WS-2275_30114_CA_RPTS_20220613

CONTAMINANT FATE AND TRANSPORT
MODELING REPORT
Arlington Branco Oil Company (Incident # 30114)
270 North Main Street
Jonesville, Yadkin County, North Carolina
December 10, 2021
Revised June 13, 2022
Terracon Project No. 75217015

Prepared for:
North Carolina Department of Environmental Quality
Division of Waste Management
Raleigh, North Carolina

Prepared by:
Terracon Consultants, Inc.
Charlotte, North Carolina

Table of Contents
A. SITE INFORMATION ............................................................................................... 1
B. EXECUTIVE SUMMARY .......................................................................................... 2
C. SITE HISTORY AND CHARACTERIZATION .......................................................... 5
C.1 Site Setting ....................................................................................................................................... 5
C.2 Release Summary ........................................................................................................................... 5
C.3 Previous Investigations .................................................................................................................. 6
C.4 Water Supply Wells ......................................................................................................................... 9
C.5 Surface Water .................................................................................................................................. 9
C.6 Land Use Information ..................................................................................................................... 9
D. ASSESSMENT INFORMATION ......................................................................... 10
D.1 Site Geology and Hydrogeology ....................................................................................................... 10
E. AQUIFER TESTING ............................................................................................... 11
F. GROUNDWATER MODELING .............................................................................. 12
G. CONCLUSIONS AND RECOMMENDATIONS ................................................... 14
FIGURES
Figure 1: Site Location Map
Figure 2: Site Plan (from previous reporting)
Figure 3 (shown as Figure 8 from previous reporting): Water Supply Well Location Map
Figure 4: Mann Kendall Analysis – Benzene

TABLES
Table 1: Water Supply Well Information (from previous reporting)
Table 2 (shown as Table 1 from previous reporting): Summary of Groundwater Analytical
Results
Table 3: Monitoring Well Construction Information and Historical Groundwater Elevations

APPENDIX
Appendix A: AQTESOLV Results
Appendix B: RBCA Toolkit Model Results
Arlington Branco Oil Company
Jonesville, North Carolina
Project Number 75217015
Incident No. 30114
December 10, 2021
Revised: June 13, 2022

Responsive ■ Resourceful ■ Reliable 1
CONTAMINANT FATE AND TRANSPORT MODELING
REPORT
A. SITE INFORMATION
Date of Report: December 10, 2021
NCDEQ Incident No: 30114
Facility ID: 0-002821
Site Name: Arlington Branco Oil Company
Site Location: 270 North Main Street, Jonesville, Yadkin County, North Carolina

Latitude / Longitude: N 36.22979 W -80.8393

UST Owner/Operator: Mr. Clay Oliver

Current Property Owner: Matt Cruz
270 N. Main Street
Jonesville, North Carolina 28642
[phone]

Current Property
Occupant: Jordan’s Pit Stop
270 North Main Street
Jonesville, North Carolina 28642

Consultant: Terracon Consultants, Inc. (Contact: Mark Miller)
7327-G West Friendly Avenue
Greensboro, North Carolina 27410
[phone]

Laboratory: Pace Analytical (NCDEQ No. 5342)
9800 Kincey Avenue
Huntersville, North Carolina 28028
704-875-9092

Release Information: Release Date: Unknown, discovered 1994
Estimated Quantity: Unknown
Cause of Release: UST System
Currently Active Tanks: None
Arlington Branco Oil Company
Jonesville, North Carolina
Project Number 75217015
Incident No. 30114
December 10, 2021
Revised: June 13, 2022

Responsive ■ Resourceful ■ Reliable 3

The results of the slug testing indicated hydraulic conductivity values of approximately 113.2 and
201.3 feet per year (ft/yr) for the slug-in tests and 5,492.5 ft/yr for the slug-out test. The average
hydraulic conductivity based on these data is approximately 1,935.66 ft/yr. The boring log for well
MW-5, installed by Schnabel Engineering in 2006, indicates the well screen (11 to 16 ft below land
surface [bls]) was installed entirely within competent gneiss bedrock (10 to 16 ft bls). As such, the
slug testing is representative of hydraulic conductivity within a bedrock fracture or fracture set
present at well MW-5. The calculated average hydraulic conductivity falls within the typical range of
published hydraulic conductivities for fractured igneous and metamorphic rocks (approximately 0.83
to 31,039 ft/year) according to Domenico and Schwartz (1990).

Terracon utilized available site-specific data (contaminant concentrations [from well MW-3, the
closest impacted well to Jonesville Creek], hydraulic gradient, and hydraulic conductivity) to
simulate natural attenuation and transport of the contaminant plume. The model simulations to
evaluate solute transport were completed using the RBCA Tool Kit for Chemical Releases® Version
2.6. Two different models were utilized: 1) a model simulating biodegradation through the use of 1st
order decay constants for contaminants of concern (i.e. decay half-lives); and 2) a dispersion only
model. The models indicate that the steady-state concentrations calculated at the point of exposure
(Jonesville Creek) range from 445 (biodegradation) to 513 µg/L (dispersion only) for benzene, both
of which exceed its North Carolina 2B standard for Class C Fresh/Salt waters (51 µg/L). The
remaining contaminant concentrations calculated at the point of exposure (toluene, ethylbenzene,
xylenes, naphthalene, cumene, diisopropyl ether, n-propylbenzene and 1,2,4-trimethylbenzene) do
not exceed their 2B standard.

Each model predicts the benzene concentration at the point of exposure would reach 190 µg/L (also
above its 2B standard) in approximately four months. Historical sampling data from the surface of
Jonesville Creek has not identified benzene above 0.76 µg/L dating back to 2006. Based on this
discrepancy, it appears that either the average hydraulic conductivity calculated from the slug
testing at well MW-5 is not representative of subsurface conditions between well MW-3 and
Jonesville Creek or the waters in the creek are diluting contaminant concentrations as they enter
the creek such that the resulting concentrations are well below 2B standards. It should be noted
that well MW-3 is screened from 9 to 19 feet bls within two feet of apparent partially weathered rock
at its base. As such, well MW-3 is located within the unconsolidated aquifer, which may have a
lower hydraulic conductivity than the fractured rock noted in well MW-5 near the source area.

Terracon completed an additional fate and transport model using contaminant concentrations from
source well MW-1 from 2005. Transport of these contaminants was modeled for 115 feet, which is
the distance between wells MW-1 and MW-3. Terracon varied the hydraulic conductivity parameter
within the model until the benzene concentrations calculated for well MW-3 (after 14 years)
approximated the concentration data from well MW-3 in 2019. The hydraulic conductivity required to
fit the concentration curve to the site-specific concentration data was 1,000 ft/year, which would be
Arlington Branco Oil Company
Jonesville, North Carolina
Project Number 75217015
Incident No. 30114
December 10, 2021
Revised: June 13, 2022

Responsive ■ Resourceful ■ Reliable 4
consistent with the high end of conductivities for silts according to Domenico and Schwartz (1990).
It should be noted that Schnabel’s boring log for well MW-3 indicates the soil lithology is sandy clay,
which would be expected to have a lower hydraulic conductivity. This version of the fate and
transport model indicates the steady state concentration at Jonesville Creek, 145 feet from well
MW-1, is 270 µg/L, which also exceeds its 2B standard.

Based on the findings of our assessment activities, the following comments and recommendations are
provided for the site.
It is not clear from review of prior boring logs and well construction records that the bedrock aquifer
is impacted. While impacts were previously identified within well MW-5, it is possible that
contaminants were dragged into the bedrock interval during installation of the monitoring well. The
sand pack within former well MW-6, which historically contained LNAPL, reportedly extended to a
depth about six inches above the top of bedrock; thus, the monitoring well may source
groundwater from the unconsolidated zone above. Well MW-4 is also screened from 7 to 22 feet
bls, which straddles the bedrock interface (10 feet bls at this location).
Given the sole remaining well (MW-5) on the site with sufficient water to complete a slug test at the
site is screened within bedrock, has a site-specific hydraulic conductivity that is representative of
the unconsolidated aquifer that is assumed to discharge to Jonesville Creek and is impacted by the
release (well MW-3 sits on top of the bedrock surface), fate and transport models utilizing the
hydraulic conductivity data from well MW-5 may not accurately reflect the actual migration of
contaminants within the subsurface.
While it is possible to back-calculate a hydraulic conductivity value for the site based on historical
contaminant concentration data, doing so arrives at a hydraulic conductivity consistent with the
high end of the range for silts (Domenico and Schwartz, 1990) that does not correlate with the
reported lithologic conditions in the unconsolidated, surficial aquifer at the site (sandy clays).
While confidence in the fate and transport models based on the calculated hydraulic gradient from
well MW-5 and using calculated and detected contaminant concentrations in well MW-3 is not high,
the models indicate there is a receptor risk to Jonesville Creek.
Following completion of the DOT roadwork, Terracon recommends reinstalling wells MW-1, MW-3
and MW-6 close to their former locations based on the new roadway/utility configuration. Once the
wells have been reinstalled and current groundwater data has been generated (last sampling at the
site occurred in 2019), further evaluation can be made to determine the appropriate next steps
towards remediation goals at the site.
Sampling of Jonesville Creek should continue annually until contaminant concentrations at the site
have been reduced and/or it can be demonstrated that there is no longer a continued receptor risk
to the creek.
LNAPL was encountered within MW-4. It appears that a fairly small surficial release from an
adjacent aboveground storage tank (AST) resulted in used oil entering the well through the
Arlington Branco Oil Company
Jonesville, North Carolina
Project Number 75217015
Incident No. 30114
December 10, 2021
Revised: June 13, 2022

Responsive ■ Resourceful ■ Reliable 5
well/manway, which were observed to be in poor condition. Terracon recommends the LNAPL
(used oil) be bailed out of MW-4 and its well cap replaced until a licensed well driller can fully
replace the manway and pad.
Abandon on-site water-supply well WSW-1.
C. SITE HISTORY AND CHARACTERIZATION
This Contaminant Fate and Transport Modeling Report was prepared for the site in response to a
request by Mr. Herb Berger, NCDEQ Incident Manager with the Division of Waste Management,
State Lead Program. The purpose of this report is to determine the appropriate remediation goals at
the former Arlington Branco Oil Company site located at 270 North Main Street in Jonesville, Yadkin
County, North Carolina (Figures 1 and 2) as well as evaluate whether hydrogen peroxide and/or
sodium percarbonate can effectively degrade the contaminants located at the site.

The Contaminant Fate and Transport Modeling Report was prepared in general accordance with
the 15A NCAC 2L.0115 regulations and the NCDEQ Underground Storage Tank (UST) Section
Guidelines for Assessment and Corrective Action for UST Releases, dated July 15, 2008, revised
May 2021, under the supervision of Mr. William O. Frazier, a North Carolina registered professional
geologist (North Carolina License No. 2576).

C.1 Site Setting
The site is a former bulk petroleum facility and gasoline filling station located at 270 North Main
Street in Jonesville, North Carolina. The property, comprised of approximately 0.92 acres, contains
an approximate 1,646 sq. ft. vehicle repair shop that operates as Jordan’s Pit Stop. A separate
garage/shed structure and mechanic’s pit are located to the northwest of the vehicle repair shop.
Several inactive aboveground petroleum storage tanks from past bulk petroleum operations are
located within the northeastern portion of the site. Jonesville Creek is located on the adjacent
property to the west of the site. The general site location and site layout is depicted in Figures 1
and 2.

The site is bound to the southwest by Main Street (U.S. Highway 21); to the southeast and east by
Dogwood Street; and to the west and northwest by Jonesville Creek. Properties to the north and
east are occupied by residences while properties to the south and west are occupied by commercial
businesses and residences.

C.2 Release Summary
According to a UST closure report completed in January 2003 by GeoScience & Technology, P.A.,
eight USTs were removed from the site in the early 1990s by Haynes Engineering Associates. Soil
Arlington Branco Oil Company
Jonesville, North Carolina
Project Number 75217015
Incident No. 30114
December 10, 2021
Revised: June 13, 2022

Responsive ■ Resourceful ■ Reliable 6
sampling by Haynes Engineering Associates (1994) and GeoScience & Technology, P.A. (2002)
discovered petroleum impacts at the locations of the former USTs, the dispenser islands and
product lines. A chronological summary of petroleum releases and assessment activities at the site
is included in the following section of the report.

C.3 Previous Investigations
A UST Closure Report prepared by GeoScience & Technology, P.A. dated January 2003 indicates
eight on-site USTs were removed in December 1992 and December 1993 by Haynes Engineering.
The eight USTs consisted of two 6,000-gallon gasoline USTs, one 4,000-gallon gasoline UST, one
3,000-gallon gasoline UST, one 2,000-gallon gasoline UST, one 1,000-gallon waste oil UST, one
550-gallon kerosene UST, and one 550-gallon fuel oil UST. The UST Closure Report indicated that
Haynes Engineering conducted limited soil sampling at the site in 1994; however, there are
reportedly no records of the sampling activities in the NCDEQ regulatory file. GeoScience &
Technology, P.A. collected soil samples in 2002 to complete the UST closure report. According to
the report, the soil samples collected in 1994 indicated petroleum impacts at the locations of the
former USTs. Laboratory results from the 2002 sampling event indicated petroleum constituents
were detected near the dispenser islands and product lines.

A Groundwater Sampling and Receptor Survey Report dated January 10, 2006, prepared by
Schnabel Engineering South (Schnabel) references an incomplete Limited Site Assessment (LSA)
in 2003 by GeoScience & Technology, P.A. Reportedly, GeoScience & Technology, P.A. installed
two monitoring wells on the site and sampled the on-site water supply well (WSW-1). Analytical
results indicated petroleum constituents were detected above the established 2L standards in the
monitoring wells and six inches of LNAPL were measured in well WSW-1. The Schnabel report
also referenced a groundwater sampling event conducted by Force Environmental Service
Company, LLC (Force) in 2005 that reported 3.8 feet of LNAPL were measured in well MW-2.
Reportedly, Force detected benzene above its Gross Contaminant Level (GCL) and multiple other
petroleum constituents above the established 2L standards in well MW-1. Naphthalene and 1,2,4-
trimethylbenzene were detected above their GCLs and sec-butylbenzene, 1,3,5-trimethylbenzene,
and xylenes were detected above the established 2L standards in well WSW-1. Schnabel also
conducted a receptor survey and identified eleven water supply wells within a 1,500-foot radius of
the site. Schnabel also noted that municipal water is available to the site area.

