08039_Conbraco - BF AWP 20230627

BROWNFIELDS ASSESSMENT WORK PLAN,
FORMER CONBRACO FACILITY (NORTHERN PARCEL)

1640 MATTHEWS TOWNSHIP PARKWAY
(ACTUAL BROWNFIELDS SITE ADDRESS LISTED AS: 701 MATTHEWS-MINT
HILL PARKWAY)
MATTHEWS, MECKLENBURG COUNTY, NORTH CAROLINA

ECS PROJECT NO. 49:20027-A
BROWNFIELDS PROJECT ID: 08039-04-060

PREPARED FOR
NAI Southern Real Estate
4201 Congress Street, Suite 170
Charlotte, North Carolina 28209

SUBMITTED: JUNE 26, 2023
Brownfields Assessment Work Plan
Former Conbraco Facility
Brownfields Project ID: 08039-04-606
ECS Project No. 49:20027-A
June 26, 2023

TABLE OF CONTENTS

1.0 INTRODUCTION ........................................................................................................ 1 2.0 SCOPE OF WORK ..................................................................................................... 2
2.1 Surface Water Sampling ....................................................................................................... 2
2.2 Soil Boring Advancement/Soil Sampling ............................................................................. 2
2.3 Temporary Monitoring Well Installation/Groundwater Sampling ...................................... 2
2.4 Sediment Sampling .............................................................................................................. 3
2.5 Exterior Soil Gas Probe Installation ..................................................................................... 3
2.6 Deviation from Approved Plan ............................................................................................ 4
3.0 SAMPLING METHODOLOGY.................................................................................... 4
3.1 Surface Water Sampling ....................................................................................................... 4
3.2 Soil Sampling ........................................................................................................................ 5
3.3 Groundwater Sampling ........................................................................................................ 5
3.4 Sediment Sampling .............................................................................................................. 6
3.5 Exterior Soil Gas Sampling ................................................................................................... 6 4.0 LABORATORY ANALYSES ...................................................................................... 7
4.1 Surface Water Sample Analyses .......................................................................................... 7
4.2 Soil Sample Analyses ............................................................................................................ 7
4.3 Groundwater Sample Analyses ............................................................................................ 8
4.4 Sediment Sample Analyses .................................................................................................. 8
4.5 Exterior Soil Gas Analyses .................................................................................................... 8 5.0 QUALITY ASSURANCE/QUALITY CONTROL ......................................................... 8 6.0 INVESTIGATIVE DERIVED WASTE .......................................................................... 8 7.0 REPORTING ............................................................................................................... 9

FIGURES

Figure 1 Site Location Map
Figure 2 Proposed Sediment and Soil Gas Sample Location Map
Figure 3 Proposed Soil Boring and Groundwater Sample Location Map
Figure 4 Site Plan with Proposed Sample Locations

TABLE

Table 1 Proposed Samples & Analysis

Brownfields Assessment Work Plan
Former Conbraco Facility
Brownfields Project ID: 08039-04-606
ECS Project No. 49:20027-A
June 26, 2023

1

1.0 INTRODUCTION

The subject property/site is located at 1640 Matthews Township Parkway in Matthews, Mecklenburg
County, North Carolina (Figure 1). The subject property is further defined by Mecklenburg County Online
Geographic Information Systems website as parcel number: 19329145, totaling approximately 6.414
acres, and is owned by LJW Land LLC c/o Mr. William W. Waters.

Currently, the subject site is undeveloped and consists of vegetated land but was previously owned by,
and was part of, the former Conbraco facility, which operated a foundry that manufactured metal valves
made of brass, bronze, and various types of steel. The former Conbraco manufacturing area was
predominately located on the adjacent property to the south of the subject site. Reportedly, Conbraco
ceased foundry operations at the adjoining property in 1998 and ceased the remaining light
manufacturing in 2003. Based on previous assessment activities conducted at the subject site and at the
adjacent former Conbraco manufacturing facility to the south, the subject site has been documented to
contain groundwater impacts (predominantly trichloroethene or TCE) at concentrations above the North
Carolina 2L Groundwater Quality Standards. Additionally, based on site operations and activities
previously conducted at the adjacent former Conbraco manufacturing facility, it is possible that the
subject site soils may be impacted by various metals from the foundry sand.

