19067_Gateway Plaza_VIMS_DC920021_20191217

AECOM AECOM Technical Services of North Carolina, Inc. 919.461.1100 tel
1600 Perimeter Park Drive, Suite 400 919.461.1415 fax
Morrisville, NC 27560
December 17, 2019
North Carolina Department of Environmental Quality
Division of Waste Management — DSCA Program
1646 Mail Services Center
Raleigh, NC 27699-1646
Att: Mr. Billy Meyer
DSCA Project Manager
Re: Pilot Test Report
T&J Cleaners DSCA Site ID #DC920021
2423 Crabtree Boulevard
Raleigh, Wake County, North Carolina
Dear Mr. Meyer:
AECOM Technical Services of North Carolina, Inc. (includes legacy URS and herein referred to as
AECOM) is pleased to provide this Pilot Test Report for the T&J Cleaners (#DC920021) site located at
2423 Crabtree Boulevard, Raleigh, North Carolina. This report was completed in accordance with the
scope of work documented in an AECOM Sub -Slab Depressurization Pilot Test Cost Proposal, dated
October 7, 2019, as approved by DSCA under State Lead Authorization for Work (SLAW) 022 on
October 7, 2019. The primary objectives of the Pilot Test Report are to document the installation of the
sub -slab depressurization (SSD) extraction points and vapor pins, pilot test results, and recommendations
for full-scale system design parameters.
Site Description and Background
The former T&J Cleaners site consists of five individual tenant spaces/units in a strip mall: 1) 2409-
122/Pawn Shop; 2) 2409-123/Carmen's Fashion; 3) Craft Habit; 4) Mordecai Beverage Co (Mordecai);
and 5) Gateway Arts Project. A Phase I Environmental Site Assessment (ESA) determined the site has
existed as a shopping center since 1968, with Medlin -Davis Cleaners operating within the current Craft
Habit tenant space from 1968 through 1994 and Peggy's Cleaners operating from 1994 to 1996 (DL
Restoration, 2002). The current configuration of the site is illustrated in Figure 1.
Interim remedial action activities were completed at the site in 2015 and 2016 to address the presence of
contaminant source area impacts identified beneath the courtyard and rear of the former dry-cleaning
facility, as these impacts were likely affecting groundwater, soil gas, and indoor air quality at the site.
Comprehensive information specific to these interim remedial actions is documented in URS' Interim
Remedial Action Report — Injection/SSDS Installation, dated February 25, 2016, and URS' Interim
Remedial Action Report Addendum, dated November 14, 2016. As part of these interim remedial action
activities, a soil vapor extraction (SVE) system was installed to reduce source area soil contaminant mass,
as well as function as a sub -slab depressurization system (SSDS) to mitigate subsurface vapors from
migrating into the former dry-cleaner tenant space.
As documented in URS' Interim Remedial Action Report Addendum, dated November 14, 2016, and as
discussed with DSCA, the SVE/SSDS was manually shut down on November 9, 2016, as the former dry-
cleaner tenant space was vacated by the Bid -Rite Sweepstakes operation and the exposure pathway was
no longer complete as there was no occupant in the tenant space. It was decided between DSCA and URS
that the SVE/SSDS would be restarted once the tenant space was re -occupied.

