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HomeMy WebLinkAbout20089_Hendrick Durham Collision Center_Soil Gas Report_20170419_MAA April 19, 2017 Mr. Eric Applefield Southern Apartment Group, LLC 1435 West Morehead Street, Suite 130 Charlotte, North Carolina 28208 Subject: SOIL GAS SAMPLING LETTER REPORT FORMER HENDRICK COLLISION CENTER 510 EAST PETTIGREW STREET DURHAM, DURHAM COUNTY, NORTH CAROLINA BROWNFIELDS PROJECT NUMBER 20089-16-32 MID-ATLANTIC JOB NUMBER: R2698.01 TASK 40000 Dear Mr. Applefield: Mid-Atlantic Associates, Inc. is pleased to present this Soil Gas Sampling Letter Report for the above-referenced site. The sampling was conducted in general accordance with Mid-Atlantic Proposal 000R2698.01 dated January 24, 2017. The subject site is located in a commercial area of Durham, North Carolina between S. Dillard Street and Fayetteville Road on the west side of the street. The site is the parcel at 510 East Pettigrew Street, which totals 2.166 acres of land and is assigned Parcel ID Number 0831-13-04-2968 according to the Durham County Tax Administration Office. This site was formerly part of the Hendrick Durham Auto Mall and is being evaluated for potential soil-gas issues as part of redevelopment under Brownfields Project Number 20089-16-32. A soil-gas sample was collected on this parcel as part of an earlier assessment by ECS Carolinas, LLP (ECS), and the laboratory analytical data yielded a result that was in excess of the IHSB Vapor Intrusion Residential Screening Level for 1,4- dichlorobenzene. At the request of the North Carolina Brownfileds Program (NCBFP) Mid- Atlantic developed a Soil Gas Sampling Work Plan for the subject site. The Soil Gas Sampling Work Plan was accepted by the NCBFP on February 20, 2017 and outlined a plan for collecting four deeper soil-gas samples at the subject site in general accordance with the North Carolina Department of Environment and Natural Resources, Division of Waste Management, Vapor Intrusion Guidance (April 2014). This report documents the results of these activities. The attached drawing shows the location of the ECS sub-slab soil gas sample location and the four deeper soil gas sample locations used for this assessment. The four soil gas Letter Report of Soil Gas Sampling April 19, 2017 Former Hendrick Collison Center Page 2 Durham, North Carolina sample locations (SG-A, SG-B, SG-C, SG-D) are located where current development plans indicate that occupied building space will be constructed, (e.g. not parking areas). At each soil-gas location, the pavement was removed and cleared from the boring location and a boring was advanced to a depth of six to seven feet below land surface using a direct push drill rig. One-quarter inch outer diameter Nylon tubing was inserted into each boring to within four inches of the bottom of the boring. A filter tip was