&EPA
United States
Environmental Protection
Agency
Final Project Report for
the Development of an
Active Soil Gas
Sampling Method
RESEARCH AND DEVELOPMENT
-------
EPA/600/R-07/076
July 2007
www.epa.gov
Final Project Report for
the Development of an
Active Soil Gas
Sampling Method
EPA Contract #EP-C-05-061
Prepared for
Dr. Brian A. Schumacher, Task Order Manager
Office of Research and Development
National Exposure Research Laboratory
Environmental Sciences Division
Las Vegas, NV89119
Prepared by
Tetra Tech EM Inc.
1230 Columbia Street
Suite 1000
San Diego, CA92101
Notice: Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official
Agency policy. Mention of trade names and commercial products does not constitute endorsement or
recommendation for use.
U.S. Environmental Protection Agency
Office of Research and Development
Washington, DC 20460
-------
-------
Notice
The information in this document has been funded wholly by the United States Environmental Protection
Agency under EP-C-05-061 to Tetra Tech EM Inc. It has been subjected to the Agency's peer and
administrative review and has been approved for publication as an EPA document. Mention of trade
names or commercial products does not constitute endorsement or recommendation for use.
HI
-------
-------
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 EPA 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 scientific support that can be used to solve environmental
problems, build the scientific knowledge base needed to manage ecological resources wisely, understand
how pollutants affect public health, and prevent or reduce environmental risks.
The National Exposure Research Laboratory (NERL) is the Agency's center for 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 scientific support needed to ensure effective implementation of environmental regulations and
strategies.
Tetra Tech EM Inc. prepared this Project Report for NERL to document the results of an investigation
into the effects of purge rate, purge volume, and sample volume on soil gas sample results. Field work for
this investigation was conducted during October 2006 at Vandenberg Air Force Base (AFB) Installation
Restoration Program (IRP) Site 15. Vandenberg AFB is home to the U.S. Air Force Western Missile Test
Range and is headquarters for the 30th Space Wing, which manages Department of Defense space and
missile testing, and placing satellites into polar orbit from the West Coast. The Vandenberg AFB IRP,
overseen by Mr. Michael McElligott, supported this project by providing access to IRP Site 15 to conduct
the testing, facilitating and expediting dig permit reviews, and providing logistical support during the
field sampling activities.
-------
VI
-------
Executive Summary
Tetra Tech EM, Inc. was contracted by the U.S. Environmental Protection Agency (EPA) to
quantitatively assess the effect of sampling procedures on soil gas sample results. Specifically, this
investigation was designed to assess the effect of purge rate, purge volume, and sample volume (the
principal parameters) on soil gas results and to develop technically defensible values or ranges of values
for these parameters that can be incorporated into active soil gas sampling guidance.
A number of research groups and local, state, and federal agencies have developed guidance concerning
sampling and analytical protocols for active soil gas measurements with the overall objective of
facilitating a technically correct approach for site investigations. However, the various guidance
documents often omit prescribed ranges for the principal parameters, or if prescribed, lack a quantitative
basis for the recommended parameter settings. This investigation was designed to evaluate the principal
parameters over the range of values commonly cited in guidance documents and provide defensible
recommendations for parameter settings.
The experiments were conducted at Installation Restoration Program (IRP) Site 15 on Vandenberg Air
Force Base (AFB). To provide data for this investigation, an array of 15 soil vapor sampling probes was
deployed at IRP Site 15 above the larger of two plumes of trichloroethylene (TCE) in the groundwater.
Three experiments were conducted for this investigation. The first consisted of collecting soil gas samples
using purge rates ranging from 100 to 2,000 milliliters per minute (ml/min) while holding the purge
volume and sample volume constant at 3 system volumes and 60 ml, respectively. The second consisted
of collecting soil gas samples after purging 1 to 100 system volumes from the probes, while holding the
purge rate and sample volume'constant at 200 ml/min and 60 ml. The third experiment consisted of
collecting samples with volumes ranging from 25 to 6,000 ml, while holding the purge rate constant at
200 ml/min.
The results of the purge rate experiment show a pronounced increase in the measured TCE concentration
at purge rates of 100 ml/min to 200 ml/min followed by a modest trend of increasing measured
concentrations with increasing purge rate. However, the observed variability in measured volatile organic
compound (VOC) concentrations would not generally be considered significant from a site
characterization or vapor intrusion perspective. Based on the data from this investigation, it appears that
purge rates of 200 to 500 ml/min should be recommended.
The results from the purge volume experiment indicate there was a statistically significant positive
correlation between the measured TCE concentrations and purge volume, with concentrations typically
more than doubling over the range of purge volumes tested. The effect of purge volume on the measured
VOC concentrations was more pronounced than the effect of purge rate; however, this variability may not
be significant in terms of site characterization. The data indicate that varying purge volume from 1 to 5
system volumes has relatively little effect on the sample results; however, increasing purge volume above
5 system volumes appears to result in somewhat higher measured TCE concentrations. These
experimental data suggest that purge volumes of 2 to 5 system volumes are most appropriate.
Measured TCE concentrations were observed to increase with increasing sample volume from 25 to 1,000
ml, but then drop off in the 6,000 ml samples. This observation is significant as the 6,000 ml sample size
is commonly used to achieve very low detection levels with EPA method TO-15; however, the drop in
measured TCE concentrations at a 6,000 ml sample volume suggests that the low detection levels
achievable with large sample size may need to be balanced against the risk of over-purging. Based on the
VII
-------
data obtained from this investigation, it appears that a sample volume of 1,000 ml should be
recommended, as this volume resulted in the highest measured TCE concentrations.
vni
-------
Contents
Section Page
Notice iii
Foreword '. v
Executive Summary vii
List of Acronyms and Abbreviations xiii
1.0 Introduction 1-1
2.0 Background, Scope, and Methods 2-1
2.1 Experimental Design 2-1
2.2 IRP Site 15 Setting and Background 2-1
2.2.1 IRP Site 15 History 2-1
2.2.2 Geology and Hydrogeology 2-4
2.2.3 Chlorinated Solvent Plume Conditions 2-4
2.2.4 Selection of Site 15 2-6
2.3 Soil Gas Probe Array 2-6
2.4 Sample Collection 2-8
2.5 Mobile Laboratory 2-12
2.5.1 Analytical Method 2-12
2.5.2 Equipment 2-12
2.5.3 Detection Limits 2-12
2.6 Quality Assurance/Quality Control 2-13
2.6.1 Field Quality Control Protocols 2-13
2.6.2 Laboratory Quality Control Protocols 2-14
2.6.2.1 Laboratory Data Logs 2-14
2.6.2.2 Instrument Calibration 2-14
2.6.2.3 Blanks -. 2-14
2.6.2.4 Laboratory Duplicates 2-14
2.6.3 Project QAPP Deviations and Additions 2-14
IX
-------
Contents (Continued)
Section Page
3.0 Experimental Procedures 3-1
3.1 Summary of Experimental Approach 3-1
3.2 Principal Parameter Ranges .'. 3-1
3.3 Sample Summary 3-9
3.4 Data Evaluation and Quality Control 3-10
4.0 Results and Discussion 4-1
4.1 Statistical Analyses 4-1
4.1.1 Sample Numbers and Parameter Settings -. 4-1
4.1.1.1 Purge Rate 4-1
4.1.1.2 Purge Volume 4-1
4.1.1.3 Sample Volume 4-1
4.1.2 Statistical Approach 4-2
4.1.2.1 Baseline Measurements 4-2
4.2 Experimental Results 4-4
4.2.1 Temporal Control 4-4
4.2.2 Purge Rate Experiment 4-5
4.2.3 Purge Volume Experiment 4-7
4.2.4 Sample Volume Experiment 4-10
5.0 Conclusions 5-1
6.0 Recommendations 6-1
7.0 References 7-1
Appendices
Appendix A Literature Review
Appendix B Sampling Trip Report
Appendix C Laboratory Data Package
Appendix D Statistical Analyses
Appendix E Active Soil Gas Sampling Method
-------
Contents (Continued)
Figures Page
2-1 Location of IRP Site 15, Vandenberg Air Force Base, California 2-2
2-2 IRP Site 15, Site Plan and Groundwater Contours, October 2005 .2-3
2-3 IRP Site 15, TCE Concentrations in Groundwater, November 2005 2-5
2-4 IRP Site 15, Location of Existing Soil Gas Sampling Probe Array 2-7
2-5 IRP Site 15, Soil Gas Probe Construction Schematic 2-9
4-1 Summary of Parameter Settings for Samples Collected During the Sample Volume
Experiment 4-2
4-2 Plot of Baseline Concentrations by Probe 4-3
4-3 Effect of Baseline Concentrations on Variance in TCE Concentrations From Purge Volume
Experiment 4-4
4-4 TCE Concentrations Measured in Temporal Control Samples 4-5
4-5 Linear Plot of Purge Rate Experiment Data 4-6
4-6 Effect of Purge Rate on Measured Soil Gas Concentrations 4-7
4-7 Linear Plot of Purge Volume Experiment Data 4-8
4-8 Effect of the Number of System Volumes Purged on Measured Soil Gas Concentrations 4-9
4-9 Linear Plot of Sample Volume Experiment Data 4-11
4-10 Plot of TCE Concentrations From the Purge Volume and Sample Volume Experiments vs.
Total Volume of Gas Removed on a Log Scale 4-12
4-11 Graphical Representation of the Results of the Newman-Kuels Multiple Range Test 4-13
Tables
2-1 Soil Gas Probe Installation Details 2-10
2-2 Baseline Sampling Round Results 2-11
2-3 Temporal Control Sample Results 2-13
3-1 Purge Rate Experiment Sample Summary, 16 October 2006 3-2
3-2 Purge Volume Experiment Sample Summary, 17 October 2006 3-5
3-3 Sample Volume Experiment Sample Summary, 18 October 2006 3-7
3-4 Field Replicate Summary 3-12
3-5 Laboratory Duplicate Summary 3-12
XI
-------
Xll
-------
List of Acronyms and Abbreviations
ABRES
ABS
AFB
ANCOVA
API
ASTM
bgs
Cal/EPA
DCE
DISC
Earth Tech
BCD
EPA
GC
HPMG
InterPhase
IPA
IRP
ITRC
LARWQCB
LOX
pg/m3
Pg/L
ml
ml/min
MO-DNR
MS
msl
NERL
NJ-DEP
NRMRL
NY-DOH
ORD
P1D
QA
QAPP
QC
RI
RP-1
RPD
RPM
SAIC
Shaw
Tetra Tech EMI
TCE
VOC
Advanced Ballistics Re-Entry System
Acrylonitrile butadiene styrene
Air Force Base
Analysis of covariance
American Petroleum Institute
American Society for Testing and Materials
Below ground surface
California Environmental Protection Agency
Dichloroethene
Department of Toxic Substances Control
Earth Tech, Inc.
Electron capture detector
U.S. Environmental Protection Agency
Gas chromatograph
H&P Mobile Geochemistry
InterPhase Environmental, Inc.
Isopropyl alcohol
Installation Restoration Program
Interstate Technology and Regulatory Council
California Regional Water Quality Control Board, Los Angeles Region
Liquid oxygen
Micrograms per cubic meter
Micrograms per liter
Milliliter
Milliliters per minute
Missouri Department of Natural Resources
Mass spectrometry
Mean sea level
National Exposure Research Laboratory
New Jersey Department of Environmental Protection
National Risk Management Research Laboratory
New York State Department of Health
Office of Research and Development
Photoionization detector
Quality Assurance
Quality assurance project plan
Quality Control
Remedial investigation
Rocket Propellant No. 1
Relative percent difference
Remedial project manager
Science Applications International Corporation
Shaw Environmental, Inc.
Tetra Tech, EM Incorporated
Trichloroethene
Volatile organic compound
Xlll
-------
XIV
-------
1.0 Introduction
Soil gas data are widely used in site investigation and remediation projects to delineate volatile organic
compound (VOC) vapor plumes, as a screening tool to refine soil and groundwater sampling efforts, to
track the progress of soil remediation, and to identify potential risks from the inhalation of indoor air
potentially contaminated by soil gas. The overall goal of any monitoring or sampling program is to enable
the collection of representative samples; that is, samples that are representative of the environmental,
chemical, and physical conditions present during the time of sample collection. Over a period of time,
collection of a sequence of representative samples can enable a better understanding of trends in the data
set regarding the fate and transport of the chemicals being monitored. However, due to numerous
environmental as well as sampling and analytical variables, the representativeness of a sample can often
be compromised, the degree to which is often not well understood or quantified.
Tetra Tech EM, Inc. (Tetra Tech) was contracted by the U.S. Environmental Protection Agency (EPA) to
quantitatively assess the effect of sampling procedures on soil gas sample results. Specifically, this
investigation was designed to assess the effect of purge rate, purge volume, and sample volume on soil
gas results and to develop technically defensible values, or ranges of values for these parameters that can
be incorporated into active soil gas sampling guidance. These three parameters (purge rate, purge volume,
and sample volume) are referred to throughout this report as the "principal parameters."
A number of research groups and local, state, and federal agencies have developed guidance concerning
sampling and analytical protocols for active soil gas measurements with the overall objective of
facilitating a technically correct approach for site investigations. The first step in developing the
experimental approach for this investigation was to review the existing soil gas sampling guidance
available from the regulatory community and other agencies. Guidance was reviewed from a variety of
sources including the American Petroleum Institute (API); American Society for Testing and Materials
(ASTM); California Environmental Protection Agency (Cal/EPA), Department of Toxic Substances
Control (DTSC) and California Regional Water Quality Control Board, Los Angeles Region
(LARWQCB); Interstate Technology and Regulatory Council (ITRC); Missouri Department of Natural
Resources (MO-DNR); New Jersey Department of Environmental Protection (NJ-DEP); New York State
Department of Health (NY-DOH); and the U.S. EPA. The Literature Review report is provided in
Appendix A, and the findings of the literature are summarized briefly below.
The general consensus of guidance documents reviewed for this investigation is that purge rates should be
minimized to limit potential short-circuiting of the sampling system (introduction of atmospheric air) and
to reduce the potential for desorption. Specific recommendations range from 100 to 200 milliliters per
minute (ml/min) (e.g., DTSC/LARWQCB 2003, MO-DNR 2005, NJ-DEP 2005, NY-DOH 2005, ITRC
2007) to 1,000 ml/min (e.g., API 2005, EPA 2006).
The guidance documents generally recommend that purge volume be minimized to increase the likelihood
that the collected sample is representative of conditions immediately surrounding the sampling probe and
to reduce the potential of short-circuiting the sampling system. However, few of the documents provide
specific recommendations for purge volumes. DTSC/LARWQCB (2003) guidance stipulates that a step
purge test be conducted by collecting samples after one, three, and seven dead-volumes have been purged.
MO-DNR (2005) and NJ-DEP (2005) recommend three volumes be purged prior to sampling. Health
Canada (2004), recommends two to three volumes and NY-DOH (2005) recommends one to three dead
volumes.
The guidance documents reviewed for this investigation provide few recommendations regarding sample
volume beyond concerns related to detection levels. There appears to be some consensus that within the
constraints imposed by analytical requirements, sample volume should be minimized for the same reasons
1-1
-------
that purge volume should be minimized. Common sample volumes cited range from 10 to 50 milliliters
(ml) collected in glass bulbs or gas-tight syringes and from 1 to 6 liters in Summa canisters for TO-
14/TO-15 analyses.
1-2
-------
2.0 Background, Scope, and Methods
2.1 Experimental Design
The concentrations of VOCs measured in soil gas samples are a function of a number of variables,
including soil properties, proximity of and magnitude of the VOC source area(s), type of sampling point,
sample collection procedures, and analytical method. The objective of this project was to.assess the nature
and magnitude of the effect on soil gas sample results of varying three principal parameters (purge rate,
purge volume, and sample volume) during sample collection. In order to achieve the project objective, it
was necessary to eliminate and/or reduce, to the extent possible, all other variables. Therefore, the overall
approach of the project consisted of the following primary elements:
• Identify a site with a known VOC contaminant plume at moderate to shallow depths and
with "homogeneous" soil conditions;
• Install an array of similarly constructed soil gas probes from which multiple samples
could be collected;
• Collect a series of soil gas samples from the probe array while varying one of the
principal parameter settings, and holding all other variables constant;
• Collect a series of soil gas samples without varying any principal parameters from a
single soil gas control probe; and
• Analyze all of the samples under identical analytical conditions.
These conditions allow the effects of varying the principal parameters to be largely isolated from other
variables and provide a data set with which to assess the effects of the principal parameters on sample
results.
2.2 IRP Site 15 Setting and Background
The site selected for this research project was Vandenberg AFB, IRP Site 15. Vandenberg is located on
the Central Coast of California, approximately 120 miles west-northwest of Los Angeles and 225 miles
southeast of San Francisco. IRP Site 15 is located approximately 1.5 miles from the Pacific Ocean and
1,300 feet north of San Antonio Creek on north Vandenberg AFB (Figure 2-1). The site is on the
southwest side of Umbra Road and comprises three former Atlas missile launch pads and two launch-
support buildings (Figure 2-2). The support buildings are the launch control center and a water pumping
station. The site was known as the Advanced Ballistic Re-Entry System (ABRES)-B Launch Complex.
Tetra Tech has been investigating Site 15 under the Vandenberg AFB IRP since 1993. Currently, Terra
Tech is conducting quarterly groundwater monitoring of 19 on-site monitoring wells.
2.2.1 IRP Site 15 History
The ABRES-B complex was constructed in 1959 to launch Atlas missiles. The complex comprises three
nearly identical launch pads, each of which consists of a concrete gantry foundation, flame bucket, deluge
water channel, and miscellaneous appurtenances. The launch pads are identified as Pad 1, Pad 2, and Pad
3, and the corresponding deluge water channels are identified as Channel A, Channel B, and Channel C,
respectively (Figure 2-2). The area selected for this project is adjacent to Pad I/Channel A. A total of 63
Atlas missiles were launched from the complex between 1960 and 1967, 14 of these were launched from
2-1
-------
PACIFIC
OCEAN
UNITED STATES AIR FORCE
VANDENBERG AIR FORCE BASE
LOCATION OF IRP SITE 15
VANDENBERG AIR FORCE BASE,
CALIFORNIA
TETRA TECH EM, INC.
1230 Columbia Street, Suite 1000
San Diego, CA9210I
T =opprox 15.000ft
Figure 2-1. Location of IRP Site 15, Vandenberg Air Force Base, California
2-2
-------
s
•d
I
I
O
o
I
I
LEGEND
CONTOUR or GROUND sum ACL
/•**\ ElfVATIOIt M fEET ABOVE MSI
(S FOOT M1ERVUS) (»*VD 19S6)
—»— FWCF
-------
Pad 1. The Atlas missile used a combination of Rocket Propellant No. 1 (RP-1), a kerosene-based fuel,
and liquid oxygen (LOX) as an bxidizer. Prior to fuel loading, the missiles were flushed with 150 to 180
gallons of trichloroethylene (TCE) for degreasing purposes. Much of the TCE used for engine flushing is
believed to have been vaporized during the subsequent launches; however, TCE that did not evaporate
may have been washed to grade with deluge water used for sound and heat suppression during launches.
During launches, deluge water that did not flash to steam flowed down the deluge water channels to
concrete lined retention basins, from which it was released to grade. Significant concentrations of TCE
have been detected in groundwater at IRP Site 15, arid the source is believed to be the pre-launch engine
degreasing followed by transport with deluge water to grade.
Initial subsurface investigations of Site 15 were conducted in the late 1970's by Leroy Crandall and
Associates and continued at various portions of the site with Battelle Corporation (1986), Science
Applications International Corporation (SAIC) (1990), the Bureau of Reclamation (1994a, b), Jacobs
Engineering Group (1993, 1998) and Shaw Environmental, Inc. (Shaw). The investigation findings are
presented in the Final Remedial Investigation Report, IRP Site 15 (Shaw 2004).
In 2005, Earth Tech, Inc. (Earth Tech) completed a supplemental remedial investigation (RI) of
groundwater beneath the Channel A and Channel B source areas using a membrane interface probe and
confirmation sampling. The supplemental RI included further characterization of the leading edges of the
chlorinated solvent plumes with the installation of four pairs of shallow and deep monitoring wells to
supplement the existing well array. The information regarding Earth Tech's supplemental RI was
presented during quarterly IRP Remedial Project Manager (RPM) meetings at Vandenberg AFB, which
Tetra Tech attends as a Vandenberg AFB IRP contractor. To date, Earth Tech's supplemental RI report
has not been made public and no formal citation is available.
2.2.2 Geology and Hydrogeology
Sediments at IRP Site 15 consist of highly uniform dune sand overlying Sisquoc Formation clayey
diatomite and siliceous shale (Dibblee 1989). The sands have low moisture content and very low organic
carbon.
Site 15 is located on the western portion of the San Antonio Creek Groundwater Basin. Groundwater at
the site exists within the unconsolidated dune sands. Groundwater levels measured in October 2005
indicate the groundwater elevation ranged from approximately 21 to 77 feet above, mean sea level (msl) or
6 to 38 feet below ground surface (bgs). During October 2005, the interpreted direction of groundwater
flow was to the southwest toward San Antonio Creek with an average hydraulic gradient of 0.01 feet per
foot (Figure 2-2). The interpreted direction of groundwater flow beneath the site appears to correlate with
the slope of bedrock topography.
Surface water at Site 15 consists of seasonal and perennial areas of standing water and storm water runoff.
In the past, deluge water releases were also part of the surface water at this site. A seasonal area of
standing water is located approximately 1,400 feet west of Pad 1. A perennial area of standing water is
located approximately 200 feet southeast of Pad 3. Storm water runoff rapidly infiltrates site soils or
collects in channels that direct flow toward the San Antonio Creek floodplain.
2.2.3 Chlorinated Solvent Plume Conditions
Two distinct chlorinated solvent plumes have been identified in groundwater at Site 15. A relatively small
plume is associated with Pad 2/Channel B and is located to the south of the study area (Figure 2-3). A
larger plume is associated with Pad I/Channel A (Figure 2-3), where this study was conducted. The larger
2-4
-------
LEGEND
CONTOUR Of GROUND SURFACE
/**\ ElfVAHOH M FEET ABO« MS.
(5-FOOT INTERVALS) (NAVD 198!)
—i— FENCE
- ..... '•"» PAVED ROAO OR S1REET
------ OBI ROAD
Hi BULDING
CONCRETE OR PAVED AREAS
VEGETATION Lit
----- UNUNED.DRAHAGE ROUTE
-A-lb-w-fGROUMWATER MONITORING MIL KITH
T '» ICE CONCENTRATION («A) MEASURED
IN NOWrBER 2005
--- — STE BOUNDARY
— 5— EXTCNT OF TCE IN juA (DASHED «HER[
INFERRED)
300' 600' 900'
SCALE
UNITED STATES AIR FORCE
VANDENBERG AIR FORCE BASE
IRP SITE 15
TCE CONCENTRATIONS IN GROUNDWATER
NOVEMBER 2005
TETRATECHEM.INC.
IJSOColumba SUM. Sute 1000
MTE
2/l/W
nuwr
PBCHAHO
TA814
TUBIS
MM.
6093
2-3
-------
plume is located to the northwest of Pad 1 and consists primarily of TCE and cw-l,2-dichloroethene
(DCE), with minor concentrations of trans-l,2-DCE. The source of this plume is likely the discharge
point of Channel A. The maximum TCE and cis-l,2-DCE concentrations detected in this groundwater
plume were 10,000 and 29 micrograms per liter (ug/L), respectively, in October 2005.
A soil vapor plume associated with the larger groundwater plume was identified during this investigation.
The only VOC detected in soil vapor during this study was TCE, at concentrations ranging from roughly
100 to 3,500 micrograms per cubic meter (pg/m3); however, it should be noted that no attempt was made
through this study to assess the extent of the TCE vapor plume.
2.2.4 Selection of Site 15
The purpose of this investigation was to assess the impact of the principal parameters (purge rate, purge
volume, and sample volume) on soil gas sample results. In order to effectively accomplish this task, it
was important to isolate the principal parameters to the extent possible, and hold all other potential
variables stable. Site 15 was selected as a suitable location because it provides a study area with a
previously characterized chlorinated solvent groundwater plume in highly permeable, relatively
homogenous subsurface sediments and underlying a relatively flat surface area. Thus, the sampling was
not expected to be impacted by significant variations in the depth to the contaminant plume, or variations
in subsurface stratigraphy.
2.3 Soil Gas Probe Array
The following paragraphs summarize the installation of the soil gas probe array at IRP Site 15. Details of
the drilling and probe installation activities are presented.in the Sampling Trip Report (Appendix B).
An array of soil gas sampling probes was installed at IRP Site 15 from October 10 through October 12,
2006. The probes were installed in a geometric grid consisting of three rows of five probes (Figure 2-4).
The probes were designated 15-SV-A1 through 15-SV-A5, 15-SV-B1 through 15-SV-B5, and 15-SV-C2
through 15-SV-C6. Each probe was set approximately 2 to 4 feet above the water table. In order to
minimize variations in the depth of the probes relative to ground surface, the rows of probes were oriented
northwest-southeast, parallel with the orientation of the sand dunes.
The sampling probes were installed in pilot holes drilled using a 6610DT GeoProbe direct push rig
equipped with 2.5-inch outside-diameter drill rods and operated by InterPhase Environmental, Inc.
(InterPhase). The 6610DT is mounted on tracks and was chosen for this project due its maneuverability
on sand dunes, where traditional two- or four-wheel-drive trucks are not practical. After identifying the
final grid location, five probes for row A were installed on October 11 and 12 with a spacing of 40 feet
between each probe along a bearing of N50°W. Rows B and C were completed on October 12 along the
same bearing and with the same spacing as row A. Row B is located 100 feet south-southwest of row A.
Row C is located 40 feet north-northeast of row A and is offset by 40 feet to the southeast. Figure 2-4
presents the location and orientation of the soil gas probe array.
Most pilot holes were advanced to the planned depth of between 14 and 19 feet bgs so that the sampling
probes could be positioned at the target distance of 2 to 4 feet above the groundwater table. One probe
location within each row (15-SV-A1, 15-SV-B3, and 15-SV-C5) was continuously cored using acetate
sleeves in order to observe the lithology and confirm its uniformity in relation to the other probe
locations. Pilot holes for probes 15-S-A1, 15-SV-B3, and 15-SV-C5 were drilled to depths of 24, 24, and
22 feet bgs, respectively, and then backfilled with #2/12 sand to the planned probe depth of between 14
and 19 feet bgs. Soils encountered in these three borings were predominantly fine grained, poorly graded,
2-6
-------
.
TO
C
o
o
3
O
•^s
x_
«'
a
O
5
x
B
"2.
I
"0
3
sr
l£ffijfi
/-\
CONTOUR OF GROUND SURFACE
EL.EVAHON N FEET ABOVE MSL
(5-FOOT INTERVALS) (NAVD 1988)
FENCE
PAVED MAD OR STREET
DDT ROAD
HUH
| | CONCRETE OR PAVED AREAS
VEGETATION LINE
nmn GROUNOHATEI! UONTONNC KU
15-sv-o SOU GAS SAMPLING GAD PONT
(INSTALLED OCTOBER J006)
50' 100' 150'
SCALE
UNITED STATES AIR FORCE
VANOENBERG AIR FORCE BASE
IRP SITE 15
LOCATION OF EXISTING SOIL. GAS
SAMPLING PROBE ARRAY
\\
TETRATECHEMJNC.
IUOC<*«nteSot«i.S
-------
subangular, slightly moist dune sands. In boring 15-SV-C5, clayey sand was encountered at 17.5 feet bgs
and Sisquoc Formation shale bedrock was encountered at 20 feet bgs. It is very common in this part of
Vandenberg AFB to encounter clayey soils immediately above the shale bedrock, and these clay horizons
are interpreted as a weathering surface on the bedrock. In boring 15-SV-B3, clayey sand was encountered
at 23.5 feet bgs. This boring was terminated before bedrock was encountered, but the clayey sand is
interpreted as weathered bedrock. Groundwater was encountered at 21 feet bgs in boring 15-SV-B3.
Groundwater was not encountered in either of the other two borings.
Sampling probes were constructed as follows. Approximately 4 inches of #2/12 sand was poured into the
bottom of the pilot holes. A 1-inch long gas-permeable membrane sampling probe, attached to 1/4-inch
Nylaflow tubing, was then lowered through the drill rod to the top of the #2/12 sand. Additional #2/12
sand was then poured around the sampling probe until it extended approximately 2 inches above the
membrane to form a sandpack around the sample point. Approximately 12 inches of dry bentonite was
then placed on top of the sandpack, followed by hydrated bentonite to the surface. During the probe
construction, the drill rod was removed slowly from the pilot hole to avoid sloughing of the sandy soils.
The sampling probes were completed at the surface with approximately 18 inches of Nylaflow tubing
extending out of the ground and a Swagelok valve was inserted into the end of the tubing. The surface
completions were protected with 3-inch diameter acrylonitrile butadiene styrene (ABS) plastic pipes
driven a few feet into the ground and then fitted with slip-cap covers. Pilot holes that were drilled deeper
than the intended probe installation depth were backfilled with #2/12 sand to the target probe depth. In
these borings, the height of the sandpack was recorded from the bottom of the boring to a depth
approximately 2 inches above the soil gas probe. Details of the probe installations are summarized in
Table 2-1 and a schematic diagram of the probe construction is provided in Figure 2-5.
2.4 Sample Collection
Based on the results of the literature review (Appendix A), baseline sampling procedures were established
for the investigation. The baseline sampling procedures are considered typical, or industry standard
procedures. The baseline principal parameter settings were as follows:
• Purge Rate: 200 ml/min
• Purge Volume: 3 system volumes
• Sample Volume: 60 ml (equivalent to disposable syringe volume; see Section 2.7.3)
A system volume was considered the volume of the 1/4-inch Nylaflow tubing plus the volume of the
probe. The tubing volume was estimated as 4 ml per foot of tubing. Calculated system volumes for each
probe are shown in Table 2-1.
2-8
-------
2-WAY
SWAGELOK
VALVE
-\
\
\*fO
CrO
1/4 \NCH -\
NYLAFLOW \
TUBING x
TO
SURFACE
MINIMUM
1FOOT
MINIMUM
6 INCHES
•L
PUMP
3-WAY
SWAGELOK
VALVE
Ml
SYRINGE
-HYDRATED
GRANULAR
BENTONITE
-DRY GRANULAR
BENTONITE
-GAS PERMEABLE
MEMBRANE
#2/12 SAND
PACK
-PUMPUSED FOR
HIGH VOLUME/
HIGH RATE
PURGING ONLY
IRPSITE15
SOIL GAS PROBE
CONSTRUCTION SCHEMATIC
TetraTech EM, Inc.
1230 Columbia Street, Suite 1000
San Diego, CA 92101
TASK NO.
18061-04
DATE
2/6/07
DRAWN BY
PRICHARD
6095
2-5
Figure 2-5. IRP Site IS, Soil Gas Probe Construction Schematic
2-9
-------
Table 2-1
Soil Gas Probe Installation Details
Vandenberg AFB, IRP Site 15
Development of Active Soil Gas Sampling Method
Location
15-SV-A1
15-SV-A2
15-SV-A3
15-SV-A4
15-SV-A5
15-SV-B1
15-SV-B2
15-SV-B3
15-SV-B4
15-SV-B5
15-SV-C2
15-SV-C3
15-SV-C4
15-SV-C5
15-SV-C6
15-SV-C4HP
Installation
Date
11-Oct-06
11-Oct-06
12-Oct-06
12-Oct-06
12-Oct-06
12-Oct-06
12-Oct-06
12-0ct-06
12-Oct-06
12-Oct-06
12-0ct-06
12-Oct-06
12-Oct-06
12-Oct-06
12-Oct-06
17-Oct-06
Latitude
34.79330957
34.79325593
34.79318619
34.79313254
34.79306817
34.79308963
34.79301453
34.79296088
34.79289115
34.79283214
34.79336321
34.79328275
34.79322374
34.79315400
34.79308963
34.79322374
Longitude
-120.6015641
-120.6014622
-120.6013549
-120.6012423
-120.6011296
-120.6017573
-120.6016553
-120.6015534
-120.6014461
-120.6013388
-120.6013764
-120.6012691
-120.6011564
-120.6010652
-120.6009472 .
-120.6011564
Probe
Depth
(feet bgs)
17.5
16.5
17
17
17
17
17
18
18.5
•- 19
14
15.5 '
15.5
15.5
15
5
Sandpack
Length
(inches)
84
12
6
6
6
6
6
58"
6
6
6
6
6
20
6
NA
System
Volume
(ml)
70
66
68
68
68
68
68
72
74
76
56
62
62
62
60
10
Notes:
AFB
.bgs
IRP
ml
Air Force Base
below ground surface
Installation Restoration Program
milliliters
Two rounds of baseline sampling were conducted at each probe, on Octqber 12 and October 16, to verify
that each probe was usable, that detectable VOC concentrations were present in each probe, and to
determine the range of VOC concentrations present. The results indicated that all 15 probes were installed
successfully and were usable for the investigation, and that TCE was present in samples from each probe
at concentrations ranging from 93 to 2,800 ug/m3. No other VOCs were detected in any of the samples.
The results of the baseline sampling are presented in Table 2-2.
Purging for the baseline sampling was accomplished using a 60-ml syringe equipped with a three-way
valve. The three-way valve was set to allow gas to be drawn from the vapor probe into the syringe and
gas was drawn into the syringe by pulling back on the plunger at a controlled rate of 200 ml/min. When
the syringe was full, the valve was set to seal the soil vapor probe and to allow the contents of the syringe
to be expelled to the atmosphere. After expelling the gas in the syringe, the valve was reset and gas was
again drawn from the probe. This process was repeated until the specified 3 system volumes were purged
from the probe. After purging was complete, a 60-ml sample was collected in the syringe by again
drawing gas in at an approximate rate of 200 ml/min, and then setting the three-way valve to seal the
contents of the syringe. Figure 2-5 provides a schematic diagram of the sampling probe and syringe
arrangement. Note that the diagram also illustrates the purge pump that was used for purge rates of 500
2-10
-------
Table 2-2
Baseline Sampling Round Results
Vandenberg AFB, Site 15
Development of Active Soil Gas Sampling Method
Location
15-SV-A1
15-SV-A2
15-SV-A3
15-SV-A4
15-SV-A5
15-SV-B1
15-SV-B2
15-SV-B3
15-SV-B4
15-SV-B5
15-SV-C2
15-SV-C3
15-SV-C4
15-SV-C5
15-SV-C6
Sample ID
V15SVA1-BL
V15SVA2-BL .
