RA-2069_12609_CA_RPTS_20210203_NAPL FORENSICS

TABLE OF CONTENTS

1.0 INTRODUCTION..............................................................................................................1
2.0 SITE DESCRIPTION ........................................................................................................1
2.1 Site Characterization ............................................................................................1
3.0 FORENSIC EVALUATION .............................................................................................1
3.1 LNAPL Observations.................................................................................................2
3.2 Sample Collection ......................................................................................................3
3.3 Analytical Methodology ............................................................................................3
3.4 Forensic Analysis Conclusions ..................................................................................4

TABLES

Table 1 Monitoring Well Construction Details
Table 2 Historical Groundwater Elevation Data
Table 3 Groundwater Analytical Results
Table 4 Historical Groundwater Analytical Results

FIGURES

Figure 1 Site Topographic Map
Figure 2 Site Map
Figure 3 Groundwater Elevation Contour Map
Figure 4 LNAPL Isoconcentration Contour Map
Figure 5 Forensics Analysis Results

APPENDICES

Appendix A ChemQuants Environmental Forensics Report

Free Product Forensics Investigation Report February 1, 2021
Former Conoco Store #33047 (RM # 6182) ATC Project No. P666182414
1
1.0 INTRODUCTION

ATC Associates of North Carolina, P.C. (ATC) was retained by Phillips 66 Company to conduct
site monitoring and remediation activities at the Former Conoco Store #33047 (RM #6182). The
project site is located at 11120 East Raleigh Boulevard in Rocky Mount, Edgecombe County, North
Carolina. This report presents investigative procedures, field activities, and laboratory analytical
results, and subsequent forensics evaluation performed during the reporting period.

2.0 SITE DESCRIPTION

2.1 Site Characterization
The site is located at the western corner of the intersection of East Raleigh Street and East Grand
Avenue in Rocky Mount, North Carolina. Figure 1 represents a site topographic map and
Figure 2 represents a site map indicating the site layout. The property consists of a single-story
concrete building and is currently a convenience store operating a retail gasoline distribution
system (Speedway #8264). Surrounding land usage is residential and commercial. Parker’s Canal
is located along the northern property boundary and discharges into Cowlick Branch. According to
the North Carolina Department of Environmental Quality (NCDEQ) Division of Water Quality,
Cowlick Branch is identified as both Class C and Nutrient Sensitive Waters. Currently, the site risk
ranking is intermediate due to the presence of a surface water body within 500 feet of the site and
the historical presence of light non-aqueous phase liquid (LNAPL) discovered in 1994.

3.0 FORENSICS EVALUATION

On February 13, 2018, the current operator of the UST system (Speedway) conducted
hydrostatic tests on the fill port spill buckets for the onsite UST system. The spill bucket for the
10,000-gallon premium unleaded gasoline UST failed the hydrostatic tests. Subsequently, a soil
and groundwater assessment was completed as part of a Site Check investigation. Soil samples
were collected and a monitoring well (MW-1M) was installed on March 28, 2018. During the
Site Check investigation, approximately 3.25 feet of LNAPL was measured in monitoring well
MW-1M. On April 30, 2018, an LNAPL sample was collected from MW-1M and submitted for
laboratory analysis for ethanol. The laboratory analysis indicated that ethanol was not present in
Free Product Forensics Investigation Report February 3, 2021
Former Conoco Store #33047 (RM # 6182) ATC Project No. P666182414
2
the LNAPL sample above the laboratory detection limits. The Site Check Report concluded that
since the LNAPL sample did not contain ethanol (a fuel additive widely used in current gasoline
production) then the LNAPL was associated with the 1994 original release and was not related
the 2018 spill bucket issue.

Due to delays in site access, ATC personnel gauged the site monitoring wells for the presence of
LNAPL and groundwater elevations on June 16, 2020. LNAPL was detected in MW-1M (1.44
feet) and MWHS-11 (2.22 feet). On September 15, 2020, ATC performed a groundwater
sampling event at the site. LNAPL was detected in monitoring wells MW-1M (1.47 feet), MW-3
(1.57 feet), MW-4 (1.59 feet), MWHS-10 (1.67 feet) and MWHS-11 (2.23 feet). Monitoring well
construction details are presented in Table 1, historical groundwater elevation data is presented in
Table 2 and historical groundwater results are presented in Table 3. A groundwater elevation
contour map is presented as Figure 3 and an LNAPL contour map is presented as Figure 4.

Based on the detection of measurable LNAPL in MW-1M, MW-3, MW-4, MWHS-10, and
MWHS-11 during the September 15, 2020, sampling event, ATC performed a forensics
evaluation to identify the type of product present in these wells and to assess the LNAPL release
scenario. The results of the forensics evaluation are presented below.

3.1 LNAPL Observations
A review of the historical LNAPL gauging data for the site indicates that; LNAPL has not been
detected in monitoring wells MW-3 and MW-4 since 2003; and that the groundwater
concentrations were below the 2L Standards between 2013-2016 in MW-3. Additionally,
LNAPL thickness in MWHS-10 and MWHS-11 ranged from a sheen to 0.32 feet since 2012.
MW-1M was installed in response to a failed hydrostatic test on the facilities fill port spill bucket
system in 2018. LNAPL thickness in MW-1M ranged from 1.44 feet to 3.25 feet since 2018. The
sudden appearance of substantial LNAPL in MW-3, MW-4, MWHS-10, and MWHS-11 in
September 2020 was indicative of a potential new petroleum release from the active UST
system.

Free Product Forensics Investigation Report February 1, 2021
Former Conoco Store #33047 (RM # 6182) ATC Project No. P666182414
3
3.2 Sample Collection
On November 16, 2020, ATC personnel collected LNAPL samples from monitoring wells MW-
1M, MW-3, and MWHS-10, and collected a product sample from the Premium Dispenser #3.
The samples from MW-1M, MW-3, MWHS-10, and Premium Dispenser #3 were submitted to
ChemQuants Environmental Forensics (ChemQuants) located in Santa Barbara, California for
analysis of Whole Oil GC/FID, C5-C12 PIANO with Oxygenates and additives quantification
and fingerprinting by GC/MS – full scan mode / EPA 8260B (Mod.), Organic Lead Speciation
by EPA 8270D (Mod.), Ethanol by EPA 8270 (Mod.), Carbon and Hydrogen Bulk Stable
Isotopes, and Sulfur in Petroleum by ASTM D4294. ChemQuants provided the forensics
analysis and an interpretive report characterizing the LNAPL. A copy of the ChemQuants
forensics report is included as Appendix A.

3.3 Analytical Methodology
ChemQuants’ forensics investigation utilized two datasets. First by characterizing LNAPL
samples via fingerprinting methods and second by analyzing routine chemical data from the
site’s groundwater monitoring activities. Gasoline refinery process and properties lines of
evidence were applied and based on well-established process forensics insights. The
characterization of gasoline released at the Site relied on the diagnostic characterization of
alkylate, isomerate, straight-run gasoline (SRG), and reformate blend stock signatures. In
addition, environmental forensics characterization and age constraining of the refined gasoline
relied on presence/absence and assemblages of oxygenate additives, organic lead additives,
organic sulfur species, and total sulfur.

The investigation included groundwater data from monitoring wells MW-2, MW-4, MW-6,
MW-7, MW-11, AND MWHS-10. These data were subject to a systematic process of analysis,
which included the following techniques: Time-series of BTEX, MTBE, and DIPE to help
evaluate the potential chemical source(s), the state of gasoline dissolution - whether the gasoline
may be entrained as a free product phase or part of a more dissolved phase plume, the
correlations of diagnostic dissolved phase chemistry (Benzene, MTBE, DIPE, etc.), the potential
impact of remediation events and for possible new or ongoing release(s). BTEX composition was
reviewed as time series bar graphs and line plots. The BTEX concentrations were used
Free Product Forensics Investigation Report February 1, 2021
Former Conoco Store #33047 (RM # 6182) ATC Project No. P666182414
4
concurrently with the relative mole fraction data to help recognize the potential input of "fresher"
gasoline (newer release or remobilized less weathered gasoline), or the input of more dissolved
phase benzene and MTBE chemistry. The groundwater samples served as additional evidence for
the source and age constraining of the new fingerprinted samples collected from the Site. A
copy of the ChemQuants forensics report is included as Appendix A.

3.4 Forensic Analysis Conclusions
Based on the historical groundwater data and the results of the forensics report (Appendix A),
ATC has prepared the following conclusions:

 Fugitive releases may have occurred in 1994 and 2002 based on historical BTEX ratios
which confirms the original release scenario;
 LNAPL in MW-1M, MW-3 and MWHS-10 is consistent with the Premium grade
gasoline (collected at Premium Dispenser #3). Figure 5 presents the diagnostic ratios for
each of the LNAPL samples collected at the site showing similarities between MW-1M,
MW-3, MWHS-10 and the sample collected at Premium Dispenser #3; and
 Based on the BTEX mole fraction distributions between MW-1M, MW-3, MWHS-10
and Premium Dispenser #3, the LNAPL is likely related to a new release rather than the
1994/2002 release scenario;

The refinery process lines of evidence and the comparison to the Premium Dispenser #3 sample
indicate that the LNAPL samples collected from MW-1M, MW-3, and MWHS-10 were likely
released within the past three years. Therefore, the LNAPL encountered in MW-1M, MW-3,
MW-4, MWHS-10, and MWHS-11 in September 2020 is not representative of the release that
occurred in 1994/2002 associated with the historical Conoco Store #33047 operations.