placed on the tip of the tubing and a sand pack was installed around the filter tip and tubing approximately one foot from the bottom of the boring. A six-inch thick hydrated bentonite seal was installed above the sand pack. The assembly was leak tested prior to sampling. A laboratory supplied summa canister was attached to the tubing to collect a soil gas sample. Air within the nylon tubing and sand pack was purged prior to sample collection. Each sample was submitted to Con-Test Analytical Laboratory, Inc. (Con-Test) in East Longmeadow, Massachusetts for analysis using EPA Method TO-15. LABORATORY ANALYTICAL RESULTS The laboratory analytical report and chain-of-custody record for the soil gas samples collected during the March 22, 2017 sampling event are provided in Appendix A and summarized in Table 1. The soil gas analytical results were initially compared to the North Carolina Department of Environmental Quality (NCDEQ) Division of Waste Management (DWM) Residential and Non-Residential Vapor Intrusion Exterior Soil Gas Screening Levels October 2016 Table (SGSLs). Risk Calculation Methodology The DWM establishes vapor intrusion SGSLs for individual compounds for residential and non-residential (industrial/commercial) exposure scenarios. The DWM allows a maximum cancer risk sum for all carcinogens of 1.0E-05 and a maximum cumulative hazard index (HI) of 1.0 for all non-carcinogens in soil gas. Samples above these values require additional assessment to evaluate the potential for vapor intrusion. The HI is the sum of the hazard quotient (HQs) calculated for each compound detected above the reporting limit. Mid-Atlantic initially compared the sub-slab sampling results to DWM residential SGSLs and then calculated the cancer risk and non-cancer risk hazard quotient for each compound detected above the laboratory reporting limit. Cancer risk sums and cumulative non-cancer hazard indexes were then determined for each sample. Residential scenario risk calculations for the exterior soil gas samples are summarized in Table 2 and discussed below. Sub-Slab Soil Gas Sampling Results As summarized in Table 2, due to a dilution factor of 20, laboratory reporting limits were too high to compare analytical results to the DWM residential SGSLs for 1,2-dibromoethane Letter Report of Soil Gas Sampling April 19, 2017 Former Hendrick Collison Center Page 3 Durham, North Carolina (EDB) and 1,1,2-trichloroethane at the sample collected at SG-D. 1,4-dichlorobenzene was not detected above the laboratory method detection limits in any of the samples collected during the March 22, 2017 soil gas assessment. A discussion of the laboratory results and risk calculations for each sample follows. SG-A As summarized in Table 1, the sample collected from SG-A exhibited concentrations of 1,3- butadiene and tetrachloroethylene (PCE) at concentrations