AECOM
Mr. Billy Meyer
T&J Cleaners - #DC920021
December 17, 2019
Page 2 of 6
The SVE/SSDS was restarted on July 7, 2017, as a new tenant (i.e., Craft Habit) began renting the unit.
Additional confirmatory indoor air sampling was completed on November 28, 2017, as documented in
AECOM's November 2017 Indoor Air Sampling Report, dated January 5, 2018, to confirm the efficacy of
the system. Based on the acceptable November 2017 indoor air results and calculated carcinogenic risks,
the SVE/SSDS was providing adequate slab depressurization, and continued operation of the system with
monthly operations and maintenance (O&M) visits was recommended as long as the tenant space was
occupied.
After a discussion on March 5, 2019 with DSCA concerning the existing SVE/SSDS with respect to
significant renovations and construction improvements in the adjacent tenant spaces, AECOM proposed
that modifications to the system be evaluated to improve operating efficacy and cost-effectiveness. As
part of the evaluation process, the existing system was shut down on April 3, 2019, and two Austin Air
Systems portable air purifying scrubbers were installed as an interim vapor intrusion mitigation measure
until renovations were complete within the Gateway Plaza. Prior to shutting down the SVE/SSDS on
April 3, 2019, AECOM collected an 8-hour indoor air sample from the former dry-cleaning tenant space
to provide baseline conditions from which future mitigation measures could be evaluated and also
determine the volatile organic compound (VOC) mass removal of the system beneath the slab for
comparison to the October 2017 mass removal calculation. As documented in AECOM's 2019 System &
Vapor Quality Evaluation Report, dated August 13, 2019, the calculated mass removal rate in April 2019
was 0.03 pounds per day (lbs/day) compared to a mass removal rate of 0.25 lbs/day in October 2017,
which indicates that the mass of VOCs present underneath the slab has been reduced and the operating
efficacy of the SVE portion of the system may be minimized.
As also documented in AECOM's 2019 System & Vapor Quality Evaluation Report, elevated sub -slab
contaminant vapor concentrations are present at unacceptable risk levels for non-residential use within the
following tenant spaces located in the Gateway Plaza shopping center: 1) 2409-122/Pawn Shop; 2) 2409-
123/Carmen's Fashion; and 3) Craft Habit (former dry-cleaner). Although sub -slab samples were not
collected in 2019 in the current Gateway Arts Project tenant space, previous sub -slab contaminant vapor
concentrations indicated unacceptable risk levels for non-residential use, therefore, the Gateway Arts
Project tenant space was proposed for inclusion in the SSDS pilot test.
With the exception of the tenant space occupied by Mordecai and Craft Habit, indoor air samples have not
been collected within any of the above listed tenant spaces following site redevelopment activities, which
were initiated in 2018. An indoor air sample collected from Mordecai in June 2019 indicated air quality
that is acceptable for non-residential use given the current conditions within the building. Historic indoor
air samples collected from within the former dry-cleaners tenant space have indicated contaminant vapor
contaminant concentrations at levels exceeding non-residential risk, which resulted in the installation of a
SSDS beneath the former dry-cleaners tenant space in 2016. Although unacceptable indoor air risk has
not been documented for the adjacent tenant spaces, the DSCA and Brownfields Programs have been in
negotiations to include the operation of an SSDS that encompasses mitigation of up to five tenant spaces
listed herein within a Brownfields Agreement, which would allow for site closure within the DSCA
Program pending the completion of a site -specific risk assessment.
As requested by DSCA, AECOM completed a rough cost estimate, dated August 28, 2019, for multiple
mitigation scenarios operated over a 20-year period for the tenant spaces of concern. The cost estimate
included: 1) continued operation of the current SSDS underneath the former dry-cleaners tenant space; 2)
installing an SSDS capable of mitigating vapor intrusion beneath the four targeted tenant spaces using
horizontal vapor extraction lines trenched beneath the floors of each of the tenant spaces; and 3) installing
an SSDS capable of mitigating vapor intrusion beneath all four tenant spaces using vertical vapor
extraction points connected to overhead piping routed to the roof of the tenant spaces. After review with
DSCA, it was determined that due to potential cost savings over a 20-year period, additional pilot testing

