MO-9494_47003_CA_FS_20231219

100 East Ruffin Street, Mebane, North Carolina 27302
Telephone [phone] ·Facsimile [phone]
www.terraquestpc.com

CORRECTIVE ACTION PLAN FEASIBILITY STUDY

LITTLE MARKET BASKET #1
3541 TAYLORSVILLE HWY
STATESVILLE, IREDELL COUNTY, NC 28677

Release Information
Date Discovered: 9/30/19 lab confirmed
Estimated Release Quantity: Unknown
Release Cause/Source: Commercial 5,000-gallon kerosene UST dispenser

Tanks removed in 1987:
1, 4,000-gallon kerosene
1, 3,000-gallon unknown contents
1, 2,000-gallon unknown contents

Tanks removed in 2019:
1, compartmentalized tank 4,000-gallon gasoline and 8,000-gallon gasoline
1, 2,000-gallon diesel
1, 5,000-gallon kerosene (release confirmed)
1, 4,000-gallon gasoline

Tanks installed in 2020:
1, compartmentalized tank gas: 10,000-gallon reg, 6,000-gallon prem, 4,000-gallon e-free mid
1, compartmentalized tank 4k-gallon diesel, 4k-gallon off-road diesel

Facility ID: 00-0-0000021441
NCDWM-UST Incident No.: 47003
NCDWM-UST Risk Ranking: High 205D
Latitude: 35.809521 N Longitude: -80.948539 W

Responsible Party & Subject UST Owner Property Owner
Bumgarner Oil Company, Inc. Ronald Hunt
PO Box 126 1337 NC Highway 16 S
Hickory, NC 28603 Taylorsville NC 28681

Terraquest Project No. 09419

December 19, 2023

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 i Statesville, Iredell County, NC
EXECUTIVE SUMMARY

Terraquest Environmental Consultants, P.C. has completed a CAP Feasibility Study for the release
incident at the Little Market Basket #1 facility located in Statesville, Iredell County, North Carolina.
This work is related to a release from a petroleum UST system. The NCDWM-UST requested the
work that included pilot testing, calculations, and considerations of active and passive remedial
methods.

In consideration of the contamination present and treatment methods investigated, Terraquest
recommends SVE and air sparging as active treatment methods for the Little Market Basket #1
release incident. Both methods proved practical during pilot testing. Terraquest roughly estimates
that 2-3 years of operating an SVE and air sparge remediation system with a possible injection of
oxidants thereafter will lower concentrations such that, following a year of monitored natural
attenuation, the site could close in April 2029. The total cost is estimated at $498,598. If the
NCDWM-UST agrees, the next step is to generate a CAP Corrective Action Design Report.

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 ii Statesville, Iredell County, NC
TABLE OF CONTENTS

EXECUTIVE SUMMARY ................................................................................................................... i
1.0 INTRODUCTION ................................................................................................................. 1
2.0 UPDATE OF SITE HISTORY AND SOURCE CHARACTERIZATION .......................................... 1
2.1 UST Owner .................................................................................................................... 1
2.2 Tank and Release Information ....................................................................................... 2
2.3 Receptor Information .................................................................................................... 4
2.4 Regional Geology and Hydrogeology ............................................................................. 6
2.5 Site Geology and Hydrogeology .................................................................................... 9
3.0 UPDDATE OF SITE ASSESSMENT INFORMATION ............................................................. 14
3.1 Soil Assessment ........................................................................................................... 14
3.2 Groundwater Assessment ........................................................................................... 16
3.1.1 Monitoring Well Network ........................................................................................ 16
4.0 OBJECTIVES FOR CORRECTIVE ACTION AT THE SITE ........................................................ 18
5.0 COMPREHENSIVE EVALUATION OF REMEDIAL ACTIONS ................................................. 18
5.1 Considered Remedial Methods ................................................................................... 18
5.2 Pilot Testing ................................................................................................................. 21
5.2.1 SVE Pilot Test ........................................................................................................... 22
5.2.2 Air Sparge Pilot Test ................................................................................................ 28
5.3 Chosen Remedial Methods .......................................................................................... 33
5.4 Contaminant Mass Removal Estimates ....................................................................... 33
5.5 Remedial System Operation and Maintenance Plan ................................................... 33
5.6 Monitoring Plan ........................................................................................................... 34
5.7 Remedial Schedule ...................................................................................................... 35
5.8 Rough Cost Estimate ................................................................................................... 36
6.0 CONCLUSIONS / RECOMMENDATIONS ........................................................................... 36
7.0 LIMITATIONS ................................................................................................................... 37
CERTIFICATION ............................................................................................................................ 38
REFERENCES ................................................................................................................................ 39

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 iii Statesville, Iredell County, NC
TABLE OF CONTENTS (continued)

TABLES

1. Site History (UST/AST System Information)
2. Surrounding Property Owner Information
3. Water Supply Well Information
4. Monitoring Well Construction Information
5. Summary of Soil Sampling Results
6. Summary of Groundwater Sampling Results
7. Corrective Action Plan Costs

FIGURES

1. Site Location Map
2. Site Vicinity Map
3. Site Layout Map
4. Soil Sample Location Map
5. Potentiometric Surface Map (4/12/23)
6. Groundwater Analytical Results (4/12/23)
7. Proposed SVE and Air Sparge Wells

APPENDICES

A. Technical Methods/Standard Procedures
B. Chronological Site History
C. Historical Groundwater Elevation Data
D. Drill Cuttings Disposal Manifest and Well Construction Records
E. SVE Pilot Test Report
F. Air Sparge Pilot Test Report
ENVIRONMENTAL ACRONYMS

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 iv Statesville, Iredell County, NC
2L Standard Groundwater Standards Title 15A NCAC 2L
0.0202(g)
2B Standard Surface Water Standards Title 15A NCAC 2B
AFVR Aggressive Fluid-Vapor Recovery
AST Aboveground Storage Tank
BGL Below Ground Level
BTEX Benzene, toluene, ethylbenzene, xylenes
C&D Construction and Demolition
CAP Corrective Action Plan
CAPR Corrective Action Performance Report
CADR Corrective Action Design Report
CSA Comprehensive Site Assessment
DPE Dual-phase Extraction
EPA Environmental Protection Agency
ePATA Electronic Pre-Approval Task Authorization
EPH Extractable Petroleum Hydrocarbons
ESA Environmental Site Assessment
GCL Gross Contamination Level
LEL Lower Explosive Limit
LSA Limited Site Assessment
IPE di-Isopropyl Ether
ISCO In-situ Chemical Oxidation
MADEP Massachusetts Department of Environmental
Protection
MDL Method Detection Limit
MNA Monitored Natural Attenuation
MMPE Mobile Multi Phase Extraction
MSCC Maximum Soil Contaminant
Concentration
MSL Mean Sea Level
MSW Municipal Solid Waste
MTBE Methyl tertiary-Butyl Ether
NC North Carolina
NCAC NC Administrative Code
NCDENR NC Department of Environment and Natural
Resources
NCDEQ NC Department of Environmental
Quality
NCDOT NC Department of Transportation
NCDWM-SW NC Division of Waste Management’s Solid
Waste Section
NCDWM-UST NC Division of Waste Management’s UST
Section
NCDWQ NC Division of Water Quality
NFA No Further Action
NORR Notice of Regulatory Requirements
NORP Notice of Residual Petroleum
NOV Notice of Violation
NPDES National Pollutant Discharge
Elimination System
OVM Organic Vapor Meter
PID Photoionization Detector
PLC Programmable Logic Controller
POE Point of Entry (water treatment system)
POTW Publicly Owned Treatment Works
RBCA Risk Based Corrective Action
RDL Reporting Detection Limit
RP Responsible Party
SCFM Standard Cubic Feet per Minute
SVE Soil Vapor Extraction
STF Leaking UST State Trust Fund
STG Soil to Groundwater
TA Task Authorization
TCC Target Cleanup Concentrations
Terraquest Terraquest Environmental Consultants,
P.C.
TPH Total Petroleum Hydrocarbon
UST Underground Storage Tank
VOA Volatile Organic Analysis
VOC Volatile Organic Compound
VPH Volatile Petroleum Hydrocarbons
XP Explosion Proof

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 1 Statesville, Iredell County, NC
1.0 INTRODUCTION

On behalf of Bumgarner Oil Company, Inc., Terraquest Environmental Consultants, P.C. is
reporting results of a Corrective Action Feasibility Study for the release incident at the Little
Market Basket #1 facility located at 3541 Taylorsville Hwy, Statesville, Iredell County, NC. This
work relates to a release from the previous onsite petroleum underground storage tank (UST)
system and was requested by the NCDWM-UST who pre-approved the work on ePATA 47003-
015.

The site location and surrounding cultural features are depicted in Figure 1. The site vicinity is
depicted in Figure 2. The site layout and monitoring well network are depicted in Figure 3.
Technical methods and standard procedure generally used by Terraquest personnel are outlined
in Appendix A and a chronological history of site events is provided in Appendix B.

2.0 UPDATE OF SITE HISTORY AND SOURCE CHARACTERIZATION

Between September 23, 24, and 25, 2019, Terraquest supervised the closure of four USTs via
excavation and offsite removal from the Little Market Basket #1 facility located in Statesville,
Iredell County, NC. Bumgarner does not own the property and is no longer involved at the site.
The property has recently been upgraded with a new UST system, paving, dispensers, and canopy
by the property owner, Ronald Hunt.

2.1 UST Owner:
The subject USTs were owned and operated by Bumgarner Oil Company, Inc.

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 2 Statesville, Iredell County, NC
2.2 Tank and Release Information:

(further summarized on Table 1):

Tank ID size contents last used closed release detected
A1A 4,000-gallon gasoline 9/2019 9/23/19 no
A1 8,000-gallon gasoline 9/2019 9/23/19 no
A2 2,000-gallon diesel 9/2019 9/23/19 no
4 5,000-gallon kerosene 9/2019 9/23/19 yes
7 4,000-gallon gasoline 9/2019 9/23/19 no

Terraquest is not aware of any AST release incidents.

As part of the September 2019 UST closure, Terraquest personnel collected soil samples along
the product lines, beneath the dispensers, and beneath the tanks as required. The number of
samples for each tank was determined by their length in accordance with the Guidelines for Site
Checks, Tank Closure, and Initial Response and Abatement for UST Releases (Guidelines). The
depth of sample at each location was at the area most likely to show contamination. Generally,
four feet below ground level for the product lines and dispensers and nine or thirteen feet at the
tanks. Soils were placed into sealable plastic bags and screened with a photoionization detector
(PID). A representative sample was then placed into the appropriate laboratory container and
labeled. All samples were analyzed by Terraquest using a SiteLab UVF (Ultraviolet Fluorescence)
Trilogy machine for Total Petroleum Hydrocarbons (TPH) as GRO and DRO. The lone sample with
a TPH Action Limit violation, CS13, was sent to an NC-certified laboratory for analysis per 8260,
8270, VPH, and EPH.

The analytical results reported a TPH Action Limit violation in one sample only. The CS13 sample,
collected below the kerosene dispenser located adjacent to the onsite building, had a reported
GRO concentration of 363 mg/kg and a DRO concentration of 125 mg/kg which exceeds the
respective 50 mg/kg and 100 mg/kg Action Limits. That sample was also submitted for risk-based
corrective action (RBCA) laboratory analysis per EPA Methods 8260, 8270, VPH, and EPH. Sample

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 3 Statesville, Iredell County, NC
CS13 had reported benzene, 1-methylnaphthalene, and C9-C22 aromatic Soil-to-Groundwater
Maximum Soil Contaminant Concentration (STG MSCC) violations. No TPH Action Limits were
exceeded in any of the gasoline USTs, product lines, or dispensers.

As part of the Limited Site Assessment (LSA), Terraquest personnel supervised the installation of
groundwater monitoring well MW1 on May 4, 2020. The well was sampled that same day and
the sample submitted for laboratory analysis of volatile and semi-volatile organic compounds
(VOCs, SVOCs) per 6200B, 625BNA+10NTP, and MADEP VPH and EPH. The analytical results for
the groundwater sample collected from monitoring well MW1 revealed several petroleum-type
contaminant concentrations in excess of the permissible limits established under Title 15A NCAC
02L.0202 Groundwater Quality Standards (2L Standards).

The relation of location of current UST system to historical UST releases, non-UST releases, and
off-site releases:
See Figure 3 for the locations of the former USTs, and dispensers. No historical UST releases,
non-UST releases, nor off-site releases have been reported in the vicinity of the current release.

Previous Reporting:
Prior reports submitted to the NCDWM-UST for this site include a UST Closure Report, an LSA
Report, and a CSA Report.

NORR:
This CAP Feasibility Report has been prepared as requested in the NCDWM-UST’s May 23, 2023
NORR.

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 4 Statesville, Iredell County, NC
Site and surrounding area characteristics and land use:
The site is currently operated as a retail fuel facility and convenience store. Properties nearby
the site include farming and residential properties with some industrial properties to the east as
shown:

2.3 Receptor Information
To determine the risk classification of the site, Terraquest personnel performed a reconnaissance
of properties within a 1,000-foot radius of the source area as part of the LSA. The reconnaissance
effort consisted of obtaining tax department and local zoning information on properties and
conducting door-to-door visits of certain properties within 1,000 feet of the source area, in
addition to collecting other pertinent information from the appropriate local and state officials.
Table 2 lists the names and addresses of surrounding property owners. Note that the PIN
Numbers presented in Table 2 correspond with those shown in Figure 2.

Throughout reconnaissance efforts, a total of sixteen sole-source water supply wells were
identified within 1,500 feet of the site. Fourteen of the identified wells are within 1,000 feet of
SITE

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 5 Statesville, Iredell County, NC
the release area. As previously noted, while some properties have connected to the municipal
water supply system, most remain on their private water wells. Surrounding property
owners/occupants are detailed in Table 3. Water supply well information is presented in Table
3.

As part of the reconnaissance effort, Terraquest also searched for any surface water bodies
within a 500-foot radius of the site. No surface water bodies were identified within this search
area. The nearest surface water bodies are an unnamed tributary of Third Creek located
approximately 1,200 feet to the southwest and an unnamed tributary of Morrison Creek located
approximately 1,600 feet to the northeast. Surface water body features are displayed on Figure
2.

Zoning:
Zoning within 1,500 feet of the site is under the jurisdiction of Iredell County, properties beyond
1,500 feet to the southeast fall within the City of Statesville’s Unified Development Ordinance
and its zoning classifications. The site itself is classified as “RA”. This acronym stands for
Residential Agricultural. All properties directly around the site share this classification. To the
east and northwest, properties are zoned “M1” for light manufacturing. Those properties
beyond 1,500 feet to the southeast include “R-15” for Urban Fringe Low Density Residential
District and “B-5” for General Business District. Zoning information is shown on Figure 2.

Risk Ranking:
Based upon the presence of groundwater contamination in excess of the 2L Standards, coupled
with the presence of active, sole-source water supply wells within 1,000 feet of the release area,
the release incident mandates a High Risk classification. With the presence of residences within
500 feet of the source area, the land-use classification should be classified as “Residential”. The
NCDWM-UST has assigned this release a High Risk 205D ranking.

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 6 Statesville, Iredell County, NC
2.4 Regional Geology and Hydrogeology
The subject property is located in the Piedmont Physiographic Province of North Carolina. On a
regional scale, the Piedmont is characterized by land with medium to high relief. Elevation at the
site and nearby area is approximately 970 feet above MSL.

The subject property slopes from northeast to southwest. Overland water across the subject
property will flow to the southwest as shown here:

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 7 Statesville, Iredell County, NC
Regionally, groundwater is directed toward Third Creek to the south. Third Creek is a class C
surface water body that is part of the Yadkin Pee-Dee River basin. The Creek is shown here:
NCDEQ Surface Water Classifications Website (interactive map) https://ncdenr.maps.arcgis.com/apps/webappviewer/index.html?id
SITE

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 8 Statesville, Iredell County, NC
More specific within the Piedmont Physiographic Province, and according to the 1985 Geologic
Map of North Carolina (Brown, et.al., 1985), the subject property lies within the Inner Piedmont
Belt of the Piedmont Physiographic Province. The subsurface geology is mapped as interlayered;
minor layers and lenses of hornblende gneiss, metagabbro, mica schist, and granitic rock.
Regolith soils are comprised of clays and silts.

The Iredell County Soil Survey lists the subject property as having mostly TuC—Tomlin-Urban land
complex that is composed of sandy clay loam, clay, clay loam, and loam. Information on that
from the USDA, Web Soil Survey, https://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx
follows:

SITE

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 9 Statesville, Iredell County, NC
2.5 Site Geology and Hydrogeology
The following lithologies were encountered at the site during the installation of the monitoring
well network:

0’ – 5’ BGL:
SILTY CLAY (CL)
Soft, reddish-brown, mostly clay with some silt and little sand.

5’ – 53’ BGL
CLAYEY SILT (ML)
Soft, brown silt with little to some clay and mica.

53’ – 55’ BGL
BEDROCK

Site topography is depicted in Figure 1. The drilling locations of the monitoring wells used to
describe the lithology are depicted on Figure 3.

Geologic cross sections of the site are presented here:

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 10 Statesville, Iredell County, NC

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 11 Statesville, Iredell County, NC
Saturated Lithologies – Aquifer Locations
Information gathered during the installation of the monitoring wells was used to construct
geologic cross sections of the phreatic aquifer. The trace of the potentiometric surface was
projected onto the cross sections in order to illustrate the site hydrogeology. Analysis of the
cross sections reveals that the phreatic aquifer resides, at its shallowest depth, in a soft, clayey
silt. This lithology becomes more consolidated with depth until competent bedrock that was
encountered via air drilling at 53 feet BGL. While there is some intermixing in the upper portion
of the weathered bedrock, at depth, the bedrock aquifer is fracture controlled and behaves
differently than the overlying water table aquifer.

Groundwater Flow Data Analysis
Groundwater measurements were collected prior to well purging and sampling on May 17, 2021
and indicated a groundwater flow direction toward the south/southwest. Further analysis shows
that the hydraulic head within the shallow phreatic aquifer ranged from a relative value of
approximately 79.32 feet at monitoring well MW2 to 76.41 at monitoring well MW10. In
conjunction with other site measurements, the results indicate flow in the phreatic aquifer in a
southwesterly direction under an average hydraulic gradient of 0.015. Note that the plume
geometry confirms a south/southwesterly flow.

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 12 Statesville, Iredell County, NC
Water level data from the Type III monitoring well (MW11 June 2021) and the interpreted
groundwater elevation in the phreatic aquifer nearby in monitoring well MW4 (May 2021) was
used to determine if a vertical head gradient existed in the phreatic aquifer. The vertical gradient
was calculated using the following equation and groundwater elevation data:

Type III monitoring well MW11 𝑉𝑉𝑔𝑔=ℎ𝑝𝑝ℎ𝑟𝑟𝑟𝑟𝑟𝑟𝑟𝑟𝑟𝑟𝑟𝑟− ℎ𝑀𝑀𝑀𝑀11𝐷𝐷
where:

Vg = Vertical head gradient
Hphreatic = Water elevation in the shallow aquifer (MW4) = 77.69’
HMW12 = Water elevation in deep well MW11 = 76.51’
D = The difference in elevation between the shallow water table and the
middle of the well screen in MW11 = (77.69’ – 49.13’) = 28.56’
therefore: 𝑉𝑉𝑔𝑔 = 77.69−76.5128.56 = +0.04

The head gradient suggests a minor recharging hydrologic flow gradient meaning groundwater
tends to flow in a downward direction. A review of regional topographic maps and the presence
of contamination in the Type III well affirms this belief. With increasing depth and distance from
the recharge area, the flow lines flatten out and become more horizontal than vertical.
Eventually, as the flow lines near lower elevations, the flow lines curve upward towards the
ground surface into areas of discharge such as streams and rivers.

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 13 Statesville, Iredell County, NC
Aquifer Tests:
To provide preliminary estimates of hydraulic conductivity (K) and groundwater flow velocity (v)
for the phreatic aquifer, Terraquest personnel performed slug tests on monitoring wells MW2
and MW4 on May 17, 2021 as detailed in the CSA Report. Hydraulic conductivity estimates were
determined using Aquifer Test Pro 2010.1, a computer model developed by Waterloo
Hydrogeologic. The data was reduced using the Bower and Rice Method (Bower and Rice 1976,
Bower 1989). The hydraulic conductivity estimates range from 0.135 feet/day to 0.364 feet/day.
The calculated hydraulic conductivity is in the range of a silt to silty sand (Heath, 1982). The
lithologies logged in the saturated zones support this.

Using an average hydraulic conductivity value of 0.249 feet/day, an average groundwater
seepage velocity value was determined to be 0.0249 feet per day or 9.08 feet per year. An
effective porosity of 0.15 and a hydraulic gradient of 0.0152 (based on May 17, 2021 data) were
used for calculating the groundwater flow velocity (Sanders, 1998 and Heath, 1983).

In consideration of whether the seepage velocity is reasonable, Terraquest has considered the
1986 installation date of the subject kerosene tank system, the length of time that may have
lapsed until the release began (~10 years), the depth to groundwater, and the current plume size.
In consideration of those factors, the calculated seepage velocity appears reasonable as follows:

• 1986 kerosene tank installed
• 1996 release begins (estimate tank system sound for first ten years)
• Travels at 9 feet per year until 2021 (2021-1996 = 25 years)
• 25 years x 9 feet per year = 225 feet.
• Water table is ~25’ BGL. Vertical travel time for fittings/piping/tank leak to head down.
• Current plume length from kerosene tank is 155 feet

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 14 Statesville, Iredell County, NC
It should be noted that the calculated seepage velocity does not provide an exact flow velocity
for dissolved-phase contamination which may be affected by retardation, absorption, and
biodegradation as it travels with groundwater.

Qualitative Fate and Transport:
The dissolved constituents present in groundwater from the release incident will migrate in the
direction of groundwater flow by advective transport and dispersion. Biodegradation,
volatilization, and dilution will reduce the concentrations of petroleum constituents in
groundwater over time. Advancement of the dissolved plume will continue until either
equilibrium conditions are reached, a discharge point is intercepted, or biodegradation processes
overtake transport processes.

Equilibrium between the advancing petroleum plume and retardation factors such as
biodegradation, volatilization, and dilution may be reached. If groundwater flow propagates the
contaminants at the same rate that retardation forces degrade it, then the plume will cease to
advance. If equilibrium is maintained over time, the plume may degrade to below regulatory
levels. Biodegradation may act on the dissolved plume more quickly than groundwater forces
advance the plume. In such a scenario, the limits of the plume would be reduced over time.

3.0 UPDDATE OF SITE ASSESSMENT INFORMATION
3.1 Soil Assessment
Soil quality associated with this release incident has been investigated with sampling during the
UST closure and LSA. Soil sample results are summarized on Table 5 and sample locations are
shown on Figure 4.

UST closure:
As previously noted, soil samples were collected at the prescribed locations during closure
activities. A total of seventeen soil samples were analyzed for TPH. Only one of those samples,
CS13, had a TPH Action Limit violation. As noted, that sample, CS13, was submitted for RBCA lab

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 15 Statesville, Iredell County, NC
analyses and had reported STG MSCC violations. This sample was collected beneath the former
kerosene dispenser location.

LSA:
As part of the LSA, Terraquest collected three soil samples. A hand auger boring was advanced
beneath the former kerosene dispenser location and a sample was collected at five feet BGL. This
sample is identified as “KDISP” on Figure 4. That depth is just below the CS13 sample collected
in the same location at a depth of four feet BGL during closure. Several feet away at the drill rig
accessible location, two soil samples (MW1 8-10’ and MW1 18-20’) were collected from a
Geoprobe boring advanced prior to auger drilling of the monitoring well (MW1). All samples
were retrieved by personnel wearing a new pair of disposable nitrile gloves who placed the
samples into laboratory-prepared containers, labeled the containers, and packed them on ice
pending transport to an NC-certified laboratory. Chain of custody documentation was
maintained. The three soil samples were submitted for laboratory analysis per methods 8260,
8270, and MADEP VPH and EPH.

