MO-9217_40687_CA_RPTS_20230726

3502 Hayes Road • Monroe, North Carolina 28110
113 West Firetower Road, Suite G • Winterville, North Carolina 28590
Phone [phone] • [phone] • Fax [phone]
Engineering Certification: C-2727 • Geology Certification: C-127
July 26, 2023

Mr. Ryan C. Mills
North Carolina Department of Environmental Quality
Underground Storage Tank Section
610 East Center Avenue
Suite 301
Mooresville, North Carolina 28115

Re: High Resolution Site Characterization Activities
Fast Phil’s 506
1541 Salisbury Road
Statesville, North Carolina
Iredell County
Incident Number: 40687
GRI Project Number: 4400

Dear Mr. Mills;

GRI presents results of the High-Resolution Site Characterization (HRSC) activities conducted by Dakota
Technologies and supervised by GRI personnel at the Fast Phil’s 506 site in Statesville, North Carolina.
The activities were conducted in response to February 8, 2022 correspondence from NCDEQ.

On June 20, 2023, GRI and Dakota personnel began HRSC activities using laser-induced fluorescence (LIF)
technology. Twenty-two borings were advanced to depths ranging from 28.0 to 35.1 feet BGS. All of the
soil borings showed signal responses indicative of LNAPL, to varying degrees. According to Dakota’s
analysis of the data, the observed waveforms and cluster plots are consistent with gasoline
contamination. The depth to water in the wells was approximately 18 feet BGS prior to sampling, and
the majority of contamination was detected between approximately 18 and 30 feet BGS. The results of
the LIF analysis suggest that the observed petroleum contamination at the site consists of gasoline-
range organics present in the ground water around MW-4 and between MW-1 and MW-5. A
topographic map showing the general site location and the surrounding area is included as Figure 1. A
Site Map is included as Figure 2. A LIF-UVOST boring location map of the work performed by Dakota
Technologies is included as Figure 3. A copy of Dakota’s HSRC report is included as Appendix A.

Incident No. 40687
Fast Phil’s 506
High Resolution Site Characterization Activities
Page 2 of 5

3502 Hayes Road • Monroe, North Carolina 28110
Phone [phone] • [phone] • Fax [phone]

Please contact me at 888-870-4133 or [e-mail] with any questions or
comments.

Sincerely,
Eric M. Eubanks, P.G.
Project Manager

FIGURES
Copyright:© 2013 National Geographic Society, i-cubed
FIGURE 1SITE LOCATION MAPFAST PHIL'S 5061541 SALISBURY ROADSTATESVILLE, IREDELL COUNTY,NORTH CAROLINAINCIDENT NO. 40687GRI PROJECT NO. 4400
PREPARED BY:GEOLOGICAL RESOURCES, INC.MARCH 29, 201702,000 4,0001,000 Feet
SCALE: 1 INCH = 2,000 FEET
MAP CENTER LOCATIONLATITUDE: 35.768617° NLONGITUDE: 80.853228° W
`
SITE LOCATION
³

APPENDIX

APPENDIX A
High Resolution Site Characterization Report

High Resolution Site Characterization Report
UVOST®-HP Investigation
Project: Fast Phil’s # 506
1541 Salisbury Rd
Statesville, NC 28677

DTC Project No: 0152.2023

July 5, 2023
Prepared For:
Geological Resources, Inc.
3502 Hayes Road
Monroe, NC 28110

Prepared by:
Christopher Horrell
Reviewed By:
Mike Jenson

Dakota Technologies Company, LLC
150 Industrial Park Rd
Forsyth, GA 31029
352-281-2975
Dakota Technologies Company, LLC
5001 Boone Ave N
New Hope, MN 55428
763-424-4803

TABLE OF CONTENTS
1.0 General Site Information ........................................................................................................... 1
2.0 Laser-Induced Fluorescence - UVOST® Technology Overview ..................................................... 1
2.1 Reference Emitter .......................................................................................................................... 2
2.2 Waveforms ..................................................................................................................................... 3
2.3 Cluster Plots .................................................................................................................................... 4
3.0 Hydraulic Profiling (HP) Description ........................................................................................... 8
4.1 Site UVOST Discussion: Waveforms ............................................................................................... 9
4.2 Site UVOST Discussion: Cluster Plots ............................................................................................ 11
5.0 GPS Data-Survey Control ......................................................................................................... 15
6.0 Limitations .............................................................................................................................. 15

APPENDICES
Appendix A UVOST®-HP Field Summary
Appendix B UVOST®-HP Logs @ 200% RE with 10% zoom
Appendix C UVOST®-HP Reference Log
Appendix D Visualization Report Summary

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DTC Project Number: 0152.2023

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1.0 General Site Information
Dakota Technologies Company, LLC (DTC) was contracted by Geological Resources, Inc. to perform a High
Resolution Site Characterization (HRSC) investigation at Fast Phil’s # 506, located at 1541 Salisbury Road,
Statesville, NC. The investigation employed the use of Dakota’s Ultra-Violet Optical Screening Tool
(UVOST®) combined with Hydraulic Profiling (HP) sensor to investigate the extent of the LNAPL plume

A description of the UVOST® technology, waveforms, cluster plots, limitations of LIF, and a UVOST®
Reference Log are included in this report.