In a Monitoring Well Installation, Groundwater and Water Supply Well Sampling Report dated
October 2006, Schnabel reportedly installed four additional monitoring wells (MW-3, MW-4, MW-5
and MW-6) at the site. According to the report, soil samples from borings MW-4, MW-5 and MW-6
exceeded the regulatory action level for total petroleum hydrocarbons-diesel range organics (TPH-
DRO). Schnabel also reported various petroleum constituents were detected above the 2L
standards in wells MW-1, MW-3, MW-5 and MW-6. LNAPL was measured in wells MW-2 (0.45
feet) and WSW-1 (0.73 feet) in August 2006. Schnabel also sampled Jonesville Creek and off-site
Arlington Branco Oil Company
Jonesville, North Carolina
Project Number 75217015
Incident No. 30114
December 10, 2021
Revised: June 13, 2022

Responsive ■ Resourceful ■ Reliable 7
water supply wells WSW-6 and WSW-7. Benzene was detected in well WSW-6 at a concentration
of 1.1 µg/L, which slightly exceeded the established 2L standard (1.0 µg/L).

A Mobile Multi-Phase Extraction (MMPE) and Groundwater Sampling Report prepared by Schnabel
dated April 2007 reported that a MMPE event was performed at on-site wells MW-1, MW-2, MW-6
and WSW-1. Prior to the MMPE event, LNAPL was measured in wells MW-2, MW-6 and WSW-1.
The on-site wells were sampled about one month after the completion of the MMPE event. Based
on the results of the sampling event, LNAPL was measured in wells MW-2 and MW-6 and various
petroleum constituents were detected in wells MW-1, MW-3, MW-4, MW-5 and WSW-1 at
concentrations above the established 2L standards. Schnabel recommended additional MMPE
events to remove the LNAPL.

Force performed a groundwater sampling event in September 2008 and identified multiple
petroleum constituents above the established 2L standards in wells MW-1, MW-3 and WSW-1.
Benzene was detected above its GCL in well MW-1. Reportedly, 0.24 feet of LNAPL was measured
in well MW-2, 0.03 feet in well MW-5, and 0.89 feet in well MW-6. Only naphthalene was detected
in off-site water supply well WSW-6 at an estimated concentration of 1.6 µg/L. No constituents of
concern were detected in the surface water sample from Jonesville Creek.

Force also conducted a groundwater sampling event in August 2009 and reported multiple
petroleum constituents above the established2L standards in wells MW-1, MW-3, MW-4, MW-5 and
WSW-1. Benzene was detected above its GCL in well MW-1. Reportedly, well MW-6 contained
0.36 feet of LNAPL. According to the report, well MW-2 could not be located. No constituents of
concern were detected in the surface water sample from Jonesville Creek. Force recommended
abandonment of well WSW-1 and an MMPE event at wells MW-1, MW-2 and MW-6.

Force completed a second MMPE event at the site in November 2009 at wells MW-1, MW-2, MW-5,
and MW-6. Reportedly, 2,800 gallons of groundwater containing volatile organic compounds were
removed from the wells during the MMPE event. Subsequent groundwater sampling in December
2009 indicated LNAPL measured in wells MW-2 and MW-6 at 0.01 and 0.02 feet, respectively.
Dissolved-phase petroleum constituents reportedly decreased significantly in wells MW-1, MW-4,
MW-5 and WSW-1.

Force performed groundwater sampling events in July 2011, October 2011 and July 2012 and
identified various petroleum constituents in wells MW-1, MW-2, MW-3, MW-4, MW-6 and WSW-1
above the established 2L standards. LNAPL was detected in well MW-6 in October 2011 and July
2012.

A third MMPE event was conducted at the site by Schnabel in January 2013 using wells MW-1,
MW-2 and MW-6. Reportedly, a total of 4,692 gallons of water with dissolved petroleum
constituents were removed from the wells during the MMPE event. Subsequent groundwater
Arlington Branco Oil Company
Jonesville, North Carolina
Project Number 75217015
Incident No. 30114
December 10, 2021
Revised: June 13, 2022

Responsive ■ Resourceful ■ Reliable 8
sampling completed by Force in February 2013 indicated LNAPL (0.4 feet) was detected in well
MW-6. Multiple petroleum constituents were detected in wells MW-1, MW-2, MW-3 and MW-5 at
concentrations above the established 2L standards; however, the dissolved-phase constituent
concentrations had decreased in these wells.

In November 2014, Terracon performed a groundwater monitoring event at the site. Terracon
sampled the six on-site groundwater monitoring wells and obtained a surface water sample from
Jonesville Creek. Terracon was unable to sample the on-site water supply well (WSW-1).
Petroleum constituents were not detected in Jonesville Creek above 2B surface water standards.
Multiple petroleum constituents were detected in wells MW-1, MW-2, MW-3, MW-5 and MW-6 at
concentrations that exceeded the established 2L standards. The findings of the sampling event
were issued in a Federal/State-Lead Monitoring Report dated February 2, 2015.

Terracon mobilized to the site in May 2015 to sample monitoring wells MW-1 through MW-6, collect
a surface water sample from Jonesville Creek and sample on-site water supply well WSW-1.
Multiple petroleum constituents were detected in wells MW-1, MW-2, MW-3, MW-5 and MW-6 at
concentrations that exceeded the established 2L groundwater standards. Petroleum constituents
were not detected in Jonesville Creek above 2B surface water standards. Benzene and
naphthalene were detected in the on-site water supply well WSW-1 at concentrations above the
established 2L standards. Terracon presented the sampling results to the NCDEQ in a
Federal/State-Lead Monitoring Report dated June 29, 2015.

In January 2016, Terracon mobilized to the site to sample monitoring wells MW-1 through MW-6,
sample on-site water supply well WSW-1, and collect a surface water sample from Jonesville Creek
Multiple petroleum constituents were detected in the on-site monitoring wells at concentrations that
exceeded the established 2L groundwater standards. Petroleum constituents were not detected in
Jonesville Creek above 2B surface water standards. Benzene and naphthalene were detected in
the on-site water supply well WSW-1 at concentrations exceeding the established 2L standards.
Reportedly, well WSW-1 is not being used as a source of potable water. Terracon presented the
sampling results to the NCDEQ in a Federal/State-Lead Monitoring Report dated February 11,
2016.

In September 2017, Terracon mobilized to the site to sample the on-site monitoring wells and
collect a surface water sample from Jonesville Creek. Multiple petroleum constituents were
detected in the wells at concentrations that exceeded the established 2L groundwater standards.
Petroleum constituents were not detected in Jonesville Creek above 2B surface water standards.
Water supply well WSW-1 was not sampled and reportedly is not being used as a source of potable
water. Terracon presented the sampling results to the NCDEQ in a Federal/State-Lead Monitoring
Report dated September 4, 2017.

Arlington Branco Oil Company
Jonesville, North Carolina
Project Number 75217015
Incident No. 30114
December 10, 2021
Revised: June 13, 2022

Responsive ■ Resourceful ■ Reliable 9
Terracon completed sampling events at the site in August 2018 and February 2019. Analytical
results were broadly similar to past sampling events, with a continued downward concentration
trend apparent. Petroleum constituents were not identified within Jonesville Creek in August 2018,
but benzene was detected at an estimated concentration of 0.30J µg/L in the creek in February
2019. After the February 2019 event, the North Carolina Department of Transportation abandoned
wells MW-1, MW-3 and MW-6 in preparation for roadwork along Main Street.

C.4 Water Supply Wells
Reportedly, eleven water supply wells (WSW-1 through WSW-11) are located within 1,500 feet of
the site including well WSW-1 which is located on the site. According to the current site occupant,
well WSW-1 is not used as a source of potable water. There are no known water supply wells
located down-gradient of the site. According to information provided from earlier assessment
activities, ten of the wells including the on-site well are inactive and are located on properties that
are reportedly connected to municipal water. It is unknown if the property containing well WSW-5
is connected to municipal water. Well WSW-5 is located about 1,300 feet southeast of the site
within a different local watershed and is not considered to be at risk of impact by the release at
Arlington Branco based on distance from the site, inferred groundwater flow direction, and
intervening topographic gradient. A water-supply well inventory prepared by others is presented in
Table 1 and the approximate well locations are depicted on Figure 3 (identified as Figure 8 from
previous reporting).

C.5 Surface Water
According to the USGS topographic map, the site is located within the drainage basin of the Yadkin
River which is situated greater than 5,000 feet north of the site. Jonesville Creek, a tributary of the
Yadkin River is located along the western property boundary of the site. Surface water features are
depicted on Figure 1.

C.6 Land Use Information
The site is bound to the southwest by Main Street (U.S. Highway 21); to the southeast and east by
Dogwood Street; and to the west and northwest by Jonesville Creek. Properties to the north and
east are occupied by residences while properties to the south and west are occupied by commercial
businesses and residences.

Arlington Branco Oil Company
Jonesville, North Carolina
Project Number 75217015
Incident No. 30114
December 10, 2021
Revised: June 13, 2022

Responsive ■ Resourceful ■ Reliable 10
D. ASSESSMENT INFORMATION
D.1 Site Geology and Hydrogeology
The following resources were reviewed to evaluate site-specific geological and hydrogeological
characteristics.

Elkin South Quadrangle, North Carolina, USGS 7.5-minute series topographic maps, dated 1996
(Figure 1).
Geologic Map of North Carolina, dated 1985.
The Geology of the Carolinas, Carolina Geological Society Fiftieth Anniversary Volume, edited by
J. Wright Horton, Jr., and Victor A. Zullo, The University of Tennessee Press, dated 1991.
Soil Survey of Yadkin County, North Carolina, US Department of Agriculture, Natural Resources
Conservation Service, Web Soil Survey via the Internet, http://websoilsurvey.nrcs.usda.gov/app/ .

The site is located within a thrust-faulted area of the Sauratown Mountains Anticlinorium in the
Piedmont Physiographic Province. The Piedmont Province generally consists of low to medium
elevation, rounded hills and long rolling northeast to southwest trending ridges with incised creeks
and river channels. Underlying rock in the site area is described as fine-grained mica gneiss and
metamorphosed granite.

In-place chemical and physical weathering of parent rocks typically form residual soils in the
Piedmont region. Weathering is facilitated by the presence of fractures, joints, and less resistant
minerals in the rock. In areas not altered by erosion, alluvial deposition or the activities of man, the
typical residual soil profile consists of clay-rich unconsolidated materials at the surface, transitioning
to sandy silts and silty sands at depth. Typically, the boundary between soil and rock is not sharply
defined. This transitional zone is termed “partially weathered rock” or saprolite. Information
obtained from the Web Soil Survey for Yadkin County, depicts soils on the site as Fairview sandy
clay loam (FdE2).

In the Piedmont, groundwater generally occurs in pore spaces within soils and in the structural
features present in the underlying rock (i.e. joints, fractures, and faults). Recharge to the water
table is primarily by precipitation infiltrating the surficial soils and percolating downward under the
influence of gravity to the water table (vadose zone). Typically, the water table is not a level
surface, but a subdued reflection of the land surface. The depth to the water table is not consistent
and is dependent upon several factors that include the amount of rainfall, permeability of the soil,
the extent of fracturing in the underlying rock and the influences of groundwater pumping.
Groundwater typically flows in directions parallel to the ground surface and under the influence of
gravity, migrates to discharge points such as surface water features, the toes of slopes or natural
springs.
Arlington Branco Oil Company
Jonesville, North Carolina
Project Number 75217015
Incident No. 30114
December 10, 2021
Revised: June 13, 2022

Responsive ■ Resourceful ■ Reliable 11
Fluctuations in the depth of the water table can be expected depending on variations in
precipitation, surface water run-off and other factors not evident at the time of our subsurface
exploration. Normally, the highest levels of the water table occur in late winter and spring and the
lowest levels occur in the late summer and fall. Based on the groundwater elevation data gathered
during this sampling event, groundwater is expected to flow to the west from the site.

E. AQUIFER TESTING
To evaluate aquifer properties (i.e., aquifer permeability and the potential suitability of contaminant
migration), Terracon mobilized to the site on October 1, 2021 and November 11, 2021 to conduct
slug testing at various on-site monitoring wells to determine a site-specific hydraulic conductivity for
use in a contaminant fate and transport model. During the October mobilization, sufficient water was
encountered within wells MW-4 and MW-5 to complete slug testing. Review of the slug testing data
upon return from the field determined that the testing results at well MW-4 had not been performed
correctly. The slug testing at well MW-5 indicated a very fast aquifer response to the insertion and
removal of the slug, such that the depth to water recharged to the static water level within one
minute. Based on the October slug testing results, Terracon remobilized to the site in November to
complete additional slug tests. Free product was encountered within MW-4; as such, slug testing
was only completed on well MW-5. The November slug testing efforts, which included two slug-in
and one slug out tests at well MW-5, confirmed a relatively fast aquifer response.

The testing was completed by introducing a solid slug of known volume into the well and measuring
the resulting change in head following the introduction (i.e., “slug-in”). A Level Troll 700 pressure
transducer was used to monitor the change in head within the well (MW-5). The tests continued
until well levels recovered to at least 95 percent of the initial static level within a reasonable time
period. After the water level had returned to its static level, a slug-out test was performed by
removing the slug and monitoring the change in head. Hydraulic conductivity was then estimated
from slug test results using AQTESOLV Pro software. Aquifer slug test summary reports and
AQTESOLV data reports are provided in Appendix A.

Time versus water displacement data collected from slug-in (falling head) and slug-out (rising head)
tests conducted at monitoring well MW-5 were analyzed using the Bower and Rice (1976) Slug Test
Solution for confined aquifers. The falling and rising head slug tests yielded the following hydraulic
conductivities (K):

Slug Test K (feet/year)
MW-5 (slug-in #1) 201.25
MW-5 (slug-out) 5,492.5
MW-5 (slug-in #2) 113.21

Arlington Branco Oil Company
Jonesville, North Carolina
Project Number 75217015
Incident No. 30114
December 10, 2021
Revised: June 13, 2022

Responsive ■ Resourceful ■ Reliable 12
The results of the slug testing indicated hydraulic conductivity values of approximately 113.2 and
201.3 feet per year (ft/yr) for the slug-in tests and of 5,492.5 ft/yr for the slug-out test. The average
hydraulic conductivity based on these data is approximately 1935.66 ft/yr. The boring log for well
MW-5, installed by Schnabel Engineering in 2006, indicates the well screen (11 to 16 ft below land
surface [bls]) was installed entirely within competent gneiss bedrock (10 to 16 ft bls). As such, the
slug testing is representative of hydraulic conductivity within fractured bedrock present at well MW-
5. The calculated average hydraulic conductivity falls within the typical range of published hydraulic
conductivities for fractured igneous and metamorphic rocks (approximately 0.83 to 31,039 ft/yr)
according to Domenico and Schwartz (1990).