The analytical results of the LSA soil samples revealed the presence of petroleum-type
compounds, including STG MSCC violations in all three samples and Residential MSCC violations
in the two deeper samples. The results are summarized on Table 5.

Soil contamination extent:
The analytical results of soil samples collected throughout assessment indicate a limited area of
soil contamination beneath the former kerosene dispenser. No actionable soil contamination
was noted beneath the product lines, remaining dispensers, or any of the tanks.

Contamination begins beneath the dispenser and extends downward to the water table in a
sloping fashion. Terraquest estimates that the average starting depth of contamination is roughly
at ground level and extends to the water table noted at approximately 25 feet below ground level
(BGL) in May 2021. The amount of soil truly in excess of the STG MSCCs with respect to the

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 16 Statesville, Iredell County, NC
varying contaminant concentrations and sloping away from the source pattern is likely 50% lower
than a 25-foot-thickness. Volumetric calculations using this data yields 60 ft2 x ((25 ft – 0 ft)(0.5))
= 750 ft3 or 28 yd3. Using a 1.5 yd3 to tons multiplier, the weight is 42 tons.

3.2 Groundwater Assessment

Monitoring Well Network:
Throughout various phases of assessment, a total of seventeen monitoring wells have been
installed to delineate groundwater quality. Those wells include sixteen Type II wells and one
Type III telescoping deep well. The well locations are shown on Figure 3 and their construction
is detailed on Table 4.

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 17 Statesville, Iredell County, NC
Groundwater Flow Direction:
Following construction of the monitoring wells, each well casing was surveyed to normalized
depth to water measurements that are used to realize the direction of groundwater flow.
Measurements collected prior to well purging and sampling on April 12, 2023 are summarized on
Table 4 and were used to construct the potentiometric surface map presented as Figure 5. As
shown on that Figure, groundwater flow is directed to the south/southwest. Historical
groundwater elevation data is provided in Appendix C. As shown in Appendix C, the average
water table elevation ranges from 22.2 to 28.66 feet below the top of casing in the Type II wells.
Also, the water table elevation has risen by 2.78 feet between October 27, 2022 and April 12,
2023.

Groundwater Sampling
The latest groundwater monitoring well sampling event was conducted on April 12, 2023 when
Terraquest personnel sampled monitoring wells MW2-17 and from water supply (potable) well
PW1. Monitoring well MW1 was dry and could not be sampled. The wells were sampled using
the standard sampling protocol detailed in Appendix A. The collected groundwater samples were
placed in laboratory-prepared sample containers, labeled, packed in ice, and shipped to a North
Carolina-certified laboratory for analysis prior to the expiration of the analytical method’s hold
time. The groundwater samples were all analyzed by method 6200B.

The analytical results revealed the presence of 2L Standard violations in the groundwater
samples. No free product was noted and no GCL violations were reported. The most-
contaminated groundwater samples were collected from monitoring wells MW4, MW6, and
MW7 that are located downgradient of the former kerosene dispenser and lateral/downgradient
of the 2,000-gallon gasoline UST.

The 2L Standard violation plume is oval in shape, measures 260 feet long by 110 wide and covers
an area of 23,300 square feet as calculated by AutoCAD. This is generally similar to previous
results with an overall increase as more data is available with the new monitoring wells present.

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 18 Statesville, Iredell County, NC
The downgradient extent of contamination is estimated as access to property across Absher Farm
Loop hasn’t been granted. Vertically, the 2L violations cease prior to the 50-foot depth of the
Type III well (MW11) screen. Groundwater analytical results are summarized on Table 6 and on
Figure 6. Historical data is summarized in Appendix C. Further details on the specific results of
the sampling event follows:

Free product: none gauged
GCL violations: none
2L Standard violations: MW4, MW5, MW6, MW7, MW9, MW10, MW12, MW13, MW14,
MW15, MW16
<2L Standards: MW2, MW3, MW8, MW11, MW17, PW1

4.0 OBJECTIVES FOR CORRECTIVE ACTION AT THE SITE

Multiple efforts with the potable well PW1 owner have revealed that they do not wish to connect
to the municipal water supply, leaving this incident ranked as a High Risk. The cleanup objectives
are the STG MSCCs for soil and the 2L Standards for groundwater. The corrective actions
proposed herein are structured to meet those standards as the objective.

5.0 COMPREHENSIVE EVALUATION OF REMEDIAL ACTIONS

5.1 Considered Remedial Methods
Remedial actions that have been considered for this release incident include excavation of
contaminated soil, natural attenuation, in-situ injection, pump and treat, soil vapor extraction
(SVE), and air sparging. Each of the methods has positive and negative features that are discussed
here:

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 19 Statesville, Iredell County, NC
Excavation
By the numbers, there appears to only be a small area of soil contaminated at concentrations
exceeding the STG MSCCs, making it a good candidate for excavation. However, while the overall
mass is low and the violations only cover a small footprint near the former kerosene dispenser,
the presence of the building and the depth of the contamination rule out excavation as an option.
The violations extend to the water table at 25-30 feet BGL.

Natural Attenuation
Natural attenuation of the release incident would take a very long time and gives no protection
to sensitive receptors. With the proximity of the active water supply well PW1, active methods
are required to reduce contaminant mass. If other remedial methods can remove most of the
contaminant mass, a short-period of monitored natural attenuation would be a good way to
verify that the plume is stable or degrading and allow site closure.

In-Situ Injection
In-situ chemical oxidation of the dissolved-phase petroleum would occur via pumping of injectant
into borings across the plume. The observed soil lithology in the saturated zone makes this site
a good candidate for injection. Injection works relatively quickly as the chemical oxidation
happens on contact. The method is not as intrusive as others and doesn’t generally upset the
onsite business. However, the cost associated with the injection would likely be more than other
methods if it is done as the sole treatment method. A 10-foot grid across the plume would look
as shown on the next page.

As shown on the next page, approximately 200 borings could be used to inject a compound
similar to Oxygen Biochem (OBC). The injectant cost alone at 500 pounds of OBC per point would
be 200 x 500 x $3.25/pound = $325,00.

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 20 Statesville, Iredell County, NC
Injection would be beneficial to use on a smaller scale following treatment of the plume by other
methods such as air sparging that aren’t as good at polishing the lower concentrations of a plume
in late-stage treatment.

Possible injection layout
(10’ x 10’ grid)

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 21 Statesville, Iredell County, NC
Pump and Treat
A pump and treat system would effectively remove dissolved-phase groundwater contamination.
This method is generally costly as it has multiple equipment components and requires a large
amount of maintenance and adjustments to operate well. The lack of any obvious discharge
options for the treated water is problematic as is the high capital and operations costs. While
the method provides hydrodynamic control of the area that offers protection to sensitive
receptors, it is more costly than other options.

Soil Vapor Extraction
Soil vapor extraction (SVE) applies a vacuum to the vadose zone soil to remove VOCs that are
then emitted to the atmosphere. The method is also capable of recovering liberated sparge
vapors. The method is lower in cost than other active methods and generally operates well with
little down time. The method is limited by the permeability of the soil matrix.

Air Sparging
Air sparging uses compressed air applied to the aquifer to liberate dissolved-phase contaminants
that can then be exhausted to the atmosphere. Compared to the other active methods, air
sparging is a lower-cost option. Air sparge systems generally run well with little down time. The
effectiveness of this method is limited by hydrogeologic heterogeneities and lower permeable
aquifer material.

5.2 Pilot Testing

Following discussion, agreement, and pre-approval of costs from the NCDWM-UST, Terraquest
personnel installed wells in Octobe 2023 and conducted SVE and air sparge pilot testing in
November 2023.

On October 10, 2023, Terraquest personnel supervised the installation of SVE pilot test well SVE1
and air sparge pilot test well AS1 at the locations shown on the attached Figure 3. SVE well SVE1

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 22 Statesville, Iredell County, NC
was installed near the former kerosene dispenser but away from the associated tank basin to
investigate SVE response for contaminated soil in that area. Air sparge well AS1 was installed
near monitoring well MW7 that has had some of the highest contaminant concentrations at the
site. All wells were installed using a Geoprobe Model 7822DT operated by an NC-licensed driller.
As there is no room onsite for disposal of drill cuttings, the cuttings were drummed and later
disposed of offsite by Superior Environmental Solutions, LLC. A disposal manifest is provided in
Appendix D.

The SVE well was constructed of 5 feet of 2”-diameter, Schedule 40 PVC casing attached to 15
feet of 2”-diameter, Schedule 40 PVC screen with a 0.010” slot size for a total well depth of 20
feet. This screen interval takes into consideration the location of the soil contamination and the
water table. The air sparge well AS1 was constructed of 44 feet of 1”-diameter, Schedule 40 PVC
casing attached to 5 feet of 1”-diameter, Schedule 40 PVC screen with a 0.010” slot size for a
total well depth of 49 feet. This screen opening forces the introduced air to spread throughout
the aquifer where it can provide treatment. Note that auger refusal due to bedrock was
encountered at 49 feet. The wells were surveyed into the network following installation. Well
construction information is further detailed in Table 4 and the well records are provided in
Appendix D.

SVE and air sparge pilot testing is detailed in reports provided in Appendices E and F. The tests
and results are summarized hereinafter.

5.2.1 SVE Pilot Test
Overview:
Terraquest performed an SVE pilot test on November 14, 2023. The basic test procedure
consisted of applying a vacuum to the extraction well while monitoring pressure response at
other points of varying distance and direction from the extraction point. Vacuum pressure and
air flow at the extraction well were also monitored. A GAST regenerative blower with a 1.5 hp
electric motor was used to create the vacuum. Various pressure and flow gauges were also used.

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 23 Statesville, Iredell County, NC
The blower and gauges were connected with air-tight seals to the various points to minimize
leakage and, thus, systematic error.

Generally, two types of SVE tests are conducted. The first type of test is an air permeability test
that typically lasts for approximately 10 minutes. Vacuum is applied to the extraction well and
the pressure responses in various observation points are recorded with time. The data is used to
calculate the vadose zone permeability to air flow (intrinsic permeability).

The second type of test performed is a steady state test. These last from approximately 1 hour
to several or more days, depending on the objectives of the test, the scale of the project, and
other cost justification factors. A relationship between applied vacuum and vapor flow yield is
developed from these tests. This relationship is used for blower selection in the design of the
full-scale system. Data from these tests can also be used to calculate intrinsic permeability.

For tests of sufficient length, it may also be possible to establish VOC mass removal rates by
measuring the steady state vapor concentrations in the off gas. To achieve steady state, at least
one pore volume of vapor must first be removed. It is not usually possible during the test to
know exactly when this occurs. One indication is a leveling of vapor concentrations after a
significant decline. This change occurs as all stagnant air is purged from the capture zone.

Testing
Terraquest personnel began testing on November 14, 2023 using SVE1 as the extraction well and
monitoring influence at monitoring wells MW1 and MW2. With a screen interval of 20-35 feet,
monitoring well MW2 was less likely to show influence as the SVE well was only screened from
5-20 feet. Monitoring well MW1 was screened from 10-30 feet. However, monitoring well MW1
was located near the former UST basin and was removed from consideration as the SVE
extraction well as that less permeable area would likely yield erroneous data that doesn’t match
in-situ conditions at the site.

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 24 Statesville, Iredell County, NC

Following setup, Terraquest turned on the SVE blower and monitored influence at wells MW1
and MW2. The SVE blower was operated with no dilution. That is, full vacuum was applied. The
influent pressure gauge on the SVE extraction well indicated that the blower applied a vacuum
pressure of -70 inches of water. Terraquest has magnehelic vacuum gauges ranging from 0-2
inches of water up to 0-100 inches of water. Using the 0-2 inches of water gauges on monitoring
wells MW1 and MW2, no influence was seen at either well at the start of the air permeability
test. That gauge has vacuum pressure measurements in 0.05 inches of water increments. None
was seen until minute 15 of the test. At minute fifteen, both monitoring wells MW1 and MW2
showed a 0.05 inches of water reading.

As the air permeability test didn’t show anything until minute 15, the test was switched to a
steady state test and the blower was allowed to continue running. As shown on the attached
SVE Table 1, a max vacuum influence of 0.05 inches of water was noted at monitoring well MW1
and a max vacuum pressure of 0.10 inches of water was noted at monitoring well MW2. Only
0.2 ppm was registered on the PID throughout the test. A near zero value.

Pore volume calculations
As previously noted, contaminant removal rates via SVE can be calculated once one pore volume
has been removed and steady-state removal concentrations are known. While the volume of
contaminated soil is low and influence to the impacted area was not realized, Terraquest
presents the following pore volume calculations for future reference.

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 25 Statesville, Iredell County, NC
From Equation (18) in Johnson et al (1990b), the estimated time to remove one pore volume (Tp)
is estimated by:

Where:
EA = air filled void fraction of soil matrix
R = radius of zone of contamination (feet)
H = thickness of zone of venting (feet)
Q = air flow rate (cubic feet per minute)

Data from the steady state test was used to estimate Tp. With the variables assigned as follows:

EA = 0.15 (based on an average effective porosity published by Sanders, 1998)
R = 4.5 feet
H = 30 feet
Q = 3 cubic feet per minute (average)

An estimated time to remove one pore volume of contamination is calculated to be 95.4 minutes.
Since the SVE steady state test ran for 90 minutes it is likely that about one pore volume was
removed.

Data analysis
Overall, the test was a success, although it was atypical for most SVE pilot tests. The overall goal
was to determine if the subsurface was responsive to SVE. The test determined that it is. A
vacuum was applied to extraction well SVE1 and a constant flow of air was recorded. It’s unusual
to have a test in a silty vadose zone soil and not register a higher vacuum pressure than 0.05
Q
HRE=T Ap
2π

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 26 Statesville, Iredell County, NC
inches of water at a monitoring well (MW1) located only 15 feet away. As noted, the former tank
basin is located nearby to the test and while extraction was made at SVE1 and not MW1 to lessen
the chance of vacuum loss to an area with much looser backfill material than the native soil, it’s
still possible that the SVE1 vacuum was partially lost to that area. In any case, the subsurface
near the lone area of soil contamination above permissible levels was shown to allow vacuum
flow indicating that the method will be suitable for treatment. With fairly homogenous
lithologies recorded across the site, SVE will also serve to recover sparge vapors from areas
whose surface cover (asphalt) will not allow release of the sparge vapors.

Radius of influence
A rule-of-thumb recommended by U.S. EPA (1995) is that the ROI will be the distance at which a
vacuum of 0.1 inches of water is yielded. While that pressure was noted at monitoring well MW2
located 18 feet away, it was not observed at monitoring well MW1 located only 15 feet away. A
12-foot radius is chosen as a conservative estimate of influence that allows for some site
heterogeneities.

Number of Extraction Wells
Based on the small area of soil contamination, Terraquest recommends one well near the former
kerosene dispenser to treat soil. Monitoring well MW1 could be used as an SVE well, however,
its screen interval of 10-30 feet is not ideal and Terraquest recommends installing another well
with a screen interval from 3-30 feet.

An additional four wells are recommended to recover air sparge vapors as shown by the yellow
triangles with anticipated radius of influence circles on the following page and on Figure 7. Note
the proposed air sparge wells (discussion forthcoming) indicated by the magenta triangles.

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 27 Statesville, Iredell County, NC

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 28 Statesville, Iredell County, NC
SVE Pilot Test Conclusions
Based on the pilot test conducted by Terraquest personnel, the site is acceptable for SVE as a
remedial method. Five dedicated SVE wells are recommended.

5.2.2 Air Sparge Pilot Test
The test procedure consists of applying air pressure to the sparging well while monitoring air flow
at this point and changes in product/groundwater levels in nearby wells. During the air sparge
test conducted on November 14, 2023, air was introduced into AS1 while measurements were
collected from observation points MW4, MW5, MW6, MW7, and MW14.

Air was supplied to the injection point from a portable, electric, oil-less air compressor powered
by a portable electrical generator brought onsite for the test. The compressor output was
connected to the injection point through a series of hoses, pipes, and fittings. Air flow into the
injection point was measured with an adjustable flow meter. A static pressure gauge was
installed downstream of the flow control valve. The change in depth to product and water in the
observation points was measured using a Solinst Model 122 Interface Meter.

The test consists of several stages in which a constant flow is applied, while the air pressure and
water levels are measured. After groundwater mounding stabilizes, the flow is stepped up and
held constant for another stage. The number of stages depends on the rate at which responses
occur.

During the November 14, 2023 test, a total of four different flow rates were applied to the air
sparge well. Flows of 1.0, 1.5, 2.0 and 3.3 standard cubic feet per minute were all applied. Those
flow intervals were provided for 1 hour, 1.75 hours, 0.42 hours, 1.17 hours, respectively. Note
that trouble with the air compressor caused a dip in flow for approximately ten minutes between
13:45 and 14:00 time period. The 1.5 scfm flow rate was run for longer to account for this. Also,
as no major effect was seen with the final increase to 2.0 scfm, Terraquest increased the flow to
3.3 scfm during the last stage. Measurements are provided in Appendix F.

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 29 Statesville, Iredell County, NC

The three main objectives of data analysis are to determine whether air sparging is suitable for
the site, determine a reasonable radius of influence for an air sparge well, and establish data for
equipment selection in the design of a full-scale system.

Suitability
The responses observed during the test indicate air sparging would be suitable for the site. Air
was injected into the subsurface and flow was maintained. Some sites have had poorly installed
air sparge wells where the screens are cemented or the lithology is too tight and air will not enter
the saturated zone at all. This was not the case at the subject facility. The injection was made
with a standard electrical air compressor suitable for short-term testing and flowable air was
maintained without a large amount of pressure. Flowable pressure for the test was 7.5-10 psi
which is a typical operating pressure. At test startup, a breakthrough pressure of 15 psi was
observed. Again, that is well within normal.

Radius of Influence
Determining the radius of influence involves a study of the influence observed in the wells
monitored during the pilot test. As the remedial method of air sparging is the mechanical
stripping of contaminants from the dissolved phase into a liberated waste air stream, the extent
of that effect is what is searched for. Air sparging also acts as a remedial method by increased
the amount of oxygen dissolved in the surrounding aquifer and that should be analyzed too.
Terraquest measured the dissolved oxygen (DO) in surrounding wells both before and after the
test for comparison.

Prior to and throughout the test, the depth to water was measured in surrounding wells. As the
test progressed, the water table was mounded by the applied air as seen at observations wells
by a rise in the water table. In a fully evolved test with a sufficiently low air flow, the water levels
will subside to near static levels after some period of time as the mounding is spread across the

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 30 Statesville, Iredell County, NC
aquifer. When this stabilization or drop occurs, the air flow rate is typically increased to the next
step.

The measured data is summarized in Appendix F and in less detail below in this text. These graphs
show the mounding and subsequent stabilization of groundwater during each flow increase. The
stabilization is slight and is realized by a tapering of water mounding in some cases. The evidence
of these water level stabilizations is an important result, since it indicates that low flow sparging
can be performed without causing sustained high water levels. These measurements also are
indicative of the radius of influence of the air sparge well. The following results were observed:

Well identification
Radial distance (feet) from
injection point Largest mounding (feet)
AS1 0: injection here
MW4 19 0.62
MW5 69 0.04
MW6 19 0.66
MW7 12 0.66
MW14 24 0.37

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 31 Statesville, Iredell County, NC

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 32 Statesville, Iredell County, NC
Calculating the radius of influence should take into account multiple factors to provide a
scientifically-reasonable value with some conservative allotment. The radius is subject to
hydrogeology and isn’t as simple as a straight-line graph. The data indicates mounding as far
away as 24 feet. The 0.04 feet of mounding recorded at monitoring well MW5, located 69 feet
away, is negligible and likely a function of operator or meter differences at each reading.

The goal is to calculate a ROI that provides air sparging to all areas without creating service gaps.
The size, shape, and placement of the free product and dissolved-phase plume onsite where the
sparging would occur also needs consideration. In consideration of all these factors, 20 feet is
recommended as a working radius of influence. A total of nine air sparge wells are recommended
and includes the existing well and eight new sparge wells. Terraquest proposes the well
placement as previously shown in the SVE discussion of this report and on Figure 7 as this
placement considers site layout, remedial goals, free product, GCLs, and radius of influence:

Design data
The air sparge test achieved sustained flow up to 3.3 scfm at a pressure of 10 psi. Equipment
should be sized for a flow demand of nine wells at a flow rate up to 4 scfm each for a total of 36
scfm with some extra to allow for an increase in sparging as needed. Pressure over 15 psi was
not observed but could have happened briefly as breakthrough was occurring. Air sparge
breakthrough is typically 1 psi for every 2.3 feet of head (US EPA 1995). With a head of
approximately 49 – 30’ = 19 feet, the entry pressure required is estimated at 8 psi. The lithology
accounts for some of the additional pressure required. Overall, the flow and pressure is within
the range of typical air sparge systems.

Air Sparge Pilot Test Conclusions
Based on the pilot test conducted by Terraquest personnel, the site is acceptable for air sparging
as a remedial method. Nine dedicated air sparge wells are recommended.

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 33 Statesville, Iredell County, NC
5.3 Chosen Remedial Methods
Based on the factors discussed, Terraquest chooses SVE and air sparging as the remedial methods
for this site. In-situ chemical oxidation via injection may be performed in later stages of
treatment to more economically push the site to closure.

5.4 Contaminant Mass Removal Estimates
While the exact time required to remediate the free and dissolved-phase contamination is
unknown, pilot test data can be used with previous assessment data to provide estimates.
Essentially, the metrics involved are the starting mass of product, the starting mass of dissolved-
phase contamination, and the removal rate of the system. However, the lack of any PID readings
on the SVE effluent and lack of SVE influence prevented the collection of air samples for either
the SVE or the air sparge pilot tests that would provide removal rates.

Based on similar sites, Terraquest estimates that several years of treatment are required to
remove contamination to levels where natural attenuation can take over and the threat to
sensitive receptors is lessened. Further refinement of treatment time will be understood as the
system is operated.

5.5 Remedial System Operation and Maintenance Plan
Terraquest proposes two, 8-hour visits per month to perform system O&M activities. Those
activities will include maintenance as recommended by the manufacturer and the collection of
data as is helpful to this investigation. In addition to an overall system check, equipment
temperatures and run hours will be inspected/adjusted/recorded. An overall check for air, water,
and lubricant leaks should be conducted. The system’s heater and exhaust fan should be
inspected/adjusted/setting recorded. The pressures and flows of the SVE and air sparge system
and lines to wells will be inspected/adjusted/recorded. The load and unload pressures of the
sparge compressor should be verified and recorded. The system’s logic controller should be
inspected. System valves including, ball valves and solenoid valves, and floats will be checked for
proper operation and serviced as needed. System alarms should be operationally verified along

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 34 Statesville, Iredell County, NC
with the variable frequency device for the SVE, pressure relief valves, system lights, hand-off-
auto switches, contacts, and overloads. Sight tubes should be inspected/cleaned/replaced across
the system. The volts and amps across the system will be recorded. The belts and impellers will
be inspected/adjusted/replaced as needed. System moisture will be dealt with along with
automatic knockouts and filters, drums, systems thereto. Aftercoolers will be cleaned and
adjusted as necessary. Pre-intake and air intake filters will be inspected/cleaned/replaced as
needed. Lubricants and associated filters and separator elements will be maintained along with
any scavenge lines, orifices, and filters. Downstream discharge coalescing filters and associated
media and regulators will be inspected/cleaned/replaced. Flows, pressures, and operation of any
associated product drum and/or oxidizer and appurtenances will be collected.

5.6 Monitoring Plan
Terraquest recommends quarterly sampling of the entire monitoring well network following
system startup to measure treatment and plume migration. Dissolved-phase contamination will
be investigated by lab analysis of VOCs via 6200B samples. Contaminant recovery and treatment
system operation should be investigated through monthly collection of air samples from the SVE
system’s exhaust stack and lab analysis per method EPA18 targeting BTEX, MTBE, and TPH.

