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Simpsons Texaco/25063-21-060/20220728
DECISION MEMORANDUM
DATE: November 8, 2023
FROM: Bill Schmithorst
TO: BF Assessment File
RE: Simpsons Texaco
4015 South Boulevard
Charlotte, Mecklenburg County
BF # 25063-21-060
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, industrial,
office, parking, retail, warehousing, entertainment, hotel, restaurant, brewery and food
production facility, distillery, open space, recreational, institutional, and with prior
written DEQ approval, other commercial uses, can be made suitable for such uses.
Introduction:
The Prospective Developer is Scaleybark CLT, LLC, with an office located at 7600
Broadway, Suite 3000, San Antonio, Texas 78209. The Brownfields Property consists of
one parcel (Mecklenburg County Parcel Identification No. 14906123). The Brownfields
Property totals approximately 4.045 acres and is located near the LYNX Blue Line light
rail corridor. The property is currently being redeveloped.
Redevelopment Plans:
The intended redevelopment for the Brownfields Property is for a high-density residential
apartment complex with ground level retail and commercial amenities including surface
parking and a multi-level parking garage. The new development will include a soil vapor
mitigation system.
Site History:
The Brownfields Property remained undeveloped and used for agricultural purposes until
the mid-1960s when the northern and eastern portions of the property were developed
with the recently demolished gas station (4001 South Blvd.), restaurant (4009 South
Blvd.), auto repair shop (200 Scaleybark Rd.), and commercial retail/office building (201
Scaleybark Rd.). The southern parcel (124 Scaleybark Rd.) was developed in the 1980s
as a self-storage facility.
The northern portion of the Brownfields Property, 4001 South Blvd. (former PIN
14906111), was occupied continuously by a gasoline fueling station from at least the
1960s to the 2010s. Soil impacts were detected at the property in May 2000 (Incident No.
21927) and in June 2000. In March of 2014, DEQ issued a No Further Action letter and a
NORP was recorded on the property on July 21, 2014, which restricted residential uses;
however, abatement action and UST removal was conducted in June 2018, and post-
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excavation sampling indicated soil impacts were below the Residential and
Industrial/Commercial MSCCs. DEQ’s UST Section approved revision of the NORP to
allow for residential re-use, and the revised NORP was recorded on March 29, 2022.
A second release (Incident No. 23918) was identified during UST closure activities at the
Brownfields Property in January 2002. However, based on the results of sampling
activities, the incident was granted closure through issuance of a No Further Action letter
dated January 25, 2002.
The portion of the Brownfields Property at 200 Scaleybark Rd. (former PIN 14906122),
operated as Simpson’s Texaco Service Station in the 1960s and ‘70s, and most recently
as an automotive repair shop from the 2000s to 2022.
Former PIN 14906111 (4001 South Blvd.) was the subject of a Notice of Residual
Petroleum (NORP) recorded on the property on July 21, 2014, which includes restrictions
that limit the parcel’s use to Industrial/Commercial uses and prohibits groundwater use
for water supply. Following abatement action in 2018 and post-excavation soil samples
indicating impacts were below Residential and Industrial/Commercial MSCCs, DEQ
UST Section approved revision of the 2014 NORP to allow for residential uses. The
revised NORP was recorded on March 29, 2022, in the Mecklenburg County land records
at Book 37198, Page 717.
The Mitchell’s Formal Wear Brownfields Property (BF# 09013-05-060) is located to the
north of the Brownfields Property.
Potential Receptors:
Potential receptors are: construction workers, on-site workers, future residents, visitors,
and trespassers. A Brownfields Receptor Survey was submitted on February 1, 2022. No
groundwater supply wells were identified within 1,500 feet of the Brownfields Property.
Contaminated Media:
DEQ has evaluated data collected from the following media at the subject property: soil,
groundwater, and exterior soil gas. DEQ relies on the following data to base its
conclusions regarding the subject property and its suitability for its intended reuse. Please
see the Brownfield Agreement’s Exhibit 2 for specific sample locations, dates, and
contaminants of concern (COCs).
Soil
Arsenic exceeded Residential PSRGs in shallow soil samples; however,
detections were within background concentrations
Hexavalent chromium was detected in one soil sample above Residential PSRGs.
Benzo(a)pyrene was detected in one shallow sample above Residential PSRGs.