Due to the documented site impacts and the desire to redevelop the site for retail and/or commercial use,
the subject site entered into the North Carolina Department of Environmental Quality (NCDEQ),
Brownfields Redevelopment Section (BRS). The site was named the Former Conbraco Facility and was
assigned the Brownfields Project number of 08039-40-060. The Brownfields Agreement for the subject
site was finalized and filed with the Mecklenburg County Register of Deeds office on January 4, 2006.

As part of due diligence evaluation of the subject site for potential purchase by NAI Southern Real Estate
to redevelop it with a medical office building, two smaller commercial/retail buildings, surface parking
and landscape areas; NAI Southern Real Estate requested ECS conduct assessment activities at the site to
further evaluate the property for the proposed redevelopment. Since the site is within the NCDEQ,
Brownfields, ECS along with representatives of NAI Southern Real Estate; Van Buren Law, PLLC; LJW Land,
LLC; and the BRS held a web-based meeting on June 6, 2023, to discuss the current site status, proposed
redevelopment, proposed due diligence sampling, and BRS requirements. Based on the results of that
meeting, ECS has prepared this Work Plan to address the requested due diligence/BRS assessment
activities, which generally includes the following:

• Assessment of surface water within an existing site pond;
• Assessment of shallow site soils;
• Assessment of site groundwater via the installation and sampling of temporary monitoring wells;
• Assessment of sediment with the site pond; and
• Assessment of exterior soil gas in the proposed building footprints.

ECS has prepared this Work Plan to conduct site sampling activities in general accordance with the
Minimum Requirements Checklist for Site Assessment Work Plans and Reports by the BRS, dated March
2023, and DWM vapor intrusion guidance.
Brownfields Assessment Work Plan
Former Conbraco Facility
Brownfields Project ID: 08039-04-606
ECS Project No. 49:20027-A
June 26, 2023

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2.0 SCOPE OF WORK

The scope of work described by media below generally includes one surface water sample from the onsite
pond, 18 soil borings (with two soil samples collected from each boring for laboratory analysis), six
temporary monitoring wells (with a groundwater sample collected from each), two sediment samples
from the onsite pond, and nine exterior soil gas samples (in the proposed footprint of future site
buildings). The drilling, well installation, and various sampling activities will be conducted in general
accordance with the following applicable guidance’s:

• NCDEQ: Well Construction Rules (NCAC 2C);
• USEPA, Region 4: Science and Ecosystem Support Division (SESD) - Standard Operating
Procedures (SOPs);
• USEPA, Region 4: Laboratory Services & Applied Science Division (LSASD) - SOPs; and
• NCDEQ Vapor Intrusion guidelines.

2.1 Surface Water Sampling

• The surface water sampling will be conducted in general accordance with the USEPA Region 4, LSASD,
SOP for surface water sampling (ID No. LSASDPROC-201-R6), effective date of April 23, 2023.
• In accordance with the above referenced June 6, 2023, discussion with the BRS, ECS is proposing to
collect one surface water sample from the onsite pond located in the approximate center of the site.
The surface water sample will be collected from the onsite pond, assuming it contains water at the
time of the sampling event. If the pond does not contain water at the time of the sampling event, a
surface water sample will not be collected.

2.2 Soil Boring Advancement/Soil Sampling

• ECS will observe the advancement of 18 borings at the site in order to assess site soils, as indicated
on Figures 3 and 4. The borings will be advanced utilizing a direct push technology (DPT) type drilling
and/or a decontaminated hand auger. Since the final grading plan has not been finalized for the site
redevelopment but is currently estimated to be seven feet or less for most of the site property, each
boring will extend to a depth of approximately five feet below ground surface (ft bgs).
• The horizontal location of each soil boring will be determined using a hand-held GPS with sub-meter
accuracy.

