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HomeMy WebLinkAbout2024.06.27_CCOA.p2.c.v_LT Remedy PMP Report No 5_Q1 2024Geosyntec consultants Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 CFR Long -Term Remedy Performance Monitoring Report #5 January — March 2024 Chemours Fayetteville Works Prepared for The Chemours Company FC, LLC 22828 NC Highway 87 Fayetteville, NC 28306 Prepared by Geosyntec Consultants of NC P.C. 2501 Blue Ridge Road, Suite 430 Raleigh, NC 27607 Project Number TR0795 June 27, 2024 `��llll�ll►�� CAR 0r`i� p_.ar�EaS�O�!y� ` a SEAL; 039872 : 0 .27l2L1 is Geosyntec° consultants Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 EXECUTIVE SUMMARY This CFR Long -Term Remedy Performance Monitoring Report #5 ("Report") has been prepared for the Q1 2024 period of January 1 through March 31, 2024 and documents the operation of the interim seep Flow -Through Cells (FTCs), the ex -situ seeps and weeps capture systems ("Ex -Situ Capture Systems"), the groundwater extraction and conveyance system (GWEC), and the groundwater treatment plant (GWTP). The table below summarizes the flow capture in millions of gallons (MG) and the per- and polyfluoroalkyl substances (PFAS) removal (Table 3+ [17 compounds]) in pounds (lbs) for each remedy element. Report Period (Jan — Mar 2024) Cumulative through Mar 2024* Remedy Element Flow Captured/ Mass Removed Flow Captured/ Mass Removed Treated (MG) (lbs) Treated (MG) (lbs) Interim FTCs 10.1 3.0 428.4 551.1 004 Treatment Plant 47.8 50.5 245.0 302.9 Ex -Situ Capture 5.9 Included in 004 17.4 Included in 004 Systems GWEC 44.4 Included in 004 233.3 Included in 004 Total** 57.9 53.5 673.4 854.0 (Interim FTCs + 004) *Cumulative values reflect the lifetime operation of each remedy component (e.g., since December 2020 for Interim FTC Seep Q. **Differences inflow totals are attributable to the measurement resolution offlow meters on the different remedy systems as well as storage time in the surge pond, break tank, and other components. The calculated total influent of the Ex -Situ Capture Systems and GWEC system above is 50.3 MG for Q1 2024. The total influent as measured by Veolia's flow meter was 49.1 MG. The total effluent as measured by Veolia's flow meter was 47.8 MG as shown. Flow into the interim FTCs has decreased significantly since the completion of the barrier wall and implementation of the Ex -Situ Capture Systems and GWEC system. Between July 2021 and June 2023, the interim FTCs collectively processed 14.8 MG per month on average. Between July 2023 and March 2024, the average monthly volume was 2.6 MG. Batch mode processing has been necessary in order to maintain treatment efficiency at the reduced flow rates. During dry weather, with the FTCs offline, the impoundment elevations at the FTCs either remain stagnant or decrease, indicating that the long-term remedy components have eliminated the seep baseflow. As the FTCs now treat predominately rainwater mixed with stagnant residual groundwater, the concentration of PFAS in the influent has also decreased. Between July 2021 and June 2023, the average influent PFAS concentration (Total Table 3+, 17 compounds) across the four FTCs was approximately 150,300 ng/L; between July 2023 and March 2024, it was 35,200 ng/L. Overall, the combination of significantly reduced flow and concentration has resulted in a mass discharge into the FTCs that TR0795 — CFR Long -Term Remedy Performance Monitoring Report #5 ES-1 June 2024 Geosyntec consultants Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 is approximately 96% reduced from baseline conditions, and an asymptotic PFAS mass removal trend. The GWEC system has been operating at a steady-state cumulative extraction rate since approximately September 2023, after the extraction well startup in March 2023 resulted in initial declines in the Black Creek aquifer water levels. The average pumping rate in Q1 2024 was 337 gallons per minute. The Ex -Situ Capture systems flow trends are dependent on weather conditions and are therefore more variable. The 004 GWTP removed greater than 99% of PFAS 1 from the combined flow of the GWEC and Ex -Situ Capture Systems. Performance monitoring activities, including hydraulic head monitoring and surface water sampling, are also documented in this Report. Similar to the previous reporting period, performance monitoring indicates that the GWEC system has resulted in a reduction in gradient between the barrier wall and the Cape Fear River, thus reducing groundwater PFAS flux to the Cape Fear River. This reduction in HAS mass discharge is evident in the diminished flows into the FTCs and is also documented in a report for the Mass Loading Model (MLM) program, submitted for the same reporting period concurrent to this Report (Geosyntec, 2024a). Collectively, the Willis Creek EWs are exerting drawdown of the Black Creek aquifer along the length of the alignment, particularly in the midsection, with nearly 8 feet of groundwater elevation reduction observed in monitoring wells. Drawdown along the alignment has also resulted in four EWs with insufficient water to pump, as compared to startup, demonstrating overlapping influence within the EWs from the collective pumping. The extensive drawdown is a line of evidence of hydraulic control. Additionally, a reduction in Willis Creek mass discharges has been observed. At sampling locations WC-2 (upstream) and WC-1 (downstream near the confluence with the Cape Fear River), the post -startup mass discharge to Willis Creek along this reach is estimated to be approximately 60% less than pre -startup. ' As measured by indicator parameters hexafluoropropylene oxide dimer (HFPO-DA), perfluoromethoxypropyl carboxylic acid (PMPA), and perfluoro-2-methoxyaceticacid (PFMOAA) TR0795 — CFR Long -Term Remedy Performance Monitoring Report #5 ES-2 June 2024 Geosyntec consultants Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 TABLE OF CONTENTS EXECUTIVE SUMMARY.......................................................................................................ES-1 1 INTRODUCTION..................................................................................................................1 1.1 Data Validation............................................................................................................1 1.2 Laboratory Analyses....................................................................................................2 2 IN -SITU SEEP FLOW -THROUGH CELLS.........................................................................4 2.1 Inspections, Operation, and Maintenance....................................................................4 2.1.1 Inspections....................................................................................................4 2.1.2 Duty Cycling.................................................................................................4 2.1.3 FTC Management During River Flooding....................................................4 2.1.4 Material Changeouts.....................................................................................5 2.1.5 Issue Resolution and System Optimization..................................................5 2.2 Data Collected..............................................................................................................5 2.3 Results..........................................................................................................................6 2.3.1 System Flowrates and Operational Periods..................................................7 2.3.2 Performance Monitoring Analytical Results.................................................8 2.3.3 System Effectiveness....................................................................................9 2.3.4 River Elevation and Precipitation.................................................................9 2.3.5 Water Quality................................................................................................9 3 EX -SITU SEEPS AND WEEPS CAPTURE.......................................................................11 3.1 Operation and Maintenance.......................................................................................11 3.2 Data Collected............................................................................................................11 3.3 Results........................................................................................................................11 4 GROUNDWATER EXTRACTION AND CONVEYANCE..............................................12 4.1 Operation and Maintenance.......................................................................................12 4.2 Data Collected............................................................................................................12 4.2.1 Extraction Well Operational Data...............................................................12 4.2.2 PFAS Data...................................................................................................12 4.3 Results........................................................................................................................13 4.3.1 Groundwater Extraction..............................................................................13 5 004 TREATMENT PLANT.................................................................................................14 5.1 Data Collected............................................................................................................14 5.1.1 Flow Rates...................................................................................................14 5.1.2 PFAS Influent and Effluent.........................................................................14 5.2 Results........................................................................................................................14 5.2.1 Flow Rates...................................................................................................14 TR0795 — CFR Long -Term Remedy Performance Monitoring Report #5 i June 2024 Geosyntec consultants Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 5.2.2 Analytical Results.......................................................................................15 5.2.3 PFAS Mass Removal..................................................................................15 6 PERFORMANCE MONITORING EVALUATION...........................................................16 6.1 Data Collected ............................................................................................................16 6.1.1 Hydraulic Head and Surface Water Elevation............................................16 6.1.2 PFAS Concentrations in Groundwater and Surface Water .........................16 6.1.3 Passive Flux Meters....................................................................................17 6.2 Results........................................................................................................................18 6.2.1 Hydraulic Head and Surface Water Elevation............................................18 6.2.2 PFAS Concentrations and Mass Discharge in Groundwater and Surface Water...........................................................................................................22 7 SUMMARY.........................................................................................................................24 8 REFERENCES .....................................................................................................................26 LIST OF TABLES Table 1-1 Summary of Sampling and Monitoring Activities Table 2-1A-D FTC Operations and Maintenance Summary Table 2-2 Cape Fear River Elevation and Local Precipitation Statistics Table 2-3A-D FTC Sampling Summary Table 2-4A-D FTC Performance Monitoring Analytical Results Table 2-5A-D FTC Water Quality Data Table 3-1 Ex -Situ Seeps and Weeps Flow Data Table 4-1 Extraction and Observation Well Construction Details Table 4-2 Summary of GWEC Flow Data Table 4-3 Extraction Well Flow Data Table 5-1 004 Treatment Plant Flow Data Table 5-2 004 Treatment Plant PFAS Analytical Results Table 6-1 Summary of Groundwater Level Information Table 6-2 PFAS Concentrations in Downgradient Groundwater Monitoring Wells Table 6-3 Willis Creek PFAS Analytical Results TR0795 — CFR Long -Term Remedy Performance Monitoring Report #5 ll June 2024 Geosyntec consultants Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 Table 6-4 Willis Creek PFAS Mass Discharge LIST OF FIGURES Figure 1-1 Remedy Layout Overview Figure 2-IA-D River Level During Reporting Period & FTC As -Built Elevations Figure 2-2A-D FTC Discharge Flowrate (Jan — Mar 2024) Figure 2-3 FTC Monthly Total Discharge Volumes (July 2021 — March 2024) Figure 24A-D FTC Influent Water Elevation (Jan — Mar 2024) Figure 2-5A-D FTC Staff Gauge Water Elevation (Jan — Mar 2024) Figure 2-6 FTC Influent PFAS Concentrations Figure 2-7 FTC Mass Removal Curve (July 2021 — March 2024) Figure 6-1 Hydraulic Head Evaluation Network for Groundwater Remedy Figure 6-2A-D Southern Alignment — Downgradient Groundwater Transects Figure 6-3A-C Southern Alignment — Dampening Analysis Transects Figure 64A-C Willis Creek Extraction Well Flood Response Figure 6-5A-C Northern Alignment — January 2023 — January/February/March 2024 Elevation Difference Figure 6-6A-C Northern Alignment — Potentiometric Map — January 2023 - January/February/March 2024 Figure 6-7A-C PFAS Analytical Results Figure 6-8 Willis Creek PFAS Concentrations and Water Elevation Figure 6-9 Cape Fear River Transect Sampling Locations and PFAS Analytical Results in Groundwater Figure 6-10 Indicator PFAS Concentrations Across Cape Fear River Transects (March 2024) Figure 6-11 Total Table 3+ (17 Compounds) Concentrations, Mass Discharge and Daily Flow at Tar Heel Ferry Road Bridge TR0795 — CFR Long -Term Remedy Performance Monitoring Report #5 iii June 2024 Geosyntec consultants Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 LIST OF APPENDICES Appendix A Laboratory Analytical Data Review Narratives Appendix B FTC Transducer Data Reduction Appendix C Corrected PFPrA Concentrations for Previously Reported Results Appendix D Updated PFPrA Calculation Discussion and Table of Previously Reported Results Along with Revised, Corrected Results, Chemours Fayetteville Works, Fayetteville, NC TR0795 — CFR Long -Term Remedy Performance Monitoring Report #5 iv June 2024 Geosyntec consultants Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 LIST OF ACRONYMS AND ABBREVIATIONS COA Addendum to Consent Order Paragraph 12 DO Dissolved Oxygen DQO Data Quality Objectives DVM Data Verification Module eDMR Electronic Discharge Monitoring Reports EIM Environmental Information Management EPA Environmental Protection Agency EW Extraction Well gpm gallons per minute FTC flow -through cells GAC Granular Activated Carbon GWEC Groundwater Extraction and Conveyance GWTP Groundwater Treatment Plant HFPO-DA hexafluoropropylene oxide-dimer acid lbs pounds MG million gallons mg/L milligram per liter µS/cm microsiemens per centimeter MLM Mass Loading Model NCDEQ North Carolina Department of Environmental Quality NAVD88 North American Vertical Datum of 1988 ng/L nanograms per liter NPDES National Pollutant Discharge Elimination System NTU nephelometric turbidity units OM&M Operations, Maintenance, and Monitoring OW Observation Well PFAS per- and polyfluoroalkyl substances PFM Passive Flux Meter PFMOAA perfluoro-2-methoxyacetic acid TR0795 — CFR Long -Term Remedy Performance Monitoring Report #5 v June 2024 Geosyntec consultants Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 PFPrA perfluoropropanoic acid PMP Performance Monitoring Plan PMPA perfluoro-2-methoxypropionic acid QA/QC Quality Assurance/Quality Control RPD Relative Percent Difference SU Standard Units USGS United States Geological Survey TR0795 — CFR Long -Term Remedy Performance Monitoring Report #5 V i June 2024 Geosynlec consultants Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 1 INTRODUCTION Geosyntec Consultants of NC, P.C. (Geosyntec) has prepared this CFR Long -Term Remedy Performance Monitoring Report #5 ("Report") on behalf of The Chemours Company FC, LLC (Chemours) to provide a summary report of Operations, Maintenance, and Monitoring (OM&M) for the groundwater and seep remedies installed at the Chemours Fayetteville Works Site (the Site) pursuant to the Addendum to the Consent Order Paragraph 12 [COA] Paragraph 2.c.v. This Report has been prepared for the period of January 1 through March 31, 2024 (Q1 2024). The remedy components consist of the interim in -situ flow -through cells (FTCs), groundwater extraction and conveyance (GWEC) system, the Ex -Situ Seeps and Weeps capture systems ("Ex - Situ Capture Systems"), and the groundwater treatment plant (GWTP). The components of the remedies are shown in an overview layout in Figure 1-1. Various monitoring and sampling activities were conducted during the reporting period as summarized in Table 1-1. 1.1 Data Validation Laboratory analytical data for the samples collected during the Q 1 2024 reporting period were reviewed using the Data Verification Module (DVM) within the LocusTM Environmental Information Management (EIM) system, a commercial data management software program. Following the DVM process, a manual review of the data was conducted. The DVM and the manual review results were combined in a DVM narrative report for each set of sample results which is consistent with Stage 2b of the USEPA Guidance for Labeling Externally Validated Laboratory Analytical Data for Superfund Use (USEPA, 2009). The DVM narrative report summarizes which samples were qualified (if any), the specific reasons for the qualification, and any potential bias in reported results. The data usability, in view of the project's data quality objectives (DQOs), was assessed, and the data were entered into the EIM system. The data were evaluated by the DVM against the following data usability checks: • Hold time criteria • Field and laboratory blank contamination • Completeness of QA/QC samples • Matrix spike/matrix spike duplicate recoveries and the relative percent differences (RPDs) between these spikes • Laboratory control sample/control sample duplicate recoveries and the RPD between these spikes • Surrogate spike recoveries for organic analyses TR0795 — CFR Long -Term Remedy Performance Monitoring Report #5 1 June 2024 Geosyntec consultants Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 • RPD between field duplicate sample pairs A manual review of the data was also conducted, which included visual inspection of sample chromatograms for appropriate integration and retention time, verification that detections in field or equipment blanks have been applied to all applicable samples, and review of temperature requirements for sample preservation during storage and shipping. Based on the results of the DVM plus manual review, the following data evaluation qualifiers were applied to the analytical results as required: • J - Analyte present, reported value may not be accurate or precise. • UJ - Analyte not present above the reporting limit, reporting limit may not be accurate or precise. • B - Analyte present in a blank sample, reported value may have a high bias. The DVM narrative reports are provided in Appendix A. Overall, the DQOs were met for accuracy and precision. During this sampling event, all samples were within the acceptable temperature requirements for preservation during storage and shipping (i.e., between not frozen to 6°C with a target of 4°C) as outlined in the Chemours PFAS Program QAPP (AECOM, 2018). The data collected are believed to be complete, representative, and comparable, with the exception of R- PSDA, Hydrolyzed PSDA, and R-EVE; matrix interference studies have shown that quantitation these compounds is inaccurate due to interferences by the sample matrix (Geosyntec, 2020). Results for these three analytes are J-qualified as estimated. 1.2 Laboratory Analyses Groundwater and surface water samples collected in Q 12024 were analyzed for 21 Table 3+ PFAS and 35 other PFAS compounds by Method 537MM. Matrix interference studies have shown that quantitation of three of the compounds included in the Table 3+ PFAS group, R-PSDA, Hydrolyzed PSDA, and R-EVE111 is inaccurate due to interferences by the sample matrix (Geosyntec, 2020a). Groundwater and surface water results for Table 3+ PFAS compounds are presented in report tables as three PFAS groupings: • Total Table 3+ (21 compounds), which is the sum of all Table 3+ PFAS compounds. • Total Table 3+ (18 compounds), which excludes R-PSDA, Hydrolyzed PSDA, and R-EVE due to the matrix interferences noted above. 2,2,3,3,4,5,5,5-octafluoro-4-(1,1,2,2-tetrafluoro-2-sulfoethoxy)-pentanoic acid (R-PSDA), 2-fluoro-2-[l,1,2,3,3,3- hexafluoro-2-(1,1,2,2-tetrafluoro-2-sulfoethoxy)propoxy]-acetic acid, (Hydrolyzed PSDA), and 4-(2-carboxy- 1,1,2,2-tetrafluoroethoxy)-2,2,3,3,4,5,5,5-octafluoro-pentanoic acid (R-EVE) TR0795 — CFR Long -Term Remedy Performance Monitoring Report #5 2 June 2024 Geosyntec consultants Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 • Total Table 3+ (17 compounds), which additionally excludes perfluoropropanoic acid (PFPrA), to allow for a direct comparison of results to prior years and to discuss mass removal of remedial components. Although the report tables include results for the three groupings above, the text and figures of this report focus on the Total Table 3+ (17 compounds) HAS grouping. 1.2.1 Correction of PFPrA Concentrations On April 23, 2024, Eurofins-Sacramento informed Chemours via email that a calculation error had been incorporated into the preparation of calibration standards for PFPrA under the laboratory's 537 Mod Max methodology. The error resulted in a 36% low bias in PFPrA concentrations. The error affected Chemours samples collected on behalf of the Fayetteville Works Site between June 2023 and April 2024. Chemours informed NCDEQ of the PFPrA calculation error via telephone on May 15, 2024, and provided NCDEQ with Eurofins-Sacramento's memo describing their root cause analysis of the PFPrA calculation error on May 22, 2024. PFPrA results that were calculated incorrectly have been corrected by Eurofins-Sacramento and provided to Chemours. These results fall into two categories: 1) results that were corrected before being reported to NCDEQ, and 2) results that were reported to NCDEQ before being corrected. The PFPrA results for Q 12024 provided in this report fall into category 1). They are being reported here for the first time. PFPrA results from July 2023 to November 2023 that have been provided in previous reports in this sampling program fall into category 2). Appendix C of this report provides a table of the results in category 2) with corrected PFPrA concentration values. Additional detail is provided in a letter submitted to NCDEQ by Chemours on June 18, 2024, which is provided in Appendix D. TR0795 — CFR Long -Term Remedy Performance Monitoring Report #5 3 June 2024 Geosyntec consultants Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 2 IN -SITU SEEP FLOW -THROUGH CELLS The in -situ FTC remedies have been in operation since December 2020 beginning with Seep C. Detailed information on the hydraulic mechanics of the FTC system, flood management practices, data collection methodology and reduction process, and flow calculation formulas is presented in previous Seeps O&M reports. As a simplifying step for presentation clarity, at various sections in this report, reference is made to these details within Seeps O&M Report #14 (Geosyntec, 2023a), the last of the bimonthly Seeps O&M Reports. 2.1 Inspections, Operation, and Maintenance The following sections describe the inspections, operation, and maintenance activities completed at the four FTCs during the current reporting period. 2.1.1 Inspections Routine inspections occurred on a weekly basis (at a minimum), and also occurred within a 24-hour period after rain events of 0.5 inches or greater. An Inspection Form was filled out by O&M personnel during each inspection. A summary of the inspection and maintenance events completed during this reporting period is provided in Tables 2-1A-D for Seeps A-D, respectively. 2.1.2 Duty Cycling Tables 2-IA-D detail the filter bed configurations for Seeps A, B, C, and D over the reporting period of January 1 through March 31, 2024. The table below summarizes the approximate number of days in the reporting period each FTC was either in batch mode operation (i.e., the FTC closed to flow); or if in operation, which filter bed was in lead. Seep FTC Closed to Flow in Batch Mode (days) FBI Lead (days) FB2 Lead (days) Total Uptime in Reporting Period (days) A 31 0 60 91 B 41 32 18 91 C 24 7.5 59.5 91 D 40 27 24 91 2.1.3 FTC Management During River Flooding During the reporting period, the Cape Fear River rose above the action leve12 from January 10 through January 18, 2024, and from March 29 through March 31, 2024. Cape Fear River elevation 2 See Section 2.3 of Seeps O&M Report #14 for details regarding the action level that was established to protect the electronic components of the autosamplers from flood events. TR0795 — CFR Long -Term Remedy Performance Monitoring Report #5 4 June 2024 Geosyntec consultants Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 data are described in Section 2.3.5. Cape Fear River elevation statistics are presented in Table 2-2, and elevation changes during the reporting period are shown on Figures 2-1A through D. 2.1.4 Material Changeouts The table below summarizes the material changeouts through this reporting period: Seep Filter Bed GAC Changeouts Date GAC Age/Lead Days GAC Removed (lbs) C FBI 1/4/2024 196/92.5 9,000 D F132 2/2/2024 344/181 27,000 B FBI 2/22/2024 231/111 27,000 Total 63,000 2.1.5 Issue Resolution and System Optimization As described in CFR Long -Term Remedy Performance Monitoring Report #4, flow was observed from the bluff face in the vicinity of the Outfall 002 discharge pipe and entered the Seep C FTC during dry weather in November 2023. Subsequent investigations indicated a potential leak in the Outfall 002 discharge pipe. A joint sealing remedy was applied to the discharge pipe in December 2023. Following the remedy, flowrate at the bluff face appeared to be reduced and O&M personnel observed continued decline through December 2023. During the current reporting period (January 1 to March 31, 2024), Site operations personnel gauged the piezometers monthly and observed further declines and ultimately stabilization in water levels. Additionally, water levels in the Seep C impoundment were stable or declined during dry periods when the FTC was in batch mode (closed to flow) from February 2 to February 9, February 16 to February 22, and March 16 to March 22, 2024 indicating no further additions to seep flow from the potential leak. 2.2 Data Collected Details regarding the procedures for each type of data collected, including pressure transducer management and data processing, rainfall and river stage data collation, and sample collection can be found in Seeps O&M Report #14. An overview is provided in the table below. The transducer data reduction process for the current reporting period is provided in Appendix B. s The Outfall 002 discharge pipe contains treated water from the 004 GWTP, and treated wastewater and non - contact cooling water from the facility. TR0795 — CFR Long -Term Remedy Performance Monitoring Report #5 5 June 2024 Geosynlec consultants Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 Data Type Monitoring During Q1 2024 Monitored every 15-minutes using pressure transducers in the influent Impoundment Elevation stilling basins, and with daily observation of the staff gauges in the impoundments. Monitored for flow every 15-minutes using pressure transducers during Flowrate Measurements passive flow operation; or measured with a flowmeter when directly pumped from the impoundment into the lead filter bed. Rainfall and River Stage Monitored every 15 minutes using data from the W.O. Huske Dam (gauge 02105500). Sampling is only able to be performed when the FTCs are not closed to flow in batch mode. After sufficient rainfall has raised the impoundment level, an FTC is opened to flow and a 24-hour composite sample is collected. As dry weather flow has terminated and the FTCs are treating predominately rainwater, in some cases rainwater that has accumulated over multiple rain events and periods of days or weeks, it is no longer practical to collect cotemporaneous wet weather monitoring samples. Performance Monitoring and Therefore, moving forward, all FTC samples will be designed Water Quality Measurements performance monitoring samples. During this reporting period, twelve sets of performance monitoring samples each were collected from Seeps A, B, and D. Thirteen sets of performance monitoring samples were collected from Seep C. There were no deviations in the reporting period. Dates of composite periods for each sample are listed in Tables 2-3A- D. Water quality in the Inlet Chamber and Effluent Stilling Basin at Seeps A-D was monitored at the same frequency as performance monitoring. Grab samples were collected from the Inlet Chamber, Transfer Basin, and Effluent Stilling Basin at Seeps A-D for evaluation of system performance and the need for GAC changeouts. Seven sets of Breakthrough Monitoring breakthrough monitoring samples were collected from Seep A, five sets of breakthrough monitoring samples were collected from Seep B and D, and eight sets of breakthrough monitoring samples were collected from Seep C during this reporting period (25 total). 2.3 Results The results for each type of data collected are described in detail in the following subsections. Laboratory analytical results are compiled in Appendix A. An overview of the results is as follows: TR0795 — CFR Long -Term Remedy Performance Monitoring Report #5 6 June 2024 Geosyntec consultants Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 Reporting Period Metric Seep A Seep B Seep C Seep D Total Rainfall, Actual (inches) 9.49 (January I —March 31, 2024) Rainfall, Historical 7.96 (January I —March 31, 2004-2020) Average (inches) River Above Spillway 5.6 5.1 5.2 5.6 N/A (days) ' Median Flow Rate over full reporting period (gpm) 22 0 20 0 42 2 Median Flow Rate (gpm) 39 36 28 14 117 when in operation' Seep Volume Treated 3.5 2.7 2.9 1.0 10.1 (MG) PFAS Removed (lbs) 4 1.49 0.66 0.7 0.18 3.03 I - Seeps A and D are approximately I ft lower in elevation than Seeps B and C. 2 — Median flow rate calculated during entire reporting period, including during batch mode operations when cells are closed to flow. 3 — Median flow rate calculated when FTCs were processing flow (i.e., not in batch mode). 4 — Total PFAS calculations are based on the total Table 3+ (17 compounds) presented in Table 2-4A-D. 2.3.1 System Flowrates and Operational Periods System Flowrates Figures 2-2A-D show the measurable flowrates through the FTC over the reporting period for Seeps A-D, respectively. As shown in Figure 2-3, total volume discharged by the FTCs has decreased dramatically. The reductions in flow are attributed to the barrier wall and the operation of the groundwater extraction system and Ex -Situ Capture Systems. Instances of Bypass The influent water level elevation and occurrences of bypass flow (if applicable) for Seeps A-D for the reporting period are shown in Figures 2-4A-D. The total rainfall received in the reporting period is shown below. The few instances of bypass were resolved with maintenance events lowering the impoundment below the spillway, similar to previous reporting periods. TR0795 — CFR Long -Term Remedy Performance Monitoring Report #5 7 June 2024 Geosyntec consultants Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 Period Rainfall (inches) Historical Rainfall (inches) % Change Compared to Historical January 2024 3.43 2.28 +50% February 2024 1.89 2.89 -35% March 2024 4.17 2.79 +50% Q 1 2024 9.49 7.96 +20% Long -Term Remedy Impacts on Baseflow Figures 2-4A-D depict the elevation of the influent pond at Seeps A-D and instances of batch mode processing. Figures 2-5A-D depict the impoundment elevation at Seeps A-D and instances of batch mode processing. As shown, even with the FTCs turned off, the impoundment elevation generally appears to respond only during rainfall events, indicating that the long-term remedy components have eliminated the Seep baseflow. 2.3.2 Performance Monitoring Analytical Results As noted in Section 2.2, after sufficient rainfall has raised the impoundment level, an FTC is opened to flow and a 24-hour composite sample is collected. As dry weather flow has terminated and the FTCs are treating predominately rainwater, in some cases rainwater that has accumulated over multiple rain events and periods of days or weeks, it is no longer practical to collect cotemporaneous wet weather monitoring samples. Therefore, moving forward, all FTC samples will be designed performance monitoring samples. Analytical results for the composite performance monitoring samples are provided in Tables 24A-D and summarized below. Figure 2-6 shows that the influent concentration of total Table 3+ PFAS (17 compounds) into the FTCs. For data up through December 2022 (approximately the time when barrier wall test panel installation began), the average influent concentration into FTCs A-D ranged from 102,000 to 236,000 nanograms per liter (ng/L). As shown below, the average influent concentration into the FTCs in Q1 2024 ranged from 21,633 to 52,750 ng/L. This reduction in concentration is attributed to the barrier wall cutting off upgradient groundwater flow, and the overall contribution of water balance into the FTCs becoming more dominated by wet weather, rainfall derived flow. The combination of significantly reduced flow and concentration has resulted in an asymptotic HAS mass removal trend as shown in Figure 2- 7. Implementation of batch mode, in which the impoundment levels are managed such that accumulated water in the basin is processed at flow rates more typical of the historical operation, TR0795 — CFR Long -Term Remedy Performance Monitoring Report #5 8 June 2024 Geosyntec consultants Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 appear to be increasing the removal efficiencies to the same level (i.e., >99%) as previous reporting periods. Analytical Results — Performance Seep A Seep B Seep C Seep D Monitoring Average Influent Total Table 3+ PFAS, 17 52,750 29,000 28,923 21,633 compounds (ng/L) Average Effluent Total Table 3+ PFAS, 17 44 136 82 40 compounds (ng/L) Average Removal Efficiency (%) >99.9 99.5 99.7 99.8 2.3.3 System Effectiveness System effectiveness calculation procedures are presented Seeps O&M Report #14. Based on the system flowrate data and the performance monitoring composite sample data of the three indicator compounds, the system effectiveness for Seeps A-D was calculated as follows. System Effectiveness (%) Seep A Seep B Seep C Seep D January 99.8 99.4 99.5 99.7 February >99.9 99.3 99.8 99.8 March 99.9 99.4 99.6 99.8 Overall Average 99.7 2.3.4 River Elevation and Precipitation On January 10, the Cape Fear River rose above the elevation of the discharge weir and bypass spillway at all four FTCs and receded below these features by January 18. On March 29, the river rose above the discharge weir (but not the bypass spillway or top of wall) at all four FTCs and receded below these features by March 31. The changes in elevation of the Cape Fear River during the reporting period (January 1 through March 31, 2024) are shown in Figures 2-IA through D. Table 2-2 presents the percent of time the elevation of the Cape Fear River has exceeded these key elevations over the lifetime of operation at each Seep FTC. As shown, the amount of time the river has been above the FTC features is similar to the historical record. 2.3.5 Water Quality The water quality measurements collected during the reporting period are provided in Tables 2-5A-D and described below: TR0795 — CFR Long -Term Remedy Performance Monitoring Report #5 9 June 2024 Geosyntec consultants Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 • Dissolved Oxygen (DO): No significant differences were observed in the fluctuations of DO between influent and effluent locations at all four Seeps. On a median basis, the DO changed by 1 milligram per liter (mg/L) or less. Aerobic (>2 mg/L) conditions were consistently observed during the reporting period. • Temperature: At all four Seeps, the median temperature of the effluent was within 1.2°C of the median temperature of the influent during this reporting period. • Specific Conductance: For all four Seeps, the difference in median specific conductance across influent and effluent locations ranged between -74 and 13 microSiemens per centimeter (µS/cm). During normal hydraulic conditions, the FTC is expected to have little effect on the anion/cation content of the seep baseflow. • pH: The median influent pH at the four Seeps ranged from 5.1 to 7.3, and the median effluent pH ranged from 5.5 to 7.48 standard units (SU) in this reporting period. From the Inlet Chamber to the Effluent Stilling Basin, the median pH of treated water at Seeps A, B, C, and D changed by 0.4, 0.7, 0.2, and 0.2 SU, respectively. • Turbidity: The median turbidity of the influent water at Seeps A-D ranged from 13 to 121 nephelometric turbidity units (NTU). The FTCs significantly decreased the turbidity of the influent water. The median turbidity of the effluent water at Seeps A-D ranged from 2 to 30 NTU. • TSS: The median influent TSS at Seeps A-D ranged from 7 to 38 mg/L. Median effluent TSS at Seeps A-D was detected in minimal concentrations (5 mg/L or lower). As was the case with turbidity, the FTCs generally decreased the TSS in the influent water. TR0795 — CFR Long -Term Remedy Performance Monitoring Report #5 10 June 2024 Geosynlec consultants Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 3 EX -SITU SEEPS AND WEEPS CAPTURE Section 3 summarizes the operation, maintenance, and monitoring activities performed by GEOServices, LLC as the operator of the Ex -Situ Capture Systems. This remedy consists of four seep capture locations (Willis Creek Tributary, Seep A, Seep A Tributary, and Seep B), and three dedicated weep capture locations (Weep 1, Weep 3, and Weep 4). Additionally, at seep capture location Seep A, the nearby Weep 7 is tied into the basin and is included in this system's capture. At seep capture location Seep A Tributary, the nearby weeps 9, 10, and 11 are tied into the wet well and are included in this system's capture. The 004 GWTP pad is connected to Weep 4 and includes its capture. Finally, the Weep 1 capture system pumps captured water directly into the GWEC force main. The seep capture locations are required to capture dry weather flows and stormwater flows from rainfall events up to 0.5 inches over 24 hours. Through the ex -situ force main, the captured water is pumped to a lined surge pond, which the GWTP periodically withdraws for treatment. 3.1 Operation and Maintenance The Ex -Situ Capture Systems have been operating since April 20, 2023. Pumping of captured water from ex -situ seep and weep locations to the surge pond continued during this reporting period. The 004 GWTP treated the captured water after periodically withdrawing from the surge pond. Routine operations and maintenance were performed on the capture systems per GEOServices' O&M Plan. 3.2 Data Collected The Ex -Situ Capture System telemetry network transmits the flow data from totalizers at Seep A, Seep A Tributary, Seep B, Willis Creek Tributary, and Weep 3 on a 15-minute frequency. Veolia records the volume conveyed from the surge pond to the 004 GWTP on a daily basis. 