TABLES
TABLE 1
MONITORING WELL CONSTRUCTION DETAILS
FORMER CONOCO STORE #33047 (RM #6182)
1122 EAST RALEIGH BOULEVARD
ROCKY MOUNT, EDGECOMBE COUNTY, NORTH CAROLINA
ATC PROJECT NO. P666182414
Depth to Water
(ft)
Depth to
LNAPL (ft)
LNAPL
Thickness (ft)
Groundwater
Elevation (ft)
MW-1 19 4-19 90.18 NM NM NM NM
MW-1M 22 11.5-21.5 NS 13.94 12.63 1.31 NS
MW-2 24 9-24 98.40 NM NM NM NM
MW-3 24 9-24 100.24 12.80 12.52 0.28 87.20
MW-4 24 9-24 100.43 NM NM NM NM
MW-5 53 48-53 102.86
MW-5R 52 47-52 100.47 NM NA NM NM
MW-6 22 7-22 97.47 NM NA NM NM
MW-7 22 7-22 97.64 NM NA NM NM
MW-7A 25 9-24 97.63 NM NA NM NM
MW-8 21 6-21 95.31 NM NA NM NM
MW-9 25 10-25 91.05 NM NM NM NM
MW-10 24 8-23 92.09 NM NA NM NM
MW-11 25 10-25 100.03 NM NA NM NM
MWHS-10 20 Unknown NS 12.93 12.33 0.60 NS
MWHS-11 20 Unknown NS NM 12.24 NM NS
Notes:
1. Elevations based on an arbitrary datum of 100.00 feet
2. NA = Not Analyzed
3. NM = Not Measured
4. NS = Not Surveyed
5. LNAPL = Light Non Aqueous Phase Liquid
6. Groundwater Elevation = TOC Elevation - [Depth to Water + (0.8581 * free product thickness)]
Well Abandoned
Well No.Top of Casing
Elevation Well Depth (ft) Screened
Interval (ft)
Date Measured: 11/16/2020
TABLE 2
HISTORICAL GROUNDWATER ELEVATION DATA
FORMER CONOCO STORE #33047 (RM #6182)
1122 EAST RALEIGH BOULEVARD
ROCKY MOUNT, EDGECOMBE COUNTY, NORTH CAROLINA
ATC PROJECT NO. P666182414
Well No.Date
Measured
Top of
Casing
Elevation
Depth to
Water (ft
btoc)
Depth to
LNAPL
LNAPL
Thickness
Groundwater
Elevation
12/16/94 7.80 NA 0.00 82.38
06/22/95 6.85 NA 0.00 83.33
04/19/96 6.90 NA 0.00 83.28
10/29/98 8.31 NA 0.00 81.8710/19/99 4.16 NA 0.00 86.02
05/03/00 6.96 NA 0.00 83.22
11/30/00 7.88 NA 0.00 82.30
03/26/01 6.51 NA 0.00 83.67
06/13/01 7.15 NA 0.00 83.03
09/05/01 7.32 NA 0.00 82.86
12/10/01 7.93 NA 0.00 82.25
02/07/02 6.10 NA 0.00 84.08
05/08/02 7.31 NA 0.00 82.87
08/05/02 8.13 NA 0.00 82.05
11/19/02 5.19 NA 0.00 84.9902/25/03 4.99 NA 0.00 85.19
05/19/03 3.11 NA 0.00 87.07
08/25/03 4.34 NA 0.00 85.84
02/19/04 6.61 NA 0.00 83.57
08/26/04 6.83 NA 0.00 83.35
02/15/05 7.26 NA 0.00 82.92
08/10/05 8.17 NA 0.00 82.0103/02/06 7.63 NA 0.00 82.55
08/08/06 7.53 NA 0.00 82.65
02/19/07 7.14 NA 0.00 83.04
10/06/07 8.70 NA 0.00 81.48
04/23/08 6.25 NA 0.00 83.93
10/21/08 8.62 NA 0.00 81.56
04/15/09 7.15 NA 0.00 83.03
11/23/09 6.62 NA 0.00 83.56
06/16/10 7.42 NA 0.00 82.76
09/08/10 NM NM NM NM
12/23/10 NM NM NM NM
03/03/11 NM NM NM NM
08/04/11 8.31 NA 0.00 81.87
02/15/12 7.13 NA 0.00 83.05
10/24/12 8.46 NA 0.00 81.72
07/22/13 6.92 NA 0.00 83.26
02/20/14 6.02 NA 0.00 84.16
03/31/15 9.83 NA 0.00 80.35
05/16/16 7.00 NA 0.00 83.18
06/16/20 7.26 NA 0.00 82.92
09/15/20 7.37 NA 0.00 82.81
04/30/18 15.80 12.55 3.25 NS
06/16/20 14.18 12.74 1.44 NS
09/15/20 14.57 13.10 1.47 NS
11/16/20 13.94 12.63 1.31 NS
12/16/94 16.58 NA 0.00 81.82
06/22/95 16.90 NA 0.00 81.50
04/19/96 16.14 NA 0.00 82.26
10/29/98 14.84 NA 0.00 83.56
10/19/99 12.63 NA 0.00 85.77
05/03/00 13.61 NA 0.00 84.79
11/30/00 14.38 NA 0.00 84.02
03/26/01 13.34 NA 0.00 85.06
06/13/01 13.65 NA 0.00 84.75
09/05/01 14.10 NA 0.00 84.30
12/10/01 14.50 NA 0.00 83.90
02/07/02 14.37 NA 0.00 84.03
05/08/02 13.99 NA 0.00 84.41
08/05/02 15.94 NA 0.00 82.4611/19/02 14.54 NA 0.00 83.86
02/25/03 11.01 NA 0.00 87.39
05/19/03 9.20 NA 0.00 89.20
08/25/03 10.04 NA 0.00 88.36
02/19/04 12.33 NA 0.00 86.07
08/26/04 11.32 NA 0.00 87.08
02/15/05 12.47 NA 0.00 85.93
08/10/05 12.18 NA 0.00 86.22
03/02/06 11.47 NA 0.00 86.93
08/08/06 12.97 NA 0.00 85.43
02/19/07 10.63 NA 0.00 87.77
10/16/07 14.77 NA 0.00 83.63
04/23/08
10/21/08 14.80 NA 0.00 83.60
04/15/09 13.47 NA 0.00 84.93
11/24/09 14.02 NA 0.00 84.38
06/16/10 13.51 NA 0.00 84.89
09/08/10 NM NM NM NM
12/23/10 NM NM NM NM
03/03/11 NM NM NM NM
08/04/11 13.13 NA 0.00 85.27
02/15/12
10/24/12
07/22/13
02/20/14
03/31/15
05/16/16
06/16/20
09/15/20
Notes:
1. Elevations based on an arbitrary datum of 100.00 feet
2. NA = Not Applicable
3. NM = Not Measured
4. NS = Not Surveyed
5. LNAPL = Light Non Aqueous Phase Liquid
Well not located
Well not located
Well not located
Well not located
Well not located
Well not located
Well not located
Well not located
MW-1 90.18
98.40MW-2
MW-1M NS
Well not located
Page 1 of 7
TABLE 2
HISTORICAL GROUNDWATER ELEVATION DATA
FORMER CONOCO STORE #33047 (RM #6182)
1122 EAST RALEIGH BOULEVARD
ROCKY MOUNT, EDGECOMBE COUNTY, NORTH CAROLINA
ATC PROJECT NO. P666182414
Well No.Date
Measured
Top of
Casing
Elevation
Depth to
Water (ft
btoc)
Depth to
LNAPL
LNAPL
Thickness
Groundwater
Elevation
MW-1 90.18
12/16/94 14.23 NA 0.00 86.01
06/22/95 13.50 NA 0.00 86.74
04/19/96 12.81 NA 0.00 87.43
10/29/98 14.37 NA 0.00 85.8710/19/99 12.54 NA 0.00 87.70
05/03/00 13.03 NA 0.00 87.21
11/30/00 13.86 NA 0.00 86.38
03/26/01 13.15 NA 0.00 87.09
06/13/01 13.17 NA 0.00 87.07
09/05/01 13.59 NA 0.00 86.65
12/10/01 14.64 NA 0.00 85.60
02/07/02 13.85 NA 0.00 86.39
05/08/02 13.84 NA 0.00 86.40
08/05/02 14.50 NA 0.00 85.74
11/19/02 12.79 NA 0.00 87.45
02/25/03 9.35 NA 0.00 90.89
05/19/03 8.41 NA 0.00 91.83
08/25/03 7.58 NA 0.00 92.66
02/19/04 12.49 NA 0.00 87.75
08/26/04 12.74 NA 0.00 87.50
02/15/05 12.82 NA 0.00 87.42
08/10/05 13.18 NA 0.00 87.0603/02/06 12.71 NA 0.00 87.53
08/08/06 12.96 NA 0.00 87.28
02/19/07 12.83 NA 0.00 87.41
10/16/07 14.24 NA 0.00 86.00
04/24/08 13.03 NA 0.00 87.21
10/21/08 14.32 NA 0.00 85.92
04/15/09 12.97 NA 0.00 87.27
11/23/09 13.91 NA 0.00 86.33
06/16/10 13.08 NA 0.00 87.16
09/08/10 NM NM NM NM
12/23/10 NM NM NM NM
03/03/11 NM NM NM NM
08/04/11 13.80 NA 0.00 86.44
02/15/12 13.43 NA 0.00 86.81
10/24/12 14.14 NA 0.00 86.10
07/22/13 12.96 NA 0.00 87.28
02/20/14 13.13 NA 0.00 87.11
03/31/15 12.23 NA 0.00 88.01
05/16/16 12.97 NA 0.00 87.27
06/16/20 22.57 NA 0.00 77.67
09/15/20 14.54 12.97 1.57 84.35
11/16/20 12.80 12.52 0.28 87.20
12/16/94 14.56 NA 0.00 85.87
06/22/95 13.85 NA 0.00 86.58
04/19/96 13.67 NA 0.00 86.76
10/29/98 15.84 14.36 1.48 84.59
10/19/99 13.91 12.62 1.29 86.52
04/12/00 14.32 13.30 1.02 86.11
05/03/00 13.94 13.34 0.60 86.49
05/31/00 14.05 13.53 0.69 86.38
11/30/00 14.73 14.04 0.69 85.70
01/29/01 14.35 14.25 0.10 86.08
02/02/01 14.51 14.18 0.33 85.92
03/26/01 13.53 13.51 0.02 86.90
06/13/01 13.65 13.47 0.18 86.7809/05/01 14.05 13.85 0.20 86.38
12/10/01 15.58 14.71 0.87 84.85
01/17/02 20.17 20.06 0.11 80.26
02/07/02 14.31 14.07 0.24 86.12
05/08/02 14.55 14.09 0.46 85.88
08/05/02 15.19 14.67 0.52 85.24
11/19/02 13.16 13.15 0.01 87.2702/25/03 10.01 10 0.01 90.42
05/19/03 9.12 NA 0.00 91.31
08/25/03 8.95 NA 0.00 91.48
02/19/04 12.69 NA 0.00 87.74
08/26/04 12.75 NA 0.00 87.68
02/15/05 12.65 NA 0.00 87.78
08/10/05 13.04 NA 0.00 87.39
03/02/06 12.36 NA 0.00 88.07
08/08/06 12.91 NA 0.00 87.52
02/19/07 12.78 NA 0.00 87.65
10/16/07 14.11 NA 0.00 86.3204/23/08 13.05 NA 0.00 87.38
10/21/08 14.08 NA 0.00 86.35
04/15/09 12.95 NA 0.00 87.48
11/24/09 13.74 NA 0.00 86.69
06/16/10 13.09 NA 0.00 87.34
09/08/10 NM NM NM NM
12/23/10 NM NM NM NM
03/03/11 NM NM NM NM
08/04/11 13.63 NA 0.00 86.80
02/15/12 13.39 NA 0.00 87.04
10/24/12 13.93 NA 0.00 86.50
07/22/13 12.85 NA 0.00 87.58
02/20/14 13.04 NA 0.00 87.39
03/31/15 12.27 NA 0.00 88.16
05/16/16 12.92 NA 0.00 87.51
06/16/20 12.50 NA 0.00 87.93
09/15/20 14.47 12.88 1.59 84.60
Notes:
1. Elevations based on an arbitrary datum of 100.00 feet
2. NA = Not Applicable
3. NM = Not Measured
4. NS = Not Surveyed
5. LNAPL = Light Non Aqueous Phase Liquid
100.24MW-3
MW-4 100.43
Page 2 of 7
TABLE 2
HISTORICAL GROUNDWATER ELEVATION DATA
FORMER CONOCO STORE #33047 (RM #6182)
1122 EAST RALEIGH BOULEVARD
ROCKY MOUNT, EDGECOMBE COUNTY, NORTH CAROLINA
ATC PROJECT NO. P666182414
Well No.Date
Measured
Top of
Casing
Elevation
Depth to
Water (ft
btoc)
Depth to
LNAPL
LNAPL
Thickness
Groundwater
Elevation
MW-1 90.18
12/16/94 4.39 NA 0.00 98.47
06/22/95 16.01 NA 0.00 86.85
04/19/96 15.86 NA 0.00 87.00
10/29/98 16.56 NA 0.00 86.3010/19/99*NA NA 0.00 86.75
05/03/00 15.65 NA 0.00 87.21
11/30/00 16.18 NA 0.00 86.68
01/29/01 16.86 16.01 0.85 86.00
02/02/01 16.85 16.03 0.82 86.01
03/26/01 15.99 15.84 0.15 86.87
4/19/2001
06/13/01 15.92 NA 0.00 84.55
09/05/01 17.96 NA 0.00 82.51
12/10/01 16.88 NA 0.00 83.59
02/07/02 18.99 NA 0.00 81.48
05/08/02 20.91 NA 0.00 79.56
08/05/02 16.72 NA 0.00 83.75
11/19/02 16.77 NA 0.00 83.70
02/25/03 14.84 NA 0.00 85.63
05/19/03 14.65 NA 0.00 85.82
08/25/03 14.18 NA 0.00 86.29
02/19/04 16.27 NA 0.00 84.2008/26/04 17.67 NA 0.00 82.80
02/15/05 15.12 NA 0.00 85.35
08/10/05 15.64 NA 0.00 84.83
03/02/06 15.08 NA 0.00 85.39
08/08/06 15.26 NA 0.00 85.21
02/19/07 15.09 NA 0.00 85.38
10/16/07 16.41 NA 0.00 84.0604/23/08 17.56 NA 0.00 82.91
10/21/08 17.20 NA 0.00 83.27
04/15/09 18.33 NA 0.00 82.14
11/23/09 17.82 NA 0.00 82.65
06/16/10 15.40 NA 0.00 85.07
09/08/10 NM NM NM NM
12/23/10 NM NM NM NM
03/03/11 NM NM NM NM
08/04/11 15.81 NA 0.00 84.66
02/15/12 15.51 NA 0.00 84.96
10/24/12 17.31 NA 0.00 83.16
07/22/13 15.85 NA 0.00 84.62
02/20/14 15.16 NA 0.00 85.31
03/31/15 14.81 NA 0.00 85.66
05/16/16 15.30 NA 0.00 85.17
06/16/20 15.14 NA 0.00 85.33
09/15/20 14.65 NA 0.00 85.82
12/16/94 11.83 NA 0.00 85.64
06/22/95 11.20 NA 0.00 86.27
04/19/96 10.64 NA 0.00 86.83
10/29/98 11.82 NA 0.00 85.65
10/19/99 10.41 NA 0.00 87.06
05/03/00 10.83 NA 0.00 86.6411/30/00 11.48 NA 0.00 85.99
03/26/01 10.95 NA 0.00 86.52
06/13/01 10.82 NA 0.00 86.65
09/05/01 11.16 NA 0.00 86.31
12/10/01 11.98 NA 0.00 85.49
02/07/02 11.28 NA 0.00 86.19
05/08/02 11.49 NA 0.00 85.98
08/05/02 12.08 NA 0.00 85.39
11/19/02 10.83 NA 0.00 86.64
02/25/03 9.23 NA 0.00 88.24
05/19/03 8.48 NA 0.00 88.99
08/25/03 8.35 NA 0.00 89.12
02/19/04 10.37 NA 0.00 87.10
08/26/04 10.33 NA 0.00 87.14
02/15/05 10.65 NA 0.00 86.82
08/10/05 10.69 NA 0.00 86.78
03/02/06 10.24 NA 0.00 87.23
08/08/06 10.61 NA 0.00 86.8602/19/07 10.59 NA 0.00 86.88
10/16/07 11.73 NA 0.00 85.74
04/23/08 10.77 NA 0.00 86.70
10/21/08 11.58 NA 0.00 85.89
04/16/09 10.80 NA 0.00 86.67
11/23/09 11.26 NA 0.00 86.21
06/16/10 10.69 NA 0.00 86.78
09/08/10 NM NM NM NM
12/23/10 NM NM NM NM
03/03/11 NM NM NM NM
08/04/11 11.08 NA 0.00 86.39
02/15/12 11.04 NA 0.00 86.43
10/24/12 11.47 NA 0.00 86.00
07/22/13 10.46 NA 0.00 87.01
02/20/14 14.82 NA 0.00 82.65
03/31/15 9.94 NA 0.00 87.53
05/16/16 10.56 NA 0.00 86.91
06/16/20 10.63 NA 0.00 86.84
09/15/20 10.89 NA 0.00 86.58
Notes:
1. Elevations based on an arbitrary datum of 100.00 feet
2. NA = Not Applicable
3. NM = Not Measured
4. NS = Not Surveyed
5. LNAPL = Light Non Aqueous Phase Liquid
MW-5 102.86
Well Abandoned
MW-5R
97.47MW-6
100.47
Page 3 of 7
TABLE 2
HISTORICAL GROUNDWATER ELEVATION DATA
FORMER CONOCO STORE #33047 (RM #6182)
1122 EAST RALEIGH BOULEVARD
ROCKY MOUNT, EDGECOMBE COUNTY, NORTH CAROLINA
ATC PROJECT NO. P666182414
Well No.Date
Measured
Top of
Casing
Elevation
Depth to
Water (ft
btoc)
Depth to
LNAPL
LNAPL
Thickness
Groundwater
Elevation
MW-1 90.18
12/16/94 14.81 NA 0.00 82.83
06/22/95 15.65 NA 0.00 81.99
04/19/96 15.14 NA 0.00 82.50
10/29/98 15.67 NA 0.00 81.9710/19/99 14.19 NA 0.00 83.45
05/03/00 15.31 NA 0.00 82.33
11/30/00 15.49 NA 0.00 82.15
03/26/01 14.72 NA 0.00 82.92
06/13/01 14.49 NA 0.00 83.15
09/05/01 13.91 NA 0.00 83.73
12/10/01 14.76 NA 0.00 82.88
02/07/02 15.09 NA 0.00 82.55
05/08/02 13.81 NA 0.00 83.83
08/05/02 15.24 NA 0.00 82.40
11/19/02 17.95 NA 0.00 79.69
02/25/03 14.75 NA 0.00 82.89
05/20/03 17.50 NA 0.00 80.14
08/25/03 17.35 NA 0.00 80.29
02/19/04 18.11 NA 0.00 79.53
08/26/04 18.20 NA 0.00 79.44
02/15/05 18.27 NA 0.00 79.37
08/10/05 17.47 NA 0.00 80.1703/02/06 16.85 NA 0.00 80.79
08/08/06 14.09 NA 0.00 83.55
02/19/07 14.00 NA 0.00 83.64
10/16/07 15.81 NA 0.00 81.83
04/23/08 15.35 NA 0.00 82.29
10/21/08 14.78 NA 0.00 82.86
04/16/09 15.57 NA 0.00 82.07
11/23/09 15.22 NA 0.00 82.42
06/16/10 13.39 NA 0.00 84.25
09/08/10 NM NM NM NM
12/23/10 NM NM NM NM
03/03/11 NM NM NM NM
08/04/11 15.79 NA 0.00 81.85
02/15/12 15.80 NA 0.00 81.84
10/24/12 15.78 NA 0.00 81.86
07/22/13 15.51 NA 0.00 82.13
02/20/14 14.82 NA 0.00 82.82
03/31/15 14.87 NA 0.00 82.77
05/16/16 15.72 NA 0.00 81.92
06/16/20 13.58 NA 0.00 84.06
09/15/20 14.65 NA 0.00 82.99
12/16/94 NM NA 0.00 NM
06/22/95 16.15 NA 0.00 81.4804/19/96 15.33 NA 0.00 82.30
10/29/98 15.75 NA 0.00 81.88
10/19/99 14.28 NA 0.00 83.35
05/03/00 15.42 NA 0.00 82.21
11/30/00 15.60 NA 0.00 82.03
03/26/01 14.82 NA 0.00 82.81
06/13/01 14.59 NA 0.00 83.0409/05/01 14.43 NA 0.00 83.20
12/10/01 14.78 NA 0.00 82.85
02/07/02 15.56 NA 0.00 82.07
05/08/02 15.12 NA 0.00 82.51
08/05/02 15.75 NA 0.00 81.88
11/19/02 17.97 NA 0.00 79.66
02/25/03 16.54 NA 0.00 81.09
05/20/03 17.85 NA 0.00 79.78
08/25/03 17.71 NA 0.00 79.92
02/19/04 18.16 NA 0.00 79.47
08/26/04 18.50 NA 0.00 79.13
02/15/05 18.06 NA 0.00 79.57
08/10/05 17.62 NA 0.00 80.01
03/02/06 17.03 NA 0.00 80.60
08/08/06 16.60 NA 0.00 81.03
02/19/07 9.25 NA 0.00 88.38
10/16/07 16.02 NA 0.00 81.61
04/23/08 15.41 NA 0.00 82.2210/21/08 15.81 NA 0.00 81.82
04/16/09 15.66 NA 0.00 81.97
11/23/09 15.43 NA 0.00 82.20
06/16/10 15.51 NA 0.00 82.12
09/08/10 NM NM NM NM
12/23/10 NM NM NM NM
03/03/11 NM NM NM NM
08/04/11 15.83 NA 0.00 81.80
02/15/12 15.78 NA 0.00 81.85
10/24/12 15.92 NA 0.00 81.71
07/22/13 15.60 NA 0.00 82.03
02/20/14 15.53 NA 0.00 82.10
03/31/15 15.22 NA 0.00 82.41
05/16/16 15.73 NA 0.00 81.90
06/16/20 10.02 NA 0.00 87.61
