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Home My WebLink AboutDERR-2025-004648 Page 1 ATLAS June 18, 2025 Mr. Mark Crim Utah Department of Environmental Quality Division of Environmental Response and Remediation 195 North 1950 West Salt Lake City, Utah 84114 SUBJECT: Groundwater Monitoring Report Red Duck II 809 28th Street Ogden, Utah Facility ID #1200062 UST Release Site MUZ Work Assignments MUZ-04 UDEQ Technical Services Contract #216364 Dear Mr. Crim: Please find attached a copy of the May 2025 Groundwater Monitoring Report for the above referenced site. INTRODUCTION The work conducted on May 7, 2025, was performed on behalf of the Utah Department Environmental Quality, Division of Environmental Response and Remediation (DERR), under Work Assignment MUZ-04. FIELD PARAMETER WELL PURGING PROCEDURES AND CHEMICAL ANALYSIS The approved work plan included collecting water samples from monitoring wells MW -A through MW -G. The site map depicting the groundwater monitoring well locations and surrounding area features is presented as Figure 1. Prior to well purging, groundwater depths were measured in each well using an electronic water level/free product interface probe. The water level/free product interface probe was decontaminated between each well with an Alconox detergent wash and tap water rinse. Following field parameter measurements, the monitoring wells were purged using new, factory-sealed disposable PVC bailers. All the monitoring wells sampled were purged three well casing volumes or until dry. Groundwater removed from the wells was poured on the ground surface and allowed to evaporate. After the purging process, the wells were allowed to recharge to within 95 percent of the pre-purge water level before groundwater samples were collected. The samples were transferred to appropriate containers and immediately placed on ice in an insulated cooler and then transported under chain-of-custody documentation to a Utah-certified laboratory. The samples were analyzed for methyl tert-butyl ether (MTBE), benzene, toluene, ethyl benzene, total xylenes, naphthalene (MBTEXN) using EPA Method 8260, and for total petroleum hydrocarbons as gasoline (TPH-GRO) TPH as diesel (TPH-DRO) using EPA Method 8015. 358 South 700 East, B518 Salt Lake City, Utah 84102 Office: 801.935.4917 www.oneatlas.com Page 2 ATLAS FIELD PARAM ETER AND CHEMICAL ANALYSIS RESULTS The May 2025 data indicate that groundwater stabilized in MW -D at a depth of 2.51 feet below grade and that a groundwater mound is present near the northern property boundary. Given the shallow depth to groundwater measured in MW -D and similar events occurring during the April 2024, November 2024, and February 2025 groundwater monitoring events, it is likely that the storm drain is compromised in the direct vicinity of MW -D. The groundwater elevation data collected from the monitoring wells were utilized to prepare a groundwater gradient map for the site. The groundwater elevation data indicates groundwater flows to the northwest at a gradient of 0.077 ft/ft between MW -D and MW -F. The groundwater gradient map is presented as Figure 2. Review of the groundwater laboratory data indicated the presence of benzene above the Initial Screening Level (ISL) of 0.005 mg/L in MW -A (0.0153 mg/L), MW -B (0.170 mg/L), MW -C (0.205 mg/L), MW -F (0.0345 mg/L), and MW-G (0.0152 mg/L). No other MBTEXN constituents were measured above their respective ISLs. TPH-GRO was measured at or above the ISL of 1.0 mg/L in MW -B (1.920 mg/L), MW -C (6.720 mg/L), and MW -F (1.030 mg/L); and TPH-DRO was measured at or above the ISL of 1.0 mg/L in MW -C (2.460 mg/L) and MW-G (2.490 mg/L). The groundwater analytical results are summarized in Table 1 and a copy of the analytical report is included in Appendix A. A field duplicate (field blank as described in the work plan) and trip blank were submitted with the primary samples for Quality Assurance/Quality Control (QA/QC). The field duplicate sample was collected/prepared in the field from a new, un-opened 1-gallon container of distilled water purchased from a grocery store. The trip blank was prepared by the laboratory and shipped along with the primary samples. The laboratory analysis of the trip blank and field duplicate indicated no detection of the MBTEXN, TPH-GRO, or TPH-DRO constituents above the laboratory reporting limits. CONCLUSIONS AND RECOMMENDATIONS Review of the groundwater data indicates the presence of benzene, TPH-GRO, and TPH-DRO above their respective ISLs in off-site wells MW -A, MW -B, MW -C, MW -D, MW -F, and MW -G. Based upon the May 2025 laboratory results and historical groundwater monitoring data collected at the site, Atlas recommends the quarterly groundwater monitoring program continue at the site. The Ma y 2025 sampling round was the fourth groundwater monitoring event under Work Assignment MUZ-04. The next groundwater monitoring event is scheduled for August 2025. Our services consist of professional opinions and recommendations made in accordance with generally accepted geotechnical and environmental engineering principles and practices. This warranty is in lieu of all other warranties either expressed or implied. Should you have any questions, please do not hesitate to call us at (801) 935-4917. Page 3 ATLAS Sincerely, Atlas Technical Consultants, LLC Olaf Questereit Jim Coletta, P.G. Senior Technician Branch Manager Utah Certified UST Consultant FIGURES 271EM00890PROJECT NUMBER:DATE:04-24-24 1 FIGURE DRAWN BY:JCAPPROVED BY:BA 358 South 700 East, B518 Salt Lake City, Utah 84102 801-935-4917 MONITORING WELL LOCATION S PROPERTY BOUNDARY ABANDONED MONITORING WELL LOCATION 271EM00890PROJECT NUMBER:DATE:06-11-25 2 FIGURE DRAWN BY:JCAPPROVED BY:JC 358 South 700 East, B518 Salt Lake City, Utah 84102 801-935-4917 MONITORING WELL LOCATION S PROPERTY BOUNDARY ESTIMATED GROUNDWATER CONTOUR LINE MEASURED IN FEET GROUNDWATER ELEVATION IN FEET ABANDONED MONITORING WELL LOCATION 271EM00890PROJECT NUMBER:DATE:06-11-25 3 FIGURE DRAWN BY:JCAPPROVED BY:BA 358 South 700 East, B518 Salt Lake City, Utah 84102 801-935-4917 MONITORING WELL LOCATION S PROPERTY BOUNDARY ESTIMATED BENZENE ISOCONCENTRATION