23018_Corey Transmission_Decision Memorandum_01.22.2020

DECISION MEMORANDUM DATE: January 22, 2020 FROM: Cody Cannon
TO: Brownfields Assessment File
RE: Corey Transmission 511 and 527 West Tremont Avenue Charlotte, Mecklenburg County BF # 23018-19-060 Based on the following information, it has been determined that the above referenced site, whose intended use is for no uses other than multi-family residential, high density residential, parking, office, open space, recreation, retail, and with prior written DEQ approval, other commercial uses, can be made suitable for such uses. Introduction:
The Brownfields Property is comprised of a single parcel totaling approximately 5.58 acres. The property is currently occupied by an automotive repair facility operated by Corey Transmission, Inc.
The Brownfields Property is bordered to the north by West Tremont Avenue followed by two vacant and undeveloped Brownfields properties: Powers Site (BF# 20045-16-060) and Adams
Property (BF# 21022-17-060); to the east and southeast by Gas Fired Products Inc. (UST Incident #18406) and Inner Peeks Climbing respectively; to the south by residential properties; and to the west by residential properties. Redevelopment Plans: The prospective developer (PD) intends to redevelop the property into a multi-family residential townhome complex comprised of 16 buildings and approximately 104 townhome units. Site History: The Brownfields property is located in an industrial area of south Charlotte, NC at 511 and 527 West Tremont Avenue. The property includes one parcel (#119-064-21) totaling 5.58 acres. According to a review of city directories, Sanborn® maps, aerial photographs, and property owner interviews, the Brownfields property consisted of vacant land as early as 1905 until as early as
1976 when a commercial building was present near the northeastern corner of the property. In approximately 1981, the north-central portion of the property was developed with the current approximately 17,500 square-foot warehouse. By at least 1983, the commercial building located
in the northeastern portion of the property was demolished. It was replaced by the current approximately 3,600 square-foot warehouse building in 1988. The Brownfields Property was occupied by an automotive repair facility called Adam’s Automotive from 1981 to 1990. From
1991 until the present, the Brownfields property has been utilized as automotive repair and recycled auto part sales facilities by Carolina Core Recycling Inc., Corey Transmission Service Inc., Gene and Greg LLC, and Used Transmission Exchanges. During a DEQ site visit conducted on July 17, 2019, the majority of the property surrounding the two warehouse buildings was largely occupied by scattered used automobiles. The following section details the history of environmental assessment at the property.
Environmental Assessment History
Environmental assessment began at the property with the completion of a Phase I Environmental Site Assessment by Salem Environmental in June 2006. The report stated that the storage of used
cars and the operation of the property as an automotive repair facility had resulted in multiple petroleum lubricants discharges on to asphalt. Additionally, the reported historical use of petroleum products, solvents, and other chemicals in the northeast portion of the property (referenced as 501
W. Tremont) was listed as a recognized environmental condition (REC). Salem subsequently completed a Phase II Environmental Assessment in July 2006 which included the installation of a temporary groundwater monitoring well in a gravel covered area with apparent staining located between the two warehouse buildings. The groundwater sample collected from TMW-1 revealed a concentration of tetrachloroethylene (PCE) of 11 µg/L which exceeds the North Carolina Administrative Code Title 15A Subchapter 2L groundwater standard (2L) of 0.7 µg/L. A soil sample was collected from the monitoring well location and an additional soil sample was collected from the vicinity of the current 3,500 square-foot warehouse located in the northeast corner of the property. Oil & Grease were detected in both samples but below the DEQ action level of 250 mg/kg.
