HomeMy WebLinkAbout21048 Wepak AWP 2018.08.27hart hickman
SMARTER ENVIRONMENTAL SOLUTIONS
Via Email
August 27, 2018
North Carolina Department of Environmental Quality
Division of Waste Management — Brownfields Program
1646 Mail Service Center
Raleigh, North Carolina 27699-1646
Attn: Ms. Caroline Goodwin
Re: Supplemental Brownfields Assessment Work Plan — Revision 1
Wepak Corporation
314 and 332 W. Bland Street
Charlotte, North Carolina
Brownfields Project No. 21048-17-060
H&H Job No. MGN-001
Dear Caroline:
1.0 Introduction and Background
On behalf of 332 West Bland Street, LLC (Prospective Developer or PD), Hart & Hickman, PC
(H&H) has prepared this Supplemental Brownfields Assessment Work Plan (Work Plan) to conduct
additional environmental assessment activities at the Wepak Corporation (Wepak) Brownfields
property (Brownfields Project No. 21048-17-060) located at 332 W. Bland Street in Charlotte,
Mecklenburg County, North Carolina (Site or subject Site). The subject Site consists of one
approximately 1.33-acre parcel of land located in a mixed commercial and residential area of South
End Charlotte. A Site location map is provided as Figure 1.
The central portion of the Site is improved with an approximately 29,000 square foot (sq ft) building
constructed in 1920 and an approximately 4,000 sq ft warehouse addition that was constructed on
the southeastern side of the original 1920 building in the late 1970s. The northern portion of the Site
is improved with an approximately 15,500 sq ft building constructed in the late 1950s and an
approximately 9,000 sq ft warehouse addition was constructed in the north -central portion of the Site
in the late 1980s and connects the original 1920s facility to the 1950s commercial building. The Site
2923 5outh Tryon Street, Suite 100 3921 Sunset Ridge Rd, 5uite 301
Charlotte, NC 28203 Raleigh, NC 27607 www.harthickman.com
704.586.0007 main 919.847.4241 main
Ms. Caroline Goodwin
August 27, 2018
Page 2
buildings are currently being renovated to include a multi -tenant commercial building. A Site map
is included as Figure 2.
The Site buildings have historically included multiple occupants, including a truck and bus repair
shop from the 1920s until the late 1950s, an electrical switchboard and electrical switch
manufacturing facility from the 1920s until the mid-1960s, a carwash, and an auto parts and oil
storage warehouse from the 1960s until the mid-1970s. Wepak Corporation began chemical
manufacturing operations in the southern portion of the original 1920s building in the mid-1970s. By
the mid-1980s, Wepak operations occupied remaining portions of the facility including the
additional warehouse buildings constructed in the 1970s and 1980s. Wepak Corporation operations
discontinued in 2018 and the chemical manufacturing equipment has been removed from the Site.
In July 2017, H&H completed Phase I Environmental Site Assessment (ESA) activities at the Site as
part of property transaction due diligence. Results of the July 2017 Phase I ESA identified potential
environment conditions in connection with historical uses at the Site including automotive repair
operations, electrical switch manufacturing, manufacturing of janitorial cleaning supplies, and
former underground storage tanks (USTs). In addition to historical on -Site uses, historical uses on
several nearby off -Site properties were also identified as potential environmental concerns for the
Site.
The Site received eligibility into the North Carolina Department of Environmental Quality (DEQ)
Brownfields Program via a Letter of Eligibility dated October 25, 2017. On November 14, 2017,
H&H attended a meeting with DEQ Brownfields personnel to discuss Site history, areas of potential
environmental concern, proposed redevelopment plans for the Site, potential data gaps, and the
scope of Brownfields assessment activities to evaluate the Site for potential impacts. H&H
subsequently prepared a Brownfields Assessment Work Plan — Revision 1 outlining proposed
assessment activities which received DEQ Brownfields approval in an email dated January 16, 2018.
