas chromatography
gas chromatograph/mass spectrometer
milligrams
milligrams per kilogram
milliliters
micrograms per kilogram
National Exposure Research Laboratory
nanograms per liter
operable unit
polynuclear aromatic hydrocarbon
tetrachloroethene
quality assurance
quality control
quality assurance/quality control
Quadrel Services, Inc.
remedial investigation/feasibility study
Small Business Administration
Superfund Innovative Technology Evaluation
Superior Manufacturing Company
semivolatile organic compound
1,1,1-trichloroethane
trichloroethene
volatile organic compound
XI
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Acknowledgments
This report was prepared for the U.S. Environmental Protection Agency s (EPA) Environmental
Technology Verification Program under the direction of Stephen Billets, Brian Schumacher, and Eric
Koglin of the EPA s National Exposure Research Laboratory—Environmental Sciences Division in
Las Vegas, Nevada. The project was also supported by the EPA s Superfund Innovative Technology
Evaluation (SITE) Program. The EPA wishes to acknowledge the support of Janice Kroone (EPA
Region 7), Joe Vranka (Colorado Department of Public Health and the Environment), Armando
Saenz (EPA Region 8), Sam Goforth (independent consultant), Alan Hewitt (Cold Regions Research
Engineering Laboratory), Bob Siegrist (Colorado School of Mines), and Ann Kern (EPA SITE
Program). In addition, we gratefully acknowledge the collection of the passive soil gas samples using
the EMFLUX system by Bruce Tucker (Quadrel); implementation of this demonstration by Eric
Hess, John Parks, and Willis Wilcoxon (Tetra Tech); editorial and publication support by Butch
Fries, Jennifer Brainerd, and Stephanie Anderson (Tetra Tech); and technical report preparation by
Ron Ohta, Roger Argus, and Ben Hough (Tetra Tech).
xn
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Executive Summary
In May and June 1997, the U.S. Environmental Protection Agency (EPA) sponsored a demonstration
of the EMFLUX passive soil gas sampling technology, one other soil gas sampling technology, and
four soil sampling technologies. This Environmental Technology Verification Report (ETVR) presents
the results of the EMFLUX Soil Gas Investigation System demonstration; similar reports have been
prepared for each of the other technologies.
The EMFLUX system is a passive soil gas sampling system distinguishable by its use of a model to
predict periods of maximum soil gas emission for geographic locations to select optimal sampling times.
The EMFLUX system allows simultaneous sample collection by multiple field collectors, thereby
eliminating movement of equipment from point to point. The EMFLUX system consists of the
EMFLUX sample cartridge, sample insertion tools, and developer-provided sample analysis and
computer modeling. The EMFLUX cartridge consists of 100 milligrams of sorbent sealed in a fine
mesh screen, which is placed in a glass vial for sample collection and shipped for laboratory analysis.
The EMFLUX system was demonstrated at two sites: the Small Business Administration (SBA) site in
Albert City, Iowa, and the Chemical Sales Company (CSC) site in Denver, Colorado. These sites were
chosen because each has a wide range of volatile organic compound (VOC) concentrations and because
each has a distinct soil type. The VOCs detected at the sites include vinyl chloride; 1,2-dichloroethene;
1,1-dichloroethane; 1,1,1-trichloroethane; trichloroethene; and tetrachloroethene. The SBA site is
composed primarily of clay soil and the CSC site is composed primarily of sandy soil.
The EMFLUX system was compared to the reference sampling method, active soil gas sampling, in
terms of the following parameters: (1) VOC detection and quantitation, (2) sample retrieval time, and
(3) cost. The demonstration data indicated the following performance characteristics:
• The EMFLUX system consistently detected all of the compounds identified by the reference
sampling method and in several instances detected VOCs that the reference sampling method did
not detect. However, VOC concentrations detected using the EMFLUX system were typically
one to four orders of magnitude lower than those reported by the reference method.
• The average sample retrieval times for the EMFLUX system were quicker than the reference
soil gas sampling method in the clay soils at the SBA site and slower than the reference method
in the sandy soils at the CSC site. For this demonstration, the EMFLUX field collectors were
left in place for 4 days at each site and required 12 days at the SBA site and 16 days at the CSC
site for cartridge analysis and reporting by the developer. The reference sampling method
required one day per site to analyze the samples and report the analytical results.
• Based on the demonstration results, the EMFLUX system cost $85 to $195 per sample plus
equipment costs of $25 to $90 per day and mobilization/demobilization costs of $200 to $600
per site. Operating costs for the EMFLUX system ranged from $660 to $1,390 at the clay
soil site and $710 and $1,440 at the sandy soil site.
In general, results for the data quality indicators selected for this demonstration met the established
quality assurance objectives and support the usefulness of the demonstration results in verifying the
performance of the EMFLUX system.
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Chapter 1
Introduction
Performance verification of innovative and alternative environmental technologies is an integral part of
the U.S. Environmental Protection Agency s (EPA) regulatory and research mission. Early efforts
focused on evaluating technologies that supported implementation of the Clean Air and Clean Water
Acts. To meet the needs of the hazardous waste program, the Superfund Innovative Technology
Evaluation (SITE) Program was established by the EPA Office of Solid Waste and Emergency Response
(OSWER) and Office of Research and Development (ORD) as part of the Superfund Amendments and
Reauthorization Act of 1986. The primary purpose of the SITE Program is to promote the acceptance
and use of innovative characterization, monitoring, and treatment technologies.
The overall goal of the SITE Program is to conduct research and performance verification studies of
alternative or innovative technologies that may be used to achieve long-term protection of human health
and the environment. The various components of the SITE Program are designed to encourage the
development, demonstration, acceptance, and use of new or innovative treatment and monitoring
technologies. The program is designed to meet four primary objectives: (1) identify and remove
obstacles to the development and commercial use of alternative technologies, (2) support a development
program that identifies and nurtures emerging technologies, (3) demonstrate promising innovative
technologies to establish reliable performance and cost information for site characterization and cleanup
decision-making, and (4) develop procedures and policies that encourage the selection of alternative
technologies at Superfund sites, as well as other waste sites and commercial facilities.
The intent of a SITE demonstration is to obtain representative, high quality, performance and cost data
on innovative technologies so that potential users can assess a given technology s suitability for a
specific application. The SITE Program includes the following elements:
Monitoring and Measurement Technology (MMT) Program — Evaluates technologies that
detect, monitor, sample, and measure hazardous and toxic substances. These technologies are
expected to provide better, faster, and more cost-effective methods for producing real-time data
during site characterization and remediation studies
• Remediation Technologies — Conducts demonstrations of innovative treatment technologies to
provide reliable performance, cost, and applicability data for site cleanup
• Technology Transfer Program — Provides and disseminates technical information in the form
of updates, brochures, and other publications that promote the program and the technology.
Provides technical assistance, training, and workshops to support the technology
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The MMT Program provides developers of innovative hazardous waste measurement, monitoring, and
sampling technologies with an opportunity to demonstrate a technology s performance under actual
field conditions. These technologies may be used to detect, monitor, sample, and measure hazardous
and toxic substances in soil, sediment, waste materials, and groundwater. Technologies include
chemical sensors for in situ (in place) measurements, groundwater sampling devices, soil and core
sampling devices, soil gas samplers, laboratory and field-portable analytical equipment, and other
systems that support field sampling or data acquisition and analysis.
The MMT Program promotes the acceptance of technologies that can be used to accurately assess the
degree of contamination at a site, provide data to evaluate potential effects on human health and the
environment, apply data to assist in selecting the most appropriate cleanup action, and monitor the
effectiveness of a remediation process. Acceptance into the program places high priority on innovative
technologies that provide more cost-effective, faster, and safer methods than conventional technologies
for producing real-time or near-real-time data. These technologies are demonstrated under field
conditions and results are compiled, evaluated, published, and disseminated by ORD. The primary
objectives of the MMT Program are the following:
• Test field analytical technologies that enhance monitoring and site characterization capabilities
• Identify the performance attributes of new technologies to address field characterization and
monitoring problems in a more cost-effective and efficient manner
• Prepare protocols, guidelines, methods, and other technical publications that enhance the
acceptance of these technologies for routine use
The SITE MMT Program is administered by ORD s National Exposure Research Laboratory (NERL-
LV) at the Environmental Sciences Division in Las Vegas, Nevada.
In 1994, the EPA created the Environmental Technology Verification (ETV) Program to facilitate the
deployment of innovative technologies in other areas of environmental concern through performance
verification and information dissemination. As in the SITE Program, the goal of the ETV Program is
to further environmental protection by substantially accelerating the acceptance and use of improved
and cost-effective technologies. The ETV Program is intended to assist and inform those involved in
the design, distribution, permitting, and purchase of various environmental technologies. The ETV
Program capitalizes on and applies the lessons learned in implementing the SITE Program.
For each demonstration, the EPA draws on the expertise of partner "verification organizations" to
design efficient procedures for conducting performance tests of environmental technologies. The EPA
selects its partners from both the public and private sectors, including federal laboratories, states,
universities, and private sector entities. Verification organizations oversee and report verification
activities based on testing and quality assurance (QA) protocols developed with input from all major
stakeholder and customer groups associated with the technology area. For this demonstration, the EPA
selected Tetra Tech EM Inc. (Tetra Tech; formerly PRC Environmental Management, Inc.) as the
verification organization.
In May and June 1997, the EPA conducted a demonstration, funded by the SITE Program, to verify
the performance of four soil and two soil gas sampling technologies: SimulProbe Technologies, Inc.,
Core Barrel Sampler; Geoprobe Systems, Inc., Large-Bore Soil Sampler; AMS™ Dual Tube Liner
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Sampler; Clements Associates, Inc., Environmentalist s Subsoil Probe; Quadrel Services, Inc.
(Quadrel), EMFLUX® Soil Gas Investigation System; and W.L. Gore & Associates GORE-SORBER®
Screening Survey passive soil gas sampling system. This environmental technology verification report
(ETVR) presents the results of the demonstration for one soil gas sampling technology, the Quadrel
EMFLUX Soil Gas Investigation System. Separate ETVRs have been published for the remaining soil
and soil gas sampling technologies.
Technology Verification Process
The technology verification process is designed to conduct demonstrations that will generate high-
quality data that the EPA and others can use to verify technology performance and cost. Four key
steps are inherent in the process: (1) needs identification and technology selection, (2) demonstration
planning and implementation, (3) report preparation, and (4) information distribution.
Needs Identification and Technology Selection
The first aspect of the technology verification process is to identify technology needs of the EPA and
the regulated community. The EPA, the U.S. Department of Energy, the U.S. Department of Defense,
industry, and state agencies are asked to identify technology needs for characterization, sampling, and
monitoring. Once a technology area is chosen, a search is conducted to identify suitable technologies
that will address that need. The technology search and identification process consists of reviewing
responses to Commerce Business Daily announcements, searches of industry and trade publications,
attendance at related conferences, and leads from technology developers. Selection of characterization
and monitoring technologies for field testing includes an evaluation of the candidate technology against
the following criteria:
• Designed for use in the field or in a mobile laboratory
• Applicable to a variety of environmentally contaminated sites
• Has potential for resolving problems for which current methods are unsatisfactory
• Has costs that are competitive with current methods
• Performs better than current methods in areas such as data quality, sample preparation, or
analytical turnaround time
• Uses techniques that are easier and safer than current methods
• Is commercially available
Demonstration Planning and Implementation
After a technology has been selected, the EPA, the verification organization, and the developer agree to
a strategy for conducting the demonstration and evaluating the technology. The following issues are
addressed at this time:
• • Identifying and defining the roles of demonstration participants, observers, and reviewers
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• Identifying demonstration sites that provide the appropriate physical or chemical attributes in the
desired environmental media
• Determining logistical and support requirements (for example, field equipment, power and
water sources, mobile laboratory, or communications network)
• Arranging analytical and sampling support
• Preparing and implementing a demonstration plan that addresses the experimental design, the
sampling design, quality assurance/quality control (QA/QC), health and safety, field and
laboratory operations scheduling, data analysis procedures, and reporting requirements
Report Preparation
Each of the innovative technologies is evaluated independently and, when possible, against a reference
technology. The technologies are usually operated in the field by the developers in the presence of
independent observers. These individuals are selected by the EPA or the verification organization and
work to ensure that the technology is operated in accordance with the demonstration plan.
Demonstration data are used to evaluate the capabilities, performance, limitations, and field applications
of each technology. After the demonstration, all raw and reduced data used to evaluate each
technology are compiled into a technology evaluation report as a record of the demonstration. A
verification statement and detailed evaluation narrative of each technology are published in an ETVR.
This document receives a thorough technical and editorial review prior to publication.
Information Distribution
The goal of the information distribution strategy is to ensure that ETVRs are readily available to
interested parties through traditional data distribution pathways, such as printed documents. Related
documents and technology updates are also available on the World Wide Web through the ETV Web
site (http://www.epa.gov/etv) and through the Hazardous Waste Clean-Up Information Web site
supported by the EPA OSWER Technology Innovation Office (http://clu-in.org). Additional
information on the SITE Program can be found on ORD s web site (http://www.epa.gov/ORD/SITE).
Demonstration Purpose
The purpose of this demonstration of the EMFLUX system was to evaluate how the sampler
performed relative to the reference sampling method, active soil gas sampling. Specifically, this
demonstration evaluated the EMFLUX system in comparison to the reference soil gas sampling
method in terms of the following parameters: (1) volatile organic compound (VOC) detection and
quantitation, (2) sample retrieval time, and (3) cost. Data quality indicators for precision, accuracy,
representativeness, completeness, and comparability were also assessed against established QA
objectives to ensure the usefulness of the data for the purpose of this verification.
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Chapter 2
Technology Description
This chapter describes the EMFLUX system, including its background, components and accessories,
sampling platform, and general operating procedures. The text in this chapter was provided by the
developer and was edited for format and relevance.
Background
Soil gas sampling techniques can be broadly divided into two categories: active and passive. The
active soil gas sampling method uses vacuum methods to collect soil gas samples at discrete depth
intervals and provides a "snapshot" of the soil gas environment at a particular moment and at a specific
depth. This approach requires detectable vapor-phase compound concentrations, relatively porous
subsurface soil, and experienced on-site personnel. Because the soil gas samples are usually analyzed
immediately, an on-site or nearby laboratory is typically required. Active soil gas sampling is generally
used for rapid screening of VOCs in the subsurface in moderately permeable soils and is generally not
applicable to detecting semivolatile organic compounds (SVOC).
Passive sampling techniques rely on diffusion and adsorption and can be used to sample for VOCs and
SVOCs, depending on the adsorbent selected and the diffusion membrane used. The developers of
passive soil gas samplers claim that the passive samplers allow for equilibrium to develop between the
soil gases and the sorbent over a period of several days to weeks. Further, the developers claim that
exposure of the passive samplers to the soil gas over extended periods concentrates the mass of VOCs
and SVOCs absorbed to the sampler; thereby enhancing contaminant detection sensitivity.
The EMFLUX system is a passive soil gas sampling system developed by Quadrel. According to
Quadrel, the EMFLUX system is based on technology developed over the past 35 years, and was
originally used in the minerals exploration industry to detect radon gas and locate uranium deposits.