V15SVA3-BL
V15SVA4-BL
V15SVA5-BL
V15SVB1-BL
V15SVB2-BL
V15SVB3-BL
V15SVB4-BL
V15SVB5-BL
V15SVC2-BL
V15SVC3-BL
V15SVC4-BL
V15SVC5-BL
V15SVC6-BL
12-Oct-2006
Sample
Time
9:20
9:21
9:22
10:00
10:00
12:52
12:51
11:46
11:45
12:50
16:41
16:40
15:45
15:45
16:10
TCE
Concentration
(MQ/m3)
260
2,000
2,050
. 1 ,000
490
120
150
720
430
120
1,800
2,650
2,800
420
660
16-Oct-2006
Sample
Time
10:47
10:50
10:59
11:09
11:17
10:03
10:10
10:20
10:28
10:39
11:24
11:31
11:38
11:46
11:54
TCE
Concentration
(ug/m3)
210
1,200
2,100
890
510
93
500
1,350
590
100
2,000
1,400
1,700
350
670
Principal Parameter Settings:
Purge Rate - 200 ml/min
Purge Volume - 3 system volumes
Sample Size - 60 ml
Notes:
AFB
IRP
M9/m3
ml
'TCE
Air Force Base
Installation restoration Program
micrograms per cubic meter
milliliters
trichloroethene
ml/min or higher; however, for purge rates of less than 500 ml/min, the pump was not used and the probe
was purged with the syringe as described above.
Following baseline sampling, the principal parameter evaluation sampling program was completed. In
order to evaluate the e'ffect of each of the principal parameters (purge rate, purge volume, and sample
volume) separately, experiments were conducted to evaluate the effect of each principal parameter while
holding all other principal parameters constant at the baseline settings. Specific details of the parameter
sampling are provided in Section 3.0.
2-11
-------
2.5 Mobile Laboratory
Soil gas samples collected for this investigation were analyzed on-site using a mobile laboratory operated
by H&P Mobile Geochemistry (HPMG). Details of the analytical method, equipment, and detection
levels are provided below.
2.5.1 Analytical Method
Soil gas samples were analyzed by direct injection using EPA method 8021. Method 8021 is a gas
chromatography method using a photoionization detector (PID) and an electron capture detector (BCD).
This method is faster, more sensitive, and has a larger linear dynamic operating range than gas
chromatography/mass spectrometry (GC/MS) methods. The contaminants of concern at IRP Site 15 (i.e.,
TCE, cw-l,2-DCE, trans-l,2-DCE, and vinyl chloride) had been previously identified based on IRP
investigation data (Section 2.3.3); therefore, the compound identification advantages of GC/MS were not
warranted.
The target compound list for this project was restricted to TCE, cis-l,2-DCE, and trans-\,2-DCE. Vinyl
chloride is known to be present in the groundwater at Site 15; however, it cannot be identified using
method 8021.
Soil gas samples collected during this investigation were sub-sampled using a 10-ml syringe and injected
directly into the gas chromatograph injection port. The injection syringes were flushed with the sample
two times prior to injection to ensure the injected aliquot was representative of the field sample and were
flushed several times with clean air between injections or discarded.
The analyses were performed using PID and ECD detectors and a DB-624 megabore capillary column
following EPA method 8000 protocols, modified for soil gas. Modifications from the EPA method
consisted of the project-specific analyte list, absence of matrix spike samples and surrogates, and changes
in calibration protocols as discussed in Section 2.7.2.
2.5.2 Equipment
The following equipment was utilized by the mobile laboratory for this project.
• Instrument: Shimadzu GC-14 or SRI 8610 Gas Chromatograph
• Column: 30 to 75 meter DB-624, megabore capillary
• Carrier flow: Helium at 15 ml/min
• Detectors: PID and ECD
• Column oven: 45°C for 2 min, 45°C to 175°C at 5°C/min.
2.5.3 Detection Limits
The detection limit for the target compounds was 5 ug/m3.
2-12
-------
2.6 Quality Assurance/Quality Control
2.6.1 Field Quality Control Protocols
It was determined in the field that a temporal control probe could provide useful data to monitor the
variability in sample results unrelated to changes in the principal parameter settings. Location 15-SV-A3
was designated as a temporal control probe because this probe is centrally located within the probe array.
Samples were collected from this probe three to four times a day during the investigation to monitor
potential temporal variations in soil gas concentrations unrelated to the principal parameters of purge rate,
purge volume, and sample volume. Each sample from 15-SV-A3 was collected using the base settings of
the principal parameters under investigation (i.e., purge rate of 200 ml/min, purge volume of three system
volumes, and sample size of 60 ml). The temporal control samples contained TCE at measured
concentrations ranging from 1,600 to 2,500 ug/m3 (Table 2-3).
Table 2-3
Temporal Control Sample Results
Vandenberg AFB, IRP Site 15
Development of Active Soil Gas Sampling Method
Date
16-Oct-2006
16-Oct-2006
16-Oct-2006
16-Oct-2006
17-Oct-2006
17-Oct-2006
17-Oct-2006
17-Oct-2006
18-Oct-2006
18-Oct-2006
18-Oct-2006
18-Oct-2006
18-Oct-2006
18-Oct-2006
Time
10:59
12:04
15:02
16:48
9:02
11:55
14:20
14:21
9:00
9:01
11:35
11:40
13:44
13:45
Sample Type
N
N
N
N
N
N
N
FR
N
FR
N
FR
N
FR
TCE
Concentration
(pg/m3)
2,100
2,500
1,600
2,350
2,450
2,250
2,300
2,400
2,150
. 2,400
2,450 '
2,700
2,400
1,900
Notes:
AFB
FR
IRP
pg/m3
N
TCE
Air Force Base
field replicate sample
Installation Restoration Program
micrograms per cubic meter
normal sample
trichloroethene
Field replicate samples were collected from the control probe (15-SV-A3) and from probe 15-SV-C5
during the sample volume test. Replicate samples were collected to measure the reproducibility and
precision of the total sampling system. Five field replicates were collected during the field program.
There were a total of 75 samples specified in the QAPP; therefore, replicates were collected at a rate of
approximately 7 percent, slightly lower than the 10 percent specified in the QAPP.
2-13
-------
Leak tests were performed at two probe locations to monitor the integrity of the probe system and surface
seals. Leak tests consisted of placing a rag soaked in isopropyl alcohol (IPA) around the Nylaflow tubing
at the surface. Leak checks were performed at location 15-SV-C4 throughout the purge volume testing
and at location 15-SV-A4 while the probe was purged at 5,000 ml/min for 1 hour (approximately 4,000
purge volumes). No IP A was detected in any of the samples associated with the leak checks.
2.6.2 Laboratory Quality Control Protocols
The laboratory data package, including Chain-of-Custody forms, sampling logs, quality assurance/quality
control (QA/QC) data, and sample results, is provided in Appendix C.
2.6.2.1 Laboratory Data Logs
The field chemist maintained analytical records, including date and time of analysis, sampler's name,
chemist's name, sample identification number, concentrations of compounds detected, calibration data,
and any unusual conditions.
2.6.2.2 Instrument Calibration
An initial 3-point calibration curve was performed at the start of the project. EPA method 8000 requires
the use of five levels for an initial calibration curve; however, existing soil gas guidance from Cal/EPA
DTSC only requires three calibration levels. A linearity check of the calibration curve for each compound
was performed by computing a correlation coefficient and an average response factor.
Continuing calibration verification samples were analyzed a minimum of twice a day, including once at
the beginning of each day as specified in the Quality Assurance Project Plan (QAPP) (Terra Tech 2006).
These standards were prepared from a traceable source at the middle concentration of the calibration
curve. Acceptable continuing calibration agreement was set at ±20 percent to the average response factor
from the calibration curve. EPA method 8000 specifies a calibration verification requirement of ±15
percent; however, the verification requirement was increased to ±20 percent to provide flexibility for
implementation of this project in the field.
2.6.2.3 Blanks
Laboratory blanks were analyzed at the start of each field day and at least once for every 20 field samples.
A total of seven blank samples were run during the sampling conducted on October 16 through 18, 2006.
2.6.2.4 Laboratory Duplicates
Eight laboratory duplicates were analyzed over the course of the sampling program, which was conducted
on October 16 through 18, 2006. Laboratory duplicates were performed by injecting a second aliquot
from a field sample into the GC instrument.
2.6.3 Project QAPP Deviations and Additions
During the course of implementing the program, several deviations occurred from the guidelines
discussed in the QAPP for the Development of Active Soil Gas Sampling Method (Terra Tech 2006).
Specific deviations are listed below, followed by the QAPP-specified parameter. In no case was a QAPP
deviation considered to have impacted the outcome of the study, or the recommendations advanced as a
result of the study.
2-14
-------
• The probe length used at each installation was a 1-inch length gas-permeable membrane sampling
probe, as opposed to a 6-inch length probe specified in the QAPP.
• The QAPP specified a sample volume of 100 milliliters to be evaluated. However, during
procurement of field supplies, the most suitable disposable syringes used for soil gas sample
collection were not available in this volume. Rather a 60 ml capacity syringe was procured for
this purpose.
• The five probes to be repeatedly sampled for the study were selected at random for the purge
volume and sample volume experiments to satisfy statistical treatment. This varies from the
QAPP, which assigned individual rows of probes to be used in evaluating a single parameter (i.e.,
Row A for parameter 1, Row B for parameter 2, etc.). The purge rate test was conducted at Row
B, consistent with the QAPP.
• The detection limit for the target compounds was 5 fxg/m3, as opposed to a QAPP specification of
1 |ig/L [equivalent to 1,000 |ig/m3].
• A leak test procedure using a rag soaked with IPA wrapped around the Nylaflow tubing at ground
surface was completed at two probe locations with no indications of leakage (i.e., detectable IPA
in the collected soil gas sample) during this program. This deviates from a test at each location as
specified in the QAPP. The absence of detectable IPA in any of the samples, particularly from
one sample obtained from 15-SV-A4 under extreme purging conditions (i.e., 5,000 ml/min for
one hour), indicated the sample probes were well sealed and no intrusion of ambient air was
occurring. Based on these findings, use of leak test chemicals was discontinued for the remainder
of the program.
• The QAPP specified collection of field replicates at a rate of 1 replicate for every 10 field
samples. The QAPP specified 75 field samples; therefore, seven to eight replicates should have
been collected. However, during the field effort it became clear that collecting field replicates
would disrupt the sample sequencing, and potentially skew the experimental results, as each
sample collected impacts the cumulative volume of gas removed from the probe. Therefore, the
total number of field replicates collected was limited to five.
• For the purge rate experiment, the QAPP specified purging at rates of 100, 200, 500, 1,000 and
2,000 ml/min. Samples were collected at each probe after purging at these five rates. In addition,
a purge rate of 5,000 ml/min was added to the sampling program at two of the probes (Section
3.3).
• For the purge volume experiment, the QAPP specified purging 1, 2, 3, 6, and 10 system volumes.
Samples were collected at each probe after purging'these five volumes. In addition, as the
experiment progressed, purge volumes of 4, 5, 8, 20, 100, and 4,400 system volumes were added
to the sampling program at a subset of the probes (Section 3.3).
2-15
-------
2-16
-------
3.0 Experimental Procedures
3.1 Summary of Experimental Approach
In order to evaluate the effect of each of the principal parameters (purge rate, purge volume, and sample
volume) separately, experiments were conducted to evaluate the effect of each principal parameter while
holding all other principal parameters constant at the baseline settings. Thus, purge rate was evaluated
while holding purge volume and sample volume constant, purge volume was evaluated while holding
purge rate and sample volume constant, and sample volume was evaluated while holding purge rate
constant. As collection of samples necessarily involves drawing gas from the probes into sample
containers, the cumulative purge volume for each probe increased over the course of the experiment, thus;
total purge volume was not truly constant throughout the sample volume experiment. However, each of
the three experiments was conducted on separate days, which allowed the sample probes to re-equilibrate
over night and minimized the effect of total purge volume.
The objective of the research was to evaluate the independent effect that each of the parameters has on the
sample results. It was not an objective of this project to evaluate interactive effects of the principal
parameters.
A subset of 5 of the 15 soil vapor probes was selected for each of the experiments. Each of the five
selected probes was sampled a minimum of five times, with the parameter under investigation at a
different setting for each sample. Therefore, a minimum of 25 samples were collected for each
experiment. Additional samples were collected for some of the experiments when time permitted and/or
preliminary results warranted. Details of the parameter settings for each sample collected are summarized
in Tables 3-1 through 3-3.
3.2 Principal Parameter Ranges
As described previously, the ranges of principal parameter settings tested during the experiment were '
selected to span the range of values commonly used by the industry as discovered during the literature
review (Appendix A).
Purge Rate
The purge rate experiment was conducted with the following purge rate settings:
• 100 ml/min
• 200 mVmin
• 500 ml/min
• 1,000 ml/min
• 2,000 ml/min
• 5,000 ml/min
Purging at rates of 100 and 200 ml/min was accomplished using a 60-ml syringe, as discussed in Section
2.5. Purging at rates of 500 ml/min and higher was conducted using a battery operated pump placed
downstream of the three-way valve as shown in Figure 2-5. Purge volume and sample volume were held
at the baseline principal parameters for this test. Parameter settings for each sample collected for the
purge rate experiment are summarized in Table 3-1.
3-1
-------
Table 3-1
Purge Rate Experiment Sample Summary
Vandenberg AFB, IRP Site 15
Development of Active Soil Gas Sampling Method
Location
15-SV-A2
15-SV-A4
15-SV-B1
15-SV-B4
Sample ID
V15SVA2-PV1
V15SVA2-PV2
V15SVA2-PV3
V15SVA2-PV4
V15SVA2-PV5
V15SVA2-PV6
V15SVA2-PV10
V15SVA2-PV20
V15SVA4-PV1
V15SVA4-PV2
V15SVA4-PV3
V15SVA4-PV4
V15SVA4-PV5
V15SVA4-PV6
V15SVA4-PV8
V15SVA4-PV10
V15SVA4-PV20
V15SVA4-PV
V15SVB1-PV1
V15SVB1-PV2
V15SVB1-PV3
V15SVB1-PV6
V15SVB1-PV10
V15SVB4-PV1
V15SVB4-PV2
V15SVB4-PV3
V15SVB4-PV4
V15SVB4-PV5
V15SVB4-PV6
V15SVB4-PV10
Sample
Time
10:58
11:00
11:10
11:12
11:28 -
11:29
11:46
11:55
12:03
12:04
12:11
12:12
12:22
12:23
12:38
12:40
12:54
14:12
9:34
9:36
9:46
9:49
9:57
10:09
10:10
10:20
10:22
10:32
10:58
11:00
Purge
Volume
(ml)
70
140
210
.280
350
420
700
1,400
68
136
204
272
340
408
544
680
1,360
300,000
68
136
204
408
680
74
148
222
296
370
444
740
Purge
Volume
(system
volumes)
1
2
3
4
5
6
10
20
1
2
3
4
5
6
8
10
20
4,400
1
2
3
6
10
1
2
3
4
5
6
10
Purge
Rate
(ml/min)
200
200
200
200
200
200
. 200
200
200
200
200
200
200
200
200
200
200
5,000
200
200
200
200
200
200
200
200
200
200
200
200
Sample
Volume
(ml)
60
60
60
60
60
60
60
60
60
60
60
60
60
60
60
60
60
60
60
60
60
60
60
60
60
60
60
60
60
60
TCE
Concentration
(ug/m3)
760
1,000
730
1,100
700
1,000
1,600
2,200
570
710
480
640
520
710
880
960
1,200
1,100
55
66
57
120
140
470
570
370
510
550
570
980
Comments
Operated pump at 5,000 ml/min for 60 min
-------
Table 3-1
Purge Rate Experiment Sample Summary
Vandenberg AFB, IRP Site 15
Development of Active Soil Gas Sampling Method (Continued)
Location
15-SV-C4
15-SV-C4HP
Sample ID
V15SVC4-PV1
V15SVC4-PV2
V15SVC4-PV3
V15SVC4-PV4
V15SVC4-PV5
V15SVC4-PV6
V15SVC4-PV8
V15SVC4-PV10
V15SVC4-PV20
V15SVC4HP-PV1
V15SVC4HP-PV2
V15SVC4HP-PV3
V15SVC4HP-PV6
V15SVC4HP-PV10
V15SVC4HP-PV20
V15SVC4HP-PV100
Sample
Time
13:01
13:02
13:14
13:15
13:37
13:38
13:52
13:53
14:04
14:46
14:47
15:00
15:01
15:15
15:16
15:38
Purge
Volume
(ml)
62
124
186
248
310
372
496
620
1,240
10
20
30
60
100
200
1,000
Purge
Volume
(system
volumes)
1
2
3
4
5
6
8
10
20
1
2
3
6
10
20
100
Purge
Rate
(ml/min)
200
200
200
200
200
200
200
200
200
200
200
200
200
200
200
200
Sample
Volume
(ml)
60
60
60
60
60
60
60
60
60
60
60
60
60
60
60
60
TCE
Concentration
(ug/m3)
1,200
1,500
760
1,000
1.000J
1.300J
1.450J
1.800J
2,600 J
180 J
470 J
400 J
570 J
660 J
590
850
Comments
Laboratory duplicate out of RPD criterion
Laboratory duplicate out of RPD criterion
Laboratory duplicate out of RPD criterion
Laboratory duplicate out of RPD criterion
Laboratory duplicate out of RPD criterion
Laboratory duplicate out of RPD criterion
Laboratory duplicate out of RPD criterion
Laboratory duplicate out of RPD criterion
Laboratory duplicate out of RPD criterion
Laboratory duplicate out of RPD criterion
Notes:
ml/min
ml
TCE
micrograms per cubic meter
milliliters per minute
milliliters
trichloroethene
-------
Purge Volume
The purge volume experiment was conducted with the following settings:
• 1 system volume
• 2 system volumes
• 3 system volumes
• 4 system volume
• 5 system volume
• 6 system volumes
• 8 system volume
• 10 system volumes
• 20 system volume
• 100 system volume
• 4,400 system volume
All of the purge volume tests were conducted with a purge rate of 200 ml/min with the exception of the
single 4,400-system-volume (300 liter) purge, which was conducted at a purge rate of 5,000 ml/minute.
Parameter settings for each sample collected for the purge volume experiment are summarized in Table
3-2.
Sample Volume
Samples were collected over a range of sample volumes, as follows:
• 25ml
• 60 ml
• 500ml
• 1,000 ml
• 6,000 ml
The 25- and 60-ml samples were collected in 60-ml syringes. The 500- and 1,000-ml samples were
collected in Tedlar bags. The 6,000 ml samples were collected in Summa canisters. A purge rate of 200
ml/min was used for all of the samples except the 6,000 ml Summa canisters which were filled at rates of
100 to 300 ml/min. Also, three system volumes were purged from each sample probe prior to collection
of the first (25-ml) sample. As additional samples were collected, the cumulative purge volumes increased
such that approximately 25 to 31 system volumes had been purged prior to collection of the 6,000 ml
samples. Parameter settings for each sample collected for the sample volume experiment
are summarized in Table 3-3.
3-4
-------
Table 3-2
Purge Volume Experiment Sample Summary
17 October 2006
Vandenberg AFB, IRP Site 15
Development of Active Soil Gas Sampling Method
Location
15-SV-A2
15-SV-A4
15-SV-B1
Sample ID
V15SVA2-PV1
V15SVA2-PV2
V15SVA2-PV3
V15SVA2-PV4
V15SVA2-PV5
V15SVA2-PV6
V15SVA2-PV10
V15SVA2-PV20
V15SVA4-PV1
V15SVA4-PV2
V15SVA4-PV3
V15SVA4-PV4
V15SVA4-PV5
V15SVA4-PV6
V15SVA4-PV8
V15SVA4-PV10
V15SVA4-PV20
V15SVA4-PV
V15SVB1-PV1
V15SVB1-PV2
V15SVB1-PV3
V15SVB1-PV6
V15SVB1-PV10
Sample
Time
10:58
11:00
11:10
11:12
11:28
11:29
11:46
11:55
12:03
12:04
12:11
12:12
12:22
12:23
12:38
12:40
12:54
14:12
9:34
9:36
9:46
9:49
9:57
Purge
Volume
(ml)
70
140
210
280
350
420
700
1,400
68
136
204
272
340
408
544
680
1,360
300,000
68
136
204
408
680
Purge
Volume
(system
volumes)
1
2
3
4
5
6
10
20
1
2
3
4
5
6
8
10
20
4,400
1
2
3
6
10
Purge
Rate
(ml/min)
200
200
200
200
200
200
200
200
200
200
200
200
200
200
200
200
200
5,000
200
200
200
200
200
Sample
Volume
(ml)
60
60
60
60
60
60
60
60
60
60
60
60
60
60
60
60
60
60
60
60
60
60
60
TCE
Concentration
(ug/m3)
760
1,000
730
1,100
700
1,000
1,600
2,200
570
710
480
640
520
710
880
960
1,200
1,100
55
66
57
120
140
Comments
-
Operated pump at 5,000 ml/min for 60 min
-------
Table 3-2
Purge Volume Experiment Sample Summary
17 October 2006
Vandenberg AFB, IRP Site 15
Development of Active Soil Gas Sampling Method (Continued)
Location
15-SV-B4
15-SV-C4
15-SV-C4HP
Sample ID
V15SVB4-PV3
V15SVB4-PV4
V15SVB4-PV5
V15SVB4-PV6
V15SVB4-PV10
V15SVC4-PV1
V15SVC4-PV2
V15SVC4-PV3
V15SVC4-PV4
V15SVC4-PV5
V15SVC4-PV6
V15SVC4-PV8
V15SVC4-PV10
V15SVC4-PV20
V15SVC4HP-PV1
V15SVC4HP-PV2
V15SVC4HP-PV3
V15SVC4HP-PV6
V15SVC4HP-PV10
V15SVC4HP-PV20
V15SVC4HP-PV100
Sample
Time
10:20
10:22
10:32
10:58
11:00
13:01
13:02
13:14
13:15
13:37
13:38
13:52
13:53
14:04
14:46
14:47
15:00
15:01
15:15
15:16
15:38
Purge
Volume
(ml)
222
296
370
444
740
62
124
186
248
310
372
496
620
1,240
10
20
30
60
100
200
1,000
Purge
Volume
(system
volumes)
3
4
5
6
10
1
2
3
4
5
6
8
10
20
1
2
3
6
10
20
100
Purge
Rate
(ml/min)
200
200
200
200
200
200
200
200
200
200
200
200
200
200
200
200
200
200
200
200
200
Sample
Volume (ml)
60
60
60
60
60
60
60
60
60
60
60
60
60
60
60
60
60
60
60
60
60
TCE
Concentration
(Mg/m3)
370
510
550
570
980
1,200
1,500
760
1,000
1.000J
1.300J
1.450J
1.800J
2,600 J
180 J
470 J
400 J
570 J
660 J
590
850
Comments
Laboratory duplicate out of RPD criterion
Laboratory duplicate out of RPD criterion
Laboratory duplicate out of RPD criterion
Laboratory duplicate out of RPD criterion
Laboratory duplicate out of RPD criterion
Laboratory duplicate out of RPD criterion
Laboratory duplicate out of RPD criterion
Laboratory duplicate out of RPD criterion
Laboratory duplicate out of RPD criterion
Laboratory duplicate out of RPD criterion
Notes:
M9/m3
ml
ml/min
TCE
micrograms per cubic meter
milliliters
milliliters per minute
trichloroethene
-------
Table 3-3
Sample Volume Experiment Sample Summary
18 October 2006
Vandenberg AFB, Site 15
Development of Active Soil Gas Sampling Method
Location
15-SV-A1
15-SV-B2
15-SV-B3
.
Sample ID
V15SVA1-SV25
V15SVA1-SV60
V15SVA1-SV500
V15SVA1-SV1000
V15SVA1-SV6000
V15SVB2-SV25
V15SVB2-SV60
V15SVB2-SV500
V15SVB2-SV1000
V15SVB2-SV6000
V15SVB3-SV25
V15SVB3-SV60
V15SVB3-SV500
V15SVB3-SV1000
V15SVB3-SV6000
Sample
Time
9:25
9:26
9:34
9:40
10:05
9:51
9:52
9:58
10:02
10:56
10:30
10:29
10:32
10:37
11:30
System
Volume
(ml)
70
68
72
Purge
Volume1
(ml)
210
235
295
795
1,795
204
229
289
789
1,789
216
241
301
801
1,801
Purge
Volume1
(system
volumes)
3.0
3.4
4.2
11.4
25.6
3.0
3.4
4.3
11.6
26.3
3.0
3.3
4.2
11.1
25.0
Total
Volume
Withdrawn2
(ml)
235
295
795
1,795
7,795
229
289
789
1,789
7,789
241
301
801
1,801
7,801
Purge
Rate
(ml/min)
200
200
200
200
300
200
200
200
200
111
200
200
200
200
115
Sample
Volume
(ml)
25
60
500
1,000
6,000
25
60
500
1,000
6,000
25
60
500
1,000
6,000
TCE
Concentration
(ug/m3)
220
160
350
430
120
500
570
780
830
690
820
1,600
2,900
3,300
2,000 '
Comments
Six-liter Summa
canister filled in 20
minutes
Six-liter Summa
canister filled in 54
minutes
Six-liter Summa
canister filled in 52
minutes
-------
Table 3-3
Sample Volume Experiment Sample Summary
18 October 2006
Vandenberg AFB, Site 15
Development of Active Soil Gas Sampling Method (Continued)
Location
15-SV-C2
15-SV-C5
Sample ID
V15SVC2-SV25
V15SVC2-SV60
V15SVC2-SV500
V15SVC2-SV1000
V15SVC2-SV6000
V15SVC5-SV25
V15SVC5-SV60
V15SVC5-SV500
V15SVC5-SV1000
V15SVC5-SV6000
Sample
Time
11:14
11:15
11:33
11:39
12:41
12:45
12:46
12:48
12:55
13:42
System
Volume
(ml)
56
62
Purge
Volume1
(ml)
168
193
253
753
1,753
186
211
271
771
1,771
Purge
Volume1
(system
volumes)
3.0
3.4
4.5
13.4
31.3
3.0
3.4
4.4
12.4
28.6
Total
Volume
Withdrawn2
(ml)
193
253
753
1,753
7,753
211
271
771
1,771
7,771
Purge
Rate
(ml/min)
200
200
200
200
100
200
200
200
200
122
Sample
Volume
(ml)
25
60
500
1,000
6,000
25
60
500
1,000
6,000
TCE
Concentration
(ug/m3)
2,500
1,500
3,000
3,600
2,000
240
350
250
660
380
Comments
Six-liter Summa
canister filled in 60
minutes
Replicate sample
result = 650
Six-liter Summa
canister filled in 49
minutes
Notes:
1
M9/m
ml
ml/min
TCE
Volume of gas purged from probe prior to start of sample collection :
Total cumulative volume of gas purged from probe at completion of sample collection
micrograms per cubic meter
milliliters
milliliters per minute
trichloroethene
-------
3.3 Sample Summary
Purge Rate Experiment
Samples for the purge rate experiment were collected on October 16, 2006 from the five probes installed
along row B (Figure 2-4). Row B was selected because the baseline sampling indicated a broad range of
TCE concentrations are present along this row. The purge volume for this experiment was set to three
system volumes for each individual probe sampled, in accordance with the QAPP. Each of the probes
were first purged.at a rate of 100 ml/min, followed by purging each probe at rates of 200 ml/min, 500
ml/min, 1,000 ml/m, and 2,000 ml/min. After three system volumes were purged, 60 ml samples were
collected from each probe using a syringe. The elapsed time between collection of consecutive samples at
a single probe ranged from 28 to 75 minutes. A complete list of the principal parameter information for
the purge rate experiment is provided in Table 3-1.
During the course of the experiment, a trend toward higher concentrations with increasing purge rates was
apparent; therefore, additional samples were collected from two probes (15-SV-B1 and 15-SV-B3) using
a higher purge rate of 5,000 ml/min to assess whether the apparent trend continued. Specifically, four
samples were collected after purging at a rate of 5,000 ml/min, two from each of the two locations. These
samples were collected after purging at 5,000 ml/min for approximately 7 seconds (approximately 8
system volumes) and after 3 minutes (approximately 208 and 221 system volumes) (Table 3-1). These
samples were collected to assess the impacts of using an excessive purge rate and a total purge volume
that is well above industry standards and considered likely to stress the system.
Purge Volume Experiment
Samples for the purge volume experiment were collected on October 17, 2006. Internal discussions
following the purge-rate test on October 16 led to the determination that for purposes of satisfying
assumptions used in statistical analysis, the sampling locations should be chosen randomly rather than
selecting an individual row for conducting the tests. Therefore, five randomly selected probes were
chosen for the purge volume test (15-SV-A2, 15-SV-A4, 15-SV-B1, 15-SV-B4, and 15-SV-C4). In
accordance with the procedures outlined in the QAPP, 60 ml samples were collected from probe 15-SV-
Bl after each of the 1, 2, 3, 6 and 10 system volumes were purged at 200 ml/min. Purging and sampling
was conducted in sequence by tracking the cumulative purge volume, which consists of the volume
purged and released from the system plus the volume of each sample collected (e.g., 15-SV-B1 has a
system volume of 68 ml, thus 68 ml were purged followed by collection of a 60-ml sample [the 1-purge-
volume sample] followed by purging of an additional 8 ml and collection of the next 60-ml sample [the 2-
purge-volume sample]). All samples from an individual probe were collected consecutively before
moving onto the next probe.
Analytical results appeared to show a step in detected soil gas concentrations between 3 and 6 purge
volumes (Table 3-2); therefore, the next two probes (15-SV-B4 and 15-SV-A2) were sampled after
purging 1, 2, 3, 4, 5, 6 and 10 system volumes. In addition, probe 15-SV-A2 was sampled after purging
20 system volumes. Analytical results from 15-SV-B4 and 15-SV-A2 suggested a step in soil gas
concentrations between 6 and 10 purge volumes; therefore, a sample was collected after purging 8 and 20
system volumes at the subsequently sampled probes (15-SV-A4 and 15-SV-C4). An additional sampling
test was performed at 15-SV-A4 to test a large volume purge, well above industry standard purge
volumes. This probe was purged for one hour at a rate of 5,000 ml/m, or approximately 4,400 purge
volumes, and then sampled.
As stated in Section 2.4, all 15 semipermanent probes were installed at depths approximately 2 to 4 feet
above the water table. During the testing, it was postulated that a reason for the apparent step in soil
3-9
-------
gas concentrations observed at higher purge volumes might be that the radius of influence around the
sampling probe was intersecting the capillary fringe and altering the flow dynamics. To test this
hypothesis, a boring was drilled using an electric rotary-hammer to a depth of 5 feet bgs at a location
approximately 2 feet southeast of probe 15-SV-C4. A temporary probe (15-SV-C4HP) was installed at 5
feet bgs and the system was purged to 1, 2, 3, 6, 10, 20, and 100 system volumes; samples were collected
after each purge. The rationale was that with a probe set at only 5 feet bgs, it was unlikely that the sphere
of influence would intersect the capillary fringe and, therefore, the step in concentrations would not be
observed.
Sample Volume Test
Samples for the sample volume experiment were collected on October 18, 2006. Samples were collected
from five probes (15-SV-A1, 15-SV-B2, 15-SV-B3, 15-SV-C2 and 15-SV-C5) randomly selected to
satisfy statistical analytical assumptions. In accordance with the procedures outlined in the QAPP, each
probe was first purged at a rate of 200 ml/min to a total of three system volumes. Five different sample
volumes (25, 60, 500, 1,000 and 6,000 ml) were then collected consecutively from each probe before
moving onto the next probe. The 25 and 60 ml samples were collected in 60 ml syringes. The 500 and
1,000 ml samples were collected in 1-liter Tedlar bags. Six-liter Summa canisters were used to collect the
6,000 ml samples. A complete list of the principal parameter information for the sample volume
experiment is provided in Table 3-3.
3.4 Data Evaluation and Quality Control
The analytical data generated during the sampling program were reviewed for quality, compliance with
the QAPP, and usability. The QC elements reviewed were completeness, holding times, calibration,
blanks, and duplicates. Complete laboratory QC results are provided in the laboratory data package in
Appendix C.
Data Completeness
The QAPP specified collection and analysis of a total of 75 samples, composed of 25 samples from each
of the three experiments. Each of the samples proposed in the QAPP was collected and successfully
analyzed. Additional samples were added to the sampling program during the purge rate and purge
volume experiments for a total of 102 samples. The data set is therefore considered complete.
Holding Times
All of the samples were analyzed on-site immediately after sampling. The data are considered compliant
with holding time requirements.
Instrument Calibration
Initial calibrations were performed as specified in the QAPP. The QAPP-specified a single continuing
calibration standard at the start of each day; however, the laboratory added additional calibration
standards and ran three on October 16 and 17 and two on October 18. With one exception, all of the
continuing calibration standards were within the QAPP-specified criterion of ±20 percent. A standard run
in the middle of the day on October 17 had a result of 75 percent recovery on the PID, slightly outside the
±20 percent criterion. However, the result on the ECD was within the ±20 percent criterion at 86 percent
recovery and the standards run before and after this one were within the criterion. As this continuing
calibration standard was only slightly outside the criterion for acceptable results, was bracketed by two
3-10
-------
results within the ±20 percent criterion, and was an additional standard not required by the QAPP, it was
judged as not having a significant negative impact on data quality.