2.3 Temporary Monitoring Well Installation/Groundwater Sampling

• ECS will subcontract with a North Carolina certified well contractor (NCCWC) to install six temporary
monitoring wells at the locations shown on Figures 3 and 4 in order to assess groundwater conditions
at the site. The monitoring wells will be installed utilizing a DPT type drilling rig equipped with either
hollow or solid stem augers.
• Each temporary monitoring well will be constructed of flush-threaded, Schedule 40 one or two-inch
polyvinyl chloride (PVC) equipped with a minimum of 10 feet section of well screen, installed to
transect the water table surface as estimated during drilling, followed by blank PVC riser to the ground
surface. Then clean well sand will be placed from the bottom of each boring to approximately one
Brownfields Assessment Work Plan
Former Conbraco Facility
Brownfields Project ID: 08039-04-606
ECS Project No. 49:20027-A
June 26, 2023

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foot above the well screen, followed by a minimum of two feet of bentonite seal. The remainder of
the annual space in each boring will either be filled with bentonite or soil, to the surrounding ground
surface. A locking expansion plug and padlock will be provided at each temporary monitoring well.
• After completion of the installations, each temporary monitoring well will be developed by bailing
and/or pumping until the water produced is visibly free of sediment and pH, temperature, and specific
conductivity have stabilized. Stabilization will be considered achieved when three consecutive
readings are within the limits shown below:

 Specific Conductance (3%).
 Temperature (3%).
 pH (± 0.1 standard pH unit).

• The horizontal location of each temporary monitoring well will be determined using a hand-held GPS
with sub-meter accuracy.

• The relative vertical elevation of the top of each temporary monitoring well casing will be determined
using a level and survey rod, as referenced from a common site benchmark. ECS will subsequently
calculate the groundwater elevation by subtracting the measured depths to water at each well located
at the site from their respective relative elevations of the top of casings. ECS will use the calculated
groundwater elevation data to infer the groundwater flow direction below the subject property.

2.4 Sediment Sampling
• ECS is proposing to collect two sediment samples from the on-site pond located in the approximate
center of the site, as indicated on Figures 2 and 4. The actual location of the sediment samples will
be determined during the sampling event but are expected to be in areas that visually appear to
contain sediment runoff from the site.
• The horizontal location of each sediment sample will be determined using a hand-held GPS with sub-
meter accuracy.

2.5 Exterior Soil Gas Probe Installation

• ECS anticipates that nine exterior soil gas sample will be collected from the locations of the proposed
future site buildings, as shown on Figures 2 and 4. The soil gas samples will be collected in 1- Liter
Summa canisters as described in subsequent paragraphs.
• The temporary soil gas sample point will be constructed by advancing a boring to a depth of six ft bgs
using a DPT type drill rig or decontaminated hand auger. The use of the DPT type drill rig involves
driving a hollow rod with plastic liner set inside the rod using a hydraulic ram. As the rod penetrates
the subsurface, soil is collected within the plastic liner. The rod is then extracted, and the liner is
removed and cut open exposing soil which can be examined.
• A vapor implant consisting of a porous air filter connected to a length of Nylaflow tubing will be
positioned in the boring at the sample point. The porous air filter will be positioned near the bottom
of the boring. The annular space around and approximately six inches above the porous air filter will
be backfilled with clean filter sand and bentonite will be placed in the remaining annular space.
Brownfields Assessment Work Plan
Former Conbraco Facility
Brownfields Project ID: 08039-04-606
ECS Project No. 49:20027-A
June 26, 2023

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Distilled water will be poured into the bentonite and allowed to hydrate for at least 30 minutes before
sampling is performed.
• The soil vapor sample will not be collected for a minimum of 24 hours after installation by DPT drilling,
in order to allow the soil vapors to stabilize prior to sample collection. This waiting period is to allow
for dissipation of potential 1,3-butadiene that has been documented to be produced due to friction
during DPT boring advancement.

2.6 Deviation from Approved Plan

This work plan is intended to be dynamic and to be adapted to specific and actual site conditions.
Accordingly, should such conditions warrant a change either by addition, deletion or modification of a
procedure, such may be accomplished with agreement between the Prospective Developers’
representative and ECS after consultation with, and subject to approval by the NCDEQ, Brownfields. Such
changes will comply with applicable local, State, and Federal rules and regulations. A written amendment
shall be prepared and submitted to NCDEQ, Brownfields for approval (the use of e-mail correspondence
shall suffice for approval) prior to implementation. The amendment and approval will be included in the
report for final documentation. Amendments must have the approval of the NCDEQ Brownfields Program
prior to implementation.

3.0 SAMPLING METHODOLOGY

The sampling activities will be conducted in general accordance with NCDEQ Well Construction Rules
(NCAC 2C), USEPA, Region 4 SESD - SOPs, USEPA, Region 4 LSASD – SOPs; and NCDEQ Vapor Intrusion
guidelines. The monitoring wells will be sampled using low-flow sampling techniques in general
conformance with USEPA Low Stress/Low Flow Purging and Sampling Procedure for the Collection of
Groundwater Samples from Monitoring Wells guidelines (Revised September 19, 2017).