The EMFLUX system components consist of a sample cartridge and installation tools. The "system"
also incorporates computer modeling to predict optimal sampling times for a specific geographic
location and sample analyses, both provided by the developer. The EMFLUX system uses a
proprietary software package to predict periods of maximum soil gas emission for any location. This
software package models the relationship between the gravitational phenomenon known as "earth tides "
and orders-of-magnitude changes in the vertical velocities of gases moving through the earth s crust.
The modeling of this relationship allows Quadrel to theoretically predict favorable (relatively
high-vertical-velocity) periods for soil gas sampling. Knowing when these favorable periods occur may
decrease the period of time the samplers must be left installed at a site; however, EMFLUX surveys
may be conducted at virtually any time.
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(K)
The EMFLUX data are reported in units of mass per sample, which Quadrel can convert to mass per
unit volume of air. For this demonstration, the EMFLUX data were reported in units of mass per unit
volume of air (nanograms per liter [ng/L]). The conversion from mass of contaminant detected to mass
of contaminant detected per volume of air was accomplished by the developer using equation 2-1.
C - 10^ (2-1)
TR
where:
C = the soil gas concentration (nanograms per liter)
K = the cartridge collection constant (1.0 second/cubic centimeter [cc])
W = the detected contaminant mass (nanograms)
T = the collection period (seconds)
R = the adsorbent recovery factor (unitless). Adsorbent recovery factors are unique to each
combination of sorbent and contaminant. The developer provided these recovery factors
and converted all the data for this demonstration.
The EMFLUX Soil Gas Investigation System is designed to identify and quantify a broad spectrum of
VOCs and SVOCs, including halogenated compounds, petroleum hydrocarbons, poly nuclear aromatic
hydrocarbons (PAH), and other compounds. The developer lists a broad range of target analytes the
EMFLUX® system can potentially detect:
Common VOCs and SVOCs quantifiable by standard EPA techniques such as methods 8021,
8081, 8260, and 8270.
• Explosives such as nitrobenzene, 2-nitrotoluene, 3-nitrotoluene, 4-nitrotoluene,
1,3-dinitrobenzene, 2,4-dinitrotoluene, 2,6-dinitrotoluene, 1,3,5-trinitrobenzene,
2,4,6-trinitrotoIuene, 2-amino-4,6-dinitrotoluene, 4-amino-2,6-dinitrotoluene, and others.
• Chemical agents and breakdown products such as 1,4-dithiane, 1,4-oxathiane, benzothiazole,
p-chlorophenylmethyIsulfide, p-chlorophenylmethylsulfoxide, p-chlorophenyImethyIsulfone,
dimethyldisulfide, diisopropyl methylphosphonate, thiodiglycol, and others.
Other developer claims regarding system performance include the following:
• The system detects VOCs and SVOCs in soil gas at concentrations proportional to the actual
soil or groundwater contaminant concentrations and can trace the distribution of VOCs and
SVOCs in subsurface soil and groundwater with a comparability rate of 90 percent with
reference soil and groundwater sampling methods.
• EMFLUX® can detect contaminant masses per sample ranging from 25 to 1,000,000
nanograms, and can allow a reporting limit of less than 1 ng/L of air.
• EMFLUX® can collect samples under artificial surfaces and in fine-grained soils such as clays.
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• The system can detect contaminants from depths over 200 feet below ground surface (bgs).
• The system employs accurate analytical techniques and relatively low detection limits to reduce
the potential for false positive or negative results.
• No special training is required to install or collect samples using the technology.
During the demonstration, only Quadrel s claims regarding sample retrieval time, cost, and the ability
of the EMFLUX system to be used to sample for VOCs were evaluated.
Components and Accessories
The EMFLUX system consists of a sample cartridge and installation tools. The EMFLUX cartridge
consists of 100 milligrams (mg) of sorbent sealed in a fine-mesh screen, which is placed in a glass vial;
the vial and cartridge make up the EMFLUX field collector. Given the target VOCs present at the
SBA and CSC sites, carboxen was selected by the developer as the absorbent material for this
demonstration. Other absorbent materials are available for use with the EMFLUX system. The
sorbent is contained in a cartridge suspended in a 7-milliliter (ml) screw-top glass vial. The cartridge
and tools are provided in an EMFLUX field kit. The standard field kit is designed for sampling in
areas where the EMFLUX cartridges can be placed 3 to 4 inches bgs, and contains all supplies
required to collect 30 samples. The standard field kit is 3 inches high, 9 inches long, 9 inches wide,
and weighs about 5 pounds. A modified EMFLUX field kit for surface-based (non-intrusive)
sampling is 9 inches high by 9 inches wide by 19 inches long, and weighs about 25 pounds. The
modified kit contains all tools and supplies needed to collect 60 samples.
General Operating Procedures
Prior to the survey, the developer can use a proprietary computer model to predict the optimal sampling
time. The field sampling program is then implemented by the technology user. The following field
procedures are routinely used during EMFLUX soil gas surveys. Modifications can be incorporated
from time to time in response to individual project requirements.
1. Surface debris or vegetation, if present, are removed by the field technician, exposing the
ground surface. Using a hammer and a 0.75-inch diameter metal stake, the technician creates a
hole approximately 3 to 4 inches deep (Figure 2-1). For locations covered with asphalt or
concrete, the technician drills a 1-inch-diameter hole through the cover to the soils beneath. If
necessary, the EMFLUX sample cartridge can be sleeved with a 0.75-inch inner diameter
copper pipe. This procedure is used at locations where asphalt surfaces may be possible
sources of PAH contamination.
2. The technician removes the solid plastic cap from an EMFLUX sampling cartridge and
replaces it with a sampling cap (a plastic cap with a hole covered by screen mesh). The
sampling cartridge has a metal retrieval wire secured around it. The technician inserts the
collector, with the sampling cap end facing down, into the hole (Figure 2-1). The collector is
then covered with either local soils or with aluminum foil and concrete or asphalt patching
material. The collector s location, time and date of emplacement, and other relevant
information are recorded.
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DEPLOYMENT THROUGH SOILS
-Retricvaf.Wirc
.^Sampler Vial'.;
ilirigjCap!
:SOILS:-: ::
DEPLOYMENT THROUGH AN ASPHALT/CONCRETE CAP
-Aluminum Foil - •
'T-Oap i&rPlug - • -
_ i _ r ^ < - i'
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3. As a quality control (QC) check during cartridge emplacement, and also during retrieval, the
technician takes periodic ambient air control samples and records the date, time, and location of
each. One or more trip blanks are also included as part of the QC procedures.
4. After all EMFLUX sampling cartridges have been deployed and appropriate control samples
collected, personnel depart, leaving the cartridges in place.
5. Field personnel retrieve the collectors at the end of the exposure period, typically 72 hours or
more. At each location, a technician withdraws the collector from its hole and wipes the outside
of the vial clean using gauze cloth; following removal of the sampling cap, the threads of the
vial are also cleaned. A solid plastic cap is screwed onto the vial and the sampling location
number is written on the vial s label. The technician then records sampling point location, date,
time, and other relevant information on the field deployment form and on a chain-of-custody
form.
Sample analysis is provided by the developer, either through its internal or contracted laboratory
facilities. The developer can also provide mobile laboratories equipped with field gas chromatography
(GC) equipment for on-site analysis, if required.
Developer Contact
For more developer information on the EMFLUX Soil Gas Investigation System, please refer to
Chapters 8 and 9 of this ETVR or contact the developer at:
Bruce Tucker
Quadrel Services, Inc.
1896 UrbanaPike, Suite 20
Clarksburg, Maryland 20871
Telephone: (800) 878-5510
Facsimile: (301) 874-5567
E-mail: quadrel@erols.com
Web Site: http://www.emflux.com
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Chapter 3
Site Descriptions and Demonstration Design
This chapter describes the demonstration sites, predemonstration sampling and analysis, and the
demonstration design. The demonstration was conducted in accordance with the "Final Demonstration
Plan for the Evaluation of Soil Sampling and Soil Gas Sampling Technologies " (PRC, 1997).
Site Selection and Description
The following criteria were used to select the demonstration sites:
• Unimpeded access for the demonstration
• A range (micrograms per kilogram [• g/kg] to milligrams per kilogram [mg/kg]) of chlorinated
or aromatic VOC contamination in soil
• Well-characterized contamination
• Different soil textures
• Minimal underground utilities
• Situated in different climates
Based on a review of 48 candidate sites, the Small Business Administration (SBA) site in Albert City,
Iowa, and the Chemical Sales Company (CSC) site in Denver, Colorado, were selected for the
demonstration of the EMFLUX system.
SBA Site Description
The SBA site is located on Orchard Street between 1st and 2nd Avenues in east-central Albert City,
Iowa (Figure 3-1). The site is the location of the former Superior Manufacturing Company (SMC)
facility and is now owned by SBA and B&B Chlorination, Inc. SMC manufactured grease guns at the
site from 1935 until 1967. Metal working, assembling, polishing, degreasing, painting, and other
operations were carried out at the site during this period. The EPA files indicate that various solvents
were used in manufacturing grease guns and that waste metal shavings coated with oil and solvents
were placed in a waste storage area. The oil and solvents were allowed to drain onto the ground, and
the metal waste was hauled off site by truck (Ecology & Environment [E&E], 1996).
10
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2nd Avenue
Former SMC
Waste Storage
Area
School
Bus
Storage
Building
Buena Vista
County
Maintenance
Facility
DEMONSTRATION GRID LOCATIONS
AND GRID NUMBER
APPROXIMATE SITE BOUNDARY
Figure 3-1. Small Business Administration Site
FEET
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The site consists of the former SMC plant property and a waste storage yard. The SMC plant property
is currently a grass-covered, relatively flat, unfenced open lot. The plant buildings have been razed. A
pole barn is the only building currently on the SMC plant property. Several buildings are present in
the waste storage yard, including three historic buildings: a garage, a museum, and a school house.
Poorly drained, loamy soils of the Nicollet series are present throughout the site area. The upper layer
of these soils is a black loam grading to a dark-gray loam. Below this layer, the soils grade to a friable,
light clay loam extending to a depth of 60 inches. Underlying these soils is a thick sequence (400 feet
or more) of glacial drift. The lithology of this glacial drift is generally a light yellowish-gray, sandy
clay with some gravel, pebbles, or boulders. The sand-to-clay ratio is probably variable throughout the
drift. Groundwater is encountered at about 6 to 7 feet bgs at the SBA site (E&E, 1996).
Tetrachloroethene (PCE), trichloroethene (TCE), cis-l,2-dichloroethene (cis-l,2-DCE), and vinyl
chloride are the primary contaminants detected in soil at the site. These chlorinated VOCs have been
detected in both surface (0 to 2 feet deep) and subsurface (3 to 5 feet deep) soil samples. TCE and cis-
1,2-DCE are the VOCs usually detected at the highest concentrations in both soil and groundwater. In
past site investigations, TCE and cis-l,2-DCE have been detected in soils at 17 and 40 mg/kg,
respectively, with vinyl chloride present at 1.4 mg/kg. The areas of highest contamination have been
found near the center of the former SMC plant property and near the south end of the former SMC
waste storage area (E&E, 1996).
CSC Site Description
The CSC site is located in Denver, Colorado, approximately 5 miles northeast of downtown Denver.
From 1962 to 1976, a warehouse at the site was used to store chemicals. The CSC purchased and first
occupied the facility in 1976. The CSC installed aboveground and underground storage tanks and
pipelines at the site between October 1976 and February 1977. From 1976 to 1992, the facility
received, blended, stored, and distributed various chemicals and acids. Chemicals were transported in
bulk to the CSC facility by train and were unloaded along railroad spurs located north and south of the
CSC facility. These operations ceased at the CSC site in 1992.
The EPA conducted several investigations of the site from 1981 through 1991. Results of these
investigations indicated a release of organic chemicals into the soil and groundwater at the site. As a
result of this finding, the CSC site was placed on the National Priorities List in 1990. The site is
divided into three operable units (OU). This demonstration was conducted at OU1, located at 4661
Monaco Parkway in Denver (Figure 3-2). In September 1989, EPA and CSC entered into an
Administrative Order on Consent requiring CSC to conduct a remedial investigation/feasibility study
(RI/FS) for CSC OU1. The RI/FS was completed at OU1 in 1991 (Engineering-Science, Inc., 1991).
The current site features of OU1 consist of the warehouse, a concrete containment pad with a few
remaining tanks from the aboveground tank farm, another smaller containment pad with aboveground
tanks north of a railroad spur, and multiple areas in which drums are stored on the west side of the
warehouse and in the northwest corner of the property. The warehouse is currently in use and is
occupied by Steel Works Corporation.
The topography, distribution of surficial deposits, and materials encountered during predemonstration
sampling suggest that the portion of OU1 near the CSC warehouse is a terrace deposit composed of
Slocum Alluvium beneath aeolian sand, silt, and clay. The terrace was likely formed by renewed
12
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00
SCALE
0 25 50 100
FEET
ABOVE-GROUND
TANKS
O O
O O
O O
ce
o
-ABOVE-GROUND
TANKS
ASPHALT
CHEMICAL SALES
WAREHOUSE
LEGEND
DC.
<
Q_
O
O
Figure 3-2. Chemical Sales Company Site
DEMONSTRATION GRID
LOCATIONS AND GRID
NUMBER
RAILROAD
FENCE
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downcutting of a tributary to Sand Creek. Borings at the CSC property indicate that soils in the vadose
zone and saturated zone are primarily fine- to coarse-grained, poorly sorted sands with some silts and
clays. The alluvial aquifer also contains some poorly sorted gravel zones. The depth to water is about
30 to 40 feet bgs near the CSC warehouse.
During previous soil investigations at the CSC property, chlorinated VOC contamination was detected
extending from near the surface (less than 5 feet bgs) to the water table depth. The predominant
chlorinated VOCs detected in site soils are PCE, TCE, 1,1,1-trichloroethane (1,1,1-TCA), and 1,1-
dichloroethane (1,1-DCA). The area of highest VOC contamination is north of the CSC tank farm,
near the northern railroad spur. The PCE concentrations detected in this area measure as high as 80
mg/kg, with TCE and 1,1,1-TCA concentrations measuring as high as 1 mg/kg. In addition, results
from field analysis of soil headspace samples using GC indicated TCE, PCE, 1,1,1-TCA, and 1,1-DCA
concentrations as high as 5,000 parts per million by volume.
Predemonstration Sampling and Analysis
Predemonstration sampling and analysis were conducted to establish the geographic location of
sampling grids, identify target sampling depths, and estimate the variability of contaminant
concentrations exhibited at each grid location and target sampling depth. Predemonstration sampling
was conducted at the SBA site between April 1 and 11, 1997, and at the CSC site between April 20 and
25, 1997. Eleven sampling grids, six at the SBA site and five at the CSC site, were investigated to
confirm that each grid exhibited chemical concentrations and soil texture characteristics that met the
criteria set forth in the predemonstration sampling plan (PRC, 1997) and to confirm that passive and
active soil gas sampling could be used at the two sites.