F. GROUNDWATER MODELING
Terracon conducted a fate and transport evaluation of petroleum constituents detected in the on-
site monitoring wells to determine the potential of the constituents to migrate into Jonesville Creek.
Historically, low levels of petroleum constituents have been detected periodically within the creek
dating back to 2006.

Terracon utilized available site-specific data (contaminant concentrations [from well MW-3, the
closest impacted well to Jonesville Creek], hydraulic gradient, and hydraulic conductivity) to
simulate natural attenuation and transport of the contaminant plume. The model simulations to
evaluate solute transport were completed using the RBCA Tool Kit for Chemical Releases® Version
2.6. Two different models were utilized: 1) a model simulating biodegradation through the use of 1st
order decay constants for contaminants of concern (i.e. decay half-lives); and 2) a dispersion only
model.

Since no remediation activities have occurred at the site other than three MMPE events, constituent
concentrations trends at the site have generally been decreasing since 2006 (as demonstrated by
Mann-Kendall statistical analysis [Figure 4]), Terracon believes the model that simulates
biodegradation is more representative of the actual physical processes occurring at the site.
However, the dispersion only model provides a more conservative risk assessment, as it models the
transport of contaminant concentrations through the surficial aquifer without any degradation. The
site-specific parameters used for the models and a discussion of the results are presented below.

Site Specific Model Inputs (RBCA Tool Kit)
Terracon utilized site-specific hydraulic conductivity data from the slug testing performed by
Terracon in November 2021. The average hydraulic conductivity was estimated at 1,935.66 ft/yr for
the site and was used in the model simulation. The average hydraulic gradient, 0.01875 ft/ft, was
estimated for the site based on the historical groundwater elevations. Using an estimated porosity of
0.38, the seepage velocity used by the model was calculated as approximately 96 feet per year.
Site specific data for soil bulk density, the partition coefficient, and fraction organic carbon were not
available so default values were used in the model simulation.
Arlington Branco Oil Company
Jonesville, North Carolina
Project Number 75217015
Incident No. 30114
December 10, 2021
Revised: June 13, 2022

Responsive ■ Resourceful ■ Reliable 13
While contamination has been identified within wells MW-5 and MW-6, which are screened within
bedrock, it is not clear from review of prior boring logs and well construction records that the
bedrock aquifer is impacted. Although impacts were previously identified within well MW-5, it is
possible that contaminants were dragged into the bedrock interval during installation of the
monitoring well. The sand pack within former well MW-6, which historically contained LNAPL,
reportedly extended to a depth of approximately six inches above the top of bedrock; thus, the
monitoring well may source groundwater from the unconsolidated zone above. Well MW-4 is also
screened from 7 to 22 feet bls, which straddles the bedrock interface (10 feet bls at this location).
Based on the screened intervals, it was assumed that impacts are limited to the unconsolidated
zone. Since the water column in the source area did not generally exceed 5 feet above the reported
competent bedrock surface, the plume thickness was estimated to be approximately 5 feet.

Since the Mann Kendall statistical results (Figure 4) indicate the plume is shrinking, the initial
modeling of the highest concentrations of benzene, toluene, ethylbenzene, total xylenes, and a few
other compounds, identified within well MW-3, were used as the contaminant concentrations in the
“source area.” While well MW-3 is not within the release source area, it was used as the starting
point for the fate and transport model and Jonesville Creek was considered the point of exposure.
Terracon also performed a fate and transport model using the contaminant concentrations in well
MW-1 (from 2005) to model transport and attenuation of the petroleum constituents to well MW-3 as
a point of exposure, 115 feet away, over a 16 year period in order to back-calculate a site-specific
hydraulic conductivity by matching the calculated point of exposure concentrations with the
concentrations detected in well MW-3 in 2019.

The data and inputs used for the model are indicated on the input screen included in Appendix B.

Biodegradation Model Results
According to the RBCA Tool Kit®, biodegradation is simulated as a first-order decay process. For
the biodegradation model, the most conservative half-lives for each constituent published in The
Handbook of Environmental Degradation Rates (Howard et al., 1991) were utilized.

Dispersion Only Model Results
According to the RBCA Tool Kit®, the dispersion only model uses the steady-state Domenico
analytical solute transport model to account for dispersion between the groundwater source zone
and off-site receptor locations but does not account for biodegradation effects (a first-order decay
process). While biodegradation may be occurring within the subsurface, exclusion of biodegradation
in the model provides a more conservative modeled result for concentrations at the point of
exposure (Jonesville Creek).

Each model predicts the benzene concentration at the point of exposure would reach 190 µg/L
(above its 2B standard) within approximately four months. Historical sampling data from the surface
of Jonesville Creek has not identified benzene above 0.76 µg/L dating back to 2006. Based on this
Arlington Branco Oil Company
Jonesville, North Carolina
Project Number 75217015
Incident No. 30114
December 10, 2021
Revised: June 13, 2022

Responsive ■ Resourceful ■ Reliable 14
discrepancy, it appears that either the average hydraulic conductivity calculated from the slug
testing at well MW-5 is not representative of conditions between well MW-3 and Jonesville Creek or
the waters in the creek are diluting contaminant concentrations as they enter the creek such that the
resulting concentrations are well below 2B standards. It should be noted that well MW-3 is
screened from 9 to 19 feet bls with two feet of apparent partially weather rock at its base. As such,
well MW-3 is located within the unconsolidated aquifer, which may have a lower hydraulic
conductivity than the fractured rock noted in well MW-5 near the source area.

Terracon completed an additional fate and transport model using contaminant concentrations from
source well MW-1 from 2005. Transport of these contaminants was modeled for 115 feet, which is
the distance between wells MW-1 and MW-3. Terracon varied the hydraulic conductivity parameter
within the model until the benzene concentrations calculated for well MW-3, after 14 years,
approximated the concentration data from well MW-3 in 2019. The hydraulic conductivity required to
fit the concentration curve to the site-specific concentration data was 1,000 ft/year, which would be
consistent with the high end of conductivities for silts according to Domenico and Schwartz (1990).
It should be noted that Schnabel’s boring logs for well MW-3 indicate the soil lithology is sandy clay,
which would be expected have a lower hydraulic conductivity. This version of the fate and transport
model indicates the steady state concentration at Jonesville Creek, 145 feet from well MW-1, is 270
µg/L, which exceeds its 2B standard. Summaries of the model results are provided in Appendix B.
G. CONCLUSIONS AND RECOMMENDATIONS
Based on the findings of our assessment activities, the following comments and recommendations are
provided for the site.
It is not clear from review of prior boring logs and well construction records that the bedrock aquifer
is impacted. While impacts were previously identified within well MW-5, it is possible that
contaminants were dragged into the bedrock interval during installation of the monitoring well. The
sand pack within former well MW-6, which historically contained LNAPL, reportedly extended to a
depth about six inches above the top of bedrock; thus, the monitoring well may source
groundwater from the unconsolidated zone above. Well MW-4 is also screened from 7 to 22 feet
bls, which straddles the bedrock interface (10 feet bls at this location).
Given the sole remaining well (MW-5) on the site with sufficient water to complete a slug test at the
site is screened within bedrock, has a site-specific hydraulic conductivity that is representative of
the unconsolidated aquifer that is assumed to discharge to Jonesville Creek and is impacted by the
release (well MW-3 sits on top of the bedrock surface), fate and transport models utilizing the
hydraulic conductivity data from well MW-5 may not accurately reflect the actual migration of
contaminants within the subsurface.
While it is possible to back-calculate a hydraulic conductivity value for the site based on historical
contaminant concentration data, doing so arrives at a hydraulic conductivity consistent with the
Arlington Branco Oil Company
Jonesville, North Carolina
Project Number 75217015
Incident No. 30114
December 10, 2021
Revised: June 13, 2022

Responsive ■ Resourceful ■ Reliable 15
high end of the range for silts (Domenico and Schwartz, 1990) that does not correlate with the
reported lithologic conditions in the unconsolidated, surficial aquifer at the site (sandy clays).
While confidence in the fate and transport models based on the calculated hydraulic gradient from
well MW-5 and using calculated and detected contaminant concentrations in well MW-3 is not high,
the models indicate there is a receptor risk to Jonesville Creek.
Following completion of the DOT roadwork, Terracon recommends reinstalling wells MW-1, MW-3
and MW-6 close to their former locations based on the new roadway/utility configuration. Once the
wells have been reinstalled and current groundwater data has been generated (last sampling at the
site occurred in 2019), further evaluation can be made to determine the appropriate next steps
towards remediation goals at the site.
Sampling of Jonesville Creek should continue annually until contaminant concentrations at the site
have been reduced and/or it can be demonstrated that there is no longer a continued receptor risk
to the creek.
LNAPL was encountered within well MW-4. It appears that a fairly small surficial release from an
adjacent aboveground storage tank (AST) resulted in used oil entering the well through the
well/manway, which were observed to be in poor condition. Terracon recommends the LNAPL
(used oil) be bailed out of MW-4 and its well cap replaced until a licensed well driller can fully
replace the manway and pad.
Terracon recommends that on-site water-supply well WSW-1 be properly abandoned.

FIGURES
SITE LOCATION MAPTOPOGRAPHIC MAP IMAGE COURTESY OF
THE U.S. GEOLOGICAL SURVEY
QUADRANGLES INCLUDE: ELKIN SOUTH, NC
(1/1/1996).
Arlington Branco Oil Company (INCIDENT #30114)
270 North Main Street
Jonesville, NC
2701 WestportRoad
Charlotte, NC
71149678A
DIAGRAM IS FOR GENERAL LOCATION ONLY,
AND IS NOT INTENDED FOR CONSTRUCTION
PURPOSES
Project Manager:
Drawn by:
Checked by:
Approved by:
MAW
CLC
CLC
MAW
1:24,000
Arlington Branco
October 2018
Project No.
Scale:
File Name:
Date:
1
Figure
SITE
2
Figure
DIAGRAM IS FOR GENERAL LOCATION ONLY,
AND IS NOT INTENDED FOR CONSTRUCTION
PURPOSES 2701 Westport Road
Charlotte, NC
SITE PLANProject Manager:
Drawn by:
Checked by:
Approved by:
MAW Project No.
File Name:
Date:
Scale:
71149678A
MAW
CLC
Arlington BrancoCLC
1” ~ 40’Arlington Branco Oil Company (INCIDENT #30114)
270 North Main Street
Jonesville, NC
RESIDENTIAL
MAIN STREET
WOODED
GARAGE
MECHANICS
PIT
SHED ARLINGTON
BRANCO OIL
COMPANY
STEEP SLOPE
STEEP SLOPE
CONCRETE WALL
BRIDGE
ASTs
PUMPS
FORMER
UST BASIN
FORMER
DISPENSERSFORMER
UST
FORMER
USTs
FORMER
DISPENSER
MW-3
MW-4
MW-1
MW-2 MW-6
MW-5
ASTs
PUMPS
WSW-1
approximate site boundary
water supply well
groundwater monitoring
well
September 2018
8
Figure
DIAGRAM IS FOR GENERAL LOCATION ONLY,
AND IS NOT INTENDED FOR CONSTRUCTIONPURPOSES 2701 Westport Road
Charlotte, NC
WATER SUPPLY WELL LOCATION MAPProject Manager:
Drawn by:
Checked by:
Approved by:
MAW Project No.
File Name:
Date:
Scale:
71149678A
MAW
CLC
CLC
1” ~ 500’Arlington Branco Oil Company (INCIDENT #30114)
270 North Main Street
Jonesville, NC
1,000 ft.
Radius
(from release
location)
1
2
4
5
3
6
8
9
7
11
10
NUMBER CORRESPONDS WITHWATER SUPPLY WELL
INFORMATION LISTED IN TABLE 1
approximate site boundary
September 2018
Arlington Branco
Figure 4
Benzene Concentration vs. Time Trend Analysis
Evaluation Date:Job ID:
Facility Name:Constituent:
Conducted By:Concentration Units:µg/L
Sampling Point ID:MW-1 MW-2 MW-3
Sampling Sampling
Event Date
1 08/03/06 9,700 740
2 03/20/07 7,000 860
3 09/10/08 6,990 1,070
4 07/17/09 7,940 1,330
5 12/09/09 2,890 862
6 07/13/11 6,600 4,100 720
7 10/19/11 7,400 4,400 1,600
8 07/19/12 6,100 4,000 1,400
9 02/14/13 2,400 1,060 923
10 11/11/14 2,830 987 953
11 05/29/15 2,850 1,510 723
12 01/08/16 2,230 782
13 08/31/17 2,280 972 894
14 08/23/18 1,710 476 701
15 02/05/19 2,600 48 581
16
17
18
19
20
Coefficient of Variation:0.54 0.88 0.31
Mann-Kendall Statistic (S):-59 -30 -33
Confidence Factor:100.0%100.0%96.0%
Concentration Trend:Decreasing Decreasing Decreasing
Notes:
1.At least four independent sampling events per well are required for calculating the trend. Methodology is valid for 4 to 40 samples.
2.Confidence in Trend = Confidence (in percent) that constituent concentration is increasing (S>0) or decreasing (S<0): >95% = Increasing or Decreasing;
≥ 90% = Probably Increasing or Probably Decreasing; < 90% and S>0 = No Trend; < 90%, S≤0, and COV ≥ 1 = No Trend; < 90% and COV < 1 = Stable.
3.Methodology based on "MAROS: A Decision Support System for Optimizing Monitoring Plans", J.J. Aziz, M. Ling, H.S. Rifai, C.J. Newell, and J.R. Gonzales,
Ground Water, 41(3):355-367, 2003.
4..-- Indicates date not sampled/well non-existent.
5.The laboratory reporting limit was entered when the laboratory did not detect concentrations above the reporting limit.
DISCLAIMER: The GSI Mann-Kendall Toolkit is available "as is". Considerable care has been exercised in preparing this software product; however, no party, including without
limitation GSI Environmental Inc., makes any representation or warranty regarding the accuracy, correctness, or completeness of the information contained herein, and no such
party shall be liable for any direct, indirect, consequential, incidental or other damages resulting from the use of this product or the information contained herein. Information in
this publication is subject to change without notice. GSI Environmental Inc., disclaims any responsibility or obligation to update the information contained herein.
BENZENE CONCENTRATION (µg/L)
GSI Environmental Inc., www.gsi-net.com
GSI MANN-KENDALL TOOLKIT
for Constituent Trend Analysis
12/10/21 75217015
Arlington Branco Oil Company Benzene
Terracon
1
10
100
1000
10000
01/04 10/06 07/09 04/12 12/14 09/17 06/20Concentration (µg/L)Sampling Date
MW-1
MW-2
MW-3