3.1 Surface Water Sampling

• ECS will provide a project professional to collect the surface water sample from the onsite pond,
assuming it contains water at the time of the sampling event. The surface water sample will be
collected by either slowly lowering a new, dedicated and disposable bailer below the water surface
to remove water from the sample containers, or by slowly submerging a laboratory provided, non-
preserved sample container below the water surface and allowing to fill up, then decanted into the
actual laboratory provided, pre-preserved sample containers.
• Although the NCDEQ, BRS does not typically accept filtered water samples, in an effort to further
evaluate the surface water for dissolved metals, a filtered sample will also be collected by pumping
the surface water through a 0.5 µm filter in an effort to further remove sediment from the sample,
and into the laboratory provided, pre-preserved sample container. The water sample will not come
into contact with the preserved sample container until after filtering.
• The filled sample containers will be placed in a cooler on ice, along with a completed Chain of Custody
(COC), for delivery to the laboratory. The samples will be labeled as to sample ID, ECS project number,
sample date and time, preservative, and requested analysis. The samples will be maintained under
COC protocol throughout the collection, transport, and receipt at the laboratory process.
Brownfields Assessment Work Plan
Former Conbraco Facility
Brownfields Project ID: 08039-04-606
ECS Project No. 49:20027-A
June 26, 2023

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• The horizontal location of the sample location will be determined using a hand-held GPS with sub-
meter accuracy.

3.2 Soil Sampling

• ECS will provide a project professional to collect soils continuously from the ground surface to the
termination depth (five ft bgs) of the soil borings. During advancement of the borings, two soil
samples will be collected for laboratory analysis from the ground surface to a depth of approximately
2.5 ft bgs, and from approximately 2.5 ft bgs to five ft bgs and placed directly into laboratory provided,
pre-preserved sample containers and placed in a cooler on ice. The samples will be labeled as to
sample ID, ECS project number, sample date and time, preservative, and requested analysis. The
samples will be maintained under COC protocol throughout the collection, transport, and receipt at
the laboratory process.
• A portion of the soils from the two sample depths will be placed into a resealable container and set
aside for approximately 15 minutes, then measured for volatile organic vapors using a photoionization
detector (PID).
• The soil borings will be backfilled with the soil cuttings generated during the boring activities and
capped with asphalt, soil, or concrete, as appropriate.

3.3 Groundwater Sampling

• After allowing the temporary monitoring wells to stabilize at least 24 hours after development, ECS
will measure depth to the groundwater water surface from the top of the well casing in each well and
collect groundwater samples. Water levels will be measured in, and groundwater samples collected
from, each of the temporary monitoring wells. Prior to sampling, the wells will be purged using “low
flow” technique using either a peristaltic pump and new, disposable tubing or other sampling devices
where the withdrawal rate can be controlled. During purging, water level measurements will be
collected using an electronic water level indicator accurate to 0.01 feet and ECS will attempt to
maintain drawdown in each well to less than 0.3 feet during sampling and water quality
measurements will be collected/recorded. Water quality measurements will be made using a flow-
through cell at intervals approximately 3 to 5 minutes apart. Parameters to be measured include
turbidity, temperature, specific conductance, pH, oxidation-reduction potential, and dissolved
oxygen. Groundwater samples will be collected when each well has stabilized. Stabilization will be
considered achieved when three consecutive readings are within the limits shown below:

 Turbidity (10% for values greater than 5 nephelometric turbidity units (NTUs); if three
turbidity values are less than 5 NTU, consider the values as stabilized).
 Dissolved Oxygen (10% for values greater than 0.5 mg/L, if three dissolved oxygen values are
less than 0.5 mg/L, consider the values as stabilized).
 Specific Conductance (3%).
 Temperature (3%).
 pH (± 0.1 standard pH unit).
 Oxidation/Reduction Potential (±10 millivolts)

Brownfields Assessment Work Plan
Former Conbraco Facility
Brownfields Project ID: 08039-04-606
ECS Project No. 49:20027-A
June 26, 2023

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• Although the NCDEQ, BRS does not typically accept filtered water samples, in an effort to further
evaluate the groundwater for dissolved metals, a filtered sample will also be collected by pumping
groundwater through a 0.5 µm filter in an effort to further remove sediment from the sample, and
into the laboratory provided, pre-preserved sample container. The water sample will not come into
contact with the preserved sample container until after filtering.
• Following completion of the Brownfields Assessment activities, the temporary monitoring wells will
be abandoned by a NCCWC, in general accordance with North Carolina well construction standards.