3.3 Results Table 3-1 shows the daily volume conveyed from the surge pond to the 004 GWTP and totalizer volumes conveyed from Seep A, Seep A Tributary, Seep B, Willis Creek Tributary, and Weep 3. During this reporting period, approximately 5.9 MG of captured water was pumped from the seep and weep capture locations to the surge pond and approximately 5.9 MG was conveyed from the surge pond to the 004 GWTP. The captured water in Q 1 2024 is 64% higher than Q4 2023 (5.9 MG vs 3.6 MG). This increase is attributed to the wetter conditions in Q 12024. TR0795 — CFR Long -Term Remedy Performance Monitoring Report #5 11 June 2024 Geosynlec consultants Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 4 GROUNDWATER EXTRACTION AND CONVEYANCE Section 4 describes the GWEC operation, maintenance, and monitoring activities that were conducted by Geosyntec as the operator of the system and provides a summary of the critical operational data that were collected and discusses the monitoring results from extraction well sampling activities during the reporting period. Construction details for the extraction wells are provided in Table 4-1. 4.1 Operation and Maintenance The GWEC system has been operating since March 14, 2023. The performance of the individual components of the GWEC system, on a well -by -well basis, are recorded via a telemetry network. System alerts and alarms have been programmed and are generated when a GWEC component is underperforming or not functioning. In such cases, Geosyntec leads the OM&M response, and performs the required corrective measures. On a minimum monthly basis, preventative maintenance and inspection is performed, in which extraction well components, control panels, and forcemain air release valves are individually checked. 4.2 Data Collected 4.2.1 Extraction Well Operational Data Table 4-2 provides a summary of flow data (daily average flow rate and daily cumulative volume) for the GWEC system (combined flow from all wells). Table 4-3 provides a summary of flow data for each extraction well during the reporting period (average monthly flow rate, and total cumulative volume by month). 4.2.2 PFAS Data The previous extraction well sampling events occurred in the pre -startup commissioning phase, from January 24 through March 14, 2023; and on April 12, 2023, approximately one month after full startup. The extraction wells were sampled most recently in April 15-16, 2024. These results will be presented in the subsequent CFR Long -Term Remedy Performance Monitoring Report #6 documenting the Q2 2024 period. TR0795 — CFR Long -Term Remedy Performance Monitoring Report #5 12 June 2024 Geosynlec consultants Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 4.3 Results 4.3.1 Groundwater Extraction The GWEC system extracted approximately 44.4 MG during the reporting period, with approximately 5.1 MG from surficial aquifer wells and 39.3 MG from Black Creek aquifer wells. The average extraction rate during the Q1 2024 reporting period was approximately 337 gallons per minute (gpm), which is similar to the extraction rate of 332 gpm in the previous reporting period (Q4 2023), and similar to the extraction rate in September 2023 (336 gpm) when this steady- state extraction flow rate was first reached. From March 2023 through August 2023, extraction rates gradually declined from a peak of 540 gpm in the initial operating period. This is attributed to the established declines seen in water levels in the Black Creek aquifer upgradient of the remedy. Section 6.2.1 describes the reduction in groundwater elevation upgradient of the barrier wall stabilized since the completion of the barrier wall and the implementation of the long-term remedy components. As shown in Table 4-3, the flow rates in the Willis Creek (Northern Alignment) are lower than the Barrier Wall (Southern Alignment) (in March, the average Willis Creek EW pumped about 3.7 gpm, whereas the average EW in the Southern Alignment pumped about 5.1 gpm). This is consistent with previous work at the site (Geosyntec, 2021 and Geosyntec, 2022) which indicates that the aquifer sands in this area are generally much thinner, less connected, and less transmissive than aquifer sands in the Southern Alignment. TR0795 — CFR Long -Term Remedy Performance Monitoring Report #5 13 June 2024 Geosynlec consultants Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 5 004 TREATMENT PLANT Section 5 provides GWTP operational data collected by Veolia as the operator of the treatment system and discusses the performance of the treatment relative to the design objectives and the COA, which requires that extracted groundwater is treated to remove PFAS compounds4 by at least 99%. As with the GWEC system, the 004 GWTP has been operating since March 14, 2023. Chemours reports various GWTP performance data in electronic Discharge Monitoring Reports (eDMRs) per the National Pollutant Discharge Elimination System (NPDES) permit NC0090042, and additionally provides laboratory reports and an analysis of the treatment efficiency (in percent removal of the indicator compounds HFPO-DA, PMPA, and PFMOAA) in a data transmittal process to North Carolina Department of Environmental Quality (NCDEQ). This Report does not reproduce that effort, and only reports on the flow and treatment aspects to comply with COA Paragraph 2.c.v. The following data are consistent with the eDMRs and data transmittals. 5.1 Data Collected 5.1.1 Flow Rates Veolia measures flow at the combined influent and effluent monitoring locations as required by the NPDES permit. Flow measurements are collected by the meters at a 15-minute frequency. 5.1.2 PFAS Influent and Effluent Veolia collects weekly (at a minimum) samples of the total influent and effluent per NPDES reporting requirements. Once per month, the samples are analyzed for Table 3+ PFAS, and once per quarter, the samples are analyzed for Table 3+ and EPA Method 537 MOD. The remaining weekly samples are analyzed for indicator compounds HFPO-DA, PFMOAA, and PMPA. All samples were analyzed by Eurofins TestAmerica Laboratories. 5.2 Results 5.2.1 Flow Rates The daily total influent volume, the volume treated and discharged, and the average daily discharge flow rate, are provided in Table 5-1. As shown, the GWTP treated and discharged a total volume of 47.8 MG over the reporting period. The average daily flow rate for this duration was 365 gpm. This is 6% higher in comparison to the previous period (344 gpm in Q4 2023). 4 As measured by indicator parameters hexafluoropropylene oxide dimer (HFPO-DA), perfluoromethoxypropyl carboxylic acid (PMPA), and perfluoro-2-methoxyaceticacid (PFMOAA) TR0795 — CFR Long -Term Remedy Performance Monitoring Report #5 14 June 2024 Geosyntec consultants Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 5.2.2 Analytical Results The laboratory analytical results for the influent and effluent samples are shown in Table 5-2. Laboratory analytical reports for 004 samples are compiled in Appendix A. As shown, the total Table 3+ (17 compounds) PFAS concentration in the influent ranged from 110,000 to 140,000 ng/L. The Table 3+ (17 compounds) PFAS analytes were not detected above laboratory reporting limits in effluent samples, indicating at least 99% removal as documented in data transmittals from Chemours to NCDEQ. 5.2.3 PFAS Mass Removal The flow rate data (monthly totals) and PFAS concentration data (monthly representative concentration per the monthly or quarterly samples, which in this reporting period were collected on January 2, February 12, and March 11) were used to calculate Table 3+ PFAS mass removal. As shown below, the total Table 3+ PFAS mass removed (17 compounds) by the GWTP in the reporting period (Q 1 2024) was 50.5 lbs. Through the end of the previous period (Q4 2023), 252.4 lbs of PFAS was removed. Therefore, the amount of PFAS removed from commissioning through March 31, 2024 is 302.9 lbs. Total Table 3+ (17 Reporting Total Volume Compounds) PFAS Table 3+ (17 Compounds) Month T Treated by Concentration per PFAS Mass Removed (lbs) GWTP (MG) Monthly/Quarterly Sample (ng/L) January 16.9 140,000 19.8 February 14.6 130,000 15.8 March 16.3 110,000 14.9 Q1 2024 Total 47.8 N/A 50.5 TR0795 — CFR Long -Term Remedy Performance Monitoring Report #5 15 June 2024 Geosyntec consultants Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 6 PERFORMANCE MONITORING EVALUATION A Performance Monitoring Plan (PMP) was prepared to address long-term groundwater remedial action effectiveness. The PMP proposed to evaluate the effectiveness of the remedy with multiple lines of evidence, which are listed below and discussed in more detail in this section: • Hydraulic head both along the barrier wall alignment and downgradient of the barrier wall between the wall and the Cape Fear River, to assess groundwater capture and the reduction in hydraulic gradient downgradient of the remedy alignment; • Passive flux meters (PFMs), to evaluate downgradient groundwater Darcy flux; • Surface water samples at Willis Creek, to evaluate reduction in PFAS loading to Willis Creek; • Surface water samples at Tar Heel Ferry Road, to evaluate PFAS concentrations and mass loads in the well -mixed Cape Fear River downstream of the facility; and • Groundwater sampling at extraction and monitoring wells between the groundwater remedy and the Cape Fear River or Willis Creek. 6.1 Data Collected 6.1.1 Hydraulic Head and Surface Water Elevation Monthly gauging events of 83 observation wells (OWs) was performed on January 31, February 27, and March 27, 2024. The hydraulic head monitoring network is shown in Figure 6-1. In addition to these manual gauging events, transducers were also deployed in a network of 16 wells that comprise 6 transects that span across the barrier wall alignment. These transducers were deployed on March 8, 2023, during the final GWEC commissioning and about one week prior to the March 14, 2023 operational startup. The transducers record groundwater elevation every 15 minutes and are downloaded monthly. Finally, data is incorporated from three transducer stilling wells that were installed at Willis Creek between September 20 and October 6, 2023. 6.1.2 PFAS Concentrations in Groundwater and Surface Water Downgradient Groundwater PMP wells, to be sampled on a semi-annual basis (Q1 and Q3), were sampled between January 17 and February 6, 2024. Out of the 20 PMP wells, 18 were sampled in Q 12024. PIW-1 OS and PIW- 5SR were not sampled because these wells have become consistently dry due to the long-term remedy. The 20 PMP wells are OW-4R, OW-30, OW-32, OW-37, OW-40, OW-51, OW-54, OW- TR0795 — CFR Long -Term Remedy Performance Monitoring Report #5 16 June 2024 Geosyntec consultants Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 55, OW-56, OW-57, PIW-4D, PIW-5SR, PIW-6S, PIW-8D, PIW-IODR, PIW-IOS, PIW-11, PIW- 15, PW-IORR, and PW-11. Mass Loading Model (MLM) wells are sampled quarterly. A total of 14 MLM monitoring wells are downgradient of the long-term remedy and are therefore potentially viable data points for effectiveness monitoring (OW-28, OW-33, LTW-01, LTW-02, LTW-03, LTW-04, LTW-05, PIW-1S, PIW-1D, PIW-3D, PIW-7S, PIW-7D, PZ-22, and SMW-12). These MLM wells were sampled from January 15 through 31, 2024. The collected samples were sent to Eurofins TestAmerica Laboratories for analysis by Table 3+ and EPA Method 537 MOD. Willis Creek Surface Water At three locations within Willis Creek (WC), routine quarterly sampling was performed to evaluate potential long-term reductions in concentration (reductions in the short-term are not necessarily anticipated). The sampling procedures were in accordance with the Cape Fear River PFAS Mass Loading Assessment Report series (Geosyntec, 2024b). WC-1, WC-2, and WC-3 were sampled on February 22, 2024. The collected samples were sent to Eurofins TestAmerica Laboratories for analysis by Table 3+ and EPA Method 537 MOD. Cape Fear River Surface Water Surface water grab samples were collected on March 12, 2024 at four transects along the Cape Fear River. Each transect consisted of three sampling locations, for a total of 12 sampling points. The sampling program was in accordance with the Final National Pollutant Discharge Elimination System (NPDES) Permit for Outfall 004 (Permit: NC0090042). The collected samples were sent to Eurofins TestAmerica Laboratories for analysis by Table 3+. From March 2020 through December 2023, sampling under this permit was performed on a monthly basis. Starting Q1 2024, samples are to be collected quarterly (i.e., six months after the completion of the barrier wall as per the Permit requirements). Since March 2020, routine sampling of the Cape Fear River has been performed at Tar Heel Ferry Road Bridge (or Tar Heel, approximately 7 miles downstream of the Site). The sampling program was in accordance with the Paragraphs 1(a) and 1(b) of the Addendum to Consent Order paragraph 12 (CO Addendum). Composite samples were collected generally twice per week using an autosampler. Grab samples were collected when the composite sampling program was temporarily interrupted due to various factors such as vandalism, equipment malfunction, or high river stages which may flood the autosampler. The collected samples were sent to Eurofins TestAmerica Laboratories for analysis by Table 3+. 6.1.3 Passive Flux Meters The first post -startup deployment of PFMs was conducted in August 2023 and its results were discussed in CFR Long -Term Remedy Performance Monitoring Report #3 (Geosyntec, 2023d). TR0795 — CFR Long -Term Remedy Performance Monitoring Report #5 17 June 2024 Geosynlec consultants Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 The next post -startup deployment is planned for June 2024, and results will be presented in CFR Long -Term Remedy Performance Monitoring Report #6 documenting the Q2 2024 period. 6.2 Results 6.2.1 Hydraulic Head and Surface Water Elevation This section discusses hydraulic head which is a critical line of evidence for evaluating hydraulic containment of groundwater. This section is developed in the following sequence: 1. As the Cape Fear River can influence some wells screened in the Black Creek aquifer, this section will first discuss the river conditions during each gauging event. Notably, during high river stages (flooding), this can exert a pressure response on the confined aquifer that has connectivity to the river. 2. The results in the Southern Alignment (Barrier Wall portion) are discussed next, which includes discussion of both the Black Creek aquifer and the surficial aquifer. 3. Last, the results in the Northern Alignment (Willis Creek area) are evaluated separately from the Southern Alignment. 1. River Stage During Gauging Events Hydraulic connectivity between the Black Creek aquifer and the Cape Fear River was discussed in CFR Long -Term Remedy Performance Monitoring Report #1 (Geosyntec, 2023b). As before, river levels for each gauging event in this reporting period were obtained from the USGS Huske station 02105500. The average river elevation for the duration of the gauging event (e.g., from 8AM to 4PM) was calculated from the 15-minute frequency data available from USGS. These average levels were compared to the available historical dataset (2007 to 2020) to calculate the corresponding percentile values, to show whether those gauging events were performed on relatively high or low river conditions. As shown below, the three gauging events in this period included a high -river event in January (89d' percentile) and two near -average events in February and March (51" and 63rd percentile). TR0795 — CFR Long -Term Remedy Performance Monitoring Report #5 18 June 2024 Geosyntec consultants Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 Date Type Average River Level During Gauging Event (ft NAVD88) Percentile (Gauging Event River Level compared to Historical Dataset) 8/4/2022 Baseline (dry summer) 30.38 52% 8/17/2022 Baseline (dry summer) 29.80 37% 1/30/2023 Baseline (wet winter) 32.50 79% 1 /31 /2024 Post -Startup (Q 1 2024) 34.30 89% 2/27/2024 Post -Startup (Q1 2024) 30.33 51% 3/27/2024 Post -Startup (Q1 2024) 30.98 63% 2. Southern Alignment (Barrier Wall) 2a. Reduction in Groundwater Flux Downgradient of Barrier Wall Table 6-1 provides groundwater elevation data for the Southern Alignment that is additionally delineated based on location relative to the barrier wall (upgradient or downgradient). Antecedent rainfall data for the previous three days are also included. Similar to the previous CFR Long -Term Remedy Performance Monitoring reports, Table 6-1 shows widespread drawdown in the Black Creek aquifer since the January 2023 baseline, and stabilized mounding of the surficial aquifer upgradient of the barrier wall. As shown in Figures 6-2A-D, the groundwater elevation data from Table 6-1 has been used to generate 11 gradient maps downgradient of the wall, with plots of the baseline data (August 17, 2022 and January 30, 2023 in greyscale5) compared to the January, February, and March gauging events (in green, blue, and red, respectively). Consistent with previous reports, the data for the three events demonstrate that the gradients in these downgradient sections have reduced (i.e., flattened) significantly: • Transects la, 2, 5, 7, and 8 indicate an essentially flat gradient. At the distal end (i.e., the most downgradient and closest to the Cape Fear River) of some of these transects, there is an apparent slight inward gradient. This is attributed to the demonstrated effect of increases 5 Transects la/lb and 2 at the southern end of the alignment were added to Report #3 per NCDEQ request. These transects include wells that were not accessible to install until after the barrier wall was complete, therefore baseline data is not available in all cases. For OW-39 in particular which is used in both Transects la and lb, the nearest available baseline data in EWs 63, 64, and 65, as well as PIW-1ODR to the east, indicate the baseline groundwater elevation in this vicinity ranged from approximately 59-64 ft NAVD88, which is substantially greater than the values measured in Q1 2024 (around 40.7 ft NAVD88), indicating a significant reduction in gradient in this area. TR0795 — CFR Long -Term Remedy Performance Monitoring Report #5 19 June 2024 Geosyntec consultants Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 in river elevation causing a corresponding increase in groundwater levels in monitoring wells screened within the Black Creek Aquifer, particularly in locations closest to the river. • Transects lb, 3, 4, 6a, and 9 indicate that the average Q1 2024 gradient was approximately 72% less than baseline, which is similar to previous reporting periods. o Transect 6b gradient comparisons cannot be performed because baseline elevation data for OW-52 and OW-53 are not available, as well construction for these wells was initially conflicted by barrier wall installation. • Despite the January gauging event being affected by the river flood event (i.e., generally increasing groundwater elevations in the downgradient area), the overall reduction in gradient is consistent with the relatively drier February and March events. The long-term remedy reduces groundwater flux beyond the barrier wall in both low and high river conditions. 2b) Hydraulic Separation of Barrier Wall In CFR Long -Term Remedy Performance Monitoring Report #2, transducer data were used to illustrate the separation of the Black Creek aquifer by the barrier wall, as the April 2023 flood event (with a peak river elevation of approximately 45 ft NAVD88) caused a clear effect on groundwater elevations downgradient of where the barrier wall had been constructed, but no discernible effect on groundwater elevations upgradient of the partially constructed wall. Where this effect was demonstrated (Transects 4, 5, and 6) the upgradient transducers were redeployed to downgradient areas, to monitor the downgradient area over the long-term. Where this effect was not able to be demonstrated yet, the transducers were not moved. As discussed in CFR Long -Term Remedy Performance Monitoring Report #4, in late December 2023, the Cape Fear River flooded for the first time since April 2023, but to a less significant extent, with a peak river elevation of approximately 39.5 ft NAVD88. In mid -January 2024, the Cape Fear River flooded again, reaching a peak river elevation close to 45 ft NAVD88. Figures 6- 3A-C show the transect plots of the transducer data for Q1 2024 above the Cape Fear River hydrograph. Transects 1, 2, and 3 demonstrate the hydraulic separation of the barrier wall, with an increase in groundwater elevation in the downgradient wells (green colors) and no discernible effect on the upgradient wells (orange). Since this separation has now been demonstrated across all transects in the wall alignment, the upgradient transducers were redeployed in late April 2024. 3. Northern Alignment (Willis Creek) 3a. Flood Response in Willis Creek Extraction Wells The river flooding event in January 2024 was also observed in the Willis Creek EWs, demonstrating Black Creek aquifer connectivity to surface water as noted for April and December TR0795 — CFR Long -Term Remedy Performance Monitoring Report #5 20 June 2024 Geosyntec consultants Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 2023 flood events discussed in previous reports. The Willis Creek elevation (shown in thick blue line) is compared to the 15 Willis Creek EWs in Figures 6-4A-C (five wells per chart for clarity): • In EWs that were pumping continuously prior to the flood event and therefore at a relatively stable water level (EW-01, 02, 05, 06 and 14), the rising river elevation that began on January 10 caused a subsequent rise in water levels in the wells. • In EWs that were pumping intermittently prior to the flood, the rising water levels generally caused the pumps to be able to run continuously, or at a much higher frequency (EW-03, 04, 06, 07, 08, 10, 12, and 13). At EW-03 for example, the oscillating water level trend prior to the flood is clearly stabilized during the surge response from the river flood and remained so through January. The flow totals for the week prior to the flood and the week after the flood are shown in each figure to demonstrate the effect the rising water levels had on increasing yield from these wells. • In EWs that were water -limited prior to the flood, the rising water levels in one case allowed the pump to activate in an intermittent mode (EW-11). In other cases, the flood caused a water level increase in the well, but not sufficient to activate the pump level switch (EW-09 and 15). Overall, as a consequence of flooding, the increase in groundwater elevation in the Willis Creek EWs temporarily increases pumping yields until groundwater elevations decline to pre -flood conditions. This indicates the capability of the Willis Creek extraction well pumps to withdraw groundwater yields, and the overall limited amount of transmissivity of the aquifer material in non - flood steady-state conditions. 3b. Hydraulic Containment of Willis Creek Black Creek Aquifer Groundwater elevation differences relative to January 2023 are shown for the January, February, and March gauging events in Figures 6-5A-C. Consistent with previous reports, the largest reduction of groundwater elevation relative to January 2023 occurred in the midsection of the Northern Alignment between EW-05 and EW-06. In January 2024, this elevation difference was not as significant as February and March 2024 due to the flood event, but the pattern of drawdown was still similar, and nearly 6 ft of drawdown was still observed around EW-05 and EW-06. Laterally along the alignment north of EW-05 and south of EW-06, elevation reductions between about 2 ft and 7 ft were observed from proximity of OW-14 (near the beginning of the barrier wall at EW-14) to OW-41 (in between EW-01 and EW-02). Drawdown along the alignment has also resulted in four EWs with insufficient water to pump, as compared to startup, demonstrating overlapping influence within the EWs from the collective pumping. The extensive drawdown is a line of evidence of hydraulic control. TR0795 — CFR Long -Term Remedy Performance Monitoring Report #5 21 June 2024 Geosyntec consultants Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 Potentiometric contour maps are provided for gauging events from January through March 2024 in Figures 6-6A-C. The January 2023 contours are shown in each figure as magenta solid lines. In January 2023, groundwater generally flows from SMW-03B (near the facility) in a northeastern direction towards the alignment. The January 2023 groundwater elevations around EW-01 and EW-02 are higher than the remainder of the alignment (on average approximately 45 ft NAVD88, as compared to approximately 30 ft NAVD88 from EW-03 to EW-15) which results in an eastward gradient towards EW-03, which is consistent with previous observations and reports for the Site (e.g., the Mass Loading Model reports). Figures 6-6A-C also provide surface water elevation at Willis Creek locations where stilling wells SW-01 through SW-05 have been installed, providing a comparison between groundwater and surface water elevations. Based on the available Q1 2024 gauging data, at SW-01 and SW-04, surface water elevations were within a few ft of groundwater elevations along Willis Creek. Surface water elevation was higher at SW-03 (33.28 ft and 33.35 ft) than elevations at nearby wells i.e., PIW-12 through PIW-14 (26.73 ft to 30.99 ft). Surface water elevation at SW-05 (35.99 ft to 36.86 ft) was lower than the nearby OW-57 (43.87 ft to 44.04 ft). However, this staff gauge is hundreds of ft away from the alignment where there is a clear hydraulic gradient of groundwater heading east toward the productive pumping areas between EW-03 and EW-08. 6.2.2 PFAS Concentrations and Mass Discharge in Groundwater and Surface Water Downgradient Groundwater PFAS Concentrations Results for the PMP and MLM wells sampled in Q 12024 that are downgradient of the long-term remedy (32 total) are provided in Table 6-2 and shown in Figure 6-7A-C. Laboratory analytical reports for the downgradient groundwater samples are compiled in Appendix A. The long-term remedy is not anticipated to have immediate impact on the downgradient PFAS concentrations, as the hydraulic remedy was designed to reduce the flux of groundwater to the river. Future reports will continue to evaluate potential long-term impacts to PFAS concentrations, if observed. However, when evaluated in conjunction with the reduced hydraulic gradients in the downgradient area, a reduction in PFAS mass discharge to the river is evident. This reduction in mass discharge is evaluated in the MLM quarterly report for this same reporting period, submitted concurrently with this report (Geosyntec, 2024c). Willis Creek Surface Water — Concentration and Mass Discharge Results for the Willis Creek surface water PFAS samples collected in Q 1 2024 are shown in Table 6-3, and also presented in Figure 6-7A-C (along with the downgradient groundwater PFAS data). Willis Creek PFAS trends since July 2022 are shown along with the Willis Creek hydrograph data from stilling well location WC-1 in Figure 6-8. Laboratory analytical reports for Willis Creek are compiled in Appendix A. TR0795 — CFR Long -Term Remedy Performance Monitoring Report #5 22 June 2024 Geosyntec consultants Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 A mass discharge analysis of Willis Creek was performed to evaluate if declines have begun to be observed. Table 6-4 shows the PFAS mass discharged at location WC-2 (upstream of remedy) and at location WC-1 (downstream of remedy). As shown, prior to startup in March 2023, the mass discharge at upstream location WC-2 ranged from 0.18 to 0.32 mg/s and the mass discharge at downstream location WC-1 ranged from 0.45 to 0.52 mg/s. The delta between the two locations is shown, and on average, the pre -startup change in mass loading is approximately 0.23 mg/s (a range of 0.16 to 0.31 mg/s). The February 2024 result of 0.11 mg/s is similar to the May 2023 and July 2023 results of 0.11 and 0.06 mg/s, respectively. Overall, the post -startup values on average (0.09 mg/s) indicate an approximate 60% mass discharge decline post-startup6. This apparent reduction effect will continue to be evaluated in future reports. Cape Fear River Surface Water — Concentration and Mass Discharge The Cape Fear River transect sampling locations are shown in Figure 6-9. The results of the three indicator compounds (HFPO-DA, PFMOAA, and PMPA) are shown in Figures 6-10. The transects for March 2024 were collected during periods of relatively high -river flow with flows ranging between 9,630 to 10,200 cubic feet per second (cfs). PFMOAA was observed in one sampling location of Transect 4. No other indicator compounds were observed. As described previously, inflows (e.g. offsite groundwater, Willis Creek, Lock and Dam seeps, the downstream offsite seeps, etc.) of Table 3+ PFAS into the Cape Fear River are not fully mixed at the transect locations and therefore concentration profiles along the transect are not necessarily homogeneous. In contrast, the mass discharge plots for the samples collected at Tar Heel (Figure 6-11) provide a mixed river location and take both flow and concentration into account. As shown, the mass discharges have decreased and remain lower than the mass discharges before Q3 2021, which corresponds to the time when the FTCs, 003 and groundwater extraction and barrier wall remedies and were installed and operating. 6 Including the November 2023 event in this comparison would have yielded an even greater mass discharge decline (80%), however it was excluded as a precaution as there was a slightly higher river stage during the event which may have caused backflowing river water into WC-1, contributing to a lower concentration at WC-1 than WC-2. TR0795 — CFR Long -Term Remedy Performance Monitoring Report #5 23 June 2024 Geosyntec consultants Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 7 SUMMARY This reporting period (January 1 to March 31, 2024) included the operation of the interim Flow - Through Cells, Ex -Situ Capture Systems, GWEC, and GWTP remedy components. The table below summarizes the flow capture and the Table 3+ (17 compounds) PFAS removal for each remedy element. Report Period (Jan — Mar 2024) Cumulative through Mar 2024* Remedy Element Flow Captured/ Mass Removed Flow Captured/ Mass Removed Treated (MG) (lbs) Treated (MG) (lbs) Interim FTCs 10.1 3.0 428.4 551.1 004 Treatment Plant 47.8 50.5 245.0 302.9 Ex -Situ Capture 5.9 Included in 004 17.4 Included in 004 Systems GWEC 44.4 Included in 004 233.3 Included in 004 Total" 57.9 53.5 673.4 854.0 (Interim FTCs + 004) *Cumulative values reflect the lifetime operation of each remedy component (e.g., since December 2020 for Interim FTC Seep Q. Please note that some previous reports have reported the total mass removed of 20 Compounds. Mass removal in this report for all remedy components is reported as 17 Compounds. **Differences inflow totals are attributable to the measurement resolution offlow meters on the different remedy systems as well as storage time in the surge pond, break tank, and other components. The calculated total influent of the Ex -Situ Capture Systems and GWEC system above is 50.3 MG for Q1 2024. The total influent as measured by Veolia's flow meter was 49.1 MG. The total effluent as measured by Veolia's flow meter was 47.8 MG as shown. Flow into the interim FTCs has decreased significantly since the completion of the barrier wall and implementation of the Ex -Situ Capture Systems and GWEC system. Between July 2021 and June 2023, the interim FTCs collectively processed 14.8 MG per month on average. Between July 2023 and March 2024, the average monthly volume was 2.6 MG. Batch mode processing has been necessary in order to maintain treatment efficiency at the reduced flow rates. During dry weather, with the FTCs offline, the impoundment elevations at the FTCs either remain stagnant or decrease, indicating that the long-term remedy components have eliminated the seep baseflow. As the FTCs now treat predominately rainwater mixed with stagnant residual groundwater, the concentration of PFAS in the influent has also decreased. Between July 2021 and June 2023, the average influent PFAS concentration (Total Table 3+, 17 compounds) across the four FTCs was approximately 150,300 ng/L; between July 2023 and March 2024, it was 35,200 ng/L. Overall, the combination of significantly reduced flow and concentration has resulted in a mass discharge into the FTCs that is approximately 96% reduced from baseline conditions, and an asymptotic PFAS mass removal trend. TR0795 — CFR Long -Term Remedy Performance Monitoring Report #5 24 June 2024 Geosyntec consultants Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 The GWEC system has been operating at a steady-state cumulative extraction rate since approximately September 2023, after the extraction well startup in March 2023 resulted in initial declines in the Black Creek aquifer water levels. The average pumping rate in Q1 2024 was 337 gallons per minute. The Ex -Situ Capture systems flow trends are dependent on weather conditions and are therefore more variable. The 004 GWTP removed greater than 99% of PFAS7 from the combined flow of the GWEC and Ex -Situ Capture Systems. Performance monitoring activities, including hydraulic head monitoring and surface water sampling, are also documented in this Report. Similar to the previous reporting period, performance monitoring indicates that the GWEC system has resulted in a reduction in gradient between the barrier wall and the Cape Fear River, thus reducing groundwater PFAS flux to the Cape Fear River. This reduction in PFAS mass discharge is evident in the diminished flows into the FTCs and is also documented in a report for the Mass Loading Model (MLM) program, submitted for the same reporting period concurrent to this Report (Geosyntec, 2024a). Collectively, the Willis Creek EWs are exerting drawdown of the Black Creek aquifer along the length of the alignment, particularly in the midsection, with nearly 8 feet of groundwater elevation reduction observed in monitoring wells. Drawdown along the alignment has also resulted in four EWs with insufficient water to pump, as compared to startup, demonstrating overlapping influence within the EWs from the collective pumping. The extensive drawdown is a line of evidence of hydraulic control. Additionally, a reduction in Willis Creek mass discharges has been observed. At sampling locations WC-2 (upstream) and WC-1 (downstream near the confluence with the Cape Fear River), the post -startup mass discharge to Willis Creek along this reach is estimated to be approximately 60% less than pre -startup. 7 As measured by indicator parameters hexafluoropropylene oxide dimer (HFPO-DA), perfluoromethoxypropyl carboxylic acid (PMPA), and perfluoro-2-methoxyaceticacid (PFMOAA) TR0795 — CFR Long -Term Remedy Performance Monitoring Report #5 25 June 2024 Geosyntec consultants Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 8 REFERENCES AECOM, 2018. Poly and Perfluoroalkyl Substance Quality Assurance Project Plan For the Chemours Corporate Remediation Group. August 2018. Geosyntec, 2020a. Matrix Interference During Analysis of Table 3+ Compounds. Chemours Fayetteville Works. June 30, 2020. Geosyntec, 2020b. Interim Seep Remediation System Plan. Chemours Fayetteville Works. August 31, 2020. Geosyntec, 2021. Pre -Design Investigation Summary (Version 2). Chemours Fayetteville Works. June 29, 2021. Geosyntec, 2022. Groundwater and Seeps Remedy 90% Design Submittal. Chemours Fayetteville Works. March 25, 2022. Geosyntec, 2023a. Interim Seep Remediation Operation and Maintenance Report #14. Chemours Fayetteville Works. May 31, 2023. Geosyntec, 2023b. CFR Long -Term Remedy Performance Monitoring Report # 1 (previously titled as Groundwater and Seeps Remediation Report #1). Chemours Fayetteville Works. June 29, 2023. Geosyntec, 2023c. CFR Long -Term Remedy Performance Monitoring Report #2. Chemours Fayetteville Works. September 29, 2023. Geosyntec, 2023d. CFR Long -Term Remedy Performance Monitoring Report #3. Chemours Fayetteville Works. December 22, 2023. Geosyntec, 2024a. CFR Long -Term Remedy Performance Monitoring Report #4. Chemours Fayetteville Works. March 28, 2024. Geosyntec, 2024b. Cape Fear River PFAS Mass Loading Assessment - Fourth Quarter 2023 Report. Chemours Fayetteville Works. March 28, 2024. Geosyntec, 2024c. Cape Fear River HAS Mass Loading Assessment - First Quarter 2024 Report. Chemours Fayetteville Works. June 27, 2024. USEPA, 2009. USEPA Guidance for Labeling Externally Validated Laboratory Analytical Data for Superfund Use. USEPA-540-R-08-005. OSWER 9200.1-85. Office of Solid Waste and Emergency Response, United States Environmental Protection Agency. January 13, 2009. TR0795 - CFR Long -Term Remedy Performance Monitoring Report #5 26 June 2024 Geosyntec consultants Tables Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 TR0795C Table 1-1 Summary of Sampling and Monitoring Activities Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, North Carolina Remedy Component Sampling and Monitoring Activities in Reporting Period (Jan -Mar) In -Situ Seep Flow- During prolonged no -flow conditions, the FTCs were generally operated in batch mode (closed to flow) and thus there is no process flow to sample. The FTCs were opened to Through Cells (FTCs) flow as needed to manage accumulated water in the impoundments. When open to flow, 24-hour composite samples were collected for performance monitoring; water quality was monitored and sampled in the same 24-hour period as the performance monitoring interval; and weekly grab samples for breakthrough monitoring were collected. Ex -Situ Seeps and Weeps Capture •Flow rates and totalized flow every 15 minutes from each capture system Groundwater Extraction ■ Extraction Well Operational Data (flow, pressure, motor speed, and water level) every 15 minutes ■ Weekly grab sampling of Effluent for PFAS indicator compounds HFPO-DA, PFMOAA, and PMPA 004 Treatment Plant • Monthly grab sampling of Influent and Effluent for Table 3+ ■ Quarterly grab sampling of Influent and Effluent for Table 3+ and EPA Method 537 MOD ■ Various other parameters required per the NPDES permit and reported in the eDMR, but not reproduced here ■ Monthly water level gauging (January 31, February 27, and March 27, 2024) Performance ■ Quarterly surface water PFAS sampling at four transects of the Cape Fear River (March 12, 2024) Evaluation ■ Quarterly PFAS sampling of Willis Creek (WC) stations WC-1, 2, 3 (February 22, 2024) ■ PFAS sampling of downgradient monitoring wells under the MLM (quarterly) and PMP (semi-annually) sampling programs (January 15 to February 6, 2024) Notes: 1 - Additional sampling details (e.g., Sample IDs, composite periods, etc.) are provided in subsequent tables. PFAS - per- and polyfluoroalkyl substances HFPO-DA - hexafluoropropylene oxide-dimer acid PFMOAA - perfluoro-2-methoxyacetic acid PMPA - perfluoro-2-methoxypropionic acid EPA - Environmental Protection Agency NPDES - National Pollutant Discharge Elimination System PMP - Performance Monitoring Plan eDMR - electronic Discharge Monitoring Report MLM - Mass Loading Model TR0795C Page 1 of 1 June 2024 Table 2-1A FTC Operations and Maintenance Summary - Seep A Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, North Carolina Date Days Since Start= Bypass Spillway Flow? Sampling Performed Operational Mode Transducers Downloaded Maintenance Activities Completed Breakthrough Monitorin Performance Monitorin Wet Weather Monitoring Arrival Departure FB1 FB2 FBI FB2 01/02/2024 980 No Series Batch Mode X Closed inlet and mid valves. 01/03/2024 981 No Batch Mode Batch Mode N/A 01/04/2024 982 No Batch Mode Batch Mode N/A 01/05/2024 983 No Batch Mode Series Opened inlet and mid valves. 01/06/2024 984 -- X Series Series N/A 01/07/2024 985 No Series Series N/A 01/08/2024 986 No X Series Series X N/A 01/09/2024 987 Yes Series Series N/A 01/10/2024 988 Yes X Series Parallel N/A 01/16/2024 994 Yes Parallel Parallel X N/A 01/17/2024 995 No Parallel Parallel N/A 01/18/2024 996 No Parallel Series Skimmed and fluffed FBI and FB2. 