TABLES
TABLE 1
Water Supply Well Information
Arlington Branco Oil Company
Jonesville, North Carolina
Terracon Project No. 71149678A
NCDEQ Incident No. 30114
Well No.Property Owner Mailing Address Property Address
Distance and
Direction from
source area
Well Status Municpal
Water Parcel No.Notes
WSW-1 Gilbert & Glenda Nance 5608 Bethel Road Jonesville, NC
28642
270 North Main Street Jonesville, NC
28642 Site Inactive Yes 495008776511 Well inactive, no power to the well.
WSW-2 Ventures Myers 5115 Jordan Myers Drive
Jonesville, NC 28642
106 Center Street Jonesville, NC
28642 1,900 feet southeast Potable Yes 495000964765
WSW-3 Ruth & Jackie Henderson 1400 Old Stage Road Yadkinville,
NC 27055
214 South Jonesville Boulevard
Jonesville, NC 28642 1,100 feet north Inactive Yes 495008789665
WSW-4 Jerry Brown 304 Haywood Street Jonesville, NC
28642
304 Haywood Street Jonesville, NC
28642 1,410 feet southeast Inactive Yes 495012861292
WSW-5 Dawn & James Waugh 144 Queensbury Road Winston
Salem, NC 27104 220 Old Street Jonesville, NC 28642 1,315 feet southeast Inactive Unknown 495012865523
WSW-6 Lester Haynes, Lynn &
Cynthis Somers
527 Union Baptist Church Road
Hamptonville, NC 27020
110 Pardue Street Jonesville, NC
28642 480 feet south Inactive Yes 495012776010
WSW-7 Ronald & Susan Childress 1220 Peanut Lane Yadkinville, NC
27055
247 North Main Street Jonesville, NC
28642 420 feet southeast Inactive Yes 495012778141
WSW-8 Loraine & John Hamby 119 Pickett Street Jonesville, NC
28642
119 Pickett Street Jonesville, NC
28642 735 feet east Inactive Yes 4950873588
WSW-9 Pemela Rumple 400 Wilkes Street Elkin, NC 28621 158 North Main Street Jonesville, NC
28642 940 feet east Inactive Yes 495012874290
WSW-10 Alejandra & Pena Solorzano 116 Vestal Avenue Jonesville, NC
28642
116 Vestal Avenue Jonesville, NC
28642 1,130 feet east Abandoned Yes 495008877682
WSW-11 Kevin Thomas 128 Hillcrest Street Jonesville, NC
28642
128 Hillcrest Street Jonesville, NC
28642 1,150 feet northwest Inactive Yes 495007688450
TABLE 1
Summary of Groundwater Analytical Results
Arlington Branco Oil Company
Jonesville, North Carolina
Terracon Project No. 71149678A
NCDEQ Incident No. 30114
Well/Sample
I.D.
Date Collected
(mm/dd/yy)
12/01/2005 9,200 <100 <100 ND NA ND <100 2,700 <100 ND 4,200 ND 1,100 220 ND 11,000 1,900 450 10,100
8/03/2006 9,700 ND ND ND NA ND NA 2,800 79 ND NA ND 760 250 ND 9,000 1,900 530 10,400
3/20/2007 7,000 ND ND ND NA ND 190 3,700 130 ND 2,600 ND 100 460 ND 15,000 3,600 960 16,000
9/10/2008 6,990 134 ND ND NA ND 161 2,590 85.2 ND 2,390 ND 760 269 ND 1,680 1,780 478 5,882
7/17/2009 7,940 <250 <250 ND NA ND 340 3,740 <250 NA 5,230 ND 1,000 524 <250 5,110 3,710 939 12,990
12/09/2009 2,890 <25 <25 ND NA ND 93.2 2,780 119 NA 1,250 ND 992 364 <25 5,920 3,250 859 13,650
7/13/2011 6,600 350 <11 ND NA ND 130 5,300 280 <0.059 1,600 ND 2,200 1,200 <6.8 2,400 7,200 2,200 15,000
10/19/2011 7,400 <100 <100 ND NA ND 140 4,500 <100 NA 1,900 ND 2,300 390 <100 1,700 4,200 1,200 13,000
7/19/2012 6,100 <250 <250 ND NA ND <250 4,000 <250 <250 1,900 ND 1,500 580 <250 1,400 3,800 1,100 12,000
2/14/2013 2,400 <25 <25 ND NA ND 94.8 3,340 179 NA 1,380 ND 1,330 463 <25 2,840 3,570 1,100 13,230
11/11/2014 2,830 <12.5 <12.5 <25 <25 <12.5 <12.5 4,510 300 NA 1,050 ND 2,630 1,160 <12.5 465 7,370 2,400 12,622
5/29/2015 2,850 <12.5 <12.5 <25 <25 <12.5 107 2,950 107 NA 1,120 ND 1,020 342 <12.5 447 2,410 700 7,792.6
1/8/2016 2,230 <6.2 70 <12.5 <12.5 9.0J 90 4,130 251 NA 963 ND 2,040 940 <6.2 432 5,380 1,900 9,598
8/31/2017 2,280 <10.0 69.6 <10.0 <12.5 12.2J 83.6 3,340 162 NA 866 ND 1,530 605 <10.0 374 3,780 1,140 8,760
8/23/2018 1,710 <10.0 <10.0 <20.0 <20.0 <10.0 18.3J 3,500 125 NA 652 <40.0 1,270 502 <10.0 212 3,800 1,040 9,966
2/5/2019 2,600 107 <25.0 <50.0 <50.0 <25.0 98.6 2,910 141 NA 622 <100 1,380 <25.0 <25.0 760 3,900 1,090 11,660
12/01/2005
8/03/06
9/14/06
2/07/2007
3/20/2007
9/10/2008
7/17/2009
12/09/2009
7/13/2011 4,100 730 <27 ND NA ND <21 2,900 <17 <0.059 4,000 ND 3,800 1,300 300 15,000 17,000 4,500 19,000
10/19/2011 4,400 <200 <200 ND NA ND <200 2,700 <200 NA 3,400 ND 730 <200 <200 20,000 3,100 800 16,000
7/19/2012 4,000 <250 <250 ND NA ND <250 2,800 <250 <250 2,300 ND 1,300 490 1,200 12,000 4,200 1,100 16,000
2/14/2013 1,060 <25 <25 ND NA ND 35.1 1,270 135 NA 852 ND 877 253 <25 4,660 2,710 729 9,980
11/11/2014 987 397 <12.5 <25 <25 <12.5 <12.5 2,080 195 NA 900 ND 1,020 715 75.7 6,070 5,690 1,780 12,320
5/29/2015 1,510 <12.5 2,740 <25 <25 <12.5 72.2 1,450 89.8 NA 1,700 ND 531 290 44.8 6,050 2,480 703 8,160
1/8/2016
8/31/2017 972 <10.0 2,740 <20.0 <20.0 <10.0 25.5 1,250 102 NA 430 ND 545 389 32.8 4,060 3,190 903 6,790
8/23/2018 476 <5.0 <5.0 <10.0 <10.0 <5.0 <5.0 754 70.4 NA 93.1 <20.0 346 <5.0 <5.0 1,480 2,420 <5.0 4,360
2/5/2019 48.1 44 <1.2 <2.5 <2.5 <1.2 <1.2 150 23.6 NA 6 <5.0 124 <1.2 <1.2 174 790 <1.2 624
1 70 70 3,000 3 0.4 70 600 70 25 20 5 6 70 70 600 400 400 500
5,000 6,900 8,500 NE 3,000 400 70,000 84,500 25,000 11,700 20,000 5,000 6,000 30,000 70,000 260,000 28,500 25,000 85,500
ND denotes not detected (Detection limits are unknown for sampling conducted prior to Terracon's involvement with the site.)
<- denotes less than method detection limit
J indicates estimated value
NS denotes not sampled.
NA denotes not analyzed.
NR denotes not reported.
Bold denotes levels above the 2L standard.
Bold and gray shading denotes levels above the GCL.
2L Standard (ug/L)
GCL (ug/L)
MW-1
MW-2
Analytical Method
BenzeneDiisopropylEther(IPE)Styrenen-ButylbenzeneContaminant of Concern→
6200B
Chloromethanesec-ButylbenzeneXylenes(Total)EthylbenzeneIsopropylbenzenep-Isopropyltoluene1,3,5-Trimethylbenzene1,2-Dichloroethane1,2,4-Trimethylbenzenen-PropylbenzeneMethyleneChlorideChloroethaneNot Sampled
Not Sampled-LNAPL
Not Sampled-LNAPLMethyltert-butylether(MTBE)NaphthaleneTolueneNot Sampled-LNAPL
Not Sampled
Not Sampled-LNAPL
Not Sampled-LNAPL
Not Sampled-LNAPL
Not Sampled-LNAPL
2 of 7
TABLE 1
Summary of Groundwater Analytical Results
Arlington Branco Oil Company
Jonesville, North Carolina
Terracon Project No. 71149678A
NCDEQ Incident No. 30114
Well/Sample
I.D.
Date Collected
(mm/dd/yy)
Analytical Method
BenzeneDiisopropylEther(IPE)Styrenen-ButylbenzeneContaminant of Concern→
6200B
Chloromethanesec-ButylbenzeneXylenes(Total)EthylbenzeneIsopropylbenzenep-Isopropyltoluene1,3,5-Trimethylbenzene1,2-Dichloroethane1,2,4-Trimethylbenzenen-PropylbenzeneMethyleneChlorideChloroethaneMethyltert-butylether(MTBE)NaphthaleneToluene8/03/2006 740 ND ND ND ND ND NA 3.5 6.7 ND NA ND 57 17 ND 4.4 ND ND 43.8
3/20/2007 860 ND ND ND ND ND 84 9.4 7.9 ND 9.3 ND 38 18 ND 6.5 4.7 ND 54
9/10/2008 1,070 ND ND ND ND ND 94.2 1.8 4.7 ND 6.4 ND 35.5 8.4 ND 4.7 2.3 ND 41
7/17/2009 1,330 <5.0 <5 ND <5 ND 149 13.5 9.3 NA 14.5 ND 50.4 18.8 <5 9.3 12.7 <5 75.7
12/09/2009 862 <5 <5 ND <5 ND 115 <5 7.5 NA 14 ND 52.4 17.4 <5 6.3 <5 <5 52
7/13/2011 720 1.9 0.8 ND <0.032 ND 68 3.3 11 <0.059 4.2 ND 70 22 <0.034 12 3 0.94 71
10/19/2011 1,600 1.9 0.77 ND <0.5 ND 140 4.4 16 NA 3.8 ND 100 31 <0.5 9 1 0.6 92
7/19/2012 1,400 2.9 1.8 ND <0.5 ND 150 2.8 13 <0.5 3.5 ND 95 27 <0.5 5.5 1.5 0.62 53
2/14/2013 923 <2.5 <2.5 ND <5 ND 124 3.6 13.1 NA 2.8 ND 63.9 18.1 <2.5 4 8.6 3.3 39.8
11/11/2014 953 <2.5 <2.5 <25 <5 <12.5 108 <2.5 7.8 NA <2.5 ND 66.4 16.9 <2.5 11.8 6.5 <2.5 41.7
5/29/2015 723 <2.5 <2.5 <5 <5 <2.5 101 3.1J 7.3 NA <2.5 ND 58.6 13.7 <2.5 <2.5 5.2 <2.5 32.2J
1/8/2016 782 <1.2 <1.2 <2.5 <2.5 <1.2 126 2.1J 9.0 NA 3.4 ND 69.2 18.7 <1.2 4.6 <1.2 3 27.8
8/31/2017 894 <1.2 <1.2 <2.5 <2.5 <1.2 106 2.9 10 NA <1.2 ND 75.9 20.4 <1.2 7.1 2.7 <1.2 32.9
8/23/2018 701 <1.0 <1.0 <2.0 <2.0 <1.0 92.5 <1.0 6.3 NA <1.0 20.5 48.3 10.5 <1.0 1.2J <1.0 <1.0 10.8
2/5/2019 581 <1.0 <1.0 <2.0 <2.0 <1.0 78.3 3.8 8.2 NA <1.0 <4.0 44.3 14.8 <1.0 4.3 1.6J <1.0 27.4
9/14/2006 ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND
3/20/2007 3 ND ND ND ND ND 0.72 14 0.93 ND ND ND 25 ND ND 1.4 120 37 143
9/10/2008 ND ND ND ND ND ND 0.6 ND ND ND ND ND ND ND ND ND ND ND ND
7/17/2009 1.9 <0.5 <0.5 ND <0.5 ND <0.5 <0.5 <0.5 NA <0.5 ND <2 <0.5 <0.5 <0.5 2.9 1 0.56
12/09/2009 <0.5 <0.5 <0.5 ND <0.5 ND <0.5 <0.5 <0.5 NA <0.5 ND <2 <0.5 <0.5 <0.5 <0.5 <0.5 <1.5
7/13/2011 <0.054 <0.059 <0.054 ND 1.5 ND <0.042 <0.054 <0.034 <0.059 <0.056 ND 6.9 <0.059 <0.034 1.1 0.56 <0.038 0.79J
10/19/2011 <0.5 <0.5 <0.5 ND <0.5 ND <0.5 <0.5 <0.5 NA <0.5 ND <1 <0.5 <0.5 <0.5 <0.5 <0.5 <1.5
7/19/2012 <0.5 <0.5 <0.5 ND <0.5 ND <0.5 <0.5 <0.5 <0.5 <0.5 ND <1 <0.5 <0.5 <0.5 <0.5 <0.5 <1.5
2/14/2013 <0.5 <0.5 <0.5 ND <1 ND <0.5 <0.5 <0.5 NA <0.5 ND <2 <0..5 <0.5 <0.5 <0.5 <0.5 <1.5
11/11/2014 <0.25 <0.25 <0.25 <25 <0.5 <12.5 <0.25 <0.25 <0.25 NA <0.25 ND <1 <0.25 <0.25 <0.25 <0.25 <0.25 <0.5
5/29/2015 <0.25 <0.25 <0.25 <0.5 <0.5 <0.5 <0.25 <0.25 <0.25 NA <0.25 ND <1 <0.25 <0.25 <0.25 <0.25 <0.25 <0.25
1/8/2016 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 NA <0.5 ND 1.3J <0.5 <0.5 <0.5 3.7 <0.5 <0.5
8/31/2017 0.72 <0.25 <0.25 <0.5 <0.5 <0.25 <0.25 2.2 2.9 NA <0.5 ND 3.1 4.8 <0.25 <0.25 93.5 <0.5 2.3
8/23/2018 <0.25 <0.25 <0.25 <0.5 <0.5 <0.25 <0.25 <0.25 <0.25 NA <0.25 <1.0 <1.0 <0.25 <0.25 <0.25 <0.25 <0.25 <0.25
2/5/2019 <0.25 <0.25 <0.25 <0.5 <0.5 <0.25 <0.25 1.5 3.3 NA <0.25 <1.0 8.7 3.1 <0.25 <0.25 11.9 4.7 1.65J
1 70 70 3,000 3 0.4 70 600 70 25 20 5 6 70 70 600 400 400 500
5,000 6,900 8,500 NE 3,000 400 70,000 84,500 25,000 11,700 20,000 5,000 6,000 30,000 70,000 260,000 28,500 25,000 85,500
ND denotes not detected (Detection limits are unknown for sampling conducted prior to Terracon's involvement with the site.)
<- denotes less than method detection limit
J indicates estimated value
NS denotes not sampled.
NA denotes not analyzed.
NR denotes not reported.
Bold denotes levels above the 2L standard.
Bold and gray shading denotes levels above the GCL.
MW-3
MW-4
2L Standard (ug/L)
GCL (ug/L)
3 of 7
TABLE 1
Summary of Groundwater Analytical Results
Arlington Branco Oil Company
Jonesville, North Carolina
Terracon Project No. 71149678A
NCDEQ Incident No. 30114
Well/Sample
I.D.
Date Collected
(mm/dd/yy)
Analytical Method
BenzeneDiisopropylEther(IPE)Styrenen-ButylbenzeneContaminant of Concern→
6200B
Chloromethanesec-ButylbenzeneXylenes(Total)EthylbenzeneIsopropylbenzenep-Isopropyltoluene1,3,5-Trimethylbenzene1,2-Dichloroethane1,2,4-Trimethylbenzenen-PropylbenzeneMethyleneChlorideChloroethaneMethyltert-butylether(MTBE)NaphthaleneToluene9/14/2006 290 ND ND ND NA ND ND 300 31 ND 120 ND 210 140 ND 900 1,000 270 1,600