LINE MEASURED IN mg/L BENZENE CONCENTRATION IN mg/L ABANDONED MONITORING WELL LOCATION 271EM00890PROJECT NUMBER:DATE:06-11-25 4 FIGURE DRAWN BY:JCAPPROVED BY:JC 358 South 700 East, B518 Salt Lake City, Utah 84102 801-935-4917 MONITORING WELL LOCATION S PROPERTY BOUNDARY ESTIMATED TPH-GRO ISOCONCENTRATION LINE MEASURED IN mg/L TPH-GRO CONCENTRATION IN mg/L ABANDONED MONITORING WELL LOCATION 271EM00890PROJECT NUMBER:DATE:06-11-25 5 FIGURE DRAWN BY:JCAPPROVED BY:JC 358 South 700 East, B518 Salt Lake City, Utah 84102 801-935-4917 MONITORING WELL LOCATION S PROPERTY BOUNDARY ESTIMATED TPH-DRO ISOCONCENTRATION LINEMEASURED IN mg/L ABANDONED MONITORING WELL LOCATION TABLES SAMPLE ETHYL-NAPH- LOCATION DATE BENZENE TOLUENE BENZENE XYLENES MTBE THALENE TPH-GRO TPH-DRO DTW FPT WTE TOC (ft.)MM/DD/YY (mg/L)(mg/L)(mg/L)(mg/L)(mg/L)(mg/L)(mg/L)(mg/L)(feet)(feet)(feet) Initial Screening Levels 0.005 1.0 0.7 10 0.2 0.7 1.0 1.0 RBCA Tier 1 Screening 0.3 3.0 4.0 10 0.2 0.7 10 10 MW-A 04/16/24 <0.005 <0.012 <0.012 <0.012 <0.005 <0.012 <0.125 <1.0 5.32 0.00 94.04 99.36 08/07/24 0.0015 <0.00100 0.000306 J <0.00100 0.000816 J <0.00500 <0.500 0.502 11.75 0.00 87.61 11/13/24 <0.00100 <0.00100 <0.00100 <0.00300 0.000771 J <0.00500 0.0544 J 0.276 14.54 0.00 84.82 02/04/25 <0.00100 <0.00100 <0.00100 <0.00300 0.000584 J <0.00500 0.0345 B,J 0.383 12.97 0.00 86.39 05/07/25 0.0153 <0.00100 0.00204 0.000461 J 0.000567 J 0.00122 C3,J 0.229 0.335 8.99 0.00 90.37 MW-B 04/16/24 0.128 <0.012 <0.012 <0.012 <0.005 0.018 0.510 <1.0 4.74 0.00 94.74 99.48 08/07/24 0.0515 0.00116 0.00324 0.00226 J 0.000469 J 0.0161 1.560 1.110 11.80 0.00 87.68 11/13/24 0.0337 0.000955 J 0.00137 0.000956 J 0.000674 J 0.00616 1.040 0.590 14.61 0.00 84.87 02/04/25 0.0702 0.000990 J 0.00265 0.00206 J 0.000449 J 0.0217 0.841 1.080 12.76 0.00 86.72 05/07/25 0.170 0.00208 J 0.0143 0.00500 0.000503 J 0.0271 C3 1.920 0.797 8.74 0.00 90.74 MW-C 04/16/24 0.062 <0.012 0.096 0.016 <0.005 0.155 4.09 3.0 6.32 0.00 93.17 99.49 08/07/24 0.177 0.00671 0.106 0.0266 0.000277 J 0.169 7.970 3.840 12.15 0.00 87.34 11/13/24 1.850 Q 0.0180 0.0637 0.0458 0.000819 J 0.136 8.190 Q 3.290 14.83 0.00 84.66 02/04/25 0.334 <0.0200 0.0694 0.0202 J <0.0200 0.144 5.600 3.500 11.89 0.00 87.60 05/07/25 0.205 <0.0200 0.0792 0.0205 J <0.0200 0.143 6.720 2.460 8.37 0.00 91.12 MW-D 04/16/24 <0.005 <0.012 <0.012 <0.012 <0.005 <0.012 <0.125 <1.0 1.23 0.00 98.77 100.00 08/07/24 0.00240 0.000294 J 0.108 0.00752 <0.00100 0.0270 1.480 0.887 11.78 0.00 88.22 11/13/24 <0.00100 Q <0.00100 <0.00100 Q <0.00300 <0.00100 <0.00500 Q <0.100 0.672 2.32 0.00 97.68 02/04/25 <0.00100 <0.00100 <0.00100 <0.00300 <0.00100 <0.00500 0.109 B 0.183 1.97 0.00 98.03 05/07/25 0.000258 J 0.000480 J <0.00100 <0.00300 <0.00100 <0.00500 C3 <0.100 1.120 2.51 0.00 97.49 MW-E 04/16/24 0.005 <0.012 0.023 <0.012 <0.005 0.127 0.918 2.3 6.49 0.00 93.37 99.86 08/07/24 0.00160 0.000322 J 0.00311 0.000199 J <0.00100 0.0195 0.519 0.535 12.35 0.00 87.51 11/13/24 <0.00100 <0.00100 <0.00100 <0.00300 <0.00100 <0.00500 <0.100 <0.100 13.98 0.00 85.88 02/04/25 0.000135 J <0.00100 <0.00100 <0.00300 <0.00100 <0.00500 0.0490 B,J 0.0777 J 12.53 0.00 87.33 05/07/25 0.00367 0.000334 J 0.0101 0.000850 J <0.00100 0.0479 C3 0.693 0.960 9.56 0.00 90.30 MW-F 04/16/24 0.107 <0.012 0.013 <0.012 <0.005 0.084 1.67 2.5 7.81 0.00 90.36 98.17 08/07/24 0.113 0.00316 0.00809 0.00250 J 0.00178 0.0869 2.140 2.470 13.82 0.00 84.35 11/13/24 0.00238 <0.00100 <0.00100 <0.00300 <0.00100 <0.00500 1.780 <0.100 15.81 0.00 82.36 02/04/25 0.0808 0.00127 0.00793 0.00224 J <0.00100 0.0219 1.690 1.180 14.57 0.00 83.60 05/07/25 0.0345 0.000609 J 0.00300 0.000997 J 0.000808 J 0.0119 C3 1.030 0.624 10.73 0.00 87.44 MW-G 04/16/24 0.190 <0.012 0.065 <0.012 <0.005 0.304 2.70 4.4 6.58 0.00 92.43 99.01 08/07/24 0.0957 0.00244 0.00369 0.00284 J 0.00129 0.0585 1.000 2.160 12.89 0.00 86.12 11/13/24 0.00270 <0.00100 0.000493 J <0.00300 0.000895 J 0.00128 J 0.667 0.355 Q 15.38 0.00 83.63 02/04/25 0.00100 J <0.00100 <0.00100 <0.00300 0.000797 J <0.00500 0.229 B 0.893 13.87 0.00 85.14 05/07/25 0.0152 0.000300 J 0.00185 0.000543 J 0.000809 J 0.00325 C3,J 0.648 2.490 9.97 0.00 89.04 Notes: TPH -GRO = Total Petroleum Hydrocarbons as Gasoline mg/L = Milligrams per Liter TPH -DRO = Total Petroleum Hydrocarbons as Diesel DTW = Depth to Water TOC = Top of Casing, Monitoring Well Surveyed Elevation NA = Not Analyzed < = Not detected above the laboratory reporting limit WTE = Water Table Elevation RBCA = Risk Based Corrective Action FPT = Free Product Thickness Bold numbers indicate an exceedence of the Initial Screening Level Q = Sample was prepared and/or analyzed past holding time as defined in the method. Concentrations should be considered minimum values. C3 = The reported concentration is an estimate. The continuing calibration standard associated with this data responded low. Method sensitivity check is acceptable. FACILITY I.D. 12000062, LUST I.D. MUZ TABLE 1 GROUNDWATER ANALYTICAL AND ELEVATION DATA SUMMARY RED DUCK II 809 28TH STREET OGDEN, UTAH APPENDIX A LABORATORY ANALYTICAL REPORT ANALYTICAL REPORT May 20, 2025 One Atlas Sample Delivery Group:L1857322 Samples Received:05/09/2025 Project Number: Description:Red Duck II Report To:Jim Coletta 1775 South 4130 West, Ste A Salt Lake City, UT 84104 Entire Report Reviewed By: May 20, 2025 [Preliminary Report] Daphne Richards Project Manager Results relate only to the items tested or calibrated and are reported as rounded values. This test report shall not be reproduced, except in full, without written approval of the laboratory. Where applicable, sampling conducted by Pace Analytical National is performed per guidance provided in laboratory standard operating procedures ENV-SOP-MTJL-0067 and ENV-SOP-MTJL-0068. Where sampling conducted by the customer, results relate to the accuracy of the information provided, and as the samples are received. Pace Analytical National 12065 Lebanon Rd Mount Juliet, TN 37122 615-758-5858 800-767-5859 mydata.pacelabs.com 1 Cp 2 Tc 3 Ss 4 Cn 5 Sr 6 Qc 7 Gl 8 Al 9 Sc ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/20/25 16:55 1 of 25 May 21, 2025 Daphne Richards Project Manager ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/21/25 09:53 1 of 25 TABLE OF CONTENTS Cp: Cover Page 1 Tc: Table of Contents 2 Ss: Sample Summary 3 Cn: Case Narrative 5 Sr: Sample Results 6 MW-A L1857322-01 6 MW-B L1857322-02 7 MW-C L1857322-03 8 MW-D L1857322-04 9 MW-E L1857322-05 10 MW-F L1857322-06 11 MW-G L1857322-07 12 FIELD BLANK L1857322-08 13 TRIP BLANK L1857322-09 14 Qc: Quality Control Summary 15 Volatile Organic Compounds (GC) by Method 8015D/GRO 15 Volatile Organic Compounds (GC/MS) by Method 8260B 18 Semi-Volatile Organic Compounds (GC) by Method 8015D 22 Gl: Glossary of Terms 23 Al: Accreditations & Locations 24 Sc: Sample Chain of Custody 25 1 Cp 2 Tc 3 Ss 4 Cn 5 Sr 6 Qc 7 Gl 8 Al 9 Sc ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/20/25 16:55 2 of 25 ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/21/25 09:53 2 of 25 SAMPLE SUMMARY Collected by Collected date/time Received date/time MW-A L1857322-01 Olaf Questereit 05/07/25 13:15 05/09/25 08:00 Method Batch Dilution Preparation Analysis Analyst Location date/time date/time Volatile Organic Compounds (GC) by Method 8015D/GRO WG2512677 1 05/12/25 06:43 05/12/25 06:43 NCD Mt. Juliet, TN Volatile Organic Compounds (GC/MS) by Method 8260B WG2516732 1 05/16/25 17:53 05/16/25 17:53 ACG Mt. Juliet, TN Semi-Volatile Organic Compounds (GC) by Method 8015D WG2514752 1 05/17/25 11:44 05/17/25 20:25 MAA Mt. Juliet, TN Collected by Collected date/time Received date/time MW-B L1857322-02 Olaf Questereit 05/07/25 13:30 05/09/25 08:00 Method Batch Dilution Preparation Analysis Analyst Location date/time date/time Volatile Organic Compounds (GC) by Method 8015D/GRO WG2512677 1 05/12/25 07:06 05/12/25 07:06 NCD Mt. Juliet, TN Volatile Organic Compounds (GC/MS) by Method 8260B WG2512640 1 05/12/25 00:16 05/12/25 00:16 DYW Mt. Juliet, TN Volatile Organic Compounds (GC/MS) by Method 8260B WG2518679 5 05/20/25 02:45 05/20/25 02:45 JHH Mt. Juliet, TN Semi-Volatile Organic Compounds (GC) by Method 8015D WG2514752 1 05/17/25 11:44 05/17/25 20:47 MAA Mt. Juliet, TN Collected by Collected date/time Received date/time MW-C L1857322-03 Olaf Questereit 05/07/25 13:45 05/09/25 08:00 Method Batch Dilution Preparation Analysis Analyst Location date/time date/time Volatile Organic Compounds (GC) by Method 8015D/GRO WG2512677 1 05/12/25 07:29 05/12/25 07:29 NCD Mt. Juliet, TN Volatile Organic Compounds (GC/MS) by Method 8260B WG2512962 20 05/12/25 19:04 05/12/25 19:04 DYW Mt. Juliet, TN Semi-Volatile Organic Compounds (GC) by Method 8015D WG2514752 1 05/17/25 11:44 05/17/25 21:09 MAA Mt. Juliet, TN Collected by Collected date/time Received date/time MW-D L1857322-04 Olaf Questereit 05/07/25 13:00 05/09/25 08:00 Method Batch Dilution Preparation Analysis Analyst Location date/time date/time Volatile Organic Compounds (GC) by Method 8015D/GRO WG2518759 1 05/20/25 00:42 05/20/25 00:42 JHH Mt. Juliet, TN Volatile Organic Compounds (GC/MS) by Method 8260B WG2512640 1 05/12/25 00:36 05/12/25 00:36 DYW Mt. Juliet, TN Volatile Organic Compounds (GC/MS) by Method 8260B WG2516732 1 05/16/25 18:16 05/16/25 18:16 ACG Mt. Juliet, TN Semi-Volatile Organic Compounds (GC) by Method 8015D WG2514752 1 05/17/25 11:44 05/17/25 21:31 MAA Mt. Juliet, TN Collected by Collected date/time Received date/time MW-E L1857322-05 Olaf Questereit 05/07/25 14:30 05/09/25 08:00 Method Batch Dilution Preparation Analysis Analyst Location date/time date/time Volatile Organic Compounds (GC) by Method 8015D/GRO WG2512677 1 05/12/25 08:16 05/12/25 08:16 NCD Mt. Juliet, TN Volatile Organic Compounds (GC/MS) by Method 8260B WG2512640 1 05/12/25 00:56 05/12/25 00:56 DYW Mt. Juliet, TN Volatile Organic Compounds (GC/MS) by Method 8260B WG2516732 1 05/16/25 18:38 05/16/25 18:38 ACG Mt. Juliet, TN Semi-Volatile Organic Compounds (GC) by Method 8015D WG2514752 1 05/17/25 11:44 05/17/25 21:53 MAA Mt. Juliet, TN Collected by Collected date/time Received date/time MW-F L1857322-06 Olaf Questereit 05/07/25 14:45 05/09/25 08:00 Method Batch Dilution Preparation Analysis Analyst Location date/time date/time Volatile Organic Compounds (GC) by Method 8015D/GRO WG2513636 1 05/13/25 15:30 05/13/25 15:30 CDD Mt. Juliet, TN Volatile Organic Compounds (GC/MS) by Method 8260B WG2512640 1 05/12/25 01:16 05/12/25 01:16 DYW Mt. Juliet, TN Volatile Organic Compounds (GC/MS) by Method 8260B WG2516732 1 05/16/25 19:00 05/16/25 19:00 ACG Mt. Juliet, TN Semi-Volatile Organic Compounds (GC) by Method 8015D WG2514752 1 05/17/25 11:44 05/17/25 22:15 MAA Mt. Juliet, TN 1 Cp 2 Tc 3 Ss 4 Cn 5 Sr 6 Qc 7 Gl 8 Al 9 Sc ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/20/25 16:55 3 of 25 ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/21/25 09:53 3 of 25 SAMPLE SUMMARY Collected by Collected date/time Received date/time MW-G L1857322-07 Olaf Questereit 05/07/25 14:15 05/09/25 08:00 Method Batch Dilution Preparation Analysis Analyst Location date/time date/time Volatile Organic Compounds (GC) by Method 8015D/GRO WG2513636 1 05/13/25 15:53 05/13/25 15:53 CDD Mt. Juliet, TN Volatile Organic Compounds (GC/MS) by Method 8260B WG2512640 1 05/12/25 01:37 05/12/25 01:37 DYW Mt. Juliet, TN Volatile Organic Compounds (GC/MS) by Method 8260B WG2516732 1 05/16/25 19:22 05/16/25 19:22 ACG Mt. Juliet, TN Semi-Volatile Organic Compounds (GC) by Method 8015D WG2514752 1 05/17/25 11:44 05/17/25 22:37 MAA Mt. Juliet, TN Collected by Collected date/time Received date/time FIELD BLANK L1857322-08 Olaf Questereit 05/07/25 14:00 05/09/25 08:00 Method Batch Dilution Preparation Analysis Analyst Location date/time date/time Volatile Organic Compounds (GC) by Method 8015D/GRO WG2513636 1 05/13/25 16:16 05/13/25 16:16 CDD Mt. Juliet, TN Volatile Organic Compounds (GC/MS) by Method 8260B WG2512640 1 05/11/25 22:35 05/11/25 22:35 DYW Mt. Juliet, TN Semi-Volatile Organic Compounds (GC) by Method 8015D WG2514752 1 05/17/25 11:44 05/17/25 22:59 MAA Mt. Juliet, TN Collected by Collected date/time Received date/time TRIP BLANK L1857322-09 Olaf Questereit 05/07/25 00:00 05/09/25 08:00 Method Batch Dilution Preparation Analysis Analyst Location date/time date/time Volatile Organic Compounds (GC/MS) by Method 8260B WG2512640 1 05/11/25 22:15 