above the DWM residential SGSLs. The residential cancer risk sum for sample SG-A was 2.2E-05 (Table 2), which is above the target cancer risk sum of 1.0E-05. The residential cumulative non-cancer hazard index for sample SG-A was 1.3E+00 which is above the target cumulative non-cancer hazard index of 1.0. SG-B As summarized in Table 1, the sample collected from SG-B exhibited concentrations of 1,3- butadiene and 1,2,4-trimethylbenzene at concentrations above the DWM residential SGSLs. The residential cancer risk sum for sample SG-B was 1.7E-05 (Table 2), which is above the target cancer risk sum of 1.0E-05. The residential cumulative non-cancer hazard index for sample SG-B was 7.20E-01 which is below the target cumulative non-cancer hazard index of 1.0. SG-C As summarized in Table 1, the sample collected from SG-C did not exhibit constituent concentrations above the DWM residential SGSLs. The residential cancer risk sum for sample SG-C was 4.5E-06 (Table 2), which is below the target cancer risk sum of 1.0E-05. The residential cumulative non-cancer hazard index for sample SG-C was 3.2E-01 which is less than the target cumulative non-cancer hazard index of 1.0. SG-D As summarized in Table 1, the sample collected from SG-D exhibited concentrations of 1,3- butadiene, ethylbenzene, 1,2,4-trimethylbenzene, m&p xylenes, and o-xylenes at concentrations above the DWM residential SGSLs. The concentration of m&p xylenes detected in the sample also exceeds the non-residential SGSL. Because the laboratory reporting limits for EDB and 1,1,2-trichloroethane exceeded the SGSLs, the values of the laboratory reporting limits were used in the risk calculations. The residential cancer risk sum for sample SG-D was 8.3E-05 (Table 2), which is above the target cancer risk sum of 1.0E- 05. The residential cumulative non-cancer hazard index for sample SG-D was 5.2E+00 which is above the target cumulative non-cancer hazard index of 1.0. Letter Report of Soil Gas Sampling April 19, 2017 Former Hendrick Collison Center Page 4 Durham, North Carolina CONCLUSIONS AND RECOMMENDATIONS The March 2017 Vapor Intrusion Assessment activities are summarized as follows:  In accordance with the NCBFP approved Work Plan four exterior soil gas samples (SG-A through SG-D) were collected from the areas of the subject site that are currently planned for development of residential structures;  Several compounds were detected in the exterior soil gas samples at concentrations exceeding the initial DWM residential SGSLs including 1,3-butadiene, ethylbenzene, PCE, 1,2,4-trimethylbenzene, and xylene (m&p and o); and  The residential cancer risk sums for the samples collected at SG-A, SG-B, and SG- D exceed the target cancer risk sum of 1.0E-05. The residential cumulative non- cancer hazard indexes also exceeded the target cumulative non-cancer hazard index of 1.0 in the