Following the first year of operation, semi-annual monitoring events may be sufficient.
Additional data collection may be required as treatment unfolds to better understand the
geochemistry and ensure that contamination is removed in the most cost-effective manner.
Knowing the aquifer’s pH, conductivity, dissolved-oxygen, and the amount of sulfates and
nitrates will help steer the need for any additional treatments.

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 35 Statesville, Iredell County, NC
5.7 Remedial Schedule
Following submittal of this report, the following schedule is anticipated:

• one month is anticipated for the NCDWM-UST to review it and respond,
• one week is anticipated for pre-approval of the Corrective Action Design Report (CADR),
• three months are anticipated to design the system and acquire bids and the RP’s
authorization for system placement,
• one month is anticipated for the NCDWM-UST to review the CADR and respond,
• one week is anticipated for pre-approval of the Record of Decision (ROD),
• one month is anticipated to write the ROD and submit it,
• one month is anticipated for the NCDWM-UST to review the ROD and respond,
• one month is anticipated for all parties to meet and sign the ROD,
• one week is anticipated for pre-approval of the system costs and supervised installation,
• three months are anticipated for construction of the system,
• three months are anticipated for installation, inspection approval, utility construction and
activation,
• one month is anticipated to schedule system startup.

A total time of 15 months and three weeks are anticipated until the treatment system will be
turned on. While experience has shown that timelines change, an early deadline is hereby
established as April 2025 for system activation .

Following system activation, Terraquest expects the dissolved-phase contaminant plume will be
drastically reduced during the first six months to a year of operation. In the subsequent year or
two of operation, the contamination will reduce and ultimately reach an asymptotic decline rate.
Terraquest recommends investigating the use of oxidizing injectants at that point to polish of the
plume to move toward closure.

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 36 Statesville, Iredell County, NC
In total, it will take 16 months to activate the system, 2-3 years of operation to remove the bulk
of the contamination, and another year to monitor natural attenuation and close the incident.

5.8 Rough Cost Estimate
The supervised installation and operation of an SVE and air sparge treatment system with one
year of monitored natural attenuation is expected to roughly cost $498,598. Costs are estimated
on Table 7.

This cost includes $7,000 for CADR, ROD, and public notification, $33,9000 for remedial well
installation, $226,120 for the purchase and supervised installation of a treatment system,
$45,020 for groundwater monitoring, $178,164 for system O&M, and $8,394 for public notice,
NORP, and monitoring well abandonment toward closure as follows:

6.0 CONCLUSIONS / RECOMMENDATIONS

In consideration of the contamination present and treatment methods investigated, Terraquest
recommends SVE and air sparging as active treatment methods followed by polishing with
oxidizing injections for the Little Market Basket #1 release incident. Both methods proved
practical during pilot testing. Terraquest roughly estimates that 2-3 years of operating an SVE
and air sparge remediation system followed by a year of monitored natural attenuation are
necessary for closure of this site in April 2029 at a cost of $498,598. If the NCDWM-UST agrees,
the next step is to generate a CAP Corrective Action Design Report.
CADR 5,500.00$
ROD 1,500.00$
Remedial well install 33,900.00$
Supervised treatment system installation 226,120.00$
Groundwater sampling 45,020.00$
System operations and maintenance (O&M)178,164.00$
Closure 8,394.00$
498,598.00$

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 37 Statesville, Iredell County, NC
7.0 LIMITATIONS

This report is limited to the investigation of petroleum-type compounds, and does not imply that
other unforeseen adverse impacts to the environment are not present at the facility. In addition,
subsurface heterogeneities not identified during the current study may influence the migration
of groundwater or contaminants in unpredicted ways. The limited amount of sampling and
testing conducted during this study cannot practically reveal all subsurface heterogeneities.
Furthermore, the subsurface conditions, particularly groundwater flow, elevations, and water
quality may very through time. The opinions and conclusions arrived at in this report are in
accordance with industry-accepted geologic and hydrogeologic practices at this time and
location. No warranty is implied or intended.

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 38 Statesville, Iredell County, NC
CERTIFICATION
1 Enter the date the Corrective Action Plan was due. 12/23/2023 Will this Corrective Action Plan
Feasibility Study be submitted after the established due date?
YES NO X
2 Was any recommended information from the above template missing from this report? YES NO X
(IF the answer to question #1 or# 2 is “YES”, please replace this note with additional information in this cell to explain what was missing and why.)
3 Are there any known or suspected factors that could prohibit risk reclassification and the use of
monitored natural attenuation to risk-based cleanup standards following the completion of two
years of active remediation under the proposed strategy?
YES NO X
(IF the answer to question #3 is “YES”, please replace this note with a short description of the possible reason(s), and outline proposed remedies. Greater detail should be provided in the report text above.)
4 Does any potential continuing source for the known contamination onsite remain (e.g., an existing,
operating system onsite where a leaking component directly responsible for the discovered release
has not been found and repaired/replaced, etc.)?
YES NO X
5 Does any known or suspected source zone soil contamination or free product remain outside of the
assessed area that could inhibit the effectiveness of the proposed strategy?
YES NO X
6 Since release discovery, has there been any unexpected increase in contaminant mass sufficient to
suggest a potential new release from a separate onsite or offsite source?
YES NO X
(IF the answer to any question from #4 - #6 is “YES”, replace this note with a short description of any recommended actions to address, assess, or clean up any
other known, suspected, or potential source. Greater detail should be provided in the report text above.) 6 Certification:
I, Michael J. Brown, a Licensed Geologist and I, John S. Haselow, a Licensed Engineer in the State of North
Carolina for TERRAQUEST ENVIRONMENTAL CONSULTANTS, P.C. do certify that the information contained in
this report is correct and accurate to the best of my knowledge. All work was performed under my direct
supervision. My seal and signature are affixed below. Additional seals and/or signatures are also listed.

Terraquest Environmental Consultants, P.C. is licensed to practice geology and engineering in North Carolina.
The geology certification number of the corporation is C-291. The engineering certification number of the
corporation is C-4634. Engineering is practiced out of the Cary, NC office.

TERRAQUEST ENVIRONMENTAL CONSULTANTS, P.C.

Ryan D. Kerins Michael J. Brown, P.G. John Haselow, PhD, PE
Project Manager President Senior Engineer

CAP Feasibility Report #47003 Little Market Basket #1
By: Terraquest Environmental Consultants, P.C. 3541 Taylorsville Hwy
Date: December 19, 2023 39 Statesville, Iredell County, NC
REFERENCES

Bouwer, H., and R.C. Rice 1976. A slug test for determining hydraulic conductivity of unconfined
aquifers with completely or partially penetrating well. Water Resources Research 12, no.
3: 423 – 428.

Bouwer, H. 1989. The Bouwer and Rice slug test – an update. Ground Water. 27, no. 3: 304 –
309.

Brown, et al., 1985. Geologic Map of North Carolina, North Carolina. Department of Natural
Resources and Community Development, 1:500,000 scale.

Heath C. Ralph. 1983. Basic Groundwater Hydrology, US Geological Survey Water-Supply Paper
2220, US Government Printing Office: 13.

Sanders, Laura L. 1998. A Manual of Field Hydrogeology. Upper Saddle River, New Jersey: Prentice
Hall Inc.: 196.

U.S. EPA. 1995. How to evaluate alternative cleanup technologies for underground storage tank
sites. Solid Waste and Emergency Response 5403W. Document Number 510-B-95-007.

TABLES

Table 1
Date: 11/21/23 Facility ID No: 00-0-0000021441
Capacity
UST Product (Gallons)Dimensions Release Discovered
Owner:
1 kerosene 4,000 unknown 5/10/1972 1/4/1987 no
2 unknown 3,000 unknown 9/25/1972 4/4/1987 no
3 unknown 2,000 unknown 9/25/1972 4/4/1987 no
Owner: Bumgarner Oil Company
4 kerosene 5,000-gallon 8' x 13.5'9/22/86 9/23/2019 yes
A1A gasoline 4,000-gallon
A1 gasoline 8,000-gallon
A2 diesel 2,000-gallon 64" x 13'12/20/93 9/23/2019 no
7 gasoline 4,000-gallon 64" x 24'6/3/94 9/23/2019
*MTBE noted in groundwater, no
soil > limits during tank closure
Owner: Ronald Hunt
B1A regular gasoline 10,000-gallon 12/22/20 active no
B1B premium gasoline 6,000-gallon 12/22/20 no
B1C e-free mid-grade gasoline 4,000-gallon 12/22/20 no
B2A diesel 4,000-gallon 12/22/20 active no
B2B off-road diesel 4,000-gallon 12/22/20 no
Notes:
1. Information obtained from the North Carolina UST Database Records and field observations.
SITE HISTORY (UST SYSTEM INFORMATION)
Incident Name: Little Market Basket #1 Incident No. 47003
Date Installed Date Closed
12/20/93
compartmentalized tank 4,000 + 8,000 = 12,000-gallon tank
8' x 32'9/23/2019 *MTBE noted in groundwater, no
soil > limits during tank closure
compartmentalized tank 10,000 + 6,000 + 4,000 = 20,000-gallon tank
compartmentalized tank 4,000 + 4,000 = 8,000-gallon tank
Table 2
Date: 11/21/23 Facility ID No. NA
Tax Parcel Number
(PIN Number)Property Owner Property Owner Address Property Address
Evelyn Graye Mitchell 3547 TAYLORSVILLE HWY 3547 TAYLORSVILLE HWYSTATESVILLE NC 28625 STATESVILLE NC 28625
Donna Williams 122 GRAYSON PARK RD TAYLORSVILLE HWY (no structure)
STATESVILLE NC 28625 STATESVILLE NC 28625
CRAWFORD FARM OF NC LLC 738 MOCK MILL RD 3522 TAYLORSVILLE HWY
STATESVILLE, NC 28677 STATESVILLE NC 28625
Michael F and Peggy L Mundwiler 111 ABSHER FARM LOOP 107 ABSHER FARM LOOP
STATESVILLE NC 28625 STATESVILLE NC 28625
Paul C. Vue and Tanya Moua 115 ABSHER FARM LOOP 115 ABSHER FARM LOOP
STATESVILLE, NC 28625 STATESVILLE, NC 28625
Octavia A Garcia 117 ABSHER FARM LOOP 117 ABSHER FARM LOOP
STATESVILLE, NC 28625 STATESVILLE, NC 28625
Ronald Hunt 255 OAKWOODS RD 3541 Taylorsville HWY
WILKESBORO NC 28697 STATESVILLE NC 28625
Notes:
1. Information gathered from field interviews and Iredell County Geographic Information System.
2. Last 4 digits of MAP ID numbers correspond with those displayed on Figure 2.
SURROUNDING PROPERTY OWNERS
Incident Name: Little Market Basket #1 Incident No.: 47003
SITE
4725252281.000
4725251228.000
4725258340.000
4725253040.000
4725240989.000
4725251572.000
4725240553.000
Table 3Date: 11/21/23 Facility ID No: 00-0-0000021441 Well Depth Type Casing Depth Screen Interva Distance from SourceWell ID No. Well Owner/Address Well Address Well Use (feet BGS)of Well (feet BGS)(feet BGS)Area of Release (feet)MITCHELL EVELYN GRAY sole sourcePW13547 TAYLORSVILLE HWY 3547 TAYLORSVILLE HWY not interested in connecting unknown drilled unknown unknown 160 STATESVILLE NC 28625 STATESVILLE NC 28625 to municipal sourceDANIEL FELICIANOPW2135 ABSHER FARM LOOP 135 ABSHER FARM LOOP sole source unknown drilled unknown unknown 449 STATESVILLE NC 28625 STATESVILLE NC 28625
Molly and Billy ClippardPW3131 ABSHER FARM LOOP 131 ABSHER FARM LOOP sole source unknown drilled unknown unknown 584
STATESVILLE NC 28625 STATESVILLE NC 28625JEANETTE WARREN
PW4 141 ABSHER FARM LOOP 141 ABSHER FARM LOOP sole source unknown drilled unknown unknown 659 STATESVILLE NC 28625 STATESVILLE NC 28625
BOWLES T R+M B STIKELEATHERPW53513 TAYLORSVILLE HWY 3513 TAYLORSVILLE HWY sole source unknown bored unknown unknown 447
STATESVILLE NC 28625 STATESVILLE NC 28625ANTHONY AND BRENDA EVEY
PW6 3509 TAYLORSVILLE HWY 3509 TAYLORSVILLE HWY sole source unknown bored unknown unknown 627 STATESVILLE NC 28625 STATESVILLE NC 28625
PATRICIA AND RONALD JOHNSONPW7176 GREYTHORN DR 176 GREYTHORN DR 335 STATESVILLE NC 28625 STATESVILLE NC 28625 sole source unknown drilled unknown unknownSMITH REAL ESTATE PROPERTIES LLCPW8124 GRAYSON PARK RD 124 GRAYSON PARK RD sole source unknown drilled unknown unknown 531 STATESVILLE NC 28625 STATESVILLE NC 28625HARRIS JAUNITAPW9116 ROBERTSON RD 134 GRAYSON PARK RD sole source unknown drilled unknown unknown 734STATESVILLE NC 28625 STATESVILLE NC 28625DONNA AND RONDA WILLIAMS sole sourcePW10122 GRAYSON PARK RD 122 GRAYSON PARK RD unknown bored unknown unknown 583
STATESVILLE NC 28625 STATESVILLE NC 28625
BETTY ELLIOTT
PW11 127 GRAYSON PARK RD 127 GRAYSON PARK RD sole source unknown drilled unknown unknown 737STATESVILLE NC 28625 STATESVILLE NC 28625
TONY AND SHELBY SHERRILLPW12135 GRAYSON PARK RD 135 GRAYSON PARK RD sole source unknown bored unknown unknown 691
STATESVILLE NC 28625 STATESVILLE NC 28625
MICHEAL AND DIANE MOOSEPW13303 N OAKLAND AVE 122 MORRIS FLATS RD sole source unknown bored unknown unknown 812STATESVILLE NC 28677 STATESVILLE NC 28625JOHN STIKELEATHERPW14695 SCOTTS CREEK RD 126 MORRIS FLATS RD sole source unknown bored unknown unknown 895 STATESVILLE NC 28625 STATESVILLE NC 28625JOHN STIKELEATHERPW15695 SCOTTS CREEK RD 132 MORRIS FLATS RD sole source unknown bored unknown unknown 1,011 STATESVILLE NC 28625 STATESVILLE NC 28625JOHN STIKELEATHERPW16695 SCOTTS CREEK RD 128 MORRIS FLATS RD sole source unknown bored unknown unknown 1,244 STATESVILLE NC 28625 STATESVILLE NC 28625
Notes:1. "BGS" = feet below ground surface, "NA" = not applicable.
2. Information obtained from Terraquest field interviews and observations, conversations with the City of Statesville's Public Works Department, and Iredell County GIS.3. Well ID numbers are displayed on Figure 2.
WATER SUPPLY WELL INFORMATION
Incident Name: Little Market Basket #1 Incident No. 47003
well supplies 122 Absher and
mobile home beside it too (Ronda
G Williams 704-902-4137)
Table 4
Date: 11/21/23 Facility ID No.: 00-0-0000021441
Well ID Date Installed
Date Water
Level
Measured
Screened Interval (x
to y ft. BGS)
Bottom of Well
(ft. BGS)
Top of
Casing
Elevation
(ft.)
Depth to
Water
from Top
of Casing
(ft.)
Free Product
Thickness
(ft.)
Groundwater
Elevation (ft.)Comments
MW1 5/4/20 4/12/23 10-30 30 103.21 well dry -2"-diameter Type II monitoring well
MW2 8/5/20 4/12/23 20-35 35 104.27 29.48 0 74.79 2"-diameter Type II monitoring well
MW3 8/5/20 4/12/23 20-35 35 98.75 25.72 0 73.03 2"-diameter Type II monitoring well
MW4 8/5/20 4/12/23 20-35 35 98.89 25.98 0 72.91 2"-diameter Type II monitoring well
MW5 5/10/21 4/12/23 20-35 35 101.88 28.58 0 73.30 2"-diameter Type II monitoring well
MW6 5/10/21 4/12/23 20-35 35 101.90 28.35 0 73.55 2"-diameter Type II monitoring well
MW7 5/10/21 4/12/23 20-35 35 99.54 26.77 0 72.77 2"-diameter Type II monitoring well
MW8 5/10/21 4/12/23 20-35 35 99.00 26.21 0 72.79 2"-diameter Type II monitoring well
MW9 5/10/21 4/12/23 20-35 35 96.01 24.00 0 72.01 2"-diameter Type II monitoring well
MW10 5/10/21 4/12/23 20-35 35 95.45 23.82 0 71.63 2"-diameter Type II monitoring well
MW11 6/28-29-21 4/12/23 IC: 40 OC: 50 50 - 55 55 101.63 28.00 0 73.63 Type III vertical delineation well
MW12 11/29/12 4/12/23 20-30 30 94.75 23.50 0 71.25 2"-diameter Type II monitoring well
MW13 4/3/23 4/12/23 20-35 35 103.48 28.55 0 74.93 2"-diameter Type II monitoring well
MW14 4/3/23 4/12/23 20-35 35 102.06 28.75 0 73.30 2"-diameter Type II monitoring well
MW15 4/4/23 4/12/23 20-35 35 95.92 24.03 0 71.88 2"-diameter Type II monitoring well
MW16 4/4/23 4/12/23 20-35 35 94.59 20.04 0 74.54 2"-diameter Type II monitoring well
MW17 4/4/23 4/12/23 20-35 35 96.68 24.32 0 72.35 2"-diameter Type II monitoring well
AS1 10/10/23 -44-49 49 99.77 -0 -1" -diameter air sparge well
SVE1 10/10/23 -5-20 20 103.05 -0 -2"-diameter soil extraction well
Notes:
1. All units in feet.
2. "-" = not detected, "IC" = inner casing, "OC" = outer casing.
MONITORING WELL CONSTRUCTION INFORMATION
Incident Name: Little Market Basket #1 Incident No. 47003
Well Casing Depth (ft.
BGS)
10
20
20
20
20
20
20
20
20
20
44
5
20
20
20
20
20
20
TPH 5030TPH 355082608260826082608260826082608260826082608260826082608260/8270826082608260827082708270827082708270827082708270MADEP VPHMADEP VPH/EPHMADEP EPHMADEP VPH/EPHSample ID Date Collected
Sample Depth
(feet BGL)
CS1 9/24/2019 13 <1 0.94 ------------------------------
CS2 9/24/2019 13 1.68 0.82 ------------------------------CS3 9/24/2019 13 1.24 1.64 ------------------------------
CS4 9/24/2019 13 1.44 1.42 ------------------------------CS5 9/24/2019 9 1.56 1.14 ------------------------------
CS6 9/24/2019 9 1.56 0.9 ------------------------------CS7 9/24/2019 9 2.02 0.7 ------------------------------
CS8 9/24/2019 3 1.46 1.06 ------------------------------CS9 9/24/2019 9 2.22 0.8 ------------------------------
CS10 9/24/2019 9 4.04 0.42 ------------------------------
CS11 9/25/2019 13 2.24 0.74 ------------------------------CS12 9/25/2019 13 2 0.66 ------------------------------
CS13 9/25/2019 4 363 125 0.0153 0.0132 0.0248 <0.000701 <0.000678 <0.00127 0.369 0.065 0.115 0.0163 -0.023 0.00274 0.0859/0.0941 0.0414 0.018 0.00183 -----0.312 0.353 --<7.56 393 <9.37 422.8CS149/25/2019 4 1.42 2.12 ------------------------------
CS15 9/25/2019 4 1.46 2.66 ------------------------------CS16 9/25/2019 4 <1 2.48 ------------------------------
CS17 9/25/2019 4 2.2 1.76 ------------------------------K Disp 5/4/2020 5 --< 0.000837 0.0138 0.0149 0.0485 < 0.00113 < 0.00212 0.215 1.27 1.12 < 0.00136 0.276 < 0.00124 0.0136 0.103/1.24 0.169 0.129 0.0568 < 0.0720 < 0.0756 < 0.0649 0.454 0.147 2.62 3.29 0.148 < 0.0756 18.8 902 < 9.29 277.7MW15/4/2020 8-10 --< 0.000678 0.00567 0.00869 0.0589 < 0.000915 < 0.00172 0.124 0.721 0.992 < 0.00110 < 0.0370 0.0566 0.981 0.0494/<0.724 0.0643 8.31 0.276 < 0.715 < 0.751 < 0.644 < 0.823 < 0.553 3.1 4.49 < 0.950 < 0.751 20.3 2,060 19.3 604MW15/4/2020 18-20 --< 0.0255 < 0.0293 0.0677 1.296 < 0.0345 < 0.0647 1.13 < 0.0439 4.69 0.133 < 1.39 0.431 4.89 27.3/7.74 1.52 65.5 15.6 6.26 4.64 3.84 < 0.0852 < 0.0572 14.6 21.3 0.24 0.189 54.9 5,790 16.6 1,557TPH Action Limit 50 100 --------------------------------0.0056 4.3 4.9 4.6 0.091 0.37 24 4.3 3.3 3.4 15 1.7 0.12 0.16 1.7 8.5 8.3 120 NE NE 0.64 47 0.004 3.6 NE 56 68 540 ##31
--18 1,200 1,560 3,129 350 156 14,000 626 626 626 7,000 1,564 100 313 626 782 782 62,571 NE NE 312 620 20 63 NE 469 939 1,500 31,000 469Notes:
1. All results in mg/kg = parts per million 2. Bold denotes a compound detection. 3. Shading denotes a TPH Action Limit or Soil-to-groundwater MSCC violation. Red italics denotes a residential MSCC violation.
4. < - denotes less than sample detection limit.5. Sample depths are in feet below ground level.
6. MSCC = Maximum Soil Contaminant Concentration.7. NE - Not Established IsopropylbenzeneDate: 11/21/23 Incident Name: Little Market Basket #1 Incident No. 47003 Facility ID No. 00-0-0000021441
Analytical Method
Table 5 SUMMARY OF SOIL SAMPLING RESULTS
2-MethylnaphthaleneNaphthalenen-PropylbenzeneEthanolC9-C18 AliphaticsC19-C36 AliphaticsFluoreneC9-C22 AromaticsResidential MSCC Acetonen-ButylbenzeneSec-Butylbenzenetert-ButylbenzeneContaminant of Concern
BenzeneTolueneEthylbenzeneTotal XylenesMTBEIPESoil to groundwater MSCC TPH Low FractionTPH High Fraction4-Isopropyltoluene1,2,4-Trimethylbenzene1,3,5-TrimethylbenzeneN-NitrosodiphenylaminePhenanthreneC5-C8 AliphaticsBenzoic Acid4-Chloroaniline4-chloro-3-methylphenol2,4-Dimethylphenol1-Methylnaphthalene
Table 6
Date: 11/22/23
6200B6200B6200B6200B6200B6200B6200B6200B6200B6200B6200B6200B6200B6200B6200B6200BWell ID
Date
Collected
MW2 4/12/23 < 0.130 < 0.410 < 0.500 < 1.60 < 0.220 < 0.200 < 0.820 < 0.560 < 1.40 < 1.00 < 0.530 < 3.00 < 0.760 < 0.690 < 0.710 < 0.700
MW3 4/12/23 < 0.130 < 0.410 < 0.500 < 1.60 < 0.220 < 0.200 < 0.820 < 0.560 < 1.40 < 1.00 < 0.530 < 3.00 < 0.760 < 0.690 < 0.710 < 0.700
MW4 4/12/23 1,060 25.5 159 1,140 213 22.2 1,010 248 < 7.00 < 5.00 54.7 337 11.1 116 < 3.55 3.96 J
MW5 4/12/23 82.8 0.866 J 1.43 17.3 64.5 8.85 14.5 < 0.560 < 1.40 < 1.00 6.65 32.9 6.56 5.26 1.06 5.47
MW6 4/12/23 1,280 45.5 238 926 16.6 6.34 J 566 152 < 14.0 21.2 30.3 175 21.4 50.6 < 7.10 < 7.00
MW7 4/12/23 5,650 1,190 2,060 7,020 867 147 1,770 468 < 70.0 < 50.0 110 594 41.3 J 286 < 35.5 < 35.0
MW8 4/12/23 < 0.130 < 0.410 < 0.500 < 1.60 0.404 J < 0.200 < 0.820 < 0.560 < 1.40 < 1.00 < 0.530 < 3.00 < 0.760 < 0.690 < 0.710 < 0.700
MW9 4/12/23 889 141 1,080 2,220 285 40.3 1,340 373 25.7 J < 10.0 99.0 421 36.3 216 8.90 J 15.1MW104/12/23 3.5 < 0.410 < 0.500 6.35 J 32.4 2.38 2.51 < 0.560 < 1.40 < 1.00 1.00 3.71 < 0.760 < 0.690 < 0.710 < 0.700
MW11 4/12/23 < 0.130 < 0.410 < 0.500 < 1.60 < 0.220 < 0.200 < 0.820 < 0.560 < 1.40 < 1.00 < 0.530 < 3.00 < 0.760 < 0.690 < 0.710 < 0.700
MW12 4/12/23 309 9.87 340 114 129 12.7 43.6 20.7 < 2.80 < 2.00 38.8 393 26.7 52.5 10.9 15.3MW134/12/23 583 3,300 4,580 21,000 67.2 J < 20.0 4,160 1,030 < 140 < 100 207 1,390 < 76.0 559 < 71.0 < 70.0
MW14 4/12/23 6.26 36.3 36.1 178 4.38 0.661 130 43.6 < 1.40 < 1.00 7.08 14.3 15.7 24.7 3.78 7.65
MW15 4/12/23 41.9 355 5,310 16,500 < 11.0 < 10.0 4,560 1,220 < 70.0 < 50.0 195 1,640 < 38.0 571 < 35.5 < 35.0
MW16 4/12/23 86.3 2.30 7.03 19.5 481 33.5 16.9 1.94 < 1.40 < 1.00 37.1 205 5.09 7.54 2.35 4.79
MW17 4/12/23 < 0.130 1.08 < 0.500 1.81 J < 0.220 < 0.200 < 0.820 < 0.560 < 1.40 < 1.00 < 0.530 < 3.00 < 0.760 < 0.690 < 0.710 < 0.700
PW1 4/12/23 < 0.130 < 0.410 < 0.500 < 1.60 < 0.220 < 0.200 < 0.820 < 0.560 < 1.40 < 1.00 < 0.530 < 3.00 < 0.760 < 0.690 < 0.710 < 0.700
1 600 600 500 20 70 400 400 40 70 70 6 70 70 25 70
5,000 260,000 84,500 85,500 20,000 70,000 28,500 25,000 40,000 70,000 25,000 6,000 6,900 30,000 11,700 8,500
Notes:
1. All results in µg/L.
2. Bold denotes a compound detection
3. Shading denotes a 2L Standard violation4. Italics denotes a GCL violation.
5. < - denotes less than sample detection limit
2L Standard
GCL IsopropylbenzeneNaphthalenen-Butylbenzene2-HexanoneChloroformDiisopropyl ether1,2,4-Trimethylbenzene1,3,5-TrimethylbenzeneSUMMARY OF GROUNDWATER SAMPLING RESULTS
Incident Name: Little Market Basket #1 Incident No. 47003 Facility ID No.: 00-0-0000021441
Analytical Method
Contaminant of Concern
BenzeneTolueneEthylbenzeneXylenes, TotalMethyl tert-butyl ethersec-ButylbenzeneN-Propylbenzenep-Isopropyltoluene
Table 7
Date: 11/28/23 Facility ID No.: 00-0-0000021441
Total remedial costs to closure GRAND TOTAL =498,598.00$
Task Description Unit Rate Subtotal Comments
6.066 Corrective Action Design Report 1 report x 5,000.00$ =5,000.00$
6.082 Public notice of 6.066 1 notice x 500.00$ =500.00$
6.067 Corrective Action Record of Decision 1 ROD x 1,000.00$ =1,000.00$
6.082 Public notice of 6.067 1 notice x 500.00$ =500.00$
3.101 Drilling supervision 500 feet x 12.50$ =6,250.00$
3.112 1-inch well cost 400 feet x 40.00$ =16,000.00$ 8, 50' sparge wells
3.113 2-inch well cost 100 feet x 50.00$ =5,000.00$ 5, 20' SVE wells
3.118 Drilling supervision increase 500 feet x 5.00$ =2,500.00$
3.351 Well casing surveying 13 wells x 80.00$ =1,040.00$
3.397 MOBE increase 1 increase x 100.00$ =100.00$
3.398 Drill rig MOBE 1 MOBE x 350.00$ =350.00$
3.500 Drill crew per diem- Driller 1 4 days x 155.00$ =620.00$
3.500 Drill crew per diem- Driller 2 4 days x 155.00$ =620.00$
6.190 Letter report 1 letter x 500.00$ =500.00$
12.030 Drill supervision per diem 4 days x 155.00$ =620.00$
12.050 Consultant MOBE 1 MOBE x 250.00$ =250.00$
12.055 MOBE increase 1 increase x 50.00$ =50.00$
TOTAL =33,900.00$
7.065 SVE and air sparge system cost 1 cost x 160,000.00$ =160,000.00$ estimated: requires bidding during CAPR
7.081 System installation supervision 40 hours x 93.00$ =3,720.00$ 4-week install: 8M,4F,4M,4F,4M,4F,4M,8F.
7.100 System installation cost 1 cost x 60,000.00$ =60,000.00$ estimated: requires bidding during CAPR
12.050 Consultant MOBE 8 MOBE x 250.00$ =2,000.00$ 3-week install: Monday and Friday visits.
12.055 MOBE increse 8 increases x 50.00$ =400.00$
TOTAL =226,120.00$
4.031 Well sampling 17 wells x 110.00$ =1,870.00$ MW1-17.
4.090 Cost for analytical 17 samples x 66.00$ =1,122.00$ 6200B
4.091 Sample shipping 1 fee x 85.00$ =85.00$
6.106 CAPR 1 report x 1,125.00$ =1,125.00$
12.050 Consultant MOBE 1 MOBE x 250.00$ =250.00$
12.055 MOBE increase 1 increase x 50.00$ 50.00$
per event =4,502.00$
Quarterly 1st year cost 18,008.00$
3 years of semi-annual 27,012.00$
TOTAL =45,020.00$
4.090 Lab cost 3 samples x 151.00$ =453.00$ EPA 18
4.091 Shipping cost 3 fees x 85.00$ =255.00$
6.106 CAPR 1 report x 1,125.00$ =1,125.00$
7.201 System O&M 48 hours x 93.00$ =4,464.00$ Monthly visits of 2 x 8 hrs for the quarter.
7.250 System parts 1 lump x 750.00$ =750.00$
7.260 Operating utilities 3 months x 2,000.00$ =6,000.00$ Estimated
12.050 Consultant MOBE 6 MOBE x 250.00$ =1,500.00$ O&M visits.
12.055 MOBE increase 6 MOBE increase x 50.00$ =300.00$ O&M visits.
quarterly =14,847.00$
yearly =59,388.00$
3 years =178,164.00$
3.398 Drill rig MOBE 1 MOBE x 350.00$ =350.00$
3.399 Well abandonment 1174 feet x 6.00$ =7,044.00$
6.082 Public notification 1 notice x 500.00$ =500.00$
6.174 NORP 1 NORP x 500.00$ =500.00$
TOTAL =8,394.00$
Units
Incident Name: Little Market Basket #1 Incident No. 47003
CORRECTIVE ACTION PLAN COSTS