05/11/25 22:15 DYW Mt. Juliet, TN 1 Cp 2 Tc 3 Ss 4 Cn 5 Sr 6 Qc 7 Gl 8 Al 9 Sc ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/20/25 16:55 4 of 25 ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/21/25 09:53 4 of 25 CASE NARRATIVE All sample aliquots were received at the correct temperature, in the proper containers, with the appropriate preservatives, and within method specified holding times, unless qualified or notated within the report. Where applicable, all MDL (LOD) and RDL (LOQ) values reported for environmental samples have been corrected for the dilution factor used in the analysis. All Method and Batch Quality Control are within established criteria except where addressed in this case narrative, a non-conformance form or properly qualified within the sample results. By my digital signature below, I affirm to the best of my knowledge, all problems/anomalies observed by the laboratory as having the potential to affect the quality of the data have been identified by the laboratory, and no information or data have been knowingly withheld that would affect the quality of the data. [Preliminary Report] Daphne Richards Project Manager 1 Cp 2 Tc 3 Ss 4 Cn 5 Sr 6 Qc 7 Gl 8 Al 9 Sc ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/20/25 16:55 5 of 25 Daphne Richards Project Manager ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/21/25 09:53 5 of 25 SAMPLE RESULTS - 01 L1857322 MW-A Collected date/time: 05/07/25 13:15 Volatile Organic Compounds (GC) by Method 8015D/GRO Result Qualifier MDL RDL Dilution Analysis Batch Analyte ug/l ug/l ug/l date / time TPH (GC/FID) Low Fraction 229 31.4 100 1 05/12/2025 06:43 WG2512677 (S) a,a,a-Trifluorotoluene(FID)91.4 78.0-120 05/12/2025 06:43 WG2512677 Volatile Organic Compounds (GC/MS) by Method 8260B Result Qualifier MDL RDL Dilution Analysis Batch Analyte ug/l ug/l ug/l date / time Benzene 15.3 0.0941 1.00 1 05/16/2025 17:53 WG2516732 Toluene U 0.278 1.00 1 05/16/2025 17:53 WG2516732 Ethylbenzene 2.04 0.137 1.00 1 05/16/2025 17:53 WG2516732 Total Xylenes 0.461 J 0.174 3.00 1 05/16/2025 17:53 WG2516732 Methyl tert-butyl ether 0.567 J 0.101 1.00 1 05/16/2025 17:53 WG2516732 Naphthalene 1.22 C3 J 1.00 5.00 1 05/16/2025 17:53 WG2516732 (S) Toluene-d8 104 80.0-120 05/16/2025 17:53 WG2516732 (S) 4-Bromofluorobenzene 105 77.0-126 05/16/2025 17:53 WG2516732 (S) 1,2-Dichloroethane-d4 103 70.0-130 05/16/2025 17:53 WG2516732 Semi-Volatile Organic Compounds (GC) by Method 8015D Result Qualifier MDL RDL Dilution Analysis Batch Analyte ug/l ug/l ug/l date / time TPH (GC/FID) High Fraction 335 60.5 100 1 05/17/2025 20:25 WG2514752 (S) o-Terphenyl 128 52.0-156 05/17/2025 20:25 WG2514752 1 Cp 2 Tc 3 Ss 4 Cn 5 Sr 6 Qc 7 Gl 8 Al 9 Sc ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/20/25 16:55 6 of 25 ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/21/25 09:53 6 of 25 SAMPLE RESULTS - 02 L1857322 MW-B Collected date/time: 05/07/25 13:30 Volatile Organic Compounds (GC) by Method 8015D/GRO Result Qualifier MDL RDL Dilution Analysis Batch Analyte ug/l ug/l ug/l date / time TPH (GC/FID) Low Fraction 1920 31.4 100 1 05/12/2025 07:06 WG2512677 (S) a,a,a-Trifluorotoluene(FID)95.5 78.0-120 05/12/2025 07:06 WG2512677 Volatile Organic Compounds (GC/MS) by Method 8260B Result Qualifier MDL RDL Dilution Analysis Batch Analyte ug/l ug/l ug/l date / time Benzene 170 0.0941 1.00 1 05/12/2025 00:16 WG2512640 Toluene 2.08 J 1.39 5.00 5 05/20/2025 02:45 WG2518679 Ethylbenzene 14.3 0.137 1.00 1 05/12/2025 00:16 WG2512640 Total Xylenes 5.00 0.174 3.00 1 05/12/2025 00:16 WG2512640 Methyl tert-butyl ether 0.503 J 0.101 1.00 1 05/12/2025 00:16 WG2512640 Naphthalene 27.1 C3 1.00 5.00 1 05/12/2025 00:16 WG2512640 (S) Toluene-d8 103 80.0-120 05/12/2025 00:16 WG2512640 (S) Toluene-d8 96.4 80.0-120 05/20/2025 02:45 WG2518679 (S) 4-Bromofluorobenzene 97.3 77.0-126 05/12/2025 00:16 WG2512640 (S) 4-Bromofluorobenzene 98.4 77.0-126 05/20/2025 02:45 WG2518679 (S) 1,2-Dichloroethane-d4 115 70.0-130 05/12/2025 00:16 WG2512640 (S) 1,2-Dichloroethane-d4 96.6 70.0-130 05/20/2025 02:45 WG2518679 Semi-Volatile Organic Compounds (GC) by Method 8015D Result Qualifier MDL RDL Dilution Analysis Batch Analyte ug/l ug/l ug/l date / time TPH (GC/FID) High Fraction 797 60.5 100 1 05/17/2025 20:47 WG2514752 (S) o-Terphenyl 123 52.0-156 05/17/2025 20:47 WG2514752 1 Cp 2 Tc 3 Ss 4 Cn 5 Sr 6 Qc 7 Gl 8 Al 9 Sc ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/20/25 16:55 7 of 25 ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/21/25 09:53 7 of 25 SAMPLE RESULTS - 03 L1857322 MW-C Collected date/time: 05/07/25 13:45 Volatile Organic Compounds (GC) by Method 8015D/GRO Result Qualifier MDL RDL Dilution Analysis Batch Analyte ug/l ug/l ug/l date / time TPH (GC/FID) Low Fraction 6720 31.4 100 1 05/12/2025 07:29 WG2512677 (S) a,a,a-Trifluorotoluene(FID)117 78.0-120 05/12/2025 07:29 WG2512677 Volatile Organic Compounds (GC/MS) by Method 8260B Result Qualifier MDL RDL Dilution Analysis Batch Analyte ug/l ug/l ug/l date / time Benzene 205 1.88 20.0 20 05/12/2025 19:04 WG2512962 Toluene U 5.56 20.0 20 05/12/2025 19:04 WG2512962 Ethylbenzene 79.2 2.74 20.0 20 05/12/2025 19:04 WG2512962 Total Xylenes 20.5 J 3.48 60.0 20 05/12/2025 19:04 WG2512962 Methyl tert-butyl ether U 2.02 20.0 20 05/12/2025 19:04 WG2512962 Naphthalene 143 20.0 100 20 05/12/2025 19:04 WG2512962 (S) Toluene-d8 107 80.0-120 05/12/2025 19:04 WG2512962 (S) 4-Bromofluorobenzene 102 77.0-126 05/12/2025 19:04 WG2512962 (S) 1,2-Dichloroethane-d4 101 70.0-130 05/12/2025 19:04 WG2512962 Semi-Volatile Organic Compounds (GC) by Method 8015D Result Qualifier MDL RDL Dilution Analysis Batch Analyte ug/l ug/l ug/l date / time TPH (GC/FID) High Fraction 2460 60.5 100 1 05/17/2025 21:09 WG2514752 (S) o-Terphenyl 143 52.0-156 05/17/2025 21:09 WG2514752 1 Cp 2 Tc 3 Ss 4 Cn 5 Sr 6 Qc 7 Gl 8 Al 9 Sc ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/20/25 16:55 8 of 25 ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/21/25 09:53 8 of 25 SAMPLE RESULTS - 04 L1857322 MW-D Collected date/time: 05/07/25 13:00 Volatile Organic Compounds (GC) by Method 8015D/GRO Result Qualifier MDL RDL Dilution Analysis Batch Analyte ug/l ug/l ug/l