22054_2100 S Tryon Decision Memorandum 20201002

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DECISION MEMORANDUM
DATE: October 2, 2020 FROM: Bill Schmithorst TO: Project Files
RE: 2100 South Tryon Street 2100 S. Tryon Street Charlotte, Mecklenburg County BF # 22054-18-060
Based on the following information, it has been determined that the above referenced site, whose intended use is for no uses other than high density residential, hotel, retail, office, restaurant, parking, open space and commercial, can be made suitable for such uses.
Introduction: The Brownfields Property (Parcel IDs 11906105 and 11906107) is approximately 2.82 acres and is undeveloped.
Redevelopment Plans: The Prospective Developer intends to develop multi-story office and commercial business space, with the possibility of adding high density residential and hotel in the future. The current grade at the Brownfields Property will require the import of fill material for development.
Site History: Based on aerial photographs, the Brownfields Property appears to have been agricultural as early 1938. As early as the 1920s, a rail spur that originated on an off-site property
located northwest of the Brownfields Property, passed through the southern portion of the
Brownfields Property, and connected to a rail line located approximately 1,000 ft southeast of the Brownfields Property. The rail spur was abandoned in the 1950s. A former Sunoco gas station #1181 was developed in the northeastern portion of the Brownfields Property in 1957 and operated at the Brownfields Property until the 1970s.
B&B Contracting and The Brake Clinic operated within the former gas station in the
1970s/1980s and the 1980s/1990s, respectively. The gas station operated six USTs that were removed in the late 1990s. The building and canopy associated with the gas station were demolished in 2005 and the Brownfields Property has remained vacant since that time.

In June 1997, a petroleum release was discovered during removal of four 4,000-gallon gasoline USTs from the Brownfields Property (NCDEQ UST Incident #18149). During UST closure activities, gasoline-range total petroleum hydrocarbon were reported in soil samples collected from the tank basin. After follow-up groundwater assessment activities,
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a mobile multi-phase extraction (MMPE) remedial event was completed in the source area monitoring wells. Soil samples collected from the former tank basin after the MMPE
event did not exceed NCDEQ residential soil screening levels. A Notice of Residual Petroleum (NORP) was filed for the Brownfields Property in September 2005, and DEQ issued a No Further Action (NFA) letter dated October 7, 2005 and closed UST release incident #18149.
A second release incident associated with the former gas station when soil contamination was identified during removal of two 550-gallon USTs that reportedly contained heating oil (also listed as diesel fuel) and waste oil in January 1999 (NCDEQ Incident # 19913). Petroleum-impacted soil was detected in the former heating oil UST basin at concentrations below screening levels. DEQ issued a no further action for the release
incident in July 1999. An environmental assessment was conducted at the Brownfields Property in August 2018 for property due diligence purposes. Soil and groundwater samples were collected and submitted to a laboratory for the analysis of VOCs, SVOCs, and RCRA metals. Based on
the soil assessment laboratory results, VOC and SVOC impacts in soil appear to be limited to the northeastern portion of the Brownfields Property. To evaluate the potential risks from soil vapor, seven soil gas sampling points were installed and sampled for VOCs by USEPA Method TO-15. Multiple petroleum-related volatile organic compounds (VOCs) were detected at concentrations above DEQ Division of Waste
Management (DWM) Non-Residential Soil Vapor Screening Levels (VISLs); however, no constituents were detected above Industrial/Commercial PSRGs. A soil gas assessment was conducted in January 2019 under a work plan approved by the NCDEQ. Two soil gas samples were collected to provide delineation near the property
boundaries. The soil gas samples were analyzed for VOCs by USEPA Method TO-15. No VOCs were detected above VISLs and no risks were identified using the Risk Calculator under Residential or Industrial/Commercial use scenarios.
Surrounding Properties
Surrounding properties consisted of mixed commercial, light industrial, and residential properties as early as the 1920s. Light industrial and commercial businesses including, a paint store, a bakery, a mattress and carpet cleaning business, a wholesale upholstery fabric company, a transmission repair business, a hydraulic service business, multiple
auto repair shops, a farm machinery manufacturing facility and a plumbing supply
business have operated at locations north of the Brownfields Property along S. Tryon Street. Properties to the east have historically been utilized for fertilizer manufacturing operations, a gas station, and multi-tenant commercial building. The property located adjacent and southeast of the Brownfields Property has historically been occupied by a
gas station since the late 1960s. The property south of the Brownfields Property was
developed with residences in the 1950s- 1960s and a commercial building from the 1970s until the 2000s and a climbing center from the 2000s until the present. Development of automotive facilities located west of the Brownfields Property began in the 1970s.
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Marathon/Petro-Express (formerly known as Conoco Store #33012, Circle K #2723935, and Kayo Oil, 2200 S. Tryon Street) is a gas station/convenience store located adjacent,
southeast, and topographically upgradient of the subject Brownfields Property. In September 1991, soil and groundwater contamination were discovered during removal of three 8,000-gallon gasoline USTs and associated product lines. DEQ issued a NFA letter dated August 23, 2002 after a NORP was filed for the gas station property, the southern portion of the subject Site (referred to as Tract 1 on the NORP), and the adjacent property
to the southwest of the Site (referred to as Tract 2 on the NORP, currently identified with an address 2220 S. Tryon Street). The NORP restricts groundwater use in the southern portion of the Site, and on the adjacent properties (2200 and 2220 S. Tryon Street). Potential Receptors:
Potential receptors are: construction workers, on-site workers, visitors, and trespassers. A receptor survey was conducted in the area surrounding the Brownfields Property. The area is urban and is served by municipal water and no water supply wells were identified within 1,500 feet of the property.
Contaminated Media: DEQ has evaluated data collected from the following media at the subject property: soil, groundwater, and soil gas. DEQ relies on the following data to base its conclusions regarding the subject property and its suitability for its intended reuse. A summary of contaminated media above screening standards is presented in Exhibit 2 of the
Brownfields Agreement. A summary of site environmental assessment data can be found in Brownfields Assessment Report, Additional Sampling Activities, Hart & Hickman, March 1, 2019 and Phase II Environmental Site Assessment, Vacant Property, 2100 S. Tryon Street, Hart & Hickman, September 18, 2019.
Soil Soil sample SB-1 was collected from the former UST area in 1998, and laboratory results indicate concentrations of TPH, naphthalene (63.3 mg/kg), and trichloroethylene (6.94 mg/kg) above Commercial/Industrial screening levels. The data from SB-1 was included
in the NCDENR Notice of Residual Petroleum issued on October 7, 2005. Results from
2018 soil assessment activities indicated concentrations of arsenic in soil above Commercial/Industrial screening levels, but comparable to concentrations found in soil at other brownfields sites in Charlotte. Historical records do not indicate any releases or use of arsenic containing products at the property.