09/15/20 14.15 NA 0.00 83.48
Notes:
1. Elevations based on an arbitrary datum of 100.00 feet
2. NA = Not Applicable
3. NM = Not Measured
4. NS = Not Surveyed
5. LNAPL = Light Non Aqueous Phase Liquid
MW-7 97.64
MW-7A 97.63
Page 4 of 7
TABLE 2
HISTORICAL GROUNDWATER ELEVATION DATA
FORMER CONOCO STORE #33047 (RM #6182)
1122 EAST RALEIGH BOULEVARD
ROCKY MOUNT, EDGECOMBE COUNTY, NORTH CAROLINA
ATC PROJECT NO. P666182414
Well No.Date
Measured
Top of
Casing
Elevation
Depth to
Water (ft
btoc)
Depth to
LNAPL
LNAPL
Thickness
Groundwater
Elevation
MW-1 90.18
12/16/94 13.22 NA 0.00 82.09
06/22/95 13.95 NA 0.00 81.36
04/19/96 13.02 NA 0.00 82.29
10/29/98 13.43 NA 0.00 81.8810/19/99 11.85 NA 0.00 83.46
05/03/00 13.10 NA 0.00 82.21
11/30/00 14.29 NA 0.00 81.02
03/26/01 12.42 NA 0.00 82.89
06/13/01 12.30 NA 0.00 83.01
09/05/01 12.42 NA 0.00 82.89
12/10/01 12.66 NA 0.00 82.65
02/07/02 13.60 NA 0.00 81.71
05/08/02 12.84 NA 0.00 82.47
08/05/02 13.43 NA 0.00 81.88
11/19/02 15.72 NA 0.00 79.59
02/25/03 14.18 NA 0.00 81.13
05/20/03 15.88 NA 0.00 79.43
08/25/03 15.58 NA 0.00 79.73
02/19/04 15.79 NA 0.00 79.52
08/26/04 9.04 NA 0.00 86.27
02/15/05 13.00 NA 0.00 82.31
08/10/05 14.40 NA 0.00 80.9103/02/06 13.87 NA 0.00 81.44
08/08/06 13.30 NA 0.00 82.01
02/19/07 14.50 NA 0.00 80.81
10/16/07 13.68 NA 0.00 81.63
04/23/08 13.06 NA 0.00 82.25
10/21/08 13.48 NA 0.00 81.83
04/16/09 13.34 NA 0.00 81.97
11/23/09 13.12 NA 0.00 82.19
06/16/10 13.20 NA 0.00 82.11
09/08/10 NM NM NM NM
12/23/10 NM NM NM NM
03/03/11 NM NM NM NM
08/04/11 13.52 NA 0.00 81.79
02/15/12 13.50 NA 0.00 81.81
10/24/12 13.61 NA 0.00 81.70
07/22/13 13.25 NA 0.00 82.06
02/20/14 13.20 NA 0.00 82.11
03/31/15 12.84 NA 0.00 82.47
05/16/16 13.41 NA 0.00 81.90
06/16/20 12.45 NA 0.00 82.86
09/15/20 11.80 NA 0.00 83.51
12/16/94 NM NA 0.00 NM
06/22/95 9.55 NA 0.00 81.5004/19/96 8.99 NA 0.00 82.06
10/29/98 9.34 NA 0.00 81.71
10/19/99 7.95 NA 0.00 83.10
05/03/00 8.99 NA 0.00 82.06
11/30/00 9.28 NA 0.00 81.77
03/26/01 10.82 NA 0.00 80.23
06/13/01 8.23 NA 0.00 82.8209/05/01 7.96 NA 0.00 83.09
12/10/01 8.45 NA 0.00 82.60
02/07/02 8.89 NA 0.00 82.16
05/08/02 8.70 NA 0.00 82.35
08/05/02 9.34 NA 0.00 81.71
11/19/02 11.39 NA 0.00 79.66
02/25/03 9.84 NA 0.00 81.21
05/20/03 11.51 NA 0.00 79.54
08/25/03 9.55 NA 0.00 81.50
02/19/04 11.54 NA 0.00 79.51
08/26/04 8.03 NA 0.00 83.02
02/15/05 9.90 NA 0.00 81.15
08/10/05 9.26 NA 0.00 81.79
03/02/06 8.72 NA 0.00 82.33
08/08/06 9.45 NA 0.00 81.60
02/19/07 5.40 NA 0.00 85.65
10/16/07 9.57 NA 0.00 81.48
04/23/08 8.98 NA 0.00 82.0710/21/08 9.47 NA 0.00 81.58
04/15/09 9.11 NA 0.00 81.94
11/23/09 9.13 NA 0.00 81.92
06/16/10 9.08 NA 0.00 81.97
09/08/10 NM NM NM NM
12/23/10 NM NM NM NM
03/03/11 NM NM NM NM
08/04/11 9.21 NA 0.00 81.84
02/15/12 9.41 NA 0.00 81.64
10/24/12 9.52 NA 0.00 81.53
07/22/13 NM NM NM NM
02/20/14 9.05 NA 0.00 82.00
03/31/15 9.81 NA 0.00 81.24
05/16/16 9.38 NA 0.00 81.67
06/16/20
09/15/20
Notes:
1. Elevations based on an arbitrary datum of 100.00 feet
2. NA = Not Applicable
3. NM = Not Measured
4. NS = Not Surveyed
5. LNAPL = Light Non Aqueous Phase Liquid
95.31MW-8
Well not located
MW-9 91.05
Well not located
Page 5 of 7
TABLE 2
HISTORICAL GROUNDWATER ELEVATION DATA
FORMER CONOCO STORE #33047 (RM #6182)
1122 EAST RALEIGH BOULEVARD
ROCKY MOUNT, EDGECOMBE COUNTY, NORTH CAROLINA
ATC PROJECT NO. P666182414
Well No.Date
Measured
Top of
Casing
Elevation
Depth to
Water (ft
btoc)
Depth to
LNAPL
LNAPL
Thickness
Groundwater
Elevation
MW-1 90.18
12/16/94 NM NA 0.00 NM
06/22/95 10.60 NA 0.00 81.49
04/19/96 10.04 NA 0.00 82.05
10/29/98 10.37 NA 0.00 81.7210/19/99 8.29 NA 0.00 83.80
05/03/00 9.87 NA 0.00 82.22
11/30/00 10.22 NA 0.00 81.87
03/26/01 9.61 NA 0.00 82.48
06/13/01 9.40 NA 0.00 82.69
09/05/01 9.30 NA 0.00 82.79
12/10/01 9.66 NA 0.00 82.43
02/07/02 9.11 NA 0.00 82.98
05/08/02 9.85 NA 0.00 82.24
08/05/02 10.38 NA 0.00 81.71
11/19/02 12.48 NA 0.00 79.61
02/25/03 11.66 NA 0.00 80.43
05/20/03 12.30 NA 0.00 79.79
08/25/03 12.55 NA 0.00 79.54
02/19/04 12.49 NA 0.00 79.60
08/26/04 9.92 NA 0.00 82.17
02/15/05 12.32 NA 0.00 79.77
08/10/05 12.57 NA 0.00 79.5203/02/06 12.06 NA 0.00 80.03
08/08/06 10.38 NA 0.00 81.71
02/19/07 10.00 NA 0.00 82.09
10/16/07 10.67 NA 0.00 81.42
04/24/08 10.17 NA 0.00 81.92
10/21/08 10.50 NA 0.00 81.59
04/15/09 10.24 NA 0.00 81.85
11/23/09 10.18 NA 0.00 81.91
06/16/10 10.22 NA 0.00 81.87
09/08/10 NM NM NM NM
12/23/10 NM NM NM NM
03/03/11 NM NM NM NM
08/04/11 10.55 NA 0.00 81.54
02/15/12 10.44 NA 0.00 81.65
10/24/12 10.57 NA 0.00 81.52
07/22/13 10.19 NA 0.00 81.90
02/20/14 10.23 NA 0.00 81.86
03/31/15 10.02 NA 0.00 82.07
05/16/16 10.42 NA 0.00 81.67
06/16/20 9.87 NA 0.00 82.22
09/15/20 10.49 NA 0.00 81.60
12/16/94 NM NA 0.00 NM
06/22/95 13.05 NA 0.00 86.9804/19/96 11.95 NA 0.00 88.08
10/29/98 14.25 NA 0.00 85.78
10/19/99 12.46 NA 0.00 87.57
05/03/00 12.37 NA 0.00 87.66
11/30/00 13.56 NA 0.00 86.47
03/26/01 12.54 NA 0.00 87.49
06/13/01 12.87 NA 0.00 87.1609/05/01 13.42 NA 0.00 86.61
12/10/01 14.48 NA 0.00 85.55
02/07/02 13.70 NA 0.00 86.33
05/08/02 13.40 NA 0.00 86.63
08/05/02 14.26 NA 0.00 85.77
11/19/02 12.94 NA 0.00 87.09
02/25/03 10.77 NA 0.00 89.26
05/19/03 10.13 NA 0.00 89.90
08/25/03 10.03 NA 0.00 90.00
02/19/04 11.76 NA 0.00 88.27
08/26/04 12.54 NA 0.00 87.49
02/15/05 12.18 NA 0.00 87.85
08/10/05 13.02 NA 0.00 87.01
03/02/06 12.48 NA 0.00 87.55
08/08/06 12.81 NA 0.00 87.22
02/19/07 12.32 NA 0.00 87.71
10/16/07 14.21 NA 0.00 85.82
04/24/08 12.61 NA 0.00 87.4210/21/08 14.41 NA 0.00 85.62
04/15/09 12.51 NA 0.00 87.52
11/23/09 14.04 NA 0.00 85.99
06/16/10 13.22 NA 0.00 86.81
09/08/10 NM NM NM NM
12/23/10 NM NM NM NM
03/03/11 NM NM NM NM
08/04/11 13.97 NA 0.00 86.06
02/15/12
10/24/12 14.22 NA 0.00 85.81
07/22/13 12.74 NA 0.00 87.29
02/20/14 12.73 NA 0.00 87.30
03/31/15 11.94 NA 0.00 88.09
05/16/16 12.61 NA 0.00 87.42
06/16/20 12.72 NA 0.00 87.31
09/15/20 13.37 NA 0.00 86.66
Notes:
1. Elevations based on an arbitrary datum of 100.00 feet
2. NA = Not Applicable
3. NM = Not Measured
4. NS = Not Surveyed
5. LNAPL = Light Non Aqueous Phase Liquid
100.03MW-11
Well not Accessible
92.09MW-10
Page 6 of 7
TABLE 2
HISTORICAL GROUNDWATER ELEVATION DATA
FORMER CONOCO STORE #33047 (RM #6182)
1122 EAST RALEIGH BOULEVARD
ROCKY MOUNT, EDGECOMBE COUNTY, NORTH CAROLINA
ATC PROJECT NO. P666182414
Well No.Date
Measured
Top of
Casing
Elevation
Depth to
Water (ft
btoc)
Depth to
LNAPL
LNAPL
Thickness
Groundwater
Elevation
MW-1 90.18
02/19/04 13.01 12.03 0.98 NS
06/10/04 13.00 12.42 0.58 NS
08/26/04 12.43 12.39 0.04 NS
11/17/04 15.10 NA 0.00 NS
02/15/05 12.71 12.61 0.10 NS
05/23/05 11.93 11.93 sheen NS
08/10/05 12.92 12.78 0.14 NS
03/02/06 12.40 12.40 sheen NS
03/23/06 13.30 13.00 0.30 NS06/12/06 12.81 12.78 0.03 NS
06/29/06 12.46 12.46 sheen NS
08/08/06 12.54 12.54 sheen NS
09/08/06 12.60 NA 0.00 NS
10/18/06 12.56 12.53 0.03 NS
10/30/06 12.58 NA 0.00 NS
11/27/06 12.53 NA 0.00 NS01/09/07 12.51 NA 0.00 NS
01/26/07 12.49 NA 0.00 NS
02/09/07 12.46 NA 0.00 NS
02/19/07 12.46 NA 0.00 NS
10/16/07 13.70 13.66 0.04 NS
04/24/08 12.76 NA 0.00 NS
10/21/08 14.46 13.72 0.74 NS
04/16/09 12.99 12.81 0.18 NS
11/24/09 14.10 13.81 0.29 NS
06/16/10 13.16 12.72 0.44 NS
09/08/10 14.01 13.57 0.44 NS
12/23/10 13.91 12.80 1.11 NS
03/03/11 13.73 12.89 0.84 NS
07/21/11 13.69 13.35 0.34 NS
08/04/11 13.64 13.30 0.34 NS
12/15/11 13.86 13.14 0.72 NS
01/26/12 13.57 13.13 0.44 NS
02/15/12 13.52 13.06 0.46 NS
07/30/12 14.45 13.15 1.30 NS
08/30/12 13.67 13.32 0.35 NS
09/27/12 13.47 NA 0.00 NS
10/24/12 14.00 13.68 0.32 NS
07/22/13 12.72 12.60 0.12 NS
02/20/14 12.93 12.78 0.15 NS
03/31/15 11.68 11.54 0.14 NS
05/16/16 12.73 12.59 0.14 NS
06/16/20 12.30 NA 0.00 NS
09/15/20 14.27 12.60 1.67 NS
11/16/20 12.93 12.33 0.60 NS
02/19/04 11.86 NA 0.00 NS
08/26/04 12.21 12.09 0.12 NS
11/17/04 14.84 NA 0.00 NS02/15/05 12.30 NA 0.00 NS
05/23/05 11.59 11.59 sheen NS
08/10/05 12.51 12.46 0.05 NS
03/02/06 11.85 11.85 sheen NS
03/23/06 12.84 12.72 0.12 NS
06/12/06 12.52 NA 0.00 NS
06/29/06 12.28 NA 0.00 NS
08/08/06 12.35 NA 0.00 NS
09/08/06 12.36 NA 0.00 NS
10/18/06 12.29 NA 0.00 NS
10/30/06 12.31 NA 0.00 NS
11/27/06 12.23 NA 0.00 NS
01/09/07 12.22 NA 0.00 NS
02/09/07 12.20 NA 0.00 NS
02/19/07 12.11 NA 0.00 NS
10/16/07 13.58 13.56 0.02 NS
04/24/08
10/21/08
04/16/09 12.62 NA 0.00 NS
11/24/09 13.25 NA sheen NS
06/16/10 13.60 NA 0.00 NS
09/08/10 NM NM NM NS
12/23/10 NM NM NM NS
03/03/11 NM NM NM NS
08/04/11 13.07 NA 0.00 NS
02/15/12 12.92 NA 0.00 NS
10/24/12 13.44 NA 0.00 NS
07/22/13 12.39 12.37 0.02 NS
02/20/14 12.67 12.65 0.02 NS
03/31/15 11.80 NA 0.00 NS
05/16/16 12.44 NA 0.00 NS
06/16/20 14.17 11.95 2.22 NS
09/15/20 14.47 12.24 2.23 NS
1. Elevations based on an arbitrary datum of 100.00 feet
2. NA = Not Applicable3. NM = Not Measured
4. NS = Not Surveyed
5. LNAPL = Light Non Aqueous Phase Liquid
MWHS-10 NS
Obstruction in well
Obstruction in well
MWHS-11 NS
Page 7 of 7
TABLE 3
HISTORICAL GROUNDWATER ANALYTICAL RESULTS
FORMER CONOCO STORE #33047 (RM #6182)
1122 EAST RALEIGH BOULEVARD
ROCKY MOUNT, EDGECOMBE COUNTY, NORTH CAROLINA
ATC PROJECT NO. P666182414
Well ID Date
Sampled Benzene Toluene Ethyl-
benzene
Total
Xylenes MTBE IPE EDB Lead
12/16/94 9.6 ND ND 23 67 ND NA NA
06/22/95 77 8 110 65 ND 530 NA NA
04/19/96 82 42 202 430 34 <100 NA NA
10/29/98 9.9 <1.0 53.9 15.7 9.1 <1.0 NA 10
10/19/99 1.9 <1.0 <1.0 <1.0 <5.0 <5.0 <0.020 <3.0
05/03/00 11 <1.0 4.7 8.3 16.0 <1.0 <0.020 <3.0
11/30/00 <1.0 <1.0 <1.0 <1.0 <5.0 <5.0 <0.020 5.4
03/27/01 1.5 <1.0 <1.0 1.7 <5.0 <5.0 <0.020 <3.0
06/14/01 <1.0 <1.0 <1.0 <1.0 <5.0 <5.0 <0.020 <3.0
09/06/01 <1.0 <1.0 <1.0 <1.0 8 <5.0 <0.020 4
12/11/01 <1.0 <1.0 <1.0 <1.0 8 <5.0 <0.020 3.9
02/07/02 <1.0 <1.0 <1.0 <1.0 <5.0 <5.0 <0.020 29
05/08/02 <1.0 <1.0 <1.0 <1.0 <5.0 <5.0 <0.020 33
08/06/02 <1.0 <1.0 <1.0 <1.0 <5.0 <5.0 <0.020 5.1
11/19/02 <1.0 0.04J <1.0 <1.0 <5.0 <5.0 <0.020 6.6
02/25/03 <1.0 <1.0 <1.0 <1.0 <5.0 <5.0 <0.020 3.8
05/20/03 <1.0 <1.0 <1.0 <1.0 <5.0 <5.0 <0.020 8.5
08/25/03 160 <5.0 <5.0 72 880 <25 <0.020 9.1
02/19/04 <0.5 <0.7 <0.8 <0.8 160 <0.8 <1 NA
08/26/04 <1 <1 <1 <1 21 <1 <1 NA
02/15/05 <5 <5 <5 <5 6.6 <5 <1 NA
08/10/05 <1 <1 <1 <1 3.5 <1 <1 NA
03/02/06 <1 <1 <1 <1 3.2 <1 <1 NA
08/08/06 <0.5 <0.7 <0.8 <0.8 2 <0.8 <1 NA
10/16/07 0.7 2 <0.8 4 0.5 <0.8 <1 NA
04/23/08 <1 <5 <5 <10 <5 <5 <5 NA
10/21/08 <0.1 <0.1 <0.1 <0.1 <0.2 <0.1 <0.1 NA
04/15/09 <0.1 <0.1 <0.1 <0.1 <0.2 <0.1 <0.1 NA
11/23/09 <0.1 <0.1 <0.1 <0.2 <0.2 <0.1 <0.1 NA
06/16/10 <0.1 <0.1 <0.1 <0.2 <0.2 <0.1 <0.1 NA
08/04/11 <0.1 <0.1 <0.1 <0.1 <0.2 <0.1 <0.1 NA
02/15/12 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 NA
10/24/12 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 NA
07/22/13 <1 <1 <1 <1 <1 <1 <1 NA
02/20/14 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 NA
03/31/15 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 NA
05/16/16 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 NA
09/15/20 37.5 1.2 <0.50 19.3 <0.50 <0.50 <0.50 NA
12/16/94 3,900 5,700 780 3,200 15,000 600 NA NA
06/22/95 1,200 1,900 1,100 2,000 5,200 140 NA NA
04/19/96 5,230 5,180 1,110 4,710 7,090 210 NA NA
10/29/98 2,860 4,270 1,060 3,650 1,360 <1.0 NA <3.0
10/19/99 2,700 4,000 1,200 4,100 1,200 <500 <0.020 <3.0
05/03/00 2,800 4,800 1,600 5,800 950 <250 <0.020 <3.0
11/30/00 2,500 3,700 1,500 4,100 1,000 300 <0.020 <3.0
03/27/01 1,800 2,100 860 2,300 650 120 <0.020 <3.0
06/14/01 1,900 3,100 1,300 3,600 660 260 <0.020 <3.0
09/06/01 1,900 2,200 1,100 2,800 920 160 <0.020 <3.0
12/11/01 2,300 2,500 1,000 2,900 <250 <250 <0.020 <3.0
02/07/02 1,900 3,600 1,200 4,000 250 <250 <0.020 <3.0
05/08/02 1,100 1,600 550 1,800 340 <250 <0.020 <3.0
08/06/02 980 1,100 510 1,600 300 260 <0.020 <3.0
11/19/02 950 110 550 900 140 <50 <0.020 <3.0
02/25/03 250 300 340 930 110 38 <0.020 <3.0
05/20/03 49 40 140 600 47 <5.0 <0.020 <3.0
08/25/03 1,200 2,100 440 1,900 6,900 <50 <0.020 <3.0
02/19/04 75 130 190 224 250 1 <1 NA
08/26/04 57 95 98 250 320 1.5 <1 NA
02/15/05 300 320 500 980 320 <5 <1 NA
08/10/05 390 210 660 960 680 <5 <5 NA
03/02/06 240 44 290 176 460 <5 <5 NA
08/08/06 180 21 160 61 270 3 <1 NA
02/19/07 48 2 30 11 300 3 <1 NA
10/16/07 200 6 190 49 480 6 <1 NA
04/23/08
10/22/08 68 4.6 13 33.7 180 3.6 <0.1 NA
04/15/09 14 0.93 1.3 7.9 42 0.76 <0.1 NA
11/24/09 54 3.2 9.7 27.4 150 4.6 <0.1 NA
06/16/10 58 7.2 9.7 42.2 110 4.2 <0.1 NA
08/04/11 13 1.2 0.79 3.5 45 2.5 <0.1 NA
02/15/12
10/24/12
07/22/13
02/20/14
03/31/15
05/16/16
09/15/20
1 600 600 500 20 70 0.02 15
51 11 97 670 690 13,000 0.31 25
5,000 260,000 84,500 85,500 20,000 70,000 50 15,000
Notes:
1. MTBE = Methyl Tertiary Butyl Ether
2. IPE = Isopropyl Ether
3. EDB = Ethylene Dibromide (1,2-Dibromoethane)
4. "<" or ND = Not Detected at or above the laboratory reporting limit
5. Concentrations are reported in micrograms per liter (ug/l) = parts per billion (ppb)
6. Concentrations in bold equal or exceed the corresponding NCDEQ Groundwater Quality 2L Standard or Surface Water Quality 2B Standard
7. GCL = Gross Contamination Limit
8. NE = Not Established
9. NS/FP = Not Sampled/Free Product
10. "J" indicates concentration is above method detection limit but below reporting limit
Not Located
Not Located
2L Standard
GCL
Not Located
Not Located
MW-1
Not Located
MW-2
Not Located
2B Standard
Not Located
Not Located