FIGURES

NVIRONMENTAL ONSULTANTS, P.C.E C
NVIRONMENTAL ONSULTANTS, P.C.E C
NVIRONMENTAL ONSULTANTS, P.C.E C
NVIRONMENTAL ONSULTANTS, P.C.E C
NVIRONMENTAL ONSULTANTS, P.C.E C

APPENDIX A

Page 1 of 8 
 TECHNICAL METHODS/STANDARD PROCEDURES 

Equipment Decontamination 

All soil sampling equipment utilized during site assessment activities is decontaminated according 
to standard and accepted protocol.  Cleaning solutions range from clean potable water to acidic 
solutions or organic solvents depending on the contaminants present at the site.  Equipment 
utilized at sites, such as hand augers, contaminated with petroleum hydrocarbons, is generally 
decontaminated with a low‐sudsing detergent such as Luiquinox® and triple rinsed with distilled 
water.  Larger equipment, such as drill rigs and associated tools, is steam cleaned.  All 
decontamination procedures are completed within an established decontamination area which is 
located away from the active study area.  Frequency of equipment decontamination depends on 
the nature of work being performed, but in no case is decontamination performed less frequently 
than once per test (i.e., soil boring, well installation, sample collection, etc.).  Equipment blanks are 
collected as a quality control measure when required by job specifications. 

Soil Boring Installation 

Soil borings are completed using hand‐operated sampling tools, truck‐mounted drills, or 
Geoprobe® drilling rigs depending on the depth of sample collection and other site‐specific 
conditions.  Hand operated stainless‐steel bucket augers are utilized to collect soil samples at 
regular intervals to determine site stratigraphy and to test for the presence of volatile organic 
compounds.  Samples retrieved from the hand auger are necessarily disturbed during the augering 
process, but can provide accurate information on soil type and contaminant concentrations when 
properly interpreted.  Soil samples from hand augered borings are generally retrieved at one to 
two foot intervals. 

Truck‐mounted or Geoprobe® drilling equipment is often utilized when sample retrieval depths 
exceed twenty feet or subsurface conditions prevent utilization of hand augers (i.e., buried rocks, 
wood, bricks or other materials occur in the subsurface).  Truck‐mounted drilling rigs usually 
retrieve soil via a hollow‐stem auger/split spoon collection method.  Geoprobe® rigs usually employ 
a Macro‐Core® tube retrieval system.   

Hollow stem augers provide relatively undisturbed 2‐foot cores of soil samples.  Soil samples are 
generally collected at five foot intervals utilizing standard penetration test procedures as defined 
by the American Society for Testing and Materials (ASTM) or are pushed to the desired depth using 
the head of the drill rig.  The standard penetration test involves driving a 2" outside diameter by 1‐
3/8" inside diameter split‐spoon sampler a minimum distance of one foot with a 340‐lb. slide 
hammer falling a distance of 30 inches.   

A Geoprobe® rig is a hydraulically‐powered soil probing machine.  The probe utilizes static force 
and percussion to advance a small diameter sampling device into the subsurface.  The sampling 
apparatus provides relatively undisturbed 5‐foot cores of soil samples.  Soil samples are collected 
Page 2 of 8 
continuously.  The Macro‐Core® tube contains an inserted poly‐vinyl chloride (PVC) liner which 
retains the soil sample as the tube is driven into the ground.  The Macro‐Core® tube is 
decontaminated between each 5‐foot sample interval in a soil boring using a Liquinox and tap‐
water mixture.  A new PVC liner is used to collect soil from each sample interval in a soil boring.    

Soil samples retrieved from the hollow‐stem augers or Geoprobe are then carefully described 
according to the Unified Soil Classification System.  Soil descriptions are recorded on a soil 
boring log. 

Soil Sampling 

Soils to be analyzed by a North Carolina‐certified laboratory are prepared according to the specified 
analytical method.  Initially, soil samples are removed from the ground using either a hand auger, 
backhoe bucket, spilt spoon auger, or a Macro‐Core® sampling tube.  During the removal, care is 
taken to keep the disturbance of the soil structure to a minimum to reduce the loss of 
contaminants.  Once removed, the samples are placed in the proper sample container for the 
specified analytical method.  For samples collected for the MADEP VPH and EPA Method 8260, a 
TerraCore® sampler is used to collect one 5‐gram allotment of soil.  The allotment is placed in 
methanol‐preserved 40 mL vials.  Also, one 5‐gram allotment of soil is placed into sodium bisulfate‐
preserved 40 mL vials (one 5‐gram allotment per vial, 2 vials per sample) for the 8260 low 
concentration method.  A 250‐mL glass jar of the sampled soil is also collected to provide moisture 
content information.  Soils sampled for MADEP EPH, EPA Method 8270 and TPH 5030 and 3550 are 
placed in a 250‐mL glass jar (for MADEP EPH analysis an amber jar is required).  TPH 5030 samples 
are preserved in methanol similar to the 8260 analysis.  Field personnel wear new, disposable 
nitrile gloves during the collection of each sample.  

The soil samples are labeled with the sample location, sample identification, date and time of 
collection, and the analytical method.  The samples are placed on ice, sent to a laboratory, and 
analyzed before the expiration of an analytical method’s prescribed holding time.  Chain‐of‐custody 
documentation is maintained for each sample collected in the field. 

If the soil is being sampled for volatile or semi‐volatile compounds, a portion of the collected soil is 
placed in a sealable bag and screened for volatile organic vapors.  Head screening procedures are 
described in the following paragraph.  

Headspace Screening 

Collected soil samples are routinely tested for the presence of volatile organic compounds (VOCs).  
After retrieval from the ground, a portion of a soil sample is placed in a sealable plastic bag.  The 
soil samples are then set aside for approximately five minutes so that volatile constituents present 
in the sample can reach equilibrium concentrations with headspace gases in the bag.  Once a 
suitable time period has passed, the probe of the sampling instrument, typically an Organic Vapor 
Monitor (OVM) or a Photo Ionization Detector (PID), is inserted into the bag and the relative 
concentration of total VOCs is measured and permanently recorded in a field note book.  VOC 
Page 3 of 8 
concentrations are measured using either a Thermo Electron Corp. Innova Series catalytic OVM or 
an Ion Science PhoCheck PID.  Both the OVM and PID instrumentation are periodically calibrated 
according to the manufacturer’s recommended procedures. 

The OVM and PID are qualitative tools employed to detect and estimate the concentration of 
organic or hydrocarbon vapors.  A thin probe is inserted through a small break in the seal of a 
bagged soil sample.  For the OVM, an air sample from the headspace of the bag is drawn through 
the probe into an internal chamber where the vapors are catalyzed.  The concentration of the VOCs 
is registered on a digital scale in parts per million (ppm).  For the PID, an air sample from the 
headspace of the bag is drawn across the face of a lamp causing the sample to emit photons, the 
presence of which are converted into a VOC ppm reading that is displayed.  Oxygen levels are field 
calibrated prior to each use.  VOC calibration occurs periodically depending upon use by using a 
span gas of known concentration in a process recommended by the manufacturer.   

Well Installation/Construction 

Monitoring wells are installed using hand‐operated sampling tools, a truck‐mounted drill rig, or a 
Geoprobe drilling rig depending on the depth of well and other site‐specific conditions. All 
monitoring wells are installed according to the requirements of 15A NCAC 2C‐Well Construction 
Standards.  Specifically, individual monitoring wells are constructed of 2‐inch diameter, schedule 40 
PVC casing riser and screen.  The screen interval is generally 10 to 15 feet of machine slotted PVC 
with a slot size of 0.010".  Only flush threaded joints are used.  The annulus space around the 
screen is filled with washed filter pack No. 2 sand.  The filter pack extends one to two feet above 
the top of the screen.  A one to two foot‐thick bentonite pellet seal is then placed above the filter 
pack.  The remainder of the well annulus is completely filled with a Portland (Type I/II) cement 
grout mixture.  A protective outer steel manhole, locking cap, and concrete pad is installed for each 
well. 

Type II Monitoring Well Construction  

Single‐cased monitoring wells are generally used in delineation of groundwater quality within the 
surficial aquifer.  The wells are constructed of 2‐inch diameter, schedule 40 PVC casing and screen.  
The screen interval is generally 10 to 15 feet of machine slotted PVC with a slot size of 0.010".  Only 
flush threaded joints are used.  The annulus space around the screen is filled with washed filter 
pack No. 2 sand.  The filter pack extends one to two feet above the top of the screen.  A one to two 
foot‐thick bentonite pellet seal is then placed above the filter pack.  The remainder of the well 
annulus is completely filled with a Portland (Type I/II) cement grout mixture.  A protective outer 
steel manhole, locking cap, and concrete pad are installed for each well. 

Type III Monitoring Well Construction 

Double‐cased monitoring wells are used in the delineation of groundwater quality within a deeper 
portion of the surficial aquifer or an additional aquifer (e.g. aquitard, bedrock).  A four to six‐inch 
outer casing is installed through the surficial aquifer until a sufficient depth or until the deeper 
Page 4 of 8 
aquifer is encountered.  The casing is secured with a Portland‐grout collar that is tremmied into the 
annular spaced from the bottom of the bore hole to the surface.  Once the grout has sufficiently 
cured, the bore hole is continued through the bottom of the outer casing to a depth approximately 
15 ‐ 20 feet beneath the outer casing.  The inner casing is constructed of 2‐inch diameter, schedule 
40 PVC casing riser and screen.  The screen interval is generally 5 to 10 feet of machine slotted PVC 
with a slot size of 0.010".  Only flush threaded joints are used.  The annulus space around the 
screen is filled with washed filter pack No. 2 sand.  The filter pack extends one to two feet above 
the top of the screen.  A one to two foot‐thick bentonite pellet seal is then placed above the filter 
pack.  The remainder of the well annulus is completely filled with the same Portland grout mixture 
used in the outer casing.  A protective outer steel manhole, locking cap, and concrete pad are 
installed for each well. 

Well Development 

Following installation of each well, surging and pumping or bailing techniques will be used to 
remove fines from the screened interval.  Groundwater is removed from each well until clear water 
is retrieved or a noticeable reduction in the amount of silt is achieved.  Purged groundwater is 
disposed of in an environmentally safe manner. 

Groundwater Sampling 

Petroleum Sites 

Groundwater samples are collected from temporary or permanent monitoring wells according to 
established sampling protocol.  When multiple monitoring wells or sampling points are sampled, 
sampling is completed beginning with the least contaminated well to the most contaminated well, 
if it is known.  When permanent monitoring wells for petroleum sites are sampled, the well is 
purged of a minimum of three well‐bore volumes prior to sample collection in order to assure that 
sampled water is representative of aquifer conditions.  In temporary wells, the first water which 
migrates into the open borehole is sampled.  Samples from both temporary and permanent 
monitoring wells are collected using individually wrapped disposable polyethylene bailers by field 
personnel wearing disposable nitrile gloves.  Only one well is sampled with a given bailer in order to 
prevent sample cross‐contamination.  During both well purging and sampling, proper protective 
clothing and equipment is used and is dependent upon the type and level of contaminants present. 
Also, field personnel change gloves between different samples to reduce the chance of cross‐
contamination. Water samples are transferred from the bailer to laboratory‐prepared sampling 
containers using slow emptying devices to reduce the chance of contamination loss through 
volatilization.  Preservatives, such as acids, are provided by the laboratory in pre‐prepared 
containers in which collected samples are placed if in‐field preservation is necessary.  The samples 
are labeled with the project name, project number, sample identification, required analysis, and 
date and time of collection.  The samples are placed on ice, shipped to a certified laboratory, and 
analyzed before the expiration of an analytical method’s prescribed holding time.  Chain‐of‐custody 
documentation is maintained for each sample collected in the field.   

Page 5 of 8 

Other Groundwater Sampling Protocols 

When required by state or federal regulations, low‐flow groundwater sampling procedures are 
instituted.  Groundwater samples collected in low‐flow situations are collected using a peristaltic 
pump. A peristaltic pump is a type of positive displacement pump. The fluid is contained within a 
flexible tube fitted inside a circular pump casing.  A rotor with a number of rollers attached to the 
external circumference compresses the flexible tube. As the rotor turns, the part of tube under 
compression closes thus forcing the fluid to be pumped to move through the tube.  Groundwater 
parameters such as water level drawdown, pH, conductivity, dissolved oxygen (DO) and turbidity. 
Pumping rate, drawdown, and the time or volume required to obtain stabilization of parameter 
readings can be used as a future guide to purge the well. Measurements are collected at a pre‐
pumping established interval (typically five to ten minutes). Once all or a majority of the 
parameters have stabilized for three successive readings, stabilization has been achieved. In lieu of 
measuring all five parameters, a minimum subset would include pH, conductivity, and turbidity or 
DO. Three successive readings should be within ± 0.1 for pH, ± 3% for conductivity, and ± 10% for 
turbidity and DO.  

Upon parameter stabilization, sampling is initiated. Sampling flow rate is maintained at the estab‐
lished purge rate or is adjusted slightly to minimize aeration, bubble formation, turbulent filling of 
sample bottles, or loss of volatiles due to extended residence time in tubing. The same device used 
for purging is used to collect the groundwater sample. Generally, volatile parameters are sampled 
first. The sequence in which samples for inorganic parameters are collected is not determined 
unless filtered (dissolved) samples are collected. Preservatives, such as acids, are provided by the 
laboratory in pre‐prepared containers in which collected samples are placed if in‐field preservation 
is necessary.  The samples are labeled with the project name, project number, sample 
identification, required analysis, and date and time of collection.  The samples are placed on ice, 
shipped to a certified laboratory, and analyzed before the expiration of an analytical method’s 
prescribed holding time.  Chain‐of‐custody documentation is maintained for each sample collected 
in the field.   

During both well purging and sampling, proper protective clothing and equipment is used and is 
dependent upon the type and level of contaminants present.   Also, field personnel change gloves 
between different monitoring wells or sampling points to reduce the chance of cross‐
contamination.  When multiple monitoring wells or sampling points are sampled, sampling is 
completed beginning with the least contaminated well to the most contaminated well, if it is 
known. 

Stockpile Sampling 

The number of composite samples collected from a stockpile or a total quantity of excavated soil is 
based upon the cubic yardage.  One composite sample is collected for every 100 cubic yards of 
contaminated soil excavated.  The volume of a stockpile or total quantity of excavated soil is 
calculated by approximating the general geometry of a stockpile or estimating the capacity of the 
Page 6 of 8 
dump trucks used for hauling.  If a stockpile is sampled, a grid pattern is laid out on the stockpile, 
dividing the stockpile into segments of approximately 200 cubic yards.  Two soil borings are 
advanced within a grid and three soil samples are collected from each soil boring at various depths. 
 The six soil samples are mixed into a composite sample by a trained TerraQuest technician.  If truck 
loads are sampled, an aliquot sample is collected from the hauling trucks at a frequency based 
upon the capacity of the hauling trucks.   

Aliquots are gently mixed into a composite sample by a trained TerraQuest technician. Every effort 
is made to minimize the loss of contaminants through volatilization.  The composited soil samples 
are jarred in the appropriate laboratory‐prepared containers, labeled with the sample location, 
sample identification, date of collection, time of collection, the analytical method, and the 
preservative.  The samples are placed on ice, shipped to a laboratory, and analyzed before the 
expiration of an analytical method’s prescribed holding time.  Chain‐of‐custody documentation is 
maintained for each sample collected in the field. 

Surface Water Sampling 

Surface water samples, specifically samples from creeks or streams, are collected from a 
moving/flowing portion of the creek or stream to ensure that stagnant water is not collected.  Field 
personnel are careful to collect samples from flowing areas that are not so turbulent as to cause a 
loss of volatile contaminants which might have been contained in the creek’s/stream’s water.  
Samples are collected by field personnel wearing disposable nitrile gloves.  Field personnel change 
gloves between different locations to reduce the chance of cross‐contamination.  Samples are 
collected directly from the appropriate creek or stream location and placed into the appropriate 
laboratory‐prepared containers.  Preservatives, such as acids, are provided by the laboratory in pre‐
prepared containers in which collected samples are placed if in‐field preservation is necessary. The 
samples are labeled with the project name, project number, sample identification, required 
analysis, and date and time of collection.  The samples are cooled on ice to approximately four 
degrees centigrade, shipped to a certified laboratory, and analyzed before the expiration of an 
analytical method’s prescribed holding time.  Chain‐of‐custody documentation is maintained for 
each sample collected in the field.    