Method Blanks
A total of seven blank samples were run during the sampling conducted on October 16 through 18, 2006.
The results were non-detect for all target compounds in all blanks.
Replicates and Duplicates
Field replicate samples were collected from the control probe, 15-SV-A3, and from 15-SV-C5 during the
sample volume test. A total of five field replicates were collected during the sampling conducted on
October 16 through 18. Replicate samples were collected from the temporal control probe 15-SV-A3. The
results of the field replicate analyses indicated good agreement between replicate pairs, with the relative
percent differences (RPDs) ranging from 2 to 23 percent (Table 3-4).
Nine laboratory duplicates were analyzed over the course of the sampling conducted on October 16
through 18. The RPD acceptance criterion for laboratory duplicates was ±30 percent. The RPDs between
all but one of the duplicate pairs ranged from 0 to 19 percent. One duplicate pair had an RPD of 33
percent (Table 3-5). This result is only slightly outside the ±30 percent criterion and the laboratory
duplicates collected before and after this sample were within the criterion; therefore, this result is
considered unlikely to be indicative of a significant negative impact to the data quality or usability.
Nevertheless, field samples analyzed between the two passing duplicates that bracketed the failed
duplicate were "J" flagged as estimated concentrations.
Data Evaluation Summary
Based on the data review, the data set is considered complete and all of the data are considered usable for
their intended purpose. No results were rejected.
3-11
-------
Table 3-4
Field Replicate Summary
Vandenberg AFB, IRP Site 15
Development of Active Soil Gas Sampling Method
Location
15-SV-A3
15-SV-A3
15-SV-A3
15-SV-C5
15-SV-A3
Sample ID
V15SVA3
V15SVA3
V15SVA3
V15SVC5-SV1000
V15SVA3
Sample
Date
17-Oct-2006
18-0ct-2006
18-Oct-2006
18-Oct-2006
18-Oct-2006
Sample
Time
14:20
9:00
11:35
12:55
13:44
Purge
Volume
(ml)
204
204
204
771
204
Purge
Volume
(system
volumes)
3
3
3
12
3
Purge
Rate
(ml/min)
200
200
200
200
200
Sample
Volume
(ml)
60
60
60
1,000
60
Sample
Result
(ng/m3)
2,300
2,150
2,450
660
2,400
Replicate
Result
(ug/m3)
2,400
2,400
2,700
650
1,900
RPD
4%
11%
10%
2%
23%
Notes:
pg/m3 - micrograms per cubic meter
ml - milliliters
ml/min - milliliters per minute
RPD - relative percent difference
Notes:
Table 3-5
Results for Laboratory Duplicate Samples
Vandenberg AFB, IRP Site 15
Development of Active Soil Gas Sampling Method
Sample ID
C4-PV2
C4-PV4
A4-PV300L
C4-PV20hp
C4-PV100hp
A1-PV60
A1-PV6000
B3-PV1000
C5-PV1000
Sample Date
17-Oct-2006
17-Oct-2006
17-Oct-2006
17-Oct-2006
17-Oct-2006
18-Oct-2006
18-Oct-2006
18-Oct-2006
18-Oct-2006
Sample Time
13:02
13:15
14:12
15:16
15:38
9:26
10:05
10:37
12:55
Sample Result
(Mg/m3)
1,500
1,000
1,100
590
850
160
120
3,300
660
Duplicate Result
(ng/m3)
1,400
1,000
790
690
760
160
140
4:000
650
RPD
7%
0%
33%
16%
11%
0%
15%
19%
2%
ug/m - micrograms per cubic meter (TCE)
RPD - relative percent difference
3-12
-------
4.0 Results and Discussion
4.1 Statistical Analyses
4.1.1 Sample Numbers and Parameter Settings
Three separate experiments were conducted to assess the effects of purge rate, purge volume, and sample
volume on measured soil gas concentrations. The results of each experiment are described below.
4.1.1.1 Purge Rate
In this experiment, five soil gas probes (15-SV-B1 through 15-SV-B5) were sampled. The sample volume
was 60 ml for all samples collected. Purge volume was 3 system volumes for all samples except those
purged at a rate of 5,000 ml/min. The 100, 200, 500, 1,000, and 2,000 ml/min purge rates were evaluated
at each of the five probes used for this test. In addition, a purge rate of 5,000 ml/min was evaluated at
probes 15-SV-B1 and 15-SV-B3 and two samples were collected from each. For the four samples with a
purge rate of 5,000 ml/min, the purge volumes fell into 2 groups: approximately 8 system volumes and
over 200 system volumes. The two samples that were collected with more than 200 system volumes
purged (from 15-SV-B1 and 15-SV-B3) are far removed from the other purge volumes used and could
bias the data analysis. Therefore, they were assumed to be outliers and were not included in the statistical
analyses.
4.1.1.2 Purge Volume
In this experiment, six soil gas probes (15-SV-A2, 15-SV-A4, 15-SV-B1, 15-SV-B4, 15-SV-C4, and 15-
SV-C4HP) were sampled. The first five of these probes were installed normally as discussed in Section
2.4. Probe 15-SV-C4HP was installed by hand to a depth of 5 feet bgs as described in Section 3.3.
The 1, 2, 3, 6, and 10 purge volumes were evaluated at each of the five probes used for this test. As
described in Section 3.3, additional purge volumes were evaluated in some of the probes: 4, 5, and 20
purge volumes were evaluated at probe 15-SV-A2, 15-SV-A4, and 15-SV-C4; 4 and 5 purge volumes
were also evaluated at probe 15-SV-B4; 20 purge volumes was also evaluated at probe 15-SV-C4HP; and
8 purge volumes were evaluated at probes 15-SV-A4 and 15-SV-C4. One sample was collected after
purging 100 system volumes (15-SV-C4HP) and 4,400 system volumes (15-SV-A4); these two samples
were considered outliers and were therefore excluded from the statistical analysis. Purge rate and sample
volume for the remaining samples were set at 200 ml/min and 60 ml, respectively.
4.1.1.3 Sample Volume
In this experiment, five soil gas probes (15-SV-A1, 15-SV-B2, 15-SV-B3, 15-SV-C2, and 15-SV-C5)
were sampled. The sample volumes were evaluated at each of the five probes used for this test. A purge
rate of 200 ml/min was used for all samples except the 6,000 ml samples collected using a Surnma
canister. For these samples, the purge rate (fill rate of the Summa canister) was either approximately 100
ml/min or 300 ml/min. The purge volume for this test necessarily varied with each sample volume and
ranged from 3 to 31.3 system volumes (Table 3-3).
The relationship between sample volume, purge volume, and purge rate for this experiment is illustrated
in Figure 4-1.
4-1
-------
System Volumes Purged (unitless)
->.->. to ro co c
o en o 01 o en o
_
• System volumes purged
D Purge rate
_
4
>
•
m o
CM CD
1
I
1
m
LJ
•
•
O;
9
1
1
...r\
mm
o o o
o o o
m o o
350
- 300
- 250
• 200
c
"E
- 150
Ot
0)
- 100
• 50
0
^3 ^3
O ^S
^3 ^5
Sample Volume (ml)
Figure 4-1. Summary of Parameter Settings for Samples Collected During the Sample Volume Experiment
4.1.2 Statistical Approach
Multiple linear regression analysis was performed on the results from the experiments to evaluate the
effects of varying the three principal parameters. When parameters other than the parameter of interest
varied in the experimental conditions (e.g., purge volume was also varied in the sample volume
experiment), their effects were included in the analysis. For the purposes of the analyses presented here, it
was assumed that each analytical result could be considered as a randomly collected independent sample.
A detailed description of the statistical analyses performed for this investigation is provided in Appendix
D.
4.1.2.1 Baseline Measurements
Prior to conducting the experiments, baseline conditions in the installed probes were measured using a
purge rate of 200 ml/min, a purge volume of 3 system volumes, and a sample volume of 60 ml. Baseline
concentrations varied from 93 u,g/m3 to 2,400 Hg/m3 amongst the probe array (Figure 4-2).
4-2
-------
Baseline
^DVJU
oonn
3.
O
CD H OQQ
"c
SH nnn
lUUU
Q
cnn
bUU
yinn
4UU
onn
«£UU
... .4
CO C
LO U
•
ft
1
? ? :
0 CO 0
O LO U
•
4
f < s
? CO 0
•> in u
«
•
>
CM C
3 CQ Q
0 CO 6
i
•5 in u
»
.
i m c
> > 2
^ co a
i
•5 m u
>
^ CM C
i 0 C
; ^> -
3 CO C
"> in u
> 0
4
0 Tj- U
J) 0 C
p co a
o in u
.
>
^ CD
) 0
5 ^
? in
Probe
Figure 4-2. Plot of Baseline Concentrations by Probe
To account for the differences in baseline concentrations, baseline concentrations were included as a
covariate in all of the statistical analyses. In addition to differences among probes in baseline
concentrations, it was observed that probes with higher baseline concentrations had greater variability in
results than those with relatively lower baseline concentrations. This observation is illustrated in Figure 4-
3, which plots TCE concentrations measured during the purge volume experiment with baseline
concentrations as the X-axis and the measured TCE concentrations as the Y-axis. This indicates that
changes in the principal parameters have a greater influence on the final concentration with increasing
baseline concentrations. The increase in variability with increasing baseline concentrations may in part be
due to the inherent variability in laboratory analytical data, which is expected to be on the order of ± 20
percent.
To correct for the effect of increasing variance with increasing concentration, all data were natural
logarithm transformed prior to statistical analysis.
The system volumes for each probe were also slightly different. This may affect both the baseline
concentrations and the concentrations measured during each of the experiments. To account for the
potential effect of the difference in system volumes among the wells, system volume was included as a
covariate in the statistical analyses.
4-3
-------
O)
I
o
o
LLJ
O
K-
~£
"c.
o>
E
o3
CL
2800
2600
2400
2200
2000
1800
1600
1400
1200
1000
800
600
400
200
0
200
400
600
800
1000 1200 1400 1600 1800 2000
Baseline TCE concentration (ug/m )
Figure 4-3. Effect of Baseline Concentrations on Variance in TCE Concentrations From
Purge Volume Experiment
4.2 Experimental Results
4.2.1 Temporal Control
Samples were collected three to four times a day from probe 15-SV-A3 to monitor temporal variations in
measured soil gas concentrations unrelated to changes in the principal parameter settings (Table 2-3).
TCE concentrations measured in samples from 15-SV-A3 ranged from 1,600 to 2,700 ug/m3.
Measurements on October 17, 2006 exhibited the least variability, with concentrations ranging from 2,250
to 2,450 ug/m3. Measurements on October 16 and October 18, 2006 showed more variability, with
concentrations ranging from 1,600 to 2,500 ug/m3 and 1,900 to 2,700 pg/m3, respectively. The RPDs
between the minimum and maximum concentrations detected in the temporal control samples on a single
day varied from 9 percent to 44 percent. A plot of the TCE concentrations measured in temporal control
samples is shown in Figure 4-4. The reason for the variability in RPDs over the three days is unclear.
Insofar as the sample collection parameters were identical over the course of the temporal control
sampling, the variability in RPDs is a good reminder of the inherent variability often encountered in
environmental monitoring.
The data collected from soil vapor well 15-SV-A3 were analyzed to determine if there were significant
temporal trends in the data using the nonparametric Mann-Kendall trend test. This test determines
whether there is a monotonic (i.e., single-direction) trend in the data over time (e.g., is the concentration
increasing or decreasing over time) and does not examine periodicity in the data. The results of the
analysis indicate that, at the 95% confidence level, there was no significant trend over time in the data.
4-4
-------
TCE Concentration (|jg/m3)
-* -x M N) GO U t
§o 01 o cn o cn c
o o o o o o c
-*-1
5-SV-A3
1
• j-
V
V
1
i
Measurement Date/Time
Figure 4-4. TCE Concentrations Measured in Temporal Control Samples
4.2.2 Purge Rate Experiment
The TCE concentrations that were observed during the purge rate experiment are summarized in Table 3-
1 and a linear plot of the purge rate experiment data is shown in Figure 4-5. In general, there was a very
modest increase in measured concentrations with increasing purge rate over the range of 100 to 5,000
ml/min. The sample results from 15-SV-B1 and 15-SV-B5 ranged from 63 to 150 pg/m3 (Bl) and 94 to
140 pg/m3 (B5). Measured concentrations in samples from 15-SV-B2 and 15-SV-B4 ranged from 480 to
700 ug/m3 (B2) and 540 to 960 pg/m3 (B4); however, the maximum concentration detected at 15-SV-B2
was associated with the 1,000 ml/min purge rate, not the 2,000 ml/min rate. Concentrations measured in
samples from 15-SV-B3 showed the widest range of concentrations, from 1,400 to 2,200 pg/m3. While
these data appear to show a trend toward increasing TCE concentrations with increased purge rate,
changes in concentration of this magnitude would not be considered significant for site characterization or
vapor intrusion applications. Furthermore, the ranges in measured concentrations at a single vapor probe
are less than the range observed in the temporal control samples on the day the purge rate experiment was
conducted (October 16, 2006) (Table 2-3, Figure 4-4). The RPDs between the maximum and minimum
concentrations measured at individual probes (excluding the outlier samples) ranged from 37 to 56
percent with the exception of the results from probe 15-SV-B1, which had an RPD of 82 percent. These
RPDs can be compared to the RPD for the temporal control sample of 44 percent.
4-5
-------
4000
3500
3000
ro
E
05
2500
c
o
1000
500
1000
2000 3000 4000
Purge Rate (ml/min)
5000
6000
Figure 4-5. Linear Plot of Purge Rate Experiment Data
Quantitative Statistical Analysis
In the purge rate experiment, sample volume was held constant; however, there was some variation in the
number of system volumes purged. Therefore, the independent variables used in the regression analysis
were: 1) purge rate (parameter of interest), 2) system volumes purged (covariate), 3) baseline
concentration (covariate), and 4) system volume (covariate). This resulted in a statistically significant
multiple linear regression with the following resulting equation (see also Appendix D):
ln(TCE in ug/m3) = -4.85 + 0.14*ln(purge rate in ml/min) - 0.044*ln(system volumes purged) +
1.00*ln(system volume in ml) + 0.99*ln(baseline TCE in ug/m3)
To directly illustrate the effect of purge rate on the measured TCE concentrations, the same regression as
above was performed, but without purge rate, and the residuals were calculated. The residuals were then
regressed on the purge rate. After accounting for the effect of the other variables, purge rate accounted for
approximately 50 percent of the variance observed in the data (Figure 4-6).
The two measurements at far right in Figure 4-6 were collected after purging approximately 8 purge
volumes, as opposed to 3 purge volumes for the other measurements. These two measurements fall
somewhat below the regression line, suggesting there may be some degree of interaction between purge
rate and purge volume; however, this cannot be rigorously evaluated given the existing data set.
4-6
-------
_c
"ro
'(/J
CD
cc
0.4
0.3
0.2
0.1
0.0
-0.1
-0.2
-0.3
-0.4
-0.5
-0.6
LN(purge rate):Residual: r2 = 0.
50; r = 0
71,p =
.00004; y = -0.66 + 0.11 *x
4.0 4.5
5.0
8.5 9.0
5.5 6.0 6.5 7.0 7.5 8.0
LN(purge rate in ml/min)
Figure 4-6. Effect of Purge Rate on Measured Soil Gas Concentrations, After Accounting for
the Effects of Baseline Conditions, System Volumes Purged, and System Volume
To summarize, although there is a statistically significant positive correlation between the measured TCE
concentrations and purge rate, the variability in measured concentrations would not be considered
significant in the context of site characterization or vapor intrusion sampling. The data generally appear to
show a sharp rise in detected TCE concentration from the sample collected at 100 ml/min to the sample
collected at 200 ml/min, and then a moderate to slight increase with increasing purge rate. These results
suggest that purge rates between 200 and 500 ml/min are the most suitable under the conditions sampled.
4.2.3 Purge Volume Experiment
The TCE concentrations that were observed during the purge volume experiment are summarized in
Table 3-2 and a linear plot of the purge rate experiment data is shown in Figure 4-7. The measured TCE
concentrations generally increased over the range of 5 to 20 purge volumes; however, there was no
obvious trend toward higher TCE concentrations with increased purge volume over the range of 1 to 6
purge volumes. The measured concentrations from each probe appear to increase from 1 to 2 purge
volumes, decrease from 2 to 3 purge volumes, increase again from 3 to 4 purge volumes, and decrease
again at 5 purge volumes. The explanation for this behavior is not clear; however, the variability of the
measured TCE concentrations over 1 to 5 purge volumes is small. The measured concentrations from
each probe more than doubled from 5 to 20 purge volumes, with the exception of 15-SV-C4HP and 15-
SV-B1, which was only tested to 10 purge volumes (but more than doubled in concentration from 3 to 10
purge volumes).
4-7
-------
4000
10
Purge Volume (system volumes)
Figure 4-7. Linear Plot of Purge Volume Experiment Data
The ranges in concentrations observed in all of the probes sampled for the purge volume experiment, with
the exception of 15-SV-B1, were significantly more than the range in concentrations observed in the
temporal control samples collected on the same day (Table 2-3). The RPDs between the maximum and
minimum concentrations measured at individual probes (excluding the outlier sample) ranged from 86 to
114 percent in the experimental samples as compared to 9 percent in the temporal control samples for that
day.
As discussed in Section 3.3, during the purge volume experiment, additional purge volume settings were
added to the sampling program, as the initial data suggested a "step" in soil gas concentrations. In
addition, a shallow (5 feet bgs) temporary vapor probe (15-SV-C4HP) was installed to test the hypothesis
that measured TCE concentrations were being affected by the sphere of influence around the vapor probes
intersecting the capillary fringe. When taken as a complete data set, the results of the purge volume
experiment do not appear to show a step in TCE concentrations; however, the TCE concentrations in
samples from the shallow probe were the only ones to decrease between the 10 and 20 volume purges,
suggesting the hypothesis regarding the sphere of influence may have some credence.
4-8
-------
Quantitative Statistical Analysis
In the purge volume experiment, the only parameter that was varied was the purge volume, expressed as
system volumes. Therefore, the independent variables used in the regression analysis were: 1) system
volumes purged (parameter of interest), 2) baseline concentration (covariate), and 3) system volume
(covariate). These parameters resulted in a statistically significant multiple linear regression with the
following equation:
ln(TCE in pg/m3) = -6.71 + 0.29*ln(system volumes purged) + 0.95*ln(baseline TCE in pg/m3) +
1.53*ln(system volume in ml)
To directly illustrate the effect of purge volume on the measured TCE concentration, the same regression
was performed, but without the system-volumes purged term, and the residuals were then calculated. The
residuals were then regressed on the number of system volumes purged. After accounting for the effect of
the other variables, purge volume accounted for approximately 50 percent of the variance observed in the
data (Figure 4-8).
1.0
0.8
0.6
0.4
0.2
0.0
-0.2
-0.4
-0.6
-0.8
LN(system volumes purged):Residual: r2 = 0.50; r = 0.71, p = 0.0000007; y = -0.41 + 0.29*x
-0.5 0.0 0.5 1.0 1.5 2.0
LN(system volumes purged)
2.5
3.0
3.5
Figure 4-8. Effect of the Number of System Volumes Purged on Measured Soil Gas Concentrations,
After Accounting for the Effect of Baseline Conditions and System Volume
4-9
-------
To summarize, there is a statistically significant positive correlation between the measured TCE
concentrations and purge volume. From a field investigation perspective, the effect of purge volume on
the measured TCE concentrations was more pronounced than the effect of purge rate, with concentrations
generally more than doubling over the range of purge volumes tested. However, this variability may not
be significant in terms of site characterization. The data indicate that varying purge volume from 1 to 5
system volumes has relatively little effect on the sample results; however, increasing purge volume above
5 system volumes appears to result in higher measured TCE concentrations. The concentrations measured
after purging 2 system volumes were consistently higher than those measured after withdrawing only one
volume. Logic dictates that it is prudent to purge more than one system volume in order to ensure that
ambient air is removed from the probe; based on this logic and the data presented here, it appears that
purge volumes of 2 to 5 system volumes are most appropriate under the conditions sampled.
4.2.4 Sample Volume Experiment
The TCE concentrations that were observed during the sample volume experiment are summarized in
Table 3-3 and a linear plot of the purge rate experiment data is shown in Figure 4-9. As noted in Section
4.1.1.3, the cumulative purge volume necessarily increased during this experiment as consecutive samples
were collected; therefore, measured TCE concentrations may be effected by changes in both purge
volume and sample volume.
In general, the measured concentrations of TCE increased somewhat with increasing sample size from 25
to 1,000 ml and then decreased in the 6,000 ml samples. This behavior is consistent with an interpretation
of over-purging between the 1,000 and 6,000 ml volumes, possibly abetted by reduced equilibration times
during the study.
The sample probes selected for the sample volume experiment fall into two groups: those with relatively
low baseline concentrations between 210 and 500 ug/m3 (15-SV-A1, 15-SV-B2, and 15-SV-C5) and
those with relatively high baseline concentrations above 1,000 ug/m3 (15-SV-B3 and 15-SV-C2). The
variability in measured concentrations in the "low" group ranged from approximately 300 to 400 ug/m3.
The variability in measured concentration in the "high" group ranged from 2,100 to 2,480 ug/m3. By
comparison, the variability observed in the temporal control samples collected on the same day (October
18) was 800 ug/m3. The temporal control probe yielded concentrations closer to the "high" group, but had
lower variability (i.e., 800 ug/m3 compared to 2,100 to 2,480 ug/m3). The RPDs between the maximum
and minimum concentrations measured at individual probes ranged from 50 to 100 percent in the
experimental samples as compared to 35 percent in the temporal control samples.
It should be noted that during the purge volume experiment, the maximum volume of gas purged from a
probe prior to sampling was on the order of 1,400 ml. During the sample volume experiment, the
cumulative volume of gas withdrawn prior to collection of the 6,000 ml samples was on the order of
1,700 ml, and the total volume withdrawn after collection of the 6,000 ml samples was close to 8,000 ml.
Thus, the total cumulative volume purged during the sample volume experiment was far greater than the
cumulative amount withdrawn during the purge volume experiment. The drop in concentration observed
in the sample volume experiment is clearly shown in Figure 4-9, while the varying effects between purge
volume and sample volume are illustrated in Figure 4-10.
The drop in measured TCE concentrations from the 1,000 ml to the 6,000 ml samples (Figures 4-9 and 4-
10) is noteworthy as the 6,000 ml sample volume is commonly used in the industry (i.e., 6-liter Summa
canisters). The 6-liter Summa canister is the typical sample container for running EPA TO-15
4-10
-------
4000
1000 2000 3000 4000
Sample Volume (ml)
5000
6000
7000
Figure 4-9. Linear Plot of Sample Volume Experiment Data
methodology, which is considered the industry standard for vapor analyses and is often utilized due to the
very low detection levels achievable with this method. However, this study suggests that 6-liter samples
may result in lower concentrations than 500 or 1,000 ml samples. As stated previously, the reason for the
observed drop in measured TCE concentrations in the 6,000 ml samples is likely over-purging of the
system.
Quantitative Statistical Analysis
In the sample volume experiment the variable of interest is sample volume; however, the cumulative
number of system volumes purged progressively increased as sampling volume increased. Therefore,
sample volume and system volumes purged are dependent variables (i.e., they co-vary) and these data
cannot be evaluated using the multiple regression approach used for the previous two experiments.
4-11
-------
co
2000
1500
1000
500
-500
-1000
-1500
-15-SV-A1 (SV)
15-SV-B2(SV)
-15-SV-B3(SV)
-15-SV-C2(SV)
-15-SV-C5(SV)
• 15-SV-A2 (PV)
•15-SV-A4(PV)
•15-SV-B4(PV)
15-SV-C4(PV)
•15-SV-B1 (PV)
100
1000
10000
Total Volume Removed (ml)
Figure 4-10. Plot of TCE Concentrations From the Purge Volume (PV) and Sample Volume (SV)
Experiments vs. Total Volume of Gas Removed (purge volume + sample volume) on
a Log Scale
The purge rate and sample fill rate for all but the 6,000-ml samples was held constant at 200 ml/min. The
flow rate during filling of the 6,000-ml Summa canisters varied from approximately 100 to 300 ml/min.
Therefore, purge rate was also considered a covariate in the statistical analyses.
To analyze the results of this experiment, sample volume was treated as an indicator of the combined
experimental conditions, and as a categorical, rather than continuous, variable. An analysis of covariance
(ANCOVA) was used to analyze the sample volume experiment data, with the natural-log-transformed
baseline concentrations treated as a continuous covariate. System volume was examined and was not
determined to have a significant effect in the analyses and was, therefore, not included as a covariate. The
ANCOVA indicated that the experimental manipulations had a significant effect on the measured TCE
concentrations after adjusting for baseline concentrations (Figure 4-11).
To determine which treatments are significantly different, the Newman-Kuels multiple range test was
used. This test indicated that the TCE concentrations measured in the 25-ml, 60-ml, and 6,000-ml sample
volumes were not significantly different from each other. In contrast, the 500-ml and 1,000-ml sample
volumes were similar to each other, but were significantly different from the other treatments (Figure 4-
11).
4-12
-------
/.b
7.4
7.2
7.0
6.8
6.6
6.4
6.2
6.0
SR
1 1 — — 1
1
" C
c
"6:32 \
)
i
(
6.99
7.11
)
"" ""
6.39
6.49
o
Mean concentrations for each sample volume after adjusting for
mean baseline TCE concentrations [ln(Baseline)=6.48].
Vertical bars denote 0.95 confidence intervals.
i i i
25
60 500 1000
Treatment: Sample Volume (ml)
6000
Figure 4-11. Graphical Representation of the Results of the Newman-Kuels Multiple Range Test for the
Sample Volume Experiment. Samples Whose Confidence Intervals Overlap the Mean of
Another Sample are not Significantly Different
To summarize, sample volume had a statistically significant effect on the measured TCE concentrations.
The most noteworthy observation was the decrease in measured TCE concentration with the 6,000 ml
samples. Additional experiments should be conducted to verify this effect. Based on the data obtained
from this investigation, it appears that a sample volume of 1,000 ml should be recommended, as this
volume appears to result in the highest measured concentrations. However, smaller sample volumes
would appear to provide acceptable results for most site characterization needs.
4-13
-------
4-14
-------
5.0 Conclusions
Three experiments were conducted to assess the effect of varying purge rate, purge volume, and sample
volume on measured VOC concentrations in soil gas samples.
Purge Rate Experiment
Samples were collected from five probes with purge rates ranging from 100 to 5,000 ml/min. The results
of the experiment show a pronounced increase in measured TCE concentration from purge rates of 100
ml/min to 200 ml/min followed by a modest trend of increasing measured concentrations with increasing
purge rate. However, the observed variability in measured VOC concentrations would not generally be
considered significant from a site characterization or vapor intrusion perspective. Based on the data from
this investigation, it appears that purge rates of 200 to 500 ml/min should be recommended for sites
possessing similar subsurface conditions.
Purge Volume Experiment
Samples were collected from six probes, with purge volumes ranging from 1 to 4,400 system volumes.
There was a statistically significant positive correlation between the measured TCE concentrations and
purge volume, with concentrations typically more than doubling over the range of purge volumes tested.
The effect of purge volume on the measured VOC concentrations was more pronounced than the effect of
purge rate; however, this variability may not be significant in terms of site characterization. The data
indicate that varying purge volume from 1 to 5 system volumes has relatively little effect on the sample
results; however, increasing purge volume above 5 system volumes appears to result in higher measured
TCE concentrations. The concentrations measured after purging 2 system volumes were consistently
higher than those measured after withdrawing only one volume. Logic dictates that it is prudent to purge
more than one system volume in order to ensure that ambient air is removed from the probe. Based on this
logic and the experimental data, it appears that purge volumes of 2 to 5 system volumes are most
appropriate.
Sample Volume Experiment
Samples were collected from five probes, with sample volumes ranging from 25 to 6,000 milliliters (ml).
Measured TCE concentrations were observed to increase with increasing sample volume from 25 to 1,000
ml, but then drop off in the 6,000 ml samples. This observation is significant as the 6,000 ml sample size
is commonly used to achieve very low detection levels with EPA method TO-15; however, the drop in
measured TCE concentrations at a 6,000 ml sample volume suggests that the low detection levels
achievable with large sample size may need to be balanced against the risk of over-purging. Based on the
data obtained from this investigation, it appears that a sample volume of 1,000 ml should be
recommended, as this volume appears to result in the highest measured concentrations. However, smaller
sample volumes would appear to provide acceptable results for most site characterization needs.
Summary
Overall, the variability in trichloroethene (TCE) concentrations that resulted from varying the principal
parameter settings was found to be similar to the variability measured in a single probe successively
sampled over the course of the program (i.e., the temporal control probe). These results indicate that while
the principal parameter settings do affect the measured TCE concentrations, the magnitude of their effect
is similar to that of other variables that could not be controlled during this study. None of the principal
parameters evaluated appear to dominate the variability in sample results. Further, site-specific factors
may affect the degree to which each of these parameters affect sample results.
5-1
-------
5-2
-------
6.0 Recommendations
Based on the results of this study, we recommend the following:
• Conduct similar experiments at other sites with differing lithologies.
• Conduct similar experiments with differing system volumes.
• Further investigate/verify the apparent decrease in measured VOC concentrations associated with
a 6-liter sample volume.
• Further investigate the effect of purge volume over the range of 1 to 6 system volumes and the
effect of varying equilibration time between collection of subsequent samples from a single
probe.
• Investigate other parameters such as probe installation method and equilibration time.
• Investigate the effects of atmospheric variables (i.e., temperature, barometric pressure,
precipitation, wind speed, etc.).
• Collect samples from the temporal probe at the same frequency as the study probe array such that
trends observed from the study array can be directly compared to those exhibited by the temporal
probe data.
6-1
-------
6-2
-------
7.0 References
American Petroleum Institute (API). 2005. Collecting and Interpreting Soil Gas Samples from the Vadose
Zone: A Practical Strategy for Assessing the Subsurface-Vapor-to-Indoor-Air Migration Pathway
at Petroleum Hydrocarbon Sites. Publication 4741. November.
Battelle Corporation. 1986. Installation Restoration Program Phase II Confirmation/Quantification
Survey Technical Operations Plan for Vandenberg Air Force Base, California.
Bureau of Reclamation. 1994a. Summary of Tank Sites- Vandenberg Air Force Base, California. July.
Bureau of Reclamation. 1994b. Cumulative Index for Location of Submitted Investigations. June.
California Environmental Protection Agency (Cal/EPA) Department of Toxic Substances Control
(DTSC). 2003. Advisory Active Soil Gas Investigations. January.
Dibblee, T.W., Jr. 1989. Geologic Map of the Casmalia and Orcutt Quadrangles, Santa Barbara County,
California. Dibblee Geologic Foundation, Santa Barbara, California.
Interstate Technology and Regulatory Council (ITRC). 2007. Vapor Intrusion Pathway: A Practical
Guideline. Appendix D: Sampling Toolbox.
Jacobs Engineering Group, Inc. 1993. Installation Restoration Program Remedial
Investigation/Feasibility Study Work Plan for Operable Units 1, 2, 3B, 4 and 5, Vandenberg Air
Force Base, California. Prepared for 703 CES/CEVCR Installation Restoration Program,
Vandenberg AFB, California, 93437, and Headquarters Air Force Space Command (HQ
AFSPACECOM), Peterson Air Force Base, Colorado.
Jacobs Engineering Group, Inc. 1998. Draft Site 15, ABRES-B Launch Complex, Site Characterization
Summary. Prepared for 30 CES/CEVCR Installation Restoration Program, Vandenberg AFB,
California. July.
Missouri Department of Natural Resources (MO-DNR). 2005. Missouri Risk-Based Corrective Action for
Petroleum Storage Tanks, Soil Gas Sampling Protocol. April.
New Jersey Department of Environmental Protection (NJ-DEP). 2005. New Jersey Department of
Environmental Protection, Vapor Intrusion Guidance. October (updated March 2006).
New York State Department of Health (NY-DOH). 2005. New York State Department of Health, Center
for Environmental Health, Bureau of Environmental Exposure Investigation, Guidance for
Evaluating Soil Vapor Intrusion in the State of New York. February.
Science Applications International Corporation (SAIC). 1990. Installation and Restoration Program
(IRP), Stage 1 - Site Characterization for Vandenberg Air Force Base, California. Prepared for
Headquarters Strategic Air Command - Environmental Compliance Division (Offutt Air Force
Base, Texas). Prepared by SAIC, Golden, Colorado. April.
Shaw Environmental, Inc. (Shaw). 2004. Remedial Investigation Report, IRP Site 15, Operable Unit 4,
Vandenberg Air Force Base, California. Final. Prepared for U.S. Air Force, Vandenberg Air
Force Base, California. August.
7-1
-------
References (Continued)
Tetra Tech, Inc. (Tetra Tech). 1995. Draft, Phase I Site Characterization Summary, -Informal Technical
Information Report, Site 15 - ABRES-B Launch Complex, Operable Unit 4, Remedial
Investigation/Feasibility Study. Prepared for 30 CES/CEVCR, Vandenberg Air Force Base,
California. December.
Tetra Tech EM, Inc. (Tetra Tech EMI). 2006. Quality Assurance Project Plan for the Development of
Active Soil Gas Sampling Method. July.
U.S. Environmental Protection Agency (EPA). 2006. Assessment of Vapor Intrusion in Homes Near the
Ray mark Superfund Site Using Basement and Sub-Slab Air Samples. Office of Research and
Development, National Risk Management Research Laboratory, Cincinnati, OH, EPA/600/R-
05/147 EPA/540/1-89/002. March.
7-2
-------
Appendix A
Literature Review
-------
April 2006
Development of Active Soil Vapor Sampling Method
Literature Review
Prepared by:
Tetra Tech EM Inc.
