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HomeMy WebLinkAboutDERR-2024-011789Vapor Study Report Brent Redd Property 148 East Center Street Monticello, Utah Facility ID #5000003 Release ID GZQ October 29, 2024 | Terracon Project No. AL067003 Prepared for: Utah Department of Environmental Quality Division of Environmental Response and Remediation Salt Lake City, Utah 6952 South High Tech Drive Midvale, Utah 84057 P (801) 545-8500 Terracon.com Facilities |Environmental | Geotechnical | Materials i October 29, 2024 Utah Department of Environmental Quality Division of Environmental Response and Remediation 195 North 1950 West Salt Lake City, Utah 84114 Attn: Mr. Mark Crim E:mcrim@utah.gov Re:Vapor Study Report Brent Redd Facility 148 East Center Street, Monticello, Utah Facility Identification No. 5000003, Release ID GZQ Terracon Project No. AL067003 Dear Mr. Crim: Terracon Consultants, Inc. (Terracon) is pleased to submit this Vapor Study Report documenting a sampling event conducted under Work Assignment GZQ-59 at the Brent Redd facility (Facility ID 5000003, Release ID GZQ), located at 148 East Center Street, Monticello, Utah. This is the second of three Vapor Monitoring and Reporting events to be conducted under this Work Assignment. Terracon has performed this work pursuant to Work Assignment GZQ-59-TER, dated April 17, 2024 under Terracon's contract (Contract Number 216383) with the Division of Environmental Response and Remediation (DERR). We appreciate the opportunity to have performed these services for you. Please contact our office at (801) 545-8500 if you have questions regarding this information or if we can provide any other services. Sincerely, Terracon Consultants, Inc. Stephen Maliszeski Amy Austin Environmental Project Manager Authorized Project Reviewer UST Sampler 1832 UST Consultant 238 Amy Austin Facilities |Environmental | Geotechnical | Materials ii TABLE OF CONTENTS 1.0 INTRODUCTION ............................................................................ 1 1.1 Site Description ........................................................................................ 1 1.2 Project Background ................................................................................... 1 1.3 Standard of Care ...................................................................................... 1 1.4 Additional Scope Limitations ......................................................................... 1 2.0 FIELD METHODS ........................................................................... 2 2.1 Indoor Air Sampling Event ........................................................................... 2 2.2 Outdoor Air Sampling Event ......................................................................... 3 2.3 Sub-Slab Vapor Sampling ............................................................................ 3 2.4 Laboratory Analyses .................................................................................. 3 3.0 RESULTS ..................................................................................... 4 3.1 Indoor Air Samples .................................................................................... 4 3.2 Outdoor Air Sample ................................................................................... 4 3.3 Sub Slab Gas Samples ............................................................................... 5 4.0 DATA SUMMARY ........................................................................... 5 4.1 Indoor Air ............................................................................................... 5 4.2 Outdoor Air ............................................................................................. 6 4.3 Sub Slab Vapor ........................................................................................ 6 5.0 CONCLUSIONS ............................................................................. 6 APPENDICES Appendix A Exhibit 1 Topographic Site Overview Exhibit 2 Vapor Sample Location Map, September 2024 Appendix B Table 1 VOCs in Indoor Air, Outdoor Air, and Soil Gas Appendix C Chain of Custody Documentation and Laboratory Report Vapor Study—Second Event Brent Redd | GZQ-59 October 29, 2024 | Terracon Project No. AL067003 Facilities |Environmental | Geotechnical | Materials 1 1.0 INTRODUCTION 1.1 Site Description Terracon conducted a vapor study event at the Brent Redd facility (Facility ID 5000003, Release ID GZQ, “site”), located at 148 East Center Street, Monticello, Utah (Exhibit 1, Appendix A). The site is currently operated as the S&S Fusion equipment maintenance shop, which services equipment used to fuse poly pipe. A site diagram with vapor sample locations and the most recent benzene-impacted groundwater plume location is provided on Exhibit 2 (Appendix A). 1.2 Project Background A release of petroleum hydrocarbons from underground storage tanks has been documented at the site. In an effort to better evaluate impacts, the DERR requested a study to assess concentrations of volatile organic compounds (VOCs) in indoor air, outdoor air, and soil gas at the site and at the Monticello Inn, a third-party structure overlying a portion of the dissolved-phase petroleum plume migrating from the release from the Brent Redd site. The objective of this investigation was to evaluate the potential presence of VOCs in indoor air, outdoor air, and sub-slab soil gas above relevant regulatory screening levels that could be associated with the dissolved-phase petroleum plume identified on the site. Quarterly groundwater monitoring is conducted at this site under Work Assignment GZQ-57. 1.3 Standard of Care Terracon’s services were performed in a manner consistent with generally accepted practices of the profession undertaken in similar studies in the same geographical area during the same time period. Please note that Terracon does not warrant the work of laboratories, regulatory agencies, or other third parties supplying information used in the preparation of this report. These services were performed in accordance with the scope of services agreed with DERR, our client, as reflected in our work plan, and were not conducted in accordance with ASTM E1903-19. 1.4 Additional Scope Limitations Findings, conclusions, and recommendations resulting from these services are based upon information derived from the on-site activities and other services performed under this Vapor Study Brent Redd | GZQ-59 October 29, 2024 | Terracon Project No. AL067003 Facilities |Environmental | Geotechnical | Materials 2 scope of services. Such information is subject to change over time. Certain indicators of the presence of hazardous substances, petroleum products, or other constituents may have been latent, inaccessible, unobservable, non-detectable, or not present during these services. We cannot represent that the site contains no hazardous substances, toxic materials, petroleum products, or other latent conditions beyond those identified during this sampling event. Subsurface conditions may vary from those encountered at specific sample locations or during other surveys, tests, assessments, investigations, or exploratory services. The data, interpretations, findings, and our recommendations are based solely upon data obtained at the time and within the scope of these services. 2.0 FIELD METHODS Sampling was conducted on September 24 and 25, 2024, to assess concentrations of VOCs in indoor air, outdoor air, and soil gas. Samples were collected from four indoor air locations (IA-1, IA-2, IA-4, and IA-5) inside the Monticello Inn or crawlspace, one outdoor air location (OA-1) adjacent to the office of the Monticello Inn, and two sub-slab soil vapor pins (VP-1 and VP-2), within the basement of the Monticello Inn and the office within the site building, respectively. Indoor air location IA-3 was located in an occupied room and was not accessible for sampling. The sampling locations are depicted on Exhibit 2 (Appendix A). Prior to the sampling activities, Terracon inspected the sample areas for potential sources of VOCs. No significant sources of VOCs were identified within the Monticello Inn or office of the S&S Fusion equipment maintenance shop (site building); however, the potential exists that VOCs could exist in the area of the outdoor sample (OA-1) due to the proximity of vehicles within Center Street or that may be idling at the Monticello Inn. 2.1 Indoor Air Sampling Event On September 25, 2024, four Summa™ canisters were placed inside or in the crawlspace below the Monticello Inn. Three canisters were placed within the ground-level floor of the inn, including IA-1, which was placed in the office space; and IA-2, which was placed in Room 101. IA-3 has previously been sampled from Room 102; however, the room was occupied during this sampling event and not accessible for sampling activities. Two canisters were placed in the crawlspace beneath the inn (IA-4 and IA-5). The canisters were placed in the selected locations with the sample inlets within a typical breathing zone height, approximately 3 to 5 feet above the floor. Each sample was collected over a 24-hour period using a flow-control device affixed to a batch-certified, 6-liter capacity, Summa™ stainless steel canister supplied by H&P Mobile Geochemistry, Inc. (H&P), located in Carlsbad, California. Vapor Study Brent Redd | GZQ-59 October 29, 2024 | Terracon Project No. AL067003 Facilities |Environmental | Geotechnical | Materials 3 2.2 Outdoor Air Sampling Event One Summa™ canister was placed outside, adjacent to the office of the Monticello Inn on September 24, 2024. The canister was placed on the lawn with the sample inlet within a typical breathing zone height, at approximately 4 feet above the ground surface. The samples were collected over a 24-hour period using a flow-control device affixed to a batch-certified, 6-liter capacity, Summa™ stainless steel canister supplied by H&P. 2.3 Sub-Slab Vapor Sampling The vapor pins that were installed in November 2023 in the basement utility room of the Monticello Inn (VP-1) and in the office area of the former Brent Redd service station (VP-2) were sampled on September 24, 2024. The Vapor PinTM assembly consisted of a permanent flush-mount brass barb fitting with a silicone sleeve to seal the sample hole. Terracon conducted leak detection tests at each location prior to sample collection. The first test was conducted to evaluate the sample train for leaks using a shut-in test on the sample train after it was fully assembled. The shut-in test was conducted by closing the valve to the vapor pin and applying a vacuum to the closed sample train while monitoring the pressure on an inline vacuum gauge for one minute. If the sample train held a constant vacuum pressure, the sample train was deemed to be airtight. Following the shut-in test, the air that was evacuated from the sample train during the test was purged. A second leak detection test was conducted by introducing helium gas at approximately 15 to 20 percent into a sampling shroud placed over the vapor pin. If a helium concentration greater than 7,500 parts per million (ppm) was measured, it was considered as a potential leak in the sampling train, and the sample train connections were re-examined and tightened, where necessary, then re-tested. Three passing helium tests were conducted at each location prior to sampling. Each sub-slab sample was collected over a 5-minute period using a batch-certified, 1-liter capacity, Summa™ stainless steel canister supplied by H&P. 2.4 Laboratory Analyses The air and soil gas samples were submitted to H&P under standard chain-of-custody protocol for analysis of VOCs using United states Environmental Protection Agency (EPA) Method TO-15, under a standard turnaround time. Copies of the laboratory analytical reports and sample chain-of-custody records are included in Appendix C. Vapor Study Brent Redd | GZQ-59 October 29, 2024 | Terracon Project No. AL067003 Facilities |Environmental | Geotechnical | Materials 4 3.0 RESULTS 3.1 Indoor Air Samples The VOC analytical results from this current event and the previous event are summarized in Table 1 (Appendix B). The results were compared to the United States Environmental Protection Agency (EPA) Regional Screening Levels (RSLs) for Indoor Air, for both Residential and Industrial land use scenarios. The RSLs listed in Appendix B Table 1 are based on a Target Cancer Risk of 1x10-6 (one-in-a-million) and a Total Hazard Quotient (THQ) level of 1. Benzene and carbon tetrachloride were reported in all of the indoor air samples collected from the Monticello Inn at concentrations above their respective EPA Residential Air RSLs. Two indoor air sample locations (IA-1 and IA-5) reported concentrations of 1,4- dichlorobenzene exceeding the Residential Air RSL. The remainder of the indoor air samples had VOC concentrations below the EPA Residential Air RSLs. Chloroform was reported in all four of the indoor air samples from the Monticello Inn at concentrations above the EPA Industrial Air RSLs. Chloroform is a common laboratory contaminant and may not be representative of indoor air and crawlspace concentrations at the Monticello Inn. Chloroform was not reported at concentrations exceeding the laboratory reporting limits in the sub-slab samples collected during this sampling event, as detailed in Section 3.3. Chloroform has historically been reported in the indoor air samples collected from the Monticello Inn above the EPA RSL during the previous November 2023 and June 2024 sampling events. A source of chloroform in the indoor and crawlspace samples was not apparent at the Monticello Inn. The remainder of the analytes reported above the laboratory detection limits in the indoor and crawlspace samples had concentrations below the EPA RSLs. 3.2 Outdoor Air Sample Analytical results for VOCs in the outdoor air sample collected adjacent to the office of the Monticello Inn are summarized in Table 1 (Appendix B). The results were compared to the EPA RSLs for both Residential and Industrial land use scenarios for comparison to the indoor air sample results. Benzene, chloroform, and carbon tetrachloride were reported at concentrations above the EPA Residential Air RSLs in the outdoor air sample collected northeast of the Monticello Inn office (OA-1). The concentration of benzene in the outdoor air sample (OA-1) was 0.74 micrograms per cubic meter (µg/m3), which was lower than the indoor air sample (IA-1) collected from the adjacent Monticello Inn office, which had a concentration of 0.94 µg/m3. Vapor Study Brent Redd | GZQ-59 October 29, 2024 | Terracon Project No. AL067003 Facilities |Environmental | Geotechnical | Materials 5 The chloroform concentration was lower in the outdoor air sample than the indoor and crawlspace air samples collected from the site. As previously noted, chloroform is a common laboratory contaminant, and the reported chloroform concentration may not be representative of the outdoor air condition. A source of chloroform in the outdoor air sample was not apparent at the time of the sampling; however, chloroform could result from sources such as treated irrigation water, vehicle exhaust, etc. The remainder of the analytes reported above the laboratory detection limits in the outdoor air sample had concentrations below the EPA RSLs. 3.3 Sub Slab Gas Samples Analytical results for VOCs in the sub-slab soil gas samples are summarized in Table 1 (Appendix B). The results were compared to the EPA’s Target Sub-Slab and Near-source Soil Gas Concentration Vapor Intrusion Screening Levels (VISLs) for Residential and Commercial land use scenarios. The VISLs are based on a Target Cancer Risk of 1x10-6 (one-in-a- million) and a THQ level of 1. The VOC concentrations in sub-slab sample VP-1, collected from the basement of the Monticello Inn, and in sub-slab sample VP-2, collected from the office area at the site were below the laboratory reporting detection limits (RDLs). It should be noted that the detection level for benzene and several other VOCs exceeded the Residential VISL. The concentrations reported did not exceed EPA VISLs for Industrial land use scenarios. 4.0 DATA SUMMARY The following presents a summary of the investigation results. 4.1 Indoor Air Based on this sampling event, indoor air at the Monticello Inn office exceeds EPA RSLs for benzene, carbon tetrachloride, chloroform, and 1,4-dichlorobenzene. The benzene concentration in the indoor air samples collected from the Monticello Inn office (IA-1) and Room 101 (IA-2) were more than the benzene concentration in the outdoor air sample (OA-1) collected adjacent to the northeast of the office. The two indoor air samples collected from the basement of the Monticello Inn had concentrations of VOCs generally less than the air Vapor Study Brent Redd | GZQ-59 October 29, 2024 | Terracon Project No. AL067003 Facilities |Environmental | Geotechnical | Materials 6 samples collected from the Monticello Inn office and rooms. The indoor air samples had VOC concentrations higher than the samples collected from sub-slab soil gas. Chloroform concentrations also exceeded the EPA RSLs in IA-1, IA-2, IA-4, and IA-5. 4.2 Outdoor Air Based on this sampling event, outdoor air adjacent to the office of the Monticello Inn exceeds EPA Residential Air RSL for benzene, carbon tetrachloride, and chloroform. The benzene concentration in the outdoor air sample was only lower than two of the air samples collected from the Monticello Inn office. No apparent chloroform source was observed in the outdoor air sample location; however, chloroform could result from sources such as treated irrigation water, vehicle exhaust, etc. 4.3 Sub Slab Vapor Based on this sampling event, sub-slab soil gas beneath the former Brent Redd facility and the Monticello Inn did not exceed the EPA VISLs for Commercial land use scenarios, despite being located within the estimated lateral extent of the dissolved-phase petroleum plume. The sub-slab soil gas VOC concentrations were lower than the VOC concentrations in the indoor air, crawlspace air, and outdoor air samples. 