Potable Well Sampling 

Groundwater samples from potable wells are collected from sampling points, typically spigots, 
located in the closest proximity to the potable well pump house as possible.  Prior to sample 
collection, the water is run for a sufficient amount of time to purge the bladder tank and assure 
that sampled water is representative of aquifer conditions.  Once purged, the flow rate is reduced 
and samples are placed in the appropriate laboratory prepared containers with the appropriate 
acid preservatives added if preservation of the sample is necessary.  The samples are labeled with 
the project name, project number, sample identification, required analysis, and date and time of 
collection.  The samples are placed on ice, shipped to a laboratory, and analyzed before the 
expiration of an analytical method’s prescribed holding time.  Chain‐of‐custody documentation is 
maintained for each sample collected in the field.  
Page 7 of 8 
Public Water Supply Line Sampling 

Groundwater samples from public water supply lines are collected from sampling points, typically 
spigots.  To sample the spigot, the flow rate is reduced and samples are placed in the appropriate 
laboratory prepared containers.  The samples are labeled with the sample location, sample 
identification, date of collection, time of collection, and required analytical method.  The samples 
are placed on ice, shipped to a laboratory, and analyzed before the expiration of an analytical 
method’s prescribed holding time.  Chain‐of‐custody documentation is maintained for each sample 
collected in the field.  

Air Sampling 

Air samples are collected with the aide of a manually operated MityVac® pump manufactured by 
Pristech, Inc.  The air sampling process begins by connecting a length of rubber hose from the 
MityVac® pump to the port to be sampled, or by hanging the hose inside of an emissions stack in 
such a manner as to ensure no outside air causes dilution.  Another length of hose is fixed to the 
outlet port of the pump and is connected to a new Tedlar bag.  Once the pump is hooked up, a 
valve on the Tedlar collection bag is opened and air is manually forced into the bag by the pumping 
action of sampling personnel.   

Field Measurements 

Field measurements taken to determine the pH, conductivity, temperature, and dissolved oxygen 
concentration of a particular groundwater sample are taken directly after a particular monitoring 
well has been adequately purged.  This ensures that the groundwater parameter data collected is 
representative of the aquifer conditions at a given location.  Once purging of the monitoring well is 
complete, the decontaminated probe head and cord of the appropriate unit is lowered into the 
required monitoring well.  If the depth to water in a specific monitoring well is greater than the 
length of cord for a particular unit, a new, disposable bailer is slowly lowered into the appropriate 
monitoring well and a representative groundwater sample is retrieved.  A slow pouring device is 
fitted onto the end of the disposable bailer and the sample is slowly poured into a new, disposable 
plastic cup.  Groundwater parameter data are then collected from the groundwater in the cup 
using the required unit.   

For pH, conductivity, and temperature, a Hanna Instruments Model 991300 portable meter is 
utilized.  This unit is periodically calibrated and maintained in accordance with the unit’s operations 
manual by field personnel.  Prior to data collection, the unit is properly decontaminated to prevent 
cross‐contamination.  The unit is decontaminated between each sample.  The procedure used for 
sample measurement involves lowering the meter’s probe into the new, disposable cup containing 
the groundwater sample to be measured and slowly stirring the probe to force groundwater across 
the probe’s membrane.  The measurements displayed by the meter are then recorded.   

For dissolved oxygen concentration measurements, a YSI® Model 55 Handheld Dissolved Oxygen 
System is utilized.  This unit is periodically calibrated and maintained in accordance with the unit’s 
Page 8 of 8 
operations manual by field personnel.  Prior to data collection, the unit is properly decontaminated 
to prevent cross‐contamination.  The unit is decontaminated between each sample.  The procedure 
used for sample measurement involves adjusting the unit for the correct altitude where the 
sampling will take place and adjusting the reported units desired.  Once this is done, the unit’s 
probe is inserted into the groundwater sample to be measured and the probe is slowly stirred to 
force the groundwater across the probe’s membrane.  The measurements displayed by the unit are 
then recorded.   

For turbidity measurements, a Hach 2100P Portable Turbidity meter or equal equivalent is utilized.  
The unit is calibrated prior to use in accordance with the unit’s operations manual by field 
personnel.  Groundwater samples are collected in glass containers for measurement by the 
instrument.  The glass containers are washed with bottled‐water between each measurement 
collection.  Once the sample is collected and inserted into the instrument, the measurements 
displayed by the instrument are then recorded.   

APPENDIX B

Chronological Site History
Little Market Basket #1
NCDWM-UST Incident No.: 47003
Terraquest Environmental Consultants, P.C.
Page 1 of 3
CHRONOLOGICAL SITE HISTORY

LITTLE MARKET BASKET #1
3541 TAYLORSVILLE HWY
STATESVILLE, IREDELL COUNTY, NC 28677

Facility ID: 00-0-0000021441
NCDWM-UST Incident No.: 47003
NCDWM-UST Risk Ranking: High 205D
Latitude: 35.809521 N Longitude: -80.948539 W

Release Information
Date Discovered: 9/30/19 lab confirmed
Estimated Release Quantity: Unknown
Release Cause/Source: Commercial 5,000-gallon kerosene UST dispenser

Tanks removed in 1987:
1, 4,000-gallon kerosene
1, 3,000-gallon unknown contents
1, 2,000-gallon unknown contents

Tanks removed in 2019:
1, compartmentalized tank 4,000-gallon gasoline and 8,000-gallon gasoline
1, 2,000-gallon diesel
1, 5,000-gallon kerosene (release confirmed)
1, 4,000-gallon gasoline

Tanks installed in 2020:
1, compartmentalized tank gas: 10,000-gallon reg, 6,000-gallon prem, 4,000-gallon e-free mid
1, compartmentalized tank 4k-gallon diesel, 4k-gallon off-road diesel

March 4, 2020 Terraquest sent a UST Closure Report to the NCDWM-UST.

March 13, 2020 The NCDWM-UST issued an NORR requesting the completion of an LSA.

September 1, 2020 Terraquest sent an LSA Report to the NCDWM-UST.

November 30, 2020 The NCDWM-UST Trust Fund issued an Eligibility Determination letter. The
incident is conditionally eligible for reimbursement following completion of a
$20,000 deductible.

August 3, 2021 Terraquest sent a CSA Report to the NCDWM-UST.

Chronological Site History
Little Market Basket #1
NCDWM-UST Incident No.: 47003
Terraquest Environmental Consultants, P.C.
Page 2 of 3
September 17, 2021 The NCDWM-UST issued an NORR approving the CSA and requesting the
installation of an additional groundwater monitoring well and the completion of a
groundwater sampling event.

November 29, 2021 Terraquest supervised the installation of groundwater monitoring well MW12 and
collected groundwater samples from MW2-12 and potable well PW1. Monitoring
well MW1 was dry.

February 21, 2022 Terraquest sent certified letters to water supply well owners to inquire as to their
willingness to connect to the municipal water supply system. Water supply well
owner at the next door location (PW1) does not wish to connect.

March 28, 2022 Terraquest collected groundwater samples from MW2-12 and potable wells PW1,
PW3, and PW4. Monitoring well MW1 was dry and water supply well PW2 was
inaccessible.

April 27, 2022 Terraquest supervised an Aggressive Fluid-Vapor Recovery (AFVR) event
conducted to remove contaminated groundwater from monitoring well MW6 as
directed by the NCDWM-UST.

June 21, 2022 Terraquest submitted a Letter Report detailing the sampling of monitoring well
MW6 on June 9, 2022.

August 10, 2022 The NCDWM-UST Mooresville Regional Supervisor Ron Taraban assigns the Little
Market Basket #1 release incident to Incident Manager Brad Newton.

Terraquest emailed Mr. Newton an update of events at the site. Mr. Newton
called Terraquest and discussed the future path of the incident. The previously
submitted ePATA for CAP development was agreed upon in theory.

September 19, 2022 The NCDWM-UST issued an NORR requesting a groundwater sampling event.

October 27, 2022 Terraquest conducted a groundwater sampling event.

January 20, 2023 Terraquest sampled the Mitchell potable well, PW1.

March 21, 2023 Terraquest sampled the Mitchell potable well, PW1.

April 3-4, 2023 Terraquest supervised the installation of groundwater monitoring wells MW13-17.

April 12, 2023 Terraquest sampled the monitoring well network.

Chronological Site History
Little Market Basket #1
NCDWM-UST Incident No.: 47003
Terraquest Environmental Consultants, P.C.
Page 3 of 3
May 23, 2023 The NCDWM-UST issued an NORR requesting the completion of a CAP Feasibility
study.

May 23, 2023 Terraquest requested pre-approval of CAP Feasibility study activities.

May 30, 2023 The NCDWM-UST granted pre-approval of CAP Feasibility study activities.

May 31, 2023 Terraquest requested signature of a Underground Injection Control Notice of
Intent from the property owner.

June 19, 2023 Terraquest again requested signature of a Underground Injection Control Notice
of Intent from the property owner.

July 6, 2023 The property owner returned a signed UIC NOI.

July 10, 2023 Terraquest personnel sampled potable water supply well PW1.

July 11, 2023 Terraquest submitted a NOI to the UIC.

October 10, 2023 Terraquest supervised the installation of pilot test wells SVE1 and AS1.

October 25, 2023 Terraquest personnel sampled potable water supply well PW1.

November 14, 2023 Terraquest personnel conducted SVE and air sparge pilot tests.

APPENDIX C

Facility ID No.: 00-0-0000021441
Well ID
Top of Casing
Elevation (ft.)
Depth to Water from
Top of Casing
Free Product
Thickness
Groundwater
Elevation
Depth to Water from
Top of Casing
Free Product
Thickness
Groundwater
Elevation
Depth to Water from
Top of Casing
Free Product
Thickness
Groundwater
Elevation
Depth to Water from
Top of Casing
Free Product
Thickness
Groundwater
Elevation
Depth to Water from
Top of Casing
Free Product
Thickness
Groundwater
Elevation
MW1 103.21 26.58 -76.21 27.00 -76.21 24.70 -78.51 dry dry dry dry dry dryMW2104.27 ---27.10 -77.17 24.95 -79.32 29.63 -74.64 30.7 -73.57MW398.75 ---23.37 -75.38 21.06 -77.69 25.95 -72.80 26.98 -71.77
MW4 98.89 ---23.65 -75.24 21.20 -77.69 26.25 -72.64 27.22 -71.67MW5101.88 ------24.07 -77.81 28.95 -72.93 29.95 -71.93MW6101.91 ------23.83 -78.08 28.79 -73.12 29.82 -72.09
MW7 99.55 ------22.09 -77.46 27.11 -72.44 28.1 -71.45MW899.00 ------21.64 -77.36 26.63 -72.37 27.63 -71.37MW996.01 ------19.40 -76.61 24.31 -71.70 25.2 -70.81MW1095.45 ------19.04 -76.41 23.05 -72.40 24.98 -70.47MW11101.63 ------25.12 *6/29/21 76.51 28.39 -73.24 29.38 -72.25MW1294.75 23.86 -70.89 24.65 -70.1Average Type II 26.58 25.28 22.20 26.45 27.52
Well ID
Top of Casing
Elevation (ft.)
Depth to
Water from
Top of Casing
Free Product
Thickness
Groundwater
Elevation
Depth to
Water from
Top of Casing
Free Product
Thickness
Groundwater
Elevation
Depth to
Water from
Top of Casing
Free Product
Thickness
Groundwater
Elevation
Depth to
Water from
Top of Casing
Free Product
Thickness
Groundwater
Elevation
Depth to
Water from
Top of Casing
Free Product
Thickness
Groundwater
ElevationMW1103.21 ---well dry --well dry --MW2 104.27 ---31.50 0 72.77 29.48 0 74.79
MW3 98.75 ---28.66 0 70.09 25.72 0 73.03
MW4 98.89 ---28.28 0 70.61 25.98 0 72.91MW5101.88 ---30.87 0 71.01 28.58 0 73.30
MW6 101.91 29.03 -72.88 30.8 0 71.11 28.35 0 73.55
MW7 99.55 ---29.17 0 70.38 26.77 0 72.77MW899.00 ---28.7 0 70.3 26.21 0 72.79
MW9 96.01 ---26.4 0 69.61 24.00 0 72.01
MW10 95.45 ---26.24 0 69.21 23.82 0 71.63MW11101.63 ---30.4 0 71.23 28 0 73.63
MW12 94.75 ---25.95 0 68.8 23.5 0 71.25
MW13 103.48 ------28.55 0 74.93MW14102.06 ------28.75 0 73.3MW1595.92 ------24.03 0 71.88
MW16 94.59 ------20.04 0 74.54MW1796.68 ------24.32 0 72.35Average Type II 28.66 25.87
Notes:
1. All units in feet.2. "-" = not detected, "IC" = inner casing, "OC" = outer casing.
6/9/2022 10/27/2022 4/12/2023
3/28/2022
Incident Name: Little Market Basket #1 Incident No. 47003HISTORICAL GROUNDWATER ELEVATION DATA
5/4/2020 8/6/2020 5/17/2021 11/29/2021
Page 1 of 2
6200B6200B6200B6200B6200B6200B6200B6200B6200B6200B6200B6200B6200B6200B6200B6200B6200B6200B6200B6200B6200B6200B6200B6200B6200B6200BWell ID Date Collected
MW1 5/5/20 < 0.119 < 0.0570 3.95 40.1 < 0.169 <0.0920 365 <0.18 92.2 <0.28 <<0.32 <<0.352 <1.09 <0.085 <3 <0.19 256 18.3 5.88 <0.06 12.9 22.5 <1.175/17/21 < 0.380 < 0.410 0.602 5.32 < 0.740 < 0.700 79.7 <0.500 25.8 < 2.60 << 3.10 <<<<<<<50.3 6.31 1.37 8.25 2.63 8.74 <
11/29/21 well dry - no sample collected <<<
3/28/22 well dry - no sample collected <<<
MW2 8/6/20 < 0.388 < 0.366 < 0.355 < 0.359 0.24 < 0.359 0.77 < 0.376 < 0.352 < 1.03 << 2.17 << 4.53 << 0.382 0.45 < 166 < 0.786 < 0.256 < 0.336 < 0.363 < 0.342 < 0.307 < 0.336 << 0.334
5/17/21 < 0.380 < 0.410 < 0.500 < 1.60 < 0.740 < 0.700 < 0.820 <0.500 < 0.560 < 2.60 << 3.10 <<<<<<<< 1.00 < 0.700 < 0.530 < 0.760 < 0.690 < 0.710 <
11/29/21 < 0.130 < 0.410 < 0.500 < 1.60 < 0.220 < 0.200 < 0.820 < 0.230 < 0.560 < 2.60 << 1.40 <<<<<<<< 1.00 < 0.700 < 0.530 < 0.760 < 0.690 < 0.710 <<
3/28/22 < 0.130 < 0.410 < 0.500 < 1.60 < 0.220 < 0.200 < 0.820 < 0.230 < 0.560 <<< 1.40 << 10.0 <<<<<< 1.00 < 0.700 < 0.530 < 0.760 < 0.690 < 0.710 <<
10/27/22 < 0.130 < 0.410 < 0.500 < 1.60 < 0.220 < 0.200 <<<<<<<<<<<46.3 <<<<<<<<<
4/12/23 < 0.130 < 0.410 < 0.500 < 0.160 < 0.220 < 0.200 <<<<<<<<<<<<<<<<<<<<<
MW3 8/6/20 < 0.388 < 0.366 < 0.355 < 0.359 < 0.198 < 0.359 0.48 < 0.376 < 0.352 < 1.03 << 2.17 << 4.53 << 0.382 0.91 < 166 < 0.786 1.66 < 0.336 < 0.363 < 0.342 < 0.307 < 0.336 << 0.334
5/17/21 < 0.380 < 0.410 < 0.500 < 1.60 < 0.740 < 0.700 9.35 <0.500 2.72 < 2.60 << 3.10 <<<<<<<20.4 < 0.700 < 0.530 < 0.760 < 0.690 < 0.710 <
11/29/21 < 0.130 < 0.410 < 0.500 < 1.60 < 0.220 < 0.200 < 0.820 < 0.230 < 0.560 < 2.60 << 1.40 <<<<<<<< 1.00 < 0.700 < 0.530 < 0.760 < 0.690 < 0.710 <<
3/28/22 < 0.130 < 0.410 < 0.500 < 1.60 < 0.220 < 0.200 < 0.820 < 0.230 < 0.560 <<< 1.40 << 10.0 <<<<<< 1.00 < 0.700 < 0.530 < 0.760 < 0.690 < 0.710 <<
10/27/22 < 0.130 < 0.410 < 0.500 < 1.60 < 0.220 < 0.200 <<<<<<<<<<<131 <<<<<<<<<
4/12/23 < 0.130 < 0.410 < 0.500 < 1.60 < 0.220 < 0.200 <<<<<<<<<<<<<<<<<<<<<
MW4 8/6/20 522 239 2,360 10,010 2,650 83.6 5,610 < 3.76 1,300 106 <78.3 <109 << 3.82 < 3.95 < 1660 12.3 1,820 30.3 390 120 934 18.1 << 3.34
5/17/21 90.4 < 0.410 < 0.500 65.4 86.1 6.15 62.2 <0.500 22.6 < 2.60 << 3.10 <<<<<<<19.5 2.09 4.32 4.98 2.44 1.65 <
11/29/21 1,530 305 725 2,830 2,430 190 1,160 < 2.30 248 < 26.0 << 14.0 <<<<<<<416 9.74 89.9 14.3 166 < 7.10 <<
3/28/22 1,200 214 668 2,770 1,400 110 1,540 < 4.60 390 <<< 28.0 << 200 <<<<<519 < 14.0 95.7 42 251 < 14.2 <<10/27/22 2,030 311 931 6,100 590 72.9 3,960 3.92 847 <<<<<<<<<<1,480 <157 49 372 11.7 16.7 <
4/12/23 1,060 25.5 159 1,140 213 22.2 1,010 248 <<<<<<<<<<<337 <54.7 11.1 116 <3.96 <MW5 5/17/21 62.5 14.7 66.5 285 93.2 6.38 526 <0.500 95.7 5.89 <5.22 <<<<<<<71.7 13.5 18.3 50.6 56.1 7.71 <
11/29/21 31.5 < 0.410 0.91 28 19.4 3.88 40.6 < 0.230 3.47 < 2.60 << 1.40 <<<<<<<9.44 19.1 6.62 43.7 11.9 3 <<3/28/22 30.4 < 0.410 0.907 J 4.24 J 13.1 2.67 8.25 < 0.230 1.16 <<< 1.40 << 10.0 <<<<<5.91 7.11 5.22 10.5 9.19 1.92 <<
10/27/22 39.6 < 0.410 2.11 2.91 13.6 3.28 6.43 <<<<<<<<<<35 <4.07 5.91 6.59 6.9 11.8 1.42 <<4/12/23 82.8 0.866 1.43 17.3 64.5 8.85 14.5 <<<<<<<<<<<<32.9 <6.65 6.56 5.26 1.06 5.47 <
MW6 5/17/21 3,980 280 233 2,030 2,180 156 751 <25.0 179 < 130 << 155 <<<<<<<422 < 35.0 35.9 < 38.0 54.1 < 35.5 <
11/29/21 11,100 1,240 3,800 13,500 1,870 322 4,760 20.1 1,200 < 130 << 70.0 <<<<<<<1,300 < 35.0 201 43 501 < 35.5 <<
3/28/22 14,800 1,030 6,760 23,600 2,060 309 7,880 32.4 J 1,950 <<150 J << 500 <<<<<1,540 48.2 263 148 756 40.4 <<
6/9/22 4,180 315 2,300 6,630 934 108 2,920 9.6 750 < 65.0 <54.9 << 250 << 25.0 < 8.00 < 600 < 75.0 791 <133 32.6 362 < 17.8 24.7 < 15.8
10/27/22 2,980 137 1,480 4,540 300 46.9 2,360 6.66 6.04 <<<<<<<<<<796 19.4 106 67.5 266 12.7 19.4 <
4/12/23 1,280 45.5 238 926 16.6 6.34 566 <152 <<<<<<21.2 <<<175 <30.3 21.4 50.6 <<<
MW7 5/17/21 2,280 3,180 2,800 14,300 4,250 190 2,200 <25.0 557 < 130 << 155 <<<<<<<724 < 35.0 113 < 38.0 257 < 35.5 <
11/29/21 3,610 1,270 3,810 10,000 2,300 277 3,480 < 4.60 954 84 <65.9 <<<<<<<1,030 32.1 240 44.6 583 18.6 <<
3/28/22 3,260 1,180 3,520 9,880 1,300 159 2,910 < 11.5 756 <<< 70.0 << 500 <<<<<1,030 < 35.0 209 54.2 581 < 35.5 <<
10/27/22 2,780 768 2,350 8,070 620 103 2,700 6.08 543 65.6 <114 33.7 278 <7.82 <145 <795 <120 44.6 319 8.02 16.7 <
4/12/23 5,650 1,190 2,060 7,020 867 147 1,770 <468 <<<<<<<<<<594 <110 41.3 286 <<<
MW8 5/17/21 < 0.380 < 0.410 < 0.500 < 1.60 < 0.740 < 0.700 < 0.820 <0.500 < 0.560 < 2.60 << 3.10 <<<<<<<2.28 < 0.700 < 0.530 < 0.760 < 0.690 < 0.710 <
11/29/21 < 0.130 < 0.410 < 0.500 < 1.60 0.353 < 0.200 < 0.820 < 0.230 < 0.560 < 2.60 << 1.40 <<<<<<<< 1.00 < 0.700 < 0.530 < 0.760 < 0.690 < 0.710 <<
3/28/22 < 0.130 < 0.410 < 0.500 < 1.60 1 < 0.200 < 0.820 < 0.230 < 0.560 <<< 1.40 << 10.0 <<<<<< 1.00 < 0.700 < 0.530 < 0.760 < 0.690 < 0.710 <<
10/27/22 < 0.130 < 0.410 < 0.500 < 1.60 0.566 < 0.200 <<<<<<<<<<<41 <<<<<<<<<
4/12/23 < 0.130 < 0.410 < 0.500 < 1.60 0.404 < 0.200 <<<<<<<<<<<<<<<<<<<<<
MW9 5/17/21 1,160 673 2,730 9,390 2,430 99 3,590 <12.5 863 < 65.0 << 77.5 <<<<<<<757 26.8 183 72.5 479 < 17.8 <
11/29/21 1,320 1,170 2,180 7,340 4,020 210 2,380 < 4.60 744 78.4 <66.8 <<<<<<<605 23.6 176 28.9 442 < 14.2 <<3/28/22 856 525 2,280 8,320 1,490 93.9 1,960 < 5.75 683 <<35.6 <300 <<<<<503 22.3 121 49.9 383 18.3 <<
10/27/22 811 187 1,120 2,820 774 89 1,100 0.953 270 <<<<<<<<<<462 <73.6 21.3 163 4.45 8.97 <4/12/23 889 141 1,080 2,220 285 40.3 1,340 <373 <<25.7 <<<<<<<421 <99.0 36.3 216 8.9 15.1 <
MW10 5/17/21 169 19.7 31.9 611 450 20.3 469 <2.50 86.4 < 13.0 << 15.5 <<<<<<<129 5.41 28.1 < 3.80 24.8 < 3.55 <11/29/21 341 10.4 10.6 527 810 49 32.4 < 0.460 1.92 < 5.20 << 2.80 <<<<<<<203 4.32 23.7 4.83 17.3 3.71 <<
3/28/22 69.6 1.72 2.24 98.5 122 8.36 2.83 < 0.230 < 0.560 <<< 1.40 << 10.0 <<<<<30 1.27 7.03 1.48 4.06 < 0.710 <<
10/27/22 4.44 < 0.410 < 0.500 8.49 12.7 1.08 3.24 <<<<<<<<<<54.2 <5.26 <1.07 <<<<<
4/12/23 3.5 < 0.410 < 0.500 6.35 32.4 2.38 2.51 <<<<<<<<<<<<3.71 <1.00 <<<<<
MW11 6/29/21 < 0.380 < 0.410 < 0.500 < 1.60 < 0.740 < 0.700 < 0.820 < 0.0159 < 0.560 4.62 << 3.10 <<<<<<<< 1.00 < 0.700 < 0.530 < 0.760 < 0.690 < 0.710 <
11/29/21 < 0.130 < 0.410 < 0.500 < 1.60 < 0.220 < 0.200 < 0.820 < 0.230 < 0.560 < 2.60 << 1.40 <<<<<<<< 1.00 < 0.700 < 0.530 < 0.760 < 0.690 < 0.710 <<
3/28/22 0.366 J < 0.410 < 0.500 < 1.60 0.235 J < 0.200 < 0.820 < 0.230 < 0.560 <<< 1.40 << 10.0 <<<<<< 1.00 < 0.700 < 0.530 < 0.760 < 0.690 < 0.710 <<
10/27/22 < 0.130 < 0.410 < 0.500 < 1.60 < 0.220 < 0.200 <<<<<<<<<<<<<<<<<<<<<
HISTORICAL GROUNDWATER ANALYTICAL RESULTS
1,2-Dibromoethane (EDB)1,3,5-Trimethylbenzene2-Chlorotoluene4-Methyl-2-pentanone (MIBK)BromodichloromethaneMTBE4-Isopropyltoluenesec-ButylbenzeneNaphthalenen-PropylbenzeneMethylene ChlorideAcetoneChloroformEthanol2-Butanone (MEK)Facility ID No.: 00-0-0000021441Incident Name: Little Market Basket #1 Incident No. 47003
Chloromethane2-HexanoneAnalytical Method
Contaminant of Concern
BenzeneTolueneEthylbenzeneTotal XylenesIPE1,2,4-Trimethylbenzenetert-Butylbenzenesec-ButylbenzeneIsopropylbenzenen-Butylbenzene
Page 2 of 2
HISTORICAL GROUNDWATER ANALYTICAL RESULTS
Facility ID No.: 00-0-0000021441Incident Name: Little Market Basket #1 Incident No. 47003
4/12/23 < 0.130 < 0.410 < 0.500 < 1.60 < 0.220 < 0.200 <<<<<<<<<<<<<<<<<<<<<
MW12 11/29/21 60.4 6.06 120 205 216 11.5 155 75.8 <2.95 << 1.40 <<<<<<<108 10.4 19.7 14.1 40.5 7.21 <<
3/28/22 84.8 1.76 88 20.3 129 8.74 200 < 0.230 100 <<< 1.40 << 10.0 <<<<<99.1 10.5 23.5 19.6 47.6 7.26 <<
10/27/22 337 7.7 324 36.8 261 26.1 86.9 0.0686 75.7 4.85 12.8 10.2 <19.3 <1.17 <<<511 <41.4 36.8 78.5 12.1 17.4 <
4/12/23 309 9.87 340 114 129 12.7 43.6 <20.7 <<<<<<<<<<393 <38.8 26.7 52.5 10.9 15.3 <
MW13 4/12/23 583 3,300 4,580 21,000 67.2 < 20.0 4,160 <1,030 <<<<<<<<<<1,390 <207 <559 <<<
MW14 4/12/23 6.26 36.3 36.1 178 4.38 0.661 130 <43.6 <<<<<<<<<<14.3 <7.08 15.7 24.7 3.78 7.65 <
MW15 4/12/23 41.9 355 5,310 16,500 < 11.0 < 10.0 4,560 <1,220 <<<<<<<<<<1,640 <195 <571 <<<
MW16 4/12/23 86.3 2.30 7.03 19.5 481 33.5 16.9 <1.94 <<<<<<<<<<205 <37.1 5.09 7.54 2.35 4.79 <
MW17 4/12/23 < 0.130 1.08 < 0.500 1.81 < 0.220 < 0.200 <<<<<<<<<<<<<<<<<<<<<
PW1 8/6/20 < 0.388 < 0.366 < 0.355 < 0.359 < 0.198 < 0.359 < 0.335 < 0.376 < 0.352 < 1.03 << 2.17 << 4.53 << 0.382 0.55 < 166 < 0.786 < 0.256 < 0.336 < 0.363 < 0.342 < 0.307 < 0.336 << 0.334
(Mitchell)5/17/21 < 0.380 < 0.410 < 0.500 < 1.60 < 0.740 < 0.700 < 0.820 <0.500 < 0.560 < 2.60 << 3.10 <<<<<<<< 1.00 < 0.700 < 0.530 < 0.760 < 0.690 < 0.710 <
11/29/21 < 0.130 < 0.410 < 0.500 < 1.60 < 0.220 < 0.200 1.28 < 0.230 0.563 < 2.60 << 1.40 <<<<<<<< 1.00 < 0.700 < 0.530 < 0.760 < 0.690 < 0.710 <<
3/28/22 < 0.130 < 0.410 < 0.500 < 1.60 < 0.220 < 0.200 < 0.820 < 0.230 < 0.560 <<< 1.40 << 10.0 <<<<<< 1.00 < 0.700 < 0.530 < 0.760 < 0.690 < 0.710 <<
10/27/22 < 0.130 < 0.410 < 0.500 < 1.60 < 0.220 < 0.200 <<<<<<<<<<<476 <<<<<<<<<1/20/23 < 0.130 < 0.410 < 0.500 < 1.60 < 0.220 < 0.200 <<<<<<<<<<<< 24.0 << 3.00 < 0.700 < 0.530 < 0.760 < 0.690 < 0.710 <<
3/21/23 < 0.130 < 0.410 < 0.500 < 1.60 < 0.220 < 0.200 <<<<<<<<<<<< 24.0 << 3.00 << 0.530 < 0.760 < 0.690 < 0.710 < 0.700 <4/12/23 < 0.130 < 0.410 < 0.500 < 1.60 < 0.220 < 0.200 <<<<<<<<<<<<<<<<<<<<<
7/10/23 < 0.500 < 0.900 < 0.500 < 1.60 < 0.220 < 0.200 <<<<<<<<<<<<<<<<<<<<<PW3 3/28/22 < 0.130 < 0.410 < 0.500 < 1.60 0.765 J < 0.200 < 0.820 < 0.230 < 0.560 <<< 1.40 << 10.0 <<<<<< 1.00 < 0.700 < 0.530 < 0.760 < 0.690 < 0.710 <<
PW4 3/28/22 < 0.130 < 0.410 < 0.500 < 1.60 < 0.220 < 0.200 < 0.820 < 0.230 < 0.560 <<< 1.40 << 10.0 <<<<<< 1.00 < 0.700 < 0.530 < 0.760 < 0.690 < 0.710 <<1 600 600 500 20 70 400 0.02 400 4,000 100 40 100 6,000 0.6 70 3 4,000 5 6 70 70 70 70 25 70 70
5,000 260,000 84,500 85,500 20,000 70,000 28,500 50 25,000 4,000,000 100,000 40,000 100,000 6,000,000 NE 70,000 3,000 4,000,000 5,000 6,000 8,500 25,000 6,900 30,000 11,700 8,500 15,000
E504.1625BNA625BNA625BNA625BNA625BNA625BNA625BNA625BNA625BNA625BNA625BNA625BNA625BNAMADEPVPHMADEPVPH/EPHMADEPEPHMADEPVPH/EPH6010CWell ID Date Collected
MW1 5/5/20 -79.6 103 <<1.74 <1.38 <<107 <1.2 <1.52 <<153 3,441 < 80.0 2,374 -MW2 8/6/20 < 0.00349 < 1.50 < 2.91 <<< 1.18 < 1.59 <<< 0.542 < 0.277 3.61 <<< 13.1 77.1 < 80.0 95.7 2.37 U
MW3 8/6/20 < 0.00349 < 1.50 < 2.91 <<< 1.18 < 1.59 <<1.51 < 0.277 3.65 <<< 13.1 78.2 < 80.0 101.41 2.37 UMW48/6/20 0.623 93.7 125 <<< 1.18 4.15 <<461 4.01 3.84 <<2,750 29,710 < 80.0 17,625 2.37 U
MW5 5/17/21 0.132 68.1 147 < 0.163 < 0.172 << 0.217 < 0.163 0.637 82.8 <<1.72 < 0.190 655 1,168 <108 4,990 <2MW65/17/21 12.4 70.2 132 < 0.182 < 0.192 << 0.242 < 0.182 < 0.182 394 <<1.13 < 0.212 9,980 7,448 <109 9,650 <2
MW7 5/17/21 3.81 161 320 0.774 0.441 << 0.239 0.362 1.58 809 <<2.02 0.483 13,700 32,817 <107 19,380 <2
MW8 5/17/21 < 0.00519 < 0.136 < 0.118 < 0.163 < 0.172 <2.03 < 0.163 < 0.163 <0.154 <<< 0.163 < 0.190 < 26.0 130 <110 <128 <2
MW9 5/17/21 1.3 81.8 143 < 0.170 < 0.180 << 0.227 < 0.170 0.298 473 <<< 0.170 < 0.198 4,910 12,017 <107 12,280 5.26
MW10 5/17/21 0.0416 8.44 10.9 < 0.161 0.543 << 0.215 < 0.161 < 0.161 30 <<< 0.161 < 0.188 610 1,068 <112 2,010 <2
MW11 6/29/21 < 0.0159 < 0.146 < 0.126 < 0.175 < 0.185 <6.05 0.206 < 0.175 <0.165 <<< 0.175 0.204 < 26.0 < 111 < 102 < 112 < 0.00200
0.02 1 30 2,000 1,000 28 6,000 300 300 6 3 NE 200 200 400 700 10,000 200*15
50 1,000 12,500 2,000 1,000,000 28,000 6,000,000,000 300 990 6,000 170 NE 410 200 NE NE NE NE 15,000
Notes:
1. All results in µg/L.
2. Bold denotes a compound detection
3. Shading denotes a 2L Standard violation
4. Italics denotes a GCL violation.
5. < - denotes less than sample detection limit
6. "NE" = Not Established 1-Methylnaphthalene2-MethylnaphthalenePyreneC5-C8 AliphaticsC9-C18 AliphaticsC19-C36 AliphaticsLeadAnthraceneFluorantheneFluoreneButyl benzyl phthalateDibenzofuranC9-C22 Aromaticsdi-n-Butyl Phthalate GCL Phenanthrene2L Standard
GCL
2L Standard
Analytical Method
Contaminant of Concern
1,2-Dibromoethanebis(2-ethylhexyl) phthalateDiethyl PhthalateNaphthalene