250 West Court Street
Suite 200 W
Cincinnati, OH 45202
EPA Contract #EP-C-05-061
Task Order No. 5
Prepared for:
Brian A. Schumacher, Task Order Project Officer
- National Exposure Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Las Vegas, NV 89114
E PA "it TETRA TECH EM
-------
CONTENTS
Section Page
1.0 INTRODUCTION 1
2.0 TECHNICAL APPROACH : 1
3.0 SOIL VAPOR MONITORING VARIABLES 2
3.1 Purge Rate 3
3.2 Dead-Space Purge Volume 3
3.3 Sample Size 4
4.0 CONCLUSIONS 5
5.0 RECOMMENDATIONS 5
6.0 REFERENCES 7
Tables
1 Summary of Literature Review Results Active Soil Vapor Sampling 8
-------
1.0 INTRODUCTION
Soil vapor data are widely used in site investigation and remediation projects to delineate volatile organic
compound (VOC) vapor plumes, as a screening tool to refine soil and groundwater sampling efforts, to
track the progress of soil remediation, and to identify potential risks from the inhalation of air associated
with soil vapor migration. The overall goal of any monitoring or sampling program is to enable the
collection of representative samples; that is samples that are representative of the environmental,
chemical, and hydrogeological conditions present during the time of sample collection. Over a period of
time, collection of a sequence of representative samples can enable a better understanding of trends in the
data set regarding the fate and transport of the chemicals being monitored. However, due to numerous
environmental as well as sampling and analytical variables, the representativeness of the sample can often
be compromised, the degree of which is often not well understood or quantified.
A number of research groups and local, state, and federal agencies have developed guidance concerning
sampling and analytical protocols for active soil vapor sampling with the overall objective of facilitating a
technically correct approach to be employed during site investigations. However, the various guidance
documents often omit a prescribed range of key parameters (e.g., purge rate ranges, purge volumes, and
sample volumes) that may be used during sample collection, or if prescribed, lack a quantitative basis in
terms of the net effect on the sampling result. As a result, adherence to any one specific guidance
document may result in sampling and analytical bias when investigation results collected under one
guidance document are compared to results obtained through adherence to another guidance document.
This Literature Review presents, compares, and discusses some of the key parameters recommended in
several widely cited and used soil vapor sampling guidance documents with the objective of identifying
key parameters that potentially require further quantification in order to develop a defensible and
standardized approach. This literature review focuses on recommendations and guidance related to purge
rates, purge volumes, and sample volumes, but includes discussion of other parameters as appropriate.
2.0 TECHNICAL APPROACH
Initially, information in the form of guidance documents and technical articles from Federal and State
entities, industrial consortiums, and the private sector were consulted for soil vapor guidance content.
From this initial search, consideration was given to the relevance and importance of the material
considered, and to the breadth of its audience. To this end, the considerable experience of the project
team was relied upon to identify what was considered to be the most widely used and cited guidance
documents and technical articles currently available. State guidance from California on the west coast,
New York and New Jersey on the east coast, Missouri, and Canada were reviewed. Other sources of
guidance included that from the American Petroleum Institute, the American Society of Testing Materials
(ASTM), the U.S. EPA, and Technical Editorials published in periodicals (LUSTLine Bulletins, etc.).
Sampling methodologies that were screened were weighted towards whole-air active soil vapor sampling
approaches, but also included consideration of guidance related to vapor intrusion studies and surface flux
chamber sampling, protocols. In the interest of providing a current picture of the state of the
understanding, some draft documents were also considered, including one from the International
Regulatory Research Council (ITRC) vapor intrusion workgroup. It is notable that the majority of recent
guidance documents focus attention on the vapor intrusion pathway into buildings; which has been
recognized as an important risk pathway at contaminated sites.
During this review, the similarities and differences in specified approaches were compiled and evaluated
for prescribed ranges of the principal test variables, including purge rate, purge volume, and sample
volume. Information related to equipment and instrumentation, quality control (QC), and field and
laboratory methodologies was also considered as it may affect the principle variables. Collected
information from the various sources is discussed below and summarized in Table 1.
-------
3.0 SOIL VAPOR MONITORING VARIABLES
Obtaining representative soil gas samples requires consideration of multiple variables associated with
physical and hydrologeologic properties of the soil, atmospheric processes, physio-chemical properties of
the targeted constituents, and sample collection and analytical methodologies. Physical soil properties
that may influence soil vapor measurements include grain-size distribution and the shape and size of soil
pores, moisture content (and thus air-filled porosity), temperature, organic carbon content, and microbial
influences. Increased clay content decreases pore size, making collection of soil vapor samples slow, if
not impossible. Grain-size distribution also affects the size of pores present in a soil sample; e.g., larger
pores increase the potential for air transfer. Moisture content reduces the volume of pore space available
to maintain air connectivity between pores. Increased organic carbon content increases the sorption of
chemicals. Microbial influences can significantly change the soil atmosphere through biological
processes, and alter the concentrations and types of chemicals present. These soil properties can, in turn,
be affected by hydrogeologic processes such as fluctuating groundwater tables, rainfall, and the transport
of volatiles in groundwater or surface water. Atmospheric processes may also influence soil vapor
measurements through barometric pressure changes or dilution of subsurface gas via ambient air
intrusion.
Chemical and physical .properties of the organic compounds include consideration of vapor pressure and
boiling point, aqueous solubility, Henry's Law constant, constituent concentration, molecular weight,
density, and organic carbon distribution coefficient. Generally speaking, it has been stated that organic
compounds that exhibit vapor pressures in excess of 10 mm Hg (at 20° C), or with-boiling points less than
150° C are amenable to sampling and detection using soil vapor techniques.
Sampling methods can influence soil vapor measurements via differences in purge rates, purge volumes,
sample volumes, the nature of the vapor sampling system installation, type of sampling train used, and the
type of sampling container used (e.g., tedlar bags vs. SUMMA canisters). Further, there are several
different analytical methods that can be used to analyze soil vapor (e.g., EPA methods TO-14 and TO-15,
modified EPA methods SW8015, SW8021, SW8260, etc.). Each of these methods has different
sensitivities. In general, air-specific EPA methods (i.e. the "TO" methods) allow for lower detection
levels than other methods. However, the "TO" methods can not be readily performed in the field and are
generally the most expensive analytical methods. SW-846 methods such as SW8015, SW8021, and
SW8260 were specifically developed for the analysis of liquid and solid matrices, but can be readily
modified for the analysis of gas matrix samples. These methods will typically provide higher detection
levels than the TO methods, but are more suited for the higher concentrations typically observed in soil
gas samples, are less expensive, and can be implemented in the field using a mobile laboratory.
It should be noted that the purge rate, purge volume, and sample volume variables are not necessarily
independent parameters. Purge rate must be taken into consideration both during dead-space purging (i.e.
purging vapor from the in-place sampling system to eliminate ambient air prior to sample collection) and
during sampling. The total volume purged from the sampling system is the sum of the dead-space purge
and the sample volume; in many cases, the sample volume may be significantly greater than the volume
purged to clear the dead-space.
This literature review focuses discussion on the three sampling process variables of sample purge rate,
sample purge volume, and sample volume, as discussed below.
-------
3.1 Purge Rate
The purge rate refers to the volume or mass rate of flow at which a gas is extracted for purposes of
purging or sampling. The principal issue to evaluate is whether elevated flow rates lead to a difference in
soil vapor measurements by causing turbulent mixing and/or desorption from the soils or water. This
issue is closely related to applied vacuums during purging as gas flow results from an induced pressure
gradient. The impact of this "induced stripping" may vary depending upon the phase of the
contamination; that is, dissolved (groundwater), sorbed (soil), or gas (soil vapor), the soil physical
properties, and the contaminant.
Purge rate is measured during purging through use of an appropriate calibrated volumetric or mass flow
meter attached to the sampling train. Vacuum is also directly measured during purging, using a vacuum
gauge or similar device. Incidence of high measured vacuums during purging may be used to qualify the
representativeness of the sample. Generally, vacuums approaching 10" Hg (136 inches of water) reflect
relatively impermeable soils and may warrant resampling or moving to an alternate location or sampling
depth (DTSC/LARWQCB 2003).
The general consensus of the documents reviewed is that purge rates should be minimized to limit
potential short-circuiting of the sampling system (introduction of atmospheric air) and to reduce the
potential for desorption. Specific recommendations range from 100 to 200 milliliters per minute (ml/min)
(e.g., DTSC/LARWQCB 2003, MO-DNR 2005, NJ-DEP 2005, NY-DOH 2005, ITRC In preparation) to
1,000 ml/min (e.g., API 2005, EPA 2006). Colder Associates (2004) recommends a purge rate of 100 to
200 ml/min, and notes that the vacuum should not exceed 10 in-H2O.
McAlary and Creamer (In Preparation) evaluated the effects of purge rate and volume on sub-slab soil
vapor samples with purge rates of 1,000 ml/min and 10,000 ml/min and found no significant impact to
detected gasoline range hydrocarbon concentrations. However, this study used soil-gas samples collected
from sub-slab engineered fill material that is expected to have much greater gas permeability than many
natural soils. In addition, the contamination source was in the immediate surrounding soils and at very
high concentrations, creating a large soil vapor volume to draw upon. McAlary and Creamer (In
Preparation) observed vacuums of approximately 10 inches of water (in-H20) at a purge rate of 10,000
ml/min.
Purge rates should generally be the same during dead-space purging and during sampling. With many
low-volume soil vapor sampling systems, the dead-space volume is small relative to the sample volume
(e.g., a 6-liter Summa canister), thus, the purge rate during sampling may have greater impact on the
representativeness of the sample than the dead-space purge rate.
3.2 Dead-Space Purge Volume
Dead-space purge volume refers to the total volume of gas purged prior to sample collection. Most soil
vapor sampling protocols developed over the past few years recognize that large "dead" volumes in
sampling trains require correspondingly large purge volumes, leaving little flexibility to address this
variable. If a complete mixing regime is assumed, three, soil-gas purge volumes will flush out
approximately 87 percent of the original air in the tube and four purge volumes will flush out
approximately 92 percent of the original air in the tube. Smaller sampling systems using either 1/8-inch
or 1/4-inch inert tubing offer much smaller dead volumes. Further, these internal diameters are
sufficiently small such that the vapor is likely to move through the tubing almost as plug flow, with very
little mixing. In a perfect plug flow scenario, one "dead volume" of the soil vapor probe plus tubing is all
that is required before the in-situ soil vapor is drawn in to fill the tubing. Limiting dead-space purging
requirements increases the likelihood that the sample is representative of a discrete, limited volume
-------
immediately adjacent to the sampling location. When large purge volumes are utilized, the area around
the probe that is sampled increases and the sample results may become representative of the "average"
conditions within the larger purged area; however the area of influence is not known. In addition, in areas
with very little localized vapor phase VOCs.or relatively tight soils, it is possible to purge away the
"available" VOC vapors, such that a false negative can result.
The general consensus of the documents reviewed is that purge volume should be minimized to increase
the likelihood that the collected sample is representative of conditions immediately surrounding the
sampling probe and to reduce the probability of short-circuiting the sampling system. However, few of
the documents provide specific recommendations for purge volumes. DTSC/LARWQCB (2003)
guidance stipulates that a step purge test be conducted by collecting samples after one, three, and seven
dead-volumes have been purged. The purge volume that yields the highest concentrations of site
contaminants of concern (COCs) should then be used for subsequent samples. In the event that the step
test does not yield a definitive result, the DTSC/LARWQCB (2003) default is three volumes. MO-DNR
(2005) and NJ-DEP (2005) recommend three volumes be purged prior to sampling. Health Canada
(2004), recommends two to three volumes and NY-DOH (2005) recommends one to three volumes.
API (2005) recommends monitoring with a field PID or FID until the purged vapor stabilizes. As an
alternative to a default value of three purge volumes, NJ-DEP recommends purging until CO2 and O2, as
measured with a field instrument, have stabilized. These monitoring methods may or may not reach a
stable value depending upon the strength of the contamination source and usually require larger volumes
(>1 liter) to be purged.
McAlary and Creamer (In Preparation) collected sub-slab soil vapor samples after purging between 1 and
604 liters from the sampling system. The results for gasoline range hydrocarbons were similar for all
samples, and suggested that the purge volume had little effect on sample results, even with extremely
large purge volumes. As noted above, McAlary and Creamer (In Preparation) studied the effects of purge
volume on vapor samples obtained from high permeability engineered fill material beneath a concrete
slab with a nearby and strong source so their findings are likely inapplicable to most typical sites.
3.3 Sample Size
Sample size refers to the volume of soil gas sample to be collected. The principal issues affecting this
variable are the required volumes necessary to achieve the desired detection limit using the specified
analytical method, which is turn dictates the size and type of container used in the sample collection, and
whether there exists a correlation between sample size and the total volume of vapor extracted. For vapor
intrusion applications, this is of particular importance because samples are collected close to the soil
surface, so there is a chance of breakthrough from the surface if large volumes are collected. In such
cases, assessment of breakthrough is typically completed through addition of a tracer gas at the surface
adjacent to the probe followed by analysis for the tracer in the collected sample. For site assessment
applications, surface breakthrough is less of a concern as samples are usually collected at greater depths
(>5 feet below ground surface [ft bgs]).
The documents reviewed provide few recommendations regarding sample volume beyond concerns
related to detection levels. There appears to be some consensus that within the constraints imposed by
analytical requirements, sample volume should be minimized for the same reasons that purge volume
should be minimized. Common sample volumes cited range from 10 to 50 ml collected in glass bulbs or
gas-tight syringes to 1-6-liter Summa canisters for TO-14/TO-15 analyses.
In general, larger sample volumes facilitate lower detection levels, and some methods specify particular
sample container types (e.g., the TO methods require Summa canisters). For vapor intrusion applications,
-------
the required detection levels for some compounds can only be achieved by the TO methods, and hence
larger volumes are required. But for site assessment applications, required detection levels can be met by
other methods using smaller volumes.
4.0 CONCLUSIONS
Except for the McAlary & Creamer paper, no published data were identified indicating whether purge
flow rate has any affect on soil gas concentrations, and if so, at what levels. In general, the documents
reviewed advocate minimizing the purge rate to reduce the potential for short-circuiting and/or
desorption; however, few data are available to provide a rationale for specific limits on flow rate. For
example, DTSC/LARWQCB (2003) specifies a flow rate of 100 to 200 ml/min, and other agencies (e.g.
MO-DNR, NJ-DEP, NY-DOH) have adopted these limits; however, there do not appear to be any data in
the published literature that provide a rationale in support of this guidance. A controlled study to quantify
the effect of purge flow-rate on sample results is warranted.
Of the documents reviewed, only two published studies exist on the influence of purge volume on soil gas
concentrations. Both of these studies showed no effect on soil gas concentrations over purge volumes
ranging from approximately 1 to 10 liters (EPA 2006) and 1 to 600 liters (McAlary & Creamer, 2006).
Both studies involved sub-slab soil gas samples with extremely different site conditions. No published
data exist for deeper soil gas samples collected in more typical site investigation application.
Quantification of the effect of changing purge volume and sample volume on soil gas results in a
controlled study is also warranted.
Soil-vapor sample size is commonly constrained by detection limit requirements and the selected
analytical methods. Therefore, there is less flexibility in this variable, and if sample volume guidance is
developed it will need to be couched' within the context of project specific analytical method and
detection level requirements. Nevertheless, there are no data in the published literature indicating what, if
any, effect sample volume has on the analytical results, and a controlled study to evaluate the potential
effects is warranted.
The results of this literature review indicate there are few data available in the published literature on the
effects of purge rate, purge volume, or sample volume on soil vapor sample results. Much attention has
been paid recently to the issue of soil vapor intrusion into indoor air, and this process has been identified
as a significant concern at, and adjacent to, many contaminated sites. Thus, there is a critical need for
collection of representative, accurate, and defensible soil vapor data in support of hazardous waste site
investigations. A carefully designed scientific study of the effects of the key variables discussed here will
be an important first step in developing a quantitative understanding of the impact of these variables on
sample results, and will be the foundation for developing guidance for use by soil-vapor investigators.
5.0 RECOMMENDATIONS
It is recommended that a well controlled, scientific study be conducted to investigate the effects of purge
rate, purge volume, and sample volume on soil-vapor sample results in a "real-world" site setting. In light
of the number of variables that may affect soil gas sample results, any rigorous program that is designed
to quantify the effect of changing one or more variables on a sample result must hold constant, or as
nearly constant as possible, any remaining variables. Thus, the recommended study should have the
following attributes:
The site selected for conducting the study should have an effectively homogeneous
vadose zone that is amenable to soil vapor sampling (i.e. sufficient permeability).
-------
• Subsurface contamination at the selected site should be well characterized and
understood.
• The selected site should have only a limited number of contaminants of concern, and
those contaminants should be present in the soil vapor at concentrations that fall within
the normal calibration range of the analytical method and equipment selected.
• The study should be conducted during a sustained dry season to eliminate variability
associated with rainfall events.
• All sampling probes used for the study should be installed using consistent procedures
and equipment.
• All sampling probes should be allowed to equilibrate for a period sufficient to eliminate
equilibration time as a variable.
• All sampling should be conducted following the same procedures and utilizing the same
equipment.
• All sample analyses should be conducted by a single analytical laboratory using the same
analytical method and equipment.
While it is not possible to completely eliminate other variables, and many of the variables associated with
soil gas sampling are inter-related (e.g. purge rate and vacuum, purge volume and sample volume),
observance of the above conditions can serve to minimize the effects of other variables and facilitate the
isolation of the key variables in question.
For the controlled field study, it is important that the method be consistent with the best and most widely
used guidance. The base soil gas method we propose to use for this program is the semi-permanent
method described by DTSC/LARWQCB (2003) and currently being adopted by many regulatory agencies
around the country. This method consists of the burial of a small diameter (either 1/8" or 1/4" OD) inert
tube to a target depth with subsequent sampling of the soil gas after a period of time. The sampling tubes
will be buried in boreholes created with a direct-push rig. Porous probe tips attached to the tubing will be
installed at each prescribed depth interval, centered in 6 inch sand packs and sealed to the surface with
bentonite. Soil vapor samples will be withdrawn from the end of the inert tubing using a syringe.
Syringe samples will be immediately transferred to the mobile lab for analysis within minutes of
collection.
An alternative approach to collecting actual soil gas for the field study is to concentrate the soil gas on an
adsorbent. Sample collection on sorbent tubes requires drawing air at a calibrated flow rate through a
hollow tube containing adsorbent media over a specified time period. However, a number of
disadvantages exist with the adsorbent method. A primary disadvantage is that only one analysis is
possible from a tube, with no possibility for a replicate analysis. Other complications are compound
breakthrough, sorbent contamination from passive adsorption of VOCs requiring extensive quality control
(i.e., duplicates, field blanks, lab blanks), more complicated field procedures, higher sample volumes, and
lack of real-time analysis. For these reasons, it is recommended that the field study use direct on-site
analysis in a mobile laboratory, following soil gas collection in a syringe, as the base method.
-------
6.0 REFERENCES
American Petroleum Institute (API)
2005 Collecting and Interpreting Soil Gas Samples from the Vadose Zone: A Practical
Strategy for Assessing the Subsurface-vapor-to-indoor-Air Migration Pathway at Petroleum
Hydrocarbon Sites. Publication 4741. November.
American Society for Testing and Materials (ASTM)
2001 ' Designation D4314-92(2001), Standard Guide for Soil Gas Monitoring in the Vadose
Zone.
California Environmental Protection Agency, Department of Toxic Substances Control (DTSC) and
California Regional Water Quality Control Board, Los Angeles Region (LARWQCB)
2003 Advisory — Active Soil Gas Investigations. January.
Colder Associates
2004 Final Draft, Soil Vapour Intrusion Guidance for Health Canada Screening Level Risk
Assessment (SLRA), Submitted to Health Canada, Burnaby, British Columbia. November.
Hartman, B.
2002 How to Collect Reliable Soil-Gas Data For Risk Based Applications, LUSTLine Bulletin
42. October.
Interstate Technology and Regulatory Council (ITRC)
In preparation Vapor Intrusion Pathway: A Practical Guideline. Appendix D: Sampling
Toolbox
McAlary, T. and Creamer, T.
In preparation The Effects of Purge Rate and Volume on Sub-slab Soil Gas Samples
Missouri Department of Natural Resources (MO-DNR)
2005 Missouri Risk-Based Corrective Action for Petroleum Storage Tanks, Soil Gas Sampling
Protocol. April
New Jersey Department of Environmental Protection (NJ_DEP)
2005 New Jersey Department of Environmental Protection, Vapor Intrusion Guidance.
October (Updated March 2006).
New York State Department of Health (NY-DOH)
2005 New York State Department of Health, Center for Environmental Health, Bureau of
Environmental Exposure Investigation, Guidance for Evaluating Soil Vapor Intrusion in the State
of New York. February.
U.S. Environmental Protection Agency (EPA)
2006 Assessment of Vapor Intrusion in Homes Near the Raymark Superfund Site Using
Basement and Sub-Slab Air Samples. Office of Research and Development, National Risk
Management Research Laboratory, Cincinnati, OH, EPA/600/R-05/147 EPA/540/1-89/002.
March
-------
Table 1
Summary of Literature Review Results
Active Soil Vapor Sampling
Document
API Soil Gas
Sampling
Guidance
EPA Sub-slab
guidance
Method Scope
Guidance generally discusses active vapor
sampling considerations for vapor intrusion
applications, although passive samplers and
flux chambers are addressed as alternatives.
Describes (rather than prescribes) general
considerations in sampling design, and
addresses various available options while
providing the reference associated with each
option discussed and the attendant
advantages/disadvantages for each option. No
single standard method is endorsed.
Document reports on investigations conducted
at 16 separate sites (1 5 homes, 1 business).
Specific methods varied at each site; all were
actively sampled. A total of 55 probes installed
through basement slabs in 16 buildings, with
average of 1 probe every 220 ft2. Generally, 1
sub-slab probe was centered, while the
remaining two were placed 1-2 meters from
building walls. "Permanent" probe installation
consisted of 1 -2" length metal piping embedded
in slab. Samples were collected using 6-Liter
Summa cannisters which collected samples over
1-hour and 24-hour periods. Samples were
analyzed for VOCs via TO-15. Also, four
radon gas samples were collected using open
face activated carbon canisters and anlayzed
using EPA 402-R-93-004.
Purge Rate
No specific recommendation.
Minimize flow rate and vacuum
during sampling.
Rates should not exceed 1 L/min.
Monitor and record the vacuum
during sampling
6-liter canisters filled (close to
atmospheric pressure) in 1 to 2
minutes. 1-liter Tedlar bags filled
in approximately 1 minute.
Purge rate prior to sample
collection generally 1 liter per
minute. Concludes that 100 to 200
ml/min sample rate is consistent
with theoretical calculations
showing little effects due to
turbulence.
Purge Volume (Sample Volume
No specific recommendation.
Minimizing the purge volume is appropriate.
Purge volume may be based on procedures such as
DTSC purge test or monitoring with a PID/FID
until stabilization.
Purge volume should be the same at all locations.
Sequentially collected five one-liter Tedlar bag
samples at a flow rate of 1 standard liter per minute
and compared vapor concentration of four VOCs.
This was performed at three locations with little
effect on sample concentration.
Simulations showed that after 5 purge volumes, the
exiting vapor concentration was 99 percent of the
entering concentration even if vapor concentration
inside the sample system had been reduced to zero
concentration prior to sampling.
One purge volume was typically less than 10 ml.
Generally, 2 liters were purged (200 volumes).
followed by collection of 1-liter Tedlar bag.
followed by 1 liter purge, followed by collection of
5 liters in canister (over 1 to 2 minutes).
Document more slanted
towards smaller sample
volumes using syringes
as photos show.
1 -liter Tedlar bags
compared to 5-liter
samples in 6-liter
canisters with similar
results.
Other Variables
6-liter summas and 1 -liter
tedlars were collected at
the same probes with
good agreement in
results.
Equilibration time of 2
hours for sub slab soil
(sand) should be
sufficient
Comments
Document focuses on
subsurface- vapor-to-
indoor-air pathway and
petroleum related
hydrocarbons.
Document primarily
concerned with collection
of sub-slab samples.
Author/Date
American Petroleum
Institute, November
2005
U.S. Environmental
Protection Agency,
March 2006
Weblink
httD://Hroundwntcr.noi.orn/
soiljtna/
http://www.enn.Bov/adn/do
wnlond/rcDorts/600R05147
/600R05147.odf
-------
Table 1
Summary of Literature Review Results
Active Soil Vapor Sampling
Document
Health Canada
2004
DTSC/CRWQCB
2003
Method Scope
Guidance document that is geared for use by
risk assessment professionals for site screening
of vapor intrusion applications. General
protocols for sampling and analysis of soil
vapor.are described in Appendix II. Describes
(rather than prescribes) general considerations
in sampling design, and addresses various
available options while providing the reference
associated with each option discussed and the
attendant advantages/disadvantages for each
option. No single standard method is endorsed.
other than a recommended purge procedure
described in following cells.
Guidance applies to active vapor sampling only
(passive sampling and flux chamber sampling
are not addressed). Guidance specifies soil
lithologic logging in selecting locations and
depths of sampling points. Soil gas "probes"
that arc considered acceptable include
permanent and semi-permanent, along with soil
vapor wells, provided DTSC staff are consulted
in advance. Installation methods preclude use
of mud rotary drilling technique and discourage
the air rotary technique. Direct-push
installation requires 20 minutes equilibration
time prior to sampling; hollow stem auger
(HSA) requires 48 hour equilibration time.
Tracer gas for leak check required at 1 00%
frequency. Recommended analytical methods
include US EPA methods 8260B, 8021 B, and
8015B.
Purge Rate
Cites recommendations of 1 L/hr to
1 L/min from others.
Higher purge rates may increase
probability of short circuiting.
leaking, or volatilization of light
end components.
Recommend 100 to 200 ml/min
(based on CRWQCB
recommendations). Do not exceed
vacuum of 10 inches water.
Purge rate should be consistent
across site.
Use same flow rate for sampling
and purging.
Recommended purge rate of 1 00 to
200 ml/min. Rates may be
modified based on individual
conditions encountered.
Purge Volume (Sample Volume
Cites recommendations of 1 to 5 volumes from
others.
Minimize purge volume.
Recommend purge 2 to 3 volumes, then allow
vacuum to dissipate before sampling.
Purge volume should be consistent across site.
Conduct step purge-test at one, three, and seven
purge volumes. Default volume is three.
Additional purge tests should be performed if
widely different soils encountered.
Should be less than a 6-
liter summa. Minimize
sample volume
Use glass bulbs or
syringes wrapped in
foil, or Summa
canisters. Smaller
volume Summas (1L)
preferred, but not
required.
Other Variables
Equilibration time for
driven (direct push)
probes is a few minutes to
hours.
Equilibration time for
semi-permanent probes
installed with direct-push
is 30 minutes.
Equilibration time for
HSA boreholes is 48
hours.
Prohibits use of Tcdlar
bags
Samples should be
analyzed on-site within
30 minutes (extended to 4
hours if surrogates
added).
72-hour hold time on
Summa canisters
Comments
Document is primarily
guidance for indoor vapor
intrusion. Guidance on
sampling protocol
provided as Appendix II.
Leak tests should be
performed with a tracer
gas at all locations.
Author/Date
Colder Associates,
November 2004
Department of Toxic
Substances Control and
California Regional
Water Quality Control
Board, LA Region,
January 2003
Weblink
http://www.hc-
sc.RC.cn/cwh-
wmt/comamsitc/proi pubs
journal c.html
httD://www.dtsc.cn.nov/Ln
wfiRensPolicics/Polictcs/Sil
cClcnnun/uolond/SMBR A
DV nctivcsoilnasinvst.ndf
-------
Table 1
Summary of Literature Review Results
Active Soil Vapor Sampling
Document
LUSTLine
Bulletin 42
MO-DNR Soil
Gas Protocol
Method Scope
Document opines on issues associated with use
of soil gas sampling on the vapor intrusion
pathway; scope addresses active soil gas sample
collection. Document describes sampling
factors which an influence soil gas results.
Specific recommendations include: collection
of samples 5-feet below grade at corner or sides
of foundation to identify hot spot(s); step out
near hot spot(s) for delineation (assess vertical
and lateral distribution); iteratively use J&li
model to assess health risk.
Guidance applies to soil gas sampling at
petroleum storage tank sites. Guidance does not
include sub-slab sampling, and defers such to
US EPA guidance. Deviations from this scope
must be detailed in work plans submitted to
MDNR. Base case: Specify uniform sample
depths (minimum 18" below grade); first depth
generally at 5-feet followed by a second depth
near groundwater; sampling point spacing at 50-
fect; sample probe accessed by small diameter
tubing (1/8 to 1/4"); probe installation using
HSA (48 hr equilibration time) or direct push
(30 minutes equilibration time); probe tip
installed in center of sand pack extending 6"
above and below probe tip; grout between
sample points in nested installation; two
sampling events minimum per site, spaced at 3
month intervals; tracer gas used for leak check.
Recommended analyses include TO-1 5 or SW-
846 Methods 8260B and 8021.
Purge Rate
Should be limited to avoid
turbulent flow and excess vacuum.
Cites Cal/EPA guidance of less
than 200 ml/min
Recommends initial flow rate of
200 ml/min, which can be modified
for field conditions. If flow rate
exceeds 200 ml/min then data must
be flagged.
Purge Volume {Sample Volume
Cites common use of one to five purge volumes.
Recommends purge tests only for sample volumes
greater than SOOcc
Purge 3 volumes at flow rate and vacuum similar to
sampling conditions.
10to40ccforDLsof
100 ug/m3
Larger volumes
(>l,OOOcc)forDLsofl
to 1 0 ug/m3
Recommends 500 ml or
1 L Summas. No
recommendations for
Tcdlar or syringe size
Other Variables
Includes brief discussion
of ambient temperature.
barometric pressure,
precipitation, and
gravitational effects.
Concludes that impacts
are generally minor,
particularly with deep (>
5 feet bgs) samples
Equilibration time for
semi-permanent probes
installed with direct-push
is 30 minutes.
Equilibration time for
HSA boreholes is 48
hours.
Sample containers should
be syringes or Tedlar
bags for on-site analysis
and Tedlar bags or
Summas for off-site
analysis.
Recommends vacuum of
less than 100 inches of
water
Comments
Cites use of Summa
canisters, teller bags, and
glass or stainless vials
Leak tests should be
performed with a tracer
gas at all locations.
Guidance appears to be
based largely on
CRWQCB/DTSC 2003
Author/Date
Hartman, Blayne
October 2002
Missouri Department of
Natural Resources April
2005
Weblink
hUD://www.tCBcnv.com/do
cumcnts/L142.B Iavnc.pdf
httD://www.dnr.mo.ftov/cn
v/hwD/tanks/docs/soil-pns-
Drotocol-2005-04-21.Ddf
-------
Table 1
Summary of Literature Review Results
Active Soil Vapor Sampling
Document
NJ-DEP Vapor
Intrusion Guidance
NY-DOH Soil
Vapor Intrusion
Guidance
ASTMD4314-
92(2001)
Method Scope
Guidance applies to soil vapor intrusion
investigation in New Jersey State. A
generalized description of soil gas sampling
methods is contained in Section 6.3.2; specifics
are to be proposed in work plans. Sub-slab
sampling is addressed in Section 6.4; specifics
arc drawn from US EPA Guidance (March
2006), and specify embedded pipe segments in
floor slab for permanent probes, and 1/8 to 3/8"
tubing inserts for temporary probes. Sub-slab
sample locations should be centered beneath
slab. Indoor air sampling is also discussed
along with appropriate analytical methods.
Guidance applies to soil vapor intrusion
investigation in New York State. Sample types
include soil vapor, sub-slab, indoor air, and
outdoor air; all are active samples. Sampling to
occur during period of structure heating
(November through March), and at one other
time for comparison. Sample locations to
include vicinity of building foundation, along
foundation perimeter, and below foundation at
footing depth. Permanent probes are
recommended. Probe 'tip installed in center of
sand pack via direct-push or HSA, with 1/8 to
1/4" tubing extending up to grade. Sampling to
occur after 24 hours equilibration. Tracer gas
used in all samples, tracer gas injected under a
ground covering tarp or within enclosure
covering sample location. Analytical
recommendations include TO- 15, NYSDOH
Method 31 1-9.
Very broad guidance document that includes
discussion of methods and materials associated
with passive and active soil gas sampling using
a variety of sampling, process, and analytical
methods; no base case scenario discussed.
Purge Rate
Maximum of 200 ml/min
Maximum of 200 ml/min
NA
Purge Volume .Sample Volume
Purge 3 volumes.
Alternative approach is to purge until field
parameters (CO2 and O2) have stabilized.
Purge volume should be minimized.
One to three volumes. Appears to imply that this
should be done only once after probe installation.
NA
Cites 1 -liter and 6-liter
Summas as the most
common, but
recommends small
sample size.
Dependent on volume
required to meet DLs
NA
Other Variables
Holding time for Tedlar
bags should not exceed 3
hours.
Holding time for a glass
bulb is 24 hours
Equilibration time of 24
hours for permanent
probes is implied. For
temporary probes.
purging should begin
"shortly after installation"
Comments
Stipulates that the lab
must be certified for an
appropriate AIR method.
and cites TO-1 5 as the
most common.
Discusses sample
collection through drive-
rods, not semi-permanent
sampling points.
Samples must be
collected using
"conventional methods"
and in "appropriate
containers."
Requires use of tracer gas
to verify an adequate seal.
but states that once this
has been demonstrated
use of the tracer can be
reconsidered, but must be
at least 10 percent of
subsequent samples.
ASTM Standard'does not
speak to purge rate, purge
volume, or sample
volume.
Author/Date
New Jersey Department
of Environmental
Protection, October
2005 (updated March
2006).
