HomeMy WebLinkAbout27024_CLT Supply_BAR Work Plan_R1_20240606
Via Email June 6, 2024
NCDEQ – Division of Waste Management Brownfields Program 1646 Mail Service Center Raleigh, NC 27699-1646
Attn: Ms. Carolyn Minnich Re: Brownfield Assessment Work Plan (Revision 1)
Charlotte Supply Co. 410 S. Mint Street Charlotte, North Carolina Brownfields Project No. 27024-23-060 H&H Project No. AGI.003
Dear Ms. Minnich: On behalf of 410 S Mint Street NC, LLC, enclosed please find a copy of the Brownfields Assessment Work Plan (Revision 1) prepared for the Charlotte Supply Co. Brownfields property.
The Assessment Work Plan Approval Signature Page and Minimum Requirements Checklist are attached with the work plan. Should you have questions or need additional information, please do not hesitate to contact us at
(704) 586-0007.
Sincerely, Hart & Hickman, PC
Matt Bramblett, PE Robert Sorgel Principal Sr. Project Geologist
Attachments: cc: Mr. Alex Hay, Mr. Max Cookes, and Mr. Wenhao Zhang, ANiMAL Group (Via Email) Ms. Laura Truesdale, Moore & Van Allen (Via Email)
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Brownfields Assessment Work Plan (Revision 1) Charlotte Supply Co. 410 S. Mint Street Charlotte, North Carolina Brownfields Project No. 27024-23-060 H&H Job No. AGI.003 Table of Contents
1.0 Introduction .............................................................................................................................1
1.1 Background Information .......................................................................................................1
1.2 Previous Assessment Activities .............................................................................................2
2.0 Brownfields Assessment Activities ........................................................................................5
2.1 Receptor Survey ....................................................................................................................5
2.2 Soil Sampling Activities ........................................................................................................6
2.3 Groundwater Sampling Activities .........................................................................................7
2.4 Soil Gas Sampling Activities .................................................................................................9
2.5 Sub-Slab Vapor Sampling Activities ...................................................................................12
2.6 Quality Assurance – Quality Control ..................................................................................13
2.7 Investigation Derived Waste ...............................................................................................14
3.0 Reporting ...............................................................................................................................15
List of Attachments
Attachment 1 Work Plan Approval Signature Page
List of Tables
Table 1 Proposed Sample Summary Table
List of Figures
Figure 1 Site Location Map
Figure 2 Site Map
Figure 3 Proposed Sample Location Map
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Brownfields Assessment Work Plan (Revision 1) Charlotte Supply Co. 410 S. Mint Street Charlotte, North Carolina Brownfields Project No. 27024-23-060 H&H Job No. AGI.003 1.0 Introduction
On behalf of 410 S Mint Street NC, LLC (Prospective Developer or PD), Hart & Hickman, PC
(H&H) has prepared this Brownfields Assessment Work Plan (Work Plan) for the Charlotte
Supply Co. Brownfields property (Brownfields Project No. [BPN] 27024-23-060) located at 410
S. Mint Street in Charlotte, Mecklenburg County, North Carolina (subject Site or Site). The Site
consists of one parcel of land (Mecklenburg County Parcel No. 07312411) that is approximately
4.78 acres and is located in Uptown Charlotte. The Site is currently developed with an open air
parking deck. A Site location map is provided as Figure 1, and the Site and surrounding area are
shown in Figure 2.
Proposed redevelopment of the Brownfields property includes the construction of a retail
building and two residential towers to the south of the existing parking deck. The existing open
air parking deck will remain at the Site. An overlay map depicting the preliminary proposed
redevelopment plans at the Site is provided as Figure 3.
1.1 Background Information
The southern portion of the Site was formerly occupied by a residential structure from at least
1900 through the 1960s. The majority of the Site was developed as a light industrial property
containing railroad tracks, an auto repair shop, cold storage facilities, and support buildings
beginning circa 1929. One of the buildings was occupied by the Charlotte Supply Co. Light
industrial uses continued until the late 1970s or early 1980s. The Site appeared to be used for
light commercial activities and as a parking lot from the early 1980s through early 1990s. In
1995, the Site was redeveloped with the current parking structure.
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1.2 Previous Assessment Activities
2021 Phase I Environmental Site Assessment
In September 2021, a Phase I Environmental Site Assessment (ESA) was conducted at the Site
by S&ME, Inc. (S&ME). The results of the Phase I ESA identified Recognized Environmental
Conditions (RECs) associated with the following:
1) Historical use of the Site for commercial operations, including the presence of a coal
yard, cold storage facilities, and automotive repair facilities.
2) Identified chlorinated solvent impacts to groundwater on an adjacent property to the north
of the Site.
2022 Phase II Environmental Site Assessment
From June to August 2022, S&ME conducted Phase II ESA activities at the Site. The Phase II
ESA activities included the collection of four (4) soil samples and two (2) groundwater samples.
The soil samples were submitted to a laboratory for analysis of volatile organic compounds
(VOCs), semi-VOCs (SVOCs), and Resource Conservation and Recovery Act (RCRA) metals
plus hexavalent chromium. The groundwater samples were submitted to a laboratory for
analysis of VOCs, SVOCs, and RCRA metals. It should be noted that two (2) additional
groundwater samples were attempted to be collected at the Site, but drill rig refusal was
encountered above the water table at these locations.