01/19/2024 997 No Series Series N/A 01/20/2024 998 -- X Series Series N/A 01/22/2024 1,000 No X Series Series X N/A 01/23/2024 1,001 No Series Series N/A 01/24/2024 1,002 No Series Series N/A 01/25/2024 1,003 No Series Series N/A 01/26/2024 1,004 No Series Series N/A 01/29/2024 1,007 No X Series Series X N/A 01/30/2024 1,008 No Series Series N/A 01/31/2024 1,009 No X Series Series N/A 02/01/2024 1,010 No X X Series Series N/A 02/02/2024 1,011 No Series Batch Mode Closed inlet and mid valves. 02/05/2024 1,014 No Batch Mode Batch Mode X N/A 02/06/2024 1,015 No Batch Mode Batch Mode N/A 02/07/2024 1,016 No Batch Mode Batch Mode N/A 02/08/2024 1,017 No Batch Mode Batch Mode N/A 02/09/2024 1,018 No Batch Mode Series Opened inlet and mid valves. 02/12/2024 1,021 No Series Series X N/A 02/13/2024 1,022 No X Series Series N/A 02/14/2024 1,023 No X Series Series N/A 02/15/2024 1,024 No Series Series N/A 02/16/2024 1,025 No Series Series Skimmed and fluffed FB2. 02/19/2024 1,028 No Series Batch Mode X Closed inlet and mid valves. 02/20/2024 1,029 No Batch Mode Batch Mode N/A 02/21/2024 1,030 No Batch Mode Batch Mode N/A 02/22/2024 1,031 No Batch Mode Batch Mode N/A 02/23/2024 1,032 No Batch Mode Batch Mode N/A 02/26/2024 1,035 No Batch Mode Batch Mode X N/A 02/27/2024 1,036 No Batch Mode Batch Mode N/A 02/28/2024 1,037 No Batch Mode Batch Mode N/A 02/29/2024 1,038 1 No Batch Mode Batch Mode N/A TR0795C Pagel of 8 June 2024 Table 2-1A FTC Operations and Maintenance Summary - Seep A Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, North Carolina Date Days Since Start= Bypass Spillway Flow? Sampling Performed Operational Mode Transducers Downloaded Maintenance Activities Completed Breakthrough Monitorin Performance Monitorin Wet Weather Monitoring Arrival Departure FB1 FB2 FBI FB2 03/01/2024 1,039 No X Batch Mode Series Opened inlet and mid valves. 03/02/2024 1,040 No X Series Series N/A 03/04/2024 1,042 No Series Series X N/A 03/05/2024 1,043 No Series Series N/A 03/06/2024 1,044 No Series Closed Lead N/A 03/07/2024 1,045 Yes X Closed I Lead Parallel N/A 03/08/2024 1,046 No Parallel Series Skimmed and fluffed FBI and FB2. 03/10/2024 1,048 No Series Series N/A 03/11/2024 1,049 No X X Series Closed Lead X N/A 03/12/2024 1,050 No Closed Lead Closed I Lead N/A 03/13/2024 1,051 No Closed Lead Series Pumped water into cell. Skimmed and fluffed FB2. 03/14/2024 1,052 No Series Batch Mode Closed inlet and mid valves. 03/15/2024 1,053 No Batch Mode Batch Mode Pumped water into cell. 03/18/2024 1,056 No X Batch Mode Batch Mode X N/A 03/19/2024 1,057 No Batch Mode Batch Mode N/A 03/20/2024 1,058 No Batch Mode Batch Mode N/A 03/21/2024 1,059 No Batch Mode Batch Mode N/A 03/22/2024 1,060 No Batch Mode Series Opened inlet and mid valves. 03/23/2024 1,061 -- X Series Series N/A 03/25/2024 1,063 No Series Series X N/A 03/26/2024 1,064 No Series Series N/A 03/27/2024 1,065 No Series Series N/A 03/28/2024 1,066 No X Series Series N/A 03/29/2024 1,067 No Series Batch Mode Closed inlet and mid valves. Notes: 1 - Batch Mode indicates the inlet and transfer basin valves were closed and the flow -through cell experienced no flow. 2 - The "Notes" column that previously documented instances of flow and amount of freeboard observed has been replaced by Figures 2-2A-D and Figures 2-5A-D, showing discharge flow rates and staff gauge data at FTCs A-D. FBI - Filter Bed 1 FB2 - Filter Bed 2 N/A - Not Applicable TR0795C Page 2 of 8 June 2024 Table 2-1B FTC Operations and Maintenance Summary - Seep B Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, North Carolina Date Days Since Start= Bypass Spillway Flow? Sampling Performed Operational Mode Transducers Downloaded Maintenance Activities Completed Breakthrough Monitorin Performance Monitorin Wet Weather Monitoring Arrival Departure FB1 FB2 FBI FB2 01/02/2024 939 No Series Batch Mode X Closed inlet and mid valves. 01/03/2024 940 No Batch Mode Batch Mode N/A 01/04/2024 941 No Batch Mode Batch Mode N/A 01/05/2024 942 No Batch Mode Batch Mode N/A 01/07/2024 944 No Batch Mode Batch Mode N/A 01/08/2024 945 No Batch Mode Batch Mode X N/A 01/09/2024 946 No Batch Mode Series Opened inlet and mid valves. 01/10/2024 947 No X Series Series N/A 01/16/2024 953 No Series Series X N/A 01/17/2024 954 No Series Series N/A 01/18/2024 955 No Series Series N/A 01/19/2024 956 No Series Series Skimmed and fluffed FBI and FB2 and replaced fabric. 01/20/2024 957 -- X Series Series N/A 01/22/2024 959 No X Series Series X N/A 01/23/2024 960 No Series Series N/A 01/24/2024 961 No Series Series N/A 01/25/2024 962 No X Series Series N/A 01/26/2024 963 No Series Series N/A 01/29/2024 966 No X Series Series X N/A 01/30/2024 967 No Series Series N/A 01/31/2024 968 No X Series Series N/A 02/01/2024 969 No X X Series Batch Mode Closed inlet and mid valves. 02/02/2024 970 No Batch Mode Batch Mode N/A 02/05/2024 973 No Batch Mode Batch Mode X N/A 02/06/2024 974 No Batch Mode Batch Mode N/A 02/07/2024 975 No Batch Mode Batch Mode N/A 02/08/2024 976 No Batch Mode Batch Mode N/A 02/09/2024 977 No Batch Mode Series Opened inlet and mid valves. 02/12/2024 980 No Series Series X N/A 02/13/2024 981 No X Series Series N/A 02/14/2024 982 No X Series Series N/A 02/15/2024 983 No Series Series N/A 02/16/2024 984 No Series Batch Mode Closed inlet and mid valves. 02/19/2024 987 No Batch Mode Batch Mode X N/A 02/20/2024 988 No Batch Mode Batch Mode N/A 02/21/2024 989 No Batch Mode Closed I Batch Mode N/A 02/22/2024 990 No Changeout I Batch Mode Batch Mode Carbon changeout FBI. 02/23/2024 991 No Batch Mode Batch Mode N/A 02/26/2024 994 No Batch Mode Batch Mode X N/A 02/27/2024 995 No Batch Mode Batch Mode N/A 02/28/2024 996 No Batch Mode Batch Mode N/A 02/29/2024 997 No Batch Mode Batch Mode N/A TR0795C Page 3 of 8 June 2024 Table 2-1B FTC Operations and Maintenance Summary - Seep B Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, North Carolina Date Days Since Start= Bypass Spillway Flow? Sampling Performed Operational Mode Transducers Downloaded Maintenance Activities Completed Breakthrough Monitorin Performance Monitorin Wet Weather Monitoring Arrival Departure FB1 FB2 FBI FB2 03/O1/2024 998 No X Batch Mode Series Opened inlet and mid valves. 03/02/2024 999 No X Series Series N/A 03/04/2024 1,001 No Series Series X N/A 03/05/2024 1,002 No Series Series N/A 03/06/2024 1,003 No Series Series N/A 03/07/2024 1,004 No X Series Series N/A 03/08/2024 1,005 No Series Series N/A 03/10/2024 1,007 No Series Series N/A 03/11/2024 1,008 No X X Series Series X N/A 03/12/2024 1,009 No Series Batch Mode Closed inlet and mid valves. 03/13/2024 1,010 No Batch Mode Batch Mode N/A 03/14/2024 1,011 No Batch Mode Batch Mode N/A 03/15/2024 1,012 No Batch Mode Batch Mode N/A 03/18/2024 1,015 No Batch Mode Batch Mode X N/A 03/19/2024 1,016 No Batch Mode Batch Mode N/A 03/20/2024 1,017 No Batch Mode Batch Mode N/A 03/21/2024 1,018 No Batch Mode Batch Mode N/A 03/22/2024 1,019 No Batch Mode Series Opened inlet and mid valves. 03/23/2024 1,020 -- X Series Series N/A 03/25/2024 1,022 No Series Series X N/A 03/26/2024 1,023 No Series Series N/A 03/27/2024 1,024 No Series Series N/A 03/28/2024 1,025 No X Series Series N/A 03/29/2024 1,026 No Series Batch Mode Closed inlet and mid valves. Notes: 1 - Batch Mode indicates the inlet and transfer basin valves were closed and the flow -through cell experienced no flow. 2 - The "Notes" column that previously documented instances of flow and amount of freeboard observed has been replaced by Figures 2-2A-D and Figures 2-5A-D, showing discharge flow rates and staff gauge data at FTCs A-D. FBI - Filter Bed 1 FB2 - Filter Bed 2 N/A - Not Applicable TR0795C Page 4 of 8 June 2024 Table 2-1C FTC Operations and Maintenance Summary - Seep C Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, North Carolina Days Since Startup Bypass Spillway Flow? Sampling Performed Operational Mode Transducers Downloaded Maintenance Activities Completed Breakthrough Monitoring Performance Monitoring Wet Weather Monitoring Arrival Departure FB1 FB2 FBI ITFB2 01/02/2024 1,113 No X Series Series X N/A 01/03/2024 1,114 No Series Series N/A 01/04/2024 1,115 No Changeout I Lead Series Carbon changeout FBI. 01/05/2024 1,116 No Series Series N/A 01/06/2024 1,117 - X Series Series N/A 01/07/2024 1,118 No Series Closed I Lead FB2 run in sole. 01/08/2024 1,119 No X Series Parallel X N/A 01/09/2024 1,120 No Parallel Parallel N/A 01/10/2024 1,121 No X Parallel Parallel N/A 01/16/2024 1,127 Yes Parallel Parallel X N/A 01/17/2024 1,128 No Parallel Lag F Lead Skimmed and fluffed FBI and FB2. 01/18/2024 1,129 No Series Series N/A 01/19/2024 1,130 No Series Series N/A 01/20/2024 1,131 -- X Series Series N/A 01/22/2024 1,133 No X Series Series X N/A 01/23/2024 1,134 No Series Series N/A 01/24/2024 1,135 No Series Series N/A 01/25/2024 1,136 No Series Series N/A 01/26/2024 1,137 No Series Series N/A 01/29/2024 1,140 No X Series Series X N/A 01/30/2024 1,141 No Series Series N/A 01/31/2024 1,142 No X Series Series N/A 02/01/2024 1,143 No X X Series Series N/A 02/02/2024 1,144 No Series Batch Mode Closed inlet and mid valves. 02/05/2024 1,147 No Batch Mode Batch Mode X N/A 02/06/2024 1,148 No Batch Mode Batch Mode N/A 02/07/2024 1,149 No Batch Mode Batch Mode N/A 02/08/2024 1,150 No Batch Mode Batch Mode N/A 02/09/2024 1,151 No Batch Mode Series Opened inlet and mid valves. 02/12/2024 1,154 No Series Closed Lead X Placed FB2 in sole processing. 02/13/2024 1,155 No X Closed Lead Closed Lead N/A 02/14/2024 1,156 No X Closed Lead Series Skimmed and fluffed F132. 02/15/2024 1,157 No Series Series N/A 02/16/2024 1,158 No Series Batch Mode Closed inlet and mid valves. 02/19/2024 1,161 No Batch Mode Batch Mode X N/A 02/20/2024 1,162 No Batch Mode Batch Mode N/A 02/21/2024 1,163 No Batch Mode Batch Mode N/A 02/22/2024 1,164 No Batch Mode Series Opened inlet and mid valves. 02/23/2024 1,165 No Series Series N/A 02/24/2024 1,166 -- X Series Series N/A 02/26/2024 1,168 No Series Batch Mode X Closed inlet and mid valves. 02/27/2024 1,169 No Batch Mode Batch Mode N/A 02/28/2024 1,170 No Batch Mode Batch Mode N/A 02/29/2024 1,171 No Batch Mode Batch Mode N/A TR0795C Page 5 of 8 June 2024 Table 2-1C FTC Operations and Maintenance Summary - Seep C Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, North Carolina k03/01/2024 Days Since Startup Bypass Spillway Flow? Sampling Performed Operational Mode Transducers Downloaded Maintenance Activities Completed Breakthrough Monitoring Performance Monitoring Wet Weather Monitoring Arrival Departure FB1 FB2 FBI ITFB2 1,172 No X Batch Mode Series Opened inlet and mid valves. 03/02/2024 1,173 No X Series Closed Lead Placed FB2 in sole processing. 03/04/2024 1,175 No Closed I Lead Series X N/A 03/05/2024 1,176 No Series Series Skimmed and fluffed FB2. 03/06/2024 1,177 Yes Series Closed Lead N/A 03/07/2024 1,178 No X Closed Lead Closed Lead N/A 03/08/2024 1,179 No Closed Lead Series Skimmed and fluffed FB2. 03/10/2024 1,181 No Series Series N/A 03/11/2024 1,182 No X X Series Series X N/A 03/12/2024 1,183 No Series Series N/A 03/13/2024 1,184 No Series Series N/A 03/14/2024 1,185 No Series Series N/A 03/15/2024 1,186 No Series Batch Mode Closed inlet and mid valves. Pumped water into cell. 03/18/2024 1,189 No X Batch Mode Batch Mode X Skimmed and fluffed FB2. 03/19/2024 1,190 No Batch Mode Batch Mode N/A 03/20/2024 1,191 No Batch Mode Batch Mode Pumped water into cell. 03/21/2024 1,192 No Batch Mode Batch Mode N/A 03/22/2024 1,193 No Batch Mode Series Opened inlet and mid valves. 03/23/2024 1,194 -- X Series Series N/A 03/25/2024 1,196 No Series Series X N/A 03/26/2024 1,197 No Series Series N/A 03/27/2024 1,198 No Series Series N/A 03/28/2024 1,199 Yes X Series Series N/A 03/29/2024 1,200 No Series Series Skimmed and fluffed FB2. Notes: 1 - Batch Mode indicates the inlet and transfer basin valves were closed and the flow -through cell experienced no flow. 2 - The "Notes" column that previously documented instances of flow and amount of freeboard observed has been replaced by Figures 2-2A-D and Figures 2-5A-D, showing discharge flow rates and staff gauge data at FTCs A-D. FBI - Filter Bed 1 FB2 - Filter Bed 2 N/A - Not Applicable TR0795C Page 6 of 8 June 2024 Table 2-1D FTC Operations and Maintenance Summary - Seep D Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, North Carolina Date Days Since Startu Bypass Spillway Flow? Sampling Performed Operational Mode Transducers Downloaded Maintenance Activities Completed Breakthrough Monitoring Performance Monitoring Wet Weather Monitoring Arrival Departure FB1 FB2 FB1 FB2 01/02/2024 923 No Series Batch Mode X Closed inlet and mid valves. 01/03/2024 924 No Batch Mode Batch Mode N/A 01/04/2024 925 No Batch Mode Batch Mode N/A 01/05/2024 926 No Batch Mode Batch Mode N/A 01/07/2024 928 No Batch Mode Batch Mode N/A 01/08/2024 929 No Batch Mode Batch Mode X N/A 01/09/2024 930 No Batch Mode Series Opened inlet and mid valves. 01/10/2024 931 No X Series Series N/A 01/16/2024 937 Yes Series Series X N/A 01/17/2024 938 No Series Series N/A 01/18/2024 939 No Series Series Skimmed and fluffed FBI and FB2. 01/19/2024 940 No Series Series N/A 01/20/2024 941 -- X Series Series N/A 01/22/2024 943 No X Series Series X Backflushed FB2. 01/23/2024 944 No Series Series Skimmed and fluffed F132. 01/24/2024 945 No Series Series N/A 01/25/2024 946 No X Series Series N/A 01/26/2024 947 No Series Series N/A 01/29/2024 950 No X Series Series X N/A 01/30/2024 951 No Series Series N/A 01/31/2024 952 No X Series Lead Closed N/A 02/01/2024 953 No X X Lead Closed Lead I Closed Removed carbon at FB2. 02/02/2024 954 No Lead Changeout Batch Mode Carbon changeout at FB2. Closed inlet and mid valves. 02/05/2024 957 No Batch Mode Batch Mode X N/A 02/06/2024 958 No Batch Mode Batch Mode N/A 02/07/2024 959 No Batch Mode Batch Mode N/A 02/08/2024 960 No Batch Mode Batch Mode N/A 02/09/2024 961 No Batch Mode Series Opened inlet and mid valves. 02/12/2024 964 No Series Series X N/A 02/13/2024 965 No X Series Series N/A 02/14/2024 966 No X Series Series N/A 02/15/2024 967 No Series Series N/A 02/16/2024 968 No Series Batch Mode Closed inlet and mid valves. 02/19/2024 971 No Batch Mode Batch Mode X N/A 02/20/2024 972 No Batch Mode Batch Mode N/A 02/21/2024 973 No Batch Mode Batch Mode N/A 02/22/2024 974 No Batch Mode Batch Mode N/A 02/23/2024 975 No Batch Mode Batch Mode N/A 02/26/2024 978 No Batch Mode Batch Mode X N/A 02/27/2024 979 No Batch Mode Batch Mode N/A 02/28/2024 980 No Batch Mode Batch Mode N/A 02/29/2024 981 No Batch Mode Batch Mode N/A TR0795C Page 7 of 8 June 2024 Table 2-1D FTC Operations and Maintenance Summary - Seep D Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, North Carolina Date Days Since Start= Bypass Spillway Flow? Sampling Performed Operational Mode Transducers Downloaded Maintenance Activities Completed Breakthrough Monitorin Performance Monitorin Wet Weather Monitoring Arrival Departure FB1 FB2 FBI FB2 982 No X Batch Mode Series Opened inlet and mid valves. 03/02/2024 983 No X Series Series N/A 03/04/2024 985 No Series Series X N/A 03/05/2024 986 No Series Series N/A 03/06/2024 987 No Series Series N/A 03/07/2024 988 No X Series Series N/A 03/08/2024 989 No Series Series N/A 03/10/2024 991 No Series Series N/A 03/11/2024 992 No X X Series Series X N/A 03/12/2024 993 No Series Batch Mode Closed inlet and mid valves. 03/13/2024 994 No Batch Mode Batch Mode N/A 03/14/2024 995 No Batch Mode Batch Mode N/A 03/15/2024 996 No Batch Mode Batch Mode N/A 03/18/2024 999 No Batch Mode Batch Mode X N/A 03/19/2024 1,000 No Batch Mode Batch Mode N/A 03/20/2024 1,001 No Batch Mode Batch Mode N/A 03/21/2024 1,002 No Batch Mode Batch Mode N/A 03/22/2024 1,003 No Batch Mode Series Opened inlet and mid valves. 03/23/2024 1,004 -- X Series Series N/A 03/25/2024 1,006 No Series Series X N/A 03/26/2024 1,007 No Series Series Skimmed and fluffed FBI. 03/27/2024 1,008 No Series Series N/A 03/28/2024 1,009 No X Series Series N/A 03/29/2024 1,010 No Series Batch Mode Closed inlet and mid valves. Notes: 1 - Batch Mode indicates the inlet and transfer basin valves were closed and the flow -through cell experienced no flow. 2 - The "Notes" column that previously documented instances of flow and amount of freeboard observed has been replaced by Figures 2-2A-D and Figures 2-5A-D, showing discharge flow rates and staff gauge data at FTCs A-D. FBI - Filter Bed 1 FB2 - Filter Bed 2 N/A - Not Applicable TR0795C Page 8 of 8 June 2024 Table 2-2 Cape Fear River Elevation and Local Precipitation Statistics Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC Seep # of Days of Operation on Record Percent of Operation Over Lifetime of System[21 River Above FTC Wall Elevation River Above Bypass Spillway Elevation River Above GAC Elevation River Above Discharge Pipe Invert Elevation C 1,202 1.7% 2.2% 3.9% 9.8% A 1,069 1.0% 1.2% 2.2% 6.4% B 1,028 0.8% 1.1% 1.7% 4.5% D 1,012 1.1% 1.2% 2.4% 6.8% Historical Annual Average (2007-2020) E3'41 1.7% 2.2% 3.7% 9.6% Precipitation (inches) Current Reporting Period (January - March 2024) 9.49 Current Reporting Period Historical Average (January - March 2004-2020) "' 7.96 2024 Year -to -Date 9.49 Historical Year -to -Date Average (2004-2020) [5] 7.96 Historical Annual Average (2004-2020) E51 43.44 Notes: 1 - River elevation and precipitation data obtained from the USGS gauge #02105500 at the William O. Huske Lock and Dam. 2 - Operational period for river flooding statistics includes the entire lifetime of the system for each seep. 3 - Seeps A and D are approximately 1 foot lower in elevation than Seeps B and C. 4 - For clarity of presentation, historical river flooding averages based on Seep C elevations only. 5 - The historical average was calculated using available data when the Huske rain gauge was operable. TR0795C Pagel of 1 June 2024 Table 2-3A FTC Sampling Summary - Seep A Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, North Carolina Performance Monitoring Composite Samples Sample ID Composite Period Sample Date SEEP-A-INFLUENT-24-010624 January 6, 2024 January 6, 2024 SEEP-A-EFFLUENT-24-010624 SEEP-A-INFLUENT-24-011024 January 9 - January 10, 2024 January 10, 2024 SEEP-A-EFFLUENT-24-011024 SEEP-A-INFLUENT-24-012024 January 20, 2024 January 20, 2024 SEEP-A-EFFLUENT-24-012024 SEEP-A-INFLUENT-24-013124 January 30 - January 31, 2024 January 31, 2024 SEEP-A-EFFLUENT-24-013124 SEEP-A-INFLUENT-24-020124 January 31 - February 1, 2024 February 1, 2024 SEEP-A-EFFLUENT-24-020124 SEEP-A-INFLUENT-24-021324 February 12 - February 13, 2024 February 13, 2024 SEEP-A-EFFLUENT-24-021324 SEEP-A-INFLUENT-24-021424 February 13 - February 14, 2024 February 14, 2024 SEEP-A-EFFLUENT-24-021424 SEEP-A-INFLUENT-24-030224 March 1 - March 2, 2024 March 2, 2024 SEEP-A-EFFLUENT-24-030224 SEEP-A-INFLUENT-24-030724 March 6 - March 7, 2024 March 7, 2024 SEEP-A-EFFLUENT-24-030724 SEEP-A-INFLUENT-24-031124 March 10 - March 11, 2024 March 11, 2024 SEEP-A-EFFLUENT-24-031124 SEEP-A-INFLUENT-24-032324 March 23, 2024 March 23, 2024 SEEP-A-EFFLUENT-24-032324 SEEP-A-INFLUENT-24-032824 March 27 - March 28, 2024 March 28, 2024 SEEP-A-EFFLUENT-24-032824 Notes: I- Sample Identification Label Key: "Seep -[A, B, C, or D] -[Sample Location Inside FTC] - [# of Aliquots in Composite Sample] - [MMDDYY]" 2 - The FTC was operating under batch mode for part of January, February, and March 2024. Performance samples were not collected while the FTC was closed. TR0795C Page 1 of 4 June 2024 Table 2-3B FTC Sampling Summary - Seep B Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, North Carolina Performance Monitoring Composite Samples Sample ID Composite Period Sample Date SEEP-B-INFLUENT-24-011024 January 9 - January 10, 2024 January 10, 2024 SEEP-B-EFFLUENT-24-011024 SEEP-B-INFLUENT-24-012024 January 20, 2024 January 20, 2024 SEEP-B-EFFLUENT-24-012024 SEEP-B-INFLUENT-24-012524 January 24 - January 25, 2024 January 25, 2024 SEEP-B-EFFLUENT-24-012524 SEEP-B-INFLUENT-24-013124 January 30 - January 31, 2024 January 31, 2024 SEEP-B-EFFLUENT-24-013124 SEEP-B-INFLUENT-24-020124 January 31 - February 1, 2024 February 1, 2024 SEEP-B-EFFLUENT-24-020124 SEEP-B-INFLUENT-24-021324 February 12 - February 13, 2024 February 13, 2024 SEEP-B-EFFLUENT-24-021324 SEEP-B-INFLUENT-24-021424 February 13 - February 14, 2024 February 14, 2024 SEEP-B-EFFLUENT-24-021424 SEEP-B-INFLUENT-24-030224 March 1 - March 2, 2024 March 2, 2024 SEEP-B-EFFLUENT-24-030224 SEEP-B-INFLUENT-24-030724 March 6 - March 7, 2024 March 7, 2024 SEEP-B-EFFLUENT-24-030724 SEEP-B-INFLUENT-24-031124 March 10 - March 11, 2024 March 11, 2024 SEEP-B-EFFLUENT-24-031124 SEEP-B-INFLUENT-24-032324 March 23, 2024 March 23, 2024 SEEP-B-EFFLUENT-24-032324 SEEP-B-INFLUENT-24-032824 March 27 - March 28, 2024 March 28, 2024 SEEP-B-EFFLUENT-24-032824 Notes: I- Sample Identification Label Key: "Seep -[A, B, C, or D] -[Sample Location Inside FTC] - [# of Aliquots in Composite Sample] - [MMDDYY]" 2 - The FTC was operating under batch mode for part of January, February, and March 2024. Performance samples were not collected while the FTC was closed. TR0795C Page 2 of 4 June 2024 Table 2-3C FTC Sampling Summary - Seep C Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, North Carolina Performance Monitoring Composite Samples Sample ID Composite Period Sample Date SEEP-C-INFLUENT-24-010624 January 6, 2024 January 6, 2024 SEEP-C-EFFLUENT-24-010624 SEEP-C-INFLUENT-24-011024 January 9 - January 10, 2024 January 10, 2024 SEEP-C-EFFLUENT-24-011024 SEEP-C-INFLUENT-24-012024 January 20, 2024 January 20, 2024 SEEP-C-EFFLUENT-24-012024 SEEP-C-INFLUENT-24-013124 January 30 - January 31, 2024 January 31, 2024 SEEP-C-EFFLUENT-24-013124 SEEP-C-INFLUENT-24-020124 January 31 - February 1, 2024 February 1, 2024 SEEP-C-EFFLUENT-24-020124 SEEP-C-INFLUENT-24-021324 February 12 - February 13, 2024 February 13, 2024 SEEP-C-EFFLUENT-24-021324 SEEP-C-INFLUENT-24-021424 February 13 - February 14, 2024 February 14, 2024 SEEP-C-EFFLUENT-24-021424 SEEP-C-INFLUENT-24-022424 February 23 - February 24, 2024 February 24, 2024 SEEP-C-EFFLUENT-24-022424 SEEP-C-INFLUENT-24-030224 March 1 - March 2, 2024 March 2, 2024 SEEP-C-EFFLUENT-24-030224 SEEP-C-INFLUENT-24-030724 March 6 - March 7, 2024 March 7, 2024 SEEP-C-EFFLUENT-24-030724 SEEP-C-INFLUENT-24-031124 March 10 - March 11, 2024 March 11, 2024 SEEP-C-EFFLUENT-24-031124 SEEP-C-INFLUENT-24-032324 March 23, 2024 March 23, 2024 SEEP-C-EFFLUENT-24-032324 SEEP-C-INFLUENT-24-032824 March 27 - March 28, 2024 March 28, 2024 SEEP-C-EFFLUENT-24-032824 Notes: I- Sample Identification Label Key: "Seep -[A, B, C, or D] -[Sample Location Inside FTC] - [# of Aliquots in Composite Sample] - [MMDDYY]" 2 - The FTC was operating under batch mode for part of February and March 2024. Performance samples were not collected while the FTC was closed. TR0795C Page 3 of 4 June 2024 Table 2-3D FTC Sampling Summary - Seep D Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, North Carolina Performance Monitoring Composite Samples Sample ID Composite Period Sample Date EEP-D-INFLUENT-24-011024 !SEEP-D-EFFLUENT-24-011024 January 9 - January 10, 2024 January 10, 2024 SEEP-D-INFLUENT-24-012024 January 20, 2024 January 20, 2024 SEEP-D-EFFLUENT-24-012024 SEEP-D-INFLUENT-24-012524 January 24 - January 25, 2024 January 25, 2024 SEEP-D-EFFLUENT-24-012524 SEEP-D-INFLUENT-24-013124 January 30 - January 31, 2024 January 31, 2024 SEEP-D-EFFLUENT-24-013124 SEEP-D-INFLUENT-24-020124 January 31 - February 1, 2024 February 1, 2024 SEEP-D-EFFLUENT-24-020124 SEEP-D-INFLUENT-24-021324 February 12 - February 13, 2024 February 13, 2024 SEEP-D-EFFLUENT-24-021324 SEEP-D-INFLUENT-24-021424 February 13 - February 14, 2024 February 14, 2024 SEEP-D-EFFLUENT-24-021424 SEEP-D-INFLUENT-24-030224 March 1 - March 2, 2024 March 2, 2024 SEEP-D-EFFLUENT-24-030224 SEEP-D-INFLUENT-24-030724 March 6 - March 7, 2024 March 7, 2024 SEEP-D-EFFLUENT-24-030724 SEEP-D-INFLUENT-24-031124 March 10 - March 11, 2024 March 11, 2024 SEEP-D-EFFLUENT-24-031124 SEEP-D-INFLUENT-24-032324 March 23, 2024 March 23, 2024 SEEP-D-EFFLUENT-24-032324 SEEP-D-INFLUENT-24-032824 March 27 - March 28, 2024 March 28, 2024 SEEP-D-EFFLUENT-24-032824 Notes: I- Sample Identification Label Key: "Seep -[A, B, C, or D] -[Sample Location Inside FTC] - [# of Aliquots in Composite Sample] - [MMDDYY]" 2 - The FTC was operating under batch mode for part of January, February, and March 2024. Performance samples were not collected while the FTC was closed. TR0795C Page 4 of 4 June 2024 Table 2-4A FTC Performance Monitoring Analytical Results - Seep A Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC Table 3 +SOP (n /L) SEEP -A -INFLUENT 24-010624 Sample Date: 6-Jan-24 SEEP -A -EFFLUENT. 24-010624 Sample Date: 6-Jan-24 Percent Removal SEEP -A -INFLUENT- 24-011024 Sample Date: 10-Jan-24 SEEP -A -EFFLUENT 24-011024 Sample Date: 10-Jan-24 Percent Removal SEEP -A -INFLUENT 24-012024 Sample Date: 20-Jan-24 SEEP -A -EFFLUENT. 24-012024 Sample Date: 20-Jan-24 Percent Removal SEEP -A -INFLUENT- 24-013124 Sample Date: 31-Jan-24 SEEP -A -EFFLUENT 24-013124 Sample Date: 31-Jan-24 Percent Removal Hfpo Dimer Acid 7,100 6.1 99.9% 4,900 2.5 >99.9% 6,400 <2.0 >99.9% 7,700 2.9 >99.9% PFMOAA 21,000 75 99.6% 12,000 43 99.6% 12,000 16 99.9% 18,000 36 99.8% PFO2HxA 13,000 20 99.8% 9,100 5.6 99.9% 8,500 2.1 >99.9% 12,000 6.8 99.9% PFO3OA 3,600 5.6 99.8% 2,900 <2.0 >99.9% 2,400 <2.0 >99.9% 3,500 <2.0 >99.9% PFO4DA 1,500 <2.0 >99.9% 1,500 <2.0 >99.9% 920 <2.0 >99.9% 1,600 <2.0 >99.9% PFO5DA 710 <2.0 >99.9% 760 <2.0 >99.9% 330 <2.0 >99.9% 730 <2.0 >99.9% PMPA 7,100 20 99.7% 4,100 13 99.7% 4,600 <10 >99.9% 6,400 14 99.8% PEPA 2,500 <20 >99.9% 1,400 <20 >99.9% 1,800 <20 >99.9% 2,600 <20 >99.9% PS Acid <20 <2.0 >99.9% 200 <2.0 >99.9% <20 <2.0 >99.9% <20 <2.0 >99.9% Hydro -PS Acid 220 <2.0 >99.9% 210 <2.0 >99.9% 140 <2.0 >99.9% 290 <2.0 >99.9% R-PSDA 530 J <2.0 >99.9% 460 J <2.0 >99.9% 640 J <2.0 >99.9% 570 J <2.0 >99.9% Hydrolyzed PSDA 1,800 J <2.0 >99.9% 1,200 J <2.0 >99.9% 870 J <2.0 >99.9% 1,800 J <2.0 >99.9% R-PSDCA <17 <2.0 >99.9% <17 <2.0 >99.9% <17 <2.0 >99.9% <17 <2.0 >99.9% NVHOS, Acid Form 280 <2.0 >99.9% 190 <2.0 >99.9% 200 <2.0 >99.9% 350 <2.0 >99.9% EVE Acid <17 <2.0 >99.9% 84 <2.0 >99.9% <17 <2.0 >99.9% <17 <2.0 >99.9% Hydro -EVE Acid 230 <2.0 >99.9% 220 <2.0 >99.9% 140 <2.0 >99.9% 260 <2.0 >99.9% R-EVE 290 J <2.0 >99.9% 180 J <2.0 >99.9% 300 J <2.0 >99.9% 300 J <2.0 >99.9% Perfluoro(2-ethoxyethane)sulfonic Acid <6.7 <2.0 >99.9% <6.7 <2.0 >99.9% <6.7 <2.0 >99.9% <6.7 <2.0 >99.9% PFECA B <27 <2.0 >99.9% <27 <2.0 >99.9% <27 <2.0 >99.9% <27 <2.0 >99.9% PFECA-G 1 <48 1 <2.0 1 >99.90/, <48 <2.0 >99.9% <48 <2.0 >99.9% <48 <2.0 >99.9% Total Table 3+ (17 compounds) 1 2 57,000 0 38,000 99.8% 37,000 >99.9% 53,000 99.9% Notes: 1 - Total Table 3+ was calculated including J qualified data but not non -detect data. The total Table 3+ sum is rounded to two significant figures. 2 - Total Table 3+ (17 Compounds) does not include R-PSDA, Hydrolyzed PSDA and R-EVE. 3 - Sample Identification Label Key: "Seep - [A, B, C, or D] - [Sample Location Inside FTC] - [# of Aliquots in Composite Sample] - [MMDDYY]" Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. ng/L - nanograms per liter FTC - flow through cell SOP - standard operating procedure < - Analyte not detected above associated reporting limit. TR0795C Page 1 of 13 June 2024 Table 2-4A FTC Performance Monitoring Analytical Results - Seep A Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC Table 3 +SOP (n /L) SEEP -A -INFLUENT 24-020124 Sample Date: O1-Feb-24 SEEP -A -EFFLUENT. 24-020124 Sample Date: 01-Feb-24 Percent Removal SEEP -A -INFLUENT- 24-021324 Sample Date: 13-Feb-24 SEEP -A -EFFLUENT 24-021324 Sample Date: 13-Feb-24 Percent Removal SEEP -A -INFLUENT 24-021424 Sample Date: 14-Feb-24 SEEP -A -EFFLUENT. 24-021424 Sample Date: 14-Feb-24 Percent Removal SEEP -A -INFLUENT- 24-030224 Sample Date: 2-Mar-24 SEEP -A -EFFLUENT 24-030224 Sample Date: 2-Mar-24 Percent Removal Hfpo Dimer Acid 7,800 2.8 >99.9% 8,400 2.0 >99.9% 8,900 <2.0 >99.9% 12,000 2.0 >99.9% PFMOAA 20,000 37 99.8% 20,000 23 J 99.9% 21,000 16 99.9% 23,000 18 99.9% PFO2HxA 13,000 7.5 99.9% 13,000 4.8 >99.9% 12,000 4.5 >99.9% 17,000 2.2 >99.9% PFO3OA 3,800 <2.0 >99.9% 3,600 <2.0 >99.9% 3,200 <2.0 >99.9% 4,600 <2.0 >99.9% PFO4DA 1,700 <2.0 >99.9% 1,300 <2.0 >99.9% 1,300 <2.0 >99.9% 1,700 <2.0 >99.9% PFO5DA 840 <2.0 >99.9% 690 <2.0 >99.9% 550 <2.0 >99.9% 690 <2.0 >99.9% PMPA 6,900 15 99.8% 6,800 12 99.8% 6,500 <10 >99.9% 9,200 <10 >99.9% PEPA 2,700 <20 >99.9% 2,800 <20 >99.9% 2,700 <20 >99.9% 3,600 <10 >99.9% PS Acid <20 <2.0 >99.9% <20 <2.0 >99.9% <20 <2.0 >99.9% <50 <2.0 >99.9% Hydro -PS Acid 310 <2.0 >99.9% 270 <2.0 >99.9% 220 <2.0 >99.9% 290 <2.0 >99.9% R-PSDA 600 J <2.0 >99.9% 620 J <2.0 >99.9% 810 J <2.0 >99.9% 830 J <2.0 >99.9% Hydrolyzed PSDA 2,000 J <2.0 >99.9% 1,900 J <2.0 >99.9% 2,000 J <2.0 >99.9% 2,300 J <2.0 >99.9% R-PSDCA <17 <2.0 >99.9% <17 <2.0 >99.9% <17 <2.0 >99.9% <50 <2.0 >99.9% NVHOS, Acid Form 370 <2.0 >99.9% 360 <2.0 >99.9% 350 <2.0 >99.9% 420 <2.0 >99.9% EVE Acid <17 <2.0 >99.9% <17 <2.0 >99.9% <17 <2.0 >99.9% <50 <2.0 >99.9% Hydro -EVE Acid 280 <2.0 >99.9% 270 <2.0 >99.9% 240 <2.0 >99.9% 280 <2.0 >99.9% R-EVE 320 J <2.0 >99.9% 320 J <2.0 >99.9% 390 J <2.0 >99.9% 470 J <2.0 >99.9% Perfluoro(2-ethoxyethane)sulfonic Acid <6.7 <2.0 >99.9% <6.7 <2.0 >99.9% <6.7 <2.0 >99.9% <50 <2.0 >99.9% PFECA B <27 <2.0 >99.9% <27 <2.0 >99.9% <27 UJ <2.0 >99.9% <50 <2.0 >99.9% PFECA-G 1 <48 <2.0 1 >99.9% 1 <48 1 <2.0 1 >99.9% 1 <48 1 <2.0 1 >99.9% <50 <2.0 >99.9% Total Table 3+ (17 compounds)" I1 99.9% 1 57,000 99.9% 1 E 111111= 1 >99.9% 73,000 >99.9% Notes: 1 - Total Table 3+ was calculated including J qualified data but not non -detect data. The total Table 3+ sum is rounded to two significant figures. 2 - Total Table 3+ (17 Compounds) does not include R-PSDA, Hydrolyzed PSDA and R-EVE. 3 - Sample Identification Label Key: "Seep - [A, B, C, or D] - [Sample Location Inside FTC] - [# of Aliquots in Composite Sample] - [MMDDYY]" Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. UJ - Analyte not detected. Reporting limit may not be accurate or precise. ng/L - nanograms per liter FTC - flow through cell SOP - standard operating procedure < - Analyte not detected above associated reporting limit. TR0795C Page 2 of 13 June 2024 Table 2-4A FTC Performance Monitoring Analytical Results - Seep A Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC Table 3 +SOP (n /L) SEEP -A -INFLUENT 24-030724 Sample Date: 7-Mar-24 SEEP -A -EFFLUENT. 24-030724 Sample Date: 7-Mar-24 Percent Removal SEEP -A -INFLUENT- 24-031124 Sample Date: 11-Mar-24 SEEP -A -EFFLUENT 24-031124 Sample Date: 11-Mar-24 Percent Removal SEEP -A -INFLUENT 24-032324 Sample Date: 23-Mar-24 SEEP -A -EFFLUENT. 24-032324 Sample Date: 23-Mar-24 Percent Removal SEEP -A -INFLUENT- 24-032824 Sample Date: 28-Mar-24 SEEP -A -EFFLUENT 24-032824 Sample Date: 28-Mar-24 Percent Removal Hfpo Dimer Acid 9,200 <2.0 >99.9% 8,100 <2.0 >99.9% 9,100 <2.0 >99.9% 9,600 <2.0 >99.9% PFMOAA 12,000 J 13 99.9% 11,000 18 99.8% 18,000 36 99.8% 19,000 J 31 99.8% PFO2HxA 11,000 2.7 >99.9% 10,000 3.2 >99.9% 13,000 3.3 >99.9% 13,000 3.8 >99.9% PFO3OA 2,800 <2.0 >99.9% 3,100 <2.0 >99.9% 4,000 <2.0 >99.9% 3,700 <2.0 >99.9% PFO4DA 1,300 <2.0 >99.9% 1,200 <2.0 >99.9% 1,500 <2.0 >99.9% 1,400 <2.0 >99.9% PFO5DA 530 <2.0 >99.9% 610 <2.0 >99.9% 880 <2.0 >99.9% 580 <2.0 >99.9% PMPA 5,700 <10 >99.9% 4,700 <10 >99.9% 7,100 <10 >99.9% 7,800 <10 >99.9% PEPA 2,100 <10 >99.9% 2,000 <10 >99.9% 2,700 <10 >99.9% 3,100 <10 >99.9% PS Acid 67 <2.0 >99.9% 140 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% Hydro -PS Acid 230 <2.0 >99.9% 230 <2.0 >99.9% 310 <2.0 >99.9% 240 <2.0 >99.9% R-PSDA 570 J <2.0 >99.9% 880 J <2.0 >99.9% 870 J <2.0 >99.9% 750 J <2.0 >99.9% Hydrolyzed PSDA 1,200 J <2.0 >99.9% 1,300 J <2.0 >99.9% 1,700 J <2.0 >99.9% 1,600 J <2.0 >99.9% R-PSDCA <50 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% NVHOS, Acid Form 240 <2.0 >99.9% 230 <2.0 >99.9% 310 <2.0 >99.9% 330 <2.0 >99.9% EVE Acid <50 <2.0 >99.9% 57 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% Hydro -EVE Acid 180 <2.0 >99.9% 200 <2.0 >99.9% 290 <2.0 >99.9% 230 <2.0 >99.9% R-EVE 280 J <2.0 >99.9% 370 J <2.0 >99.9% 400 J <2.0 >99.9% 380 J <2.0 >99.9% Perfluoro(2-ethoxyethane)sulfonic Acid <50 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% PFECA B <50 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% PFECA-G <50 <2.0 >99.9% 1 <50 1 <2.0 1 >99.9% 1 <50 1 <2.0 1 >99.9% <50 <2.0 >99.9% Total Table 3+ (17 compounds)" III >99.9% 42,000 1 1 >99.9% 99.9% 59,000 99.9% Notes: 1 - Total Table 3+ was calculated including J qualified data but not non -detect data. The total Table 3+ sum is rounded to two significant figures. 2 - Total Table 3+ (17 Compounds) does not include R-PSDA, Hydrolyzed PSDA and R-EVE. 3 - Sample Identification Label Key: "Seep - [A, B, C, or D] - [Sample Location Inside FTC] - [# of Aliquots in Composite Sample] - [MMDDYY]" Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. ng/L - nanograms per liter FTC - flow through cell SOP - standard operating procedure < - Analyte not detected above associated reporting limit. TR0795C Page 3 of 13 June 2024 Table 2-4B FTC Performance Monitoring Analytical Results - Seep B Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC Table 3 + SOP (n /L) SEEP-B-INFLUENT 24-011024 Sample Date: 10-Jan-24 SEEP-B-EFFLUENT. 24-011024 Sample Date: 10-Jan-24 Percent Removal SEEP-B-INFLUENT- 24-012024 Sample Date: 20-Jan-24 SEEP-B-EFFLUENT 24-012024 Sample Date: 20-Jan-24 Percent Removal SEEP-B-INFLUENT 24-012524 Sample Date: 25-Jan-24 SEEP-B-EFFLUENT. 24-012524 Sample Date: 25-Jan-24 Percent Removal SEEP-B-INFLUENT- 24-013124 Sample Date: 31-Jan-24 SEEP-B-EFFLUENT 24-013124 Sample Date: 31-Jan-24 Percent Removal Hfpo Dimer Acid 3,300 <2.0 >99.9% 3,400 <2.0 >99.9% 3,300 4.9 99.9% 3,400 11 99.7% PFMOAA 8,600 23 99.7% 5,700 14 99.8% 5,500 51 99.1 % 5,700 140 97.5% PFO2HxA 4,400 3.4 99.9% 3,700 2.1 99.9% 3,700 7.1 99.8% 3,800 19 99.5% PFO3OA 960 <2.0 >99.9% 880 <2.0 >99.9% 770 <2.0 >99.9% 900 <2.0 >99.9% PFO4DA 320 <2.0 >99.90 210 <2.0 >99.9% 200 <2.0 >99.9% 220 <2.0 >99.9% PFO5DA 98 <2.0 >99.9% <78 <2.0 >99.9% <78 <2.0 >99.9% <78 <2.0 >99.9% PMPA 4,600 <10 >99.9% 3,600 <10 >99.9% 3,500 17 99.5% 3,600 40 98.9% PEPA 1,700 <20 >99.9% 1,500 <20 >99.9% 1,400 <20 >99.9% 1,700 <20 >99.9% PS Acid 130 <2.0 >99.9% 46 <2.0 >99.9% 36 <2.0 >99.9% 46 <2.0 >99.9% Hydro -PS Acid 130 <2.0 >99.9% 81 <2.0 >99.9% 78 <2.0 >99.9% 120 <2.0 >99.9% R-PSDA 270 J <2.0 >99.9% 430 J <2.0 >99.9% 370 J <2.0 >99.9% 290 J <2.0 >99.9% Hydrolyzed PSDA 910 J <2.0 >99.9% 940 J <2.0 >99.9% 940 J <2.0 >99.9% 1,100 J 4.9 J 99.6% R-PSDCA <17 <2.0 >99.9% <17 <2.0 >99.9% <17 <2.0 >99.9% <17 <2.0 >99.9% NVHOS, Acid Form 170 <2.0 >99.9% 160 <2.0 >99.9% 160 <2.0 >99.9% 220 <2.0 >99.9% EVE Acid 150 <2.0 >99.9% 42 <2.0 >99.9% 30 <2.0 >99.9% 33 <2.0 >99.9% Hydro -EVE Acid 210 <2.0 >99.9% 120 <2.0 >99.9% 120 <2.0 >99.9% 150 <2.0 >99.9% R-EVE 210 J <2.0 >99.9% 280 J <2.0 >99.9% 260 J <2.0 >99.9% 210 J <2.0 >99.9% Perfluoro(2-ethoxyethane)sulfonic Acid <6.7 <2.0 >99.9% <6.7 <2.0 >99.9% <6.7 <2.0 >99.9% <6.7 <2.0 >99.9% PFECA B <27 <2.0 >99.9% <27 <2.0 >99.9% <27 <2.0 >99.9% <27 <2.0 >99.9% PFECA-G 1 <48 1 <2.0 1 >99.9% 1 <48 1 <2.0 1 >99.9% 1 <48 1 <2.0 1 >99.9% 1 <48 1 <2.0 1 >99.9% Total Table 3+ (17 compounds) 121 25,000 26 1 99.9% 1 19,000 1 1 99.9% 19,000 80 1 99.6% 1 20,000 1 1 1 99.00% Notes: 1 - Total Table 3+ was calculated including J qualified data but not non -detect data. The total Table 3+ sum is rounded to two significant figures. 2 - Total Table 3+ (17 Compounds) does not include R-PSDA, Hydrolyzed PSDA and R-EVE. 3 - Sample Identification Label Key: "Seep - [A, B, C, or D] - [Sample Location Inside FTC] - [# of Aliquots in Composite Sample] - [MMDDYY]" Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. ng/L - nanograms per liter FTC - flow through cell SOP - standard operating procedure < - Analyte not detected above associated reporting limit. TR0795C Page 4 of 13 June 2024 Table 2-4B FTC Performance Monitoring Analytical Results - Seep B Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC Table 3 + SOP (n /L) SEEP-B-INFLUENT 24-020124 Sample Date: O1-Feb-24 SEEP-B-EFFLUENT. 24-020124 Sample Date: 01-Feb-24 Percent Removal SEEP-B-INFLUENT- 24-021324 Sample Date: 13-Feb-24 SEEP-B-EFFLUENT 24-021324 Sample Date: 13-Feb-24 Percent Removal SEEP-B-INFLUENT 24-021424 Sample Date: 14-Feb-24 SEEP-B-EFFLUENT. 24-021424 Sample Date: 14-Feb-24 Percent Removal SEEP-B-INFLUENT- 24-030224 Sample Date: 2-Mar-24 SEEP-B-EFFLUENT 24-030224 Sample Date: 2-Mar-24 Percent Removal Hfpo Dimer Acid 3,300 11 99.7% 4,400 15 99.7% 4,900 3.0 99.9% 6,800 9.9 99.9% PFMOAA 5,900 150 97.5% 7,200 160 97.8% 10,000 21 99.8% 12,000 120 99.0% PFO2HxA 3,800 21 99.4% 4,400 32 99.3% 5,300 8.8 99.8% 7,300 16 99.8% PFO3OA 910 2.0 99.8% 1,100 2.2 99.8% 1,100 <2.0 >99.9% 1,700 <2.0 >99.9% PFO4DA 220 <2.0 >99.9% 210 <2.0 >99.9% 260 <2.0 >99.9% 360 <2.0 >99.9% PFO5DA <78 <2.0 >99.9% <78 <2.0 >99.9% <78 <2.0 >99.9% 88 <2.0 >99.9% PMPA 3,600 43 98.8% 4,000 58 98.6% 5,200 12 99.8% 7,000 45 99.4% PEPA 1,600 <20 >99.9% 1,900 <20 >99.9% 2,200 <20 >99.9% 3,000 11 99.6% PS Acid 51 <2.0 >99.9% 36 <2.0 >99.9% <20 <2.0 >99.9% <50 <2.0 >99.9% Hydro -PS Acid 120 <2.0 >99.9% 110 <2.0 >99.9% 120 <2.0 >99.9% 180 <2.0 >99.9% R-PSDA 280 J <2.0 >99.9% 360 J 2.4 J 99.3% 470 J <2.0 >99.9% 570 J <2.0 >99.9% Hydrolyzed PSDA 1,100 J 5.3 J 99.5% 1,400 J 7.2 J 99.5% 940 J <2.0 >99.9% 1,700 J 3.6 J 99.8% R-PSDCA <17 <2.0 >99.9% <17 <2.0 >99.9% <17 <2.0 >99.9% <50 <2.0 >99.9% NVHOS, Acid Form 230 <2.0 >99.9% 330 2.2 99.3% 260 <2.0 >99.9% 310 <2.0 >99.9% EVE Acid 30 <2.0 >99.9% 23 <2.0 >99.9% <17 <2.0 >99.9% <50 <2.0 >99.9% Hydro -EVE Acid 150 <2.0 >99.9% 150 <2.0 >99.9% 170 <2.0 >99.9% 200 <2.0 >99.9% R-EVE 210 J <2.0 >99.9% 240 J <2.0 >99.9% 280 J <2.0 >99.9% 370 J <2.0 >99.9% Perfluoro(2-ethoxyethane)sulfonic Acid <6.7 <2.0 >99.9% <6.7 <2.0 >99.9% <6.7 <2.0 >99.9% <50 <2.0 >99.9% PFECA B <27 <2.0 >99.9% <27 <2.0 >99.9% <27 <2.0 >99.9% <50 <2.0 >99.9% PFECA-G 1 <48 1 <2.0 1 >99.9% <48 <2.0 >99.9% <48 <2.0 >99.9% <50 <2.0 >99.9% Total Table 3+ (17 compounds)�'� 230 98.9% 24,000 98.9% 0,000 45 1 99.9% 1 39,000 99.5% Notes: 1 - Total Table 3+ was calculated including J qualified data but not non -detect data. The total Table 3+ sum is rounded to two significant figures. 2 - Total Table 3+ (17 Compounds) does not include R-PSDA, Hydrolyzed PSDA and R-EVE. 3 - Sample Identification Label Key: "Seep - [A, B, C, or D] - [Sample Location Inside FTC] - [# of Aliquots in Composite Sample] - [MMDDYY]" Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. ng/L - nanograms per liter FTC - flow through cell SOP - standard operating procedure < - Analyte not detected above associated reporting limit. TR0795C Page 5 of 13 June 2024 Table 2-4B FTC Performance Monitoring Analytical Results - Seep B Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC Table 3 + SOP (n /L) SEEP-B-INFLUENT 24-030724 Sample Date: 7-Mar-24 SEEP-B-EFFLUENT. 24-030724 Sample Date: 7-Mar-24 Percent Removal SEEP-B-INFLUENT- 24-031124 Sample Date: 11-Mar-24 SEEP-B-EFFLUENT 24-031124 Sample Date: 11-Mar-24 Percent Removal SEEP-B-INFLUENT 24-032324 Sample Date: 23-Mar-24 SEEP-B-EFFLUENT. 