23055_Battery&Igntion_ Dec Memo 20211108

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Battery&ignition/23055-19-060/draft 20211108
DECISION MEMORANDUM
DATE: November 8, 2021 FROM: Carolyn Minnich TO: BF Assessment File
RE: Battery & Ignition Distribution 3631, 3621, 3615, 3611, 3609, 3601 Tryclan Drive 3700 Ellenwood Place Charlotte, Mecklenburg County
BF # 23055-19-060 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, office, parking, retail, recreational, and subject to DEQ’s prior written approval, other commercial uses.
Introduction: 3615 Tryclan LP is the Prospective Developer. The entity is a limited partnership that is registered to do business in North Carolina. The manager is Stuart Proffitt and the principal office address is 1420 E 7th Street, Suite 150, Charlotte, North Carolina, 28204.
The Brownfields Property is approximately 3.4132 acres. The following addresses are associated with the Brownfields Property3601, 3609, 3611, 3615, 3621, & 3631 Tryclan Drive and 3700 Ellenwood Place. The Brownfields Property is currently vacant and the structures are being razed and demolished.
The Brownfields Property is located in a rapidly densifying area of Charlotte referred to as lower SouthEnd. Nearby is the Lynx Blue Line light rail system and Uptown Charlotte. The surrounding area is transitioning from industrial and commercial to residential. Three other Brownfields Properties are in the immediate area:

Stax Gym (23002-19-060) Yorkshire Drive (22033-18-060) Affordable Custom Iron (23056-19-060)
Redevelopment Plans:
The proposed redevelopment includes razing the existing structures and construction of a high-density multi-story residential apartment building, landscape areas, and associated parking. The project name is LoSo, known as Lower SouthEnd. Redevelopment is on the fast track. Grading and utility work is scheduled for August 2021, vertical construction
December 2021-2023, and the first units to be occupied by April 2023.
Site History: From at least the 1930s until the 1960s, the Brownfields Property was undeveloped woodland. The following is a summary of each parcel.
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3601-3615 Tryclan Parcel was previously a multi-tenant office warehouse building. The building consisted of three commercial suites that were occupied by a lamp store, a
musical instrument repair shop, and a general contractor. Various tenants have rented on the property primarily for office, storage, and distribution purposes. 3621 Tryclan Parcel was previously a photography studio, auto parts store, a supply house for electrical work, and an auto shop. This parcel is listed in the NC Leaking
Underground Storage Tank (LUST) database under the name Canteen Co. or Canteen Food Service. It was assigned UST Incident No 6923 and is associated with 3631 and 3621 Tryclan Drive. 3631 Tryclan Drive parcel was occupied by Canteen Corporation whose operations
included a vending machine business until the late 1980s. In the 1980s, the building was leased for automotive service and body repair activities. This included an automotive paint booth, parts washers, and a used oil aboveground storage tank (AST). The building was occupied by Battery and Ignition Distribution from the late 1980s until
recently in 2021. Molina Auto Report and Body Shop was also listed from the mid-2000s until recently on this same parcel. In 1969, an 8000-gallon diesel underground storage tank (UST) was installed but was later removed in 1989. Upon removal of the UST, groundwater samples were collected. Laboratory reports indicated that groundwater contamination above 2L standards was detected. The incident was assigned number 6923
by the NC UST Section and this incident remains open. It is classified as low risk and low priority. In June 2021, the three monitoring wells were closed and abandoned. A Well Abandonment Summary Report was submitted by Hart & Hickman dated July 27, 2021.
The parcel at 3700 Ellenwood is vacant. It was undeveloped woodland from the early 1930s through the 1960s. The land was cleared during nearby development activities but no construction occurred on the parcel. A former gully was filled in the central portion of the site and later it was used for storage from the mid-1990s through the late 2010s.

Potential Receptors: Potential receptors are construction workers, on-site workers, future residents, visitors, animals (dog park), and trespassers.
In February 2020, a Brownfields Receptor Survey was conducted. The following was
reported that is out of the norm for city limits:
• One inactive water supply well was located approximately 525 ft west and topographically downgradient of the Brownfields Property.
• One residence with a potential basement was observed approximately 875
ft south of the Brownfields Property.
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Contaminated Media: DEQ has evaluated data collected from the following media at the subject property: soil
groundwater, and soil vapor. DEQ relies on the following data to base its conclusions regarding the subject property and its suitability for its intended reuse.