Results of Phase II ESA soil assessment activities indicated the presence of the SVOCs
benzo(a)anthracene, benzo(a)pyrene, benzo(b)fluoranthene, dibenz(a,h)anthracene, indeno(1,2,3-
cd)pyrene, and 1-methylnaphthalene in the SB-1 soil sample collected from the southern portion
of the Site at concentrations above Protection of Groundwater, Residential, and/or
Industrial/Commercial Preliminary Soil Remediation Goals (PSRGs). Additionally, the metals
arsenic and/or hexavalent chromium were detected in the SB-1, SB-2, and/or SB-3 soil samples
collected from the southern, southeastern, and northern portions of the Site, respectively, at
concentrations above Residential and/or Industrial/Commercial PSRGs.
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Results of Phase II ESA groundwater assessment activities indicated the presence of the
chlorinated VOCs tetrachloroethylene (PCE) and trichloroethylene (TCE) and the metal
chromium in the GW-3 groundwater sample collected from the northern portion of the Site at
concentrations above North Carolina Department of Environmental Quality (DEQ) 2L
Groundwater Standards (2L Standards). No VOCs, SVOCs, or metals were detected in the GW-
2 groundwater sample collected from the southeastern portion of the Site at concentrations above
2L Standards.
2023 Phase I Environmental Site Assessment
In February 2023, a Phase I ESA was conducted at the Site by S&ME. The results of the Phase I
ESA identified RECs associated with the following:
1) Historical use of the Site for commercial operations, including the presence of a coal
yard, cold storage facilities, automotive repair facilities, and railroad activities.
2) Identified chlorinated solvent impacts to groundwater at the Site and at an adjacent
property to the north.
3) Identified petroleum impacts to groundwater at an adjacent property to the east.
To address potential environmental concerns associated with historical on-Site and off-site
operations, the Site was entered into the North Carolina DEQ Brownfields Program and received
eligibility in a letter dated August 25, 2023. The PD elected to participate in the Brownfields
Program Redevelopment Now option. As part of this process, a kick-off/data gap meeting with
the PD, DEQ Brownfields personnel, and H&H was held on October 24, 2023, to discuss Site
history, proposed redevelopment plans, data gaps, and the proposed schedule for completing the
Brownfields Agreement. To address data gaps and DEQ Brownfields requests for additional
assessment, H&H has prepared this Work Plan to conduct Brownfields assessment activities at
the Site.
The purpose of the Brownfields assessment activities described herein is to further evaluate the
potential for impacts at the Site for the protection of Site workers during redevelopment and for
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future Site occupants. The Brownfields assessment activities discussed in the following sections
include the collection of soil, groundwater, sub-slab vapor, and soil gas samples. In addition to
the soil, groundwater, sub-slab vapor, and soil gas assessment activities, a Brownfields receptor
survey will be conducted to obtain information associated with land use, water supply well use,
and potential sensitive receptors in the area surrounding the Site. A summary of the proposed
Brownfields assessment activities is provided below.
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2.0 Brownfields Assessment Activities
The Brownfields assessment activities will be conducted in general accordance with the DEQ
Inactive Hazardous Sites Branch (IHSB) Guidelines for Assessment and Cleanup of
Contaminated Sites (Guidelines) dated September 2023, the DEQ Division of Waste
Management (DWM) Vapor Intrusion Guidance (VI Guidance) dated March 2018, most recent
versions of the U.S. Environmental Protection Agency (EPA) Region IV Laboratory Services
and Applied Science Division (LSASD) Field Branches Quality System and Technical
Procedures guidance, and the DEQ Brownfields Minimum Requirements Checklist for Site
Assessment Work Plans and Reports dated March 2023.
Prior to conducting the proposed assessment field activities, H&H will contact North Carolina
811, the public utility locator, to mark subsurface utilities located on the Site. Additionally,
H&H will contract with a private utility locator to screen proposed sample locations for subgrade
utilities that may not be marked by the public locator. The private utility locator will utilize
electromagnetic and ground-penetrating radar (GPR) methods to locate and demark subsurface
anomalies in the vicinity of the proposed boring locations. Additionally, soil boring locations
will be hand cleared to approximately 5 feet below ground surface (ft bgs) prior to use of
mechanical drilling equipment to further screen the boring locations for the presence of
subsurface utilities.
In accordance with Mecklenburg County regulations, H&H will also obtain a Subsurface
Investigation Permit (SIP) from Mecklenburg County prior to temporary monitoring well
installation and sampling. After completion of the activities, H&H will update the SIP and
provide the County with temporary monitoring well abandonment records provided by a North
Carolina licensed driller.
2.1 Receptor Survey
H&H will perform a Brownfields receptor survey in accordance with DEQ Brownfields Section
guidance. The receptor survey will include information about land use in the Site area, including
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zoning. H&H will also conduct a field search for water supply wells, basements, utility
manways and chases, storm sewers, other underground utilities, drains, and surface water within
a 1,500 ft radius of the Brownfield property boundary. In addition, H&H will review the online
Mecklenburg County Well Information System for potential wells in the area and, if warranted,
contact utility companies for information concerning underground utilities in the immediate area
of the Site. The receptor survey will be completed using the most current version of the
Brownfields Property Receptor Survey template form.