A=COM
Mr. Billy Meyer
T&J Cleaners - #DC920021
December 17, 2019
Page 3 of 6
should be completed to obtain design criteria for an SSDS that would provide adequate slab
depressurization, in accordance with applicable guidance documents. The design criteria could be
utilized to more accurately estimate the cost of installing the SSDS in the targeted tenant spaces.
Pilot Testing
The purpose of the SSD pilot test was to gather performance data to assist with the design of a full-scale
system for vapor intrusion mitigation. The overall approach of the pilot test was to extract air from the
subsurface from extraction points, evaluate the resulting airflow rates and applied vacuums at the
extraction points, evaluate vacuum influence at radially located and spaced vapor pins, and monitor
extracted air for concentrations of VOCs throughout the testing. A similar test was conducted in July
2017 in the tenant space currently occupied by Craft Habit. Specific design data obtained during the 2019
pilot test included the following:
• Airflow extraction rate and applied vacuum;
• VOC concentrations in the extracted air stream from the extraction point; and
• Subsurface vacuum at vapor pins.
Sub -Slab Depressurization Test
On October 16 and 17, 2019, AECOM installed five sub -slab extraction points, nine permanent vapor
points, and 15 temporary monitoring points and conducted five individual sub -slab depressurization tests.
The objective was to achieve a differential pressure of -0.02 inches water column (IWC), or 5 pascals,
beneath the slab, as the permanently installed SSDS will need to induce a differential pressure of -0.02
IWC across the entire slab of a tenant space.
Each SSD extraction point consisted of a 1.5-inch core installed through the concrete slab utilizing a
hammer drill to access the subgrade. A 3.5-horsepower shop vacuum was connected to the extraction
point equipped with a dilution valve to adjust the applied vacuum and a sample port to collect airflow
measurements, vacuum readings, and sub -slab soil gas samples. The permanent (vapor pins) and
temporary vapor monitoring points were installed in select locations to collect vacuum readings at
different distances/directions from the extraction points. A micromanometer was connected to each
monitoring point to monitor applied vacuum and to calculate the radius of influence (ROI) of the applied
vacuum. Additionally, photoionization detector (PID) readings were collected from each monitoring
point to assess VOC concentrations and distribution beneath the slab. The locations of the extraction
points and monitoring points, as well as, the baseline PID readings are illustrated on Figure 2.
SSD-1 Test Details and Results
As indicated on Figures 1 and 2, SSD-1 was installed in the Pawn Shop, along the shared wall with
Carmen's Fashion. Multiple vacuum steps (low to high) were utilized to evaluate the relationship between
applied vacuum and airflow in the subsurface. Vacuum readings were collected from three vapor pins and
one temporary monitoring point. It should be noted that sub -slab vapor pins SSV-12 and SSV-13, as
shown on Figures 1 and 2, are associated with the October 2019 testing and not the June/July 2019 sub -
slab vapor analytical testing, as documented in AECOM's 2019 System & Vapor Quality
Evaluation Report, dated August 13, 2019. The sub -slab conditions under this unit appear to be
loosely compacted gravel fill that allows for good airflow. The extraction point in the Pawn Shop was
able to influence monitoring points inside Carmen's Fashion, suggesting that the wall between Carmen's
Fashion and the Pawn Shop does not have a concrete footer that would block radial vacuum influence
between the units.

A=COM
Mr. Billy Meyer
T&J Cleaners - #DC920021
December 17, 2019
Page 4 of 6
A wellhead vacuum of 2.0 IWC and an airflow rate of 25 cubic feet per minute (cfm) is needed for an
ROI of approximately 41 feet to achieve a differential pressure of -0.02 IWC. Two vapor samples were
collected from the extracted air stream and screened with a PID and values ranged from 7.3 to 8.3 parts
per million (ppm). The pilot test results for extraction point SSD-1 are presented in Table 1. The ROI
calculations are included in Appendix A.
SSD-2 & SSD-5 Test Details and Results
As indicated on Figures 1 and 2, SSD-2 was installed in Carmen's Fashion, along the shared wall with
Craft Habit, towards the northern end of the tenant space. Multiple vacuum steps (low to high were
utilized to evaluate the relationship between applied vacuum and airflow in the subsurface. Several floor
drains were observed to run along this shared wall and there may be underground utilities/structures
impacting sub -slab flow, as shown on Figure 2. Thus, another extraction point (SSD-5) was installed in
the middle of the unit for further testing, as discussed in further detail below. The extent of the subsurface
obstruction near SSD-2 is unknown and achieving a differential vacuum of 0.02 IWC does not appear to
be feasible in that area. However, it should be noted that the PID readings collected in this area were less
than 1 ppm so mitigation in this area may not be necessary. The wall between Carmen's Fashion and
Craft Habit is load -bearing and it is unlikely that an extraction point can influence across it. The area
restricted by drain lines is illustrated on Figure 2.
As indicated on Figures 1 and 2, SSD-5 was installed in the center of Carmen's Fashion after testing at
SSD-2 provided evidence of limited ROI. Additional monitoring points were added between SSD-2 and
SSD-5 to evaluate the extent of the subsurface obstruction around SSD-2. Multiple vacuum steps (low to
high) were utilized to evaluate the relationship between applied vacuum and airflow in the subsurface.
Vacuum readings were collected from six vapor pins and five temporary monitoring points. It should be
noted that sub -slab vapor pins SSV-9, SSV-10, and SSV-11, as shown on Figures 1 and 2, are associated
with the October 2019 testing and not the June/July 2019 sub -slab vapor analytical testing, as
documented in AECOM's 2019 System & Vapor Quality Evaluation Report, dated August 13,
2019. The sub -slab conditions under this unit appear to be loosely compacted gravel fill that allows for
good airflow. The extraction point did influence monitoring points inside the Pawn Shop, suggesting that
the wall between Carmen's Fashion and the Pawn Shop does not have a concrete footer that would block
radial vacuum influence between the units.
A wellhead vacuum of 2.0 IWC and an airflow rate of 20 cfm is needed for an ROI of approximately 41
feet. Five air samples were collected from the extracted air stream and screened with a PID and values
ranged from 1.8 to 6 ppm. The pilot test results for extraction point SSD-5 are presented in Table 2. The
ROI calculations are included in Appendix A.
SSD-3 Test Details and Results
As indicated on Figures 1 and 2, SSD-3 was installed in Mordecai, along the shared wall with Craft
Habit. Multiple vacuum steps (low to high) were utilized to evaluate the relationship between applied
vacuum and airflow in the subsurface. Vacuum readings were collected from four vapor pins and five
temporary monitoring points. The sub -slab conditions under this unit appear to be tightly compacted dirt
fill. The extraction point in Mordecai was not able to influence monitoring points inside Craft Habit or
points past a concrete step running across the unit (i.e., SSV-2 and SSV-3), suggesting that the wall and
concrete step block radial vacuum influence. Suspected structural walls and the concrete step are shown
in Figure 1.