Groundwater
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The following VOC contaminants were detected at high concentrations and are
considered risk drivers: benzene, ethylbenzene, toluene, xylenes, naphthalene and
methyl tert-butyl ether.
VOC contaminants also exceeded NC DEQ Ground to Indoor Air Vapor Intrusion
Screening Levels (VISLs).
Groundwater contaminants are suspected to have primarily originated from onsite
sources, including former underground storage tanks.
Depth to groundwater ranged from approximately 12 to 21 feet.
Surface Water
Surface water is not present at the site.
Exterior Soil Gas
Benzene and naphthalene exceeded Residential VISLs.
Trichloroethylene was detected below Residential VISLs in one sample at a
concentration of 1.96 J µg/m3.
Sub-Slab Vapor
Sub-slab vapor samples were not collected. The existing buildings have been
demolished and a passive vapor mitigation system that can be made active is
proposed for the new building.
Indoor Air
Indoor air samples were not collected. Existing buildings were demolished.
Risk Calculations:
Risk calculations were performed using the DEQ Risk Calculator (January 2022)
https://deq.nc.gov/permits-rules/risk-based-remediation/risk-evaluation-resources.
To conservatively evaluate site risk, the highest site wide concentrations for each
compound detected was used for each environmental media. The risk calculations
indicated the following based on available data, including the following media:
groundwater, soil, and exterior soil gas.
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Risk for Individual Pathways Output Form 1A
Version Date: January 2022
Basis: November 2021 EPA RSL Table
Site ID: 25063-21-060
Exposure Unit ID: Site Wide Soil, Soil Gas, and Groundwater
Receptor Pathway
Carcinogenic
Risk Hazard Index Risk exceeded?
Soil 5.1E-05 1.2E+00 YES
Groundwater Use* 5.8E-02 1.0E+03 YES
Soil 9.2E-06 2.4E-01 NO
Groundwater Use* 1.4E-02 2.3E+02 YES
Construction Worker Soil 2.4E-06 6.2E-01 NO
Soil 1.8E-05 2.0E-01 NO
Surface Water* NC NC NC
Receptor Pathway
Carcinogenic
Risk Hazard Index Risk exceeded?
Groundwater to Indoor Air 1.4E-02 2.3E+02 YES
Soil Gas to Indoor Air 1.2E-04 1.7E+00 YES
Indoor Air NC NC NC
Groundwater to Indoor Air 3.1E-03 5.5E+01 YES
Soil Gas to Indoor Air 9.2E-06 1.3E-01 NO
Indoor Air NC NC NC
VAPOR INTRUSION CALCULATORS
Resident
Non-Residential Worker
DIRECT CONTACT SOIL AND WATER CALCULATORS
Resident
Non-Residential Worker
Recreator/Trespasser
Due to high concentrations of contaminants detected in groundwater, the Risk Hazard
Index and Carcinogenic Risk residential were exceeded for groundwater use and
groundwater to indoor air vapor intrusion under a residential use scenario. In addition, a
Hazard Index of 1.0 was exceeded for the soil gas to indoor air pathway, and for the soil
Resident Receptor pathway.
Elevated concentrations of petroleum-related compounds detected in groundwater will
require a land use restriction prohibiting the use of groundwater; however, municipal
water is available at the Brownfields Property, further minimizing the potential risks. An
Environmental Management Plan (EMP), approved by DEQ, was prepared before the
start of soil grading and excavation activities to prevent exposure to site workers and
future residents from unacceptable levels of contaminants, and to manage the safe
handling and disposal of potentially contaminated materials during construction. In
addition, final grade soil sampling will be required prior to occupying the Brownfields
Property. A passive vapor intrusion mitigation system is being installed by the PD.
Land Use Restrictions:
The standard land use restrictions including land use, Environmental Management Plan
and reporting requirements, prohibition on groundwater use, soil restrictions, the need for
vapor intrusion mitigation, access, notification, and prohibition on the use of known
contaminants, and the annual land use update obligation are required for this Brownfields
Agreement.
Commented [NB1]: Is it capable of being made active?
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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
Environmental Management Plan
A passive vapor intrusion mitigation system is being installed.
Final grade soil sampling required.
Soil management
Trichloroethylene was detected in exterior soil gas at a low concentration.