21040_Chemstreams Work Plan Draft #2 21071213

December 13, 2017

Mr. Bill Schmithorst, P.G
Brownfields Section-Division of Waste Management
North Carolina Department of Environmental Quality
217 West Jones Street
1646 Mail Service Center
Raleigh, North Carolina 27699-1646

Re: Work Plan – Draft #2
Data Gap Assessment Activities
Former Chemstreams, Inc.
3501 Gribble Road
Stallings, North Carolina
ID #21040-17-090

Dear Mr. Schmithorst:

On November 1, 2017, a data gap meeting was conducted with representatives from the North Carolina Department
of Environmental Quality (NCDEQ) – Brownfields Program, Resolve Environmental, Mr. John Dippert and his
attorney, Ms. Mary Katherine Stukes. The purpose of this meeting was to determine if additional assessment work
was required at the Chemstreams, Inc. facility located at 3501 Gribble Road in Stallings, North Carolina prior to
preparing a Brownfields Agreement for this property. Based on this, additional assessment was requested by the
Brownfields Program to cover the data gaps identified during this meeting. Based upon discussions with the
NCDEQ’s Brownfields Program personnel the following data gaps were identified:

• Ground water flow direction at the site.
• Potential receptors within 1,500 feet.
• Vapor intrusion sampling for volatile organic compounds (VOCs) in the existing 10,000 ft2 warehouse.
• Soil gas survey for VOCs in the vicinity of 2017 soil sample SB-6 near the former bulk AST at the
southwestern corner of the property.
• Soil gas survey for VOCs in the vicinity of 2017 ground water sample TW-3 near the former glycol recycling
processor.
• Soil gas survey for VOCs within the footprint of the proposed shop building.
• Abandonment of the obstructed on-site monitoring well.

Ground Water Flow Direction
Top of grout elevations were obtained by Resolve personnel on November 4, 2017. Ground water flow direction
was determined and will be paced on the Surveyed Plat, once completed by the surveyor.

1,500-foot Receptor Survey
Resolve will conduct a 1,500-foot receptor survey to identify any potential receptors (private water supply wells,
surface water features, etc.), zoning and land usage data.

Vapor Intrusion Sampling
Vapor intrusion sampling will be completed as detailed below. Resolve will provide a drill crew, tooling and staff
geologist to obtain sub slab and/or soil gas samples for VOCs by Method TO 15.

Existing Warehouse
Install two (2) temporary sub slab vapor monitoring points in the onsite warehouse and collect sub slab
vapor samples for volatile organic compounds.

Proposed Building Footprint
Install two (2) temporary soil-gas monitoring points in the vicinity of the proposed new structure, along
northern property boundary, near the former bulk AST area.

Former Ground Water Sample TW-3 Vicinity
Install two (2) soil-gas monitoring points in the vicinity of 2017 soil sample SB-6 near the former bulk AST
area near the southwestern corner of the property.

Former Soil Sample SB-6 Vicinity
Install two (2) soil-gas monitoring points in the vicinity of 2017 ground water sample TW-3 near the former
glycol recycling processor.

The proposed sample locations are provided on Figure 1. A summary of the proposed sample analytical methods
is provided in Table 1. The following work plan briefly discusses the additional assessment activities planned at the
site.

METHODOLOGY
Samples will be collected and analyzed in accordance with the NCDEQ, Division of Waste Management, Inactive
Hazardous Sites Program “Guidelines for Assessment and Cleanup”.

1. Sub-Slab Vapor Sampling
Sub-slab sampling methodology will follow the NC Division of Waste Management’s Vapor Intrusion Guidance.
Permanent vapor sampling points will be installed and sampled using brass VAPOR PINs®. The concrete core holes
for the vapor pins will be installed using an electric hammer drill and drill bits. Once installed, the sampling point
will be purged using a peristaltic pump to remove any ambient air that may have entered the sub slab environment.
Sub-slab vapor samples will be collected by connecting new tubing from the vapor pin to a one-liter Summa canister
with a calibrated flow controller set to a 30-minute collection time. Vapor sampling quality control measures are
further discussed below.

2. Soil-Gas Sampling
Soil-gas sampling methodology will follow the NC Division of Waste Management's Vapor Intrusion Guidance
protocol. Resolve will utilize Soil a Geoprobe Post-Run Tubing (PRT) ™ sampling system with Teflon™ tubing.
Sample depths will be at five feet and above the water table for each soil gas sampling point. Once installed, the
sampling point will be purged using a peristaltic pump to remove any stagnant or ambient air within the sampling
string. Soil gas samples will be collected by connecting new tubing from the sampling orifice to a one-liter Summa
canister with a calibrated flow controller set to a 30-minute collection time.