A=COM
Mr. Billy Meyer
T&J Cleaners - #DC920021
December 17, 2019
Page 5 of 6
A wellhead vacuum of 35 IWC and an airflow rate of 35 cfm is needed for an ROI of approximately 21
feet. Five air samples were collected from the extracted air stream and screened with a PID and values
ranged from 12.3 to 21.9 ppm. The pilot test results for extraction point SSD-3 are presented in Table 3.
The ROI calculations are included in Appendix A.
SSD-4 Test Details and Results
As indicated on Figures 1 and 2, SSD-4 was installed in the Gateway Arts Project tenant space, located
behind the other tenant spaces and courtyard area. Multiple vacuum steps (low to high) were utilized to
evaluate the relationship between applied vacuum and airflow in the subsurface. Vacuum readings were
collected from two vapor pins and four temporary monitoring points. The sub -slab conditions under this
unit appear to be loosely compacted gravel fill that allows for good airflow. The extraction point in the
Gateway Arts Project tenant space was not able to influence monitoring points inside Carmen's Fashion,
suggesting that the wall between the units blocks radial vacuum influence.
A wellhead vacuum of 2.5 IWC and an airflow rate of 21 cfm is needed for an ROI of approximately 32
feet. Four air samples were collected from the extracted air stream and screened with a PID, values
ranged from 1.2 to 2.0 ppm. The pilot test results for extraction point SSD-4 are presented in Table 4.
The ROI calculations are included in Appendix A.
SSD Test Conclusions
Baseline PID readings were collected from monitoring points prior to conducting the pilot test and two of
the 25 locations had a PID reading over 100 ppm, as indicated on Figure 2. Both of the monitoring
points with PID readings over 100 ppm were located along the shared wall between Craft Habit and
Mordecai. The vapor monitoring points and baseline PID readings can be found on Figure 2. A vapor
isocontour figure is included as Figure 3, which includes sub -slab vapor quality data (collected in
June/July 2019) and provides an interpretation of the elevated sub -slab soil gas concentrations that may
be targeted for future mitigation.
Based on the extraction tests at Craft Habit in 2017 and the four different tenant spaces in 2019, the
operating parameters of a sub -slab depressurization point at the Site can vary depending on the location.
The sub -slab soil conditions for all units, except Mordecai and Craft Habit, consists of loose, gravel -like
fill with good airflow. Mordecai and Craft Habit are the only units that appear to have compacted, dirt fill,
requiring a higher wellhead vacuum. Previous testing in Craft Habit, as documented in AECOM's Indoor
Air Sampling and Radius -of -Influence Report, dated August 29, 2017, indicated an ROI of approximately
22 feet at a wellhead vacuum of 6.7 IWC.
A summary of each location is below:
SSD-1: Pawn Shop
• The calculated ROI for SSD-1 is approximately 41 feet at a wellhead vacuum of 2 1WC and an
airflow rate of 25 cfm.
SSD-2 & SSD-5 Carmen's Fashion
• The area around SSD-2 (northwestern corner) had no influence and there may be subsurface
obstructions preventing airflow within this limited area.
• The calculated ROI for SSD-5 is approximately 41 feet at a wellhead vacuum of 2 IWC and an
airflow rate of 20 cfm.