S:\AAA-Master ProjectsWagnus Capital Partners (MGN)\314 W. Bland Street\Supplemental Brownfields
Assessment\Supplmental Brownfields Assessment Work Plan Revl_Wepak Corporation (BPN 21048-17-
060)_20180827.doc
hart hickman
SMARTER ENVIRONMENTAL SOLUTIONS
Ms. Caroline Goodwin
August 27, 2018
Page 3
In March 2018, H&H completed soil and groundwater assessment activities at the Site in accordance
with the DEQ approved January 2018 Work Plan to evaluate for impacts in areas of potential
concern identified during the July 2017 Phase I ESA activities and the November 2017 data gap
meeting. The Brownfields assessment activities are documented in our Brownfields Assessment
Report dated May 11, 2018. A brief summary of the Brownfields soil and groundwater assessment
activities is provided below.
• Results soil assessment activities identified arsenic (up to 17 mg/kg) at concentrations
exceeding DEQ Inactive Hazardous Sites Branch (IHSB) Industrial/Commercial Preliminary
Soil Remediation Goal (PSRG) of 3.0 mg/kg in the soil sample collected in the area of the
former electrical switchboard manufacturing facility (SB-6) and adjacent to the former bulk
chemical storage above ground storage (AST) secondary containment system (SB-8). Lead
was also detected above the Industrial/Commercial screening criteria of 800 mg/kg in the
SB-6 (2,900 mg/kg) soil sample collected near the former electrical switchboard
manufacturing facility. However, lead concentrations were detected at 9,300 mg/kg in the
SB-6 duplicate soil sample due to heterogeneity of shallow soil in the area near the former
switch manufacturing operations. No other compounds were detected in Site soil at
concentrations exceeding the Industrial/Commercial PSRGs.
Because the lead and arsenic concentrations exceed the Industrial/Commercial PSRGs in the
former electrical switch manufacturing area and because of the discrepancy in lead
concentrations in the SB-6 parent soil sample and its duplicate soil sample, DEQ requested
collection of an additional soil sample from the former electrical switch manufacturing area
to confirm the level of arsenic and lead impacts.
• Results of groundwater assessment activities identified trichloroethylene (TCE) at a
concentration of 11 micrograms per liter (µg/L) in groundwater sample TMW-2 collected
downgradient of the former bus repair and Wepak production areas. The detected TCE
concentration in TMW-2 exceeds the DEQ 2L Groundwater Quality Standard (2L Standard)
hart hickman
S:\AAA-Master ProjectsWagnus Capital Partners (MGN)\314 W. Bland Street\Supplemental Brownfields
Assessment\Supplmental Brownfields Assessment Work Plan Revl_Wepak Corporation(BPN 21048-17- SMARTER ENVIRONMENTAL SOLUTIONS
060)_20180827.doc
Ms. Caroline Goodwin
August 27, 2018
Page 4
of 3.0 µg/L and the DEQ Division of Waste Management (DWM) Residential (1.0 µg/L) and
Non -Residential (4.4 µg/L) Vapor Intrusion Groundwater Screening Levels (GWSLs). A
low level of vinyl chloride (0.85 J µg/L) was also detected in the TMW-2 groundwater
sample at a concentration exceeding the 2L Standard of 0.03 µg/L, but below the Residential
and Non -Residential GWSLs of 1.5 µg/L and 25 µg/L, respectively.
Two upgradient groundwater samples also contained volatile organic compound (VOC)
concentrations above 2L Standards and/or GWSLs. Groundwater sample TMW-4 collected
topographically upgradient of the Site building in the southeastern corner of the Site
contained carbon tetrachloride at an estimated concentration of 4.8 J µg/L, which exceeds the
2L Standard of 0.3 µg/L and the Residential GWSL of 4.1 µg/L, but is below the Non -
Residential GWSL of 18 µg/L. Upgradient groundwater sample TMW-5 collected from the
south-central portion of the Site contained benzene and naphthalene at concentrations above
2L Standards, but below the GWSLs. No other compounds were detected at concentrations
exceeding DEQ groundwater screening criteria in the groundwater samples collected at the
Site.