New York State
Department of Health,
February 2005 (public
comment draft)
American Society for
Testing and Materials,
1992 (updated 2001)
Webllnk
littD://www.statc.ni .us/den/
sro/Ruidancc/viiDorintrusio
n/vJR.hlm
httD://www.hcnlth.statc.nv.
us/nvsdoh/nas/svi euidanc
c/loc.htm,
httD://www,f»Rtm .ore/cRi -
bin/SoflCnrt.exc/DATA BA
SE.CART/REDLINE PAG
ES/D5314.htm?L+mvstorc
+krcm2800+l 144733377
-------
Table 1
Summary of Literature Review Results
Active Soil Vapor Sampling
Document
McAlary &
Creamer
ITRC Vapor
Intrusion Guidance
Method Scope
Paper researching purge rate and purge volume
on sample result for sub-slab vapor sample
collection. Standard method used was
accessing existing sub-slab probes for high
volume purging and sampling; helium was used
as tracer during purging; samples collected in
Tedlar bags for field analysis (oxygen, carbon
dioxide, and VOCs [using P!D]), and for lab
analysis of gasoline range hydrocarbons using
TO-3.
Guidance document that is geared for use by
regulators, consultants, and stakeholders for
assessing the vapor intrusion pathway.
Protocols for sampling and analysis of soil
vapor are described in an Appendix. Describes
(rather than prescribes) general considerations
in sampling design, and addresses various
available options, while providing the reference
associated with each option discussed, and the
attendant advantages/disadvantages for each
option. No single standard method is endorsed,
other than a recommended purge procedure.
Purge Rate
Purged discrete samples at <150
ml/min.
Followed by study of purge rate
and volume effects with purge rates
of 1 L/min and 10 L/min
References 200 ml/min standard
required by most agencies.
Purge Volume (Sample Volume
Purged appoximately 0.7 L for discrete samples.
volume of sample system deadspace not specified.
Purged up to 600 L for study of purge rate and
volume effects.
Recommends minimum of three to four purge
volumes. Purge volume test optional.
Not specified
t
Volumes <1 liter
recommended for
shallow (<3' bgs)
samples.
Other Variables
Vacuum at 1 L/min purge
rate was ~1 inch H2O.
Vacuum at 10 L/min was
-10 inches H2O.
References most agencies
require vacuums less than
15 percent of atmospheric
(5 in Hg).
Comments
Study evaluated results
for C5 to CIO
hydrocarbons in soil
vapor sampled from
subslab engineered fill
material. Goal was to
compare the mean results
from a number of
"discrete" (low purge rate.
low purge volume)
samples to "representative
elemental volume"
samples expected to be
representative of average
subslab conditions (high
purge rate, high volume).
Document going through
final review, but criteria
listed here unlikely to
change.
Author/Date
McAlary, T. and
Creamer, T., in
preparation
ITRC Vapor Intrusion
Team, in preparation
Web link
NA
wwwJtrCDCt.ora
-------
Appendix B
Sampling Trip Report
-------
SAMPLING TRIP REPORT
for
DEVELOPMENT OF ACTIVE SOIL GAS
SAMPLING METHOD
Prepared by:
Tetra Tech EM Inc.
1230 Columbia Street
Suite 1000
San Diego, CA 92101
EPA Contract #EP-C-05-061
Task Order No. 5
November 2006
Prepared for:
Brian A. Schumacher, Task Order Project Officer
National Exposure Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Las Vegas, NV 89114
&EPA
TETRA TECH EM INC.
-------
Revision: 0
Date: October 2006
Page: 1
1.0 INTRODUCTION
This Trip Report provides a summary of the sampling activities that were conducted between October 10
and October 18, 2006 at Vandenberg Air Force Base (AFB) Installation Restoration Program (IRP) Site
15. The sampling was conducted on behalf of the U.S. Environmental Protection Agency (EPA), Office
of Research and Development, in support of the project titled Development of Active Soil Gas Sampling
Method, conducted under EPA Contract Number EP-C-05-061, Task Order Number 5 (TO-05).
Vandenberg AEB is located on the south-central coast of California, approximately halfway between San
Diego and San Francisco. The base covers approximately 98,000 acres in western Santa Barbara County
and is headquarters for the 30th Space Wing. IRP Site 15 consists of three coffin-type missile launchers
that were used to launch Atlas missiles from 1960 to 1967. Site 15 is located immediately southeast of
the intersection of Umbra and Tethys Roads, on north Vandenberg AFB (Figure 1). The survey site
consists of an open area of sand dunes directly south of Building 1833 (Figure 2).
The project field team included environmental consultants from Tetra Tech, Inc. (James Elliot, David
Springer, Michele Mykris, and Joachim Eberharter), technicians from H&P Mobile Geochemistry
(Tamara Davis, Blayne Hartman, and Dave Balkenbush), and drill rig operators from Interphase
Environmental, Inc. (Erik Alvarez and Danny Alvarez). Observers on site during the study included Mike
Martin (EPA), Andy Edwards and Pablo Martinez (Vandenberg AFB IRP), Kathy Gerber (Air Force
Center for Environmental Excellence), Linda Stone (Regional Water Quality Control Board) and Matt
Peterson and Paul LeCheminant (Tetra Tech). Personnel from Tetra Tech, H&P, and Interphase arrived
at the survey site on Tuesday October 10. Field work continued through October 18 and included
exploratory drilling, soil-gas probe installation, and soil gas sampling and analysis. Photographs of the
field effort are provided in Appendix A.
2.0 WEEK ONE: DRILLING AND PROBE INSTALLATION
For clarity, the following nomenclature is used in discussing the field effort. The term "temporary
sampling point" is used to refer to soil gas sampling locations that were installed with the intention of
sampling only once to qualitatively assess the concentrations of soil gas present. The term "soil gas
probe" is used to refer to sampling locations that were constructed according to the guidelines presented
in the Quality Assurance Project Plan (QAPP) and that were installed with the intention of sampling as
part of the method development testing.
Exploratory Drilling and Grid Planning
The objective of the first phase of the field investigation was to identify a suitable area of Site 15 to install
the soil-gas probe grid. The strategy used was to collect soil gas samples from temporary sampling points
in geoprobe borings and then use the information obtained for subsequent borehole/sampling point
placement, until an appropriate area was identified to install the semi-permanent probe grid. A total of 17
boreholes were drilled and sampled during this effort, over a 1.5-day period.
The first week of the field study began on Tuesday, October 10. The project field team began work with
exploratory drilling and probe location planning. Mr. James Elliot, Site Superintendent, was primarily
responsible for field coordination and was assisted by Michele Mykris. Ms. Tamara Davis, analytical
chemist, operated all mobile lab instruments and collected soil gas samples. Erik Alvarez and Danny
Alvarez, drill rig operators with InterPhase, were responsible for operating the 6610DT GeoProbe direct
push drill rig (Appendix A: Photograph 1). A drill rig mounted on tracks was chosen for this project due
its maneuverability on sand dunes where traditional four-wheel-drive trucks are not practical.
-------
SANTA
MARIA
PACIFIC
OCEAN
UNITED STATES AIR FORCE
VANDENBERG AIR FORCE BASE
LOCATION OF IRP SITE 15
VANDENBERG AIR FORCE BASE,
CALIFORNIA
TETRA TECH EM, INC.
1230 Columbia Street, Suite 1000
San Diego, CA92IOI
1" =dpprox 15,000ft
-------
LEGEND
CONTOUR OF GROUND SURFACE
/"^\ ELEVATION IN FEET ABOVE MSL
(5-FOOT INTERVALS) (NAVD 1968)
— >— FENCE
*»o»* PAVED ROAD OR STREET
DIRT ROAD
•HI BUILDING
| CONCRETE OR PAVED AREAS
VEGETATION LINE
-4.I5-MK-7GROUNDWATER MONITORING WELL WITH
120 TCE CONCENTRATION (>jg/L) MEASURED
IN NOVEMBER 2005
— . . — SITE BOUNDARY
.'"' EXTENT OF TCE IN (jg/L (DASHED WHERE
INFERRED)
SOIL GAS SAMPLING GRID POINT
PROPOSED IN QAPP
150' 300' 450'
SCALE
UNITED STATES AIR FORCE
VANDENBERG AIR FORCE BASE
IRP SITE 15
SOIL GAS SAMPLING GRID
PROPOSED IN QAPP
TASK NO.
18061-0
TETRA TECH EM, INC.
1230 Columbia Street. Suite 1000
San Diego. CA 921Q1
DATE
11/6/06
DRAWN BY
RANDALL
DWG NO.
5925
Fi9ure
2
-------
Revision: 0
Date: October 2006
Page: 4
Site field operations began with the measurement of groundwater elevation at the existing monitoring
wells 15MW11 and 15MW12 (Figure 2). At well 15MW11, groundwater was encountered at
approximately 18.5 feet below ground surface (bgs). Groundwater in well 15MW12 was approximately
22.4 feet bgs.
Trichloroethene (TCE) concentrations in groundwater at IRP Site 15 have been investigated through the
Vandenberg IRP and the groundwater plume is reasonably well understood. Figure 2 shows groundwater
TCE concentrations contours, based on data collected in November 2005, which were used to identify the
approximate location for the soil gas sampling grid, as proposed in the QAPP. However, no previous soil
gas samples had been collected in the specific area of Site 15 proposed for this investigation; therefore, a
preliminary soil gas survey was necessary to gather soil gas data and optimize placement of the sampling
grid. Using the proposed soil gas probe location map prepared for the QAPP, temporary sampling points
were placed at locations Al and Cl (Figure 2, Appendix A: Photograph 2). Locations Al and Cl were
drilled to a depth of 18 feet bgs in an attempt to sample soil gas directly above the water table. The
targeted sampling depths were selected based on the depth to groundwater at well 15MW11 and the
estimated difference in surface elevation between well 15MW11 and the boring locations. Temporary
sampling points were placed at the bottom of each boring by placing an expendable steel drive point on
the drill rod, drilling to the target sampling depth, threading 1/4-inch Nylaflow tubing onto the
expendable drive point, and pulling the drill rod up approximately 6 to 12 inches leaving the drive tip in
place. After allowing 30 minutes for re-equilibration, soil gas samples were collected from the temporary
sampling points and analyzed for TCE, c/s-l,2-dichloroethene (DCE), and trans-\,2-DCE by the on-site
mobile laboratory operated by H&P Mobile Geochemistry. The results for samples Al and Cl were non-
detect (ND) for all three compounds. Step-out locations were completed to the north of locations Al and
Cl and to the south of locations A5, and C5. Results for soil gas samples collected from south of
locations A5 and C5 were ND; however, the samples collected north of locations Al and Cl contained
TCE at concentrations ranging from 120 to 210 micrograms per cubic meter (ug/m3). Based on these
results, it was determined that subsequent soil gas sampling would focus on areas to the north of the grid
proposed in the QAPP, where higher groundwater concentrations were known to exist and where
detectable levels of TCE were present in soil gas.
Additional borings were completed at locations near 15MW11 and in areas to the northeast of the QAPP
sampling grid. Results for soil gas samples collected from these borings ranged from ND to 400 ug/m3
for TCE. A temporary sampling point was left in the ground overnight at a location approximately 350
feet northeast of location Bl, where a TCE concentration of 300 ug/m3 was measured; other sampling
points were abandoned after initial sampling results were recorded.
On October 11, project personnel returned to the Site and resampled the point that had been left in the
ground overnight. TCE was measured at a concentration of 3,300 ug/m3. This point was resampled twice
more throughout the day, with results of 5,500 and 2,000 ug/m3 for TCE. Based on these observations, it
became apparent that while the concentrations obtained on the previous day (October 10) were relatively
low, the relatively low measured concentrations may have been due to the short time between sampling
point installation and sample collection.
Additional exploratory borings at location B1 and areas to the north were advanced on October 11.
Temporary sampling points were installed in each boring, and were allowed to equilibrate while other
borings were advanced. Results from location Bl were ND; however, results from three borings to the
south of Building 1833 ranged from 940 to 2,300 ug/m3 for TCE.
-------
Revision: 0
Date: October 2006
Page: 5
Semi-Permanent Soil-Gas Probe Installation
Based on preliminary soil gas results, it was determined that soil gas concentrations were highest in an
area to the northeast of the grid location proposed in the QAPP, south of Building 1833, and northwest of
the area of seasonal standing water shown on Figure 2; therefore, the semi-permanent probe grid was
developed within this area.
After identifying the final grid area and orientation, five probes for the Site 15 "A" tract were installed on
October 11 and 12 with a spacing of 40 feet between each probe along a bearing of N50°W (to. parallel
the orientation of sand dune swales) (Figure 3, Appendix A: Photograph 3). The A tract probes were
designated 15-SV-A1 through 15-SV-A5. The "B" and "C" tracts were completed on October 12. The
five tract "B" probes were completed along the same bearing and with the same spacing as tract A, but the
tract was located 100 feet to the south-southwest. Tract B probes were designated 15-SV-B1 through 15-
SV-B5. Tract C probes were completed with the same bearing and spacing as tract A, but the tract was
located 40 feet to the north-northeast of tract A (Appendix A: Photograph 4). The tract C probes were
offset by 40 feet to the southeast and were designated 15-SV-C2 through 15-SV-C6. The latitude and
longitude of each installed probe is summarized in Table 1 and the locations are plotted on Figure 3. One
probe location within each tract was continuously cored using acetate soil sleeves in order to log the
subsurface lithology. These locations were 15-SV-A1, 15-SV-B3, and 15-SV-C5 (Appendix A:
Photographs 5 and 6).
Most pilot holes were advanced to the planned depth, which ranged from 14 to 19 feet bgs, as needed to
position the sampling probes a targeted distance of 2 to 4 feet above the groundwater table (Table 1).
Pilot holes for probes 15-S-A1, 15-SV-B3, and 15-SV-C5 were installed to depths of 24, 24, and 22 feet
bgs, respectively, for soil logging purposes, and then backfilled with 2/12 sand to the planned probe
depth.
Sampling probes were constructed as follows. Approximately 4 inches of 2/12 sand was poured into the
bottom of the borehole. A 1-inch long gas-permeable membrane sampling probe, attached to 1/4-inch
Nylaflow tubing, was then lowered through the drill rod to the top of the 2/12 sand. Additional 2/12 sand
was then poured around the sampling probe until it extended approximately 2 inches above the membrane
to comprise a sand pack. Approximately 12 inches of dry bentonite was then placed on top of the sand
pack, followed by hydrated bentonite to the surface. The sampling probes were completed at the surface
with approximately 18 inches of Nylaflow tubing extending out of the borehole and with a Swagelok
valve inserted at the end of the tubing to seal it. The surface completions were protected with 3-inch
diameter acrylonitrile butadiene styrene (ABS) plastic pipes with slip-cap covers. The procedure for
installing the soil gas sampling probes was repeated at all of the borings. Borings that were drilled deeper
than the intended probe installation depth were backfilled with sand to the target probe depth. In these
borings, sand packs were recorded as the total length of the sand from the bottom of the boring to a depth
approximately 2 inches above the soil gas probe (Table 1).
All 15 soil gas probes were sampled on October 12 (no less than 30 minutes after installation) and
analyzed for TCE, c/5-l,2-DCE, and trans-\,2-DCE. Probes were purged at a rate of 200 milliliters per
minute (ml/min) to a total volume equal to three times the system volume. A 60 milliliter (ml) sample
was then collected using a syringe. Soil gas probe installation data and the October 12 sample results are
presented in Table 1. TCE was the only compound detected in any of the samples; no cis- or trans-\,1-
DCE was detected.
-------
\
CONTOUR OF GROUND SURFACE
ELEVATION IN FEET ABOVE MSL
(5-FOOT INTERVALS) (NAVD 1988)
FENCE
PAVED ROAD OR STREET
DIRT ROAD
BUILDING
CONCRETE OR PAVED AREAS
VEGETATION LINE
^ is-Mw-li GROUNDWATER MONITORING WELL
15-SV-C2 SOIL GAS SAMPLING GRID POINT
(INSTALLED OCTOBER 2006)
50' 100' 150'
SCALE
UNITED STATES AIR FORCE
VANDENBERG AIR FORCE BASE
IRP SITE 15
SOIL GAS SAMPLING GRID
TETRA TECH EM, INC.
1230 Columbia Street, Suite 1000
Son Diego. CA 92101
DATE
11/6/06
DRAWN BY
RANDALL
Figure
3
-------
Revision: 0
Date: October 2006
Page: 7
Table 1
Soil Gas Probe Installation Details
Location
15-SV-A1
15-SV-A2
15-SV-A3
15-SV-A4
15-SV-A5
15-SV-B1
15-SV-B2
15-SV-B3
15-SV-B4
15-SV-B5
15-SV-C2
15-SV-C3
15-SV-C4
15-SV-C5
15-SV-C6
Installation Date
October 11,2006
October 11,2006
October 12, 2006
October 12, 2006
October 12, 2006
October 12,2006
October 12, 2006
October 12,2006
October 12,2006
October 12, 2006
October 12, 2006
October 12, 2006
October 12, 2006
October 12, 2006
October 12, 2006
Coordinates
(latitude and
longitude)
34.79330957,
-120.6015641
34.79325593,
-120.6014622
34.79318619,
-120.6013549
34.79313254,
-120.6012423
34.79306817,
-120.6011296
34.79308963,
-120.6017573
34.79301453,
-120.6016553
34.79296088,
-120.6015534
34.79289115,
-120.6014461
34.79283214,
-120.6013388
34.79336321,
-120.6013764
34.79328275,
-120.6012691
34.79322374,
-120.6011564
34.793154,
-120.6010652
34.79308963,
-120.6009472,
Probe
Depth
(feet bgs)
17.5
16.5
17
17
17
17
17
18
18.5
19
14
15.5
15.5
15.5
15
Length of
Sandpack
(inches)
84
12
6
6
6
6
6
58
6
6
6
6
6
20
6
System
Volume
(ml)
70
66
68
68
68
68
68
72
74
76
56
62
62
62
60
October 12
TCE Result
(jig/m3)
260
1400
1700
840
490
120
140
720
430
120
1600
2300
2400
420 .
660
Notes:
bgs - below ground surface
ug/m3 - micrograms per cubic meter
ml - milliliters
, TCE - trichloroethene
-------
Revision: 0
Date: October 2006
Page: 8
3.0 WEEK TWO: SAMPLE COLLECTION
Analytical data collected during the first week of sampling were considered screening level data only and
were therefore not subject to careful quality control (QC) review. Analytical data collected during the
second week are considered the quantitative data upon which the results of this investigation will be
based. These data are currently under QC review and are therefore considered draft data and are not
presented in this report. All of the analytical data will be presented in the final project report.
Baseline Sampling
During the second week of the field study, the Tetra Tech field team (James Elliot, David Springer, and
Joachim Eberharter) were responsible for field coordination. H&P Mobile Geochemistry personnel
(Tamara Davis, Blayne Hartman, and David Balkenbush) operated all mobile lab instruments and
collected all soil gas samples (Appendix A: Photographs 7 and 8). The first day of sampling (Monday
October 16) began with baseline sampling of all of the probes installed during the prior week. Sample
probes were purged at a rate of 200 ml/min to a total volume equal to three system volumes. The system
volume was considered the volume of the 1/4-inch Nylaflow tubing plus the volume of the probe, and
was calculated using 4 ml per foot as the tubing volume. System volumes for each probe are shown on
Table 1. The sample volume for all baseline samples was 60 ml. Results of the October 16 baseline
sampling will be included in the final report.
x
Purge Rate Test
The sampling test to explore the affect of purge rate on analytical results was performed on October 16.
All samples for the test were collected from the five probes installed along the B tract (Figure 3). The B
tract was selected because the baseline sampling indicated a broad range of TCE concentrations are
present along this tract. Purge volumes were equal to three system volumes for each individual probe.
According to procedures outlined in the QAPP, three system volumes were purged from each probe for
each sample collected. Each of the probes was first purged at a rate of 100 ml/min, followed by purging
each probe at rates of 200 ml/min, 500 ml/min, 1,000 ml/m, and 2,000 ml/min. Purging at 100 and 200
ml/min was performed using a syringe. Purging at faster rates was performed using a portable, battery
operated pump (Appendix A: Photograph 9). After purging, 60 ml samples were collected from each
probe using a syringe.
With time available at the end of the first day of sampling, additional variations were tested. Two
samples each were collected from probes 15-SV-B1 and 15-SV-B3 using the pump to purge at a rate of
5,000 ml/min. For the first sample, the probes were purged for 6 seconds, or approximately seven system
volumes. For the second sample, the probes were purged for 3 minutes, or approximately 200 system
volumes. These samples were collected to assess the impacts of using an excessive purge rate and a total
purge volume that is well above industry standards and considered likely to stress the system.
Purge Volume Test
The sampling test to explore the effect of purge volumes on analytical results was performed on October
17. Internal discussions following the purge-rate test the previous day led to the determination that the
sampling locations should be chosen randomly rather than selecting an individual tract for conducting the
tests. Therefore, five randomly selected probes were chosen for the purge volume test: 15-SV-B1,
15-SV-B4, 15-SV-A2, 15-SV-A4 and 15-SV-C4. In accordance with the procedures outlined in the
QAPP, probe 15-SV-B1 was purged to 1, 2, 3, 6 and 10 system volumes with 60 ml samples collected
after each purge interval. Purging and sampling was conducted in sequence by tracking the cumulative
purge volume, which consists of the volume purged and released from the system plus the volume of each
-------
Revision: 0
Date: October 2006
Page: 9
sample collected (e.g. 15-SV-B1 has a system volume of 68 ml, thus 68 ml were purged followed by
collection of a 60 ml sample [the 1-purge-voume sample] followed by purging of an additional 8 ml and
collection of the next 60 ml sample [the 2-purge-volume sample]). Analytical results appeared to show a
step in detected soil gas concentrations between 3 and 6 purge volumes; therefore, the next two probes
(15-SV-B4 and 15-SV-A2) were sampled after purging 1, 2, 3, 4, 5, 6 and 10 system volumes. In
addition, probe 15-SV-A2 was sampled after purging 20 system volumes. Analytical results from 15-SV-
B4 and 15-SV-A2 suggested a step in soil gas concentrations between 6 and 10 purge volumes. For this
reason, a sample was collected after purging 8 and 20 system volumes at subsequent probes (15-SV-A4
and 15-SV-C4). An additional sampling test was performed at 15-SV-A4 to test a large volume purge,
well above industry standard purge volumes. The probe was purged for one hour at a rate of 5,000 ml/m,
or approximately 4,000 purge volumes, and then sampled.
As stated above, all fifteen semi-permanent probes were installed at depths approximately 2 to 4 feet
above the water table. During the testing, it was postulated that the reason for the apparent step in soil gas
concentrations observed at higher purge volumes might be that the radius of influence around the
sampling probe was intersecting the capillary fringe and altering the flow dynamics. To test this
hypothesis, a boring was drilled using an electric rotohammer to a depth of 5 feet bgs at a location
approximately 2 feet southeast of probe 15-SV-C4. A temporary probe was installed at 5 feet bgs and the
system was purged to 1, 2, 3, 6, 10, 20, and 120 system volumes; samples were collected after each purge.
The rationale was that with a probe set at only 5 feet bgs, it was unlikely that the sphere of influence
would intersect the capillary fringe and, therefore, the step in concentrations would not be observed. The
analytical results suggest a step may have been observed between 20 and 120 system volumes; however,
it remains to be determined if the apparent step is statistically significant
Sample Volume Test
The sampling test to explore the affect of sample volume on analytical results was performed on October
18. Samples were collected from five randomly selected probes: 15-SV-A1, 15-SV-B2, 15-SV-B3,
15-SV-C2 and 15-SV-C5. In accordance with the procedures outlined in the QAPP, each probe was first
purged at a rate of 200 ml/min to a volume equal to three system volumes. Five different sample volumes
were collected from each probe: 25, 60, 500, 1,000 and 6,000 ml. The 25 and 60 ml samples were
collected in 60 ml syringes. The 500 and 1,000 ml samples were collected in 1-liter Tedlar bags. Six-liter
SUMMA canisters were used to collect the 6,000 ml samples (Appendix A: Photograph 10).
4.0 FIELD QUALITY CONTROL
Beginning on the first day of quantitative sample collection (October 16), location 15-SV-A3 was
designated as the control probe. Samples were collected from this probe three to four times a day
throughout test sampling to monitor potential temporal variations in soil gas concentrations unrelated to
the principal parameters of purge rate, purge volume, and sample volume. Each sample from 15-SV-A3
was collected using the base settings of the principal parameters under investigation (i.e., purge rate of
200 ml/min, purge volume of three system volumes, and sample size of 60 ml).
Field replicate samples were collected from the control probe, 15-SV-A3, from 15-SV-C4 during the
.purge volume test, and from 15-SV-A1 and 15-SV-C5 during the sample volume test. Replicate samples
were collected to measure the reproducibility and precision of the total sampling system. Field replicates
were collected at a rate of approximately one replicate for every 10 QAPP specified field samples.
Leak tests were performed at two probe locations to monitor the integrity of the probe system and surface
seals. Leak tests consisted of placing a rag soaked in isopropyl alcohol (IPA) around the Nylaflow tubing
at the surface. Leak checks were performed at locations 15-SV-A4 and 15-SV-C4 during the purge
-------
Revision: 0
Date: October 2006
Page: 10
volume test. The leak test was performed at 15-SV-C4 throughout the purge volume test sampling at this
location. The leak test was performed at 15-SV-A4 while the probe was purged at 5,000 ml/min for 1
hour (approximately 4,000 purge volumes). No IPA was detected in any of the samples associated with
the leak checks. The absence of detectable IPA in any of the samples, particularly the sample obtained
from 15-SV-A4 under extreme purging conditions (5,000 ml/min for one hour) indicated the sample
probes were well sealed an no intrusion of ambient air was occurring. Based on these findings, use of
leak test chemicals was discontinued for the remainder of the program.
5.0 HEALTH AND SAFETY
Each field team member was required to sign a form acknowledging they had received and understood the.
site-specific health and safety plan. Each day of field work began with a Tailgate Health and Safety
meeting followed by equipment checking and preparation. The daily health and safety meetings were
conducted by the Tetra Tech site supervisor and covered site-specific health and safety concerns
(including physical, chemical, and biological hazards).
A hand held MiniRAE photoionization detector (PID) was used throughout the two weeks of field work
to monitor for potential volatile organic compounds (VOCs) in the ambient breathing space air. The
MiniRAE PID did not indicate the presence of any VOCs elevated above background at any time.
There were no accidents or other health and safety incidents during the field program.
-------
APPENDIX A SITE PHOTOGRAPHS
-------
Photograph 1 - Geoprobe 6610DT track mounted direct push drill rig.
Photograph 2 - Drilling at location Cl
PageA-1
-------
Photograph 3 - "A" Tract soil vapor probes.
Photograph 4 - Installation of "C" Tract probes
Page A-2
-------
Photograph 5 - Soil cores from 15-SV-A1. Soils increase in depth from right to left and from bottom to
top of field of view. Each acetate sleeve is 4 feet long. Soils from greater depths are darker due to higher
moisture content; soil type and composition is homogeneous throughout borehole.
Photograph 6 - Close-up of soil cores from 15-SV-A1.
Page A-3
-------
Photograph 7 - Sampling at 15-SV-B5
Photograph 8 — Gas chromatograph used for study.
Page A-4
-------
Photograph 9 - Sampling using battery operated pump to purge and 60 ml syringe for sample collection.
Photograph 10 - Sampling using a 6-liter SUMMA canister.
Page A-5
-------
Appendix C
Laboratory Data Package
-------
MOBILE f GEOCHEMISTRY
H&P
Mr. Greg Swanson
Tetra Tech EMI Inc.
1230 Columbia Street
10th Floor, Suite 1000
San Diego, CA 92101
October 30, 2006
SUBJECT: DATA REPORT - IRP SITE 15 STREAMS - VANDENBERG AFB, CA -
TETRA TECH EMI PROJECT #06LW-P0013
H&P Project #TT101006-L5
Mr. Swanson:
Please find enclosed a data report for the above referenced location. Vapor samples were analyzed on-
.site in H&P's mobile laboratory.
Project Summary
The following analyses were conducted:
• 202 vapors for TCE by EPA Method 8021
The samples were received on-site in appropriate containers with appropriate labels, seals, and chain-of-
custody documentation.
Project Narrative
The results for all analyses and required QA/QC analyses are summarized in the enclosed tables. All
calibrations, blanks, surrogates, and spike recoveries fulfill quality control criteria. No data qualifiers
(flags) apply to any of the reported data.
H&P Mobile GeoChemistry appreciates the opportunity to provide analytical services to Tetra Tech EMI
Inc. on this project. If you have any questions relating to this data or report, please do not hesitate to
contact us.
Sincerely,
lfl$\/Jfy\AAw\
Harmian
2470 Impala Drive, Carlsbad .California 92010 f 760.804.9678— Fax 760.804.9159
3825 Industry Avenue, Lakewood , California 90712 | 562.426.6991— Fax 562.426.6995
www.HandPmg.com
1-800-834-9888
-------
MOBILE f GEOCHEMISTRY
H&P
TETRA TECH PROJECT #06LW-P0013
IRP SITE 15 STREAMS
VANDENBERGAFB, CA
H&P Project #TT101006-L5
TCE (EPA METHOD 8021) ANALYSES OF SOIL VAPOR
Sample ID
A1
C1
A5-1
C5
C1-1
C1-1 dupe
15M211
C1-2
A1-1
A1-1 dupe
B1-1
B1-1 dupe
B1-2
C1-2B
B1-3
B1-3dupe
A1-2
DETECTION LIMITS
ND INDICATES NOT
DATE
10/10/06
10/10/06
10/10/06
10/10/06
10/10/06
10/10/06
10/TO/06
10/10/06
10/10/06
10/10/06
10/10/06
10/10/06
10/10/06
10/10/06
10/10/06
10/10/06
10/10/06
DETECTED AT LISTED
TIME
11:15
11:15
11:53
11:53
12:40
12:40
13:08
14:24
15:10
15:10
15:44
15:44
16:10
16:10
16:40
.16:40
17:16
DETECTION LIMITS
TCE
(ug/m3)
ND
10
ND
ND
210
230
ND
10
180
120
460
380
230
15
200
200
400
5
ANALYSES PERFORMED IN H&P'S MOBILE LABORATORY
ANALYSES PERFORMED BY: MS. TAMARA DAVIS
ANALYSES REVIEWED BY: DR. BLAYNE HARTMAN
-------
MOBILE f GEOCHEMISTRY
H&P
TETRATECH PROJECT #06LW-P0013
IRP SITE 15 STREAMS
VANDENBERG AFB, CA
H&P Project #TT101006-L5
TCE (EPA METHOD 8021) ANALYSES OF SOIL VAPOR
Sample ID
B1-1
A1-4
A1-3
B1-4
C-5
A5-1
B-1
B1-1 R
15-SV-A-1
15-SV-A-2
DETECTION LIMITS
ND INDICATES NOT
DATE
10/11/06
10/11/06
10/11/06
10/11/06
10/11/06
10/11/06
10/11/06
10/11/06
10/11/06
10/11/06
DETECTED AT LISTED DETECTION
TIME
8:21
8:57
9:18
9:36
10:02
10:02
11:37
12:10
16:50
16:55
LIMITS
TCE
(ug/m3)
3,300
2,100
940
1,800
170
32
ND
5,500
110
770
5
ANALYSES PERFORMED IN H&P'S MOBILE LABORATORY
ANALYSES PERFORMED BY: MS. TAMARA DAVIS
ANALYSES REVIEWED BY: DR. BLAYNE HARTMAN
-------
MOBILE f GEOCHEMISTRY
H&P
TETRA TECH PROJECT #06LW-P0013
IRP SITE 15 STREAMS
VANDENBERG AFB, CA
H&P Project #TT101006-L5
TCE (EPA METHOD 8021) ANALYSES OF SOIL VAPOR
Sample ID
B-1
B-1-1
B-1-1 dupe
A5-1'
B-3
C5-1
B1-5
15-SV-A1
15-SV-A2
15-SV-A3
1 5-SV-A4
15-SV-A5
A5-1
C5-1
B-3
15-SV-B4
15-SV-B3
15-SV-B5
15-SV-B2
15-SV-B1
B-1-1 resample
15-SV-C4
1 5-SV-C5
15-SV-C6
B-1-1 resample
B-1-1 resample dupe
15-SV-C3
15-SV-C2
DETECTION LIMITS
ND INDICATES NOT
DATE
10/12/06
10/12/06
10/12/06
10/12/06
10/12/06
10/12/06
10/12/06
10/12/06
10/12/06
10/12/06
10/12/06
10/12/06
10/12/06
10/12/06
10/12/06
10/12/06
10/12/06
10/12/06
10/12/06
10/12/06
10/12/06
10/12/06
10/12/06
10/12/06
10/12/06
10/12/06
10/12/06
10/12/06
DETECTED AT LISTED
TIME
8:05
8:05
8:05
8:30
8:35
8:20
8:40
9:20
9:21
9:22
10:00
10:00
11:40
11:41
11:42
11:45
11:46
12:50
12:51
12:52
13:15
15:45
15:45
16:10
16:12
16:12
16:40
16:41
DETECTION LIMITS
TCE
(ug/m3)
ND
6,400
6,000
ND
ND
ND
230
260
2,000
2,050
1,000
490
ND
ND
ND
430
720
120
150
120
7,000
2,800
420
660
4,500
4,500
2,650
1 ,800 ..
5 :; •
ANALYSES PERFORMED IN H&P'S MOBILE LABORATORY
ANALYSES PERFORMED BY: MS. TAMARA DAVIS
ANALYSES REVIEWED BY: DR. BLAYNE HARTMAN
-------
MOBILE f GEOCHEMISTRY
H&P
TETRA TECH PROJECT #06LW-P0013
IRP SITE 15 STREAMS
VANDENBERG AFB, CA
H&P Project #TT101006-L5
TCE (EPA METHOD 8021) ANALYSES OF SOIL VAPOR
Sample ID
B1-BL
B2-BL
B3-BL
B4-BL
B5-BL
A1-BL
A2-BL
A3-BL
A4-BL
A5-BL
C2-BL
C3-BL
C4-BL
C5-BL
C6-BL
A3-BL1200
B2-BL1200
B1-PR100
B2-PR100
B3-PR100
B4-PR100
B5-PR100
B1-PR200
B2-PR200
B3-PR200
B4-PR200
B5-PR200
DETECTION LIMITS
ND INDICATES NOT
DATE
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
DETECTED AT LISTED DETECTION
TIME
10:03
10:10
10:20
10:28
10:39
10:47
10:52
10:59
11:09
11:17
11:24
11:31
11:38
11:46
11:54
12:04
12:14
12:27
12:35
12:44
12:50
12:56
13:06
13:17
13:12
13:47
13:53
LIMITS
TCE
(ug/m3)
93
500
1,350
590
100
210
1,200
2,100
890
510
2,000
1,400
1,700
350
670
2,500
470
63
480
1,400
540
94
120
490
1,450
690
120 :. , ': .