A=COM
Mr. Billy Meyer
T&J Cleaners - #DC920021
December 17, 2019
Page 6 of 6
SSD-3: Mordecai
The calculated ROI for SSD-3 is approximately 21 feet at a wellhead vacuum of 35 IWC and an
airflow rate of 35 cfm.
SSD-4: Gateway Arts Project
• The calculated ROI for SSD-4 is approximately 32 feet at a wellhead vacuum of 2.5 IWC and an
airflow rate of 21 cfm.
Craft Hahit
The calculated ROI for the extraction point tested in July 2017 was approximately 22 feet at a
wellhead vacuum of 6.7 IWC.
If you have any questions or require additional information, please do not hesitate to call either Rob
MacWilliams at 704-499-4839 or Carlin Slusher at 919-461-1341.
Sincerely,
AECOM TECHNICAL SERVICES OF NORTH CAROLINA, INC.
Carlin E. Slusher
Project Manager
Table I Pilot Test Results - SSD-1
Table 2 Pilot Test Results - SSD-5
Table 3 Pilot Test Results - SSD-3
Table 4 Pilot Test Results - SSD-4
Figure 1 Site Map
Figure 2 Sub -Slab Vapor Screening and Sample Results
Figure 3 Vapor Isocontour Map
Appendix A Radius of Influence Calculations
Appendix B Photo Log
Robert H. MacWilliams, PG
Program Manager

TABLES

Table 1
Pilot Test Results - SSD-1
Former T&J Cleaners
Raleigh, NC
Vapor Monitoring Points
SSV-15
TP-1
SSV-12
SSV-14
SSV-16
SSV-11
Time
Wellhead
Vacuum
IWC)
Airflow
(CFM)
PID
Reading
(ppm
d= 10.4 ft. SSD-1
d= 15 ft. SSD-1
d= 20.3 ft. SSD-1
d= 35.8 ft. SSD-1
Carmen's Fashion
Carmen's Fashion
Vacuum (IWC)
Vacuum (IWC)
Vacuum (IWC)
Vacuum (IWC)
Vacuum (IWC)
Vacuum (IWC)
Baseline
1
-0.011
-0.001
-0.041
-0.022
-0.002
0.004
14:50
1.5
21
7.3
0.216
0.119
0.111
0.041
0.046
0.078
15:00
2.0
25
8.3
0.312
0.162
0.156
0.050
0.034
0.095
15:25
1.0
1
1
0.250
0.127
0.140
0.058
0.017
0.072
IWC = inches of water d = distance away
CFM = cubic feet per minute (-) denotes pressure
PID = photoionization detector ft. = feet
ppm = parts per million blank cell = not collected

Table 2
Pilot Test Results - SSD-5
Former T&J Cleaners
Raleigh, NC
Vapor Monitoring Points
TP-15
TP-13
SSV-11
TP-12
SSV-16
SSD-2
TP-2
SSV-17
TP-14
SSV-4
SSV-10
Wellhead
d= 4.5 ft. (SSD-5)
d= 6.5 ft. (SSD-5)
d= 8.5 ft. (SSD-5)
d= 11 ft. (SSD-5)
d= 14 ft. (SSD-5)
d= 16.5 ft. (SSD-5)
d= 20 ft. (SSD-5)
d= 21 ft. (SSD-5)
d= 25 ft. (SSD-5)
Craft Habit
46.5
Time
Vacuum
IWC
Airflow
CFM
PID Reading
m
Vacuum (IWC)
Vacuum (IWC)
Vacuum (IWC)
Vacuum (IWC)
Vacuum (IWC)
Vacuum (IWC)
Vacuum (IWC)
Vacuum (IWC)
Vacuum (IWC)
Vacuum (IWC)
Vacuum (IWC)
Baseline
1 0.000
0.000
-0.015
-0.005
0.000
0.000
0.000
1 -0.002
-0.008
0.005
-0.008
15:15
1.0
21
6.0
0.129
0.050
0.009
0.000
0.000
0.000
-0.009
15:30
2.0
25
3.2
0.252
0.106
0.032
-0.002
0.000
0.000
0.000
16:15
1.0
15
1.8
0.128
0.005
0.157
0.060
0.012
-0.001
0.000
0.000
0.012
0.004
0.000
16:30
2.0
20
1.9
0.212
0.009
1 0.281
0.111
0.024
0.000
0.000
0.001
0.038
1 0.005
0.001
16:45
3.0
1 22
2
0.322
1 0.013
0.397
1 0.162
0.048
1 0.000
1 0.000
0.002
1 0.046
0.004
-0.004
IWC = inches of water d = distance away
CFM = cubic feet per minute (-) denotes pressure
PID = photoionization detector ft. = feet
ppm = parts per million blank cell = not collected