samples collected at SG-A and SG-D. The objective of this investigation was to assess the degree and extent of potential soil-gas contamination at the subject site. Mid-Atlantic recommends a copy of this report be submitted to the North Carolina Brownfields Program. Based on the data collected Mid- Atlantic considers it likely that the North Carolina Brownfields program will require vapor intrusion mitigation measures for new residential construction at the site. We appreciate the opportunity to present this report to Southern Apartment Group, LLC. If you have any questions or need additional information, please feel free to contact us at 919- 250-9918. Sincerely, MID-ATLANTIC ASSOCIATES, INC. Gregory L. Hutchins Daniel H. Nielsen, PE Staff Scientist Principal Engineer Attachment: Drawing Tables Laboratory Report DRAWING !A !A!A !A !A !A !A !A ´ SOIL GAS SAMPLE LOCATION MAP FORMER COLLISION CENTER510 EAST PETTIGREW STREETDURHAM, NORTH CAROLINABROWNFIELDS PROJECT NO.: 20089-16-32 DRAWN BY: DRAFT CHECK BY: ENGINEER CHECK BY: APPROVED BY: DATE: APRIL 2017 JOB NO.: 000R2698.01 GIS NO.: 4G-R2698.01 T40000 DRAWING NO.: 2 REFERENCE: 2013 AERIAL IMAGERY FROM NC ONE MAPS. PROPERTY BOUNDARY AND ROAD GIS FROM DURHAM COUNTY GIS. ECS SUB-SLAB SAMPLE LOCATION DATA FROM ECS CAROLINAS SOIL-GAS SAMPLE LOCATION MAP. LEGEND !A MID-ATLANTIC SOIL GAS SAMPLE LOCATION !A ECS SUB-SLAB SAMPLE LOCATION PLANNED BUILDING LOCATIONSSUBJECT SITE 0 60 120 180Feet 1:720 JACKIE R O B I N S O N SG-1 A B C D E PETT IGREW S T TABLES TABLE 1 SUMMARY OF CHEMICAL CONSTITUENTS DETECTED IN EXTERIOR SOIL GAS FORMER HENDRICK COLLISION CENTER DURHAM, NORTH CAROLINA MID-ATLANTIC JOB NO. 000R2698.01 T40000 Residential Vapor Intrusion Screening Levels Non-Residential Vapor Intrusion Screening Levels SG-A SG-B SG-C SG-D Residential Soil- Gas ug/m3 Non-Residential Soil-Gas ug/m3 Sampling Date 3/22/2017 11:49 AM 3/22/2017 11:17 AM 3/22/2017 12:19 PM 3/22/2017 10:49 AM Sample Depth - Feet - Feet - Feet - Feet EPA TO-15 Acetone 130 150 V-06 ND (6.6)120 V-06 216000 2720000 Benzene 44 46 23 36 120 1570 Benzyl Chloride ND (0.50)ND (0.20)ND (0.20)ND (1.0)6.95 87.6 Bromodichloromethane ND (0.73)ND (0.29)ND (0.29)ND (1.5)21.9 331 Bromoform ND (0.99)ND (0.40)ND (0.40)ND (2.0)~~ Bromomethane ND (1.3)ND (0.53)ND (0.53)ND (2.7)34.8 438 1,3-Butadiene 20 19 ND (0.23)27 13.9 175 2-Butanone (MEK)38 J 55 35 66 J 34800 438000 Carbon Disulfide 27 13 25 ND (1.1)4870 61300 Carbon Tetrachloride ND (0.76)0.81 J 0.45 J ND (1.5)156 2040 Chlorobenzene ND (0.80)ND (0.32)ND (0.32)ND (1.6)348 4380 Chloroethane 49 7.3 4.0 ND (1.0)69500 876000 Chloroform 2.0 J 1.8 1.0 ND (1.1)40.7 533 Chloromethane 200 84 28 10 626 7880 Cyclohexane 13 14 86 8.9 41700 526000 Dibromochloromethane ND (1.1)ND (0.45)ND (0.45)ND (2.3)34.7 454 1,2-Dibromoethane (EDB)ND (0.86)ND (0.34)ND (0.34)ND (1.7)1.56 20.4 