5 . V: .•: . -;:
: /:'• '•••'<:.
ANALYSES PERFORMED IN H&P'S MOBILE LABORATORY
ANALYSES PERFORMED BY: MS. TAMARA DAVIS
ANALYSES REVIEWED BY: DR. BLAYNE HARTMAN
-------
MOBILE f GEOCHEMISTRY
H&P
TETRATECH PROJECT #06LW-P0013
IRP SITE 15 STREAMS
VANDENBERG AFB, CA
H&P Project #TT101006-L5
TCE (EPA METHOD 8021) ANALYSES OF SOIL VAPOR
Sample ID
B1-PR500
B2-PR500
B3-PR500
B4-PR500
B5-PR500
B1-PR1000
A3-BL1500
B2-PR1000
B3-PR1000
B4-PR1000.
B5-PR1000
B1-PR2000
B2-PR2000
B3-PR2000
B4-PR2000
B5-PR2000
B1-PR5000
B1-PR5000Arep
B3-PR5000
B3-PR5000A rep
A3-BL 1548
DETECTION LIMITS
ND INDICATES NOT
DATE
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
10/16/06
DETECTED AT LISTED DETECTION
TIME
16:13
14:20
14:27
14:33
14:40
14:54
15:03
15:10
15:18
15:24
15:30
15:44
15:50
15:55
16:02
16:08
16:27
16:31
16:35
16:41
16:48
LIMITS
TCE
(ug/m3)
120
520
1 ,700
760
150
120
1,600
700
1,700
800
150
130
660
1,800
960
140
150
150
2,100
2,200
2,350
5
ANALYSES PERFORMED IN H&P'S MOBILE LABORATORY
ANALYSES PERFORMED BY: MS. TAMARA DAVIS
ANALYSES REVIEWED BY: DR. BLAYNE HARTMAN
-------
MOBILE ^ GEOCHEMISTRY
H&P
TETRA TECH PROJECT #06LW-P0013
IRP SITE 15 STREAMS
VANDENBERG AFB, CA
H&P Project #TT101006-L5
TCE (EPA METHOD 8021) ANALYSES OF SOIL VAPOR
Sample ID
BLANK
A3-BL 09:00
B1-PV1
B1-PV2
B1-PV3
B1-PV6
B1-PV10
B4-PV1
B4-PV2
B4-PV3
B4-PV4
B4-PV5
B4-PV6
B4-PV10
A2-PV1
A2-PV2
A2-PV3
A2-PV4
A2-PV5
A2-PV6
A2-PV10
A2-PV20
A3-BL 12:00
A4-PV1
A4-PV2
A4-PV3
A4-PV4
A4-PV5
A4-PV6
A4-PV8
A4-PV10
A4-PV20
DATE
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
TIME
8:55
9:02
9:34
9:36
9:46
9:49
9:57
10:09
• 10:10
10:20
10:22
10:32
10:33
10:46
10:58
11:00
11:10
11:12
11:28
11:29
11:37
1 1 :46
11:55
12:03
12:04
12:11
12:12
12:22
12:23
12:38
12:40
12:54
TCE
(ug/m3)
ND
2,450
55
66
57
120
140
470
570
370
5.10
550
570
980
760
1,000
730
1,100
700
1,000
1,600
2,200
2,250
570 • .
710
480
640
520
710 •':
880 .:••'
960 .•"••';••''
1,200 ,. >>/
DETECTION LIMITS ; -5 ;:'
ND INDICATES NOT
DETECTED AT LISTED
DETECTION LIMITS
ANALYSES PERFORMED IN H&P'S MOBILE LABORATORY
ANALYSES PERFORMED BY: MS. TAMARA DAVIS
ANALYSES REVIEWED BY: DR. BLAYNE HARTMAN
-------
MOBILE f GEOCHEMISTRY
H&P
TETRATECH PROJECT #06LW-P0013
IRP SITE 15 STREAMS
VANDENBERG AFB, CA
H&P Project #TT101006-L5
TCE (EPA METHOD 8021) ANALYSES OF SOIL VAPOR
Sample ID
C4-PV1
C4-PV2
C4-PV2 dupe
C4-PV3
C4-PV4
C4-PV4 dupe
C4-PV5
C4-PV6
C4-PV8
C4-PV10
C4-PV20
A4-PV300L
A4-PV300L dupe
A3-BL 14:20
A3-BL REP
A5-BL
A1-BL
C4-PV1hp
C4-PV2hp
C4-PV3hp
C4-PV6hp
C4-PV10hp
C4-PV20hp
C4-PV20hp dupe
C4-PV100hp
C4-PV100hpdupe
DETECTION LIMITS
ND INDICATES NOT
DATE
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06 '
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
1.0/17/06
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
10/17/16
10/17/06
DETECTED AT LISTED DETECTION
TIME
13:01
13:02
13:02
13:14
• 13:15
13:15
13:37
13:38
13:52
13:53
14:04
14:12
14:12
14:20
14:21
14:37
14:39
14:46
14:47
15:00
15:01
15:15
15:16
15:16
15:38
15:38
LIMITS
TCE
(ug/m3)
1,200
1,500
1,400
760
1,000
1,000
1,000
1,300
1,450
1,800
2,600
1,100
790
2,300
2,400
670
270
180
470
400
570
660
590
690
850
760
5
ANALYSES PERFORMED IN H&P'S MOBILE LABORATORY
ANALYSES PERFORMED BY: MS. TAMARA DAVIS
ANALYSES REVIEWED BY: DR. BLAYNE HARTMAN
-------
MOBILE f GEOCHEMISTRY
H&P
TETRATECH PROJECT #06LW-P0013
IRP SITE 15 STREAMS
VANDENBERG AFB, CA
H&P Project #TT101006-L5
TCE (EPA METHOD'8021) ANALYSES OF SOIL VAPOR
Sample ID
A3-BL
A3-BL REP
A1-PV25
A1-PV60
A1-PV60dupe
A1-PV500
A1-PV1000
B2-PV25
B2-PV60
B2-PV500
B2-PV1000
A1-PV6000
A1-PV6000dupe
B3-PV25
B3-PV60
SB3-PV500
B3-PV1000
B3-PV1 000 dupe
B2-PV6000
C2-PV25
C2-PV60
A3-BL
A3-BL REP
B3-PV6000
C2-PV500
C2-PV1000
A1 after 6L
C2-PV6000
C5-PV25
C5-PV60
C5-PV500
C5-PV1000
C5-PV1 000 dupe
A3-BL
A3-BL REP
C5 PV6000
DATE
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
TIME
9:00
9:01
9:25
9:26
9:26
9:31
9:40
9:51
9:52
9:58
10:02
10:05
10:05
10:30
10:29
10:32
10:37
10:37
10:56
11:14
11:15
11:35
1 1 :40
11:30
11:33
11:39
12:11
12:41
12:45
12:46
12:48
12:55
12:55
13:44
13:45
13:42
TCE
(ug/m3)
2,150
2,400
220
160
160
350
430
500
570
780
830
120
140
820
1,600
2,900
3,300
4,000
690
2,500
1 .500
2,450
2,700
2,000
3,000
3,600
280
2,000 :
240
350 :-;:
250 "".-•
660 ,•.•:•'•".
650 ; .- :
2,400 .-:-: '"' x'v
.•'•"1.-J900 •:
..-:/.--'380 ;.;.
DETECTION LIMITS :.;W : 5 •','•' A
ND INDICATES NOT
DETECTED AT LISTED
DETECTION LIMITS
•••,:.£.;-. .. ^.'i;.v
ANALYSES PERFORMED IN H&P'S MOBILE LABORATORY
ANALYSES PERFORMED BY: MS. TAMARA DAVIS
ANALYSES REVIEWED BY: DR. BLAYNE HARTMAN
-------
MOBILE f- GEOCHEMISTRY
H&P
TETRA TECH PROJECT #06LW-P0013
IRP SITE 15 STREAMS
VANDENBERG AFB,CA
H&P Project #TT101006-L5
TCE (EPA METHOD 8021) ANALYSES OF SOIL VAPOR
Sample ID
C1-1
C1-1 dupe '
A1-1
A1-1 dupe
B1-1
B1-1 dupe
B1-3
B1-3dupe
B-1-1
B-1-1 dupe
B-1-1 resample
B-1-1 resample dupe
B1-P R6000
B1-PR5000Arep
B3-PR5000
B3-PR5000A rep
C4-PV2
C4-PV2 dupe
C4-PV4
C4-PV4 dupe
DETECTION LIMITS
ND INDICATES NOT
DATE
10/10/06
10/10/06
10/10/06
10/10/06
10/10/06
10/10/06
10/10/06
10/10/06
10/12/06
10/12/06
10/12/06
10/12/06
10/16/06
10/16/06
10/16/06
10/16/06
10/17/06
10/17/06
' 10/17/06
10/17/06
DETECTED AT LISTED DETECTION
TIME
12:40
12:40
15:10
15:10
3:44
3:44
16:40
16:40
8:05
8:05
16:12
16:12
16:27
16:31
16:35
16:41
13:02
13:02
13:15
13:15
LIMITS
TCE
(ug/m3)
210
230
120
120
300
340
190
200
6,400
6,000
4,500
4,500
150
150
2,100
2,200
1,500
1 ,400
1 ,000 . A :
1 ,000 . ' \
5 '";:.";
.. .'-xi'-:.:.
ANALYSES PERFORMED IN H&P'S MOBILE LABORATORY
ANALYSES PERFORMED BY: MS. TAMARA DAVJS
ANALYSES REVIEWED BY: DR. BLAYNE HARTMAN
-------
MOBILE f GEOCHEMISTRY
H&P
TETRA TECH PROJECT #06LW-P0013
IRPSITE 15 STREAMS
VANDENBERG AFB, CA
H&P Project #TT101006-L5
TCE (EPA METHOD 8021) ANALYSES OF SOIL VAPOR
Sample ID
A4-PV300L
A4-PV300L dupe
A3-BL 14:20
A3-BL REP
C4-PV20hp
C4-PV20hp dupe
C4-PV100hp
C4-PV100hpdupe
A3-BL
A3-BL REP
A1-PV60
A1-PV6Odupe
A1-PV6000
A1-PV6000dupe
B3-PV1000
B3-PV1 000 dupe
A3-BL
A3-BL REP
C5-PV1000
C5-PV1 000 dupe
A3-BL
A3-BL REP
DATE
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
10/17/06
10/17/16
10/17/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
10/18/06
TIME
14:12
14:12
14:20
14:21
'15:16.
15:16
15:38
15:38
9:00
9:01
9:26
9:26
10:05
10:05
10:37
10:37
11:35
11:40
12:55
12:55
13:44
13:45
TCE
(ug/m3)
1,100
790
2,300
2,400
590
690
850
760
2,200
2,400
160
160
120
140
3,300
4,000
2,450
2,700
660
650 .:v'
2,400 •''..'?
1,900 0,;<
DETECTION LIMITS :. .;5 -; "
ND INDICATES NOT
DETECTED AT LISTED
DETECTION LIMITS
.-• •''''-•'••.'.;.' ' ' '• :;--.:•'
ANALYSES PERFORMED IN H&P'S MOBILE LABORATORY
ANALYSES PERFORMED BY: MS. TAMARA DAVIS
ANALYSES REVIEWED BY: DR. BLAYNE HARTMAN
-------
MOBILE f GEOCHEMISTRY
H&P
TETRA TECH PROJECT #06LW-P0013
IRP SITE 15 STREAMS
VANDENBERG AFB, CA
H&P Project #TT101006-L5
TCE (EPA METHOD 8021) ANALYSES OF SOIL VAPOR
Sample ID DATE TCE
. (ug/m3)
A1-PV6000 11/03/06 180
B2-PV6000 11/03/06 530
B3-PV6000 11/03/06 2,200
C2-PV6000 11/03/06 2,700
C5-PV6000 11/03/06 400
DETECTION LIMITS 5
ND INDICATES NOT DETECTED AT LISTED DETECTION LIMITS
ANALYSES PERFORMED IN H&P'S MOBILE LABORATORY
ANALYSES PERFORMED BY: MS. JANIS VILLARREAL
ANALYSES REVIEWED BY: DR. BLAYNE HARTMAN
-------
MOBILE f GEOCHEMISTRY
H&P
TETRA TECH PROJECT #06LW-P0013
IRP SITE 15 STREAMS
VANDENBERG AFB, CA
H&P Project #TT101006-L5
TCE (EPA METHOD 8021) ANALYSES OF SOIL VAPOR
Sample ID
BLANK .
BLANK
BLANK
BLANK
BLANK
BLANK
BLANK
BLANK
BLANK
BLANK
BLANK
DETECTION LIMITS
ND INDICATES NOT
DATE
10/10/06
10/11/06
10/12/06
10/12/06
10/16/06
10/16/06 '
10/17/06
10/17/06
10/17/06
10/18/06
10/18/06
DETECTED AT LISTED
TIME
11:02
11:25
8:01
11:26
9:19
12:17
9:01
11:02
. 14:13
9:09
12:09
DETECTION LIMITS
TCE
(ug/m3)
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
5
ANALYSES PERFORMED IN H&P'S MOBILE LABORATORY
ANALYSES PERFORMED BY: MS. TAMARA DAVIS
ANALYSES REVIEWED BY: DR. BLAYNE HARTMAN
-------
MOBILE f GEOCHEMISTRY
H&P
TETRA TECH PROJECT #06LW-P0013
IRP SITE 15 STREAMS
VANDENBERG AFB, CA
H&P Project #TT101006-L5
TCE (EPA METHOD 8021) ANALYSES OF SOIL VAPOR
Sample ID
CCAL
CCAL
CCAL .
CCAL
CCAL
CCAL
CCAL
CCAL
CCAL
CCAL
CCAL
CCAL
CCAL
CCAL
CCAL
CCAL
CCAL
CCAL
DATE
10/10/06
10/10/06
10/10/06
10/11/06
10/11/06
10/11/06
10/11/06
10/12/06
10/12/06
10/12/06
10/16/06
10/16/06
10/16/06
10/17/06
10/17/06
10/17/06
10/18/06
10/18/06
TIME
12:21
17:12
17:44
8:00
8:24
11:52
17:35
7:52
.14:00
17:07
9:09
12:12
17:07
8:54
13:03
16:03
10:53
14:21
TCE
(%)
ECD
112%
—
120%
96%
—
98%
99%
114%
124%
122%
90%
107%
104%
102%
86%
116%
98%
98%
TCE
(%)
PID
108%
83%
~
98%
84%
83%
105%
87%
91%
85%
94%
100%
87%
75%
85%
112%
87%
ANALYSES PERFORMED IN H&P'S MOBILE LABORATORY
ANALYSES PERFORMED BY: MS. TAMARA DAVIS
ANALYSES REVIEWED BY: DR. BLAYNE HARTMAN
-------
MOBILE f GEOCHEMISTRY
H&P
TETRATECH PROJECT #06LW-P0013
IRP SITE 15 STREAMS
VANDENBERG AFB, CA
H&P Project #TT101006-L5
TCE (EPA METHOD 8021) ANALYSES OF SOIL VAPOR
Sample ID
ICAL - ECD
AVERAGE .
STDEV
RSD
ICAL-PID
AVERAGE
STDEV
RSD
DATE AMOUNT
(ug/m3)
10/10/06 0
5
25
75
100
10/10/06 0
100
1000
10000
100000
AREA
(counts)
0
13.6
67
188
256
0
6
39
350
4921
RF
0.37
0.37
0.40
0.39
0.38
0.01
3%
17.2
25.6
28.6
20.3
22.9
4.4
19%
ANALYSES PERFORMED IN H&P'S MOBILE LABORATORY
ANALYSES PERFORMED BY: MS. TAMARA DAVIS
ANALYSES REVIEWED BY: DR. BLAYNE HARTMAN
-------
MOBILE f GEOCHEMISTRY
H&P
TETRATECH PROJECT #06LW-P0013
IRP SITE 15 STREAMS
VANDENBERG AFB, CA
H&P Project #TT101006-L5
TCE (EPA METHOD 8021) ANALYSES OF SOIL VAPOR
Sample ID
ICAL - ECD
AVERAGE
STDEV
RSD
ICAL-PID
AVERAGE
STDEV
RSD
DATE AMOUNT
(ug/m3)
10/18/06 0
5
25
100
500
10/18/06 0
500
1000
10000
AREA
(counts)
0
23.3
106
418
1798
0
11.4
21.8
197
RF
0.21
0.24
0.24
0.28
0.24
0.02
9%
43.9
45.9
50.8
46.8
2.9
6%
ANALYSES PERFORMED IN H&P'S MOBILE LABORATORY
ANALYSES PERFORMED BY: MS. TAMARA DAVIS
ANALYSES REVIEWED BY: DR. BLAYNE HARTMAN
-------
GEOCHEMISTRY
MOBILE^ GEOCHEMI
H&P
Chain of Custody Record
148 S. Vinewoodlst., Escondido, CA 92029 • ph 760.735.32*08 • fax 760'.735.2'469"'
432 N. Cedros Ave., Solana Beach, CA 92075 • ph 858.793.0401 • fax 858.793.0404
3825 Industry Avenue, Lakewood, CA90712 -ph 562.426.6991 • fax 562.426.6995
Date:
H&P Project*.
Outside Lab:
— r' "/ —
Client: 1 C Ar C( ( -fcl\
Address:
Phone: ' Fax:
Global ID:
Sample Name
* M
' &\
*A5-i
- C^7
*Csl~l
^^muji)
-C/o.
•A\-\
i- i
$i - v
A/f- JL#
~&i 3
•1-3-
Field Point Name
EOF: Yes /No
Depth
•'
Time
l|!S
IDs
//63
I f,.ft
D'/O
foot
H^-^j
ftto
\ 'y-N
lU' IO
IvijO
fiff i ^*
/ t /'•X
Date
Icy-/)
I
i
^
Relinquished by: (Signature) (company)
Relinquished by: (Signature) (company)
Relinquished by: (Signature) (company)
Collector:
Client Project
Location: v
#
fltti IfiPS.ls l€> f
Pag
Proj
e: / Of
ect Manac
/
~\ rt f*~ i t
ier ^jji n^1 ^ fc // / ,it-
s
Turn around time:
Sample Receipt
Intact: n Yes n No
Seal Intact: D Yes D No D N/A
Cold: D Yes D No
N/A (Received on Site)
Sample
Type
5^1
y
4i
Container
Type
;'\
f
J
TPH gasoline / diesel
TPH extended
8021 for BTEX/MTBE
.'
8021 for Halogenated compounds
CO
5
8260B
BTEX / Oxygenates
Oxygenates
i
VOC's and Oxygenates
Methane
Fixed Gases
Received by: (Signature) (company)
Received by: (Signature) (company)
Received by: (Signature) (company)
^
X,
\
<
X
<
<
f
V.
<
.<•
v^
f
f
Date:
Date:
Date:
Total # of containers
Time:
Time:
Time:
'Signature constitutes authorization to proceed with analysis and acceptance of condition on back.
Sample disposal instruction:
I I Disposal @ $2.00 each I I Return to client I I Pickup
-------
Chain bfCiifetdtly Record
Date:.
. ...
148 S. Vinewood St., Escondido, CA 92029 • ph 760.735.3208 • fax 760.735.2469
432 N. Cedros Ave., Solana Beach, CA 92075 • ph 858.793.0401 • fax 858.793.0404
3825 Industry Avenue, Lakewood, CA 90712 • ph 562.426.6991 • fax 562.426.6995
H&P Project #
Outside Lab:
V
Ji
•*••
*«*
**
*^
"•»»,
?
Client: |r~M^ \fC l~\
Address:
--
Phone: •-, Fax:
Collector:
Client Project
Location:
#
Pag
Pro
e: ' Of
ect Manac
ier
/
Turn around time:
Global ID: v. " ., .-
Sample Nanie
fcft|'
'4l-S
*-A \- ^
-A/-"!
C-6
•ft *}-
-&j
&\-\ a.
-fa '1 ll^M-f^^U
O~ / 'KJb&J^M
$l'l JLJ^U^I
'&\J~ ft' '
l^-Sv-A -i^
Field Point Name
V
&
*<,/ pj jif jO
5< (•& Hoo*>
EOF: Yes /No
Depth
Time
fo\
t-tt
i I O
J • ^^(^9
to: 01
ta.cn>
H:33
tilo
Mo
faiXJ
IveSj
(Iff5v
1(0*2
Date
ky/i
,
Relinquished by: (Signature) (company)
Relinquished by: (Signature) (company)
Relinquished by: (Signature) (company)
Sample Receipt
Intact: D Yes D No
Seal Intact: n Yes D No n N/A
Cold: D Yes D No
N/A (Received on Site)
Sample
Type
sv
:
•<
Container
Type
H J
3
i -
TPH gasoline / diesel
TPH extended
8021 for BTEX/MTBE
Ul
1
i
1
i
Q.
CO
8260B
BTEX / Oxygenates
Oxygenates
CO
b
O
VOC's and Oxygenates
Methane
Fixed Gases
Received by: (Signature) (company)
Received by: (Signature) (company)
Received by: (Signature) (company)
-*•»
r*+*.
— • —
i
X
x
x
V
N
N
N
^
>/:
>/
\
>
V
-
Date:
Date:
Date:
Total # of containers
Time:
Time:
Time:
'Signature constitutes authorization to proceed with analysis and acceptance of condition on back.
Sample disposal instruction:
I I Disposal @ $2.00 each I I Return to client I I Pickup
-------
GEOCHEMISTRY
MOBILE^-GEOCHEMI
H&P
Chain 6f Custody Record
Date:.
CD 148 S. Vinewood St., Escondido, CA92029• ph 760.735.3208 -fax 760735.2469
CD 432 H. Cedros Ave., Solana Beach! CA 92075 • ph 858.793.0401 • fax 858.793.0404
CD 3825 Industry Avenue, Lakewood, CA 90712 • ph 562.426.6991 • fax 562.426.6995
H&P Project**,
Outside Lab:
^N
^*.
^»i
^
•—.
***
-»••
-»,
•ta.
•*«,
Client: \fbraTtch Collector:
Address: • ' . C
. L
lient Project
acation:
#
Pag
Pro]
e: . / Of
ect Manac
jer
V
Phone: Fax: Turn around time:
Global ID:
\
Sample Name
-#-/
-&-l'\<
•fi
C
-6- I
%--*)•
6- 1
fy'CJ
1?-S>\J-A) '
T^ SV-42-
7«=>- ^v- 4 *>
-f5-Si/^-v
•/e'-Sv/-/?-^
•VI 6-1
CS>" !
-f^r3
Field Point Name
EOF: Yes /No
Depth
,
Time
atoft
ofo?
O^o
'JoJ2
ctfw
0^0
010®
e>W
O123--
it)°V
/O&ti
l/^o
IH>
/H3"
Date
£>//3
,
7
Relinquished by: (Signature) (company)
Relinquished by: (Signature) (company)
Relinquished by: (Signature) (company)
Sample Receipt
Intact: D Yes D No
Se%l Intact: D Yes D No O N/A
Cold :D Yes DNo
N/A (Received on Site)
Sample
Type
sv
,
Container
Type
.^tW
j
TPH gasoline / diesel
TPH extended
8021 forBTEX/MTBE
8021 for Halogenated compounds
I
a.
Q£
CO
82&OB
BTEX / Oxygenates
Oxygenates
CO
b
§
VOC's and Oxygenates
Methane
Fixed Gases
Received by: (Signature) * (company)
Received by: (Signature) (company)
Received by: (Signature) (company)
r~
-O
•X
^
N(
\
X
X
^
^
X
X
X
•x
<•
X
N
Date:
Date:
Date:
Total # of containers
Time:
Time:
Time:
•Signature constitutes authorization to proceed with analysis and acceptance of condition on back.
Sample disposal instruction:
I I D;sposa/@ $2.00 each I I Return to client I I Pickup
-------
Chain of Custody Record
Date:
148 S. Vinewood St., Escondido, CA 92029 • ph 760.735.3208 • fax 760.735.2469
432 N. Cedros Ave., Solana Beach, CA92075 • ph 858.793.0401 • fax 858.793.0404
3825. Industry Avenue, Lakewood, CA90712 • ph 562.426.6991 • fax 562.426.6995
H&P Project #.
Outside Lab:
Client:
Address:
Phone:
Global ID:
£-{"Y& ttY. »\ Collector:
C
L
/lient Project
ocation:
#
Pag
Pro
e: & Of
ect Manac
ler
o-
Fax: Turn around time:
Sample Name
- I5-SV-B4
-b-sv/-«
HO-S\/ -6^>
-l-vSv- 62-
No'Sv ft)
/I. t I
-|5--SV-^ V
,5-Sv C5
f5-Sv t o
/y. i - i fl ti /' s
"•«)"/' i /t7 btf /• k
-/5-.Sv ~C5
IS- W-£>-
Field Point Name
-
^-f
l(ff
EOF: Yes /No
Depth
\&
Time
//«/*)
j /*/(#
/~~y ^~~/ ~?
ttf)i
f&^-** £s~
•ftfy
WO
Ifyif '"C
/cc /^
\(^l ^J^"
Ifcfo
Ml
•" 7
Date
/^fe
r.
Relinquished by: (Signature) (company)
Relinquished by: (Signature) - (company)
Relinquished by: (Signature) (company)
Sample Receipt
Intact: D Yes D No
Seal Intact: D Yes D No D N/A
Cold: D Yes D No ;
N/A (Received on Site)
Sample
Type
5\/
i
i
Container
Type
V' /
JtVrts
' i
':
•
TPH gasoline / diesel
TPH extended
8021 for BTEX/MTBE
i
1
1
1
CQ
I
.0
I
Q.
DC.
h-
co
5
8260B
BTEX / Oxygenates
Oxygenates
in
b
§
VOC's and Oxygenates
Methane
Fixed Gases
Received by: (Signature) (company)
Received by: (Signature) (company)
Received by: (Signature) (company)
a
Y
s/
,
v
vr
X'
V
V"
y
v
>c
7
N
Date:
Date:
Date:
Total # of containers
Time:
Time:
Time:
'Signature constitutes authorization to proceed with analysis and acceptance of condition on back.
Sample disposal instruction:
I I Disposal @ $2.00 each I I Return to client I I Pickup
-------
GEOCHEMISTRY
MOBILE^-GEOCHEMI
H&P
Chain of Custody Record
Date: • /..-.//•-
148 S. Vinewoo'd St., Escondido, CA92029 • ph 760.735.3208 • fax 760.735.2469
432 N. Cedros Ave., Solana Beach, CA 92075 • ph 858.793.0401 • fax 858.793.0404
3825 Industry Avenue, Lakewood, CA90712 • ph 562.426.6991 • fax 562.426.6995
H&P Project*.
Outside-Lab:
Client: /d^/7751 rtT/) Collector: ( \ V/f
Address: " C
L
Client Project
ocation: w
# ' , •
ftpfr S,is i*>
Pag
Proj
e: /Of
ect Manac
ier
u.
Phone: "* Fax: Turn around time:
Global ID:
-
Sample Name
fll-ftl
f}"~\ _ $]
[J ^^
far /$L
•Qjj &\
Ui "O*—
te-i?i_
'rj/'tSU
^3-e>»-
fa-&u
•M-fti-'
fey-ftU
C2~&^
^.2rfo<—
2.4-6^
C&^ft-*-
Field Point Name
EOF: Yes /No
Depth
Time
foo^
(OtO
/6?3ti
/C&s
/f}3f)
I'Ytt
lost
IO$°I
llo°i
HQ
n>l
I6|
/i^>£
/Hy
Date
to
Relinquished by: (Signature) (company)
Relinquished by: (Signature) ' (company)
V
Relinquished by. (Signature) (company)
Sample Receipt
Intact: n Yes D No
Seal Intact: D Yes D No DM/A
Cold: D Yes D No
N/A (Received on Site)
Sample
Type
•W,
1
Container
Type
S
'1
1
.
1
TPH gasoline / diesel
TPH extended
8021 for BTEX/MTBE
VI
•o
1
1 §
I
s
00
^
X
y.
^
V
^
x(
'Y
N:
V
V
•%
y-
./
CL
IE
CO
8260B
BTEX / Oxygenates
Oxygenates
b
o
VOC's and Oxygenates
Methane
Fixed Gases
^JWKSaT^u/i <; -ff^f
Revived by: (Signature) '(company)
Received by: (Signature) (company)
t
Date:
JOJ/G?,
Date: f J
Date:
Total # of containers
Time:
/Jen
Time:
Time:
'Signature constitutes authorization to proceed with analysis and acceptance of condition on back.
Sample disposal instruction:
I I Disposal @ $2.00 each I I Return to client I I Pickup
-------
i»iv_.i_.n_i_^>-»-»*wi ii_miuii ii ^^iiuui \jt N^VIO txsva jr i-%«*w«*ivi Date' IL)i 1 La K'La
1 l/\ 1 ^J CH 1 48 S.Vinewood St., Escondido.CA 92029 -ph 760.735.3208 -fax 760.735.2469 H&f
1 1 ^j( 1 ~^ n 432 N. Cedros Ave., Solana Beach, CA 92075 • ph 858.793.0401 • fax 858.793.0404
MM M n 3825 Industry Avenue, Lakewood, CA 9071 2- ph 562.426.6991 -fax 562.426.6995 °ut
Client: \P-tf~ffr~\C C ''A Collector: \Ol\rf
Address: Cli
Lo
snt Project
:ation:
#
Pag
Pro
' Project *
side Lab:
e: 3" Of V •'•'•
ect Manac
f
jer
Phone: Fax: Turn around time:
Global ID:
Sample Name
"VfcB-A^ -|5*1*"^'
•{&-&L. ])00
foj -Q&IOO
&-PR wo
-fa-Pkioo.
#-l - P(( wo
fVPRlflO
fa-PKlnn
-hb-PI\^(X)
f^-pR^^
M-^jScr^
fe- PlSStf)
Field Point Name
EOF: Yes /No
Depth
-
Time
/£•-/
DoV
P-'V
P?&
feW
P60
Pfy
l*tt,
P>l1
Bl^
/3f?-
|55^
H-13
Date
lo/fo
5
Relinquished by: (Signature) • (company)
Relinquished by: (Signature) (company)
Relinquished by: (Signature) (company)
Sample Receipt
Intact: DYes DNo
Seal Intact D Yes D No a N/A
Cold: D Yes D No
N/A (Received on Site)
Sample
Type
^
xp
x
X
X
x
x
V
*,
x
^
X
|
00
8260B
BTEX / Oxygenates
Oxygenates
b
§
VOC's and Oxygenates
Methane
-
Fixed Gases
^jfeS^J ^^ ^ ^ny>
Reqewed by: (Signature) ~" (company)
Received by: (Signature) (company)
Total # of containers
/u//^y/O^y f f(3&
Date: ' Time:
Date: Time:
•Signature constitutes authorization to proceed with analysis and acceptance of condition on back. Sample disposal instruction: QU Disposal @ $2.00 each d Return to client ' d P/ctop
-------
lyivjoiLc^utwonavnoirn Vslldlll V/l \SM9l\SUy l>drVM1« Dg,
1 N| /^^ |~^P a 148 S' V"116*0011 st- Escondido, CA 92029 • ph 760.735.3208 -fax 760.735.2469 H&f
1 1 ^^( 1 ~^ ED 432 N. Cedros Ave., Solana Beach, CA 92075 • ph 858.793.0401 • fax 858.793.0404
MM M n 3825 Industry Avenue, Lakewood. CA 9071 2- ph 562.426.6991 -fax 562.426.6995 Out
Client: j ?J fy?% j^f fa ' Collector: LoA^f
Address: C
L
/lient Project
ocation:
#
Pag
Pro
a: lUt/fr JU&
' Project #
side Lab:
f ' /
e: 3 Of
ect Manac
ier
LJ
/
Phone: • Fax: Turn around time:
Global ID:
Sample Name
£Q'pg5co
P& ~ ?£{ff~cO
t^-^^fl}
&?~9£5Od
f»i - PR. IODO
T^V fti^ fon
fo-pfrioo;
^-/•K 100}
vl'T/s \OoO
$&~ PR 1 £7(2^
-ft/ .. D/? 3QCO
•fe- P63ffi)
-M- P^ ^ocO
~b\- Ptoox)
Field Point Name
(
EOF: Yes /No
Depth
Time
JLfjO
\i\^^
14^-a
i»HO
/^v
/5o">
/5//?
/5/J?
/52*/
1530
&W
1550
Yf^>
11 ^
Date
lQ//fo
1
1
1
I
j
J
j
J
Relinquished by: (Signature) company)
Relinquished by: (Signature) (company)
Relinquished by: (Signature) . (company)
Sample Receipt
Intact: D Yes Q No
Seal Intact: D Yes D No D N/A
Cold: D Yes DNo
N/A (Received on Site)'
Sample
Type
,Sv.
J
_
Container
Type
.^W
U
^
TPH gasoline / diesel •
TPH extended
8021 for BTEX/MTBE
1
1 °"
ft
^&X
8"
(0
X
1
H
)(
X
K
X
X
X
K
X
X
>c
X
<
S
I
EL
or
H
co
5
8260B
BTEX / Oxygenates
Oxygenates
VOC's and Oxygenates
Methane
in
•o
8
il.
/
Receded by: (Signature) (company)
Received by: (Signature) (company)
,
/(}//&/C%0
Date: '
Date:
•Signature constitutes authorrzation to proceed with analysis and acceptance of condition on back. Sample disposal instruction: EH Disposal @ $2.00 each EH Return to client ED P"*"P
Total # of containers
Tme/%&
Time:
Time: .