Page 1 of 7
TABLE 3
HISTORICAL GROUNDWATER ANALYTICAL RESULTS
FORMER CONOCO STORE #33047 (RM #6182)
1122 EAST RALEIGH BOULEVARD
ROCKY MOUNT, EDGECOMBE COUNTY, NORTH CAROLINA
ATC PROJECT NO. P666182414
Well ID Date
Sampled Benzene Toluene Ethyl-
benzene
Total
Xylenes MTBE IPE EDB Lead
12/16/94 7.2 1.3 ND ND 7.4 ND NA NA
06/22/95 ND ND ND ND ND ND NA NA
04/19/96 3 <1.0 <1.0 <1.0 <1.0 <10 NA NA
10/29/98 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <3.0
10/19/99 9,300 24,000 2,400 11,000 <2,000 <2,000 <0.020 <3.0
05/03/00 10 <1.0 1.5 <1.0 20 2 <0.020 <3.0
11/30/00 1.9 <1.0 <1.0 1.4 9.7 <5.0 <0.020 <3.0
03/27/01 <1.0 <1.0 <1.0 <1.0 6.0 <5.0 <0.020 <3.0
06/14/01 <1.0 <1.0 <1.0 <1.0 <5.0 <5.0 <0.020 4.1
09/06/01 <1.0 <1.0 <1.0 <1.0 <5.0 <5.0 <0.020 6.6
12/11/01 3.2 <1.0 <1.0 <1.0 <5.0 <5.0 <0.020 4.4
02/07/02 620 950 130 460 <120 <120 <0.020 5.6
05/08/02 1.4 <1.0 <1.0 <1.0 5.4 <5.0 <0.020 3.4
08/06/02 43 16 4.0 16 7.5 5.5 <0.020 <3.0
11/19/02 17,000 35,000 2,400 10,000 970J <2,500 <0.020 <3.0
12/16/02 16,000 37,000 3,400 14,000 <2,500 <2,500 NA NA
02/25/03 10,000 32,000 3,800 18,000 <2,500 <2,500 <0.020 <3.0
05/20/03 2,000 24,000 3,300 17,000 <1,200 <1,200 <0.020 <3.0
08/25/03 790 12,000 3,900 18,000 5,400 <120 <0.020 <3.0
02/19/04 310 370 1,300 2,700 150 2 <3 NA
08/26/04 400 74 1,000 460 470 22 <100 NA
02/15/05 270 <5 490 8.1 380 <5 <1 NA
08/10/05 73 <5 35 <5 370 <5 <5 NA
03/02/06 9.6 <1 2.5 <1 340 3.8 <1 NA
08/08/06 2 <0.7 <0.8 <0.8 260 3 <1 NA
02/19/07 0.9 <0.7 <0.8 <0.8 200 3 <1 NA
10/16/07 <0.5 <0.7 <0.8 <0.8 150 3 <1 NA
04/24/08 <1 <5 <5 <10 94 1.7J <5 NA
10/21/08 0.5 <0.1 <0.1 <0.1 29 2.9 <0.1 NA
04/15/09 0.11 <0.1 <0.1 0.12 51 2.7 <0.1 NA
11/23/09 240E 20 72 74.2 140 14 <0.1 NA
06/16/10 <0.1 <0.1 <0.1 <0.2 22 2.3 <0.1 NA
08/04/11 0.34 <0.1 <0.1 <0.1 2.2 3.4 <0.1 NA
02/15/12 <0.5 <0.5 <0.5 <0.5 6.9 2 <0.5 NA
10/24/12 1.3 0.2J 0.3J 0.2J 2.7 1.4 <0.5 NA
07/22/13 <0.5 <0.5 <0.5 <0.5 4.1 1.6 <0.5 NA
02/20/14 0.5J <0.5 0.1J 0.1J 3.1 2 <0.5 NA
03/31/15 0.4J <0.1 <0.1 0.1J 3.7 1.5 <0.1 NA
05/16/16 <0.1 <0.1 <0.1 <0.1 1.5 1.3 <0.1 NA
09/15/20 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
11/16/20 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
12/16/94 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
06/22/95 1,300 2,100 1,200 1,000 4,800 120 NS NS
04/19/96 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
10/29/98 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
10/19/99 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
05/03/00 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
11/30/00 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
03/27/01 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
06/14/01 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
09/06/01 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
12/11/01 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
02/07/02 4,100 <100 880 1,300 <500 <500 <0.020 <3.0
05/08/02 2,200 <500 510 750 <2,500 <2,500 <0.020 18
08/06/02 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
11/19/02 13 1.1 40 53 <5.0 <5.0 <0.020 <3.0
12/16/02 13 <1.0 28 14 <5.0 <5.0 NA NA
02/25/03 46 170 100 300 140 19 <0.020 <3.0
05/20/03 8.6 <130 <250 <1,100 <12 <12 <0.020 3.8
08/25/03 42 19 180 110 1,100 <25 <0.020 <3.0
02/19/04 150 1,100 440 850 200 <2 <2 NA
08/26/04 220 420 760 1,290 210 27 <25 NA
02/15/05 290 82 890 810 210 <5 <1 NA
08/10/05 270 13 630 240 320 <5 <5 NA
03/02/06 230 32 430 99 410 <5 <5 NA
08/08/06 240 19 430 85 260 4 <1 NA
02/19/07 290 21 100 110 1,600 20 <5 NA
10/16/07 100 3 11 5 370 6 <3 NA
04/23/08 130 55 42 110 470 8.3J <25 NA
10/21/08 140 7.3 25 48 260 8.3 <0.1 NA
04/15/09 200 170 120 230 380 9 <0.1 NA
11/24/09 5 0.91 1.3 3.02 150 9.3 <0.1 NA
06/16/10 190 28 94 209.3 140 8 <0.1 NA
08/04/11 16 2.9 1.8 3.7 40 8.4 <1 NA
02/15/12 110 17 11 42.3 33 5.5 <5 NA
10/24/12 6.5 0.6 0.5 1.2 13 6 <0.5 NA
07/22/13 66 8.2 3.8 20.4 26 5.2 <0.5 NA
02/20/14 45 2.7 0.6J 2.7 18 5.0 <2.5 NA
03/31/15 120 13 4.5J 17 19 3.5J <2 NA
05/16/16 210 16 16 46.7 19 3.6J <1 NA
09/15/20 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
1 600 600 500 20 70 0.02 15
51 11 97 670 690 13,000 0.31 25
5,000 260,000 84,500 85,500 20,000 70,000 50 15,000
Notes:
1. MTBE = Methyl Tertiary Butyl Ether
2. IPE = Isopropyl Ether
3. EDB = Ethylene Dibromide (1,2-Dibromoethane)
4. "<" or ND = Not Detected at or above the laboratory reporting limit
5. Concentrations are reported in micrograms per liter (ug/l) = parts per billion (ppb)
6. Concentrations in bold equal or exceed the corresponding NCDEQ Groundwater Quality 2L Standard or Surface Water Quality 2B Standard
7. GCL = Gross Contamination Limit
8. NE = Not Established
9. NS/FP = Not Sampled/Free Product
10. "J" indicates concentration is above method detection limit but below reporting limit
2L Standard
GCL
MW-3
MW-4
2B Standard
Page 2 of 7
TABLE 3
HISTORICAL GROUNDWATER ANALYTICAL RESULTS
FORMER CONOCO STORE #33047 (RM #6182)
1122 EAST RALEIGH BOULEVARD
ROCKY MOUNT, EDGECOMBE COUNTY, NORTH CAROLINA
ATC PROJECT NO. P666182414
Well ID Date
Sampled Benzene Toluene Ethyl-
benzene
Total
Xylenes MTBE IPE EDB Lead
12/16/94 ND 1.3 ND ND ND ND NA NA
06/22/95 ND ND ND ND ND ND NA NA
04/19/96 <1.0 <1.0 <1.0 <1.0 <1.0 <10 NA NA
10/29/98 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <3.0
10/19/99
05/03/00 <1.0 <1.0 <1.0 <1.0 1.3 <1.0 <0.020 16
11/30/00 <1.0 <1.0 <1.0 <1.0 76 <5.0 <0.020 74
03/27/01 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
04/19/01
06/14/01 6.3 2.1 <1.0 <1.0 14 <5.0 <0.020 3.1
09/06/01 5.3 1.5 2.4 2 10 <5.0 <0.020 <3.0
12/11/01 5.6 1.4 2.0 <1.0 5.9 <5.0 <0.020 22
02/07/02 13 2.9 2.9 1.3 <5.0 <5.0 <0.020 <3.0
05/08/02 7.6 1.4 1.8 <1.0 7.9 <5.0 <0.020 17
08/06/02 4.4 <1.0 <1.0 <1.0 6.8 <5.0 <0.020 35
11/19/02 8.5 <1.0 8.6 5.7 <5.0 <5.0 <0.020 11
02/25/03 19 2 1.4 2.1 9.7 <5.0 <0.020 6.3
05/20/03 87 34 15.0 29 42 <5.0 <0.020 <3.0
08/25/03 11 2.9 1.8 3 46 <5.0 <0.020 <3.0
02/19/04 5 <0.7 <0.8 <0.8 73 4 <1 NA
08/26/04 <1 <1 <1 <1 41 <1 <1 NA
02/15/05 <5 <5 <5 <5 42 <5 <1 NA
08/10/05 <1 <1 <1 2.5 40 <1 <1 NA
03/02/06 12 25 3 17.4 490 2.7 <1 NA
08/08/06 10 48 8 79 47 <0.8 <1 NA
02/19/07 3 4 2 10 36 <0.8 <1 NA
10/16/07 <0.5 <0.7 <0.8 <0.8 4 <0.8 <1 NA
04/24/08 9.9 6.7 11 14 32 1.1J <5 NA
10/22/08 21 16 34 41 56 1.6 <0.1 NA
04/16/09 9.4 4.4 9.9 13.1 55 1.8 <0.1 NA
11/23/09 1.8 0.95 2.2 2.51 34 1.2 <0.1 NA
06/16/10 <0.1 <0.1 <0.1 <0.2 6 0.14 <0.1 NA
08/04/11 <0.1 <0.1 0.13 0.6 26 0.82 <0.1 NA
02/15/12 <0.5 <0.5 <0.5 <0.5 17 0.4J <0.5 NA
10/24/12 <0.5 <0.5 <0.5 <0.5 25 0.7 <0.5 NA
07/22/13 1.2 3.4 1.3 11.1 12 0.4J <1 NA
02/20/14 0.3J 0.1J <0.5 0.5J 45 1.3 <0.5 NA
03/31/15 <0.1 <0.1 0.3J 1.3 11 0.4J <0.1 NA
05/16/16 <0.1 <0.1 <0.1 <0.1 10 0.3J <0.1 NA
09/15/20 <0.50 1.4 <0.50 1.6 <0.50 <0.50 <0.50 NA
12/16/94 ND 2.3 1.9 13 35 9.6 NA NA
06/22/95 ND ND ND ND ND ND NA NA
04/19/96 <1.0 <1.0 <1.0 <1.0 2.4 10.0 NA NA
10/29/98 476 <1.0 65.7 <1.0 <1.0 <1.0 NA 9
10/19/99 8.4 <1.0 1.3 1.3 5.8 <5.0 <0.020 <3.0
05/03/00 2.1 <1.0 <1.0 <1.0 3.0 2.1 <0.020 <3.0
11/30/00 1.7 <1.0 <1.0 <1.0 5.5 5.1 <0.020 <3.0
03/27/01 2.3 <1.0 <1.0 <1.0 8.7 8.0 <0.020 <3.0
06/14/01 1.7 <1.0 <1.0 <1.0 6.6 <5.0 <0.020 <3.0
09/06/01 <1.0 <1.0 <1.0 <1.0 <5.0 <5.0 <0.020 <3.0
12/11/01 <1.0 <1.0 <1.0 <1.0 <5.0 <5.0 <0.020 4.2
02/07/02 <1.0 <1.0 <1.0 <1.0 <5.0 <5.0 <0.020 3.2
05/08/02 <1.0 <1.0 <1.0 <1.0 <5.0 <5.0 <0.020 3.8
08/06/02 <1.0 <1.0 <1.0 <1.0 <5.0 <5.0 <0.020 <3.0
11/19/02 47 5.4 1.6 5.1 27 6 <0.020 3.8
02/25/03 3,500 750 900 1,300 400 <250*<0.020 <3.0
05/20/03 850 <10 410 31 570 <50 <0.020 <3.0
08/25/03 600 530 1,000 1,900 1,700 <50 <0.020 4.0
02/20/04 1,400 260 1,100 2,800 830 25 <2 NA
08/26/04 1,100 66 1,400 2,129 540 27 <50 NA
02/15/05 810 40 1,200 440 410 11 <1 NA
08/10/05 440 17 650 52 360 9.1 <5 NA
03/02/06 460 10 15 18 470 11 <5 NA
08/08/06 220 8 1 14 300 10 <1 NA
02/19/07 22 <0.7 <0.8 2 30 9 <1 NA
10/16/07 <0.5 <0.7 <0.8 <0.8 9 7 <1 NA
04/23/08 9.8 4.5J 3.4J 6.3J 2.7J 4.8J <5 NA
10/22/08 0.87 <0.1 <0.1 0.68 1.9 3.4 <0.1 NA
04/16/09 15 0.31 <0.1 3.5 2.8 5.4 <0.1 NA
11/23/09 0.28 <0.1 <0.1 <0.2 1.8 4 <0.1 NA
06/16/10 <0.1 <0.1 <0.1 <0.2 3.9 3.2 <0.1 NA
08/04/11 <0.1 <0.1 <0.1 <0.1 0.57 2 <0.1 NA
02/15/12 <0.5 <0.5 <0.5 <0.5 0.6 2.1 <0.5 NA
10/24/12 <0.5 <0.5 <0.5 0.2J 0.5J 1.8 <0.5 NA
07/22/13 <0.5 <0.5 <0.5 <0.5 0.7 1.5 <0.5 NA
02/20/14 <0.5 <0.5 <0.5 <0.5 0.6 1.9 <0.5 NA
03/31/15 <0.1 <0.1 <0.1 <0.1 0.5 1.6 <0.1 NA
05/16/16 <0.1 <0.1 <0.1 <0.1 0.7 1.6 <0.1 NA
09/15/20 499 21.3 43.7 190 13.8 8.8 <5.0 NA
1 600 600 500 20 70 0.02 15
51 11 97 670 690 13,000 0.31 25
5,000 260,000 84,500 85,500 20,000 70,000 50 15,000
Notes:
1. MTBE = Methyl Tertiary Butyl Ether
2. IPE = Isopropyl Ether
3. EDB = Ethylene Dibromide (1,2-Dibromoethane)
4. "<" or ND = Not Detected at or above the laboratory reporting limit
5. Concentrations are reported in micrograms per liter (ug/l) = parts per billion (ppb)
6. Concentrations in bold equal or exceed the corresponding NCDEQ Groundwater Quality 2L Standard or Surface Water Quality 2B Standard
7. GCL = Gross Contamination Limit
8. NE = Not Established
9. NS/FP = Not Sampled/Free Product
10. "J" indicates concentration is above method detection limit but below reporting limit
Not Sampled
2L Standard
GCL
Well Abandoned
MW-5
2B Standard
MW-6
MW-5R
Page 3 of 7
TABLE 3
HISTORICAL GROUNDWATER ANALYTICAL RESULTS
FORMER CONOCO STORE #33047 (RM #6182)
1122 EAST RALEIGH BOULEVARD
ROCKY MOUNT, EDGECOMBE COUNTY, NORTH CAROLINA
ATC PROJECT NO. P666182414
Well ID Date
Sampled Benzene Toluene Ethyl-
benzene
Total
Xylenes MTBE IPE EDB Lead
12/16/94 8,500 10,000 1,300 5,000 34,000 760 NA NA
06/22/95 1,400 920 350 490 6,200 180 NA NA
04/19/96 120 <50.0 <50 <50 6,780 95 NA NA
10/29/98 <1.0 <1.0 <1.0 <1.0 158 38 NA <3.0
10/19/99 12 3.9 17 11 230 25 <0.020 <3.0
05/03/00 320 28 <25 35 310 59 <0.020 <3.0
11/30/00 <1.0 2.5 <1.0 <1.0 42 53 <0.020 <3.0
03/27/01 <1.0 2.5 <1.0 <1.0 84 41 <0.020 <3.0
06/14/01 1.5 2.3 <1.0 <1.0 30 32 <0.020 <3.0
09/06/01 <1.0 <1.0 <1.0 <1.0 <5.0 32 <0.020 <3.0
12/11/01 <1.0 <1.0 <1.0 <1.0 13 20 <0.020 <3.0
02/07/02 <1.0 <1.0 <1.0 <1.0 15 21 <0.020 <3.0
05/08/02 <1.0 <1.0 <1.0 <1.0 <5.0 34 <0.020 <3.0
08/06/02 <1.0 <1.0 <1.0 <1.0 <5.0 25 <0.020 <3.0
11/19/02 <1.0 <1.0 <1.0 <1.0 5.4 19 <0.020 2.8J
02/25/03 <1.0 <1.0 <1.0 <1.0 31 9.4 <0.020 5.5
05/20/03 <1.0 <1.0 <1.0 <1.0 11 <5.0 <0.020 <3.0
08/25/03 <1.0 <1.0 <1.0 <1.0 320 <5.0 <0.020 <3.0
02/20/04 <0.5 <0.7 <0.8 <0.8 2 4 <1 NA
08/26/04 <1 <1 1.8 2.9 <8 2 <1 NA
02/15/05 <5 <5 <5 <5 9.7 6.6 <1 NA
08/10/05 <1 <1 <1 <1 6.9 15 <1 NA
03/02/06 <1 <1 <1 <1 2.3 4 <1 NA
08/08/06 2 <0.7 <0.8 <0.8 18 42 <1 NA
02/19/07 <0.5 <0.7 <0.8 <0.8 0.5 2 <1 NA
10/16/07 <0.5 <0.7 <0.8 <0.8 2 2 <1 NA
04/23/08 <1 <5 <5 <10 <5 1.1J <5 NA
10/21/08 <0.1 <0.1 <0.1 <0.1 2.8 21 <0.1 NA
04/15/09 1.9 <0.1 <0.1 <0.1 4.4 38 <0.1 NA
11/23/09 0.46 <0.1 <0.1 <0.2 8.4 38 <0.1 NA
06/16/10 3 <0.1 <0.1 <0.1 11 49 <0.1 NA
08/04/11 <0.1 <0.1 <0.1 <0.1 4.1 33 <0.1 NA
02/15/12 <0.5 <0.5 <0.5 <0.5 3 23 <0.5 NA
10/24/12 <0.5 <0.5 <0.5 0.1J 3.1 25 <0.5 NA
07/22/13 0.1J <0.5 <0.5 0.1J 2.6 24 <0.5 NA
02/20/14 <0.5 <0.5 <0.5 <0.5 2.9 31 <0.5 NA
03/31/15 0.2J <0.1 <0.1 0.1J 1.7 23 <0.1 NA
05/16/16 <0.1 <0.1 <0.1 <0.1 1.7 24 <0.1 NA
09/15/20 583 86.6 45.2 304 20.4 26.3 <5.0 NA
12/16/94 NA NA NA NA NA NA NA NA
06/22/95 350 70 10 40 4,500 50 NA NA
04/19/96 505 80 <50 <50.0 7,520 125 NA NA
10/29/98 66 <1.0 <1.0 <1.0 68 40 NA <3.0
10/19/99 300 7.7 26 35 120 67 <0.020 <3.0
05/03/00 370 <25 <25 53 170 35 <0.020 <3.0
11/30/00 73 2.7 1.2 <1.0 120 71 <0.020 <3.0
03/27/01 48 8.7 2.0 6 60 66 <0.020 <3.0
06/14/01 <1.0 1.3 <1.0 <1.0 120 D 45 <0.020 <3.0
09/06/01 <1.0 <1.0 <1.0 5.1 410 <5.0 <0.020 29
12/11/01 8.5 <1.0 <1.0 5.1 220 8.8 <0.020 5
02/07/02 <1.0 <1.0 <1.0 <1.0 110 9 <0.020 4.4
05/08/02 <1.0 <1.0 <1.0 <1.0 240 15 <0.020 5.3
08/06/02 <1.0 <1.0 <1.0 <1.0 86 34 <0.020 <3.0
11/19/02 <1.0 <1.0 <1.0 <1.0 150 20 <0.020 3.7
02/25/03 <1.0 <1.0 <1.0 <1.0 44 <5.0 <0.020 8.8
05/20/03 <1.0 <1.0 <1.0 6.8 5 <5.0 <0.020 <3.0
08/25/03 <1.0 <1.0 <1.0 <1.0 440 <5.0 <0.020 3.3
02/20/04 <0.5 <0.7 <0.8 <0.8 8 0.9 <1 NA
08/26/04 <1 <1 <1 <1 <8 <1 <1 NA
02/15/05 <5 <5 <5 <5 <5 7.1 <1 NA
08/10/05 <1 <1 <1 <1 1 7.3 <1 NA
03/02/06 <1 <1 <1 <1 5.7 7.3 <1 NA
08/08/06 0.7 <0.7 <0.8 <0.8 7 10 <1 NA
02/19/07 <0.5 <0.7 <0.8 <0.8 1 3 <1 NA
10/16/07 <0.5 <0.7 <0.8 <0.8 4 13 <1 NA
04/23/08 <1 <5 <5 <10 2.4J 8.2 <5 NA
10/22/08 4.8 <0.1 <0.1 0.22 2.4 9.7 <0.1 NA
04/16/08 <0.1 <0.1 <0.1 <0.1 1.9 13 <0.1 NA
11/23/09 <0.1 <0.1 <0.1 <0.2 2.1 9.2 <0.1 NA
06/16/10 <0.1 <0.1 <0.1 <0.2 4.9 12 <0.1 NA
08/04/11 <0.1 <0.1 <0.1 <0.1 1.6 11 <0.1 NA
02/15/12 <0.5 <0.5 <0.5 <0.5 1.5 12 <0.5 NA
10/24/12 <0.5 <0.5 0.1J 0.4J 1.3 8.3 <0.5 NA
07/22/13 <0.5 <0.5 <0.5 <0.5 1.3 7.9 <0.5 NA
02/20/14 <0.5 <0.5 <0.5 <0.5 1.4 9 <0.5 NA
03/31/15 <0.1 <0.1 <0.1 <0.1 1.2 5.2 <0.1 NA
05/16/16 <0.1 <0.1 <0.1 <0.1 1.8 9.9 <0.1 NA
09/15/20
1 600 600 500 20 70 0.02 15
51 11 97 670 690 13,000 0.31 25
5,000 260,000 84,500 85,500 20,000 70,000 50 15,000
Notes:
1. MTBE = Methyl Tertiary Butyl Ether
2. IPE = Isopropyl Ether
3. EDB = Ethylene Dibromide (1,2-Dibromoethane)
4. "<" or ND = Not Detected at or above the laboratory reporting limit
5. Concentrations are reported in micrograms per liter (ug/l) = parts per billion (ppb)