1,2-Dichlorobenzene ND (0.80)ND (0.32)ND (0.32)ND (1.6)1390 17500 1,3-Dichlorobenzene ND (0.67)ND (0.27)ND (0.27)ND (1.3)~~ 1,4-Dichlorobenzene ND (0.76)ND (0.30)ND (0.30)ND (1.5)73.7 1110 Dichlorodifluoromethane (Freon 12)2.4 J 2.9 2.6 2.3 J 695 8760 1,1-Dichloroethane ND (0.57)ND (0.23)ND (0.23)ND (1.1)507 7670 1,2-Dichloroethane ND (0.56)ND (0.23)ND (0.23)ND (1.1)36 472 1,1-Dichloroethylene ND (0.48)ND (0.19)ND (0.19)ND (0.97)1390 17500 cis-1,2-Dichloroethylene ND (0.75)ND (0.30)ND (0.30)ND (1.5)~~ trans-1,2-Dichloroethylene ND (0.52)ND (0.21)ND (0.21)ND (1.0)417 5260 1,2-Dichloropropane ND (0.80)ND (0.32)ND (0.32)ND (1.6)27.8 350 cis-1,3-Dichloropropene ND (0.60)ND (0.24)ND (0.24)ND (1.2)~~ trans-1,3-Dichloropropene ND (0.61)ND (0.24)ND (0.24)ND (1.2)~~ 1,2-Dichloro-1,1,2,2-tetrafluoroethane (Freon 114)ND (0.83)ND (0.33)ND (0.33)ND (1.7)~~ 1,4-Dioxane ND (12)ND (4.6)ND (4.6)ND (23)~~ Ethanol 80 21 13 J 34 J ~~ Ethyl Acetate ND (1.3)ND (0.54)3.7 ND (2.7)~~ Ethylbenzene 23 32 34 2200 374 4910 4-Ethyltoluene 8.3 9.5 6.6 23 ~~ Heptane 48 52 33 46 ~~ Hexachlorobutadiene ND (2.0)ND (0.80)ND (0.80)ND (4.0)~~ Hexane 96 79 46 51 J 4870 61300 2-Hexanone (MBK)ND (0.52)17 ND (0.21)ND (1.0)209 2630 Isopropanol 8.4 J 9.3 J 3.4 J ND (3.0)~~ Methyl tert-Butyl Ether (MTBE)0.76 J 2.0 20 ND (1.1)3600 47200 Methylene Chloride ND (2.1)1.7 J ND (0.84)ND (4.2)4170 52600 4-Methyl-2-pentanone (MIBK)9.4 19 11 14 20900 263000 Naphthalene 6.6 7.9 V-06 2.3 V-06 4.8 J, V-06 20.9 263 Propene 43 ND (1.1)230 410 20900 263000 Styrene 16 14 2.0 27 6950 87600 1,1,2,2-Tetrachloroethane ND (0.82)ND (0.33)ND (0.33)ND (1.6)16.1 211 Tetrachloroethylene 860 12 1.3 J 2.0 J 278 3500 Tetrahydrofuran ND (0.62)1.4 ND (0.25)ND (1.2)13900 175000 Toluene 170 230 120 270 34800 438000 1,2,4-Trichlorobenzene ND (1.4)ND (0.56)ND (0.56)ND (2.8)13.9 175 1,1,1-Trichloroethane ND (0.49)ND (0.20)ND (0.20)ND (0.98)34800 438000 1,1,2-Trichloroethane ND (0.83)ND (0.33)ND (0.33)ND (1.7)1.39 17.5 Trichloroethylene 13 0.39 J ND (0.32)ND (1.6)13.9 175 Trichlorofluoromethane 2.1 J 1.7 J 0.79 J ND (2.0)4870 61300 1,1,2-Trichloro-1,2,2-trifluoroethane (Freon 113)1.7 J 0.92 J 0.55 J ND (2.1)209000 2630000 1,2,4-Trimethylbenzene ND (0.60)52 47 110 48.7 613 1,3,5-Trimethylbenzene 6.8 7.0 6.9 17 ~~ Vinyl Acetate ND (0.89)ND (0.36)ND (0.36)ND (1.8)1390 17500 Vinyl Chloride 27 13 2.7 ND (1.1)55.9 2790 Xylene, m&p 89 120 150 9800 695 8760 Xylene, o-30 37 61 4000 695 8760 NOTES: 1. ND = Not detected above the lab reporting limits shown in parenthesis. 2. NT = Not tested. 3. ~ = No IHSB Residential or Non-Residential screening limits limits. 4. Values in italics exceed the IHSB Residential Indoor Air Screening Limits. 5. Bold values exceed the IHSB Non-Residential Indoor Air Screening Limits. 6. Yellow Shaded values exceed the IHSB Residential Soil-Gas Screening Limits. 