2.0 Laser-Induced Fluorescence - UVOST® Technology Overview
Fluorescence is luminescent behavior of certain compounds where absorbed excitation light stimulates
the emission of photons (light) of a longer wavelength relative to the source emission. The release of
these photons can be used to detect small amounts of certain substances such as Polycyclic Aromatic
Hydrocarbons (PAHs) in a larger matrix (e.g., soil). This method of PAH detection has been used in
laboratories for decades. With the commercial availability of lasers and optical fibers, this technology can
also be applied in situ in the field to identify the presence of light non-aqueous phase liquids (LNAPL).

The UVOST® system sends ultraviolet (UV) laser light (308 nanometer wavelength) through a fiber optic
cable strung through probe rods on a direct push drill rig. The light is reflected by a parabolic mirror within
the Shock-Protected Optical Chamber (SPOC) through a sapphire window on the side of the SPOC. As the
probe is advanced, soil that is contiguous to the sapphire window is exposed to the pulsed UV laser light.
If PAHs (compounds in petroleum, oils and lubricants that fluoresce) are present, these PAHs absorb a
portion of the UV light and enter an electronically excited state. When returning to ground state, the
PAHs release excess absorbed energy by emitting photons of longer wavelength light than the original UV
excitation light. This fluorescence is transmitted through a return fiber to the surface where the OST
system transforms the fluorescence light into multi-wavelength waveform “signals” that represent the
intensity, wavelength, and lifetime information of the return fluorescence.

The UVOST system is designed to focus on NAPL, the source term contaminant at many sites. Vapor,
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DTC Project Number: 0152.2023

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dissolved, and absorbed hydrocarbon phases are usually invisible to the UVOST system, with dissolved
phase PAHs in the vicinity of heavy NAPLs like coal tar being a notable (and confounding) exception. In
most cases, only the NAPL-entrained PAHs respond to the UVOST system. These phase-separate PAHs
can be free product in the subsurface or light sheens of product adsorbed to soil particles. In addition,
valid fluorescence data can be collected both above and below the water table.
2.1 Reference Emitter
The UVOST® system is checked for optical quality by observing the background signal for sources of signal
in the fiber, filter, mirror, and sapphire window. A proprietary LNAPL mixture known as the Reference
Emitter (RE) is used for quality assurance and quality control for the qualitative and semi-quantitative
response of the UVOST. During the pre-log calibration, a cuvette containing the RE fluid is placed over
the sapphire window; the response from the RE is recorded and the RE’s fluorescence intensity
(brightness) is then used as a definition of fluorescence intensity of 100%. Typically, the RE will fall
between 10,000 and 12,000 picovolt-seconds (pVs), which is a measure of waveform area or total
fluorescence. The system background fluorescence can vary from 0.1% to 1% RE, or 0 to 100 pVs. The
operator ensures the RE response has the correct shape and intensity so that the UVOST® system is
“calibrated” for each log and minimizes system background by keeping the mirror and window clean and
the SPOC purged of moisture. All the fluorescence responses obtained in the subsequent borehole are
gauged against the RE’s fluorescence response.

The relationship between the instrument responses from NAPL in the subsurface and the RE depends on
the properties of the NAPL. The calibration of the system is therefore not to a concentration, but to a
fluorescent material with a known waveform, intensity, and color. In this way, all UVOST data points are
normalized to the RE, allowing for an “apples to apples” comparisons of boring data across the site, from
logs completed during earlier mobilizations, or at other locations. There are NAPLs that fluoresce with a
higher signal than the RE, so they readily return fluorescence intensity greater than 100%.
The combined fluorescence of natural soils and system background (the optic surfaces) generally fall in
the range 0.25-0.75% RE. A signal response greater than 1.0% RE typically indicates the presence of
LNAPL, however, various natural materials including calcareous and carbonaceous soils may produce
“false positive” results with signal responses as high as 10% to 20% RE. Buried wood and organics can be
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Fast Phil’s #506 Statesville, NC
DTC Project Number: 0152.2023

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even more fluorescent. Therefore, it is crucial that consumers of fluorescence data rigorously inspect the
fluorescence responses to distinguish the presence of NAPL from false positives from natural soils and
organic materials.
2.2 Waveforms
Waveforms are fluorescence “signatures” that are used to differentiate LNAPL types such as kerosene
versus intact gasoline, weathered gasoline versus diesel fuel, etc. Waveforms also provide the capability
to effectively differentiate false positives from intact LNAPLs. Various waveform patterns for pure PAHs,
fuels/oils, weathered gasoline, and false positive substances can be viewed at Dakota’s website:
http://www.dakotatechnologies.com/learn-more/intro-to-lif/data-interpretation.

Figure 1 shows three sample waveforms used to characterize NAPL.

