22059_GSK_LVI_20200429

hart hickman
SMARTER ENVIRONMENTAL SOLUTIONS
Via Email
April 29, 2020
North Carolina Department of Environmental Quality
Division of Waste Management — Brownfields Program
1646 Mail Service Center
Raleigh, North Carolina 27699-1646
Attn: Mr. Brad Atkinson
Re: Vapor Intrusion Compliance Request for Phase I Buildings
G1axoSmithKline — North Campus
3029 E. Cornwallis Road
Durham, North Carolina
H&H Job No. TKC-005
Dear Brad:
On behalf of TKC — 3029 Holdings, LLC (the Prospective Developer or PD), Hart & Hickman,
PC (H&H) is submitting this vapor intrusion compliance request for the G1axoSmithKline —
North Campus Brownfields property at 3029 E. Cornwallis Road in Durham, North Carolina
(Site or subject Site). As described in H&H's September 25, 2019 Brownfields Assessment
Report, proposed redevelopment for the Brownfields property includes bifurcation of the Site
into two phases (Phases 1 and 2) for mixed -use built -to -suit development for office, laboratory
research and development, and/or light research manufacturing. Figure 3 from the September
2019 Brownfields Assessment Report is provided as an attachment and includes proposed
building locations for redevelopment Phases 1 and 2.
To evaluate potential structural vapor intrusion into proposed Buildings 1 through 6 located
within the Phase I redevelopment area, H&H conducted soil vapor assessment activities at the
Site in July and August 2019. Specifically, 20 temporary soil vapor monitoring points (SVMP-1
through SVMP-20) were installed within the footprints of the proposed buildings. Following
sampling of the soil vapor monitoring points and receipt of the laboratory analytical results,
H&H utilized the North Carolina Department of Environmental Quality's (DEQ's) risk
calculator to evaluate calculated cumulative risks for the soil gas to indoor air vapor intrusion
pathway at the Site. H&H calculated cumulative risks on a per building basis using the highest
concentration of any compound detected in any soil vapor sample collected from within the
respective building footprint. Risk calculations from the September 2019 Brownfields
Assessment Report are provided as an attachment. In addition, risk calculations are shown on
Figure 3.
The results of the soil vapor assessment activities are documented in the aforementioned
September 2019 Brownfields Assessment Report and indicate that structural vapor intrusion into
future Phase 1 Buildings 1 through 6 does not pose a significant risk and does not warrant further
2923 South Tryon Street, Suite 100 3921 Sunset Ridge Rd, Suite 301
Charlotte, NC 28203 Raleigh, INC 27607 www.harthickman.com
704.586.0007 main 919.847.4241 main

Mr. Brad Atkinson
April 29, 2020
Page 2
assessment in accordance with the DEQ Division of Waste Management Vapor Intrusion
Guidance. Further, the assessment indicates that vapor mitigation measures do not appear
warranted for buildings proposed in Phase I of the Brownfields property. As such, proposed
Phase I Buildings 1 through 6 would be protective of the building's users, public health, and the
environment from risk of vapor intrusion based on Site assessment data and a Site -specific risk
assessment.
On behalf of the PD, we request your written concurrence that proposed Phase I Buildings 1
through 6 are in compliance with regards to structural vapor intrusion under DEQ guidance.
Please contact me if you have any questions or require additional information.
Sincerely,
Hart & Hickman, PC
i6glz�l
Justin Ballard, PG
Project Manager
cc: Jimbo Harrell — The Keith Corporation
Attachments
SAAAA-Master Projects\TKC - GSK\Brownfields Assessment\Compliance Letter\Vapor Intrusion Compliance Request_ GlaxoSmithKline - North Campus_4-29-2020.doc

I
(DEED RESTRICTED
W" .
BUILDING 6
CARCINOGENIC RISK 1.6E-06
HAZARD INDEX 5.9E-02
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BUILDING 5
CARCINOGENIC RISK 1.4E-06
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LEGEND
BROWNFIELDS PROPERTY BOUNDARY
PARCELBOUNDARY
GROUNDWATER MONITORING WELL
R MONITORING WELL
• PHASE II NZVI INJECTION WELL - 5L
■ NZVI INJECTION WELL - CLASS 5L
FRACTURED BEDROCK SVE WELL ALSO USED AS NZVI
J INJECTION WELL
EXTRACTION WELL INCLUDED IN MONITORING
NETWORK
`, EXISTING WELLS FOR COMPLIANCE MONITORING
a
BUILDING 4 A EXTRACTION WELL
CARCINOGENIC RISK 4.0E-07 j a
d ---- REDEVELOPMENT PHASING BIFURCATION
HAZARD INDEX 1.2E-02
PROPOSED BUILDING FOOTPRINT
BUILDING 3
CARCINOGENIC RISK 4.5E-06 ® SOIL VAPOR SAMPLING POINT (HRH, 2019)
HAZARD INDEX 5.1 E-02 (81 SOIL VAPOR SAMPLE DEPTH
* CDAPPROXIMATE AREA OF NC 2L GROUNDWATER
EXCEEDANCES (APRIL 2018)
IF _I I WETLANDS AREA
DEED RESTRICTED AREA, SWMU, AND/OR EXISTING STRUCTURE
NG 3 �'� M' SAMPLE LOCATION
BUILDING 3
r 4 a> CONSTITUENT CARCINOGENIC RISK I 4.5E-06
P-14 q
NOTES: HAZARD INDEX 5.1E-02
RISK VALUE
1. LOCATIONS OF SOLID WASTE MANAGEMENT UNITS (SWMUs),
MONITORING WELLS, REMEDIATION WELLS, AND INC 2L
t GROUNDWATER EXCEEDANCES ARE OBTAINED FROM JULY
31, 2018 FOURTH ANNUAL ASSESSMENT REPORT PREPARED
BY GOLDER ASSOCIATES INC, INC.
e, 2. AERIAL IMAGERY OBTAINED FROM DURHAM COUNTY GIS
.,' (2018).
3. r-r- INDICATES SOIL VAPOR SAMPLING POINT SET AT DEPTH
OF REFUSAL
BUILDING 1 0 4. CUMULATIVE NON-RESIDENTIAL RISK CALCULATIONS
CARCINOGENIC RISK 1.2E-06 PERFORMED USING THE INC DEPARTMENT OF
ENVIRONMENTAL QUALITY (DES) RISK CALCULATOR (MAY
HAZARD INDEX 5.0E-02 '� ;p� 2019) UNDER WORST -CASE SCENARIO CONDITIONS (LE.,
i .. MAXIMUM DETECTED CONSTITUENT CONCENTRATIONS) FOR
EACH BUILDING.
r
BUILDING 2
CARCINOGENIC RISK 1.8E-06
HAZARD INDEX 9.2E-02
mGW-32SI -33 NIW-34
«n `
GW-485I
s
� 11
t
APPROXIMATE
0 250 500
�.
SCALE IN FEET
SOIL VAPOR ASSESSMENT SUMMARY
PROJECT MONSANTO
3029 E. CORNWALLIS ROAD
DURHAM, DURHAM COUNTY, NORTH CAROLINA
hart '" hickman 3921 kigh,'s ,th �,.R°i.276073°'
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SMARTER ENVIRONMENTAL SOLUTIONS i.iccnsc # C-1269 / #C-245 Gcololrp
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DATE: 9-10-19
REVISION NO. 0
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JOB NO. TKC-005
FIGURE NO. 3

DEQ Risk Calculators (May 2019)
hart hickman
SMARTER ENVIRONMENTAL SOLUTIONS

North Carolina Department of Environmental Quality
Risk Calculator
Version Date:
May 2019
Basis:
May 2019 EPA RSL Table
Site Name:
Monsanto
Site Address:
3029 East Cornwallis Road, Durham, North Carolina
DEQ Section:
Brownfields Program
Site ID:
BPN #22059-18-032
Exposure Unit ID:
Proposed Building 1
Submittal Date:
Prepared By:
Hart & Hickman, PC
Reviewed By:
North Carolina DEQ Risk Calculator

Complete Exposure Pathways
Version Date: May 2019
Basis: May 2019 EPA RSL Table
Site ID: BPN #22059-18-032
Exposure Unit ID: Proposed Building 1
Note: Risk output will only be calculated for complete exposure pathways.
Receptor
Pathway
Check box if
pathway
complete
DIRECT CONTACT SOIL AND WATER PATHWAYS
Resident
Soil
El
Groundwater Use
I_I
Non -Residential Worker
Soil
❑
Groundwater Use
❑
Construction Worker
Soil
❑
Recreator/Trespasser
Soil
❑
Surface Water
❑
VAPOR INTRUSION PATHWAYS
Resident
Groundwater to Indoor Air
❑
Soil Gas to Indoor Air
❑
Indoor Air
❑
Non -Residential Worker
Groundwater to Indoor Air
❑
Soil Gas to Indoor Air
0
Indoor Air
❑
CONTAMINANT MIGRATION PATHWAYS
Groundwater
Source Soil
❑
Source Groundwater
❑
Surface Water
Source Soil
❑
Source Groundwater
❑
North Carolina DEQ Risk Calculator