24-032324 Sample Date: 23-Mar-24 Percent Removal SEEP-B-INFLUENT- 24-032824 Sample Date: 28-Mar-24 SEEP-B-EFFLUENT 24-032824 Sample Date: 28-Mar-24 Percent Removal Hfpo Dimer Acid 4,000 2.5 99.9% 6,600 2.7 >99.9% 7,900 5.8 99.93% 8,200 9.2 99.9% PFMOAA 4,800 39 99.2% 9,400 24 99.7% 16,000 120 99.25% 14,000 190 98.6% PFO2HxA 3,800 5.8 99.8% 7,200 3.5 >99.9% 9,700 12 99.88% 9,400 23 99.8% PFO3OA 750 <2.0 >99.9% 1,800 <2.0 >99.9% 2,300 <2.0 >99.9% 2,300 <2.0 >99.9% PFO4DA 270 <2.0 >99.9% 450 <2.0 >99.9% 590 <2.0 >99.9% 500 <2.0 >99.9% PFO5DA <78 <2.0 >99.9% 110 <2.0 >99.9% 150 <2.0 >99.9% 130 <2.0 >99.9% PMPA 3,600 12 99.7% 6,300 10 99.8% 8,800 35 99.60% 8,900 56 99.4% PEPA 1,400 <10 >99.9% 2,600 <10 >99.9% 3,600 <10 >99.9% 3,400 10 99.7% PS Acid <50 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% Hydro -PS Acid 110 <2.0 >99.9% 190 <2.0 >99.9% 250 <2.0 >99.9% 250 <2.0 >99.9% R-PSDA 260 J <2.0 >99.9% 590 J <2.0 >99.9% 780 J <2.0 >99.9% 740 J <2.0 >99.9% Hydrolyzed PSDA 440 J <2.0 >99.9% 760 J <2.0 >99.9% 1,900 J 4.7 J 99.75% 1,600 J 5.9 J 99.6% R-PSDCA <50 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% NVHOS, Acid Form 120 <2.0 >99.9% 240 <2.0 >99.9% 380 <2.0 >99.9% 350 <2.0 >99.9% EVE Acid <50 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% Hydro -EVE Acid 110 <2.0 >99.9% 200 <2.0 >99.9% 280 <2.0 >99.9% 280 <2.0 >99.9% R-EVE 190 J <2.0 >99.9% 350 J <2.0 >99.9% 540 J <2.0 >99.9% 540 J <2.0 >99.9% Perfluoro(2-ethoxyethane)sulfonic Acid <50 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% PFECA B <50 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% PFECA-G 1 <50 1 <2.0 1 >99.9% <50 <2.0 >99.90/. <50 <2.0 >99.9% <50 <2.0 >99.9 0 Total Table 3+ (17 compounds) 19,000 59 99.7% 35,000 99.9% ,000 99.7% 48,000 99.4% Notes: 1 - Total Table 3+ was calculated including J qualified data but not non -detect data. The total Table 3+ sum is rounded to two significant figures. 2 - Total Table 3+ (17 Compounds) does not include R-PSDA, Hydrolyzed PSDA and R-EVE. 3 - Sample Identification Label Key: "Seep - [A, B, C, or D] - [Sample Location Inside FTC] - [# of Aliquots in Composite Sample] - [MMDDYY]" Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. ng/L - nanograms per liter FTC - flow through cell SOP - standard operating procedure < - Analyte not detected above associated reporting limit. TR0795C Page 6 of 13 June 2024 Table 2-4C FTC Performance Monitoring Analytical Results - Seep C Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC Table 3 +SOP n /L SEEP-C-INFLUENT 24-010624 Sample Date: 6-Jan-24 SEEP-C-EFFLUENT. 24-010624 Sample Date: 6-Jan-24 Percent Removal SEEP-C-INFLUENT- 24-011024 Sample Date: 10-Jan-24 SEEP-C-EFFLUENT 24-011024 Sample Date: 10-Jan-24 Percent Removal SEEP-C-INFLUENT 24-012024 Sample Date: 20-Jan-24 SEEP-C-EFFLUENT 24-012024 Sample Date: 20-Jan-24 Percent Removal SEEP-C-INFLUENT- 24-013124 Sample Date: 31-Jan-24 SEEP-C-EFFLUENT 24-013124 Sample Date: 31-Jan-24 Percent Removal Hfpo Dimer Acid 7,100 10 99.9% 3,900 18 99.5% 6,200 7.5 99.9% 4,900 9.2 99.8% PFMOAA 13,000 71 99.5% 8,300 32 99.6% 10,000 45 99.6% 9,500 68 99.3% PFO2HxA 8,700 22 99.7% 5,100 11 99.8% 6,700 9.3 99.9% 6,100 14 99.8% PFO3OA 3,200 4.9 99.8% 1,800 3.0 99.8% 2,700 2.1 99.9% 2,300 3.3 99.9% PFO4DA 1,300 <2.0 >99.9% 840 <2.0 >99.9% 980 <2.0 >99.9% 870 <2.0 >99.9% PFO5DA <78 <2.0 >99.9% <78 <2.0 >99.9% <78 <2.0 >99.9% <78 <2.0 >99.9% PMPA 3,600 17 99.5% 2,200 15 99.3% 2,700 16 99.4% 2,300 19 99.2% PEPA 1,300 <20 >99.9% 720 <20 >99.9% 940 <20 >99.9% 920 <20 >99.9% PS Acid <20 <2.0 >99.9% <20 <2.0 >99.9% <20 <2.0 >99.9% <20 <2.0 >99.9% Hydro -PS Acid 190 <2.0 >99.9% 120 <2.0 >99.9% 140 <2.0 >99.9% 170 <2.0 >99.9% R-PSDA 290 J <2.0 >99.9% 180 J <2.0 >99.9% 430 J <2.0 >99.9% 240 J <2.0 >99.9% Hydrolyzed PSDA <38 <2.0 >99.9% <38 <2.0 >99.9% <38 <2.0 >99.9% <38 <2.0 >99.9% R-PSDCA <17 <2.0 >99.9% <17 <2.0 >99.9% <17 <2.0 >99.9% <17 <2.0 >99.9% NVHOS, Acid Form 240 <2.0 >99.9% 140 <2.0 >99.9% 180 <2.0 >99.9% 250 <2.0 >99.9% EVE Acid <17 <2.0 >99.9% <17 <2.0 >99.9% <17 <2.0 >99.9% <17 <2.0 >99.9% Hydro -EVE Acid 640 <2.0 >99.9% 410 <2.0 >99.9% 500 <2.0 >99.9% 470 <2.0 >99.9% R-EVE 300 J <2.0 >99.9% 150 J <2.0 >99.9% 390 J <2.0 >99.9% 220 J <2.0 >99.9% Perfluoro(2-ethoxyethane)sulfonic Acid <6.7 <2.0 >99.9% <6.7 <2.0 >99.9% <6.7 <2.0 >99.9% <6.7 <2.0 >99.9% PFECA B <27 <2.0 >99.9% <27 <2.0 >99.9% <27 <2.0 >99.9% <27 <2.0 >99.9% PFECA-G 1 <48 1 <2.0 1 >99.9% <48 <2.0 >99.9% <48 <2.0 >99.90/, <48 <2.0 >99.9% Total Table 3+ (17 compounds) 12 39,000 0 99.7% 99.7% 31,000 0 99.7% 99.6% Notes: 1 - Total Table 3+ was calculated including J qualified data but not non -detect data. The total Table 3+ sum is rounded to two significant figures. 2 - Total Table 3+ (17 Compounds) does not include R-PSDA, Hydrolyzed PSDA and R-EVE. 3 - Sample Identification Label Key: "Seep - [A, B, C, or D] - [Sample Location Inside FTC] - [# of Aliquots in Composite Sample] - [MMDDYY]" 4 - Percent removal is not calculated, since, for unknown reasons, the analyte was not detected in the influent. Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. ng/L - nanograms per liter FTC - flow through cell SOP - standard operating procedure < - Analyte not detected above associated reporting limit. TR0795C Page 7 of 13 June 2024 Table 2-4C FTC Performance Monitoring Analytical Results - Seep C Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC Table 3 +SOP n /L SEEP-C-INFLUENT 24-020124 Sample Date: O1-Feb-24 SEEP-C-EFFLUENT. 24-020124 Sample Date: 01-Feb-24 Percent Removal SEEP-C-INFLUENT- 24-021324 Sample Date: 13-Feb-24 SEEP-C-EFFLUENT 24-021324 Sample Date: 13-Feb-24 Percent Removal SEEP-C-INFLUENT 24-021424 Sample Date: 14-Feb-24 SEEP-C-EFFLUENT 24-021424 Sample Date: 14-Feb-24 Percent Removal SEEP-C-INFLUENT- 24-022424 Sample Date: 24-Feb-24 SEEP-C-EFFLUENT 24-022424 Sample Date: 24-Feb-24 Percent Removal Hfpo Dimer Acid 5,000 8.0 99.8% 5,200 10 99.8% 3,300 7.7 99.8% 5,600 8.4 99.9% PFMOAA 9,500 61 99.4% 9,500 31 99.7% 6,400 4.5 99.9% 8,100 6.8 99.9% PFO2HxA 6,000 12 99.8% 5,900 14 99.8% 3,700 4.1 99.9% 6,100 12 99.8% PFO3OA 2,400 2.7 99.9% 2,500 3.3 99.9% 1,200 <2.0 >99.9% 2,500 3.1 99.9% PFO4DA 860 <2.0 >99.9% 800 <2.0 >99.9% 520 <2.0 >99.9% 850 <2.0 >99.9% PFO5DA <78 <2.0 >99.9% <78 <2.0 >99.9% <78 <2.0 >99.9% <78 <2.0 >99.9% PMPA 2,300 17 99.3% 2,400 13 99.5% 1,400 <10 >99.9% 2,100 <10 >99.9% PEPA 880 <20 >99.9% 890 <20 >99.9% 520 <20 >99.9% 900 <20 >99.9% PS Acid <20 <2.0 >99.9% <20 <2.0 >99.9% <20 <2.0 >99.9% <20 <2.0 >99.9% Hydro -PS Acid 180 <2.0 >99.9% 160 <2.0 >99.9% 110 <2.0 >99.9% 180 <2.0 >99.9% R-PSDA 260 J <2.0 >99.9% 250 J <2.0 >99.9% 230 J <2.0 >99.9% 300 J <2.0 >99.9% Hydrolyzed PSDA <38 <2.0 >99.9% <38 <2.0 >99.9% <38 <2.0 >99.9% 41 J <2.0 >99.9% R-PSDCA <17 <2.0 >99.9% <17 <2.0 >99.9% <17 <2.0 >99.9% <17 <2.0 >99.9% NVHOS, Acid Form 220 <2.0 >99.9% 280 <2.0 >99.9% 160 <2.0 >99.9% 200 <2.0 >99.9% EVE Acid <17 <2.0 >99.9% <17 <2.0 >99.9% <17 <2.0 >99.9% <17 <2.0 >99.9% Hydro -EVE Acid 480 <2.0 >99.9% 480 <2.0 >99.9% 260 <2.0 >99.9% 440 <2.0 >99.9% R-EVE 250 J <2.0 >99.9% 230 J <2.0 >99.9% 170 J <2.0 >99.9% 250 J <2.0 >99.9% Perfluoro(2-ethoxyethane)sulfonic Acid <6.7 <2.0 >99.9% <6.7 <2.0 >99.9% <6.7 <2.0 >99.9% <6.7 <2.0 >99.9% PFECA B <27 <2.0 >99.9% <27 <2.0 >99.9% <27 <2.0 >99.9% <27 <2.0 >99.9% PFECA-G <48 <2.0 >99.90/, <48 <2.0 >99.9% 1 <48 1 <2.0 1 >99.9% <48 <2.0 >99.9% Total Table 3+ (17 compounds)" 2 28,000 0 99.7% 18,000 =6 99.9% Aiiiii 99.9% Notes: 1 - Total Table 3+ was calculated including J qualified data but not non -detect data. The total Table 3+ sum is rounded to two significant figures. 2 - Total Table 3+ (17 Compounds) does not include R-PSDA, Hydrolyzed PSDA and R-EVE. 3 - Sample Identification Label Key: "Seep - [A, B, C, or D] - [Sample Location Inside FTC] - [# of Aliquots in Composite Sample] - [MMDDYY]" 4 - Percent removal is not calculated, since, for unknown reasons, the analyte was not detected in the influent. Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. ng/L - nanograms per liter FTC - flow through cell SOP - standard operating procedure < - Analyte not detected above associated reporting limit. TR0795C Page 8 of 13 June 2024 Table 2-4C FTC Performance Monitoring Analytical Results - Seep C Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC Table 3 +SOP n /L SEEP-C-INFLUENT 24-030224 Sample Date: 2-Mar-24 SEEP-C-EFFLUENT. 24-030224 Sample Date: 2-Mar-24 Percent Removal SEEP-C-INFLUENT- 24-030724 Sample Date: 7-Mar-24 SEEP-C-EFFLUENT 24-030724 Sample Date: 7-Mar-24 Percent Removal SEEP-C-INFLUENT 24-031124 Sample Date: II-Mar-24 SEEP-C-EFFLUENT 24-031124 Sample Date: II-Mar-24 Percent Removal SEEP-C-INFLUENT- 24-032324 Sample Date: 23-Mar-24 SEEP-C-EFFLUENT 24-032324 Sample Date: 23-Mar-24 Percent Removal Hfpo Dimer Acid 5,700 7.8 99.9% 4,600 19 99.6% 6,800 3.3 >99.9% 7,200 19 99.7% PFMOAA 9,300 25 99.7% 4,800 20 99.6% 9,000 30 99.7% 12,000 120 99.0% PFO2HxA 6,500 5.2 99.9% 4,000 9.9 99.8% 6,800 3.8 99.9% 8,100 55 99.3% PFO3OA 2,500 <2.0 >99.9% 1,500 2.2 99.9% 2,700 <2.0 >99.9% 3,400 16 99.5% PFO4DA 940 <2.0 >99.9% 700 <2.0 >99.9% 1,000 <2.0 >99.9% 1,300 5.0 99.6% PFO5DA <78 <2.0 >99.9% <78 <2.0 >99.9% <78 <2.0 >99.9% <78 2.3 [41 PMPA 2,600 <10 >99.9% 1,600 <10 >99.9% 2,700 <10 >99.9% 3,300 20 99.4% PEPA 900 <10 >99.9% 590 <10 >99.9% 950 <10 >99.9% 1,100 <10 >99.9% PS Acid <50 <2.0 >99.90 0 <50 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% Hydro -PS Acid 200 <2.0 >99.9% 140 <2.0 >99.9% 210 <2.0 >99.9% 280 <2.0 >99.9% R-PSDA 350 J <2.0 >99.9% 200 J <2.0 >99.9% 480 J <2.0 >99.9% 480 J 4.3 J 99.1% Hydrolyzed PSDA <50 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% <50 4.7 J [41 R-PSDCA <50 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% NVHOS, Acid Form 190 <2.0 >99.9% 96 <2.0 >99.9% 180 <2.0 >99.9% 240 <2.0 >99.9% EVE Acid <50 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% Hydro -EVE Acid 490 <2.0 >99.9% 400 <2.0 >99.9% 630 <2.0 >99.9% 770 <2.0 >99.9% R-EVE 290 J <2.0 >99.9% 160 J <2.0 >99.9% 390 J <2.0 >99.9% 430 J <2.0 >99.9% Perfluoro(2-ethoxyethane)sulfonic Acid <50 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% PFECA B <50 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% PFECA-G <50 <2.0 >99.9% 1 <50 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% Total Table 3+ (17 compounds)" 29,000 1 M8 99.9% 99.7% 99.9% 38,000 99.4% Notes: 1 - Total Table 3+ was calculated including J qualified data but not non -detect data. The total Table 3+ sum is rounded to two significant figures. 2 - Total Table 3+ (17 Compounds) does not include R-PSDA, Hydrolyzed PSDA and R-EVE. 3 - Sample Identification Label Key: "Seep - [A, B, C, or D] - [Sample Location Inside FTC] - [# of Aliquots in Composite Sample] - [MMDDYY]" 4 - Percent removal is not calculated, since, for unknown reasons, the analyte was not detected in the influent. Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. ng/L - nanograms per liter FTC - flow through cell SOP - standard operating procedure < - Analyte not detected above associated reporting limit. TR0795C Page 9 of 13 June 2024 Table 2-4C FTC Performance Monitoring Analytical Results - Seep C Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC Table 3 +SOP n /L SEEP-C-INFLUENT 24-032824 Sample Date: 28-Mar-24 SEEP-C-EFFLUENT. 24-032824 Sample Date: 28-Mar-24 Percent Removal Hfpo Dimer Acid 7,100 5.9 99.9% PFMOAA 12,000 64 99.5% PFO2HxA 7,800 11 99.9% PFO3OA 3,100 <2.0 >99.9% PFO4DA 1,200 <2.0 >99.9% PFO5DA <78 <2.0 >99.9% PMPA 3,200 12 99.6% PEPA 1,100 <10 >99.9% PS Acid <50 <2.0 >99.9% Hydro -PS Acid 240 <2.0 >99.9% R-PSDA 440 J <2.0 >99.9% Hydrolyzed PSDA <50 <2.0 >99.9% R-PSDCA <50 <2.0 >99.9% NVHOS, Acid Form 230 <2.0 >99.9% EVE Acid <50 <2.0 >99.9% Hydro -EVE Acid 750 <2.0 >99.9% R-EVE 360 J <2.0 >99.9% Perfluoro(2-ethoxyethane)sulfonic Acid <50 <2.0 >99.9% PFECA B <50 <2.0 >99.9% PFECA-G <50 <2.0 >99.9% Total Table 3+ (17 compounds) 12 37,000 99.7% Notes: 1 - Total Table 3+ was calculated including J qualified data but not non -detect data. The total Table 3+ sum is rounded to two significant figures. 2 - Total Table 3+ (17 Compounds) does not include R-PSDA, Hydrolyzed PSDA and R-EVE. 3 - Sample Identification Label Key: "Seep - [A, B, C, or D] - [Sample Location Inside FTC] - [# of Aliquots in Composite Sample] - [MMDDYY]" 4 - Percent removal is not calculated, since, for unknown reasons, the analyte was not detected in the influent. Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. ng/L - nanograms per liter FTC - flow through cell SOP - standard operating procedure < - Analyte not detected above associated reporting limit. TR0795C Page 10 of 13 June 2024 Table 2-4D FTC Performance Monitoring Analytical Results - Seep D Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC Table 3 +SOP (n /L) SEEP-D-INFLUENT 24-011024 Sample Date: 10-Jan-24 SEEP-D-EFFLUENT. 24-011024 Sample Date: 10-Jan-24 Percent Removal SEEP-D-INFLUENT- 24-012024 Sample Date: 20-Jan-24 SEEP-D-EFFLUENT 24-012024 Sample Date: 20-Jan-24 Percent Removal SEEP-D-INFLUENT 24-012524 Sample Date: 25-Jan-24 SEEP-D-EFFLUENT. 24-012524 Sample Date: 25-Jan-24 Percent Removal SEEP-D-INFLUENT- 24-013124 Sample Date: 31-Jan-24 SEEP-D-EFFLUENT 24-013124 Sample Date: 31-Jan-24 Percent Removal Hfpo Dimer Acid 2,600 <2.0 >99.9% 1,100 <2.0 >99.9% 1,300 <2.0 >99.9% 1,400 <2.0 >99.9% PFMOAA 15,000 55 99.6% 4,600 13 99.7% 4,800 16 99.7% 5,400 40 99.3% PFO2HxA 5,400 4.1 99.9% 1,900 <2.0 >99.9% 2,200 <2.0 >99.9% 2,500 4.5 99.8% PFO3OA 1,500 <2.0 >99.9% 540 <2.0 >99.9% 570 <2.0 >99.9% 760 <2.0 >99.9% PFO4DA 550 <2.0 >99.9% 170 <2.0 >99.9% 200 <2.0 >99.9% 250 <2.0 >99.9% PFO5DA <78 <2.0 >99.9% <78 <2.0 >99.9% <78 <2.0 >99.9% <78 <2.0 >99.9% PMPA 1,900 <10 >99.9% <620 <10 >99.9% 770 <10 >99.9% 880 <10 >99.9% PEPA 600 <20 >99.9% 210 <20 >99.9% 280 <20 >99.9% 340 <20 >99.9% PS Acid <20 <2.0 >99.9% <20 <2.0 >99.9% <20 <2.0 >99.9% <20 <2.0 >99.9% Hydro -PS Acid 87 <2.0 >99.9% 27 <2.0 >99.9% 34 <2.0 >99.9% 59 <2.0 >99.9% R-PSDA 140 J <2.0 >99.9% 100 J <2.0 >99.9% 120 J <2.0 >99.9% 110 J <2.0 >99.9% Hydrolyzed PSDA 190 J <2.0 >99.9% 62 J <2.0 >99.9% 69 J <2.0 >99.9% 88 J <2.0 >99.9% R-PSDCA <17 <2.0 >99.9% <17 <2.0 >99.9% <17 <2.0 >99.9% <17 <2.0 >99.9% NVHOS, Acid Form 130 <2.0 >99.9% <15 <2.0 >99.9% 84 <2.0 >99.9% 130 <2.0 >99.9% EVE Acid <17 <2.0 >99.9% <17 <2.0 >99.9% <17 <2.0 >99.9% <17 <2.0 >99.9% Hydro -EVE Acid 200 <2.0 >99.9% 62 <2.0 >99.9% 61 <2.0 >99.9% 89 <2.0 >99.9% R-EVE 130 J <2.0 >99.9% 73 J <2.0 >99.9% 86 J <2.0 >99.9% 77 J <2.0 >99.9% Perfluoro(2-ethoxyethane)sulfonic Acid <6.7 <2.0 >99.9% <6.7 <2.0 >99.9% <6.7 <2.0 >99.9% <6.7 <2.0 >99.9% PFECA B <27 <2.0 >99.9% <27 <2.0 >99.9% <27 <2.0 >99.9% <27 <2.0 >99.9% PFECA-G <48 <2.0 >99.9% <48 <2.0 >99.9% <48 <2.0 >99.9% <48 <2.0 >99.9% Total Table 3+ (17 compounds)" 28, 9IN 99.8% 99.8% 12,000 99.6% Notes: 1 - Total Table 3+ was calculated including J qualified data but not non -detect data. The total Table 3+ sum is rounded to two significant figures. 2 - Total Table 3+ (17 Compounds) does not include R-PSDA, Hydrolyzed PSDA and R-EVE. 3 - Sample Identification Label Key: "Seep - [A, B, C, or D] - [Sample Location Inside FTC] - [# of Aliquots in Composite Sample] - [MMDDYY]" Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. ng/L - nanograms per liter FTC - flow through cell SOP - standard operating procedure < - Analyte not detected above associated reporting limit. TR0795C Page 11 of 13 June 2024 Table 2-4D FTC Performance Monitoring Analytical Results - Seep D Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC Table 3 +SOP (n /L) SEEP-D-INFLUENT 24-020124 Sample Date: O1-Feb-24 SEEP-D-EFFLUENT. 24-020124 Sample Date: 01-Feb-24 Percent Removal SEEP-D-INFLUENT- 24-021324 Sample Date: 13-Feb-24 SEEP-D-EFFLUENT 24-021324 Sample Date: 13-Feb-24 Percent Removal SEEP-D-INFLUENT 24-021424 Sample Date: 14-Feb-24 SEEP-D-EFFLUENT. 24-021424 Sample Date: 14-Feb-24 Percent Removal SEEP-D-INFLUENT- 24-030224 Sample Date: 2-Mar-24 SEEP-D-EFFLUENT 24-030224 Sample Date: 2-Mar-24 Percent Removal Hfpo Dimer Acid 1,500 <2.0 >99.9% 2,400 <2.0 >99.9% 2,500 3.0 99.9% 4,100 <2.0 >99.9% PFMOAA 5,800 11 99.8% 7,400 26 99.6% 8,600 49 99.4% 11,000 9.9 99.9% PFO2HxA 2,600 <2.0 >99.9% 3,300 6.9 99.8% 3,600 20 99.4% 5,600 2.4 >99.9% PFO3OA 810 <2.0 >99.9% 900 <2.0 >99.9% 890 <2.0 >99.9% 1,600 <2.0 >99.9% PFO4DA 280 <2.0 >99.9% 330 <2.0 >99.9% 350 <2.0 >99.9% 510 <2.0 >99.9% PFO5DA <78 <2.0 >99.9% <78 <2.0 >99.9% <78 <2.0 >99.9% <78 <2.0 >99.9% PMPA 930 <10 >99.9% 1,500 <10 >99.9% 1,300 <10 >99.9% 2,400 <10 >99.9% PEPA 360 <20 >99.9% 590 <20 >99.9% 540 <20 >99.9% 850 <10 >99.9% PS Acid <20 <2.0 >99.9% <20 <2.0 >99.9% <20 <2.0 >99.9% <50 <2.0 >99.9% Hydro -PS Acid 63 <2.0 >99.9% 70 <2.0 >99.9% 69 <2.0 >99.9% 100 <2.0 >99.9% R-PSDA 120 J <2.0 >99.9% 170 J <2.0 >99.9% 200 J <2.0 >99.9% 290 J <2.0 >99.9% Hydrolyzed PSDA 90 J <2.0 >99.9% 120 J <2.0 >99.9% 160 J <2.0 >99.9% 260 J <2.0 >99.9% R-PSDCA <17 <2.0 >99.9% <17 <2.0 >99.9% <17 <2.0 >99.9% <50 <2.0 >99.9% NVHOS, Acid Form 130 <2.0 >99.9% 200 <2.0 >99.9% <15 <2.0 >99.9% 150 <2.0 >99.9% EVE Acid <17 <2.0 >99.9% <17 <2.0 >99.9% <17 <2.0 >99.9% <50 <2.0 >99.9% Hydro -EVE Acid 110 <2.0 >99.9% 120 <2.0 >99.9% 140 <2.0 >99.9% 210 <2.0 >99.9% R-EVE <72 <2.0 >99.9% 100 J <2.0 >99.9% 130 J <2.0 >99.9% 190 J <2.0 >99.9% Perfluoro(2-ethoxyethane)sulfonic Acid <6.7 <2.0 >99.9% <6.7 <2.0 >99.9% <6.7 <2.0 >99.9% <50 <2.0 >99.9% PFECA B <27 <2.0 >99.9% <27 <2.0 >99.9% <27 <2.0 >99.9% <50 <2.0 >99.9% PFECA-G 1 <48 <2.0 >99.90/, <48 <2.0 >99.9% <48 <2.0 >99.9% <50 <2.0 >99.9% Total Table 3+ (17 compounds)" 1 17,000 99.8% 99.6% 27,000 >99.9% Notes: 1 - Total Table 3+ was calculated including J qualified data but not non -detect data. The total Table 3+ sum is rounded to two significant figures. 2 - Total Table 3+ (17 Compounds) does not include R-PSDA, Hydrolyzed PSDA and R-EVE. 3 - Sample Identification Label Key: "Seep - [A, B, C, or D] - [Sample Location Inside FTC] - [# of Aliquots in Composite Sample] - [MMDDYY]" Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. ng/L - nanograms per liter FTC - flow through cell SOP - standard operating procedure < - Analyte not detected above associated reporting limit. TR0795C Page 12 of 13 June 2024 Table 2-4D FTC Performance Monitoring Analytical Results - Seep D Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC Table 3 +SOP (n /L) SEEP-D-INFLUENT 24-030724 Sample Date: 7-Mar-24 SEEP-D-EFFLUENT. 24-030724 Sample Date: 7-Mar-24 Percent Removal SEEP-D-INFLUENT- 24-031124 Sample Date: 11-Mar-24 SEEP-D-EFFLUENT 24-031124 Sample Date: 11-Mar-24 Percent Removal SEEP-D-INFLUENT 24-032324 Sample Date: 23-Mar-24 SEEP-D-EFFLUENT. 24-032324 Sample Date: 23-Mar-24 Percent Removal SEEP-D-INFLUENT- 24-032824 Sample Date: 28-Mar-24 SEEP-D-EFFLUENT 24-032824 Sample Date: 28-Mar-24 Percent Removal Hfpo Dimer Acid 3,900 2.6 99.9% 4,400 5.3 99.9% 4,300 2.8 99.9% 4,500 <2.0 >99.9% PFMOAA 8,200 26 99.7% 11,000 67 99.4% 14,000 58 99.6% 15,000 12 99.9% PFO2HxA 4,500 8.3 99.8% 5,700 19 99.7% 6,300 10 99.8% 6,500 2.0 >99.9% PFO3OA 1,100 <2.0 >99.9% 1,700 <2.0 >99.9% 1,800 <2.0 >99.9% 1,800 <2.0 >99.9% PFO4DA 470 <2.0 >99.9% 550 <2.0 >99.9% 600 <2.0 >99.9% 600 <2.0 >99.9% PFO5DA <78 <2.0 >99.9% <78 <2.0 >99.9% <78 <2.0 >99.9% <78 <2.0 >99.9% PMPA 2,000 <10 >99.9% 2,400 <10 >99.9% 2,900 <10 >99.9% 3,000 <10 >99.9% PEPA 710 <10 >99.9% 850 <10 >99.9% 990 <10 >99.9% 1,000 <10 >99.9% PS Acid <50 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% Hydro -PS Acid 81 <2.0 >99.9% 100 <2.0 >99.9% 120 <2.0 >99.9% 120 <2.0 >99.9% R-PSDA 220 J <2.0 >99.9% 360 J <2.0 >99.9% 330 J <2.0 >99.9% 330 J <2.0 >99.9% Hydrolyzed PSDA 220 J <2.0 >99.9% 330 J <2.0 >99.9% 300 J <2.0 >99.9% 290 J <2.0 >99.9% R-PSDCA <50 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% NVHOS, Acid Form 120 <2.0 >99.9% 150 <2.0 >99.9% 170 <2.0 >99.9% 180 <2.0 >99.9% EVE Acid <50 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% Hydro -EVE Acid 170 <2.0 >99.9% 220 <2.0 >99.9% 230 <2.0 >99.9% 250 <2.0 >99.9% R-EVE 160 J <2.0 >99.9% 270 J <2.0 >99.9% 220 J <2.0 >99.9% 230 J <2.0 >99.9% Perfluoro(2-ethoxyethane)sulfonic Acid <50 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% PFECA B <50 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% PFECA-G <50 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% <50 <2.0 >99.9% Total Table 3+ (17 compounds)" 7 27,000 99.7% 99.8% 33,000 >99.9% Notes: 1 - Total Table 3+ was calculated including J qualified data but not non -detect data. The total Table 3+ sum is rounded to two significant figures. 2 - Total Table 3+ (17 Compounds) does not include R-PSDA, Hydrolyzed PSDA and R-EVE. 3 - Sample Identification Label Key: "Seep - [A, B, C, or D] - [Sample Location Inside FTC] - [# of Aliquots in Composite Sample] - [MMDDYY]" Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. ng/L - nanograms per liter FTC - flow through cell SOP - standard operating procedure < - Analyte not detected above associated reporting limit. TR0795C Page 13 of 13 June 2024 Table 2-5A FTC Water Quality Data - Seep A Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, North Carolina Date DO (mg/L) Influent Effluent Difference pH (SU) Influent Effluent Difference Specific Conductance (AS/cm) Influent Effluent Difference Temperature (°C) Influent Effluent Difference Turbidity (NTU) Influent Effluent Difference TSS'' (mg/L) Influent Effluent Difference[21 1/6/2024 10.21 6.46 -3.75 4.85 7.65 2.80 0.08 458.86 458.78 9.51 9.22 -0.29 0 0 0 11 <1 -11 1/10/2024 9.23 9.99 0.76 5.39 5.9 0.5 253.3 211.43 -41.9 7.2 6.22 -1.0 51.59 86.7 35.1 68 <1 -68 1/20/2024 5.88 3.73 -2.15 4.58 6.55 1.97 413.07 301.57 -111.50 15.04 13.6 -1.4 12.8 1.24 -11.6 9.9 <1 -9.9 1/31/2024 3.07 6.43 3.36 5.64 7.34 1.70 429.54 322.89 -106.65 15.36 15.48 0.12 26.4 2.51 -23.9 13 <1 -13 2/1/2024 2.36 7.18 4.82 7.13 7.5 0.4 813.45 499.27 -314.18 16.14 14.35 -1.79 21.6 1.83 -19.8 NS NS -- 2/13/2024 7.86 9.28 1.42 6.54 5.38 -1.16 625.3 408.7 -216.6 18.36 16.06 -2.30 19.77 0.93 -18.84 3.5 2.1 J -1.4 2/14/2024 10.44 11.84 1.40 5.38 5.62 0.24 590 360 -230 10.34 8.12 -2.22 2.33 0.53 -1.80 3.6 11 -3 3/2/2024 9.34 8.86 -0.48 4.8 5.08 0.3 140.44 101.21 -39.23 10.64 9.52 -1.12 4.75 2.14 -2.61 7.7 1.5 J -6.2 3/7/2024 9.17 8.44 -0.73 4.86 4.81 -0.05 100.51 85.74 -14.77 10.11 9.6 -0.5 30.81 1.94 -28.87 70 2 J -68 3/11/2024 8.6 8.56 0.0 6.86 5.22 -1.64 351.57 274.83 -76.74 14.46 14.62 0.16 27.25 0 -27 NS NS -- 3/23/2024 9.82 9.73 -0.09 4.12 4.5 0.4 399.76 338.39 -61.37 19.16 18.88 -0.28 1.05 2.19 1.14 18 1.3 J -17 3/28/2024 8.84 8.52 -0.32 4.11 4.58 0.47 403.53 336.26 -67.27 16.55 15.95 -0.60 8.37 0 -8 3 2.6 J 0 Average 7.9 8.15 0.3 5.4 5.8 0.4 411 308 -103 13.6 12.6 -0.9 19 9 -10 21 1 -20 Median 9.0 8.54 -0.5 5.1 5.5 0.4 1 404 330 -74 14.8 14.0 -0.8 20 2 -18 10 1 -9 Notes: 1 - TSS was measured by laboratory method SM 2540 D from grab samples collected concurrent with the performance samples. 2 - Non -detect influent and effluent TSS sample results were assigned a value of zero for statistical calculations. 3 - Influent specific conductance and turbidity measurements from 1/6/2024 are considerably lower than expected and have been excluded from statistical calculations. 4 - Specific conductance recorded on 2/14/24 was inadvertently recorded in mS/cm and has been converted to PS/cm. J - Analyte detected. Reported value may not be accurate or precise. °C - degrees Celsius DO - dissolved oxygen FTC - flow through cell mg/L - milligrams per liter mS/cm - milliSiemens per centimeter NTU - nephelometric turbidity units SU - standard units TSS - total suspended solids µS/cm - microSiemens per centimeter NS - Sample not collected. Performance samples on 2/1/2024 and 3/11/2024 were inadvertently collected as wet weather samples, and concurrent TSS samples were not collected. TR0795C Page 1 of 4 June 2024 Table 2-5B FTC Water Quality Data - Seep B Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, North Carolina Date DO (mg/L) Influent Effluent Difference pH (SU) Influent Effluent Difference Specific Conductance (AS/cm) Influent Effluent Difference Temperature (°C) Influent Effluent Difference Turbidity (NTU) Influent Effluent Difference TSS'' (mg/L) Influent Effluent Difference[21 1/10/2024 9.91 10.23 0.32 6.42 7.28 0.86 142.61 135.36 -7.25 5.2 4.76 -0.4 375.39 266.29 -109.10 71 29 -42 1/20/2024 6.82 7.54 0.72 6.59 7.18 0.59 163.64 42.1 -121.5 13.02 12.44 -0.58 41.2 50 9 24 5.9 -18 1/25/2024 9.85 10.46 0.61 7.12 7.07 -0.05 148.99 128.75 -20.24 13.34 13.25 -0.09 3.19 38.9 35.7 11 3.6 -7 1/31/2024 7.64 7.44 -0.20 7.56 7.82 0.26 131.37 106.08 -25.29 14.51 14.51 0.00 37.6 33.1 -4.5 13 4.9 -8 2/l/2024 7.42 8.24 0.82 8.19 8.35 0.16 329.06 151.32 -177.74 13.7 14.76 1.1 27.1 29.3 2.2 NS NS -- 2/13/2024 9.97 9.82 -0.15 6.39 6.91 0.52 228.23 246.94 18.71 15.64 15.04 -0.60 29.27 11.13 -18.14 12 1.2 J -11 2/14/2024 12.36 12.17 -0.19 6.13 6.42 0.29 180 230 50 7.65 8.41 0.76 40.88 9.37 -31.51 11 1.2 J -10 3/2/2024 9.03 9.98 0.95 5.81 6.54 0.73 54.18 56.26 2.08 10.07 8.9 -1.2 91.56 30.39 -61.17 27 1.6 J -25 3/7/2024 8.66 9.37 0.71 5.92 6.5 0.6 41.05 47.24 6.19 9.34 9.21 -0.13 445.94 277.83 -168.11 110 34 -76 3/11/2024 8.57 8 -1 6.07 6.96 0.89 188.35 196.99 8.64 14.08 14.3 0.2 87.56 30.29 -57.27 NS NS -- 3/23/2024 9.81 8.21 -1.60 6.14 7.07 0.93 219.15 245.54 26.39 18.8 18.54 -0.3 8.6 0.02 -8.6 17 <1 -17 3/28/2024 9.65 8.11 -1.54 6.55 7.5 1.0 208.91 227.43 18.52 16.06 15.66 -0.40 9.75 0 -10 8.7 <1 -8.7 Average 9.14 9 0 6.57 7.1 0.6 170 151 -18 12.6 12.5 -0.1 99.8 65 -35 30 8 -22 Median 9.34 9 -1 6.41 7.1 0.7 172 143 -28 1 13.5 13.8 0.3 39.2 30 -9 15 3 -12 Notes: 1 - TSS was measured by laboratory method SM 2540 D from grab samples collected concurrent with the performance samples. 2 - Non -detect influent and effluent TSS sample results were assigned a value of zero for statistical calculations. 3 - Specific conductance recorded on 2/14/24 was inadvertently recorded in mS/cm and has been converted to PS/cm. J - Analyte detected. Reported value may not be accurate or precise. °C - degrees Celsius DO - dissolved oxygen FTC - flow through cell mg/L - milligrams per liter mS/cm - milliSiemens per centimeter NTU - nephelometric turbidity units SU - standard units TSS - total suspended solids µS/cm - microSiemens per centimeter NS - Sample not collected. Performance samples on 2/1/2024 and 3/11/2024 were inadvertently collected as wet weather samples, and concurrent TSS samples were not collected. TR0795C Page 2 of 4 June 2024 Table 2-5C FTC Water Quality Data - Seep C Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, North Carolina Date DO (mg/L) Influent Effluent Difference pH (SU) Influent Effluent Difference Specific Conductance (AS/cm) Influent Effluent Difference Temperature (°C) Influent Effluent Difference Turbidity (NTU) Influent Effluent Difference TSS'' (mg/L) Influent Effluent Difference [21 1/6/2024 8.8 9.31 0.5 7.62 7.54 -0.08 283.65 243.19 -40.46 9.65 9.85 0.20 197.63 39.42 -158.21 52 J 6.2 -46 1/10/2024 10.61 10.4 -0.2 7.52 8.21 0.69 180.82 175.32 -5.50 5.06 6.06 1.00 373.23 183.79 -189.44 100 30 -70 1/20/2024 7.79 4.81 -2.98 7.11 7.43 0.32 202.8 211.02 8.2 12.17 13.13 0.96 34.1 9.31 -24.8 21 <1 -21 1/31/2024 7.67 7.48 -0.19 8.1 8.13 7.95 -0.1 214.69 217.64 2.95 15.37 15.88 0.51 31 3.46 -28 18 <1 -18 2/l/2024 8.27 8.12 -0.15 8.19 0.06 276.17 271.46 -4.71 13.41 13.29 -0.12 25.8 2.67 -23.1 NS NS -- 2/13/2024 10.16 9.55 -0.61 7.07 6.98 -0.09 246.1 257.81 11.7 15.56 15.97 0.41 236.39 100.42 -135.97 50 6.6 -43 2/14/2024 12.19 12.12 -0.07 6.55 6.75 0.20 260 290 30 7.92 7.22 -0.70 121.12 52.06 -69.06 42 6.5 -36 2/24/2024 6.69 7.29 0.60 8.05 8.17 0.12 304.53 313.67 9.14 21.09 20.25 -0.84 31 2.6 -28 NS NS -- 3/2/2024 9.71 10.15 0.44 6.8 6.76 -0.04 75.06 72.34 -2.72 9.07 8.69 -0.38 167.68 44.81 -122.87 34 3 -31 3/7/2024 9.5 9.32 -0.2 6.63 6.77 0.14 54.37 54.88 0.51 9.38 9.22 -0.16 671.67 289.11 -382.56 120 33 -87 3/11/2024 9.02 8.07 -0.9 7.03 7.21 0.18 238.34 294.36 56.02 14.37 14.67 0.30 256.8 23.56 -233.2 NS NS -- 3/23/2024 9.91 10.2 0.3 7.21 7.38 0.17 279.45 290.96 11.51 18.63 18.55 -0.08 34.7 0.15 -34.6 13 <1 -13 3/28/2024 8.78 8.43 -0.35 7.5 7.46 0.0 262.53 278.09 15.56 16.02 15.95 -0.07 42.98 0.14 -42.84 21 <1 -21 Average 9.2 8.9 -0.3 7.3 7.4 0.1 221 229 7 12.90 12.98 0.10 171 57.8 -113 47 9 -39 Median 9.0 9.3 0.3 7.2 7.4 0.2 246 258 12 13.41 13.29 -0.10 121 23.6 -98 38 5 -33 Notes: 1 - TSS was measured by laboratory method SM 2540 D from grab samples collected concurrent with the performance samples. 2 - Non -detect influent and effluent TSS sample results were assigned a value of zero for statistical calculations. 3 - Specific conductance recorded on 2/14/24 was inadvertently recorded in mS/cm and has been converted to PS/cm. J - Analyte detected. Reported value may not be accurate or precise. °C - degrees Celsius DO - dissolved oxygen FTC - flow through cell mg/L - milligrams per liter mS/cm - milliSiemens per centimeter NTU - nephelometric turbidity units SU - standard units TSS - total suspended solids µS/cm - microSiemens per centimeter NS - Sample not collected. Performance samples on 2/l/2024, 2/24/2024, and 3/11/2024 were inadvertently collected as wet weather samples, and concurrent TSS samples were not collected. TR0795C Page 3 of 4 June 2024 Table 2-5D FTC Water Quality Data - Seep D Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, North Carolina Date DO (mg/L) Influent Effluent Difference pH (SU) Influent Effluent Difference Specific Conductance (AS/cm) Influent Effluent Difference Temperature (°C) Influent Effluent Difference Turbidity (NTU) Influent Effluent Difference TSS'' (mg/L) Influent Effluent Difference[21 1/10/2024 9.96 10.55 0.59 8.11 7.88 -0.23 190.56 239.71 49.15 7.3 6.01 -1.3 57.87 2 -56 24 1.2 J -23 1/20/2024 7.56 5.6 -2.0 7.4 7.38 0.0 119 113.39 -6 12.31 12.75 0.44 13 5.61 -7 3.9 1.5 J -2.4 1/25/2024 9.46 11.45 1.99 7.26 7.46 0.20 123.5 154.49 31.0 14.78 16.9 2.1 13.3 7.58 -5.7 <1 4.6 4.6 1/31/2024 7.81 6.05 -1.76 7.98 7.88 -0.10 102.18 94.8 -7.4 16.68 16.7 0.0 14.3 8.63 -5.7 15 2.3 J -13 2/l/2024 8.15 7.99 -0.16 8.32 7.57 -0.75 158.46 98.4 -60.1 13.52 15.95 2.43 13.4 6.43 -7.0 NS NS -- 2/13/2024 10.06 10.05 -0.01 7.03 7.17 0.14 126.94 169.41 42.47 15.88 15.64 -0.24 26.72 1.62 -25.10 7.8 1.9 J -5.9 2/14/2024 12.2 12.74 0.5 6.94 7.14 0.20 150 170 20 7.29 8.46 1.17 8.3 0.85 -7.5 6.6 <1 -6.6 3/2/2024 9.76 10.15 0.39 6.79 7.06 0.27 47.87 50.83 2.96 9.7 9.8 0.1 10.75 0.16 -10.59 6.2 <1 -6.2 3/7/2024 9.15 8.4 -0.8 6.8 7.03 0.2 40.36 43.93 3.57 9.67 9.98 0.31 32.86 2.81 -30.05 11 <1 -11 3/11/2024 8.72 9.22 0.50 7.28 7.52 0.24 174.36 174.22 -0.14 14.58 14.88 0.30 7.8 0 -8 NS NS -- 3/23/2024 10.01 8.17 -1.84 7.37 7.49 0.12 157.64 180.49 22.85 18.89 18.9 0.0 0.54 0 -1 3.9 <1 -3.9 3/28/2024 9.32 7.74 -1.58 7.44 7.53 0.09 144.55 143.03 -1.52 16.01 15.84 -0.17 8.15 0 -8 17 <1 -17 Average 9.3 9.0 -0.3 7.4 7.43 0.0 128 136 8 13.1 13.5 0.4 17 3 -14 10 1 -8 Median 9.4 8.8 -0.6 7.3 7.48 0.2 136 149 13 14.1 15.3 1.2 13 1 2 -11 1 7 1 -7 Notes: 1 - TSS was measured by laboratory method SM 2540 D from grab samples collected concurrent with the performance samples. 2 - Non -detect influent and effluent TSS sample results were assigned a value of zero for statistical calculations. 3 - Specific conductance recorded on 2/14/24 was inadvertently recorded in mS/cm and has been converted to PS/cm. J - Analyte detected. Reported value may not be accurate or precise. °C - degrees Celsius DO - dissolved oxygen FTC - flow through cell mg/L - milligrams per liter mS/cm - milliSiemens per centimeter NTU - nephelometric turbidity units SU - standard units TSS - total suspended solids µS/cm - microSiemens per centimeter NS - Sample not collected. Performance samples on 2/1/2024 and 3/11/2024 were inadvertently collected as wet weather samples, and concurrent TSS samples were not collected. TR0795C Page 4 of 4 June 2024 Table 3-1 Ex -Situ Seeps and Weeps Flow Data Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, North Carolina qr Flow Totalizer Data from Seeps and Weeps Capture Systems Operated by GEOServices (gallons) Surge Pond Flow to 004 GWTP Operated by Veolia Date Seep A Totalizer (Cumulative) Seep Tributary Totalizerr (Cumulative) Seep B Totalizer (Cumulative) Willis Creek Tributary Totalizer (Cumulative) Weep 3 Totalizer (Cumulative) Cumulative Volume Calculated from Capture System Totalizers Daily Volume Conveyed from Surge Pond to 004 Treatment Plant (gallons) Cumulative Volume Conveyed from Surge Pond to 004 Treatment Plant (gallons) Prior Total 5,964,450 1,228,013 3,361,104 528,576 404,083 11,486,226 12,029,484 1/1/2024 5,980,309 1,231,023 3,374,581 530,228 404,475 11,520,616 31,812 12,061,296 1/2/2024 5,993,858 1,233,839 3,390,023 531,658 404,802 11,554,180 30,520 12,091,817 1/3/2024 6,008,649 1,236,112 3,401,525 533,059 405,084 11,584,429 27,022 12,118,838 1/4/2024 6,023,169 1,238,791 3,415,545 534,684 405,373 11,617,562 28,220 12,147,059 1/5/2024 6,037,226 1,241,171 3,427,311 536,091 405,576 11,647,375 27,036 12,174,095 1/6/2024 6,128,889 1,257,803 3,439,909 537,471 413,834 11,777,906 32,194 12,206,290 1/7/2024 6,145,703 1,261,056 3,535,978 543,585 415,810 11,902,132 128,678 12,334,967 1/8/2024 6,162,930 1,264,268 3,555,969 545,898 416,916 11,945,981 131,030 12,465,997 1/9/2024 6,216,435 1,317,642 3,571,782 547,246 445,328 12,098,433 89,495 12,555,492 1/10/2024 6,371,098 1,336,364 3,759,007 554,555 456,376 12,477,400 127,791 12,683,284 1/11/2024 6,432,282 1,342,167 3,818,406 556,806 462,305 12,611,966 132,630 12,815,914 1/12/2024 6,455,531 1,363,769 3,852,073 559,118 477,629 12,708,120 133,314 12,949,228 1/13/2024 6,574,188 1,371,011 3,954,390 565,332 494,578 12,959,499 132,328 13,081,556 1/14/2024 6,598,579 1,376,893 3,990,872 567,928 499,600 13,033,872 135,167 13,216,724 1/15/2024 6,618,534 1,382,286 4,021,499 570,203 502,127 13,094,649 134,534 13,351,258 1/16/2024 6,636,946 1,387,739 4,053,266 572,200 505,165 13,155,316 132,987 13,484,244 1/17/2024 6,655,696 1,391,871 4,081,857 574,024 507,958 13,211,406 134,008 13,618,252 1/18/2024 6,671,785 1,395,893 4,104,740 575,694 511,170 13,259,282 133,681 13,751,933 1/19/2024 6,689,554 1,399,954 4,126,536 577,377 514,878 13,308,299 130,802 13,882,735 1/20/2024 6,706,560 1,403,941 4,151,422 579,007 520,695 13,361,625 132,288 14,015,023 1/21/2024 6,720,456 1,407,634 4,170,180 580,362 521,893 13,400,525 127,240 14,142,264 1/22/2024 6,737,065 1,411,281 4,195,277 581,705 522,832 13,448,160 127,104 14,269,368 1/23/2024 6,752,521 1,414,993 4,211,161 583,273 524,546 13,486,494 86,332 14,355,700 1/24/2024 6,769,344 1,418,362 4,233,025 584,679 526,308 13,531,718 39,752 14,395,452 1/25/2024 6,785,414 1,422,062 4,252,634 586,253 530,832 13,577,195 43,072 14,438,524 1/26/2024 6,802,564 1,425,603 4,278,320 587,666 540,821 13,634,974 50,782 14,489,306 1/27/2024 6,816,998 1,428,894 4,298,163 589,220 547,892 13,681,167 44,230 14,533,536 1/28/2024 6,833,132 1,432,099 4,318,960 590,742 550,658 13,725,591 38,935 14,572,471 1/29/2024 6,847,105 1,434,845 4,335,496 592,026 552,146 13,761,618 35,304 14,607,775 1/30/2024 6,861,676 1,437,694 4,351,041 593,259 553,441 13,797,111 28,823 14,636,597 1/31/2024 6,878,047 1,441,521 4,369,610 594,696 555,293 13,839,167 39,271 14,675,869 January Total 913,597 213,508 1,008,506 66,120 151,210 2,352,941 2,646,385 TR0795C Page 1 of 3 June 2024 Table 3-1 Ex -Situ Seeps and Weeps Flow Data Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, North Carolina qr Flow Totalizer Data from Seeps and Weeps Capture Systems Operated by GEOServices (gallons) Surge Pond Flow to 004 GWTP Operated by Veolia Date Seep A Totalizer (Cumulative) Seep Tributary Totalizerr (Cumulative) Seep B Totalizer (Cumulative) Willis Creek Tributary Totalizer (Cumulative) Weep 3 Totalizer (Cumulative) Cumulative Volume Calculated from Capture System Totalizers Daily Volume Conveyed from Surge Pond to 004 Treatment Plant (gallons) Cumulative Volume Conveyed from Surge Pond to 004 Treatment Plant (gallons) 2/1/2024 6,893,134 1,444,194 4,391,098 596,212 557,136 13,881,774 8,432 14,684,301 2/2/2024 6,907,235 1,447,106 4,406,243 597,216 558,566 13,916,366 22 14,684,324 2/3/2024 6,922,481 1,449,839 4,422,581 598,491 559,836 13,953,228 0 14,684,324 2/4/2024 6,936,228 1,452,314 4,435,930 599,653 561,215 13,985,340 0 14,684,324 2/5/2024 6,951,094 1,454,935 4,451,403 600,798 562,605 14,020,835 0 14,684,324 2/6/2024 6,964,536 1,457,298 4,464,165 601,919 566,403 14,054,321 0 14,684,324 2/7/2024 6,979,018 1,459,666 4,477,349 603,016 572,904 14,091,953 0 14,684,324 2/8/2024 6,992,529 1,461,533 4,489,153 604,120 574,549 14,121,884 4,342 14,688,666 2/9/2024 7,006,736 1,463,001 4,501,725 604,668 575,369 14,151,499 21,663 14,710,329 2/10/2024 7,020,713 1,464,227 4,513,244 604,991 576,173 14,179,348 106,590 14,816,918 2/11/2024 7,036,454 1,465,684 4,526,505 605,428 577,042 14,211,113 107,533 14,924,451 2/12/2024 7,099,832 1,478,265 4,542,817 605,753 588,972 14,315,639 108,225 15,032,676 2/13/2024 7,127,604 1,483,765 4,637,387 609,391 594,543 14,452,690 108,512 15,141,188 2/14/2024 7,142,776 1,485,510 4,653,793 610,116 596,462 14,488,657 110,248 15,251,436 2/15/2024 7,157,346 1,487,182 4,670,435 610,524 598,471 14,523,958 108,987 15,360,422 2/16/2024 7,173,003 1,488,609 4,683,907 610,836 600,969 14,557,324 92,150 15,452,573 2/17/2024 7,186,529 1,490,215 4,698,936 611,179 603,068 14,589,927 35,249 15,487,822 2/18/2024 7,200,968 1,491,431 4,710,669 611,481 605,653 14,620,202 26,613 15,514,435 2/19/2024 7,214,759 1,492,725 4,723,528 611,771 613,264 14,656,047 25,299 15,539,735 2/20/2024 7,229,431 1,493,894 4,733,948 612,057 621,837 14,691,167 24,811 15,564,546 2/21/2024 7,242,493 1,495,201 4,745,999 612,331 624,942 14,720,966 21,058 15,585,604 2/22/2024 7,259,099 1,496,449 4,756,456 612,608 626,053 14,750,665 22,799 15,608,403 2/23/2024 7,282,830 1,500,529 4,769,522 612,897 628,393 14,794,171 31,825 15,640,228 2/24/2024 7,296,813 1,502,101 4,798,430 614,131 629,672 14,841,147 42,378 15,682,605 2/25/2024 7,310,626 1,503,068 4,811,570 614,463 630,512 14,870,239 37,148 15,719,754 2/26/2024 7,325,324 1,504,356 4,822,003 614,746 631,488 14,897,917 19,558 15,739,312 2/27/2024 7,339,468 1,505,452 4,833,462 615,080 632,405 14,925,867 14,751 15,754,063 2/28/2024 7,354,695 1,506,813 4,844,320 615,394 634,873 14,956,095 16,201 15,770,264 2/29/2024 7,388,581 1,512,880 4,874,909 616,881 637,125 15,030 376 16,647 15,786,911 FebruaryTotal S1Q534 71,359 505,299 22,185 81,832 1,191,209 1,111,042 TR0795C Page 2 of 3 June 2024 Table 3-1 Ex -Situ Seeps and Weeps Flow Data Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, North Carolina qr Flow Totalizer Data from Seeps and Weeps Capture Systems Operated by GEOServices (gallons) Surge Pond Flow to 004 GWTP Operated by Veolia Date Seep A Totalizer (Cumulative) Seep Tributary Totalizerr (Cumulative) Seep B Totalizer (Cumulative) Willis Creek Tributary Totalizer (Cumulative) Weep 3 Totalizer (Cumulative) Cumulative Volume Calculated from Capture System Totalizers Daily Volume Conveyed from Surge Pond to 004 Treatment Plant (gallons) Cumulative Volume Conveyed from Surge Pond to 004 Treatment Plant (gallons) 3/l/2024 7,402,029 1,514,576 4,886,429 617,261 641,116 15,061,411 17,245 15,804,156 3/2/2024 7,489,262 1,531,305 4,985,929 621,275 668,176 15,295,947 17,560 15,821,716 3/3/2024 7,513,440 1,533,855 5,011,819 623,140 672,416 15,354,670 17,945 15,839,660 3/4/2024 7,528,150 1,535,776 5,034,428 623,664 677,852 15,399,870 18,380 15,858,040 3/5/2024 7,544,394 1,537,939 5,051,750 624,075 678,884 15,437,042 18,592 15,876,633 3/6/2024 7,699,057 1,583,476 5,068,900 624,441 697,402 15,673,276 27,984 15,904,616 3/7/2024 7,782,972 1,590,649 5,256,125 630,495 706,202 15,966,443 72,532 15,977,148 3/8/2024 7,805,602 1,594,149 5,299,594 632,130 711,335 16,042,810 73,920 16,051,068 3/9/2024 7,857,432 1,604,379 5,345,754 632,743 719,883 16,160,191 74,346 16,125,414 3/10/2024 7,879,754 1,607,958 5,399,176 636,405 722,340 16,245,633 74,535 16,199,949 3/11/2024 7,895,379 1,607,958 5,429,496 637,499 724,155 16,294,487 72,247 16,272,197 3/12/2024 7,910,891 1,608,008 5,438,674 638,061 726,520 16,322,154 81,705 16,353,902 3/13/2024 7,927,096 1,610,644 5,483,227 638,538 728,770 16,388,275 80,191 16,434,092 3/14/2024 7,979,875 1,613,077 5,490,116 638,987 730,708 16,452,763 115,952 16,550,045 3/15/2024 7,993,979 1,615,561 5,490,749 639,405 733,170 16,472,864 115,216 16,665,261 3/16/2024 8,007,804 1,617,855 5,506,378 639,830 735,424 16,507,291 115,356 16,780,616 3/17/2024 8,022,901 1,620,070 5,526,912 640,234 737,762 16,547,879 115,413 16,896,029 3/18/2024 8,036,595 1,621,944 5,543,845 640,815 739,902 16,583,101 115,204 17,011,233 3/19/2024 8,050,940 1,623,944 5,561,103 641,121 741,693 16,618,801 109,383 17,120,616 3/20/2024 8,064,244 1,625,767 5,575,544 641,452 743,273 16,650,280 69,429 17,190,045 3/21/2024 8,078,816 1,627,553 5,591,513 641,986 744,619 16,684,487 68,745 17,258,790 3/22/2024 8,092,467 1,629,413 5,605,164 642,293 746,198 16,715,535 45,806 17,304,596 3/23/2024 8,112,576 1,634,064 5,639,231 643,245 748,645 16,777,761 42,432 17,347,029 3/24/2024 8,125,663 1,635,565 5,658,539 644,141 749,921 16,813,829 42,647 17,389,676 3/25/2024 8,139,764 1,637,340 5,673,738 644,399 751,566 16,846,807 42,209 17,431,884 3/26/2024 8,153,538 1,638,836 5,687,644 644,700 753,067 16,877,785 42,308 17,474,192 3/27/2024 8,168,769 1,640,887 5,703,704 645,218 759,491 16,918,069 42,814 17,517,007 3/28/2024 8,268,358 1,656,793 5,794,854 650,037 782,885 17,152,927 42,189 17,559,196 3/29/2024 8,283,123 1,658,934 5,846,661 652,306 815,805 17,256,829 134,316 17,693,512 3/30/2024 8,298,571 1,660,832 5,866,649 653,657 818,640 17,298,349 142,411 17,835,923 3/31/2024 8,312,979 1,662,642 5,886,153 654,716 849,827 17,366,317 142,117 17,978,040 March Total 924,398 149,762 1,011,244 37,835 212,702 2,335,941 2,191,129 Reporting Period Total 2,348,529 434,629 2,525,049 126,140 445,744 5,880,091 5,948,556 Notes: 1 - Flow data from the Surge Pond through the 004 ground water treatment plant (GWTP) is collected and managed by Veolia. 