Figure 1: Waveforms generated by gasoline, diesel and kerosene. The four colored peaks in the waveforms
(referred to as channels) represent different PAH emission wavelengths (colors) that are filtered by the UVOST
system into four categories: 350 nanometers (blue), 400 nanometers (green), 450 nanometers (orange), and
500 nanometers (red). In the waveform callouts (graphs from selected parts of a log) shown, the y-axis
represents the intensity of the fluorescence signal (V) and the x-axis is time (approximately 350-nanoseconds).

The relative contribution of each channel’s area to the total waveform area defines the Signal (% RE) fill
color on the main UVOST log. For example, a waveform with a stronger contribution by the blue channel
relative to the other three channels will plot with a bluish color on the UVOST log (see the kerosene
waveform in Figure 1). In the case of the RE waveform, the calculated color is a pale green that is displayed
in a box in the upper right-hand corner of the waveform plot window.
The shorter wavelength channels on the left (blue/green) represent smaller PAHs with two to three
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DTC Project Number: 0152.2023

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benzene rings; the middle two channels (green/orange) contain response from intermediate size PAHs
with three to four benzene rings; the rightmost channels (orange/red) correspond to larger PAHs with
four or more benzene rings. Note, the blue, green, orange, and red colors associated with the four channel
wavelengths are not the actual color of fluorescence, they are place-holder colors. Actual fluorescence
colors range from dominantly ultraviolet in the first channel (invisible to the human eye or visible-light
spectrum cameras such as the OIP (Optical Image Profiler)) increasing in wavelength from violet to green
moving from left to right in the waveform.

The four waveform channels are sequentially delayed by the UVOST system so that they will arrive as a
“train” on the graph. The amplitude of each channel corresponds to the intensity of the fluorescence
released by the PAHs following the excitation by the UVOST laser pulse. The time it takes for the excitation
energy to dissipate (and the subsequent fluorescence to fade away to darkness) is recorded on the times
axis and leads to a “ski slope” on the right side of each peak. The point in time at which each channel’s
fluorescence has decayed to approximately 1/e of the maximum is referred to as that channel’s “lifetime”.
In general, longer lifetimes (wide peaks) are indicative of intact LNAPL as opposed to false positive
substances, which usually have shorter lifetimes (skinny peaks). Heavy NAPLs like coal tar are a notable
exception, as they experience intramolecular energy transfer during fluorescence due to their excessive
PAH content, resulting in narrow peaks. High or atmospheric levels of molecular oxygen present under
“bench-top” conditions artificially lower fluorescence lifetimes compared to in-situ conditions where
oxygen is lacking due to bioremediation processes.
2.3 Cluster Plots
Cluster plots provide a method for viewing the waveform data in the context of a Cartesian coordinate
system. The cluster plot axes correspond to fluorescence wavelength (λ) on the X-axis and the
fluorescence lifetime (τ) on the Y-axis as measured and weighted in the four channels. Data points
collected during UVOST® logging are hexadecimal color-coded based on fluorescence lifetimes and
wavelengths calculated from the waveform and are plotted individually in the cluster plot. In this fashion,
all data points from a boring are sorted by waveform and can be viewed in a single figure, allowing intuitive
comparisons to be made among potential fluorescence categories. Figure 2 demonstrates the
relationship between data points in the log and how they appear in the cluster plot.
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DTC Project Number: 0152.2023

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Figure 2: The X-axis of the Cluster Plot (right) corresponds to the balance of the four colored channels in the
waveform; the Y-axis relates to fluorescence decay or “lifetimes” of the four-waveform channels.

Responses dominated in the blue/green channels will plot in the left side of the cluster plot; likewise, if
the orange and red channels make up bulk of the fluorescence response, the data point will plot on the
right side of the cluster. Waveforms with a relatively equivalent contribution from all four channels, or
with the two central peaks dominating, will plot somewhere in the middle. Similarly, longer-lived
responses (wide at the base of the waveform) will plot higher on the Y-axis and waveforms with shorter
lifetimes (narrow at the base of the waveform) plot lower on the Y-axis.

To further aid in determining the source on the UVOST® log for a point cluster, the main callouts from the
log with their respective depth intervals are depicted on the upper left corner of the cluster plot (not
depicted here). Polygons (for depth ranges) and circled data points (for discrete depths) with the same
coloration as the callout waveform enclose the point clusters included in that callout.

Weathering and formulation of each LNAPL will influence where the LNAPL appears on the cluster plot.
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DTC Project Number: 0152.2023

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In other words, it is not possible to identify a fuel solely by its location on a cluster plot. In Figure 3, the
formulation of the 2 different diesel signatures labeled 1995 and 2007, fall into different regions of the
plot. This is due to the difference in Lifetime and Wavelength characteristics of the 4 channels that make
up these slightly different diesel waveforms.
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DTC Project Number: 0152.2023

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Figure 3: Reference examples of LNAPL types that were placed on the window of a UVOST® system in a
laboratory setting. The cluster plot positions displayed illustrates the cluster separation of LNAPL types
achievable with the UVOST and is not indicative of exclusive plotting location—LNAPL may plot across multiple
grid cells as the plume weathers or interacts with the native soil.