-------
GEOCHEMISTRY
MOBILE^-GEOCHEMI
H&P
Chain of Custody Record
Date:
n
148 S. Vinewood St., Escondido, CA 92029 • ph 760.735.3208 '*fax 760.735.2469
432 N. CedrpsAve., Solana Beach, CA 92075 • ph 858.793.0401 • fax 858.793.0404
3825 Industry Avenue, Lakewood, CA 90712 • ph 562.426.6991 • fax 562.426.6995
H&P Project*.
. Outside Lab:
Client:
Address:
Phone: Fax:
Global ID:
Sample Name
~ff>~P8'dOQ}
-#| - pf^OCO
$1 - p^6co?4
•6*>- fUso&o
$3- p£ "ocot; -A
A3-6i-
Field Point Name
EDF: Yes /No
Depth
Ibtf
/(^9
\\
/U3S
H >/ /
/U/ f /
(j) \O
Time
-W&
Date
Wo,
<1
Relinquished by: (Signature) (company)
Relinquished by: (Signature) (company)
Relinquished by: (Signature) (company)
Collector: / /XX//
(
'
Client Project
.ocation:
#
Pag
Proj
e: 4 Of
ect Manac
ler
//
/
Turn around time:
Sample Receipt
Intact: D Yes D No
Seal Intact: D Yes D No D N/A
Cold: D Yes O No
N/A (Received on Site)
Sample
Type
.Si/
/i
Receiv
/
Repeijf
IL
Container
Type
5j
/
t,
rl/
Qdby: (Signatured
Ur [VI tf j ,•-* 1
ed by: (Signature)
Received by: (Signature)
TPH gasoline / diesel
TPH extended
8021 for BTEX/MTBE
1
0)
81
CD
I
§
><
X
Nk
SI
^
•J
D_
tr
H
CD
5
8260B
BTEX / Oxygenates
Oxygenates
b
§
VOC's and Oxygenates
Methane
Fixed Gases
2b>Vs (7ffl
(company)
(company)
Date-
/(}//&/&{&
Date:
Date:
Total # of containers
rff^fy')
Time:
Time:
'Signature constitutes authorization to proceed with analysis and acceptance of condition on back.
Sample disposal instruction:
I I Disposal® $2.00 each I I Return to client \ I Pickup
-------
GEOCHEMISTRY
MOBHE^GEOCHEMI
H&P
' *
Chain of Custody Record
"u . .-«•»--»'«i'*'»» ., "
Date:
CH 148 S. Vinewood St., Escondido. CA92029 • ph 760.735.3208 -fax760.735.2469
CD 432 N. Cedros Aye.; Solana Beach, CA 92075 • ph 858.793.0401 • fax 858.793.0404
CD 3825 Industry Avenue, Lakewood, CA 90712 • ph 562.426.6991 • fax 562.426.6995
H&P Project*.
Outside Lab:
*^
•<
"m
•*•.
^.
>*,
^*.
Client
f? \"\C\ rf ,'" i'\ Collector: / )/1 (/-<"
Address: ' (
I
Client Project
.ocation:
#
Pag
Proj
e: / Of
ect Manac
ier J'-^/l,
i^!-Pvu/
$-/ P^5
i^i ^(j
~&\-N\O
Field Point Name
EOF: Yes /No
Depth
Time
0365
(flO*
&I3^
tf&b
ffl*l(*
<7W?
QVa
ioo<]
/o/o
loio
lODir
i(i?Q,
/o^
lulu
Date
loin
1
1.
Relinquished by: (Signature) (company) M'
Relinquished by: (Signature) (company)
Relinquished by: (Signature) (company)
Sample Receipt
Intact: D Yes D No
Seal Intact D Yes D No D N/A
Cold: D Yes D No
N/A (Received on Site) ,
Sample
Type
^o\y
1
Container
Type
Su-/
0>
.§
1
CO
en
TPH extended
8021 for BTEX/MTBE
1
O
Q.
OJ
^
Y
>
^
Y
^
^
\
\
\
H
X
^
<
rl
or
i-
00
, 8260B
BTEX / Oxygenates
Oxygenates
W
b
§
VOC's and Oxygenates
Methane
u_
RecerV'ed by: (Signature (company)
Received by: (Signature) (company)
Received by: (Signature) . (company)
Date:
Date:
Date:
.
Total # of containers
Time:
Time:
Time:
•Signature constitutes authorization to proceed with analysis and acceptance of condition on back.
Sample disposal instruction:
I I Disposal @ $2.00 each I I Return to client I I Pickup
-------
GEOCHEMISTRY
MUBILhf" GEOUHbMI
H&P
Chain of Custody Record
Date:
CD
148 S. Vinewood St.; Escondido, CA 92029 • ph 760.735.3208 • fax 760.735.2469
432 N. Cedros Ave., Solana Beach, CA 92075 • ph 858.793.0401 • fax 858.793.0404
3825 Industry Avenue, Lakewood, CA 90712 • ph 562.426.6991 • fax 562.426.6995
H&P Project #_
Outside Lab:
Client: \(S,1\C( f-A. ' ") Collector: //li//7
Address: Cli
Lo
ent Project
;ation:
#
Pag
Proj
e: *: Of
ect Mana
:er J.J I A>\ c
-A3- ftu
/M' PV)
•&A- PV>
.A^|.pv'3
'/W- lV4
Field Point Name
EOF: Yes /No
Depth
Time
/&>$
f I0t)
})}U
\\\D
\m
li^l
115?
Ufa
\\y>
/X3)
fo(M
Dii
fr&
Date
jO/tf
Relinquished by: (Signature) (company)
Relinquished by: (Signature) (company)
Relinquished by: (Signature) (company)
Sample Receipt
Intact: D Yes D No
Seal Intact: n Yes D No D N/A
Cold: n Yes n NO
N/A (Received on Site)
Sample
Type
Sv/
Container
Type
v
J
~u
1
0)
C
1
(0
O)
TPH extended
8021 for BTEX/MTBE
UJ
Q.
1
£
§
X
^
V
^
4
j
^
<
4
\
^l
4
4
418.1 TRPH
8260B
BTEX / Oxygenates
Oxygenates
en
b
§
VOC's and Oxygenates
Methane
Fixed Gases
Received by: (Signature) (company)
Received by: (Signature) (company)
Received by: (Signature) (company)
Date:
Date:
Date:
Total # of containers
Time:
Time:
Time:
'Signature constitutes authorization to proceed with analysis and acceptance of condition on back.
Sample disposal instruction:
I I D/sposa/@$2.00each I I Return to client I I Pickup
-------
MOBILE^ GEOCHEMISTRY
H&Pi
Chain of Custody Record
Date:
148 S. Vinewood St., Escondido, CA 92029 • ph 760.735.3208 • fax 760.735.2469
432 N. Cedros Ave., Solana Beach, CA 92075 • ph 858.793.0401 • fax 858.793.0404
3825 Industry Avenue, Lakewood, CA 90712 • ph 562.426.6991 • fax 562.426.6995
H&P Project*.
Outside Lab:
Client: \P ^(A \-f C l\ Collector:
I '
Address: • C
L
Client Project
ocation:
#
Pag
Proj
e: 3 Of
ect Manac
er
(f
1
Phone: Fax: Turn around time:
Global ID:
Sample Name
•44-fV5
"A ^4 - PV (o
•/H-/V8
•/
H-/V/O
A-N^u
•C4-/VJ
(_]l\ -\^J^
f\i/ -/-V3
c^i ~? v7
-CH- PVr;>
CA- \V 0>
fi52
;2»63
}W
Date
lo/R
Relinquished by: (Signature) (company)
Relinquished by: (Signature) (company)
Relinquished by: (Signature) (company)
Sample Receipt
Intact: O Yes D No
Seal Intact: a Yes a No o N/A
Cold: a Yes a No
N/A (Received on Site)
Sample
Type
s\/
Container
Type
Qurf
0
TPH gasoline / diesel
TPH extended
8021 for BTEX/MTBE
1
a
1
(0
r
°
1
y.
y.
/N
^
v/
Jx
X
X
^
X
X
X
,v
A
X
X
Q_
QC
od
8260B
BTEX / Oxygenates
Oxygenates
b
o
VOC's and Oxygenates
Methane
Fixed Gases
Received B : (Signature) *J* (company)
Received by: (Signature) (company)
Received by: (Signature) . (company)
Date:
Date:
Date:
Total # of containers
Time:
Time:
Time:
•Signature constitutes authorization to proceed with analysis and acceptance of condition on back.
Sample disposal Instruction:
I I Disposal @ $2.00 each I I Return to client I I Pickup
-------
MOBILES-GEOCHEMISTRY
MOBILE^- GEOCHEMI
H&P
Chain of Custody Record
Date:
d 148 S. Vinewood St., Escondido, CA 92029 • ph 760.735.3208 • fax 760.735.2469
EU 432 N. Cedros Ave., Solana Beach, CA 92075 • ph 858.793.0401 • fax 858.793.0404
n 3825 Industry Avenue, Lakewood, CA 90712 • ph 562.426.6991 • fax 562.426.6995
IO//1-/OC,
H&P Project #_
Outside Lab:
Client:
V \"\n Vff \'\ Collector:
Address: . Client Pr
Location
Dject
#
Pag
Proj
'1 Of
ect Manac
i
ier
4
;
Phone: Fax: Turn around time:
Global ID:
Sample Name
~\L
- P\J-'50OL-
-AS- 5c
*A a
-f\^
Cu Pv .. ,••-.,.- (
} DL_ FJA.JZ' j.
M-PV/I hip
pLJ-PV^hp
/\u px/'a. u
CM- fN/Yoho
^M-
C4
• fV \0h\o
Ps/9OKi.-»
r'Vl-vVicoiO1
r
Field Point Narine
L?p
'
EOF: Yes /No
Depth
^n
M-
[-JJV
/cta-f
/W3_7
AV3«
M^b
mg>
I5O>
ISO j
|5|^
ISl^?
65^
Date
/t//'-f
H
Relinquished by: (Signature) (company)
Relinquished by: (Signature) (company)
Relinquished by: (Signature) (company)
Sample Receipt
Intact: D Yes D No
Seal Intact: D Yes n No n N/A
Cold: D Yes n No
N/A (Received on Site)
Sample
Type
Container
Type
TPH gasoline / diesel
TPH extended
8021 for BTEX/MTBE
8021 for Halogenated compounds
X
CO
8260B
BTEX / Oxygenates
(A
1
(A
b
VOC's and Oxygenates
Methane
Fixed Gases
Received by: (Signature) (company)
Received by: (Signature) (company)
Received by: (Signature) . (company)
Date:
Date:
Date:
Total # of containers
Time:
Time:
Time:
'Signature constitutes authorization to proceed with analysis and acceptance of condition on back.
Sample disposal instruction:
I I Disposal @ $2.00 each I I Return to client \ \ Pickup
-------
MOBILE £ GEOCHEMISTRY V Chain of Custody Rgcord Dat
1 1^\ 1 ~J CD 1 48 S.Vinewood St., Escondido.CA 92029 -ph 760.735.32^15 -fax 766.735.2469V H&f
1 1 v3( 1 CD 432 N. Cedros Ave., Solana Beach, CA 92075 • ph 858.793.0401 • fax 858.793.0404
MM M Q 3825 Industry Avenue, Lakewood, CA 9071 2- ph 562.426.6991 -fax 562.426.6995 . °ut
"••»
^K
*•*
-*•
Client: /^ ./V/fl /TV A
A
P
« , ? '^ ' " 1
ddress:
' • •: ' ,
hone: Fax:
Global ID:
/#*
Sample tyame
A
-/
•/
4
4
3-B^y
3- fiuiii p
l-^v25
1-SV6O
1- SW fioO
•A-i Sw 7ooa
^a -Ss/a ^
•fio-S\/6p6^
•ft-p- -SV 5cW
^5 ^j loccJ
"A,\- SV6?c^
f^'.Sv^
Tfe3'^\/6O
-S3-s>v5oo
Field Point Name
EOF: Yes /No
Depth
Time
Cfjbo
sflOl
73SP5
'jt&p
<\;7^J
&HO
&&
O^d
tfftit
PO-^
Irrf?
foJO
>D^
)c&2.
Date
i/ij/0
/Ut( a
1
Relinquished by: (Signature) (company) T
Relinquished by: (Signature) (company)
Relinquished by: (Signature) (company)
Collector: / M lf~S
Client Project
Location:
Turn around ti
Sample Receipt
Intact D Yes D No
Seal Intact: D Yes a No D N/A
Cold: D Yes D No
N/A (Received on Site)
Sample
Type
cv
<
6 A
i
Container
Type
-W
•Si
W/
/^r
t
\er\\^
5u
3
Si
1
ur
}
*•
"fa:!/*/
TPH gasoline / diesel
#
Pag
Prq
B: iblltlni*
3 Project #
side Lab:
e: ; / Of
ect Manac
ier
me:
-j
TPH extended
8021 for BTEX/MTBE
CA
I
OJ
A
X
IV
/ \
X
X
X
X
X
X
X
X
X
V
X
GO
8260B
BTEX / Oxygenates
Oxygenates
CO
b
O
VOC's and Oxygenates
Methane
Fixed Gases
Received by: (Signature) (company)
Received by: (Signature) (company)
Received by: (Signature) (company)
•
Date:
Date:
Date:
Total it of containers
1
^
Time:
Time:
Time:
•Signature constitutes authorization to proceed with analysis and acceptance of condition on back. Sample disposal instruction: Q Disposal @ $2.00 each £H Return to client O Pickup
-------
•"•^"-'"-'-r »-—»*-^i ,•_,., .^i ,i, ^^i iuii i %^i ^^M^tvviy i v>*^*" vl Date' ks/'h/L^r
11 /\ l_^ CH 148 S.Vinewood St., Escondido.CA 92029 -ph 760.735.3208 -fax 760!735.2469 H&[
1 1 V^C 1""^ CH 432 N. Cedros Ave., Solana Beach, CA 92075 • ph 858.793.0401 • fax 858.793.0404
MM M EH 3825 Industry Avenue, Lakewood, CA 90712 • ph 562.426.6991 • fax 562.426.6995 Out
Client: \Y"4"TOrW C \~^\
Address:
Phone: Fax:
Collector:
Client Project
Location:
#
Pag
Pro
3 Project *
side Lab:
/7
e: ^--" Of
ect Manat
aer
^
-^
Turn around time:
Global ID:
Sample Name
^3- sv \ooo
•fe^-Sv/fcoco
C2'3b*;>p\/^5
CO- - ft/6>6?
43 -B*-
v!3^5L £-£,£>
p3-5\/&0o£>
O - Q\J5co
-C2 5>\J/ooO
4 I- allu In L
~Q.2-^M(f>ocO
fa. Sv/,^5
C6-3\/^0
C,5-Bv5<^
Field Point Name
••'
EOF: Yes /No
Depth
Time
/w
£5fe
Jlic
Hfa
lll%
Hffi
1/3°
1133
//3?
/^l
Ml
PV5
^(p
(^^
Date
A3#?
j
,,
Relinquished by: (Signature) (company)
Relinquished by: (Signature) (company)
Relinquished by: (Signature) (company)
Sample Receipt
Intact: DYes DNo
Seal Intact: D Yes D No D N/A
Cold: O Yes D No
N/A (Received on S te)
Sample
Type
w
(^^panv
1
/
1
1
4)
Container
Type
~fid/ay
,/H-A—
S
-s
V
S,
Lt.ttli'M^i
-fdW
T<
<&
;'1V .
•j
JM f
SJ\Y
teA
TPH gasoline / diesel
TPH extended
8021 for BTEX/MTBE
i
I
o .
00
X
^
\
X
X
X
X
X
X
\
X
X
V
>:
|
5
8260B
0)
O
m
Oxygenates
i
VOC's and Oxygenates
Methane
Fixed Gases
Received by: (Signature) (company)
Received by: (Signature) (company)
Received by: (Signature) (company)
Date:
Date:
Date:
Total # of containers
Time:
Time:
Time:
•Signature constitutes authorization to proceed with analysis and acceptance of condilion on back. Sample disposal instruction: EH Disposal @ $2.00 each EH Return to client EH Pickup
-------
MOBILE^ GEOCHEMISTRY
H&PI
Chain of Custody Record
148 S. Vinewood St., Escondido, CA 92029 • ph 760.735.3208 • fax 760.735.2469
432 N. Cedros Ave., Solana Beach, CA 92075 • ph 858.793.0401 • fax 858.793.0404
3825 Industry Avenue, Lakewood, CA 90712 • ph 562.426.6991 • fax 562.426.6995
Date:
H&P Project #_
Outside Lab:
Client: \$s\ffj( KC^ Collector: IMLtf
Address: (
I
Client Project
.ocation:
tt
Pag
Proj
e: 3 Of
ect Manac
ler
^
Phone: Fax: Turn around time:
Global ID:- .
Sample Name
Cl5"S\y loou
'f&~ftU
4-3~ &L, SJLP
•£6'S^(t&&)
Field Point Name
EOF: Yes /No
Depth
Time
055
\^
/3V*5
P&
Date
Ic/i*
' -
Relinquished by. (Signature) (company)
Relinquished by: (Signature) . (company)
Relinquished by: (Signature) (company)
Sample Receipt
Intact: O Yes D No
Seal Intact: D Yes D No D N/A
Cold: D Yes D No
N/A (Received on Site)
Sample
Type
fffikf
'Surf
^vn
§aU/ri
Container
Type
9
a ^
v/
7
Received by. (Signature)
Received by: (Signature)
Received by: (Signature)
0}
1
O
c
O)
TPH extended
8021 for BTEX/MTBE
3
0)
"ra
£
§
CO
^
Y
/^
V-X1
Q.
CO
8260B
1 saiBua6Xxo/X319
1
|
CO
b
§
VOC's and Oxygenates
Methane
Fixed Gases
(company)
(company)
(company)
Date:
Date:
Date:
Total # of containers
Time:
Time:
Time:
'Signature constitutes authorization to proceed with analysis and acceptance of condition on back.
Samp/9 disposal instruction:
I I Disposal @ $2.00 each I I Return to client I I Pickup
-------
•eject Name & Location TT
Soil Vapor Survey Sheet
T&-H
Date: lQiL,(t>i*
/ /
iL,(t>
lent: T^WK
Rep:
Start Time:
&P Operator
Finish Time:
'eath'er Conditions:
Bags of Bentonite:
Purg
Point ID
Flow
Rate
Time
Placed
Time
Sampled
-Aetttal
V^-V
epth
e
Volume
Moisture
Contn
Field Notes
•|0o3
CQ-feL
fOiQ
Jii.
- et
4
ft-
5 •'
7
9-10^
8
41^1
IS"
10
A?-fit
11
(DH
H'
12
13
IUS
14
15
a -PL
15'
16,
16
17
Avgu-
V'
18
j-^jvfi
19
V
20
21
22
23
24
25
roken/Unrecovered Tools:
Overtime:
Accepted By:
-------
•eject Name & Location
Soil Vapor Survey Sheet
flow iy*j
Date:
lent:
Field Rep: V
Start Tjme:
&P Operator
Irtish |Ti
l*\ r-\ If rv«
Finish fime:
'eath'er Conditions:
Bags of Bentonite':
Purge
Volume
Point ID
FlOW
Rate
Time
Placed
Time
Sampled
Target
Depth
Actual
Depth
Moisture
Content
Field Notes
(*'
ill
I?7
6
-------
•qject Name & Location
oil Vapor Survey Sheet
rM / /
Date: lo/ihfo,
Start TirVie:
lent:
Field Rep:
&P Operator
Finish Time:
'eath'er Conditions; Bags of Bentonite:
1
2
3
4
• 5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
.24
25
Point ID
C-\-?^5«7-;
•S"U/^/v
i
<»'
v
Time
Placed
Time
Sampled
\f>X±
U\l
tu^r
»H(
M?tt
Tji'JSO*
Depth
\-t
V
It'
u
Jl^ACA^VM
'depfti
«•'
v.<
\V
t<
Purge
Volume
^•K> A-<
!.«-
^8*«<
Moisture
Content
'
Field Notes
(fcSV-^cj
3 -N\A-\irt*^
6-ST ia>
^ fvAAjfa
'
roken/Unrecovered Tools: Overtime: Accepted By:
-------
x>ject Name & Location
Soil Vapor Survey Sheet
Date:
lent:
F- Tr'.vU
Field Rep:
L
Start Time
&P Operator
Finish Time:
'eath'er Conditions:
Bags of Bentonite:
Purg
Point ID
FIOW
Rate
Time
Placed
Tim©
Sampled
Depth
Ae
waf
'»*rf\
e
Volume
Moisture
Content
Field Notes
l - W I
ir
i i'L
MfiL
ifcL
5
Bl- Mo
(l
ft f v/
IKS
,%
7
(6/h
8
10
11
6K- PvC,
12
13
ll-S"
14
\ICTD
1404
ID
15
lo
16
17
18
- f V fc
-T^-
li^T
19
20
21
II
22
ISH-(
23
24
-
25
V'
roken/Unrecovered Tools:
Overtime:
Accepted By:
AM (
-------
•qje.ct Name & Location TTfQ/?-ObTEx>H"
Soil Vapor Survey Sheet
Date;
[oc*
lent:
Field Rep:
Start Time:
&P Operator
Finish Time:
'eatrrer Conditions;
Bags of Bentonite:
4£
Pi
Point ID
FlOW
Rate
Time
Placed
Time
Sampled
urge
Volume
Moisture
Content
Field Notes
&
OMo
5
7
CW-Pv/3'
8
10
11
7-2.
12
CH-PViO
13
14
15
16
17
- PV/I ^
- ^J-L tl£
18
19
Ui
20
I'sot-
21
22
23
24
25
roken/Unrecovered Tools:
Overtime:
Accepted By:
-------
Soil Vapor Survey Sheet / ,
•oject Name & Location ~TTloftalTRjl \W<-U-r A/ft Date; lony-fa
lent; Ttk* Tec1- - Field Rep: T^^S ' Start Time: #frj&
&P Operator p^ft . Finish Time:
'eath'er Conditions: • . • Bags of Bentonite:
1
2
3
4
5
6
7
8
9
10
11
12.
13
14
15
16
17
18
19
20
21
22
23
24
25
Point ID
A3-&V-A
A* - &t e.
/\5 -
-------
oject Name & Location •'TT(o i _
•\- '; ^ 63 ci c
Overtime:
Accepted By:
-------
Soil Vapor Survey Sheet / /
•oject Name & Location TTTO/ko&TFck \fovXJLr* Af=6 Date: /
-------
Appendix D
Statistical Analyses
-------
Appendix D
Statistical Analyses
Development of Active Soil Gas Sampling Method
Experimental Design
Three separate experiments were conducted to assess the primary effects of purge rate, purge volume, and
sample volume on measured soil gas concentrations. The experimental designs for each of these
experiments are described below. Full experimental designs and results from these experiments are
provided in Sections 3.0 and 4.0 of the Project Report for the Development of Active Soil Gas Sampling
Method (Tetra Tech EMI 2007).
Purge Volume
In this experiment, five permanent, and one temporary, soil gas probes were sampled:
• 15-SV-A2
15-SV-A4
• 15-SV-B1
• • 15-SV-B4
• 15-SV-C4
• 15-SV-C4HP (temporary)
The purge volumes that were tested included the following:
• 1 system volumes
• 2 system volumes
• 3 system volumes
• 4 system volumes
• 5 system volumes
• 6 system volumes
• 10 system volumes
• 20 system volumes
Purge rate and sample volume were the same in all of the samples collected; i.e., 200 ml/min and 60 ml,
respectively. At the highest purge volume used in the experiment (i.e., 4,400 system volumes from 15-
SV-A4), only one sample was collected and that purge volume was more than 100 times greater than the
next highest purge volume. This data point can be considered an outlier that may bias the data analysis as
the system volume purged is very far removed from all other system volumes measured. Therefore, this
data point was removed from the analyses.
Purge Rate
In this experiment, five permanent soil gas probes were sampled:
• 15-SV-B1
• 15-SV-B2
• 15-SV-B3
• 15-SV-B4
• 15-SV-B5
D-l
-------
The purge rates that were tested included the following:
• lOOml/min
• 200 ml/min
• 500 ml/min
• 1,000 ml/min
• 2,000 mVmin
• 5,000 ml/min
Sample volume was the same in all samples collected (i.e., 60 ml). Purge volume was the same in the
majority of the samples collected; i.e., 3 system volumes (204-228 ml). For the four samples with a
purge rate of 5,000 ml/min, the number of system volumes purged fell into 2 groups: 8 and 208-221
system volumes purged. The two samples that were collected with more than 200 system volumes purged
(from 15-SV-B1 and 15-SV-B3) are far removed from the other purge volumes used and may bias the
data analysis. Therefore, they were assumed to be outliers and were not included in the analyses.
Sample Volume
The third experiment varied sample volume, while intending to hold purge rate constant. In this
experiment, five permanent soil gas probes were sampled:
• 15-SV-A1
• 15-SV-B2
• 15-SV-B3
• 15-SV-C2
• • 15-SV-C5
The sample volumes that were tested included the following:
• 25 ml (syringe)
• 60 ml (syringe)
- • 500 ml (Tedlar bag)
• 1,000 ml (Tedlar bag)
• 6,000 ml (stainless steel Summa canister)
A purge rate of 200 ml/min used was for all samples except the 6,000 ml samples collected using a
Summa canister. For this sample volume, a purge rate of either approximately 100 ml/min (100 - 122
ml/min; 4 probes) or 300 ml/min (1 probe) was used (Figure D-l). The number of system volumes
purged necessarily increased with increasing sample volume, and ranged from 3 to 31.3 system volumes
(Figure D-l).
D-2
-------
O3
30
1 25
J,
T3
0) 20
Q.
(0
CD
1 15
"o
E
r°
n
o System volumes purged
+ Purge rate
i
i
:: :f -
+
i !
i
4 o
i _ i . . .
f
i !
p
-+---
o
o
0
i c
o
-j-§ i -
+
i ,
OOU
f}r\r\
300
250
^
c
200 ^
CD
"ffl
Jg
150 a,
E1
£
100
en
DU
n
O
o
in
Sample Volume (ml)
Figure I)-1. Sample Volume experimental design. The number of system volumes purged varied
directly with sample volume, whereas purge rate was a function of the sampling device
Analysis
Multiple linear regression analysis was performed on the results from the experiments to evaluate the
effect of the treatment. When parameters other than the parameter of interest varied in the experimental
conditions (e.g., purge volume was also varied in the sample volume experiment), their effects were
included in the analysis. Interaction effects (i.e., does the manipulation of one variable have the same
effect at all levels of the other variables manipulated?) were not included in the analysis. For the
purposes of the analyses presented here, it was assumed the each analytical result could be considered as a
randomly collected independent sample.
Effect of Baseline
Prior to conducting analysis of the experiments, baseline conditions in the installed probes were
evaluated. Baseline conditions were measured using a purge rate of 200 ml/min, a sample volume of 60
ml, and 3 system volumes purged (i.e., 180 to 228 ml) prior to any of the other experiment. Baseline
concentrations varied from 93 ng/m3 to 2,400 jag/m3 (Figure D-2).
D-3
-------
Baseline
*1OUU
•o^ iftnn
~B) 1 Ann
_o
| 1200
c
TUUU
c
bUU
/inn
4UU
9nn
«
< s
> ;
CO 0
LO U
•
>
•
•
I »
J CO ^" LO T-
^C ^^ ^1 C
> £ £ > 5
3 CO C/3 CO C/
i uS in LT> u
•
5 a- s
5 £ £
5 tO U
»
4
•3 •<} U
5 m c
> > =
1 CO 0
•> 10 u
I
I
,
h
i •
*
•
3 CN CO ^ LO CD
3 O O O O 0
3 CO CO CO CO CO
3 1O 1O 1O LO 1O
Probe
Figure D-2. Plot of baseline concentrations by probe.
To account for the differences in baseline concentrations between the wells in the analyses, baseline
concentrations were added as a covariate in all of the analyses. In addition to differences among wells in
baseline concentrations, baseline conditions may also have a significant effect on the variation in the
response of measured TCE concentrations, with increasing variation in the response at higher baseline
concentrations. This effect is seen below in the data from the purge volume experiment (Figure D-3).
D-4
-------
2800
2600
2400
"E 2200
~ 2000
I 1800
1 1600
o
§ 1400
O 1200
3 1000
m
E 800
600
400
200
0
200
400
600 800 1000 1200
Baseline TCE concentration
1400 1600 1800 2000
Figure D-3. Effect of baseline concentration on the variance in experimentally measured TCE
concentrations from the purge volume experiment. Measured concentrations show a
significant correlation with baseline (r = 0.74). Similarly, the variance in the result
increases with increasing baseline concentrations
To correct for the effect of increasing variance, all data were natural logarithm (i.e., In) transformed prior
to analysis.
As noted above, the system volumes for each well were also slightly different. This may affect both the
baseline concentrations and the concentrations measured during each of the experiments. To account for
the potential effect of the difference in system volumes among the wells, system volume was used as a
covariate in the analyses.
Purge Rate
In this experiment, the variable of interest was purge rate. While sample volume was held constant, there
was some variation in the number of system volumes purged. Therefore, the independent variables used
in the regression analysis were: 1) purge rate, 2) system volumes purged, 3) baseline concentration, and
4) system volume. This resulted in a highly significant multiple linear regression with the following
parameters F4,22= 626.99, p < 0.0001, adjusted r2 = 0.99, where:
Adjusted r2 = the proportion of variation explained by the independent variables in a multiple linear
regression. Includes an adjustment for the number of variables in the regression.
F = the ratio of Mean Square for the effect of interest to Mean Square for the error term.
p = the probability of the observed result happening by chance. By convention, a p value of less
than 0.05 is used to indicate that the observed effect is significant (e.g., due to the experimental
manipulations).
D-5
-------
The resulting equation is:
ln(TCE in ng/m3) = -4.85 + 0.14*ln(purge rate in ml/min) - 0.044*ln(system volumes purged) +
1.00*ln(system volume in ml)+ 0.99*ln(baseline TCE in (ig/m3)
These results are presented in Table D-l.
Table D-l
Standard Error
Parameter Parameter
Estimate Estimate
Intercept
LN(purge rate)
LN(system volumes
purged )
LN(Baseline TCE)
LN(system volume)
-4.85
0.14
-0.044
0.99
1.00
2.12
0.021
0.11
0.020
0.49
of
'(22)
-2.29
6.89
-0.41
49.11
2.03
P
0.03
0.000001
0.7
O.000001
0.06
Notes:
p - the probability of the observed result happening by chance. By convention, a p value of less
than 0.05 is used to indicate that the observed effect is significant (e.g., due to the experimental
manipulations).
/ - the value calculated from the t distribution given a sample size and standard deviation.
To directly illustrate the effect of purge rate on the measured TCE concentrations, the regression above
was performed without purge rate, and the residuals were calculated. These residuals were then regressed
on the purge rate. After accounting for the effect of the other variables, purge rate accounted for
approximately 50 percent of the variance observed in the data (Figure D-4).
D-6
-------
0.4
0.3
0.2
0.1
0.0
-0.1
S.
-0.3
-0.4
-0.5
-0.6
LN(purge rate):Residual: r2 = 0.50; r = 0.71, p = 0
.00004; y = -0.66 + 0.11*x
4.0
4.5
5.0
8.0
8.5
9.0
5.5 6.0 6.5 7.0 7.5
LN(purge rate in ml/min)
Figure D-4. Effect of purge rate on measured soil gas concentrations, after accounting for the
effects of baseline conditions, system volumes purged, and system volume
The two measurements at far right in Figure D-4 were collected using a different number of system
volumes purged than the other samples.
Purge Volume
In this experiment, only system volumes purged was varied. Therefore, the independent variables used in
the regression analysis were: 1) system volumes purged, 2) baseline concentration, and 3) system
volume. These parameters resulted in a highly significant multiple linear regression (F334=163.46, p <
0.0001, adjusted r2 = 0.93). The resulting equation is:
ln(TCE in ng/m3) = -6.71 + 0.29*ln(system volumes purged) + 0.95*ln(baseline TCE in ng/m3) +
1.53*ln(system volume in ml)
These results are presented in the Table D-2.
D-7
-------
Table D-2
Standard Error of
Parameter Parameter
Estimate Estimate f(34)
Intercept
LN(system volumes
purged )
LN(Baseline TCE)
LN(system volume)
-6.71
0.29
0.95
1.53
3.55
0.049
0.051
0.80
-1.89
5.96
18.56
1.91
P
0.07
0.000001
O.000001
0.06
Notes:
p - the probability of the observed result happening by chance. By convention, a p value of less
than 0.05 is used to indicate that the observed effect is significant (e.g., due to the
experimental manipulations).
/ - the value calculated from the t distribution given a sample size and standard deviation.
To directly illustrate the effect of the number of system volumes purged on the measured TCE
concentration, the regression described above was performed without system volumes purged, and the
residuals were calculated. These residuals were then regressed on the number of system volumes purged
(Figure D-5). After accounting for the effect of the other variables, purge volume accounted for
approximately 50 percent of the variance observed in the data.
1.0
0.8
0.6
0.4
o> 0.2
"ro
3 0.0
in
-------
Sample Volume
In this experiment, the variable of interest is sample volume. However, the number of system volumes
purged necessarily increased with increasing sample volume. Purge rate was held constant, with the
exception of the final sample. Sample volume and system volumes purged are not independent variables;
i.e., they covary. Purge rate is also not independent. Therefore, these data cannot be evaluated using the
multiple regression approach used for the previous two experiments.
To analyze the results of this experiment, we treated sample volume as an indicator of the combined
experimental conditions, and as a categorical, rather than continuous, variable. To analyze these data an
analysis of covariance (ANCOVA) was used, with the baseline concentrations (In-transformed) treated as
a continuous covariate for the reasons stated above. System volume was examined and was not
determined to have a significant effect in the analyses and was, therefore, not included as a covariate.