APPENDIX D

WELL CONSTRUCTION RECORD (GW-1) For Internal Use Only:
Form GW-1 North Carolina Department of Environmental Quality - Division of Water Resources Revised 2-22-2016
1. Well Contractor Information:
Well Contractor Name
NC Well Contractor Certification Number
Company Name
2. Well Construction Permit #:
List all applicable well construction permits (i.e. UIC, County, State, Variance, etc.)
3. Well Use (check well use):
Water Supply Well:
□Agricultural □Municipal/Public
□Geothermal (Heating/Cooling Supply) □Residential Water Supply (single)
□Industrial/Commercial □Residential Water Supply (shared)
□Irrigation
Non-Water Supply Well:
□Monitoring □Recovery
Injection Well:
□Aquifer Recharge □Groundwater Remediation
□Aquifer Storage and Recovery □Salinity Barrier
□Aquifer Test □Stormwater Drainage
□Experimental Technology □Subsidence Control
□Geothermal (Closed Loop) □Tracer
□Geothermal (Heating/Cooling Return) □Other (explain under #21 Remarks)
4. Date Well(s) Completed: Well ID#
5a. Well Location:

Facility/Owner Name Facility ID# (if applicable)

Physical Address, City, and Zip

County Parcel Identification No. (PIN)
5b. Latitude and longitude in degrees/minutes/seconds or decimal degrees:
(if well field, one lat/long is sufficient)
N W
6. Is(are) the well(s): □Permanent or □Temporary
7. Is this a repair to an existing well: □Yes or □No
If this is a repair, fill out known well construction information and explain the nature of the
repair under #21 remarks section or on the back of this form.
8. For Geoprobe/DPT or Closed-Loop Geothermal Wells having the same
construction, only 1 GW-1 is needed. Indicate TOTAL NUMBER of wells
drilled:
9. Total well depth below land surface: (ft.)
For multiple wells list all depths if different (example- 3@200’ and 2@100′)
10. Static water level below top of casing: (ft.)
If water level is above casing, use “+”
11. Borehole diameter: (in.)
12. Well construction method:
(i.e. auger, rotary, cable, direct push, etc.)
FOR WATER SUPPLY WELLS ONLY:
13a. Yield (gpm) Method of test:
13b. Disinfection type: Amount:
14. WATER ZONES
FROM TO DESCRIPTION
ft.ft.
ft.ft.
15. OUTER CASING (for multi-cased wells) OR LINER (if applicable)
FROM TO DIAMETER THICKNESS MATERIAL
ft.ft.in.
16. INNER CASING OR TUBING (geothermal closed-loop)
FROM TO DIAMETER THICKNESS MATERIAL
ft.ft.in.
ft.ft.in.
17. SCREEN
FROM TO DIAMETER SLOT SIZE THICKNESS MATERIAL
ft.ft.in.
ft.ft.in.
18. GROUT
FROM TO MATERIAL EMPLACEMENT METHOD & AMOUNT
ft.ft.
ft.ft.
ft.ft.
19. SAND/GRAVEL PACK (if applicable)
FROM TO MATERIAL EMPLACEMENT METHOD
ft.ft.
ft.ft.
20. DRILLING LOG (attach additional sheets if necessary)
FROM TO DESCRIPTION (color, hardness, soil/rock type, grain size, etc.)
ft.ft.
ft.ft.
ft.ft.
ft.ft.
ft.ft.
ft.ft.
ft.ft.
21. REMARKS
22. Certification:
Signature of Certified Well Contractor Date
By signing this form, I hereby certify that the well(s) was (were) constructed in accordance
with 15A NCAC 02C .0100 or 15A NCAC 02C .0200 Well Construction Standards and that a
copy of this record has been provided to the well owner.
23. Site diagram or additional well details:
You may use the back of this page to provide additional well site details or well
construction details. You may also attach additional pages if necessary.
SUBMITTAL INSTRUCTIONS
24a. For All Wells: Submit this form within 30 days of completion of well
construction to the following:
Division of Water Resources, Information Processing Unit,
1617 Mail Service Center, Raleigh, NC 27699-1617
24b. For Injection Wells: In addition to sending the form to the address in 24a
above, also submit one copy of this form within 30 days of completion of well
construction to the following:
Division of Water Resources, Underground Injection Control Program,
1636 Mail Service Center, Raleigh, NC 27699-1636
24c. For Water Supply & Injection Wells: In addition to sending the form to
the address(es) above, also submit one copy of this form within 30 days of
completion of well construction to the county health department of the county
where constructed.
ificatioooooooooooooooooon:
of Certified Well Contractor
Wesley J. Sorrells
3577
Terraquest Environmental Consultants
1
10/10/23 SVE1
Little Market Basket
3541 Talylorsville Hwy. Statesville NC
Iredell
35.809841 -80.948711
20
N/A
4.25
Solid Stem Auger
10/17/23
5202 10Slot Schd.40 PVC
0.5
1
3
1
3
20
Portland
Bentonite
No. 2 Sand Pour
Pour
0
0.5
1
14
0.5
1
14
20
Asphalt
Gravel
Clay with some silt
Silt with a little clay
Print Form
Pour
WELL CONSTRUCTION RECORD (GW-1) For Internal Use Only:
Form GW-1 North Carolina Department of Environmental Quality - Division of Water Resources Revised 2-22-2016
1. Well Contractor Information:
Well Contractor Name
NC Well Contractor Certification Number
Company Name
2. Well Construction Permit #:
List all applicable well construction permits (i.e. UIC, County, State, Variance, etc.)
3. Well Use (check well use):
Water Supply Well:
□Agricultural □Municipal/Public
□Geothermal (Heating/Cooling Supply) □Residential Water Supply (single)
□Industrial/Commercial □Residential Water Supply (shared)
□Irrigation
Non-Water Supply Well:
□Monitoring □Recovery
Injection Well:
□Aquifer Recharge □Groundwater Remediation
□Aquifer Storage and Recovery □Salinity Barrier
□Aquifer Test □Stormwater Drainage
□Experimental Technology □Subsidence Control
□Geothermal (Closed Loop) □Tracer
□Geothermal (Heating/Cooling Return) □Other (explain under #21 Remarks)
4. Date Well(s) Completed: Well ID#
5a. Well Location:

Facility/Owner Name Facility ID# (if applicable)

Physical Address, City, and Zip

County Parcel Identification No. (PIN)
5b. Latitude and longitude in degrees/minutes/seconds or decimal degrees:
(if well field, one lat/long is sufficient)
N W
6. Is(are) the well(s): □Permanent or □Temporary
7. Is this a repair to an existing well: □Yes or □No
If this is a repair, fill out known well construction information and explain the nature of the
repair under #21 remarks section or on the back of this form.
8. For Geoprobe/DPT or Closed-Loop Geothermal Wells having the same
construction, only 1 GW-1 is needed. Indicate TOTAL NUMBER of wells
drilled:
9. Total well depth below land surface: (ft.)
For multiple wells list all depths if different (example- 3@200’ and 2@100′)
10. Static water level below top of casing: (ft.)
If water level is above casing, use “+”
11. Borehole diameter: (in.)
12. Well construction method:
(i.e. auger, rotary, cable, direct push, etc.)
FOR WATER SUPPLY WELLS ONLY:
13a. Yield (gpm) Method of test:
13b. Disinfection type: Amount:
14. WATER ZONES
FROM TO DESCRIPTION
ft.ft.
ft.ft.
15. OUTER CASING (for multi-cased wells) OR LINER (if applicable)
FROM TO DIAMETER THICKNESS MATERIAL
ft.ft.in.
16. INNER CASING OR TUBING (geothermal closed-loop)
FROM TO DIAMETER THICKNESS MATERIAL
ft.ft.in.
ft.ft.in.
17. SCREEN
FROM TO DIAMETER SLOT SIZE THICKNESS MATERIAL
ft.ft.in.
ft.ft.in.
18. GROUT
FROM TO MATERIAL EMPLACEMENT METHOD & AMOUNT
ft.ft.
ft.ft.
ft.ft.
19. SAND/GRAVEL PACK (if applicable)
FROM TO MATERIAL EMPLACEMENT METHOD
ft.ft.
ft.ft.
20. DRILLING LOG (attach additional sheets if necessary)
FROM TO DESCRIPTION (color, hardness, soil/rock type, grain size, etc.)
ft.ft.
ft.ft.
ft.ft.
ft.ft.
ft.ft.
ft.ft.
ft.ft.
21. REMARKS
22. Certification:
Signature of Certified Well Contractor Date
By signing this form, I hereby certify that the well(s) was (were) constructed in accordance
with 15A NCAC 02C .0100 or 15A NCAC 02C .0200 Well Construction Standards and that a
copy of this record has been provided to the well owner.
23. Site diagram or additional well details:
You may use the back of this page to provide additional well site details or well
construction details. You may also attach additional pages if necessary.
SUBMITTAL INSTRUCTIONS
24a. For All Wells: Submit this form within 30 days of completion of well
construction to the following:
Division of Water Resources, Information Processing Unit,
1617 Mail Service Center, Raleigh, NC 27699-1617
24b. For Injection Wells: In addition to sending the form to the address in 24a
above, also submit one copy of this form within 30 days of completion of well
construction to the following:
Division of Water Resources, Underground Injection Control Program,
1636 Mail Service Center, Raleigh, NC 27699-1636
24c. For Water Supply & Injection Wells: In addition to sending the form to
the address(es) above, also submit one copy of this form within 30 days of
completion of well construction to the county health department of the county
where constructed.
rtificatttttttttttttion:
re of CertifiedWWWWWWWWWWWWWWell Contractor
Wesley J. Sorrells
3577
Terraquest Environmental Consultants
1
10/10/23 AS1
Little Market Basket
3541 Talylorsville Hwy. Statesville NC
Iredell
35.809841 -80.948711
49
N/A
6.25
Solid Stem Auger
10/17/23
44 49 1 10Slot Schd.40 PVC
0.5
40
42
40
42
49
Portland
Bentonite
No. 2 Sand Pour
Pour
0
0.5
1
14
0.5
1
14
49
Asphalt
Gravel
Clay with some silt
Silt with very little clay
Print Form
Pour

APPENDIX E

Soil Vapor Extraction Pilot Test Report
For: Little Market Basket #1, Statesville, Iredell County, NC
Prepared by: Terraquest Environmental Consultants, P.C.
Test Date: 11/14/23
Report Prepared: 11/20/23

1

Little Market Basket #1
Bumgarner Oil Company
3541 Taylorsville Hwy
Statesville, Iredell County, NC 28677
NCDWM-UST Incident No. 47003
Terraquest Project No. 09419

INTRODUCTION

Terraquest Environmental Consultants, P.C. has performed a soil vapor extraction pilot test at
the Little Market Basket #1 release incident located in Statesville, Iredell County, North Carolina.
The site’s location, vicinity, and layout are depicted on Figures 1, 2, and 3. The test reveals how
the subsurface responds to vapor extraction. Data is used to evaluate the suitability of the site
for SVE and to design a full-scale SVE system.

On November 14, 2023, Terraquest performed an SVE test using SVE pilot test well SVE1 and
monitoring wells MW1 and MW2. SVE1 was utilized as the extraction well and the other wells
were monitored for influence.

Terraquest personnel supervised the construction of SVE well SVE1 on October 10, 2023. The
well was installed in preparation for the pilot test. Monitoring wells MW1 and MW2 were
installed as part of previous assessment activities. The new well was installed by an NC-licensed
driller operating a Geoprobe model 7822DT drilling unit that turned solid-stem augers. Well SVE1
was constructed of five feet of 2”-diameter PVC casing attached to fifteen feet of 2”-diameter
screen with a 0.010” slot size for a total well depth of twenty feet. A sand gravel pack was placed
around the screened section of the well. This section was isolated from the surface by bentonite
and grout seals. A well construction record is attached.
SVE Pilot Test Report

Soil Vapor Extraction Pilot Test Report
For: Little Market Basket #1, Statesville, Iredell County, NC
Prepared by: Terraquest Environmental Consultants, P.C.
Test Date: 11/14/23
Report Prepared: 11/20/23

2

Site Hydrogeology

The subject property is located in the Piedmont Physiographic Province of North Carolina. On a
regional scale, the Piedmont is characterized by land with medium to high relief. Elevation at the
site and nearby area is approximately 970 feet above MSL. More specific within the Piedmont
Physiographic Province, and according to the 1985 Geologic Map of North Carolina (Brown, et.al.,
1985), the subject property lies within the Inner Piedmont Belt of the Piedmont Physiographic
Province. The subsurface geology is mapped as interlayered; minor layers and lenses of
hornblende gneiss, metagabbro, mica schist, and granitic rock. Regolith soils are comprised of
clays and silts. The following lithologies were encountered at the site during the various stages
of assessment:

0’ – 5’ BGL:
SILTY CLAY (CL)
Soft, reddish-brown, mostly clay with some silt and little sand.

5’ – 53’ BGL
CLAYEY SILT (ML)
Soft, brown silt with little to some clay and mica.

53’ – 55’ BGL
BEDROCK

Soil Vapor Extraction Pilot Test Report
For: Little Market Basket #1, Statesville, Iredell County, NC
Prepared by: Terraquest Environmental Consultants, P.C.
Test Date: 11/14/23
Report Prepared: 11/20/23

3

Geological cross sections of the subject area are as follows:

Soil Vapor Extraction Pilot Test Report
For: Little Market Basket #1, Statesville, Iredell County, NC
Prepared by: Terraquest Environmental Consultants, P.C.
Test Date: 11/14/23
Report Prepared: 11/20/23

4

Soil Vapor Extraction Pilot Test Report
For: Little Market Basket #1, Statesville, Iredell County, NC
Prepared by: Terraquest Environmental Consultants, P.C.
Test Date: 11/14/23
Report Prepared: 11/20/23

5

General applicability based on soil type and contamination (gasoline at this release incident):
The following chart presented as Exhibit II-4 from the EPA publication entitled “How to evaluate
alternative cleanup technologies for underground storage tank sites,” depicts the ranges of
intrinsic permeability for various soil types and the effectiveness of SVE on those soils
contaminated with various petroleum products. Based on permeability and the contaminants,
the site is generally suitable for implementation of SVE.