)sure Point Concentrations
lion Date: May 2019
s: May 2019 EPA RSL Table
ID: BPN #22059-18-032
)sure Unit ID: Proposed Builc
Description of Exposure Point Concentration Selection:
Maximum concentrations of constituents detected in soil gas samples within Building 1 footprint.
Note: Chemicals highlighted in orange are non-volatile chemicals. Since these chemicals do not pose a vapor intrusion risk, no risk values are calculated for these chemicals.
Exposure Point
Minimum
Maximum
Location of
Range of
Concentration
Screening
Potential
Potential
Rationale for
Concentration
Notes:
CAS Number
Chemical
Concentration
Concentration
Units
Maximum
Detection
Detection
Used f
Background
Toxicity Value
ARAR/TBC
ARAR/TBC
COPC Flagor
Selection or
s
(ug/m)
(Qualifier)
(Qualifier)
Concentration
Frequency
Limits
Screening
Value
(Screening
Value
Source
(Y/N)
Deletion
Level) (n/c)
130
67-64-1
Acetone
ug/m3
34
71-43-2
Benzene
ug/m3
8.6
106-99-0
Butadiene, 1,3-
ug/m3
62
75-15-0
Carbon Disulfide
ug/m3
7.5
56-23-5
Carbon Tetrachloride
ug/m3
9.8
67-66-3
Chloroform
ug/m3
9.6
95-50-1
Dichlorobenzene,l,2-
ug/m3
9.1
106-46-7
Dichlorobenzene,l,4-
ug/m3
5.9
75-35-4
Dichloroeth lene, 1,1-
ug/m3
5.4
156-59-2
Dichloroeth lene, 1,2-cis-
ug/m3
5.9
156-60-5
Dichloroeth lene, 1,2-trans-
ug/m3
33
100-41-4
Eth lbenzene
ug/m3
21
142-82-5
He tape, N-
ug/m3
10
67-63-0
Iso ro anol
ug/m3
19
78-93-3
Methyl Ethyl Ketone 2-Butanone
ug/m3
3.6
108-10-1
Methyl Isobutyl Ketone 4-meth 1-2- entanone
ug/m3
9.6
75-09-2
Methylene Chloride
ug/m3
13
91-20-3
—Naphthalene
ug/m3
94
100-42-5
Styrene
ug/m3
9.2
127-18-4
Tetrachloroeth lene
ug/m3
370
108-88-3
Toluene
ug/m3
12
120-82-1
Trichlorobenzene,1,2,4-
ug/m3
6.3
71-55-6
Trichloroethane, 1,1,1-
ug/m3
7.1
79-01-6
Trichloroeth lene
ug/m3
9.2
75-69-4
Trichlorofluoromethane
ug/m3
22
95-63-6
Trimeth lbenzene,1,2,4-
ug/m3
12
108-67-8
Trimeth lbenzene,1,3,5-
ug/m3
115
1330-20-7
X lens
ug/m3
North Carolina DEQ Risk Calwlalor

Risk for Individual Pathways
-FIR
IM
Version Date: May 2019
Basis: May 2019 EPA RSL Table
Site ID: BPN #22059-18-032
Exposure Unit ID: Proposed Building
1
DIRECT CONTACT SOIL AND WATER CALCULATORS
Receptor
Pathway
CarcinogenicHazard
Risk
Index
Risk exceeded?
Resident
Soil
NC
NC
NC
NC
Groundwater Use*
NC
NC
Non -Residential Worker
Soil
NC
NC
NC
NC
Groundwater Use*
NC
NC
Construction Worker
Soil
NC
NC
NC
Recreator/Trespasser
Soil
NC
NC
NC
Surface Water*
NC
NC
NC
VAPOR INTRUSION CALCULATORS
Receptor
Pathway
CarcinogenicHazard
Risk
Index
Risk exceeded?
Resident
Groundwater to Indoor Air
NC
NC
NC
Soil Gas to Indoor Air
NC
NC
NC
Indoor Air
NC
NC
NC
Non -Residential Worker
Groundwater to Indoor Air
NC
NC
NC
Soil Gas to Indoor Air
1.2E-06
5.0E-02
NO
Indoor Air
NC
NC
NC
CONTAMINANT
MIGRATION CALCULATORS
Pathway
Source
Target Receptor Concentrations Exceeded?
Groundwater
Source Soil
Exceedence of 2L at Receptor?
NC
Source Groundwater
Exceedence of 2L at Receptor?
NC
Surface Water
Source Soil
Exceedence of 2B at Receptor?
NC
Source Groundwater
Exceedence of 2B at Receptor?
NC
Notes:
1. If lead concentrations were entered in the exposure point concentration tables, see the individual calculator sheets for lead
concentrations in comparison to screening levels. Note that lead is not included in cumulative risk calculations.
2. * = If concentrations in groundwater exceed the NC 2L Standards or IMAC, or concentrations in surface water exceed the
NC 2B Standards, appropriate remediation and/or institutional control measures will be necessary to be eligible for a risk -based
closure.
3. NM = Not Modeled
4. NC = Pathway not complete
North Carolina DEQ Risk Calculator

Risk Calculator - Vapor Intrusion - Non -Residential Worker Soil Gas to Indoor Air
.ion Date: May 2019
s: May 2019 EPA RSL Table
ID: BPN #22059-18-032
osure Unit ID: Proposed Building 1
Carcinogenic risk and hazard quotient cells highlighted in orange are associated with non-volatile chemicals. Since these chemicals do not pose a vapor intrusion
risk, no risk values are calculated for these chemicals.
All concentrations are in ue/m3
CAS #
Chemical Name:
Soil Gas
Concentration
3
(ug/m)
Calculated
Indoor Air
Concentration
Co
(ug/ro)
Target Indoor
Air Conc. for
Carcinogens @
TCR = 1E-06
Target Indoor Air
Conc. for Non -
Carcinogens @
THQ = 0.2
Calculated
Carcinogenic
Risk
Calculated
Non -
Carcinogenic
Hazard
Quotient
67-64-1
Acetone
130
1.3
2.7E+04
9.6E-06
7143-2
Benzene
34
0.34
1.6E+00
2.6E+01
2.2E-07
2.6E-03
106-99-0
Butadiene, 1,3-
8.6
0.086
4.1E-01
1.8E+00
2.1E-07
9.8E-03
75-15-0
Carbon Disulfide
62
0.62
6.1E+02
2.0E-04
56-23-5
Carbon Tetrachloride
7.5
0.075
2.0E+00
8.8E+01
3.7E-08
1.7E-04
67-66-3
Chloroform
9.8
0.098
5.3E-01
8.6E+01
1.8E-07
2.3E-04
95-50-1
Dichlorobenzene, 1,2-
9.6
0.096
1.8E+02
1.1E-04
10646-7
Dichlorobenzene, 1,4-
9.1
0.091
1.1E+00
7.0E+02
8.2E-08
2.6E-05
75-35-4
Dichloroethylene, 1,1-
5.9
0.059
1.8E+02
6.7E-05
156-59-2
Dichloroethylene, 1,2-cis-
5.4
0.054
156-60-5
Dichloroethylene, 1,2-trans-
5.9
0.059
10041-4
Ethylbenzene
33
0.33
4.9F,+00
8.8E+02
6.7E-08
7.5E-05
142-82-5
Heptane, N-
21
0.21
3.5E+02
1.2E-04
67-63-0
Isopropanol
10
0.1
1.8E+02
1.1E-04
78-93-3
Methyl Ethyl Ketone (2-Butanone)
19
0.19
4.4E+03
8.7E-06
108-10-1
Methyl Isobutyl Ketone (4-methyl-2-pentanone)
3.6
0.036
2.6E+03
2.7E-06
75-09-2
Methylene Chloride
9.6
0.096
1.2E+03
5.3E+02
7.8E-11
3.7E-05
91-20-3
-Naphthalene
13
0.13
3.6E-01
2.6E+00
3.6E-07
9.9E-03
10042-5
Styrene
94
0.94
8.8E+02
2.1E-04
127-18-4
Tetrachloroethylene
9.2
0.092
4.7E+01
3.5E+01
2.0E-09
5.3E-04
108-88-3
Toluene
370
3.7
4.4E+03
1.7E-04
120-82-1
Trichlorobenzene, 1,2,4-
12
0.12
1.8E+00
1.4E-02
71-55-6
Trichloroethane, 1,1,1-
6.3
0.063
4.4E+03
2.9E-06
79-01-6
Trichloroethylene
7.1
0.071
3.OF,+00
1.8E+00
2.4E-08
8.1E-03
75-69-4
Trichlorofluoromethane
9.2
0.092
95-63-6
Trimethylbenzene, 1,2,4-
22
0.22
5.3E+01
8.4E-04
108-67-8
1 Trimethylbenzene, 1,3,5-
12
0.12
5.3E+01
4.6E-04
1330-20-7
1 Xylenes
115
1 1.15
1
8.8E+01
I
2.6E-03
Cumulative: I 1.2E-06 I 5.0E-02
North Carolina DEQ Risk Calculator