3/20/2007 34 26 ND ND NA ND ND ND 30 26 15 ND 110 94 3.5J 66 800 140 540
9/10/2008
7/17/2009 230 <2.5 <2.5 ND NA ND 4.9 294 47.8 NA 56.3 ND 320 164 7.8 409 1,190 340 1,743
12/09/2009 16.7 36.3 <2.5 ND NA ND <2.5 13.9 17 NA 3.3 ND 82.5 36.1 <2.5 11.6 483 87.9 172.9
7/13/2011
10/19/2011 350 25 7.6 ND NA ND <0.5 160 24 NA 72 ND 80 57 <0.5 140 610 82 630
7/19/2012 35 31 11 ND NA ND <0.5 11 19 2.2 <1 ND 36 27 2.6 11 230 22 56
2/14/2013 7.7 <1.2 <1.2 ND NA ND <1.2 5.9 9.4 NA <1.2 ND 28.8 14.2 <1.2 3.1 131 16.3 44.1
11/11/2014 8.5 16.1 5.4 <25 <0.5 <12.5 <0.25 21.6 14.1 NA 0.73 ND 35.6 46 <0.25 9 182 39.9 60.7
5/29/2015 3.5 10.3 <0.25 <0.5 <0.5 <0.25 <0.25 18.8 10.7 NA <0.25 ND 28.7 33.3 <0.25 7.1 146 29.2 51.1
1/8/2016 1.4 <0.5 2 <0.5 <0.5 <0.5 <0.5 3 2 NA <0.5 ND 6.7 6.6 <0.5 1 58.9 10.6 10.1
8/31/2017
8/23/2018 <0.25 <0.25 <0.25 <0.5 <0.5 <0.25 <0.25 1.3 1.4 NA <0.25 <1.0 3.6 8.6 <0.25 <0.25 32.4 0.86 1.1
2/5/2019 <0.25 <0.25 <0.25 <0.5 <0.5 <0.25 <0.25 <0.25 <0.25 NA <0.25 <1.0 1.8J 0.71 <0.25 <0.25 <0.25 <0.25 <0.5
9/14/2006 3,400 <250 <250 NA <250 4,100 <250 ND <250 ND 2,000 720 ND 30,000 5,600 1,600 19,000
2/07/2007
3/20/2007
9/10/2008
7/17/2009
12/9/2009
7/13/2011 410 <12 <11 NA <8.4 3,200 <6.8 <0.059 <11 ND 1,700 460 220 14,000 4,300 1,100 17,000
10/19/2011
7/19/2012
2/14/2013
11/11/2014 48.8 226 <12.5 <25 <25 <12.5 <12.5 2,390 157 NA <12.5 ND 1,680 609 95.2 4,730 4,870 1,440 11,890
5/29/2015 50.1 <12.5 <12.5 <25 <25 <12.5 <12.5 2,530 123 NA <12.5 ND 1,260 412 109 6,640 3,250 897 11,450
1/8/2016
8/31/2017 52.8 <10.0 <10.0 <20.0 <20.0 <10.0 <10.0 2,210 74 NA <10.0 ND 927 225 101 5,450 2,090 <10.0 10,330
8/23/2018 68.4 <6.2 <6.2 <12.5 <12.5 <6.2 <6.2 2,580 99.1 NA 12.7 <25.0 1,000 <6.2 76.1 3,990 3,520 <6.2 11,770
2/5/2019 <6.2 <6.2 <6.2 <12.5 <12.5 <6.2 <6.2 2,280 90.2 NA <6.2 <25.0 930 309 90.9 3,250 2,660 705 9,920
1 70 70 3,000 3 0.4 70 600 70 25 20 5 6 70 70 600 400 400 500
5,000 6,900 8,500 NE 3,000 400 70,000 84,500 25,000 11,700 20,000 5,000 6,000 30,000 70,000 260,000 28,500 25,000 85,500
ND denotes not detected (Detection limits are unknown for sampling conducted prior to Terracon's involvement with the site.)
<- denotes less than method detection limit
J indicates estimated value
NS denotes not sampled.
NA denotes not analyzed.
NR denotes not reported.
Bold denotes levels above the 2L standard.
Bold and gray shading denotes levels above the GCL.
Not Sampled-LNAPL
MW-6 Not Sampled-LNAPL
Not Sampled-LNAPL
Not Sampled-LNAPL
Not Sampled-LNAPL
MW-5
Not Sampled-LNAPL
Not Sampled-LNAPL
Not Sampled-LNAPL
Not Sampled
Not Analyzed-Glassware Broke During Transit
2L Standard (ug/L)
GCL (ug/L)
Not Sampled-LNAPL
Not Sampled-LNAPL
4 of 7
TABLE 1
Summary of Groundwater Analytical Results
Arlington Branco Oil Company
Jonesville, North Carolina
Terracon Project No. 71149678A
NCDEQ Incident No. 30114
Well/Sample
I.D.
Date Collected
(mm/dd/yy)
Analytical Method
BenzeneDiisopropylEther(IPE)Styrenen-ButylbenzeneContaminant of Concern→
6200B
Chloromethanesec-ButylbenzeneXylenes(Total)EthylbenzeneIsopropylbenzenep-Isopropyltoluene1,3,5-Trimethylbenzene1,2-Dichloroethane1,2,4-Trimethylbenzenen-PropylbenzeneMethyleneChlorideChloroethaneMethyltert-butylether(MTBE)NaphthaleneToluene9/14/2006 ND ND ND ND NA ND ND ND ND ND ND ND ND ND ND ND ND ND ND
9/10/2008 <0.5 <0.5 <0.5 ND NA ND <0.5 <0.5 <0.5 <0.5 <0.5 ND <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <1.5
7/17/2009 <0.5 <0.5 <0.5 ND NA ND <0.5 <0.5 <0.5 NA <0.5 ND <2 <0.5 <0.5 <0.5 <0.5 <0.5 <1.5
12/9/2009
7/13/2011 0.58 <0.059 <0.054 ND NA ND <0.042 <0.054 <0.034 <0.059 <0.056 ND 3.5 <0.059 <0.034 0.85 <0.038 <0.038 0.84J
10/19/2011 0.76 <0.5 <0.5 ND NA ND <0.5 0.52 <0.5 <0.5 0.65J ND 0.59J <0.5 <0.5 <0.5 0.91 <0.5 1.4J
7/19/2012
2/14/2013
11/11/2014 <0.25 <0.25 <0.25 <25 <0.50 <12.5 <0.25 <0.25 <0.25 NA <0.25 ND <1 <0.25 <0.25 <0.25 <0.25 <0.25 <0.25
5/29/2015 <0.25 <0.25 <0.25 <0.5 <0.5 <0.5 <0.25 <0.25 <0.25 NA <0.25 ND <1 <0.25 <0.25 <0.25 <0.25 <0.25 <0.25
1/8/2016 0.49J <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 NA 0.27J ND <1 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5
8/31/2017 <0.25 <0.25 <0.25 <0.5 <0.5 <0.25 <0.25 <0.25 <0.25 NA <0.25 ND <0.25 <0.25 <0.25 <0.25 <0.25 <0.25 <0.25
8/23/2018 <0.25 <0.25 <0.25 <0.5 <0.5 <0.25 <0.25 <0.25 <0.25 NA <0.25 ND <0.25 <0.25 <0.25 <0.25 <0.25 <0.25 <0.25
2/5/2019 0.30J <0.25 <0.25 <0.5 <0.5 <0.25 <0.25 <0.25 <0.25 NA <0.25 <1.0 <1.0 <0.25 <0.25 <0.25 <0.25 <0.25 <0.5
12/1/2005 <250 <250 1,600 ND NA ND <250 <250 <250 NA <250 ND 18,000 <250 NA <250 76,000 12,000 15,600
8/3/2006
9/14/2006
2/7/2007
3/20/2007 19,000 <250 210J ND NA ND 2,100 7,400 310 ND 12,000 ND 3,100 100 NA 56,000 9,000 2,500 40,000
9/10/2008 10.1 <0.5 <0.5 ND NA ND <0.5 63.7 8.3 <0.5 1.6 ND 36.6 26.3 <0.5 10.6 103 45.9 62.5
7/17/2009 19.2 <2.5 <2.5 ND NA ND <2.5 260 27.7 NA 3.3 ND 227 90.5 <2.5 47 567 161 551.7
12/9/2009 14.2 43.2 <2.5 ND NA ND <2.5 289 36.8 NA <2.5 ND 197 113 <2.5 43.9 655 183 566.3
7/13/2011 8.8 7.7 4.7 ND NA ND <0.042 140 26 2.6 <0.056 ND 92 84 0.74 21 390 120 210
10/19/2011 12 9 4.3 ND NA ND <0.5 190 29 NA <1 ND 120 91 <0.5 27 380 120 260
7/19/2012 8.6 7.9 5.4 ND NA ND <0.5 200 23 3.5 <1 ND 150 80 <0.5 16 450 110 220.0
2/14/2013
11/11/2014
5/29/2015 4 <0.25 <0.25 <0.5 <0.5 <0.5 <0.25 55.5 9.9 NA 0.29J ND 43.8 25.7 <0.25 6.6 226 26.9 63.9
1/8/2016 41.3 <0.5 6 0.55J <0.5 <0.5 2 248.0 32.6 NA 6 ND 141.0 96.2 <0.5 37.4 489 158.0 381.3
8/31/2017
1 70 70 3,000 3 0.4 70 600 70 25 20 5 6 70 70 600 400 400 500
5,000 6,900 8,500 NE 3,000 400 70,000 84,500 25,000 11,700 20,000 5,000 6,000 30,000 70,000 260,000 28,500 25,000 85,500
ND denotes not detected (Detection limits are unknown for sampling conducted prior to Terracon's involvement with the site.)
<- denotes less than method detection limit
J indicates estimated value
NS denotes not sampled.
NA denotes not analyzed.
NR denotes not reported.
Bold denotes levels above the 2L standard.
Bold and gray shading denotes levels above the GCL.
Not Sampled-LNAPL
Not Sampled
Creek Not Sampled
Not Sampled-LNAPL
Not Sampled-LNAPL
Not Sampled
Not Sampled
2L Standard (ug/L)
GCL (ug/L)
WSW-1
Not Sampled
Not Sampled
5 of 7
TABLE 1
Summary of Groundwater Analytical Results
Arlington Branco Oil Company
Jonesville, North Carolina
Terracon Project No. 71149678A
NCDEQ Incident No. 30114
Well/Sample
I.D.
Date Collected
(mm/dd/yy)
Analytical Method
BenzeneDiisopropylEther(IPE)Styrenen-ButylbenzeneContaminant of Concern→
6200B
Chloromethanesec-ButylbenzeneXylenes(Total)EthylbenzeneIsopropylbenzenep-Isopropyltoluene1,3,5-Trimethylbenzene1,2-Dichloroethane1,2,4-Trimethylbenzenen-PropylbenzeneMethyleneChlorideChloroethaneMethyltert-butylether(MTBE)NaphthaleneToluene8/3/2006 1.1 ND ND NA NA ND ND ND NA ND ND NA ND ND ND ND
3/20/2007 ND ND ND NA ND ND ND ND ND 1.6J ND NA ND ND ND ND
9/10/2008 <0.5 <0.5 <0.5 NA <0.5 <0.5 <0.5 <0.5 <0.5 <2 <0.5 <0.5 <0.5 <0.5 <0.5 <1.5
11/11/2014
5/29/2015
1/8/2016
8/31/2017
8/3/2006 ND ND ND NA NA ND ND ND NA ND ND ND ND ND ND ND
3/20/2007 ND ND ND NA ND ND ND ND ND ND ND NA ND ND ND ND
9/10/2008 <0.5 <0.5 <0.5 NA <0.5 <0.5 <0.5 <0.5 <0.5 <2 <0.5 <0.5 <0.5 <0.5 <0.5 <1.5
11/11/2014
5/29/2015
1/8/2016
8/31/2017
1 70 70 3,000 3 0.4 70 600 70 25 20 5 6 70 70 600 400 400 500
5,000 6,900 8,500 NE 3,000 400 70,000 84,500 25,000 11,700 20,000 5,000 6,000 30,000 70,000 260,000 28,500 25,000 85,500
ND denotes not detected (Detection limits are unknown for sampling conducted prior to Terracon's involvement with the site.)
<- denotes less than method detection limit
J indicates estimated value
NS denotes not sampled.
NA denotes not analyzed.
NR denotes not reported.
Bold denotes levels above the 2L standard.
Bold and gray shading denotes levels above the GCL.
GCL (ug/L)
2L Standard (ug/L)
WSW-7
WSW-6
Not Sampled
Not Sampled
Not Sampled
Not Sampled
Not Sampled
Not Sampled
Not Sampled
Not Sampled
6 of 7
TABLE 3
Monitoring Well Construction Information
and Historical Groundwater Elevations
Arlington Branco Oil Company
Jonesville, North Carolina
Terracon Project No. 71149678A
NCDEQ Incident No. 30114
Well Id DateInstalled Date Water LevelMeasured Bottom of Well(ft. BGS)Top of CasingElevation (ft.)
Depth to Waterfrom Top ofCasing (ft.)
Free ProductThickness (ft)GroundwaterElevation (ft.)Comments
12/1/2005 13.49 -86.519/14/2006 13.43 -86.573/20/2007 12.74 -87.269/10/2008 14.26 -85.7412/9/2009 14.82 -85.187/17/2009 13.60 -86.407/13/2011 13.66 -86.3410/19/2011 13.50 -86.507/19/2012 13.21 -86.792/14/2013 12.66 -87.3411/11/2014 13.54 -86.465/29/2015 15.99 -84.011/8/2016 12.16 -87.848/31/2017 13.90 -86.108/23/2018 12.03 -87.97
12/1/2005 11.47 1.10 -
9/14/2006 13.60 0.17 -
2/7/2007 -0.09 -
3/20/2007 12.80 0.20 -
9/10/2008 14.51 0.24 -
12/9/2009 12.07 0.01 -
7/17/2009 ---
7/13/2011 13.80 -86.89
10/19/2011 13.97 -86.72
7/19/2012 13.13 -87.56
2/14/2013 12.67 -88.02
11/11/2014 13.74 -86.95
5/29/2015 14.95 -85.74
1/8/2016 ---
8/31/2017 14.14 -86.55
8/23/2018 11.82 -88.87
9/14/2006 14.66 -85.883/20/2007 14.73 -85.819/10/2008 15.55 -84.9912/9/2009 13.67 -86.877/17/2009 15.25 -85.297/13/2011 15.16 -85.3810/19/2011 15.06 -85.487/19/2012 15.01 -85.532/14/2013 14.75 -85.7911/11/2014 14.94 -85.605/29/2015 15.06 -85.481/8/2016 14.64 -85.908/31/2017 15.28 -85.268/23/2018 14.42 -86.12
9/14/2006 7.46 -94.11
3/20/2007 15.20 -86.37
9/10/2008 16.62 -84.95
12/9/2009 16.25 -85.32
7/17/2009 16.20 -85.37
7/13/2011 16.06 -85.51
10/19/2011 16.02 -85.55
7/19/2012 15.69 -85.88
2/14/2013 15.10 -86.47
11/11/2014 15.49 -86.08
5/29/2015 15.71 -85.86
1/8/2016 14.57 -87.00
8/31/2017 16.03 -85.548/23/2018 14.20 -87.37
9/14/2006 14.37 -87.64
3/20/2007 13.95 -88.06
9/10/2008 15.71 0.03 -
12/9/2009 13.61 -88.40
7/17/2009 14.44 -87.57
7/13/2011 15.97 -86.04
10/19/2011 15.15 -86.86
7/19/2012 14.24 -87.77
2/14/2013 13.64 -88.37
11/11/2014 14.92 -87.09
5/29/2015 14.98 -87.03
1/8/2016 13.11 -88.90
8/31/2017 ---
8/23/2018 12.89 -89.12
9/14/2006 13.47 -87.372/7/2007 -0.96 -3/20/2007 13.18 0.18 -9/10/2008 15.19 0.89 -12/9/2009 14.12 0.02 -7/17/2009 13.98 0.36 -7/13/2011 14.03 -86.8110/19/2011 16.40 Unknown -7/19/2012 13.51 0.03 -2/14/2013 13.11 0.04 -11/11/2014 14.12 -86.725/29/2015 14.12 -86.721/8/2016 12.53 0.02 88.338/31/2017 14.45 86.398/23/2018 12.40 -88.44
MW-5 9/14/2006 16.00 102.01
MW-6 9/14/2006 20.00 100.84
Odor/sheenpresent(8/31/17sampling)
MW-1 Unknown 17.00 100.00
Unknown 15.00 100.69
Odor/sheen
present
(8/31/17
sampling)
MW-3 8/03/2006 19.00 100.54
MW-2
MW-4 9/14/2006 22.00 101.57