3.4 Sediment Sampling

• ECS will provide a project professional to collect the sediment samples using decontaminated,
stainless-steel equipment and new, disposable latex or nitrile gloves.
• The sediment samples will be placed directly into laboratory provided, pre-preserved sample
containers, and placed in a cooler on ice. The samples will be labeled as to sample ID, ECS project
number, sample date and time, preservative, and requested analysis. The samples will be maintained
under COC protocol throughout the collection, transport, and receipt at the laboratory process.
• The sediment samples will be placed directly into laboratory provided, pre-preserved sample
containers and placed on ice, in a cooler. The samples will be labeled as to sample ID, ECS project
number, sample date and time, preservative and requested analysis. The samples will be maintained
under COC protocol throughout the collection, transport and receipt at the laboratory process.
•
3.5 Exterior Soil Gas Sampling

• ECS will check and note the vacuum on the Summa Canister before initiating the sampling procedure.
If the initial vacuum prior to sample collection is less than 10 percent of the vacuum documented by
the laboratory at shipment, the Summa canister will not be used. Prior to collecting the soil gas
sample, a sample train consisting of non-reactive tubing and micro-valves will be connected to the
Nylaflow tubing at each sample point and to a Summa canister. The sample train will be used to purge
the sample lines and direct flow to the Summa canister being used to collect the sample. A shut-in
test will be performed on the sample train to confirm that leaks are not present in the sampling train.
A micro-valve at the connection between the sampling train and the Nylaflow tubing will be closed,
and a vacuum will be applied to the sampling train using a disposable syringe. The vacuum gauge on
the Summa canister will be monitored for declining vacuum indicative of a leak.
• Prior to collecting the soil gas sample, a helium shroud leak test will be performed at the sample point
to confirm the integrity of the subsurface bentonite seal. The shroud will be placed and sealed over
the sampling point and entire sampling train including the Summa canister. The vapor implant sample
tubing and tracer gas tubing will be routed through small diameter holes in the wall of the shroud.
The shroud will be flooded with helium from a compressed gas tank through tracer gas tubing routed
through the shroud wall. The helium gas concentration inside the shroud will be measured with a
helium gas detector. After the shroud has been flooded with helium gas concentration, three volumes
of vapor will be purged from the tubing and interstitial space of the boring, following which, a soil gas
sample will be screened from a Tedlar bag for the presence of helium. If the soil gas sample contains
less than 10 percent of the concentration inside the shroud, the test will be considered acceptable. If
the test results are not acceptable, ECS will take steps to achieve a better bentonite seal.
Brownfields Assessment Work Plan
Former Conbraco Facility
Brownfields Project ID: 08039-04-606
ECS Project No. 49:20027-A
June 26, 2023

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• Following successful shut-in and helium shroud tests, ECS will collect the soil gas sample. ECS will
obtain a one-liter Summa canisters for each sampling point from a commercial laboratory that follows
National Environmental Laboratory Accreditation Conference (NELAC) standards and participates in
the National Environmental Laboratory Accreditation Program (NELAP). The canisters will be pre-
cleaned and pre-evacuated so that it is under negative (i.e., under vacuum). The canisters will be
batch certified by the laboratory. The Summa canisters will be outfitted with a flow regulator set to
200 milliliters per minute and a vacuum gauge. ECS will open the valve on the Summa canisters and
soil gas will flow into the canister. ECS will note the time the valve is opened and the initial vacuum.
If the initial vacuum prior to sample collection is less than 10 percent of the vacuum documented by
the laboratory at shipment, the Summa canister will not be used. When the vacuum has decreased
to approximately 5 inches of mercury, ECS will shut the valve and record the time and final vacuum.
In addition, the vacuum will not be allowed to reach zero inches of mercury. ECS will request that the
laboratory report the vacuum reading for each cannister when it is received by the laboratory.
• Following completion of soil gas sampling activities, the soil gas sampling point will be abandoned,
and the boring backfilled with the soil cuttings generated during the boring activities and capped with
asphalt, soil, or concrete, as appropriate.