Several additional Phase I Environmental Site Assessments were completed in the years following initial assessment including: a report completed by Enviro Scan on October 15, 2014 which did not identify any on-site or off-site RECs, a report completed by Summit Engineering, Laboratory &
Testing, Inc.(Summit) on November 25, 2015 which listed the previously identified (2006) soil and groundwater contamination as RECs, and a report completed by ECS Southeast, LLP (ECS) on August 9, 2017 which identified on-site operations and historical off-site operations associated with
the Powers Site (BF# 20045-16-060) and the eastern neighboring Steve Lit, Inc. property (UST Incident #18406) as RECs. ECS completed a limited geotechnical assessment at the property in August 2017 which included the drilling of 10 soil test borings across the property ranging in depths from 0 to 20 feet below land surface (ft BLS). Five of the soil borings located on the southern and eastern sections of the property contained petroleum odors. Following the geotechnical assessment, ECS completed a Draft Report of Environmental Assessment on October 24, 2017. The assessment included the collection of eight soil samples varying in depth from 2 to 10 ft BLS across the property, the installation and sampling of two temporary groundwater monitoring wells in the northeastern portion of the property, and the collection of five exterior soil gas samples from various locations across the property. All soil
samples were analyzed for total petroleum hydrocarbons (TPH) with detectable concentrations being observed in each sample. However, only sample SB-7 (389.6 mg/kg) in the southeast portion of the property contained a concentration of diesel range organics (TPH-DRO) above the DEQ UST action limit of 100 mg/kg. Several semi-volatile organic compounds (SVOCs) and volatile organic compounds (VOCs) were detected in the groundwater samples but none exceeded the 2L groundwater standards. Several VOCs and SVOCs were detected in all of the exterior soil gas
samples but exceedances of the DEQ Residential Vapor Intrusion Screening Level (VISL) were observed in only one sample (SG-2) located just south of the northeastern warehouse building. Concentrations of methyl tertiary-butyl ether (MTBE; 5,300 µg/m3) and total xylenes (1,010 µg/m3)
exceeded Residential VISLs in soil gas sample SG-2. DEQ Brownfields issued a Request for Additional Assessment Letter to the PD on July 18, 2019. A Brownfields Assessment Report was completed by ECS on September 10, 2019 covering additional soil, soil-gas, and groundwater sampling across the property. Five temporary monitoring wells were installed and sampled across the property. No SVOCs were detected in any of the monitoring wells and MTBE was the only VOC detected (below 2L). Arsenic was detected at a
concentration exceeding the 2L groundwater standard in monitoring well MW-4 (170 µg/L) located
just south of the northeastern warehouse building. Mercury was detected at a concentration exceeding the 2L groundwater standard and Residential VISL in monitoring well MW-5 (1.3 µg/L) located in the northwestern corner of the property. The Brownfields property was divided into five
areas for the collection of surficial (0-2 ft BLS) composite soil samples in an effort to maximize aerial coverage and assess the many locations with used automobiles across the property. Each composite soil sample was comprised of five grab samples from within each predetermined area
and was analyzed for SVOCs and Resource Conservation and Recovery Act (RCRA) metals. Two grab soil samples were selected from each composite area for VOC analysis based on visual, olfactory, and photoionization detector (PID) observations. Several polycyclic aromatic hydrocarbons (PAHs) were detected in each of the composite soil samples but only benzo(a)pyrene exceeded the DEQ Residential Preliminary Soil Remediation Goal (PSRG) in composite sample B (0.322J mg/kg) located in the southeastern most composite area. Hexavalent chromium was detected at concentrations exceeding the Residential PSRG in composite samples D and E (0.509J and 0.316J mg/kg) located on the western portion of the property. Arsenic was detected above the Residential PSRG in composite samples C and E (1.0 and 1.5 mg/kg) at concentrations considered to be within the range of naturally occurring background levels for the region. No VOCs were detected above Residential PSRGs in any of the grab soil samples.
Eight soil gas samples were collected in the vicinity of buildings included in the proposed redevelopment layout. All soil gas sample points were screened for methane due to the presence
of elevated methane at the adjacent Powers Site and Adams Property associated with historical quarry and landfill operations. The highest concentration of methane detected at the Brownfields Property was 0.6 % by volume or 12 % of the lower explosive limit (LEL). Several VOCs were
detected above the Residential VISLs in soil gas samples SG-5 located in the vicinity of the former SG-2 (2017) including Ethylbenzene, n-Heptane, 2-Hexane, 1,2,4-Trimethylbenzene, and total Xylenes. Trichloroethylene was detected above the Residential VISL in soil gas sample SG-6 located in the vicinity of the northeastern warehouse building near W. Tremont Ave. Potential Receptors: Potential receptors are: construction workers, residents, on-site workers, visitors, and trespassers. Contaminated Media: DEQ has evaluated data collected from the following media at the subject property: soil, soil-gas, and groundwater. DEQ relies on the following data to base its conclusions regarding the subject property and its suitability for its intended reuse.
Soil
Data from surficial soil samples (0-2 ft BLS) collected as part of the 2019 Brownfields Assessment Report was utilized for risk assessment for residential soil exposure. Concentrations of benzo(a)pyrene, arsenic, and hexavalent chromium exceeded the Residential PSRGs. The
associated carcinogenic and non-carcinogenic risk values calculated using the DEQ Risk Calculator (May 2019) do not exceed thresholds for residents or construction workers.
