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Home My WebLink About21048 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)