2.2 Soil Sampling Activities
H&H will conduct soil sampling as part of the Brownfields assessment activities. The purpose
of the soil sampling will be to evaluate potential impacts in areas that may be disturbed during
planned redevelopment and grading activities and to further evaluate general Site conditions. As
requested by the DEQ Brownfields Redevelopment Section during the October 24, 2023 kick-
off/data gap meeting, a soil sample (HHSB-3) will be collected near the location of prior soil
sample SB-1. Locations of the proposed soil borings are shown in Figure 3; and the soil sample
depths, objectives, and laboratory analyses are summarized in Table 1.
H&H will team with a qualified drilling contractor to advance five (5) soil borings (HHSB-1
through HHSB-5) in the southern portion of the Site and one (1) soil boring (HHSB-6) in the
northern portion of the Site for the purpose of soil sample collection. The soil borings will be
advanced to a depth of approximately 5 ft bgs using a decontaminated stainless-steel hand auger.
Additionally, a concrete core drill or drill rig capable of direct push technology (DPT) will be
used to initially penetrate concrete at certain soil boring locations. During boring advancement,
soil will be logged for lithological description and field screened for indications of potential
impacts by observation for obvious staining, unusually odors, and the presence of volatile
organic vapors using a calibrated photoionization detector (PID). Soil samples will be collected
from the depth interval that exhibits the highest potential for impact. If significant impact is not
expected based on the results of field screening, the soil samples will be collected from the
surficial depth interval (i.e., 0-2 ft bgs) due to the likelihood of disturbance during future
redevelopment and grading.
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The soil samples selected for laboratory analysis will be placed directly into dedicated laboratory
supplied sample containers, labeled with the sample identification, date, and requested analysis,
and placed in a laboratory supplied cooler with ice. Soil samples will be submitted to a North
Carolina certified laboratory under standard chain of custody protocols for analysis of VOCs by
EPA Method 8260, SVOCs by EPA Method 8270, RCRA metals by EPA Methods 6020/7471,
and hexavalent chromium by EPA Method 7199. Metal concentrations will be compared to
background concentrations reported in literature and at other nearby Brownfields properties, if
available.
Following sampling activities, the soil borings will be properly abandoned and surfaces will be
patched similar to pre-drilling conditions. Additionally, the soil sample locations will be
estimated using a hand-held global positioning system (GPS) unit. In the event that the GPS unit
cannot achieve sub-meter accuracy (i.e., due to multipath errors or other signal obstruction), the
soil sample locations will be estimated by measuring from known benchmarks.
2.3 Groundwater Sampling Activities
H&H will contract a qualified drilling contractor to further advance three (3) of the soil borings
located at the Site for installation of three (3) temporary groundwater monitoring wells
(HHTMW-1 through HHTMW-3). The purpose of the temporary groundwater monitoring wells
will be to further evaluate groundwater conditions and to prepare a groundwater potentiometric
map for the Site. Locations of the proposed temporary monitoring wells are shown in Figure 3;
and anticipated well depths, objectives, and laboratory analyses are summarized in Table 1.
The temporary groundwater monitoring well borings will be advanced to approximate depths of
20 to 25 ft bgs or until drill rig refusal is encountered using a decontaminated stainless-steel hand
auger and a track-mounted drill rig capable of DPT and hollow-stem auger drilling techniques.
As discussed during the October 24, 2023 kick-off/data gap meeting, additional groundwater
analytical data is not critical for this Site. Therefore, in the event that drill rig refusal is
encountered above the water table using DPT and hollow-stem auger drilling methods,
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groundwater samples will not be collected from these locations.
During drilling, soil cuttings will be collected and logged for lithologic description and field
screened for the presence of obvious staining, unusual odors, and elevated volatile organic
vapors using a calibrated PID. Should obvious evidence of vadose zone soil impacts be observed
based on field screening results, a soil sample will be collected for laboratory analysis using the
aforementioned parameters.
The temporary groundwater monitoring wells will be constructed with 15 ft sections of pre-
packed well screen set to bracket the water table and 2-inch diameter polyvinyl chloride (PVC)
well casing to the ground surface. A sand filter pack will be placed from the bottom of the
borings to approximately 2 ft above the top of the well screens. The temporary wells will be
completed by placing a minimum of an approximately 2 ft thick hydrated bentonite seal above
the sand filter pack.
Once the temporary monitoring wells are installed, the groundwater within the wells will be
allowed to equilibrate to static condition, and a decontaminated electronic water level indicator
will be used to measure the depth to the water table relative to the ground surface and tops of
well casings in each well. The wells will then be developed by removing a minimum of 3
volumes and until field parameters have stabilized (pH± 0.1 Standard Units [SU] and
conductivity varies no more than 5%).
After development, the temporary monitoring wells will be allowed to equilibrate to static
condition for a minimum of 24 hours prior to collection of groundwater samples. Groundwater
samples will be collected utilizing low flow/low stress purging techniques using a peristaltic
pump and dedicated polyethylene tubing. The intake point of the pump tubing will be placed in
the approximate mid-portion of the screened interval of the groundwater column, and
groundwater will be removed at a rate no greater than 200 milliliters per minute (mL/min).