Groundwater Shallow groundwater samples were collected from monitoring wells at the Brownfields Property during multiple environmental assessments. Exceedances of NCAC 2L Groundwater Standards were detected in a number of monitoring wells from 1998 to
2018. Elevated concentrations of TPH were initially detected in monitoring wells MW-1,
MW-2, MW-4, MW-5 in 1998; however, the wells were not sampled for TPH after 1998 as the laboratory analysis changed to a focus on specific chemical compounds. The most recent concentrations of compounds exceeding NC 2 L Standards include benzene (2,090
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ug/l, MW-5), toluene (2,500 ug/l, MW-1), xylenes (6,600 ug/l, MW-1), tetrachloroethylene (2.2 ug/l, MW-9), and methyl-tert-butyl ether (1,210 ug/l, MW-5).
Non-Residential groundwater to indoor air VISLs were also exceeded. Laboratory results indicate groundwater vapor intrusion risks from multiple VOCs in groundwater including benzene, ethylbenzene, and xylenes.
Soil Vapor Seven soil gas sampling points (SG-1 through SG-7) were installed and sampled at the Brownfields Property in August 2018 for property due diligence purposes. Analytical results from the laboratory analysis of VOCs by USEPA Method TO-15 indicate the presence of VOCs at concentrations above North Carolina Non-Residential VISLs
(Vapor Intrusion Screening Levels). Two additional soil gas samples were collected in January 2019 under a NCDEQ-approved work plan to provide soil gas delineation near the property boundaries. Laboratory results indicate that no constituents analyzed for VOCs by USEPA Method
TO-15 were detected above risk screening levels.

Risk Calculations Risk Calculations were performed using Excel worksheets provided by Sandy Mort, NCDEQ Brownfields Toxicologist. For the purposes of providing a conservative estimate
of risk, data from the samples with the highest concentrations were used in the risk model. This included SG-2 for soil gas, SB-1 for soil, and monitoring wells, MW-5 for groundwater. The risk calculations indicated the following based on available data, including the following media: groundwater, shallow soil, and soil gas:

PRIMARY CALCULATORS
Receptor Pathway Carcinogenic Risk Hazard Index Residential Risk exceeded? Resident Soil Combined Pathways 2.1E-05 6.1E+00 YES
Groundwater Combined Pathways 6.4E-03 1.0E+02 YES
Non-Residential Worker Soil Combined Pathways 4.4E-06 1.2E+00 YES
Groundwater Combined Pathways 1.5E-03 2.2E+01 YES
Construction Worker Soil Combined Pathways 8.8E-07 1.2E+01 YES
VAPOR INTRUSION CALCULATORS
Receptor Pathway Carcinogenic Risk Hazard Index Residential Risk exceeded?
Resident Groundwater to Indoor Air 1.4E-03 1.9E+01 YES
Soil Gas to Indoor Air 2.3E-02 6.1E+02 YES
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Non-Residential Worker Groundwater to Indoor Air 3.3E-04 4.4E+00 YES
Soil Gas to Indoor Air 1.8E-03 4.8E+01 YES
Red shading LICR> 1E-04 or HI> 1. LICR = Lifetime Incremental Cancer Risk HI = Hazard Index
Results from the risk analysis indicate that groundwater, soil and soil gas exceed an acceptable risk requiring vapor mitigation measures for non-residential use. The PD will submit a Vapor Intrusion Mitigation System Plan to the DEQ for approval and install the system according to the VIMS Plan before any new buildings are occupied. Construction
work conducted at the Brownfields Property will be completed under a DEQ-approved Environmental Management Plan to control potential risks from environmental contamination. In addition, final grade soil sampling will be conducted before the Brownfields Property can be occupied for its proposed use in areas not covered with clean fill or impervious surfaces.
Required Land Use Restrictions: Based on the site-specific data provided to the Brownfield program, the site reuse is suitable for the site as long as the agreed upon land use restrictions in the BFA are abided by.
1. No use other than for multi-family residential, retail, office, recreational, open space, parking, restaurant, and commercial, can be made suitable for such uses. 2. No groundwater use 3. No disturbing soil without DEQ approval or for landscape/mowing/pruning/repair of
underground infrastructure (written notice to DEQ)/work for EMP. 4. Soil Import/Export protocol is followed. 5. Standard VI LUR 6. EMP 7. Access to Brownfields Property for environmental assessment.
8. NBP reference in deed. 9. No contaminants on property except for de minimis amounts, fluid in vehicles, fuels for generators/equipment. 10. Ongoing maintenance of vapor mitigation systems. 11. Final grade soil sampling for RCRA metals, SVOCs, and VOCs will be conducted in
exposed areas. 12. LURU submission January 1st