At each of the grids sampled during the predemonstration, five borings were advanced from which
soil samples were collected for VOC and soil texture analysis. As expected, the primary VOCs
detected in the soil samples at the SBA site were vinyl chloride, cis-l,2-DCE, TCE, and PCE. The
primary VOCs detected at the CSC site were 1,1,1-TCA, TCE, and PCE. TCE and cis-l,2-DCE were
detected at the highest concentrations.
An active soil gas sampling method sample was collected from an area adjacent to each of the soil
sampling grids at each site. Analyses of samples from these locations confirmed that (1) the active soil
gas sampling method could be used at the two sites, and (2) soil gas contamination was detectable by
the reference method. Of the eleven grids investigated, nine were selected for demonstration sampling,
five grids at the SBA site and four grids at the CSC site.
Demonstration Design
The demonstration was designed to evaluate the EMFLUX system in comparison to the reference
sampling method, active soil gas sampling, in terms of the following parameters: (1) VOC detection
and quantitation, (2) sample retrieval rate, and (3) cost. These parameters were assessed in two
different soil textures (clay soil at the SBA site and sandy soil at the CSC site). The demonstration
design is described in detail in the demonstration plan (PRC, 1997) and is summarized below.
Predemonstration sampling identified nine grids (Grids 1, 2, 4, 5, and 6 at the SBA site and Grids 1,2,
4, and 5 at the CSC site) that exhibited consistent soil texture and acceptable VOC concentrations for
the demonstration. Each grid was 10.5 by 10.5 feet in area and was divided into seven rows and seven
14
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columns producing 49, 18- by 18-inch sampling cells (Figure 3-3). Each grid was sampled at a depth
of approximately 3 feet in each of the seven columns (labeled A through G) using the reference soil gas
sampling method; the EMFLUX cartridges were emplaced at a depth of about 3 to 4 inches for
passive sampling. For each grid, seven soil gas samples were collected using the EMFLUX system
and the reference soil gas sampling method. The seven cells that were sampled using each method were
selected randomly. The procedure used to collect samples using the EMFLUX system is described in
Chapter 2 and the procedure used to collect samples using the reference soil gas sampling method is
described in Chapter 4.
VOC Detection and Quantitation
A Quadrel representative installed and collected the EMFLUX samples and shipped them to Quadrel s
team laboratory, Maryland Spectral Services, Inc., in Baltimore Maryland, where the samples were
desorbed and analyzed. The samples were analyzed using gas chromatography/mass spectrometry
(GC/MS) techniques according to EPA SW-846 modified Method 8260 for detection of VOCs, as
described in EPA Office of Solid Waste and Emergency Response 'Test Methods for Evaluating Solid
Waste "(EPA, 1986).
The reference soil gas samples were analyzed using an on-site laboratory following the guidelines
discussed in the quality assurance project plan (PRC, 1997). The guidelines used for on-site analysis
were similar to SW-846 Method 5021 (Volatile Organic Compounds in Soils and Other Solid Matrices
Using Equilibrium Headspace Analysis), modified to include high- and low-concentration procedures
similar to those described in SW-846 Method 5035 (Closed-System Purge-and-Trap and Extraction for
Volatile Organics in Soil and Waste Samples) (EPA, 1986). The target compounds were vinyl
chloride, 1,2-DCE, TCE, and PCE at the SBA site, and 1,2-DCE, 1,1-DCA, 1,1,1-TCA, TCE, and
PCE at the CSC site. Soil gas samples collected from the CSC site were not analyzed for vinyl chloride
because it was not detected in soil during site characterization activities.
The reference soil gas samples were collected in 40-milliliter (ml) glass volatile organic analysis vials.
The standard injection volume used for soil gas analysis was 2 ml. A gas-tight glass syringe was used
to directly inject the soil gas samples onto the GC column. An electrolytic conductivity detector was
used for compound identification and quantitation. The GC was a Hewlett-Packard Series II equipped
with a packed injection port and a DB-624 column.
The demonstration plan (PRC, 1997) stated that data for the EMFLUX and reference soil gas
sampling methods would undergo a statistical analysis. However, comparison of the EMFLUX and
reference method data indicated significant differences between the two data sets, with mean VOC
concentrations for the data sets differing by several orders of magnitude in most instances. For this
reason, a statistical analysis of the data was not performed.
In addition, there appears to be no consistent proportional relationship between contaminant
concentrations detected using the EMFLUX system and those detected using the reference sampling
method. Therefore, interpretation of the chemical concentration data for this demonstration is limited to
qualitative observations.
15
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B
D
Ref.
EMF
EMF
Ref.
Ref.
EMF
EMF
Ref.
EMF
Ref.
Ref.
EMF
Ref.
EMF
1 n c; fnrit
CD
in
CD
EMF EMFLUX® System Sampling Location
Ref. Reference Sampling Method Location
Figure 3-3. Typical Sampling Locations and Random Sampling Grid
16
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Sample Retrieval Time
Sample retrieval time was measured as the time required to set up on a sampling grid, install and collect
the seven EMFLUX field collectors from each grid, decontaminate the sampler installation and
collection equipment, and move to a new sampling grid. The time required to install the samplers was
added to the time required to collect the samplers to obtain the sample retrieval time.
Cost
The cost estimate focused on the range of costs for using the EMFLUX system and reference soil gas
sampling method to collect 40 subsurface soil gas samples at a clay soil site (similar to the SBA site) and
a sandy soil site (similar to the CSC site). The cost analysis is based on the results and experience
gained from the demonstration and cost information provided by Quadrel. Factors that could affect the
cost of operating the EMFLUX system and the reference soil gas sampler include:
• • Equipment costs
• • Labor costs
• • Sample analysis and reporting costs
• • Decontamination costs
• • Site restoration costs
Deviations from the Demonstration Plan
Three project-wide deviations from the approved demonstration plan were identified: (1) vinyl chloride
was eliminated from the target compound list at the CSC site because vinyl chloride was not present in
the soil gas at the site; (2) a statistical comparison of the EMFLUX system data to the reference
sampling method data was not performed because, in most cases, the data sets differed by several
orders of magnitude; and (3) reference soil gas sampling method results were not available from Grid 6
at the SBA site because of laboratory error. Cases where the performance of an individual sampling
technology caused it to deviate from the demonstration plan are discussed on a technology-specific basis
in Chapters 4 (reference method) and 5 (EMFLUX system) of this ETVR.
17
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Chapter 4
Description and Performance of the Reference Method
This chapter describes the active soil gas sampling system used during the demonstration as the
reference soil gas sampling method, and includes its associated background information, components
and accessories, platform description, demonstration operating procedures, qualitative performance
factors, quantitative performance factors, and data quality measures.
Background
Soil gas screening technology was used as early as 1929 as a surface geochemical technique in oil and
gas exploration. In the early 1980s, active soil gas sampling became widely used as an environmental
investigative tool for aiding in the delineation of subsurface organic contamination. The intent of active
soil gas sampling is to reduce site characterization costs by identifying areas with suspected
contamination, thereby minimizing the number of soil borings and monitoring wells required to
delineate the extent of contamination.
Active soil gas sampling produces a discrete sample that provides a "snapshot" of the soil gas
environment at the time the sample is collected. The sampling technique used in this demonstration
requires the presence of vapor-phase compounds at detectable concentrations, relatively porous
subsurface soil, experienced analytical instrument operators at the site, and portable analytical
equipment for on-site analysis of samples.
Components and Accessories
Two active soil gas sampling systems were used during this demonstration: an AMS™ active sampling
system at the SBA site, and a Geoprobe® sampling system at the CSC site. The systems are similar, and
this description of system components and accessories applies to both technologies. The components of
the reference sampling method consist of an expendable drive point, a drive-point holder, drive rods,
expendable plastic tubing, a tubing connector, and a vacuum pump. The 2-inch-long, expendable drive
point is a solid steel or aluminum component that has a cone-shaped drive end and a cylindrical shank
on the other end that fits into the point holder. The drive-point holder is a hollow tube, 4 inches long
by 1-inch outside-diameter. One end of the point holder holds the expendable point; the other has
female threads for attaching the tubing connector. The 2-inch-long, hollow metal tubing connector has
a nipple for the plastic tubing on one end and male threads with a rubber gasket on the other end,
which attaches to the drive-point holder. The 36- to 48-inch-long by 1-inch outside-diameter drive rod
is a hollow metal tube with male threads on one end and female threads on the other. The vacuum
pump is capable of drawing a vacuum of 20 to 30 inches of mercury, is constructed of metal, and has
pressure gauges on the sampling line and vacuum tank.
18
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Other components of the reference soil gas sampling system include a drive cap, pull cap, ancillary
tools, and expendable sampling supplies. The drive and pull caps are metal and have female threads on
one end for attaching to the top drive rod. Ancillary tools required include drill bits, vise grips, pipe
wrenches, crescent wrenches, knives, hemostats, and screwdrivers. Expendable sampling supplies
required include the plastic tubing (tygon, Teflon™, or polyethylene), silicone tubing, 40-ml volatile
organic analysis vials, syringe with needle, double-ended needles, and a container for waste.
Because the soil gas samples are usually analyzed immediately, an on-site or nearby laboratory is
typically required. A GC in an on-site, mobile laboratory was used to analyze the samples during this
demonstration.
Description of Platform
The AMS™ and Geoprobe® soil gas sampling systems use similar platforms to place the samplers. The
platform consists of a hydraulically powered hammer mounted in the bed of a three-quarter-ton pickup
truck. Additional equipment required includes an oil reservoir, a pump, a hammer support structure,
hydraulic control levers, and three hydraulic cylinders: one to fold the hammer for transport, one to
adjust the hammer height, and one to adjust the foot height.
The mobility and performance of the platform were adequate for the conditions at both demonstration
sites. The size of the truck and the ability of the hammer to pivot in multiple directions allowed for
smooth transition from one sampling location to another. The platform easily pushed or hammered the
soil gas samplers to the 4.5-foot sampling depth at each demonstration site, and the platform easily
extracted the soil gas samplers. The clay soil at the SBA site required less hammering to place the soil
gas samplers than did the sandy soil at the CSC site.
Demonstration Operating Procedures
The reference soil gas sampling method involved assembling and installing the sampling system and
collecting the soil gas sample. Initially, a 1-inch outside-diameter hollow rod was driven to the target
sampling depth within the selected grid cell. The rod was fitted with an expendable drive point. Once
the rod reached the target depth of 4.5 feet bgs, it was withdrawn approximately 6 inches. The
expendable drive point remained in place, producing a 6-inch void space that allowed a soil gas sample
to be collected. Once the rod was retracted 6 inches, a 0.25-inch inside-diameter, high-density
polyethylene or Teflon™ tube was lowered into the drive rod. The end of the tubing was fitted with a
reverse threaded, barbed fitting. The barb was inserted into the tubing and the reverse threaded end
was screwed into the expendable drive point holder at the end of the drive rod when the tubing reached
the end of the drive rod. A butyl rubber 0-ring around the threaded end of the barb fitting ensured an
airtight seal between the tubing and the end of the drive rod.
Once the tubing was in place, the soil gas sample was collected by attaching an evacuated 40-ml
sampling vial with a double-ended needle to the top end of the system tubing as follows.
1. The sampling vial was evacuated using a 60 cc plastic syringe. The syringe pulled a vacuum on
the closed sampling vial for 10 seconds. This vacuum was applied by attempting to draw 60 cc
of air out of the vial.
19
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2. A volume-calibrated vacuum system was attached to the end of the polyethylene tube connected
to the end of the hollow rod. The vacuum system removed a volume of air equal to one tubing
volume that was calculated to be 16.4 cc in this demonstration.
3. The vacuum system was shut off and the sampling string was allowed to equilibrate with
ambient air pressure. The system was closed so that equilibration occurred only by drawing
soil gas into the sample tubing. (A vacuum line integrity test was successfully completed before
each sampling event to ensure that there were no leaks in the soil gas system.)
4. When no vacuum was left in the tubing, a double-end hypodermic needle was inserted into the
tygon tubing that connected the polyethylene tubing with the vacuum pump. The exposed end
of the needle was sealed with a soft rubber sheath. The evacuated sampling vial was pushed
onto the exposed needle. The needle penetrated the vial s septum and exposed the soil gas in
the tubing to the vacuum in the vial, causing the vial to fill with soil gas. The sampling vial was
allowed to collect a sample for 40 seconds at the CSC site and 2 minutes at the SBA site. These
times were selected after several tests on refilling evacuated vials were conducted by observing
(1) septa "spring back " to their original positions, and (2) lack of an air hiss upon opening the
vial.
Each sampling vial containing a soil gas sample was numbered according to the sample grid and cell
where it was collected. After the samples were properly labeled, they were analyzed within 24 hours
of collection. Prior to analysis, the active soil gas samples were stored at ambient temperatures.
All reusable soil gas sampling equipment was decontaminated by heating with a portable propane heater
for approximately 30 seconds. The sampling vials and needles were not reused, and the sample tubing
was discarded after a single use.
Qualitative Performance Factors
The following qualitative performance factors were assessed for the reference soil gas sampling
method: (1) reliability and ruggedness under the test conditions, (2) training requirements and ease of
operation, (3) logistical requirements, (4) sample handling, and (5) performance range.
Reliability and Ruggedness
The reliability and ruggedness of the reference soil gas sampling method was adequate for conditions at
both demonstration sites. The sampler was pushed or hammered to the 4.5-foot sampling depth at each
site without incident. During the demonstration, operators noted that attaching the tubing adapter to the
point holder was easier when the tubing was precut to the required length (per the sampling depth);
otherwise, the tubing tended to unwind when released, which would either loosen or unscrew the
tubing adapter from the point holder. The clay soil at the SBA site caused the system to hold its
vacuum at several sampling locations; hence, soil gas was not completely drawn into the system for
sampling. In these cases, the rod was withdrawn in additional 6-inch increments until the vacuum was
broken and the system s pressure reached equilibrium with atmospheric pressure. The vacuum
problem was not encountered in the sandy soil at the CSC site. The reference soil gas sampling method
operated without any equipment failure or mechanical breakdown during the demonstration.
20
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Training Requirements and Ease of Operation
The active soil gas sampling technology requires minimal training due to the ease of operating the
system. Special certifications, advanced degrees, or other specialized training are not required to
operate the sampling platform and use the system. However, health and safety training is required by
the Occupational Safety and Health Administration when operating at hazardous waste sites. A novice
would require 3 to 6 hours of hands-on training to become proficient at using the sampling platform
and the soil gas sampling system. A crew of two is recommended for sampling and operation of the
system and platform, but one person may safely operate the system.
Logistical Requirements
Logistical requirements for the reference soil gas sampling method include obtaining utility clearances
and grouting the sampling holes. Permits to operate the system were not required by the states of Iowa
and Colorado, but may be required in other states. The system, platform, and ancillary equipment are
mounted on or contained in the platform vehicle.
The physical disruption caused by the sampling platform was minimal during the demonstration. No
soil cuttings were generated and a 1-inch diameter hole was left at each sampling location after the
reference soil gas sampling system was extracted. These holes were grouted with bentonite after
samples were collected.