6. Concentrations in bold equal or exceed the corresponding NCDEQ Groundwater Quality 2L Standard or Surface Water Quality 2B Standard
7. GCL = Gross Contamination Limit
8. NE = Not Established
9. NS/FP = Not Sampled/Free Product
10. "J" indicates concentration is above method detection limit but below reporting limit
MW-7A
Well blocked, not sampled.
MW-7
2B Standard
2L Standard
GCL
Page 4 of 7
TABLE 3
HISTORICAL GROUNDWATER ANALYTICAL RESULTS
FORMER CONOCO STORE #33047 (RM #6182)
1122 EAST RALEIGH BOULEVARD
ROCKY MOUNT, EDGECOMBE COUNTY, NORTH CAROLINA
ATC PROJECT NO. P666182414
Well ID Date
Sampled Benzene Toluene Ethyl-
benzene
Total
Xylenes MTBE IPE EDB Lead
12/16/94 ND ND ND 27 2,200 38 NA NA
06/22/95 ND ND ND ND 2,700 17 NA NA
04/19/96 <10 <10 10 13 3,420 41 NA NA
10/29/98 <1.0 <1.0 <1.0 <1.0 96 10 NA 33
10/19/99 120 310 620 1,100 88 <50 <0.020 <3.0
05/03/00 <1.0 <1.0 <1.0 <1.0 28 4 <0.020 6
11/30/00 <1.0 <1.0 <1.0 <1.0 20 <5.0 <0.020 <3.0
03/27/01 <1.0 <1.0 <1.0 <1.0 20 <5.0 <0.020 <3.0
06/14/01 <1.0 <1.0 <1.0 <1.0 18 5.4 <0.020 <3.0
09/06/01 <1.0 <1.0 <1.0 2 30 <5.0 <0.020 4.8
12/11/01 <1.0 <1.0 <1.0 <1.0 12 <5.0 <0.020 3.2
02/07/02 <1.0 <1.0 <1.0 <1.0 59 5.6 <0.020 6.0
05/08/02 <1.0 <1.0 <1.0 <1.0 17 5.6 <0.020 8.8
08/06/02 <1.0 <1.0 <1.0 <1.0 6.2 12 <0.020 <3.0
11/19/02 <1.0 1.3 0.32 J 0.44 J 2.0 J <5.0 <0.020 10
02/25/03 <1.0 <1.0 <1.0 <1.0 41 <5.0 <0.020 3.6
05/20/03 <1.0 <1.0 <1.0 <1.0 24 <5.0 <0.020 3.8
08/25/03 <1.0 <1.0 <1.0 <1.0 87 <5.0 <0.020 <3.0
02/20/04 <0.5 <0.7 <0.8 <0.8 <0.5 <0.8 <1 NA
08/26/04 <1 <1 <1 <1 <8 <1 <1 NA
02/15/05 <5 <5 <5 <5 11 <5 <1 NA
08/10/05 <1 <1 <1 <1 19 4 <1 NA
03/02/06 <1 <1 <1 <1 13 4.7 <1 NA
08/08/06 <0.5 <0.7 <0.8 <0.8 3 2 <1 NA
02/19/07 <0.5 <0.7 <0.8 <0.8 2 <0.8 <1 NA
10/16/07 <0.5 <0.7 <0.8 <0.8 5 3 <1 NA
04/23/08 <1 <5 <5 <10 2J <5 <5 NA
10/22/08 <0.1 <0.1 <0.1 <0.1 1.1 1 <0.1 NA
04/16/09 <0.1 <0.1 <0.1 <0.1 0.38 0.1 <0.1 NA
11/23/09 <0.1 <0.1 <0.1 <0.2 <0.2 0.13 <0.1 NA
06/16/10 <0.1 <0.1 <0.1 <0.2 6.8 8.5 <0.1 NA
08/04/11 <0.1 <0.1 <0.1 <0.1 1.4 2.4 <0.1 NA
02/15/12 <0.5 <0.5 <0.5 <0.5 1.2 2.5 <0.5 NA
10/24/12 <0.5 <0.5 <0.5 <0.5 1.4 2.0 <0.5 NA
07/22/13 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 NA
02/20/14 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 NA
03/31/15 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 NA
05/16/16 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 NA
09/15/20 775 226 211 594 <5.0 <5.0 <5.0 NA
12/16/94 NA NA NA NA NA NA NA NA
06/22/95 ND ND ND ND ND ND NA NA
04/19/96 <1.0 <1.0 <1.0 <1.0 1.8 <10 NA NA
10/29/98 17.9 <1.0 <1.0 12.6 28.8 <1.0 NA <3.0
10/19/99 <1.0 <1.0 <1.0 <1.0 <5.0 <5.0 <0.020 <3.0
05/03/00 1.2 <1.0 <1.0 <1.0 6.8 <1.0 <0.020 3.2
11/30/00 6.3 <1.0 <1.0 8.5 19 <5.0 <0.020 3.9
03/27/01 1.3 <1.0 <1.0 2.0 24 <5.0 <0.020 3.9
06/14/01 <1.0 <1.0 <1.0 <1.0 11 <5.0 <0.020 30
09/06/01 <1.0 <1.0 <1.0 <1.0 20 <5.0 <0.020 14
12/11/01 <1.0 <1.0 <1.0 <1.0 9 <5.0 <0.020 10
02/07/02 <1.0 <1.0 <1.0 <1.0 <5.0 <5.0 <0.020 11
05/08/02 <1.0 <1.0 <1.0 <1.0 5.2 <5.0 <0.020 5.1
08/06/02 <1.0 <1.0 <1.0 <1.0 5.5 <5.0 <0.020 <3.0
11/19/02 <1.0 0.39 J <1.0 <1.0 <5.0 <5.0 <0.020 <3.0
02/25/03 <1.0 <1.0 <1.0 <1.0 <5.0 <5.0 <0.020 <3.0
05/20/03 <1.0 <1.0 <1.0 <1.0 21 <5.0 <0.020 <3.0
08/25/03 <1.0 <1.0 <1.0 <1.0 68 <5.0 <0.020 <3.0
02/20/04 <0.5 <0.7 <0.8 <0.8 7 <0.8 <1 NA
08/26/04 <1 <1 <1 <1 100 <1 <1 NA
02/15/05 <5 <5 <5 <5 9.8 <5 <1 NA
08/10/05 <1 <1 <1 <1 49 <1 <1 NA
03/02/06 <1 <1 <1 <1 27 <1 <1 NA
08/08/06 <0.5 <0.7 <0.8 <0.8 40 <0.8 <1 NA
02/19/07 <0.5 <0.7 <0.8 <0.8 5 <0.8 <1 NA
10/16/07 <0.5 <0.7 <0.8 <0.8 5 <0.8 <1 NA
04/23/08 <1 <5 <5 <10 <5 <5 <5 NA
10/21/08 <0.1 <0.1 <0.1 <0.1 2.4 0.24 <0.1 NA
04/15/09 <0.1 <0.1 <0.1 <0.1 <0.2 <0.1 <0.1 NA
11/23/09 <0.1 <0.1 <0.1 <0.2 1.8 0.15 <0.1 NA
06/16/10 <0.1 <0.1 <0.1 <0.2 3.5 <0.1 <0.1 NA
08/04/11 <0.1 <0.1 <0.1 <0.1 0.33 0.12 <0.1 NA
02/15/12 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 NA
10/24/12 <0.5 <0.5 <0.5 <0.5 0.3J <0.5 <0.5 NA
07/22/13
02/20/14 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 NA
03/31/15 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 NA
05/16/16 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 NA
09/15/20
1 600 600 500 20 70 0.02 15
51 11 97 670 690 13,000 0.31 25
5,000 260,000 84,500 85,500 20,000 70,000 50 15,000
Notes:
1. MTBE = Methyl Tertiary Butyl Ether
2. IPE = Isopropyl Ether
3. EDB = Ethylene Dibromide (1,2-Dibromoethane)
4. "<" or ND = Not Detected at or above the laboratory reporting limit
5. Concentrations are reported in micrograms per liter (ug/l) = parts per billion (ppb)
6. Concentrations in bold equal or exceed the corresponding NCDEQ Groundwater Quality 2L Standard or Surface Water Quality 2B Standard
7. GCL = Gross Contamination Limit
8. NE = Not Established
9. NS/FP = Not Sampled/Free Product
10. "J" indicates concentration is above method detection limit but below reporting limit
GCL
2L Standard
Not Sampled
MW-9
2B Standard
Could not locate, not sampled
MW-8
Page 5 of 7
TABLE 3
HISTORICAL GROUNDWATER ANALYTICAL RESULTS
FORMER CONOCO STORE #33047 (RM #6182)
1122 EAST RALEIGH BOULEVARD
ROCKY MOUNT, EDGECOMBE COUNTY, NORTH CAROLINA
ATC PROJECT NO. P666182414
Well ID Date
Sampled Benzene Toluene Ethyl-
benzene
Total
Xylenes MTBE IPE EDB Lead
12/16/94 NA NA NA NA NA NA NA NA
06/22/95 ND ND ND ND 3,500 30 NA NA
04/19/96 <1.0 <1.0 <1.0 <1.0 37 <10 NA NA
10/29/98 60 <1.0 17 2 144 20 NA <3.0
10/19/99 <1.0 <1.0 <1.0 <1.0 5 <5.0 <0.020 <3.0
05/03/00 <1.0 <1.0 <1.0 <1.0 15 <1.0 <0.020 <3.0
11/30/00 <1.0 <1.0 <1.0 <1.0 59 <5.0 <0.020 <3.0
03/27/01 <1.0 <1.0 <1.0 <1.0 15 <5.0 <0.020 <3.0
06/14/01 <1.0 <1.0 <1.0 <1.0 56 <5.0 <0.020 <3.0
09/06/01 <1.0 <1.0 <1.0 <1.0 52 <5.0 <0.020 <3.0
12/11/01 <1.0 <1.0 <1.0 <1.0 31 <5.0 <0.020 <3.0
02/07/02 <1.0 <1.0 <1.0 <1.0 21 <5.0 <0.020 <3.0
05/08/02 <1.0 <1.0 <1.0 <1.0 19 <5.0 <0.020 <3.0
08/06/02 <1.0 <1.0 <1.0 <1.0 17 <5.0 <0.020 <3.0
11/19/02 <1.0 <1.0 <1.0 <1.0 17 <5.0 <0.020 2.1 J
02/25/03 <1.0 <1.0 <1.0 <1.0 <5.0 <5.0 <0.020 4.8
05/20/03 <1.0 <1.0 <1.0 <1.0 13 <5.0 <0.020 <3.0
08/25/03 <1.0 <1.0 <1.0 <1.0 91 <5.0 <0.020 5.8
02/20/04 <0.5 <0.7 <0.8 <0.8 50 <0.8 <1 NA
08/26/04 <1 <1 <1 <1 9 <1 <1 NA
02/15/05 <5 <5 <5 <5 <5 <5 <1 NA
08/10/05 <1 <1 <1 <1 2.8 1 <1 NA
03/02/06 <1 <1 <1 <1 3.9 <1 <1 NA
08/08/06 <0.5 <0.7 <0.8 <0.8 0.8 <0.8 <1 NA
02/19/07 <0.5 <0.7 <0.8 <0.8 1 <0.8 <1 NA
10/16/07 <0.5 <0.7 <0.8 <0.8 4 2 <1 NA
04/24/08 <1 <5 <5 <10 <5 <5 <5 NA
10/02/08 <0.1 0.61 <0.1 <0.1 1.5 2.9 <0.1 NA
04/15/09 <0.1 <0.1 <0.1 <0.1 <0.2 <0.1 <0.1 NA
11/23/09 <0.1 <0.1 <0.1 <0.2 0.67 0.86 <0.1 NA
06/16/10
08/04/11 <0.1 <0.1 <0.1 <0.1 <0.2 <0.1 <0.1 NA
02/15/12 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 NA
10/24/12 <0.5 <0.5 <0.5 <0.5 0.2J 0.5 <0.5 NA
07/22/13 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 NA
02/20/14 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 NA
03/31/15 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 NA
05/16/16 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 NA
09/15/20 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 NA
12/16/94 NA NA NA NA NA NA NA NA
06/22/95 ND ND ND ND ND ND NA NA
04/19/96 <1.0 <1.0 <1.0 <1.0 <1.0 <10 NA NA
10/29/98 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <3.0
10/19/99 <1.0 <1.0 <1.0 <1.0 <5.0 <5.0 <0.020 5
05/03/00 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <0.020 3
11/30/00 <1.0 <1.0 <1.0 <1.0 <5.0 <5.0 <0.020 <3.0
03/27/01 <1.0 <1.0 <1.0 <1.0 <5.0 <5.0 <0.020 <3.0
06/14/01 <1.0 <1.0 <1.0 <1.0 <5.0 <5.0 <0.020 3.7
09/06/01 <1.0 <1.0 <1.0 <1.0 <5.0 <5.0 <0.020 4.0
12/11/01 <1.0 <1.0 <1.0 <1.0 <5.0 <5.0 <0.020 3.2
02/07/02 <1.0 <1.0 <1.0 <1.0 <5.0 <5.0 <0.020 3.3
05/08/02 <1.0 <1.0 <1.0 <1.0 <5.0 <5.0 <0.020 4.9
08/06/02 <1.0 <1.0 <1.0 <1.0 <5.0 <5.0 <0.020 <3.0
11/19/02 <1.0 <1.0 <1.0 <1.0 <5.0 <5.0 <0.020 4.5
02/25/03 <1.0 <1.0 <1.0 <1.0 <5.0 <5.0 <0.020 4.9
05/20/03 1,600 7,200 910 5,300 <1,200 <1,200 <0.020 4.6
08/25/03 1,100 10,000 2,200 11,000 1,800 <1,200 <0.020 <3.0
02/20/04 520 900 1,100 4,400 1,100 3 <3 NA
08/26/04 100 4.3 130 12.8 200 28 <1 NA
02/15/05 970 <50 810 160 560 <50 <10 NA
08/10/05 1.1 <1 <1 <1 110 1.5 <1 NA
03/02/06 <1 <1 <1 <1 100 1.1 <1 NA
02/19/07 <0.5 <0.7 <0.8 <0.8 77 0.9 <1 NA
10/16/07 <0.5 <0.7 <0.8 <0.8 89 0.9 <1 NA
04/24/08 <1 <5 <5 <10 35 <5 <5 NA
10/21/08 <0.1 <0.1 <0.1 <0.1 99 0.88 <0.1 NA
04/15/09 <0.1 <0.1 <0.1 <0.1 <0.2 8.9 <0.1 NA
11/23/09 <0.1 <0.1 <0.1 <0.2 78 0.83 <0.1 NA
06/16/10 <0.1 <0.1 <0.1 <0.2 35 0.3 <0.1 NA
08/04/11 <0.1 <0.1 <0.1 <0.1 34 <0.1 <0.1 NA
02/15/12
10/24/12 <0.5 <0.5 <0.5 <0.5 36 0.3J <0.5 NA
07/22/13 <0.5 <0.5 <0.5 <0.5 10 <0.5 <0.5 NA
02/20/14 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 NA
03/31/15 <0.1 <0.1 <0.1 <0.1 2.9 <0.1 <0.1 NA
05/16/16 <0.1 <0.1 <0.1 <0.1 4.3 <0.1 <0.1 NA
09/15/20 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 NA
1 600 600 500 20 70 0.02 15
51 11 97 670 690 13,000 0.31 25
5,000 260,000 84,500 85,500 20,000 70,000 50 15,000
Notes:
1. MTBE = Methyl Tertiary Butyl Ether
2. IPE = Isopropyl Ether
3. EDB = Ethylene Dibromide (1,2-Dibromoethane)
4. "<" or ND = Not Detected at or above the laboratory reporting limit
5. Concentrations are reported in micrograms per liter (ug/l) = parts per billion (ppb)
6. Concentrations in bold equal or exceed the corresponding NCDEQ Groundwater Quality 2L Standard or Surface Water Quality 2B Standard
7. GCL = Gross Contamination Limit
8. NE = Not Established
9. NS/FP = Not Sampled/Free Product
10. "J" indicates concentration is above method detection limit but below reporting limit
Not Accessible
MW-10
MW-11
Not Sampled
2L Standard
2B Standard
GCL
Page 6 of 7
TABLE 3
HISTORICAL GROUNDWATER ANALYTICAL RESULTS
FORMER CONOCO STORE #33047 (RM #6182)
1122 EAST RALEIGH BOULEVARD
ROCKY MOUNT, EDGECOMBE COUNTY, NORTH CAROLINA
ATC PROJECT NO. P666182414
Well ID Date
Sampled Benzene Toluene Ethyl-
benzene
Total
Xylenes MTBE IPE EDB Lead
05/20/03 7,600 33,000 6,700 35,000 <5,000 <5,000 NA NA
08/25/03 <1,000 6,500 5,100 31,000 1,400 <5,000 <0.020 <3.0
02/20/04 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
08/26/04 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
02/15/05 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
08/10/05 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
03/04/06 860 4,800 1,400 8,200 450 <50 <50 NA
08/08/06 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
02/20/07 1,900 11,000 2,900 15,000 560 21 <20 NA
10/16/07 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
04/23/08 1,100 1,900 1,900 8,700 520 21J <100 NA
10/21/08 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
04/15/09 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
11/23/09 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
06/16/10 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
08/04/11 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
02/01/12 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
10/24/12 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
07/22/13 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
02/20/14 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
03/31/15 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
05/16/16 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
09/15/20 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
11/16/20 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
08/25/03 380 1,700 1,400 3,700 1,800 <500 <0.020 <3.0
02/20/04 790 1,000 1,400 3,800 670 18 <2 NA
08/26/04 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
02/15/05 950 <50 790 160 510 <50 <10 NA
08/10/05 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
03/02/06 830 7.9 120 32 350 20 <5 NA
08/08/06 160 3 160 34 120 17 <2 NA
02/20/07 32 2 140 29 5 14 <3 NA
10/16/07 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
04/23/08
10/21/08
04/16/06 <0.1 <0.1 <0.1 <0.1 38 0.44 <0.1 NA
11/24/09 <0.1 <0.1 <0.1 <0.2 0.63 4.2 <0.1 NA
06/16/10 <0.1 <0.1 <0.1 <0.2 <0.2 5.4 <0.1 NA
08/04/11 0.76 0.12 0.21 0.3 0.73 2.9 <0.1 NA
02/15/12 <5 <5 <5 <5 <5 2.3J <5 NA
10/24/12 <1 <1 <1 0.2J 0.5J 1.6 <1 NA
07/22/13 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
02/20/14 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
03/31/15 <2 <2 <2 <2 <2 3.7J <2 NA
05/16/16 <0.1 <0.1 <0.1 <0.1 1 4 <0.1 NA
09/15/20 NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP NS/FP
1 600 600 500 20 70 0.02 15
51 11 97 670 690 13,000 0.31 25
5,000 260,000 84,500 85,500 20,000 70,000 50 15,000
Notes:
1. MTBE = Methyl Tertiary Butyl Ether
2. IPE = Isopropyl Ether
3. EDB = Ethylene Dibromide (1,2-Dibromoethane)
4. "<" or ND = Not Detected at or above the laboratory reporting limit
5. Concentrations are reported in micrograms per liter (ug/l) = parts per billion (ppb)
6. Concentrations in bold equal or exceed the corresponding NCDEQ Groundwater Quality 2L Standard or Surface Water Quality 2B Standard
7. GCL = Gross Contamination Limit
8. NE = Not Established
9. NS/FP = Not Sampled/Free Product
10. "J" indicates concentration is above method detection limit but below reporting limit
Not Sampled/Obstruction in well
Not Sampled/Obstruction in well
MWHS-10
GCL
2L Standard
MWHS-11
2B Standard
Page 7 of 7