The ANCOVA indicated that the experimental manipulations had a significant effect on the TCE
concentrations measured, after adjusting for the effect of baseline concentrations (Table D-3).
Table D-3
Effect
Intercept
Sample Volume
Baseline
Error
Sum of
Squares
0.0275
2.63
19.47
1.48
d.f.
1
4
1
19
Mean Square
0.0275
0.658
19.47
0.078
F
0.351
8.42
249.0
P
0.56
0.0004
<0.0001
Notes:
d.f. - degrees of freedom. The total degrees of freedom are equal to the sample size minus one. In
regression and ANOVA, the total degrees of freedom are partitioned among the factors,
treatment, and error terms.
F- the ratio of Mean Square for the effect of interest to Mean Square for the error term.
p - the probability of the observed result happening by chance. By convention, a p value of less than
0.05 is used to indicate that the observed effect is significant (e.g., due to the experimental
manipulations).
To determine which treatments are significantly different, the Newman-Kuels multiple range test was
used. This test indicated that the TCE concentrations measured in the 25 ml, 60 ml, and 6,000 ml sample
volumes were not significantly different from each other. In contrast, the 500 ml and 1,000 ml sample
volumes were similar to each other, but were significantly different from the other treatments (Figure D-).
D-9
-------
I .U
7 A
70
•o""1
^) fi A
§> b.S
"5
_c
6 A
6.2
6.0
-------
3,000
2,500
2,000
1,500
1,000
10/16/06 12:00
10/17/06 12:00
Date and Time
10/18/06 12:00
Figure D-7. Temporal control point data
Equilibration Time Analysis
To determine if there was an effect of the amount of time that a soil vapor well was allowed to equilibrate
after installation, 13 wells were sampled approximately 1 hour (41 to 85 minutes; mean 59 minutes) after
installation and again four days later using the same purge rate, purge volume, and sample volume. The
data were analyzed using a matched-pairs Mest which showed that waiting four days did not have a
significant effect on the mean concentration (df = 12, t = -1.13, p = 0.3). The results are shown in Figure
D-8, below.
D-ll
-------
^,uuu
1 ftfifi
1,600
~~. I^IJU
n^
5* 1 onn
0)
c
^ 1 000
^5
g
O nnn
o
finn
Ann
onn
n
•
- Mean
12-oct-oe 16-oct-oe
Date
Figure D-8. Results of matched-pairs /-test analysis.
D-12
-------
Appendix E
Active Soil Gas Sampling Method
-------
1.0 INTRODUCTION
Active soil gas investigations are useful to obtain vapor phase data at sites potentially
affected by volatile organic compounds (VOCs), including chlorinated and aromatic
hydrocarbons. Active soil gas investigations may also be used to investigate sites
potentially affected by methane and hydrogen sulfide, and to measure fixed and biogenic
gasses (e.g., oxygen, carbon dioxide, or carbon monoxide). Among other things, the data
can be used to identify the source and determine the spatial distribution of VOC
contamination at a site, or to estimate indoor air concentrations for risk assessment
purposes.
For site characterization, it is encouraged that both soil gas and soil matrix sampling be
completed. Typically, soil gas data are more representative of actual site conditions in
coarse-grained soil formations while soil matrix data are more representative of actual site
conditions in fine-grained soil formations. For evaluating the risk associated with vapor
intrusion to indoor air, soil gas data are the preferred contaminant data set, where
practicable. Flux chamber and passive sampling methods are not discussed in this
guidance. Any sites where such sampling methods are necessary will be addressed
separately.
2.0 SUPPLEMENTAL RECOMMENDATIONS
The following sections are included in an effort to ensure that consistent methodologies are
applied during soil gas investigations to produce reliable and defensible data of high quality.
All sampling probe installation, sampling, and analytical procedures, whether or not
discussed below, are subject to review and approval by the United States Environmental
Protection USEPA (USEPA).
2.1 Project Management
2.2 Soil Gas Sampling Probe Installation
2.3 Purge Volume Test
2.4 Leak Test
2.5 Purge/Sample Flow Rate
2.6 Soil Gas Sampling
2.1 Project Management
2.1.1 Workplan: An appropriate workplan should be prepared and submitted to USEPA
and/or responsible oversight agency [Agency] for review and approval at least 30 days prior
to its implementation. Any variations or deviations from this guidance should be specified in
the workplan. The soil gas workplan can either be incorporated as part of a comprehensive
site investigation workplan or as a stand-alone document, depending on site-specific
circumstances.
2.1.2 Field Activities
A. The USEPA/Agency should be notified 10 working days prior to implementation of field
activities. All necessary permits and utility clearance(s) should be obtained prior to
conducting any investigations described in this guidance.
-------
B. All engineering or geologic work (e.g., logging continuous soil cores, soil description)
should be performed or supervised by a Registered Professional in the State under which
the work is completed. In addition, where applicable, all work performed should be under
the direction and supervision of a project coordinator experienced in soil gas investigations.
C. Evaluation of raw data by USEPA/Agency staff may occur either in the field or in the
office.
1. Hard copies of the complete raw laboratory data, including handwritten data and field
notes, should be provided to the USEPA/Agency staff upon request.
2. Adjustments or modifications to the sampling program may be required by
USEPA/Agency staff to accommodate changes mandated by evaluation of the data set or
unforeseen site conditions.
D. Investigation derived wastes (IDW) should be managed as hazardous waste until proven
otherwise or until specifically approved by the USEPA/Agency as being non-hazardous
waste. IDW should be handled and disposed in accordance with federal, state and local
requirements.
E. Field Variations
1. To expedite the completion of field activities and avoid potential project delays,
contingencies should be proposed and included in the project workplan (e.g., soil matrix
samples will also be collected if clayey soils [as defined in the Unified Soil Classification
System (USCS)] are encountered during the proposed soil gas investigation; provisions for
step-out sampling activities, etc.).
2. The USEPA/Agency field staff should be informed of any problems, unforeseen site
conditions, or deviations from the approved workplan. When it becomes necessary to
implement modifications to the approved workplan, the USEPA/Agency should be notified
and a verbal approval should be obtained before implementing changes.
F. Soil Matrix Sampling Requirements: Companion soil matrix sampling may be conducted
concurrently with a soil gas investigation except where extremely coarse-grained soils (as
defined in USCS) are encountered or when specifically excluded by the USEPA/Agency.
2.1.3 Soil Gas Investigation Reports: A soil gas investigation report including a discussion of
field operations, deviations from the approved workplan, data inconsistencies, and other
significant operational details should be prepared. The report may either be a stand-alone
document in a format recommended by the USEPA/Agency or be included within a site-
specific assessment report. At a minimum, the report should contain the following:
A. Site plan map and probe location map at an appropriate scale as specified in the
workplap (e.g., scale: one inch = 25 to 50 feet);
B. Final soil gas iso-concentration maps for contaminants of concern at the same scale as
the site plan map;
C. Summary tables for analytical data in units consistent with the method;
-------
D. Legible copies of field and laboratory notes or logs;
E. All analytical results and Quality Assurance/Quality Control (QA/QC) information
including tables and explanations of procedures, results, corrective actions and effect on the
data, in the format specified by the USEPA/Agency; and
F. Upon request, all raw data including chromatograms and calibration data should be
submitted to the USEPA/Agency.
2.2 Soil Gas Sampling Probe Installation
2.2.1 Lithology: Site soil or lithologic information should be used to select appropriate
locations and depths for soil gas probes. If on-site lithologic information is not available prior
to conducting the soil gas investigation, at least one (1) continuously cored boring to the
proposed greatest depth of the soil gas investigation should be installed at the first sampling
location, unless specifically waived or deferred by USEPA/Agency. Depending on site
conditions, additional continuously cored borings may be necessary. For site assessment
purposes, sampling depths should target lithologic zones permeable to gas. For vapor
intrusion assessments, sampling depths may be chosen based upon proximity to receptor
rather than lithology.
A. Lithologic logs should be prepared for all borings (e.g., continuously cored borings, soil
matrix sampling, geotechnical sampling, etc.). Note: This does not apply to direct-push soil
gas probe installations that are not logged.
B. Information gathered from the continuously cored borings may include soil physical
parameters, geotechnical data, and contaminant data.
C. If low-flow or no-flow conditions (e.g., fine-grained soil, clay, soil with vacuum readings
that exceed approximately 10 inches of mercury or 136 inches of water) are encountered,
soil matrix sampling using EPA Method 5035A should be conducted in these specific areas.
D. If the bottom five (5) feet of a continuously cored boring is composed of clay or soil with a
vacuum exceeding approximately 10 inches of mercury or 136 inches of water, the
continuously cored boring should be extended an additional five (5) feet to identify potential
permeable zones. If the extended boring is also composed entirely of clay, the boring may
be terminated. Special consideration should always be given to advancing borings and
ensuring that a contaminant pathway is not being created through a low permeability zone.
2.2.2 Sample Spacing: There is no single rule regarding ideal sample spacing since each
site investigation entails a unique set of considerations and objectives. In general, a
sampling grid is an affective approach to objectively assess an overall area. Sample
spacing within the grid should consider the overall project objectives, and include
consideration of scale, site-specific features, and available investigative information during
the preparation of the workplan. A scaled site plan depicting potential or known areas of
concern (e.g., existing or former sumps, trenches, drains, sewer lines, clarifiers, septic
systems, piping, underground storage tanks [USTs]; chemical or waste management units)
should be provided in the project workplan. The sampling grid is then projected over the
-------
site plan such that each area of concern or interest is captured within the investigative
scope. A background location where no contamination is expected is an important feature
to include in all investigations.
Generally speaking, for characterization of known contamination areas and definitions of
plume margins, a minimum sample spacing of 25 feet on center is applicable. For overall
site coverage, a larger spacing of 50 feet may be more appropriate. For large sites in a
general reconnaissance mode of investigation, increased sample spacing may be proposed
based on site-specific conditions, with USEPA/Agency approval. To optimize detection and
delineation of VOCs, the grid spacing should be modified to include biased (i.e. locations
intended to detect areas of known or suspected contamination) sampling locations.
For vapor intrusion assessments, sample spacing will depend upon the size of the receptor
(i.e. footprint of the building), location of the source relative to the receptor, and access to
the receptor. At a minimum, enough points should be collected near or around the structure
to get a representative value of the contaminant concentrations near the footprint of the
building.
2.2.3 Sample Depth: Sample depths should be chosen to minimize the effects of changes in
barometric pressure, temperature, or breakthrough of ambient air from the surface; and to
ensure that representative samples ar-e collected. Consideration should be given to the
types of chemicals of concern, the lithology encountered, the depth to underlying
groundwater, and the depth/location of the contaminant source.
A. At each sample location, soil gas probes are to be installed at a minimum of one sample
depth. Five (5) feet below ground surface (bgs) is a common depth, but site specific
considerations must always be considered, including shallower or deeper depths as
appropriate.
B. In addition, samples should be collected near lithologic interfaces or based on field
instrument readings (e.g., Flame lonization Detector [FID], Photo lonization Detector [PID])
from soil cuttings and/or cores to determine the location of maximum analyte concentrations
at the top or bottom of the interface, depending upon the analyte.
C. Multi-depth sampling is appropriate for any of the following conditions:
1. To determine the source of the contamination vertically in the vadose zone.
2. To determine the vertical attenuation of the soil gas concentrations in the vadose
zone
3. To determine the presence and zone of bioattenuation.
D. If no lithologic change or contamination is observed, default sampling depths may be
selected for multi-depth sampling. For example, soil gas samples may be collected at 5, 15,
25, 40 feet bgs, etc., until either the groundwater is encountered or VOCs are not detected,
whichever comes first.
2.2.4 Sampling Conveyance Tubing: Sample tubing should be of a small diameter (1/8 to
1/4 inch) to minimize "dead volume" and made of rigid wall material (e.g., nylon, Teflon,
polyethylene, copper or stainless steel) which will not react or interact with site
-------
contaminants. For example, metal tubing should not be used for collection of hydrogen
sulfide samples. If copper tubing is used, the copper must first be adequately cleaned to
remove oil residue that might be present from the manufacturing process.
A. Clean, dry tubing should be utilized at all times. If moisture, water, or an unknown
material is present in the probe prior to insertion, the tubing should be decontaminated or
replaced. All tubing should be flushed immediately prior to installation to ensure any vapors
picked up during storage and transport are removed.
B. After use at each location:
1. Non-reusable (e.g., nylon or Teflon) sampling tubes should be discarded; or
2. Reusable sampling tubes should be properly decontaminated between locations.
C. At least once each day, equipment blanks should be collected by pulling clean air or
nitrogen through the sampling probe and sample train. Positive detections > 20% of the
minimum sample analyte concentrations in an equipment blank will form the basis for
corrective action, including but not limited to replacement of tubing and/or sampling train
components.
D. A drawing of the proposed probe tip design and construction should be included in the
project workplan.
2.2.5 Soil Gas Probe Emplacement Methods
A. Permanent or Semi-permanent Soil Gas Probe Methods:
Permanent or semi-permanent soil gas probes may be installed, using a variety of drilling
methods. Note that the mud rotary drilling method is not acceptable for soil gas probe
emplacement. Other drilling methods such as air rotary and rotosonic can adversely affect
soil gas data during and after drilling and will require extensive equilibration times.
Therefore, they are not recommended when other methods can reach the target depths.
Other soil gas probe designs and construction (e.g., soil gas wells or nested wells) may be
appropriate and should be discussed with USEPA/Agency staff prior to emplacement.
When additional sampling is not anticipated per consultation with the USEPA/Agency, such
probes may be properly removed or decommissioned after completion of the soil gas
investigation. Unless logistically complicated, it is recommended for all installed probes,
whether temporary or permanent, that the locations be recorded with descriptive and/or
physical measurements using a measuring tape (or equivalent) to the nearest foot, or
Global Positioning Satellite (GPS) coordinates, accurate to within 0.5 feet.
1. The probe tip should be emplaced midway within the sand pack. Typical sand pack
thicknesses are 1 foot, but smaller or larger sand packs may be appropriate depending
upon the purpose. The sand pack should be appropriately sized (e.g., average particle
diameter equal to or greater in size than the adjacent formation) and installed to minimize
disruption of airflow to the sampling tip. See Figure 1 for more information.
2. At least one (1) foot of dry granular bentonite should be emplaced on top of each sand
pack to preclude the infiltration of hydrated bentonite grout. The borehole should be grouted
to the surface with hydrated bentonite grout. With respect to deep probe construction with
-------
multiple probe depths, the borehole should be grouted between probes. One (1) foot of dry
granular bentonite should be emplaced between the filter pack and the grout at each probe
location. See Figure 2 for more information.
3. The use of a down hole probe support may be required for deep probe construction (e.g.,
40 feet bgs for direct push probes).
a. Such probe support may be constructed from a one-inch diameter
bentonite/cement grouted PVC pipe or other solid rod, or equivalent, allowing probes
to be positioned at measured intervals.
b. The support should be properly sealed or solid (internally or externally) to avoid
possible cross-contamination or ambient air intrusion.
c. The probes should be properly attached to the exterior of the support prior to
placement down hole.
d. Alternative probe support designs should be described in the project workplan. If
probe support will not be used for deep probes, justification should be included in the
project workplan.
4. Tubing should be properly marked at the surface to identify the probe location and depth.
5. As-built diagrams for probes or wells should be submitted with the soil gas investigation
report detailing the well identification and corresponding probe depths. A typical probe
construction diagram may be submitted for probes with common design and installation.
6. Unless soil gas probes are removed or decommissioned, probes should be properly
secured, capped and completed to prevent infiltration of water or ambient air into the
subsurface and to prevent accidental damage or vandalism. For surface completions, the
following components may be installed:
a. Gas-tight valve or fitting for capping the sampling tube;
b. Utility vault or meter box with ventilation holes and lock;
c. Surface seal; and
d. Guard posts.
B. Temporary Soil Gas Probe Emplacement Method: In general, the drive rod is driven to a
predetermined depth and then pulled back to expose the inlets of the soil gas probe. After
sample collection, both the drive rod and tubing are removed.
1. During installation of the probe, hydrated bentonite should be used to seal around the
drive rod at ground surface to prevent ambient air intrusion from occurring.
2. The inner soil gas pathway from probe tip to the surface should be continuously sealed
(e.g., a sampling tube attached to a screw adapter fitted with an o-ring and connected to the
probe tip) to prevent infiltration.
-------
2.2.6 Equilibration Time: During probe emplacement, subsurface conditions may be
disturbed. To allow for subsurface conditions to equilibrate, the following equilibration times
are recommended:
A. For probes installed by hand methods or direct-push methods where sampling is done
through the drive rod, the equilibration time may be highly variable and dependent upon a
variety of factors including, but not limited to, probe rod diameter, depth of probe, soil
lithology (i.e. tight soils which can result in frictional heating), and soil permeability. A time-
series test is recommended to assess the equilibration time when practical (i.e. on-site
mobile laboratory). When a time-series test is not practical, an equilibration time of at least
60 minutes is recommended.
B. For probes installed with direct push or hand methods where the drive rod does not
remain in the ground (semi-permanent or permanent method), purging of the sand pack is
warranted. If the sand pack volume is purged, no equilibration time should be required. If
the sand pack is not purged, an equilibration time of at least 60 minutes is recommended
unless a time-series test is conducted that shows the soil gas concentrations remain steady.
C. For probes installed with hollow stem drilling methods, purge volume test, leak test, and
soil gas sampling should not be conducted for at least 48 hours (depending on site lithologic
or drilling conditions) after the soil gas probe installation unless a time-series test is
conducted that shows the soil gas concentrations remain steady.
D. Probe installation time should be recorded in the field log book.
E. When an investigation continues over the course of multiple days, and time-series test
data are not available, at least one existing probe should be resampled after a 24 hour
period in order to assess whether site-specific equilibration times should be increased
beyond the default recommendations above.
2.2.7 Decontamination: After each use, drive rods and other reusable components should
be properly decontaminated to prevent cross contamination. The proposed decontamination
process should be addressed in the site-specific work plan.
2.3 Purge Volume Test
To ensure stagnant or ambient air is removed from the sampling system and near the probe
tip after emplacement, a purge volume versus contaminant concentration test may be useful
to assure collected soil vapor samples are representative of subsurface conditions. The
purge volume test is conducted by collecting and analyzing a sample for target compounds
after the removal of appropriate purge volumes. Various soil gas guidance documents
recommend purging a probe sequentially after one through seven dead volumes, and
plotting the analytic result to obtain an optimum number of purge volume to be applied to all
successive probes.
The following considerations apply when determining the need for a purge volume test:
-------
• Sample volume relative to the "dead-space" volume of the sampling probe. For
probes with small dead-space volume (<150 ml), a 6-liter sample (i.e. SUMMA)
corresponds to approximately 40 dead-space volumes. In this extreme case, a purge
volume test is unlikely to yield useful data since the large sample volume overwhelms
any measurable effect on modifying the small dead space volume purge.
• Therefore, if the sum of the dead space volume and the sample volume is greater than
or equal to 7 times the dead space volume; it is recommended that a single dead
space purge volume is sufficient to yield a representative result. The basis for this
contention is that the sample container, once filled, will effectively average more than
six dead space purge volumes, which spans the entire recommended range of purge
volumes to be studied.
• In cases where the sum of the dead space volume and the sample volume is less than
7 times the dead space volume, it is recommended that a purge volume test be
completed by collecting and analyzing the samples for target compounds after the
removal of seven dead volumes as described in the next section to determine the
nearest whole number of purge volumes that result in maximum target contaminant
concentrations.
• When permanent or semi-permanent probes (tubes) are installed, the dead volume of
the sand pack should be included in the total system dead volume if they are to be
sampled the same day.
2.3.1 Purge Test Locations: The purge test location should be selected as near as possible
to the anticipated or confirmed contaminant source, and in an area where soil gas
concentrations are expected to be greatest based on lithology (e.g., coarse-grained
sediments). The first purge test location should be selected through the workplan approval
process or as a field decision in conjunction with USEPA/Agency staff.
2.3.2 Purge Volume: The purge volume or "dead space volume" can be estimated based on
a summation of the internal volume of tubing used, and annular space around the probe tip.
Sample containers (e.g., SUMMA™ canisters, syringes, and Tedlar™ bags) are not included
in the dead space volume calculation when the sum of the dead space volume arid the
sample volume is less than 7 times the dead space volume.
The USEPA/Agency recommends step purge tests of one (1), three (3), five (5) and seven
(7) purge volumes be conducted as a means to determine the purge volume to be applied
at all subsequent sampling points.
A. The appropriate purge volume should be selected based on the highest concentration for
the compound(s) of concern detected during the step purge tests. The purge volume should
be optimized for the compound(s) of greatest concern.
B. If VOCs are not detected in any of the step purge tests, a default of three (3) purge
volumes should be extracted prior to sampling.
-------
C. The step purge tests and purging should be conducted at the same rate soil gas is to be
sampled (see Section 2.5).
D. The purge test data (e.g., calculated purge volume, rate and duration of each purge step)
should be included in the report to support the purge volume selection. The report should
include a simple analysis of system purge volume versus targeted analyte concentration to
document that the selected number of system volumes coincides with the highest
concentration detected.
E. When an investigation continues over the course of multiple days, the purge test should
be completed using the same probe array twice over a 24-hour interval to assess the effect
of equilibration time on analytic results.
2.3.3 Additional Purge Volume Test
A. Additional purge volume tests should be performed to ensure appropriate purge volumes
are extracted if:
1. Widely variable or different site soils are encountered; or
2. The default purge volume is used and a VOC is newly detected.
B. If a new purge volume is selected after additional step purge tests are conducted, the soil
gas investigation should be continued as follows:
1. In areas of the same or similar lithologic conditions:
a. Re-sample 20 percent of the previously completed probes.
This re-sampling requirement may be reduced or waived in consultation with
USEPA/Agency staff, depending on site conditions. If re-sampling indicates higher
detections (e.g., more than 50 percent difference in samples detected at greater than
or equal to 10 ng/L), all other previous probes should be re-sampled using the new
purge volume.
b. Continue the soil gas investigation with the newly selected purge volume in the
remaining areas.
2. In areas of different lithologic conditions: Continue the soil gas investigation with the
newly selected purge volume in the remaining areas.
2.4 Leak Test
Leak tests involve introducing a known compound (e.g., the leak check compound is
detected and confirmed in the test sample after its application) in the vicinity of a sample
collection to ensure there are no leaks around the installed probe and/or the soil-gas
sampling train. Leakage during soil gas sampling may dilute samples with ambient air and
produce results that underestimate actual site concentrations or contaminate the sample
with external contaminants. In all leak test applications, the practitioner must exercise care
when handling leak check compounds so as not to introduce contaminants onto reusable
-------
sampling equipment, into a mobile laboratory environment, or onto their persons which may
otherwise result in a series of "false positives" as the contaminant is systematically carried
from one location to the next.
2.4.1 Leak tests should be conducted at a minimum of 10% of the soil gas probes sampled,
at regular intervals over the course of a program. When on-site analysis is used, leaks can
be found in real-time and samples can be recollected, as necessary.
2.4.2 Leak Check Compounds: Methods exist using gases (e.g., helium, propane, SF6,
Freon) or liquids (Freon, isopropanol, butane in shaving cream). Both types of tracers have
pros and cons.
A. Gaseous tracers can permit quantitative evaluation of the magnitude of a leak given
knowledge of the starting concentration and the concentration detected in the sample.
However, gaseous tracers do require additional hardware such as tanks, regulators, tubing,
a "hood" within which to disperse the gas, etc. Helium offers a nice advantage in that it is
readily measured on-site with a field meter, but due to its small molecular size, helium more
readily permeates sampling materials than larger molecules typical of VOCs, so it may
result in false positives.
B. Volatile liquid tracers offer logistical simplicity and accomplish the primary goal: detecting
any leaks in the probe or sample train. Typically, the use of liquid tracers is not quantitative
since the concentration at the point of application is typically not known. However, liquid
tracers are readily available and easily and quickly supplied at multiple locations (probe,
sampling rod, and sampling train) simultaneously using paper towels or clean rags. This
method is particularly more suited for sampling through the probe rod since it can be
applied at the base and top of the rod.
2.4.3 A leak check compound should be placed at any location where ambient air could
enter the sampling system or where cross contamination may occur, immediately before
sampling. Locations of potential ambient air intrusion include:
A. Sample system connections;
B. Surface bentonite seals (e.g., around rods and tubing); or
C. Top of the Temporary Soil Gas Probe (see Section 2.2.5.B).
2.4.4 The leak test should include an analysis of the leak check compound. Consideration
must be given to interpretation of positive leak check detections. It is important to recognize
that a small amount of tracer in a sample does not necessarily indicate a significant leak,
and some discretion is advised. For instance, when a quantitative leak check process is
used, if the concentration of the tracer in a sample is insignificant (i.e. less than 5 percent of
the starting concentration) USEPA/Agency staff may be consulted to assess whether the
sample result may be considered valid.
If a leak check compound is detected in the sample that is otherwise considered significant,
the.following actions should be followed:
-------
A. The cause of the leak should be evaluated, determined and corrected through
confirmation sampling;
B. If the leak check compound is suspected or detected as a site specific contaminant, a
new leak check compound should be used;
C. If leakage is confirmed and the problem can not be corrected, the soil gas probe should
be properly decommissioned;
D. A replacement probe should be installed at least five (5) feet from the original probe, or
consult with USEPA/Agency staff; and
E. The leak check compound concentration detected in the soil gas sample should be
included and discussed in the report.
2.5 Purge/Sample Flow Rate
Sampling and purging flow rates should not enhance compound partitioning (i.e. excessive
vacuum reading) during soil gas sampling. Samples should not be collected if field
conditions as specified in Section 2.6.4 exist.
2.5.1 The purging or sampling flow rate should be attainable in the lithology adjacent to the
soil gas probe.
A. 'To evaluate lithologic conditions adjacent to the soil gas probe (e.g., where no-flow or
low-flow conditions exist), a vacuum gauge or similar device should be used between the
soil gas sample tubing and the soil gas extraction devices (e.g., vacuum pump, SUMMA™
canister).
B. Gas tight syringes may also be used to qualitatively determine if a high vacuum soil
condition (e.g., suction is felt while the plunger is being withdrawn) is present.
2.5.2 The USEPA/Agency recommends purging or sampling at rates between 100 to 500
milliliters per minute (ml/min) to limit stripping, prevent ambient air from diluting the soil gas
samples, and to reduce the variability of purging rates. The low flow purge rate increases
the likelihood that representative samples may be collected. At sites with permeable soils
(e.g., clean sands), higher purge rates (i.e. on the order of liters per minute) have been
shown to yield valid results and may be proposed in the workplan. The purge/sample rate
may be modified based on conditions encountered in individual soil gas probes. These
modified rates should be documented in the soil gas report.
2.6 Soil Gas Sampling
After the soil gas probe is adequately purged, samples should be collected by appropriate
methodologies.
-------
2.6.1 Sample Container: Samples should be collected in gas-tight, opaque/dark containers
(e.g., syringes, glass bulbs wrapped in aluminum foil, SUMMA™ canisters), so that light-
sensitive or halogenated VOCs (e.g., vinyl chloride) will not degrade.
A. If a syringe is used, it should be leak-checked before each use by closing the exit valve
and attempting to force ambient air through the needle.
B. If syringe samples are analyzed within five (5) minutes of collection, aluminum foil
wrapping may not be necessary.
C. Discretion is warranted when specifying use of SUMMA™ canisters due to the high
canister volumes (i.e. 1 liter, 3-liter, 6-liter, etc.), and its potential effect on masking the
determination of the appropriate number of dead purge volumes (see Section 2.3).
D. If a SUMMA™ canister is used, a flow regulator should be placed between the probe and
the SUMMA™ canister to ensure the SUMMA™ canister is filled at the flow rate as specified
in Section 2.5.2.
E. Tedlar™ bags may be used depending upon the project DQOs. Samples in Tedlar bags
should not be stored for more than 24 hours to 48 hours.
2.6.2 Sample Collection
A. Vacuum Pump: When a vacuum pump is used, samples should be collected on the
intake side of the vacuum pump to prevent potential contamination from the pump. Vacuum
readings or qualitative evidence of a vacuum should be recorded on field data sheets for
each sample.
B. Shallow Samples: Care needs to be taken when collecting shallow soil gas samples to
avoid sample breakthrough from the surface. Extensive purging or use of large volume
sample containers (e.g., SUMMA™ canisters) should be avoided for collection of near-
surface samples [e.g., shallower than five (5) feet bgs].
2.6.3 Sample Container Cleanliness and Decontamination
A. Prior to its first use and after each subsequent use at a site, sample containers should be
assured clean by the analytical laboratory.
1. Glass syringes or bulbs should be disassembled and properly decontaminated using an
appropriate method.
2. SUMMA™ canisters should be properly decontaminated in the laboratory as specified by
appropriate EPA analytical methods to reach required detection levels.
3. During sampling activities using reused/recycled sampling containers (e.g., SUMMAs,
glass syringes, glass bulbs), at a minimum one (1) decontaminated sample container per 20
samples or per every 12 hours, whichever is more often, should be used as a method blank
to verily and evaluate the effectiveness of decontamination procedures.
-------
C. Plastic syringes should be used only once and then properly discarded.
1. An equipment blank should be run for each batch of plastic syringes used on a project, to
document syringe conditions prior to use.
2.6.4 Field Conditions: Field conditions, such as rainfall, irrigation, fine grained sediments,
or drilling conditions may affect the ability to collect soil gas samples.
A. Wet Conditions: If no-flow or low-flow conditions are caused by wet soils, the soil gas
sampling should cease.
B. If low flow conditions are determined to be from a specific lithology, a new probe should
be installed at a greater depth or a new lateral location should be selected after evaluation
of the site lithologic logs (See Section 2.2.1) or in consultation with USEPA/Agency staff.
C. If moisture or unknown material is observed in the glass bulb or syringe, soil gas
sampling should cease until the cause of the problem is determined and corrected.
D. If refusal occurs during drilling, soil gas samples should be collected as follows or in
consultation with USEPA/Agency staff.
1. For sample depths less than five feet, collect a soil gas sample following the precautions
outlined in Section 2.6.2.B.
2. For sample depths greater than five feet, collect a soil gas sample at the depth of refusal.
3. A replacement probe .should be installed within five (5) feet laterally from the original
probe decommissioned due to refusal. If refusal still occurs after three attempts, the
sampling location may be abandoned.
2.6.5 Chain of Custody Records: A chain of custody form should be completed to maintain
the custodial integrity of a sample. Probe installation times and sample collection times
should be included in the soil gas report.
-------
3.0 BIBLIOGRAPHY
Additional information may be found in the following documents:
American Petroleum Institute (API)
2005 Collecting and Interpreting Soil Gas Samples from the Vadose Zone: A Practical
Strategy for Assessing the Subsurface-Vapor-to-lndoor-Air Migration Pathway at
Petroleum Hydrocarbon Sites. Publication 4741. November.
American Society for Testing and Materials (ASTM)
2001 Designation 04314-92(2001), Standard Guide for Soil Gas Monitoring in the
Vadose Zone.
California Environmental Protection Agency, Department of Toxic Substances Control (DTSC)
and California Regional Water Quality Control Board, Los Angeles Region (LARWQCB)
2003 Advisory - Active Soil Gas Investigations. January.
California Environmental Protection USEPA/Agency (Cal/EPA), Office of Environmental
Health Hazard (OEHHA), Toxicity Criteria Database; website
http://www.oehha.ca.gov/risk/ChemicalDB/index.asp
California Regional Water Quality Control Board, Los Angeles Region, "General Laboratory
Testing Requirements for Petroleum Hydrocarbon Impacted Sites," June 22, 2000
Colder Associates
2004 Final Draft, Soil Vapour Intrusion Guidance for Health Canada Screening Level
Risk Assessment (SLRA), Submitted to Health Canada, Burnaby, British Columbia.
November.
Hartman, B.
2002 How to Collect Reliable Soil-Gas Data For Risk Based Applications, LUSTLine
Bulletin 42. October.
Interstate Technology and Regulatory Council (ITRC)
In preparation Vapor Intrusion Pathway: A Practical Guideline. Appendix D: Sampling
Toolbox
McAlary, T. and Creamer, T.
In preparation. The Effects of Purge Rate and Volume on Sub-slab Soil Gas Samples
Missouri Department of Natural Resources (MO-DNR)
2005 Missouri Risk-Based Corrective Action for Petroleum Storage Tanks, Soil Gas
Sampling Protocol. April
New Jersey Department of Environmental Protection (NJ_DEP)
2005 New Jersey Department of Environmental Protection, Vapor Intrusion Guidance.
October (Updated March 2006).
-------
New York State Department of Health (NY-DOH)
2005 New York State Department of Health, Center for Environmental Health, Bureau
of Environmental Exposure Investigation, Guidance for Evaluating Soil Vapor Intrusion in
the State of New York. February.
U.S. Environmental Protection Agency (EPA)
2006 Assessment of Vapor Intrusion in Homes Near the Raymark Superfund Site
Using Basement and Sub-Slab Air Samples. Office of Research and Development,
National Risk Management Research Laboratory, Cincinnati, OH, EPA/600/R-05/147
EPA/540/1-89/002. March
U.S. Environmental Protection USEPA/Agency, "Test Methods for Evaluating Solid Waste,
Physical/Chemical Methods, EPA Publication SW-846, Third Edition," November 1986,
as amended by Updates I (Jul. 1992), II (Sep. 1994), IIA (August 1993), MB (Jan. 1995),
III (Dec. 1996), IMA (Apr. 1998), IVA (Jan. 1998) and IVB (Nov. 2000);
website http://www.epa.gov/SW-846/main.html
U.S. Environmental Protection USEPA/Agency, "U.S. EPA Contract Laboratory Program
National Functional Guidelines for Organic Data Review, EPA 540/R-94/012,"
February 1994; website http://www.epa.gov/region09/qa/superfundclp.html
United States Environmental Protection USEPA/Agency, Integrated Risk Information
System (IRIS) Database; website http://www.epa.gov/iris/
------- |