North Carolina Department of Environmental Quality
Risk Calculator
Version Date:
May 2019
Basis:
May 2019 EPA RSL Table
Site Name:
Monsanto
Site Address:
3029 East Cornwallis Road, Durham, North Carolina
DEQ Section:
Brownfields Program
Site ID:
BPN #22059-18-032
Exposure Unit ID:
Proposed Building 2
Submittal Date:
Prepared By:
Hart & Hickman, PC
Reviewed By:
North Carolina DEQ Risk Calculator

Complete Exposure Pathways
Version Date: May 2019
Basis: May 2019 EPA RSL Table
Site ID: BPN #22059-18-032
Exposure Unit ID: Proposed Building 2
Note: Risk output will only be calculated for complete exposure pathways.
Receptor
Pathway
Check box if
pathway
complete
DIRECT CONTACT SOIL AND WATER PATHWAYS
Resident
Soil
El
Groundwater Use
I_I
Non -Residential Worker
Soil
❑
Groundwater Use
❑
Construction Worker
Soil
❑
Recreator/Trespasser
Soil
❑
Surface Water
❑
VAPOR INTRUSION PATHWAYS
Resident
Groundwater to Indoor Air
❑
Soil Gas to Indoor Air
❑
Indoor Air
❑
Non -Residential Worker
Groundwater to Indoor Air
❑
Soil Gas to Indoor Air
0
Indoor Air
❑
CONTAMINANT MIGRATION PATHWAYS
Groundwater
Source Soil
❑
Source Groundwater
❑
Surface Water
Source Soil
❑
Source Groundwater
❑
North Carolina DEQ Risk Calculator

)sure Point Concentrations
lion Date: May 2019
s: May 2019 EPA RSL Table
ID: BPN #22059-18-032
)sure Unit ID: Proposed Builc
Description of Exposure Point Concentration Selection:
Maximum concentrations of constituents detected in soil gas samples within Building 2 footprint.
Note: Chemicals highlighted in orange are non-volatile chemicals. Since these chemicals do not pose a vapor intrusion risk, no risk values are calculated for these chemicals.
Exposure Point
Minimum
Maximum
Location of
Range of
Concentration
Screening
Potential
Potential
Rationale for
Concentration
Notes:
CAS Number
Chemical
Concentration
Concentration
Units
Maximum
Detection
Detection
Used f
Background
Toxicity Value
ARAR/TBC
ARAR/TBC
COPC Flagor
Selection or
s
(ug/m)
(Qualifier)
(Qualifier)
Concentration
Frequency
Limits
Screening
Value
(Screening
Value
Source
(Y/N)
Deletion
Level) (n/c)
130
67-64-1
Acetone
ug/m3
82
71-43-2
Benzene
ug/m3
33
106-99-0
Butadiene,l,3-
ug/m3
540
75-15-0
Carbon Disulfide
ug/m3
4.4
56-23-5
Carbon Tetrachloride
ug/m3
1.2
108-90-7
Chlorobenzene
ug/m3
2.6
67-66-3
Chloroform
ug/m3
4.9
124-48-1
Dibromochloromethane
ug/m3
2.5
156-59-2
Dichloroeth lene, 1,2-cis-
ug/m3
1.6
156-60-5
Dichloroeth lene, 1,2-trans-
ug/m3
0.98
78-87-5
Dichloro ro ane, 1,2-
ug/m3
390
141-78-6
Ethyl Acetate
ug/m3
90
100-41-4
Eth lbenzene
ug/m3
62
142-82-5
He tape, N-
ug/m3
11
591-78-6
Hexanone,2-
ug/m3
13
67-63-0
Iso ro anol
ug/m3
30
78-93-3
Methyl Ethyl Ketone 2-Butanone
ug/m3
19
108-10-1
Methyl Isobutyl Ketone 4-meth 1-2- entanone
ug/m3
4.9
75-09-2
Methylene Chloride
ug/m3
8.2
91-20-3
—Naphthalene
ug/m3
2700
115-07-1
Propylene
ug/m3
3.2
100-42-5
Styrene
ug/m3
20
127-18-4
Tetrachloroeth lene
ug/m3
1900
108-88-3
Toluene
ug/m3
6.9
76-13-1
Trichloro-1,2,2-trifluoroethane, 1,1,2-
ug/m3
7.1
120-82-1
Trichlorobenzene,1,2,4-
ug/m3
3.3
71-55-6
Trichloroethane, 1,1,1-
ug/m3
1.3
79-01-6
Trichloroeth lene
ug/m3
4.8
75-69-4
Trichlorofluoromethane
ug/m3
27
95-63-6
Trimeth lbenzene,1,2,4-
ug/m3
10
108-67-8
Trimeth lbenzene,1,3,5-
ug/m3
414
1330-20-7
X lens
ug/m3
North Carolina DEQ Risk Calwlalor

Risk for Individual Pathways
-FIR
IM
Version Date: May 2019
Basis: May 2019 EPA RSL Table
Site ID: BPN #22059-18-032
Exposure Unit ID: Proposed Building
2
DIRECT CONTACT SOIL AND WATER CALCULATORS
Receptor
Pathway
CarcinogenicHazard
Risk
Index
Risk exceeded?
Resident
Soil
NC
NC
NC
NC
Groundwater Use*
NC
NC
Non -Residential Worker
Soil
NC
NC
NC
NC
Groundwater Use*
NC
NC
Construction Worker
Soil
NC
NC
NC
Recreator/Trespasser
Soil
NC
NC
NC
Surface Water*
NC
NC
NC
VAPOR INTRUSION CALCULATORS
Receptor
Pathway
CarcinogenicHazard
Risk
Index
Risk exceeded?
Resident
Groundwater to Indoor Air
NC
NC
NC
Soil Gas to Indoor Air
NC
NC
NC
Indoor Air
NC
NC
NC
Non -Residential Worker
Groundwater to Indoor Air
NC
NC
NC
Soil Gas to Indoor Air
1.8E-06
9.2E-02
NO
Indoor Air
NC
NC
NC
CONTAMINANT
MIGRATION CALCULATORS
Pathway
Source
Target Receptor Concentrations Exceeded?
Groundwater
Source Soil
Exceedence of 2L at Receptor?
NC
Source Groundwater
Exceedence of 2L at Receptor?
NC
Surface Water
Source Soil
Exceedence of 2B at Receptor?
NC
Source Groundwater
Exceedence of 2B at Receptor?
NC
Notes:
1. If lead concentrations were entered in the exposure point concentration tables, see the individual calculator sheets for lead
concentrations in comparison to screening levels. Note that lead is not included in cumulative risk calculations.
2. * = If concentrations in groundwater exceed the NC 2L Standards or IMAC, or concentrations in surface water exceed the
NC 2B Standards, appropriate remediation and/or institutional control measures will be necessary to be eligible for a risk -based
closure.
3. NM = Not Modeled
4. NC = Pathway not complete
North Carolina DEQ Risk Calculator