H&H will utilize a calibrated water quality meter to collect measurements of pH, temperature,
dissolved oxygen, oxidation reduction potential, turbidity, and specific conductivity at three to
five-minute intervals during the purging process. Purging will be considered complete when the
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field parameters stabilize (pH ± 0.1 SU, conductivity varies no more than 5%, and turbidity is
less than 10 Nephelometric Turbidity Units [NTUs]), if practical.
Once groundwater parameters stabilize, groundwater samples for VOC analysis will be collected
directly into laboratory supplied sample containers using the “soda straw” method to eliminate
the potential for volatile compound loss through the pump head. Samples for the remaining
analyses will be collected directly into laboratory supplied sample containers from the dedicated
sample tubing discharge. The sample containers will be labeled with the sample identification,
date, time, and requested analysis, and placed in a laboratory supplied cooler with ice. The
groundwater samples will be delivered to a North Carolina certified laboratory under standard
chain of custody protocols for analysis of VOCs by EPA Method 8260, SVOCs by EPA Method
8270, and RCRA metals by EPA Methods 6020/7471.
If groundwater is encountered in each of the three (3) temporary monitoring wells, H&H will
utilize surveying techniques to estimate the top of casing elevation and ground surface elevation
at each temporary monitoring well. H&H will use the measured depths to groundwater and
relative top of casing elevations to estimate the potentiometric surface and groundwater flow
direction at the Site. In addition, the groundwater sample locations will be estimated using a
hand-held GPS unit. If groundwater is not encountered in one or more of the temporary
monitoring wells, development of a potentiometric map will not be possible, and H&H will infer
the direction of groundwater flow at the Site based on available historical data for the Site area
and topographic considerations. Following sampling and estimating groundwater elevations, the
temporary monitoring wells will be properly abandoned by a licensed well driller and the
surfaces will be patched similar to pre-drilling conditions.
2.4 Soil Gas Sampling Activities
To evaluate the potential for structural vapor intrusion into the proposed future buildings in the
southern portion of the site, H&H will install and sample five (5) temporary soil gas monitoring
points at the Site (HHSG-1 through HHSG-5). Additionally, H&H will install and sample one
(1) temporary soil gas monitoring point (HHSG-6) in the northern portion of the Site to evaluate
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soil gas conditions in the vicinity of previously identified chlorinated solvents in groundwater.
Locations of the proposed temporary soil gas monitoring points are shown in Figure 3; and the
sample depths, objectives, and laboratory analyses are summarized in Table 1.
The temporary soil gas monitoring points will be installed at depths of approximately 6 ft bgs
using a decontaminated stainless-steel hand auger. During boring advancement, soil cuttings
will be collected and logged for lithologic description and field screened for the presence of
obvious staining, unusual odors, and elevated volatile organic vapors using a calibrated PID.
Should obvious evidence of vadose zone soil impacts be observed based on field screening
results, a soil sample will be collected for laboratory analysis using the aforementioned
parameters. The temporary soil gas monitoring points will be installed by placing an
approximate 6-inch stainless steel vapor implant screen attached to Teflon® sample tubing at the
base of each borehole. Annular space around the vapor implant screens will be filled with filter
sand to a depth of approximately 6 inches above the vapor screen. Following installation of the
sand, hydrated bentonite will be installed in the boring from the top of the sand to near the
ground surface. An airtight cap will then be placed on the end of the Teflon® sample tubing and
the temporary soil gas monitoring points will be allowed to equilibrate for a minimum of 24
hours after installation prior to sample collection.
The soil gas samples will be collected utilizing laboratory supplied Summa® canisters (1 or 3-
Liter canisters depending on laboratory availability) connected to an air-flow regulator calibrated
by the laboratory to collect the soil gas sample at a rate of approximately 100 mL/min. Prior to
collection of the soil gas samples, a “shut-in” test will be conducted on the sampling train and
helium leak checks will be conducted at each soil gas sampling point. The shut-in test and
helium leak check are conducted to check that short circuiting with ambient air does not occur
during sampling. A description of the shut-in test and helium leak testing procedures is provided
below.
The shut-in test will be conducted by connecting the flow regulator with the vacuum gauge to the
Summa® canister and sealing the flow regulator with the laboratory provided brass cap. Once
the sampling train is “closed”, the sample valve on the Summa® canister will be opened and the
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reading on the vacuum gauge will be recorded. The Summa® canister sample valve will then be
closed, and the vacuum gauge will be observed to ensure no vacuum loss occurs. If the vacuum
reading remains the same, the shut-in test will be considered successful. If vacuum loss occurs,
the flow regulator and/or brass cap will be reseated and the shut-in test will be repeated until the
vacuum reading remains stable.
Following the shut-in test, the Summa® canister will be connected to the sample point via
Teflon® sample tubing using a brass nut and ferrule assembly to create an airtight seal and the
leak check will be performed. The leak check will be performed by constructing a shroud over
the sampling train, including the canister, and flooding the shroud with helium gas. A calibrated
helium gas detector will be utilized to measure helium concentrations within the shroud. Once
helium concentrations stabilize within the shroud, the sample tubing will be purged outside of
the shroud using a syringe and a three-way valve to collect purged soil gas into a Tedlar® bag.
The purged soil gas will then be analyzed using the helium gas detector to ensure that helium
concentrations in the soil gas point are less than 10% of the helium concentrations measured
within the shroud.