To further evaluate the potential vapor intrusion risk associated with the TCE detection in
groundwater sample TMW-2, H&H calculated cumulative risks using the DEQ risk
calculator and the compound concentrations detected in TMW-2. The calculations for a non-
residential use scenario (planned use of the Site) indicate a cumulative carcinogenic risk
(LICR) of 2.4 x 10-6 and a non -carcinogenic hazard index of 0.51. Risk calculator results
indicate that the cumulative carcinogenic exposure risks are below the acceptable level of
1 x 10-4 and the cumulative non -carcinogenic exposure risks are below the acceptable level
of 1.
Because the source of TICE in groundwater at the Site is unknown and the concentration exceeds the
DEQ DWM Non -Residential Vapor Intrusion GWSL, the Brownfields Program requested additional
evaluation of the vapor intrusion risks. In addition, the Brownfields Program requested additional
hart hickman
S:\AAA-Master ProjectsWagnus Capital Partners (MGN)\314 W. Bland Street\Supplemental Brownfields
Assessment\Supplmental Brownfields Assessment Work Plan Revl_Wepak Corporation(BPN 21048-17- SMARTER ENVIRONMENTAL SOLUTIONS
060)_20180827.doc
Ms. Caroline Goodwin
August 27, 2018
Page 5
evaluation of lead impacted soil in the area of the former electrical switchboard manufacturing
facility. Therefore, H&H proposes to conduct supplemental Brownfields assessment activities at the
Site to further evaluate the potential for impacts and potential exposure risks to future occupants.
The proposed supplemental Brownfields assessment activities are outlined in the following sections.
2.0 Supplemental Brownfields Assessment Activities
H&H proposes conduct Brownfields soil assessment activities in the area of previous soil sample
S13-6 collected near the former electrical switch manufacturing facility. In addition, H&H proposes
to collect sub -slab soil gas samples within the north -central warehouse building to evaluate the
potential for vapor intrusion. The proposed assessment activities will be performed in general
accordance with the DEQ IHSB Guidelines for Assessment and Cleanup dated October 2015, the
DEQ DMW Vapor Intrusion Guidance dated March 2018, and the most recent versions of the U.S.
Environmental Protection Agency (EPA) Region IV Science and Ecosystem Support Division
(SESD) Field Branches Quality System and Technical Procedures guidance.
Prior to conducting field activities, H&H will contact North Carolina 811, the public utility locator
service, to mark subsurface utilities at the Site. In addition, assessment activities are proposed in
shallow soil and will be completed with hand tools to further minimize potential contact with
subsurface utilities.
2.1 Soil Sampling Activities
H&H proposes to collect a soil sample in the vicinity of previous soil sample S13-6 near the former
electrical switch manufacturing area to further evaluate the potential for arsenic and lead impacts in
shallow soil. The location of previous soil sample SB-6 and the proposed soil sample location are
shown on Figure 2.
S:\AAA-Master ProjectsWagnus Capital Partners (MGN)\314 W. Bland Street\Supplemental Brownfields
Assessment\Supplmental Brownfields Assessment Work Plan Revl_Wepak Corporation (BPN 21048-17-
060)_20180827.doc
hart hickman
SMARTER ENVIRONMENTAL SOLUTIONS
Ms. Caroline Goodwin
August 27, 2018
Page 6
The soil boring will be advanced utilizing a decontaminated stainless steel hand auger to a depth of
approximately 3 feet below the ground surface (ft bgs). Continuous soil samples will be collected
from the center of the hand auger and logged for lithological description and field screened for
indication of potential impacts by visual and olfactory observation, and the presence of volatile
organic vapors using a calibrated photoionization detector (PID). Based upon field screening
results, one soil sample will be collected for laboratory analysis from the depth interval interpreted
most likely to be impacted. If there are no obvious indications of potential impact based on field
screening results, then soil sample selected for laboratory analysis will be collected from 0-1 ft bgs
to be consistent with the depth of the previous SB-6 soil sample.
Following collection, the soil sample will be placed in 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 arsenic and lead by EPA
Method 6020.