date / time TPH (GC/FID) Low Fraction U 31.4 100 1 05/20/2025 00:42 WG2518759 (S) a,a,a-Trifluorotoluene(FID)120 78.0-120 05/20/2025 00:42 WG2518759 Volatile Organic Compounds (GC/MS) by Method 8260B Result Qualifier MDL RDL Dilution Analysis Batch Analyte ug/l ug/l ug/l date / time Benzene 0.258 J 0.0941 1.00 1 05/16/2025 18:16 WG2516732 Toluene 0.480 J 0.278 1.00 1 05/16/2025 18:16 WG2516732 Ethylbenzene U 0.137 1.00 1 05/16/2025 18:16 WG2516732 Total Xylenes U 0.174 3.00 1 05/16/2025 18:16 WG2516732 Methyl tert-butyl ether U 0.101 1.00 1 05/12/2025 00:36 WG2512640 Naphthalene U C3 1.00 5.00 1 05/16/2025 18:16 WG2516732 (S) Toluene-d8 106 80.0-120 05/12/2025 00:36 WG2512640 (S) Toluene-d8 106 80.0-120 05/16/2025 18:16 WG2516732 (S) 4-Bromofluorobenzene 96.3 77.0-126 05/12/2025 00:36 WG2512640 (S) 4-Bromofluorobenzene 109 77.0-126 05/16/2025 18:16 WG2516732 (S) 1,2-Dichloroethane-d4 111 70.0-130 05/12/2025 00:36 WG2512640 (S) 1,2-Dichloroethane-d4 100 70.0-130 05/16/2025 18:16 WG2516732 Semi-Volatile Organic Compounds (GC) by Method 8015D Result Qualifier MDL RDL Dilution Analysis Batch Analyte ug/l ug/l ug/l date / time TPH (GC/FID) High Fraction 1120 60.5 100 1 05/17/2025 21:31 WG2514752 (S) o-Terphenyl 127 52.0-156 05/17/2025 21:31 WG2514752 1 Cp 2 Tc 3 Ss 4 Cn 5 Sr 6 Qc 7 Gl 8 Al 9 Sc ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/20/25 16:55 9 of 25 ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/21/25 09:53 9 of 25 SAMPLE RESULTS - 05 L1857322 MW-E Collected date/time: 05/07/25 14:30 Volatile Organic Compounds (GC) by Method 8015D/GRO Result Qualifier MDL RDL Dilution Analysis Batch Analyte ug/l ug/l ug/l date / time TPH (GC/FID) Low Fraction 693 31.4 100 1 05/12/2025 08:16 WG2512677 (S) a,a,a-Trifluorotoluene(FID)96.2 78.0-120 05/12/2025 08:16 WG2512677 Volatile Organic Compounds (GC/MS) by Method 8260B Result Qualifier MDL RDL Dilution Analysis Batch Analyte ug/l ug/l ug/l date / time Benzene 3.67 0.0941 1.00 1 05/12/2025 00:56 WG2512640 Toluene 0.334 J 0.278 1.00 1 05/16/2025 18:38 WG2516732 Ethylbenzene 10.1 0.137 1.00 1 05/12/2025 00:56 WG2512640 Total Xylenes 0.850 J 0.174 3.00 1 05/12/2025 00:56 WG2512640 Methyl tert-butyl ether U 0.101 1.00 1 05/12/2025 00:56 WG2512640 Naphthalene 47.9 C3 1.00 5.00 1 05/12/2025 00:56 WG2512640 (S) Toluene-d8 101 80.0-120 05/12/2025 00:56 WG2512640 (S) Toluene-d8 101 80.0-120 05/16/2025 18:38 WG2516732 (S) 4-Bromofluorobenzene 95.9 77.0-126 05/12/2025 00:56 WG2512640 (S) 4-Bromofluorobenzene 102 77.0-126 05/16/2025 18:38 WG2516732 (S) 1,2-Dichloroethane-d4 109 70.0-130 05/12/2025 00:56 WG2512640 (S) 1,2-Dichloroethane-d4 102 70.0-130 05/16/2025 18:38 WG2516732 Semi-Volatile Organic Compounds (GC) by Method 8015D Result Qualifier MDL RDL Dilution Analysis Batch Analyte ug/l ug/l ug/l date / time TPH (GC/FID) High Fraction 960 60.5 100 1 05/17/2025 21:53 WG2514752 (S) o-Terphenyl 121 52.0-156 05/17/2025 21:53 WG2514752 1 Cp 2 Tc 3 Ss 4 Cn 5 Sr 6 Qc 7 Gl 8 Al 9 Sc ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/20/25 16:55 10 of 25 ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/21/25 09:53 10 of 25 SAMPLE RESULTS - 06 L1857322 MW-F Collected date/time: 05/07/25 14:45 Volatile Organic Compounds (GC) by Method 8015D/GRO Result Qualifier MDL RDL Dilution Analysis Batch Analyte ug/l ug/l ug/l date / time TPH (GC/FID) Low Fraction 1030 31.4 100 1 05/13/2025 15:30 WG2513636 (S) a,a,a-Trifluorotoluene(FID)111 78.0-120 05/13/2025 15:30 WG2513636 Volatile Organic Compounds (GC/MS) by Method 8260B Result Qualifier MDL RDL Dilution Analysis Batch Analyte ug/l ug/l ug/l date / time Benzene 34.5 0.0941 1.00 1 05/12/2025 01:16 WG2512640 Toluene 0.609 J 0.278 1.00 1 05/16/2025 19:00 WG2516732 Ethylbenzene 3.00 0.137 1.00 1 05/12/2025 01:16 WG2512640 Total Xylenes 0.997 J 0.174 3.00 1 05/12/2025 01:16 WG2512640 Methyl tert-butyl ether 0.808 J 0.101 1.00 1 05/12/2025 01:16 WG2512640 Naphthalene 11.9 C3 1.00 5.00 1 05/12/2025 01:16 WG2512640 (S) Toluene-d8 98.6 80.0-120 05/12/2025 01:16 WG2512640 (S) Toluene-d8 103 80.0-120 05/16/2025 19:00 WG2516732 (S) 4-Bromofluorobenzene 95.5 77.0-126 05/12/2025 01:16 WG2512640 (S) 4-Bromofluorobenzene 106 77.0-126 05/16/2025 19:00 WG2516732 (S) 1,2-Dichloroethane-d4 113 70.0-130 05/12/2025 01:16 WG2512640 (S) 1,2-Dichloroethane-d4 101 70.0-130 05/16/2025 19:00 WG2516732 Semi-Volatile Organic Compounds (GC) by Method 8015D Result Qualifier MDL RDL Dilution Analysis Batch Analyte ug/l ug/l ug/l date / time TPH (GC/FID) High Fraction 624 60.5 100 1 05/17/2025 22:15 WG2514752 (S) o-Terphenyl 137 52.0-156 05/17/2025 22:15 WG2514752 1 Cp 2 Tc 3 Ss 4 Cn 5 Sr 6 Qc 7 Gl 8 Al 9 Sc ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/20/25 16:55 11 of 25 ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/21/25 09:53 11 of 25 SAMPLE RESULTS - 07 L1857322 MW-G Collected date/time: 05/07/25 14:15 Volatile Organic Compounds (GC) by Method 8015D/GRO Result Qualifier MDL RDL Dilution Analysis Batch Analyte ug/l ug/l ug/l date / time TPH (GC/FID) Low Fraction 648 31.4 100 1 05/13/2025 15:53 WG2513636 (S) a,a,a-Trifluorotoluene(FID)91.6 78.0-120 05/13/2025 15:53 WG2513636 Volatile Organic Compounds (GC/MS) by Method 8260B Result Qualifier MDL RDL Dilution Analysis Batch Analyte ug/l ug/l ug/l date / time Benzene 15.2 0.0941 1.00 1 05/12/2025 01:37 WG2512640 Toluene 0.300 J 0.278 1.00 1 05/16/2025 19:22 WG2516732 Ethylbenzene 1.85 0.137 1.00 1 05/12/2025 01:37 WG2512640 Total Xylenes 0.543 J 0.174 3.00 1 05/12/2025 01:37 WG2512640 Methyl tert-butyl ether 0.809 J 0.101 1.00 1 05/12/2025 01:37 WG2512640 Naphthalene 3.25 C3 J 1.00 5.00 1 05/12/2025 01:37 WG2512640 (S) Toluene-d8 100 80.0-120 05/12/2025 01:37 WG2512640 (S) Toluene-d8 106 80.0-120 05/16/2025 19:22 WG2516732 (S) 4-Bromofluorobenzene 97.4 77.0-126 05/12/2025 01:37 WG2512640 (S) 4-Bromofluorobenzene 109 77.0-126 05/16/2025 19:22 WG2516732 (S) 1,2-Dichloroethane-d4 111 70.0-130 05/12/2025 01:37 WG2512640 (S) 1,2-Dichloroethane-d4 101 70.0-130 05/16/2025 19:22 WG2516732 Semi-Volatile Organic Compounds (GC) by Method 8015D Result Qualifier MDL RDL Dilution Analysis Batch Analyte ug/l ug/l ug/l date / time TPH (GC/FID) High Fraction 2490 60.5 100 