Cluster plots from the UVOST boreholes will be included as an Appendix to this report (if applicable).
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DTC Project Number: 0152.2023

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3.0 Hydraulic Profiling (HP) Description
The Hydraulic Profiling add-on is a logging tool that measures the pressure required to inject a flow of
water into the soil as the probe is advanced into the subsurface. The injection pressure log is an excellent
indicator of formation permeability. In addition to injection pressure, hydrostatic pressure can be
measured under a zero-flow condition, called a dissipation test. This allows a calculation of
potentiometric surface (water table) upon successful completion of the dissipation test.

Prior to starting a log, quality assurance (QA) checks on the down-hole transducer are performed to
ensure proper function. The probe is submerged in a reference tube and filled with water. A reading is
taken at the hydraulic port when it is submerged to a depth of 1 foot and a second reading at 0 feet, or
baseline, under zero flow conditions. The reading at 0 feet, or the baseline pressure, is equal to the
measurement of atmospheric pressure. Subtracting reading 2 from reading 1 should produce a result of
0.433 psi (+/- 10%), which is the hydrostatic weight of a 1-foot column of water.

The UVOST®-HP probe is advanced into the ground at a rate of approximately 2 cm/sec. The pump in the
HP flow module draws water from the supply tank and pumps water down the trunk line at a constant
flow rate (60 mL/min). The downhole transducer monitors the pressure generated by injecting water into
the formation matrix. The log provides graphs of the pressure and flow rate versus depth alongside the
fluorescence plot. If a dissipation test is performed below the water table and the test successfully
stabilizes, the result can be corrected to an absolute hydrostatic value, from which a potentiometric
surface (water table) can be calculated. Using the calculated water table to correct for hydrostatic
pressure increase, a hydraulic conductivity (K) value for a given depth below the water table can be
estimated using the following equation:

K = ln(Q/P’) * 20.0 + 7.0

where P’= downhole pressure – (0.433 * depth below water table) – atmospheric pressure, and Q is equal
to flow. K values above the water table are also reported after a successful dissipation test even though
they are suspect due to varying permeability behavior of dry soils. These values still maintain some
qualitative value to the eye and may lend insight into preferential pathways in the vadose zone.
HP data can be incorporated into a 4DIM visualization protocol
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DTC Project Number: 0152.2023

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4.0 Site-Specific Results and Discussion
Field activities included the completion of 22 UVOST®-HP borings. Water was gauged at two wells and
found to be 18.0 and 18.4 feet bgs. The borings ranged from 28.0 to 35.1 feet bgs.

All the UVOST®-HP borings pushed, showed at least some signal responses indicative of LNAPL. See
appendix A for details. The waveforms and cluster plots are consistent with the signal seen with gasoline.

Dissipation tests were not performed at this site.

Further lines of evidence such as soil cores and analytical lab results are needed to fully substantiate the
UVOST data.

4.1 Site UVOST Discussion: Waveforms
In this section, several waveforms have been selected to assist with understanding the major waveforms
encountered on the site, including background (natural soil fluorescence) waveforms and LNAPL-like
responses (See Figures 4). Several waveforms were captured by UVOST® at this site. Their corresponding
Cluster Plot diagrams were created to aid with data interpretation. Waveforms and Cluster plot diagrams
are a very powerful tool used in conjunction with other lines of evidence to develop a conceptual site
model of how the NAPL body varies in fluorescent nature with respect to depth below surface and even
across the entire site. This data is also useful for identifying false positives such as limestone or other
fluorescing material.

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DTC Project Number: 0152.2023

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Figure 4: Waveforms typical across the site: The natural (presumed clean) soil background appears in the left
waveform. The blue-dominant waveform from LIF-18 at 19.2-19.9’ in the center may represent an intact LNAPL.
The callout from LIF-01 at 16.1-16.8’ most likely represents a weathered version of the waveform shown in the
center of figure 4.
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DTC Project Number: 0152.2023

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4.2 Site UVOST Discussion: Cluster Plots
A Clustering Plot diagram for each individual log is displayed in Appendix B. Typically, the low soil signal
will be included with the clustering presentation to help distinguish this natural signal from low NAPL
signal. This section is a summary of the site’s cluster diagram output data.

Cluster Plot - LIF-11
LIF-11 had the highest signal encountered on this site. Callouts 3 and 4, labelled in the cluster image below,
show these high signal data. Callouts 1 and 2 are from depths where the NAPL shows signs of weathering
(longer , red-shifted wavelength signal). The data points in grids F0 to H0 are from NAPL-free natural soil
background.

Figure 5: LIF-11
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Fast Phil’s #506 Statesville, NC
DTC Project Number: 0152.2023

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Cluster Plot - LIF-18
Callouts 3, 4, and 5 taken between 13.5 and 33.0 feet are examples of the shortest wavelengths and
longest decay times at this site. The intensities are lower than at LIF-11 but the NAPL here is probably
less weathered than the NAPL seen in LIF-11’. Callouts 1 and 2 show small amounts of very weathered
NAPL, with decay times and wavelengths barely different from the natural background fluorescence.