APPENDIX A
AQTESOLV RESULTS
0.2.6 5.2 7.8 10.4 13.
0.001
0.01
0.1
1.
Time (min)Displacement(ft)MW-5 TEST 1
Data Set:N:\...\MW-5 Slug In Test 1.aqt
Date:12/07/21 Time:13:23:56
PROJECT INFORMATION
Company:Terracon Consultants
Client:NCDEQ
Project:75217015
Location:Jonesville, NC
Test Well:MW-5
Test Date:11/18/21
AQUIFER DATA
Saturated Thickness:3.68 ft Anisotropy Ratio (Kz/Kr):1.
WELL DATA (MW--5)
Initial Displacement:0.676 ft Static Water Column Height:12.32 ft
Total Well Penetration Depth:3.68 ft Screen Length:3.68 ft
Casing Radius:0.083 ft Well Radius:0.333 ft
SOLUTION
Aquifer Model:Confined Solution Method:Bouwer-Rice
K =0.0003829 ft/min y0 =0.04679 ft
AQTESOLV for Windows MW-5 Test 1
Data Set: N:\71 Environmental\Frazier Folder\75217015 - Arlington Branco\Slug Testing Data\MW-5 Slug In Test 1.aqt
Title: MW-5 Test 1
Date: 12/07/21
Time: 13:24:09
PROJECT INFORMATION
Company: Terracon Consultants
Client: NCDEQ
Project: 75217015
Location: Jonesville, NC
Test Date: 11/18/21
Test Well: MW-5
AQUIFER DATA
Saturated Thickness: 3.68 ft
Anisotropy Ratio (Kz/Kr): 1.
SLUG TEST WELL DATA
Test Well:MW--5
X Location: 0. ft
Y Location: 0. ft
Initial Displacement: 0.676 ft
Static Water Column Height: 12.32 ft
Casing Radius: 0.083 ft
Well Radius: 0.333 ft
Well Skin Radius: 0.333 ft
Screen Length: 3.68 ft
Total Well Penetration Depth: 3.68 ft
No. of Observations: 107
Observation Data
Time (min)Displacement (ft)Time (min)Displacement (ft)
0.0.0.562 0.006
0.00418 0.003 0.596 0.
0.00835 0.002 0.631 0.003
0.01467 0.0.668 0.003
0.01672 -0.001 0.708 0.001
0.02085 0.004 0.75 -0.001
0.02502 0.0.794 0.002
0.02918 -0.001 0.841 0.004
0.03373 0.005 0.891 0.005
0.03752 -0.003 0.944 0.676
0.04168 0.001 1.0.315
0.04585 -0.001 1.06 0.137
0.05002 0.003 1.12 0.078
0.05418 0.1.193 0.058
0.05835 0.002 1.26 0.051
0.06252 0.1.33 0.045
12/07/21 1 13:24:09
AQTESOLV for Windows MW-5 Test 1
Time (min)Displacement (ft)Time (min)Displacement (ft)
0.06668 0.005 1.41 0.037
0.07085 0.003 1.5 0.039
0.07502 0.1.58 0.028
0.07918 0.004 1.68 0.02
0.08335 0.1.78 0.026
0.08752 0.005 1.88 0.023
0.09168 0.005 1.99 0.021
0.09585 0.2.111 0.028
0.1 0.003 2.24 0.024
0.106 0.002 2.37 0.016
0.112 0.2.51 0.022
0.119 0.003 2.66 0.016
0.126 -0.002 2.82 0.016
0.133 0.002 2.98 0.016
0.141 0.006 3.16 0.019
0.15 0.001 3.35 0.015
0.158 0.006 3.55 0.013
0.168 0.001 3.76 0.015
0.178 0.002 3.98 0.015
0.188 0.001 4.22 0.011
0.199 0.005 4.47 0.013
0.211 -0.001 4.73 0.009
0.224 0.002 5.01 0.015
0.237 0.002 5.31 0.008
0.251 -0.005 5.62 0.007
0.266 0.004 5.96 0.016
0.282 0.003 6.31 0.011
0.298 0.002 6.68 0.012
0.316 0.7.08 0.008
0.335 0.006 7.5 0.009
0.355 0.003 7.94 0.012
0.376 0.004 8.41 0.014
0.398 0.005 8.91 0.014
0.422 0.01 9.44 0.018
0.447 0.003 10.0.011
0.473 0.004 10.6 0.017
0.501 0.005 11.2 0.016
0.531 0.004
SOLUTION
Slug Test
Aquifer Model: Confined
Solution Method: Bouwer-Rice
ln(Re/rw): 1.728
VISUAL ESTIMATION RESULTS
Estimated Parameters
Parameter Estimate
K 0.0003829 ft/min
y0 0.04679 ft
12/07/21 2 13:24:09
AQTESOLV for Windows MW-5 Test 1
K = 0.0001945 cm/sec
T = K*b = 0.001409 ft²/min (0.02182 sq. cm/sec)
12/07/21 3 13:24:10
0.6.12.18.24.30.
-1.
-0.6
-0.2
0.2
0.6
1.
Time (min)NormalizedHead(ft/ft)SLUG OUT
Data Set:N:\...\MW-5 Slug Out.aqt
Date:12/07/21 Time:13:19:43
PROJECT INFORMATION
Company:Terracon Consultants
Client:NCDEQ
Project:75217015
Location:Jonesville, NC
Test Well:MW-5
Test Date:11/18/21
AQUIFER DATA
Saturated Thickness:3.68 ft Anisotropy Ratio (Kz/Kr):1.
WELL DATA (MW-5)
Initial Displacement:0.472 ft Static Water Column Height:12.32 ft
Total Well Penetration Depth:3.68 ft Screen Length:3.68 ft
Casing Radius:0.083 ft Well Radius:0.333 ft
0.0.1 0.2 0.3 0.4 0.5
0.001
0.01
0.1
1.
Time (min)NormalizedHead(ft/ft)SLUG OUT
Data Set:N:\...\MW-5 Slug Out.aqt
Date:12/07/21 Time:13:21:21
PROJECT INFORMATION
Company:Terracon Consultants
Client:NCDEQ
Project:75217015
Location:Jonesville, NC
Test Well:MW-5
Test Date:11/18/21
AQUIFER DATA
Saturated Thickness:3.68 ft Anisotropy Ratio (Kz/Kr):1.
WELL DATA (MW-5)
Initial Displacement:0.472 ft Static Water Column Height:12.32 ft
Total Well Penetration Depth:3.68 ft Screen Length:3.68 ft
Casing Radius:0.083 ft Well Radius:0.333 ft
SOLUTION
Aquifer Model:Confined Solution Method:Bouwer-Rice
K =0.01045 ft/min y0 =0.008032 ft
AQTESOLV for Windows Slug Out
Data Set: N:\71 Environmental\Frazier Folder\75217015 - Arlington Branco\Slug Testing Data\MW-5 Slug Out.aqt
Title: Slug Out
Date: 12/07/21
Time: 13:21:34
PROJECT INFORMATION
Company: Terracon Consultants
Client: NCDEQ
Project: 75217015
Location: Jonesville, NC
Test Date: 11/18/21
Test Well: MW-5
AQUIFER DATA
Saturated Thickness: 3.68 ft
Anisotropy Ratio (Kz/Kr): 1.
SLUG TEST WELL DATA
Test Well:MW-5
X Location: 0. ft
Y Location: 0. ft
Initial Displacement: 0.472 ft
Static Water Column Height: 12.32 ft
Casing Radius: 0.083 ft
Well Radius: 0.333 ft
Well Skin Radius: 0.333 ft
Screen Length: 3.68 ft
Total Well Penetration Depth: 3.68 ft
No. of Observations: 120
Observation Data
Time (min)Displacement (ft)Time (min)Displacement (ft)
0.0.0.794 -0.118
0.00418 0.006 0.841 -0.079
0.00835 -0.002 0.891 -0.058
0.01252 -0.004 0.944 -0.043
0.01668 0.002 1.-0.033
0.02085 -0.001 1.06 -0.029
0.02502 0.004 1.12 -0.02
0.02918 0.004 1.19 -0.023
0.03335 0.001 1.26 -0.028
0.03752 0.006 1.33 -0.022
0.04168 0.004 1.41 -0.021
0.04585 0.006 1.5 -0.017
0.05002 0.002 1.58 -0.016
0.05418 0.006 1.68 -0.02
0.05835 0.1.78 -0.017
0.06252 0.002 1.88 -0.02
12/07/21 1 13:21:34
AQTESOLV for Windows Slug Out
Time (min)Displacement (ft)Time (min)Displacement (ft)
0.06668 0.004 1.99 -0.015
0.07085 -0.005 2.11 -0.024
0.07502 0.002 2.24 -0.013
0.07918 0.002 2.37 -0.018
0.08335 -0.002 2.51 -0.02
0.08752 0.002 2.66 -0.014
0.09168 -0.001 2.822 -0.015
0.09585 0.002 2.98 -0.016
0.1 0.3.16 -0.013
0.106 -0.002 3.35 -0.013
0.112 0.3.55 -0.015
0.119 0.011 3.76 -0.006
0.126 0.001 3.98 -0.011
0.133 -0.002 4.22 -0.015
0.141 0.005 4.47 -0.011
0.15 0.002 4.73 -0.01
0.158 0.005 5.01 -0.011
0.168 0.001 5.31 -0.007
0.178 -0.004 5.62 -0.006
0.188 0.003 5.96 -0.005
0.199 -0.002 6.31 -0.016
0.211 0.6.68 -0.016
0.224 0.005 7.08 -0.002
0.237 0.7.5 0.
0.251 -0.003 7.94 -0.005
0.266 -0.002 8.41 -0.011
0.282 -0.001 8.91 -0.011
0.298 0.9.44 0.
0.316 0.001 10.-0.013
0.335 -0.001 10.6 -0.01
0.355 -0.003 11.2 -0.007
0.376 -0.003 11.9 -0.009
0.398 0.004 12.6 -0.006
0.422 -0.002 13.3 -0.004
0.447 -0.002 14.1 -0.006
0.473 -0.004 15.-0.005
0.501 0.15.8 -0.013
0.5314 -0.001 16.8 -0.006
0.562 -0.001 17.8 -0.009
0.596 0.006 18.8 -0.005
0.631 -0.001 19.8 -0.009
0.668 -0.303 20.8 -0.006
0.708 -0.472 21.8 -0.008
0.75 -0.219 22.8 -0.012
SOLUTION
Slug Test
Aquifer Model: Confined
Solution Method: Bouwer-Rice
ln(Re/rw): 1.728
VISUAL ESTIMATION RESULTS
12/07/21 2 13:21:34
AQTESOLV for Windows Slug Out
Estimated Parameters
Parameter Estimate
K 0.01045 ft/min
y0 0.008032 ft
K = 0.00531 cm/sec
T = K*b = 0.03846 ft²/min (0.5956 sq. cm/sec)
12/07/21 3 13:21:34
0.2.4 4.8 7.2 9.6 12.
0.001
0.01
0.1
1.
Time (min)Displacement(ft)SLUG TEST 2
Data Set:N:\...\MW-5 Test 2.aqt
Date:12/07/21 Time:12:01:01
PROJECT INFORMATION
Company:Terracon Consultants
Client:NCDEQ
Project:75217015
Location:Jonesville, NC
Test Well:MW-5
Test Date:11/18/21
AQUIFER DATA
Saturated Thickness:3.68 ft Anisotropy Ratio (Kz/Kr):1.
WELL DATA (MW-5)
Initial Displacement:0.828 ft Static Water Column Height:12.32 ft
Total Well Penetration Depth:3.68 ft Screen Length:3.68 ft
Casing Radius:0.083 ft Well Radius:0.333 ft
SOLUTION
Aquifer Model:Confined Solution Method:Bouwer-Rice
K =0.0002154 ft/min y0 =0.02314 ft
AQTESOLV for Windows Slug Test 2
Data Set: N:\71 Environmental\Frazier Folder\75217015 - Arlington Branco\Slug Testing Data\MW-5 Test 2.aqt
Title: Slug Test 2
Date: 12/07/21
Time: 12:02:04
PROJECT INFORMATION
Company: Terracon Consultants
Client: NCDEQ
Project: 75217015
Location: Jonesville, NC
Test Date: 11/18/21
Test Well: MW-5
AQUIFER DATA
Saturated Thickness: 3.68 ft
Anisotropy Ratio (Kz/Kr): 1.
SLUG TEST WELL DATA
Test Well:MW-5
X Location: 0. ft
Y Location: 0. ft
Initial Displacement: 0.828 ft
Static Water Column Height: 12.32 ft
Casing Radius: 0.083 ft
Well Radius: 0.333 ft
Well Skin Radius: 0.333 ft
Screen Length: 3.68 ft
Total Well Penetration Depth: 3.68 ft
No. of Observations: 107
Observation Data
Time (min)Displacement (ft)Time (min)Displacement (ft)
0.0.0.562 0.168
0.004167 0.004 0.596 0.114
0.008333 0.005 0.631 0.08
0.01467 0.002 0.668 0.058
0.01672 0.006 0.708 0.05
0.02083 -0.002 0.75 0.047
0.025 0.003 0.794 0.042
0.02917 0.001 0.841 0.042
0.03542 0.008 0.891 0.029
0.03745 0.001 0.9493 0.026
0.04167 -0.002 1.0.026
0.04583 -0.002 1.06 0.025
0.05 0.005 1.12 0.023
0.05417 0.002 1.19 0.028
0.05833 0.004 1.26 0.026
0.0625 0.003 1.33 0.017
12/07/21 1 12:02:04
AQTESOLV for Windows Slug Test 2
Time (min)Displacement (ft)Time (min)Displacement (ft)
0.06667 0.002 1.41 0.022
0.07083 0.003 1.5 0.019
0.075 0.004 1.58 0.015
0.07917 0.006 1.68 0.019
0.08333 0.01 1.784 0.016
0.0875 0.003 1.88 0.012
0.09167 0.003 1.99 0.021
0.09583 -0.003 2.11 0.016
0.1 -0.001 2.24 0.015
0.106 -0.001 2.37 0.02
0.1147 -0.002 2.51 0.014
0.119 0.007 2.66 0.015
0.126 0.2.82 0.01
0.133 0.001 2.98 0.015
0.141 -0.002 3.16 0.016
0.15 0.001 3.35 0.012
0.158 0.001 3.55 0.012
0.168 0.001 3.76 0.011
0.178 -0.006 3.98 0.014
0.188 0.003 4.22 0.007
0.199 0.004 4.47 0.012
0.211 0.002 4.73 0.004
0.224 0.005 5.01 0.008
0.237 -0.002 5.31 0.006
0.251 0.5.62 0.007
0.266 0.006 5.962 0.006
0.282 -0.001 6.31 0.003
0.298 0.006 6.68 0.008
0.316 0.7.08 0.009
0.335 0.7.5 0.011
0.355 0.7.94 0.011
0.376 -0.002 8.41 0.004
0.398 -0.001 8.91 0.01
0.422 0.005 9.44 0.001
0.4484 -0.001 10.0.004
0.473 0.828 10.6 0.006
0.501 0.456 11.2 0.002
0.5319 0.268
SOLUTION
Slug Test
Aquifer Model: Confined
Solution Method: Bouwer-Rice
ln(Re/rw): 1.728
VISUAL ESTIMATION RESULTS
Estimated Parameters
Parameter Estimate
K 0.0002154 ft/min
y0 0.02314 ft
12/07/21 2 12:02:04
AQTESOLV for Windows Slug Test 2
K = 0.0001094 cm/sec
T = K*b = 0.0007925 ft²/min (0.01227 sq. cm/sec)
12/07/21 3 12:02:04