1 05/17/2025 22:37 WG2514752 (S) o-Terphenyl 126 52.0-156 05/17/2025 22:37 WG2514752 1 Cp 2 Tc 3 Ss 4 Cn 5 Sr 6 Qc 7 Gl 8 Al 9 Sc ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/20/25 16:55 12 of 25 ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/21/25 09:53 12 of 25 SAMPLE RESULTS - 08 L1857322 FIELD BLANK Collected date/time: 05/07/25 14:00 Volatile Organic Compounds (GC) by Method 8015D/GRO Result Qualifier MDL RDL Dilution Analysis Batch Analyte ug/l ug/l ug/l date / time TPH (GC/FID) Low Fraction U 31.4 100 1 05/13/2025 16:16 WG2513636 (S) a,a,a-Trifluorotoluene(FID)92.6 78.0-120 05/13/2025 16:16 WG2513636 Volatile Organic Compounds (GC/MS) by Method 8260B Result Qualifier MDL RDL Dilution Analysis Batch Analyte ug/l ug/l ug/l date / time Benzene U 0.0941 1.00 1 05/11/2025 22:35 WG2512640 Toluene U 0.278 1.00 1 05/11/2025 22:35 WG2512640 Ethylbenzene U 0.137 1.00 1 05/11/2025 22:35 WG2512640 Total Xylenes U 0.174 3.00 1 05/11/2025 22:35 WG2512640 Methyl tert-butyl ether U 0.101 1.00 1 05/11/2025 22:35 WG2512640 Naphthalene U C3 1.00 5.00 1 05/11/2025 22:35 WG2512640 (S) Toluene-d8 102 80.0-120 05/11/2025 22:35 WG2512640 (S) 4-Bromofluorobenzene 93.4 77.0-126 05/11/2025 22:35 WG2512640 (S) 1,2-Dichloroethane-d4 122 70.0-130 05/11/2025 22:35 WG2512640 Semi-Volatile Organic Compounds (GC) by Method 8015D Result Qualifier MDL RDL Dilution Analysis Batch Analyte ug/l ug/l ug/l date / time TPH (GC/FID) High Fraction U 60.5 100 1 05/17/2025 22:59 WG2514752 (S) o-Terphenyl 129 52.0-156 05/17/2025 22:59 WG2514752 1 Cp 2 Tc 3 Ss 4 Cn 5 Sr 6 Qc 7 Gl 8 Al 9 Sc ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/20/25 16:55 13 of 25 ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/21/25 09:53 13 of 25 SAMPLE RESULTS - 09 L1857322 TRIP BLANK Collected date/time: 05/07/25 00:00 Volatile Organic Compounds (GC/MS) by Method 8260B Result Qualifier MDL RDL Dilution Analysis Batch Analyte ug/l ug/l ug/l date / time Benzene U 0.0941 1.00 1 05/11/2025 22:15 WG2512640 Toluene U 0.278 1.00 1 05/11/2025 22:15 WG2512640 Ethylbenzene U 0.137 1.00 1 05/11/2025 22:15 WG2512640 Total Xylenes U 0.174 3.00 1 05/11/2025 22:15 WG2512640 Methyl tert-butyl ether U 0.101 1.00 1 05/11/2025 22:15 WG2512640 Naphthalene U C3 1.00 5.00 1 05/11/2025 22:15 WG2512640 (S) Toluene-d8 103 80.0-120 05/11/2025 22:15 WG2512640 (S) 4-Bromofluorobenzene 92.6 77.0-126 05/11/2025 22:15 WG2512640 (S) 1,2-Dichloroethane-d4 124 70.0-130 05/11/2025 22:15 WG2512640 1 Cp 2 Tc 3 Ss 4 Cn 5 Sr 6 Qc 7 Gl 8 Al 9 Sc ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/20/25 16:55 14 of 25 ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/21/25 09:53 14 of 25 QUALITY CONTROL SUMMARYWG2512677 Volatile Organic Compounds (GC) by Method 8015D/GRO L1857322-01,02,03,05 Method Blank (MB) (MB) R4217102-2 05/12/25 01:30 MB Result MB Qualifier MB MDL MB RDL Analyte ug/l ug/l ug/l TPH (GC/FID) Low Fraction U 31.4 100 (S) a,a,a-Trifluorotoluene(FID)90.8 78.0-120 Laboratory Control Sample (LCS) (LCS) R4217102-1 05/12/25 00:33 Spike Amount LCS Result LCS Rec.Rec. Limits LCS Qualifier Analyte ug/l ug/l %% TPH (GC/FID) Low Fraction 5000 5380 108 72.0-127 (S) a,a,a-Trifluorotoluene(FID) 95.3 78.0-120 1 Cp 2 Tc 3 Ss 4 Cn 5 Sr 6 Qc 7 Gl 8 Al 9 Sc ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/20/25 16:55 15 of 25 ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/21/25 09:53 15 of 25 QUALITY CONTROL SUMMARYWG2513636 Volatile Organic Compounds (GC) by Method 8015D/GRO L1857322-06,07,08 Method Blank (MB) (MB) R4213896-4 05/13/25 10:07 MB Result MB Qualifier MB MDL MB RDL Analyte ug/l ug/l ug/l TPH (GC/FID) Low Fraction U 31.4 100 (S) a,a,a-Trifluorotoluene(FID)91.8 78.0-120 Laboratory Control Sample (LCS) • Laboratory Control Sample Duplicate (LCSD) (LCS) R4213896-2 05/13/25 08:57 • (LCSD) R4213896-3 05/13/25 09:20 Spike Amount LCS Result LCSD Result LCS Rec.LCSD Rec.Rec. Limits LCS Qualifier LCSD Qualifier RPD RPD Limits Analyte ug/l ug/l ug/l %%%%% TPH (GC/FID) Low Fraction 5000 5350 5500 107 110 72.0-127 2.76 20 (S) a,a,a-Trifluorotoluene(FID) 94.2 94.5 78.0-120 1 Cp 2 Tc 3 Ss 4 Cn 5 Sr 6 Qc 7 Gl 8 Al 9 Sc ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/20/25 16:55 16 of 25 ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/21/25 09:53 16 of 25 QUALITY CONTROL SUMMARYWG2518759 Volatile Organic Compounds (GC) by Method 8015D/GRO L1857322-04 Method Blank (MB) (MB) R4217323-2 05/19/25 21:02 MB Result MB Qualifier MB MDL MB RDL Analyte ug/l ug/l ug/l TPH (GC/FID) Low Fraction 35.7 J 31.4 100 (S) a,a,a-Trifluorotoluene(FID)120 78.0-120 Laboratory Control Sample (LCS) (LCS) R4217323-1 05/19/25 20:13 Spike Amount LCS Result LCS Rec.Rec. Limits LCS Qualifier Analyte ug/l ug/l %% TPH (GC/FID) Low Fraction 5000 5280 106 72.0-127 (S) a,a,a-Trifluorotoluene(FID) 116 78.0-120 1 Cp 2 Tc 3 Ss 4 Cn 5 Sr 6 Qc 7 Gl 8 Al 9 Sc ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/20/25 16:55 17 of 25 ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/21/25 09:53 17 of 25 QUALITY CONTROL SUMMARYWG2512640 Volatile Organic Compounds (GC/MS) by Method 8260B L1857322-02,04,05,06,07,08,09 Method Blank (MB) (MB) R4215820-3 05/11/25 20:50 MB Result MB Qualifier MB MDL MB RDL Analyte ug/l ug/l ug/l Benzene U 0.0941 1.00 Toluene U 0.278 1.00 Ethylbenzene U 0.137 1.00 Total Xylenes U 0.174 3.00 Methyl tert-butyl ether U 0.101 1.00 Naphthalene U 1.00 5.00 (S) Toluene-d8 101 80.0-120 (S) 4-Bromofluorobenzene 90.6 77.0-126 (S) 1,2-Dichloroethane-d4 120 70.0-130 Laboratory Control Sample (LCS) • Laboratory Control Sample Duplicate (LCSD) (LCS) R4215820-1 05/11/25 19:08 • (LCSD) R4215820-2 05/11/25 20:29 Spike Amount LCS Result LCSD Result LCS Rec.LCSD Rec.Rec. Limits LCS Qualifier LCSD Qualifier RPD RPD Limits Analyte ug/l ug/l ug/l %%%%% Benzene 5.00 4.81 4.87 96.2 97.4 70.0-123 1.24 20 Toluene 5.00 5.22 5.00 104 100 79.0-120 4.31 20 Ethylbenzene 5.00 4.96 4.68 99.2 93.6 79.0-123 5.81 20 Total Xylenes 15.0 14.4 13.2 96.0 88.0 79.0-123 8.70 20 Methyl tert-butyl ether 5.00 5.01 4.76 100 95.2 68.0-125 5.12 20 Naphthalene 5.00 3.08 2.83 61.6 56.6 54.0-135 J J 8.46 20 (S) Toluene-d8 103 103 80.0-120 (S) 4-Bromofluorobenzene 96.4 96.3 77.0-126 (S) 