FIGURES
2725 E. Millbrook Road, Ste 121
Raleigh, NC 27604
[phone]
PROJECT NO: 45.75118.6182
DATE: 8/2011 REVIEWED BY: GA
Former Conoco Store #33047 (RM #6182)
1122 East Raleigh Boulevard
Rocky Mount, Edgecombe County, North Carolina
SOURCE: 1977 TOPOGRAPHIC MAP -MSRMAPS.COM.
SCALE: SEE ABOVE
FIGURE 1: SITE TOPOGRAPHIC MAP
N
SITE
N
CAD FILEPREP. BYTYPE CODEREV. BYSCALEPROJECT NO.TITLEDATENOTES: GEOTECHNICALENVIRONMENTAL MATERIALS TESTINGBUILDING SCIENCES2725 E. Millbrook Road, Suite 121(919) 871-0999 FAX [phone]Raleigh, North Carolina 27604
CAD FILEPREP. BYTYPE CODEREV. BYSCALEPROJECT NO.TITLEDATENOTES: GEOTECHNICALENVIRONMENTAL MATERIALS TESTINGBUILDING SCIENCES2725 E. Millbrook Road, Suite 121(919) 871-0999 FAX [phone]Raleigh, North Carolina 27604
CAD FILEPREP. BYTYPE CODEREV. BYSCALEPROJECT NO.TITLEDATENOTES: GEOTECHNICALENVIRONMENTAL MATERIALS TESTINGBUILDING SCIENCES2725 E. Millbrook Road, Suite 121(919) 871-0999 FAX [phone]Raleigh, North Carolina 27604
FIGURE 5
FORENSIC ANALYSIS