Risk Calculator - Vapor Intrusion - Non -Residential Worker Soil Gas to Indoor Air
.ion Date: May 2019
s: May 2019 EPA RSL Table
ID: BPN #22059-18-032
osure Unit ID: Proposed Building 2
Carcinogenic risk and hazard quotient cells highlighted in orange are associated with non-volatile chemicals. Since these chemicals do not pose a vapor intrusion
risk, no risk values are calculated for these chemicals.
All concentrations are in ue/m3
CAS #
Chemical Name:
Soil Gas
Concentration
3
(ug/m)
Calculated
Indoor Air
Concentration
Co
(ug/ro)
Target Indoor
Air Conc. for
Carcinogens @
TCR = 1E-06
Target Indoor Air
Conc. for Non -
Carcinogens @
THQ = 0.2
Calculated
Carcinogenic
Risk
Calculated
Non -
Carcinogenic
Hazard
Quotient
67-64-1
Acetone
130
1.3
2.7E+04
9.6E-06
7143-2
Benzene
82
0.82
1.6E+00
2.6E+01
5.2E-07
6.2E-03
106-99-0
Butadiene, 1,3-
33
0.33
4.1E-01
1.8E+00
8.1E-07
3.8E-02
75-15-0
Carbon Disulfide
540
5.4
6.1E+02
1.8E-03
56-23-5
Carbon Tetrachloride
4.4
0.044
2.0E+00
8.8E+01
2.2E-08
1.0E-04
108-90-7
Chlorobenzene
1.2
0.012
4.4E+01
5.5E-05
67-66-3
Chloroform
2.6
0.026
5.3E-01
8.6E+01
4.9E-08
6.1E-05
12448-1
Dibromochloromethane
4.9
0.049
156-59-2
Dichloroethylene, 1,2-cis-
2.5
0.025
156-60-5
Dichloroethylene, 1,2-trans-
1.6
0.016
78-87-5
Dichloropropane, 1,2-
0.98
0.0098
3.3E+00
3.5E+00
3.0E-09
5.6E-04
141-78-6
Ethyl Acetate
390
3.9
6.1E+01
1.3E-02
10041-4
Ethylbenzene
90
0.9
4.9E+00
8.8E+02
1.8E-07
2.1E-04
142-82-5
Heptane, N-
62
0.62
3.5E+02
3.5E-04
591-78-6
Hexanone, 2-
11
0.11
2.6E+01
8.4E-04
67-63-0
Isopropanol
13
0.13
1.8E+02
1.5E-04
78-93-3
Methyl Ethyl Ketone (2-Butanone)
30
0.3
4.4E+03
1.4E-05
108-10-1
Methyl Isobutyl Ketone (4-methyl-2-pentanone)
19
0.19
2.6E+03
1.4E-05
75-09-2
Methylene Chloride
4.9
0.049
1.2E+03
5.3E+02
4.0E-11
1.9E-05
91-20-3
-Naphthalene
8.2
0.082
3.6E-01
2.6E+00
2.3E-07
6.2E-03
115-07-1
Propylene
2700
27
2.6E+03
2.1E-03
10042-5
Styrene
3.2
0.032
8.8E+02
7.3E-06
127-18-4
Tetrachloroethylene
20
0.2
4.7F,+01
3.5E+01
4.2E-09
1.1E-03
108-88-3
Toluene
1900
19
4.4E+03
8.7E-04
76-13-1
Trichloro-1,2,2-trifluoroethane, 1,1,2-
6.9
0.069
4.4E+03
3.2E-06
120-82-1
Trichlorobenzene, 1,2,4-
7.1
0.071
1.8E+00
8.1E-03
71-55-6
Trichloroethane, 1,1,1-
3.3
0.033
1
4.4E+03
1.5E-06
79-01-6
Trichloroethylene
1.3
0.013
3.OF,+00
1.8E+00
4.3E-09
1.5E-03
75-69-4
Trichlorofluoromethane
4.8
0.048
95-63-6
Trimethylbenzene, 1,2,4-
27
0.27
5.3E+01
1.0E-03
108-67-8
Trimethylbenzene, 1,3,5-
1 10
0.1
5.3E+01
3.8E-04
1330-20-7
Xylenes
414
4.14
8.8E+01
9.5E-03
Cumulative: I 1.8E-06 I 9.2E-02
North Carolina DEQ Risk Calculator

North Carolina Department of Environmental Quality
Risk Calculator
Version Date:
May 2019
Basis:
May 2019 EPA RSL Table
Site Name:
Monsanto
Site Address:
3029 East Cornwallis Road, Durham, North Carolina
DEQ Section:
Brownfields Program
Site ID:
BPN #22059-18-032
Exposure Unit ID:
Proposed Building 3
Submittal Date:
Prepared By:
Hart & Hickman, PC
Reviewed By:
North Carolina DEQ Risk Calculator

Complete Exposure Pathways
Version Date: May 2019
Basis: May 2019 EPA RSL Table
Site ID: BPN #22059-18-032
Exposure Unit ID: Proposed Building 3
Note: Risk output will only be calculated for complete exposure pathways.
Receptor
Pathway
Check box if
pathway
complete
DIRECT CONTACT SOIL AND WATER PATHWAYS
Resident
Soil
El
Groundwater Use
I_I
Non -Residential Worker
Soil
❑
Groundwater Use
❑
Construction Worker
Soil
❑
Recreator/Trespasser
Soil
❑
Surface Water
❑
VAPOR INTRUSION PATHWAYS
Resident
Groundwater to Indoor Air
❑
Soil Gas to Indoor Air
❑
Indoor Air
❑
Non -Residential Worker
Groundwater to Indoor Air
❑
Soil Gas to Indoor Air
0
Indoor Air
❑
CONTAMINANT MIGRATION PATHWAYS
Groundwater
Source Soil
❑
Source Groundwater
❑
Surface Water
Source Soil
❑
Source Groundwater
❑
North Carolina DEQ Risk Calculator

)sure Point Concentrations
lion Date: May 2019
s: May 2019 EPA RSL Table
ID: BPN #22059-18-032
)sure Unit ID: Proposed Builc
Description of Exposure Point Concentration Selection:
Maximum concentrations of constituents detected in soil gas samples within Building 3 footprint.
Note: Chemicals highlighted in orange are non-volatile chemicals. Since these chemicals do not pose a vapor intrusion risk, no risk values are calculated for these chemicals.
Exposure Point
Minimum
Maximum
Location of
Range of
Concentration
Screening
Potential
Potential
Rationale for
Concentration
Notes:
CAS Number
Chemical
Concentration
Concentration
Units
Maximum
Detection
Detection
Used f
Background
Toxicity Value
ARAR/TBC
ARAR/TBC
COPC Flagor
Selection or
s
(ug/m)
(Qualifier)
(Qualifier)
Concentration
Frequency
Limits
Screening
Value
(Screening
Value
Source
(Y/N)
Deletion
Level) (n/c)
42
67-64-1
Acetone
ug/m3
25
71-43-2
Benzene
ug/m3
18
106-99-0
Butadiene,l,3-
ug/m3
300
75-15-0
Carbon Disulfide
ug/m3
5.5
56-23-5
Carbon Tetrachloride
ug/m3
14
67-66-3
Chloroform
ug/m3
7.3
124-48-1
Dibromochloromethane
ug/m3
6.8
106-93-4
Dibromoethane, 1,2-
ug/m3
6.9
95-50-1
Dichlorobenzene,l,2-
ug/m3
7.5
106-46-7
Dichlorobenzene,l,4-
ug/m3
4.3
75-35-4
Dichloroeth lene, 1,1-
ug/m3
3.7
156-59-2
Dichloroeth lene, 1,2-cis-
ug/m3
4.3
156-60-5
Dichloroeth lene, 1,2-trans-
ug/m3
2.2
78-87-5
Dichloro ro ane, 1,2-
ug/m3
17
100-41-4
Eth lbenzene
ug/m3
3.8
109-99-9
—Tetrah drofuran
ug/m3
23
142-82-5
He tape, N-
ug/m3
7.9
67-63-0
Iso ro arol
ug/m3
9.5
78-93-3
Methyl Ethyl Ketone 2-Butanone
ug/m3
5.4
108-10-1
Methyl Isobutyl Ketone 4-meth 1-2- entanone
ug/m3
5.8
75-09-2
Methylene Chloride
ug/m3
7.4
91-20-3
—Naphthalene
ug/m3
420
115-07-1
Propylene
ug/m3
6.8
127-18-4
Tetrachloroeth lene
ug/m3
150
108-88-3
Toluene
ug/m3
5.4
76-13-1
Trichloro-1,2,2-trifluoroethane, 1,1,2-
ug/m3
7.9
120-82-1
Trichlorobenzene,1,2,4-
ug/m3
4.5
71-55-6
Trichloroethane, 1,1,1-
ug/m3
4.9
79-01-6
Trichloroeth lene
ug/m3
6.9
75-69-4
Trichlorofluoromethane
ug/m3
14
95-63-6
Trimeth lbenzene,1,2,4-
ug/m3
7.4
108-67-8
Trimeth lbenzene,1,3,5-
ug/m3
71
1330-20-7
X lens
ug/m3
North Carolina DEQ Risk Calwlalor

Risk for Individual Pathways
-FIR
IM
Version Date: May 2019
Basis: May 2019 EPA RSL Table
Site ID: BPN #22059-18-032
Exposure Unit ID: Proposed Building
3
DIRECT CONTACT SOIL AND WATER CALCULATORS
Receptor
Pathway
CarcinogenicHazard
Risk
Index
Risk exceeded?
Resident
Soil
NC
NC
NC
NC
Groundwater Use*
NC
NC
Non -Residential Worker
Soil
NC
NC
NC
NC
Groundwater Use*
NC
NC
Construction Worker
Soil
NC
NC
NC
Recreator/Trespasser
Soil
NC
NC
NC
Surface Water*
NC
NC
NC
VAPOR INTRUSION CALCULATORS
Receptor
Pathway
CarcinogenicHazard
Risk
Index
Risk exceeded?
Resident
Groundwater to Indoor Air
NC
NC
NC
Soil Gas to Indoor Air
NC
NC
NC
Indoor Air
NC
NC
NC
Non -Residential Worker
Groundwater to Indoor Air
NC
NC
NC
Soil Gas to Indoor Air
4.5E-06
5.1E-02
NO
Indoor Air
NC
NC
NC
CONTAMINANT
MIGRATION CALCULATORS
Pathway
Source
Target Receptor Concentrations Exceeded?
Groundwater
Source Soil
Exceedence of 2L at Receptor?
NC
Source Groundwater
Exceedence of 2L at Receptor?
NC
Surface Water
Source Soil
Exceedence of 2B at Receptor?
NC
Source Groundwater
Exceedence of 2B at Receptor?
NC
Notes:
1. If lead concentrations were entered in the exposure point concentration tables, see the individual calculator sheets for lead
concentrations in comparison to screening levels. Note that lead is not included in cumulative risk calculations.
2. * = If concentrations in groundwater exceed the NC 2L Standards or IMAC, or concentrations in surface water exceed the
NC 2B Standards, appropriate remediation and/or institutional control measures will be necessary to be eligible for a risk -based
closure.
3. NM = Not Modeled
4. NC = Pathway not complete
North Carolina DEQ Risk Calculator