1,2-Dichloroethane-d4 119 122 70.0-130 1 Cp 2 Tc 3 Ss 4 Cn 5 Sr 6 Qc 7 Gl 8 Al 9 Sc ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/20/25 16:55 18 of 25 ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/21/25 09:53 18 of 25 QUALITY CONTROL SUMMARYWG2512962 Volatile Organic Compounds (GC/MS) by Method 8260B L1857322-03 Method Blank (MB) (MB) R4215550-3 05/12/25 10:31 MB Result MB Qualifier MB MDL MB RDL Analyte ug/l ug/l ug/l Benzene U 0.0941 1.00 Toluene U 0.278 1.00 Ethylbenzene U 0.137 1.00 Total Xylenes U 0.174 3.00 Methyl tert-butyl ether U 0.101 1.00 Naphthalene U 1.00 5.00 (S) Toluene-d8 103 80.0-120 (S) 4-Bromofluorobenzene 102 77.0-126 (S) 1,2-Dichloroethane-d4 100 70.0-130 Laboratory Control Sample (LCS) (LCS) R4215550-1 05/12/25 09:09 Spike Amount LCS Result LCS Rec.Rec. Limits LCS Qualifier Analyte ug/l ug/l %% Benzene 5.00 5.13 103 70.0-123 Toluene 5.00 5.13 103 79.0-120 Ethylbenzene 5.00 4.86 97.2 79.0-123 Total Xylenes 15.0 14.7 98.0 79.0-123 Methyl tert-butyl ether 5.00 5.45 109 68.0-125 Naphthalene 5.00 4.00 80.0 54.0-135 J (S) Toluene-d8 103 80.0-120 (S) 4-Bromofluorobenzene 98.9 77.0-126 (S) 1,2-Dichloroethane-d4 100 70.0-130 L1857577-03 Original Sample (OS) • Matrix Spike (MS) • Matrix Spike Duplicate (MSD) (OS) L1857577-03 05/12/25 17:41 • (MS) R4215550-4 05/12/25 19:45 • (MSD) R4215550-5 05/12/25 20:06 Spike Amount Original Result MS Result MSD Result MS Rec.MSD Rec.Dilution Rec. Limits MS Qualifier MSD Qualifier RPD RPD Limits Analyte ug/l ug/l ug/l ug/l %%%%% Benzene 5.00 U 4.75 5.37 95.0 107 1 17.0-158 12.3 27 Toluene 5.00 U 4.72 5.25 94.4 105 1 26.0-154 10.6 28 Ethylbenzene 5.00 U 4.57 5.11 91.4 102 1 30.0-155 11.2 27 Total Xylenes 15.0 U 13.5 15.0 90.0 100 1 29.0-154 10.5 28 Methyl tert-butyl ether 5.00 U 4.85 5.45 97.0 109 1 28.0-150 11.7 29 Naphthalene 5.00 U 3.48 3.52 69.6 70.4 1 12.0-156 J J 1.14 35 (S) Toluene-d8 100 102 80.0-120 (S) 4-Bromofluorobenzene 98.3 98.4 77.0-126 (S) 1,2-Dichloroethane-d4 101 99.6 70.0-130 1 Cp 2 Tc 3 Ss 4 Cn 5 Sr 6 Qc 7 Gl 8 Al 9 Sc ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/20/25 16:55 19 of 25 ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/21/25 09:53 19 of 25 QUALITY CONTROL SUMMARYWG2516732 Volatile Organic Compounds (GC/MS) by Method 8260B L1857322-01,04,05,06,07 Method Blank (MB) (MB) R4217016-3 05/16/25 12:31 MB Result MB Qualifier MB MDL MB RDL Analyte ug/l ug/l ug/l Benzene U 0.0941 1.00 Toluene U 0.278 1.00 Ethylbenzene U 0.137 1.00 Total Xylenes U 0.174 3.00 Methyl tert-butyl ether U 0.101 1.00 Naphthalene U 1.00 5.00 (S) Toluene-d8 106 80.0-120 (S) 4-Bromofluorobenzene 102 77.0-126 (S) 1,2-Dichloroethane-d4 108 70.0-130 Laboratory Control Sample (LCS) • Laboratory Control Sample Duplicate (LCSD) (LCS) R4217016-1 05/16/25 11:25 • (LCSD) R4217016-2 05/16/25 11:47 Spike Amount LCS Result LCSD Result LCS Rec.LCSD Rec.Rec. Limits LCS Qualifier LCSD Qualifier RPD RPD Limits Analyte ug/l ug/l ug/l %%%%% Benzene 5.00 4.17 4.00 83.4 80.0 70.0-123 4.16 20 Toluene 5.00 4.44 4.37 88.8 87.4 79.0-120 1.59 20 Ethylbenzene 5.00 4.51 4.60 90.2 92.0 79.0-123 1.98 20 Total Xylenes 15.0 14.6 13.9 97.3 92.7 79.0-123 4.91 20 Methyl tert-butyl ether 5.00 4.83 4.57 96.6 91.4 68.0-125 5.53 20 Naphthalene 5.00 3.72 4.10 74.4 82.0 54.0-135 J J 9.72 20 (S) Toluene-d8 105 106 80.0-120 (S) 4-Bromofluorobenzene 103 103 77.0-126 (S) 1,2-Dichloroethane-d4 111 109 70.0-130 1 Cp 2 Tc 3 Ss 4 Cn 5 Sr 6 Qc 7 Gl 8 Al 9 Sc ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/20/25 16:55 20 of 25 ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/21/25 09:53 20 of 25 QUALITY CONTROL SUMMARYWG2518679 Volatile Organic Compounds (GC/MS) by Method 8260B L1857322-02 Method Blank (MB) (MB) R4217498-2 05/19/25 17:49 MB Result MB Qualifier MB MDL MB RDL Analyte ug/l ug/l ug/l Toluene U 0.278 1.00 (S) Toluene-d8 97.4 80.0-120 (S) 4-Bromofluorobenzene 95.7 77.0-126 (S) 1,2-Dichloroethane-d4 101 70.0-130 Laboratory Control Sample (LCS) (LCS) R4217498-1 05/19/25 17:06 Spike Amount LCS Result LCS Rec.Rec. Limits LCS Qualifier Analyte ug/l ug/l %% Toluene 5.00 4.18 83.6 79.0-120 (S) Toluene-d8 95.6 80.0-120 (S) 4-Bromofluorobenzene 96.9 77.0-126 (S) 1,2-Dichloroethane-d4 99.6 70.0-130 1 Cp 2 Tc 3 Ss 4 Cn 5 Sr 6 Qc 7 Gl 8 Al 9 Sc ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/20/25 16:55 21 of 25 ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/21/25 09:53 21 of 25 QUALITY CONTROL SUMMARYWG2514752 Semi-Volatile Organic Compounds (GC) by Method 8015D L1857322-01,02,03,04,05,06,07,08 Method Blank (MB) (MB) R4216893-1 05/17/25 15:59 MB Result MB Qualifier MB MDL MB RDL Analyte ug/l ug/l ug/l TPH (GC/FID) High Fraction U 60.5 100 (S) o-Terphenyl 139 52.0-156 Laboratory Control Sample (LCS) • Laboratory Control Sample Duplicate (LCSD) (LCS) R4216893-2 05/17/25 16:21 • (LCSD) R4216893-3 05/17/25 16:43 Spike Amount LCS Result LCSD Result LCS Rec.LCSD Rec.Rec. Limits LCS Qualifier LCSD Qualifier RPD RPD Limits Analyte ug/l ug/l ug/l %%%%% TPH (GC/FID) High Fraction 1500 1550 1560 103 104 50.0-150 0.643 20 (S) o-Terphenyl 109 109 52.0-156 1 Cp 2 Tc 3 Ss 4 Cn 5 Sr 6 Qc 7 Gl 8 Al 9 Sc ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/20/25 16:55 22 of 25 ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/21/25 09:53 22 of 25 GLOSSARY OF TERMS Guide to Reading and Understanding Your Laboratory Report The information below is designed to better explain the various terms used in your report of analytical results from the Laboratory. This is not intended as a comprehensive explanation, and if you have additional questions please contact your project representative. Results Disclaimer - Information that may be provided by the customer, and contained within this report, include Permit Limits, Project Name, Sample ID, Sample Matrix, Sample Preservation, Field Blanks, Field Spikes, Field Duplicates, On-Site Data, Sampling Collection Dates/Times, and Sampling Location. Results relate to the accuracy of this information provided, and as the samples are received. Abbreviations and Definitions MDL Method Detection Limit. RDL Reported Detection Limit. Rec.Recovery. RPD Relative Percent Difference. SDG Sample Delivery Group. (S) Surrogate (Surrogate Standard) - Analytes added to every blank, sample, Laboratory Control Sample/Duplicate and Matrix Spike/Duplicate; used to evaluate analytical efficiency by measuring recovery. Surrogates are not expected to be detected in all environmental media. U Not detected at the Reporting Limit (or MDL where applicable). Analyte The name of the particular compound or analysis performed. Some Analyses and Methods will have multiple analytes reported. Dilution If the sample matrix contains an interfering material, the sample preparation volume or weight values differ from the standard, or if concentrations of analytes in the sample are higher than the highest limit of concentration that the laboratory can accurately report, the sample may be diluted for analysis. If a value different than 1 is used in this field, the result reported has already been corrected for this factor. Limits These are the target % recovery ranges or % difference value that the laboratory has historically determined as normal for the method and analyte being reported. Successful QC Sample analysis will target all analytes recovered or duplicated within these ranges. Original Sample The non-spiked sample in the prep batch used to determine the Relative Percent Difference (RPD) from a quality control sample. The Original Sample may not be included within the reported SDG. Qualifier This column provides a letter and/or number designation that corresponds to additional information concerning the result reported. If a Qualifier is present, a definition per Qualifier is provided within the Glossary and Definitions page and potentially a discussion of possible implications of the Qualifier in the Case Narrative if applicable. Result The actual analytical final result (corrected for any sample specific characteristics) reported for your sample. If there was no measurable result returned for a specific analyte, the result in this column may state “ND” (Not Detected) or “BDL” (Below Detectable Levels). The information in the results column should always be accompanied by either an MDL (Method Detection Limit) or RDL (Reporting Detection Limit) that defines the lowest value that the laboratory could detect or report for this analyte. Uncertainty (Radiochemistry)Confidence level of 2 sigma. Case Narrative (Cn) A brief discussion about the included sample results, including a discussion of any non-conformances to protocol observed either at sample receipt by the laboratory from the field or during the analytical process. If present, there will be a section in the Case Narrative to discuss the meaning of any data qualifiers used in the report. Quality Control Summary (Qc) This section of the report includes the results of the laboratory quality control analyses required by procedure or analytical methods to assist in evaluating the validity of the results reported for your samples. These analyses are not being performed on your samples typically, but on laboratory generated material. Sample Chain of Custody (Sc) This is the document created in the field when your samples were initially collected. This is used to verify the time and date of collection, the person collecting the samples, and the analyses that the laboratory is requested to perform. This chain of custody also documents all persons (excluding commercial shippers) that have had control or possession of the samples from the time of collection until delivery to the laboratory for analysis. Sample Results (Sr) This section of your report will provide the results of all testing performed on your samples. These results are provided by sample ID and are separated by the analyses performed on each sample. The header line of each analysis section for each sample will provide the name and method number for the analysis reported. Sample Summary (Ss)This section of the Analytical Report defines the specific analyses performed for each sample ID, including the dates and times of preparation and/or analysis. Qualifier Description C3 The reported concentration is an estimate. The continuing calibration standard associated with this data responded low. Method sensitivity check is acceptable. J The identification of the analyte is acceptable; the reported value is an estimate. 1 Cp 2 Tc 3 Ss 4 Cn 5 Sr 6 Qc 7 Gl 8 Al 9 Sc ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/20/25 16:55 23 of 25 ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/21/25 09:53 23 of 25 Pace Analytical National 12065 Lebanon Rd Mount Juliet, TN 37122 Alabama 40660 Nebraska NE-OS-15-05 Alaska 17-026 Nevada TN000032021-1 Arizona AZ0612 New Hampshire 2975 Arkansas 88-0469 New Jersey–NELAP TN002 California 2932 New Mexico ¹TN00003 Colorado TN00003 New York 11742 Connecticut PH-0197 North Carolina Env375 Florida E87487 North Carolina ¹DW21704 Georgia NELAP North Carolina ³41 Georgia ¹923 North Dakota R-140 Idaho TN00003 Ohio–VAP CL0069 Illinois 200008 Oklahoma 9915 Indiana C-TN-01 Oregon TN200002 Iowa 364 Pennsylvania 68-02979 Kansas E-10277 Rhode Island LAO00356 Kentucky ¹ ⁶KY90010 South Carolina 84004002 Kentucky ²16 South Dakota n/a Louisiana AI30792 Tennessee ¹ ⁴2006 Louisiana LA018 Texas T104704245-20-18 Maine TN00003 Texas ⁵LAB0152 Maryland 324 Utah TN000032021-11 Massachusetts M-TN003 Vermont VT2006 Michigan 9958 Virginia 110033 Minnesota 047-999-395 Washington C847 Mississippi TN00003 West Virginia 233 Missouri 340 Wisconsin 998093910 Montana CERT0086 Wyoming A2LA A2LA – ISO 17025 1461.01 AIHA-LAP,LLC EMLAP 100789 A2LA – ISO 17025 ⁵1461.02 DOD 1461.01 Canada 1461.01 USDA P330-15-00234 EPA–Crypto TN00003 ACCREDITATIONS & LOCATIONS ¹ Drinking Water ² Underground Storage Tanks ³ Aquatic Toxicity ⁴ Chemical/Microbiological ⁵ Mold ⁶ Wastewater n/a Accreditation not applicable * Not all certifications held by the laboratory are applicable to the results reported in the attached report. * Accreditation is only applicable to the test methods specified on each scope of accreditation held by Pace Analytical. 1 Cp 2 Tc 3 Ss 4 Cn 5 Sr 6 Qc 7 Gl 8 Al 9 Sc ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/20/25 16:55 24 of 25 ACCOUNT:PROJECT:SDG:DATE/TIME:PAGE: One Atlas L1857322 05/21/25 09:53 24 of 25