APPENDIX B
RBCA TOOLKIT MODEL RESULTS

RBCA Tool Kit for Chemical Releases, Version 2.6
#4. RBCA Evaluation Process
1. Project Information
Site Name:
Location:
Completed By:
Date:10-Dec-21 Job ID:75217015
2. Which Type of RBCA Analysis?
####
####
####
3. Calculation Options
###
###
Individual Constituent Risk Goals Only
Individual and Cumulative Risk Goals 5. Commands and Options
Apply Source Depletion Algorithm
Time to Future Exposure 0 (yr)
Terracon Consultants, Inc.
270 North Main Street, Jonesville, North Carolina
Arlington Branco Oil Company (Incident #30114)
Baseline Risks (Forward mode)
RBCA Cleanup Levels (Backward mode)
Main Screen
Affects which input data are required
Prepare Input Data Review Output
Data Complete? ( = yes, = no)
Site-Specific
Target Levels
Risk-Based
Screening
Levels
Tier 1 Tier 2/3
RBCA Tool Kit for Chemical Releases
© 2011 GSI Environmental Inc.Version 2.6
User Chemical
Database
?
Print Sheet
New Site
QuitHelp
Save Data As...
?
Set Units Print Report
Load Data...
Exposure Pathways
Air ParametersAir Parameters
GW Parameters
Soil ParametersSoil Parameters
Transport Models
Constituents of Concern
(COC s)
Exposure Flowchart
COC Chem. Parameters
Input Data Summary
User-Spec. COC Data...
Transient Domenico Analysis...
Baseline Risks...
Cleanup Levels...Cleanup Levels...
RBCA Tool Kit for Chemical Releases, Version 2.6
#Site Name: Arlington Branco Oil Company (Incident #30114)
Location: 270 North Main Street, Jonesville, North Carolina 1. Groundwater Exposure Compl. By: Terracon Consultants, Inc.
Groundwater Ingestion/Job ID: 75217015 Date: 10-Dec-21
Surface Water Impact 3. Air Exposure
Receptor: to Outdoor Air Inhalation
On-site Off-site1 Off-site2 Receptor:
Distance:0 30 0 (ft)On-site Off-site1 Off-site2
Source Media:Distance:0 0 0 (ft)
Affected Groundwater Source Media:Construction worker
Affected Soils Leaching to Groundwater Affected Soils--Volatilization to Ambient Outdoor Air
Option:Affected Groundwater--Volatilization to Ambient Outdoor Air
Apply MCL value as ingestion RBEL (backward mode only)Affected Surface Soils--Particulates to Ambient Outdoor Air
GW Discharge to Surface Water Exposure Volatilization to Indoor Air Inhalation
Swimming Receptor:
Fish Consumption On-site Off-site1 Off-site2
Specified Water Quality Criteria Source Media:Distance:0 0 0 (ft)
Affected Soils--Volatilization to Enclosed Space
Affected Soils Leaching to GW--Volatilization to Enclosed Space 2. Surface Soil Exposure Affected Groundwater--Volatilization to Enclosed Space
Source Media:
Receptor: Direct Ingestion 4. Commands and Options
On-site Dermal Contact
Construction Worker Inhalation (vol+part)
Option: Vegetable Ingestion
Apply UK (CLEA) SGV as soil concentration limit
Combined Exposure
Volatilization and Particulates
Exposure Pathway Identification
Main Screen Print Sheet Help
?
?
?
Exposure Flowchart
Set Units
?
Veg OptionsVeg Options
Bldg OptionsBldg Options
Exposure Factors & Target Risks
Enter CriteriaEnter Criteria
RBCA Tool Kit for Chemical Releases, Version 2.6
#Site Name: Arlington Branco Oil Company (Incident #30114)Job ID: 75217015
Location: 270 North Main Street, Jonesville, North Carolina Date: 10-Dec-21
1. Water-Bearing Unit Compl. By: Terracon Consultants, Inc.
Hydrogeology 3. Groundwater Dispersion
Groundwater Darcy velocity 3.6E+1 (ft/yr)Model:GW Ingestion
Groundwater seepage velocity 9.6E+1 (ft/yr)Off-site 1 Off-site 2 Off-site 1 Off-site 2
or Distance to GW receptors 30 0 0 0 (ft)
Hydraulic conductivity 1.9E+3 (ft/yr)
Hydraulic gradient 0.01875 (-)Longitudinal dispersivity 3 0 0 0 (ft)
Effective porosity 0.38 (-)Transverse dispersivity 0.99 0 0 0 (ft)
Sorption Vertical dispersivity 0.15 0 0 0 (ft)
Fraction organic carbon--saturated zone 0.001 (-) 4. Groundwater Discharge to Surface Water
Groundwater pH 6.2 (-)
2. Groundwater Source Zone Off-site 2
Groundwater plume width at source 35 (ft)Distance to GW/SW disharge point NA (ft)
Plume (mixing zone) thickness at source 5 (ft)
Plume width at GW/SW discharge 0 (ft)
Saturated thickness 5 (ft)Plume thickness at GW/SW discharge 0 (ft)
Length of source zone 147.637795 (ft)
Surface water flowrate at GW/SW discharge (ft^3/yr)
5. Commands and Options
0.0E+0
GW to Indoor Air
Site-Specific Groundwater Parameters
or
or
?
?
?
Main Screen Use/Set Default
ValuesSet Units
Print Sheet
Help
?
RBCA Tool Kit for Chemical Releases, Version 2.6
##Site Name: Arlington Branco Oil Company (Incident #30114)Job ID: 75217015
Location: 270 North Main Street, Jonesville, North Carolina Date: 10-Dec-21
1. Vertical Transport, Surface Soil Column Compl. By: Terracon Consultants, Inc.
Outdoor Air Volatilization Factors 3. Groundwater Dilution Attenuation Factor
Surface soil volatilization model only
Combination surface soil/Johnson & Ettinger models
Thickness of surface soil zone 3.28 (ft)Calculate DAF using Domenico Model
User-specified VF from other model Domenico equation with dispersion only (no biodegradation)
Indoor Air Volatilization Factors Domenico equation first-order decay
Johnson & Ettinger model for soil and groundwater volatilization Modified Domenico equation using
Johnson & Ettinger for soil, Mass Flux model for groundwater electron acceptor superposition
User-specified VF from other model Biodegradation Capacity NC (mg/L)
Soil-to-Groundwater Leaching Factor — or —
ASTM Model User-Specified DAF Values
Apply Soil Attenuation Model (SAM)DAF values from other model or site data
Allow first-order biodecay
User-specified LF from other model 4. Chemical Decay and Source Depletion
Modeling Options
Disable Mass Balance Limit
Apply Dual Equilibrium Desorption Model
2. Lateral Air Dispersion Factor 5. Commands and Options
3-D Gaussian dispersion model Off-site 1 Off-site 2
User-Specified ADF 1.00E+0 1.00E+0 (-)
Transport Modeling Options
C
Enter VF ValuesEnter VF Values
Print SheetMain Screen Help
?
?
ASTM ModelASTM Model
?
Enter Source MassEnter Source Mass
Enter Decay RatesEnter Decay Rates
Enter DAF ValuesEnter DAF Values
Enter Site DataEnter Site Data
Enter Decay RatesEnter Decay Rates
Enter Decay RatesEnter Decay Rates
Enter LF ValuesEnter LF Values
Enter VF ValuesEnter VF Values
?
?
?
?
C
RBCA Tool Kit for Chemical Releases, Version 2.6
RBCA SITE ASSESSMENT Tier 2 Domenico Groundwater Modeling Summary
Site Name: Arlington Branco Oil Company (Incident #30114)Site Location: 270 North Main Street, Jonesville, North CarolinaCompleted By: Terracon Consultants, Inc. Date Completed: 10-Dec-21 2 OF 2
DOMENICO GROUNDWATER MODELING SUMMARY
OFF-SITE GROUNDWATER EXPOSURE PATHWAYS n (CHECKED IF PATHWAY IS ACTIVE)
GROUNDWATER:
INGESTION 1) Source Medium 2) Steady-state Exposure Concentration 3) POE Concentration Limit 4) Time to Reach POE Conc. Limit
Groundwater: POE Conc. (mg/L)Groundwater: POE Conc. (mg/L)Conc reaches limit? ("n" If yes) ; Time (yr)
Groundwater Off-site 1
(30 ft)
Off-site 2
(0 ft)
Off-site 1
(30 ft)
Off-site 2
(0 ft)
Off-site 1
(30 ft)
Off-site 2
(0 ft)
Constituents of Concern Conc. (mg/L)Commercial None Commercial None Commercial None
Benzene 5.8E-1 5.1E-1 1.9E-1 n 3.5E-1 NA
Toluene 4.3E-3 3.8E-3 8.2E+0 o NA NA
Ethyl benzene 3.8E-3 3.4E-3 1.0E+1 o NA NA
Xylenes (mixed isomers)2.7E-2 2.4E-2 2.0E+1 o NA NA
Naphthalene 4.4E-2 3.9E-2 2.0E+0 o NA NA
Cumene 8.2E-3 7.2E-3 1.0E+1 o NA NA
Diisopropyl ether (2,2'-oxybis-propane)7.8E-2 6.9E-2 1.0E+1 o NA NA
Propylbenzene, n-1.5E-2 1.3E-2 4.1E+0 o NA NA
Trimethylbenzene, 1,2,4-1.6E-3 1.4E-3 5.1E+0 o NA NA
NOTE: POE = Point of exposure
RBCA Tool Kit for Chemical Releases, Version 2.6
##Site Name: Arlington Branco Oil Company (Incident #30114)Job ID: 75217015
Location: 270 North Main Street, Jonesville, North Carolina Date: 10-Dec-21
1. Vertical Transport, Surface Soil Column Compl. By: Terracon Consultants, Inc.
Outdoor Air Volatilization Factors 3. Groundwater Dilution Attenuation Factor
Surface soil volatilization model only
Combination surface soil/Johnson & Ettinger models
Thickness of surface soil zone 3.28 (ft)Calculate DAF using Domenico Model