Table 3
Pilot Test Results - SSD-3
Former T&J Cleaners
Raleigh, NC
Vapor Monitoring Points
TP-8
SSV-19
TP-9
TP-7
TP-11
TP-10
SSV-20
SSV-1
SSV-18
SSV-4
Time
Wellhead
Vacuum
IWC)
Airflow
(CFM)
PID Reading
(ppm
d= 8 ft. (SSD-3)
d= 8 ft. (SSD-3)
d=10.5 ft. (SSD-3)
d= 12 ft. (SSD-3)
d= 14 ft. (SSD-3)
d= 16 ft. (SSD-3)
d= 17.5 ft. (SSD-3)
d= 23.3 ft. (SSD-3)
d= ft. (SSD-3)
d= ft. (SSD-3)
Vacuum (IWC)
Vacuum (IWC)
Vacuum (IWC)
Vacuum (IWC)
Vacuum (IWC)
Vacuum (IWC)
Vacuum (IWC)
Vacuum (IWC)
Vacuum (IWC)
Vacuum (IWC)
Baseline
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.021
0.005
11:55
5.0
22
21.9
0.000
0.018
0.002
0.004
0.000
0.021
0.004
12:10
10.0
25
21.5
0.003
0.031
0.004
0.012
0.000
0.002
0.000
12:30
10.0
0.002
0.031
0.051
0.004
0.012
0.011
0.000
12:45
10.0
0.022
0.051
0.000
0.011
12:50
15.0
26
14.2
0.003
0.041
0.075
0.005
0.000
0.019
0.017
0.000
0.013
0.004
13:05
25.0
33
14.3
0.006
0.070
0.115
0.009
0.002
0.023
0.024
0.000
13:15
35.0
35
12.3
0.008
0.100
0.157
0.012
0.004
0.032
0.037
0.000
0.010
0.000
IWC = inches of water d = distance away
CFM = cubic feet per minute (-) denotes pressure
PID = photoionization detector ft. = feet
ppm = parts per million blank cell = not collected

Table 4
Pilot Test Results - SSD-4
Former T&J Cleaners
Raleigh, NC
Vapor Monitoring Points
SSV-21
TP-3
TP-5
SSV-22
TP-6
TP-4
SSV-9
Time
Wellhead
Vacuum
IWC)
Airflow
(CFM)
PID
Reading
(ppm
d= 7 ft. SSD-4
d= 15 ft (SSD-4
d= 15 ft SSD-4
d= 20 ft. SSD-4
d= 22 ft. (SSD-4
d= 30 ft. SSD-4)
Carmen's Fashion
Vacuum (IWC)
Vacuum (IWC) I
Vacuum (IWC)
Vacuum (IWC)
Vacuum (IWC)
Vacuum (IWC)
Vacuum (IWC)
Baseline
0.000
0.000
0.000
0.000
0.000
0.002
9:35
1.0
17
1.3
0.062
0.071
0.000
0.040
0.000
0.014
0.006
9:50
1.5
16
2.0
0.081
0.094
-0.002
0.048
0.000
0.016
0.007
10:05
2.5
21
1.7
0.141
0.159
0.000
0.096
0.000
0.016
0.005
10:20
3.0
20
1.2
0.163
0.189
0.112
0.05
0.005
IWC = inches of water d = distance away
CFM = cubic feet per minute (-) denotes pressure
PID = photoionization detector ft. = feet
ppm = parts per million blank cell = not collected

FIGURES

PARKING
%lSV-1
/ T/ 10
9 P-7
/ P-90 / / SSV-4 / / SSV-
/ SSV- / • SD-3 * �/
RESTAURANT/
EVENT SPACE
APPROXIMATE AREA OF 5 FLOOR
DRAINS AND SEALED UP PIPES
DTP-1
V-16 / /
SSV-0
STRUCTURAL WALL w/ FOOTER
EXTRACTION POINT
PERMANENT VAPOR
MONITORING POINT
TEMPORARY VAPOR
MONITORING POINT
0 30
APPROX. SCALE, ft.
N
CN
N
0 r N o
o -D F
3 - O
QO
L S 0
0
SHEET
Fig. 1