Sample Handling
The reference soil gas samples were easily collected and handled. When no vacuum was left in the
sampling tubing, one end of a double-end hypodermic needle was inserted into the polyethylene tubing
and the other end was inserted through the septum of the evacuated sampling vial. Soil gas in the
tubing was drawn into the sampling vial until the pressure reached equilibrium. This took about 40 to
120 seconds. The sampling vial containing the soil gas sample was numbered according to the sample
grid and cell where it was collected. The samples were properly labeled and were then stored at
ambient temperature until analysis. The samples were analyzed within 24 hours of collection.
Performance Range
The performance range of the reference sampling method is limited by soil texture, permeability, soil
moisture content, contaminant type, and depth to groundwater. During the demonstration, reference
soil gas samples were collected from a depth of 4.5 feet; however, the system is capable of collecting
samples at depths of 30 to 60 feet. Soil such as glacial till with cobbles or fill with pieces of concrete
can cause refusal of the reference sampling method before it reaches the desired depth. Clay soil may
also impede sample collection because the vacuum is not readily released. The active soil gas sampling
must be conducted above the water table to avoid drawing water into the sampling tube.
Quantitative Performance Factors
Three quantitative performance indicators were measured for the reference soil gas sampling method:
(1) VOC detection and quantitation, (2) sample retrieval time, and (3) cost. The following sections
discuss the first two performance factors; a cost analysis of the reference soil gas sampling method is
provided in Chapter 6.
21
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VOC Detection and Quantitation
Seven samples were collected using the reference soil gas sampling method within each grid as
described in Chapter 3 and specified in the demonstration plan (PRC, 1997). Samples were analyzed
for VOCs by GC analysis according to the standard operating guideline provided in the demonstration
plan (PRC, 1997). Table 4-1 presents the range and mean VOC concentrations for samples collected
using the reference method. The VOC results for each sample collected are presented in Appendix A.
For Grid 6 at the SB A site, VOC data for the reference method were not available because of
laboratory error. For one of the sampling grids, VOC data for all seven samples are not available due
to laboratory error; in this case, the range and mean were calculated from the available data. Chapter 5
presents a graphical comparison of the analytical results obtained using the reference sampling method
to those obtained using the EMFLUX system.
Sample Retrieval Time
The reference soil gas method required 458 minutes to collect 35 samples at the SB A site, an average of
13.1 minutes per sample, and 183 minutes to collect 28 samples at the CSC site, an average of 6.5
minutes per sample. Sample retrieval time was measured as the amount of time per sample required to
set up at a sampling grid, collect the required samples, grout the hole, decontaminate the sampling
equipment, and move to a new sampling location. Analytical results were available from the on-site
laboratory within one day; this time was not included in calculating the sample retrieval rate. A three-
person sampling and analysis crew was used to collect and analyze soil gas samples using the reference
soil gas sampling method at both sites. The difference in sample retrieval time between the SBA and
CSC sites may be due in part to differences in soil type (clay versus sandy soil).
Data Quality
Data quality for the reference sampling method was assessed throughout this demonstration by
implementing an approved quality assurance project plan (PRC, 1997). The QA/QC procedures
included the consistent application of approved methods for sample collection, chemical analysis, and
data reduction. Based on the intended use of the data, QA objectives for precision, accuracy,
representativeness, comparability, and completeness were established, and QC samples were collected
to assess whether the QA objectives were met. Based on the results of a field audit conducted by the
EPA and a detailed validation of the demonstration data by Tetra Tech, the data have been deemed
acceptable for use as described in the demonstration design (Chapter 3). The results of the QC
indicators used for the reference soil gas sampling method are provided in the technology evaluation
report for this demonstration (Tetra Tech, 1997) and are summarized below.
All reference method soil gas samples were analyzed within 24 hours of collection, as specified in the
QAPP. Some initial calibrations of the Hewlett-Packard Series II GC had to be abbreviated to meet
acceptance criteria, and either a five-point or a three-point calibration was utilized instead of the
specified six-point calibration. However, all continuing calibrations met the acceptance criteria for
percent difference, indicating that the calibration was reproducible.
Two method blanks were analyzed at the SBA site and one at the CSC site. In addition, one ambient air
blank and one equipment blank were analyzed at each site. None of these blanks exhibited any target
compounds above the quantitation limit, indicating that there were no apparent sample contamination
problems at either site.
22
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Table 4-1. Volatile Organic Compound Concentrations in Samples Collected Using the Reference Soil Gas Sampling Method
Concentration (ng/L)
Site Grid
SBA 1
SBA 2
SBA 4
SBA 5
SBA 6*
CSC 1
CSC 2
CSC 4
CSC 5 T
Vinyl Chloride
Range Mean
230,000- 2,390,000
5,180,000
<100 <100
<100 <100
<100- 1,980
8,270
NA NA
NA NA
NA NA
NA NA
NA NA
Total DCE
Range Mean
279,000- 958,000
2,220,000
< 50 -151 65
< 50 -261 101
3,180- 9,980
21,000
NA NA
2,260- 10,800
21,300
<500- 1,850
3,780
<500- 6,190
10,500
<500- 738
1,400
1,1 DCA
Range Mean
<50 <50
<50 <50
<50 <50
<50 <50
NA NA
< 500 < 500
< 500 < 500
< 500 < 500
< 500 < 500
1,1,1 TCA
Range Mean
<50 <50
<50 <50
<50 <50
<50 <50
NA NA
7,530- 314,000
670,000
33,900 - 288,000
439,000
19,600- 142,000
217,000
12,600- 69,900
132,000
TCE
Range Mean
<50 <50
183-5,380 1,250
744 - 9,390
33,600
132-6,250 2,010
NA NA
7,450- 41,800
77,400
11,400- 89,500
154,000
1,880- 22,200
41,800
2,430- 11,500
24,700
PCE
Range Mean
<50 <50
<50 <50
<50 <50
<50 <50
NA NA
79,000- 330,000
770,000
32,000- 223,000
427,000
20,800- 192,000
389,000
24,800- 98,500
220,000
ng/L Nanograms per liter Total DCE Total Dichloroethene
NA Not analyzed 1,1 -DCA 1, 1-Dichloroethane
SBA Small Business Administration site 1,1,1 -TCA 1,1, 1 -Trichloroethane
CSC Chemical Sales Company site TCE Trichloroethene
t VOC data for only five samples are available PCE Tetrachloroethene
* VOC data were collected but are not available
because of laboratory error
23
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Tetra Tech performed a data validation review of all data, and an EPA Region 8 QC chemist performed
an audit of the laboratory during the predemonstration phase. Neither of these reviews noted any
significant data quality issues. Thus, the data appear to be of sufficient quality for the intended use.
24
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Chapter 5
Technology Performance
This chapter describes the performance of the EMFLUX® system in terms of qualitative and
quantitative performance factors. A description of the EMFLUX® system is provided in Chapter 2.
Qualitative Performance Factors
The following qualitative performance factors were assessed for the EMFLUX® system: (1) reliability
and ruggedness under the test conditions, (2) training requirements and ease of operation, (3) logistical
requirements, (4) sample handling, and (5) performance range.
Reliability and Ruggedness
The Quadrel representative collected 100 percent (63 of 63) of the EMFLUX® field collectors without
sample loss or downtime. This accomplishment verifies the developer's claim that the EMFLUX®
system can collect samples in clay or poorly drained soils and under artificial surfaces. The sample
vials used with this technology are protected before deployment and after collection by custom-made
packaging materials, minimizing any possible breakage of the vials.
Training Requirements and Ease of Operation
Complete written instructions for sample deployment and retrieval accompany all EMFLUX® field kits.
At the client's request, the developer also furnishes a 16-minute training video. During the
demonstration, the EMFLUX® sample cartridges were installed and retrieved by the developer, but the
developer claims that no specialized training is required to install, collect, or ship the samples.
Logistical Requirements
No special licensing requirements are necessary to use the EMFLUX system. The system requires
two mobilizations: one trip to install the samplers, and a second trip to collect the samplers. Once the
samples are collected, they are sent back to the developer or to another qualified laboratory for
analysis.
Installation of the EMFLUX® system only requires drilling a 3- to 4-inch deep hole for each sample.
No specific logistical support is required for surveys in unpaved areas. Shallow underground utilities
such as cable, telephone, and electrical lines should be located and utility clearances should be obtained
before the holes are drilled. Installation of samplers through paved surfaces requires the use of a roto-
25
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hammer or drill, and holes in the pavement are usually patched after sampling. The use of the roto-
hammer requires an electrical power source.
The physical impact of demonstration sampling on the site was minimal, as no advancement platforms
are required for the EMFLUX system. The EMFLUX samplers left 0.75-inch-diameter holes, which
were grouted with granular bentonite after the samplers were collected.
Sample Handling
At each sampling location, a field technician withdraws the field collector from its hole and wipes the
outside of the vial clean using gauze cloth; following removal of the sampling cap, the threads of the
vial are also cleaned. A solid plastic cap is screwed onto the vial and the sampling location number is
written on the label. The samples must be securely packaged for shipment, but do not require cooling.
The technician records the sampling point location, date, time, and other relevant information on the
field deployment form and on the chain-of-custody form. The samples are shipped to the developer or
other qualified laboratory for analysis. Samples are usually analyzed using GC/MS techniques,
although other analytical techniques are offered by Quadrel.
Performance Range
The EMFLUX field collectors are typically inserted in to the soil to a depth of 3 to 4 inches and are
capable of sampling soil gas beneath artificial surfaces, such as asphalt and concrete, as well as in soils
with sandy to clay textures. The system s use of computer modeling to predict optimal sampling times
and the relatively long sample collection period may enhance the sensitivity of the EMFLUX system.
During the demonstration, the system successfully detected VOCs in both the clay soil at the SBA site
and the sandy soil at the CSC site, at detection limits ranging from 0.09 to 0.28 ng/L. According to
the developer, the EMFLUX system can detect VOCs and SVOCs from soil or groundwater at depths
as great as 200 feet bgs or more. Because the system relies on diffusion of soil gas from subsurface
sources such as contaminated soil or groundwater, the performance range for the EMFLUX system
may be controlled by factors such as depth to the source, contaminant concentrations and diffusion
rates, soil type and organic content, the detection limits of the methods used to analyze the samples, and
possibly other factors. However, during the demonstration, the system was evaluated at locations with
relatively shallow subsurface contamination and was only evaluated with regard to its ability to detect
certain targeted VOCs. For these reasons, the performance range of the EMFLUX system was not
fully established by the demonstration data.
Quantitative Performance Assessment
Quantitative measures of the performance of the EMFLUX system consisted of (1) VOC detection and
quantitation, (2) sample retrieval rate, and (3) cost. The following sections discuss the first two
performance factors; a cost analysis of the EMFLUX system is provided in Chapter 6.
VOC Detection and Quantitation
Seven samples were collected with the EMFLUX system within each sampling grid, as described in
Chapter 3. Samples were analyzed for VOCs by the technology developer s subcontract laboratory
using GC/MS techniques (EPA SW-846 modified Method 8260) in accordance with the demonstration
plan (PRC, 1997). Quadrel converted the raw VOC data, initially reported as mass of each VOC
26
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detected in each cartridge, to mass per unit volume of air, using the conversion equation presented in
Chapter 2. Table 5-1 presents the range and mean VOC concentrations calculated from soil gas samples
collected using the EMFLUX system. The VOC results for each sample collected are presented in
Appendix A. For all of the sampling grids, VOC data for all seven samples were used to calculate
range and mean concentrations for the EMFLUX samples. Reporting limits for the target VOCs were
less than 1 ng/L, typically ranging from 0.09 ng/L for 1,2-DCE to 0.28 ng/L for PCE.
Table 5-2 compares the mean VOC concentrations detected using the EMFLUX system to those
detected in the samples collected using the reference soil gas sampling method. Based on the mean
VOC concentrations for each sampling method at both sites, the EMFLUX system identified the
presence of all of the VOC compounds detected by the reference soil gas sampling method in 24 of 25
cases. In addition, the EMFLUX system reported VOCs that the reference method did not detect in
seven of 31 cases. For example, the EMFLUX system detected 1,1-DCA at all four grids sampled at
the CSC site at concentrations ranging from 0.13 to 6.69 ng/L; however, the reference method did not
detect 1,1-DCA in any of the samples. Previous analyses of soil samples and soil headspace samples
has indicated the presence of 1,1-DCA in soils at the CSC site (ESI, 1991). This performance
characteristic suggests that the EMFLUX system can detect the presence of lower concentrations of
VOCs in the soil gas than the reference soil gas sampling method.
Graphical presentations of the mean 1,2-DCE, 1,1,1-TCA, TCE, and PCE concentrations for samples
collected using the EMFLUX system and the reference sampling method are provided in Figures 5-1
through 5-4 (insufficient data are available to provide meaningful graphs of vinyl chloride and 1,1-
DCA data). Based on a review of the data distribution presented in Figures 5-1 through 5-4, a
significant difference between the EMFLUX and reference method data is evident, with mean VOC
concentrations for the data sets differing by several orders of magnitude in most instances. Because of
this difference, a statistical analysis of the data was not performed. The sample locations where the
EMFLUX system detected high VOC concentrations generally corresponded to the sample locations
where the reference method also detected high VOC concentrations; however, the values in the two
data sets do not appear to exhibit any direct or consistent proportional relationship. According to the
technology developer, it is possible that the differences between the VOC concentrations detected using
the two technologies may be due to one or a combination of several factors. These factors include: (1)
the longer sample collection period for the EMFLUX samples, which causes the EMFLUX data to be
subject to factors such as diurnal temperature, barometric pressure, and "earth tide " variations,
resulting in concentrations that may be more representative of long-term, average soil gas flux; (2) the
aggressive sample collection technique used for the reference method, which may draw more soil gas
from the surrounding area than the amount that passively infiltrates the EMFLUX field collectors; and
(3) the different sampling depths used for the two techniques.
It should be noted that the EMFLUX system and reference method are field screening techniques that
provide only an estimate of the actual concentration of contaminants in soil gas. Because the
EMFLUX system and reference method use different techniques to collect soil gas samples, it is not
expected that the two methods will provide the same response and that the data will be directly
comparable. Because the mean VOC concentrations for the data sets differ by several orders of
magnitude in most instances, a statistical analysis of the data was not performed and interpretation of the
chemical concentration data for this demonstration is limited to qualitative observations.
