18052_Gelco Trailer_DM_20170914

DECISION MEMORANDUM

DATE: September 14, 2017

FROM: Jordan Thompson

TO: BF Assessment File

RE: Gelco Trailer
1906 Bancroft Street
Charlotte, Mecklenburg County
BF # 18052-14-060

Based on the following information, it has been determined that the above referenced site,
whose intended use is for no uses other than industrial, office, retail, multi-family
residential, hotel, open space, institutional, and subject to DEQ’s prior written approval,
other commercial uses, can be made suitable for such uses.

Introduction:
The Brownfields Property consists of one parcel that is 7.933 acres and is developed with
a maintenance building totaling 3,750 square feet. The building was constructed in 1996
with prefabricated metal walls and a slab-on-grade foundation. The maintenance building
is currently vacant and was previously occupied by tractor trailer maintenance operations.
Current operations consist of tractor trailer storage operations.

Redevelopment Plans:
The immediate redevelopment use of the Brownfields Property is for tractor trailer storage.
Long term redevelopment of the Brownfields Property is proposed to be for industrial,
office, retail, multi-family residential, hotel, open space, institutional, and subject to DEQ’s
prior written approval, other commercial uses.

Site History:
The Brownfields Property was developed with an office building and paved driveway in
1986 on previously vacant land. The office building was demolished and the current
maintenance building constructed in 1996, along with the installation of a modular office
building. Site operations included tractor trailer maintenance operations (i.e. brake
maintenance, refrigerator unit repairs, etc.) from initial development of the property in
1986 until approximately 2013, when all operations ceased until 2015. Prior to
construction of the maintenance building, brake maintenance operations were completed
on asphalt paved surfaces in the northern portion of the property. The property has been
utilized for tractor trailer storage operations since 2015 and trailer maintenance operations
have not resumed.

Soil and groundwater assessment of the Property was completed in 2012 that detected
groundwater impacts of Volatile Organic Compounds (VOCs) above 2L Groundwater
Standards and soil impacts of arsenic above the Unrestricted Use Preliminary Soil
Remediation Goal (PSRG) standard but within reasonable background concentrations.
Additional VOC and metal impacts were detected below PSRGs in site soils.

A vapor intrusion evaluation completed in August 2013 did not identify impacts of VOCs
above unrestricted use standards in soil gas beneath the Site building.

Surface water and sediment from within an intermittent stream in the southern portion of
the Brownfields Property were sampled in December 2016 that identified impacts of VOCs
in the upgradient sample point above 2B Surface Water standards that were migrating onto
the Site. Impacts were not detected in sediment samples or the downgradient surface water
sample.

Potential Receptors:
Potential receptors are: construction workers, on-site workers, future residences, visitors,
and trespassers. A receptor survey completed in August 2016 did not identify public or
private water supply wells within 1,500 ft of the Brownfields Property.

Contaminated Media:
DEQ has evaluated data collected from the following media at the subject property: soil,
groundwater, surface water, and sub-slab vapor. DEQ relies on the following data to base
its conclusions regarding the subject property and its suitability for its intended reuse.

Soil
Soil samples were collected in the vicinity of the maintenance building and along the
perimeter of the Brownfields Property parcel and analyzed for VOCs, Semi-VOCs
(SVOCs), Total Petroleum Hydrocarbons (TPH), Polychlorinated Biphenyls (PCBs), and
Resource Conservation and Recovery Act (RCRA) metals. Surficial impacts of arsenic
were identified above DEQ IHSB Unrestricted Use PSRGs throughout the Site and appear
to be at background concentrations.

The table below demonstrates the hazard quotient of soils on the property based on the
highest concentrations identified. The residential hazard quotient is 0.11 and the non-
residential hazard quotient is 0.00833. Refer to the attached August 2012 Phase II ESA
and August 2012 Supplemental Investigation.

Groundwater
Nine monitoring wells were installed on the property in 2011 that have been abandoned.
The monitoring wells were sampled in 2011 and 2013 and impacts of VOCs were detected
above 2L Groundwater Standards. Refer to attached Exhibit 2 for detected concentrations
of VOCs. The table below demonstrates the hazard quotient of groundwater on the
property based on the highest concentrations identified during the most recent (2013)
groundwater sampling event. The highest concentrations detected during the 2013
sampling event were calculated with the VISL Calculator and a Hazard Index of 6.27 was
identified.

Surface Water
A Limited Site Investigation was completed in December 2016 and sediment and surface
water from within the on-site intermittent tributary were sampled. Samples were collected
at the upgradient portion of the tributary adjacent to the upgradient property boundary and
on the downgradient portion of the stream downstream from Site operations and analyzed
for VOCs. VOCs were detected in the upgradient surface water sample above DEQ 2B
Surface Water Quality Standards (SWQS). VOCs were not detected in the downgradient
surface water sample or in the sediment samples above DEQ Standards collected from the
intermittent stream on the Brownfields Property. The results of the Limited Site
Investigation indicate that impacted surface water is migrating onto the Brownfields
Property from an upgradient source. Refer to the attached Exhibit 2 and Limited Site
Investigation.

Soil Vapor
No soil vapor testing was completed.

Sub-Slab Vapor
A Vapor Intrusion Assessment Report was completed in August 2013 that installed four
sub-slab vapor sampling points beneath the maintenance building. Low concentrations of
PCE were detected that were below residential and non-residential screening criteria. The
table below demonstrates the hazard quotient of sub-slab vapor on the property based on
the highest concentrations identified. The highest concentration of PCE detected was
calculated with the VISL Calculator and a Hazard Index of 0.17 was identified. Refer to
the attached Vapor Intrusion assessment and table below.

Indoor Air
No indoor air testing was completed.

Risk Calculations
Risk Calculations were performed using Excel worksheets provided by Sandy Mort,
NCDEQ Brownfields Toxicologist. Based on the small size of the property and impacts
identified, the property impacts were reviewed as a whole. Based on the potential future
use of the property for residential use, the impacts were calculated using residential and
non-residential standards. The risk calculations indicated the following based on available
data, including the following media: groundwater, soil, and soil gas samples:

Medium Site Area Residential Non-Residential
LICR HI LICR HI
Groundwater All – 2013 1.3 x 10-4 29.6 2.3 x 10-5 7.06
Soil Vapor Building 6.4 x 10-7 0.165 4.9 x 10-8 0.0131
Residual Soil Max All 5.9 x 10-6 0.28 1.33 x 10-6 0.0439
Red shading LICR> 1E-04 or HI> 1.
LICR = Lifetime Incremental Cancer Risk
HI = Hazard Index

The immediate planned use of the property is for storage of tractor trailers with
redevelopment to be determined at a later date. Based on the sub-slab results beneath the
current building and the open nature of the remainder of the property, the current hazard
quotients are acceptable. Final grade sampling will be required during any soil disturbance
as part of an EMP to ensure lack of potential exposure. Additionally, vapor intrusion will
be addressed for any future buildings on the property.

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.

- No child or adult care centers
- No playgrounds, parks, or for ground-contact sports
- No groundwater/surface water use
- No soil disturbance without DEQ approval
- No soil import or export without DEQ approval
- No enclosed building without VI assessment
- No surface water use
- Maintenance of fence along drainage feature
- Notification of building demolition or renovation
- EMP required for redevelopment
- Redevelopment notification
- DEQ shall not be denied access
- Deed conveyance of BFA
- None of the contaminants present may be stored on-site
- LURU submittal