PARKING
ram,
CO
z %lSV-�
/ TP//10
• �I P-7 •
/ P-9• / / SSV-4 / / SSV-
/ SSV- / • SD-3 �/
RESTAURANT/
EVENT SPACE
APPROXIMATE AREA OF 5 FLOOR
DRAINS AND SEALED UP PIPES
V-16 / /
SSV-•
ULD
ppm
NS
Location
PID (ppm)
SSV-1
5.7
SSV-2
2.3
SSV-3
NS
SSV-19
156.8
SSV-20
23.6
TP-7
1.6
TP-8
0.4
TP-9
14.1
TP-10
5.3
TP-11
0.0
SSV-4
4.1
L csa
U =
SSV-5
20.7
SSV-18
437.0
SSD-2
0.0
SSV-9
19.5
SSV-10
51.7
SSV-11
58.0
o
SSV-16
21.4
a
SSV-17
3.4
TP-2
0.0
TP5
0.9
TP-6
10.2
TP-12
3.0
TP-13
0.2
TP-14
2.3
TP-15
0.0
SSV-12
8.4
a
C
s
=
aSSV-15
SSV-13
NS
SSV-14
58.5
78.8
TP-1
32.8
a
SSV-21
0.8
SSV-22
0.4
TP-3
0.4
TP-4
0.0
STRUCTURAL WALL w/ FOOTER
EXTRACTION POINT
PERMANENT VAPOR
MONITORING POINT
TEMPORARY VAPOR
MONITORING POINT
PHOTOIONIZATION DETECTOR
PARTS PER MILLION
NOT SAMPLED
0 30
APPROX. SCALE, ft.
N
o CN
N
o -
SHrET
Fig. 2

PARKING
LEGEND
STRUCTURAL WALL w/ FOOTER
SSD-•
EXTRACTION POINT (OCTOBER 2019)
SSV-•
PERMANENT VAPOR MONITORING
POINT (OCTOBER 2019)
TEMPORARY VAPOR MONITORING
POINT (OCTOBER 2019)
(##)®
SUB -SLAB VAPOR SAMPLE POINT
AND PCE CONCENTRATION
(JUNE/JULY 2019)
PID
PHOTOIONIZATION DETECTOR
ppm
PARTS PER MILLION
NS
NOT SAMPLED
ug/m3
MICROGRAMS PER CUBIC METER
/ ,00 COVE
i
% T % • / -7 (15,000) //•
/ -90 / SSV-k SSV-
/ SSV- • D-3
----- GREATER THAN 50 ppm (FIELD, 2019)
AND/OR GREATER THAN 10,000 ug/m3
PCE (LAB, 2019)
GREATER THAN 20 ppm (FIELD, 2019)
AND/OR GREATER THAN 1,000 ug/m3
PCE (LAB, 2019)
----- LESS THAN 20 ppm (FIELD, 2019)
AND/OR LESS THAN 1,000 ug/m3 PCE
(LAB, 2019)
APPROXIMATE AREA OF 5 FLOOR
DRAINS AND SEALED UP PIPES
Location IDs*
PID
PCE
Units
ppm
lag/m'
Date
October 2019
June/July 2019
a�i
o
SSV-1
5.7
6,000 (SSV-1)
SSV-2
2.3
130 (SSV-2)
SSV-3
NS
74 (SSV-3)
SSV-19
156.8
-
SSV-20
23.6
-
TIP-7
1.6
-
TP-8
0.4
-
TP-9
14.1
-
TP-10
5.3
-
TP-11
0.0
-
L
v =
SSV-4
4.1
15,000 (SSV-4)
SSV-5
20.7
17,000 (SSV-5)
SSV-18
437.0
-
o
t
LL
a=i
£
v
SSD-2
0.0
-
SSV-9
19.5
46,000 (SSV-8)
SSV-10
51.7
91,000 (SSV-7)
SSV-11
58.0
25,0000 (SSV-6)
SSV-16
21.4
-
SSV-17
3.4
-
TP-2
0.0
-
TP5
0.9
-
TP-6
10.2
TP-12
3.0
-
TP-13
0.2
-
TP-14
2.3
-
TP-15
0.0
-
a
SSV-12
8.4
-
Cn
SSV-13
NS
7,900 (SSV-11)
SSV-14
58.5
-
SSV-15
78.8
-
°'
TP-1
32.8
-
>,
SSV-21
0.8
-
3
a
SSV-22
0.4
-
TIP-3
0.4
-
TP-4
0.0
-
* SUB -SLAB LOCATION IDs MAY NOT BE THE
SAME FOR OCTOBER 2019 FIELD ROI
TESTING AND JUNE/JULY 2019 SUB -SLAB
VAPOR ANALYTICAL RESULTS.
`71 > o
�paU
�o6 o5 CZCl)
o�U�¢
R. C7 U
� C\] Q
N
o
N
I�
o �
m =
3
o
�
0 O
0 30
SI EET
APPROX. SCALE, ft.
Fig. 3

