22007 S Tryon Commercial Decision Memorandum_20190610

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DECISION MEMORANDUM

DATE: June 10, 2019

FROM: Bill Schmithorst

TO: South Tryon Commercial BF Assessment File

RE: South Tryon Commercial
2001 and 2027 S. Tryon Street
Charlotte, Mecklenburg County
BF # 22007-18-060

Based on the following information, it has been determined that the above referenced
site, whose intended use is for no uses other than multi-family residential, retail, office,
recreational, open space, parking, restaurant, brewery or food production facility, and
commercial, can be made suitable for such uses.

Introduction:
The Brownfields Property (Parcel IDs 12103301 and 12103302) is approximately 2.39
acres and is undeveloped.

Redevelopment Plans:
The Prospective Developer intends to construct a mixed use development on the subject
property including multi-family residential and first floor commercial businesses.

Site History:
West-central portions of the Brownfields Property along S. Tryon Street were developed
with a farm machinery service company in 1937 that was later used as an electrical
supply warehouse. An addition was constructed on the northern side of the electrical
supply warehouse in the late 1970s. The electrical service warehouse operated until the
1990s when the building was occupied by Grinnell Fire Sprinkler Systems. The property
was then vacant until 2005 when it was purchased by DCI properties and leased to a dog
daycare center. A restaurant operated in the west-central portion of the Brownfields
Property south of the electrical supply warehouse building between 1948 and the mid-
1960s. The restaurant building was demolished in the early 1980s.

The southern portions of the Brownfields Property (312 West Tremont) were occupied by
a motor freight company beginning in the 1940s and later a welding supply company in
the 1960s. The southeastern portion of the Site was occupied by an electrical service
company and an automotive repair company from 1948 until the mid-1960s, and a
warehouse building from 1947 until the late 1960s. In 1980, B&B Contracting Co, Inc.
purchased the three buildings and utilized the facility as a drywall contracting business
from 1980 until the late 2000s.

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B&B Contracting Company, Inc. is identified in the EDR Underground Storage Tank
(UST), FINDS, and NC Facility Identification Template for States (NC FITS) databases.
Information provided in the UST database indicates that a 4,000-gallon gasoline UST and
a 6,000-gallon gasoline UST were installed at the Site in 1971 and were removed in
1991. There are no reported releases from either UST in the North Carolina Department
of Environmental Quality UST Database. As reported in the Phase I report, the two tanks,
all product and vent lines, and dispenser island were removed. Analytical results of UST
closure confirmation soil samples indicated that no compounds were detected above
applicable screening criteria. DEQ issued a No Further Action (NFA) letter based on
results of the UST closure activities.

The northern portion of the Brownfields Property was undeveloped until the 1960s when
it was developed with a Terminix pest control facility and operated until the late 2000s.
Environmental assessment activities and remedial activities were conducted on the
adjacent property under NCDEQ Brownfields Agreement No. 14009-10-60. Results from
the brownfields assessments indicated that a source area from historical release of
pesticides was delineated on the adjacent property. A total of approximately 8,473 tons
of nonhazardous pesticide impacted soil and approximately 556 tons of hazardous
pesticide impacted soil was removed from and transported off-site for disposal. Results of
post-excavation soil samples indicate that no pesticide compounds were detected at
concentrations exceeding the IHSB PSRGs.

The buildings on the Brownfields Property were demolished in 2011 and the property is
currently vacant.

Potential Receptors:
Potential receptors are: construction workers, on-site workers, future residences, visitors,
and trespassers. A receptor survey was conducted in the area surrounding the
Brownfields Property. The area 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.

Soil
Six soil borings were advanced within the footprint of the farm machinery service
building and electrical supply warehouse and within the footprint of the former motor
freight station and welding house building on May 18, 2018. One soil sample was
collected from each boring and submitted for laboratory analysis of VOCs, SVOCs,
RCRA metals, and PCBs. No VOCs were detected above Residential PSRGs.
Laboratory analytical results indicate that benzo(a)pyrene was detected at a concentration
of 0.17 J mg/kg from sample location SB-6 parent sample which is slightly above the
Residential PSRG of 0.11 mg/kg. Analytical results of the soil samples collected from
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soil borings SB-1, SB-2, and SB-3 did not indicate the presence of PCBs at
concentrations above the laboratory method detection limits.

Arsenic and hexavalent chromium were detected above Residential PSRGs. A similar
level of hexavalent chromium and arsenic was also detected in the background soil
sample.