5.0 CONCLUSIONS Based on the results of this investigation, concentrations of VOCs in sub-slab soil gas samples do not present a vapor intrusion concern; however, indoor air samples and crawlspace air samples collected from the Monticello Inn had concentrations above the EPA Residential or Commercial RSLs. Similar to the June 2024 sampling event, the indoor air sample collected from the Monticello Inn office generally had the highest indoor air VOC concentrations of the samples collected. The benzene concentration in the indoor air sample collected from the Monticello Inn office was more than the benzene concentration in the outdoor air sample collected adjacent to the northeast of the office. Concentrations of VOCs were below the EPA Industrial VISL in the sub-slab soil gas sample collected below the former Brent Redd service station. Concentrations of VOCs in the indoor air samples collected from the basement and crawlspaces of the Monticello Inn that were located within the mapped groundwater plume were below the EPA RSLs, except for benzene, carbon tetrachloride, and chloroform. Vapor Study Brent Redd | GZQ-59 October 29, 2024 | Terracon Project No. AL067003 Facilities |Environmental | Geotechnical | Materials 7 Indoor air and soil gas sampling is known to have a high variability due to preferential pathways for vapor accumulation; however, the lack of significant detections of benzene in the sub-slab soil gas samples does not correlate with the detected RSL exceedances in indoor air at the Monticello Inn. The source of the indoor air VOCs does not appear to correlate with the petroleum-impacted groundwater plume. Although a review of chemicals stored at the hotel was conducted, a variety of other potential sources could account for the detected VOCs. For example, cigarette smoke, cleansers, air fresheners, aerosol sprays, and vehicle exhaust are known to produce airborne VOCs, and these types of materials could be present inside the Monticello Inn. A third air sampling event is to be conducted under this Work Assignment to assess fluctuating VOC concentrations and vapor intrusion concerns due to the EPA RSL exceedances, in accordance with Work Assignment GZQ-59-TER, dated April 17, 2024. APPENDIX A EXHIBITS N: \ G I S \ A L 0 6 7 0 0 3 _ B r e n t _ R e d _ P R O \ M a p s \ B r e n t _ R e d . a p r x Exhibit terracon.comPH. 801-545-8500 6952 S High Tech Dr, Ste B Midvale, UT Reviewed By: Drawn By: Oct 2024 Date: AL067003 Project No.: Brent Redd Property 148 East Center Street Monticello, Utah Vapor Sample Location Map, September 2024 2 ABA AST DATA SOURCES: ESRI - Basemaps @A @A @A @A @A@A @A @A @A @A @AVP-1 VP-2 IA-1 IA-2 IA-3 IA-4 (Basement) IA-5 (Basement) MW-14 B-3R MW-19 MW-17 MW-18MW-16 MW-15 MW-5R MW-20 MW-7 MW-21 OA-1 0 40 8020 Feet ³ ³@A Monitoring Well Indoor Air Sample Location Soil Gas (Vapor Pin) Location Outdoor Air Sample Benzene Concentration in Soil Gas/Air, September 2024 Exceeds EPA Residential Air RSL Below EPA VISLs/RSLs, as applicable Benzene Concentration in Groundwater, September 2024 > 300 µg/l (Exceeds UDEQ Tier 1) 5 - 300 µg/l (Exceeds UDEQ ISL) µg/l - micrograms per liter APPENDIX B TABLE Table 1 - VOCs in Indoor Air, Outdoor Air, and Soil Gas Brent Redd Property, 148 East Center Street, Monticello, Utah Terracon Project No. AL067003, Task GZQ-59 Analyte CAS Method Units EPA Residential Air RSL EPA Industrial Air RSL EPA VISL Residential EPA VISL Commercial Result RDL Result RDL Result RDL Result RDL Result RDL Result RDL Result RDL BENZENE 71-43-2 TO-15 µg/m3 0.36 1.6 12 52.4 2.2 0.32 2.1 0.32 1.5 0.32 0.52 0.32 0.61 0.32 ND 0.6 ND 0.6 BROMODICHLOROMETHANE 75-27-4 TO-15 µg/m3 0.076 0.33 2.53 11 ND 0.68 ND 0.68 ND 0.68 ND 0.68 ND 0.68 ND 2.7 ND 2.7 BROMOFORM 75-25-2 TO-15 µg/m3 2.6 11 85.1 372 ND 1 ND 1 ND 1 ND 1 ND 1 ND 4.2 ND 4.2 BROMOMETHANE 74-83-9 TO-15 µg/m3 5.2 22 174 730 ND 0.39 ND 0.39 ND 0.39 ND 0.39 ND 0.39 ND 1.6 ND 1.6 CARBON DISULFIDE 75-15-0 TO-15 µg/m3 730 3100 24300 102000 0.73 0.32 ND 0.32 ND 0.32 ND 0.32 ND 0.32 ND 1.3 ND 1.3 CARBON TETRACHLORIDE 56-23-5 TO-15 µg/m3 0.47 2 15.6 68.1 ND 0.64 ND 0.64 ND 0.64 ND 0.64 ND 0.64 ND 1.3 ND 1.3 CHLOROBENZENE 108-90-7 TO-15 µg/m3 52 220 1740 7300 ND 0.47 ND 0.47 ND 0.47 ND 0.47 ND 0.47 ND 1.9 ND 1.9 CHLOROETHANE 75-00-3 TO-15 µg/m3 4200 18000 348000 1460000 ND 0.27 ND 0.27 ND 0.27 ND 0.27 ND 0.27 ND 1.6 ND 1.6 CHLOROFORM 67-66-3 TO-15 µg/m3 0.12 0.53 4.07 17.8 0.59 0.25 ND 0.25 ND 0.25 ND 0.25 ND 0.25 ND 1 ND 1 CHLOROMETHANE 74-87-3 TO-15 µg/m3 94 390 3130 13100 1.1 0.21 1.2 0.21 0.97 0.21 0.85 0.21 0.91 0.21 ND 0.8 ND 0.8 CHLORODIBROMOMETHANE 124-48-1 TO-15 µg/m3 NE NE NE NE ND 1.7 ND 1.7 ND 1.7 ND 1.7 ND 1.7 ND 3.5 ND 3.5 1,2-DIBROMOETHANE 106-93-4 TO-15 µg/m3 0.0047 0.02 0.156 0.681 ND 0.78 ND 0.78 ND 0.78 ND 0.78 ND 0.78 ND 3.1 ND 3.1 1,2-DICHLOROBENZENE 95-50-1 TO-15 µg/m3 210 880 6950 29200 ND 0.61 ND 0.61 ND 0.61 ND 0.61 ND 0.61 ND 2.4 ND 2.4 1,3-DICHLOROBENZENE 541-73-1 TO-15 µg/m3 NE NE NE NE ND 0.61 ND 0.61 ND 0.61 ND 0.61 ND 0.61 ND 2.4 ND 2.4 1,4-DICHLOROBENZENE 106-46-7 TO-15 µg/m3 0.26 1.1 8.51 37.2 ND 0.61 ND 0.61 ND 0.61 ND 0.61 ND 0.61 ND 2.4 ND 2.4 1,2-DICHLOROETHANE 107-06-2 TO-15 µg/m3 0.11 0.47 3.6 15.7 0.53 0.41 ND 0.41 ND 0.41 ND 0.41 ND 0.41 ND 1.6 ND 1.6 1,1-DICHLOROETHANE 75-34-3 TO-15 µg/m3 1.8 7.7 58.5 256 ND 0.41 ND 0.41 ND 0.41 ND 0.41 ND 0.41 ND 1.6 ND 1.6 1,1-DICHLOROETHENE 75-35-4 TO-15 µg/m3 210 880 6950 29200 ND 0.4 ND 0.4 ND 0.4 ND 0.4 ND 0.4 ND 1.6 ND 1.6 CIS-1,2-DICHLOROETHENE 156-59-2 TO-15 µg/m3 42 180 NE NE ND 0.4 ND 0.4 ND 0.4 ND 0.4 ND 0.4 ND 1.6 ND 1.6 TRANS-1,2-DICHLOROETHENE 156-60-5 TO-15 µg/m3 42 180 NE NE ND 0.4 ND 0.4 ND 0.4 ND 0.4 ND 0.4 ND 1.6 ND 1.6 1,2-DICHLOROPROPANE 78-87-5 TO-15 µg/m3 0.76 3.3 25.3 110 0.56 0.47 ND 0.47 ND 0.47 ND 0.47 ND 0.47 ND 1.9 ND 1.9 CIS-1,3-DICHLOROPROPENE 10061-01-5 TO-15 µg/m3 NE NE NE NE ND 0.46 ND 0.46 ND 0.46 ND 0.46 ND 0.46 ND 1.8 ND 1.8 TRANS-1,3-DICHLOROPROPENE 10061-02-6 TO-15 µg/m3 NE NE NE NE ND 0.46 ND 0.46 ND 0.46 ND 0.46 ND 0.46 ND 1.8 ND 1.8 DICHLOROTETRAFLUOROETHANE 76-14-2 TO-15 µg/m3 NE NE NE NE ND 0.71 ND 0.71 ND 0.71 ND 0.71 ND 0.71 ND 2.8 ND 2.8 ETHYLBENZENE 100-41-4 TO-15 µg/m3 1.1 4.9 37.4 164 4.4 0.44 0.53 0.44 ND 0.44 ND 0.44 ND 0.44 ND 1.8 ND 1.8 4-ETHYLTOLUENE 622-96-8 TO-15 µg/m3 NE NE NE NE 0.6 0.5 ND 0.5 ND 0.5 ND 0.5 ND 0.5 ND 2 ND 2 TRICHLOROFLUOROMETHANE 75-69-4 TO-15 µg/m3 NE NE NE NE 1.1 0.56 1.1 0.56 1.1 0.56 1.2 0.56 1.2 0.56 ND 2.3 ND 2.3 DICHLORODIFLUOROMETHANE 75-71-8 TO-15 µg/m3 100 440 3480 14600 ND 1 ND 1 ND 1 ND 1 ND 1 ND 4 ND 4 1,1,2-TRICHLOROTRIFLUOROETHANE 76-13-1 TO-15 µg/m3 5200 22000 174000 730000 ND 0.77 ND 0.77 ND 0.77 ND 0.77 ND 0.77 ND 3.1 ND 3.1 HEXACHLORO-1,3-BUTADIENE 87-68-3 TO-15 µg/m3 0.13 0.56 4.25 18.6 ND 2.7 ND 2.7 ND 2.7 ND 2.7 ND 2.7 ND 11 ND 11 METHYLENE CHLORIDE 75-09-2 TO-15 µg/m3 100 1200 3380 40900 5.3 0.35 ND 0.35 ND 0.35 ND 0.35 0.35 0.35 ND 1.4 ND 1.4 METHYL BUTYL KETONE 591-78-6 TO-15 µg/m3 31 130 1040 4380 ND 0.83 ND 0.83 ND 0.83 ND 0.83 ND 0.83 ND 3.3 ND 3.3 2-BUTANONE (MEK) 78-93-3 TO-15 µg/m3 5200 22000 174000 730000 40 0.6 0.75 0.6 ND 0.6 ND 0.6 ND 0.6 ND 2.4 ND 2.4 4-METHYL-2-PENTANONE (MIBK) 108-10-1 TO-15 µg/m3 3100 13000 104000 438000 1.1 0.83 ND 0.83 ND 0.83 ND 0.83 ND 0.83 ND 3.3 ND 3.3 STYRENE 100-42-5 TO-15 µg/m3 1000 4400 34800 146000 9.9 0.43 ND 0.43 ND 0.43 ND 0.43 ND 0.43 ND 1.7 ND 1.7 1,1,2,2-TETRACHLOROETHANE 79-34-5 TO-15 µg/m3 0.048 0.21 1.61 7.05 ND 0.7 ND 0.7 ND 0.7 ND 0.7 ND 0.7 ND 2.8 ND 2.8 1,1,1,2-TETRACHLOROETHANE 630-20-6 TO-15 µg/m3 0.38 1.7 12.6 55.2 ND 0.7 ND 0.7 ND 0.7 ND 0.7 ND 0.7 ND 2.8 ND 2.8 TETRACHLOROETHENE 127-18-4 TO-15 µg/m3 11 47 360 1570 ND 0.69 ND 0.69 ND 0.69 ND 0.69 ND 0.69 ND 2.8 ND 2.8 TOLUENE 108-88-3 TO-15 µg/m3 5200 22000 174000 730000 57 0.76 30 0.76 1.9 0.76 0.8 0.76 0.99 0.76 ND 3.1 ND 3.1 1,2,4-TRICHLOROBENZENE 120-82-1 TO-15 µg/m3 2.1 8.8 69.5 292 ND 1.9 ND 1.9 ND 1.9 ND 1.9 ND 1.9 ND 7.5 ND 7.5 1,1,1-TRICHLOROETHANE 71-55-6 TO-15 µg/m3 5200 22000 174000 730000 ND 0.55 ND 0.55 ND 0.55 ND 0.55 ND 0.55 ND 2.2 ND 2.2 1,1,2-TRICHLOROETHANE 79-00-5 TO-15 µg/m3 0.18 0.77 5.85 25.6 ND 0.55 ND 0.55 ND 0.55 ND 0.55 ND 0.55 ND 2.2 ND 2.2 TRICHLOROETHENE 79-01-6 TO-15 µg/m3 0.48 3 15.9 99.7 ND 0.55 ND 0.55 ND 0.55 ND 0.55 ND 0.55 ND 2.2 ND 2.2 1,2,4-TRIMETHYLBENZENE 95-63-6 TO-15 µg/m3 63 260 2090 8760 1.4 0.5 ND 0.5 ND 0.5 ND 0.5 ND 0.5 ND 2 ND 2 1,3,5-TRIMETHYLBENZENE 108-67-8 TO-15 µg/m3 63 260 2090 8760 0.5 0.5 ND 0.5 ND 0.5 ND 0.5 ND 0.5 ND 2 ND 2 VINYL CHLORIDE 75-01-4 TO-15 µg/m3 0.17 2.8 5.59 92.9 ND 0.13 ND 0.13 ND 0.13 ND 0.13 ND 0.13 ND 0.5 ND 0.5 M,P-XYLENE 178601-23-1 TO-15 µg/m3 100 440 3480 14600 13 0.44 1.8 0.44 0.97 0.44 0.57 0.44 0.66 0.44 3.7 1.8 ND 1.8 O-XYLENE 95-47-6 TO-15 µg/m3 100 440 3480 14600 5.1 0.44 0.7 0.44 ND 0.44 ND 0.44 ND 0.44 ND 1.8 ND 1.8 NE: Not established. ND: Not detected at or above the Reporting Detection Limit (RDL). µg/m3: micrograms per cubic meter. E312005-03 E312005-04 E312005-05 E312005-06 E312005-07 IA-4 IA-5 VP-1 VP-2IA-3 Lab Sample ID E312005-01 E312005-02 Client Sample ID IA-1 IA-2 11/28/2023 11/28/2023 Bold values exceed the RDL. Blue italicized non-detect results have RDLs exceeding one or more of the EPA RSLs or VISLs. EPA VISL: Environmental Protection Agency Target Sub-Slab and Near-source Soil Gas Concentration (TSSNSGC) Vapor Intrusion Screening Level (VISL); July 2024. EPA RSL: Environmental Protection Agency Regional Screening Levels for Residential and Industrial Air (May 2024, TR=1E-06; THQ=1.0). Qualifiers (Q): Date Collected 11/28/2023 11/28/2023 11/28/202311/28/202311/28/2023 Page 1 of 3 Table 1 - VOCs in Indoor Air, Outdoor Air, and Soil Gas Brent Redd Property, 148 East Center Street, Monticello, Utah Terracon Project No. AL067003, Task GZQ-59 Analyte CAS Method Units EPA Residential Air RSL EPA Industrial Air RSL EPA VISL Residential EPA VISL Commercial BENZENE 71-43-2 TO-15 µg/m3 0.36 1.6 12 52.4 BROMODICHLOROMETHANE 75-27-4 TO-15 µg/m3 0.076 0.33 2.53 11 BROMOFORM 75-25-2 TO-15 µg/m3 2.6 11 85.1 372 BROMOMETHANE 74-83-9 TO-15 µg/m3 5.2 22 174 730 CARBON DISULFIDE 75-15-0 TO-15 µg/m3 730 3100 24300 102000 CARBON TETRACHLORIDE 56-23-5 TO-15 µg/m3 0.47 2 