27
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Table 5-1. Volatile Organic Compound Concentrations in Samples Collected Using the EMFLUX® System
Concentration (ng/L)
Site Grid
SBA 1
SBA 2
SBA 4
SBA 5
SBA 6
CSC 1
CSC 2
CSC 4
CSC 5
Vinyl Chloride
Range Mean
0.19-104 38.0
<0.17 <0.17
<0.17 <0.17
<0.17 <0.17
<0.17 <0.17
NA NA
NA NA
NA NA
NA ' NA
1,2-DCE
Range Mean
16.0 - 958 520
0.12-5.34 3.28
< 0.09 -0.11 0.09
<0.09-8.40 2.92
<0.09 <0.09
19.7-157 58.3
0.78-9.91 3.32
0.47 - 6.52 2.58
<0.10-0.27 0.17
1,1-DCA
Range Mean
<0.10 <0.10
<0.10 <0.10
<0.10 <0.10
<0.10 <0.10
<0.10 <0.10
<0.11-6.69 4.09
0.15-1.17 0.55
0.13-1.34 0.52
<0.11-0.30 0.17
1,1,1-TCA
Range Mean
<0.11 <0.11
<0.11 <0.11
<0.11 <0.11
<0.11 <0.11
<0.11 <0.11
350-918 619
118-259 203
24.9-261 115
11.1-65.6 34.4
TCE
Range Mean
0.69 - 16.3 7.35
13.0-63.6 35.6
0.24 - 121 20.8
0.34-33.6 11.7
<0.12 <0.12
65.7-1,960 857
36.0 - 224 156
2.55 - 46.0 14.0
0.28-5.82 3.79
PCE
Range Mean
<0.28 <0.28
<0.28-3.53 1.79
<0.28-0.80 0.35
<0.28 <0.28
<0.28 <0.28
2,360 - 54,800 29,200
338-2,630 1,370
142 - 863 403
57.8 - 362 249
ng/L Nanograms per liter 1,1-DCA 1,1-Dichloroethane
SBA Small Business Administration site 1,2-DCE Cis-l,2-Dichloroethene
CSC Chemical Sales Company site 1,1,1-TCA 1,1,1-Trichloroethane
NA Not analyzed PCE Tetrachloroethene
TCE Trichloroethene
s>
oo
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Table 5-2. Mean Chemical Concentrations of EMFLUX® and Reference Soil Gas Sampling Method Data
Mean Concentration (ng/L)
Site Grid
SBA 1
SBA 2
SBA 4
SBA 5
SBA 6
CSC 1
CSC 2
CSC 4
CSC 5
ng/L
1,2-DCE
1,1 -DC A
1,1,1-TCA
Vinyl Chloride
EMFLUX* Ref.
38.0 2,390,000
<0.17 <100
<0.17 <100
<0.17 1,980
<0.17 NA
NA NA
NA NA
NA NA
NA NA
1,2-DCE
EMFLUX" Ref.
520 958,000
3.28 65
0.09 101
2.92 9,980
<0.09 NA
58.3 10,800
3.32 1,850
2.58 6,190
0.17 738
1,1-DCA
EMFLUX* Ref.
<0.10 <50
<0.10 <50
<0.10 <50
<0.10 <50
<0.10 NA
4.09 <500
0.55 <500
0.52 <500
0.17 <500
1,1,1-TCA
EMFLUX* Ref.
<0.11 <50
<0.11 <50
<0.11 <50
<0.11 <50
<0.11 NA
619 314,000
203 288,000
115 142,000
34.4 69,900
TCE
EMFLUX* Ref.
7.35 <50
35.6 1,250
20.8 9,390
11.7 2,010
<0.12 NA
857 41,800
156 89,500
14.0 22,200
3.79 11,500
PCE
EMFLUX* Ref.
<0.28 <50
1.79 <50
0.35 <50
<0.28 <50
<0.28 NA
29,200 330,000
1,370 223,000
403 192,000
249 98,500
Nanograms per liter PCE Tetrachloroethene
,2-Dichloroethene Ref. Reference soil gas sampling method
,1-Dichloroethane SBA Small Business Administration site
i 1 , 1 -Trichloroethane CSC Chemical Sales Company site
TCE Trichloroethene NA Not analyzed
-------
o
O
1000000-
100000-
10000-
1000-
100-
10-
SBA
Grid 1
SBA
Grid 2
SBA SBA
Grid 4 Grid 5
CSC
Grid 1
CSC
Grid 2
CSC CSC
Grid 4 Grid 5
Site and Grid Number
D EMFLUX Data
D Reference Data
ng/L Nanograms per Liter
SBA Small Business
Adminstration
CSC Chemical Sales
Company
Figure 5-1. Comparison of Mean 1,2-Dichloroethene Concentration in Samples Collected Using
EMFLUX® System and the Reference Soil Gas Sampling Method
lOOOOOOn
100000-
10000-
1000-
100-
10-
1
D EMFLUX Data
D Reference Data
ng/L Nanograms per Liter
CSC Chemical Sales
Company
CSC Grid 1 CSC Grid 2 CSC Grid 4
Site and Grid Number
CSC Grid 5
Figure 5-2. Comparison of Mean 1,1,1-Tnchloroethane Concentration in Samples Collected Using
EMFLUX® System and the Reference Soil Gas Sampling Method
30
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lOOOOOn
10000-
1000-
100-
10-
1-
X
«/
XT
7
SBA
Grid 2
X.
£
fL
7
JO
XT
7
X
X.
?
|X-
7
X
^
7
.x~
/
X
J
XT
7
X
^
xq
7
xV
SBA SBA CSC CSC CSC CSC
Grid 4 Grid 5 Grid 1 Grid 2 Grid 4 Grid 5
Site and Grid Number
D EMFLUX Data
D Reference Data
ng/L Nanograms per Liter
SBA Small Business
Adminstration
CSC Chemical Sales
Company
Figure 5-3. Comparison of Mean Trichloroethene Concentration in Samples Collected
Using EMFLUX® System and the Reference Soil Gas Sampling Method
1000000-
100000-
10000-
1000-
100
D EMFLUX Data
D Reference Data
ng/L Nanograms per Liter
CSC Chemical Sales
Company
CSC Grid 1
CSC Grid
CSC Grid 4
CSC Grid 5
Site and Grid Number
Figure 5-4. Comparison of Mean Tetrachloroethene Concentration in Samples Collected Using
EMFLUX® System and the Reference Soil Gas Sampling Method
31
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Sample Retrieval Time
During the demonstration, installation of the EMFLUX system averaged 3.0 minutes per sample at
the SBA site and 4.0 minutes per sample at the CSC site. For this demonstration, the samplers were
left in place for approximately 4 days at each site. Collection of the samplers required an average of
2.3 minutes per sample at the SBA site and 3.2 minutes at the CSC site. Overall, installation and
collection of 35 samples at the SBA site required 187 minutes, an average of 5.3 minutes per sample,
and installation and collection of 28 samples at the CSC site required 201 minutes, an average of 7.2
minutes per sample. The analysis and reporting by the technology developer required an additional
12 days for the SBA site data and 16 days for the CSC site data from the time samples were collected
until the laboratory report was delivered. The sample retrieval time for each site was determined
based on the total length of time required to set up at a sampling grid, implant and collect the seven
EMFLUX field collectors, collect any necessary QA samples, grout the holes with bentonite,
decontaminate any sampling equipment, and move to a new grid location. One person collected soil
gas samples with the EMFLUX system at the SBA and CSC sites.
Table 5-3 presents a comparison of the average sample collection rates for the EMFLUX system and
those for the reference soil gas sampling method. The average sample collection times for the
EMFLUX system were quicker than those of the reference sampling method in the clay soils at the
SBA site and slightly slower than those of the reference sampling method in the sandy soils at the
CSC site. The results also suggest that the sample collection rate for the EMFLUX system may be
less dependent on soil type than the collection rate for the reference method, possibly because the
EMFLUX samplers require only shallow placement and minimal equipment decontamination.
Table 5-3. Average Sample Retrieval Times for the EMFLUX® System and the Reference Soil
Gas Sampling Method
Average Time (minutes per sample)
Sampler
SBA Site CSC Site
EMFLUX® Soil Gas Sampler
Average Sample Installation Time
Average Sample Collection Time
Average Sample Retrieval Time
Reference Sampling Method
Average Sample Retrieval Time
3.0
2.3
5.3
13.1
4.0
3.2
7.2
6.5
Note: One person collected soil gas samples using the EMFLUX system at the SBA and CSC
sites, and a three-person sampling and analysis crew was used to collect and analyze the
soil gas samples using the reference soil gas sampling method.
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Data Quality
Data quality for the EMFLUX system was assessed throughout this demonstration by implementing
an approved quality assurance project plan (PRC, 1997). The QA/QC procedures included the
consistent application of approved methods for sample collection, chemical analyses, and data
reduction. Based on the intended use of the data, QA objectives for precision, accuracy,
representativeness, comparability, and completeness were established and QC samples were collected
to determine whether the QA objectives were met. Based on the results of a field audit conducted by
EPA and a detailed validation of the demonstration data, the data have been deemed acceptable for use
as described in the demonstration design (Chapter 3). The results of the QC indicators used for this
demonstration for the EMFLUX system are provided in the Technology Evaluation Report for this
demonstration (Tetra Tech, 1997) and are summarized below.
As planned, adsorbent samples from the SBA site were sent to a laboratory (Maryland Spectral
Services) that had been selected by the developer for analysis in accordance with the laboratory s
Standard Operating Procedures. The QC samples included field blanks, trip blanks, method blanks,
and surrogate spikes.
At both the SBA and the CSC site, the QC program incorporated the analysis of three field blanks,
one trip blank, and at least three method blanks. One trip blank, from the CSC site, exhibited minor
contamination (just above the quantitation limit) with methylene chloride, which is commonly used as
a laboratory solvent. No other target VOCs were detected in any of the above-described blanks,
indicating that contamination of samples in the field, in transport, or in the laboratory was not
occurring to any significant degree.
Surrogate spike recovery data were not reported, but no deviations from acceptance criteria were
reported by the laboratory.
In summary, although the QC program implemented by the developer laboratory was limited, the
results of that QC program did not suggest that any significant data quality issues exist. Therefore,
the data from the Quadrel laboratory appears to be of sufficient quality for use in this report as
planned.
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Chapter 6
Economic Analysis
The Quadrel EMFLUX Soil Gas Investigation System was demonstrated at two sites that varied
geologically and were contaminated with VOCs at a range of concentrations. This chapter presents an
economic analysis for applying the EMFLUX system at sites similar to those used in this
demonstration. The demonstration costs for the reference soil gas sampling method are also
provided.
This economic analysis estimates the range of costs for using the EMFLUX Soil Gas Investigation
System to collect 40 subsurface soil gas samples at a clay soil site (similar to the SBA site) and a sandy
soil site (similar to the CSC site). The analysis is based on the results and experience gained from this
demonstration and costs provided by Quadrel. To account for variability in cost data and
assumptions, the economic analysis is presented as a list of cost elements and a range of costs for
collecting soil gas samples using the EMFLUX system and reference sampling method.
Assumptions
Several factors affect the cost of subsurface soil gas sampling. Wherever possible, these factors are
identified so that decision makers can independently complete a site-specific economic analysis. For
example, this cost estimate is based on the soil types and average sample retrieval times calculated
during the demonstrations of 5.3 minutes per sample for the clay soil site and 7.2 minutes pers
sample at the sandy soil site. This cost estimate assumes that a hammer-driven steel rod is used to
install the EMFLUX system 3- to 4-inches bgs, and a direct-push platform is used to advance the
active soil gas sampling system to a depth of 4.5 feet bgs for sample collection. The cost estimate
also assumes that a one-person sampling crew collects soil gas samples using the EMFLUX system
and that a two-person sampling and analysis crew collects and analyzes soil gas samples using the
reference method.
EMFLUX® System
The costs for collecting soil gas samples using the EMFLUX system are presented in two categories:
(1) sampler, sample analysis, and equipment costs, which include mobilization/demobilization costs,
equipment use costs, and sampler and sample analysis costs for the EMFLUX system and (2)
operating costs, which include labor costs for sampler installation and retrieval, and other direct costs
such as supplies and site restoration.
The cost categories and associated cost elements are defined and discussed below and serve as the
basis for the estimated cost ranges presented in Table 6-1.
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®
Table 6-1. Estimated Subsurface Soil Gas Sampling Costs for the EMFLUX^ System
Sampler, Sample Analysis, and Equipment Costs
Mobilization/Demobilization = $200 to $600 per site
Equipment = $25 to $90 per day
EMFLUX System and Sample Analysis = $85 to $195 per sample
Operating Costs
Clay Soil Site
Sample Retrieval Time = 4 to 6 hours (1 day)
Total Samples Collected = 40
Total Sample Depth =13 feet (4 inches/sample)
Sampling Crew Size = 1 Person
Labor Costs
Mobilization/Demobilization
Travel
Per Diem
Sample Retrieval
Other Direct Costs
Supplies
Site Restoration
Range of Operating Costs*
$400 - $600
$12-$60
0 - $300
$200 - $300
$25-$75
$25-$50
$660-$1,390
Sandy Soil Site
Sample Retrieval Time = 5 to 7 hours (1 day)
Total Samples Collected = 40
Total Sample Depth =13 feet (4 inches/sample)
Sampling Crew Size = 1 Person
Labor Costs
Mobilization/Demobilization
Travel
Per Diem
Sample Retrieval
Other Direct Costs
Supplies
Site Restoration
$400 - $600
$12-$60
0 - $300
$250-$350
$25-$75
$25-$50
$710-$1,440
* The range of Operating Costs is rounded to the nearest tens of dollars and does not include Sampler,
Sample Analysis, or Equipment Costs
Sampler, Sample Analysis, and Equipment Costs. These costs include the mobilization/demobilization
costs, equipment costs, and sampler and sample analysis costs for the EMFLUX system. Cost
ranges were estimated as a daily equipment use fee and sampler and sample analysis charges. The
costs include:
• Mobilization/Demobilization Costs — These costs include preparing, delivering, and setting
up the sampling equipment, as well as packing up and returning the equipment to the
vendor s yard. Equipment mobilization and demobilization costs are estimated to range from
$200 to $600 for each site.
• Equipment Costs — Based on the average sample retrieval times for the demonstration and on
collecting 40 samples at each site, it is assumed that 1 day will be required to install the
passive soil gas detectors at a clay soil site and 1 day at a sandy soil site. Equipment costs are
estimated to range from $25 to $90 per day and include the cost of equipment to install the
passive soil gas sampler (hammer-driven steel rod [$25 per day]), rental of a roto-hammer
($60 per day), and purchase of copper tubing ($5 per day). A roto-hammer is only required
if samplers must be installed below pavement. Copper tubing is required when installing the
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sampler through pavement. No equipment is needed during collection of the passive soil gas
detectors.
• Sampler and Sample Analysis Costs — Unit costs of the EMFLUX samplers include passive
soil gas detectors, laboratory analysis, data tables, maps, and a final report. The EMFLUX
field collector costs range from $85 to $195 per sample, depending on the selected target
analytes. The EMFLUX system costs include off-site laboratory analysis using a GC/MS.
Operating Costs. Operating costs are limited to mobilization/demobilization labor, travel, per diem,
and sample collection labor. Operating costs for collecting samples with the EMFLUX system are
segregated into labor costs and other direct costs, as shown below.
Labor costs include mobilization/demobilization labor, travel costs, per diem, and sample retrieval.
• Labor Mobilization/Demobilization Labor Costs — This cost element includes the time for one
person to prepare for and travel to each site and includes 4 to 6 hours at a rate of $50 per
hour for two trips (one for sampler installation and one for sampler collection).
• Travel costs — Travel costs for each site are limited to round-trip mileage costs and are
estimated to be between 20 to 100 miles at a rate of $0.30 per mile for 2 trips (one for
sampler installation and one for sampler collection).