7. Red Shaded values exceed the IHSB Non-Residential Soil-Gas Screening Limits. Parameter SAMPLING LOCATION TABLE 2 SUMMARY OF RISK CALCULATIONS: SG-A FORMER HENDRICK COLLISION CENTERDURHAM, NORTH CAROLINA MID-ATLANTIC JOB NO. 000R2698.01 T40000 DEQ Risk Calculator - Vapor Intrusion - Resident Soil Gas to Indoor Air Site ID: Hendrick Collision Center Exposure Unit ID: SG-A CAS #Chemical Name:Soil Gas Concentration (ug/m3) Calculated Indoor Air Concentration (ug/m3) 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 3.9 -6.5E+03 1.2E-04 71-43-2 Benzene 44 1.32 3.6E-01 6.3E+00 3.7E-06 4.2E-02 106-99-0 Butadiene, 1,3-20 0.6 9.4E-02 4.2E-01 6.4E-06 2.9E-01 75-15-0 Carbon Disulfide 27 0.81 -1.5E+02 1.1E-03 67-66-3 Chloroform 2 0.06 1.2E-01 2.0E+01 4.9E-07 5.9E-04 74-87-3 Chloromethane 200 6 -1.9E+01 6.4E-02 110-82-7 Cyclohexane 13 0.39 -1.3E+03 6.2E-05 75-71-8 Dichlorodifluoromethane 2.4 0.072 -2.1E+01 6.9E-04 75-00-3 Ethyl Chloride (Chloroethane)49 1.47 -2.1E+03 1.4E-04 100-41-4 Ethylbenzene 23 0.69 1.1E+00 2.1E+02 6.1E-07 6.6E-04 110-54-3 Hexane, N-96 2.88 -1.5E+02 3.9E-03 67-63-0 Isopropanol 8.4 0.252 -4.2E+01 1.2E-03 78-93-3 Methyl Ethyl Ketone (2-Butanone)38 1.14 -1.0E+03 2.2E-04 108-10-1 Methyl Isobutyl Ketone (4-methyl-2-pentanone)9.4 0.282 -6.3E+02 9.0E-05 1634-04-4 Methyl tert-Butyl Ether (MTBE)0.76 0.0228 1.1E+01 6.3E+02 2.1E-09 7.3E-06 91-20-3 ~Naphthalene 6.6 0.198 8.3E-02 6.3E-01 2.4E-06 6.3E-02 115-07-1 Propylene 43 1.29 -6.3E+02 4.1E-04 100-42-5 Styrene 16 0.48 -2.1E+02 4.6E-04 127-18-4 Tetrachloroethylene 860 25.8 1.1E+01 8.3E+00 2.4E-06 6.2E-01 108-88-3 Toluene 170 5.1 -1.0E+03 9.8E-04 76-13-1 Trichloro-1,2,2-trifluoroethane, 1,1,2-1.7 0.051 -6.3E+03 1.6E-06 79-01-6 Trichloroethylene 13 0.39 4.8E-01 4.2E-01 8.2E-07 1.9E-01 75-69-4 Trichlorofluoromethane 2.1 0.063 -- 108-67-8 Trimethylbenzene, 1,3,5-6.8 0.204 -- 75-01-4 Vinyl Chloride 27 0.81 1.7E-01 2.1E+01 4.8E-06 7.8E-03 1330-20-7 Xylenes 119 3.57 -2.1E+01 3.4E-02 Cumulative:2.2E-05 1.3E+00 Output Form 3B 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 ug/m3 North Carolina DEQ Risk Calculator August 2016 VersionBasis: May 2016 EPA RSL Table TABLE 2 SUMMARY OF RISK CALCULATIONS: SG-B FORMER HENDRICK COLLISION CENTERDURHAM, NORTH CAROLINA MID-ATLANTIC JOB NO. 000R2698.01 T40000 DEQ Risk Calculator - Vapor Intrusion - Resident Soil Gas to Indoor Air Site ID: Hendrick Collision Center Exposure Unit ID: SG-B CAS #Chemical Name:Soil Gas Concentration (ug/m3) Calculated Indoor Air Concentration (ug/m3) 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 150 4.5 -6.5E+03 1.4E-04 71-43-2 Benzene 46 1.38 3.6E-01 6.3E+00 3.8E-06 4.4E-02 106-99-0 Butadiene, 1,3-19 0.57 9.4E-02 4.2E-01 6.1E-06 2.7E-01 75-15-0 Carbon Disulfide 13 0.39 -1.5E+02 5.3E-04 56-23-5 Carbon Tetrachloride 0.81 0.0243 4.7E-01 2.1E+01 5.2E-08 2.3E-04 67-66-3 Chloroform 1.8 0.054 1.2E-01 2.0E+01 4.4E-07 5.3E-04 