Groundwater Data from the five groundwater monitoring wells collected as part of the 2019 Brownfields
Assessment Report was utilized to assess direct groundwater exposure risk and groundwater to
indoor air risk for future residents of the property. Concentrations of arsenic exceeded the 2L
groundwater standards and concentrations of mercury exceeded 2L standards and the Residential VISL. The DEQ Risk Calculator (May 2019) was used to calculate the direct exposure risk and groundwater to indoor air risk on a site wide worst case scenario basis. The carcinogenic and non-
carcinogenic thresholds for direct groundwater exposure were exceeded at 3.3E-03 and 30 respectively. However, neither threshold was exceeded for the groundwater to indoor air pathway risk.
Soil-Gas Data from the eight soil-gas VOC samples collected as part of the 2019 Brownfields Assessment Report was utilized to assess the risk to residents for a soil-gas to indoor air vapor intrusion pathway. Several VOCs were detected above Residential VISLs in soil gas sample SG-5 including Ethylbenzene, n-Heptane, 2-Hexane, 1,2,4-Trimethylbenzene, and total Xylenes. Trichloroethylene was detected above the Residential VISL in soil gas sample SG-6. The DEQ Risk Calculator (May 2019) was utilized to calculate the soil gas to indoor air risk on a cumulative site-wide worst case scenario using the highest concentration of each constituent from all samples. Additionally, the DEQ Risk Calculator was used to calculate the soil gas to indoor air risk for areas
excluding soil gas sample SG-5. The residential carcinogenic and non-carcinogenic hazard indices for soil-gas to indoor air for the site-wide worst case scenario exceeded both risk thresholds at 6.7E-04 and 6.3 respectively. However, the calculated risk for the soil gas to indoor air pathway for
sample locations excluding SG-5 did not exceed the non-carcinogenic or carcinogenic hazard indices.
Risk Calculations Risk Calculations were performed using the DEQ Risk Calculator (May 2019). The risk from each environmental media was evaluated on a site-wide basis to evaluate a worst case scenario. The risk calculations indicated the following based on available data, including soil, groundwater, and soil gas samples:
Medium Site Area
Resident
LICR HI
Groundwater Exposure Entire Site 3.3E-03 30
Groundwater to Indoor
Air
Entire Site 1.4E-08 7.9E-01
Soil Exposure Entire Site 5.8E-06 8.9E-02
Soil-Gas to Indoor Air Entire Site 6.7E-04 6.3
Soil-Gas to Indoor Air Entire Site Excluding SG-5
9.4E-06 5.1E-01

Medium Site Area
Construction Worker
LICR HI
Soil Exposure Entire Site 1.1E-07 1.1E-01
Medium Site Area
Trespasser/Recreator
LICR HI
Soil Exposure Entire Site 3.2E-06 4.6E-02

Red shading LICR> 1E-04 or HI> 1
LICR = Lifetime Incremental Cancer Risk HI = Hazard Index Due to the results of the risk calculators, restrictions are in place regarding soil, groundwater, and soil gas exposure at the Brownfields Property.
Work to Be Performed Requirements: 1. Home Owner’s Association (HOA) Declaration of Covenants – Prospective Developer must
use DEQ-Prepared HOA declarations rider for attachment to their Declaration of Covenants. a. HOA must have the Obligation, Authority, and Resources to enforce the LURs. b. HOA obligated to submit annual Land Use Restriction Update.
c. HOA obligated to maintain Vapor Intrusion Mitigation Systems (VIMS) d. Minimum financial assurance reserve for environmental and or legal work: Amount is based on cost proposal from consultant for additional fees plus standard amount for legal enforcement of LURs. To be discussed further in Brownfields Agreement. 2. Development of a vapor intrusion mitigation system (VIMS) operations & maintenance plan. 3. Development of work plan for pre-occupancy sub-slab soil gas and indoor air sampling and post-occupancy annual sub-slab soil gas sampling (may be reduced to once per five years after 3 consecutive stable events). 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 multi-family residential, high density residential, parking, office, open space,
recreation, and with prior written DEQ approval, other commercial uses, can be made suitable for such uses. 2. No use for child care, adult care centers, or schools without prior written DEQ approval.
3. No groundwater use. 4. No disturbance of soil beyond 0-2 ft below land surface without prior written DEQ approval. 5. Soil Import/Export.
6. Standard Vapor Intrusion Language.
• Vapor Mitigation System – At a minimum passive with the capability to go active.
7. Development may not occur until an approved EMP.
• Final grade soil sampling.