4.0 LABORATORY ANALYSES

The surface water, soil, groundwater, and sediment samples will be submitted to a North Carolina certified
laboratory for analysis. Since North Carolina does not certify laboratories for analyses of air samples, ECS
will request that the laboratory analyze air samples for the most current and applicable standards from
NELAP. The laboratory will be instructed to use reporting limits below the 15A NCAC 02B Surface Water
Quality Standards, IHSB Preliminary Soil Remediation Goals, 15A NCAC 02L Groundwater Quality
Standards, and the NCDEQ, Division of Waste Management residential and non-residential Vapor
Intrusion Screening Levels (VISLs). Additionally, it will be requested that the method detection limits
(MDL), and J-flags be included. The laboratory will also be instructed to report the vacuum measurement
for each Summa canisters at receipt by the laboratory. Level II QA/QC will be requested to be reported
by the laboratory. A summary of the proposed samples and analyses are provided in Table 1.

4.1 Surface Water Sample Analyses

The surface water sample collected from the onsite pond will be shipped under COC protocol to a North
Carolina certified laboratory to be analyzed for volatile organic compounds (VOCs) by EPA Method 8260;
semi-volatile organic compounds (SVOCs) by EPA Method 8270; total and field filtered dissolved RCRA
metals including copper (Cu), zinc (Zn), iron (Fe), and manganese (Mn) by EPA Method 6020 and 7470;
and hardness by EPA Method 200.7. Comparison of the concentrations of total versus dissolved RCRA
metals will provide information as to whether the concentrations of total RCRA metals may be biased high
as the result of sediment or particulate matter in samples.

4.2 Soil Sample Analyses

The soil samples collected from the borings will be shipped under COC protocol to a North Carolina
certified laboratory to be analyzed for VOCs by EPA Method 8260; SVOCs by EPA Method 8270; total RCRA
metals including Cu, Zn, Fe & Mn by EPA Method 6020 and 7470; and Cr VI by EPA Method 7199.
Brownfields Assessment Work Plan
Former Conbraco Facility
Brownfields Project ID: 08039-04-606
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4.3 Groundwater Sample Analyses

Groundwater samples from the wells will be shipped under COC protocol to a North Carolina certified
laboratory to be analyzed for VOCs by EPA Method 8260; SVOCs by EPA Method 8270; and total and field
filtered dissolved RCRA metals including Cu, Zn, Fe & Mn by EPA Method 6020 and 7470. Comparison of
the concentrations of total versus dissolved RCRA metals will provide information as to whether the
concentrations of total RCRA metals may be biased high as the result of sediment or particulate matter in
samples.

4.4 Sediment Sample Analyses

Sediment samples from the onsite pond will be shipped under COC protocol to a North Carolina certified
laboratory to be analyzed for VOCs by EPA Method 8260, SVOCs by EPA Method 8270, total RCRA metals
including Cu, Zn, Fe & Mn by EPA Method 6020 and 7470; and Cr VI by EPA Method 7199. Comparison of
the concentrations of total versus dissolved RCRA metals will provide information as to whether the
concentrations of total RCRA metals may be biased high as the result of sediment or particulate matter in
samples.

4.5 Exterior Soil Gas Analyses

The soil gas samples will be shipped under COC protocols to a commercial laboratory that follows NELAC
standards and participates in the NELAP for analyses of VOCs plus naphthalene by EPA Method TO-15.

5.0 QUALITY ASSURANCE/QUALITY CONTROL

Following the collection of the samples described above, the sample containers will be labeled and
shipped to a commercial laboratory using COC protocols to be analyzed.

In addition to the above samples, for Level II quality control/quality assurance (QA/QC) purposes one
surface water, two soil, one groundwater, and nine exterior soil gas duplicate samples will be collected.
The duplicate exterior soil gas sample will be collected in conjunction with the respective record sample
via a “tee” connection in the tubing. The duplicates will be submitted for the same analyses as the record
sample they are associated with. Duplicate samples will be submitted to the laboratory without
identification as to their respective record samples.

Also, one equipment blank sample will be collected of groundwater sampling from the tubing and
submitted for laboratory analysis of VOCs, SVOCs, and total and dissolved RCRA metals. One trip blank
sample will accompany groundwater sample containers from laboratory to the field, and back to the
laboratory and will be analyzed for VOCs.