Risk Calculator - Vapor Intrusion - Non -Residential Worker Soil Gas to Indoor Air
.ion Date: May 2019
s: May 2019 EPA RSL Table
ID: BPN #22059-18-032
osure Unit ID: Proposed Building 3
Carcinogenic risk and hazard quotient cells highlighted in orange are associated with non-volatile chemicals. Since these chemicals do not pose a vapor intrusion
risk, no risk values are calculated for these chemicals.
All concentrations are in ue/m3
CAS #
Chemical Name:
Soil Gas
Concentration
3
(ug/m)
Calculated
Indoor Air
Co
Concentration
(ug/ro)
Target Indoor
Air Conc. for
Carcinogens @
TCR = 1E-06
Target Indoor Air
Conc. for Non -
Carcinogens @
THQ = 0.2
Calculated
Carcinogenic
Risk
Calculated
Non -
Carcinogenic
Hazard
Quotient
67-64-1
Acetone
42
0.42
2.7E+04
3.1E-06
7143-2
Benzene
25
0.25
1.6E+00
2.6E+01
1.6E-07
1.9E-03
106-99-0
Butadiene, 1,3-
18
0.18
4.1E-01
1.8E+00
4.4E-07
2.1E-02
75-15-0
Carbon Disulfide
300
3
6.1E+02
9.8E-04
56-23-5
Carbon Tetrachloride
5.5
0.055
2.0E+00
8.8E+01
2.7E-08
1.3E-04
67-66-3
Chloroform
14
0.14
5.3E-01
8.6E+01
2.6E-07
3.3E-04
12448-1
Dibromochloromethane
7.3
0.073
106-93-4
Dibromoethane, 1,2-
6.8
0.068
2.0E-02
7.9E+00
3.3E-06
1.7E-03
95-50-1
Dichlorobenzene, 1,2-
6.9
0.069
1.8E+02
7.9E-05
10646-7
Dichlorobenzene, 1,4-
7.5
0.075
1.1E+00
7.0E+02
6.7E-08
2.1E-05
75-35-4
Dichloroethylene, 1,1-
4.3
0.043
1.8E+02
4.9E-05
156-59-2
Dichloroethylene, 1,2-cis-
3.7
0.037
156-60-5
Dichloroethylene, 1,2-trans-
4.3
0.043
78-87-5
Dichloropropane, 1,2-
2.2
0.022
3.3E+00
3.5E+00
6.6E-09
1.3E-03
10041-4
Ethylbenzene
17
0.17
1 4.9E+00
8.8E+02
3.5E-08
3.9E-05
109-99-9
-Tetrahydrofuran
3.8
0.038
1.8E+03
4.3E-06
142-82-5
Heptane, N-
23
0.23
3.5E+02
1.3E-04
67-63-0
Isopropanol
7.9
0.079
1.8E+02
9.0E-05
78-93-3
Methyl Ethyl Ketone (2-Butanone)
9.5
0.095
4.4E+03
4.3E-06
108-10-1
Methyl Isobutyl Ketone (4-methyl-2-pentanone)
5.4
0.054
2.6E+03
4.1E-06
75-09-2
Methylene Chloride
5.8
0.058
1.2E+03
5.3E+02
4.7E-11
2.2E-05
91-20-3
-Naphthalene
7.4
0.074
3.6E-01
2.6E+00
2.1E-07
5.6E-03
115-07-1
Propylene
420
4.2
2.6E+03
3.2E-04
127-18-4
Tetrachloroethylene
6.8
0.068
4.7E+01
3.5E+01
1.4E-09
3.9E-04
108-88-3
Toluene
150
1.5
4.4E+03
6.8E-05
76-13-1
Trichloro-1,2,2-trifluoroethane, 1,1,2-
5.4
0.054
4.4E+03
2.5E-06
120-82-1
Trichlorobenzene, 1,2,4-
7.9
0.079
1
1.8E+00
9.0E-03
71-55-6
Trichloroethane, 1,1,1-
4.5
0.045
4.4E+03
2.1E-06
79-01-6
Trichloroethylene
4.9
0.049
3.OF,+00
1.8E+00
1.6E-08
5.6E-03
75-69-4
Trichlorofluoromethane
6.9
0.069
95-63-6
Trimethylbenzene, 1,2,4-
14
0.14
5.3E+01
5.3E-04
108-67-8
Trimethylbenzene, 1,3,5-
7.4
0.074
5.3E+01
2.8E-04
1330-20-7
Xylenes
71
0.71
8.8E+01
1.6E-03
Cumulative: I 4.5E-06 I 5.1E-02
North Carolina DEQ Risk Calculator

North Carolina Department of Environmental Quality
Risk Calculator
Version Date:
May 2019
Basis:
May 2019 EPA RSL Table
Site Name:
Monsanto
Site Address:
3029 East Cornwallis Road, Durham, North Carolina
DEQ Section:
Brownfields Program
Site ID:
BPN #22059-18-032
Exposure Unit ID:
Proposed Building 4
Submittal Date:
Prepared By:
Hart & Hickman, PC
Reviewed By:
North Carolina DEQ Risk Calculator

Complete Exposure Pathways
Version Date: May 2019
Basis: May 2019 EPA RSL Table
Site ID: BPN #22059-18-032
Exposure Unit ID: Proposed Building 4
Note: Risk output will only be calculated for complete exposure pathways.
Receptor
Pathway
Check box if
pathway
complete
DIRECT CONTACT SOIL AND WATER PATHWAYS
Resident
Soil
El
Groundwater Use
I_I
Non -Residential Worker
Soil
❑
Groundwater Use
❑
Construction Worker
Soil
❑
Recreator/Trespasser
Soil
❑
Surface Water
❑
VAPOR INTRUSION PATHWAYS
Resident
Groundwater to Indoor Air
❑
Soil Gas to Indoor Air
❑
Indoor Air
❑
Non -Residential Worker
Groundwater to Indoor Air
❑
Soil Gas to Indoor Air
0
Indoor Air
❑
CONTAMINANT MIGRATION PATHWAYS
Groundwater
Source Soil
❑
Source Groundwater
❑
Surface Water
Source Soil
❑
Source Groundwater
❑
North Carolina DEQ Risk Calculator

)sure Point Concentrations
lion Date: May 2019
s: May 2019 EPA RSL Table
ID: BPN #22059-18-032
)sure Unit ID: Proposed DO(
Description of Exposure Point Concentration Selection:
Maximum concentrations of constituents detected in soil gas samples within Building 4 footprint.
Note: Chemicals highlighted in orange are non-volatile chemicals. Since these chemicals do not pose a vapor intrusion risk, no risk values are calculated for these chemicals.
Exposure Point
Minimum
Maximum
Location of
Range of
Concentration
Screening
Potential
Potential
Rationale for
Concentration
Notes:
CAS Number
Chemical
Concentration
Concentration
Units
Maximum
Detection
Detection
Used f
Background
Toxicity Value
ARAR/TBC
ARAR/TBC
COPC Flagor
Selection or
s
(ug/m)
(Qualifier)
(Qualifier)
Concentration
Frequency
Limits
Screening
Value
(Screening
Value
Source
(Y/N)
Deletion
Level) (n/c)
170
67-64-1
Acetone
ug/m3
27
71-43-2
Benzene
ug/m3
35
75-15-0
Carbon Disulfide
ug/m3
9.1
56-23-5
Carbon Tetrachloride
ug/m3
1.4
67-66-3
Chloroform
ug/m3
5.9
110-82-7
C clohexane
ug/m3
3.3
75-71-8
Dichlorodiflumomethare
ug/m3
7.3
156-60-5
Dichloroeth lene, 1,2-trans-
ug/m3
36
100-41-4
Eth lbenzene
ug/m3
13
142-82-5
He tape, N-
ug/m3
23
110-54-3
Hexane, N-
ug/m3
12
67-63-0
Iso ro anol
ug/m3
21
78-93-3
Methyl Ethyl Ketone 2-Butanone
ug/m3
10
75-09-2
Methylene Chloride
ug/m3
2.9
91-20-3
—Naphthalene
ug/m3
230
115-07-1
Propylene
ug/m3
1.9
100-42-5
Styrene
ug/m3
9.8
127-18-4
Tetrachloroeth lene
ug/m3
230
108-88-3
Toluene
ug/m3
7
71-55-6
Trichloroethane, 1,1,1-
ug/m3
9.9
75-69-4
Trichlorofluoromethane
ug/m3
20
95-63-6
Trimeth lbenzene,1,2,4-
ug/m3
5
108-67-8
Trimeth lbenzene,1,3,5-
ug/m3
204
1330-20-7
X lens
ug/m3
North Carolina DEQ Risk Calwlalor