2 - The daily volume conveyed from surge pond to 004 Treatment Plant is recorded on a 24-hour basis, ending daily at 1 pm. For simplicity, the volume totaled through 1 pm is shown as the daily total in this table. TR0795C Page 3 of 3 June 2024 Table 4-1 Extraction and Observation Well Construction Details Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, North Carolina WELL ID TARGET AQUIFER NORTHING (FT, NAD83) EASTING (FT, NAD83) TOP OF CASING ELEVATION (FT, NAVD88) WELL DIAMETER (INCHES) WELL DEPTH (FT, BGS) WELL SCREEN INTERVAL (FT, BGS) BCA-01 Black Creek Aquifer 399779.96 2050662.48 146.25 2 101 91-101 BCA-02 Black Creek Aquifer 396242.02 2051062.07 148.37 2 102 92-102 EW-01 Black Creek Aquifer 401683.69 2049951.04 92.04 6 85 60-80 EW-02 Black Creek Aquifer 401683.61 2050289.26 87.97 6 65 40-60 EW-03 Black Creek Aquifer 401723.50 2050594.78 84.67 6 72 57-67 EW-04 Black Creek Aquifer 401714.92 2050848.03 80.00 6 65 50-60 EW-05 Black Creek Aquifer 401654.63 2051059.46 82.93 6 78 63-73 EW-06 Black Creek Aquifer 401489.44 2051117.72 83.58 6 75 50-70 EW-07 Black Creek Aquifer 401350.61 2051160.78 86.45 6 68 53-63 EW-08 Black Creek Aquifer 401184.55 2051164.30 89.05 6 73 58-68 EW-09 Black Creek Aquifer 401008.87 2051129.57 81.08 6 65 40-60 EW-10 Black Creek Aquifer 400870.94 2051128.67 74.12 6 55 30-50 EW-11 Black Creek Aquifer 400683.82 2051280.71 93.12 6 75 60-70 EW-12 Black Creek Aquifer 400591.86 2051415.21 92.10 6 75 50-70 EW-13 Black Creek Aquifer 400527.75 2051513.14 87.95 6 79 54-74 EW-14 Black Creek Aquifer 400375.11 2051570.80 82.23 6 62 47-57 EW-15 Black Creek Aquifer 400223.63 2051556.86 77.23 6 53 38-48 EW-16 Black Creek Aquifer 400042.92 2051489.09 88.11 6 65 50-60 EW-17 Black Creek Aquifer 399975.22 2051517.08 87.84 6 65 40-60 EW-18 Surficial Aquifer 399828.16 2051586.65 74.56 6 30 15-25 EW-19 Black Creek Aquifer 399819.25 2051590.67 74.65 6 51 36-46 EW-20 Surficial Aquifer 399696.08 2051667.78 78.48 6 30 15-25 EW-21 Black Creek Aquifer 399549.59 2051687.61 84.66 6 62 47-57 EW-22 Surficial Aquifer 399298.40 2051754.69 82.54 6 37 22-32 EW-23 Black Creek Aquifer 399289.65 2051759.07 83.05 6 70 45-65 EW-24 Surficial Aquifer 399105.96 2051845.20 83.63 6 31 16-26 EW-25 Black Creek Aquifer 399097.14 2051848.27 83.44 6 75 60-70 EW-26S Surficial Aquifer 398992.13 2051869.73 83.50 6 30 15-25 EW-27 Surficial Aquifer 398883.14 2051881.19 85.81 6 33 18-28 EW-28 Black Creek Aquifer 398873.71 2051882.01 85.83 6 55 40-50 EW-29 Surficial Aquifer 398743.82 2051874.08 80.62 6 34 19-29 EW-30 Black Creek Aquifer 398733.15 2051872.90 82.01 6 80 55-75 EW-31 Surficial Aquifer 398619.06 2051860.80 80.84 6 33 18-28 EW-32 Black Creek Aquifer 398606.76 2051858.39 81.55 6 53 38-48 EW-33 Surficial Aquifer 398413.39 2051843.45 78.32 6 25 10-20 EW-34 Black Creek Aquifer 398403.44 2051844.29 77.11 6 75 40-70 EW-35 Surficial Aquifer 398342.37 2051862.99 74.44 6 18 8-13 EW-36 Black Creek Aquifer 398333.72 2051867.55 73.98 6 73 38-48,58-68 EW-37 Surficial Aquifer 398234.57 2051923.02 74.03 6 54 39-49 EW-38 Black Creek Aquifer 398229.45 2051926.24 74.19 6 80 55-75 EW-39 Surficial Aquifer 398113.89 2051992.69 77.19 6 21 6-16 EW-40 Black Creek Aquifer 398104.84 2051997.57 77.00 6 85 60-80 TR0795C Page 1 of 4 June 2024 Table 4-1 Extraction and Observation Well Construction Details Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, North Carolina WELL ID TARGET AQUIFER NORTHING (FT, NAD83) EASTING (FT, NAD83) TOP OF CASING ELEVATION (FT, NAVD88) WELL DIAMETER (INCHES) WELL DEPTH (FT, BGS) WELL SCREEN INTERVAL (FT, BGS) EW-41 Black Creek Aquifer 397944.33 2052019.70 84.99 6 75 50-70 EW-42 Black Creek Aquifer 397792.20 2052011.87 81.93 6 74 49-69 EW-43 Black Creek Aquifer 397657.42 2052005.16 81.80 6 76 51-71 EW-44 Surficial Aquifer 397520.77 2051997.72 75.22 6 18 8-13 EW-45 Black Creek Aquifer 397511.10 2051997.30 75.33 6 71 46-66 EW-46 Surficial Aquifer 397374.10 2051993.17 74.94 6 32 17-27 EW-47 Black Creek Aquifer 397364.92 2051992.87 75.02 6 68 43-63 EW-48 Surficial Aquifer 397290.64 2052028.52 79.87 6 31 16-26 EW-49 Black Creek Aquifer 397282.27 2052032.79 79.65 6 79 54-74 EW-50 Surficial Aquifer 397105.59 2052107.53 77.80 6 30 15-25 EW-51 Black Creek Aquifer 397096.10 2052109.76 78.36 6 70 45-65 EW-52 Black Creek Aquifer 396902.85 2052151.05 75.84 6 70 45-65 EW-53 Black Creek Aquifer 396713.03 2052190.03 76.33 6 67 42-62 EW-54 Black Creek Aquifer 396559.35 2052223.00 75.31 6 65 40-60 EW-55 Black Creek Aquifer 396358.87 2052225.92 86.59 6 80 55-75 EW-56 Black Creek Aquifer 396173.96 2052249.38 79.69 6 71 46-66 EW-57 Black Creek Aquifer 395992.47 2052247.52 84.92 6 70 45-65 EW-58 Black Creek Aquifer 395810.15 2052290.53 74.69 6 65 40-60 EW-60 Black Creek Aquifer 395425.21 2052313.29 77.65 6 68 43-63 EW-61 Black Creek Aquifer 395283.80 2052271.16 78.46 6 75 50-70 EW-62 Black Creek Aquifer 395170.54 2052195.07 83.12 6 65 40-60 EW-63 Black Creek Aquifer 395055.17 2052033.12 122.53 6 103 88-98 EW-64 Black Creek Aquifer 394924.16 2051976.78 121.67 6 85 60-80 EW-65 Black Creek Aquifer 394819.93 2051918.54 116.36 6 75 50-70 EW-66 Black Creek Aquifer 394823.51 2051780.19 115.77 6 101 76-96 EW-67 Black Creek Aquifer 394780.57 2051655.69 103.22 6 98 73-93 EW-68 Black Creek Aquifer 394728.65 2051563.34 96.82 6 92 67-87 EW-69 Black Creek Aquifer 394649.04 2051478.42 87.55 6 85 60-80 LTW-02 Black Creek Aquifer 398847.57 2052355.48 51.39 2 38 28-38 LTW-03 Floodplain Deposits 398114.45 2052558.35 51.75 2 30 15-30 LTW-04 Floodplain Deposits 397279.61 2052584.95 50.66 2 27 12-27 LTW-05 Black Creek Aquifer 396430.31 2052740.40 50.94 2 44 29-44 NAF-11B Surficial Aquifer 398911.13 2050995.88 140.74 2 44 33.5-43.5 OW-02 Black Creek Aquifer 398572.28 2051801.62 84.37 2 73 63-73 OW-03 Black Creek Aquifer 398601.08 2051812.32 84.64 2 73 63-73 OW-04 Black Creek Aquifer 395049.16 2052210.81 80.85 2 57 47-57 OW-04R Black Creek Aquifer 394990.53 2052236.29 80.03 2 61 51-61 OW-07 Black Creek Aquifer 397180.06 2052052.69 81.45 2 67 57-67 OW-08 Black Creek Aquifer 397202.33 2052041.98 82.30 2 67 57-67 OW-09 Black Creek Aquifer 395075.14 2052211.07 79.78 2 64 54-64 OW-09R Black Creek Aquifer 395001.93 2052252.38 78.53 2 65 55-65 OW-11 Black Creek Aquifer 401683.39 2049913.61 94.92 1 84 74-84 OW-12 Black Creek Aquifer 401731.33 2050721.09 83.65 1 60 50-60 OW-13 Black Creek Aquifer 400769.33 2051210.62 85.12 1 60 50-60 OW-14 Black Creek Aquifer 400311.42 2051608.03 80.67 1 56 46-56 TR0795C Page 2 of 4 June 2024 Table 4-1 Extraction and Observation Well Construction Details Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, North Carolina WELL ID TARGET AQUIFER NORTHING (FT, NAD83) EASTING (FT, NAD83) TOP OF CASING ELEVATION (FT, NAVD88) WELL DIAMETER (INCHES) WELL DEPTH (FT, BGS) WELL SCREEN INTERVAL (FT, BGS) OW-15 Black Creek Aquifer 399719.91 2051608.62 87.86 1 44 34-44 OW-16 Black Creek Aquifer 399828.66 2051993.25 52.94 1 25 15-25 OW-17 Black Creek Aquifer 399433.03 2051661.47 89.67 1 68 58-68 OW-18 Black Creek Aquifer 398846.69 2051836.19 90.88 1 55 45-55 OW-19 Black Creek Aquifer 398067.23 2051976.50 86.68 1 80 70-80 OW-20 Black Creek Aquifer 398229.85 2052080.86 69.59 1 58 48-58 OW-21 Black Creek Aquifer 397521.83 2051950.75 80.85 1 67 57-67 OW-22 Black Creek Aquifer 397325.34 2052218.74 66.63 1 53 43-53 OW-23 Black Creek Aquifer 396776.73 2052355.66 67.83 1 55 45-55 OW-24 Black Creek Aquifer 396677.42 2052158.17 78.67 1 60 50-60 OW-25 Black Creek Aquifer 396182.38 2052428.46 70.91 1 55 45-55 OW-26 Black Creek Aquifer 395503.74 2052268.81 80.85 1 60 50-60 OW-27 Black Creek Aquifer 395555.17 2052622.16 55.6 1 43 33-43 OW-28 Black Creek Aquifer 395570.57 2052838.21 48.49 2 30 20-30 OW-29 Black Creek Aquifer 395193.45 2052143.81 85.67 1 52 42-52 OW-30 Black Creek Aquifer 394988.72 2052537.53 70.92 2 59 49-59 OW-31 Black Creek Aquifer 394812.07 2051595.90 106.1 1 95 85-95 OW-32 Black Creek Aquifer 394563.76 2051792.16 85.05 2 72 62-72 OW-33 Black Creek Aquifer 395116.90 2052806.54 48.59 2 29 19-29 OW-34 Surficial Aquifer 398593.54 2051813.31 83.76 1 33 23-33 OW-35 Surficial Aquifer 398060.78 2051977.75 87.45 1 30 20-30 OW-36 Surficial Aquifer 397257.46 2051997.45 80.61 1 21 11-21 OW-37 Surficial Aquifer 396154.99 2052264.10 77.82 2 35 25-35 OW-38 Black Creek Aquifer 394885.22 2051883.97 123.7 1 70 60-70 OW-39 Black Creek Aquifer 394728.70 2052105.68 92.07 2 78 68-78 OW-40 Black Creek Aquifer 394588.05 2052521.39 72.88 2 59 49-59 OW-41 Black Creek Aquifer 401683.74 2050119.92 93.66 1 92 82-92 OW-42 Black Creek Aquifer 401696.05 2050448.24 87.37 1 68 58-68 OW-43 Black Creek Aquifer 400937.73 2051116.17 76.94 1 50 40-50 OW-44 Black Creek Aquifer 399741.48 2051736.45 73.18 1 44 34-44 OW-45 Black Creek Aquifer 398836.07 2051955.99 77.1 1 60 50-60 OW-46 Black Creek Aquifer 398164.94 2052050.69 72.05 1 69 59-69 OW-47 Black Creek Aquifer 397243.89 2052136.32 71.47 1 59 49-59 OW-48 Black Creek Aquifer 396698.39 2052275.93 69.54 1 52 42-52 OW-49 Black Creek Aquifer 396180.56 2052348.51 79.56 1 63 53-63 OW-50 Black Creek Aquifer 395529.59 2052379.97 71.53 1 53 43-53 OW-51 Black Creek Aquifer 396166.08 2052262.14 77.72 2 66 56-66 OW-52 Black Creek Aquifer 397562.30 2052151.03 60.66 2 47 37-47 OW-53 Black Creek Aquifer 397530.83 2052055.05 75.16 2 68 56-66 OW-54 Black Creek Aquifer 401068.86 2051275.96 47.42 2 12 7-12 OW-55 Black Creek Aquifer 401761.92 2050875.02 75.45 2 58 43-58 OW-56 Black Creek Aquifer 401983.45 2050634.71 44.69 2 12 7-12 OW-57 Black Creek Aquifer 401781.20 2050174.65 68.87 2 43 33-43 PIW-10DR Black Creek Aquifer 395093.99 2052297.30 75.91 2 58 53-58 PIW-11 Black Creek Aquifer 401911.03 2050416.29 67.02 2 57 47-57 TR0795C Page 3 of 4 June 2024 Table 4-1 Extraction and Observation Well Construction Details Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, North Carolina WELL ID TARGET AQUIFER NORTHING (FT, NAD83) EASTING (FT, NAD83) TOP OF CASING ELEVATION (FT, NAVD88) WELL DIAMETER (INCHES) WELL DEPTH (FT, BGS) WELL SCREEN INTERVAL (FT, BGS) PIW-12 Black Creek Aquifer 401703.10 2051025.77 83.78 2 74 64-74 PIW-13 Black Creek Aquifer 401464.29 2051122.60 83.18 2 64 54-64 PIW-14 Black Creek Aquifer 401163.98 2051186.57 87.43 2 66 56-66 PIW-15 Black Creek Aquifer 400706.51 2051532.80 67.85 2 44 34-44 PIW-1D Black Creek Aquifer 400548.00 2051801.28 52.16 2 30 24.5-29.5 PIW-2D Black Creek Aquifer 399925.40 2051315.80 96.19 2 50 40-50 PIW-3D Black Creek Aquifer 399711.25 2052086.94 53.42 2 24 19-24 PIW-4D Black Creek Aquifer 398816.52 2052101.94 52.85 2 37 32.3-37.3 PIW-5S Surficial Aquifer 398519.70 2051950.49 75.02 2 19.8 9.8-19.8 PIW-5SR Surficial Aquifer 398545.03 2051977.42 79.60 2 25 15-25 PIW-6S Floodplain Deposits 398117.93 2052539.79 53.40 2 28 18-28 PIW-7D Black Creek Aquifer 396787.77 2052595.65 48.93 2 34 29-34 PIW-7S Floodplain Deposits 396786.97 2052589.10 47.97 2 17 7-17 PIW-8D Black Creek Aquifer 396403.37 2052682.10 48.66 2 40 35-40 PW-02 Surficial Aquifer 399779.06 2050649.47 146.43 2 60 50-60 PW-03 Surficial Aquifer 397339.81 2050765.32 147.97 2 45 35-45 PW-04 Surficial Aquifer 394659.55 2050940.66 97.75 2 27 17-27 PW-1 OR Black Creek Aquifer 398516.12 2051936.59 75.90 2 67 57-67 PW-IORR Black Creek Aquifer 398532.53 2051965.93 79.97 2 71 61-71 PW-11 Black Creek Aquifer 394354.36 2052226.72 73.26 2 64 53-63 PW-14 Black Creek Aquifer 397325.65 2050766.36 147.97 2 146 136-146 PW-15R Black Creek Aquifer 398900.88 2051011.75 136.14 2 120 110-120 PZ-22 Black Creek Aquifer 397271.94 2052585.34 50.70 1 48 42.5-47.5 SMW-03B Black Creek Aquifer 399785.75 2049421.54 150.43 2 82 72-82 SMW-09 Surficial Aquifer 401076.89 2050017.41 141.43 2 62 52-62 SMW-12 Black Creek Aquifer 401314.20 2051007.22 118.22 2 98 88-98 Notes: 1 - This table provides well construction details for the wells included under the Performance Monitoring Plan (PMP). It is not comprehensive to the entire well network at the Site. 2 - At one drilling location, EW-59, Black Creek aquifer material was not encountered, therefore there was not a suitable interval to install the well screen. This borehole was abandoned prior to well installation. BGS - below ground surface EW - extraction well NAD83 - North American Datum of 1983 NAVD88 - North American Vertical Datum of 1988 OW - observation well TR0795C Page 4 of 4 June 2024 Table 4-2 Summary of GWEC Flow Data Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, North Carolina Date Average Extraction Flow Rate (gpm) Cumulative Volume Extracted (gallons) Prior Total N/A 188,853,643 1/1/2024 346 189,353,371 1/2/2024 341 189,851,019 l /3/2024 345 190,350,859 1 /4/2024 338 190,840,139 1/5/2024 327 191,314,171 1 /6/2024 340 191,807,195 1 /7/2024 335 192,292,491 1/8/2024 324 192,762,171 1/9/2024 331 193,252,283 1/10/2024 328 193,731,387 1/11/2024 337 194,217,467 1/12/2024 338 194,707,467 1/13/2024 340 195,199,659 1/14/2024 341 195,693,067 1/15/2024 336 196,178,011 1/16/2024 337 196,673,723 1/17/2024 339 197,164,859 1/18/2024 354 197,676,795 1/19/2024 352 198,186,011 1/20/2024 348 198,688,667 1/21/2024 345 199,191,323 1/22/2024 342 199,694,539 1/23/2024 342 200,187,483 1/24/2024 340 200,680,635 1/25/2024 340 201,173,035 1/26/2024 338 201,661,291 1/27/2024 334 202,144,843 1/28/2024 334 202,629,995 1/29/2024 333 203,111,787 1/30/2024 346 203,609,708 1/31/2024 351 204,114,139 January Total N/A 15,260,496 TR0795C Page 1 of 3 June 2024 Table 4-2 Summary of GWEC Flow Data Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, North Carolina Date Average Extraction Flow Rate (gpm) Cumulative Volume Extracted (gallons) 2/1/2024 349 204,619,115 2/2/2024 348 205,124,123 2/3/2024 344 205,621,611 2/4/2024 345 206,120,715 2/5/2024 344 206,618,667 2/6/2024 340 207,111,611 2/7/2024 343 207,608,123 2/8/2024 346 208,109,435 2/9/2024 346 208,610,971 2/10/2024 347 209,111,771 2/11/2024 345 209,611,995 2/12/2024 346 210,114,411 2/13/2024 341 210,608,347 2/14/2024 341 211,100,635 2/15/2024 324 211,569,867 2/16/2024 344 212,067,915 2/17/2024 346 212,568,539 2/18/2024 345 213,067,867 2/19/2024 343 213,565,723 2/20/2024 340 214,058,187 2/21/2024 318 214,525,419 2/22/2024 294 214,949,835 2/23/2024 339 215,447,515 2/24/2024 344 215,943,947 2/25/2024 343 216,439,035 2/26/2024 345 216,938,795 2/27/2024 344 217,437,083 2/28/2024 339 217,928,459 2/29/2024 337 218,416,891 February Total N/A 14,302,752 TR0795C Page 2 of 3 June 2024 Table 4-2 Summary of GWEC Flow Data Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, North Carolina Date Average Extraction Flow Rate (gpm) Cumulative Volume Extracted (gallons) 3/1/2024 342 218,911,195 3/2/2024 343 219,408,459 3/3/2024 343 219,904,491 3/4/2024 346 220,405,243 3/5/2024 344 220,902,747 3/6/2024 345 221,402,763 3/7/2024 340 221,894,347 3/8/2024 338 222,383,963 3/9/2024 342 222,878,939 3/10/2024 338 223,348,395 3/11/2024 337 223,835,963 3/12/2024 295 224,263,387 3/13/2024 266 224,651,339 3/14/2024 326 225,128,635 3/15/2024 332 225,610,347 3/16/2024 334 226,092,939 3/17/2024 333 226,574,267 3/18/2024 331 227,053,211 3/19/2024 327 227,526,315 3/20/2024 323 227,995,035 3/21/2024 301 228,430,971 3/22/2024 333 228,909,830 3/23/2024 335 229,392,611 3/24/2024 330 229,867,288 3/25/2024 325 230,335,968 3/26/2024 334 230,817,011 3/27/2024 332 231,294,397 3/28/2024 331 231,771,480 3/29/2024 330 232,247,068 3/30/2024 333 232,726,081 3/31/2024 333 233,205,457 March Total I N/A 14,788,566 Reporting Period Total 44,351,814 Notes: 1 - Flow rate measurements are collected by the manifold flow meter every 15 minutes. 2 - The cumulative volume extracted is recorded by the GWEC system flow totalizer. 3 - The monthly and reporting period totals are not applicable (N/A) for flow rate values. GWEC - Groundwater Extraction and Conveyance gpm - gallons per minute TR0795C Page 3 of 3 June 2024 Table 4-3 Extraction Well Flow Data Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, North Carolina Average Extraction Flow Rate (gpm) Total Volume (gal) Well ID January February March January February March Total Reporting Period Willis Creek (Northern Alinment) EW-01 12.84 12.12 12.93 573,193 506,287 576,979 1,656,459 EW-02 5.83 5.57 5.96 260,442 232,749 266,189 759,381 EW-03 2.38 2.34 2.49 106,131 97,916 111,014 315,061 EW-04 1.01 0.75 0.55 45,055 31,470 24,717 101,241 EW-05 13.88 12.93 13.75 619,474 540,113 613,978 1,773,565 EW-06 7.93 7.50 7.86 353,906 313,348 350,861 1,018,115 EW-07 2.27 1.87 0.68 101,142 78,245 30,294 209,681 EW-08 4.28 4.21 4.08 191,060 175,812 182,078 548,949 EW-09 0.03 0.01 0.00 1,416 601 145 2,162 EW-10 1.15 0.77 0.57 51,262 32,285 25,288 108,835 EW-11 1.64 0.54 0.26 73,402 22,537 11,770 107,710 EW-12 1.32 0.86 1.06 58,919 35,778 47,193 141,890 EW-13 0.80 0.67 0.61 35,867 28,150 27,343 91,359 EW-14 4.46 4.45 4.40 199,131 185,883 196,611 581,625 EW-15 0.00 0.00 0.00 0 0 0 0 Average Northern Alignment EW 3.99 3.64 3.68 N/A N/A N/A N/A Barrier Wall (Southern Alignment) AM EW-16 0.00 0.00 0.00 0 0 0 0 EW-17 0.01 0.01 0.19 580 615 8,526 9,720 EW-18 1.00 0.67 0.75 44,774 28,061 33,348 106,183 EW-19 1.04 2.17 2.45 46,570 90,410 109,555 246,535 EW-20 0.23 0.25 0.30 10,318 10,413 13,344 34,075 EW-21 0.00 0.00 0.00 0 0 0 0 EW-22 6.94 6.92 6.98 309,793 289,128 311,430 910,351 EW-23 0.00 0.00 0.00 0 0 0 0 EW-24 2.97 2.97 2.99 132,769 123,901 133,484 1 390,154 EW-25 1.42 1.73 1.60 63,488 72,305 71,463 207,256 EW-26S 0.76 0.71 0.80 33,839 29,539 35,642 99,020 EW-27 4.96 4.94 4.98 221,311 206,447 222,477 650,234 EW-28 0.74 0.71 0.74 32,919 29,787 33,029 95,734 EW-29 4.46 4.45 4.49 199,181 185,808 200,229 585,219 EW-30 3.96 3.95 3.99 176,997 165,153 177,955 520,105 EW-31 7.93 7.91 7.97 354,031 330,301 355,921 1 1,040,254 EW-32 0.68 0.47 1.13 30,561 19,482 50,441 100,484 EW-33 1.46 1.63 1.65 65,168 68,105 73,714 206,987 EW-34 5.16 5.94 4.99 230,336 247,871 222,583 700,791 EW-35 0.00 0.00 0.00 0 0 4 4 EW-36 7.80 7.91 7.97 348,320 330,335 355,928 1,034,584 EW-37 4.46 4.45 4.49 199,190 185,770 200,243 585,202 EW-38 16.77 16.68 16.94 748,710 696,735 756,382 2,201,828 EW-39 1.37 1.41 1.46 60,952 58,963 65,039 184,953 EW40 19.83 19.78 19.93 885,010 826,006 889,836 2,600,851 EW-41 5.95 5.92 4.04 265,423 247,186 180,360 692,968 EW42 3.96 3.95 3.98 176,926 165,121 177,871 519,918 EW-43 4.95 4.91 4.98 220,925 204,966 222,451 648,343 EW44 0.00 0.00 0.00 0 0 0 0 EW-45 2.96 3.18 3.99 132,037 132,852 177,903 442,792 EW46 0.00 0.00 0.00 0 0 0 0 EW47 3.73 3.96 3.99 166,624 165,226 177,917 509,767 EW48 0.68 0.76 0.87 30,523 31,717 38,637 100,877 EW49 5.90 5.93 5.98 263,383 247,742 267,123 778,248 EW-50 1.98 1.98 1.99 88,402 82,503 88,962 259,867 EW-51 3.86 3.95 3.99 172,193 165,137 178,059 1 515,389 EW-52 3.86 5.93 5.98 172,152 247,801 267,140 687,093 EW-53 4.30 4.45 4.49 191,901 185,869 200,399 578,170 EW-54 2.60 2.97 2.99 115,933 123,911 133,431 373,275 EW-55 3.24 3.47 3.49 144,623 145,029 155,620 445,273 EW-56 5.92 5.92 5.98 264,121 247,297 266,871 778,289 EW-57 0.00 0.00 0.00 0 0 0 0 EW-58 1 1.48 1 1.46 1 1.61 1 66,014 1 60,790 72,090 198,893 EW-60 1 0.24 1 0.21 1 0.01 1 10,758 1 8,614 641 20,012 TR0795C Page 1 of 2 June 2024 Table 4-3 Extraction Well Flow Data Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, North Carolina Average Extraction Flow Rate (gpm) Total Volume (gal) Well ID January February March January February March Total Reporting Period EW-61 2.08 2.06 2.23 93,021 86,048 99,624 278,693 EW-62 1.57 1.84 2.16 69,968 76,772 96,642 243,382 EW-63 10.85 10.79 10.95 484,311 450,736 488,673 1,423,720 EW-64 0.00 0.00 0.00 0 0 0 0 EW-65 0.84 1.24 1.31 37,309 51,592 58,648 147,549 EW-66 11.88 11.78 11.95 530,284 491,987 533,341 1,555,612 EW-67 31.72 1 31.65 1 31.86 1,415,999 1,321,605 1 1,422,148 1 4,159,752 EW-68 27.75 27.69 27.87 1,238,702 1,156,354 1,244,330 3,639,386 EW-69 27.74 27.58 27.88 1,238,131 1,151,841 1,244,354 3,634,326 Average Southern Alignment EW 4.98 1 5.08 5.12 N/A N/A N/A N/A Notes: 1 - Each well's flowmeter records flow rate every 15 minutes, including instances of no flow for pumps that are cycling as opposed to operating continuously. The calculated monthly average accounts for these instances of no flow. The values above are therefore not necessarily representative of the target flow rate setpoint for each well. gpm - gallons per minute gal - gallons TR0795C Page 2 of 2 June 2024 Table 5-1 004 Treatment Plant Flow Data Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, North Carolina Date Daily Volume Influent (gallons) Cumulative Volume Inflaent (gallons) Average Discharge Flow Rate (gpm) Daily Volume Treated and Discharged (gallons) Cumulative Volume Treated and Discharged (gallons) Prior Total 193,886,310 N/A 196,690,733 1/l/2024 517,798 194,404,108 353 508,195 197,198,928 1/2/2024 514,440 194,918,548 349 502,725 197,701,653 1/3/2024 507,935 195,426,483 341 491,278 198,192,931 1/4/2024 508,858 195,935,341 338 486,708 198,679,639 1/5/2024 483,832 196,419,173 331 476,231 199,155,870 1/6/2024 503,990 196,923,163 344 495,699 199,651,569 1/7/2024 603,452 197,526,615 406 584,249 200,235,818 1/8/2024 582,894 198,109,509 400 576,521 200,812,339 1/9/2024 550,896 198,660,405 376 541,185 201,353,524 1/10/2024 590,004 199,250,409 401 577,470 201,930,994 1/11/2024 598,861 199,849,270 404 582,384 202,513,378 1/12/2024 596,982 200,446,252 406 585,324 203,098,702 1/13/2024 608,322 201,054,574 416 598,686 203,697,388 1/14/2024 606,900 201,661,474 411 592,010 204,289,398 1/15/2024 604,734 202,266,208 407 585,363 204,874,761 1/16/2024 610,525 202,876,733 413 595,378 205,470,139 1/17/2024 605,970 203,482,703 413 595,392 206,065,531 1/18/2024 619,788 204,102,491 401 577,967 206,643,498 1/19/2024 620,171 204,722,662 409 589,000 207,232,498 1/20/2024 643,320 205,365,982 443 637,281 207,869,779 1/21/2024 581,084 205,947,066 397 572,260 208,442,039 1/22/2024 614,183 206,561,249 415 597,478 209,039,517 1/23/2024 566,155 207,127,404 382 549,644 209,589,161 1/24/2024 523,011 207,650,415 356 512,090 210,101,251 1/25/2024 519,568 208,169,983 353 508,116 210,609,367 1/26/2024 532,392 208,702,375 363 522,174 211,131,541 1/27/2024 510,276 209,212,651 346 498,492 211,630,033 1/28/2024 508230 209,720,881 343 493573 212,123,606 1/29/2024 509,050 210,229,931 345 496,158 212,619,764 1/30/2024 493,548 210,723,479 332 478,354 213,098,118 1/31/2024 529,135 211,252,614 354 510,104 213,608,222 January Total 17,366,304 N/A 16,917,489 TR0795C Page 1 of 3 June 2024 Table 5-1 004 Treatment Plant Flow Data Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, North Carolina e Daily Volume Influent (gallons) Cumulative Volume Inflaent (gallons) Average Discharge Flow Rate (gpm) Daily Volume Treated and Discharged (gallons) Cumulative Volume Treated and Discharged (gallons) 2/1/2024 498,309 211,750,923 341 491,424 214,099,646 2/2/2024 487,063 212,237,986 324 466,579 214,566,225 2/3/2024 474,005 212,711,991 322 463,915 215,030,140 2/4/2024 483,588 213,195,579 328 472,394 215,502,534 2/5/2024 476,726 213,672,305 321 462,862 215,965,396 2/6/2024 471,496 214,143,801 318 457,473 216,422,869 2/7/2024 492,925 214,636,726 342 492,863 216,915,732 2/8/2024 461,128 215,097,854 324 465,987 217,381,719 2/9/2024 497,573 215,595,427 343 493,403 217,875,122 2/10/2024 577,047 216,172,474 394 567,804 218,442,926 2/11/2024 603,682 216,776,156 414 596,386 219,039,312 2/12/2024 585,852 217,362,008 400 576,590 219,615,902 2/13/2024 587,064 217,949,072 400 575,682 220,191,584 2/14/2024 586,430 218,535,502 396 570,400 220,761,984 2/15/2024 551,759 219,087,261 379 546,276 221,308,260 2/16/2024 573,514 219,660,775 388 559,297 221,867,557 2/17/2024 520,738 220,181,513 351 504,812 222,372,369 2/18/2024 512,240 220,693,753 346 497,891 222,870,260 2/19/2024 505,793 221,199,546 340 489,935 223,360,195 2/20/2024 509,974 221,709,520 343 493,862 223,854,057 2/21/2024 496,409 222,205,929 336 483,764 224,337,821 2/22/2024 442,976 222,648,905 297 428,079 224,765,900 2/23/2024 470,093 223,118,998 313 450,958 225,216,858 2/24/2024 521,879 223,640,877 339 488,190 225,705,048 2/25/2024 524,532 224,165,409 355 511,771 226,216,819 2/26/2024 505,890 224,671,299 356 512,387 226,729,206 2/27/2024 500,454 225,171,753 341 1 490,530 227,219,736 2/28/2024 494,224 225,665,977 334 480,729 227,700,465 2/29/2024 491,983 226,157,960 334 480,590 228,181,055 February Total 14,905,346 14,572,833 TR0795C Page 2 of 3 June 2024 Table 5-1 004 Treatment Plant Flow Data Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, North Carolina e Daily Volume Influent (gallons) Cumulative Volume Inflaent (gallons) Average Discharge Flow Rate (gpm) Daily Volume Treated and Discharged (gallons) Cumulative Volume Treated and Discharged (gallons) 3/1/2024 488,325 226,646,285 327 471,090 228,652,145 3/2/2024 502,819 227,149,104 336 483,399 229,135,544 3/3/2024 492,191 227,641,295 345 497,094 229,632,638 3/4/2024 501,594 228,142,889 340 489,279 230,121,917 3/5/2024 501,769 228,644,658 325 468,385 230,590,302 3/6/2024 497,782 229,142,440 324 466,429 231,056,731 3/7/2024 560,516 229,702,956 347 499,082 231,555,813 3/8/2024 543,484 230,246,440 395 569,447 232,125,260 3/9/2024 560,433 230,806,873 387 557,326 232,682,586 3/10/2024 551,008 231,357,881 371 534,181 233,216,767 3/11/2024 535,963 231,893,844 361 520,458 233,737,225 3/12/2024 524,107 232,417,951 356 512,146 234,249,371 3/13/2024 488,618 232,906,569 330 474,776 234,724,147 3/14/2024 547,151 233,453,720 365 525,443 235,249,590 3/15/2024 589,009 234,042,729 404 581,456 235,831,046 3/16/2024 602,567 234,645,296 408 588,085 236,419,131 3/17/2024 595,998 235,241,294 408 587,087 237,006,218 3/18/2024 594,441 235,835,735 404 581,748 237,587,966 3/19/2024 583,880 236,419,615 395 568,862 238,156,828 3/20/2024 542,202 236,961,817 360 518,047 238,674,875 3/21/2024 505,600 237,467,417 316 455,102 239,129,977 3/22/2024 524,085 237,991,502 352 507,368 239,637,345 3/23/2024 537,363 238,528,865 355 511,667 240,149,012 3/24/2024 523,771 239,052,636 362 521,088 240,670,100 3/25/2024 513,653 239,566,289 345 496,134 241,166,234 3/26/2024 517,588 240,083,877 332 478,760 241,644,994 3/27/2024 527,641 240,611,518 353 507,965 242,152,959 3/28/2024 521,052 241,132,570 338 486,165 242,639,124 3/29/2024 606,743 241,739,313 427 614,670 243,253,794 3/30/2024 610,341 242,349,654 417 601,128 243,854,922 3/31/2024 614,603 242,964,257 420 604,402 1 244,459,324 March Total 16,806,297 N/A 16,278,269 Reporting Period Total 49,077,947 47,768,591 Notes: 1 - The 004 Treatment Plant operational data is collected and managed by Veolia. 2 - The monthly and reporting period totals are not applicable (N/A) for flow rate values. 3 - The daily influent volume and volume treated and discharged is recorded on a 24-hour basis, ending daily at 1 pm. For simplicity, the volume totaled through 1 pm is shown as the daily total in this table. 4 - Differences in daily and cumulative volumes between influent and discharged are attributable to the measurement resolution of the flow meters at the influent and effluent locations. TR0795C Page 3 of 3 June 2024 Table 5-2 004 Treatment Plant PFAS Analytical Results Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC Table 3+ SOP (ng/L) 004 Influent 004-INF-0124-2 Sample Date: 2-Jan-24 004 Effluent 004-EFF-0124-2 Sample Date: 2-Jan-24 004 Influent 004-INF-0124-2A Sample Date: 8-Jan-24 004 Effluent 004-EFF-0124-2A Sample Date: 8-Jan-24 004 Influent 004-INF-0124-3 Sample Date: 15-Jan-24 004 Effluent 004-EFF-0124-3 Sample Date: 15-Jan-24 004 Influent 004-INF-0124-4 Sample Date: 22-Jan-24 004 Effluent 004-EFF-0124-4 Sample Date: 22-Jan-24 004 Influent 004-INF-0124-5 Sample Date: 29-Jan-24 004 Effluent 004-EFF-0124-5 Sample Date: 29-Jan-24 Hfpo Dimer Acid 14,000 <2.0 20,000 <2.0 14,000 <2.0 17,000 <2.0 12,000 <2.0 PFMOAA 69,000 <2.0 UJ 56,000 <2.0 UJ 63,000 <2.0 57,000 <2.0 56,000 <2.0 PFO2HxA 26,000 <2.0 -- -- -- -- -- -- -- -- PFO3OA 7,500 <2.0 -- -- -- -- -- -- -- -- PFO4DA 1,900 <2.0 -- -- -- -- -- -- -- -- PFO5DA 640 <2.0 -- -- -- -- -- -- -- -- PMPA 10,000 <10 18,000 <10 11,000 <10 16,000 <10 9,300 <10 PEPA 3,200 <20 -- -- -- -- -- -- -- -- PS Acid 760 <2.0 -- -- -- -- -- -- -- -- Hydro-PS Acid 300 <2.0 UJ -- -- -- -- -- -- -- -- R-PSDA 940 J <2.0 -- -- -- -- -- -- -- -- Hydrolyzed PSDA 6,800 J <2.0 UJ -- -- -- -- -- -- -- -- R-PSDCA 24 <2.0 -- -- -- -- -- -- -- -- NVHOS, Acid Form 980 <2.0 -- -- -- -- -- -- -- -- EVE Acid 170 <2.0 -- -- -- -- -- -- -- -- Hydro-EVE Acid 890 <2.0 -- -- -- -- -- -- -- -- R-EVE 530 J <2.0 -- -- -- -- -- -- -- -- Perfluoro(2-ethoxyethane)sulfonic Acid <6.7 <2.0 -- -- -- -- -- -- -- -- PFECA B <27 <2.0 -- -- -- -- -- -- -- -- PFECA-G <48 <2.0 -- -- -- -- -- -- -- -- Total Table 3+ (17 compounds)"2'3 140,000 -- -- -- Notes: 1 - Total Table 3+ was calculated including J qualified data but not non -detect data. The total Table 3+ sum is rounded to two significant figures. 2 - Total Table 3+ (17 Compounds) does not include R-PSDA, Hydrolyzed PSDA and R-EVE. 3 - Total Table 3+ (17 Compounds) is not applicable for the weekly sampling for only PFAS indicator compounds (HFPO-DA, PFMOAA, and PMPA). Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. UJ — Analyte not detected. Reporting limit may not be accurate or precise. ng/L - nanograms per liter SOP - standard operating procedure -- - No data reported < - Analyte not detected above associated reporting limit. ND - No Table 3+ compounds were detected above their associated reporting limits. TR0795C Page 1 of 4 June 2024 Table 5-2 004 Treatment Plant PFAS Analytical Results Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC Table 3+ SOP (ng/L) 004 Influent 004-INF-0224 Sample Date: 5-Feb-24 004 Effluent 004-EFF-0224 Sample Date: 5-Feb-24 004 Influent 004-INF-0224-2 Sample Date: 12-Feb-24 004 Effluent 004-EFF-0224-2 Sample Date: 12-Feb-24 004 Influent 004-INF-0224-3 Sample Date: 19-Feb-24 004 Effluent 004-EFF-0224-3 Sample Date: 19-Feb-24 004 Influent 004-INF-0224-4 Sample Date: 26-Feb-24 004 Effluent 004-EFF-0224-4 Sample Date: 26-Feb-24 Hfpo Dimer Acid 11,000 <2.0 17,000 <2.0 11,000 <2.0 14,000 <2.0 PFMOAA 71,000 <2.0 59,000 <2.0 74,000 <2.0 UJ 62,000 <2.0 UJ PFO2HxA -- -- 23,000 <2.0 -- -- -- -- PFO3OA -- -- 6,400 <2.0 -- -- -- -- PFO4DA -- -- 1,600 <2.0 -- -- -- -- PFO5DA -- -- 470 <2.0 -- -- -- -- PMPA 10,000 <10 14,000 <10 10,000 <10 10,000 <10 UJ PEPA -- -- 6,000 <20 -- -- -- -- PS Acid -- -- 1,600 <2.0 -- -- -- -- Hydro-PS Acid -- -- 620 <2.0 -- -- -- -- R-PSDA -- -- 1,800 J <2.0 -- -- -- -- Hydrolyzed PSDA -- -- 16,000 J <2.0 -- -- -- -- R-PSDCA -- -- 33 <2.0 -- -- -- -- NVHOS, Acid Form -- -- 1,200 <2.0 -- -- -- -- EVE Acid -- -- 1,200 <2.0 -- -- -- -- Hydro-EVE Acid -- -- 1,200 <2.0 -- -- -- -- R-EVE -- -- 930 J <2.0 -- -- -- -- Perfluoro(2-ethoxyethane)sulfonic Acid -- -- 5.3 <2.0 -- -- -- -- PFECA B -- -- <13 <2.0 -- -- -- -- PFECA-G -- -- <24 <2.0 -- -- -- -- Total Table 3+ (17 compounds)" '3 130,000 -- -- -- -- Notes: 1 - Total Table 3+ was calculated including J qualified data but not non -detect data. The total Table 3+ sum is rounded to two significant figures. 2 - Total Table 3+ (17 Compounds) does not include R-PSDA, Hydrolyzed PSDA and R-EVE. 3 - Total Table 3+ (17 Compounds) is not applicable for the weekly sampling for only PFAS indicator compounds (HFPO-DA, PFMOAA, and PMPA). Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. UJ — Analyte not detected. Reporting limit may not be accurate or precise. ng/L - nanograms per liter SOP - standard operating procedure -- - No data reported < - Analyte not detected above associated reporting limit. ND - No Table 3+ compounds were detected above their associated reporting limits. TR0795C Page 2 of 4 June 2024 Table 5-2 004 Treatment Plant PFAS Analytical Results Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC Table 3+ SOP (ng/L) 004 Influent 004-INF-0324 Sample Date: 4-Mar-24 004 Effluent 004-EFF-0324 Sample Date: 4-Mar-24 004 Influent 004-INF-0324-2 Sample Date: 11-Mar-24 004 Effluent 004-EFF-0324-2 Sample Date: 11-Mar-24 004 Influent 004-INF-0324-3 Sample Date: 18-Mar-24 004 Effluent 004-EFF-0324-3 Sample Date: 18-Mar-24 004 Influent 004-INF-0324-4 Sample Date: 25-Mar-24 004 Effluent 004-EFF-0324-4 Sample Date: 25-Mar-24 Hfpo Dimer Acid 12,000 <2.0 16,000 <2.0 15,000 <2.0 14,000 <2.0 PFMOAA 62,000 <2.0 46,000 <2.0 53,000 <2.0 62,000 <2.0 PFO2HxA -- -- 21,000 <2.0 -- -- -- -- PFO3OA -- -- 5,200 <2.0 -- -- -- -- PFO4DA -- -- 1,600 <2.0 -- -- -- -- PFO5DA -- -- 510 <2.0 -- -- -- -- PMPA 10,000 <10 10,000 <10 13,000 <10 10,000 <10 PEPA -- -- 3,600 <10 -- -- -- -- PS Acid -- -- 1,100 <2.0 -- -- -- -- Hydro-PS Acid -- -- 560 <2.0 -- -- -- -- R-P D -- -- 1300 J , <2.0 -- -- -- -- Hydrolyzed PSDA -- -- 12,000 J <2.0 -- -- -- -- R-PSDCA -- -- <25 <2.0 -- -- -- -- NVHOS, Acid Form -- -- 830 <2.0 -- -- -- -- EVE Acid -- -- 570 <2.0 -- -- -- -- Hydro-EVE Acid -- -- 840 <2.0 -- -- -- -- R-EVE -- -- 500 J <2.0 -- -- -- -- Perfluoro(2-ethoxyethane)sulfonic Acid -- -- <25 <2.0 -- -- PFECA B -- -- <25 <2.0 -- -- -- -- PFECA-G -- -- <25 <2.0 -- -- -- -- Total Table 3+ (17 compounds)" '3 110,000 -- -- -- -- Notes: 1 - Total Table 3+ was calculated including J qualified data but not non -detect data. The total Table 3+ sum is rounded to two significant figures. 2 - Total Table 3+ (17 Compounds) does not include R-PSDA, Hydrolyzed PSDA and R-EVE. 3 - Total Table 3+ (17 Compounds) is not applicable for the weekly sampling for only PFAS indicator compounds (HFPO-DA, PFMOAA, and PMPA). Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. ng/L - nanograms per liter SOP - standard operating procedure -- - No data reported < - Analyte not detected above associated reporting limit. ND - No Table 3+ compounds were detected above their associated reporting limits. TR0795C Page 3 of 4 June 2024 Table 5-2 004 Treatment Plant PFAS Analytical Results Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC METHOD 537 MOD SOP COMPOUNDS LIST 1,2 (ng2) 004 Influent 004-INF-0224-2 Sample Date: 12-Feb-24 004 Effluent 004-EFF-0224 Sample Date: 12-Feb-24 10:2 Fluorotelomer sulfonate <2.0 <2.0 l l Cl-PF3OUdS <2.0 <2.0 1H,1H,2H,2H-perfluorodecanesulfonate (8:2 FTS) <2.0 <2.0 1H,1H,2H,2H-perfluorohexanesulfonate (4:2 FTS) <2.0 <2.0 2-(N-ethyl perfluoro-l-octanesulfonamido)-ethanol <2.0 <2.0 2-(N-methyl perfluoro-l-octanesulfonamido)-ethanol <4.0 <4.0 6:2 Fluorotelomer sulfonate <5.0 <5.0 9C1-PF3ONS <2.0 <2.0 DONA <2.0 <2.0 N-Ethyl Perfluorooctane Sulfonamidoacetic Acid <5.0 <5.0 N-ethylperfluoro-l-octanesulfonamide <2.0 <2.0 N-methyl perfluoro-l-octanesulfonamide <2.0 <2.0 N-Methyl Perfluorooctane Sulfonamidoacetic Acid <5.0 <5.0 Perfluorobutane Sulfonic Acid <2.0 <2.0 Perfluorobutanoic Acid 250 <5.0 Perfluorodecane Sulfonic Acid <2.0 <2.0 Perfluorodecanoic Acid <2.0 <2.0 Perfluorododecane Sulfonic Acid (PFDoS) <2.0 <2.0 Perfluorododecanoic Acid <2.0 <2.0 Perfluoroheptane Sulfonic Acid (PFHpS) <2.0 <2.0 Perfluoroheptanoic Acid 99 <2.0 Perfluorohexadecanoic Acid (PFHxDA) <2.0 <2.0 Perfluorohexane Sulfonic Acid <2.0 <2.0 Perfluorohexanoic Acid 35 <2.0 Perfluorononanesulfonic Acid <2.0 <2.0 Perfluorononanoic Acid 8.2 <2.0 Perfluorooctadecanoic Acid <2.0 UJ <2.0 UJ Perfluorooctane Sulfonamide <2.0 <2.0 Perfluoropentane Sulfonic Acid (PFPeS) <2.0 <2.0 Perfluoropentanoic Acid 810 <2.0 Perfluorotetradecanoic Acid <2.0 <2.0 Perfluorotridecanoic Acid <2.0 <2.0 Perfluoroundecanoic Acid <2.0 <2.0 PFOA 23 <2.0 PFOS <2.0 <2.0 Notes.- 1 - The EPA Method 537 was modified to incorporate the Table 3+ compounds. 