US EPA. 1995. How to evaluate alternative cleanup technologies for underground storage tank sites.
Solid Waste and Emergency Response 5403W. Document Number 510-B-95-007.

Soil Vapor Extraction Pilot Test Report
For: Little Market Basket #1, Statesville, Iredell County, NC
Prepared by: Terraquest Environmental Consultants, P.C.
Test Date: 11/14/23
Report Prepared: 11/20/23

6

Hydrology:
The phreatic aquifer resides, at its shallowest depth, in a soft, clayey silt. This lithology becomes
more consolidated with depth until competent bedrock that was encountered via air drilling at
53 feet BGL. While there is some intermixing in the upper portion of the weathered bedrock, at
depth, the bedrock aquifer is fracture controlled and behaves differently than the overlying water
table aquifer. As part of the CSA, the groundwater elevation measurements reveal that the
hydraulic head within the shallow phreatic aquifer ranged from a relative value of approximately
79.32 feet at monitoring well MW2 to 76.41 at monitoring well MW10. In conjunction with other
site measurements, the results indicate flow in the phreatic aquifer in a southwesterly direction
under an average hydraulic gradient of 0.015. Note that the plume geometry confirms a
south/southwesterly flow. The most recent potentiometric surface was measured on April, 12,
2023 as such:

Soil Vapor Extraction Pilot Test Report
For: Little Market Basket #1, Statesville, Iredell County, NC
Prepared by: Terraquest Environmental Consultants, P.C.
Test Date: 11/14/23
Report Prepared: 11/20/23

7

Subject Soil Contamination

The analytical results of soil samples collected throughout assessment indicate a limited area of
soil contamination beneath the former kerosene dispenser only. No actionable soil
contamination was noted beneath the product lines, remaining dispensers, or any of the tanks.

Contamination begins beneath the dispenser and extends downward to the water table in a
sloping fashion. Terraquest estimates that the average starting depth of contamination is roughly
at ground level and extends to the water table noted at approximately 25 feet below ground level
(BGL) in May 2021. The amount of soil truly in excess of the STG MSCCs with respect to the
varying contaminant concentrations and sloping away from the source pattern is likely 50% lower
than a 25-foot-thickness. Volumetric calculations using this data yields 60 ft2 x ((25 ft – 0 ft)(0.5))
= 750 ft3 or 28 yd3. Using a 1.5 yd3 to tons multiplier, the weight is 42 tons.

Soil Vapor Extraction Pilot Test Report
For: Little Market Basket #1, Statesville, Iredell County, NC
Prepared by: Terraquest Environmental Consultants, P.C.
Test Date: 11/14/23
Report Prepared: 11/20/23

8

GENERAL PROCEDURES

Terraquest performed the test on November 14, 2023. The basic test procedure consisted of
applying a vacuum to the extraction well while monitoring pressure response at other points of
varying distance and direction from the extraction point. Vacuum pressure and air flow at the
extraction well were also monitored. A GAST regenerative blower with a 1.5 hp electric motor
was used to create the vacuum. Various pressure and flow gauges were also used. The blower
and gauges were connected with air-tight seals to the various points to minimize leakage and,
thus, systematic error. Pictures of the setup are as follows:

Regen blower
Flow gauge
Vac gauge
Former UST basin
Airtight rubber boots
Extraction well SVE1
Observation well MW1
Magnehelic vacuum gauge 0.05” H20 increments max 2” H2O

Soil Vapor Extraction Pilot Test Report
For: Little Market Basket #1, Statesville, Iredell County, NC
Prepared by: Terraquest Environmental Consultants, P.C.
Test Date: 11/14/23
Report Prepared: 11/20/23

9

Generally, two types of SVE tests are conducted. The first type of test is an air permeability test
that typically lasts for approximately 10 minutes. Vacuum is applied to the extraction well and
the pressure responses in various observation points are recorded with time. The data is used to
calculate the vadose zone permeability to air flow (intrinsic permeability).

The second type of test performed is a steady state test. These last from approximately 1 hour
to several or more days, depending on the objectives of the test, the scale of the project, and
other cost justification factors. A relationship between applied vacuum and vapor flow yield is
developed from these tests. This relationship is used for blower selection in the design of the
full-scale system. Data from these tests can also be used to calculate intrinsic permeability.

For tests of sufficient length, it may also be possible to establish VOC mass removal rates by
measuring the steady state vapor concentrations in the off gas. To achieve steady state, at least
one pore volume of vapor must first be removed. It is not usually possible during the test to
know exactly when this occurs. One indication is a leveling of vapor concentrations after a
significant decline. This change occurs as all stagnant air is purged from the capture zone.

SPECIFIC PROCEDURES AND RESULTS

Terraquest personnel began testing on November 14, 2023 using SVE1 as the extraction well and
monitoring influence at monitoring wells MW1 and MW2. With a screen interval of 20-35 feet,
monitoring well MW2 was less likely to show influence as the SVE well was only screened from
5-20 feet. Monitoring well MW1 was screened from 10-30 feet. However, monitoring well MW1
was located near the former UST basin and was removed from consideration as the SVE
extraction well as that less permeable area would likely yield erroneous data that doesn’t match
in-situ conditions at the site.

Soil Vapor Extraction Pilot Test Report
For: Little Market Basket #1, Statesville, Iredell County, NC
Prepared by: Terraquest Environmental Consultants, P.C.
Test Date: 11/14/23
Report Prepared: 11/20/23

10

Following setup, Terraquest turned on the SVE blower and monitored influence at wells MW1
and MW2. The SVE blower was operated with no dilution. That is, full vacuum was applied. The
influent pressure gauge on the SVE extraction well indicated that the blower applied a vacuum
pressure of -70 inches of water. Terraquest has magnehelic vacuum gauges ranging from 0-2
inches of water up to 0-100 inches of water. Using the 0-2 inches of water gauges on monitoring
wells MW1 and MW2, no influence was seen at either well at the start of the air permeability
test. That gauge has vacuum pressure measurements in 0.05 inches of water increments. None
was seen until minute 15 of the test. At minute fifteen, both monitoring wells MW1 and MW2
showed a 0.05 inches of water reading.

As the air permeability test didn’t show anything until minute 15, the test was switched to a
steady state test and the blower was allowed to continue running. As shown on the attached
SVE Table 1, a max vacuum influence of 0.05 inches of water was noted at monitoring well MW1
and a max vacuum pressure of 0.10 inches of water was noted at monitoring well MW2. Only
0.2 ppm was registered on the PID throughout the test. A near zero value.

Pore volume calculations:
As previously noted, contaminant removal rates via SVE can be calculated once one pore volume
has been removed and steady-state removal concentrations are known. While the volume of
contaminated soil is low and influence to the impacted area was not realized, Terraquest
presents the following pore volume calculations for future reference.

Soil Vapor Extraction Pilot Test Report
For: Little Market Basket #1, Statesville, Iredell County, NC
Prepared by: Terraquest Environmental Consultants, P.C.
Test Date: 11/14/23
Report Prepared: 11/20/23

11

From Equation (18) in Johnson et al (1990b), the estimated time to remove one pore volume (Tp)
is estimated by:

Where:
EA = air filled void fraction of soil matrix
R = radius of zone of contamination (feet)
H = thickness of zone of venting (feet)
Q = air flow rate (cubic feet per minute)

Data from the steady state test was used to estimate Tp. With the variables assigned as follows:

EA = 0.15 (based on an average effective porosity published by Sanders, 1998)
R = 4.5 feet
H = 30 feet
Q = 3 cubic feet per minute (average)

An estimated time to remove one pore volume of contamination is calculated to be 95.4 minutes.
Since the SVE steady state test ran for 90 minutes it is likely that about one pore volume was
removed.

DATA ANALYSIS

Overall, the test was a success, although it was atypical for most SVE pilot tests. The overall goal
was to determine if the subsurface was responsive to SVE. The test determined that it is. A
vacuum was applied to extraction well SVE1 and a constant flow of air was recorded. It’s unusual
Q
HRE=T Ap
2π

Soil Vapor Extraction Pilot Test Report
For: Little Market Basket #1, Statesville, Iredell County, NC
Prepared by: Terraquest Environmental Consultants, P.C.
Test Date: 11/14/23
Report Prepared: 11/20/23

12

to have a test in a silty vadose zone soil and not register a higher vacuum pressure than 0.05
inches of water at a monitoring well (MW1) located only 15 feet away. As noted, the former tank
basin is located nearby to the test and while extraction was made at SVE1 and not MW1 to lessen
the chance of vacuum loss to an area with much looser backfill material than the native soil, it’s
still possible that the SVE1 vacuum was partially lost to that area. In any case, the subsurface
near the lone area of soil contamination above permissible levels was shown to allow vacuum
flow indicating that the method will be suitable for treatment. With fairly homogenous
lithologies recorded across the site, SVE will also serve to recover sparge vapors from areas
whose surface cover (asphalt) will not allow release of the sparge vapors.

Radius of influence:
A rule-of-thumb recommended by U.S. EPA (1995) is that the ROI will be the distance at which a
vacuum of 0.1 inches of water is yielded. While that pressure was noted at monitoring well MW2
located 18 feet away, it was not observed at monitoring well MW1 located only 15 feet away. A
12-foot radius is chosen as a conservative estimate of influence that allows for some site
heterogeneities.

Number of Extraction Wells:
Based on the small area of soil contamination, Terraquest recommends one well near the former
kerosene dispenser to treat soil. Monitoring well MW1 could be used as an SVE well, however,
its screen interval of 10-30 feet is not ideal and Terraquest recommends installing another well
with a screen interval from 3-30 feet.

An additional four wells are recommended to recover air sparge vapors as shown by the yellow
triangles with anticipated radius of influence circles on the following page. Note the proposed
air sparge wells indicated by the magenta triangles.

Soil Vapor Extraction Pilot Test Report
For: Little Market Basket #1, Statesville, Iredell County, NC
Prepared by: Terraquest Environmental Consultants, P.C.
Test Date: 11/14/23
Report Prepared: 11/20/23

13

Soil Vapor Extraction Pilot Test Report
For: Little Market Basket #1, Statesville, Iredell County, NC
Prepared by: Terraquest Environmental Consultants, P.C.
Test Date: 11/14/23
Report Prepared: 11/20/23

14

CONCLUSIONS

Based on the pilot test conducted by Terraquest personnel, the site is acceptable for SVE as a
remedial method. Five dedicated SVE wells are recommended.

Soil Vapor Extraction Pilot Test Report
For: Little Market Basket #1, Statesville, Iredell County, NC
Prepared by: Terraquest Environmental Consultants, P.C.
Test Date: 11/14/23
Report Prepared: 11/20/23
15

REFERENCES

Brown, et al., 1985. Geologic Map of North Carolina, North Carolina. Department of Natural
Resources and Community Development, 1:500,000 scale.

Johnson, P.C., C.C. Stanley, M.W. Kemblowski, D.L. Beyers, and J.D. Colthart. 1990b. A practical
approach to the design, operation, and monitoring of in situ soil-venting systems.
Ground Water Monitoring Review (GWMR), Spring Issue, pp. 159-178.

Sanders, Laura L. 1998. A Manual of Field Hydrogeology. Upper Saddle River, New Jersey: Prentice
Hall Inc.: 196.

U.S. EPA. 1995. How to evaluate alternative cleanup technologies for underground storage tank
sites. Solid Waste and Emergency Response 5403W. Document Number 510-B-95-007.
NVIRONMENTAL ONSULTANTS, P.C.E C
WELL CONSTRUCTION RECORD (GW-1) For Internal Use Only:
Form GW-1 North Carolina Department of Environmental Quality - Division of Water Resources Revised 2-22-2016
1. Well Contractor Information:
Well Contractor Name
NC Well Contractor Certification Number
Company Name
2. Well Construction Permit #:
List all applicable well construction permits (i.e. UIC, County, State, Variance, etc.)
3. Well Use (check well use):
Water Supply Well:
□Agricultural □Municipal/Public
□Geothermal (Heating/Cooling Supply) □Residential Water Supply (single)
□Industrial/Commercial □Residential Water Supply (shared)
□Irrigation
Non-Water Supply Well:
□Monitoring □Recovery
Injection Well:
□Aquifer Recharge □Groundwater Remediation
□Aquifer Storage and Recovery □Salinity Barrier
□Aquifer Test □Stormwater Drainage
□Experimental Technology □Subsidence Control
□Geothermal (Closed Loop) □Tracer
□Geothermal (Heating/Cooling Return) □Other (explain under #21 Remarks)
4. Date Well(s) Completed: Well ID#
5a. Well Location:

Facility/Owner Name Facility ID# (if applicable)

Physical Address, City, and Zip

County Parcel Identification No. (PIN)
5b. Latitude and longitude in degrees/minutes/seconds or decimal degrees:
(if well field, one lat/long is sufficient)
N W
6. Is(are) the well(s): □Permanent or □Temporary
7. Is this a repair to an existing well: □Yes or □No
If this is a repair, fill out known well construction information and explain the nature of the
repair under #21 remarks section or on the back of this form.
8. For Geoprobe/DPT or Closed-Loop Geothermal Wells having the same
construction, only 1 GW-1 is needed. Indicate TOTAL NUMBER of wells
drilled:
9. Total well depth below land surface: (ft.)
For multiple wells list all depths if different (example- 3@200’ and 2@100′)
10. Static water level below top of casing: (ft.)
If water level is above casing, use “+”
11. Borehole diameter: (in.)
12. Well construction method:
(i.e. auger, rotary, cable, direct push, etc.)
FOR WATER SUPPLY WELLS ONLY:
13a. Yield (gpm) Method of test:
13b. Disinfection type: Amount:
14. WATER ZONES
FROM TO DESCRIPTION
ft.ft.
ft.ft.
15. OUTER CASING (for multi-cased wells) OR LINER (if applicable)
FROM TO DIAMETER THICKNESS MATERIAL
ft.ft.in.
16. INNER CASING OR TUBING (geothermal closed-loop)
FROM TO DIAMETER THICKNESS MATERIAL
ft.ft.in.
ft.ft.in.
17. SCREEN
FROM TO DIAMETER SLOT SIZE THICKNESS MATERIAL
ft.ft.in.
ft.ft.in.
18. GROUT
FROM TO MATERIAL EMPLACEMENT METHOD & AMOUNT
ft.ft.
ft.ft.
ft.ft.
19. SAND/GRAVEL PACK (if applicable)
FROM TO MATERIAL EMPLACEMENT METHOD
ft.ft.
ft.ft.
20. DRILLING LOG (attach additional sheets if necessary)
FROM TO DESCRIPTION (color, hardness, soil/rock type, grain size, etc.)
ft.ft.
ft.ft.
ft.ft.
ft.ft.
ft.ft.
ft.ft.
ft.ft.
21. REMARKS
22. Certification:
Signature of Certified Well Contractor Date
By signing this form, I hereby certify that the well(s) was (were) constructed in accordance
with 15A NCAC 02C .0100 or 15A NCAC 02C .0200 Well Construction Standards and that a
copy of this record has been provided to the well owner.
23. Site diagram or additional well details:
You may use the back of this page to provide additional well site details or well
construction details. You may also attach additional pages if necessary.
SUBMITTAL INSTRUCTIONS
24a. For All Wells: Submit this form within 30 days of completion of well
construction to the following:
Division of Water Resources, Information Processing Unit,
1617 Mail Service Center, Raleigh, NC 27699-1617
24b. For Injection Wells: In addition to sending the form to the address in 24a
above, also submit one copy of this form within 30 days of completion of well
construction to the following:
Division of Water Resources, Underground Injection Control Program,
1636 Mail Service Center, Raleigh, NC 27699-1636
24c. For Water Supply & Injection Wells: In addition to sending the form to
the address(es) above, also submit one copy of this form within 30 days of
completion of well construction to the county health department of the county
where constructed.
ificatioooooooooooooooooon:
of Certified Well Contractor
Wesley J. Sorrells
3577
Terraquest Environmental Consultants
1
10/10/23 SVE1
Little Market Basket
3541 Talylorsville Hwy. Statesville NC
Iredell
35.809841 -80.948711
20
N/A
4.25
Solid Stem Auger
10/17/23
5202 10Slot Schd.40 PVC
0.5
1
3
1
3
20
Portland
Bentonite
No. 2 Sand Pour
Pour
0
0.5
1
14
0.5
1
14
20
Asphalt
Gravel
Clay with some silt
Silt with a little clay
Print Form
Pour
SVE-Table 1
Date: 11/21/23
Extraction Well: SVE1 Extraction Well: SVE1 PID (ppm) Well: MW1 Well: MW2
Time Vacuum Flow VOCs Vacuum Vacuum
(minutes)(inches of water)(standard cubic feet/minute)at extraction well (inches of water)(inches of water)
0 -70 3.0 0.2 0 0
5 -70 3.0 0.2 0 0
10 -70 3.0 0.2 0 0
15 -70 3.0 0.2 0.05 0.05
20 -70 3.0 0.2 0.05 0.10
30 -70 3.0 0.2 0.05 0.10
40 -68 3.0 0.2 0.05 0.075
50 -68 3.0 0.2 0.05 0.075
60 -68 2.8 0.2 0.05 0.10
70 -68 2.8 0.2 0.05 0.075
80 -68 2.8 0.2 0.05 0.075
90 -68 2.8 0.2 0.05 0.075
Distance from extraction well in feet: 15 18
STEADY STATE TEST RESULTS
Incident Name: Little Market Basket #1 Incident No. 47003
Dilution valve closed throughout test

APPENDIX F

Air Sparge Pilot Test Report
Little Market Basket, Statesville, Iredell County, North Carolina
Prepared by: Terraquest Environmental Consultants, P.C.
Test Dates: 11/14/23
Report Prepared: 11/17/23

1

Little Market Basket #1
Bumgarner Oil Company
3541 Taylorsville Hwy
Statesville, Iredell County, NC 28677
NCDWM-UST Incident No. 47003
Terraquest Project No. 09419

INTRODUCTION

On November 14, 2023, Terraquest Environmental Consultants, P.C. performed air sparging pilot
tests for the Little Market Basket #1 release incident located in Statesville, Iredell County, North
Carolina. The site’s location, vicinity, and layout are depicted on Figures 1, 2, and 3.

Air sparging is an in-situ method of groundwater remediation, in which compressed air is injected
into the aquifer via wells screened in the saturated zone. The compressed air is entrained as
small air bubbles and air streams which rise through the pore network in the soil structure and
fractures of saprolite. Volatile organic compounds dissolved in the water column or adsorbed to
soil particles will, depending on subsurface conditions and properties of the target compounds,
volatilize in the air stream. The entrained air eventually emerges to the vadose zone, where the
load of organic gases is released to the soil vapor domain. In aquifers with concentrations of
dissolved oxygen that have been lowered through natural aerobic degradation of the
hydrocarbon contaminants, the injection of air can replenish the dissolved oxygen and accelerate
the rate of biodegradation.

As part of the remedial action toward closure for this site, Terraquest identified air sparging as a
potentially viable groundwater remediation method. The purpose of the pilot test was to confirm
Air Sparge Pilot Test Report

Air Sparge Pilot Test Report
Little Market Basket, Statesville, Iredell County, North Carolina
Prepared by: Terraquest Environmental Consultants, P.C.
Test Dates: 11/14/23
Report Prepared: 11/17/23

2
the subsurface would be agreeable to the method, to provide information for well spacing
requirements, and provide system performance requirements for an onsite system.

The tests revealed how the subsurface responds to injection of air bubbles within the aquifer.
Data was collected for air injection pressure, air injection flow, changes in groundwater levels,
and changes in dissolved oxygen. Prior to the start of the test a Notice of Intent was filed with
NCDEQ’s Water Quality Regional Operations Section. After the injection (ambient air via pilot
testing) an Injection Event Record was filed.

Site Hydrogeology

The subject property is located in the Piedmont Physiographic Province of North Carolina. On a
regional scale, the Piedmont is characterized by land with medium to high relief. Elevation at the
site and nearby area is approximately 970 feet above MSL. More specific within the Piedmont
Physiographic Province, and according to the 1985 Geologic Map of North Carolina (Brown, et.al.,
1985), the subject property lies within the Inner Piedmont Belt of the Piedmont Physiographic
Province. The subsurface geology is mapped as interlayered; minor layers and lenses of
hornblende gneiss, metagabbro, mica schist, and granitic rock. Regolith soils are comprised of
clays and silts. The following lithologies were encountered at the site during the various stages
of assessment:

0’ – 5’ BGL:
SILTY CLAY (CL)
Soft, reddish-brown, mostly clay with some silt and little sand.

5’ – 53’ BGL
CLAYEY SILT (ML)
Soft, brown silt with little to some clay and mica.

53’ – 55’ BGL
BEDROCK

Air Sparge Pilot Test Report
Little Market Basket, Statesville, Iredell County, North Carolina
Prepared by: Terraquest Environmental Consultants, P.C.
Test Dates: 11/14/23
Report Prepared: 11/17/23

3

Geological cross sections of the subject area are as follows:

Air Sparge Pilot Test Report
Little Market Basket, Statesville, Iredell County, North Carolina
Prepared by: Terraquest Environmental Consultants, P.C.
Test Dates: 11/14/23
Report Prepared: 11/17/23

4

Air Sparge Pilot Test Report
Little Market Basket, Statesville, Iredell County, North Carolina
Prepared by: Terraquest Environmental Consultants, P.C.
Test Dates: 11/14/23
Report Prepared: 11/17/23

5

The phreatic aquifer resides, at its shallowest depth, in a soft, clayey silt. This lithology becomes
more consolidated with depth until competent bedrock that was encountered via air drilling at
53 feet BGL. While there is some intermixing in the upper portion of the weathered bedrock, at
depth, the bedrock aquifer is fracture controlled and behaves differently than the overlying water
table aquifer. As part of the CSA, the groundwater elevation measurements reveal that the
hydraulic head within the shallow phreatic aquifer ranged from a relative value of approximately
79.32 feet at monitoring well MW2 to 76.41 at monitoring well MW10. In conjunction with other
site measurements, the results indicate flow in the phreatic aquifer in a southwesterly direction
under an average hydraulic gradient of 0.015. Note that the plume geometry confirms a
south/southwesterly flow.

To provide preliminary estimates of hydraulic conductivity (K) and groundwater flow velocity (v)
for the phreatic aquifer, Terraquest personnel performed slug tests on monitoring wells MW2
and MW4 on May 17, 2021. Hydraulic conductivity estimates were determined using Aquifer
Test Pro 2010.1, a computer model developed by Waterloo Hydrogeologic. The data was
reduced using the Bower and Rice Method (Bower and Rice 1976, Bower 1989). The hydraulic
conductivity estimates range from 0.135 feet/day to 0.364 feet/day. The calculated hydraulic
conductivity is in the range of a silt to silty sand (Heath, 1982). The lithologies logged in the
saturated zones support this. Using an average hydraulic conductivity value of 0.249 feet/day,
an average groundwater seepage velocity value was determined to be 0.0249 feet per day or
9.08 feet per year. An effective porosity of 0.15 and a hydraulic gradient of 0.0152 (based on
May 17, 2021 data) were used for calculating the groundwater flow velocity.

Air Sparge Pilot Test Report
Little Market Basket, Statesville, Iredell County, North Carolina
Prepared by: Terraquest Environmental Consultants, P.C.
Test Dates: 11/14/23
Report Prepared: 11/17/23

6
The most recent potentiometric surface was measured on April, 12, 2023 as such:

Air Sparge Pilot Test Report
Little Market Basket, Statesville, Iredell County, North Carolina
Prepared by: Terraquest Environmental Consultants, P.C.
Test Dates: 11/14/23
Report Prepared: 11/17/23

7
The groundwater contaminant plume that is the target of this remedial testing is shown here:

Air Sparge Pilot Test Report
Little Market Basket, Statesville, Iredell County, North Carolina
Prepared by: Terraquest Environmental Consultants, P.C.
Test Dates: 11/14/23
Report Prepared: 11/17/23

8
Based on the previous hydrogeologic descriptions alone, the phreatic aquifer at the site is a
reasonable candidate for air sparging. The amount of clay versus silt will play a large role in the
effectiveness of sparging.