6.0 INVESTIGATIVE DERIVED WASTE

Investigative derived waste (IDW) generated from the soil borings (i.e., soil cuttings) will be thinly spread
onsite in the vicinity of the boring location to the extent possible, unless impacted soil is apparent based
Brownfields Assessment Work Plan
Former Conbraco Facility
Brownfields Project ID: 08039-04-606
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on field observations (i.e., visual and/or olfactory senses or elevated PID readings). If soil cuttings appear
to be impacted or sufficient space to thinly spread the cuttings is not available, the soil cuttings will be
containerized. If soil cuttings are containerized, additional waste characterization will be conducted based
on the requirements of the disposal facility.

IDW generated from the construction, development, and sampling of monitoring wells (i.e., soil cuttings,
development water, and purge water) will managed in general accordance with NCDEQ-DWM-IHSB
Program’s Guidelines for Assessment and Cleanup of Contaminated Sites (September 2022). IDW will be
placed onsite in the vicinity of the monitoring well location, unless impacts are apparent based on field
observations (i.e., visual and/or olfactory senses or elevated PID/FID readings), in which case these
materials will be containerized.

7.0 REPORTING

ECS will prepare a written report documenting the field activities, sampling procedures, sample locations,
laboratory procedures and analytical results discussion, and conclusions for submission to the NCDEQ,
Brownfields. The report will include a sample location figure, groundwater potentiometric map, boring
logs, and data tables. The surface water samples will be compared to the NCAC 15A 02B Surface Water
Quality Standards. The sediment and soil samples results will be compared to the current NCDEQ Non-
Residential PSRGs. The groundwater samples will be compared to the current NCAC 15A 02L Groundwater
Quality Standards and Groundwater Screening Levels (GWSL) for Vapor Intrusion (VI). The exterior soil
gas sample results will be compared to the current NCDEQ, IHSB, Non-Residential VISLs for Sub-slab and
Exterior Soil Gas. If positive detections are noted, the soil, groundwater, and exterior soil gas sample
results will also be input into the NCDEQ Risk Calculator to assess if the results exceed applicable risk
thresholds. Sample collection logs for soil gas and groundwater samples will be included in the report.
The sample collection logs for soil gas samples will include helium leak checks results, and photographs of
the sample arrays. The sample collection logs for groundwater samples will include well information and
field geochemistry data for low-flow groundwater sampling. The report will be signed and sealed by a
North Carolina Professional Engineer or Licensed Geologist. The report will also include the identification
numbers for ECS’s corporate Professional Engineers and Geologists Licenses.

FIGURES

FIGURE 1SITE LOCATION MAP
Conbraco BF Site1640 Matthews Township ParkwayMatthews, Mecklenburg County, North Carolina
ECS Proposal Number 49:20027-A
SOURCE:
USGS 7.5’ TOPOGRAPHIC MAP
MATTHEWS NC 2022
MINT HILL NC 2022
SCALE:
AS SHOWN
SITE
AREA
FIGURE 2
PROPOSED SEDIMENT AND SOIL GAS SAMPLE
LOCATION MAP
Conbraco BF Site
1640 Matthews Township Parkway
Matthews, Mecklenburg County, North Carolina
ECS Proposal Number 49:20027-A
SOURCE:
MECKLENBURG COUNTY GIS
DATED 2022
SCALE:
AS SHOWN
APPROXIMATE SITE BOUNDARY LEGEND
APPROXIMATE PROPOSED SOIL GAS SAMPLE LOCATION APPROXIMATE PROPOSED SEDIMENT SAMPLE LOCATION
SS-1
SS-2
SG-1SG-2
SG-3
SG-4
SG-6
SG-7
SG-8
SG-9
SG-5
FIGURE 3
PROPOSED SOIL BORING AND GROUNDWATER
SAMPLE LOCATION MAP
Conbraco BF Site
1640 Matthews Township Parkway
Matthews, Mecklenburg County, North Carolina
ECS Proposal Number 49:20027-A
SOURCE:
MECKLENBURG COUNTY GIS
DATED 2022
SCALE:
AS SHOWN
APPROXIMATE PROPOSED SOIL SAMPLE LOCATION
APPROXIMATE SITE BOUNDARY LEGEND
APPROXIMATE PROPOSED SOIL AND GROUNDWATER SAMPLE LOCATION
SB-2/TW-2 SB-1/TW-1
SB-3/TW-3
SB-4/TW-4
SB-5/TW-5
SB-6/TW-6
SB-7SB-8
SB-9SB-10SB-11
SB-12
SB-13SB-14SB-15
SB-16
SB-17
SB-18
SOURCE:
MATTHEWS TOWNSHIP PARKWAY MOB/RETAIL
CONCEPTUAL SITE PLAN
DATED 2023
SCALE:
AS SHOWN
FIGURE 4SITE PLAN WITH PROPOSED SAMPLE LOCATIONS
Conbraco BF Site1640 Matthews Township ParkwayMatthews, Mecklenburg County, North Carolina
ECS Proposal Number 49:20027-A
APPROXIMATE PROPOSED SOIL SAMPLE LOCATION
APPROXIMATE SITE BOUNDARY LEGEND
APPROXIMATE PROPOSED SOIL GAS SAMPLE LOCATION
APPROXIMATE PROPOSED GROUNDWATER SAMPLE LOCATION
APPROXIMATE PROPOSED SEDIMENT SAMPLE LOCATIONAPPROXIMATE PROPOSED SOIL AND GROUNDWATER SAMPLE LOCATION