Following successful leak checks, the soil gas samples will be collected. Vacuum readings on
the Summa® canisters will be recorded prior to and following the sampling period to ensure
adequate sample volume was collected. In accordance with DEQ DWM Vapor Intrusion
guidance, a vacuum of approximately 5 inches of mercury will be maintained within the
canisters at the conclusion of the sampling event.
Following sample collection, the Summa® canisters will be placed in laboratory supplied
shipping containers, properly labeled, and shipped under standard chain-of-custody protocols to
a qualified laboratory for analysis of VOCs by EPA Method TO-15. The laboratory will be
requested to use reporting limits that are below DEQ DWM Residential Soil Gas Screening
Levels (SGSLs). The sample locations will be estimated using a hand-held GPS unit and the soil
gas monitoring points will be abandoned and the surfaces will be patched similar to pre-drilling
conditions.
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2.5 Sub-Slab Vapor Sampling Activities
To further evaluate the potential for structural vapor intrusion into the proposed future buildings,
H&H will also collect one sub-slab vapor sample (HHSSV-1) in the parking office located on the
ground floor of the existing parking garage. The location of the proposed sub-slab vapor sample
is shown in Figure 3; and the objectives and laboratory analyses are summarized in Table 1.
The sub-slab vapor sampling point will be installed using a rotary hammer drill and 1½-inch
diameter drill bit to advance a pilot hole into the concrete slab to a depth of approximately 1¾
inches below the slab surface. A drill guide will then be placed within the pilot hole, and a ⅝-
inch diameter drill bit will be utilized to advance a boring through the concrete slab and
approximately 6 inches into the underlying soil. Following borehole advancement, loose
concrete cuttings will be removed from the boring, and a Cox-Colvin Vapor Pin™ (vapor pin)
assembly (brass sampling point and silicone sleeve) will be seated in the borehole using an
installation/extraction tool and dead blow hammer to form an airtight seal. An airtight cap will
then be placed on the vapor pin. The sub-slab vapor sampling point will be allowed to
equilibrate for a minimum of 2 hours after installation prior to sample collection.
The sub-slab vapor sample will be collected utilizing a laboratory supplied Summa® canister (1
or 3-Liter canister depending on laboratory availability) connected to an air-flow regulator
calibrated by the laboratory to collect the sub-slab vapor sample at a rate of approximately 100
mL/min. Prior to collection of the sub-slab vapor sample, a “shut-in” test will be conducted on
the sampling train and a helium leak check will be conducted at the sub-slab vapor sampling
point. The shut-in test and helium leak check will be conducted in accordance with the
procedures described in Section 2.4.
Following a successful leak check, the sub-slab vapor sample will be collected. Vacuum
readings on the Summa® canister will be recorded prior to and following the sampling period to
ensure adequate sample volume was collected. In accordance with DEQ DWM Vapor Intrusion
guidance, a vacuum of approximately 5 inches of mercury will be maintained within the canister
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at the conclusion of the sampling event.
Following sample collection, the Summa® canister will be placed in a laboratory supplied
shipping container, properly labeled, and shipped under standard chain-of-custody protocols to a
qualified laboratory for analysis of VOCs by EPA Method TO-15. The laboratory will be
requested to use reporting limits that are below DEQ DWM Residential SGSLs.
After sample collection, the vapor pin will be removed from the building slab and the surface
will be patched similar to pre-drilling conditions. The sample location will be estimated using a
hand-held GPS unit. If the sub-slab vapor sample location cannot be estimated using a GPS unit
(i.e., due to signal interference associated with existing structures), H&H will estimate the
sample location by measuring from known benchmarks.
2.6 Quality Assurance – Quality Control
Non-dedicated equipment and tools will be decontaminated prior to use at each boring or
sampling location or following exposure to soil or groundwater. The following samples will be
collected for quality assurance/quality control (QA/QC) purposes:
• one duplicate soil sample and one duplicate groundwater sample will be collected and
analyzed for the same parameters as the parent samples;
• one trip blank will accompany the groundwater samples during the field activities as well
as during sample shipment and will be analyzed for VOCs by EPA Method 8260; and
• one duplicate soil gas or sub-slab vapor sample will be collected for analysis of VOCs by
EPA Method TO-15 using a laboratory supplied “t-fitting” which allows for two samples
to be collected from one sampling point simultaneously.
Laboratory QA/QC procedures will be employed for appropriate sample handling and analysis
and to aid in the review and validation of the analytical data. QA/QC procedures will be
conducted in accordance with the method protocols and will include regular equipment
maintenance, equipment calibration, and adherence to specific sample custody and data
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management procedures. Samples will be analyzed in conjunction with appropriate blanks,
laboratory duplicates, continuing calibration standards, surrogate standards, and matrix spiking
standards in accordance with approved methodologies to monitor both instrument and analyst
performance. Laboratory reporting limits for each analyte will be at or below appropriate
screening criteria, where possible. Additionally, H&H will request that the laboratory include
estimated concentrations for compounds that are detected at levels above the laboratory method
detection limit, but below the laboratory reporting limit (J flags).
The laboratory analytical data report and QA package for each group of samples submitted to
and analyzed by the subcontracted laboratory will be provided in an appendix to the final report.
Laboratory QA data consistent with Level II documentation will be provided for this project.
A copy of the completed chain of custody record will be appended to the corresponding
laboratory analytical report included with the final report.