Risk for Individual Pathways
-FIR
IM
Version Date: May 2019
Basis: May 2019 EPA RSL Table
Site ID: BPN #22059-18-032
Exposure Unit ID: Proposed Building
4
DIRECT CONTACT SOIL AND WATER CALCULATORS
Receptor
Pathway
CarcinogenicHazard
Risk
Index
Risk exceeded?
Resident
Soil
NC
NC
NC
NC
Groundwater Use*
NC
NC
Non -Residential Worker
Soil
NC
NC
NC
NC
Groundwater Use*
NC
NC
Construction Worker
Soil
NC
NC
NC
Recreator/Trespasser
Soil
NC
NC
NC
Surface Water*
NC
NC
NC
VAPOR INTRUSION CALCULATORS
Receptor
Pathway
CarcinogenicHazard
Risk
Index
Risk exceeded?
Resident
Groundwater to Indoor Air
NC
NC
NC
Soil Gas to Indoor Air
NC
NC
NC
Indoor Air
NC
NC
NC
Non -Residential Worker
Groundwater to Indoor Air
NC
NC
NC
Soil Gas to Indoor Air
4.0E-07
1.2E-02
NO
Indoor Air
NC
NC
NC
CONTAMINANT
MIGRATION CALCULATORS
Pathway
Source
Target Receptor Concentrations Exceeded?
Groundwater
Source Soil
Exceedence of 2L at Receptor?
NC
Source Groundwater
Exceedence of 2L at Receptor?
NC
Surface Water
Source Soil
Exceedence of 2B at Receptor?
NC
Source Groundwater
Exceedence of 2B at Receptor?
NC
Notes:
1. If lead concentrations were entered in the exposure point concentration tables, see the individual calculator sheets for lead
concentrations in comparison to screening levels. Note that lead is not included in cumulative risk calculations.
2. * = If concentrations in groundwater exceed the NC 2L Standards or IMAC, or concentrations in surface water exceed the
NC 2B Standards, appropriate remediation and/or institutional control measures will be necessary to be eligible for a risk -based
closure.
3. NM = Not Modeled
4. NC = Pathway not complete
North Carolina DEQ Risk Calculator

Risk Calculator - Vapor Intrusion - Non -Residential Worker Soil Gas to Indoor Air
.ion Date: May 2019
s: May 2019 EPA RSL Table
ID: BPN #22059-18-032
osure Unit ID: Proposed Building 4
Carcinogenic risk and hazard quotient cells highlighted in orange are associated with non-volatile chemicals. Since these chemicals do not pose a vapor intrusion
risk, no risk values are calculated for these chemicals.
All concentrations are in ue/m3
CAS #
Chemical Name:
Soil Gas
Concentration
3
(ug/m)
Calculated
Indoor Air
Concentration
Co
(ug/ro)
Target Indoor
Air Conc. for
Carcinogens @
TCR = 1E-06
Target Indoor Air
Conc. for Non -
Carcinogens @
THQ = 0.2
Calculated
Carcinogenic
Risk
Calculated
Non -
Carcinogenic
Hazard
Quotient
67-64-1
Acetone
170
1.7
2.7E+04
1.3E-05
7143-2
Benzene
27
0.27
1.6E+00
2.6E+01
1.7E-07
2.1E-03
75-15-0
Carbon Disulfide
35
0.35
6.1E+02
1.1E-04
56-23-5
Carbon Tetrachloride
9.1
0.091
2.0E+00
8.8E+01
4.5E-08
2.1E-04
67-66-3
Chloroform
1.4
0.014
5.3E-01
8.6E+01
2.6E-08
3.3E-05
110-82-7
Cyclohexane
5.9
0.059
5.3E+03
2.2E-06
75-71-8
Dichlorodifluoromethane
3.3
0.033
8.8E+01
7.5E-05
156-60-5
Dichloroethylene, 1,2-trans-
7.3
0.073
10041-4
Ethylbenzene
36
0.36
4.9E+00
8.8E+02
7.3E-08
8.2E-05
142-82-5
Heptane, N-
13
0.13
3.5E+02
7.4E-05
110-54-3
Hexane, N-
23
0.23
6.1E+02
7.5E-05
67-63-0
Isopropanol
12
0.12
1.8E+02
1.4E-04
78-93-3
Methyl Ethyl Ketone (2-Butanone)
21
0.21
4.4E+03
9.6E-06
75-09-2
Methylene Chloride
10
0.1
1.2E+03
5.3E+02
8.2E-11
3.8E-05
91-20-3
-Naphthalene
2.9
0.029
3.6E-01
2.6E+00
8.0E-08
2.2E-03
115-07-1
Propylene
230
2.3
2.6E+03
1.8E-04
10042-5
Styrene
1.9
0.019
8.8E+02
4.3E-06
127-18-4
Tetrachloroethylene
9.8
0.098
4.7E+01
3.5E+01
2.1E-09
5.6E-04
108-88-3
Toluene
230
2.3
4.4E+03
1.1E-04
71-55-6
Trichloroethane, 1,1,1-
7
0.07
4.4E+03
3.2E-06
75-69-4
Trichlorofluoromethane
9.9
0.099
95-63-6
Trimethylbenzene, 1,2,4-
20
0.2
5.3E+01
7.6E-04
108-67-8
Trimethylbenzene, 1,3,5-
5
1 0.05
1
5.3E+01
1.9E-04
1330-20-7
Xylenes
204
1 2.04
1
8.8E+01
4.7E-03
Cumulative: I 4.0E-07 1 1.2E-02
North Carolina DEQ Risk Calculator

North Carolina Department of Environmental Quality
Risk Calculator
Version Date:
May 2019
Basis:
May 2019 EPA RSL Table
Site Name:
Monsanto
Site Address:
3029 East Cornwallis Road, Durham, North Carolina
DEQ Section:
Brownfields Program
Site ID:
BPN #22059-18-032
Exposure Unit ID:
Proposed Building 5
Submittal Date:
Prepared By:
Hart & Hickman, PC
Reviewed By:
North Carolina DEQ Risk Calculator

Complete Exposure Pathways
Version Date: May 2019
Basis: May 2019 EPA RSL Table
Site ID: BPN #22059-18-032
Exposure Unit ID: Proposed Building 5
Note: Risk output will only be calculated for complete exposure pathways.
Receptor
Pathway
Check box if
pathway
complete
DIRECT CONTACT SOIL AND WATER PATHWAYS
Resident
Soil
El
Groundwater Use
I_I
Non -Residential Worker
Soil
❑
Groundwater Use
❑
Construction Worker
Soil
❑
Recreator/Trespasser
Soil
❑
Surface Water
❑
VAPOR INTRUSION PATHWAYS
Resident
Groundwater to Indoor Air
❑
Soil Gas to Indoor Air
❑
Indoor Air
❑
Non -Residential Worker
Groundwater to Indoor Air
❑
Soil Gas to Indoor Air
0
Indoor Air
❑
CONTAMINANT MIGRATION PATHWAYS
Groundwater
Source Soil
❑
Source Groundwater
❑
Surface Water
Source Soil
❑
Source Groundwater
❑
North Carolina DEQ Risk Calculator

)sure Point Concentrations
lion Date: May 2019
s: May 2019 EPA RSL Table
ID: BPN #22059-18-032
)sure Unit ID: Proposed Builc
Description of Exposure Point Concentration Selection:
Maximum concentrations of constituents detected in soil gas samples within Building 5 footprint.
Note: Chemicals highlighted in orange are non-volatile chemicals. Since these chemicals do not pose a vapor intrusion risk, no risk values are calculated for these chemicals.
Exposure Point
Minimum
Maximum
Location of
Range of
Concentration
Screening
Potential
Potential
Rationale for
Concentration
Notes:
CAS Number
Chemical
Concentration
Concentration
Units
Maximum
Detection
Detection
Used f
Background
Toxicity Value
ARAR/TBC
ARAR/TBC
COPC Flagor
Selection or
s
(ug/m)
(Qualifier)
(Qualifier)
Concentration
Frequency
Limits
Screening
Value
(Screening
Value
Source
(Y/N)
Deletion
Level) (n/c)
320
67-64-1
Acetone
ug/m3
62
71-43-2
Benzene
ug/m3
24
106-99-0
Butadiene,l,3-
ug/m3
140
75-15-0
Carbon Disulfide
ug/m3
1.7
56-23-5
Carbon Tetrachloride
ug/m3
6.7
67-66-3
Chloroform
ug/m3
38
110-82-7
C clohexane
ug/m3
3.5
75-71-8
Dichlorodifluoromethare
ug/m3
2.6
156-60-5
Dichloroeth lene, 1,2-trans-
ug/m3
39
100-41-4
Eth lbenzene
ug/m3
12
142-82-5
He tape, N-
ug/m3
30
110-54-3
Hexane, N-
ug/m3
72
67-63-0
Iso ro anol
ug/m3
21
78-93-3
Methyl Ethyl Ketone 2-Butanone
ug/m3
9.2
108-10-1
Methyl Isobutyl Ketone 4-meth 1-2- entanone
ug/m3
6.7
75-09-2
Methylene Chloride
ug/m3
5.7
91-20-3
—Naphthalene
ug/m3
500
115-07-1
Propylene
ug/m3
3.8
100-42-5
Styrene
ug/m3
3.1
127-18-4
Tetrachloroeth lene
ug/m3
380
108-88-3
Toluene
ug/m3
2.6
120-82-1
Trichlorobenzene,1,2,4-
ug/m3
1.6
71-55-6
Trichloroethane, 1,1,1-
ug/m3
1.3
79-01-6
Trichloroeth lene
ug/m3
86
75-69-4
Trichlorofluoromethane
ug/m3
40
95-63-6
Trimeth lbenzene,1,2,4-
ug/m3
10
108-67-8
Trimeth lbenzene,1,3,5-
ug/m3
200
1330-20-7
X lens
ug/m3
North Carolina DEQ Risk Calwlalor