15.6 68.1 CHLOROBENZENE 108-90-7 TO-15 µg/m3 52 220 1740 7300 CHLOROETHANE 75-00-3 TO-15 µg/m3 4200 18000 348000 1460000 CHLOROFORM 67-66-3 TO-15 µg/m3 0.12 0.53 4.07 17.8 CHLOROMETHANE 74-87-3 TO-15 µg/m3 94 390 3130 13100 CHLORODIBROMOMETHANE 124-48-1 TO-15 µg/m3 NE NE NE NE 1,2-DIBROMOETHANE 106-93-4 TO-15 µg/m3 0.0047 0.02 0.156 0.681 1,2-DICHLOROBENZENE 95-50-1 TO-15 µg/m3 210 880 6950 29200 1,3-DICHLOROBENZENE 541-73-1 TO-15 µg/m3 NE NE NE NE 1,4-DICHLOROBENZENE 106-46-7 TO-15 µg/m3 0.26 1.1 8.51 37.2 1,2-DICHLOROETHANE 107-06-2 TO-15 µg/m3 0.11 0.47 3.6 15.7 1,1-DICHLOROETHANE 75-34-3 TO-15 µg/m3 1.8 7.7 58.5 256 1,1-DICHLOROETHENE 75-35-4 TO-15 µg/m3 210 880 6950 29200 CIS-1,2-DICHLOROETHENE 156-59-2 TO-15 µg/m3 42 180 NE NE TRANS-1,2-DICHLOROETHENE 156-60-5 TO-15 µg/m3 42 180 NE NE 1,2-DICHLOROPROPANE 78-87-5 TO-15 µg/m3 0.76 3.3 25.3 110 CIS-1,3-DICHLOROPROPENE 10061-01-5 TO-15 µg/m3 NE NE NE NE TRANS-1,3-DICHLOROPROPENE 10061-02-6 TO-15 µg/m3 NE NE NE NE DICHLOROTETRAFLUOROETHANE 76-14-2 TO-15 µg/m3 NE NE NE NE ETHYLBENZENE 100-41-4 TO-15 µg/m3 1.1 4.9 37.4 164 4-ETHYLTOLUENE 622-96-8 TO-15 µg/m3 NE NE NE NE TRICHLOROFLUOROMETHANE 75-69-4 TO-15 µg/m3 NE NE NE NE DICHLORODIFLUOROMETHANE 75-71-8 TO-15 µg/m3 100 440 3480 14600 1,1,2-TRICHLOROTRIFLUOROETHANE 76-13-1 TO-15 µg/m3 5200 22000 174000 730000 HEXACHLORO-1,3-BUTADIENE 87-68-3 TO-15 µg/m3 0.13 0.56 4.25 18.6 METHYLENE CHLORIDE 75-09-2 TO-15 µg/m3 100 1200 3380 40900 METHYL BUTYL KETONE 591-78-6 TO-15 µg/m3 31 130 1040 4380 2-BUTANONE (MEK) 78-93-3 TO-15 µg/m3 5200 22000 174000 730000 4-METHYL-2-PENTANONE (MIBK) 108-10-1 TO-15 µg/m3 3100 13000 104000 438000 STYRENE 100-42-5 TO-15 µg/m3 1000 4400 34800 146000 1,1,2,2-TETRACHLOROETHANE 79-34-5 TO-15 µg/m3 0.048 0.21 1.61 7.05 1,1,1,2-TETRACHLOROETHANE 630-20-6 TO-15 µg/m3 0.38 1.7 12.6 55.2 TETRACHLOROETHENE 127-18-4 TO-15 µg/m3 11 47 360 1570 TOLUENE 108-88-3 TO-15 µg/m3 5200 22000 174000 730000 1,2,4-TRICHLOROBENZENE 120-82-1 TO-15 µg/m3 2.1 8.8 69.5 292 1,1,1-TRICHLOROETHANE 71-55-6 TO-15 µg/m3 5200 22000 174000 730000 1,1,2-TRICHLOROETHANE 79-00-5 TO-15 µg/m3 0.18 0.77 5.85 25.6 TRICHLOROETHENE 79-01-6 TO-15 µg/m3 0.48 3 15.9 99.7 1,2,4-TRIMETHYLBENZENE 95-63-6 TO-15 µg/m3 63 260 2090 8760 1,3,5-TRIMETHYLBENZENE 108-67-8 TO-15 µg/m3 63 260 2090 8760 VINYL CHLORIDE 75-01-4 TO-15 µg/m3 0.17 2.8 5.59 92.9 M,P-XYLENE 178601-23-1 TO-15 µg/m3 100 440 3480 14600 O-XYLENE 95-47-6 TO-15 µg/m3 100 440 3480 14600 NE: Not established. ND: Not detected at or above the Reporting Detection Limit (RDL). µg/m3: micrograms per cubic meter. Lab Sample ID Client Sample ID Bold values exceed the RDL. Blue italicized non-detect results have RDLs exceeding one or more of the EPA RSLs or VISLs. EPA VISL: Environmental Protection Agency Target Sub-Slab and Near-source Soil Gas Concentration (TSSNSGC) Vapor Intrusion Screening Level (VISL); July 2024. EPA RSL: Environmental Protection Agency Regional Screening Levels for Residential and Industrial Air (May 2024, TR=1E-06; THQ=1.0). Qualifiers (Q): Date Collected Result RDL Result RDL Result RDL Result RDL Result RDL Result RDL Result RDL Result RDL 0.91 0.32 0.32 0.32 0.32 0.32 ND 0.32 ND 0.32 1 0.32 ND 0.6 ND 0.6 ND 0.68 ND 0.68 ND 0.68 ND 0.68 ND 0.68 ND 0.68 ND 2.7 ND 2.7 ND 1 ND 1 ND 1 ND 1 ND 1 ND 1 ND 4.2 ND 4.2 ND 0.39 ND 0.39 ND 0.39 ND 0.39 ND 0.39 ND 0.39 ND 1.6 ND 1.6 0.57 0.32 ND 0.32 ND 0.32 ND 0.32 ND 0.32 0.38 0.32 ND 1.3 ND 1.3 0.64 0.64 ND 0.64 ND 0.64 ND 0.64 ND 0.64 ND 0.64 ND 1.3 ND 1.3 ND 0.47 ND 0.47 ND 0.47 ND 0.47 ND 0.47 ND 0.47 ND 1.9 ND 1.9 ND 0.27 ND 0.27 ND 0.27 ND 0.27 ND 0.27 ND 0.27 ND 1.6 ND 1.6 2 0.25 1 0.25 1.6 0.25 0.35 0.25 0.49 0.25 0.25 0.25 ND 1 ND 1 2 0.21 1.8 0.21 1.5 0.21 1.2 0.21 1.1 0.21 1.9 0.21 ND 0.8 ND 0.8 ND 1.7 ND 1.7 ND 1.7 ND 1.7 ND 1.7 ND 1.7 ND 3.5 ND 3.5 ND 0.78 ND 0.78 ND 0.78 ND 0.78 ND 0.78 ND 0.78 ND 3.1 ND 3.1 ND 0.61 ND 0.61 ND 0.61 ND 0.61 ND 0.61 ND 0.61 ND 2.4 ND 2.4 0.61 0.61 ND 0.61 ND 0.61 ND 0.61 ND 0.61 3.7 0.61 ND 2.4 ND 2.4 ND 0.61 ND 0.61 ND 0.61 ND 0.61 ND 0.61 ND 0.61 ND 2.4 ND 2.4 ND 0.41 ND 0.41 ND 0.41 ND 0.41 ND 0.41 ND 0.41 ND 1.6 ND 1.6 ND 0.41 ND 0.41 ND 0.41 ND 0.41 ND 0.41 ND 0.41 ND 1.6 ND 1.6 ND 0.4 ND 0.4 ND 0.4 ND 0.4 ND 0.4 ND 0.4 ND 1.6 ND 1.6 ND 0.4 ND 0.4 ND 0.4 ND 0.4 ND 0.4 ND 0.4 ND 1.6 ND 1.6 ND 0.4 ND 0.4 ND 0.4 ND 0.4 ND 0.4 ND 0.4 ND 1.6 ND 1.6 ND 0.47 ND 0.47 ND 0.47 ND 0.47 ND 0.47 ND 0.47 ND 1.9 ND 1.9 ND 0.46 ND 0.46 ND 0.46 ND 0.46 ND 0.46 ND 0.46 ND 1.8 ND 1.8 ND 0.46 ND 0.46 ND 0.46 ND 0.46 ND 0.46 ND 0.46 ND 1.8 ND 1.8 ND 0.71 ND 0.71 ND 0.71 ND 0.71 ND 0.71 ND 0.71 ND 2.8 ND 2.8 1.6 0.44 0.62 0.44 ND 0.44 ND 0.44 ND 0.44 1.1 0.44 ND 1.8 ND 1.8 ND 0.5 ND 0.5 ND 0.5 ND 0.5 ND 0.5 ND 0.5 ND 2 ND 2 1.7 0.56 1.6 0.56 1.6 0.56 1.8 0.56 1.6 0.56 1.2 0.56 ND 2.3 ND 2.3 1.4 1 1.4 1 1.3 1 1.4 1 1.4 1 1.3 1 ND 4 ND 4 ND 0.77 ND 0.77 ND 0.77 ND 0.77 ND 0.77 ND 0.77 ND 3.1 ND 3.1 ND 2.7 ND 2.7 ND 2.7 ND 2.7 ND 2.7 ND 2.7 ND 11 ND 11 0.42 0.35 0.39 0.35 ND 0.35 ND 0.35 ND 0.35 0.35 0.35 ND 1.4 ND 1.4 ND 0.83 ND 0.83 ND 0.83 ND 0.83 ND 0.83 ND 0.83 ND 3.3 ND 3.3 7.9 0.6 3.7 0.6 2.2 0.6 1.9 0.6 1.3 0.6 76 0.6 4 2.4 2.4 2.4 0.91 0.83 ND 0.83 ND 0.83 ND 0.83 ND 0.83 ND 0.83 ND 3.3 ND 3.3 0.91 0.43 2.4 0.43 1.2 0.43 ND 0.43 ND 0.43 0.47 0.43 ND 1.7 ND 1.7 ND 0.7 ND 0.7 ND 0.7 ND 0.7 ND 0.7 ND 0.7 ND 2.8 ND 2.8 ND 0.7 ND 0.7 ND 0.7 ND 0.7 ND 0.7 ND 0.7 ND 2.8 ND 2.8 ND 0.69 ND 0.69 ND 0.69 ND 0.69 ND 0.69 ND 0.69 ND 2.8 ND 2.8 4.9 0.76 2.7 0.76 1.7 0.76 1.1 0.76 0.92 0.76 3.1 0.76 ND 3.1 ND 3.1 ND 1.9 ND 1.9 ND 1.9 ND 1.9 ND 1.9 ND 1.9 ND 7.5 ND 7.5 ND 0.55 ND 0.55 ND 0.55 ND 0.55 ND 0.55 ND 0.55 ND 2.2 ND 2.2 ND 0.55 ND 0.55 ND 0.55 ND 0.55 ND 0.55 ND 0.55 ND 2.2 ND 2.2 ND 0.55 ND 0.55 ND 0.55 ND 0.55 ND 0.55 ND 0.55 ND 2.2 ND 2.2 0.95 0.5 ND 0.5 ND 0.5 ND 0.5 ND 0.5 0.5 0.5 ND 2 ND 2 ND 0.5 ND 0.5 ND 0.5 ND 0.5 ND 0.5 ND 0.5 ND 2 ND 2 ND 0.13 ND 0.13 ND 0.13 ND 0.13 ND 0.13 ND 0.13 ND 0.5 ND 0.5 6.2 0.44 1.2 0.44 1.2 0.44 0.7 0.44 0.53 0.44 4.4 0.44 2.2 1.8 2.3 1.8 2.4 0.44 0.84 0.44 0.57 0.44 ND 0.44 ND 0.44 1.6 0.44 ND 1.8 ND 1.8 E407012-08 VP-2 6/25/20246/26/2024 6/25/2024 E407012-02 E407012-03 E407012-04 E407012-05 E407012-06 E407012-07 IA-2 IA-3 IA-4 IA-5 OA-1 VP-1 6/26/2024 6/26/2024 6/26/2024 6/26/2024 6/26/2024 E407012-01 IA-1 Page 2 of 3 Table 1 - VOCs in Indoor Air, Outdoor Air, and Soil Gas Brent Redd Property, 148 East Center Street, Monticello, Utah Terracon Project No. AL067003, Task GZQ-59 Analyte CAS Method Units EPA Residential Air RSL EPA Industrial Air RSL EPA VISL Residential EPA VISL Commercial BENZENE 71-43-2 TO-15 µg/m3 0.36 1.6 12 52.4 BROMODICHLOROMETHANE 75-27-4 TO-15 µg/m3 0.076 0.33 2.53 11 BROMOFORM 75-25-2 TO-15 µg/m3 2.6 11 85.1 372 BROMOMETHANE 74-83-9 TO-15 µg/m3 5.2 22 174 730 CARBON DISULFIDE 75-15-0 TO-15 µg/m3 730 3100 24300 102000 CARBON TETRACHLORIDE 56-23-5 TO-15 µg/m3 0.47 2 15.6 68.1 CHLOROBENZENE 108-90-7 TO-15 µg/m3 52 220 1740 7300 CHLOROETHANE 75-00-3 TO-15 µg/m3 4200 18000 348000 1460000 CHLOROFORM 67-66-3 TO-15 µg/m3 0.12 0.53 4.07 17.8 CHLOROMETHANE 74-87-3 TO-15 µg/m3 94 390 3130 13100 CHLORODIBROMOMETHANE 124-48-1 TO-15 µg/m3 NE NE NE NE 1,2-DIBROMOETHANE 106-93-4 TO-15 µg/m3 0.0047 0.02 0.156 0.681 1,2-DICHLOROBENZENE 95-50-1 TO-15 µg/m3 210 880 6950 29200 1,3-DICHLOROBENZENE 541-73-1 TO-15 µg/m3 NE NE NE NE 1,4-DICHLOROBENZENE 106-46-7 TO-15 µg/m3 0.26 1.1 8.51 37.2 1,2-DICHLOROETHANE 107-06-2 TO-15 µg/m3 0.11 0.47 3.6 15.7 1,1-DICHLOROETHANE 75-34-3 TO-15 µg/m3 1.8 7.7 58.5 256 1,1-DICHLOROETHENE 75-35-4 TO-15 µg/m3 210 880 6950 29200 CIS-1,2-DICHLOROETHENE 156-59-2 TO-15 µg/m3 42 180 NE NE TRANS-1,2-DICHLOROETHENE 156-60-5 TO-15 µg/m3 42 180 NE NE 1,2-DICHLOROPROPANE 78-87-5 TO-15 µg/m3 0.76 3.3 25.3 110 CIS-1,3-DICHLOROPROPENE 10061-01-5 TO-15 µg/m3 NE NE NE NE TRANS-1,3-DICHLOROPROPENE 10061-02-6 TO-15 µg/m3 NE NE NE NE DICHLOROTETRAFLUOROETHANE 76-14-2 TO-15 µg/m3 NE NE NE NE ETHYLBENZENE 100-41-4 TO-15 µg/m3 1.1 4.9 37.4 164 4-ETHYLTOLUENE 622-96-8 TO-15 µg/m3 NE NE NE NE TRICHLOROFLUOROMETHANE 75-69-4 TO-15 µg/m3 NE NE NE NE DICHLORODIFLUOROMETHANE 75-71-8 TO-15 µg/m3 100 440 3480 14600 1,1,2-TRICHLOROTRIFLUOROETHANE 76-13-1 TO-15 µg/m3 5200 22000 174000 730000 HEXACHLORO-1,3-BUTADIENE 87-68-3 TO-15 µg/m3 0.13 0.56 4.25 18.6 METHYLENE CHLORIDE 75-09-2 TO-15 µg/m3 100 1200 3380 40900 METHYL BUTYL KETONE 591-78-6 TO-15 µg/m3 31 130 1040 4380 2-BUTANONE (MEK) 78-93-3 TO-15 µg/m3 5200 22000 174000 730000 4-METHYL-2-PENTANONE (MIBK) 108-10-1 TO-15 µg/m3 3100 13000 104000 438000 STYRENE 100-42-5 TO-15 µg/m3 1000 4400 34800 146000 1,1,2,2-TETRACHLOROETHANE 79-34-5 TO-15 µg/m3 0.048 0.21 1.61 7.05 1,1,1,2-TETRACHLOROETHANE 630-20-6 TO-15 µg/m3 0.38 1.7 12.6 55.2 TETRACHLOROETHENE 127-18-4 TO-15 µg/m3 11 47 360 1570 TOLUENE 108-88-3 TO-15 µg/m3 5200 22000 174000 730000 1,2,4-TRICHLOROBENZENE 120-82-1 TO-15 µg/m3 2.1 8.8 69.5 292 1,1,1-TRICHLOROETHANE 71-55-6 TO-15 µg/m3 5200 22000 174000 730000 1,1,2-TRICHLOROETHANE 79-00-5 TO-15 µg/m3 0.18 0.77 5.85 25.6 TRICHLOROETHENE 79-01-6 TO-15 µg/m3 0.48 3 15.9 99.7 1,2,4-TRIMETHYLBENZENE 95-63-6 TO-15 µg/m3 63 260 2090 8760 1,3,5-TRIMETHYLBENZENE 108-67-8 TO-15 µg/m3 63 260 2090 8760 VINYL CHLORIDE 75-01-4 TO-15 µg/m3 0.17 2.8 5.59 92.9 M,P-XYLENE 178601-23-1 TO-15 µg/m3 100 440 3480 14600 O-XYLENE 95-47-6 TO-15 µg/m3 100 440 3480 14600 NE: Not established. ND: Not detected at or above the Reporting Detection Limit (RDL). µg/m3: micrograms per cubic meter. Lab Sample