APPENDIX A
RADIUS OF INFLUENCE CALCULATIONS

Calculations for SSD-1: Pawn Shop
Site Name: Former T&J Cleaners
Site Address: 2423 Crabtree Blvd, Raleigh, NC
Data Point
Distance (feet)
D Vacuum (IWC)
SSV-15
10.4
0.323
TP-1
15
0.163
SSV-12
20.3
0.197
SSV-14
35.8
0.072
0.35
0.3
0.25
0.2
0.15
0.1
y =-0.0082x + 0.3557
0.05
0
0 5 10 15 20 25 30 35 40
* Target vacuum utilized in calculations was 0.02 IWC or 5 pascals
-ROI is approximately 40 feet
-Wellhead vacuum of 2.0 IWC and an airflow rate of 25 cfm
ROI = Radius of Influence A = change
IWC = inches of water cfm = cubic feet per minute

Calculations for SSD-5 ROI: Carmen's Fashion
Site Name: Former T&J Cleaners
Site Address: 2423 Crabtree Blvd, Raleigh, NC
Data Point
Distance (feet)
D Vacuum (IWC)
TP-15
4.5
0.212
SSV-11
8.5
0.296
TP-12
11
0.116
SSV-16
14
0.024
TP-14
25
0.046
SSV-10
46.5
0.009
0.35
0.3
0.25
0.2
0.15
0.1
0.05
0
-0.05
* Target vacuum utilized in calculations was 0.02 IWC or 5 pascals
-R01 is approximately 40 feet
-Wellhead vacuum of 2.0 IWC and an airflow rate of 25 cfm
R01 = Radius of Influence A = change
IWC = inches of water cfm = cubic feet per minute

Calculations for SSD-3 ROI: Mordecai Beverage Co
Site Name: Former T&J Cleaners
Site Address: 2423 Crabtree Blvd, Raleigh, NC
Data Point
Distance feet
A Vacuum IWC
SSV-19
8
0.100
TP-9
10.5
0.157
SSV-20
17.5
0.037
0.180
0.160
0.140
0.120
0.100
0.080
0.060
0.040
0.020
0.000
0 5 10
* Target vacuum utilized in calculations was 0.02 IWC or 5 pascals
-RO1 is approximately 21 feet
-Wellhead vacuum of 35 IWC and an airflow rate of 35 cfm
RO1 = Radius of Influence 0 = change
IWC = inches of water cfm = cubic feet per minute
15 20

Calculations for SSD-4 ROI: Gateway Arts
Site Name: Former T&J Cleaners
Site Address: 2423 Crabtree Blvd, Raleigh, NC
Data Point
Distance (feet)
A Vacuum (IWC)
SSV-21
7
0.141
TP-3
15
0.159
SSV-22
20
0.096
TP-4
30
0.014
0.18
0.16
0.14
0.12
0.1
0.08
0.06
0.04 y =-0.006x + 0.2105
0.02
M
0 5 10 15
20 25 30 35
* Target vacuum utilized in calculations was 0.02 IWC or 5 pascals
-RO1 is approximately 31 feet
-Wellhead vacuum of 2.5 IWC and an airflow rate of 21 cfm
RO1 = Radius of Influence 0 = change
IWC = inches of water cfm = cubic feet per minute

APPENDIX B
PHOTOGRAPHIC LOG

A=COM
PHOTOGRAPHIC LOG
Site Name:
Site Location:
DSCA Site No.
T&J Cleaners
2423 Crabtree Boulevard, Raleigh,
NC
DC920021
Photo No.
Date:
10/17/19
- -
Direction Photo Taken:
South
14
Description:
Pilot test of extraction point
SSD-4 (circled). Shop
c
vacuum used as blower
fi '
system, all extracted air
vented outside building.
a.
y,
f
r
Photo No. Date:
2 N/A
Direction Photo °
Taken:
N/A
Description:
Typical setup of temporary
vapor monitoring point for
PID reading and vacuum
influence pilot test.
Opening in floor sealed -.
with polymer clay. �''

A=COM PHOTOGRAPHIC LOG
Site Name:
Site Location:
DSCA Site No.
T&J Cleaners
2423 Crabtree Boulevard, Raleigh, NC
DC920021
Photo No.
Date:
3
10/17/19
Direction Photo Taken:
South
.-
Description:
Change in exterior wall
bricking between Craft
�I
Habit and Carmen's
Fashion.