Risk for Individual Pathways
-FIR
IM
Version Date: May 2019
Basis: May 2019 EPA RSL Table
Site ID: BPN #22059-18-032
Exposure Unit ID: Proposed Building
5
DIRECT CONTACT SOIL AND WATER CALCULATORS
Receptor
Pathway
CarcinogenicHazard
Risk
Index
Risk exceeded?
Resident
Soil
NC
NC
NC
NC
Groundwater Use*
NC
NC
Non -Residential Worker
Soil
NC
NC
NC
NC
Groundwater Use*
NC
NC
Construction Worker
Soil
NC
NC
NC
Recreator/Trespasser
Soil
NC
NC
NC
Surface Water*
NC
NC
NC
VAPOR INTRUSION CALCULATORS
Receptor
Pathway
CarcinogenicHazard
Risk
Index
Risk exceeded?
Resident
Groundwater to Indoor Air
NC
NC
NC
Soil Gas to Indoor Air
NC
NC
NC
Indoor Air
NC
NC
NC
Non -Residential Worker
Groundwater to Indoor Air
NC
NC
NC
Soil Gas to Indoor Air
1.4E-06
5.0E-02
NO
Indoor Air
NC
NC
NC
CONTAMINANT
MIGRATION CALCULATORS
Pathway
Source
Target Receptor Concentrations Exceeded?
Groundwater
Source Soil
Exceedence of 2L at Receptor?
NC
Source Groundwater
Exceedence of 2L at Receptor?
NC
Surface Water
Source Soil
Exceedence of 2B at Receptor?
NC
Source Groundwater
Exceedence of 2B at Receptor?
NC
Notes:
1. If lead concentrations were entered in the exposure point concentration tables, see the individual calculator sheets for lead
concentrations in comparison to screening levels. Note that lead is not included in cumulative risk calculations.
2. * = If concentrations in groundwater exceed the NC 2L Standards or IMAC, or concentrations in surface water exceed the
NC 2B Standards, appropriate remediation and/or institutional control measures will be necessary to be eligible for a risk -based
closure.
3. NM = Not Modeled
4. NC = Pathway not complete
North Carolina DEQ Risk Calculator

Risk Calculator - Vapor Intrusion - Non -Residential Worker Soil Gas to Indoor Air
.ion Date: May 2019
s: May 2019 EPA RSL Table
ID: BPN #22059-18-032
osure Unit ID: Proposed Building 5
Carcinogenic risk and hazard quotient cells highlighted in orange are associated with non-volatile chemicals. Since these chemicals do not pose a vapor intrusion
risk, no risk values are calculated for these chemicals.
All concentrations are in ue/m3
CAS #
Chemical Name:
Soil Gas
Concentration
3
(ug/m)
Calculated
Indoor Air
Concentration
Co
(ug/ro)
Target Indoor
Air Conc. for
Carcinogens @
TCR = 1E-06
Target Indoor Air
Conc. for Non -
Carcinogens @
THQ = 0.2
Calculated
Carcinogenic
Risk
Calculated
Non -
Carcinogenic
Hazard
Quotient
67-64-1
Acetone
320
3.2
2.7E+04
2.4E-05
7143-2
Benzene
62
0.62
1.6E+00
2.6E+01
3.9E-07
4.7E-03
106-99-0
Butadiene, 1,3-
24
0.24
4.1E-01
1.8E+00
5.9E-07
2.7E-02
75-15-0
Carbon Disulfide
140
1.4
6.1E+02
4.6E-04
56-23-5
Carbon Tetrachloride
1.7
0.017
2.0E+00
8.8E+01
8.3E-09
3.9E-05
67-66-3
Chloroform
6.7
0.067
5.3E-01
8.6E+01
1.3E-07
1.6E-04
110-82-7
Cyclohexane
38
0.38
5.3E+03
1.4E-05
75-71-8
Dichlorodifluoromethane
3.5
0.035
8.8E+01
8.0E-05
156-60-5
Dichloroethylene, 1,2-trans-
2.6
0.026
10041-4
Ethylbenzene
39
0.39
4.9E+00
8.8E+02
8.0E-08
8.9E-05
142-82-5
Heptane, N-
12
0.12
3.5E+02
6.8E-05
110-54-3
Hexane, N-
30
0.3
6.1E+02
9.8E-05
67-63-0
Isopropanol
72
0.72
1.8E+02
8.2E-04
78-93-3
Methyl Ethyl Ketone (2-Butanone)
21
0.21
4.4E+03
9.6E-06
108-10-1
Methyl Isobutyl Ketone (4-methyl-2-pentanone)
9.2
0.092
2.6E+03
7.0E-06
75-09-2
Methylene Chloride
6.7
0.067
1.2E+03
5.3E+02
5.5E-11
2.5E-05
91-20-3
-Naphthalene
5.7
0.057
3.6E-01
2.6E+00
1.6E-07
4.3E-03
115-07-1
Propylene
500
5
2.6E+03
3.8E-04
10042-5
Styrene
3.8
0.038
8.8E+02
8.7E-06
127-18-4
Tetrachloroethylene
3.1
0.031
4.7E+01
3.5E+01
6.6E-10
1.8E-04
108-88-3
Toluene
380
3.8
4.4E+03
1.7E-04
120-82-1
Trichlorobenzene, 1,2,4-
2.6
0.026
1.8E+00
3.0E-03
71-55-6
Trichloroethane, 1,1,1-
1.6
0.016
1
4.4E+03
7.3E-07
79-01-6
Trichloroethylene
1.3
0.013
3.OF,+00
1.8E+00
4.3E-09
1.5E-03
75-69-4
Trichlorofluoromethane
86
0.86
95-63-6
Trimethylbenzene, 1,2,4-
40
0.4
5.3E+01
1.5E-03
108-67-8
Trimethylbenzene, 1,3,5-
10
0.1
5.3E+01
3.8E-04
1330-20-7
Xylenes
200
2
8.8E+01
4.6E-03
Cumulative: I 1.4E-06 I 5.0E-02
North Carolina DEQ Risk Calculator

North Carolina Department of Environmental Quality
Risk Calculator
Version Date:
May 2019
Basis:
May 2019 EPA RSL Table
Site Name:
Monsanto
Site Address:
3029 East Cornwallis Road, Durham, North Carolina
DEQ Section:
Brownfields Program
Site ID:
BPN #22059-18-032
Exposure Unit ID:
Proposed Building 6
Submittal Date:
Prepared By:
Hart & Hickman, PC
Reviewed By:
North Carolina DEQ Risk Calculator

Complete Exposure Pathways
Version Date: May 2019
Basis: May 2019 EPA RSL Table
Site ID: BPN #22059-18-032
Exposure Unit ID: Proposed Building 6
Note: Risk output will only be calculated for complete exposure pathways.
Receptor
Pathway
Check box if
pathway
complete
DIRECT CONTACT SOIL AND WATER PATHWAYS
Resident
Soil
El
Groundwater Use
I_I
Non -Residential Worker
Soil
❑
Groundwater Use
❑
Construction Worker
Soil
❑
Recreator/Trespasser
Soil
❑
Surface Water
❑
VAPOR INTRUSION PATHWAYS
Resident
Groundwater to Indoor Air
❑
Soil Gas to Indoor Air
❑
Indoor Air
❑
Non -Residential Worker
Groundwater to Indoor Air
❑
Soil Gas to Indoor Air
0
Indoor Air
❑
CONTAMINANT MIGRATION PATHWAYS
Groundwater
Source Soil
❑
Source Groundwater
❑
Surface Water
Source Soil
❑
Source Groundwater
❑
North Carolina DEQ Risk Calculator