Well Installation and Layout

In addition to the existing monitoring well network, an air sparge well was installed in anticipation
of the subject air sparge test.

Terraquest personnel supervised the installation of air sparge well AS1 on October 10, 2023. Well
AS1 was installed using a Geoprobe Model 7728DT drilling rig operated by an NC-Licensed driller.
The air sparge well AS1 was constructed of 44 feet of 1”-diameter, Schedule 40 PVC casing
attached to 5 feet of 1”-diameter, Schedule 40 PVC screen with a 0.010” slot size for a total well
depth of 49 feet. This screen opening forces the introduced air to spread throughout the aquifer
where it can provide treatment. Note that rock was encountered at 49 feet.

A summary of the injection well AS1 and other wells used for event monitoring follows:

Well
identification
Radial distance
(feet) from
injection point
Screened
interval (feet)
Total depth
(feet)
Well diameter
(inches)
AS1 0: injection here 44-49 49 1
MW4 19 20-35 35 2
MW5 69 20-35 35 2
MW6 19 20-35 35 2
MW7 12 20-35 35 2
MW14 24 20-35 35 2

Air Sparge Pilot Test Report
Little Market Basket, Statesville, Iredell County, North Carolina
Prepared by: Terraquest Environmental Consultants, P.C.
Test Dates: 11/14/23
Report Prepared: 11/17/23

9
Equipment and Connections

Air was supplied to the injection point from a portable, electric air compressor powered by a
portable electrical generator brought onsite for the test. The compressor output was connected
to the injection point through a series of hoses, pipes, and fittings. Air flow into the injection
point was measured with an adjustable flow meter. A static pressure gauge was installed
downstream of the flow control valve. The change in depth to product and water in the
observation points was measured using a Solinst Model 122 Interface Meter. The wellhead setup
is shown here:

Air Sparge Pilot Test Report
Little Market Basket, Statesville, Iredell County, North Carolina
Prepared by: Terraquest Environmental Consultants, P.C.
Test Dates: 11/14/23
Report Prepared: 11/17/23

10
GENERAL PROCEDURES

The test procedure consists of applying air pressure to the sparging well while monitoring air flow
at this point and changes in groundwater levels in nearby wells. During the air sparge test
conducted on November 14, 2023, air was introduced into AS1 while measurements were
collected from observation points MW4, MW5, MW6, MW7, MW14.

The test consists of several stages in which a constant flow is applied, while the air pressure and
water levels are measured. After groundwater mounding stabilizes, the flow is stepped up and
held constant for another stage. The number of stages depends on the rate at which responses
occur.

During the November 14, 2023 test, a total of three different flow rates were applied to the air
sparge well. Flows of 1.0, 1.5, and 3.33 standard cubic feet per minute were all applied. The test
was conducted for four total hours with one hour at 1.0 scfm, one hour and forty-five minutes at
1.5 scfm, twenty-five minutes at 2 scfm, and fifty minutes at 3.33 scfm. The odd intervals are, in
part, due to the compressor sinking into the ground and unknowingly turning off due to a low oil
alarm. The unit was braced level and the was continued, however, there was ~30 minutes around
the 1:45 pm time where the flow valve was constantly being opened and a steady flow of 1.5
scfm wasn’t maintained. Measurements recorded during these stages are presented on Sparge
Table 1.

MEASUREMENTS AND RESULTS

The three main objectives of data analysis are to determine whether air sparging is suitable for
the site, determine a reasonable radius of influence for an air sparge well, and establish data for
equipment selection in the design of a full-scale system.

Air Sparge Pilot Test Report
Little Market Basket, Statesville, Iredell County, North Carolina
Prepared by: Terraquest Environmental Consultants, P.C.
Test Dates: 11/14/23
Report Prepared: 11/17/23

11
Suitability
The responses observed during the test indicate air sparging would be suitable for the site. Air
was injected into the subsurface and flow was maintained. Some sites have had poorly installed
air sparge wells where the screens are cemented or the lithology is too tight and air will not enter
the saturated zone at all. This was not the case at the subject facility. The injection was made
with a standard electrical air compressor suitable for short-term testing and flowable air was
maintained without a large amount of pressure. Flowable pressure for the test was generally at
or below 10 psi with a breakthrough pressure that didn’t exceed 15 psi.

There are other general conditions that contribute to AS effectiveness. These are discussed in
US EPA (1995), and some are listed and addressed below.

• Basements, subsurface utilities, etc. - Air sparging has the potential to exhaust elevated
concentrations of VOCs to the vadose zone, where they could accumulate in basements,
sewers, crawl spaces, etc. Implementation of AS should consider this possibility. At this site,
no basements are known to exist nor are there any building crawl spaces as structures appear
of slab construction. As some of the subject area is covered in asphalt or concrete, air sparge
off-gassing could migrate along utility pathways. To reduce those risks and as part of an
overall treatment strategy, Terraquest recommends regulation of the sparge rate and
operation of vapor extraction wells while actively sparging.

• Unconfined or Confined Aquifer - Air sparging is generally not recommended for confined
aquifers. The target zone at this site would be in the unconfined aquifer, so this factor should
not be prohibitive.

Air Sparge Pilot Test Report
Little Market Basket, Statesville, Iredell County, North Carolina
Prepared by: Terraquest Environmental Consultants, P.C.
Test Dates: 11/14/23
Report Prepared: 11/17/23

12
• Type of Contamination - Gasoline is the contaminant at this site. Of the common petroleum
fuels, gasoline is the most amenable to remediation by sparging. That is shown on the
following exhibit from the EPA’s 1995 guidance document (US EPA 1995):

• Soil Type - If the stratigraphy is comprised of tight soils or large amounts of clay, then
sparging is not likely to be effective. The saturated zone is mostly comprised of silt. This was
confirmed by the low pressure needed to maintain injection flow and by the response at
surrounding wells.

US EPA. 1995. How to evaluate alternative cleanup technologies for underground storage tank sites. Solid Waste and
Emergency Response 5403W. Document Number 510-B-95-007.

Air Sparge Pilot Test Report
Little Market Basket, Statesville, Iredell County, North Carolina
Prepared by: Terraquest Environmental Consultants, P.C.
Test Dates: 11/14/23
Report Prepared: 11/17/23

13
Radius of Influence
Determining the radius of influence involves a study of the influence observed in the wells
monitored during the pilot test. As the remedial method of air sparging is the mechanical
stripping of contaminants from the dissolved phase into a liberated waste air stream, the extent
of that effect is what is searched for. Air sparging also acts as a remedial method by increased
the amount of oxygen dissolved in the surrounding aquifer and that should be analyzed too.

Prior to and throughout the test, the depth to water was measured in surrounding wells. As the
test progressed, the water table was mounded by the applied air as seen at observations wells
by a rise in the water table. In a fully evolved test with a sufficiently low air flow, the water levels
will subside to near static levels after some period of time as the mounding is spread across the
aquifer. When this drop occurs, the air flow rate is typically increased to the next step.

The measured data is summarized on the attached Sparge Table 1 and a graph of the depth to
water versus time for each of the wells monitored is also provided at the end of this sparge
report. These graphs show the mounding and subsequent stabilization of groundwater during
each flow increase. The stabilization is slight and is realized by a tapering of water mounding in
some cases. The evidence of these water level stabilizations is an important result, since it
indicates that low flow sparging can be performed without causing sustained high water levels.

Air Sparge Pilot Test Report
Little Market Basket, Statesville, Iredell County, North Carolina
Prepared by: Terraquest Environmental Consultants, P.C.
Test Dates: 11/14/23
Report Prepared: 11/17/23

14
These measurements collected during the pilot test are indicative of the radius of influence of
the air sparge well. The following results were observed:

Well identification
Radial distance (feet) from
injection point Largest mounding (feet)
AS1 0: injection here
MW4 19 0.62
MW5 69 0.04
MW6 19 0.66
MW7 12 0.66
MW14 24 0.37

Air Sparge Pilot Test Report
Little Market Basket, Statesville, Iredell County, North Carolina
Prepared by: Terraquest Environmental Consultants, P.C.
Test Dates: 11/14/23
Report Prepared: 11/17/23

15
Calculating the radius of influence should take into account multiple factors to provide a
scientifically-reasonable value with some conservative allotment. The radius is subject to
hydrogeology and isn’t as simple as a straight-line graph. The data indicates mounding at MW14
located 24 feet away and no real influence at MW5 located almost 70 feet away. The influence
appears to be stronger within the first 20 feet from the injection well. The goal is to calculate a
ROI that provides air sparging to all areas without creating service gaps. The size and shape of
the dissolved-phase plume onsite where the sparging would occur also needs consideration.

Dissolved oxygen measurements were collected from the observation monitoring wells before
and after the sparge test as shown on Sparge Table 1. Monitoring well MW7, located closest to
the injection site had the largest increase with no change noted at MW6 and a slight increase at
monitoring well MW14. Other wells, did not show significant change.

In consideration of all these factors, 20 feet is recommended as a working radius of influence.
Terraquest recommends well placement as shown on the next page that considers site layout,
remedial goals, GCLs, 2Ls, and radius of influence. The layout contains a total of nine wells
including the existing well and eight new air sparge wells.

(See Figure next page)

Air Sparge Pilot Test Report
Little Market Basket, Statesville, Iredell County, North Carolina
Prepared by: Terraquest Environmental Consultants, P.C.
Test Dates: 11/14/23
Report Prepared: 11/17/23

16

9 wells total
1 existing (AS1)
8 new
Proposed air
sparge wells
(magenta
triangles)
20’ radius of
influence

Air Sparge Pilot Test Report
Little Market Basket, Statesville, Iredell County, North Carolina
Prepared by: Terraquest Environmental Consultants, P.C.
Test Dates: 11/14/23
Report Prepared: 11/17/23

17

Design data
The air sparge test achieved sustained flow up to 3.33 scfm at a pressure of 10 psi. Equipment
should be sized for a flow demand of nine wells at a flow rate up to 4 scfm each for a total of 36
scfm with some extra to allow for an increase in sparging as needed. Pressure over 15 psi was
not observed but could have happened briefly as breakthrough was occurring. Air sparge
breakthrough is typically 1 psi for every 2.3 feet of head (US EPA 1995). With a head of 44 – 29.5
(nearby MW7) = 14.5 feet, the entry pressure required is estimated at 6-7 psi. The lithology
accounts for some of the additional pressure required. Overall, the flow and pressure are within
the range of typical air sparge systems.

Remedial time
Based on Terraquest’s prior field experience, the application of air sparging is generally effective
at reducing contaminant mass by half in the first six months to a year of operation. With only
one well having a reported GCL violation, the cleanup time will be quicker than sites with multiple
wells having GCL violations and/or free product present. Cleanup can be accelerated by the
addition of more wells and higher flow rates, however, sparging too aggressively may push the
plume offsite in the direction of the active water supply well. Additionally, time is needed for the
water table to fluctuate and present different contaminated areas that can be exposed to
treatment. Realistically, two to three years of treatment is anticipated to lower concentrations
sufficiently that the plume is stable, and the risk of the incident can be lowered. Remediation to
concentrations below the 2L Standards will likely take several more years than that without the
concurrent injection of oxidants to further polish plume degradation. Further refinement of
treatment time will be understood as the system is operated or by conducting a level of research
and pilot testing of length that exceeds the scope of work for NCDWM-UST RRD pilot testing.

Note that SVE exhaust stack samples are often collected during air sparge pilot testing to aid in
rough estimation calculations of cleanup time. However, SVE influence was not seen during the

Air Sparge Pilot Test Report
Little Market Basket, Statesville, Iredell County, North Carolina
Prepared by: Terraquest Environmental Consultants, P.C.
Test Dates: 11/14/23
Report Prepared: 11/17/23

18
SVE pilot test that would have allowed collection of any samples from the closest well from the
sparge injection point that would have provided data useful enough to extrapolate treatment
rates from. This data is usually grossly misleading as it does not account for a decrease in
treatment rates over time or the necessity of water table fluctuations and the time those take.

CONCLUSIONS AND RECOMMENDATIONS

A November 14, 2023 air sparge pilot test conducted for the release incident at the L&L Food
Store #5 facility indicates favorable remedial response from the subsurface. Air sparging was
conducted at flows and pressures of typical systems, influence was observed at surrounding
wells. Overall, air sparging appears to be a viable option for treatment and is recommended.

Air Sparge Pilot Test Report
Little Market Basket, Statesville, Iredell County, North Carolina
Prepared by: Terraquest Environmental Consultants, P.C.
Test Dates: 11/14/23
Report Prepared: 11/17/23

19
REFERENCE

Bouwer, H., and R.C. Rice 1976. A slug test for determining hydraulic conductivity of unconfined
aquifers with completely or partially penetrating well. Water Resources Research 12, no.
3: 423 – 428.

Bouwer, H. 1989. The Bouwer and Rice slug test – an update. Ground Water. 27, no. 3: 304 –
309.

Brown, Philip M. et al. 1985. Geologic Map of North Carolina, 1 : 500,000 Scale. North Carolina
Department of Natural Resources and Community Development.

Heath C. Ralph. 1983. Basic Groundwater Hydrology, US Geological Survey Water-Supply Paper
2220, US Government Printing Office: 13.

Sanders, Laura L. 1998. A Manual of Field Hydrogeology. Upper Saddle River, New Jersey: Prentice
Hall Inc.: 196.

US EPA. 1995. How to evaluate alternative cleanup technologies for underground storage tank
sites. Solid Waste and Emergency Response 5403W. Document Number 510-B-95-007.

NVIRONMENTAL ONSULTANTS, P.C.E C
WELL CONSTRUCTION RECORD (GW-1) For Internal Use Only:
Form GW-1 North Carolina Department of Environmental Quality - Division of Water Resources Revised 2-22-2016
1. Well Contractor Information:
Well Contractor Name
NC Well Contractor Certification Number
Company Name
2. Well Construction Permit #:
List all applicable well construction permits (i.e. UIC, County, State, Variance, etc.)
3. Well Use (check well use):
Water Supply Well:
□Agricultural □Municipal/Public
□Geothermal (Heating/Cooling Supply) □Residential Water Supply (single)
□Industrial/Commercial □Residential Water Supply (shared)
□Irrigation
Non-Water Supply Well:
□Monitoring □Recovery
Injection Well:
□Aquifer Recharge □Groundwater Remediation
□Aquifer Storage and Recovery □Salinity Barrier
□Aquifer Test □Stormwater Drainage
□Experimental Technology □Subsidence Control
□Geothermal (Closed Loop) □Tracer
□Geothermal (Heating/Cooling Return) □Other (explain under #21 Remarks)
4. Date Well(s) Completed: Well ID#
5a. Well Location:

Facility/Owner Name Facility ID# (if applicable)

Physical Address, City, and Zip

County Parcel Identification No. (PIN)
5b. Latitude and longitude in degrees/minutes/seconds or decimal degrees:
(if well field, one lat/long is sufficient)
N W
6. Is(are) the well(s): □Permanent or □Temporary
7. Is this a repair to an existing well: □Yes or □No
If this is a repair, fill out known well construction information and explain the nature of the
repair under #21 remarks section or on the back of this form.
8. For Geoprobe/DPT or Closed-Loop Geothermal Wells having the same
construction, only 1 GW-1 is needed. Indicate TOTAL NUMBER of wells
drilled:
9. Total well depth below land surface: (ft.)
For multiple wells list all depths if different (example- 3@200’ and 2@100′)
10. Static water level below top of casing: (ft.)
If water level is above casing, use “+”
11. Borehole diameter: (in.)
12. Well construction method:
(i.e. auger, rotary, cable, direct push, etc.)
FOR WATER SUPPLY WELLS ONLY:
13a. Yield (gpm) Method of test:
13b. Disinfection type: Amount:
14. WATER ZONES
FROM TO DESCRIPTION
ft.ft.
ft.ft.
15. OUTER CASING (for multi-cased wells) OR LINER (if applicable)
FROM TO DIAMETER THICKNESS MATERIAL
ft.ft.in.
16. INNER CASING OR TUBING (geothermal closed-loop)
FROM TO DIAMETER THICKNESS MATERIAL
ft.ft.in.
ft.ft.in.
17. SCREEN
FROM TO DIAMETER SLOT SIZE THICKNESS MATERIAL
ft.ft.in.
ft.ft.in.
18. GROUT
FROM TO MATERIAL EMPLACEMENT METHOD & AMOUNT
ft.ft.
ft.ft.
ft.ft.
19. SAND/GRAVEL PACK (if applicable)
FROM TO MATERIAL EMPLACEMENT METHOD
ft.ft.
ft.ft.
20. DRILLING LOG (attach additional sheets if necessary)
FROM TO DESCRIPTION (color, hardness, soil/rock type, grain size, etc.)
ft.ft.
ft.ft.
ft.ft.
ft.ft.
ft.ft.
ft.ft.
ft.ft.
21. REMARKS
22. Certification:
Signature of Certified Well Contractor Date
By signing this form, I hereby certify that the well(s) was (were) constructed in accordance
with 15A NCAC 02C .0100 or 15A NCAC 02C .0200 Well Construction Standards and that a
copy of this record has been provided to the well owner.
23. Site diagram or additional well details:
You may use the back of this page to provide additional well site details or well
construction details. You may also attach additional pages if necessary.
SUBMITTAL INSTRUCTIONS
24a. For All Wells: Submit this form within 30 days of completion of well
construction to the following:
Division of Water Resources, Information Processing Unit,
1617 Mail Service Center, Raleigh, NC 27699-1617
24b. For Injection Wells: In addition to sending the form to the address in 24a
above, also submit one copy of this form within 30 days of completion of well
construction to the following:
Division of Water Resources, Underground Injection Control Program,
1636 Mail Service Center, Raleigh, NC 27699-1636
24c. For Water Supply & Injection Wells: In addition to sending the form to
the address(es) above, also submit one copy of this form within 30 days of
completion of well construction to the county health department of the county
where constructed.
rtificatttttttttttttion:
re of CertifiedWWWWWWWWWWWWWWell Contractor
Wesley J. Sorrells
3577
Terraquest Environmental Consultants
1
10/10/23 AS1
Little Market Basket
3541 Talylorsville Hwy. Statesville NC
Iredell
35.809841 -80.948711
49
N/A
6.25
Solid Stem Auger
10/17/23
44 49 1 10Slot Schd.40 PVC
0.5
40
42
40
42
49
Portland
Bentonite
No. 2 Sand Pour
Pour
0
0.5
1
14
0.5
1
14
49
Asphalt
Gravel
Clay with some silt
Silt with very little clay
Print Form
Pour
Actual Elapsed AS1 Injection Point:
Time Time Pressure Flow DTW Groundwater D.O.DTW Groundwater D.O.DTW Groundwater D.O.DTW Groundwater D.O.DTW Groundwater D.O.
(min)hour min minutes (psig)(scfm)(ft)Elevation (ft)(mg/L)(ft)Elevation (ft)(mg/L)(ft)Elevation (ft)(mg/L)(ft)Elevation (ft)(mg/L)(ft)Elevation (ft)(mg/L)
noon 0 0 0 0 0.0 28.63 70.26 1.75*31.21 70.67 1.53 29.50 72.40 2.1 29.50 70.04 1.65 31.49 70.57 1.81
12:05 PM 0 5 5 15 1.0 28.53 70.36 31.20 70.68 29.35 72.55 29.35 70.19 31.45 70.61
12:10 PM 0 10 10 8.0 1.0 28.50 70.39 31.19 70.69 29.19 72.71 29.19 70.35 31.42 70.64
12:15 PM 0 15 15 7.5 1.0 28.43 70.46 31.17 70.71 29.13 72.77 29.13 70.41 31.39 70.67
12:20 PM 0 20 20 7.5 1.0 28.42 70.47 31.20 70.68 29.09 72.81 29.09 70.45 31.38 70.68
12:25 PM 0 25 25 7.5 1.0 28.40 70.49 31.19 70.69 29.08 72.82 29.08 70.46 31.34 70.72
12:30 PM 0 30 30 6.5 1.0 28.40 70.49 31.18 70.70 29.07 72.83 29.07 70.47 31.33 70.73
12:40 PM 0 40 40 6.5 1.0 28.36 70.53 31.17 70.71 29.09 72.81 29.09 70.45 31.32 70.74
12:50 PM 0 50 50 6.5 1.0 28.39 70.50 31.18 70.70 29.10 72.80 29.10 70.44 31.31 70.75
1:00 PM 1 0 60 0.9 1.5 28.39 70.50 31.18 70.70 29.15 72.75 29.15 70.39 31.31 70.75
1:10 PM 1 10 70 7.0 1.5 28.36 70.53 31.17 70.71 29.13 72.77 29.13 70.41 31.30 70.76
1:20 PM 1 20 80 7.5 1.5 28.34 70.55 31.18 70.70 29.09 72.81 29.09 70.45 31.28 70.78
1:30 PM 1 30 90 7.0 1.5 28.31 70.58 31.18 70.70 29.09 72.81 29.09 70.45 31.27 70.79
1:45 PM 1 45 105 6.0 1.5 28.38 70.51 31.17 70.71 29.14 72.76 29.14 70.40 31.27 70.79
2:00 PM 2 0 120 6.0 1.5 28.39 70.50 31.18 70.70 29.18 72.72 29.18 70.36 31.27 70.79
2:20 PM 2 20 140 5.0 1.5 28.39 70.50 31.18 70.70 29.20 72.70 29.20 70.34 31.27 70.79
2:30 PM 2 30 150 5.0 1.5 28.39 70.50 31.18 70.70 29.22 72.68 29.22 70.32 31.30 70.76
2:45 PM 2 45 165 6.0 2.0 28.39 70.50 31.18 70.70 29.19 72.71 29.19 70.35 31.29 70.77
2:55 PM 2 55 175 7.0 2.0 28.32 70.57 31.18 70.70 29.18 72.72 29.18 70.36 31.28 70.78
3:10 PM 3 10 185 10.0 3.3 28.23 70.66 31.18 70.70 29.02 72.88 29.02 70.52 31.26 70.80
3:20 PM 3 20 195 10.0 3.3 28.10 70.79 31.17 70.71 28.90 73.00 28.90 70.64 31.22 70.84
3:30 PM 3 30 205 10.0 3.3 28.07 70.82 31.17 70.71 28.86 73.04 28.86 70.68 31.17 70.89
3:40 PM 3 40 215 10.0 3.3 28.05 70.84 31.17 70.71 28.85 73.05 28.85 70.69 31.15 70.91
3:50 PM 3 50 225 10.0 3.3 28.04 70.85 31.17 70.71 28.84 73.06 28.84 70.70 31.13 70.93
4:00 PM 4 0 235 10.0 3.3 28.01 70.88 31.17 70.71 28.84 73.06 28.84 70.70 31.12 70.94
4:20 PM 4 20 255 0 0.0 28.43 70.46 1.58 31.17 70.71 1.75 29.38 72.52 2.04 29.38 70.16 2.82 31.20 70.86 2.01
* DO measurement may have been high as meter had trouble settling down.
Observation Well: MW14
Time
compressor shut off. Possibly due to unit sinking on hillside into a tilt that caused a low oil pressure alarm. Got running ASAP, but likely didn't have 1.5 scfm for 1/2 hour or so. Kept adding air at valve as flow was dropping.
Facility ID No.: 00-0-0000021441Incident Name: Little Market Basket #1 Incident No. 47003
BIOSPARGING TEST DATA TABLESparge Table 1
Test Date: 11/14/23
Elapsed Observation Well: MW4 Observation Well: MW5 Observation Well: MW6 Observation Well: MW7
0.5
1.0
1.5
2.0
2.5
3.0
3.5
70.00
70.50
71.00
71.50
72.00
72.50
73.00
0 15 30 45 60 75 90 105 120 135 150 165 180 195 210 225 240 255 270Groundwater Elevation (feet)Elapsed Time (Minutes)
Flow Rate vs. Groundwater Elevation
MW4 MW5 MW6 MW7 MW14 Flow Rate
dist from AS1:
MW4: 19
MW5: 69
MW6: 19
MW7: 12
MW14: 24