A soil investigation was conducted at the former B&B Contracting Company, Inc.
location in July 2007 for the purposes of assessing the former fuel pump island and UST
areas. Two soil samples collected from the area were submitted for laboratory analysis of
VOCs. One soil sample was collected at the former location of the fuel dispenser pump
island at a depth of 1-2 feet bgs and one soil sample was collected at a depth of 8-10 feet
bgs near the former UST locations. Laboratory results indicate no VOCs were detected
above Residential PSRGs. The report is identified as draft and unsigned; however, a
laboratory report, data tables and a sample location map was provided by the Prospective
Developer.

Groundwater
Shallow groundwater samples were collected from one location at the Brownfields
Property in July and August 2007 and analyzed by a NC certified laboratory for VOCs
and pesticides. Laboratory results indicate that trichloroethylene was detected in DPT-2
(5.7µg/L), DPT-9 (14 µg/L), and MW-3 (11 µg/L), above the NCAC 2L Groundwater
Standard of 3 µg/L and the North Carolina Vapor Intrusion Screening Level (VISL) of 1
µg/L. Laboratory results also indicate concentrations Aldrin and Dieldrin above NCAC
2L Groundwater Standards. The assessment results were provided in a letter report from
Hart & Hickman dated November 19, 2018.

Soil Vapor
Seven soil gas sampling points were installed and sampled at the Brownfields Property in
May 2018. Analytical results indicate the presence of chloroform in the samples collected
from VMP-1 (72 μg/m3), VMP-2 (69 μg/m3), VMP-4 (54 μg/m3),VMP-5 (46 μg/m3),
VMP-6 (290 μg/m3) and VMP-7 (360 μg/m3) at concentrations above North Carolina
Residential VISLs of 41 μg/m3. Additionally, trichloroethylene was detected at
concentrations above the Residential VISL of 14 μg/m3 in the soil vapor samples
collected from VMP-1 (66 μg/m3), VMP-2 (42 μg/m3), VMP-3 (52 μg/m3), and VMP-5
(70 μg/m3).

An additional soil gas investigation was conducted at the Brownfields Property on May
18, 2019 to evaluate the vertical distribution of soil gas constituents. Laboratory results
indicated that VOCs did not exceed Non-Residential VISLs.

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
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model. These samples include VMP-5 and VMP-6 combined for soil gas, SB-6 for soil,
and DPT-9 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
Risk
exceeded?
Resident Soil Combined Pathways 5.4E-06 6.4E-02 NO
Groundwater Combined
Pathways*
1.0E-04 5.4E+00 YES
Non-Residential Worker Soil Combined Pathways 6.9E-07 5.1E-03 NO
Groundwater Combined
Pathways*
2.3E-05 1.2E+00 NO
VAPOR INTRUSION CALCULATORS
Receptor Pathway Carcinogenic
Risk
Hazard
Index
Risk
exceeded?
Resident Groundwater to Indoor Air 2.9E-05 2.7E+00 YES
Soil Gas to Indoor Air 8.7E-05 1.5E+00 YES
Non-Residential Soil Gas to Indoor Air 1.8E-06 1.1E-01 NO
Non-Residential Worker Groundwater to Indoor Air 6.4E-06 2.7E-01 NO
Soil Gas to Indoor Air 6.5E-06 1.2E-01 NO

Red shading LICR> 1E-04 or HI> 1.
LICR = Lifetime Incremental Cancer Risk
HI = Hazard Index

Results from the risk analysis indicate that groundwater and soil gas exceed an acceptable
risk for Residential, but not for Non-Residential. The site use was changed to Non-
Residential from the original proposed Residential use. An additional soil gas assessment
was conducted in May 2019 to assess the vertical distribution of soil gas VOCs. Results
indicate that VOCs do not exceed Non-Residential VISLs, risk hazard criteria or
carcinogenic risks. The PD will manage soil and potential environmental exposures with
measures under an approved Environmental Management Plan..

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. The Prospective Developer is proposing to incorporate vapor mitigation measures
with site development. In addition, final grade soil sampling will be conducted before the
Brownfields Property can be occupied for its proposed use.

1. No use other than for multi-family residential, retail, office, recreational, open space,
parking, restaurant, brewery or food production facility, and commercial, can be made
suitable for such uses.
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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.
5. Soil Import/Export protocol is followed.
6. Standard VI LUR
7.
8. EMP
9. Access to Brownfields Property for environmental assessment.
10. NBP reference in deed.
11. No contaminants on property except for de minimis amounts, fluid in vehicles, fuels
for generators/equipment.
14. Ongoing maintenance of vapor mitigation systems.
15. Final grade soil sampling for RCRA metals, SVOCs, and VOCs will be conducted in
exposed areas.
14. LURU submission January 1st