Figure 6: LIF-18

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DTC Project Number: 0152.2023

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Cluster Plot – LIF-01
This plot suggests small amounts of very weathered NAPL .

Figure 7: LIF-01

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Fast Phil’s #506 Statesville, NC
DTC Project Number: 0152.2023

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Composite Cluster Plot
This image shows the sum of all the data points created at this site. Note many data points in the bottom
rows, Row 0 and Row 1, indicating very weathered NAPL, barely distinguishable from the background
fluorescence at the site. These data waveform and cluster plot data are consistent with gasoline.

Figure 8: Composite Cluster Plot for the site.

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DTC Project Number: 0152.2023

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5.0 GPS Data/Survey Control
Dakota surveyed the UVOST® borehole locations using a Trimble Geo7x centimeter grade GPS.
Differential corrections were applied to enhance the accuracy of the field collected data points. This
differential correction relies on publicly available base station data. The proximity of the site to the
nearest high-quality base station can have an impact on positional accuracy. When possible, Dakota uses
the Continuously Operating Reference Station (CORS) operated by the national Geodetic Survey (NGS).
When a CORS base station is not available, Dakota uses the closest alternative selected based on the
integrity index provided by the GPS Pathfinder Office processing software. Dakota provides coordinates
in NAD 83 US Feet, with the appropriate state plane projection.

6.0 Limitations
The UVOST® system is limited in that it can only detect phase-separated material, making it an ideal tool
for source delineation. The UVOST® system does not respond to dissolved phase VOCs or SVOCs. In
addition, the soil matrix can influence how a product fluoresces. UVOST® responses are typically higher
on sands than in clays. Due to fluorescence quenching, the UVOST® system should not be used to
delineate coal tars and creosotes.

The use of specific language to identify UVOST® signal as LNAPL, gasoline, diesel or other specific
petroleum, oil or lubricant types are intended to describe these compounds within the limited context of
the UVOST® data set and must be interpreted with other lines of evidence to confirm stated findings.
Signal identified and listed in this report as false positives, natural soil, etc. should also be viewed within
these same constraints.

The analysis and opinions expressed in this report are based upon data obtained from the specific test
locations and from other information discussed in this report. Exceptions, if any, are discussed in the
accompanying comments section of this report. This report is prepared for the exclusive use of our client
for specific application to the project discussed and has been prepared in accordance with generally
accepted practices. Reported results shall not be reproduced, except in full, without written approval of
Dakota. No warranties, expressed or implied, are intended or made.

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DTC Project Number: 0152.2023

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The HP portion of the tool is limited to a max working depth of 120 feet below ground water and the
pressure transducer output range is 0-100 psi. Coarse (sandy), saturated soils are required for dissipation
tests to be performed. Successful (fully stabilized) dissipations are required for water table and hydraulic
conductivity (Est. K) calculations. The lower K boundary for the empirical calculation model is about 0.1
ft./day and the upper boundary is near 75 ft./day.

Hydraulic data acquired from the UVOST®-HP tool should be reviewed in conjunction with representative
soil samples to best understand soil behavior.

Appendix A

UVOST®-HP Field Summary

Stable Calculated
Pre-Probe Final Depth Max Signal Max Signal Initial RE Background Dissipation Water
File Log ID Date / Time (ft) (ft) (%RE) Depth (ft) Area (pVs) Area (pVs) (yes or no) Table (bgs)
LIF-01 6/20/23 9:56 AM 4 30.1 5 4.5 11324 31 N/A N/A 0.0-27.4
LIF-02 6/20/23 11:07 AM 4 28.5 6 18.6 11809 9 N/A N/A 0.0-27.4
LIF-03 6/20/23 11:51 AM 4 31.1 9 23.2 10950 6 N/A N/A 0.0-30.4
LIF-04 6/20/23 12:46 PM 4 29.3 19 19.4 11046 9 N/A N/A 0.0-27.4
LIF-05 6/20/23 2:22 PM 4 29.3 23 23.7 11627 9 N/A N/A 0.0-25.8
LIF-06 6/21/23 8:37 AM 4 28.0 18 20.2 10406 -2 N/A N/A 0.0-26.6
LIF-07 6/21/23 9:26 AM 4 28.2 20 21.8 10668 -1 N/A N/A 0.0-25.8
LIF-08 6/21/23 10:07 AM 4 28.1 2 17.1 11294 23 N/A N/A 0.0-27.7
LIF-09 6/21/23 10:49 AM 4 29.3 3 20.4 11174 24 N/A N/A 0.0-27.2
LIF-10 6/21/23 11:52 AM 4 31.2 29 19.3 10335 11 N/A N/A 0.0-29.8
LIF-11 6/21/23 1:27 PM 4 33.3 197 25.3 11747 5 N/A N/A 0.0-30.3
LIF-12 6/21/23 2:23 PM 4 28.0 7 18.9 11100 8 N/A N/A 0.0-25.2
LIF-13 6/21/23 3:04 PM 4 29.3 3 14.3 11247 3 N/A N/A 0.0-24.4
LIF-14 6/21/23 3:45 PM 4 28.0 11 4.4 11558 1 N/A N/A 0.0-22.0
LIF-15 6/21/23 4:23 PM 4 28.0 4 9.2 10880 -3 N/A N/A 0.0-24.5, 26.0
LIF-16 6/22/23 9:24 AM 4 28.9 8 19.2 12080 -2 N/A N/A 0.0-1.3, 15.1-24.3
LIF-17 6/22/23 11:01 AM 4 31.5 4 20.8 11693 8 N/A N/A 0.0-29.8
LIF-18 6/22/23 11:43 AM 4 35.1 91 20.7 10108 11 N/A N/A 0.0-33.9
LIF-19 6/22/23 12:22 PM 4 33.3 18 23.4 10468 6 N/A N/A 0.0-31.6
LIF-20 6/22/23 1:48 PM 4 29.5 21 17.3 10248 12 N/A N/A 0.0-23.8
LIF-21 6/22/23 3:30 PM 4 32.0 4 25.8 13133 10 N/A N/A 0.0-28.3
LIF-22 6/22/23 4:11 PM 4 29.4 4 0.5 12478 -6 N/A N/A 0.0-1.1, 3.9-6.1, 16.2-21.4, 23.9-24.9
Total Footage (this sheet)659.4
(1) Signal responses in the indicated pre-probed regions may not be accurate due to soil disturbance
*Indicates that water table data was manually entered from adjacent well measurement (not derived from a dissipation test calculation)
Top - Bottom (ft)
UVOST®-HP Field Summary Log
Fast Phil 506
Statesville, NC 28677
Fluorescence