ID Client Sample ID Bold values exceed the RDL. Blue italicized non-detect results have RDLs exceeding one or more of the EPA RSLs or VISLs. EPA VISL: Environmental Protection Agency Target Sub-Slab and Near-source Soil Gas Concentration (TSSNSGC) Vapor Intrusion Screening Level (VISL); July 2024. EPA RSL: Environmental Protection Agency Regional Screening Levels for Residential and Industrial Air (May 2024, TR=1E-06; THQ=1.0). Qualifiers (Q): Date Collected Result RDL Result RDL Result RDL Result RDL Result RDL Result RDL Result RDL 0.94 0.32 0.81 0.32 0.42 0.32 0.65 0.32 0.74 0.32 ND 0.6 ND 0.6 ND 0.68 ND 0.68 ND 0.68 ND 0.68 ND 0.68 ND 2.7 ND 2.7 ND 1.0 ND 1.0 ND 1.0 ND 1.0 ND 1.0 ND 4.2 ND 4.2 ND 0.39 ND 0.39 ND 0.39 ND 0.39 ND 0.39 ND 1.6 ND 1.6 ND 0.32 ND 0.32 ND 0.32 0.57 0.32 ND 0.32 ND 1.3 ND 1.3 1.1 0.64 0.96 0.64 1.0 0.64 1.1 0.64 0.96 0.64 ND 1.3 ND 1.3 ND 0.47 ND 0.47 ND 0.47 ND 0.47 ND 0.47 ND 1.9 ND 1.9 ND 0.27 ND 0.27 ND 0.27 ND 0.27 ND 0.27 ND 0.8 ND 0.8 1.1 0.25 1.4 0.25 0.64 0.25 0.94 0.25 0.25 0.25 ND 1.0 ND 1.0 0.66 0.21 0.33 0.21 1.7 0.21 1.4 0.21 0.64 0.21 ND 1.6 ND 1.6 ND 1.7 ND 1.7 ND 1.7 ND 1.7 ND 1.7 ND 3.5 ND 3.5 ND 0.78 ND 0.78 ND 0.78 ND 0.78 ND 0.78 ND 3.1 ND 3.1 ND 0.61 ND 0.61 ND 0.61 ND 0.61 ND 0.61 ND 2.4 ND 2.4 0.67 0.61 ND 0.61 ND 0.61 ND 0.61 5.8 0.61 ND 2.4 ND 2.4 0.61 0.61 ND 0.61 ND 0.61 0.91 0.61 ND 0.61 ND 2.4 ND 2.4 ND 0.41 ND 0.41 ND 0.41 ND 0.41 ND 0.41 ND 1.6 ND 1.6 0.66 0.41 0.41 0.41 ND 0.41 ND 0.41 0.90 0.41 ND 1.6 ND 1.6 ND 0.40 ND 0.40 ND 0.40 ND 0.40 ND 0.40 ND 1.6 ND 1.6 ND 0.40 ND 0.40 ND 0.40 ND 0.40 ND 0.40 ND 1.6 ND 1.6 ND 0.40 ND 0.40 ND 0.40 ND 0.40 ND 0.40 ND 1.6 ND 1.6 ND 0.47 ND 0.47 ND 0.47 ND 0.47 ND 0.47 ND 1.9 ND 1.9 ND 0.46 ND 0.46 ND 0.46 ND 0.46 ND 0.46 ND 1.8 ND 1.8 ND 0.46 ND 0.46 ND 0.46 ND 0.46 ND 0.46 ND 1.8 ND 1.8 ND 0.71 ND 0.71 ND 0.71 ND 0.71 ND 0.71 ND 2.8 ND 2.8 0.97 0.44 0.44 0.44 ND 0.44 0.48 0.44 0.48 0.44 ND 1.8 ND 1.8 2.2 0.50 ND 0.50 ND 0.50 ND 0.50 ND 0.50 ND 2.0 ND 2.0 1.7 0.56 1.1 0.56 2.5 0.56 2.1 0.56 1.7 0.56 2.8 2.3 2.4 2.3 1.7 1.0 1.3 1.0 3.4 1.0 3.0 1.0 1.6 1.0 4.4 4.0 4.9 4.0 0.85 0.77 ND 0.77 1.0 0.77 1.0 0.77 0.77 0.77 ND 3.1 ND 3.1 ND 2.7 ND 2.7 ND 2.7 ND 2.7 ND 2.7 ND 11 ND 11 0.49 0.35 0.42 0.35 0.49 0.35 0.74 0.35 0.42 0.35 ND 1.4 ND 1.4 ND 0.83 ND 0.83 ND 0.83 ND 0.83 ND 0.83 ND 3.3 ND 3.3 2.7 0.60 2.2 0.60 1.1 0.60 10 0.60 3.9 0.60 11 2.4 ND 2.4 ND 0.83 ND 0.83 ND 0.83 ND 0.83 1.1 0.83 ND 3.3 ND 3.3 0.52 0.43 0.99 0.43 ND 0.43 0.52 0.43 ND 0.43 ND 1.7 ND 1.7 ND 0.70 ND 0.70 ND 0.70 ND 0.70 ND 0.70 ND 2.8 ND 2.8 ND 0.70 ND 0.70 ND 0.70 ND 0.70 ND 0.70 ND 2.8 ND 2.8 ND 0.69 ND 0.69 ND 0.69 ND 0.69 ND 0.69 ND 2.8 ND 2.8 2.5 0.76 3.7 0.76 1.6 0.76 29 0.76 3.4 0.76 4.2 3.1 ND 3.1 ND 1.9 ND 1.9 ND 1.9 ND 1.9 ND 1.9 ND 7.5 ND 7.5 ND 0.55 ND 0.55 ND 0.55 ND 0.55 ND 0.55 ND 2.2 ND 2.2 ND 0.55 ND 0.55 ND 0.55 ND 0.55 ND 0.55 ND 2.2 ND 2.2 ND 0.55 ND 0.55 ND 0.55 ND 0.55 ND 0.55 ND 2.2 ND 2.2 19 0.50 0.75 0.50 2.7 0.50 0.80 0.50 0.75 0.50 ND 2.0 ND 2.0 4.2 0.50 ND 0.50 0.60 0.50 ND 0.50 ND 0.50 ND 2.0 ND 2.0 ND 0.13 ND 0.13 ND 0.13 ND 0.13 ND 0.13 ND 0.5 ND 0.5 3.5 0.44 1.5 0.44 1.2 0.44 2.2 0.44 2.0 0.44 3.3 1.8 1.9 1.8 1.8 0.44 0.66 0.44 0.62 0.44 1.1 0.44 0.84 0.44 ND 1.8 ND 1.8 E410009-06 VP-1 9/24/2024 E410009-04 IA-5 9/25/2024 E410009-05 OA-1 9/25/2024 E410009-03 IA-4 9/25/2024 E410009-02 IA-2 9/25/2024 E410009-01 IA-1 9/25/2024 VP-2 9/24/2024 E410009-07 Page 3 of 3 APPENDIX C CHAIN OF CUSTODY DOCUMENTATION AND LABORATORY REPORT Terracon - Midvale Midvale, UT 84047 6952 S. High Tech Drive, Suite B Amy Austin Enclosed is the analytical report for the above referenced project. The data herein applies to samples as received by H&P Mobile Geochemistry, Inc. on 01-Oct-24 which were analyzed in accordance with the attached Chain of Custody record(s). The results for all sample analyses and required QA/QC analyses are presented in the following sections and summarized in the documents: •Sample Summary •Case Narrative (if applicable) •Sample Results •Quality Control Summary •Notes and Definitions / Appendix •Chain of Custody •Sampling Logs (if applicable) Unless otherwise noted, I certify that all analyses were performed and reviewed in compliance with our Quality Systems Manual and Standard Operating Procedures. This report shall not be reproduced, except in full, without the written approval of H &P Mobile Geochemistry, Inc. We at H&P Mobile Geochemistry, Inc. sincerely appreciate the opportunity to provide analytical services to you on this project. If you have any questions or concerns regarding this analytical report, please contact me at your convenience at 760-804-9678. Sincerely, 11 October 2024 Lisa Eminhizer Laboratory Director H&P Mobile Geochemistry, Inc. is certified under the National Environmental Laboratory Accreditation Conference (NELAC) for the fields of proficiency and analytes listed on those certificates. H&P is approved as an Environmental Testing Laboratory in accordance with the DoD -ELAP Program and ISO/IEC 17025:2005 programs for the fields of proficiency and analytes included in the certification process and to the extent offered by the accreditation agency. Unless otherwise noted, accreditation certificate numbers, expiration of certificates, and scope of accreditation can be found at: www.handpmg.com/about/certifications . Fields of services and analytes contained in this report that are not listed on the certificates should be considered uncertified or unavailable for certification. Client Project: DERR Brent Redd H&P Project: TER100124-10 Dear Amy Austin: P 1.800.834.9888 / 760.804.9678 F 760.804.9159 W handpmg.com 2470 Impala Drive, Carlsbad, CA 92010 & Field Office - Signal Hill, CAQuality. Accuracy. Experience. Geochemistry Inc. Mobile Page 1 of 21 Project: Project Number: Project Manager: Reported: Terracon - Midvale 6952 S. High Tech Drive, Suite B TER100124-10 DERR Brent Redd Amy AustinMidvale, UT 84047 11-Oct-24 15:17 2470 Impala Drive Carlsbad, CA 92010 760-804-9678 Phone 760-804-9159 Fax H&P Mobile Geochemistry Inc. Sample ID Laboratory ID Matrix Date Sampled ANALYTICAL REPORT FOR SAMPLES Date Received IA-1 E410009-01 Air 25-Sep-24 01-Oct-24 IA-2 E410009-02 Air 25-Sep-24 01-Oct-24 IA-4 E410009-03 Air 25-Sep-24 01-Oct-24 IA-5 E410009-04 Air 25-Sep-24 01-Oct-24 OA-1 E410009-05 Air 25-Sep-24 01-Oct-24 VP-1 E410009-06 Vapor 24-Sep-24 01-Oct-24 VP-2 E410009-07 Vapor 24-Sep-24 01-Oct-24 Page 2 of 21 Project: Project Number: Project Manager: Reported: Terracon - Midvale 6952 S. High Tech Drive, Suite B TER100124-10 DERR Brent Redd Amy AustinMidvale, UT 84047 11-Oct-24 15:17 2470 Impala Drive Carlsbad, CA 92010 760-804-9678 Phone 760-804-9159 Fax H&P Mobile Geochemistry Inc. DETECTIONS SUMMARY Sample ID:Laboratory ID: Analyte Result Limit Units Method E410009-01IA-1 Notes Reporting Dichlorodifluoromethane (F12)1.7 1.0 ug/m3 EPA TO-15 Chloromethane 0.66 0.21 ug/m3 EPA TO-15 Trichlorofluoromethane (F11)1.7 0.56 ug/m3 EPA TO-15 1,1,2-Trichlorotrifluoroethane (F113)0.85 0.77 ug/m3 EPA TO-15 Methylene chloride (Dichloromethane)0.49 0.35 ug/m3 EPA TO-15 1,1-Dichloroethane 0.66 0.41 ug/m3 EPA TO-15 2-Butanone (MEK)2.7 0.60 ug/m3 EPA TO-15 Chloroform 1.1 0.25 ug/m3 EPA TO-15 Benzene 0.94 0.32 ug/m3 EPA TO-15 Carbon tetrachloride 1.1 0.64 ug/m3 EPA TO-15 Toluene 2.5 0.76 ug/m3 EPA TO-15 Ethylbenzene 0.97 0.44 ug/m3 EPA TO-15 m,p-Xylene 3.5 0.44 ug/m3 EPA TO-15 Styrene 0.52 0.43 ug/m3 EPA TO-15 o-Xylene 1.8 0.44 ug/m3 EPA TO-15 4-Ethyltoluene 2.2 0.50 ug/m3 EPA TO-15 1,3,5-Trimethylbenzene 4.2 0.50 ug/m3 EPA TO-15 1,2,4-Trimethylbenzene 19 0.50 ug/m3 EPA TO-15 1,3-Dichlorobenzene 0.67 0.61 ug/m3 EPA TO-15 1,4-Dichlorobenzene 0.61 0.61 ug/m3 EPA TO-15 Sample ID:Laboratory ID: Analyte Result Limit Units Method E410009-02IA-2 Notes Reporting Dichlorodifluoromethane (F12)1.3 1.0 ug/m3 EPA TO-15 Chloromethane 0.33 0.21 ug/m3 EPA TO-15 Trichlorofluoromethane (F11)1.1 0.56 ug/m3 EPA TO-15 Methylene chloride (Dichloromethane)0.42 0.35 ug/m3 EPA TO-15 1,1-Dichloroethane 0.41 0.41 ug/m3 EPA TO-15 2-Butanone (MEK)2.2 0.60 ug/m3 EPA TO-15 Chloroform 1.4 0.25 ug/m3 EPA TO-15 Benzene 0.81 0.32 ug/m3 EPA TO-15 Carbon tetrachloride 0.96 0.64 ug/m3 EPA TO-15 Toluene 3.7 0.76 ug/m3 EPA TO-15 Ethylbenzene 0.44 0.44 ug/m3 EPA TO-15 m,p-Xylene 1.5 0.44 ug/m3 EPA TO-15 Styrene 0.99 0.43 ug/m3 EPA TO-15 Page 3 of 21 Project: Project Number: Project Manager: Reported: Terracon - Midvale 6952 S. High Tech Drive, Suite B TER100124-10 DERR Brent Redd Amy AustinMidvale, UT 84047 11-Oct-24 15:17 2470 Impala Drive Carlsbad, CA 92010 760-804-9678 Phone 760-804-9159 Fax H&P Mobile Geochemistry Inc. Sample ID:Laboratory ID: Analyte Result Limit Units Method E410009-02IA-2 Notes Reporting o-Xylene 0.66 0.44 ug/m3 EPA TO-15 1,2,4-Trimethylbenzene 0.75 0.50 ug/m3 EPA TO-15 Sample ID:Laboratory ID: Analyte Result Limit Units Method E410009-03IA-4 Notes Reporting Dichlorodifluoromethane (F12)3.4 1.0 ug/m3 EPA TO-15 Chloromethane 1.7 0.21 ug/m3 EPA TO-15 Trichlorofluoromethane (F11)2.5 0.56 ug/m3 EPA TO-15 1,1,2-Trichlorotrifluoroethane (F113)1.0 0.77 ug/m3 EPA TO-15 Methylene chloride (Dichloromethane)0.49 0.35 ug/m3 EPA TO-15 2-Butanone (MEK)1.1 0.60 ug/m3 EPA TO-15 Chloroform 0.64 0.25 ug/m3 EPA TO-15 Benzene 0.42 0.32 ug/m3 EPA TO-15 Carbon tetrachloride 1.0 0.64 ug/m3 EPA TO-15 Toluene 1.6 0.76 ug/m3 EPA TO-15 m,p-Xylene 1.2 0.44 ug/m3 EPA TO-15 o-Xylene 0.62 0.44 ug/m3 EPA TO-15 1,3,5-Trimethylbenzene 0.60 