Upon completion of soil sampling activities, the soil boring will be properly abandoned and the
ground surface will be repaired to generally match pre -sampling conditions. The soil sample
location will be recorded in the field using a hand-held global positioning system (GPS) unit.
2.2 Sub -Slab Soil Gas Sampling Activities
H&H proposes to collect two (2) sub -slab soil gas samples within the warehouse building located in
the north -central portion of the Site to evaluate the potential for structural vapor intrusion. The
proposed sub -slab soil gas sample locations are depicted on Figure 2.
H&H will install a Cox -Colvin Vapor Pin® (vapor pin) at each proposed sub -slab soil gas sample
location. For installation of a vapor pin, a hammer drill with a 5/8-inch diameter bit will be utilized
to penetrate the concrete slab with a drilled pilot hole. The vapor pin assembly (sampling point and
hart hickman
S:\AAA-Master ProjectsWagnus Capital Partners (MGN)\314 W. Bland Street\Supplemental Brownfields
Assessment\Supplmental Brownfields Assessment Work Plan Revl_Wepak Corporation(BPN 21048-17- SMARTER ENVIRONMENTAL SOLUTIONS
060)_20180827.doc
Ms. Caroline Goodwin
August 27, 2018
Page 7
silicone sleeve) will then be placed into the pilot hole and secured using an installation/extraction
tool and a "dead blow" hammer to form an air -tight seal. Once the vapor pin assembly has been
secured in the pilot hole, 1/4-inch diameter Teflon® sample tubing will then be attached to the vapor
pin assembly sample port barb.
After installation of the vapor pins and prior to sample collection, a leak check will be conducted at
each sample location by constructing a shroud around the sampling point and flooding the air within
the shroud with helium gas. Helium within the shroud will be monitored using a helium gas
detector. Using a syringe and three-way valve, the sample point will be purged and then vapor will
be collected outside of the shroud into a Tedlar® bag and analyzed using the helium gas detector to
ensure that helium concentrations are less than 10% of the concentration measured within the
shroud.
Following a successful leak check, the sub -slab soil gas samples will be collected into
laboratory -supplied Summa canisters connected to in -line flow controllers with a laboratory
calibrated vacuum gauge. The flow controller will be connected to the sample tubing at each
sampling point using a brass nut and ferrule assembly to form an air -tight seal. The flow regulator
will be pre-set by the laboratory to regulate the intake rate to approximately 100 milliliters per
minute. Once the sample train is assembled, the intake valve on the canister will be fully opened to
begin collection of the sub -slab soil gas sample. Vacuum readings on the Summa canister will be
recorded prior to and following the sampling period to ensure adequate sample volume was
collected. A vacuum will be maintained within the canisters at the conclusion of the sampling event.
To evaluate the reproducibility of the sample results, one duplicate sub -slab soil gas sample will be
collected using a laboratory -supplied T-sampler which allows collection of two samples from a
single sample port simultaneously.
Upon completion of sample collection, the Summa canister's valve will be closed, and the regulator
will be disconnected from the canister. The canisters will be placed in laboratory -supplied shipping
containers, properly labeled, and shipped under standard chain -of -custody protocols to a qualified
S:\AAA-Master ProjectsWagnus Capital Partners (MGN)\314 W. Bland Street\Supplemental Brownfields
Assessment\Supplmental Brownfields Assessment Work Plan Revl_Wepak Corporation (BPN 21048-17-
060)_20180827.doc
hart hickman
SMARTER ENVIRONMENTAL SOLUTIONS
Ms. Caroline Goodwin
August 27, 2018
Page 8
laboratory for analysis of the select VOCs provided in the table below by EPA Method TO-15. The
laboratory will be requested to use reporting limits that are below DEQ DWM Non -Residential
Vapor Intrusion Sub -slab and Exterior Soil Gas Screening Levels (SGSLs).
Sub Slab Soil Gas Sample Analytes
Acetone Benzene Chloroform 1, 1 -Dichloroethene
cis-1,2-DCE trans-1,2-DCE Diisopropyl Ether Methyl tert-Butyl Ether
Toluene TCE Vinyl Chloride
Notes:
DCE= dichloroethene; TCE = trichloroethene
Upon completion of sampling activities, the sub -slab soil gas sample points will be abandoned and
the surfaces will be repaired similar to pre -drilling conditions. Each sample location will be
estimated by measuring from known benchmarks (e.g. doorways, walls, etc.).