Appendix B

UVOST®-HP Logs

Appendix C

UVOST®-HP Reference Log

Flow (Q)
Dakota Technologies
UVOST®‐HP Reference Log
Callouts Main Plot
Hydraulic 
Pressure Est. K
Main Plot:Signal (total fluorescence) versus depth 
where signal is relative to the Reference Emitter (RE). 
The total area of the waveform is divided by the total 
area of the Reference Emitter yielding the %RE. This 
%RE scales with the NAPL fluorescence. The fill color is 
based on the relative distribution of each channel’s 
area to the total waveform area (see callout 
waveform). The channel‐to‐color relationship and 
corresponding wavelengths are given in the upper 
right corner of the plot.
Callouts:Waveforms from selected depths or depth 
ranges showing the multi‐wavelength waveform for 
that depth. The four peaks are due to fluorescence at 
four wavelengths and referred to as “channels”. Each 
channel is assigned a color. Various NAPLs will have a 
unique waveform “fingerprint” due to the relative 
amplitude of the four channels and/or broadening of 
one or more channels. Basic waveform statistics and 
any operator notes are given below the callout.
Hydraulic Pressure (P Dwn):Downhole hydraulic 
pressure is measured in response to pumping water 
into the formation at a constant rate. Measurements 
are logged simultaneously with UVOST data. The 
resulting log gives insight into the permeability of the 
soils. 
Flow (Q):Water is pumped out of the port of the 
UVOST‐HP probe at a constant rate of 60 mL/min. A 
change in flow (usually accompanied by an inverse 
pressure change) is an indicator of hydraulic 
properties of the soil.
Estimated K:The estimated hydraulic conductivity (K) 
is internally calculated by utilizing pressure and flow 
data in conjunction with dissipation test(s) performed 
at each location. The estimated K is calculated by the 
equation: K = ln(Q/P’)*20.0 + 7.0. 
Note A: The water table has been 
calculated and plotted at 24.4’ bgs.
Note B:The circle on the Estimated K 
plot represents the location(s) of 
dissipation tests. Here, a single dissipation 
test was performed at 26.67 bgs’.
Note C:The highest LNAPL response in this 
log is present in an area of relatively higher 
permeability, as indicated by low pressure and 
higher estimated k values at approximately 26’ 
to 28’.
Note A Note B
Note D
Note D:The increase in pressure starting 
near 29’ (transducer is maxed out, 100 psi) is 
due to low permeability conditions. In this 
example, the increase in pressure below the 
LNAPL represents a potential confining unit.
Note C
*.lif.raw.bin
Raw data file. Header is ASCII format and contains information stored when the file was initially written (e.g. date, 
total depth, max signal, gps, etc., and any information entered by the operator). All raw waveforms are appended 
to the bottom of the file in a binary format.
*.lif.plt Stores the plot scheme history (e.g. callout depths) for associated Raw file. Transfer along with the raw file in 
order to recall previous plots.
*.lif.jpg A jpg image of the OST log including the main signal vs. depth plot, callouts, information, etc.
*.lif.dat.txt
Data export of a single Raw file. Tab delimited format. No string header is provided for the columns to make 
importing into some programs easier. Each row is a unique depth reading. The columns are: 1‐Depth; 2‐Total 
Signal (%RE); 3‐Ch1%; 4‐Ch2%; 5‐Ch3%; 6‐Ch4%; 7‐Rate; 8‐EC Depth; 9‐EC Signal; 10‐Hammer Rate Depth; 11‐
Hammer Rate; 12‐Color (RRGGBB). Summing channels 1 to 4 yields the Total Signal.
*.lif.sum.txt
A summary file for a number of Raw files. ASCII tab delimited format. The file contains a string header. The 
summary includes one row for each Raw file and contains information for each file including: the file name, gps 
coordinates, max depth, max signal, and depth at which the max signal occurred.
*.lif.log.txt
An activity log generated autmatically located in the OST application directory in the 'log' subfolder. Each OST unit 
the computer operates will generate a separate log file per month. A log file contains much of the header 
information contained within each seprate raw file, including: date, total depth, max signal, etc.
Data Files
Waveform Signal Calculation
Common Waveforms (highly dependent on soil, weathering, etc.)
Dakota Technologies
UVOST® Reference Log
An activity log generated automatically is located in the OST application directory in the ‘log’ subfolder. Each OST unit
the computer operates will generate a separate log file per month. A log file contains much of the header information
contained within each separate Raw file, including: data rate, total depth, max signal, etc.
A summary file for a number of Raw files. ASCII tab delimited format. The file contains a string header. The summary
includes one row for each Raw file and contains information for each filed including: the file name, GPS coordinates, max