Sub-Slab Sampling
To evaluate potential indoor air quality risks in the 10,000 ft2 warehouse, two (2) sub-slab vapor samples (VP-1 and
VP-2) will be collected and results will be used for evaluating potential indoor vapor intrusion risk. The samples will
be analyzed for VOCs by EPA Method TO-15. The laboratory used will be a nationally certified lab by the National
Environmental Laboratory Accreditation Program (NELAP) or equivalent.

Soil-Gas Survey
A total of 6 (six) soil-gas survey sampling points (VP-3 through VP-8) will be installed at the site. Two (2) soil-gas
samples will be collected within the footprint of the proposed maintenance shop. Two (2) soil-gas sampling
locations will be advanced in the area of 2017 ground water sample TW-3 and two (2) will be installed in the area
of former 2017 soil sample SB-6, both of which had detectable VOC concentrations.

Receptor Survey
Resolve personnel will conduct a reconnaissance within 1,500 feet of the site and submit the information requested
in the NC Brownfields Program receptor survey form. The reconnaissance will document the presence and usage
of potential receptors within the search radius. Receptors will include potable and non-potable water supply wells,
basements, utility vaults, and surface water bodies. Resolve will determine the zoning and land usage of the
properties within the search radius. Identified receptors will be placed on an orthographic map and presented in
the assessment report. Well owners and associated parcel identification from the Union County GIS will also be
provided in the assessment report.

Well Abandonment
The existing onsite ground water monitoring well will be abandoned in accordance with the NCDEQ’s 2C rules. The
well casing will be removed and the well borehole will be grouted with bentonite and grout by a NC licensed well
driller. A well abandonment record will be provided in the assessment report.

QUALITY ASSURANCE/QUALITY CONTROL

1. Vapor Sampling

Sub-slab and vapor and soil-gas samples will be collected using laboratory provided and certified Summa canisters
with calibrated flow controllers. To evaluate for possible short circuiting from the surface or leakage from tubing
connections for the sub-slab samples, a cover (a clear, plastic storage bin) will be placed over the sampling point
and tubing, and helium placed within the cover. The percentage of helium will be less than 5 percent in the soil gas
measured from the sample tubing. If the helium concentration is measured above 5 percent, then the probe tube
seal will be reseated and the leak test repeated. The actual percentage will be measured using a Dielectric
MGD2002 helium detector and recorded in field notes. The sample tubing will be connected to a helium detector
and air drawn through the sample point from the sub-slab soils and monitored for helium break through. The
volume of air removed from the vapor well will be at a minimum the size of the Summa canisters used in collecting
the sample. If no helium is detected, it will be assumed that the sample point and connected tubing are properly
sealed. The sample ports and tubing will be checked to verify that water has not entered the probe prior to or
during sampling. The helium testing will purge the tubing and sub-slab sample point prior to collecting a sub-slab
vapor sample. To evaluate laboratory quality control and repeatability, one duplicate vapor sample will be collected
during each sampling event. An ambient air sample will be collected as a quality check. Negative pressure will be
maintained in the Summa canisters at the completion of sampling. Vapor sampling points installed by hand auger
will be allowed 24 hours to equilibrate after installation and purging, and will undergo a second purge prior to
collecting the sample. Direct Push (micro-purge/PRT design) sampling points will be allowed 2 hours to equilibrate
after installation. Vapor pin sampling points will be allowed 20 minutes to equilibrate after installation. The
laboratory detection limits will be reported below North Carolina vapor intrusion screening levels and J flags will be
reported.

2. Duplicates and Trip Blanks

All sampling will follow appropriate quality assurance protocols that will include vapor duplicate samples and trip
blanks. The vapor/soil gas samples will be shipped under chain of custody and analyzed by a nationally certified
laboratory (NELAP or equivalent).

Investigation Derived Waste
Soil cuttings from soil borings will be field screened and/or visually inspected. If no indication of impacts are noted,
soils will be used to backfill the soil borings and/or spread onto the ground in the vicinity of the boring. If field
screening and/or visual observations indicate soils are impacted, impacted soils will be placed into labeled 55-gallon
drums and appropriate samples collected to characterize the soils for proper disposal in accordance with
appropriate regulations.

Health and Safety
A Site-Specific Health and Safety Plan will be prepared by Resolve in accordance with 29 CFR 1910.120 (HAZWOPER).
All on-site Resolve personnel will be current with HAZWOPER training. The Health and Safety Plan will be present
on site during all field activities.

Reporting
All of the results and field data from the assessment activities will be summarized and presented in an Assessment
Report that will include all applicable field data, laboratory analytical results, tables reporting detections compared
to VISLs, figures, leak testing results and summa canister pressure readings, conclusions and recommendations for
the site, and will be certified by signature and seal of a Professional Engineer or Professional Geologist duly licensed
in North Carolina.

Please do not hesitate to call with any further questions and/or comments during your review.

Sincerely,
Resolve Environmental Services, PLLC

Terry D. Kennedy, P.G.

enclosures