74-87-3 Chloromethane 84 2.52 -1.9E+01 2.7E-02 110-82-7 Cyclohexane 14 0.42 -1.3E+03 6.7E-05 75-71-8 Dichlorodifluoromethane 2.9 0.087 -2.1E+01 8.3E-04 75-00-3 Ethyl Chloride (Chloroethane)7.3 0.219 -2.1E+03 2.1E-05 100-41-4 Ethylbenzene 32 0.96 1.1E+00 2.1E+02 8.5E-07 9.2E-04 110-54-3 Hexane, N-79 2.37 -1.5E+02 3.2E-03 591-78-6 Hexanone, 2-17 0.51 -6.3E+00 1.6E-02 67-63-0 Isopropanol 9.3 0.279 -4.2E+01 1.3E-03 78-93-3 Methyl Ethyl Ketone (2-Butanone)55 1.65 -1.0E+03 3.2E-04 108-10-1 Methyl Isobutyl Ketone (4-methyl-2-pentanone)19 0.57 -6.3E+02 1.8E-04 1634-04-4 Methyl tert-Butyl Ether (MTBE)2 0.06 1.1E+01 6.3E+02 5.6E-09 1.9E-05 75-09-2 Methylene Chloride 1.7 0.051 1.0E+02 1.3E+02 5.0E-10 8.2E-05 91-20-3 ~Naphthalene 7.9 0.237 8.3E-02 6.3E-01 2.9E-06 7.6E-02 100-42-5 Styrene 14 0.42 -2.1E+02 4.0E-04 127-18-4 Tetrachloroethylene 12 0.36 1.1E+01 8.3E+00 3.3E-08 8.6E-03 108-88-3 Toluene 230 6.9 -1.0E+03 1.3E-03 76-13-1 Trichloro-1,2,2-trifluoroethane, 1,1,2-0.92 0.0276 -6.3E+03 8.8E-07 79-01-6 Trichloroethylene 0.39 0.0117 4.8E-01 4.2E-01 2.4E-08 5.6E-03 75-69-4 Trichlorofluoromethane 1.7 0.051 -- 95-63-6 Trimethylbenzene, 1,2,4-52 1.56 -1.5E+00 2.1E-01 108-67-8 Trimethylbenzene, 1,3,5-7 0.21 -- 75-01-4 Vinyl Chloride 13 0.39 1.7E-01 2.1E+01 2.3E-06 3.7E-03 1330-20-7 Xylenes 157 4.71 -2.1E+01 4.5E-02 Cumulative:1.7E-05 7.2E-01 Output Form 3B 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 ug/m3 North Carolina DEQ Risk CalculatorAugust 2016 Version Basis: May 2016 EPA RSL Table TABLE 2 SUMMARY OF RISK CALCULATIONS: SG-C FORMER HENDRICK COLLISION CENTER DURHAM, NORTH CAROLINA MID-ATLANTIC JOB NO. 000R2698.01 T40000 DEQ Risk Calculator - Vapor Intrusion - Resident Soil Gas to Indoor Air Site ID: Hendrick Collision Center Exposure Unit ID: SG-C CAS #Chemical Name:Soil Gas Concentration (ug/m3) Calculated Indoor Air Concentration (ug/m3) 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 71-43-2 Benzene 23 0.69 3.6E-01 6.3E+00 1.9E-06 2.2E-02 75-15-0 Carbon Disulfide 25 0.75 -1.5E+02 1.0E-03 56-23-5 Carbon Tetrachloride 0.45 0.0135 4.7E-01 2.1E+01 2.9E-08 1.3E-04 67-66-3 Chloroform 1 0.03 1.2E-01 2.0E+01 2.5E-07 2.9E-04 74-87-3 Chloromethane 28 0.84 -1.9E+01 8.9E-03 110-82-7 Cyclohexane 86 2.58 -1.3E+03 4.1E-04 75-71-8 Dichlorodifluoromethane 2.6 0.078 -2.1E+01 7.5E-04 141-78-6 Ethyl Acetate 3.7 0.111 -1.5E+01 1.5E-03 75-00-3 Ethyl Chloride (Chloroethane)4 0.12 -2.1E+03 1.2E-05 100-41-4 Ethylbenzene 34 1.02 1.1E+00 2.1E+02 9.1E-07 9.8E-04 110-54-3 Hexane, N-46 1.38 -1.5E+02 1.9E-03 67-63-0 Isopropanol 3.4 0.102 -4.2E+01 4.9E-04 78-93-3 Methyl Ethyl Ketone (2-Butanone)35 1.05 -1.0E+03 2.0E-04 108-10-1 Methyl Isobutyl Ketone (4-methyl-2-pentanone)11 0.33 -6.3E+02 1.1E-04 1634-04-4 Methyl tert-Butyl Ether (MTBE)20 0.6 1.1E+01 6.3E+02 5.6E-08 1.9E-04 91-20-3 ~Naphthalene 2.3 0.069 8.3E-02 6.3E-01 8.4E-07 2.2E-02 115-07-1 