8. Access to Brownfields Property for environmental assessment. 9. NBP reference in deed. 10. No contaminants on property except for de minimis amounts, fluid in vehicles, fuels for generators/equipment 11. LURU submission January 1st of each year.
Property Management Unit Note: Ongoing monitoring based on Townhome Minimum Requirements Checklist. The money required to be kept by the HOA is based on VIMS plan and PD provided cost proposal.
FIGURE 2SITE LOCATION MAP
511 and 527 West Tremont AvenueCharlotte, Mecklenburg County, North Carolina
ECS Project Number 49:8458-B
SOURCE:
MECKLENBURG COUNTY POLARIS GEOGRAPHIC
INFORMATION SYSTEM
SEPTEMBER 3, 2019
SCALE NOT INDICATED
Gas-Fired
Products, Inc.
Residential
Residential
Inner Peaks
Climbing
Center
Vacant Land
FIGURE 3GROUNDWATER SAMPLE LOCATION MAP
511 and 527 West Tremont AvenueCharlotte, Mecklenburg County, North Carolina
ECS Project Number 49:8458-B
SOURCE:
GOOGLE EARTH, DATED 2017
SCALE:
AS SHOWN
GROUNDWATER SAMPLE LOCATION
APPROXIMATE SITE BOUNDARY
LEGEND
MW-5
MW-4
MW-3
MW-2
MW-1
FIGURE 4SOIL SAMPLE LOCATION MAP
511 and 527 West Tremont AvenueCharlotte, Mecklenburg County, North Carolina
ECS Project Number 49:8458-AB
SOURCE:
GOOGLE EARTH, DATED 2017
SCALE:
AS SHOWN
SOIL SAMPLE LOCATION
APPROXIMATE SITE BOUNDARY
LEGEND
SUBSECTION A
SUBSECTION D
SUBSECTION C
SUBSECTION B
SUBSECTION E
D-1
D-2
D-3
D-4
E-5 E-4
E-2
E-1
E-3
A-5
A-4
A-3
A-1
B-3
B-1
B-4
B-2
B-5A-2
D-5 C-2
C-1
C-5
C-4
C-3
FIGURE 5SOIL GAS SAMPLE LOCATION MAP
511 and 527 West Tremont AvenueCharlotte, Mecklenburg County, North Carolina
ECS Project Number 49:8458-B
SOURCE:
GOOGLE EARTH, DATED 2017
SCALE:
AS SHOWN
SOIL GAS SAMPLE LOCATION
APPROXIMATE SITE BOUNDARY
LEGEND
SG-1
SG-8
SG-7
SG-6
SG-5
SG-4
SG-3
SG-2
FIGURE 6GROUNDWATER POTENTIOMETIC MAP AUGUST 19, 2019511 and 527 West Tremont AvenueCharlotte, Mecklenburg County, North Carolina
ECS Project Number 49:8458-B
SOURCE:
GOOGLE EARTH, DATED 2017
SCALE:
AS SHOWN
GROUNDWATER MONITORINGWELL LOCATION
APPROXIMATE SITE BOUNDARY
LEGEND
MW-1
MW-5
MW-3
MW-4
MW-2(697.76)(702.36)
(699.77)
(695.68)
(680.98)
(697.76)GROUNDWATER ELEVATION
GROUNDWATER POTENTIOMETRIC CONTOUR
INFERRED GROUNDWATER FLOW DIRECTION
POTENTIAL OPEN SPACE
AREA AMENITIES:
1. FIRE PITS / gAThERINg AREAS FOR SOCIAL EvENTS
ThAT MAY NCLUDE:
-COMMUNITY OUTREACh AND ChARITY EvENTS
-LOCAL wINE TASTINgS
-bOOk CLUbS
-LOCAL bREwERY TASTINgS
-FOOD TRUCkS
-CORN hOLE TOURNAMENTS
2. OUTDOOR ExERCISE AREAS
3. ShARED bIkE FACILITIES (10-12 bIkES OwNED bY ThE
COMMUNITY whICh CAN bE USED bY RESIDENTS)
4. ONE OR TwO DEDICATED RIDE ShARINg SPACES FOR
PICk-UP AND DROP OFF
5. MINI wALkINg TRAIL NETwORk
6. FENCED IN DOggY ExERCISE AREA

OPEN SPACE AREAS
527 TREMONT CHARLOTTE, NC •
PN 1018435 | 05.01.2019 | THE ARDENT COMPANIES
OPEN SPACE EXHIBIT