Former Conoco Store # 33047 (RM #6182)
1122 East Raleigh Boulevard
Rocky Mount, North Carolina
NCDEQ Incident No. 12609
Compound MW-1M Compound MW-3
Paraffinic 17.0 Paraffinic 15.1
Isoparaffinic 41.2 Isoparaffinic 38.7
Aromatic 24.8 Aromatic 31.2
Naphthenic 11.0 Naphthenic 10.7
Olefinic 6.0 Olefinic 4.3
Compound MWHS-10 Compound Premium Dispenser #3
Paraffinic 18.1 Paraffinic 12.0
Isoparaffinic 42.2 Isoparaffinic 44
Aromatic 24.4 Aromatic 32.2
Naphthenic 9.4 Naphthenic 6.8
Olefinic 5.9 Olefinic 5
MW-1M
Paraffinic Isoparaffinic Aromatic Naphthenic Olefinic
MW-3
Paraffinic Isoparaffinic Aromatic Naphthenic Olefinic
MWHS-10
Paraffinic Isoparaffinic Aromatic Naphthenic Olefinic
Premium Dispenser #3
Paraffinic Isoparaffinic Aromatic Naphthenic Olefinic

APPENDIX A

CHEMQUANTS ENVIRONMENTAL FORENSICS REPORT
[C] 305-342-2250
[e-mail]
ChemQuants,LLC
1338 Kenwood Rd.
Santa Barbara, CA 93109

Client: ATC
ATTN: Gabriel Araos
Project#: 0155
Project name: RM 6182
Laboratory#: L2050590

ChemQuants,LLC
Santa Barbara, CA 93109
www.ChemQuants.com
January 21 2021

Gabriel Araos CQ Project# 0155
ATC Project Name: RM 6182
2725 E. Millbrook Road, Suite 121
Raleigh, NC 27612
Introduction
ChemQuants, LLC is gratified to provide you with this report that focuses on the chemical
fingerprinting results conducted recently on behalf of ATC. The chemical fingerprinting analysis
was carried out on 4 NAPL samples. The client initiated the study to understand the chemical
source nature of the project samples' gasoline contamination. The objective of this interpretive
report was to characterize the petroleum signatures and estimate the time of release, if at all
possible.

Client ID Lab ID Date
Collected
Date
Received
Matrix C3-C44
Whole
Oil
GC/FID
C5-C12
VOC
Fingerprin
ting
Organic
Lead
Isomers
Total
Sulfur
Bulk Stable
Isotopes
Ethanol
MW-1M L2050590-01 11/16/2020 11/17/2020 Product X X X X
X

X
MW-3 L2050590-02 11/16/2020 11/17/2020 Product X X X X
X

X
MWHS-10 L2050590-03 11/16/2020 11/17/2020 Product X X X X
X

X
PREMIUM
DISPENSER
#3
L2050590-04 11/16/2020 11/17/2020 Product X X X X

X

X
The samples were delivered to Alpha Analytical, Inc. (Mansfield, MA) and analyzed with the
following analytical methods1:
1) Whole Oil fingerprinting by GC/FID / EPA 8015B (Mod.)
2) C5-C12 PIANO w/ Oxygenates and additives quantification and fingerprinting by GC/MS –
full scan mode / EPA 8260B (Mod.)
3) Organic lead Speciation by EPA 8270D (Mod.)
4) Ethanol by EPA 8270D (Mod.)
5) Carbon and Hydrogen Bulk Stable Isotopes
6) Sulfur in Petroleum by ASTM D4294

1 Douglas, G.D., Emsbo-Mattingly, S.D., Stout, S.A., Uhler, A.D., and McCarthy, K.J. (2007) Chemical
fingerprinting of hydrocarbons and polychlorinated biphenyls. In: Introduction to Environmental Forensics,
2nd Ed., B. Murphy and R. Morrison, Eds., Academic Press, New York, pp. 317-459.

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Investigative methodology
This report dealt with the analysis of two datasets. 1) The NAPL sample that was characterized by
fingerprinting methods. 2) Routine chemical data from the Site's groundwater monitoring
activities.
NAPL Samples
The forensics quality chemical data employed data analysis techniques typically used in a
subsurface gasoline forensics investigation. Weathering of the refined parent gasoline was
assessed with petroleum geochemistry molecular ratios 2 . Gasoline refinery process and
properties lines of evidence were applied and based on well-established process forensics
insights. These insights included historical knowledge of refiners' gasoline blending strategies of
hydrocarbon feedstocks and additives over time3. The characterization of gasoline released at
the Site relied on the diagnostic characterization of alkylate, isomerate, straight-run gasoline
(SRG), and reformate blendstock signatures. Also, environmental forensics characterization and
age constraining of the refined gasoline relied on presence/absence and assemblages of
oxygenate additives, organic lead additives, organic sulfur species, and total sulfur. Also,
solubility matched diagnostic ratios of saturate hydrocarbons, and C3+ mono-aromatics were
used as tools to compare the gasoline fingerprints 4. The solubility matched ratios were
developed from compound pairs of paraffin, isoparaffins, naphthenes, and C3+ mono-aromatics
that shared similar aqueous solubility properties (Sw).
BTEX and MTBE time-series data
Our investigation included groundwater data from MW-2, MW-4, MW-6, MW-7, MW-11, and
MWHS-10 that exhibited entrained gasoline signatures throughout the sampling program.
Regarding the selected subset of sample locations, free phase gasoline occurrence was limited
to MW-4 and MWHS-10. These data were subject to a systematic process of analysis, which
included the following techniques.
Time-series data from groundwater monitoring efforts can provide valuable supportive
information for the forensics practitioner5. The time series of the BTEX, MTBE, and DIPE offered
useful information to help evaluate: 1) potential chemical source(s) 2) the state of gasoline
dissolution - whether the gasoline may be entrained as a free product phase or part of a more
dissolved phase plume 3) correlations of diagnostic dissolved phase chemistry (Benzene, MTBE,
DIPE, etc.) 4) potential impact of remediation events 5) possible new or ongoing release(s). BTEX
composition was reviewed as time series bar graphs (top) and line plots (middle) (figures 5-10).
BTEX grouped bar graphs were based on relative mole fraction calculations w/overlaid line plots
of Rb (BTEX ratio B+T/E+X).
Essentially, relative mole fractions normalize the absolute concentration data to help reduce
partitioning between NAPL and water. The normalization allows for the comparison between
groundwater samples, and between NAPL and groundwater samples. The BTEX concentrations
were used concurrently with the relative mole fraction data to help recognize the potential input

2 Peters, K. E., C. C. Walters, and J. M. Moldowan. The biomarker guide: Volume 2, Biomarkers and isotopes in
petroleum systems and earth history. Cambridge University Press, 2007.
3 Stout, Scott A., Gregory S. Douglas, and Alen D. Uhler. "Automotive gasoline." Environmental Forensics Contaminant
Specific Guide (2006): 465-531.
4 Sauer, Ted C., and Helder J. Costa. "Fingerprinting of gasoline and coal tar NAPL volatile hydrocarbons dissolved in
groundwater." Environmental Forensics 4.4 (2003): 319-329.
5 Stout, Scott A., Gregory S. Douglas, and Allen D. Uhler. "Assessing temporal and spatial variations of gasoline-
impacted groundwater using relative mole fractions and PIANO fingerprinting." Environmental Forensics 11.4 (2010):
328-341.