TABLE
Table 1
Proposed Samples & Analysis
Former Conbraco Facility
1640 Matthews Township Road
Matthews, Mecklenburg County, North Carolina
Brownfields Project No.: 08039-04-060
ECS Project No.: 49:20027-A
Surface Water Sample
VOCs & VOCs / EPA Method 8260 & 8270
Total RCRA Metals + Cu, Zi, Fe & Mn / EPA Methods 6020/7470
Dissolved RCRA Metals + Cu, Zi, Fe & Mn / EPA Methods 6020/7470
Hardness / EPA Method 200.7
Soil Samples
SB-1 (0.0 - 2.5')N/A
SB-1 (2.5 - 5.0')N/A
SB-2 (0.0 - 2.5')N/A
SB-2 (2.5 - 5.0')N/A
SB-3 (0.0 - 2.5')N/A
SB-3 (2.5 - 5.0')N/A
SB-4 (0.0 - 2.5')N/A
SB-4 (2.5 - 5.0')N/A
SB-5 (0.0 - 2.5')N/A
SB-5 (2.5 - 5.0')N/A
SB-6 (0.0 - 2.5')N/A
SB-6 (2.5 - 5.0')N/A
SB-7 (0.0 - 2.5')N/A
SB-7 (2.5 - 5.0')N/A
SB-8 (0.0 - 2.5')N/A
SB-8 (2.5 - 5.0')N/A
SB-9 (0.0 - 2.5')N/A
SB-9 (2.5 - 5.0')N/A
SB-10 (0.0 - 2.5')N/A
SB-10 (2.5 - 5.0')N/A
SB-11 (0.0 - 2.5')N/A
SB-11 (2.5 - 5.0')N/A
SB-12 (0.0 - 2.5')N/A
SB-12 (2.5 - 5.0')N/A
SB-13 (0.0 - 2.5')N/A
SB-13 (2.5 - 5.0')N/A
SB-14 (0.0 - 2.5')N/A
SB-14 (2.5 - 5.0')N/A
SB-15 (0.0 - 2.5')N/A
SB-15 (2.5 - 5.0')N/A
SB-16 (0.0 - 2.5')N/A
SB-16 (2.5 - 5.0')N/A
SB-17 (0.0 - 2.5')N/A
SB-17 (2.5 - 5.0')N/A
SB-18 (0.0 - 2.5')N/A
SB-18 (2.5 - 5.0')N/A
SB-DUP1 N/A
SB-DUP2 N/A
Notes:
VOCs = Volatile Organic Compounds
SVOCs - Semi-Volatile Organic Compounds
Cu = Copper
Zn = Zinc
Fe = Iron
Mn = Manganese
Chromium VI = Hexavalent Chromium
Dup = Duplicate Sample
Sample Media Laboratory Analysis / Analytical Method Batch / Individual Certified Summa
Canister
SW-1
SW-DUP N/A
N/A
VOCs & SVOCs / EPA Method 8260 & 8270
Total RCRA Metals + Cu, Zn, Fe, Mn / EPA Method 6020/7470
Chromium VI / EPA Method 7199
06/27/2023