2.2 Quality Assurance — Quality Control
Non -dedicated equipment and tools will be decontaminated prior to use at each sampling location
following exposure to Site media. For quality assurance and quality control purposes (QA/QC), one
duplicate sub -slab soil gas sample will be collected and submitted for the same laboratory analysis
as the parent sample.
Laboratory QA/QC procedures will be employed to ensure 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 calibrations, and adherence to specific sample custody and data 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
Ad
hart hickman
S:\AAA-Master ProjectsWagnus Capital Partners (MGN)\314 W. Bland Street\Supplemental Brownfields
Assessment\Supplmental Brownfields Assessment Work Plan Revl_Wepak Corporation(BPN 21048-17- SMARTER ENVIRONMENTAL SOLUTIONS
060)_20180827.doc
Ms. Caroline Goodwin
August 27, 2018
Page 9
levels above the laboratory method detection limit, but below the laboratory reporting limit (i.e.,
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 requested for this project. A
copy of the completed chain -of -custody record and shipping receipt will be appended to the
corresponding laboratory analytical report included with the final report.
2.3 Investigation Derived Waste
Investigation derived waste (IDW) generated during the assessment activities will be thin spread on -
Site. However, if significant impacts are suspected (i.e., high PID readings, free -product, etc.) the
soil cuttings will be containerized and staged on -Site pending analytical results of composite IDW
samples. IDW generated during the proposed assessment activities will be managed in accordance
with DEQ IHSB Guidelines.
2.4 Reporting
Following completion of the assessment activities and receipt of the analytical data, H&H will
document our findings in a Supplemental Brownfields Assessment Report. The report will include a
description of the sampling activities, a figure depicting sample locations, laboratory analytical data,
a discussion of the data in comparison to regulatory screening levels, and conclusions and
recommendations concerning our activities.
S:\AAA-Master ProjectsWagnus Capital Partners (MGN)\314 W. Bland Street\Supplemental Brownfields
Assessment\Supplmental Brownfields Assessment Work Plan Revl_Wepak Corporation (BPN 21048-17-
060)_20180827.doc
hart hickman
SMARTER ENVIRONMENTAL SOLUTIONS
Ms. Caroline Goodwin
August 27, 2018
Page 10
Should you have any questions or need additional information please do not hesitate to call us at
(704) 586-0007.
Sincerely,
J
l
Senior Project Geologist
Attachments
S.\AAA-Master Projects\Magnus Capital Partners (MGN)\314 W. Bland Street\Supplemental Brownfields
Assessment\Supplmental Brownfields Assessment Work Plan Revl_Wepak Corporation (BPN 21048-17-
060)_20180827.doc
14
hart hickman
SMARTER ENVIRONMENTAL SOLUTIONS
�- 1• ;. x f� .a� 1 .. 1 FT'rXPU"T/ r WFi
'-� `� 'r' •,tip:: s y.: xc'. ' ),
1� YN ,.
d /
"• r tio
VYT —f . I• - rue 5S �• - J � �'a D7 �; 4F. .� _� j r
T 29 -I• ' t PArkn g 1 'i Y p
�FY_: 1+L,q vt.- � �� '� _1 ' �� •i" �4o- I4 �� ¢ - r „7.., :'
SITE A .�
f'.�r.
ol
l , `• .... 'T a �, %4 y i" "yY ,-.: - -.�.. 1%. . `�f �,• "'•'f 75 ra Sxu
WC A\X
wo
_ it
thieh
■ _ - v �.y_ -� Par
iA
APPROXIMATE
N 0 2000 4000
SCALE IN FEET
U.S.G.S. QUADRANGLE MAP
CHARLOTTE EAST, NORTH CAROLINA, 1991
QUADRANGLE
7.5 MINUTE SERIES (TOPOGRAPHIC)