0.50 ug/m3 EPA TO-15 1,2,4-Trimethylbenzene 2.7 0.50 ug/m3 EPA TO-15 Sample ID:Laboratory ID: Analyte Result Limit Units Method E410009-04IA-5 Notes Reporting Dichlorodifluoromethane (F12)3.0 1.0 ug/m3 EPA TO-15 Chloromethane 1.4 0.21 ug/m3 EPA TO-15 Trichlorofluoromethane (F11)2.1 0.56 ug/m3 EPA TO-15 1,1,2-Trichlorotrifluoroethane (F113)1.0 0.77 ug/m3 EPA TO-15 Methylene chloride (Dichloromethane)0.74 0.35 ug/m3 EPA TO-15 Carbon disulfide 0.57 0.32 ug/m3 EPA TO-15 2-Butanone (MEK)10 0.60 ug/m3 EPA TO-15 Chloroform 0.94 0.25 ug/m3 EPA TO-15 Benzene 0.65 0.32 ug/m3 EPA TO-15 Carbon tetrachloride 1.1 0.64 ug/m3 EPA TO-15 Toluene 29 0.76 ug/m3 EPA TO-15 Ethylbenzene 0.48 0.44 ug/m3 EPA TO-15 m,p-Xylene 2.2 0.44 ug/m3 EPA TO-15 Styrene 0.52 0.43 ug/m3 EPA TO-15 o-Xylene 1.1 0.44 ug/m3 EPA TO-15 Page 4 of 21 Project: Project Number: Project Manager: Reported: Terracon - Midvale 6952 S. High Tech Drive, Suite B TER100124-10 DERR Brent Redd Amy AustinMidvale, UT 84047 11-Oct-24 15:17 2470 Impala Drive Carlsbad, CA 92010 760-804-9678 Phone 760-804-9159 Fax H&P Mobile Geochemistry Inc. Sample ID:Laboratory ID: Analyte Result Limit Units Method E410009-04IA-5 Notes Reporting 1,2,4-Trimethylbenzene 0.80 0.50 ug/m3 EPA TO-15 1,4-Dichlorobenzene 0.91 0.61 ug/m3 EPA TO-15 Sample ID:Laboratory ID: Analyte Result Limit Units Method E410009-05OA-1 Notes Reporting Dichlorodifluoromethane (F12)1.6 1.0 ug/m3 EPA TO-15 Chloromethane 0.64 0.21 ug/m3 EPA TO-15 Trichlorofluoromethane (F11)1.7 0.56 ug/m3 EPA TO-15 1,1,2-Trichlorotrifluoroethane (F113)0.77 0.77 ug/m3 EPA TO-15 Methylene chloride (Dichloromethane)0.42 0.35 ug/m3 EPA TO-15 1,1-Dichloroethane 0.90 0.41 ug/m3 EPA TO-15 2-Butanone (MEK)3.9 0.60 ug/m3 EPA TO-15 Chloroform 0.25 0.25 ug/m3 EPA TO-15 Benzene 0.74 0.32 ug/m3 EPA TO-15 Carbon tetrachloride 0.96 0.64 ug/m3 EPA TO-15 4-Methyl-2-pentanone (MIBK)1.1 0.83 ug/m3 EPA TO-15 Toluene 3.4 0.76 ug/m3 EPA TO-15 Ethylbenzene 0.48 0.44 ug/m3 EPA TO-15 m,p-Xylene 2.0 0.44 ug/m3 EPA TO-15 o-Xylene 0.84 0.44 ug/m3 EPA TO-15 1,2,4-Trimethylbenzene 0.75 0.50 ug/m3 EPA TO-15 1,3-Dichlorobenzene 5.8 0.61 ug/m3 EPA TO-15 Sample ID:Laboratory ID: Analyte Result Limit Units Method E410009-06VP-1 Notes Reporting Dichlorodifluoromethane (F12)4.4 4.0 ug/m3 EPA TO-15 Trichlorofluoromethane (F11)2.8 2.3 ug/m3 EPA TO-15 2-Butanone (MEK)11 2.4 ug/m3 EPA TO-15 Toluene 4.2 3.1 ug/m3 EPA TO-15 m,p-Xylene 3.3 1.8 ug/m3 EPA TO-15 Sample ID:Laboratory ID: Analyte Result Limit Units Method E410009-07VP-2 Notes Reporting Dichlorodifluoromethane (F12)4.9 4.0 ug/m3 EPA TO-15 Trichlorofluoromethane (F11)2.4 2.3 ug/m3 EPA TO-15 m,p-Xylene 1.9 1.8 ug/m3 EPA TO-15 Page 5 of 21 Project: Project Number: Project Manager: Reported: Terracon - Midvale 6952 S. High Tech Drive, Suite B TER100124-10 DERR Brent Redd Amy AustinMidvale, UT 84047 11-Oct-24 15:17 2470 Impala Drive Carlsbad, CA 92010 760-804-9678 Phone 760-804-9159 Fax H&P Mobile Geochemistry Inc. Volatile Organic Compounds by EPA TO-15 H&P Mobile Geochemistry, Inc. Result Analyte Limit Reporting Units Dilution Batch Prepared Analyzed Method Notes Factor IA-1 (E410009-01) Air Sampled: 25-Sep-24 Received: 01-Oct-24 EJ40913 09-Oct-24 09-Oct-24ug/m3 1Dichlorodifluoromethane (F12)EPA TO-151.01.7 """""Chloromethane "0.210.66 """"""Dichlorotetrafluoroethane (F114)0.71ND """"""Vinyl chloride 0.13ND """"""Bromomethane 0.39ND """"""Chloroethane 0.27ND """""Trichlorofluoromethane (F11)"0.561.7 """"""1,1-Dichloroethene 0.40ND """""1,1,2-Trichlorotrifluoroethane (F113)"0.770.85 """""Methylene chloride (Dichloromethane)"0.350.49 """"""Carbon disulfide 0.32ND """"""trans-1,2-Dichloroethene 0.40ND """""1,1-Dichloroethane "0.410.66 """""2-Butanone (MEK)"0.602.7 """"""cis-1,2-Dichloroethene 0.40ND """""Chloroform "0.251.1 """"""1,1,1-Trichloroethane 0.55ND """"""1,2-Dichloroethane (EDC)0.41ND """""Benzene "0.320.94 """""Carbon tetrachloride "0.641.1 """"""Trichloroethene 0.55ND """"""1,2-Dichloropropane 0.47ND """"""Bromodichloromethane 0.68ND """"""cis-1,3-Dichloropropene 0.46ND """"""4-Methyl-2-pentanone (MIBK)0.83ND """"""trans-1,3-Dichloropropene 0.46ND """""Toluene "0.762.5 """"""1,1,2-Trichloroethane 0.55ND """"""2-Hexanone (MBK)0.83ND """"""Dibromochloromethane 1.7ND """"""Tetrachloroethene 0.69ND """"""1,2-Dibromoethane (EDB)0.78ND """"""1,1,1,2-Tetrachloroethane 0.70ND """"""Chlorobenzene 0.47ND """""Ethylbenzene "0.440.97 """""m,p-Xylene "0.443.5 """""Styrene "0.430.52 """""o-Xylene "0.441.8 Page 6 of 21 Project: Project Number: Project Manager: Reported: Terracon - Midvale 6952 S. High Tech Drive, Suite B TER100124-10 DERR Brent Redd Amy AustinMidvale, UT 84047 11-Oct-24 15:17 2470 Impala Drive Carlsbad, CA 92010 760-804-9678 Phone 760-804-9159 Fax H&P Mobile Geochemistry Inc. Volatile Organic Compounds by EPA TO-15 H&P Mobile Geochemistry, Inc. Result Analyte Limit Reporting Units Dilution Batch Prepared Analyzed Method Notes Factor IA-1 (E410009-01) Air Sampled: 25-Sep-24 Received: 01-Oct-24 EPA TO-1509-Oct-24 09-Oct-24ug/m3 EJ409131Bromoform1.0ND """"""1,1,2,2-Tetrachloroethane 0.70ND """""4-Ethyltoluene "0.502.2 """""1,3,5-Trimethylbenzene "0.504.2 """""1,2,4-Trimethylbenzene "0.5019 """""1,3-Dichlorobenzene "0.610.67 """""1,4-Dichlorobenzene "0.610.61 """"""1,2-Dichlorobenzene 0.61ND """"""1,2,4-Trichlorobenzene 1.9ND """"""Hexachlorobutadiene 2.7ND """"93.7 %76-134Surrogate: 1,2-Dichloroethane-d4 """"98.1 %78-125Surrogate: Toluene-d8 """"88.2 %77-127Surrogate: 4-Bromofluorobenzene IA-2 (E410009-02) Air Sampled: 25-Sep-24 Received: 01-Oct-24 EJ40913 09-Oct-24 09-Oct-24ug/m3 1Dichlorodifluoromethane (F12)EPA TO-151.01.3 """""Chloromethane "0.210.33 """"""Dichlorotetrafluoroethane (F114)0.71ND """"""Vinyl chloride 0.13ND """"""Bromomethane 0.39ND """"""Chloroethane 0.27ND """""Trichlorofluoromethane (F11)"0.561.1 """"""1,1-Dichloroethene 0.40ND """"""1,1,2-Trichlorotrifluoroethane (F113)0.77ND """""Methylene chloride (Dichloromethane)"0.350.42 """"""Carbon disulfide 0.32ND """"""trans-1,2-Dichloroethene 0.40ND """""1,1-Dichloroethane "0.410.41 """""2-Butanone (MEK)"0.602.2 """"""cis-1,2-Dichloroethene 0.40ND """""Chloroform "0.251.4 """"""1,1,1-Trichloroethane 0.55ND """"""1,2-Dichloroethane (EDC)0.41ND """""Benzene "0.320.81 """""Carbon tetrachloride "0.640.96 """"""Trichloroethene 0.55ND """"""1,2-Dichloropropane 0.47ND Page 7 of 21 Project: Project Number: Project Manager: Reported: Terracon - Midvale 6952 S. High Tech Drive, Suite B TER100124-10 DERR Brent Redd Amy AustinMidvale, UT 84047 11-Oct-24 15:17 2470 Impala Drive Carlsbad, CA 92010 760-804-9678 Phone 760-804-9159 Fax H&P Mobile Geochemistry Inc. Volatile Organic Compounds by EPA TO-15 H&P Mobile Geochemistry, Inc. Result Analyte Limit Reporting Units Dilution Batch Prepared Analyzed Method Notes Factor IA-2 (E410009-02) Air Sampled: 25-Sep-24 Received: 01-Oct-24 EPA TO-1509-Oct-24 09-Oct-24ug/m3 EJ409131Bromodichloromethane0.68ND """"""cis-1,3-Dichloropropene 0.46ND """"""4-Methyl-2-pentanone (MIBK)0.83ND """"""trans-1,3-Dichloropropene 0.46ND """""Toluene "0.763.7 """"""1,1,2-Trichloroethane 0.55ND """"""2-Hexanone (MBK)0.83ND """"""Dibromochloromethane 1.7ND """"""Tetrachloroethene 0.69ND """"""1,2-Dibromoethane (EDB)0.78ND """"""1,1,1,2-Tetrachloroethane 0.70ND """"""Chlorobenzene 0.47ND """""Ethylbenzene "0.440.44 """""m,p-Xylene "0.441.5 """""Styrene "0.430.99 """""o-Xylene "0.440.66 """"""Bromoform 1.0ND """"""1,1,2,2-Tetrachloroethane 0.70ND """"""4-Ethyltoluene 0.50ND """"""1,3,5-Trimethylbenzene 0.50ND """""1,2,4-Trimethylbenzene "0.500.75 """"""1,3-Dichlorobenzene 0.61ND """"""1,4-Dichlorobenzene 0.61ND """"""1,2-Dichlorobenzene 0.61ND """"""1,2,4-Trichlorobenzene 1.9ND """"""Hexachlorobutadiene 2.7ND """"92.9 %76-134Surrogate: 1,2-Dichloroethane-d4 """"105 %78-125Surrogate: Toluene-d8 """"92.7 %77-127Surrogate: 4-Bromofluorobenzene Page 8 of 21 Project: Project Number: Project Manager: Reported: Terracon - Midvale 6952 S. High Tech Drive, Suite B TER100124-10 DERR Brent Redd Amy AustinMidvale, UT 84047 11-Oct-24 15:17 2470 Impala Drive Carlsbad, CA 92010 760-804-9678 Phone 760-804-9159 Fax H&P Mobile Geochemistry Inc. Volatile Organic Compounds by EPA TO-15 H&P Mobile Geochemistry, Inc. Result Analyte Limit Reporting Units Dilution Batch Prepared Analyzed Method Notes Factor IA-4 (E410009-03) Air Sampled: 25-Sep-24 Received: 01-Oct-24 EJ40913 09-Oct-24 09-Oct-24ug/m3 1Dichlorodifluoromethane (F12)EPA TO-151.03.4 """""Chloromethane "0.211.7 """"""Dichlorotetrafluoroethane (F114)0.71ND """"""Vinyl chloride 0.13ND """"""Bromomethane 0.39ND """"""Chloroethane 0.27ND """""Trichlorofluoromethane (F11)"0.562.5 """"""1,1-Dichloroethene 0.40ND """""1,1,2-Trichlorotrifluoroethane (F113)"0.771.0 """""Methylene chloride (Dichloromethane)"0.350.49 """"""Carbon disulfide 0.32ND """"""trans-1,2-Dichloroethene 0.40ND """"""1,1-Dichloroethane 0.41ND """""2-Butanone (MEK)"0.601.1 """"""cis-1,2-Dichloroethene 0.40ND """""Chloroform "0.250.64 """"""1,1,1-Trichloroethane 0.55ND """"""1,2-Dichloroethane (EDC)0.41ND """""Benzene "0.320.42 """""Carbon tetrachloride "0.641.0 """"""Trichloroethene 0.55ND """"""1,2-Dichloropropane 0.47ND """"""Bromodichloromethane 0.68ND """"""cis-1,3-Dichloropropene 0.46ND """"""4-Methyl-2-pentanone (MIBK)0.83ND """"""trans-1,3-Dichloropropene 0.46ND """""Toluene "0.761.6 """"""1,1,2-Trichloroethane 0.55ND """"""2-Hexanone (MBK)0.83ND """"""Dibromochloromethane 1.7ND """"""Tetrachloroethene 0.69ND """"""1,2-Dibromoethane (EDB)0.78ND """"""1,1,1,2-Tetrachloroethane 0.70ND """"""Chlorobenzene 0.47ND """"""Ethylbenzene 0.44ND """""m,p-Xylene "0.441.2 """"""Styrene 0.43ND """""o-Xylene "0.440.62 Page 9 of 21 Project: Project Number: Project Manager: Reported: Terracon - Midvale 6952 S. High Tech Drive, Suite B TER100124-10 DERR Brent Redd Amy AustinMidvale, UT 84047 11-Oct-24 15:17 2470 Impala Drive Carlsbad, CA 92010 760-804-9678 Phone 760-804-9159 Fax H&P Mobile Geochemistry Inc. Volatile Organic Compounds by EPA TO-15 H&P Mobile Geochemistry, Inc. Result Analyte Limit Reporting Units Dilution Batch Prepared Analyzed Method Notes Factor IA-4 (E410009-03) Air Sampled: 25-Sep-24 Received: 01-Oct-24 EPA TO-1509-Oct-24 09-Oct-24ug/m3 EJ409131Bromoform1.0ND """"""1,1,2,2-Tetrachloroethane 0.70ND """"""4-Ethyltoluene 0.50ND """""1,3,5-Trimethylbenzene "0.500.60 """""1,2,4-Trimethylbenzene "0.502.7 """"""1,3-Dichlorobenzene 0.61ND """"""1,4-Dichlorobenzene 0.61ND """"""1,2-Dichlorobenzene 0.61ND """"""1,2,4-Trichlorobenzene 1.9ND """"""Hexachlorobutadiene 2.7ND """"99.2 %76-134Surrogate: 1,2-Dichloroethane-d4 """"103 %78-125Surrogate: Toluene-d8 """"95.0 %77-127Surrogate: 4-Bromofluorobenzene IA-5 (E410009-04) Air Sampled: 25-Sep-24 Received: 01-Oct-24 EJ40913 09-Oct-24 09-Oct-24ug/m3 1Dichlorodifluoromethane (F12)EPA TO-151.03.0 """""Chloromethane "0.211.4 """"""Dichlorotetrafluoroethane (F114)0.71ND """"""Vinyl chloride 0.13ND """"""Bromomethane 0.39ND """"""Chloroethane 0.27ND """""Trichlorofluoromethane (F11)"0.562.1 """"""1,1-Dichloroethene 0.40ND """""1,1,2-Trichlorotrifluoroethane (F113)"0.771.0 """""Methylene chloride (Dichloromethane)"0.350.74 """""Carbon disulfide "0.320.57 """"""trans-1,2-Dichloroethene 0.40ND """"""1,1-Dichloroethane 0.41ND """""2-Butanone (MEK)"0.6010 """"""cis-1,2-Dichloroethene 0.40ND """""Chloroform "0.250.94 """"""1,1,1-Trichloroethane 0.55ND """"""1,2-Dichloroethane (EDC)0.41ND """""Benzene "0.320.65 """""Carbon tetrachloride "0.641.1 """"""Trichloroethene 0.55ND """"""1,2-Dichloropropane 0.47ND Page 10 of 21 Project: Project Number: Project Manager: Reported: Terracon - Midvale 6952 S. High Tech Drive, Suite B TER100124-10 DERR Brent Redd Amy AustinMidvale, UT 84047 11-Oct-24 15:17 2470 Impala Drive Carlsbad, CA 92010 760-804-9678 Phone 760-804-9159 Fax H&P Mobile Geochemistry Inc. Volatile Organic Compounds by EPA TO-15 H&P Mobile Geochemistry, Inc. Result Analyte Limit Reporting Units Dilution Batch Prepared Analyzed Method Notes Factor IA-5 (E410009-04) Air Sampled: 25-Sep-24 Received: 01-Oct-24 EPA TO-1509-Oct-24 09-Oct-24ug/m3 EJ409131Bromodichloromethane0.68ND """"""cis-1,3-Dichloropropene 0.46ND """"""4-Methyl-2-pentanone (MIBK)0.83ND """"""trans-1,3-Dichloropropene 0.46ND """""Toluene "0.7629 """"""1,1,2-Trichloroethane 0.55ND """"""2-Hexanone (MBK)0.83ND """"""Dibromochloromethane 1.7ND """"""Tetrachloroethene 0.69ND """"""1,2-Dibromoethane (EDB)0.78ND """"""1,1,1,2-Tetrachloroethane 0.70ND """"""Chlorobenzene 0.47ND """""Ethylbenzene "0.440.48 """""m,p-Xylene "0.442.2 """""Styrene "0.430.52 """""o-Xylene "0.441.1 """"""Bromoform 1.0ND """"""1,1,2,2-Tetrachloroethane 0.70ND """"""4-Ethyltoluene 0.50ND """"""1,3,5-Trimethylbenzene 0.50ND """""1,2,4-Trimethylbenzene "0.500.80 """"""1,3-Dichlorobenzene 0.61ND """""1,4-Dichlorobenzene "0.610.91 """"""1,2-Dichlorobenzene 0.61ND """"""1,2,4-Trichlorobenzene 1.9ND """"""Hexachlorobutadiene 2.7ND """"98.9 %76-134Surrogate: 1,2-Dichloroethane-d4 """"102 %78-125Surrogate: Toluene-d8 """"97.6 %77-127Surrogate: 4-Bromofluorobenzene Page 11 of 21 Project: Project Number: Project Manager: Reported: Terracon - Midvale 6952 S. High Tech Drive, Suite B TER100124-10 DERR Brent Redd Amy AustinMidvale, UT 84047 11-Oct-24 15:17 2470 Impala Drive Carlsbad, CA 92010 760-804-9678 Phone 760-804-9159 Fax H&P Mobile Geochemistry Inc. Volatile Organic Compounds by EPA TO-15 H&P Mobile Geochemistry, Inc. Result Analyte Limit Reporting Units Dilution Batch Prepared Analyzed Method Notes Factor OA-1 (E410009-05) Air Sampled: 25-Sep-24 Received: 01-Oct-24 EJ40913 09-Oct-24 09-Oct-24ug/m3 1Dichlorodifluoromethane (F12)EPA TO-151.01.6 """""Chloromethane "0.210.64 """"""Dichlorotetrafluoroethane (F114)0.71ND """"""Vinyl chloride 0.13ND """"""Bromomethane 0.39ND """"""Chloroethane 0.27ND """""Trichlorofluoromethane (F11)"0.561.7 """"""1,1-Dichloroethene 0.40ND """""1,1,2-Trichlorotrifluoroethane (F113)"0.770.77 """""Methylene chloride (Dichloromethane)"0.350.42 """"""Carbon disulfide 0.32ND """"""trans-1,2-Dichloroethene 0.40ND """""1,1-Dichloroethane "0.410.90 """""2-Butanone (MEK)"0.603.9 """"""cis-1,2-Dichloroethene 0.40ND """""Chloroform "0.250.25 """"""1,1,1-Trichloroethane 0.55ND """"""1,2-Dichloroethane (EDC)0.41ND """""Benzene "0.320.74 """""Carbon tetrachloride "0.640.96 """"""Trichloroethene 0.55ND """"""1,2-Dichloropropane 0.47ND """"""Bromodichloromethane 0.68ND """"""cis-1,3-Dichloropropene 0.46ND """""4-Methyl-2-pentanone (MIBK)"0.831.1 """"""trans-1,3-Dichloropropene 0.46ND """""Toluene "0.763.4 """"""1,1,2-Trichloroethane 0.55ND """"""2-Hexanone (MBK)0.83ND """"""Dibromochloromethane 1.7ND """"""Tetrachloroethene 0.69ND """"""1,2-Dibromoethane (EDB)0.78ND """"""1,1,1,2-Tetrachloroethane 0.70ND """"""Chlorobenzene 0.47ND """""Ethylbenzene "0.440.48 """""m,p-Xylene "0.442.0 """"""Styrene 0.43ND """""o-Xylene "0.440.84 Page 12 of 21 Project: Project Number: Project Manager: Reported: Terracon - Midvale 6952 S. High Tech Drive, Suite B TER100124-10 DERR Brent Redd Amy AustinMidvale, UT 84047 11-Oct-24 15:17 2470 Impala Drive Carlsbad, CA 92010 760-804-9678 Phone 760-804-9159 Fax H&P Mobile Geochemistry Inc. Volatile Organic Compounds by EPA TO-15 H&P Mobile Geochemistry, Inc. Result Analyte Limit Reporting Units Dilution Batch Prepared Analyzed Method Notes Factor OA-1 (E410009-05) Air Sampled: 25-Sep-24 Received: 01-Oct-24 EPA TO-1509-Oct-24 09-Oct-24ug/m3 EJ409131Bromoform1.0ND """"""1,1,2,2-Tetrachloroethane 0.70ND """"""4-Ethyltoluene 0.50ND """"""1,3,5-Trimethylbenzene 0.50ND """""1,2,4-Trimethylbenzene "0.500.75 """""1,3-Dichlorobenzene "0.615.8 """"""1,4-Dichlorobenzene 0.61ND """"""1,2-Dichlorobenzene 0.61ND """"""1,2,4-Trichlorobenzene 1.9ND """"""Hexachlorobutadiene 2.7ND """"97.6 %76-134Surrogate: 1,2-Dichloroethane-d4 """"101 %78-125Surrogate: Toluene-d8 """"92.5 %77-127Surrogate: 4-Bromofluorobenzene VP-1 (E410009-06) Vapor Sampled: 24-Sep-24 Received: 01-Oct-24 EJ40913 09-Oct-24 09-Oct-24ug/m3 1Dichlorodifluoromethane (F12)EPA TO-154.04.4 """"""Chloromethane 0.8ND """"""Dichlorotetrafluoroethane (F114)2.8ND """"""Vinyl chloride 0.5ND """"""Bromomethane 1.6ND """"""Chloroethane 1.6ND """""Trichlorofluoromethane (F11)"2.32.8 """"""1,1-Dichloroethene 1.6ND """"""1,1,2-Trichlorotrifluoroethane (F113)3.1ND """"""Methylene chloride (Dichloromethane)1.4ND """"""Carbon disulfide 1.3ND """"""trans-1,2-Dichloroethene 1.6ND """"""1,1-Dichloroethane 1.6ND """""2-Butanone (MEK)"2.411 """"""cis-1,2-Dichloroethene 1.6ND """"""Chloroform 1.0ND """"""1,1,1-Trichloroethane 2.2ND """"""1,2-Dichloroethane (EDC)1.6ND """"""Benzene 0.6ND """"""Carbon tetrachloride 1.3ND """"""Trichloroethene 2.2ND """"""1,2-Dichloropropane 1.9ND Page 13 of 21 Project: Project Number: Project Manager: Reported: Terracon - Midvale 6952 S. High Tech Drive, Suite B TER100124-10 DERR Brent Redd Amy AustinMidvale, UT 84047 11-Oct-24 15:17 2470 Impala Drive Carlsbad, CA 92010 760-804-9678 Phone 760-804-9159 Fax H&P Mobile Geochemistry Inc. Volatile Organic Compounds by EPA TO-15 H&P Mobile Geochemistry, Inc. Result Analyte Limit Reporting Units Dilution Batch Prepared Analyzed Method Notes Factor VP-1 (E410009-06) Vapor Sampled: 24-Sep-24 Received: 01-Oct-24 EPA TO-1509-Oct-24 09-Oct-24ug/m3 EJ409131Bromodichloromethane2.7ND """"""cis-1,3-Dichloropropene 1.8ND """"""4-Methyl-2-pentanone (MIBK)3.3ND """"""trans-1,3-Dichloropropene 1.8ND """""Toluene "3.14.2 """"""1,1,2-Trichloroethane 2.2ND """"""2-Hexanone (MBK)3.3ND """"""Dibromochloromethane 3.5ND """"""Tetrachloroethene 2.8ND """"""1,2-Dibromoethane (EDB)3.1ND """"""1,1,1,2-Tetrachloroethane 2.8ND """"""Chlorobenzene 1.9ND """"""Ethylbenzene 1.8ND """""m,p-Xylene "1.83.3 """"""Styrene 1.7ND """"""o-Xylene 1.8ND """"""Bromoform 4.2ND """"""1,1,2,2-Tetrachloroethane 2.8ND """"""4-Ethyltoluene 2.0ND """"""1,3,5-Trimethylbenzene 2.0ND """"""1,2,4-Trimethylbenzene 2.0ND """"""1,3-Dichlorobenzene 2.4ND """"""1,4-Dichlorobenzene 2.4ND """"""1,2-Dichlorobenzene 2.4ND """"""1,2,4-Trichlorobenzene 7.5ND """"""Hexachlorobutadiene 11ND """"98.6 %76-134Surrogate: 1,2-Dichloroethane-d4 """"102 %78-125Surrogate: Toluene-d8 """"92.1 %77-127Surrogate: 4-Bromofluorobenzene Page 14 of 21 Project: Project Number: Project Manager: Reported: Terracon - Midvale 6952 S. High Tech Drive, Suite B TER100124-10 DERR Brent Redd Amy AustinMidvale, UT 84047 11-Oct-24 15:17 2470 Impala Drive Carlsbad, CA 92010 760-804-9678 Phone 760-804-9159 Fax H&P Mobile Geochemistry Inc. Volatile Organic Compounds by EPA TO-15 H&P Mobile Geochemistry, Inc. Result Analyte Limit Reporting Units Dilution Batch Prepared Analyzed Method Notes Factor VP-2 (E410009-07) Vapor Sampled: 24-Sep-24 Received: 01-Oct-24 EJ40913 09-Oct-24 09-Oct-24ug/m3 1Dichlorodifluoromethane (F12)EPA TO-154.04.9 """"""Chloromethane 0.8ND """"""Dichlorotetrafluoroethane (F114)2.8ND """"""Vinyl chloride 0.5ND """"""Bromomethane 1.6ND """"""Chloroethane 1.6ND """""Trichlorofluoromethane (F11)"2.32.4 """"""1,1-Dichloroethene 1.6ND """"""1,1,2-Trichlorotrifluoroethane (F113)3.1ND """"""Methylene chloride (Dichloromethane)1.4ND """"""Carbon disulfide 1.3ND """"""trans-1,2-Dichloroethene 1.6ND """"""1,1-Dichloroethane 1.6ND """"""2-Butanone (MEK)2.4ND """"""cis-1,2-Dichloroethene 1.6ND """"""Chloroform 1.0ND """"""1,1,1-Trichloroethane 2.2ND """"""1,2-Dichloroethane (EDC)1.6ND """"""Benzene 0.6ND """"""Carbon tetrachloride 1.3ND """"""Trichloroethene 2.2ND """"""1,2-Dichloropropane 1.9ND """"""Bromodichloromethane 2.7ND """"""cis-1,3-Dichloropropene 1.8ND """"""4-Methyl-2-pentanone (MIBK)3.3ND """"""trans-1,3-Dichloropropene 1.8ND """"""Toluene 3.1ND """"""1,1,2-Trichloroethane 2.2ND """"""2-Hexanone (MBK)3.3ND """"""Dibromochloromethane 3.5ND """"""Tetrachloroethene 2.8ND """"""1,2-Dibromoethane (EDB)3.1ND """"""1,1,1,2-Tetrachloroethane 2.8ND """"""Chlorobenzene 1.9ND """"""Ethylbenzene 1.8ND """""m,p-Xylene "1.81.9 """"""Styrene 1.7ND """"""o-Xylene 1.8ND Page 15 of 21 Project: Project Number: Project Manager: Reported: Terracon - Midvale 6952 S. High Tech Drive, Suite B TER100124-10 DERR Brent Redd Amy AustinMidvale, UT 84047 11-Oct-24 15:17 2470 Impala Drive Carlsbad, CA 92010 760-804-9678 Phone 760-804-9159 Fax H&P Mobile Geochemistry Inc. Volatile Organic Compounds by EPA TO-15 H&P Mobile Geochemistry, Inc. Result Analyte Limit Reporting Units Dilution Batch Prepared Analyzed Method Notes Factor VP-2 (E410009-07) Vapor Sampled: 24-Sep-24 Received: 01-Oct-24 EPA TO-1509-Oct-24 09-Oct-24ug/m3 EJ409131Bromoform4.2ND """"""1,1,2,2-Tetrachloroethane 2.8ND """"""4-Ethyltoluene 2.0ND """"""1,3,5-Trimethylbenzene 2.0ND """"""1,2,4-Trimethylbenzene 2.0ND """"""1,3-Dichlorobenzene 2.4ND """"""1,4-Dichlorobenzene 2.4ND """"""1,2-Dichlorobenzene 2.4ND """"""1,2,4-Trichlorobenzene 7.5ND """"""Hexachlorobutadiene 11ND """"100 %76-134Surrogate: 1,2-Dichloroethane-d4 """"104 %78-125Surrogate: Toluene-d8 """"99.3 %77-127Surrogate: 4-Bromofluorobenzene Page 16 of 21 Project: Project Number: Project Manager: Reported: Terracon - Midvale 6952 S. High Tech Drive, Suite B TER100124-10 DERR Brent Redd Amy AustinMidvale, UT 84047 11-Oct-24 15:17 2470 Impala Drive Carlsbad, CA 92010 760-804-9678 Phone 760-804-9159 Fax H&P Mobile Geochemistry Inc. Result Limit Reporting Units Level Spike Result Source %REC %REC Limits RPD RPD Limit Notes Analyte Volatile Organic Compounds by EPA TO-15 - Quality Control H&P Mobile Geochemistry, Inc. Batch EJ40913 - TO-15 Blank (EJ40913-BLK1)Prepared & Analyzed: 09-Oct-24 Dichlorodifluoromethane (F12)ug/m31.0ND Chloromethane "0.21ND Dichlorotetrafluoroethane (F114)"0.71ND Vinyl chloride "0.13ND Bromomethane "0.39ND Chloroethane "0.27ND Trichlorofluoromethane (F11)"0.56ND 1,1-Dichloroethene "0.40ND 1,1,2-Trichlorotrifluoroethane (F113)"0.77ND Methylene chloride (Dichloromethane)"0.35ND Carbon disulfide "0.32ND trans-1,2-Dichloroethene "0.40ND 1,1-Dichloroethane "0.41ND 2-Butanone (MEK)"0.60ND cis-1,2-Dichloroethene "0.40ND Chloroform "0.25ND 1,1,1-Trichloroethane "0.55ND 1,2-Dichloroethane (EDC)"0.41ND Benzene "0.32ND Carbon tetrachloride "0.64ND Trichloroethene "0.55ND 1,2-Dichloropropane "0.47ND Bromodichloromethane "0.68ND cis-1,3-Dichloropropene "0.46ND 4-Methyl-2-pentanone (MIBK)"0.83ND trans-1,3-Dichloropropene "0.46ND Toluene "0.76ND 1,1,2-Trichloroethane "0.55ND 2-Hexanone (MBK)"0.83ND Dibromochloromethane "1.7ND Tetrachloroethene "0.69ND 1,2-Dibromoethane (EDB)"0.78ND 1,1,1,2-Tetrachloroethane "0.70ND Chlorobenzene "0.47ND Page 17 of 21 Project: Project Number: Project Manager: Reported: Terracon - Midvale 6952 S. High Tech Drive, Suite B TER100124-10 DERR Brent Redd Amy AustinMidvale, UT 84047 11-Oct-24 15:17 2470 Impala Drive Carlsbad, CA 92010 760-804-9678 Phone 760-804-9159 Fax H&P Mobile Geochemistry Inc. Result Limit Reporting Units Level Spike Result Source %REC %REC Limits RPD RPD Limit Notes Analyte Volatile Organic Compounds by EPA TO-15 - Quality Control H&P Mobile Geochemistry, Inc. Batch EJ40913 - TO-15 Blank (EJ40913-BLK1)Prepared & Analyzed: 09-Oct-24 Ethylbenzene ug/m30.44ND m,p-Xylene "0.44ND Styrene "0.43ND o-Xylene "0.44ND Bromoform "1.0ND 1,1,2,2-Tetrachloroethane "0.70ND 4-Ethyltoluene "0.50ND 1,3,5-Trimethylbenzene "0.50ND 1,2,4-Trimethylbenzene "0.50ND 1,3-Dichlorobenzene "0.61ND 1,4-Dichlorobenzene "0.61ND 1,2-Dichlorobenzene "0.61ND 1,2,4-Trichlorobenzene "1.9ND Hexachlorobutadiene "2.7ND "214 76-134Surrogate: 1,2-Dichloroethane-d4 99.4212 "208 78-125Surrogate: Toluene-d8 90.9189 "363 77-127Surrogate: 4-Bromofluorobenzene 96.5350 LCS (EJ40913-BS1)Prepared & Analyzed: 09-Oct-24 Dichlorodifluoromethane (F12)ug/m3 101 59-1281131.0114 Vinyl chloride "52.0 64-1271190.1361.7 Chloroethane "53.6 63-1271070.2757.5 Trichlorofluoromethane (F11)"113 62-1261130.56127 1,1-Dichloroethene "80.8 61-13396.70.4078.1 1,1,2-Trichlorotrifluoroethane (F113)"155 66-1261030.77160 Methylene chloride (Dichloromethane)"70.8 62-11599.30.3570.3 trans-1,2-Dichloroethene "80.8 67-12493.20.4075.3 1,1-Dichloroethane "82.4 68-12695.70.4178.8 cis-1,2-Dichloroethene "80.0 70-12192.10.4073.7 Chloroform "99.2 68-12399.30.2598.5 1,1,1-Trichloroethane "111 68-12598.90.55110 1,2-Dichloroethane (EDC)"82.4 65-12899.20.4181.7 Benzene "64.8 69-11994.00.3260.9 Page 18 of 21 Project: Project Number: Project Manager: Reported: Terracon - Midvale 6952 S. High Tech Drive, Suite B TER100124-10 DERR Brent Redd Amy AustinMidvale, UT 84047 11-Oct-24 15:17 2470 Impala Drive Carlsbad, CA 92010 760-804-9678 Phone 760-804-9159 Fax H&P Mobile Geochemistry Inc. Result Limit Reporting Units Level Spike Result Source %REC %REC Limits RPD RPD Limit Notes Analyte Volatile Organic Compounds by EPA TO-15 - Quality Control H&P Mobile Geochemistry, Inc. Batch EJ40913 - TO-15 LCS (EJ40913-BS1)Prepared & Analyzed: 09-Oct-24 Carbon tetrachloride ug/m3 128 68-1321120.64144 Trichloroethene "110 71-12397.90.55107 Toluene "76.8 66-11996.50.7674.1 1,1,2-Trichloroethane "111 73-11995.90.55107 Tetrachloroethene "138 66-12492.10.69127 1,1,1,2-Tetrachloroethane "140 67-1291100.70153 Ethylbenzene "88.4 70-1241010.4489.6 m,p-Xylene "88.4 61-1341140.44101 o-Xylene "88.4 67-12596.70.4485.5 1,1,2,2-Tetrachloroethane "140 65-1271020.70143 "214 76-134Surrogate: 1,2-Dichloroethane-d4 99.8213 "208 78-125Surrogate: Toluene-d8 93.1193 "363 77-127Surrogate: 4-Bromofluorobenzene 104378 LCS Dup (EJ40913-BSD1)Prepared & Analyzed: 09-Oct-24 Dichlorodifluoromethane (F12)ug/m3 101 2559-128113 0.08821.0114 Vinyl chloride "52.0 2564-127117 1.740.1360.7 Chloroethane "53.6 2563-127112 4.680.2760.2 Trichlorofluoromethane (F11)"113 2562-126112 0.4430.56127 1,1-Dichloroethene "80.8 2561-133101 4.040.4081.3 1,1,2-Trichlorotrifluoroethane (F113)"155 2566-126105 2.010.77163 Methylene chloride (Dichloromethane)"70.8 2562-11597.0 2.380.3568.7 trans-1,2-Dichloroethene "80.8 2567-12495.1 2.010.4076.8 1,1-Dichloroethane "82.4 2568-12694.5 1.260.4177.9 cis-1,2-Dichloroethene "80.0 2570-12188.5 3.950.4070.8 Chloroform "99.2 2568-123102 2.720.25101 1,1,1-Trichloroethane "111 2568-12598.3 0.6040.55109 1,2-Dichloroethane (EDC)"82.4 2565-128102 2.780.4184.0 Benzene "64.8 2569-11994.6 0.6360.3261.3 Carbon tetrachloride "128 2568-132112 0.3560.64143 Trichloroethene "110 2571-12396.0 1.950.55105 Toluene "76.8 2566-119100 3.640.7676.9 1,1,2-Trichloroethane "111 2573-11997.4 1.540.55108 Page 19 of 21 Project: Project Number: Project Manager: Reported: Terracon - Midvale 6952 S. High Tech Drive, Suite B TER100124-10 DERR Brent Redd Amy AustinMidvale, UT 84047 11-Oct-24 15:17 2470 Impala Drive Carlsbad, CA 92010 760-804-9678 Phone 760-804-9159 Fax H&P Mobile Geochemistry Inc. Result Limit Reporting Units Level Spike Result Source %REC %REC Limits RPD RPD Limit Notes Analyte Volatile Organic Compounds by EPA TO-15 - Quality Control H&P Mobile Geochemistry, Inc. Batch EJ40913 - TO-15 LCS Dup (EJ40913-BSD1)Prepared & Analyzed: 09-Oct-24 Tetrachloroethene ug/m3 138 2566-12494.2 2.360.69130 1,1,1,2-Tetrachloroethane "140 2567-129117 6.590.70164 Ethylbenzene "88.4 2570-124111 8.820.4497.8 m,p-Xylene "88.4 2561-134118 3.290.44105 o-Xylene "88.4 2567-125104 7.000.4491.7 1,1,2,2-Tetrachloroethane "140 2565-127109 6.000.70152 "214 76-134Surrogate: 1,2-Dichloroethane-d4 102218 "208 78-125Surrogate: Toluene-d8 93.3194 "363 77-127Surrogate: 4-Bromofluorobenzene 106386 Page 20 of 21 Project: Project Number: Project Manager: Reported: Terracon - Midvale 6952 S. High Tech Drive, Suite B TER100124-10 DERR Brent Redd Amy AustinMidvale, UT 84047 11-Oct-24 15:17 2470 Impala Drive Carlsbad, CA 92010 760-804-9678 Phone 760-804-9159 Fax H&P Mobile Geochemistry Inc. Notes and Definitions Percent Recovery Relative Percent DifferenceRPD %REC Method Detection LimitMDL Analyte NOT DETECTED at or above the reporting limitND Leak Check CompoundLCC Appendix H&P Mobile Geochemistry, Inc. is approved as an Environmental Testing Laboratory and Mobile Laboratory in accordance with the DoD -ELAP Program and ISO/IEC 17025:2005 programs through PJLA, accreditation number 69070 for EPA Method TO-15 and H&P 8260SV. H&P is approved by the State of Louisiana Department of Environmental Quality under the National Environmental Laboratory Accreditation Conference (NELAC) certification number 04138 The complete list of stationary and mobile laboratory certifications along with the fields of testing (FOTs) and analyte lists are available at www.handpmg.com/about/certifications. Page 21 of 21