)sure Point Concentrations
lion Date: May 2019
s: May 2019 EPA RSL Table
ID: BPN #22059-18-032
)sure Unit ID: Proposed Bail(
Description of Exposure Point Concentration Selection:
Maximum concentrations of constituents detected in soil gas samples within the building 6 footprint.
Note: Chemicals highlighted in orange are non-volatile chemicals. Since these chemicals do not pose a vapor intrusion risk, no risk values are calculated for these chemicals.
Exposure Point
Minimum
Maximum
Location of
Range of
Concentration
Screening
Potential
Potential
Rationale for
Concentration
Notes:
CAS Number
Chemical
Concentration
Concentration
Units
Maximum
Detection
Detection
Used f
Background
Toxicity Value
ARAR/TBC
ARAR/TBC
COPC Flagor
Selection or
s
(ug/m)
(Qualifier)
(Qualifier)
Concentration
Frequency
Limits
Screening
Value
(Screening
Value
Source
(Y/N)
Deletion
Level) (n/c)
260
67-64-1
Acetone
ug/m3
95
71-43-2
Benzene
ug/m3
500
75-15-0
Carbon Disulfide
ug/m3
1.9
56-23-5
Carbon Tetrachloride
ug/m3
2.1
67-66-3
Chloroform
ug/m3
5.9
74-87-3
Chloromethare
ug/m3
28
110-82-7
C clohexane
ug/m3
1.6
124-48-1
Dibromochloromethane
ug/m3
4.5
75-71-8
Dichlorodifluoromethane
ug/m3
17
141-78-6
Ethyl Acetate
ug/m3
250
100-41-4
Eth lbenzene
ug/m3
5.6
109-99-9
—Tetrah drofuran
ug/m3
69
142-82-5
He tape, N-
ug/m3
170
110-54-3
Hexane, N-
ug/m3
36
591-78-6
Hexanone,2-
ug/m3
18
67-63-0
Iso ro anol
ug/m3
30
78-93-3
Methyl Ethyl Ketone 2-Butanone
ug/m3
6.6
108-10-1
Methyl Isobutyl Ketone 4-meth 1-2- entanone
ug/m3
4.4
91-20-3
—Naphthalene
ug/m3
1700
115-07-1
Propylene
ug/m3
11
100-42-5
Styrene
ug/m3
5.2
127-18-4
Tetrachloroeth lene
ug/m3
1300
108-88-3
Toluene
ug/m3
5.1
76-13-1
Trichloro-1,2,2-trifluoroethane, 1,1,2-
ug/m3
2.5
120-82-1
Trichlorobenzene,1,2,4-
ug/m3
0.94
71-55-6
Trichloroethane, 1,1,1-
ug/m3
0.99
79-01-6
Trichloroeth lene
ug/m3
3.3
75-69-4
Trichlorofluoromethane
ug/m3
110
95-63-6
Trimeth lbenzene,1,2,4-
ug/m3
29
108-67-8
Trimeth lbenzene,1,3,5-
ug/m3
1.4
75-01-4
Vinyl Chloride
ug/m3
1300
1330-20-7
X lens
ug/m3
North Carolina DEQ Risk Calwlalor

Risk for Individual Pathways
-FIR
IM
Version Date: May 2019
Basis: May 2019 EPA RSL Table
Site ID: BPN #22059-18-032
Exposure Unit ID: Proposed Building
6
DIRECT CONTACT SOIL AND WATER CALCULATORS
Receptor
Pathway
CarcinogenicHazard
Risk
Index
Risk exceeded?
Resident
Soil
NC
NC
NC
NC
Groundwater Use*
NC
NC
Non -Residential Worker
Soil
NC
NC
NC
NC
Groundwater Use*
NC
NC
Construction Worker
Soil
NC
NC
NC
Recreator/Trespasser
Soil
NC
NC
NC
Surface Water*
NC
NC
NC
VAPOR INTRUSION CALCULATORS
Receptor
Pathway
CarcinogenicHazard
Risk
Index
Risk exceeded?
Resident
Groundwater to Indoor Air
NC
NC
NC
Soil Gas to Indoor Air
NC
NC
NC
Indoor Air
NC
NC
NC
Non -Residential Worker
Groundwater to Indoor Air
NC
NC
NC
Soil Gas to Indoor Air
1.3E-06
5.9E-02
NO
Indoor Air
NC
NC
NC
CONTAMINANT
MIGRATION CALCULATORS
Pathway
Source
Target Receptor Concentrations Exceeded?
Groundwater
Source Soil
Exceedence of 2L at Receptor?
NC
Source Groundwater
Exceedence of 2L at Receptor?
NC
Surface Water
Source Soil
Exceedence of 2B at Receptor?
NC
Source Groundwater
Exceedence of 2B at Receptor?
NC
Notes:
1. If lead concentrations were entered in the exposure point concentration tables, see the individual calculator sheets for lead
concentrations in comparison to screening levels. Note that lead is not included in cumulative risk calculations.
2. * = If concentrations in groundwater exceed the NC 2L Standards or IMAC, or concentrations in surface water exceed the
NC 2B Standards, appropriate remediation and/or institutional control measures will be necessary to be eligible for a risk -based
closure.
3. NM = Not Modeled
4. NC = Pathway not complete
North Carolina DEQ Risk Calculator

Risk Calculator - Vapor Intrusion - Non -Residential Worker Soil Gas to Indoor Air
.ion Date: May 2019
s: May 2019 EPA RSL Table
ID: BPN #22059-18-032
osure Unit ID: Proposed Building 6
Carcinogenic risk and hazard quotient cells highlighted in orange are associated with non-volatile chemicals. Since these chemicals do not pose a vapor intrusion
risk, no risk values are calculated for these chemicals.
All concentrations are in ue/m3
CAS #
Chemical Name:
Soil Gas
Concentration
3
(ug/m)
Calculated
Indoor Air
Concentration
Co
(ug/ro)
Target Indoor
Air Conc. for
Carcinogens @
TCR = 1E-06
Target Indoor Air
Conc. for Non -
Carcinogens @
THQ = 0.2
Calculated
Carcinogenic
Risk
Calculated
Non -
Carcinogenic
Hazard
Quotient
67-64-1
Acetone
260
2.6
2.7E+04
1.9E-05
7143-2
Benzene
95
0.95
1.6E+00
2.6E+01
6.0E-07
7.2E-03
75-15-0
Carbon Disulfide
500
5
6.1E+02
1.6E-03
56-23-5
Carbon Tetrachloride
1.9
0.019
2.0E+00
8.8E+01
9.3E-09
4.3E-05
67-66-3
Chloroform
2.1
0.021
5.3E-01
8.6E+01
3.9E-08
4.9E-05
74-87-3
Chloromethane
5.9
0.059
7.9E+01
1.5E-04
110-82-7
Cyclohexane
28
0.28
5.3E+03
1.1E-05
12448-1
Dibromochloromethane
1.6
0.016
75-71-8
Dichlorodifluoromethane
4.5
0.045
8.8E+01
1.0E-04
141-78-6
Ethyl Acetate
17
0.17
6.1E+01
5.5E-04
10041-4
Ethylbenzene
250
2.5
1 4.9E+00
8.8E+02
5.1E-07
5.7E-04
109-99-9
-Tetrahydrofuran
5.6
0.056
1.8E+03
6.4E-06
142-82-5
Heptane, N-
69
0.69
3.5E+02
3.9E-04
110-54-3
Hexane, N-
170
1.7
6.1E+02
5.5E-04
591-78-6
Hexanone, 2-
36
0.36
2.6E+01
2.7E-03
67-63-0
Isopropanol
18
0.18
1.8E+02
2.1E-04
78-93-3
Methyl Ethyl Ketone (2-Butanone)
30
0.3
4.4E+03
1.4E-05
108-10-1
Methyl Isobutyl Ketone (4-methyl-2-pentanone)
6.6
0.066
2.6E+03
5.0E-06
91-20-3
-Naphthalene
4.4
0.044
3.6E-01
2.6E+00
1.2E-07
3.3E-03
115-07-1
Propylene
1700
17
2.6E+03
1.3E-03
10042-5
Styrene
11
0.11
8.8E+02
2.5E-05
127-18-4
Tetrachloroethylene
5.2
0.052
4.7E+01
3.5E+01
1.1E-09
3.0E-04
108-88-3
Toluene
1300
13
4.4E+03
5.9E-04
76-13-1
Trichloro-1,2,2-trifluoroethane, 1,1,2-
5.1
0.051
4.4E+03
2.3E-06
120-82-1
Trichlorobenzene, 1,2,4-
2.5
0.025
1.8E+00
2.9E-03
71-55-6
Trichloroethane, 1,1,1-
0.94
0.0094
4.4E+03
4.3E-07
79-01-6
Trichloroethylene
0.99
0.0099
1 3.0E+00
1.8E+00
3.3E-09
1.1E-03
75-69-4
Trichlorofluoromethane
3.3
0.033
95-63-6
Trimethylbenzene, 1,2,4-
110
1.1
5.3E+01
4.2E-03
108-67-8
Trimethylbenzene, 1,3,5-
29
0.29
5.3E+01
1.1E-03
75-01-4
Vinyl Chloride
1.4
0.014
2.8E+00
8.8E+01
5.0E-09
3.2E-05
1330-20-7
Xylenes
1300
13
8.8E+01
3.0E-02
Cumulative: I 1.3E-06 I 5.9E-02
North Carolina DEQ Risk Calculator