depth, max signal, and depth at which the max signal occurred.
Data export of a single Raw file. Tab delimited format. No string header is provided for the columns to make importing
into some programs easier. Each row is a unique depth reading. The columns are: 1-Depth; 2-Total Signal (%RE);
3-CH1%; 4-Ch2%; 5-CH3%; 6-Ch4%; 7-Rate; 8-EC Depth; 9-EC Signal; 10-Hammer Rate Depth; 11-Hammer Rate;
12-Color (RRGGBB). Summing channels 1 to 4 yields the Total Signal.
A .jpg image of the OST log including the main signal vs. depth plot, callouts, information, etc.
Stores the plot scheme history (e.g. callout depths) for associated Raw file. Transfer along with the Raw file in order to
recall previous plots.
Raw data file. Header is ASCII format and contains information stored when the file was initially written (e.g. date, total depth,
max signal, GPS, etc., and any information entered by the operator). All Raw waveforms are appended to the bottom of the
file in a binary format.*.lif.raw.bin
*.lif.plt
*.lif.jpg
*.lif.dat.txt
*.lif.sum.txt
*.lif.log.txt
CH1 CH2 CH3 CH4 Total
1522           3714         2625        1360                              9221
16.5            40.3          28.5         14.7                                100+               +             +                          =
CH1 CH2 CH3 CH4 Total
2339           3585         3433        2674                             11,995
19.4            29.8          28.6         22.2                                100+               +             +                          =
Reference Emitter (RE) Example
Dakota Technologies
UVOST® Reference Log
Predominant response in 350nm (UV) and 400nm (violet) channels at 17 to 
23‐foot depth interval indicate modest levels of diesel pore saturation. 
Note fill color shift to green (as opposed to orange in the 4 to 5‐foot 
interval) – visually indicating a difference in NAPL type. The shorter 
lifetime in the 350 nm vs subsequent channels is only observed in diesel.
Predominant response in 350nm (UV) channel and consistent lifetimes 
across all channels at 9 to 13 foot depth interval is consistent with intact 
(unweathered) gasoline or kerosene. However, intact gasoline can also be 
observed with a blue‐green or slightly green dominant response.
Predominant response in 450nm channel with consistent lifetimes 
across all channels indicate that the NAPL from 4 to 5‐foot depth 
interval is likely a weathered gasoline. An intact gasoline is typically UV 
dominant (most fluorescence in the 350nm channel) as noted below.
Note low intensity, distinct signal responses separated from zones of 
higher NAPL saturation, indicating the presence of discontinuous, 
residual NAPL. The waveforms confirm diesel signature – allows the 
user to eliminate the possibility of calcite’s fluorescence, which has a 
different waveform.

Appendix D

Visualization Report

High Resolution Site Characterization Report
2D Visualization Report

Project: Fast Phil’s # 506
1541 Salisbury Road
Statesville, NC 28677

DTC Project Number: 0152.2023

Prepared For:
Geological Resources, Inc.
3502 Hayes Road
Monroe, NC 28110

Prepared by:
Matthew Jorden
Dakota Technologies Company, LLC
July 11, 2023

TABLE OF CONTENTS
1.0 General Summary ........................................................................................................... 1
2.0 GPS DATA ....................................................................................................................... 1
2.1 GPS LOCATIONS (TABLE) ........................................................................................................................ 2
3.0 2-Dimensional Visualization of Observed Signal ............................................................... 4
3.1 Gridding Parameters ............................................................................................................................. 4

Figures
2D Locations Map ..................................................................................................................... 5
2D UVOST® Response Map ....................................................................................................... 6

2D Visualization Report – HRSC Investigation
Fast Phil’s # 506, Statesville, NC
Project Number: 0152.2023

1

1.0 General Summary
Dakota Technologies Company, LLC (Dakota) has prepared a 2D integrated site visualization (ISV) of the
high resolution site characterization (HRSC) that was conducted and acquired at the Fast Phil’s # 506
project in Statesville, NC for Geological Resources, Inc. This data and ISV are intended to help Geological
Resources, Inc. further characterize the extent of potential contamination and serve as a guide for further
data acquisition and delineation. While plume extents and predicted contamination status are not
definitive, Dakota strives to use the latest and most scientifically accurate methods in visualizing the data
acquired.