2 - Sample analysis under EPA Method 537 MOD SOP is required one time per quarter. Bold - Analyte detected above associated reporting limit. UJ - Analyte not detected. Reporting limit may not be accurate or precise. ng/L - nanograms per liter SOP - standard operating procedure < - Analyte not detected above associated reporting limit. TR0795C Page 4 of 4 June 2024 Table 6-1 Summary of Groundwater Level Information Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, North Carolina Aug 1 (0.00) Aug 14 (0.41) Jan 27 (0.00) Feb 25 (0.07) Mar 26 (0.45) April 17 (0.00) May 20 (0.00) Jun 18 (0.00) Jul 17 (0.00) Aug. 15 (0.09) Antecedent Daily Total Rainfall (inches): Aug 2 (0.00) Aug 15 (0.09) Jan 28 (0.00) Feb 26 (0.00) Mar 27 (0.63) Apr 18 (0.00) May 21 (0.00) Jun 19 (0.16) Jul 18 (0.00) Aug. 16 (0.00) Aug 3 (0.00) Aug 16 (0.00) Jan 29 (0.08) Feb 27 (0.00) Mar 28 (0.28) Apr 19 (0.00) May 22 (0.00) Jun 20 (1.11) Jul 19 (0.00) Aug. 17 (0.00) Groundwater Elevation from Water Level Gauging Events (feet, NAVD88) Well ID Aquifer Baseline Mid -Commissioning Post -Startup Monthly O&M Monthly O&M Monthly O&M Monthly O&M Monthly O&M August 4, 2022 August 17, 2022 January 30, 2023 February 28, 2023 March 29, 2023 April 20, 2023 May 23, 2023 June 21, 2023 July 20, 2023 August 18, 2023 Willis Creek Observation Wells (Northern Alignment): 18 Wells OW-11 Black Creek Aquifer 49.63 49.57 49.02 48.39 46.58 46.62 48.25 46.16 45.98 45.89 OW-12 Black Creek Aquifer 34.08 34.08 34.81 31.61 29.71 30.26 29.32 29.15 29.08 28.95 OW-13 Black Creek Aquifer 34.10 34.05 34.42 33.63 32.32 33.61 32.02 31.43 31.50 31.20 OW-14 Black Creek Aquifer 33.62 33.47 34.67 34.09 33.11 36.60 32.97 32.08 32.76 32.05 OW-41 Black Creek Aquifer 49.13 49.12 48.33 47.66 46.46 46.51 46.11 45.97 45.78 45.69 OW42 Black Creek Aquifer 47.89 47.86 47.42 46.81 45.90 45.94 45.52 45.47 45.27 45.15 OW43 Black Creek Aquifer 34.49 34.42 34.62 33.64 32.04 33.09 31.76 31.20 31.13 31.14 OW-54 Black Creek Aquifer Well Installed January 24, 2023 35.87 35.00 33.45 35.90 36.19 Dry Dry Dry OW-55 Black Creek Aquifer Well Installed January 18, 2023 34.77 32.06 28.43 29.75 28.30 28.07 27.97 27.80 OW-56 Black Creek Aquifer Well Installed January 24, 2023 36.92 36.50 36.63 37.17 35.99 36.18 35.89 35.74 OW-57 Black Creek Aquifer Well Installed January 17, 2023 45.75 45.24 44.58 44.62 44.27 44.22 44.07 43.92 PIW-lD Black Creek Aquifer 32.59 32.47 33.95 33.15 32.25 35.09 31.96 31.25 32.06 31.27 PIW-11 Black Creek Aquifer 43.28 43.24 43.89 43.62 43.14 43.65 42.87 42.61 43.10 42.70 PIW-12 Black Creek Aquifer 33.74 33.69 34.39 31.90 26.64 28.38 26.68 26.43 26.36 26.17 PIW-13 Black Creek Aquifer 33.66 33.60 34.20 30.68 24.95 28.16 25.74 25.00 25.21 25.38 PIW-14 Black Creek Aquifer 34.05 34.00 34.44 32.47 29.90 31.36 29.80 29.20 28.98 29.45 PIW-15 Black Creek Aquifer 32.74 32.65 33.54 32.88 32.00 33.87 31.69 31.10 31.50 31.01 SMW-12 Black Creek Aquifer 33.03 33.03 33.52 31.19 29.17 30.17 28.82 28.23 27.97 Not Gauged Median (Black Creek Aquifer wells) 34.07 34.03 34.72 33.64 32.29 34.48 31.99 31.25 31.50 31.24 Observation Wells <200 ft Upgradient of Barrier Wall: 19 Wells OW-02 Black Creek Aquifer 48.82 48.72 49.79 44.34 39.18 42.55 34.58 32.97 32.29 33.10 OW-03 Black Creek Aquifer 49.52 49.44 49.60 44.06 38.43 42.24 34.14 32.57 32.56 32.79 OW-07 Black Creek Aquifer 44.87 44.75 45.36 41.10 37.61 35.00 29.91 27.90 25.40 25.73 OW-08 Black Creek Aquifer 44.12 43.98 44.60 40.37 36.86 34.14 29.09 27.05 25.50 24.85 OW-15 Black Creek Aquifer Well Installed September 22, 2022 56.91 56.50 57.53 57.66 57.21 57.16 57.14 57.23 OW-17 Black Creek Aquifer 44.87 44.82 43.53 39.81 34.88 32.77 32.96 32.87 32.90 32.87 OW-18 Black Creek Aquifer 47.17 47.37 48.61 48.79 47.95 46.93 46.58 46.44 46.42 46.44 OW-19 Black Creek Aquifer 46.36 46.23 46.68 41.42 37.73 38.50 30.38 28.05 26.48 25.83 OW-21 Black Creek Aquifer 45.13 45.00 45.51 41.70 37.87 35.40 30.65 28.15 26.50 25.75 OW-24 Black Creek Aquifer 43.17 43.15 43.73 38.94 36.23 34.77 30.02 28.27 26.97 26.15 OW-26 Black Creek Aquifer 55.22 55.16 54.84 53.79 45.67 44.05 42.50 40.15 39.08 40.15 OW-29 Black Creek Aquifer 59.58 59.54 59.14 58.57 51.34 49.72 47.54 45.62 44.64 43.90 OW-31 Black Creek Aquifer 60.44 60.41 60.07 59.43 47.00 50.58 42.85 41.55 40.60 39.98 OW-34 Surficial Aquifer 62.98 62.81 62.03 64.53 66.36 67.30 67.50 67.41 67.45 67.36 OW-35 Surficial Aquifer 66.33 66.10 65.67 65.71 65.45 68.18 68.35 68.35 68.73 68.55 OW-36 Surficial Aquifer 62.72 62.61 62.07 61.85 61.64 61.48 61.51 61.52 61.51 61.71 OW-37 Surficial Aquifer Well Installed June 21, 2023 57.38 57.27 OW-38 Black Creek Aquifer Well Installed September 22, 2022 61.93 61.94 61.64 61.60 61.45 61.40 61.22 61.28 OW-51 Black Creek Aquifer Well Installed June 20, 2023 26.21 25.17 Median (Black Creek Aquifer wells) 46.77 46.80 48.70 44.20 38.81 42.40 34.36 32.92 32.56 32.87 Median (Surficial Aquifer wells) 62.98 62.81 62.07 64.53 65.45 67.30 67.50 67.41 64.48 64.54 TR0795C Page 1 of 6 June 2024 Table 6-1 Summary of Groundwater Level Information Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, North Carolina Antecedent Daily Total Rainfall (inches): Sep. 18 (0.00) Oct 27 (0.00) Nov. 25 (0.00) Dec. 17 (3.34) Jan. 28 (0.02) Feb. 24 (0.01) Mar. 24 (0.00) Most Recent Calculated Head Differential (feet, positive value indicates drawdown) Change in Magnitude of Head Differential Sept. 19 (0.00) Oct 28. (0.00) Nov. 26 (0.06) Dec. 18 (0.04) Jan. 29 (0.00) Feb. 25 (0.00) Mar. 25 (0.00) Sept. 20 (0.00) Oct 29 (0.00) Nov. 27 (0.03) Dec. 19 (0.00) Jan. 30 (0.00) Feb. 26 (0.01) Mar. 26 (0.00) Well ID Aquifer Groundwater Elevation from Water Level Gauging Events (feet, NAVD88) Monthly O&M Monthly O&M Monthly O&M Monthly O&M Monthly O&M Monthly O&M Monthly O&M September 21, 2023 October 30, 2023 November 28, 2023 December 20, 2023 January 31, 2024 February 27, 2024 March 27, 2024 March 27, 2024 vs. January 30, 2023 March 27 vs February 27, 2024 Willis Creek Observation Wells (Northern Alignment): 18 Wells OW-11 Black Creek Aquifer 45.82 45.80 45.63 46.82 45.92 45.72 45.72 3.30 0.00 OW-12 Black Creek Aquifer 29.39 29.10 29.19 31.32 30.65 29.17 28.94 5.87 0.23 OW-13 Black Creek Aquifer 31.54 31.32 31.04 32.25 32.92 31.98 31.77 2.65 0.21 OW-14 Black Creek Aquifer 32.22 31.59 31.36 32.42 34.77 33.07 33.10 1.57 0.03 OW41 Black Creek Aquifer 45.64 45.66 45.45 45.59 45.79 45.57 45.57 2.76 0.00 OW-42 Black Creek Aquifer 45.16 45.12 44.95 45.17 45.25 45.03 45.02 2.40 0.01 OW-43 Black Creek Aquifer 31.49 31.55 31.44 31.69 32.69 32.04 31.95 2.67 0.09 OW-54 Black Creek Aquifer Dry Dry Dry Dry 35.87 33.37 33.21 2.66 0.16 OW-55 Black Creek Aquifer 28.60 28.05 28.20 28.12 29.65 28.44 28.16 6.61 0.28 OW-56 Black Creek Aquifer 36.01 35.89 36.09 Not Gauged 36.99 35.99 36.46 0.46 0.47 OW-57 Black Creek Aquifer 43.95 43.92 43.78 44.12 44.04 43.87 43.87 1.88 0.00 PIW-lD Black Creek Aquifer 31.51 30.96 30.75 32.07 34.31 32.18 32.25 1.70 0.07 PIW-11 Black Creek Aquifer 42.96 42.57 42.61 43.34 43.40 43.44 43.72 0.17 0.28 PIW-12 Black Creek Aquifer 27.27 26.54 26.73 28.96 28.20 27.05 26.73 7.66 0.32 PIW-13 Black Creek Aquifer 26.70 26.48 26.70 27.26 28.70 27.68 27.28 6.92 0.40 PIW-14 Black Creek Aquifer 30.02 29.98 29.93 30.10 30.99 30.07 29.94 4.50 0.13 PIW-15 Black Creek Aquifer 31.29 30.85 30.59 32.85 33.55 31.80 31.68 1.86 0.12 SMW-12 Black Creek Aquifer Not Gauged 28.42 28.64 28.70 28.78 29.10 28.87 4.65 0.23 Median (Black Creek Aquifer wells) 31.53 31.32 31.04 32.16 33.93 32.11 32.10 2.67 0.21 Observation Wells <200 ft Upgradient of Barrier Wall: 19 Wells OW-02 Black Creek Aquifer 33.95 34.55 34.62 34.25 34.92 35.07 35.07 13.72 0.00 OW-03 Black Creek Aquifer 33.62 34.29 34.34 33.94 34.69 34.79 34.84 14.76 0.05 OW-07 Black Creek Aquifer 28.39 29.50 29.80 29.90 31.00 31.25 31.55 13.81 0.30 OW-08 Black Creek Aquifer 27.61 28.75 29.06 29.14 30.25 30.40 30.80 13.80 0.40 OW-15 Black Creek Aquifer 57.21 57.31 57.28 57.06 57.13 57.73 57.91 -1.00 0.18 OW-17 Black Creek Aquifer 32.90 33.17 32.82 32.72 33.22 32.96 33.06 10.47 0.10 OW-18 Black Creek Aquifer 46.56 46.43 46.25 46.71 46.33 46.12 46.63 1.98 0.51 OW-19 Black Creek Aquifer 28.36 29.53 29.78 29.67 30.57 30.73 31.26 15.42 0.53 OW-21 Black Creek Aquifer 28.68 30.08 30.43 30.51 31.45 31.57 32.01 13.50 0.44 OW-24 Black Creek Aquifer 27.54 28.27 28.43 28.54 29.63 29.77 30.35 13.38 0.58 OW-26 Black Creek Aquifer 41.05 42.33 42.07 41.99 41.98 42.00 42.17 12.67 0.17 OW-29 Black Creek Aquifer 43.68 44.69 44.43 44.27 44.44 44.55 44.65 14.49 0.10 OW-31 Black Creek Aquifer 40.08 40.55 40.02 39.79 40.02 41.05 41.10 18.97 0.05 OW-34 Surficial Aquifer 67.57 67.82 67.64 67.53 67.71 67.61 67.70 -5.67 0.09 OW-35 Surficial Aquifer 68.58 68.40 68.32 68.34 68.64 68.65 68.75 -3.08 0.10 OW-36 Surficial Aquifer 61.66 62.01 61.91 62.01 62.29 62.31 62.24 -0.17 0.07 OW-37 Surficial Aquifer 57.30 57.02 56.61 56.79 56.42 56.24 56.46 N/A 0.22 OW-38 Black Creek Aquifer 61.45 61.82 61.89 61.90 62.38 62.72 62.80 -0.87 0.08 OW-51 Black Creek Aquifer 26.36 27.14 27.45 27.61 28.52 28.77 29.14 N/A 0.37 Median (Black Creek Aquifer wells) 33.62 34.29 34.34 33.94 34.69 34.79 34.84 13.61 0.24 Median (Surficial Aquifer wells) 64.62 64.92 64.78 64.77 65.00 64.96 64.97 -3.08 0.10 TR0795C Page 2 of 6 June 2024 Table 6-1 Summary of Groundwater Level Information Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, North Carolina Aug 1 (0.00) Aug 14 (0.41) Jan 27 (0.00) Feb 25 (0.07) Mar 26 (0.45) April 17 (0.00) May 20 (0.00) Jun 18 (0.00) Jul 17 (0.00) Aug. 15 (0.09) Antecedent Daily Total Rainfall (inches): Aug 2 (0.00) Aug 15 (0.09) Jan 28 (0.00) Feb 26 (0.00) Mar 27 (0.63) Apr 18 (0.00) May 21 (0.00) Jun 19 (0.16) Jul 18 (0.00) Aug. 16 (0.00) Aug 3 (0.00) Aug 16 (0.00) Jan 29 (0.08) Feb 27 (0.00) Mar 28 (0.28) Apr 19 (0.00) May 22 (0.00) Jun 20 (1.11) Jul 19 (0.00) Aug. 17 (0.00) Groundwater Elevation from Water Level Gauging Events (feet, NAVD88) Well ID Aquifer Baseline Mid -Commissioning Post -Startup Monthly O&M Monthly O&M Monthly O&M Monthly O&M Monthly O&M August 4, 2022 August 17, 2022 January 30, 2023 February 28, 2023 March 29, 2023 April 20, 2023 May 23, 2023 June 21, 2023 July 20, 2023 August 18, 2023 Observation Wells <200 it Downgradient of Barrier Wall: 21 Wells OW-04/04R Black Creek Aquifer 59.45 59.42 Well Abandoned; Replacement Well Installed July 31, 2023 Replaced July 31, 2023 52.03 OW-09/09R Black Creek Aquifer 59.61 59.57 Well Abandoned; Replacement Well Installed August 1, 2023 Replaced August 1, 2023 40.33 OW-20 Black Creek Aquifer 46.34 46.24 46.53 41.54 39.35 37.91 38.39 38.49 39.03 38.44 OW-22 Black Creek Aquifer 43.95 43.89 44.50 40.94 37.53 37.36 38.41 38.55 39.08 38.58 OW-23 Black Creek Aquifer 43.27 43.18 43.86 39.75 36.73 35.88 38.31 38.36 38.80 38.28 OW-25 Black Creek Aquifer 41.95 41.90 42.52 39.00 36.50 35.77 38.62 38.36 38.36 37.89 OW-32 Black Creek Aquifer Well Installed August 2, 2023 Replaced August 2, 2023 38.45 OW-39 Black Creek Aquifer Well Installed August 1, 2023 Replaced August 1, 2023 40.36 OW-44 Black Creek Aquifer 36.51 36.31 36.28 36.94 36.34 37.41 36.06 35.28 35.38 34.63 OW45 Black Creek Aquifer 44.39 44.20 44.78 45.24 40.05 39.93 39.10 38.82 39.78 38.50 OW46 Black Creek Aquifer 46.28 46.20 46.59 41.41 38.85 37.88 38.35 38.50 39.03 38.42 OW-47 Black Creek Aquifer 43.84 43.72 44.33 40.45 36.98 37.05 38.18 38.32 38.87 38.32 OW-48 Black Creek Aquifer 43.11 43.06 43.69 39.33 36.40 35.29 38.24 38.27 38.64 38.13 OW-49 Black Creek Aquifer 42.13 42.06 42.67 38.83 36.23 35.42 38.43 38.34 38.36 37.88 OW-50 Black Creek Aquifer 41.42 41.35 42.01 41.78 35.37 36.17 39.50 39.33 39.48 39.00 OW-52 Black Creek Aquifer Well Installed August 2, 2023 Replaced August 2, 2023 38.01 OW-53 Black Creek Aquifer Well Installed October 11, 2023 PIW-41) Black Creek Aquifer 43.59 43.45 43.90 46.26 39.89 39.88 38.90 38.65 39.64 38.30 PIW-5S/5SR Surficial Aquifer 59.70 59.52 58.82 56.31 Replaced on April 12, 2023 54.13 53.15 53.37 53.54 53.25 PW-10R/lORR Black Creek Aquifer 47.78 47.62 47.99 42.18 Replaced on April 12, 2023 41.20 38.52 38.39 39.19 38.32 PIW-IODR Black Creek Aquifer Not Gauged (Interim Remedy Location; Pump Removed by August 23, 2023) Not Gauged (Interim Pumping) 41.50 Median (Black Creek Aquifer wells) 43.84 43.72 43.90 40.94 36.86 37.36 38.41 38.39 39.03 38.42 Observation Wells >200 ft Downgradient of Barrier Wall: 14 Wells LTW-02 Black Creek Aquifer 42.97 42.80 43.50 45.36 40.01 39.97 38.94 38.71 39.67 38.31 LTW-03 Floodplain 38.05 37.93 39.27 38.48 36.95 37.85 36.70 36.40 36.53 36.05 LTW-05 Black Creek Aquifer 41.24 41.20 41.93 38.69 36.30 35.71 37.89 37.86 38.02 37.46 OW-16 Black Creek Aquifer 35.39 35.24 36.69 36.49 35.86 37.27 35.34 34.59 34.94 34.17 OW-27 Black Creek Aquifer 41.16 41.12 41.70 41.36 36.09 36.80 39.35 39.21 39.32 38.85 OW-28 Black Creek Aquifer 40.04 40.01 40.63 40.43 38.16 38.86 39.04 39.00 38.99 38.99 OW-30 Black Creek Aquifer 40.38 40.33 40.98 39.55 36.80 37.91 38.94 38.95 39.17 Not Gauged OW-33 Black Creek Aquifer 40.42 40.39 41.07 39.89 37.45 38.32 39.29 39.34 39.44 Not Gauged OW-40 Black Creek Aquifer 40.58 40.53 40.66 40.68 40.09 40.86 40.13 40.15 40.23 Not Gauged PIW-3D Black Creek Aquifer 35.39 35.26 36.61 36.39 35.97 37.14 35.36 34.67 35.07 34.32 PIW-7S Floodplain 42.28 42.16 43.03 39.55 36.56 35.79 37.74 37.80 38.28 37.61 PIW-7D Black Creek Aquifer 43.18 43.10 43.78 39.98 36.96 36.36 38.38 38.45 38.88 38.33 PW-11 Black Creek Aquifer Not Gauged (Interim Remedy Location; Pump Removed by August 23, 2023) Not Gauged (Interim Pumping) PZ-22 Black Creek Aquifer 43.24 43.15 43.81 40.36 37.28 36.89 38.21 38.37 38.85 38.33 Median (Black Creek Aquifer wells) 40.58 40.53 41.07 39.98 36.96 37.27 38.94 38.71 38.99 38.32 TR0795C Page 3 of 6 June 2024 Table 6-1 Summary of Groundwater Level Information Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, North Carolina Antecedent Daily Total Rainfall (inches): Sep. 18 (0.00) Oct 27 (0.00) Nov. 25 (0.00) Dec. 17 (3.34) Jan. 28 (0.02) Feb. 24 (0.01) Mar. 24 (0.00) Most Recent Calculated Head Differential (feet, positive value indicates drawdown) Change in Magnitude of Head Differential Sept. 19 (0.00) Oct 28. (0.00) Nov. 26 (0.06) Dec. 18 (0.04) Jan. 29 (0.00) Feb. 25 (0.00) Mar. 25 (0.00) Sept. 20 (0.00) Oct 29 (0.00) Nov. 27 (0.03) Dec. 19 (0.00) Jan. 30 (0.00) Feb. 26 (0.01) Mar. 26 (0.00) Well ID Aquifer Groundwater Elevation from Water Level Gauging Events (feet, NAVD88) Monthly O&M Monthly O&M Monthly O&M Monthly O&M Monthly O&M Monthly O&M Monthly O&M September 21, 2023 October 30, 2023 November 28, 2023 December 20, 2023 January 31, 2024 February 27, 2024 March 27, 2024 March 27, 2024 vs. January 30, 2023 March 27 vs February 27, 2024 Observation Wells <200 It Downgradient of Barrier Wall: 21 Wells OW-04/04R Black Creek Aquifer 40.33 40.27 40.12 40.28 40.97 40.52 40.53 N/A 0.01 OW-09/09R Black Creek Aquifer 40.33 40.27 40.12 40.28 40.95 40.53 40.53 N/A 0.00 OW-20 Black Creek Aquifer 38.57 38.04 37.75 38.23 39.54 39.31 39.73 6.80 0.42 OW-22 Black Creek Aquifer 38.63 38.12 37.83 38.23 39.61 39.35 39.78 4.72 0.43 OW-23 Black Creek Aquifer 38.33 37.83 37.64 38.19 39.38 39.06 39.41 4.45 0.35 OW-25 Black Creek Aquifer 37.99 37.61 37.54 38.47 39.06 38.61 38.84 3.68 0.23 OW-32 Black Creek Aquifer 38.75 39.03 38.49 38.27 38.49 38.50 38.70 N/A 0.20 OW-39 Black Creek Aquifer 40.42 40.32 40.20 40.35 40.89 40.57 40.57 N/A 0.00 OW-44 Black Creek Aquifer 34.18 33.79 33.58 33.69 36.23 36.02 36.20 0.08 0.18 OW-45 Black Creek Aquifer 38.85 38.07 38.01 39.10 40.20 40.01 40.22 4.56 0.21 OW-46 Black Creek Aquifer 38.55 37.95 37.75 38.22 39.53 39.33 39.74 6.85 0.41 OW47 Black Creek Aquifer 38.38 37.87 37.58 37.99 39.39 39.12 39.53 4.80 0.41 OW48 Black Creek Aquifer 38.17 37.74 37.55 38.12 39.26 38.89 39.24 4.45 0.35 OW-49 Black Creek Aquifer 37.99 37.61 37.54 38.43 39.04 38.61 38.84 3.83 0.23 OW-50 Black Creek Aquifer 39.13 38.75 38.60 39.20 40.53 39.73 40.11 1.90 0.38 OW-52 Black Creek Aquifer 38.06 37.56 37.26 37.69 39.05 38.79 39.24 N/A 0.45 OW-53 Black Creek Aquifer Well Installed October 11, 2023 37.96 37.74 38.08 39.48 39.25 39.66 N/A 0.41 PIW-413 Black Creek Aquifer 38.67 37.85 37.83 38.95 40.01 39.82 40.05 3.85 0.23 PIW-5S/5SR Surficial Aquifer 53.30 Dry Dry Dry Dry Dry Dry N/A N/A PW-10R/lORR Black Creek Aquifer 38.52 35.00 37.82 38.57 39.79 39.56 39.92 8.07 0.36 PIW-10DR Black Creek Aquifer 41.31 41.05 40.62 40.45 41.53 40.89 41.04 N/A 0.15 Median (Black Creek Aquifer wells) 38.57 37.96 37.79 38.35 39.54 39.32 39.74 4.45 0.35 Observation Wells >200 ft Downgradient of Barrier Wall: 14 Wells LTW-02 Black Creek Aquifer 38.71 37.89 37.89 39.13 40.07 39.88 40.09 3.41 0.21 LTW-03 Floodplain 35.91 35.80 35.55 36.03 37.98 37.63 38.25 1.02 0.62 LTW-05 Black Creek Aquifer 37.57 37.22 37.14 38.39 38.76 38.26 38.47 3.46 0.21 OW-16 Black Creek Aquifer 33.79 33.41 33.06 33.68 36.32 35.50 35.71 0.98 0.21 OW-27 Black Creek Aquifer 38.94 38.62 38.49 39.05 40.32 39.60 39.88 1.82 0.28 OW-28 Black Creek Aquifer 38.69 38.32 38.26 39.08 39.99 39.29 39.58 1.05 0.29 OW-30 Black Creek Aquifer 38.87 38.64 38.52 Not Gauged 40.15 39.32 39.57 1.41 0.25 OW-33 Black Creek Aquifer 39.17 38.97 38.87 Not Gauged 40.42 39.64 39.87 1.20 0.23 OW-40 Black Creek Aquifer 40.08 40.00 39.88 Not Gauged 40.87 40.30 40.35 0.31 0.05 PIW-313 Black Creek Aquifer 33.97 33.53 33.25 33.95 36.45 35.62 35.82 0.79 0.20 PIW-7S Floodplain 37.77 37.22 37.10 37.79 38.82 38.52 38.82 4.21 0.30 PIW-713 Black Creek Aquifer 38.42 37.95 37.73 38.31 39.46 39.13 39.48 4.30 0.35 PW-1 l Black Creek Aquifer 40.61 40.51 40.37 40.56 41.13 41.28 40.75 N/A 0.53 PZ-22 Black Creek Aquifer 38.43 37.85 37.65 38.12 39.40 39.11 39.50 4.31 0.39 Median (Black Creek Aquifer wells) 38.70 38.14 38.08 38.39 40.03 39.31 39.58 1.41 0.24 TR0795C Page 4 of 6 June 2024 Table 6-1 Summary of Groundwater Level Information Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, North Carolina Aug 1 (0.00) Aug 14 (0.41) Jan 27 (0.00) Feb 25 (0.07) Mar 26 (0.45) April 17 (0.00) May 20 (0.00) Jun 18 (0.00) Jul 17 (0.00) Aug. 15 (0.09) Antecedent Daily Total Rainfall (inches): Aug 2 (0.00) Aug 15 (0.09) Jan 28 (0.00) Feb 26 (0.00) Mar 27 (0.63) Apr 18 (0.00) May 21 (0.00) Jun 19 (0.16) Jul 18 (0.00) Aug. 16 (0.00) Aug 3 (0.00) Aug 16 (0.00) Jan 29 (0.08) Feb 27 (0.00) Mar 28 (0.28) Apr 19 (0.00) May 22 (0.00) Jun 20 (1.11) Jul 19 (0.00) Aug. 17 (0.00) Groundwater Elevation from Water Level Gauging Events (feet, NAVD88) Well ID Aquifer Baseline Mid -Commissioning Post -Startup Monthly O&M Monthly O&M Monthly O&M Monthly O&M Monthly O&M August 4, 2022 August 17, 2022 January 30. 2023 February 28, 2023 March 29, 2023 April 20, 2023 May 23, 2023 June 21, 2023 July 20, 2023 August 18, 2023 Observation Wells >200 ft Upgradient of Barrier Wall/Willis Creek Alignments: 11 Wells BCA-01 Black Creek Aquifer Not Gauged (Interim Remedy Location; Pump Removed by August 23, 2023) Not Gauged (Interim Pumping) BCA-02 Black Creek Aquifer Not Gauged (Interim Remedy Location; Pump Removed by August 23, 2023) Not Gauged (Interim Pumping) NAF-1113 Surficial Aquifer Not Gauged (Interim Remedy Location; Pump Removed by August 23, 2023) Not Gauged (Interim Pumping) PIW-21) Black Creek Aquifer 58.08 57.94 57.64 57.59 57.67 57.74 57.64 57.42 57.34 57.29 PW-02 Surficial Aquifer 87.27 87.00 85.32 85.09 84.85 84.73 84.40 83.13 83.93 83.71 PW-03 Surficial Aquifer 104.95 104.87 104.39 104.45 104.24 104.33 104.42 104.38 104.35 102.09 PW-04 Surficial Aquifer 68.40 68.33 67.49 68.36 68.55 68.55 68.72 68.43 69.13 69.45 PW-14 Black Creek Aquifer Not Gauged (Interim Remedy Location; Pump Removed by August 23, 2023) Not Gauged (Interim Pumping) PW-15R Black Creek Aquifer Not Gauged (Interim Remedy Location; Pump Removed by August 23, 2023) Not Gauged (Interim Pumping) SMW-03B Black Creek Aquifer 89.92 89.71 87.73 87.47 87.19 87.03 86.79 86.60 86.35 86.23 SMW-09 Surficial Aquifer 82.14 82.03 80.43 80.26 80.12 79.20 79.71 79.93 79.75 79.75 Median (Surficial Aquifer wells) 84.71 84.52 82.88 82.68 82.49 81.97 82.06 81.53 81.84 81.73 Median (Black Creek Aquifer wells) 74.00 73.83 72.69 72.53 72.43 72.39 72.22 72.01 71.85 71.76 TR0795C Page 5 of 6 June 2024 Table 6-1 Summary of Groundwater Level Information Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, North Carolina Antecedent Daily Total Rainfall (inches): Sep. 18 (0.00) Oct 27 (0.00) Nov. 25 (0.00) Dec. 17 (3.34) Jan. 28 (0.02) Feb. 24 (0.01) Mar. 24 (0.00) Most Recent Calculated Head Differential (feet, positive value indicates drawdown) Change in Magnitude of Head Differential Sept. 19 (0.00) Oct 28. (0.00) Nov. 26 (0.06) Dec. 18 (0.04) Jan. 29 (0.00) Feb. 25 (0.00) Mar. 25 (0.00) Sept. 20 (0.00) Oct 29 (0.00) Nov. 27 (0.03) Dec. 19 (0.00) Jan. 30 (0.00) Feb. 26 (0.01) Mar. 26 (0.00) Well ID Aquifer Groundwater Elevation from Water Level Gauging Events (feet, NAVD88) Monthly O&M Monthly O&M Monthly O&M Monthly O&M Monthly O&M Monthly O&M Monthly O&M September 21, 2023 October 30, 2023 November 28, 2023 December 20, 2023 January 31, 2024 February 27, 2024 March 27, 2024 March 27, 2024 vs. January 30, 2023 March 27 vs February 27, 2024 Observation Wells >200 ft Upgradient of Barrier Wall/Willis Creek Alignments: 11 Wells BCA-01 Black Creek Aquifer 80.01 79.65 79.77 79.63 79.56 79.95 79.45 N/A 0.50 BCA-02 Black Creek Aquifer Not Gauged 70.63 70.35 69.96 70.28 70.17 70.27 N/A 0.10 NAF-11B Surficial Aquifer Dry Dry Dry Dry Dry Dry Dry N/A N/A PlW-2D Black Creek Aquifer 57.19 56.94 56.78 57.04 57.41 56.99 57.04 0.60 0.05 PW-02 Surficial Aquifer 83.53 83.41 83.38 83.34 83.33 83.88 83.30 2.02 0.58 PW-03 Surficial Aquifer Not Gauged 104.38 104.08 103.66 104.20 104.22 104.48 -0.09 0.26 PW-04 Surficial Aquifer 70.79 70.10 69.28 68.77 69.30 69.33 69.43 -1.94 0.10 PW-14 Black Creek Aquifer Not Gauged 81.55 81.42 81.25 81.26 81.27 81.19 N/A 0.08 PW-15R Black Creek Aquifer 68.92 68.57 68.84 68.76 69.34 69.63 68.93 N/A 0.70 SMW-03B Black Creek Aquifer 86.05 85.90 85.75 85.57 85.38 85.71 85.25 2.48 0.46 SMW-09 Surficial Aquifer 79.68 79.45 79.55 79.45 80.20 79.35 79.28 1.15 0.07 Median (Surficial Aquifer wells) 79.68 81.43 81.47 81.40 81.77 81.62 81.29 0.53 0.18 Median (Black Creek Aquifer wells) 74.47 75.14 75.06 74.80 74.92 75.06 74.86 1.54 0.28 Notes: 1 - For comparison and calculation of head differentials, elevation data for replacement wells (OW-04R, OW-09R, PlW-SSR, and PW-IORR) has been merged with the corresponding original wells. Since the replacement wells were not installed in exactly the same location as the originals, some spatial variation might exist. TR0795C Page 6 of 6 June 2024 Table 6-2 PFAS Concentrations in Downgradient Groundwater Monitoring Wells Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC METHOD 537 MOD SOP COMPOUNDS LIST' (ng/L) Mass Loading Model Sampling Program (Quarterly) LTW-01 LTW-02 CAP1Q23-LTW-01- 021623 Sample Date: 16-Feb-23 CAP2Q23-LTW-01- 051723 Sample Date: 17-May-23 CAP3Q23-LTW-01- 071323 Sample Date: 13-Jul-23 CAP4Q23-LTW-01- 110323 Sample Date: 3-Nov-23 CAP1Q24-LTW-01- 011724 Sample Date: 17-Jan-24 CAP1Q23-LTW-02- 021623 Sample Date: 16-Feb-23 CAP2Q23-LTW-02- 051723 Sample Date: 17-May-23 CAP3Q23-LTW-02- 071223 Sample Date: 12-Jul-23 CAP4Q23-LTW-02- 110323 Sample Date: 3-Nov-23 CAP1Q24-LTW-02- 011724 Sample Date: 17-Jan-24 Hfpo Dimer Acid 18,000 18 000 8,500 15 000 15,000 2 800 7,000 6 800 J 9,800 12 000 PFMOAA 23,000 21,000 27,000 24,000 12,000 9,300 17,000 31,000 27,000 32,000 PF02HxA 23,000 21,000 28,000 25,000 17,000 4,800 10,000 22,000 21,000 28,000 PF030A 5,700 5,300 6,400 5,700 3,300 1 100 1,900 3 700 4,100 5 200 PF04DA 1,300 1,500 1,600 1,300 950 86 120 180 160 200 PF05DA 170 170 200 210 140 <78 <78 <2.0 <100 <130 PMPA 16,000 16,000 19,000 18,000 15,000 1 800 5,700 11 000 11,000 14,000 PEPA 5,900 5 700 7,200 6,200 6,800 580 1,800 3,600 3 500 5,100 PS Acid <20 <20 <2.0 <40 <50 <20 <20 <2.0 <40 <50 Hydro -PS Acid 310 300 280 280 200 <6.1 15 17 <44 <55 R-PSDA 960 J <71 940 J 790 J 830 J <71 <71 620 J 520 J 780 J Hydrolyzed PSDA 560 J 690 J 760 J 590 J 83 J 270 J <38 1300 J 1 500 J 1,800 J R-PSDCA <17 <17 6.9 <140 <180 <17 <17 <3.0 <140 <180 NVHOS, Acid Form 390 440 320 430 270 160 300 320 410 450 EVE Acid <17 <17 <2.0 <40 <50 <17 <17 <2.0 <40 <50 Hydro -EVE Acid 160 140 150 140 51 <14 38 39 42 <30 R-EVE 550 J 580 J 560 J 530 J 310 J <72 <72 260 J 410 J 440 J Perfluoro 2-ethox ethane sulfonic Acid <6.7 <6.7 <2.0 <29 <36 <6.7 <6.7 <2.0 <29 <36 PFECA B <27 <27 <2.0 <62 <78 <27 <27 <2.0 <62 <78 PFECA-G <48 <48 <2.0 <29 <36 <48 <48 <2.0 <29 <36 PFPrA 22,000 24,000 15,000 16,000 21,000 23,000 Total Table 3+ (17 compounds) 2,3 93,90 ,600 98,700 96,300 70,700 20,600 43,900 78,700 77,000 97,000 Total Table 3+ (18 compounds) 2,4 -- 121,000 120,000 85,700 1 94,700 98,000 1201000 Total Table 3+ (21 compounds) 2,5 123,000 122,000 86,900 96,800 1 100,000 123,000 Notes: 1 - The EPA Method 537 was modified to incorporate the Table 3+ compounds. Beginning with the 3Q 2023 sampling, perfluoropropionic acid (PFPrA) was added to the compounds list. 2 - Total Table 3+ was calculated including J qualified data but not non -detect data. The total Table 3+ sum is rounded to three significant figures. 3 - Total Table 3+ (17 compounds) does not include R-PSDA, Hydrolyzed PSDA, R-EVE, and PFPrA. 4 - Total Table 3+ (18 compounds) does not include R-PSDA, Hydrolyzed PSDA, and R-EVE. 5 - Total Table 3+ (21 compounds) is the sum of all Table 3+ PFAS compounds. Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. UJ - Analyte not detected. Reporting limit may not be accurate or precise. ng/L - nanograms per liter SOP - standard operating procedure -- - No data reported < - Analyte not detected above associated reporting limit. TR0795C Page 1 of 24 June 2024 Table 6-2 PFAS Concentrations in Downgradient Groundwater Monitoring Wells Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC METHOD 537 MOD SOP COMPOUNDS LIST' (ng/L) Mass Loading Model Sampling Program (Quarterly) LTW-03 LTW-04 CAP1Q23-LTW-03- 022123 Sample Date: 21-Feb-23 CAP2Q23-LTW-03- 052323 Sample Date: 23-May-23 CAP3Q23-LTW-03- 071223 Sample Date: 12-Jul-23 CAP4Q23-LTW-03- 111323 Sample Date: 13-Nov-23 CAP1Q24-LTW-03- 013124 Sample Date: 31-Jan-24 CAP1Q23-LTW-04- 021723 Sample Date: 17-Feb-23 CAP2Q23-LTW-04- 052323 Sample Date: 23-May-23 CAP3Q23-LTW-04- 071123 Sample Date: 11-Jul-23 CAP4Q23-LTW-04- 110223 Sample Date: 2-Nov-23 CAP1Q24-LTW-04- 011624 Sample Date: 16-Jan-24 Hfpo Dimer Acid 11,000 10,000 8,600 5,800 J 7 800 18,000 19 000 9,800 J 17 000 17,000 PFMOAA 120,000 120,000 140,000 J 110,000 J 86,000 55,000 55,000 57,000 J 61 000 55 000 PF02HxA 34,000 41,000 49,000 J 24,000 J 28,000 23 000 28,000 29,000 26,000 26,000 PF030A 5,800 6,700 7,600 5,900 3,800 4,400 5 200 5,200 5,300 5,100 PF04DA 200 220 230 240 150 630 620 780 650 560 PF05DA <78 <78 <2.0 <2.0 <130 <78 <78 26 <100 <130 PMPA 14,000 15,000 16,000 18,000 11 000 17,000 16,000 20 000 17,000 16,000 PEPA 3,400 3,500 3 600 3,700 2,200 6,400 6,000 6,900 6100 5,500 PS Acid <20 <20 <2.0 <2.0 <50 UJ <20 <20 5 <40 <50 Hydro -PS Acid <6.1 28 26 26 <55 170 210 190 180 150 R-PSDA 1,000 J 950 J 900 J 870 J 770 J 2,000 J 1,700 J 1,700 J 1,700 J 1,400 J Hydrolyzed PSDA 7,100 J 5,800 J 5,900 J 6,500 J 5,300 J 4,200 J 2,300 J 3 000 J 3,800 J 2 800 J R-PSDCA <17 <17 <3.0 <3.0 <180 <17 <17 12 <140 <180 NVHOS, Acid Form 1300 1300 1,900 1,400 1 100 1300 1200 1,400 1 100 1,200 EVE Acid <17 <17 <2.0 <2.0 <50 UJ <17 <17 <2.0 <40 <50 Hydro -EVE Acid 71 64 63 56 42 500 390 540 470 370 R-EVE 520 J 430 J 150 J 180 J 320 J 2,000 J 1,500 J 1,300 J 1,700 J 1,100 J Perfluoro 2-ethox ethane sulfonic Acid <6.7 <6.7 6.1 6 <36 <6.7 <6.7 8.2 <29 <36 PFECA B <27 <27 <2.0 <2.0 <78 <27 <27 <2.0 <62 <78 PFECA-G <48 <48 <2.0 <2.0 <36 <48 <48 <2.0 <29 <36 PFPrA 62,000 J 61,000 J 47,000 53,000 48,000 43,000 J Total Table 3+ (17 compounds) 2,3 190,000 227,000 169,000 140,000 126,000 1 131,000 135,000 127,000 Total Table 3+ (18 compounds) 2,4 -- 289,000 230,000 1 187,000 -- - 184,000 183,000 170,000 Total Table 3+ (21 compounds) 2,5 296,000 238,000 1 193,000 1-- - 190,000 190,000 175,000 Notes: 1 - The EPA Method 537 was modified to incorporate the Table 3+ compounds. Beginning with the 3Q 2023 sampling, perfluoropropionic acid (PFPrA) was added to the compounds list. 2 - Total Table 3+ was calculated including J qualified data but not non -detect data. The total Table 3+ sum is rounded to three significant figures. 3 - Total Table 3+ (17 compounds) does not include R-PSDA, Hydrolyzed PSDA, R-EVE, and PFPrA. 4 - Total Table 3+ (18 compounds) does not include R-PSDA, Hydrolyzed PSDA, and R-EVE. 5 - Total Table 3+ (21 compounds) is the sum of all Table 3+ PFAS compounds. Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. UJ - Analyte not detected. Reporting limit may not be accurate or precise. ng/L - nanograms per liter SOP - standard operating procedure -- - No data reported < - Analyte not detected above associated reporting limit. TR0795C Page 2 of 24 June 2024 Table 6-2 PFAS Concentrations in Downgradient Groundwater Monitoring Wells Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC METHOD 537 MOD SOP COMPOUNDS LIST I (ng/L) Mass Loading Model Sampling Program (Quarterly) LTW-05 OW-28 CAP1Q23-LTW-05- 021523 Sample Date: 15-Feb-23 CAP2Q23-LTW-05- 052223 Sample Date: 22-May-23 CAP3Q23-LTW-05- 071123 Sample Date: 11-Jul-23 CAP4Q23-LTW-05- 110223 Sample Date: 2-Nov-23 CAP1Q24-LTW-05- 011524 Sample Date: 15-Jan-24 CAP1Q23-OW-28- 022023 Sample Date: 20-Feb-23 CAP2Q23-OW-28- 052523 Sample Date: 25-May-23 CAP3Q23-OW-28- 071123 Sample Date: 11-Jul-23 CAP4Q23-OW-28- 110223 Sample Date: 2-Nov-23 CAP1Q24-OW-28- 011824 Sample Date: 18-Jan-24 Hf o Dimer Acid 18,000 19 000 J 9 000 18 000 31,000 4 800 4,800 4 400 4,400 3 800 PFMOAA 120,000 130,000 J 120,000 J 170,000 200,000 1,500 1,900 1,600 1,600 1,600 PF02HxA 36,000 48,000 J 41,000 J 58,000 68,000 2,500 3,500 3 400 3,100 3 300 PF030A 8,300 11 000 J 9,500 14 000 21,000 510 670 550 680 620 PF04DA 2,100 2,100 J 2,000 1,900 2,300 110 83 94 120 85 PF05DA <78 <78 UJ <2.0 <100 <130 <78 <78 <2.0 <100 <130 PMPA 4,000 4 600 J 4,200 5 500 9,200 5 000 6,400 5,200 6 000 5,700 PEPA 620 530 J 440 510 1,800 1,900 2 500 1,800 2,200 2,800 PS Acid <20 <20 UJ <2.0 <40 <50 <20 <20 <2.0 <40 <50 Hydro -PS Acid 190 190 J 200 200 330 75 74 75 75 84 R-PSDA 490 J 670 J 500 J 950 J 1,300 J 340 J 310 J 250 J 230 J 280 J Hydrolyzed PSDA 880 J 1,100 J 950 J 1,900 J 2 600 J <38 <38 2.2 J <27 UJ <34 R-PSDCA 19 <17 UJ 17 <140 <180 <17 <17 <3.0 <140 <180 NVHOS, Acid Form 1,100 1 300 J 1,000 1 500 2,100 110 <15 31 <130 <160 EVE Acid <17 <17 UJ <2.0 <40 <50 <17 <17 <2.0 <40 <50 Hydro -EVE Acid 750 720 J 720 770 1300 <14 <14 14 <24 <30 R-EVE 610 J 760 J 610 J 1,200 J 1,500 J 190 J 180 J 380 J 140 J 120 J Perfluoro 2-ethox ethane sulfonic Acid <6.7 <6.7 UJ 11 <29 <36 <6.7 <6.7 <2.0 <29 <36 PFECA B <27 <27 UJ <2.0 <62 <78 <27 <27 <2.0 <62 <78 PFECA-G <48 <48 UJ <2.0 <29 <36 <48 <48 <2.0 <29 <36 PFPrA 83,000 J 120 000 120,000 5,200 5,500 6 500 Total Table 3+ (17 compounds) 2,3 191,000 188,000 270,000 337,000 16,500 19,900 17,200 18,200 18,000 Total Table 3+ (18 compounds) 2,4 -- NJ 271,000 390,000 457,000 -- -- 22,400 23,700 24,500 Total Table 3+ (21 com ounds)2,5 -- -- 1 273,000 394,000 462,000 -- -- 23,000 24,000 24,900 Notes: 1 - The EPA Method 537 was modified to incorporate the Table 3+ compounds. Beginning with the 3Q 2023 sampling, perfluoropropionic acid (PFPrA) was added to the compounds list. 2 - Total Table 3+ was calculated including J qualified data but not non -detect data. The total Table 3+ sum is rounded to three significant figures. 3 - Total Table 3+ (17 compounds) does not include R-PSDA, Hydrolyzed PSDA, R-EVE, and PFPrA. 4 - Total Table 3+ (18 compounds) does not include R-PSDA, Hydrolyzed PSDA, and R-EVE. 5 - Total Table 3+ (21 compounds) is the sum of all Table 3+ PFAS compounds. Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. UJ - Analyte not detected. Reporting limit may not be accurate or precise. ng/L - nanograms per liter SOP - standard operating procedure -- - No data reported < - Analyte not detected above associated reporting limit. TR0795C Page 3 of 24 June 2024 Table 6-2 PFAS Concentrations in Downgradient Groundwater Monitoring Wells Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC METHOD 537 MOD SOP COMPOUNDS LIST I (ng/L) Mass Loading Model Sampling Program (Quarterly) OW-33 PIW-1D CAP1Q23-OW-33- 021423 Sample Date: 14-Feb-23 CAP2Q23-OW-33- 051823 Sample Date: 18-May-23 CAP3Q23-OW-33- 071223 Sample Date: 12-Jul-23 CAP4Q23-OW-33- 110223 Sample Date: 2-Nov-23 CAP1Q24-OW-33- 013024 Sample Date: 30-Jan-24 CAP1Q23-PIW-1D- 021623 Sample Date: 16-Feb-23 CAP2Q23-PIW-1D- 052323 Sample Date: 23-May-23 CAP3Q23-PIW-1D- 080223 Sample Date: 2-Aug-23 CAP4Q23-PIW-1D- 110723 Sample Date: 7-Nov-23 CAP1Q24-PIW-1D- 012224 Sample Date: 22-Jan-24 Hf o Dimer Acid 5,300 5 000 4,000 4 900 4,400 9 800 9 900 9 200 J 8,800 8 600 PFMOAA 7,900 8,400 11,000 9,800 7,700 12,000 12,000 11,000 J 9,900 10,000 PF02HxA 4,700 4 300 6,500 5,900 3,800 8 800 11,000 9 900 J 12,000 9 800 PF030A 810 840 1,100 1,100 560 1,500 1,700 1 600 1,700 1 900 PF04DA <59 <59 71 66 <50 430 440 410 430 250 PF05DA <78 <78 <2.0 <100 <130 <78 <78 <100 <100 <130 PMPA 4,800 5 200 6100 6 000 4,500 7 800 9,000 9 600 J 8,600 9 800 PEPA 2,000 1,800 2,300 2 200 1300 2 600 3,000 3 200 3,100 3 700 PS Acid <20 <20 8 <40 <50 UJ <20 <20 <40 <40 <50 Hydro -PS Acid 29 53 43 <44 <55 87 98 86 76 95 R-PSDA 280 J <71 290 J 250 J 210 J 330 J 380 J 370 J 320 J 380 J Hydrolyzed PSDA <38 <38 58 J 61 J 38 J <38 <38 <27 <27 <34 R-PSDCA <17 <17 <3.0 <140 <180 <17 <17 <140 <140 <180 NVHOS, Acid Form 170 240 130 140 <160 190 160 150 J 140 <160 EVE Acid <17 <17 <2.0 <40 <50 UJ <17 <17 <40 <40 <50 Hydro -EVE Acid <14 <14 14 <24 <30 31 <14 29 28 32 R-EVE 130 J <72 220 J 170 J 140 J 190 J 200 J 280 J 220 J 180 J Perfluoro 2-ethox ethane sulfonic Acid <6.7 <6.7 <2.0 <29 <36 <6.7 <6.7 <29 <29 <36 PFECA B <27 <27 <2.0 <62 <78 <27 <27 <62 <62 <78 PFECA-G <48 <48 <2.0 <29 <36 <48 <48 <29 <29 <36 PFPrA 9,900 9 400 7,300 12,000 J 12,000 11,000 Total Table 3+ (17 compounds) 2,3 25,700 25,800 31,300 30,100 22,300 43,200 47,300 45,200 44,800 44,200 Total Table 3+ (18 compounds) 2,4 -- -- 41,200 39,500 29,600 -- -- 57,200 1 56,800 1 55,200 Total Table 3+ (21 compounds) 2,5 -- --M 1 41,700 40,000 29,900 -- -- 57,800 1 57,300 1 55,700 Notes: 1 - The EPA Method 537 was modified to incorporate the Table 3+ compounds. Beginning with the 3Q 2023 sampling, perfluoropropionic acid (PFPrA) was added to the compounds list. 2 - Total Table 3+ was calculated including J qualified data but not non -detect data. The total Table 3+ sum is rounded to three significant figures. 3 - Total Table 3+ (17 compounds) does not include R-PSDA, Hydrolyzed PSDA, R-EVE, and PFPrA. 4 - Total Table 3+ (18 compounds) does not include R-PSDA, Hydrolyzed PSDA, and R-EVE. 5 - Total Table 3+ (21 compounds) is the sum of all Table 3+ PFAS compounds. Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. UJ - Analyte not detected. Reporting limit may not be accurate or precise. ng/L - nanograms per liter SOP - standard operating procedure -- - No data reported < - Analyte not detected above associated reporting limit. TR0795C Page 4 of 24 June 2024 Table 6-2 PFAS Concentrations in Downgradient Groundwater Monitoring Wells Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC METHOD 537 MOD SOP COMPOUNDS I ft/L) Mass Loading Model Sampling Program (Quarterly) PIW-1S PIW-31) CAP1Q23-PIW-1S- 021623 Sample Date: 16-Feb-23 Not Sampled in 2Q 2023 (Dry) Not Sampled in 3Q 2023 (Dry) Not Sampled in 4Q 2023 (Dry)LIST CAP1Q24-PIW-1S- 011624 Sample Date: 16-Jan-24 CAP1Q23-PIW-3D- 021623 Sample Date: 16-Feb-23 CAP2Q23-PIW-3D- 051723 Sample Date: 17-May-23 CAP3Q23-PIW-3D- 071323 Sample Date: 13-Jul-23 CAP4Q23-PIW-3D- 110323 Sample Date: 3-Nov-23 CAP1Q24-PIW-3D- 011824 Sample Date: 18-Jan-24 Hf o Dimer Acid 7,400 -- -- -- 1,400 12,000 12 000 9,700 12 000 15,000 PFMOAA 2,000 -- -- -- 390 J 9,400 8,500 13,000 19,000 25,000 PF02HxA 4,700 -- -- -- 1,200 12,000 10,000 16,000 19,000 27,000 PF030A 900 -- -- -- 240 2,200 2 100 3,100 4 000 5,600 PF04DA 440 110 940 800 890 1,20 1,800 PF05DA <78 -- -- -- <130 130 <78 160 200 380 PMPA 4,400 -- -- -- 1,100 9,500 8 800 12,000 13,000 16,000 PEPA 1,900 -- -- -- 330 3,700 3,400 4,500 4 700 6,100 PS Acid <20 -- -- -- <50 <20 <20 <2.0 <40 <50 Hydro -PS Acid 210 -- -- -- 230 240 200 240 290 340 R-PSDA <71 -- -- -- 110 J 520 J <71 610 J 750 J 780 J Hydrolyzed PSDA <38 -- -- -- <34 <38 <38 15 J 300 J 470 J R-PSDCA <17 -- -- -- <180 <17 <17 4.7 <140 <180 NVHOS, Acid Form <15 -- -- -- <160 190 290 170 310 360 EVE Acid <17 -- -- -- <50 <17 <17 <2.0 <40 <50 Hydro -EVE Acid 62 -- -- -- 30 72 70 74 100 100 R-EVE 180 J -- -- -- <39 220 J <72 280 J 420 J 390 J Perfluoro 2-ethox ethane sulfonic Acid <6.7 -- -- -- <36 <6.7 <6.7 <2.0 <29 <36 PFECA B <27 -- -- -- <78 <27 <27 <2.0 <62 <78 PFECA-G <48 -- -- -- <36 <48 <48 <2.0 <29 <36 PFPrA -- 1,300 J 19,000 21,000 22,000 Total Table 3+ (17 compounds) 2,3 22,000 --IME IMIN--IME MEMEL. 1 5,030 50,400 46,200 59,800 73,800 97,700 Total Table 3+ (18 compounds) 2,4 -- -- -- 6,330 1 78,800 94,800 1 120,000 Total Table 3+ (21 compounds) 2,5 -- -- -- 6,440 1 79,700 96,300 1 121,000 Notes: 1 - The EPA Method 537 was modified to incorporate the Table 3+ compounds. Beginning with the 3Q 2023 sampling, perfluoropropionic acid (PFPrA) was added to the compounds list. 2 - Total Table 3+ was calculated including J qualified data but not non -detect data. The total Table 3+ sum is rounded to three significant figures. 3 - Total Table 3+ (17 compounds) does not include R-PSDA, Hydrolyzed PSDA, R-EVE, and PFPrA. 4 - Total Table 3+ (18 compounds) does not include R-PSDA, Hydrolyzed PSDA, and R-EVE. 5 - Total Table 3+ (21 compounds) is the sum of all Table 3+ PFAS compounds. Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. UJ - Analyte not detected. Reporting limit may not be accurate or precise. ng/L - nanograms per liter SOP - standard operating procedure -- - No data reported < - Analyte not detected above associated reporting limit. TR0795C Page 5 of 24 June 2024 Table 6-2 PFAS Concentrations in Downgradient Groundwater Monitoring Wells Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC METHOD 537 MOD SOP COMPOUNDS LIST I (ng/L) Mass Loading Model Sampling Program (Quarterly) PIW-71) PIW-7S CAP1Q23-PIW-7D- 021523 Sample Date: 15-Feb-23 CAP2Q23-PIW-7D- 052223 Sample Date: 22-May-23 CAP3Q23-PIW-7D- 071123 Sample Date: 11-Jul-23 CAP4Q23-PIW-7D- 110223 Sample Date: 2-Nov-23 CAP1Q24-PIW-7D- 011524 Sample Date: 15-Jan-24 CAP1Q23-PIW-7S- 021523 Sample Date: 15-Feb-23 CAP2Q23-PIW-7S- 052223 Sample Date: 22-May-23 CAP3Q23-PIW-7S- 071123 Sample Date: 11-Jul-23 CAP4Q23-PIW-7S- 110223 Sample Date: 2-Nov-23 CAP1Q24-PIW-7S- 011524 Sample Date: 15-Jan-24 Hf o Dimer Acid 17,000 8 800 J 9,600 J 13,000 14,000 15,000 12,000 J 8,000 12,000 13,000 PFMOAA 140,000 130,000 J 140,000 J 150,000 150,000 18,000 16 000 J 15,000 17 000 17,000 PF02HxA 47,000 37,000 J 42,000 J 43,000 38,000 13,000 12,000 J 11 000 12,000 13,000 PF030A 9,200 5 900 J 6,800 6 100 6,500 5 100 3,800 J 2,800 4 300 3,800 PF04DA 1,700 1,100 J 890 1,000 870 660 440 J 350 420 400 PF05DA <78 <78 UJ <2.0 <100 <130 <78 <78 UJ 19 <100 <130 PMPA 5,100 4 500 J 4,300 5200 5,600 11 000 7,900 J 6 900 9,200 9 500 PEPA 1,100 950 J 950 1,000 1,100 4,500 3,300 J 2,500 3,400 3 800 PS Acid <20 <20 UJ <2.0 <40 <50 <20 <20 UJ <2.0 <40 <50 Hydro -PS Acid 180 98 J 110 110 110 340 270 J 220 250 230 R-PSDA 710 J 470 J 460 J 510 J 570 J 1,200 J 960 J 710 J 910 J 790 J Hydrolyzed PSDA 1,200 J 740 J 890 J 1,100 J 1,100 J <38 63 J 110 J 60 J 45 J R-PSDCA <17 <17 UJ 7.3 <140 <180 <17 <17 UJ 5.4 <140 <180 NVHOS, Acid Form 1,200 990 J 1,100 1,200 1300 830 630 J 520 690 680 EVE Acid <17 <17 UJ <2.0 <40 <50 <17 <17 UJ <2.0 <40 <50 Hydro -EVE Acid 610 330 J 360 360 320 650 460 J 360 430 360 R-EVE 870 J 550 J 560 J 680 J 540 J 1,400 J 1,000 J 820 J 1,200 J 880 J Perfluoro 2-ethox ethane sulfonic Acid 12 <6.7 UJ 8.5 <29 <36 <6.7 <6.7 UJ 3.3 <29 <36 PFECA B <27 <27 UJ <2.0 <62 <78 <27 <27 UJ <2.0 <62 <78 PFECA-G <48 <48 UJ <2.0 <29 <36 <48 <48 UJ <2.0 <29 <36 PFPrA 79,000 J 86,000 71,000 J 14,000 18,000 17 000 J Total Table 3+ (17 compounds) 2,3 223,000 a 190,000 206,000 221,000 218,000 69,100 56,800 47,700 59,700 61,800 Total Table 3+ (18 compounds) 2,4 -- --1 285,000 1 307,000 1 289,000 -- -- 61,700 77,700 1 78,800 Total Table 3+ (21 compounds) 2,5 -- --1 287,000 It 309,000 1 291,000 1-- --1 63,300 79,900 1 80,500 Notes: 1 - The EPA Method 537 was modified to incorporate the Table 3+ compounds. Beginning with the 3Q 2023 sampling, perfluoropropionic acid (PFPrA) was added to the compounds list. 2 - Total Table 3+ was calculated including J qualified data but not non -detect data. The total Table 3+ sum is rounded to three significant figures. 3 - Total Table 3+ (17 compounds) does not include R-PSDA, Hydrolyzed PSDA, R-EVE, and PFPrA. 4 - Total Table 3+ (18 compounds) does not include R-PSDA, Hydrolyzed PSDA, and R-EVE. 5 - Total Table 3+ (21 compounds) is the sum of all Table 3+ PFAS compounds. Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. UJ - Analyte not detected. Reporting limit may not be accurate or precise. ng/L - nanograms per liter SOP - standard operating procedure -- - No data reported < - Analyte not detected above associated reporting limit. TR0795C Page 6 of 24 June 2024 Table 6-2 PFAS Concentrations in Downgradient Groundwater Monitoring Wells Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC METHOD 537 MOD SOP COMPOUNDS LIST I (ng/L) Mass Loading Model Sampling Program (Quarterly) PW-04 PZ-22 CAP1Q23-PW-04- 022323 Sample Date: 23-Feb-23 CAP2Q23-PW-04- 052523 Sample Date: 25-May-23 CAP3Q23-PW-04- 072823 Sample Date: 28-Jul-23 CAP4Q23-PW-04- 110923 Sample Date: 9-Nov-23 CAP1Q24-PW-04- 011724 Sample Date: 17-Jan-24 CAP1Q23-PZ-22-022023 Sample Date: 20-Feb-23 CAP2Q23-PZ-22-052323 Sample Date: 23-May-23 CAP3Q-PZ-22-071123 Sample Date: 11-Jul-23 CAP4Q23-PZ-22-110223 Sample Date: 2-Nov-23 CAP1Q24-PZ-22-011624 Sample Date: 16-Jan-24 Hfpo Dimer Acid 730 980 950 670 1,000 13,000 12,000 7,300 J 11,000 11,000 PFMOAA 300 490 380 300 370 140,000 150,000 140,000 170 000 150,000 PF02HxA 640 1,100 1,000 930 1,000 38,000 49,000 50,000 47,000 42,000 PF030A 330 520 520 340 450 3,600 5,400 4,800 5 400 5,100 PF04DA 63 95 120 100 110 120 270 240 210 220 PF05DA <78 <78 <100 <100 <130 <78 <78 <2.0 <100 <130 PMPA 860 1,200 1,200 950 1,400 5 000 6 200 6,100 6 700 6,300 PEPA 330 440 480 320 590 1,200 1,500 1,600 1,500 1 400 PS Acid <20 <20 <40 <40 <50 <20 <20 3.1 <40 <50 Hydro -PS Acid 22 <6.1 <44 <44 <55 28 36 35 <44 <55 R-PSDA 160 J 150 J 78 J <28 130 J 540 J 560 J 540 J 510 J 440 J Hydrolyzed PSDA <38 <38 <27 <27 <34 890 J 1,000 J 1,100 J 1,600 J 1,100 J R-PSDCA <17 <17 <140 <140 <180 <17 <17 3.2 <140 <180 NVHOS, Acid Form <15 <15 <130 <130 <160 1,100 1300 1,500 1,200 1300 EVE Acid <17 <17 <40 <40 <50 <17 <17 <2.0 <40 <50 Hydro -EVE Acid <14 <14 <24 <24 <30 46 84 79 73 73 R-EVE <72 86 J 49 J 66 J 66 J 450 J 430 J 220 J 420 J 300 J Perfluoro 2-ethox ethane sulfonic Acid <6.7 <6.7 <29 <29 <36 <6.7 <6.7 6.3 <29 <36 PFECA B <27 <27 <62 <62 <78 <27 <27 <2.0 <62 <78 PFECA-G <48 <48 <29 <29 <36 <48 <48 <2.0 <29 <36 PFPrA 1,400 1,500 1,400 76,000 84,000 72 000 J Total Table 3+ (17 compounds) 2,3 3,280 4,650 3,610 4,920 202,000 226,000 212,000 243,000 217,000 Total Table 3+ (18 compounds) 2,4 -- -- 6,050 5,110 6,320 -- -- 288,000 327,000 289,000 Total Table 3+ (21 compounds) 2,5 -- -- 6,180 5,180 6,520 -- 290,000 330,000 291,000 Notes: 1 - The EPA Method 537 was modified to incorporate the Table 3+ compounds. Beginning with the 3Q 2023 sampling, perfluoropropionic acid (PFPrA) was added to the compounds list. 2 - Total Table 3+ was calculated including J qualified data but not non -detect data. The total Table 3+ sum is rounded to three significant figures. 