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of "fresher" gasoline (newer release or remobilized less weathered gasoline), or the input of
more dissolved phase benzene and MTBE chemistry. The groundwater samples served as
additional evidence for the source and age constraining of the new fingerprinted samples
collected from the Site.

Results and Discussion
LNAPL Samples (L2050590)
Weathering Properties
Chemical alteration due to disolution was assessed by comparing key pairs of more water-
soluble compounds with less soluble isomers. Both dissolution ratios share similar volatility
properties (Table 1, ratio 3, 4). The BTEX ratio served as a dissolution ratio (Table 1 ratio 13).
Evaporative weathering was assessed by comparing the relationship of more volatile compounds
about less volatile isomers. Both pairs of evaporation ratios share similar aqueous solubility
properties (Table 1 ratio 1, 2). The evaporation ratios presented in table 1, visualized in figure 2
(top) and figure 1 indicate that the parent gasoline in MW-3 experienced slight evaporation. The
dissolution ratios and their corresponding visualizations in figure 2 (top) indicate that the project
samples were less than slightly impacted by dissolution forms of weathering.
Refining Properties
Evaluations of diagnostic refinery and additives blending features of spilt gasoline are at the
heart of a forensics investigation since gasoline refineries have changed blending strategies over
time due to a myriad of regulatory-driven, and technology innovation-driven factors.
Alkylate Properties - The alkylation process produces alkylate, (dominated by trimethylpentane
isomers - TMP), a valuable blendstock to the refiner as it significantly enhances the octane rating
in the gasoline. Alkylate abundance is often reinforced by a refiner to produce premium
gasoline. Thus, alkylate abundance is one of the variables that are altered in gasoline for octane
adjusting. During the lead phase down period in the U.S alkylate, gasoline was progressively
added to offset reductions and eventual elimination of organic lead additives. Ratios 5 and 7 of
Table 1 reflect the abundance of the alkylate feedstock. Ratio six indicates the character of
alkylate in the parent gasoline. All environmental product samples (L2050590-01 to 03) exhibited
abundance values (ratio 5) between 0.68 and 0.7, while L2050590-04 expressed a value of 0.9.
The alkylated ratios are also presented as star plots in figure 2 (bottom). These alkylate
abundance ratios indicate that the environmental samples 01 to 03 were likely moderately
enriched alkylate gasoline products and the dispenser collected sample 04 was a high alkylate
gasoline. Regarding the alkylate feedstock character, all of the samples exhibited ratio values
between 0.51 and 0.55, which suggest that the gasoline products were manufactured with a
hydrofluoric catalyzed alkylation unit.
SRG, Reformate, and Isomerate Properties - Differential blending and reformulation strategies
of these feedstocks varied overtime at refineries and were triggered by the need for octane and
quality enhancement of gasoline6. Isomerization rearranges straight-chain paraffin to branched
isoparaffins and produces isomerate feedstock. Some isomerate diagnostic aspects were
demonstrated in patterns of C5-C8 isoparaffins (Figure 1 – isoparaffins-red bars). However, low
in octane value, gasoline production's primary distillation products are straight-run gasoline
(SRG). SRG can be relatively light or heavy and serve as intermediary mixtures to produce other
feedstocks. The product of catalytic reforming, reformates, are also significant blendstocks for

6 Speight, James G. The chemistry and technology of petroleum. CRC press, 2014.

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the manufacture of gasoline. Reformates are typically blended directly into gasoline, and the
proportions between many of the mono-aromatics may provide diagnostic information on the
reforming conditions (Figure 1 – primarily green & black bars).
Seven diagnostic ratios (Table 1 ratios 7-14) and a qualitative review of the isomerate, straight-
run gasoline (SRG), and reformate feedstock features were used to evaluate their overall
abundances and characteristics. Due to documented changes in refinery processes and
technologies over time, the relationships between these feedstock properties can provide
diagnostic information for the characterization and age constraining of refined gasoline. Ratio 10
is diagnostic for isomerate abundance, while Ratios 8 and 9 are diagnostic measures of SRG
abundance. Ratios 11 and 12 are diagnostic for the proportion of reformate in parent gasoline.
All of the samples collected from environmental wells (01 – 03) exhibited lower isomerate,
reformate, and conversely higher SRG attributes than the dispenser collected sample 04. These
diagnostic attributes are presented visually in the star plot in figure 2 (bottom) Regarding
differences between the samples collected from the environmental wells 01 to 03, samples 01
and 02 were compositional matches. Sample 03 expressed similar isomerate and reformate
properties, yet more SRG enriched (figure 2 bottom). This SRG distinction in 03 could have
stemmed from mixing in the subsurface with a different gasoline (figure 2 bottom).
Total Sulfur Properties – Total sulfur was determined by ASTM D4294. The sulfur values in all
samples were less than 2005 tier 2 gasoline and more than the tier 3 2017 limits of 80 ppb
(Table 1). Given that sample 04 was a dispenser sample collected in 2020, these data suggest
that the gasoline utilized in this service station was possibly from a small refinery with a sulfur
limit exemption. Sample 03 exhibited the highest sulfur concentration of the project sample set.
Bulk Stable Isotopes – Bulk stable isotopes of carbon and hydrogen were measured in this
project. The results are listed in table 1 and visualized as a scatter plot in figure 4. The resulting
fractionation values indicated that the dispenser collected sample was the most "genetically"
distinct gasoline. Also, sample 03 exhibited an isotopic signature distinctive from the other
samples collected from environmental wells (figure).
Chemical Solubility Matched Ratios – Diagnostic ratios of compounds that share similar
solubility, and volatility properties were calculated for the project samples. The resulting values
are shown as star plots in figure 3. Figure 3 (top) presents ratios composed of saturate
hydrocarbons, while figure 3 (bottom) presents ratios consisting of C3 to C4 monoaromatic
compounds. Figure 3 (top) shows that the main distinction in the nC5-nC9 saturate hydrocarbons
fingerprint was driven by ratios that reflect alkylate feedstock abundances. In contrast, figure 3
(bottom) suggests that all project samples share similar reformate fingerprint attributes. These
ratio diagnostics results indicate that the project gasoline samples were likely manufactured at
the same refinery. As such, the specific differences shown in the previous sections likely
stemmed from differential feedstock finishing strategies and mixing in the environment.
Source Characterization of BTEX, MTBE time-series data
This section addresses time-series groundwater data for MW-2, MW-3, MW-4, MW-6, MW-7,
MW-11, and MWHS-10. The time-series study's central aim was to understand the potential
chemical source signature identities as a function of BTEX dissolution characteristics and
concentration trends. The principal purpose of this section is to diagnose the dynamics of BTEX,
MTBE, and DIPE occurrences and to serve as an additional line of evidence for signalling
potential impacts from differential fugitive release time frames.
MW-2 exhibited concentration trends - concentrations of BTEX and MTBE trended toward a
more dissipated state. Also, the chemistry in the well trended toward a more weathered state
(figure 5). The free product did not occur in the well during the extent of the routine monitoring

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campaign. The BTEX signature (high concentrations/toluene enriched relative to xylenes) from
the earliest collection event in MW-2 suggests that a fugitive release may have occurred on or
before 1994. MW-4 and MW-7 exhibit occurrence events in on or before 1994.
MW-2 (figure 5), MW-3 (figure 6), MW-4 (figure 7), MW6 (figure 8), MW-11 (figure 10), and
MWHS-10 (figure 11) showed occurrence events of free phase, entrained or more dissolved
phase gasoline in 2002 to 2003. A qualitative review of MTBE and BTEX correlation factors, in
addition to weathered state attributes, suggest that the occurrence events in 2003 were likely
not MTBE containing or significantly dissipated by aqueous dissolution. These lines of evidence
indicate that an independent release may have occurred in the proximity of 2002.
MW-4 (figure 7), MW-3 (figure 6), and MW-6 (figure 8) showed events of gasoline in 2003 to
2004 that were significantly more dissipated by aqueous solubility as well as more correlated to
MTBE concentrations. These observations may suggest that the higher concentration events in
these periods were from remobilization of the 1994 era release.
Extended Discussion
Free product thickness was measured in 2020 from wells MW-3, MW-4, MW-1M (figure not
shown), MWHS-11 (figure not shown), and MWHS11. Products from these wells were collected in
2020 for this forensics report. This forensics report's main objective is to opine on the potential
source and time of the release of these product samples.
The following lines of evidence must first be presented before laying out the forensics opinions:
1) A release of gasoline was confirmed in 2018 (incident communicated to CQ by client);
however, neither chemical data nor free product thickness was determined until 2020.
2) The gasoline product collected from the dispenser for forensics (L2050590-04) was not
representative of the confirmed 2018 release – the dispenser product was collected in 2020.
3) A fugitive release may have occurred circa 1994. The most observable weathered aspect of
this potential release is evident in the concentration events that were likely from remobilization –
MW-4 (August 26, 2004), MW-6 (February 20, 2004). The average Rb (BTEX) ratio for these
events is 0.37.
4) A fugitive release may have occurred circa 2002. The most observable weathered aspect of
this potential release is evident in the concentration events – MW-4 (February 19, 2004), MW-11
(May 20, 2003). The average Rb (BTEX) ratio for these events is 1.19.

ChemQuants,LLC
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Conclusion
In this report, multiple lines of evidence were presented to support an age constraint opinion on
the product samples collected in 2020. CQs opinion of 2020 collected NAPLs was likely
manufactured at the same refinery as sample 04 collected from the dispenser in 2020.
Nonetheless, the gasoline collected from the environmental wells – samples 01 to 03 – were not
identical to the source material of sample 04. The preponderance of evidence suggests that the
gasoline in sample 03 was a mixture of the gasoline expressed in the product samples 01 and
02, with a more SRG enriched and likely more weathered earlier release era gasoline on Site. It is
unlikely that gasoline's dominant aspects in samples 01, 02, and 03 were related to the 1994 era
release. Therefore the principal question is was the gasoline in 01, 02, and 03 related to the
2002 era release or the chemically undocumented presumed release of 2018. The slight
differences of the BTEX mole fraction distributions between the dispenser sample 04 and
product samples 01, 02, and 03 (figure 12) - in the context of the overall forensics lines of
evidence presented in this report - indicates that the dominant aspects of the gasoline free
product samples were more likely related to a circa 2018 release, that a remobilized product
from a circa 2002 release.
You may email any questions or concerns to [e-mail]
regarding chemistry data or interpretation.
Respectfully submitted,

Mark Jonathan Cejas
Principal

ChemQuants,LLC
Santa Barbara, CA 93109
www.ChemQuants.com

Table 1. Diagnostic ratios and bulk properties of the project samples.

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Figure 1. VOC PIANO bar graphs for the project samples.

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Figure 2. Star plot of evaporation ratios (top), diagnostic ratios (bottom).

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Figure 3. Star plot of saturate solubility matched ratios (top), monoaromatics solubility matched ratios (bottom).

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Figure 4. Scatter plot of bulk stable isotopes.

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Figure 5. Displaying time series BTEX data as mole ratios – left y-axis – and BTEX data as BTEX ratio Rb= (B+T) /
(E+X) – right axis (Top) ). Line chart for MW-2. Displaying Toluene concentration – left axis – and xylenes
concentration – right axis (third). Line chart for MW-2. Displaying Benzene concentration – left axis – and MTBE -
right axis (fourth). Line chart for MW-2. Displaying Benzene concentration – left axis – and DIPE - right axis (fourth).

ChemQuants,LLC
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Figure 6. Displaying time series BTEX data as mole ratios – left y-axis – and BTEX data as BTEX ratio Rb= (B+T) /
(E+X) – right axis (Top) ). Line chart for MW-2. Displaying Toluene concentration – left axis – and xylenes
concentration – right axis (third). Line chart for MW-2. Displaying Benzene concentration – left axis – and MTBE -
right axis (fourth). Line chart for MW-2. Displaying Benzene concentration – left axis – and DIPE - right axis (fourth).

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Figure 7. Displaying time series BTEX data as mole ratios – left y-axis – and BTEX data as BTEX ratio Rb= (B+T) /
(E+X) – right axis (Top). ). Line chart for MW-4. Displaying Toluene concentration – left axis – and xylenes
concentration – right axis (third). Line chart for MW-4. Displaying Benzene concentration – left axis – and MTBE -
right axis (fourth). Line chart for MW-4. Displaying Benzene concentration – left axis – and DIPE - right axis (fourth).

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Figure 8. Displaying time series BTEX data as mole ratios – left y-axis – and BTEX data as BTEX ratio Rb= (B+T) /
(E+X) – right axis (Top). ). Line chart for MW-6. Displaying Toluene concentration – left axis – and xylenes
concentration – right axis (third). Line chart for MW-6. Displaying Benzene concentration – left axis – and MTBE -
right axis (fourth). Line chart for MW-6. Displaying Benzene concentration – left axis – and DIPE - right axis (fourth).

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Figure 9. Displaying time series BTEX data as mole ratios – left y-axis – and BTEX data as BTEX ratio Rb= (B+T) /
(E+X) – right axis (Top). ). Line chart for MW-7. Displaying Toluene concentration – left axis – and xylenes
concentration – right axis (third). Line chart for MW-8. Displaying Benzene concentration – left axis – and MTBE -
right axis (fourth). Line chart for MW-9. Displaying Benzene concentration – left axis – and DIPE - right axis (fourth).

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Figure 10. Displaying time series BTEX data as mole ratios – left y-axis – and BTEX data as BTEX ratio Rb= (B+T) /
(E+X) – right axis (Top). ). Line chart for MW-11. Displaying Toluene concentration – left axis – and xylenes
concentration – right axis (third). Line chart for MW-11. Displaying Benzene concentration – left axis – and MTBE -
right axis (fourth). Line chart for MW-11. Displaying Benzene concentration – left axis – and DIPE - right axis (fourth).

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Figure 11. Displaying time series BTEX data as mole ratios – left y-axis – and BTEX data as BTEX ratio Rb= (B+T) /
(E+X) – right axis (Top). ). Line chart for MWHS-11. Displaying Toluene concentration – left axis – and xylenes
concentration – right axis (third). Line chart for MWHS-11. Displaying Benzene concentration – left axis – and MTBE -
right axis (fourth). Line chart for MWHS-11. Displaying Benzene concentration – left axis – and DIPE - right axis
(fourth).

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Figure 12. Displaying BTEX data from the 2020 LNAPL collection as mole ratios