• Per Diem Costs — This cost element includes food, lodging, and incidental expenses and is
estimated to range from zero (for a local site) to $150 per day per person for one person for
2 days at the clay soil site ('/! day each for sampler installation and collection and 1 day for
mobilization/demobilization and site restoration). Costs are estimated to be the same for the
clay site and the sandy site.
• Sample Retrieval Labor Costs — On-site labor costs include labor for sampler installation and
sampler collection. Because installation and collection of the EMFLUX system is relatively
simple, additional oversight labor is not required. The total number of personnel required on
site is one. Based on the average demonstration sample retrieval times, sample installation and
collection labor times are estimated to be 4 to 6 hours for 1 person at each site (clay or sandy
soil). Labor rates are estimated at $50 per hour.
Other direct costs include supplies and site restoration costs.
• Supplies — This cost element includes decontamination supplies, such as buckets, soap, high-
purity rinse water, and brushes as well as personal protective equipment (Level D, the
minimum level of protection, is assumed). Supplies are estimated to cost between $25 and
$75.
• Site Restoration — Site restoration costs include grouting the sample boreholes and site
restoration labor. Grouting costs for each site are limited to grout and grouting tools ($25 to
$50). Site restoration labor costs are included under sample collection labor costs.
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Reference Sampling Method
The costs for implementing the reference method (active soil gas sampler) during the demonstration
include categories for sampling and analysis and for oversight, as presented in Table 6-2 and
discussed below.
Table 6-2. Estimated Subsurface Soil Gas Sampling Costs for the Reference Sampling Method
Sampling and Analysis Equipment Costs
Lump Sum = $4,700 for each site
Oversight Costs
Clay Soil Site
Total Sampling Time = 9 to 11 hours (2 days)
Total Samples Collected = 40
Total Sample Depth = 180 feet (4 feet/sample)
Sampling Crew Size = 2 People
Sandy Soil Site
Total Sampling Time = 5 to 7 hours (1 day)
Total Samples Collected = 40
Total Sample Depth = 180 feet (4 feet/sample)
Sampling Crew Size = 2 People
Labor Costs
Mobilization/Demobilization
Travel
Per Diem
Sampling Oversight
Other Direct Costs
Supplies
Range of Oversight Costs*
$200 - $300
$6 - $30
0 - $300
$450 -$550
$25 -$75
$680 -$1,260
Labor Costs
Mobilization/Demobilization
Travel
Per Diem
Sampling Oversight
Other Direct Costs
Supplies
$200 - $300
$6 - $30
0-$150
$250 -$350
$25 -$75
$480 - $910
* The range of Oversight Costs is rounded to the nearest tens of dollars and does not include Sampling and
Analysis Equipment Costs
Sampling and Analysis Costs. Total lump sum sampling and analysis equipment costs for the clay and
sandy soil sites was $4,700 for each site, and included:
• Mobilization and demobilization
• Drilling footage
• Active soil gas sampling system
• On-site laboratory analysis using a GC and an electrolytic conductivity detector (ELCD)
• Active soil gas sampling and analysis crew labor costs (2 people)
• Per diem for the crew (2 people)
• Grouting boreholes
• Site restoration
• Decontamination supplies
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• Waste collection and containerization
• Data tables
Additional mobilization/demobilization and per diem costs will apply if the site is more than 100 miles
from the active soil gas service provider. The minimum active soil gas cost is $2,500 per day for the
collection and analysis of 20 samples for six or fewer VOCs. Up to 20 additional samples could be
collected per day at an additional cost of $90 per sample and $5 per linear sample depth foot.
Oversight Costs. Oversight costs are presented as ranges to provide an estimate of oversight costs
that may be incurred at other sites. Costs for overseeing the reference sampling are segregated into
labor costs and other direct costs, as shown below.
Labor costs include mobilization/demobilization, travel, per diem, and sampling oversight costs.
• Mobilization/Demobilization Labor Costs — This cost element includes the time for one
person to prepare for and travel to each site, and includes 4 to 6 hours each at a rate of $50
per hour.
• Travel Costs — Travel costs for each site are limited to round-trip mileage costs for 20 to 100
miles at a rate of $0.30 per mile.
• Per Diem Costs — This cost element includes food, lodging, and incidental expenses and is
estimated to range from zero (for a local site) to $150 per day for one person for 2 days at
the clay soil site (1 day for sample collection and '/; day for mobilization and demobilization
and site restoration) and for one person for 1 day at the sandy soil site ('/! day for sample
collection and '/; day for mobilization/demobilization and site restoration). No per diem costs
are presented for the sampling and analysis crew because these costs are included in the
sampling and analysis equipment lump sum.
• Sampling Oversight Labor Costs — On-site labor, often a registered geologist, is required to
oversee sample collection. Active soil gas collection labor typically includes a platform
operator and one helper to collect samples and decontaminate sampling equipment.
Therefore, the total number of personnel on site would be three: one person to oversee
sampling activities and two people to operate the direct-push equipment and collect samples.
Based on the average sample retrieval rates determined during the demonstration, sampling
oversight labor times are estimated to be 9 to 11 hours for one person at the clay soil site and
5 to 7 hours for one person at the sandy soil site. Labor rates are assumed to be $50 per
hour. Labor costs for the active soil gas sampler operators are included in the equipment
costs.
Other direct costs include supplies. Decontamination and site restoration costs are included under the
sampling and analysis equipment costs.
• Supplies — This cost element includes personal protective equipment (Level D, the minimum
level of protection, is assumed) and other miscellaneous field supplies. Supplies are estimated
to cost between $25 and $75.
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Chapter 7
Summary of Demonstration Results
This chapter summarizes the technology performance results. The EMFLUX® system was compared to
reference sampling methods (AMS™ and Geoprobe® active soil gas sampling systems) in terms of the
following parameters: (1) VOC detection and quantitation, (2) sample retrieval time, and (3) cost. The
demonstration data indicate the following performance characteristics for the EMFLUX® system:
• VOC Detection and Quantitation Soil gas samples collected using the EMFLUX® system and
the reference soil gas sampling method at nine grids at both the sites were analyzed for six target
VOCs. Analysis of EMFLUX® samples yielded results in total nanograms per sample, which
Quadrel converted to mass per unit volume of air (ng/L). The reference method also produced
results in mass per unit volume of air. A comparison of the mean VOC concentrations
calculated for each sampling method at each grid indicates that the EMFLUX ® system identified
the presence of all of the VOC compounds detected by the reference soil gas sampling method in
24 of 25 cases. In addition, in 7 of 31 cases, the EMFLUX® system also reported VOCs that the
reference method did not detect but were identified as present during previous soil and
groundwater investigations at the demonstration sites. This performance characteristic suggests
that the EMFLUX® system can detect the presence of lower concentrations of VOCs in soil gas
than the reference soil gas sampling method. In addition, the sample locations where the
EMFLUX® system reported high VOC concentrations generally corresponded to the sample
locations where the reference method also reported high VOC concentrations. However, the
values in the two data sets do not appear to exhibit any direct or consistent proportional
relationship, and the mean concentrations of VOCs calculated using the reference method data
were typically one to four orders of magnitude higher than those calculated using the
EMFLUX® system for samples from the same grid. Because the EMFLUX® system relies on
diffusion of soil gas from subsurface sources such as contaminated soil or groundwater, the
performance range for the EMFLUX® system may be controlled by factors such as depth to the
contaminant source, contaminant concentrations and diffusion rates, soil type and organic
content, the detection limits of the methods used to analyze the samples, and possibly other
factors. However, during the demonstration, the system was evaluated at locations with
relatively shallow subsurface contamination, and was only evaluated with regard to its ability to
detect certain targeted VOCs. For these reasons, the performance range of the EMFLUX®
system was not fully established by the demonstration data. It should be noted that the
EMFLUX® system and reference method are field screening techniques that provide only an
estimate of the actual concentration of contaminants in soil gas. Because the EMFLUX®system
and reference method use different techniques to collect soil gas samples, it is not expected that
the two methods will provide the same response and that the data will be directly comparable.
Because the mean VOC concentrations for the data sets differ by several orders of magnitude in
most instances, a statistical analysis of the data was not
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performed and interpretation of the chemical concentration data for this demonstration is
limited to qualitative observations.
• Sample Retrieval Time: Installation of the EMFLUX® system averaged 3.0 minutes per sample
at the SBA site and 4.0 minutes per sample at the CSC site. For the demonstration, the samplers
were left in place for approximately 4 days at each site. Collection of the samplers required an
average of 2.3 minutes per sample at the SBA site and 3.2 minutes at the CSC site. Overall,
installation and collection of 35 samples at the SBA site required 187 minutes, an average of 5.3
minutes per sample and installation and collection of 28 samples at the CSC site required 201
minutes, an average of 7.2 minutes per sample. The analysis and reporting by the technology
developer required an additional 12 days for the SBA site data and 16 days for the CSC site data
from the time samples were collected until the laboratory report was delivered. The reference
soil gas method required 458 minutes to collect 35 samples at the SBA site, an average of 13.1
minutes per sample, and 183 minutes to collect 28 samples at the CSC, an average of 6.5
minutes per sample. One day was required per site to analyze the samples and report the results.
Based on the demonstration results, the average sample retrieval times for the EMFLUX® system
were quicker than those of the reference soil gas sampling method in the clay soils at the SBA
site and slower than those of the reference sampling method in the sandy soils at the CSC site.
During sample collection using the reference soil gas sampler, the clay soil at the SBA site
caused the system to hold its vacuum at several sampling locations; therefore, soil gas was not
completely drawn into the system for sampling. In these cases, the rod was withdrawn in
additional 6-inch increments until the vacuum was broken and the system s pressure reached
equilibrium with atmospheric pressure. The vacuum problem was not encountered in the sandy
soil at the CSC site. At both sites, one person collected soil gas samples with the EMFLUX®
system, and a three-person sampling crew collected and analyzed soil samples using the
reference sampling method.
• Cost: Based on the demonstration results, the EMFLUX®system costs $85 to $195 per sample
plus equipment costs of $25 to $90 per day and mobilization/demobilization costs of $200 to
$600 per day. Operating costs for the EMFLUX®system ranged from $660 to $1,390 at the
clay soil site and $710 and $1,440 at the sandy soil site. For this demonstration, the active soil
gas sampling method was procured at a lump sum of $4,700 for each site. The oversight costs
for the active soil gas sampling method ranged from $680 to $1,260 at the clay soil site and $480
to $910 at the sandy soil site. A site-specific cost and performance analysis is recommended
when selecting a subsurface soil gas sampling method.
In general, the data quality indicators met the established quality assurance objectives and support the
usefulness of the demonstration results in verifying the performance of the EMFLUX®system.
A qualitative performance assessment of the EMFLUX®system indicated that (1) the samplers are
reliable in that 100 percent of the required samples were collected with no sample losses; (2) the
samplers are easy to use and require minimal training (a 16-minute training video is available from the
developer); (3) logistical requirements for the EMFLUX® system differ from those of the reference
sampling method because samplers are installed using a hammer-driven, 6-inch steel rod, left in place
for several days, retrieved by hand, and sent to the developer for analysis; and (4) sample handling in
the field was easier than the reference method because the only requirements are that the recovered
cartridges be properly packed, and shipped to the developer for analysis.
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The demonstration results indicate that the EMFLUX® system can provide useful, cost-effective data for
environmental problem-solving. The EMFLUX® system successfully collected soil gas samples in clay
and sandy soils. The sampler provided positive identification of target compounds and may be able to
detect lower concentrations of VOCs in the soil gas than the reference soil gas sampling method. The
results of the demonstration did not indicate consistent proportional comparability between the
EMFLUX® data and that of the reference method data. As with any technology selected, the user must
determine what is appropriate for the application and the project data quality objectives.
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Chapter 8
Technology Update
Empirical and Theoretical Bases for EMFLU>T System
Quadrel s EMFLUX® technology is based on the existence of cyclical periods of favorable (high) and
unfavorable (low) gas-migration velocities through the earth s crust and on the ability to predict the
occurrence of those cycles consistently and reliably. The existence of order-of-magnitude cyclical
changes in upward trace-gas velocity is predicated on empirical evidence; the utility of the EMFLUX®
system rests on a theoretical connection between that empirical data and earth-tidal (gravitational)
phenomena recorded by U.S. Geological Survey and National Aeronautics and Space Administration.
The relationship was developed in the early 1970s by Quadrel s Chief Scientist, George H. Milly, who
holds doctorates in Geochemistry and Atmospheric Physics. Identification of this relationship grew out
of Dr. Milly s search for the cause of observed cyclical variations in atmospheric concentrations of
radon, which all but negated attempts to use atmospheric radon as an indicator in uranium exploration.
Previously recognized factors influencing vertical trace-gas migration through soils (such as
temperature, barometric pressure, and moisture changes) failed to correlate with the recorded cyclical
variations, and this divergence ultimately led to the discovery of relationships between gravitational
phenomena and soil-gas migration rates. Subsequent development includes computerization of the
algorithms used to predict favorable soil-gas sampling periods. EMFLUX® was first used in the 1970s
to support uranium exploration programs and located more than 34 million pounds of uranium reserves.
Quadrel was founded in the late 1980s to commercialize applications of this fundamental technology in
the field of environmental testing. It is Quadrel s belief now—given available data, field verifications of
soil-gas-velocity predictions, and successes in governmental, industrial, and private projects—that the
company s predictive earth-tide model has established itself as a practical method for identifying
favorable emission flux periods at any point on the earth s surface. This capability has, in turn, spurred
development of an environmental field sampling system which can take advantage of the phenomenon:
the passive, noninvasive EMFLUX® Soil-Gas Investigation System.
Chapter 8 was written solely by Quadrel Services, Inc. The statements presented in this chapter
represent the vendor s point of view and summarize the claims made by the vendor regarding the
EMFLUX® system. Publication of this material does not represent the EPA s approval or
endorsement of the statements made in this chapter; results of the performance evaluation of the
EMFLUX® system are discussed in other chapters of this report.
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In 1989, the EMFLUX® system was first formally evaluated on a (now closed) U.S. EPA test bed
under the auspices of the National Environmental Technology Applications Center (NETAC). The
objective of the test was to determine EMFLUX s® ability to detect and quantify the relative source
strength of various contaminants in ground water. NETAC reported a 0.91 correlation coefficient
between EMFLUX® soil-gas data and groundwater contaminant concentrations and that EMFLUX®
correctly identified the dominant contaminant, chloroform. The most recent evaluation of the
technology is the subject of the present ETVR.
The ETV Demonstrations
The demonstrations described herein compared the passive EMFLUX%ystem with an active (reference
method) soil gas system, rather than with data from soil or water samples. This procedure unfortunately
leaves unresolved questions concerning the relative merits of the two systems, as no third source of
reference data is available to serve as an independent standard for comparison. When discrepancies
appear, it is impossible to determine which method is at fault. Nevertheless, the demonstration points
out a number of EMFLUX® system advantages.
• EMFLUX® field samplers are small, lightweight, and easy to install (requiring a depth of no more
than 3 inches).