User-specified VF from other model Domenico equation with dispersion only (no biodegradation)
Indoor Air Volatilization Factors Domenico equation first-order decay
Johnson & Ettinger model for soil and groundwater volatilization Modified Domenico equation using
Johnson & Ettinger for soil, Mass Flux model for groundwater electron acceptor superposition
User-specified VF from other model Biodegradation Capacity NC (mg/L)
Soil-to-Groundwater Leaching Factor — or —
ASTM Model User-Specified DAF Values
Apply Soil Attenuation Model (SAM)DAF values from other model or site data
Allow first-order biodecay
User-specified LF from other model 4. Chemical Decay and Source Depletion
Modeling Options
Disable Mass Balance Limit
Apply Dual Equilibrium Desorption Model
2. Lateral Air Dispersion Factor 5. Commands and Options
3-D Gaussian dispersion model Off-site 1 Off-site 2
User-Specified ADF 1.00E+0 1.00E+0 (-)
Transport Modeling Options
C
Enter VF ValuesEnter VF Values
Print SheetMain Screen Help
?
?
ASTM ModelASTM Model
?
Enter Source MassEnter Source Mass
Enter Decay RatesEnter Decay Rates
Enter DAF ValuesEnter DAF Values
Enter Site DataEnter Site Data
Enter Decay Rates
Enter Decay RatesEnter Decay Rates
Enter LF ValuesEnter LF Values
Enter VF ValuesEnter VF Values
?
?
?
?
C
RBCA Tool Kit for Chemical Releases, Version 2.6
RBCA SITE ASSESSMENT Tier 2 Domenico Groundwater Modeling Summary
Site Name: Arlington Branco Oil Company (Incident #30114)Site Location: 270 North Main Street, Jonesville, North CarolinaCompleted By: Terracon Consultants, Inc. Date Completed: 10-Dec-21 2 OF 2
DOMENICO GROUNDWATER MODELING SUMMARY
OFF-SITE GROUNDWATER EXPOSURE PATHWAYS n (CHECKED IF PATHWAY IS ACTIVE)
GROUNDWATER:
INGESTION 1) Source Medium 2) Steady-state Exposure Concentration 3) POE Concentration Limit 4) Time to Reach POE Conc. Limit
Groundwater: POE Conc. (mg/L)Groundwater: POE Conc. (mg/L)Conc reaches limit? ("n" If yes) ; Time (yr)
Groundwater Off-site 1
(30 ft)
Off-site 2
(0 ft)
Off-site 1
(30 ft)
Off-site 2
(0 ft)
Off-site 1
(30 ft)
Off-site 2
(0 ft)
Constituents of Concern Conc. (mg/L)Commercial None Commercial None Commercial None
Benzene 5.8E-1 4.5E-1 1.9E-1 n 3.7E-1 NA
Toluene 4.3E-3 1.2E-4 8.2E+0 o NA NA
Ethyl benzene 3.8E-3 1.8E-3 1.0E+1 o NA NA
Xylenes (mixed isomers)2.7E-2 1.6E-2 2.0E+1 o NA NA
Naphthalene 4.4E-2 5.1E-3 2.0E+0 o NA NA
Cumene 8.2E-3 2.5E-13 1.0E+1 o NA NA
Trimethylbenzene, 1,2,4-1.6E-3 1.0E-5 5.1E+0 o NA NA
NOTE: POE = Point of exposure
RBCA Tool Kit for Chemical Releases, Version 2.6
#Site Name: Arlington Branco Oil Company (Incident #30114)
Location: 270 North Main Street, Jonesville, North Carolina 1. Groundwater Exposure Compl. By: Terracon Consultants, Inc.
Groundwater Ingestion/Job ID: 75217015 Date: 10-Dec-21
Surface Water Impact 3. Air Exposure
Receptor: to Outdoor Air Inhalation
On-site Off-site1 Off-site2 Receptor:
Distance:0 115 145 (ft)On-site Off-site1 Off-site2
Source Media:Distance:0 0 0 (ft)
Affected Groundwater Source Media:Construction worker
Affected Soils Leaching to Groundwater Affected Soils--Volatilization to Ambient Outdoor Air
Option:Affected Groundwater--Volatilization to Ambient Outdoor Air
Apply MCL value as ingestion RBEL (backward mode only)Affected Surface Soils--Particulates to Ambient Outdoor Air
GW Discharge to Surface Water Exposure Volatilization to Indoor Air Inhalation
Swimming Receptor:
Fish Consumption On-site Off-site1 Off-site2
Specified Water Quality Criteria Source Media:Distance:0 0 0 (ft)
Affected Soils--Volatilization to Enclosed Space
Affected Soils Leaching to GW--Volatilization to Enclosed Space 2. Surface Soil Exposure Affected Groundwater--Volatilization to Enclosed Space
Source Media:
Receptor: Direct Ingestion 4. Commands and Options
On-site Dermal Contact
Construction Worker Inhalation (vol+part)
Option: Vegetable Ingestion
Apply UK (CLEA) SGV as soil concentration limit
Combined Exposure
Volatilization and Particulates
Exposure Pathway Identification
Main Screen Print Sheet Help
?
?
?
Exposure Flowchart
Set Units
?
Veg OptionsVeg Options
Bldg OptionsBldg Options
Exposure Factors & Target Risks
Enter CriteriaEnter Criteria
RBCA Tool Kit for Chemical Releases, Version 2.6
Site Name: Arlington Branco Oil Company (Incident #30114)Job ID: 75217015 Commands and Options
Location: 270 North Main Street, Jonesville, North Carolina Date: 10-Dec-21
Compl. By: Terracon Consultants, Inc.
Selected COCs Representative COC Concentration
Groundwater Source Zone Soil Source Zone Mole Fraction
o n in Source
n o Material
(mg/L)note (mg/kg)note (-)
Benzene 9.2E+0 2005 Concentrations for MW-1
Toluene 1.1E+1
Ethyl benzene 2.7E+0
Xylenes (mixed isomers)1.0E+1
Naphthalene 1.1E+0
Cumene 7.9E-2
Trimethylbenzene, 1,2,4-4.5E-1
Apply
Raoult's
Law
Source Media Constituents of Concern (COCs)
COC Select:Sort List:
Top
Bottom
MoveUpAdd/Insert
Delete MoveDown
Main Screen Print Sheet Help
?
??
View Chemical Parameters
Enter Site DataEnter Site Data Enter Site DataEnter Site Data
RBCA Tool Kit for Chemical Releases, Version 2.6
RBCA SITE ASSESSMENT TIER 2 TRANSIENT DOMENICO ANALYSIS
Site Name: Arlington Branco Oil Company (Incident #30114)Completed By: Terracon Consultants, Inc.Job ID: 75217015
Site Location: 270 North Main Street, Jonesville, North CarolinaDate Completed: 10-Dec-21 1 of 7
Constiuent:Benzene
Source Medium:Affected Groundwater
Biodegredation:1st Order
Concentration vs. Distance from Source Time (yr)14.0 FALSE 10 Off-site1 Off-site2
(for given time)1 ##Commercial Commercial
Distance (ft)0 14.5 29 43.5 58 72.5 87 101.5 116 130.5 145 ###115 145
t = 14.0 yr 9.2E+0 8.1E+0 6.4E+0 4.1E+0 2.6E+0 1.6E+0 1.1E+0 7.3E-1 5.1E-1 3.7E-1 2.7E-1 ###5.2E-1 2.7E-1
Steady-state 9.2E+0 8.1E+0 6.4E+0 4.1E+0 2.6E+0 1.6E+0 1.1E+0 7.3E-1 5.1E-1 3.7E-1 2.7E-1 #####5.2E-1 2.7E-1
POE Concentration Limit (mg/L)1.9E-1 4.1E-1
t = 14.0 yr
Concentration vs. Time Distance (ft)15 1
(for given distance from source)0 0 9.0E+0
Time (yr)0 3 6 9 12 15 18 21 24 27 30 30 Time to Reach
x = 15 ft 0.0E+0 8.0E+0 8.0E+0 8.0E+0 8.0E+0 8.0E+0 8.0E+0 8.0E+0 8.0E+0 8.0E+0 8.0E+0 #####Conc. Limit (yr)
Off-site1 (115 ft)0.0E+0 3.5E-1 5.2E-1 5.2E-1 5.2E-1 5.2E-1 5.2E-1 5.2E-1 5.2E-1 5.2E-1 5.2E-1 Off-site1 2.2
Off-site2 (145 ft)0.0E+0 1.3E-1 2.6E-1 2.7E-1 2.7E-1 2.7E-1 2.7E-1 2.7E-1 2.7E-1 2.7E-1 2.7E-1 Off-site2 NA
x = 15 ftConc.(mg/L)Conc.(mg/L)0.0E+0
2.0E+0
4.0E+0
6.0E+0
8.0E+0
1.0E+1
0 20 40 60 80 100 120 140Conc.(mg/L)Distance
Steady-state
t = 14.0 yr
Off-site1 Conc.Limit
Off-site2 Conc.Limit
0.0E+0
1.0E+0
2.0E+0
3.0E+0
4.0E+0
5.0E+0
6.0E+0
7.0E+0
8.0E+0
9.0E+0
0 5 10 15 20 25 30Conc.(mg/L)Time (yr)
x = 15 ft
Off-site1 (115 ft)
Off-site2 (145 ft)
Off-site1 Conc.Limit
Off-site2 Conc.Limit
RBCA Tool Kit for Chemical Releases, Version 2.6
RBCA SITE ASSESSMENT Tier 2 Domenico Groundwater Modeling Summary
Site Name: Arlington Branco Oil Company (Incident #30114)Site Location: 270 North Main Street, Jonesville, North CarolinaCompleted By: Terracon Consultants, Inc. Date Completed: 10-Dec-21 2 OF 2
DOMENICO GROUNDWATER MODELING SUMMARY
OFF-SITE GROUNDWATER EXPOSURE PATHWAYS n (CHECKED IF PATHWAY IS ACTIVE)
GROUNDWATER:
INGESTION 1) Source Medium 2) Steady-state Exposure Concentration 3) POE Concentration Limit 4) Time to Reach POE Conc. Limit
Groundwater: POE Conc. (mg/L)Groundwater: POE Conc. (mg/L)Conc reaches limit? ("n" If yes) ; Time (yr)
Groundwater Off-site 1
(115 ft)
Off-site 2
(145 ft)
Off-site 1
(115 ft)
Off-site 2
(145 ft)
Off-site 1
(115 ft)
Off-site 2
(145 ft)
Constituents of Concern Conc. (mg/L)Commercial Commercial Commercial Commercial Commercial Commercial
Benzene 9.2E+0 5.2E-1 2.7E-1 1.9E-1 4.1E-1 n 2.2E+0 o NA
Toluene 1.1E+1 1.2E-6 8.3E-8 8.2E+0 8.2E+0 o NA o NA
Ethyl benzene 2.7E+0 1.1E-2 3.4E-3 1.0E+1 1.0E+1 o NA o NA
Xylenes (mixed isomers)1.0E+1 1.0E-1 3.9E-2 2.0E+1 2.0E+1 o NA o NA
Naphthalene 1.1E+0 1.4E-5 1.9E-6 2.0E+0 2.0E+0 o NA o NA
Cumene 7.9E-2 1.9E-34 8.7E-39 1.0E+1 1.0E+1 o NA o NA
Trimethylbenzene, 1,2,4-4.5E-1 4.3E-10 1.7E-11 5.1E+0 5.1E+0 o NA o NA
NOTE: POE = Point of exposure