Propylene 230 6.9 -6.3E+02 2.2E-03 100-42-5 Styrene 2 0.06 -2.1E+02 5.8E-05 127-18-4 Tetrachloroethylene 1.3 0.039 1.1E+01 8.3E+00 3.6E-09 9.3E-04 108-88-3 Toluene 120 3.6 -1.0E+03 6.9E-04 76-13-1 Trichloro-1,2,2-trifluoroethane, 1,1,2-0.55 0.0165 -6.3E+03 5.3E-07 75-69-4 Trichlorofluoromethane 0.79 0.0237 -- 95-63-6 Trimethylbenzene, 1,2,4-47 1.41 -1.5E+00 1.9E-01 108-67-8 Trimethylbenzene, 1,3,5-6.9 0.207 -- 75-01-4 Vinyl Chloride 2.7 0.081 1.7E-01 2.1E+01 4.8E-07 7.8E-04 1330-20-7 Xylenes 211 6.33 -2.1E+01 6.1E-02 Cumulative:4.5E-06 3.2E-01 Output Form 3B 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 ug/m3 North Carolina DEQ Risk Calculator August 2016 Version Basis: May 2016 EPA RSL Table TABLE 2 SUMMARY OF RISK CALCULATIONS: SG-D FORMER HENDRICK COLLISION CENTER DURHAM, NORTH CAROLINA MID-ATLANTIC JOB NO. 000R2698.01 T40000 DEQ Risk Calculator - Vapor Intrusion - Resident Soil Gas to Indoor Air Site ID: Hendrick Collision Center Exposure Unit ID: SG-D CAS #Chemical Name:Soil Gas Concentration (ug/m3) Calculated Indoor Air Concentration (ug/m3) 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 120 3.6 -6.5E+03 1.1E-04 71-43-2 Benzene 36 1.08 3.6E-01 6.3E+00 3.0E-06 3.5E-02 106-99-0 Butadiene, 1,3-27 0.81 9.4E-02 4.2E-01 8.7E-06 3.9E-01 74-87-3 Chloromethane 10 0.3 -1.9E+01 3.2E-03 110-82-7 Cyclohexane 8.9 0.267 -1.3E+03 4.3E-05 106-93-4 Dibromoethane, 1,2-1.7 0.051 4.7E-03 1.9E+00 1.1E-05 5.4E-03 75-71-8 Dichlorodifluoromethane 2.3 0.069 -2.1E+01 6.6E-04 100-41-4 Ethylbenzene 2200 66 1.1E+00 2.1E+02 5.9E-05 6.3E-02 110-54-3 Hexane, N-51 1.53 -1.5E+02 2.1E-03 78-93-3 Methyl Ethyl Ketone (2-Butanone)66 1.98 -1.0E+03 3.8E-04 108-10-1 Methyl Isobutyl Ketone (4-methyl-2-pentanone)14 0.42 -6.3E+02 1.3E-04 91-20-3 ~Naphthalene 4.8 0.144 8.3E-02 6.3E-01 1.7E-06 4.6E-02 115-07-1 Propylene 410 12.3 -6.3E+02 3.9E-03 100-42-5 Styrene 27 0.81 -2.1E+02 7.8E-04 127-18-4 Tetrachloroethylene 2 0.06 1.1E+01 8.3E+00 5.6E-09 1.4E-03 108-88-3 Toluene 270 8.1 -1.0E+03 1.6E-03 79-00-5 Trichloroethane, 1,1,2-1.7 0.051 1.8E-01 4.2E-02 2.9E-07 2.4E-01 95-63-6 Trimethylbenzene, 1,2,4-110 3.3 -1.5E+00 4.5E-01 108-67-8 Trimethylbenzene, 1,3,5-17 0.51 -- 106-42-3 Xylene, P--2.1E+01 108-38-3 Xylene, m--2.1E+01 95-47-6 Xylene, o--2.1E+01 1330-20-7 Xylenes 13800 414 -2.1E+01 4.0E+00 Cumulative:8.3E-05 5.2E+00 Output Form 3B 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 ug/m3 North Carolina DEQ Risk Calculator August 2016 Version Basis: May 2016 EPA RSL Table LABORATORY REPORT Page 1 of 26 Page 2 of 26 Page 3 of 26 Page 4 of 26 Page 5 of 26 Page 6 of 26 Page 7 of 26 Page 8 of 26 Page 9 of 26 Page 10 of 26 Page 11 of 26 Page 12 of 26 Page 13 of 26 Page 14 of 26 Page 15 of 26 Page 16 of 26 Page 17 of 26 Page 18 of 26 Page 19 of 26 Page 20 of 26 Page 21 of 26 Page 22 of 26 Page 23 of 26 Page 24 of 26 Page 25 of 26 Page 26 of 26