• EMFLUX® field samplers can be rapidly deployed (demonstration results support a rate in excess of
100 per field person per day), making it possible to sample even large sites during favorable soil-gas
emission periods with minimal personnel and consequent savings in time and cost.
• The technology s low detection thresholds permit EMFLUX®users to identify subsurface
contamination at concentrations previously considered impossible, thus minimizing the risk of false
negatives.
• Although the active (reference) soil-gas method collected higher mean concentrations of vapor-
phase VOCs than EMFLUX®, the reference system failed, paradoxically, to pick up very low VOC
concentrations that EMFLUX® did detect. Such paradoxes may stem from the fact that the vacuum
system used in an active technique forcible extracts gases from a larger area than that sampled by a
passive device, but this characteristic does not denote superior sensitivity; on the contrary, it can
actually distort survey data.
• Because simultaneousEMFLUX® samples were taken continuously over several days, while the
reference system collected sequential samples, each during only a brief fraction of the total survey
period, Quadrel contends that the EMFLUX® data much more consistently—and much more
accurately—represent the degree and extent of subsurface contamination. Therefore,
Chapter 8 was written solely by Quadrel Services, Inc. The statements presented in this chapter
represent the vendor s point of view and summarize the claims made by the vendor regarding the
EMFLUX® system. Publication of this material does not represent the EPA s approval or
endorsement of the statements made in this chapter; results of the performance evaluation of the
EMFLUX® system are discussed in other chapters of this report.
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the demonstration s failure to show consistent proportional comparability between the EMFLUX® data
and that collected by the reference method would not only be predictable, but also highly probable.
It is to be emphasized that, while the EMFLUX® demonstrations conducted under the ETV program
involved sample analyses by an off-site laboratory affiliated with Quadrel, this is not an analytical
requirement. Although most users have historically employed Quadrel laboratories for sample analysis,
clients are free to contract with the qualified laboratory of their choice, provided that the facility has
high-temperature thermal-desorption capabilities as well as GC and flame ionization detector,
photoionization detector, ELCD, electron capture detector, or FPD detectors or GC/MS equipment.
Specific analytical protocols (identical or very similar to standard EPA methods) are available from
Quadrel for user organizations to determine whether in-house laboratories can successfully perform
EMFLUX® sample analysis. Approximately one-third of the sampler and sample analysis cost
component in Table 6-1 of the report is related to laboratory services.
Expanding Applications
In its ongoing efforts to find useful new applications for the EMFLUX Soil Gas detection system,
Quadrel has recently completed successful projects involving:
• • Detection of elemental mercury in the subsurface soils of industrial sites
• • Identification of methane-producing landfill cells, and subsequent calculation of annual methane
production levels
• • Detection of non-methane landfill gases (adsorptive and nonadsorptive)
• • Collection of target-gas emissions from soil to atmosphere as data for risk assessment studies
• • Extension of all-weather, all-terrain procedures.
Chapter 8 was written solely by Quadrel Services, Inc. The statements presented in this chapter
represent the vendor s point of view and summarize the claims made by the vendor regarding the
EMFLUX® system. Publication of this material does not represent the EPA s approval or
endorsement of the statements made in this chapter; results of the performance evaluation of the
EMFLUX® system are discussed in other chapters of this report.
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Chapter 9
Previous Deployment
The EMFLUX Soil-Gas Investigation System has been employed successfully on nearly 450 projects
by more than 190 user organizations on sites located in 47 U.S. states or territories and in several
foreign countries. The following illustrates the range of typical projects. Specific references are
available from the developer.
Western U.S. Air Force Base. More than 630 EMFLUX® collectors have been deployed at over 34
known or suspected release areas to date to determine hot spots and migration pathways of a full range
of VOC and lighter SVOC contaminants. EMFLUX results were later confirmed with follow-on
intrusive sampling. Periodic reports under this ongoing program are issued within 3 weeks of each
sampling event.
Mid-Atlantic U.S. Landfill Site. More than 150 EMFLUX® VOC samplers and 15 methane samplers
were deployed across a 15-acre landfill reportedly used in the past for unpermitted dumping of liquid
chemical solvents. The VOC samples were analyzed for a range of halogenated hydrocarbons, and
methane locations were sampled periodically with hand-held infrared instrumentation to determine the
methane generation rate from the landfill. EMFLUX results were used to assist in landfill closure
design and planning activities. The final report was received by the client 4 weeks after the start of
field work.
North Central U.S. Manufacturing Site. Nearly 450 EMFLUX® samplers were deployed in a two-
phase project at this site to determine potential emission rates of seven targeted halogenated compounds
for the purpose of finding "hot spots " of contamination and determining the lateral extent of
contaminant migration. Approximately half of the samplers were deployed through artificial caps.
Data indicated several areas of potential concern consistent with previous, limited, invasive sampling
values. The final reports, including extensive color isopleth mapping, were issued within 30 days of
completion of each phase of field work.
Southeastern U.S. Army Depot. More than 300 EMFLUX® collectors were used in a series of
investigations by the client of 16 subareas, including several chemical waste pits, equipment
Chapter 9 was written solely by Quadrel Services, Inc. The statements presented in this chapter
represent the vendor s point of view and summarize the claims made by the vendor regarding the
EMFLUX® system. Publication of this material does not represent the EPA s approval or
endorsement of the statements made in this chapter; results of the performance evaluation of the
EMFLUX® system are discussed in other chapters of this report.
45
-------
cleaning facilities, lagoons, and landfill areas, for the presence of various VOC and lighter SVOC
contaminants. Subsequent invasive sampling results to date have closely correlated with the EMFLUX
data. Analytical data began flowing to the client within 48 hours of completion of field sampling, with
the final reports delivered three weeks after the beginning of field work.
Southeastern U.S. Air Force Base. Approximately 2,000 EMFLUX® samplers were deployed to
investigate nine different sites at this base for VOC contamination involving analysis of the entire EPA
contract laboratory program (CLP) Target Compound List. The survey encompassed a series of
sampling events over a 2-month period, with working draft reports delivered immediately following
analysis of samples from each site. The final report was delivered within 10 working days of
completion of the final sampling event.
Western U.S. DOE National Laboratory. More than 280 EMFLUX® samplers were deployed across
10 sites on three operable units as an initial screening survey to assist in planning a follow-on drilling
program. Areas of study included landfills, burial pits, leach fields, drainage ditches, and trenches.
Target compounds included halogenated and petroleum-related compounds. The client s QA program
required full CLP data packages to be provided with 15 randomly chosen field samples to illustrate the
quality of analytical data. The final report was received by the client within 5 weeks of the beginning
of field work.
Northeastern U.S. Air Force Base. More than 180 EMFLUX® samplers were deployed on five
survey areas, including landfills, drainage ditches, and suspected disposal areas. Survey data were used
to assist in (1) the planning of a confirmatory drilling program, and (2) air contamination assessments.
All samples were analyzed for CLP Target Compound List contaminants. The final report was received
by the client 4 weeks after the beginning of field work.
Northeastern Airport Annex Site. Some 180 EMFLUX® samplers were deployed over 13 areas of
concern to assess the nature and extent of VOC contamination at several disposal areas, two leach
fields, several underground storage tank areas, and drainage ditches. All samples were analyzed for
the presence of CLP Target Compound List contaminants. The final report was received by the client
within 4 weeks of the beginning of field work.
Eastern U.S. DOE National Laboratory. More than 70 EMFLUX® samplers were deployed on and
in the vicinity of a mixed waste landfill in an effort to determine the presence of halogenated and
petroleum-related compounds through caliche soils. The final report was received by the client 4 weeks
after the beginning of field work.
North Central Abandoned Missile Site. More than 125 EMFLUX® collectors were used to determine
the presence and extent of soil and groundwater contamination at a former NIKE missile installation.
EMFLUX results identified the suspected contaminant locations. The final report was received by the
client 3 weeks from the beginning of field work.
Chapter 9 was written solely by Quadrel Services, Inc. The statements presented in this chapter
represent the vendor s point of view and summarize the claims made by the vendor regarding the
EMFLUX system. Publication of this material does not represent the EPA s approval or
endorsement of the statements made in this chapter; results of the performance evaluation of the
EMFLUX system are discussed in other chapters of this report.
46
-------
Southern U.S. Dry Cleaner Site. Six EMFLUX® samplers were installed in and around a dry-
cleaning establishment located in a strip mall to determine the presence and extent of subsurface PCE
and TCE contamination. Because of the shallow groundwater depth and because the entire site was in
the middle of a large asphalt cap (parking lot), valid results were obtained with only a 5-hour passive
exposure. Analytical results were provided to the client within 48 hours of sample retrieval, with the
formal report following 2 days later. Subsequent intrusive sampling confirmed the EMFLUX
findings.
Southwestern U.S. Air Force Base. More than 150 EMFLUX® collectors were used in two
associated surveys to track soil and groundwater contamination comprising selected VOCs and lighter
SVOCs from a suspected source facility at this base. The final report, including extensive color
isopleth maps, was issued 4 weeks after the start of field work.
North Central Manufacturing Site. More than 100 EMFLUX® collectors were deployed at five
discrete areas on this site, over 75 percent through asphalt and concrete, to determine the presence,
identity, and relative strength of a suite of targeted solvent and fuel-related contaminants in soil and
groundwater as part of the initial site characterization program. EMFLUX data indicated the presence
of a number of the targeted contaminants at several areas of concern on the site. The final report was
issued 2 weeks following the completion of field work.
Midwestern Abandoned Industrial Site. Nearly 150 EMFLUX® collectors were used to survey this
site for soil-gas emissions of a host of fuel and solvent-related contaminants. Survey results indicated
the presence of soil gas emission of several of the targeted compounds, confirming suspicions based on
a review of past practices at various subareas on the site. The report was issued to the client 14 days
following completion of the field work.
Mid-Atlantic U.S. Army Facility. More than 300 EMFLUX® collectors were deployed at various
areas of concern across a former disposal area, seeking to determine the presence of any of the full
range of VOC contamination. Sampling was conducted in a series of events over an extensive range of
terrain and weather conditions, including snow, ice, dry land, and marsh beds below several feet of
water. Several key halogenated and petroleum-based compounds were identified and tracked, and their
presence and locations were later confirmed with follow-on intrusive sampling. Reports were issued
within 3 weeks of the start of each sampling event.
Chapter 9 was written solely by Quadrel Services, Inc. The statements presented in this chapter
represent the vendor s point of view and summarize the claims made by the vendor regarding the
EMFLUX system. Publication of this material does not represent the EPA s approval or
endorsement of the statements made in this chapter; results of the performance evaluation of the
EMFLUX system are discussed in other chapters of this report.
47
-------
References
Ecology & Environment. 1996. 'Expanded Site Inspection for the Albert City, SB A Site, Albert
City, Iowa. " July.
Engineering-Science, Inc. 1991. "Remedial Investigation/Feasibility Report for the Chemical Sales
Company Superfund Site, OU1, Leyden Street Site. "
PRC Environmental Management, Inc. 1997. "Final Demonstration Plan for the Evaluation of Soil
Sampling and Soil Gas Sampling Technologies. "
Quadrel Services, Inc. 1997. Product Schematics.
Tetra Tech EM, Inc. 1997. "Soil and Soil Gas Technology Evaluation Report. "
U.S. Environmental Protection Agency (EPA). 1986. Test Methods for Evaluating Solid Waste.
SW-846. Third Edition.
48
-------
APPENDIX A
DATA SUMMARY TABLES
FOR THE
QUADREL SERVICES, INC.
EMFLUX® SOIL GAS INVESTIGATORY SYSTEM
A-l
-------
TABLE Al. VOLATILE ORGANIC COMPOUND CONCENTRATIONS
FOR QUADREL AND REFERENCE DATA
SBA SITE - GRID 1
Sample
Name
Sample
Location
Soil
Type
Contaminant Concentration (ng/L)
Vinyl Chloride
1,2-DCE
1,1-DCA | l,l,l-TCA
TCE
PCE
QUADREL SAMPLER DATA
1A2-QUADREL
1B3-QUADREL
1C6-QUADREL
1D1-QUADREL
1E1-QUADREL
1F5-QUADREL
1G7-QUADREL
Quantitation Limit
A2
B3
C6
Dl
El
F5
G7
-
Fine
Fine
Fine
Fine
Fine
Fine
Fine
-
97.3
104
0.54
1.72
1.39
23.7
0.19
0.17
720
958
21.8
533
411
475
16.0
0.09
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.11
0.11
0.11
0.11
0.11
0.11
0.11
0.11
9.56
16.2
2.00
5.19
3.06
8.09
0.69
0.12
0.28
0.28
0.28
0.28
0.28
0.28
0.28
0.28
Range:
Mean:
0.19- 104
38.0
16.0-958
520
0.10 0.11 0.69-16.3 0.28
0.10 0.11 7.35 0.28
REFERENCE SAMPLING METHOD DATA
ACTAG1A105.0
ACTAG1B605.0
ACTAG1C105.0
ACTAG1D605.0
ACTAG1E705.0
ACTAG1F405.0
ACTAG1G605.0
Al
B6
Cl
D6
E7
F4
G6
Fine
Fine
Fine
Fine
Fine
Fine
Fine
230,224
3,830,535
2,808,445
1,059,056
3,102,754
517,255
5,178,313
343,072
2,223,217
1,705,212
640,633
1,218,334
297,770
279,336
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
Range: 230,000-5,180,000
Mean: 2,390,000
279,000-2,220,000 50
958,000 50
50
50
50
50
Notes:
Quadrel Data: Quantitation limits are listed in the last row of the table.
Reference Data: Values reported as "50" are actually non-detects with a detection limit of 50 ng/L.
50
50
-------
TABLE A2. VOLATILE ORGANIC COMPOUND CONCENTRATIONS
FOR QUADREL AND REFERENCE DATA
SBA SITE - GRID 2
>
GO
Sample
Name
Sample
Location
Soil
Type
Contaminant Concentration (ng/L)
Vinyl Chloride
1,2-DCE
1,1-DCA
1,1,1-TCA| TCE
PCE
QUADREL SAMPLER DATA
2A3-QUADREL
2B7-QUADREL
2C6-QUADREL
2D1-QUADREL
2E3-QUADREL
2F7-QUADREL
2G5-QUADREL
Quantitation Limit
A3
B7
C6
Dl
E3
F7
G5
-
Fine
Fine
Fine
Fine
Fine
Fine
Fine
-
0.17
0.17
0.17
0.17
0.17
0.17
0.17
0.17
4.15
2.33
5.34
2.80
0.12
2.91
5.31
0.09
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.11
0.11
0.11
0.11
0.11
0.11
0.11
0.11
19.1
29.7
50.0
36.9
36.6
13.0
63.6
0.12
0.75
0.75
2.44
1.88
3.53
0.28
2.89
0.28
Notes:
Quadrel Data:
Reference Data:
Range:
Mean:
0.17 0.12-5.34 0.10
0.17 3.28 0.10
Range:
Mean:
100 50-151 50 50 183-5,380 50
100 65 50 50 1,250 50
0.11 13.0 - 63.6 0.28 - 3.53
0.11 35.6 1.79
REFERENCE SAMPLING METHOD DATA
ACTAG2A405.0
ACTAG2B605.0
ACTAG2C305.0
ACTAG2D205.0
ACTAG2E605.0
ACTAG2F505.0
ACTAG2G705.0
A4
B6
C3
D2
E6
F5
G7
Fine
Fine
Fine
Fine
Fine
Fine
Fine
100
100
100
100
100
100
100
50
50
50
151
50
58
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
491
560
508
5,378
323
1,283
183
50
50
50
50
50
50
50
Quantitation limits are listed in the last row of the table.