2.7 Investigation Derived Waste
IDW generated during the proposed assessment activities will be managed in general accordance
with DEQ IHSB Guidelines, including 15A NCAC 02T.1503 and 15A NCAC 02H.0106. Based
on the results of previous Phase II ESA activities conducted at the Site, hazardous waste is not
likely to be encountered during the assessment activities. Therefore, IDW generated during the
assessment activities will be thin spread on-Site. However, if significant impacts are suspected
(i.e., free-product), the impacted media will be containerized in labeled 55-gallon drums and
staged on-Site pending analytical results of a composite IDW sample. Based on laboratory
analytical results of IDW samples, the drums would then be transported off-Site to a suitable
facility for disposal.
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3.0 Reporting
Following completion of the assessment activities and receipt of the analytical data, H&H will
document our findings in a Brownfields Assessment Report. The report will include a
description of the sampling activities; a figure depicting sample locations; boring logs for the soil
borings, temporary monitoring well borings, and soil gas monitoring points; temporary
monitoring well and temporary soil gas monitoring point construction logs; groundwater
sampling logs; laboratory analytical data; a discussion of the data in comparison to regulatory
screening levels; and conclusions and recommendations concerning our activities. For the soil
gas and sub-slab vapor results, H&H will use the most recent version of the NC DEQ risk
calculator to further evaluate potential risks based on the data, if needed. The report will also
include the firm’s professional license numbers and an individual professional seal and signature.
06/07/2024
Table
Table 1
Proposed Sample Summary Table
Charlotte Supply Co.
410 S. Mint Street
Charlotte, North Carolina
Brownfields Project No. 27024-23-060
H&H Project No. AGI.003
HHSB-1 through HHSB-6 Soil Evaluate Soil Conditions 5 varies 6 VOCs (8260), SVOCs (8270), RCRA Metals (6020/7471), and hexavalent
chromium (7199)
HHTMW-1 through HHTMW-3 Groundwater Temporary Wells to Evaluate Groundwater
Conditions 25 10-25 3 VOCs (8260), SVOCs (8270), and RCRA Metals (6020/7471)
HHSG-1 through HHSG-6 Soil Gas Evaluate Potential VI Risks 6 5.5-6 6 VOCs (TO-15) - Batch Certified Canisters
HHSSV-1 Sub-Slab Vapor Evaluate Potential VI Risks vapor pin vapor pin 1 VOCs (TO-15) - Batch Certified Canister
SB-DUP Duplicate Soil Sample Quality Control Check Duplicate Duplicate 1 VOCs (8260), SVOCs (8270), RCRA Metals (6020/7471), and hexavalent
chromium (7199)
GW-DUP Duplicate Groundwater Sample Quality Control Check Duplicate Duplicate 1 VOCs (8260), SVOCs (8270), and RCRA Metals (6020/7471)
SG-DUP or SSV-DUP Duplicate Soil Gas or Sub-Slab
Vapor Sample Quality Control Check Duplicate Duplicate 1 VOCs (TO-15) - Batch Certified Canister
Trip Blank Trip Blank Quality Control Check NA NA 1 VOCs (8260)
Notes:
The EPA method number follows the laboratory parameter in parentheses in the table above.
VOCs = Volatile Organic Compounds; SVOCs = Semi-VOCs; RCRA = Resource Conservation and Recovery Act
ft = feet; QA/QC = Quality Assurance/ Quality Control; VI = Vapor Intrusion; NA = not applicable
Laboratory AnalysisSample IDs Sample Type Sample Objective Approximate Boring
Depth (ft)
Approximate
Sample Depth (ft)
Number of
Samples
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Table 1 (Page 1 of 1)
Hart & Hickman, PC
Figures
SITE LOCATION MAP
CHARLOTTE SUPPLY CO.410 S. MINT STREET CHARLOTTE, NORTH CAROLINA
DATE: 10-16-23
JOB NO: AGI-003
REVISION NO: 0
FIGURE. 1
2923 South Tryon Street - Suite 100
Charlotte, North Carolina 28203
704-586-0007 (p) 704-586-0373 (f)
License # C-1269 / # C-245 Geology
TITLE
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JOB NO. AGI-003
DATE: 10-16-23
FIGURE NO. 2
CHARLOTTE SUPPLY CO.410 S. MINT STREET
CHARLOTTE, NORTH CAROLINA
SITE MAP
LEGEND
SITE PROPERTY BOUNDARY
PARCEL LINE
EXISTING PARKING OFFICE AREA
SOIL BORING LOCATION (S&ME; 2022)
CO-LOCATED SOIL BORING AND
TEMPORARY MONITORING WELL
LOCATION (S&ME; 2022)
NOTES:
1. AERIAL IMAGERY AND BASE DATA OBTAINED FROM
MECKLENBURG COUNTY GIS, 2023.
2923 South Tryon Street-Suite 100
Charlotte, North Carolina 28203
704-586-0007(p) 704-586-0373(f)
License # C-1269 / #C-245 Geology
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DATE: 11-1-23
FIGURE NO. 3
CHARLOTTE SUPPLY CO.