The visualizations displayed in this report are based upon data obtained from the specific UVOST®
locations and from other information discussed in this report. Exceptions, if any, are discussed in the
accompanying comments section of this report. This report is prepared for the exclusive use of our client
for specific application to the project discussed and has been prepared in accordance with generally
accepted practices. Reported results shall not be reproduced, except in full, without written approval of
Dakota. No warranties expressed or implied are intended or made.

2.0 GPS DATA
Dakota pushed a total of 22 UVOST® borings on site. Location data for the borings was collected on
location by the HRSC specialist using a Trimble Geo 7x GPS device. Positional accuracy with GPS is
dependent on topography and obstructions and satellite lock. Positional error is provided alongside the
locations. Dakota provides coordinates in NAD 83 US Feet, with the appropriate state plane projection for
the location.
The State Plane projection used in this project is:
• North Carolina

Dakota applies a differential correction to enhance the accuracy of the field collected GPS points. This
differential correction relies on a fixed base station reading. Dakota does not provide base stations,
opting instead to use publicly available base station data. The proximity of the site to the nearest high-
2D Visualization Report – HRSC Investigation
Fast Phil’s # 506, Statesville, NC
Project Number: 0152.2023

2

quality base station can have an impact of positional accuracy. When possible, Dakota uses the
Continuously Operating Reference Stations (CORS) operated by the National Geodetic Survey (NGS). The
NGS is a division of the National Oceanic and Atmospheric Administration (NOAA). When CORS base
station data is unavailable, Dakota uses the closest alternative chosen based on the Integrity Index
provided by the GPS Pathfinder Office processing software.

Dakota also maintains a set of coordinates that are maintained as field notes and used internally. These
are collected and stored in a Google Earth Keyhole Markup Language (KML) file, which is used for internal
purposes. This file is available for download on the Dakota file sharing portal if desired.

The base station used in the differential processing of this location is:
• CORS, BLACKSBURGVA2006 (BLA1)

2.1 GPS LOCATIONS (TABLE)
Boring Name Easting Northing
LIF-01 1450282 739749.8
LIF-02 1450288 739759.4
LIF-03 1450292 739767.4
LIF-04 1450298 739777.1
LIF-05 1450306 739788.1
LIF-06 1450306 739736.9
LIF-07 1450311 739744.8
LIF-08 1450316 739753.9
LIF-09 1450324 739751.2
LIF-10 1450318 739741.8
LIF-11 1450313 739733.0
LIF-12 1450317 739730.7
LIF-13 1450293 739744.2
LIF-14 1450296 739752
LIF-15 1450303 739761.7
LIF-16 1450265 739755.8
LIF-17 1450312 739797.4
2D Visualization Report – HRSC Investigation
Fast Phil’s # 506, Statesville, NC
Project Number: 0152.2023

3

LIF-18 1450316 739781.4
LIF-19 1450328 739777.0
LIF-20 1450338 739774.9
LIF-21 1450327 739788.2
LIF-22 1450325 739737.2

UVOST Locations
UVOST Locations
UVOST Response (%RE)
<- 5
5 - 10
10 - 25
25 - 50
50 - 75
75 - 100
> 100
2D Visualization Report – HRSC Investigation
Fast Phil’s # 506, Statesville, NC
Project Number: 0152.2023

4

3.0 2-Dimensional Visualization of Observed Signal
The signal acquired is processed using internal software and formatted for the gridding and visualization.
Two dimensional UVOST® response displays are created and delivered using the C Tech EVS software, and
then converted to a vector format (shapefile) for use in GIS software. Maps are delivered in the PDF
format.

Delivery of maps includes the following files:
• Locations – This file contains a map showing the locations of UVOST® and if applicable any
additional monitoring or recovery wells as well as other locations of interest.
• UVOST® Response – This file contains the gridded UVOST® response contours. These contours are
created in two dimensions (unlike the full ISV product, which is gridded in 3D even when displayed
in 2D), using the maximum observed response at each location.

3.1 Gridding Parameters
Gridding is done using a kriging algorithm in the EVS software published by C Tech. Unless otherwise
requested, gridding is constrained to a convex hull around the borings to avoid any excessive
extrapolation beyond the reliable data extents. Once the desampling is applied, all points are used with
an adaptive gridding approach. To create a 2D observed response contour grid, the maximum observed
response is taken for each point, and then these maximum responses are used in the gridding.

The gridding resolution for the final volumes is 120 cells in both the Easting and Northing directions.
The 2D map is created by re-gridding the 3D plume volume into a 2D grid, favoring maximum values. This
is delivered in PNG format, though by request can be delivered in alternate formats (if needed in ArcGIS
format, a commercial plug in for ArcMap or ArcScene may be required).