Values reported as "50" (or 100 for vinyl chloride) are actually non-detects with a detection limit of 50 ng/L
(or 100 ng/L for vinyl chloride).
-------
TABLE A3. VOLATILE ORGANIC COMPOUND CONCENTRATIONS
FOR QUADREL AND REFERENCE DATA
SBA SITE - GRID 4
Sample
Name
Sample
Location
Soil
Type
Contaminant Concentration (ng/L)
Vinyl Chloride
1,2-DCE
1,1-DCA
1,1,1-TCA| TCE
PCE
QUADREL SAMPLER DATA
4A7-QUADREL
4B6-QUADREL
4C4-QUADREL
4D3-QUADREL
4E6-QUADREL
4F4-QUADREL
4G1-QUADREL
Quantitation Limit
A7
B6
C4
D3
E6
F4
Gl
-
Fine
Fine
Fine
Fine
Fine
Fine
Fine
-
0.17
0.17
0.17
0.17
0.17
0.17
0.17
0.17
0.11
0.09
0.09
0.09
0.09
0.09
0.09
0.09
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.11
0.11
0.11
0.11
0.11
0.11
0.11
0.11
121
1.62
9.11
3.04
0.24
9.9
0.85
0.12
0.80
0.28
0.28
0.28
0.28
0.28
0.28
0.28
Range:
Mean:
0.17 0.09-0.11 0.10
0.17 0.09 0.10
0.11 0.24-121 0.28-0.80
0.11 20.8 0.35
REFERENCE SAMPLING METHOD DATA
ACTAG4A305.0
ACTAG4B505.0
ACTAG4C105.0
ACTAG4D205.0
ACTAG4E405.0
ACTAG4F305.0
ACTAG4G105.0
A3
B5
Cl
D2
E4
F3
Gl
Fine
Fine
Fine
Fine
Fine
Fine
Fine
100
100
100
100
100
100
100
50
195
261
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
3,429
14,259
33,558
744
1,088
3,330
9,295
50
50
50
50
50
50
50
Notes:
Quadrel Data:
Reference Data:
Range:
Mean:
100 50-261 50 50 744-33,600 50
100 101 50 50 9,390 50
Quantitation limits are listed in the last row of the table.
Values reported as "50" (or 100 for vinyl chloride) are actually non-detects with a detection limit of 50 ng/L
(or 100 ng/L for vinyl chloride).
-------
TABLE A4. VOLATILE ORGANIC COMPOUND CONCENTRATIONS
FOR QUADREL AND REFERENCE DATA
SBA SITE - GRID 5
>
en
Sample
Name
Sample
Location
Soil
Type
Contaminant Concentration (ng/L)
Vinyl Chloride
1,2-DCE
1,1-DCA
1,1,1-TCA| TCE
PCE
QUADREL SAMPLER DATA
5A7-QUADREL
5B4-QUADREL
5C4-QUADREL
5D7-QUADREL
5E3-QUADREL
5F5-QUADREL
5G1-QUADREL
Quantitation Limit
A7
B4
C4
D7
E3
F5
Gl
-
Fine
Fine
Fine
Fine
Fine
Fine
Fine
-
0.17
0.17
0.17
0.17
0.17
0.17
0.17
0.17
0.09
4.11
3.05
0.09
0.45
4.23
8.40
0.09
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.11
0.11
0.11
0.11
0.11
0.11
0.11
0.11
0.34
8.89
10.9
8.69
1.80
33.6
17.7
0.12
0.28
0.28
0.28
0.28
0.28
0.28
0.28
0.28
Notes:
Quadrel Data:
Reference Data:
Range:
Mean:
0.17 0.09-8.40 0.10
0.17 2.92 0.10
Range: 100-8,270 3,180-21,000 50
Mean: 1,980 9,980 50
0.11 0.34-33.6 0.28
0.11 11.7 0.28
REFERENCE SAMPLING METHOD DATA
ACTAG5A405.0
ACTAG5B605.0
ACTAG5C405.0
ACTAG5D705.0
ACTAG5E205.0
ACTAG5F705.0
ACTAG5G705.0
A4
B6
C4
D7
E2
F7
G7
Fine
Fine
Fine
Fine
Fine
Fine
Fine
100
275
100
8,265
100
4,889
100
5,544
4,773
8,745
17,865
3,175
21,028
8,734
50
50
50
50
50
50
50
50
50
50
50
50
50
50
355
1,222
545
6,253
132
2,710
2,867
50
50
50
50
50
50
50
50 132-6,250 50
50 2,010 50
Quantitation limits are listed in the last row of the table.
Values reported as "50" (or 100 for vinyl chloride) are actually non-detects with a detection limit of 50 ng/L
(or 100 ng/L for vinyl chloride).
-------
TABLE A5. VOLATILE ORGANIC COMPOUND CONCENTRATIONS
FOR QUADREL AND REFERENCE DATA
SBA SITE - GRID 6
Sample
Name
Sample
Location
Soil
Type
Contaminant Concentration (ng/L)
Vinyl Chloride
1,2-DCE
1,1-DCA|1,1,1-TCA| TCE
PCE
QUADREL SAMPLER DATA
6A6-QUADREL
6B4-QUADREL
6C5-QUADREL
6D2-QUADREL
6E1-QUADREL
6F2-QUADREL
6G4-QUADREL
Quantitation Limit
A6
B4
C5
D2
El
F2
G4
-
Fine
Fine
Fine
Fine
Fine
Fine
Fine
-
0.17
0.17
0.17
0.17
0.17
0.17
0.17
0.17
0.09
0.09
0.09
0.09
0.09
0.09
0.09
0.09
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.11
0.11
0.11
0.11
0.11
0.11
0.11
0.11
0.12
0.12
0.12
0.12
0.12
0.12
0.12
0.12
0.28
0.28
0.28
0.28
0.28
0.28
0.28
0.28
Range: 0.17 0.09 0.10 0.11 0.12 0.28
Mean: 0.17 0.09 0.10 0.11 0.12 0.28
REFERENCE SAMPLING METHOD DATA
REFERENCE SAMPLES NOT ANALYZED IN THIS GRID
Note:
Quadrel Data:
Quantitation limits are listed in the last row of the table.
-------
TABLE A6. VOLATILE ORGANIC COMPOUND CONCENTRATIONS
FOR QUADREL AND REFERENCE DATA
CSC SITE - GRID 1
Sample
Name
Sample
Location
Soil
Type
Contaminant Concentration (ng/L)
1,2-DCE
1,1-DCA
1,1,1-TCA
TCE
PCE
QUADREL SAMPLER DATA
1A7-QUADREL
1B1-QUADREL
1C5-QUADREL
1D1-QUADREL
1E7-QUADREL
1F4-QUADREL
1G1-QUADREL
Quantitation Limit
A7
Bl
C5
Dl
E7
F4
Gl
-
Coarse
Coarse
Coarse
Coarse
Coarse
Coarse
Coarse
-
19.7
30.5
30.4
79.9
157
49.2
41.1
0.10
0.11
1.69
6.69
6.04
4.19
5.29
4.64
0.11
550
350
615
629
918
592
680
0.12
647
162
1,294
274
1,955
1,602
65.7
0.12
47,133
2,357
36,356
6,692
53,291
54,831
3,589
0.30
19.7-157 0.11-6.69 350-918
Mean:
58.3
4.09
619
65.7- 1,960
857
2,360- 54,800
29,200
REFERENCE SAMPLING METHOD DATA
ACTCG1A505.0
ACTCG1B605.0
ACTCG1C405.0
ACTCG1D405.0
ACTCG1E205.0
ACTCG1F305.0
ACTCG1G605.0
A5
B6
C4
D4
E2
F3
G6
Coarse
Coarse
Coarse
Coarse
Coarse
Coarse
Coarse
7,242
2,255
21,311
12,637
19,039
6,246
6,683
500
500
500
500
500
500
500
7,526
170,724
670,474
411,390
478,451
225,933
236,256
26,349
7,450
77,382
44,031
54,857
14,739
67,632
249,342
79,017
769,940
438,473
480,887
117,979
170,967
Range: 2,260-21,300 500 7,530-670,0007,450-77,40079,000-770,000
Mean: 10,800 500 314,000 41,800 330,000
Notes:
Quadrel Data: Quantitation limits are listed in the last row of the table.
Reference Data: Values reported as "500" are actually non-detects with a detection limit of 500 ng/L.
-------
TABLE A7. VOLATILE ORGANIC COMPOUND CONCENTRATIONS
FOR QUADREL AND REFERENCE DATA
CSC SITE - GRID 2
>
00
Sample
Name
Sample
Location
Soil
Type
Contaminant Concentration (ng/L)
1,2-DCE
1,1-DCA
1,1,1-TCA
TCE
PCE
QUADREL SAMPLER DATA
2A2-QUADREL
2B1-QUADREL
2C6-QUADREL
2D2-QUADREL
2E5-QUADREL
2F4-QUADREL
2G3-QUADREL
Quantitation Limit
A2
Bl
C6
D2
E5
F4
G3
-
Coarse
Coarse
Coarse
Coarse
Coarse
Coarse
Coarse
-
2.50
2.67
2.73
9.91
2.40
2.25
0.78
0.10
0.45
0.52
0.62
1.17
0.43
0.50
0.15
0.11
259
256
118
127
232
242
186
0.12
153
133
173
224
172
200
36.0
0.12
752
776
1,953
1,113
2,001
2,629
338
0.30
0.78-9.91 0.15 - 1.17
Mean:
3.32
0.55
118- 259
203
36.0- 224
156
338- 2,630
1,370
REFERENCE SAMPLING METHOD DATA
ACTCG2A405.0
ACTCG2B405.0
ACTCG2C505.0
ACTCG2D405.0
ACTCG2E105.0
ACTCG2F205.0
ACTCG2G405.0
A4
B4
C5
D4
El
F2
G4
Coarse
Coarse
Coarse
Coarse
Coarse
Coarse
Coarse
500
500
942
1,708
2,694
2,827
3,780
500
500
500
500
500
500
500
33,875
138,681
219,486
353,483
413,456
415,093
439,087
11,353
42,596
76,171
99,223
123,487
119,787
153,683
31,950
101,902
201,050
222,623
288,770
287,739
427,089
Range: 500-3,780 500 33,900-439,00011,400-154,00032,000-427,000
Mean: 1,850 500 288,000 89,500 223,000
Notes:
Quadrel Data: Quantitation limits are listed in the last row of the table.
Reference Data: Values reported as "500" are actually non-detects with a detection limit of 500 ng/L.
-------
TABLE A8. VOLATILE ORGANIC COMPOUND CONCENTRATIONS
FOR QUADREL AND REFERENCE DATA
CSC SITE - GRID 4
Sample
Name
Sample
Location
Soil
Type
Contaminant Concentration (ng/L)
1,2-DCE
1,1-DCA
1,1,1-TCA
TCE
PCE
QUADREL SAMPLER DATA
4A3-QUADREL
4B2-QUADREL
4C7-QUADREL
4D2-QUADREL
4E1-QUADREL
4F4-QUADREL
4G6-QUADREL
Quantitation Limit
A3
B2
C7
D2
El
F4
G6
-
Coarse
Coarse
Coarse
Coarse
Coarse
Coarse
Coarse
-
1.92
3.59
1.86
1.38
0.47
6.52
2.34
0.10
0.31
0.64
0.53
0.27
0.13
1.34
0.43
0.11
65.6
167
141
32.8
24.9
261
111
0.12
8.03
21.1
5.82
4.24
2.55
46.0
10.5
0.12
344
586
378
166
142
863
345
0.30
Range: 0.47-6.520.13-1.34 24.9-261 2.55-46.0 142-863
Mean: 2.58 0.52 115 14.0 403
REFERENCE SAMPLING METHOD DATA
ACTCG4A405.0
ACTCG4B305.0
ACTCG4C105.0
ACTCG4D605.0
ACTCG4E405.0
ACTCG4F105.0
ACTCG4G305.0
A4
B3
Cl
D6
E4
Fl
G3
Coarse
Coarse
Coarse
Coarse
Coarse
Coarse
Coarse
7,008
500
6,882
3,964
10,513
6,650
7,823
500
500
500
500
500
500
500
168,233
19,627
162,682
115,537
216,980
123,393
184,170
20,043
1,881
21,872
15,855
41,798
21,178
32,812
143,142
20,753
152,164
129,093
388,861
194,826
313,472
Range: 500-10,500 500 19,600-217,0001,880-41,80020,800-389,000
Mean: 6,190 500 142,000 22,200 192,000
Notes:
Quadrel Data: Quantitation limits are listed in the last row of the table.
Reference Data: Values reported as "500" are actually non-detects with a detection limit of 500 ng/L.
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TABLE A9. VOLATILE ORGANIC COMPOUND CONCENTRATIONS
FOR QUADREL AND REFERENCE DATA
CSC SITE - GRID 5
o
Sample
Name
Sample
Location
Soil
Type
Contaminant Concentration (ng/L)
1,2-DCE
1,1-DCA
1,1,1-TCA
TCE
PCE
QUADREL SAMPLER DATA
5A7-QUADREL
5B5-QUADREL
5C7-QUADREL
5D2-QUADREL
5E3-QUADREL
5F3-QUADREL
5G4-QUADREL
Quantitation Limit
A7
B5
C7
D2
E3
F3
G4
-
Coarse
Coarse
Coarse
Coarse
Coarse
Coarse
Coarse
-
0.17
0.10
0.27
0.10
0.23
0.19
0.13
0.10
0.13
0.11
0.27
0.11
0.30
0.15
0.14
0.11
26.3
43.9
65.6
11.1
20.6
24.2
49.3
0.12
3.06
3.06
5.77
0.28
3.79
4.75
5.82
0.12
210
281
350
57.8
233
251
362
0.30
Notes:
Quadrel Data:
Reference Data:
Range: 0.10-0.270.11-0.30 11.1-65.6 0.28-5.82 57.8-362
Mean: 0.17 0.17 34.4 3.79 249
REFERENCE SAMPLING METHOD DATA
ACTCG5A105.0
ACTCG5D505.0
ACTCG5E405.0
ACTCG5F105.0
ACTCG5G705.0
Al
D5
E4
Fl
G7
Coarse
Coarse
Coarse
Coarse
Coarse
545
744
500
500
1,401
500
500
500
500
500
67,314
78,631
58,536
12,571
132,480
8,995
12,097
9,166
2,429
24,684
76,084
99,169
71,940
24,812
220,317
Range: 500-1,400 500 12,600-132,0002,430-24,70024,800-220,000
Mean: 738 500 69,900 11,500 98,500
Quantitation limits are listed in the last row of the table.
Values reported as "500" are actually non-detects with a detection limit of 500 ng/L.
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