Soil In February 2021, soil assessment activities were conducted in the areas planned for redevelopment. Composite soil samples were collected in the area of the proposed parking deck and proposed courtyard/pool area. The lab samples were 5-point composites collected from a shallow depth of 0-2 ft below ground surface (bgs) for semi-
volatile organic compounds (SVOCs) and metals plus hexavalent chromium. A grab sample for volatile organic compounds (VOCs) was collected from each area also. No organic compounds were detected at concentrations above the laboratory method detection limits in the soil samples.
Metal concentrations were detected but are consistent across Brownfields Property and with other samples in the area. They appear to be naturally occurring. Groundwater In February 2021, four temporary groundwater monitoring wells were installed,
developed, sampled, and abandoned.
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During well installation, continuous soil samples were collected. Field screening results did not indicate the presence of impacted soil during the boring advancement. Wells
were 1-inch diameter and total depth was 16-21 ft bgs. Groundwater samples were collected and analyzed for VOCs, SVOCS, RCRA metals. Groundwater collected from temporary monitoring well TMW-3 had a detection of trichloroethylene (TCE) at 10.7 µg/L, which exceeds the NC 2L groundwater standard of
3 micrograms per liter (µg/L) for TCE. An estimated J value of cis-1,2-dichloroethene (cis-1,2-DCE) of 0.37J µg/L was also reported in the groundwater sample collected from TMW-3. Groundwater collected from temporary monitoring well TMW-1 and its duplicate sample
were reported to contain concentrations of acetone (up to 33.2 µg/L) and methyl-tert-butyl ether (up to 2.0 µg/L). In addition, acetone was also reported in the groundwater sample from well TMW-4 (16.7 J µg/L). These detections are all below their respective NC 2L groundwater standards.Organic compounds were not detected in TMW-2 at concentrations above the laboratory reporting limits.
TCE groundwater impacts appear to be limited to the central and south-central portions of the Brownfields Property. The PD has opted for a vapor mitigation system versus additional sampling for vapor.
In June 2021, three monitoring wells were abandoned on the north-northwest side of the Brownfields Property. These wells are believed to have been associated with the 1989 removal of an 8,000-gallon diesel UST. Limited information was found addressing UST Incident No. 6923 or these monitoring wells. One statement included in historical reports is that benzene and xylene concentrations were detected exceeding 2L standards;
however, the originating documents indicating these results from over 30 years ago are not readily available. No report could be located with laboratory reports or sampling information. Therefore this data set was not included in our data analysis.
Surface Water
Surface water is not located on the Brownfields Property.
Exterior Soil Gas In February 2021, seven exterior soil gas sampling points were installed within the
footprint of the proposed residential building. The soil gas wells were installed to
approximately 5.5 ft bgs. Samples were collected and analyzed for VOCs by TO-15 method. The laboratory report for the soil gas samples reported low concentrations of several compounds detected at concentrations above the method detection limit, but below the residential vapor intrusion screening level (VISL)screening value. TCE was
detected in only one soil gas point centrally located on the Brownfields Property, SGP-4,
at 17 micrograms per cubic meter (µg/m3) above its residential VISL of 14 µg/m3. In addition, benzene was detected in several of the soil gas samples up to 22 µg/m3, exceeding its residential VISL of 12 µg/m3.
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Sub-Slab Vapor No sub-slab samples collected because new construction is planned. Existing structures
are being demolished.
Indoor Air No indoor air samples collected. Current structures are being demolished and new construction is planned. Indoor air sampling is required for pre-occupancy in the new
structures.

Risk Calculations Risk calculations were performed using the June 2021 version of the DEQ Risk Calculator https://deq.nc.gov/permits-rules/risk-based-remediation/risk-evaluation-
resources. The risk calculations indicated the following based on available data, including the following media: groundwater, soil, and exterior soil gas.

The available site data used for this risk calculator input indicated that there was no unacceptable carcinogenic risk in any of these media for these various exposure scenarios. The threshold value of 1.0 for a noncancer hazard index was exceeded for direct residential groundwater use, and by the groundwater to indoor air vapor intrusion analysis for residential exposures. While the residential soil gas to indoor air hazard
index of 0.4 does not exceed 1.0, that calculation is based on exterior soil gas and not on the more reliable sub-slab soil vapor data that indicates what may occur when a building is constructed over this impacted area. This increased vapor intrusion risk is driven by TCE.
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On September 9, 2021, DEQ Brownfields Program approved the Vapor Intrusion
Mitigation Plan dated September 3, 2021 prepared by Hart & Hickman. The VIMP includes the installation of Vaporblock Plus 20 vapor barrier beneath the ground level under the concrete slab of each building. The VIMP also includes installation of an enhanced passive mitigation system beneath the building slab to reduce the potential for vapor intrusion into the proposed building by vapor extraction. Vapor extraction will be
accomplished by using syphon ventilations, vapor collection/conveyances piping, and soil gas collector mat to collect vapor from beneath the slab of the building and discharge the vapor through exhaust stacks installed above the building roofs. Required Land Use Restrictions:
The standard land use restrictions as to land use, no physical redevelopment without an EMP, reporting, prohibitions on groundwater use, restrictions on soil disturbance, vapor intrusion provisions, known contaminant uses, notices, access, and land use restriction update provisions will be included.
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.
PROPERTY MANAGEMENT ISSUES
• EMP reviewed, approved, and signed on May 27, 2021
• VIMP reviewed, approved, and compliance letter sent on September 9, 2021.
Vapor Intrusion Mitigation Plan dated September 3, 2021 prepared by Hart &
Hickman.