410 S. MINT STREET
CHARLOTTE, NORTH CAROLINA
PROPOSED SAMPLE LOCATION MAP
LEGEND
SITE PROPERTY BOUNDARY
PARCEL LINE
EXISTING PARKING OFFICE AREA
SOIL BORING LOCATION (S&ME; 2022)
CO-LOCATED SOIL BORING AND
TEMPORARY MONITORING WELL
LOCATION (S&ME; 2022)
PROPOSED CO-LOCATED SOIL
SAMPLE AND TEMPORARY
MONITORING WELL LOCATION
PROPOSED SHALLOW SOIL SAMPLE
PROPOSED SOIL GAS OR SUB-SLAB
VAPOR SAMPLE LOCATION
PROPOSED RETAIL - GROUND FLOOR
PROPOSED RESIDENTIAL TOWER 1 -
GROUND FLOOR
PROPOSED RESIDENTIAL TOWER 2 -
GROUND FLOOR
NOTES:
1. AERIAL IMAGERY AND BASE DATA OBTAINED FROM
MECKLENBURG COUNTY GIS, 2023.
2923 South Tryon Street-Suite 100
Charlotte, North Carolina 28203
704-586-0007(p) 704-586-0373(f)
License # C-1269 / #C-245 Geology
SB-1
SB-2\GW-2
SB-4
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HHSG-2
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Work Plan and Report Checklist
Version 3 March 2023
Minimum Requirements Checklist Site Assessment Work Plans and Reports NCDEQ Brownfields Redevelopment Section– March 2023 Instructional Page
All references to Prospective Developers include follow-on owners who may be conducting work in accordance with the Brownfields Property Management Branch.
To increase predictability and most efficiently assess Brownfields Properties and the redevelopment timing requirements of Prospective Developers or follow-on owners, the Brownfields Redevelopment Section has standardized the format for Site Assessments. This
format has been generated in the form of a checklist to allow for ease in submission by the
prospective developer’s consultant and for the Brownfields Redevelopment Section’s completeness review. This checklist outlines the minimum requirements and submittal format under the Brownfields Redevelopment Section for Assessment Requirements and Reporting. All Assessment Work Plans and Report submissions to the Brownfields Redevelopment Section must
include this completed checklist in the outlined format.
These requirements allow DEQ to reduce review time for the Assessment Work Plan and Report and increase process predictability for prospective developers. This checklist will also provide reliable data for risk-based decisions and further expedite the project timeline. Any divergence from these requirements will lengthen the process of assessing risks on the site, may necessitate
reprioritization of a project manager’s queue towards projects that meet these requirements.
Therefore, delaying production of the brownfields agreement and/or environmental management plan. Any alterations to the checklist on a site-specific basis must be reviewed and approved by the Section prior to implementation. However, in order to respect the schedule of all projects in house and keep the Section’s entire project pipeline moving, we strongly recommend against
seeking changes to the checklist.
Based on a review of environmental and risk data from our project inventory, please note there are some new points of emphasis that are included herein:
1. For ALL residential reuses; sub-slab vapor assessment (full list EPA TO-15) is required, regardless if existing structures will be removed. If no structures or slabs exist on the Brownfields Property, exterior soil gas assessment is required within all proposed
structure footprints.
2. ALL properties require groundwater data (VOCs, SVOCs and RCRA Metals) from a
minimum of three sample locations, depth to groundwater and a resulting potentiometric map. 3. Soil shall be assessed based on areas of concern and redevelopment plans and across the depth interval of the cut/grading.
Work Plan and Report Checklist
Version 3 March 2023
Environmental Site Assessment Work Plan Checklist Reviewed and checked by (Name): Carolyn Minnich, Brownfields Redevelopment Section
Title Page
The title page should include the following information. Letter style reports are acceptable, as long as
this information is somewhere on the first page.
☒ Title of Work Plan
☒ Brownfields Project Name (not the development name)
☒ Brownfields Project Number
☒ Date (updated with each revision)
☒ Revision Number
☒ Firm PE/PG License Number
☒ Individual PE/PG seal & signature
Section 1 – Introduction
☒ Provide the site location, address, and acreage.
☒ Provide a BRIEF summary of the history of the property and its history in the Section. For example:
reiterate RECs from a Phase I ESA, indicate if the scope of work was negotiated during a Data
Gap Meeting, etc.
☒ Briefly list and describe the data gaps the assessment is attempting to fill
☒ Indicate if the assessment data is for the use of any other DEQ programs in addition to the
Brownfields Redevelopment Section (i.e. the site is a regulated UST, IHSB, etc. property)
Section 2 – Scope of Work
☒ Provide a general description of proposed scope of work covered in this plan (i.e. 2 new monitoring
wells, 6 groundwater samples, 5 exterior soil gas sampling points and 6 soil borings)
☒ Discuss samples to be collected by media and source area/location. Generally, the reasoning for the
sample locations selected.
☒ Describe depths of samples to be collected (Reference Table 1) or how that decision will be made
in the field, if needed.
☒ State for what each sample will be analyzed (briefly). Reference Table 1.
Note: For all residential reuses, sub slab vapor is required, if no slabs exist, exterior soil gas is required within all proposed footprints.
Section 3 – Sampling Methodology
☒ Reference the guidance documents you intend to use. IHSB, EPA SESD, VI Guidance, Well
Construction Rules (NCAC 2C). Note deviations or methodology planned that is not covered by
Work Plan and Report Checklist
Version 3 March 2023
such guidance (e.g., multi-increment sampling, passive air samplers, mobile labs, Hapsite, simultaneous indoor/outdoor radon, high-volume sub-slab vapor testing, PFAS sampling).
☒ Describe what will be installed (soil boring, temporary well, permanent well, sub-slab vapor, exterior
soil gas, etc.). Include construction details.
☒ Discuss installation methodology (Hand Auger, DPT, etc.) Discuss Equilibration Times
• Monitoring wells (equilibration time prior to development and equilibration post well development should be 24 hours, per EPA standard protocols).
• Vapor: a. Sub slab vapor with minimally invasive points (e.g. Vapor Pins): Manufacturer’s guidelines generally suggest 20 minutes may be sufficient with an airtight cap installed;
or b. Sub slab vapor points (other than minimally invasive points) or exterior soil gas points: at least 24 hours (to be purged at installation and at time of sampling with an
air-tight cap in place in the interim).
☒ Discuss sample collection procedures. Include the following, at a minimum:
• Equipment to be used
• Purging methods and volumes
• Stabilization parameters for groundwater sampling
• Field screening methods
• Leak check procedures for sub-slab vapor and exterior soil gas samples (Note this is
required)
• Discuss how and when vacuum readings will be collected (for summa cans)
• Submission of the samples to the laboratory within 48 hours of collection and/or written
documentation of temperature maintenance if the situation requires extension beyond 48
hours prior to lab submittal
☒ Discuss sample point abandonment
Section 4 – Laboratory Analyses
☒ Discuss the proposed analyses (include method number, preparation method, if there are concerns
with short hold times, etc).
☒ Discuss any proposed limitations on the contaminants of concern, if any, and the reason for such
limitation (sufficient previous data, indoor air interferences, etc).
☒ Discuss laboratory certifications. Please note, NC does not certify labs for air samples. Please
specify what certification the proposed air lab holds.
☒ Indicate that the Reporting Limits/Method Detection Limits will meet applicable screening criteria
(to the extent feasible). Include reporting of J-Flags to meet criteria.
☒ Indicate what Level QA/QC will be reported by the laboratory. Level II QA/QC is typically
acceptable.
Section 5 – QA/QC
☒ Specify the duplicate sample frequency. Minimum requirement: 1 duplicate per 20 samples, per
media, per method.
☒ Discuss Trip Blank. 1 Trip Blank per cooler/shipment of groundwater VOC analyses is required.
☒ Discuss how the lab will have sufficient sample volume for MS/MSD analyses.
Work Plan and Report Checklist
Version 3 March 2023
☒ Discuss chain of custody and shipping.
Section 6 – Investigation Derived Waste (IDW) Management
☒ Discuss what IDW will be generated and how it is proposed to be managed. Management
recommendations should be in accordance with 15A NCAC 02T.1503 and 15A NCAC 02H.
0106. Generally, if the Brownfields Property has not previously been assessed, then all IDW
must be containerized and characterized prior to management. Previous assessment data that
indicate no Hazardous Waste (listed or characteristic) is likely to be encountered in the area of
proposed assessment will be required before thin spreading of IDW on-site is permitted.
Section 7 – Reporting
This section should discuss the components of the assessment report which will be prepared as a result
of the above sample collection. At a minimum, the report shall include:
☒ Title Page that is consistent with the requirements listed above.
☒ Reporting/summary of site work conducted for all sections outlined above in this checklist;
☒ Summary of findings and possible recommendations;
☒ All applicable tables and figures (shall include at a minimum the items below)
☒ Tables for tabulated analytical data per media sampled and analyzed, compared against
applicable screening levels, sample depths and depth to groundwater;
☒ Figure depicting actual sample locations collected, with each media depicted in the
legend, graphic scale and north arrow; and
☐ Groundwater potentiometric map, with graphic scale and north arrow.
☒ Appendices shall include (as applicable):
☒ Copies of field notes
☒ Boring logs for all soil borings, newly constructed monitoring wells, and exterior soil gas locations
☒ Well construction and abandonment records
Work Plan Approval Signature Page (see Attachment 1). The Consultant shall complete and submit the Approval Signature Page with the work plan submittal for DEQ signature.
Work Plan and Report Checklist
Version 3 March 2023
Attachments
☒ Attachment 1 – Work Plan Approval Signature Page
☒ Table 1 – Proposed Sample Locations and Analyses on a Summary Table that includes:
☒ Sample ID
☒ Sample Objective
☒ Proposed Depth(s)
☒ Analytical Method(s)
☒ QA/QC Samples
☐ Background Samples
☒ Figure 1 – Site Location Map
☒ Site location on a topographic map base
☒ Graphic scale and north arrow
☒ Figure 2 – Site Map should include the following
☒ Buildings
☒ Historical sample locations
☐ RECs or other areas of concern
☒ Proposed sample locations
☒ Sample identification labels
☐ Background samples
☐ QA/QC samples
☒ Graphic scale and north arrow
☒ High quality aerial suggested as the base map
☐ Figure 3 – Site Potentiometric Map that includes the following
☐ Buildings
☐ Groundwater sample identification labels
☐ Arrow noting direction of groundwater flow
☐ Graphic scale and north arrow
☐ Figure 4 – Site Plume Maps (groundwater, soil vapor, etc.)
☒ Figure 5 – Proposed Development (if available)
☒ Overlay of historical and proposed sample locations
☒ Graphic scale and north arrow
☐ Appendix – Summary of Historical Analytical Data (if needed) – to include tables and figures only.