3 - Total Table 3+ (17 compounds) does not include R-PSDA, Hydrolyzed PSDA, R-EVE, and PFPrA. 4 - Total Table 3+ (18 compounds) does not include R-PSDA, Hydrolyzed PSDA, and R-EVE. 5 - Total Table 3+ (21 compounds) is the sum of all Table 3+ PFAS compounds. Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. UJ - Analyte not detected. Reporting limit may not be accurate or precise. ng/L - nanograms per liter SOP - standard operating procedure -- - No data reported < - Analyte not detected above associated reporting limit. TR0795C Page 7 of 24 June 2024 Table 6-2 PFAS Concentrations in Downgradient Groundwater Monitoring Wells Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC METHOD 537 MOD SOP COMPOUNDS LIST I (ng/L) Mass Loading Model Sampling Program (Quarterly) Performance Monitoring Plan Sampling Program (Semi -Annually) SMW-12 OW-411 OW-30 CAP1Q23-SMW-12- 022323 Sample Date: 23-Feb-23 CAP2Q23-SMW-12- 051723 Sample Date: 17-May-23 CAP3Q23-SMW-12- 071823 Sample Date: 18-Jul-23 CAP4Q23-SMW-12- 110823 Sample Date: 8-Nov-23 CAP1Q24-SMW-12- 011624 Sample Date: 16-Jan-24 CAP3Q23-OW-4R- 080423 Sample Date: 4-Aug-23 CAP1Q24-OW-4R- 012924 Sample Date: 29-Jan-24 CAP1Q23-OW-30- 021523 Sample Date: 15-Feb-23 CAP3Q23-OW-30- 071323 Sample Date: 13-Jul-23 CAP1Q24-OW-30- 013024 Sample Date: 30-Jan-24 Hf o Dimer Acid 1,500 1900 2,200 1900 1,900 11 000 9,400 9 500 6,200 5 900 PFMOAA 2,900 5,100 5,800 8,300 9,600 42,000 35,000 32,000 27,000 21,000 PF02HxA 1,200 1 900 3,500 4,200 3,200 17,000 13,000 12,000 11,000 8,300 PF030A 78 150 230 420 490 5,400 3 100 2,100 1 700 1300 PF04DA <59 <59 <36 <40 <50 1,800 1,200 <59 8.9 <50 PF05DA <78 <78 <91 <100 <130 <100 <130 <78 <2.0 <130 PMPA 2,300 2 900 2,600 1 700 1,900 8 600 5,700 4 300 4,400 3,200 PEPA 460 550 620 340 300 2,700 1,900 1300 1300 900 PS Acid <20 <20 <36 <40 <50 <40 <50 UJ <20 <2.0 <50 UJ Hydro -PS Acid <6.1 <6.1 <40 <44 <55 290 250 <6.1 <2.0 <55 R-PSDA 150 J <71 87 J 76 B 65 J 760 J 570 J 460 J 330 J 340 J Hydrolyzed PSDA <38 <38 <25 <27 <34 3,100 J 2 300 J 760 J 570 J 520 J R-PSDCA <17 <17 <130 <140 <180 <140 <180 <17 <3.0 <180 NVHOS, Acid Form 48 <15 <120 <130 <160 580 480 370 220 270 EVE Acid <17 <17 <36 <40 <50 <40 <50 UJ <17 <2.0 <50 UJ Hydro -EVE Acid <14 <14 <22 <24 <30 1,100 890 24 12 <30 R-EVE 97 J <72 69 J 67 J 45 J 630 J 390 J 410 J 290 J 270 J Perfluoro 2-ethox ethane sulfonic Acid <6.7 <6.7 <26 <29 <36 <29 <36 <6.7 <2.0 <36 PFECA B <27 <27 <56 <62 <78 <62 <78 <27 <2.0 <78 PFECA-G <48 <48 <26 <29 <36 <29 <36 <48 <2.0 <36 PFPrA 5,900 7 000 6,400 J 25,000 21,000 19,000 16,000 Total Table 3+ (17 compounds) 2,3 12,500 15,000 16,900 17,400 90,500 70,900 61,600 51,800 40,900 Total Table 3+ (18 compounds) 2,4 -- -- 20,900 23,900 23,800 115,000 91,900 70,800 56,900 Total Table 3+ (21 compounds) -- -- 21,000 24,000 23,900 120,000 95,200 72,000 58,000 Notes: 1 - The EPA Method 537 was modified to incorporate the Table 3+ compounds. Beginning with the 3Q 2023 sampling, perfluoropropionic acid (PFPrA) was added to the compounds list. 2 - Total Table 3+ was calculated including J qualified data but not non -detect data. The total Table 3+ sum is rounded to three significant figures. 3 - Total Table 3+ (17 compounds) does not include R-PSDA, Hydrolyzed PSDA, R-EVE, and PFPrA. 4 - Total Table 3+ (18 compounds) does not include R-PSDA, Hydrolyzed PSDA, and R-EVE. 5 - Total Table 3+ (21 compounds) is the sum of all Table 3+ PFAS compounds. Wells OW-4R, OW-32, OW-37, and OW-51 were installed between late June 2023 and August 2023, so were unavailable for sampling before 3Q 2023. Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. UJ - Analyte not detected. Reporting limit may not be accurate or precise. ng/L - nanograms per liter SOP - standard operating procedure -- - No data reported < - Analyte not detected above associated reporting limit. TR0795C Page 8 of 24 June 2024 Table 6-2 PFAS Concentrations in Downgradient Groundwater Monitoring Wells Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC METHOD 537 MOD SOP COMPOUNDS LIST I (ng/L) Performance Monitoring Plan Sampling Program (Semi -Annually) OW-32 OW-37 OW-40 OW-51 OW-54 CAP3Q23-OW-32- 090823 Sample Date: 8-Sep-23 CAP1Q24-OW-32- 012924 Sample Date: 29-Jan-24 CAP3Q23-OW-37- 081023 Sample Date: 10-Aug-23 CAP1Q24-OW-37- 011724 Sample Date: 17-Jan-24 CAP1Q23-OW-40- 021523 Sample Date: 15-Feb-23 CAP3Q23-OW-40- 071323 Sample Date: 13-Jul-23 CAP1Q24-OW-40- 013024 Sample Date: 30-Jan-24 CAP3Q23-OW-51- 080323 Sample Date: 3-Aug-23 CAP1Q24-OW-51- 013124 Sample Date: 31-Jan-24 CAP1Q23-OW-54- 021623 Sample Date: 16-Feb-23 Not Sampled in 3Q 2023 (Dry) CAP1Q24-OW-54- 020624 Sample Date: 6-Feb-24 Hf o Dimer Acid 580 3,200 4,000 J 290 5,200 3 300 3 400 33,000 11,000 4,500 -- 740 PFMOAA 1,800 14,000 15 000 J 1,100 6,900 7 000 6,100 140,000 43,000 360 -- 250 PF02HxA 790 4,500 5,900 J 690 4,200 4,700 3200 64,000 19 000 2 600 -- 690 PF030A 130 1,200 2,600 J 260 1,100 1 400 650 23,000 6,500 410 -- <110 PF04DA <40 100 3,900 J 140 130 170 130 4,800 1,10 230 -- 110 PF05DA <100 <130 140 J 420 <78 <2.0 <130 <100 <130 <78 -- <130 PMPA 260 1,800 2 000 J 200 4,300 4,400 3 700 9,400 3 200 2 600 -- 760 PEPA 83 460 580 J 79 1,600 1 900 1,100 1,900 720 1,000 -- 200 PS Acid <40 <50 UJ <40 UJ <50 <20 <2.0 <50 UJ <40 <50 UJ <20 -- <50 UJ Hydro -PS Acid <44 <55 370 J 110 35 44 <55 660 150 120 -- <55 R-PSDA 44 J 220 J 1,500 J 100 J <71 200 J 200 J 1,900 J 650 J <71 -- 78 J Hydrolyzed PSDA 100 J 650 J 1,200 J 83 J 160 J 130 J 65 J 4,300 J 1 400 J <38 -- <34 R-PSDCA <140 <180 <140 UJ <180 <17 <3.0 <180 <140 <180 <17 -- <180 NVHOS, Acid Form <130 220 170 J <160 130 90 <160 1,800 620 <15 -- <160 EVE Acid <40 <50 UJ <40 UJ <50 <17 <2.0 <50 UJ <40 <50 UJ <17 -- <50 UJ Hydro -EVE Acid <24 70 120 J <30 94 99 67 2,400 550 <14 -- <30 R-EVE 36 J 140 J 390 J <39 170 J 240 J 100 J 2,600 J 700 J <72 -- 42 J Perfluoro 2-ethox ethane sulfonic Acid <29 <36 <29 UJ <36 <6.7 <2.0 <36 <29 <36 <6.7 -- <36 PFECA B <62 <78 <62 UJ <78 <27 <2.0 <78 <62 <78 <27 -- <78 PFECA-G <29 <36 <29 UJ <36 <48 <2.0 <36 <29 <36 <48 -- <36 PFPrA 990 7,200 8,200 J 1 800 5,700 5 400 92,000 31,000 1,400 Total Table 3+ (17 compounds) 2,3 3,640 25,600 34,800 3,290 23,700 23,100 18,300 281,000 85,800 11,800 -- 2,750 Total Table 3+ (18 compounds) 2,4 4,630 1 32,800 43,000 1 5,090 1 28,800 1 23,700 373,000 117,000 -- -- 4,150 Total Table 3+ (21 compounds) 2,5 4,810 33,800 46,100 5,270 -- 29,400 24,100 382,000 120,000 -- -- 4,270 Notes: 1 - The EPA Method 537 was modified to incorporate the Table 3+ compounds. Beginning with the 3Q 2023 sampling, perfluoropropionic acid (PFPrA) was added to the compounds list. 2 - Total Table 3+ was calculated including J qualified data but not non -detect data. The total Table 3+ sum is rounded to three significant figures. 3 - Total Table 3+ (17 compounds) does not include R-PSDA, Hydrolyzed PSDA, R-EVE, and PFPrA. 4 - Total Table 3+ (18 compounds) does not include R-PSDA, Hydrolyzed PSDA, and R-EVE. 5 - Total Table 3+ (21 compounds) is the sum of all Table 3+ PFAS compounds. Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. UJ - Analyte not detected. Reporting limit may not be accurate or precise. ng/L - nanograms per liter SOP - standard operating procedure -- - No data reported < - Analyte not detected above associated reporting limit. TR0795C Page 9 of 24 June 2024 Table 6-2 PFAS Concentrations in Downgradient Groundwater Monitoring Wells Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC METHOD 537 MOD SOP COMPOUNDS LIST I (ng/L) Performance Monitoring Plan Sampling Program (Semi -Annually) OW-55 OW-56 OW-57 PIW-41) CAP1Q23-OW-55- 021623 Sample Date: 16-Feb-23 CAP3Q23-OW-55- 072523 Sample Date: 25-Jul-23 CAP1Q24-OW-55- 020524 Sample Date: 5-Feb-24 CAP1Q23-OW-56- 022123 Sample Date: 21-Feb-23 CAP3Q23-OW-56- 073123 Sample Date: 31-Jul-23 CAP1Q24-OW-56- 020124 Sample Date: 1-Feb-24 CAP1Q23-OW-57- 021523 Sample Date: 15-Feb-23 CAP3Q23-OW-57- 073123 Sample Date: 31-Jul-23 CAP1Q24-OW-57- 020624 Sample Date: 6-Feb-24 CAP3Q23-PIW-4D- 071323 Sample Date: 13-Jul-23 CAP1Q24-PIW-4D- 012224 Sample Date: 22-Jan-24 Hfpo Dimer Acid 1,800 1 800 1,600 4,200 3 300 2,200 11,000 11,000 11,000 140 320 PFMOAA 220 300 550 350 520 420 130,000 130,000 130,000 1 300 1,900 PF02HxA 690 940 820 1,800 2,100 1,300 36,000 37,000 37,000 470 1,100 PF030A 58 <89 <110 200 260 220 8,600 7 700 6 700 47 110 PF04DA <59 <40 <50 <59 <40 <50 1,100 1,000 1,000 <2.0 5.3 PF05DA <78 <100 <130 <78 <100 <130 <78 <100 <130 <2.0 <2.0 PMPA 2,800 3 800 1,800 2,600 2 800 1,500 22 000 21,000 16,000 150 290 PEPA 740 890 470 990 1,100 530 5,100 4 700 3,800 37 71 PS Acid <20 <40 <50 UJ <20 <40 <50 UJ 770 360 330 J <2.0 <2.0 Hydro -PS Acid <6.1 <44 <55 120 150 100 220 260 240 <2.0 <2.0 R-PSDA <71 140 J 100 J 310 J 150 J 140 J 970 J 1,200 J 1,200 J 8.9 J 20 J Hydrolyzed PSDA <38 <27 <34 <38 <27 <34 16,000 J 14,000 J 15,000 J 25 J 801 R-PSDCA <17 <140 <180 <17 <140 <180 17 <140 <180 <3.0 <3.0 NVHOS, Acid Form <15 <130 <160 110 <130 <160 2,000 2 400 2,200 11 19 EVE Acid <17 <40 <50 UJ <17 <40 <50 UJ <17 <40 <50 UJ <2.0 <2.0 Hydro -EVE Acid <14 <24 <30 <14 <24 <30 200 210 180 <2.0 <2.0 R-EVE 160J 180J 85J 1901 120J 1101 240J 180J 210J 6.2J 12J Perfluoro 2-ethox ethane sulfonic Acid <6.7 <29 <36 <6.7 <29 <36 <6.7 <29 <36 <2.0 <2.0 PFECA B <27 <62 <78 <27 <62 <78 <27 <62 <78 <2.0 <2.0 PFECA-G <48 <29 <36 <48 <29 <36 <48 <29 <36 <2.0 <2.0 PFPrA 2,900 1 700 2,200 1,500 44,000 48 000 880 1,300 Total Table 3+ (17 compounds) 2,3 6,310 7,730 5,240 10,400 10,200 6,270 217,000 216,000 208,000 2,160 3,820 Total Table 3+ (18 compounds) 2,4 --1 10,600 1 6,940 -- 12,400 7,770 -- 260,000 256,000 3,040 5,120 Total Table 3+ (21 compounds) 2,5 -- 11,000 M 7,130 12,700 8,020 -- 275,000 273,000 3,080 5,230 Notes: 1 - The EPA Method 537 was modified to incorporate the Table 3+ compounds. Beginning with the 3Q 2023 sampling, perfluoropropionic acid (PFPrA) was added to the compounds list. 2 - Total Table 3+ was calculated including J qualified data but not non -detect data. The total Table 3+ sum is rounded to three significant figures. 3 - Total Table 3+ (17 compounds) does not include R-PSDA, Hydrolyzed PSDA, R-EVE, and PFPrA. 4 - Total Table 3+ (18 compounds) does not include R-PSDA, Hydrolyzed PSDA, and R-EVE. 5 - Total Table 3+ (21 compounds) is the sum of all Table 3+ PFAS compounds. Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. UJ - Analyte not detected. Reporting limit may not be accurate or precise. ng/L - nanograms per liter SOP - standard operating procedure -- - No data reported < - Analyte not detected above associated reporting limit. TR0795C Page 10 of 24 June 2024 Table 6-2 PFAS Concentrations in Downgradient Groundwater Monitoring Wells Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC METHOD 537 MOD SOP COMPOUNDS LIST' (ng/L) Performance Monitoring Plan Sampling Program (Semi -Annually) PIW-5SR PIW-6S PIW-81) PIW-IODR PIW-10S PIW-11 CAP3Q23-PIW-5SR- 080423 Sample Date: 4-Aug-23 Not Sampled in 1Q 2024 (Dry) CAP3Q23-PIW-6S- 071223 Sample Date: 12-Jul-23 CAP1Q24-PIW-6S- 013124 Sample Date: 31-Jan-24 CAP3Q23-PIW-8D- 071123 Sample Date: 11-Jul-23 CAP1Q24-PIW-8D- 012224 Sample Date: 22-Jan-24 CAP3Q23-PIW- 10DR-071423 Sample Date: 14-Jul-23 CAP1Q24-PIW- 10DR-012224 Sample Date: 22-Jan-24 CAP3Q23-PIW-I0S- 071323 Sample Date: 13-Jul-23 Not Sampled in 1Q 2024 (Dry) CAP3Q23-PIW-11- 073123 Sample Date: 31-Jul-23 CAP1Q24-PIW-11- 020124 Sample Date: 1-Feb-24 Hf o Dimer Acid 24,000 -- 8,400 9 500 12,000 J 46,000 6 600 8,300 3,800 -- 3 500 1 400 PFMOAA 44,000 -- 150,000 J 100,000 72,000 J 190,000 51,000 J 31,000 3 700 -- 1,600 2,100 PF02HxA 28,000 -- 61,000 J 29,000 34,000 J 110 000 19,000 14 000 4,400 -- 2,600 1,000 PF030A 7,000 -- 5,500 4,100 14,000 43,000 5 800 4,800 800 -- 420 230 PF04DA 2,200 -- 200 180 2,300 5,300 1,500 930 340 -- 46 <50 PF05DA 690 -- <2.0 <130 <2.0 <130 4 <130 6.8 -- <100 <130 PMPA 32,000 -- 16,000 11,000 8 600 19,000 6,600 6,700 4 500 -- 3,100 1 400 PEPA 15,000 -- 3 400 2 300 2 500 5,500 2,400 2,300 2 100 -- 1,000 320 PS Acid 40 -- <2.0 <50 UJ <2.0 <50 <2.0 <50 <2.0 -- <40 <50 UJ Hydro -PS Acid 140 -- 25 <55 350 1,200 210 200 67 -- <44 <55 R-PSDA 1,600 J -- 820 J 730 J 1,000 J 2,600 J 690 J 610 J 160 J -- 240 J 230 J Hydrolyzed PSDA 1,700 J -- 4,100 J 4,300 J 2,600 J 5 300 J 2 700 J 2,300 J <2.0 -- 1,500 J 2,800 J R-PSDCA <140 -- <3.0 <180 25 <180 9.9 <180 <3.0 -- <140 <180 NVHOS, Acid Form 640 -- 1,800 1300 1 100 2,500 390 390 62 -- <130 <160 EVE Acid <40 -- <2.0 <50 UJ <2.0 <50 <2.0 <50 <2.0 -- <40 <50 UJ Hydro -EVE Acid 190 -- 54 40 1,200 3,500 910 640 14 -- <24 <30 R-EVE 1,300 J -- 230 J 360 J 1,300 J 2 300 J 250 J 400 J 230 J -- 130 J 77 J Perfluoro 2-ethox ethane sulfonic Acid <29 -- 7.1 <36 13 <36 3.9 <36 <2.0 -- <29 <36 PFECA B <62 -- <2.0 <78 <2.0 <78 <2.0 <78 <2.0 <62 <78 PFECA-G <29 -- <2.0 <36 <2.0 <36 <2.0 <36 <2.0 <29 <36 PFPrA 44,000 64,000 J 54,000 57,000 120,000 26,000 18,000 5,300 3,400 2,200 Total Table 3+ (17 compounds) 2,3 154,000 - 246,000 157,000 148,000 426,000 94,400 69,300 19,800 12,300 6,450 Total Table 3+ (18 compounds) 2,4 198,000 - 310,000 211,000 205,000 546,000 120,000 87,300 25,100 15,700 8,650 Total Table 3+ (21 compounds) 2,5 203,000 - 316,000 217,000 210,000 556,000 1 124,000 90,600 1 25,500 17,500 11,800 Notes: 1 - The EPA Method 537 was modified to incorporate the Table 3+ compounds. Beginning with the 3Q 2023 sampling, perfluoropropionic acid (PFPrA) was added to the compounds list. 2 - Total Table 3+ was calculated including J qualified data but not non -detect data. The total Table 3+ sum is rounded to three significant figures. 3 - Total Table 3+ (17 compounds) does not include R-PSDA, Hydrolyzed PSDA, R-EVE, and PFPrA. 4 - Total Table 3+ (18 compounds) does not include R-PSDA, Hydrolyzed PSDA, and R-EVE. 5 - Total Table 3+ (21 compounds) is the sum of all Table 3+ PFAS compounds. Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. UJ - Analyte not detected. Reporting limit may not be accurate or precise. ng/L - nanograms per liter SOP - standard operating procedure -- - No data reported < - Analyte not detected above associated reporting limit. TR0795C Page 11 of 24 June 2024 Table 6-2 PFAS Concentrations in Downgradient Groundwater Monitoring Wells Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC METHOD 537 MOD SOP COMPOUNDS LIST I (ng/L) Performance Monitoring Plan Sampling Program (Semi -Annually) Corrective Action Plan Sampling Program (Annually) PIW-15 PW-10RR PW-11 PIW-12 PIW-13 PIW-14 CAP3Q23-PIW-15- 072523 Sample Date: 25-Jul-23 CAP1Q24-PIW-15- 020524 Sample Date: 5-Feb-24 CAP3Q23-PW-IORR- 080323 Sample Date: 3-Aug-23 CAP1Q24-PW-IORR- 013124 Sample Date: 31-Jan-24 CAP3Q23-PW-11-070723 Sample Date: 7-Jul-23 CAP1Q24-PW-11-013124 Sample Date: 31-Jan-24 CAP3Q23-PIW-12- 072423 Sample Date: 24-Jul-23 CAP3Q23-PIW-13- 072423 Sample Date: 24-Jul-23 CAP3Q23-PIW-14- 072423 Sample Date: 24-Jul-23 Hf o Dimer Acid 7,800 8 200 6,700 4 000 6,900 6 800 1,800 3100 6,200 PFMOAA 8,700 9,200 93,000 59,000 54,000 J 29,000 490 520 1,000 PF02HxA 7,000 6 800 26,000 14,000 28,000 11,000 1,200 2,100 3,800 PF030A 1,200 1300 1300 410 7,300 5 000 190 250 520 PF04DA 65 100 <40 <50 4,500 4 200 41 <40 160 PF05DA <100 <130 <100 <130 1,600 1300 <100 <100 <100 PMPA 8,400 6 300 4,400 2 200 7,800 3 000 2,300 4 200 5,000 PEPA 2,400 1,900 590 150 2,200 910 640 1,100 1,600 PS Acid <40 <50 UJ <40 <50 UJ 1,400 97 J <40 <40 <40 Hydro -PS Acid <44 <55 <44 <55 840 440 <44 <44 <44 R-PSDA 250 J 190 J 180 J 84 J 850 J 300 J 130 J 260 J 310 J Hydrolyzed PSDA <27 <34 220 J 84 J 7,900 J 850 J <27 <27 <27 R-PSDCA <140 <180 <140 <180 24 <180 <140 <140 <140 NVHOS, Acid Form 130 <160 850 510 850 510 <130 <130 <130 EVE Acid <40 <50 UJ <40 <50 UJ 47 <50 UJ <40 <40 <40 Hydro -EVE Acid <24 <30 <24 <30 620 240 <24 <24 <24 R-EVE 200 J 130 J 240 J 120 J 360 J 110 J 130 J 260 J 230 J Perfluoro 2-ethox ethane sulfonic Acid <29 <36 <29 <36 <2.0 <36 <29 <29 <29 PFECA B <62 <78 <62 <78 <2.0 <78 <62 <62 <62 PFECA-G <29 <36 <29 <36 <2.0 <36 <29 <29 <29 PFPrA 14,000 10,000 60,000 41,000 25,000 14,000 2,800 4,600 6,700 Total Table 3+ (17 compounds) 2,3 35,700 33,800 133,000 80,300 116,000 62,500 6,660 11,300 18,300 Total Table 3+ (18 compounds) 2,4 499700 43,800 193,000 121,000 141,000 769500 9,460 15,900 259000 Total Table 3+ (21 compounds) 2,5 50,100 in 44,100 193,000 122,000 150,000 779800 9,720 16,400 259500 Notes: 1 - The EPA Method 537 was modified to incorporate the Table 3+ compounds. Beginning with the 3Q 2023 sampling, perfluoropropionic acid (PFPrA) was added to the compounds list. 2 - Total Table 3+ was calculated including J qualified data but not non -detect data. The total Table 3+ sum is rounded to three significant figures. 3 - Total Table 3+ (17 compounds) does not include R-PSDA, Hydrolyzed PSDA, R-EVE, and PFPrA. 4 - Total Table 3+ (18 compounds) does not include R-PSDA, Hydrolyzed PSDA, and R-EVE. 5 - Total Table 3+ (21 compounds) is the sum of all Table 3+ PFAS compounds. Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. UJ - Analyte not detected. Reporting limit may not be accurate or precise. ng/L - nanograms per liter SOP - standard operating procedure -- - No data reported < - Analyte not detected above associated reporting limit. TR0795C Page 12 of 24 June 2024 Table 6-2 PFAS Concentrations in Downgradient Groundwater Monitoring Wells Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC METHOD 537 MOD SOP COMP0l7NDs LIST' (ng/L) Mass Loading Model Sampling Program (Quarterly) LTW-01 LTW-02 CAP1Q23-LTW-01- 021623 Sample Date: CAP2Q23-LTW-01- 051723 Sample Date: CAP3Q23-LTW-01- 071323 Sample Date: CAP4Q23-LTW-01- 110323 Sample Date: CAP1Q24-LTW-01- 011724 Sample Date: CAP1Q23-LTW-02- 021623 Sample Date: CAP2Q23-LTW-02- 051723 Sample Date: CAP3Q23-LTW-02- 071223 Sample Date: CAP4Q23-LTW-02- 110323 Sample Date: CAP1Q24-LTW-02- 011724 Sample Date: 10:2 Fluorotelomer sulfonate <2.0 <2.0 UJ <2.0 <67 <84 <2.0 <2.0 UJ <2.0 <67 <84 11Cl-PF3OUdS <2.0 <2.0 UJ <2.0 <32 <40 <2.0 <2.0 UJ <2.0 <32 <40 11-1,1H,2H,2H-perfluorodecanesulfonate (8:2 FTS) <2.0 <2.0 UJ <2.0 <46 <58 <2.0 <2.0 UJ <2.0 <46 <58 1H, I H,2H,2H-perfluorohexanesulfonate (4:2 FTS) <2.0 <2.0 UJ <2.0 <24 <30 <2.0 <2.0 UJ <2.0 <24 <30 2-(N-ethyl perfluoro-l-octanesulfonamido)-ethanol <2.0 <2.0 UJ <2.0 <85 <110 <2.0 <2.0 UJ <2.0 <85 <110 2-(N-methyl perfluoro-l-octanesulfonamido)-ethanol <4.0 <4.0 UJ <4.0 <140 <180 <4.0 <4.0 UJ <4.0 <140 <180 6:2 Fluorotelomer sulfonate <5.0 <5.0 UJ <5.0 <250 <310 <5.0 <5.0 UJ <5.0 <250 <310 9CI-PF30NS <2.0 <2.0 UJ <2.0 <24 <30 <2.0 <2.0 UJ <2.0 <24 <30 DONA <2.0 <2.0 UJ <2.0 <40 <50 <2.0 <2.0 UJ <2.0 <40 <50 N-EthylPerfluorooctane Sulfonamidoacetic Acid <5.0 <5.0 UJ <5.0 <130 <160 <5.0 <5.0 UJ <5.0 <130 <160 N-ethylperfluoro- I -octanesulfonamide <2.0 <2.0 UJ <2.0 <87 <110 <2.0 <2.0 UJ <2.0 <87 <110 N-methyl perfluoro- I -octanesulfonamide <2.0 <2.0 UJ <2.0 <43 <54 <2.0 <2.0 UJ <2.0 <43 <54 N-MethylPerfluorooctane Sulfonamidoacetic Acid <5.0 <5.0 UJ <5.0 <120 <150 <5.0 <5.0 UJ <5.0 <120 <150 Perfluorobutane Sulfonic Acid 4.2 4.7 J 3.6 <20 <25 <2.0 <2.0 UJ <2.0 <20 <25 Perfluorobutanoic Acid 170 1101 120 <240 <300 30 61 J 86 <240 <300 Perfluorodecane Sulfonic Acid <2.0 <2.0 UJ <2.0 <32 <40 <2.0 <2.0 UJ <2.0 <32 <40 Perfluorodecanoic Acid <2.0 <2.0 UJ <2.0 <31 <39 <2.0 <2.0 UJ <2.0 <31 <39 Perfluorododecane Sulfonic Acid (PFDoS) <2.0 <2.0 UJ <2.0 <97 <120 <2.0 <2.0 UJ <2.0 <97 <120 Perfluorododecanoic Acid <2.0 <2.0 UJ <2.0 <55 <69 <2.0 <2.0 UJ <2.0 <55 <69 Perfluoroheptane Sulfonic Acid (PFHpS) <2.0 <2.0 UJ <2.0 <19 <24 <2.0 <2.0 UJ <2.0 <19 <24 Perfluoroheptanoic Acid 46 48 J 44 47 J 40 4.7 Ili 11 <25 <31 Perfluorohexadecanoic Acid (PFHxDA) <2.0 <2.0 UJ <2.0 <89 <110 <2.0 <2.0 UJ <2.0 <89 <110 Perfluorohexane Sulfonic Acid 6 6.3 J 5.2 <57 <71 <2.0 <2.0 UJ <2.0 <57 <71 Perfluorohexanoic Acid 22 23 J 23 <58 <73 3.3 8.4 J 11 <58 <73 Perfluorononanesulfonic Acid <2.0 <2.0 UJ <2.0 <37 <46 <2.0 <2.0 UJ <2.0 <37 <46 Perfluorononanoic Acid <2.0 2.3 J <2.0 <27 <34 <2.0 <2.0 UJ <2.0 <27 <34 Perfluorooctadecanoic Acid <2.0 <2.0 UJ <2.0 <94 <120 <2.0 <2.0 UJ <2.0 <94 <120 Perfluorooctane Sulfonamide <2.0 <2.0 UJ <2.0 <98 <120 <2.0 <2.0 UJ <2.0 <98 <120 Perfluoropentane Sulfonic Acid (PFPeS) <2.0 <2.0 UJ <2.0 <30 <38 <2.0 <2.0 UJ <2.0 <30 <38 Perfluoropentanoic Acid 320 250 J 260 330 220 99 190 J 250 300 320 Perfluorotetradecanoic Acid <2.0 <2.0 UJ <2.0 <73 <91 <2.0 <2.0 UJ <2.0 <73 <91 Perfluorotridecanoic Acid <2.0 <2.0 UJ <2.0 <130 <160 <2.0 <2.0 UJ <2.0 <130 <160 Perfluoroundecanoic Acid <2.0 <2.0 UJ <2.0 <110 <140 <2.0 <2.0 UJ <2.0 <110 <140 PFOA 41 49 J 39 <85 <110 <2.0 <2.0 UJ <2.0 <85 <110 PFOS 9.9 J 22 J Ili <54 <68 <2.0 <2.0 UJ <2.0 <54 <68 Notes: 1 - The EPA Method 537 was modified to incorporate the Table 3+ compounds. Beginning with the 3Q 2023 sampling, perfluoropropionic acid (PFPrA) was added to the compounds list. Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. ng/L - nanograms per liter SOP - standard operating procedure UJ - Analyte not detected. Reporting limit may not be accurate or precise. -- - No data reported < - Analyte not detected above associated reporting limit. TR0795C Page 13 of 24 June 2024 Table 6-2 PFAS Concentrations in Downgradient Groundwater Monitoring Wells Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC METHOD 537 MOD SOP COMP017NDs LIST' (ng/L) Mass Loading Model Sampling Program (Quarterly) LTW-03 LTW-04 CAP1Q23-LTW-03- 022123 Sample Date: CAP2Q23-LTW-03- 052323 Sample Date: CAP3Q23-LTW-03- 071223 Sample Date: CAP4Q23-LTW-03- 111323 Sample Date: CAP1Q24-LTW-03- 013124 Sample Date: CAP1Q23-LTW-04- 021723 Sample Date: CAP2Q23-LTW-04- 052323 Sample Date: CAP3Q23-LTW-04- 071123 Sample Date: CAP4Q23-LTW-04- 110223 Sample Date: CAP1Q24-LTW-04- 011624 Sample Date: 10:2 Fluorotelomer sulfonate <2.0 <2.0 <2.0 <2.0 <84 <2.0 <2.0 <2.0 <67 <84 11C1-PF3OUdS <2.0 <2.0 <2.0 <2.0 <40 <2.0 <2.0 <2.0 <32 <40 1H,1H,2H,2H-perfluorodecanesulfonate (8:2 FTS) <2.0 <2.0 <2.0 <2.0 <58 <2.0 <2.0 <2.0 <46 <58 1H,1H,2H,2H-perfluorohexanesulfonate(4:2FTS) <2.0 <2.0 <2.0 <2.0 <30 <2.0 <2.0 <2.0 <24 <30 2-(N-ethyl perfluoro-l-octanesulfonamido)-ethanol <2.0 <2.0 <2.0 <2.0 <110 <2.0 <2.0 <2.0 <85 <110 2-(N-methyl perfluoro-l-octanesulfonamido)-ethanol <4.0 <4.0 <4.0 <4.0 <180 <4.0 <4.0 <4.0 <140 <180 6:2 Fluorotelomer sulfonate <5.0 <5.0 <5.0 <5.0 <310 <5.0 <5.0 <5.0 <250 <310 9C1-PF30NS <2.0 <2.0 <2.0 <2.0 <30 <2.0 <2.0 <2.0 <24 <30 DONA <2.0 <2.0 <2.0 <2.0 <50 <2.0 <2.0 <2.0 <40 <50 N-Ethyl Perfluorooctane Sulfonamidoacetic Acid <5.0 <5.0 <5.0 <5.0 <160 <5.0 <5.0 <5.0 <130 <160 N-ethylperfluoro-l-octanesulfonamide <2.0 <2.0 <2.0 <2.0 <110 <2.0 <2.0 <2.0 <87 <110 N-methyl perfluoro-l-octanesulfonamide <2.0 <2.0 <2.0 <2.0 <54 <2.0 <2.0 <2.0 <43 <54 N-Methyl Perfluorooctane Sulfonamidoacetic Acid <5.0 <5.0 <5.0 <5.0 <150 <5.0 <5.0 <5.0 <120 <150 Perfluorobutane Sulfonic Acid <2.0 <2.0 <2.0 <2.0 <25 <2.0 2.2 <2.0 <20 <25 Perfluorobutanoic Acid 130 120 130 120 <300 310 230 290 330 <300 Perfluorodecane Sulfonic Acid <2.0 <2.0 <2.0 <2.0 <40 <2.0 <2.0 <2.0 <32 <40 Perfluorodecanoic Acid <2.0 <2.0 <2.0 <2.0 <39 <2.0 <2.0 <2.0 <31 <39 Perfluorododecane Sulfonic Acid (PFDoS) <2.0 <2.0 <2.0 <2.0 <120 <2.0 <2.0 <2.0 <97 <120 Perfluorododecanoic Acid <2.0 <2.0 <2.0 <2.0 <69 <2.0 <2.0 <2.0 <55 <69 Perfluoroheptane Sulfonic Acid (PFHpS) <2.0 <2.0 <2.0 <2.0 <24 <2.0 <2.0 <2.0 <19 <24 Perfluoroheptanoic Acid 26 28 25 24 <31 66 52 60 60 68 Perfluorohexadecanoic Acid (PFHxDA) <2.0 <2.0 <2.0 <2.0 <110 <2.0 <2.0 <2.0 <89 <110 Perfluorohexane Sulfonic Acid <2.0 <2.0 <2.0 <2.0 <71 <2.0 3.3 <2.0 <57 <71 Perfluorohexanoic Acid 16 17 16 17 <73 35 33 34 <58 <73 Perfluorononanesulfonic Acid <2.0 <2.0 <2.0 <2.0 <46 <2.0 <2.0 <2.0 <37 <46 Perfluorononanoic Acid <2.0 <2.0 <2.0 <2.0 <34 <2.0 <2.0 <2.0 <27 <34 Perfluorooctadecanoic Acid <2.0 <2.0 <2.0 <120 UJ <120 <2.0 <2.0 <2.0 <94 <120 Perfluorooctane Sulfonamide <2.0 <2.0 <2.0 <2.0 <120 <2.0 <2.0 <2.0 <98 <120 Perfluoropentane Sulfonic Acid (PFPeS) <2.0 <2.0 <2.0 <2.0 <38 <2.0 <2.0 <2.0 <30 <38 Perfluoropentanoic Acid 600 690 750 610 560 J 1,200 1,100 1,400 1,200 1,100 Perfluorotetradecanoic Acid <2.0 <2.0 <2.0 <2.0 <91 <2.0 <2.0 <2.0 <73 <91 Perfluorotridecanoic Acid <2.0 <2.0 <2.0 <2.0 <160 <2.0 <2.0 <2.0 <130 <160 Perfluoroundecanoic Acid <2.0 <2.0 <2.0 <2.0 <140 <2.0 <2.0 <2.0 <110 <140 PFOA <2.0 <2.0 <2.0 <2.0 <110 10 11 10 <85 <110 PFOS <2.0 <2.0 <2.0 <2.0 <68 <2.0 <2.0 <2.0 <54 <68 Notes: 1 - The EPA Method 537 was modified to incorporate the Table 3+ compounds. Beginning with the 3Q 2023 sampling, perfluoropropionic acid (PFPrA) was added to the compounds list. Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. ng/L - nanograms per liter SOP - standard operating procedure UJ - Analyte not detected. Reporting limit may not be accurate or precise. -- - No data reported < - Analyte not detected above associated reporting limit. TR0795C Page 14 of 24 June 2024 Table 6-2 PFAS Concentrations in Downgradient Groundwater Monitoring Wells Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC METHOD 537 MOD SOP COMPOl7NDs LIST' (ng/L) Mass Loading Model Sampling Program (Quarterly) LTW-05 OW-28 CAP1Q23-LTW-05- 021523 Sample Date: CAP2Q23-LTW-05- 052223 Sample Date: CAP3Q23-LTW-05- 071123 Sample Date: CAP4Q23-LTW-05- 110223 Sample Date: CAP1Q24-LTW-05- 011524 Sample Date: CAP1Q23-OW-28- 022023 Sample Date: CAP2Q23-OW-28- 052523 Sample Date: CAP3Q23-OW-28- 071123 Sample Date: CAP4Q23-OW-28- 110223 Sample Date: CAP4Q23-OW-28- 011824 Sample Date: 10:2 Fluorotelomer sulfonate <2.0 <2.0 <2.0 <67 <84 <2.0 <2.0 <2.0 <67 <84 11C1-PF3OUdS <2.0 <2.0 <2.0 <32 <40 <2.0 <2.0 <2.0 <32 <40 1H,1H,2H,2H-perfluorodecanesulfonate (8:2 FTS) <2.0 <2.0 <2.0 <46 <58 <2.0 <2.0 <2.0 <46 <58 1H,1H,2H,2H-perfluorohexanesulfonate (4:2 FTS) <2.0 <2.0 <2.0 <24 <30 <2.0 <2.0 <2.0 <24 <30 2-(N-ethyl perfluoro-l-octanesulfonamido)-ethanol <2.0 <2.0 <2.0 <85 <110 <2.0 <2.0 <2.0 <85 <110 2-(N-methyl perfluoro-l-octanesulfonamido)-ethanol <4.0 <4.0 <4.0 <140 <180 <4.0 <4.0 <4.0 <140 <180 6:2 Fluorotelomer sulfonate <5.0 <5.0 <5.0 <250 <310 <5.0 <5.0 <5.0 <250 880 9C1-PF30NS <2.0 <2.0 <2.0 <24 <30 <2.0 <2.0 <2.0 <24 <30 DONA <2.0 <2.0 <2.0 <40 <50 <2.0 <2.0 <2.0 <40 <50 N-Ethyl Perfluorooctane Sulfonamidoacetic Acid <5.0 <5.0 <5.0 <130 <160 <5.0 <5.0 <5.0 <130 <160 N-ethylperfluoro-l-octanesulfonamide <2.0 <2.0 <2.0 <87 <110 <2.0 <2.0 <2.0 <87 <110 N-methyl perfluoro-l-octanesulfonamide <2.0 <2.0 <2.0 <43 <54 <2.0 <2.0 <2.0 <43 <54 N-Methyl Perfluorooctane Sulfonamidoacetic Acid <5.0 <5.0 <5.0 <120 <150 <5.0 <5.0 <5.0 <120 <150 Perfluorobutane Sulfonic Acid <2.0 <2.0 <2.0 <20 <25 <2.0 2 <2.0 <20 <25 Perfluorobutanoic Acid 230 170 170 270 420 51 51 46 <240 <300 Perfluorodecane Sulfonic Acid <2.0 <2.0 <2.0 <32 <40 <2.0 <2.0 <2.0 <32 <40 Perfluorodecanoic Acid <2.0 <2.0 <2.0 <31 <39 <2.0 <2.0 <2.0 <31 <39 Perfluorododecane Sulfonic Acid (PFDoS) <2.0 <2.0 <2.0 <97 <120 <2.0 <2.0 <2.0 <97 <120 Perfluorododecanoic Acid <2.0 <2.0 <2.0 <55 <69 <2.0 <2.0 <2.0 <55 <69 Perfluoroheptane Sulfonic Acid (PFHpS) <2.0 <2.0 <2.0 <19 <24 <2.0 <2.0 <2.0 <19 <24 Perfluoroheptanoic Acid 210 200 210 250 310 7.2 7.3 6.5 <25 <31 Perfluorohexadecanoic Acid (PFHxDA) <2.0 <2.0 <2.0 <89 <110 <2.0 <2.0 <2.0 <89 <110 Perfluorohexane Sulfonic Acid <2.0 <2.0 <2.0 <57 <71 <2.0 <2.0 <2.0 <57 <71 Perfluorohexanoic Acid 38 52 43 66 99 9.9 12 9.1 <58 <73 Perfluorononanesulfonic Acid <2.0 <2.0 <2.0 <37 <46 <2.0 <2.0 <2.0 <37 <46 Perfluorononanoic Acid <2.0 <2.0 <2.0 <27 <34 <2.0 <2.0 <2.0 <27 <34 Perfluorooctadecanoic Acid <2.0 <2.0 <2.0 <94 <120 <2.0 <2.0 <2.0 <94 <120 Perfluorooctane Sulfonamide <2.0 <2.0 <2.0 <98 <120 <2.0 <2.0 <2.0 <98 <120 Perfluoropentane Sulfonic Acid (PFPeS) <2.0 <2.0 <2.0 <30 <38 <2.0 <2.0 <2.0 <30 <38 Perfluoropentanoic Acid 1,300 1,700 1,600 2,300 2,700 68 75 73 49 69 Perfluorotetradecanoic Acid <2.0 <2.0 <2.0 <73 <91 <2.0 <2.0 <2.0 <73 <91 Perfluorotridecanoic Acid <2.0 <2.0 <2.0 <130 <160 <2.0 <2.0 <2.0 <130 <160 Perfluoroundecanoic Acid <2.0 <2.0 <2.0 <110 <140 <2.0 <2.0 <2.0 <110 <140 PFOA 4.1 4.1 2.1 <85 <110 4.3 4 3.3 <85 <110 PFOS <2.0 <2.0 <2.0 <54 <68 <2.0 <2.0 <2.0 <54 <68 Notes: 1 - The EPA Method 537 was modified to incorporate the Table 3+ compounds. Beginning with the 3Q 2023 sampling, perfluoropropionic acid (PFPrA) was added to the compounds list. Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. ng/L - nanograms per liter SOP - standard operating procedure UJ - Analyte not detected. Reporting limit may not be accurate or precise. -- - No data reported < - Analyte not detected above associated reporting limit. TR0795C Page 15 of 24 June 2024 Table 6-2 PFAS Concentrations in Downgradient Groundwater Monitoring Wells Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC METHOD 537 MOD SOP COMP0I7NDs LIST' (ng/L) Mass Loading Model Sampling Program (Quarterly) OW-33 PIW-11) CAP1Q23-OW-33- 021423 Sample Date: CAP2Q23-OW-33- 051823 Sample Date: CAP3Q23-OW-33- 071223 Sample Date: CAP4Q23-OW-33- 110223 Sample Date: CAP1Q24-OW-33- 013024 Sample Date: CAP1Q23-PIW-1D- 021623 Sample Date: CAP2Q23-PIW-1D- 052323 Sample Date: CAP3Q23-PIW-1D- 080223 Sample Date: CAP4Q23-PIW-1D- 110723 Sample Date: CAP1Q24-PIW-1D- 012224 Sample Date: 10:2 Fluorotelomer sulfonate <2.0 <2.0 UJ <2.0 <67 <84 <2.0 <2.0 <67 <67 <84 11C1-PF3OUdS <2.0 <2.0 UJ <2.0 <32 <40 <2.0 <2.0 <32 <32 <40 IH,1H,2H,2H-perfluorodecanesulfonate (8:2 FTS) <2.0 <2.0 UJ <2.0 <46 <58 <2.0 <2.0 <46 <46 <58 1H,1H,2H,2H-perfluorohexanesulfonate (4:2 FTS) <2.0 <2.0 UJ <2.0 <24 <30 <2.0 <2.0 <24 UJ <24 <30 2-(N-ethyl perfluoro-l-octanesulfonamido)-ethanol <2.0 <2.0 UJ <2.0 <85 <110 <2.0 <2.0 <85 <85 <110 2-(N-methyl perfluoro-l-octanesulfonamido)-ethanol <4.0 <4.0 UJ <4.0 <140 <180 <4.0 <4.0 <140 <140 <180 6:2 Fluorotelomer sulfonate <5.0 <5.0 UJ <5.0 <250 <310 <5.0 <5.0 <250 <250 1,200 9C1-PF30NS <2.0 <2.0 UJ <2.0 <24 <30 <2.0 <2.0 <24 <24 <30 DONA <2.0 <2.0 UJ <2.0 <40 <50 <2.0 <2.0 <40 <40 <50 N-Ethyl Perfluorooctane Sulfonamidoacetic Acid <5.0 <5.0 UJ <5.0 <130 <160 <5.0 <5.0 <130 <130 <160 N-ethylperfluoro-l-octanesulfonamide <2.0 <2.0 UJ <2.0 <87 <110 <2.0 <2.0 <87 UJ <87 <110 N-methyl perfluoro-l-octanesulfonamide <2.0 <2.0 UJ <2.0 <43 <54 <2.0 <2.0 <43 <43 <54 N-Methyl Perfluorooctane Sulfonamidoacetic Acid <5.0 <5.0 UJ <5.0 <120 <150 <5.0 <5.0 <120 <120 <150 Perfluorobutane Sulfonic Acid <2.0 <2.0 UJ <2.0 <20 <25 <2.0 <2.0 <20 <20 <25 Perfluorobutanoic Acid 45 60 J 62 <240 <300 83 59 <240 <240 <300 Perfluorodecane Sulfonic Acid <2.0 <2.0 UJ <2.0 <32 <40 <2.0 <2.0 <32 <32 <40 Perfluorodecanoic Acid <2.0 <2.0 UJ <2.0 <31 <39 <2.0 <2.0 <31 <31 <39 Perfluorododecane Sulfonic Acid (PFDoS) <2.0 <2.0 UJ <2.0 <97 <120 <2.0 <2.0 <97 <97 <120 Perfluorododecanoic Acid <2.0 <2.0 UJ <2.0 <55 <69 <2.0 <2.0 <55 <55 <69 Perfluoroheptane Sulfonic Acid (PFHpS) <2.0 <2.0 UJ <2.0 <19 <24 <2.0 <2.0 <19 <19 <24 Perfluoroheptanoic Acid 5.6 7.6 J 7.1 <25 <31 16 19 <25 <25 <31 Perfluorohexadecanoic Acid (PFHxDA) <2.0 <2.0 UJ <2.0 <89 <110 <2.0 <2.0 <89 <89 <110 Perfluorohexane Sulfonic Acid <2.0 <2.0 UJ <2.0 <57 <71 <2.0 <2.0 <57 <57 <71 Perfluorohexanoic Acid 7.8 10.1 10 <58 <73 9.5 11 <58 <58 <73 Perfluorononanesulfonic Acid <2.0 <2.0 UJ <2.0 <37 <46 <2.0 <2.0 <37 <37 <46 Perfluorononanoic Acid <2.0 <2.0 UJ <2.0 <27 <34 <2.0 <2.0 <27 <27 <34 Perfluorooctadecanoic Acid <2.0 <2.0 UJ <2.0 <94 UJ <120 <2.0 <2.0 <94 <94 <120 Perfluorooctane Sulfonamide <2.0 <2.0 UJ <2.0 <98 <120 <2.0 <2.0 <98 <98 <120 Perfluoropentane Sulfonic Acid (PFPeS) <2.0 <2.0 UJ <2.0 <30 <38 <2.0 <2.0 <30 <30 <38 Perfluoropentanoic Acid 93 120 J 130 14 1120 J 150 140 160 150 150 Perfluorotetradecanoic Acid <2.0 <2.0 UJ <2.0 <73 <91 <2.0 <2.0 <73 <73 <91 Perfluorotridecanoic Acid <2.0 <2.0 UJ <2.0 <130 <160 <2.0 <2.0 <130 <130 <160 Perfluoroundecanoic Acid <2.0 <2.0 UJ <2.0 <110 <140 <2.0 <2.0 <110 <110 <140 PFOA <2.0 2.2 J <2.0 <85 <110 18 19 <85 <85 <110 PFOS <2.0 <2.0 UJ <2.0 <54 <68 <2.0 <2.0 <54 <54 <68 Notes: 1 - The EPA Method 537 was modified to incorporate the Table 3+ compounds. Beginning with the 3Q 2023 sampling, perfluoropropionic acid (PFPrA) was added to the compounds list. Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. ng/L - nanograms per liter SOP - standard operating procedure UJ - Analyte not detected. Reporting limit may not be accurate or precise. -- - No data reported < - Analyte not detected above associated reporting limit. TR0795C Page 16 of 24 June 2024 Table 6-2 PFAS Concentrations in Downgradient Groundwater Monitoring Wells Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC METHOD 537MOD SOP COMPOUNDS LIST' (ng/L) Mass Loading Model Sampling Program (Quarterly) PIW-lS PIW-3D CAP1Q23-PIW-1S- 021623 Sample Date: Not Sampled in 2Q 2023 (Dry) Not Sampled in 3Q 2023 (Dry) Not Sampled in 4Q 2023 (Dry) CAP1Q24-PIW-1S- 011624 Sample Date: CAP1Q23-PIW-3D- 021623 Sample Date: CAP2Q23-PIW-3D- 051723 Sample Date: CAP3Q23-PIW-3D- 071323 Sample Date: CAP4Q23-PIW-3D- 110323 Sample Date: CAP1Q24-PIW-3D- 011824 Sample Date: 10:2 Fluorotelomer sulfonate <2.0 <84 <2.0 <2.0 UJ <2.0 <67 <84 11C1-PF3OUdS <2.0 <40 <2.0 <2.0 UJ <2.0 <32 <40 III, 1H,2H,2H-perfluorodecanesulfonate(8:2FTS) <2.0 <58 <2.0 <2.0 UJ <2.0 <46 <58 1H,1H,2H,2H-perfluorohexanesulfonate (4:2 FTS) <2.0 <30 <2.0 <2.0 UJ <2.0 <24 <30 2-(N-ethyl perfluoro-l-octanesulfonamido)-ethanol <2.0 <110 <2.0 <2.0 UJ <2.0 <85 <110 2-(N-methyl perfluoro-l-octanesulfonamido)-ethanol <4.0 <180 <4.0 <4.0 UJ <4.0 <140 <180 6:2 Fluorotelomer sulfonate <5.0 <310 <5.0 <5.0 UJ <5.0 <250 <310 9C1-PF30NS <2.0 <30 <2.0 <2.0 UJ <2.0 <24 <30 DONA <2.0 <50 <2.0 <2.0 UJ <2.0 <40 <50 N-Ethyl Perfluorooctane Sulfonamidoacetic Acid <5.0 <160 <5.0 <5.0 UJ <5.0 <130 <160 N-ethylperfluoro-l-octanesulfonamide <2.0 <110 <2.0 <2.0 UJ <2.0 <87 <110 N-methyl perfluoro- I -octanesulfonamide <2.0 <54 <2.0 <2.0 UJ <2.0 <43 <54 N-Methyl Perfluorooctane Sulfonamidoacetic Acid <5.0 <150 <5.0 <5.0 UJ <5.0 <120 <150 Perfluorobutane Sulfonic Acid <2.0 <25 2.2 2.1 J 2.3 <20 <25 Perfluorobutanoic Acid 51 <300 110 73 J 79 <240 <300 Perfluorodecane Sulfonic Acid <2.0 <40 <2.0 <2.0 UJ <2.0 <32 <40 Perfluorodecanoic Acid <2.0 <39 <2.0 <2.0 UJ <2.0 <31 <39 Perfluorododecane Sulfonic Acid (PFDoS) <2.0 <120 <2.0 <2.0 UJ <2.0 <97 <120 Perfluorododecanoic Acid <2.0 <69 <2.0 <2.0 UJ <2.0 <55 <69 Perfluoroheptane Sulfonic Acid (PFHpS) <2.0 <24 <2.0 <2.0 UJ <2.0 <19 <24 Perfluoroheptanoic Acid 18 <31 32 32 J 33 49 44 Perfluorohexadecanoic Acid (PFHxDA) <2.0 <110 <2.0 <2.0 UJ <2.0 <89 <110 Perfluorohexane Sulfonic Acid 8.6 <71 3.4 3.5 J 3.7 <57 <71 Perfluorohexanoic Acid 7.7 <73 15 14 J 16 <58 <73 Perfluorononanesulfonic Acid <2.0 <46 <2.0 <2.0 UJ <2.0 <37 <46 Perfluorononanoic Acid 4.1 <34 5.2 4.8 J 5 <27 <34 Perfluorooctadecanoic Acid <2.0 <120 <2.0 <2.0 UJ <2.0 <94 <120 Perfluorooctane Sulfonamide <2.0 <120 <2.0 <2.0 UJ <2.0 <98 <120 Perfluoropentane Sulfonic Acid (PFPeS) <2.0 <38 <2.0 <2.0 UJ <2.0 <30 <38 Perfluoropentanoic Acid 78 <61 150 150 J 150 190 250 Perfluorotetradecanoic Acid <2.0 <91 <2.0 <2.0 UJ <2.0 <73 <91 Perfluorotridecanoic Acid <2.0 <160 <2.0 <2.0 UJ <2.0 <130 <160 Perfluoroundecanoic Acid <2.0 <140 <2.0 <2.0 UJ <2.0 <110 <140 PFOA 69 <110 44 43 J 42 <85 <110 PFOS 22 <68 15 14 J 14 <54 <68 Notes: 1 - The EPA Method 537 was modified to incorporate the Table 3+ compounds. Beginning with the 3Q 2023 sampling, perfluoropropionic acid (PFPrA) was added to the compounds list. Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. ng/L - nanograms per liter SOP - standard operating procedure UJ - Analyte not detected. Reporting limit may not be accurate or precise. -- - No data reported < - Analyte not detected above associated reporting limit. TR0795C Page 17 of 24 June 2024 Table 6-2 PFAS Concentrations in Downgradient Groundwater Monitoring Wells Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC METHOD 537 MOD SOP COMP0l7NDs LIST' (ng/L) Mass Loading Model Sampling Program (Quarterly) PIW-71) PIW-7S CAP1Q23-PIW-7D- 021523 Sample Date: CAP2Q23-PIW-7D- 052223 Sample Date: CAP3Q23-PIW-7D- 071123 Sample Date: CAP4Q23-PIW-7D- 110223 Sample Date: CAP1Q24-PIW-7D- 011524 Sample Date: CAP1Q23-PIW-7S- 021523 Sample Date: CAP2Q23-PIW-7S- 052223 Sample Date: CAP3Q23-PIW-7S- 071123 Sample Date: CAP4Q23-PIW-7S- 110223 Sample Date: CAP1Q24-PIW-7S- 011524 Sample Date: 10:2 Fluorotelomer sulfonate <2.0 <2.0 <2.0 <67 <84 <2.0 <2.0 <2.0 <67 <84 11C1-PF30UdS <2.0 <2.0 <2.0 <32 <40 <2.0 <2.0 <2.0 <32 <40 11-1,1H,2H,2H-perfluorodecanesulfonate (8:2 FTS) <2.0 <2.0 <2.0 <46 <58 <2.0 <2.0 <2.0 <46 <58 11-1,11-1,21-1,21-1-perfluorohexanesulfonate (4:2 FTS) <2.0 <2.0 <2.0 <24 <30 <2.0 <2.0 <2.0 <24 <30 2-(N-ethylperfluoro-l-octanesulfonamido)-ethanol <2.0 <2.0 <2.0 <85 <110 <2.0 <2.0 <2.0 <85 <110 2-(N-methyl perfluoro-l-octanesulfonamido)-ethanol <4.0 <4.0 <4.0 <140 <180 <4.0 <4.0 <4.0 <140 <180 6:2 Fluorotelomer sulfonate <5.0 <5.0 <5.0 <250 <310 <5.0 <5.0 <5.0 <250 <310 9C1-PF30NS <2.0 <2.0 <2.0 <24 <30 <2.0 <2.0 <2.0 <24 <30 DONA <2.0 <2.0 <2.0 <40 <50 <2.0 <2.0 <2.0 <40 <50 N-Ethyl Perfluorooctane Sulfonamidoacetic Acid <5.0 <5.0 <5.0 <130 <160 <5.0 <5.0 <5.0 <130 <160 N-ethylperfluoro-l-octanesulfonamide <2.0 <2.0 <2.0 <87 <110 <2.0 <2.0 <2.0 <87 <110 N-methyl perfluoro-I-octanesulfonamide <2.0 <2.0 <2.0 <43 <54 <2.0 <2.0 <2.0 <43 <54 N-Methyl Perfluorooctane Sulfonamidoacetic Acid <5.0 <5.0 <5.0 <120 <150 <5.0 <5.0 <5.0 <120 <150 Perfluorobutane Sulfonic Acid <2.0 <2.0 <2.0 <20 <25 3.6 2.8 2.5 <20 <25 Perfluorobutanoic Acid 290 150 160 <240 <300 210 120 100 <240 <300 Perfluorodecane Sulfonic Acid <2.0 <2.0 <2.0 <32 <40 <2.0 <2.0 <2.0 <32 <40 Perfluorodecanoic Acid <2.0 <2.0 <2.0 <31 <39 <2.0 <2.0 <2.0 <31 <39 Perfluorododecane Sulfonic Acid (PFDoS) <2.0 <2.0 <2.0 <97 <120 <2.0 <2.0 <2.0 <97 <120 Perfluorododecanoic Acid <2.0 <2.0 <2.0 <55 <69 <2.0 <2.0 <2.0 <55 <69 Perfluoroheptane Sulfonic Acid (PFHpS) <2.0 <2.0 <2.0 <19 <24 <2.0 <2.0 <2.0 <19 <24 Perfluoroheptanoic Acid 140 81 85 97 100 71 52 41 61 56 Perfluorohexadecanoic Acid (PFHxDA) <2.0 <2.0 <2.0 <89 <110 <2.0 <2.0 <2.0 <89 <110 Perfluorohexane Sulfonic Acid <2.0 <2.0 <2.0 <57 <71 4.1 3.5 3 <57 <71 Perfluorohexanoic Acid 49 33 30 <58 <73 30 26 19 <58 <73 Perfluorononanesulfonic Acid <2.0 <2.0 <2.0 <37 <46 <2.0 <2.0 <2.0 <37 <46 Perfluorononanoic Acid <2.0 <2.0 <2.0 <27 <34 <2.0 <2.0 <2.0 <27 <34 Perfluorooctadecanoic Acid <2.0 <2.0 <2.0 <94 <120 <2.0 <2.0 <2.0 <94 <120 Perfluorooctane Sulfonamide <2.0 <2.0 <2.0 <98 <120 <2.0 <2.0 <2.0 <98 <120 Perfluoropentane Sulfonic Acid (PFPeS) <2.0 <2.0 <2.0 <30 <38 <2.0 <2.0 <2.0 <30 <38 Perfluoropentanoic Acid 1,500 1,300 1,400 1,500 1,300 630 530 470 620 580 Perfluorotetradecanoic Acid <2.0 <2.0 <2.0 <73 <91 <2.0 <2.0 <2.0 <73 <91 Perfluorotridecanoic Acid <2.0 <2.0 <2.0 <130 <160 <2.0 <2.0 <2.0 <130 <160 Perfluoroundecanoic Acid <2.0 <2.0 <2.0 <110 <140 <2.0 <2.0 <2.0 <110 <140 PFOA 4.5 2.9 2 <85 <110 17 14 9.6 <85 <110 PFOS <2.0 <2.0 <2.0 <54 <68 6.4 J 5.4 .J <2.0 <54 <68 Notes: 1 - The EPA Method 537 was modified to incorporate the Table 3+ compounds. Beginning with the 3Q 2023 sampling, perfluoropropionic acid (PFPrA) was added to the compounds list. Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. ng/L - nanograms per liter SOP - standard operating procedure UJ - Analyte not detected. Reporting limit may not be accurate or precise. -- - No data reported < - Analyte not detected above associated reporting limit. TR0795C Page 18 of 24 June 2024 Table 6-2 PFAS Concentrations in Downgradient Groundwater Monitoring Wells Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC METHOD 537 MOD SOP COMPOUNDS LIST' (ng/L) Mass Loading Model Sampling Program (Quarterly) PW-04 PZ-22 CAP1Q23-PW-04- 022323 Sample Date: CAP2Q23-PW-04- 052523 Sample Date: CAP3Q23-PW-04- 072823 Sample Date: CAP4Q23-PW-04- 110923 Sample Date: CAP1Q24-PW-04- 011724 Sample Date: CAP1Q23-PZ-22-022023 Sample Date: CAP2Q23-PZ-22-052323 Sample Date: CAP3Q-PZ-22-071123 Sample Date: CAP4Q23-PZ-22-110223 Sample Date: CAP1Q24-PZ-22-011624 Sample Date: 10:2 Fluorotelomer sulfonate <2.0 <2.0 <67 <67 <84 <2.0 <2.0 <2.0 <67 <84 11C1-PF3OUdS <2.0 <2.0 <32 <32 <40 <2.0 <2.0 <2.0 <32 <40 1H,1H,2H,2H-perfluorodecanesulfonate (8:2 FTS) <2.0 <2.0 <46 <46 <58 <2.0 <2.0 <2.0 <46 <58 1H,1H,2H,2H-perfluorohexanesulfonate(4:2FTS) <2.0 <2.0 <24 <24 <30 <2.0 <2.0 <2.0 <24 <30 2-(N-ethyl perfluoro-l-octanesulfonamido)-ethanol <2.0 <2.0 <85 <85 <110 <2.0 <2.0 <2.0 <85 <110 2-(N-methyl perfluoro-l-octanesulfonamido)-ethanol <4.0 <4.0 <140 <140 <180 <4.0 <4.0 <4.0 <140 <180 6:2 Fluorotelomer sulfonate <5.0 <5.0 <250 <250 <310 <5.0 <5.0 <5.0 <250 <310 UJ 9C1-PF30NS <2.0 <2.0 <24 <24 <30 <2.0 <2.0 <2.0 <24 <30 DONA <2.0 <2.0 <40 <40 <50 <2.0 <2.0 <2.0 <40 <50 N-Ethyl Perfluorooctane Sulfonamidoacetic Acid <5.0 <5.0 <130 <130 <160 <5.0 <5.0 <5.0 <130 <160 N-ethylperfluoro-l-octanesulfonamide <2.0 <2.0 <87 <87 <110 <2.0 <2.0 <2.0 <87 <110 N-methyl perfluoro-l-octanesulfonamide <2.0 <2.0 <43 <43 <54 <2.0 <2.0 <2.0 <43 <54 N-Methyl Perfluorooctane Sulfonamidoacetic Acid <5.0 <5.0 <120 <120 <150 <5.0 <5.0 <5.0 <120 <150 Perfluorobutane Sulfonic Acid <2.0 <2.0 32 <20 <25 <2.0 <2.0 <2.0 <20 <25 Perfluorobutanoic Acid 8.3 10 <240 <240 <300 120 110 120 <240 <300 Perfluorodecane Sulfonic Acid <2.0 <2.0 <32 <32 <40 <2.0 <2.0 <2.0 <32 <40 Perfluorodecanoic Acid <2.0 <2.0 <31 <31 <39 <2.0 <2.0 <2.0 <31 <39 Perfluorododecane Sulfonic Acid (PFDoS) <2.0 <2.0 <97 <97 <120 <2.0 <2.0 <2.0 <97 <120 Perfluorododecanoic Acid <2.0 <2.0 <55 <55 <69 <2.0 <2.0 <2.0 <55 <69 Perfluoroheptane Sulfonic Acid (PFHpS) <2.0 <2.0 <19 <19 <24 <2.0 <2.0 <2.0 <19 <24 Perfluoroheptanoic Acid 6.6 8.8 <25 <25 <31 20 34 30 31 36 Perfluorohexadecanoic Acid (PFHxDA) <2.0 <2.0 <89 <89 <110 <2.0 <2.0 <2.0 <89 <110 Perfluorohexane Sulfonic Acid <2.0 <2.0 <57 <57 <71 <2.0 <2.0 <2.0 <57 <71 Perfluorohexanoic Acid 2.7 3.5 <58 <58 <73 17 19 18 <58 <73 Perfluorononanesulfonic Acid <2.0 <2.0 <37 <37 <46 <2.0 <2.0 <2.0 <37 <46 Perfluorononanoic Acid <2.0 <2.0 <27 <27 <34 <2.0 <2.0 <2.0 <27 <34 Perfluorooctadecanoic Acid <2.0 <2.0 <94 <94 <120 <2.0 <2.0 <2.0 <94 <120 Perfluorooctane Sulfonamide <2.0 <2.0 <98 <98 <120 <2.0 <2.0 <2.0 <98 <120 Perfluoropentane Sulfonic Acid (PFPeS) <2.0 <2.0 <30 <30 <38 <2.0 <2.0 <2.0 <30 <38 Perfluoropentanoic Acid 18 21 <49 <49 <61 820 930 1,100 1,100 880 Perfluormetradecanoic Acid <2.0 <2.0 <73 <73 <91 <2.0 <2.0 <2.0 <73 <91 Perfluorotridecanoic Acid <2.0 <2.0 <130 <130 <160 <2.0 <2.0 <2.0 <130 <160 Perfluoroundecanoic Acid <2.0 <2.0 <110 <110 <140 <2.0 <2.0 <2.0 <110 <140 PFOA <2.0 <2.0 <85 <85 <110 <2.0 <2.0 <2.0 <85 <110 PFOS <2.0 <2.0 <54 <54 <68 <2.0 <2.0 <2.0 <54 <68 Notes: 1 - The EPA Method 537 was modified to incorporate the Table 3+ compounds. Beginning with the 3Q 2023 sampling, perfluoropropionic acid (PFPrA) was added to the compounds list. Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. ng/L - nanograms per liter SOP - standard operating procedure UJ - Analyte not detected. Reporting limit may not be accurate or precise. -- - No data reported < - Analyte not detected above associated reporting limit. TR0795C Page 19 of 24 June 2024 Table 6-2 PFAS Concentrations in Downgradient Groundwater Monitoring Wells Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC METHOD 537 MOD SOP COMPO(7NDs LIST' (ng/L) Mass Loading Model Sampling Program (Quarterly) Performance Monitoring Plan Sampling Program (Semi -Annually) SMW-12 OW-411 OW-30 CAP1Q23-SMW-12- 022323 Sample Date: CAP2Q23-SMW-12- 051723 Sample Date: CAP3Q23-SMW-12- 071823 Sample Date: CAP4Q23-SMW-12- 110823 Sample Date: CAP1Q24-SMW-12- 011624 Sample Date: CAP3Q23-OW-4R- 080423 Sample Date: CAP1Q24-OW-4R- 012924 Sample Date: CAP1Q23-OW-30- 021523 Sample Date: CAP3Q23-OW-30- 071323 Sample Date: CAP1Q24-OW-30- 013024 Sample Date: 10:2 Fluorotelomer sulfonate <2.0 <2.0 UJ <61 <67 <84 <67 <84 <2.0 <2.0 <84 11C1-PF3OUdS <2.0 <2.0 UJ <29 <32 <40 <32 <40 <2.0 <2.0 <40 1H,1H,2H,2H-perfluorodecanesulfonate (8:2 FTS) <2.0 <2.0 UJ <42 <46 <58 <46 <58 <2.0 <2.0 <58 IH,1H,2H,2H-perfluorohexanesulfonate (4:2 FTS) <2.0 <2.0 UJ <22 <24 <30 <24 <30 <2.0 <2.0 <30 2-(N-ethyl perfluoro-l-octanesulfonamido)-ethanol <2.0 <2.0 UJ <77 <85 <110 <85 <110 <2.0 <2.0 <110 2-(N-methylperfluoro-l-octanesulfonamido)-ethanol <4.0 <4.0 UJ <130 <140 <180 <140 <180 <4.0 <4.0 <180 6:2 Fluorotelomer sulfonate <5.0 <5.0 UJ <230 <250 <310 <250 <310 <5.0 <5.0 <310 9C1-PF30NS <2.0 <2.0 UJ <22 <24 <30 <24 <30 <2.0 <2.0 <30 DONA <2.0 <2.0 UJ <36 <40 <50 <40 <50 <2.0 <2.0 <50 N-Ethyl Perfluorooctane Sulfonamidoacetic Acid <5.0 <5.0 UJ <120 <130 <160 <130 <160 <5.0 <5.0 <160 N-ethylperfluoro-l-octanesulfonamide <2.0 <2.0 UJ <79 <87 <110 <87 <110 <2.0 <2.0 <110 N-methylperfluoro-l-octanesulfonamide <2.0 <2.0 UJ <39 <43 <54 <43 <54 <2.0 <2.0 <54 N-Methyl Perfluorooctane Sulfonamidoacetic Acid <5.0 <5.0 UJ <110 <120 <150 <120 <150 <5.0 <5.0 <150 Perfluorobutane Sulfonic Acid <2.0 <2.0 UJ <18 <20 <25 <20 <25 <2.0 <2.0 <25 Perfluorobutanoic Acid 19 25 J <220 <240 <300 <240 <300 150 95 <300 Perfluorodecane Sulfonic Acid <2.0 <2.0 UJ <29 <32 <40 <32 <40 <2.0 <2.0 <40 Perfluorodecanoic Acid <2.0 <2.0 UJ <28 <31 <39 <31 <39 <2.0 <2.0 <39 Perfluorododecane Sulfonic Acid (PFDoS) <2.0 <2.0 UJ <88 <97 <120 <97 <120 <2.0 <2.0 <120 Perfluorododecanoic Acid <2.0 <2.0 UJ <50 <55 <69 <55 <69 <2.0 <2.0 <69 Perfluoroheptane Sulfonic Acid (PFHpS) <2.0 <2.0 UJ <17 <19 <24 <19 <24 <2.0 <2.0 <24 Perfluoroheptanoic Acid <2.0 <2.0 UJ <23 <25 <31 90 77 12 7 <31 Perfluorohexadecanoic Acid (PFHxDA) <2.0 <2.0 UJ <81 <89 <110 <89 <110 <2.0 <2.0 <110 Perfluorohexane Sulfonic Acid <2.0 <2.0 UJ <52 <57 <71 <57 <71 <2.0 <2.0 <71 Perfluorohexanoic Acid <2.0 2.5 J <53 <58 <73 <58 <73 16 13 <73 Perfluorononanesulfonic Acid <2.0 <2.0 UJ <34 <37 <46 <37 <46 <2.0 <2.0 <46 Perfluorononanoic Acid <2.0 <2.0 UJ <25 <27 <34 <27 <34 <2.0 <2.0 <34 Perfluorooctadecanoic Acid <2.0 <2.0 UJ <86 <94 <120 <94 <120 <2.0 <2.0 <120 Perfluorooctane Sulfonamide <2.0 <2.0 UJ <89 <98 <120 <98 <120 <2.0 <2.0 <120 Perfluoropentane Sulfonic Acid (PFPeS) <2.0 <2.0 UJ <27 <30 <38 <30 <38 <2.0 <2.0 <38 Perfluoropentanoic Acid 43 62 J 73 92 83 480 390 530 340 460 J Perfluorotetradecanoic Acid <2.0 <2.0 UJ <67 <73 <91 <73 <91 <2.0 <2.0 <91 Perfluorotridecanoic Acid <2.0 <2.0 UJ <120 <130 <160 <130 <160 <2.0 <2.0 <160 Perfluoroundecanoic Acid <2.0 <2.0 UJ <100 <110 <140 <110 <140 <2.0 <2.0 <140 PFOA <2.0 <2.0 UJ <77 <85 <110 <85 <110 <2.0 <2.0 <110 PFOS <2.0 17 J <49 <54 <68 <54 <68 <2.0 <2.0 <68 Notes: 1 - The EPA Method 537 was modified to incorporate the Table 3+ compounds. Beginning with the 3Q 2023 sampling, perfluoropropionic acid (PFPrA) was added to the compounds list. Wells OW-4R, OW-32, OW-37, and OW-51 were installed between late June 2023 and August 2023, so were unavailable for sampling before 3Q 2023. Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. ng/L - nanograms per liter SOP - standard operating procedure UJ - Analyte not detected. Reporting limit may not be accurate or precise. -- - No data reported < - Analyte not detected above associated reporting limit. TR0795C Page 20 of 24 June 2024 Table 6-2 PFAS Concentrations in Downgradient Groundwater Monitoring Wells Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC METHOD 537 MOD SOP COMPOUNDS LIST' (ng/L) Performance Monitoring Plan Sampling Program (Semi -Annually) OW-32 OW-37 OW40 OW-51 OW-54 CAP3Q23-OW-32- 090823 Sample Date: CAP1Q24-OW-32- 012924 Sample Date: CAP3Q23-OW-37- 081023 Sample Date: CAP1Q24-OW-37- 011724 Sample Date: CAP1Q23-OW-40- 021523 Sample Date: CAP3Q23-OW-40- 071323 Sample Date: CAP1Q24-OW-40- 013024 Sample Date: CAP3Q23-OW-51- 080323 Sample Date: CAP1Q24-OW-51- 013124 Sample Date: CAP1Q23-OW-54- 021623 Sample Date: Not Sampled in 3Q 2023 (Dry) CAP1Q24-OW-54- 020624 Sample Date: 10:2 Fluorotelomer sulfonate <67 <84 <67 UJ <84 <2.0 <2.0 <84 <67 <84 <2.0 <84 11C1-PF3OUdS <32 <40 <32 UJ <40 <2.0 <2.0 <40 <32 <40 <2.0 <40 1H,1H,2H,2H-perfluorodecanesulfonate (8:2 FTS) <46 <58 <46 UJ <58 <2.0 <2.0 <58 <46 <58 <2.0 <58 1H,1H,2H,2H-perfluorohexanesulfonate (4:2 FTS) <24 <30 <24 UJ <30 <2.0 <2.0 <30 <24 <30 <2.0 <30 2-(N-ethyl perfluoro-l-octanesulfonamido)-ethanol <85 <110 <85 UJ <110 <2.0 <2.0 <110 <85 <110 <2.0 <110 2-(N-methyl perfluoro-l-octanesulfonamido)-ethanol <140 <180 <140 UJ <180 <4.0 <4.0 <180 <140 <180 <4.0 <180 6:2 Fluorotelomer sulfonate <250 <310 <250 UJ <310 <5.0 <5.0 <310 <250 <310 <5.0 <310 9C1-PF30NS <24 <30 <24 UJ <30 <2.0 <2.0 <30 <24 <30 <2.0 <30 DONA <40 <50 <40 UJ <50 <2.0 <2.0 <50 <40 <50 <2.0 <50 N-Ethyl Perfluorooctane Sulfonamidoacetic Acid <130 <160 <130 UJ <160 <5.0 <5.0 <160 <130 <160 <5.0 <160 N-ethylperfluoro-l-octanesulfonamide <87 <110 <87 UJ <110 <2.0 <2.0 <110 <87 <110 <2.0 <110 N-methylperfluoro-l-octanesulfonamide <43 <54 <43 UJ <54 <2.0 <2.0 <54 <43 <54 <2.0 <54 N-Methyl Perfluorooctane Sulfonamidoacetic Acid <120 <150 <120 UJ <150 <5.0 <5.0 <150 <120 <150 <5.0 <150 Perfluorobutane Sulfonic Acid <20 <25 <20 UJ <25 <2.0 <2.0 <25 <20 <25 2.3 <25 Perfluorobutanoic Acid <240 <300 <240 UJ <300 60 43 <300 530 <300 23 <300 Perfluorodecane Sulfonic Acid <32 <40 <32 UJ <40 <2.0 <2.0 <40 <32 <40 <2.0 <40 Perfluorodecanoic Acid <31 <39 <31 UJ <39 <2.0 <2.0 <39 <31 <39 <2.0 <39 Perfluorododecane Sulfonic Acid (PFDoS) <97 <120 <97 UJ <120 <2.0 <2.0 <120 <97 <120 <2.0 <120 Perfluorododecanoic Acid <55 <69 <55 UJ <69 <2.0 <2.0 <69 <55 <69 <2.0 <69 Perfluoroheptane Sulfonic Acid (PFHpS) <19 <24 <19 UJ <24 <2.0 <2.0 <24 <19 <24 <2.0 <24 Perfluoroheptanoic Acid <25 <31 <25 UJ <31 16 18 <31 400 200 J 9.3 <31 Perfluorohexadecanoic Acid (PFHxDA) <89 <110 <89 UJ <110 <2.0 <2.0 <110 <89 <110 <2.0 <110 Perfluorohexane Sulfonic Acid <57 <71 <57 UJ <71 <2.0 <2.0 <71 <57 <71 <2.0 <71 Perfluorohexanoic Acid <58 <73 <58 UJ <73 11 11 <73 140 <73 5.3 <73 Perfluorononanesulfonic Acid <37 <46 <37 UJ <46 <2.0 <2.0 <46 <37 <46 <2.0 <46 Perfluorononanoic Acid <27 <34 UJ <27 UJ <34 <2.0 <2.0 <34 <27 <34 <2.0 <34 Perfluorooctadecanoic Acid <94 <120 <94 UJ <120 <2.0 <2.0 <120 <94 <120 <2.0 <120 Perfluorooctane Sulfonamide <98 <120 <98 UJ <120 <2.0 <2.0 <120 <98 <120 <2.0 <120 Perfluoropentane Sulfonic Acid (PFPeS) <30 <38 <30 UJ <38 <2.0 <2.0 <38 <30 <38 <2.0 <38 Perfluoropentanoic Acid <49 120 55 J --61 120 74 75 J 2,700 1,400 J 40 <61 Perfluorotetradecanoic Acid <73 <91 <73 UJ <91 <2.0 <2.0 <91 <73 <91 <2.0 <91 Perflumotridecanoic Acid <130 <160 <130 UJ <160 <2.0 <2.0 <160 <130 <160 <2.0 <160 Perfluoroundecanoic Acid <110 <140 <110 UJ <140 <2.0 <2.0 <140 <110 <140 <2.0 <140 PFOA <85 <110 <85 UJ <110 2.3 <2.0 <110 <85 <110 17 <110 PFOS <54 <68 <54 UJ <68 <2.0 <2.0 <68 <54 <68 <2.0 <68 Notes: 1 - The EPA Method 537 was modified to incorporate the Table 3+ compounds. Beginning with the 3Q 2023 sampling, perfluoropropionic acid (PFPrA) was added to the compounds list. Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. ng/L - nanograms per liter SOP - standard operating procedure UJ - Analyte not detected. Reporting limit may not be accurate or precise. -- - No data reported < - Analyte not detected above associated reporting limit. TR0795C Page 21 of 24 June 2024 Table 6-2 PFAS Concentrations in Downgradient Groundwater Monitoring Wells Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC METHOD 537 MOD SOP COMPOUNDS LIST' (ng/L) Performance Monitoring Plan Sampling Program (Semi -Annually) OW-55 OW-56 OW-57 PIW-41) CAP1Q23-OW-55- 021623 Sample Date: CAP3Q23-OW-55- 072523 Sample Date: CAP1Q24-OW-55- 020524 Sample Date: CAP1Q23-OW-56- 022123 Sample Date: CAP3Q23-OW-56- 073123 Sample Date: CAP1Q24-OW-56- 020124 Sample Date: CAP1Q23-OW-57- 021523 Sample Date: CAP3Q23-OW-57- 073123 Sample Date: CAP1Q24-OW-57- 020624 Sample Date: CAP3Q23-PIW-4D- 071323 Sample Date: CAP1Q24-PIW-4D- 012224 Sample Date: 10:2 Fluorotelomer sulfonate <2.0 <67 <84 <2.0 <67 <84 <2.0 <67 <84 <2.0 <2.0 11C1-PF3OUdS <2.0 <32 <40 <2.0 <32 <40 <2.0 <32 <40 <2.0 <2.0 1H,1H,2H,2H-perfluorodecanesulfonate (8:2 FTS) <2.0 <46 <58 <2.0 <46 <58 <2.0 <46 <58 <2.0 <2.0 1H,1H,2H,2H-perfluorohexanesulfonate (4:2 FTS) <2.0 <24 <30 <2.0 <24 <30 <2.0 <24 <30 <2.0 <2.0 2-(N-ethyl perfluoro-l-octanesulfonamido)-ethanol <2.0 <85 <110 <2.0 <85 <110 <2.0 <85 <110 <2.0 <2.0 2-(N-methyl perfluoro-l-octanesulfonamido)-ethanol <4.0 <140 <180 <4.0 <140 <180 <4.0 <140 <180 <4.0 <4.0 6:2 Fluorotelomer sulfonate <5.0 <250 <310 <5.0 <250 <310 <5.0 <250 <310 <5.0 <5.0 9C1-PF30NS <2.0 <24 <30 <2.0 <24 <30 <2.0 <24 <30 <2.0 <2.0 DONA <2.0 <40 <50 <2.0 <40 <50 <2.0 <40 <50 <2.0 <2.0 N-Ethyl Perfluorooctane Sulfonamidoacetic Acid <5.0 <130 <160 <5.0 <130 <160 <5.0 <130 <160 <5.0 <5.0 N-ethylperfluoro-l-octanesulfonamide <2.0 <87 <110 <2.0 <87 <110 <2.0 <87 <110 <2.0 <2.0 N-methyl perfluoro-l-octanesulfonamide <2.0 <43 <54 <2.0 <43 <54 <2.0 <43 <54 <2.0 <2.0 N-Methyl Perfluorooctane Sulfonamidoacetic Acid <5.0 <120 <150 <5.0 <120 <150 <5.0 <120 <150 <5.0 <5.0 Perfluorobutane Sulfonic Acid <2.0 <20 <25 2.5 33 <25 4.1 33 <25 <2.0 <2.0 Perfluorobuanoic Acid 18 <240 <300 22 <240 <300 140 <240 <300 <5.0 <5.0 Perfluorodecane Sulfonic Acid <2.0 <32 <40 <2.0 <32 <40 <2.0 <32 <40 <2.0 <2.0 Perfluorodecanoic Acid <2.0 <31 <39 <2.0 <31 <39 <2.0 <31 <39 <2.0 <2.0 Perfluorododecane Sulfonic Acid (PFDoS) <2.0 <97 <120 <2.0 <97 <120 <2.0 <97 <120 <2.0 <2.0 Perfluorododecanoic Acid <2.0 <55 <69 <2.0 <55 <69 <2.0 <55 <69 <2.0 <2.0 Perfluoroheptane Sulfonic Acid (PFHpS) <2.0 <19 <24 <2.0 <19 <24 <2.0 <19 <24 <2.0 <2.0 Perfluoroheptanoic Acid <2.0 <25 <31 3.5 <25 <31 71 86 87 <2.0 <2.0 Perfluorohexadecanoic Acid (PFHxDA) <2.0 <89 <110 <2.0 <89 <110 <2.0 <89 <110 <2.0 <2.0 Perfluorohexane Sulfonic Acid <2.0 <57 <71 <2.0 <57 <71 2.3 <57 <71 <2.0 <2.0 Perfluorohexanoic Acid 2.6 <58 <73 6.7 <58 <73 63 97 84 <2.0 <2.0 Perfluorononanesulfonic Acid <2.0 <37 <46 <2.0 <37 <46 <2.0 <37 <46 <2.0 <2.0 Perfluorononanoic Acid <2.0 <27 <34 <2.0 <27 <34 <2.0 <27 <34 <2.0 <2.0 Perfluorooctadecanoic Acid <2.0 <94 <120 <2.0 <94 <120 <2.0 <94 <120 <2.0 <2.0 Perfluorooctane Sulfonamide <2.0 <98 <120 <2.0 <98 <120 <2.0 <98 <120 <2.0 <2.0 Perfluoropentane Sulfonic Acid (PFPeS) <2.0 <30 <38 <2.0 <30 <38 <2.0 <30 <38 <2.0 <2.0 Perfluoropentanoic Acid 27 <49 <61 44 56 <61 320 380 310 11 14 Perfluorotetradecanoic Acid <2.0 <73 <91 <2.0 <73 <91 <2.0 <73 <91 <2.0 <2.0 Perfluorotridecanoic Acid <2.0 <130 <160 <2.0 <130 <160 <2.0 <130 <160 <2.0 <2.0 Perfluoroundecanoic Acid <2.0 <110 <140 <2.0 <110 <140 <2.0 <110 <140 <2.0 <2.0 PFOA <2.0 <85 <110 2.7 <85 <110 750 1,000 930 <2.0 <2.0 PFOS <2.0 <54 <68 <2.0 <54 <68 <2.0 <54 <68 <2.0 <2.0 Notes: 1 - The EPA Method 537 was modified to incorporate the Table 3+ compounds. Beginning with the 3Q 2023 sampling, perfluoropropionic acid (PFPrA) was added to the compounds list. Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. ng/L - nanograms per liter SOP - standard operating procedure UJ-Analyte not detected. Reporting limit may not be accurate or precise. -- - No data reported < - Analyte not detected above associated reporting limit. TR0795C Page 22 of 24 June 2024 Table 6-2 PFAS Concentrations in Downgradient Groundwater Monitoring Wells Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC METHOD 537MOD SOP COMPOUNDS LIST' (ng/L) Performance Monitoring Plan Sampling Program (Semi -Annually) PIW-5SR PIW-6S PIW-81) PIW-10DR PIW-10S PIW-11 CAP3Q23-PIW-5SR- 080423 Sample Date: Not Sampled in 1Q 2024 (Dry) CAP3Q23-PIW-6S- 071223 Sample Date: CAP1Q24-PIW-6S- 013124 Sample Date: CAP3Q23-PIW-8D- 071123 Sample Date: CAP1Q24-PIW-8D- 012224 Sample Date: CAP3Q23-PIW- IODR-071423 Sample Date: CAP1Q24-PIW- 10DR-012224 Sample Date: CAP3Q23-PIW-10S- 071323 Sample Date: Not Sampled in 1Q 2024 (Dry) CAP3Q23-PIW-11- 073123 Sample Date: CAP1Q24-PIW-11- 020124 Sample Date: 10:2 Fluorotelomer sulfonate <67 <2.0 <84 <2.0 <84 <2.0 <84 <2.0 <67 <84 11C1-PF30UdS <32 <2.0 <40 <2.0 <40 <2.0 <40 <2.0 <32 <40 1H,1H,2H,2H-perfluorodecanesulfonate (8:2 FTS) <46 <2.0 <58 <2.0 <58 <2.0 <58 <2.0 <46 <58 1H,1H,2H,2H-perfluorohexanesulfonate (4:2 FTS) <24 <2.0 <30 <2.0 <30 <2.0 <30 <2.0 <24 <30 2-(N-ethyl perfluoro-l-octanesulfonamido)-ethanol <85 <2.0 <110 <2.0 <110 <2.0 <110 <2.0 <85 <110 2-(N-methylperfluoro-l-octanesulfonamido)-ethanol <140 <4.0 <180 <4.0 <180 <4.0 <180 <4.0 <140 <180 6:2 Fluorotelomer sulfonate <250 <5.0 <310 9.4 <310 <5.0 <310 <5.0 <250 <310 9C1-PF30NS <24 <2.0 <30 <2.0 <30 <2.0 <30 <2.0 <24 <30 DONA <40 <2.0 <50 <2.0 <50 <2.0 <50 <2.0 <40 <50 N-Ethyl Perfluorooctane Sulfonamidoacetic Acid <130 <5.0 <160 <5.0 <160 <5.0 <160 <5.0 <130 <160 N-ethylperfluoro-l-octanesulfonamide <87 <2.0 <110 <2.0 <110 <2.0 <110 <2.0 <87 <110 N-methylperfluoro-l-octanesulfonamide <43 <2.0 <54 <2.0 <54 <2.0 <54 <2.0 <43 <54 N-MethylPerfluorooctane Sulfonamidoacetic Acid <120 <5.0 <150 <5.0 <150 <5.0 <150 <5.0 <120 <150 Perfluorobutane Sulfonic Acid <20 <2.0 <25 <2.0 <25 <2.0 <25 <2.0 29 <25 Perfluorobutanoic Acid 780 150 <300 310 660 130 <300 47 <240 <300 Perfluorodecane Sulfonic Acid <32 <2.0 <40 <2.0 <40 <2.0 <40 <2.0 <32 <40 Perfluorodecanoic Acid <31 <2.0 <39 <2.0 <39 <2.0 <39 <2.0 <31 <39 Perfluorododecane Sulfonic Acid (PFDoS) <97 <2.0 <120 <2.0 <120 <2.0 <120 <2.0 <97 <120 Perfluorododecanoic Acid <55 <2.0 <69 <2.0 <69 <2.0 <69 <2.0 <55 <69 Perfluoroheptane Sulfonic Acid (PFHpS) <19 <2.0 <24 <2.0 <24 <2.0 <24 <2.0 <19 <24 Perfluoroheptanoic Acid 80 23 <31 250 760 76 80 11 <25 <31 Perfluorohexadecanoic Acid (PFHxDA) <89 <2.0 <110 <2.0 <110 <2.0 <110 <2.0 <89 <110 Perfluorohexane Sulfonic Acid <57 <2.0 <71 <2.0 <71 <2.0 <71 <2.0 <57 <71 Perfluorohexanoic Acid <58 17 <73 75 210 29 <73 8.6 <58 <73 Perfluorononanesulfonic Acid <37 <2.0 <46 <2.0 <46 <2.0 <46 <2.0 <37 <46 Perfluorononanoic Acid <27 <2.0 <34 <2.0 <34 <2.0 <34 <2.0 <27 <34 Perfluorooctadecanoic Acid <94 <2.0 <120 <2.0 <120 <2.0 <120 <2.0 <94 <120 Perfluomoctane Sulfonamide <98 <2.0 <120 <2.0 <120 <2.0 <120 <2.0 <98 <120 Perfluoropentane Sulfonic Acid (PFPeS) <30 <2.0 <38 <2.0 <38 <2.0 <38 <2.0 <30 <38 Perfluoropentanoic Acid 1,100 820 760 J 1,700 3,500 350 400 59 63 <61 Perfluorotetradecanoic Acid <73 <2.0 <91 <2.0 <91 <2.0 <91 <2.0 <73 <91 Perfluorotridecanoic Acid <130 <2.0 <160 <2.0 <160 <2.0 <160 <2.0 <130 <160 Perfluoroundecanoic Acid <110 <2.0 <140 <2.0 <140 <2.0 <140 <2.0 <110 <140 PFOA <85 <2.0 <110 2.5 <110 4.1 <110 9.1 <85 <110 PFOS <54 <2.0 <68 <2.0 <68 <2.0 <68 <2.0 <54 <68 Notes: 1 - The EPA Method 537 was modified to incorporate the Table 3+ compounds. Beginning with the 3Q 2023 sampling, perfluoropropionic acid (PFPrA) was added to the compounds list. Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. ng/L - nanograms per liter SOP - standard operating procedure UJ - Analyte not detected. Reporting limit may not be accurate or precise. -- - No data reported < - Analyte not detected above associated reporting limit. TR0795C Page 23 of 24 June 2024 Table 6-2 PFAS Concentrations in Downgradient Groundwater Monitoring Wells Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC METHOD 537 MOD SOP COMPOUNDS LIST' (ng/L) Performance Monitoring Plan Sampling Program (Semi -Annually) Corrective Action Plan Sampling Program (Annually) PIW-15 PW-IORR PW-11 PIW-12 PIW-13 PIW-14 CAP3Q23-PIW-15- 072523 Sample Date: CAP1Q24-PIW-15- 020524 Sample Date: CAP3Q23-PW-10RR- 080323 Sample Date: CAP1Q24-PW-IORR- 013124 Sample Date: CAP3Q23-PW-11-070723 Sample Date: CAP1Q24-PW-11-013124 Sample Date: CAP3Q23-PIW-12- 072423 Sample Date: CAP3Q23-PIW-13- 072423 Sample Date: CAP3Q23-PIW-14- 072423 Sample Date: 10:2 Fluorotelomer sulfonate <67 <84 <67 <84 <2.0 <84 <67 <67 <67 11Cl-PF30UdS <32 <40 <32 <40 <2.0 <40 <32 <32 <32 1H,1H,2H,2H-perfluorodecanesulfonate (8:2 FTS) <46 <58 <46 <58 <2.0 <58 <46 <46 <46 1H,1H,2H,2H-perfluorohexanesulfonate (4:2 FTS) <24 <30 <24 <30 <2.0 <30 <24 <24 <24 2-(N-ethylperfluoro-l-octanesulfonamido)-ethanol <85 <110 <85 <110 <2.0 <110 <85 <85 <85 2-(N-methylperfluoro-l-octanesulfonamido)-ethanol <140 <180 <140 <180 <4.0 <180 <140 <140 <140 6:2 Fluorotelomer sulfonate <250 <310 <250 <310 <5.0 <310 <250 <250 <250 9C1-PF30NS <24 <30 <24 <30 <2.0 <30 <24 <24 <24 DONA <40 <50 <40 <50 <2.0 <50 <40 <40 <40 N-Ethyl Perfluorooctane Sulfonamidoacetic Acid <130 <160 <130 <160 <5.0 <160 <130 <130 <130 N-ethylperfluoro-l-octanesulfonamide <87 <110 <87 <110 <2.0 <110 <87 <87 <87 N-methylperfluoro-l-octanesulfonamide <43 <54 <43 <54 <2.0 <54 <43 <43 <43 N-MethylPerfluorooctane Sulfonamidoacetic Acid <120 <150 <120 <150 <5.0 <150 <120 <120 <120 Perfluorobutane Sulfonic Acid <20 <25 <20 <25 2.1 <25 <20 <20 <20 Perfluorobutanoic Acid <240 <300 <240 <300 100 <300 <240 <240 <240 Perfluorodecane Sulfonic Acid <32 <40 <32 <40 <2.0 <40 <32 <32 <32 Perfluorodecanoic Acid <31 <39 <31 <39 <2.0 <39 <31 <31 <31 Perfluorododecane Sulfonic Acid (PFDoS) <97 <120 <97 <120 <2.0 <120 <97 <97 <97 Perfluorododecanoic Acid <55 <69 <55 <69 <2.0 <69 <55 <55 <55 Perfluoroheptane Sulfonic Acid (PFHpS) <19 <24 <19 <24 <2.0 <24 <19 <19 <19 Perfluoroheptanoic Acid <25 <31 <25 <31 100 1101 <25 <25 <25 Perfluorohexadecanoic Acid (PFHxDA) <89 <110 <89 <110 <2.0 <110 <89 <89 <89 Perfluorohexane Sulfonic Acid <57 <71 <57 <71 2.8 <71 <57 <57 <57 Perfluorohexanoic Acid <58 <73 <58 <73 26 <73 <58 <58 <58 Perfluorononanesulfonic Acid <37 <46 <37 <46 <2.0 <46 <37 <37 <37 Perfluorononanoic Acid <27 <34 <27 <34 22 <34 <27 <27 <27 Perfluorooctadecanoic Acid <94 <120 <94 <120 <2.0 <120 <94 <94 <94 Perfluorooctane Sulfonamide <98 <120 <98 <120 <2.0 <120 <98 <98 <98 Perfluoropentane Sulfonic Acid (PFPeS) <30 <38 <30 <38 <2.0 <38 <30 <30 <30 Perfluoropentanoic Acid 140 120 710 520 J 420 230 J <49 <49 80 Perfluorotetradecanoic Acid <73 <91 <73 <91 <2.0 <91 <73 <73 <73 Perfluorotridecanoic Acid <130 <160 <130 <160 <2.0 <160 <130 <130 <130 Perfluoroundecanoic Acid <110 <140 <110 <140 <2.0 <140 <110 <110 <110 PFOA <85 <110 <85 <110 42 <110 <85 <85 <85 PFOS <54 <68 <54 <68 4.7 <68 <54 <54 <54 Notes: 1 - The EPA Method 537 was modified to incorporate the Table 3+ compounds. Beginning with the 3Q 2023 sampling, perfluoropropionic acid (PFPrA) was added to the compounds list. Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. ng/L - nanograms per liter SOP - standard operating procedure UJ — Analyte not detected. Reporting limit may not be accurate or precise. -- - No data reported < - Analyte not detected above associated reporting limit. TR0795C Page 24 of 24 June 2024 Table 6-3 Willis Creek PFAS Analytical Results Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC Jul 18 (0.00) Nov 6 (0.00) Feb 22 (0.00) May 9 (0.00) Jul 24 (0.20) Nov 20 (0.00) Feb 19 (0.00) Jul 18 (0.00) Nov 6 (0.00) Feb 22 (0.00) May 9 (0.00) Jul 24 (0.20) Nov 20 (0.00) Feb 19 (0.00) dent Daily Total Rainfall (inches): Jul 19 (0.10) Nov 7 (0.00) Feb 23 (0.00) May 10 (0.00) Jul 25 (0.00) Nov 21(0.41) Feb 20 (0.00) Jul 19 (0.10) Nov 7 (0.00) Feb 23 (0.00) May 10 (0.00) Ju125 (0.00) Nov 21(0.41) Feb 20 (0.00) Jul 20 (0.47) Nov 8 (0.00) Feb 24 (0.01) May 11 (0.00) Jul 26 (0.00) Nov 22 (1.26) Feb 21 (0.00) Jul 20 (0.47) Nov 8 (0.00) Feb 24 (0.01) May 11(0.00) Jul 26 (0.00) Nov 22 (1.26) Feb 21(0.00) D 537 MOD SOP COMPOUNDS LIST' (aglE) (7FMOAA WC-1 WC-2 CAP3Q22-WC-1-24- 072122 Sample Date: 21-Jul-22 CAP4Q22-WC-1-24- 110922 Sample Date: 9-Nov-22 CAP1Q23-WC-1-24- 022523 Sample Date: 25-Feb-23 CAP2Q23-WC-1-24- 051223 Sample Date: 12-May-23 CAP3Q23-WC-1-24- 072723 Sample Date: 27-Jul-23 CAP4Q23-WC-1- 112323 Sample Date: 23-Nov-23 CAP1Q24-WC-1-24- 022224 Sample Date: 22-Feb-24 CAP3Q22-WC-2-24- 072122 Sample Date: 21-Jul-22 CAP4Q22-WC-2-22- 110922 Sample Date: 9-Nov-22 CAP1Q23-WC-2-24- 022523 Sample Date: 25-Feb-23 CAP2Q23-WC-2-24- 051223 Sample Date: 12-May-23 CAP3Q23-WC-2-24- 072723 Sample Date: 27-Jul-23 CAP4Q23-WC-2- 112323 Sample Date: 23-Nov-23 CAP1Q24-WC-2-24- 022224 Sample Date: 22-Feb-24 560 580 310 430 360 89 J 240 320 490 180 290 260 120 160 1,300 1,900 480 830 970 200 420 250 1,000 300 360 610 290 J 250 650 960 280 500 500 150 310 250 640 160 280 350 190 J 180 PFO3OA 130 160 45 90 87 23 J 57 40 89 21 42 55 27 25 PFO4DA 25 29 10 15 16 5.4 J 9.4 12 17 4.5 8.2 10 5.3 4.8 PFO5DA <3.9 <7.8 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 PMPA 640 790 340 430 490 170 290 330 570 240 310 410 230 J 200 PEPA 150 200 74 120 120 45 72 70 150 52 86 92 48 J 41 PS Acid <2.0 2.6 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 Hydro -PS Acid 14 14 8 11 12 5.2 7.3 12 11 7.2 8.2 9.5 6.1 6.6 R-PSDA 42J 36J 30J 86J 170J 111 36J 26J 31J 181 49J 96J 9.4J 12J Hydrolyzed PSDA 230 J 230 J 190 J 380 J 290 J 28 J 160 J 44 J 130 J 28 J 44 J 75 J 20 J 14 J R-PSDCA <2.0 <2.0 <2.0 <2.0 <3.0 <3.0 <3.0 <2.0 <2.0 <2.0 <2.0 <3.0 <3.0 <3.0 NVHOS, Acid Form 21 30 14 20 25 3.8 15 8.3 19 5.7 8.6 16 5.7 J 5.7 EVE Acid <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 Hydro -EVE Acid 9.9 13 5.1 6.7 7.4 <2.0 4 4.5 12 <2.0 3.1 2.2 2.2 2.1 R-EVE 24J 16J 14J 38J 59J 5.9J 18J 9.4J 191 9.6J 28J 41J 7.4J 7.7J Perfluoro(2-ethoxyethane)sulfonic Acid <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 UJ <2.0 PFECA B <2.0 <2.7 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 PFECA-G <2.4 <4.8 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 PFPrA 770 250 530 570 340 J 320 Total Table 3+ (17 compounds)2,3 it 3,500 4,680 1,570 2,450 2,590 691 1,420 1,300 3,000 970 1,400 1,810 9 875 Total Table 3+ (18 compounds)"" - - - - 3,360 941 1,950 - - - - 2,380 1,260 1,200 Total Table 3+ (21 compounds)"' mom- - - - 3,880 1986 12,170 1- - - - 2,600 11,300 11,230 Notes: 1 - The EPA Method 537 was modified to incorporate the Table 3+ compounds. Beginning with the July 27, 2023 sampling, perfluoropropionic acid (PFPrA) was added to the compounds list. 2 - Total Table 3+ was calculated including J qualified data but not non -detect data. The total Table 3+ sum is rounded to three significant figures. 3 - Total Table 3+ (17 Compounds) does not include R-PSDA, Hydrolyzed PSDA, R-EVE, and PFPrA. 4 - Total Table 3+ (18 compounds) does not include R-PSDA, Hydrolyzed PSDA, and R-EVE. 5 - Total Table 3+ (21 compounds) is the sum of all Table 3+ PFAS compounds. Precipitation data obtained from USGS gauge #02105500 at the William O. Huske Lock and Dam. Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. UJ - Analyte not detected. Reporting limit may not be accurate or precise. ng/L - nanograms per liter SOP - standard operating procedure -- - No data reported < - Analyte not detected above associated reporting limit. TR0795C Page 1 of 4 June 2024 Table 6-3 Willis Creek PFAS Analytical Results Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC Antecedent Daily Total Rainfall (inches): Jul 18 (0.00) Nov 6 (0.00) Feb 22 (0.00) May 9 (0.00) Jul 24 (0.20) Nov 20 (0.00) Feb 19 (0.00) Jul 19 (0.10) Nov 7 (0.00) Feb 23 (0.00) May 10 (0.00) Jul25 (0.00) Nov 21(0.41) Feb 20 (0.00) Jul 20 (0.47) Nov 8 (0.00) Feb 24 (0.01) May 11(0.00) Jul 26 (0.00) Nov 22 (1.26) Feb 21(0.00) METHOD 537 MOD SOP COMPOUNDS LIST' (aglE) WC-3 CAP3Q22-WC-3-24- 072122 Sample Date: 21-Jul-22 CAP4Q22-WC-3-24- 110922 Sample Date: 9-Nov-22 CAP1Q23-WC-3-24- 022523 Sample Date: 25-Feb-23 CAP2Q23-WC-3-24- 051223 Sample Date: 12-May-23 CAP3Q23-WC-3-24- 072723 Sample Date: 27-Jul-23 CAP4Q23-WC-3- 112323 Sample Date: 23-Nov-23 CAP1Q24-WC-3-24- 022224 Sample Date: 22-Feb-24 Hfpo Dimer Acid 180 190 100 150 130 49 50 J PFM0, 45 72 35 55 58 25 22 J PFO2HxA 140 190 74 130 140 61 44 J PFO3OA 19 21 8.7 16 19 7.6 <8.9 PFO4DA 5.3 4.8 2.1 3.5 5.1 2.2 <4.0 PFO5DA <2.0 <2.0 <2.0 <2.0 2.1 <2.0 <10 PMPA 230 260 160 190 200 120 83 J PEPA 45 70 32 53 50 24 31 PS Acid <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <4.0 Hydro -PS Acid 9.3 7.8 6.5 6.8 7.8 4.2 <4.4 R-PSDA <2.0 12J 151 32J 65J 4.3J 3.3J Hydrolyzed PSDA <2.0 <2.0 <2.0 <2.0 7.6 J <2.0 <2.7 R-PSDCA <2.0 <2.0 <2.0 <2.0 <3.0 <3.0 <14 NVHOS, Acid Form 4.6 3.2 2.5 2.8 <3.0 <3.0 <13 EVE Acid <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <4.0 Hydro -EVE Acid <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.4 R-EVE 5.6J 6.1J 7.5J 16J 23J 2.7J <3.1 Perfluoro(2-ethoxyethane)sulfomc Acid <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.9 PFECA B <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <6.2 PFECA-G <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.9 PFPrA - - - 280 150 210 Total Table 3+ (17 compounds)2,3 678 819 612 293 230 Total Table 3+ (18 compounds)2'0 - - - - 892 443 440 Total Table 3+ (21 compounds)a's - - - - 988 450 443 Notes: 1 - The EPA Method 537 was modified to incorporate the Table 3+ compounds. Beginning with the July 27, 2023 sampling, perfluoropropionic acid (PFPrA) was added to the compounds list. 2 - Total Table 3+ was calculated including J qualified data but not non -detect data. The total Table 3+ sum is rounded to three significant figures. 3 - Total Table 3+ (17 Compounds) does not include R-PSDA, Hydrolyzed PSDA, R-EVE, and PFPrA. 4 - Total Table 3+ (18 compounds) does not include R-PSDA, Hydrolyzed PSDA, and R-EVE. 5 - Total Table 3+ (21 compounds) is the sum of all Table 3+ PFAS compounds. Precipitation data obtained from USGS gauge #02105500 at the William O. Huske Lock and Dam. Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. UJ - Analyte not detected. Reporting limit may not be accurate or precise. ng/L - nanograms per liter SOP - standard operating procedure -- - No data reported < - Analyte not detected above associated reporting limit. TR0795C Page 2 of 4 June 2024 Table 6-3 Willis Creek PFAS Analytical Results Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC Jul18 (0.00) Nov 6 (0.00) Feb 22 (0.00) May 9 (0.00) Jul 24 (0.20) Nov 20 (0.00) Feb 19 (0.00) Jul 18 (0.00) Nov 6 (0.00) Feb 22 (0.00) May 9 (0.00) Ju124 (0.20) Nov 20 (0.00) Feb 19 (0.00) Antecedent Daily Total Rainfall (inches): Jul 19 (0.10) Nov 7 (0.00) Feb 23 (0.00) May 10 (0.00) Jul25 (0.00) Nov 21 (0.41) Feb 20 (0.00) Jul 19 (0.10) Nov 7 (0.00) Feb 23 (0.00) May 10 (0.00) Jul25 (0.00) Nov 21 (0.41) Feb 20 (0.00) Jul 20 (0.47) Nov 8 (0.00) Feb 24 (0.01) May 11 (0.00) Jul 26 (0.00) Nov 22 (1.26) Feb 21 (0.00) Jul 20 (0.47) Nov 8 (0.00) Feb 24 (0.01) May 11 (0.00) Jul 26 (0.00) Nov 22 (1.26) Feb 21 (0.00) METHOD 537MOD SOP COMPOUNDS LIST' (ng,E) WC-1 WC-2 CAP3Q22-WC-1-24- 072122 Sample Date: 21-Jul-22 CAP4Q22-WC-1-24- 110922 Sample Date: 9-Nov-22 CAP1Q23-WC-1-24- 022523 Sample Date: 25-Feb-23 CAP2Q23-WC-1-24- 051223 Sample Date: 12-May-23 CAP3Q23-WC-1-24- 072723 Sample Date: 27-Jul-23 CAP4Q23-WC-1- 112323 Sample Date: 23-Nov-23 CAP1Q24-WC-1-24- 022224 Sample Date: 22-Feb-24 CAP3Q22-WC-2-24- 072122 Sample Date: 21-Jul-22 CAP4Q22-WC-2-22- 110922 Sample Date: 9-Nov-22 CAP1Q23-WC-2-24- 022523 Sample Date: 25-Feb-23 CAP2Q23-WC-2-24- 051223 Sample Date: 12-May-23 CAP3Q23-WC-2-24- 072723 Sample Date: 27-Jul-23 CAP4Q23-WC-2- 112323 Sample Date: 23-Nov-23 CAP1Q24-WC-2-24- 022224 Sample Date: 22-Feb-24 10:2 Fluorotelomer sulfonate <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 UJ <2.0 11C1-PF3OUdS <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 UJ <2.0 1H,1H,2H,2H-perfluorodecanesulfonate (8:2 FTS) <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 1H,1H 2H,2H-perfluorohexanesulfonate (4:2 FTS) <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 2-(N-ethyl perfluoro-l-octanesulfonamido)-ethanol <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 2-(N-methylperfluoro-l-octanesulfonamido)-ethanol <4.0 <4.0 <4.0 <4.0 <4.0 <4.0 <4.0 <4.0 <4.0 <4.0 <4.0 <4.0 <4.0 <4.0 6:2 Fluorotelomer sultanate <5.0 <5.0 <5.0 <5.0 <5.0 <5.0 <5.0 <5.0 <5.0 <5.0 <5.0 <5.0 <5.0 <5.0 9C1-PF3ONS <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 UJ <2.0 DONA <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 UJ <2.0 N-Ethyl Perfluorooctane Sulfonamidoacetic Acid <5.0 <5.0 <5.0 <5.0 <5.0 <5.0 <5.0 <5.0 <5.0 <5.0 <5.0 <5.0 <5.0 UJ <5.0 N-ethylperfluoro-l-octanesulfonamide <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 N-methyl perfluoro-l-octanesulfonamide <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 N-Methyl Perfluorooctane Sulfonamidoacetic Acid <5.0 <5.0 <5.0 <5.0 <5.0 <5.0 <5.0 <5.0 <5.0 <5.0 <5.0 <5.0 <5.0 UJ <5.0 Perfluorobutane Sulfonic Acid 4.6 3.9 4.4 4.6 4.9 3.7 5.7 4.4 3.6 4.5 4.6 4.6 4.7 J 6.2 Perfluorobutanoic Acid 6.6 9.1 7 6.3 9 <5.0 5.2 <5.0 10.0 <5.0 <5.0 7.6 <5.0 UJ <5.0 Perfluorodecane Sulfonic Acid <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 UJ <2.0 Perfluorodecanoic Acid <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 UJ <2.0 Perfluorododecane Sulfonic Acid (PFDoS) <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 UJ <2.0 Perfluorododecanoic Acid <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 UJ <2.0 Perfluoroheptane Sulfonic Acid (PFHpS) <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 Perfluoroheptanoic Acid 2.4 2.9 <2.0 2.4 2.4 <2.0 <2.0 <2.0 2.4 <2.0 <2.0 2.0 <2.0 <2.0 Perfluorohexadecanoic Acid (PFHxDA) <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <8.9 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <8.9 Perfluorohexane Sulfonic Acid <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 Perfluorohexanoic Acid 3.5 4.1 2.8 3.7 4.3 <2.0 3.1 3.0 3.9 2.6 3.1 3.8 2.3 2.8 Perfluorononanesulfonic Acid <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 UJ <2.0 Perfluorononanoic Acid <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 Perfluomoctadecanoic Acid <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <9.4 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <9.4 Perfluorooctane Sulfonamide <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 Perfluoropentane Sulfonic Acid (PFPeS) <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 UJ <2.0 Perfluoropentanoic Acid 13 13 7.8 11 9.9 3.4 6.7 8.8 13.0 5.0 7.3 8.1 5.1 J 4.7 Perfluorotetradecanoic Acid <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 UJ <2.0 Perfluorotridecanoic Acid <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 UJ <2.0 Perfluoroundecanoic Acid <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 UJ <2.0 PFOA 9.7 10 5.8 7.7 7.2 2.1 5.1 3.4 5.1 2.8 3.1 5.6 2.3 2.7 PFOS 2.5 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 2.0 J <2.0 Notes: 1 - The EPA Method 537 was modified to incorporate the Table3+ compounds. Beginning with the July 27, 2023 sampling, perfluoropropionic acid (PFPrA) was added to the compounds list. Precipitation data obtained from USGS gauge #02105500 at the William 0. Huske Lock and Dam. Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. UJ - Analyte not detected. Reporting limit may not be accurate or precise. ng/L - nanograms per liter SOP - standard operating procedure <- Analyte not detected above associated reporting limit. TR0795C Page 3 of 4 June 2024 Table 6-3 Willis Creek PFAS Analytical Results Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC Antecedent Daily Total Rainfall (inches): Jul18 (0.00) Nov 6 (0.00) Feb 22 (0.00) May 9 (0.00) Jul 24 (0.20) Nov 20 (0.00) Feb 19 (0.00) Jul19 (0.10) Nov 7 (0.00) Feb 23 (0.00) May 10 (0.00) Jul25 (0.00) Nov 21 (0.41) Feb 20 (0.00) Jul 20 (0.47) Nov 8 (0.00) Feb 24 (0.01) May 11 (0.00) Jul 26 (0.00) Nov 22 (1.26) Feb 21 (0.00) METHOD 537MOD SOP COMPOUND, LIST' (nglL) WC-3 CAP3Q22-WC-3-24- 072122 Sample Date: 21-Jul-22 CAP4Q22-WC-3-24- 110922 Sample Date: 9-Nov-22 CAP1Q23-WC-3-24- 022523 Sample Date: 25-Feb-23 CAP2Q23-WC-3-24- 051223 Sample Date: 12-May-23 CAP3Q23-WC-3-24- 072723 Sample Date: 27-Jul-23 CAP4Q23-WC-3- 112323 Sample Date: 23-Nov-23 CAP1Q24-WC-3-24- 022224 Sample Date: 22-Feb-24 10:2 Fluorotelomer sulfonate <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <6.7 11C1-PF3OUdS <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <3.2 1H,1H,2H,2H-perfluorodecanesulfonate (8:2 FTS) <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <4.6 1H,1H,2H,2H-perfluorohexanesulfonate (4:2 FTS) <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.4 2-(N-ethyl perfluoro-l-octanesulfonamido)-ethanol <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <8.5 2-(N-methyl perfluoro-l-octanesulfonamido)-ethanol <4.0 <4.0 <4.0 <4.0 <4.0 <4.0 <14 6:2 Fluorotelomer sulfonate <5.0 <5.0 <5.0 <5.0 <5.0 <5.0 <25 9Cl-PF3ONS <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.4 DONA <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <4.0 N-Ethyl Perfluorooctane Sulfonamidoacetic Acid <5.0 <5.0 <5.0 <5.0 <5.0 <5.0 UJ <13 N-ethylperfluoro-l-octanesulfonamide <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <8.7 N-methylperfluoro-l-octanesulfonamide <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <4.3 N-Methyl Perfluorooctane Sulfonamidoacetic Acid <5.0 <5.0 <5.0 <5.0 <5.0 <5.0 <12 Perfluorobutane Sulfonic Acid 4.7 3.1 4.6 4.3 4.6 3.5 4.3 J Perfluorobutanoic Acid <5.0 <5.0 <5.0 <5.0 5.8 <5.0 <24 Perfluorodecane Sulfonic Acid <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <3.2 Perfluorodecanoic Acid <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <3.1 Perfluorododecane Sulfonic Acid (PFDoS) <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <9.7 Perfluorododecanoic Acid <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <5.5 Perfluoroheptane Sulfonic Acid (PFHpS) <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 Perfluorohepanoic Acid <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.5 Perfluorohexadecanoic Acid (PFHxDA) <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <8.9 Perfluorohexane Sulfonic Acid <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <5.7 Perfluorohexanoic Acid 2.6 2.3 2.1 2.7 3.0 <2.0 <5.8 Perfluorononanesulfonic Acid <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <3.7 Perfluorononanoic Acid <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.7 Perfluorooctadecanoic Acid <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <9.4 Perfluorooctane Sulfonamide <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <9.8 Perfluoropentane Sulf ntic Acid (PFPeS) <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <3.0 Perfluoropentanoic Acid 5.5 4.5 3.6 5.1 4.9 2.6 <4.9 Perfluorotetradecanoic Acid <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <7.3 Perfluorotridecanoic Acid <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <13 Perfluoroundecanoic Acid <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <11 PFOA 2.4 <2.0 <2.0 <2.0 2.1 <2.0 <8.5 PFOS 2.3 <2.0 <2.0 <2.0 <2.0 <2.0 <5.4 Notes: 1 - The EPA Method 537 was modified to incorporate the Table3+ compounds. Beginning with the July 27, 2023 sampling, perfluoropropionic acid (PFPrA) was added to the compounds list. Precipitation data obtained from USGS gauge 902105500 at the William O. Huske Lock and Dam. Bold - Analyte detected above associated reporting limit. J - Analyte detected. Reported value may not be accurate or precise. UJ - Analyte not detected. Reporting limit may not be accurate or precise. ng/L - nanograms per liter SOP - standard operating procedure <- Analyte not detected above associated reporting limit. TR0795C Page 4 of 4 June 2024 Table 6-4 Willis Creek PFAS Mass Discharge Quarterly Report #5 (Jan - Mar 2024) Chemours Fayetteville Works Fayetteville, NC Sample Date Willis Creek Flow (ft3/sec) Total Table 3+ Concentration (17 compounds) (ng/L) PFAS Mass Discharge (Total Table 3+ 17 compounds) (mg/sec) A PFAS Mass Discharge (Total Table 3+ 17 compounds) (mg/sec) WC-2 WC-1 WC-2 WC-1 A WC-2 TO WC-1 21-Jul-22 5.0 1,300 3,500 0.18 0.49 0.31 9-Nov-22 3.4 3,000 4,700 0.29 0.45 0.16 25-Feb-23 11.5 970 1,600 0.32 0.52 0.21 14-Mar-23 Startup of the Groundwater Extraction and Conveyance (GWEC) System 12-May-23 3.5 1,400 2,500 0.14 0.25 0.11 27-Jul-23 2.8 1,800 2,600 0.14 0.20 0.06 23-Nov-23 15.5 920 690 0.40 0.30 -0.10 22-Feb-24 7.3 875 1,420 0.18 0.29 0.11 Notes: 1 - Willis Creek (WC) flow was measured using the Marsh-McBirney method. Flow measurements were made at location WC-1 on the same day as analytical sampling, except for the February 25, 2023 and February 22, 2024 sampling events. For the February 25, 2023 event, flow was measured at WC-6 on February 13, 2023. For the February 22, 2024 event, flow was measured at WC-1 on February 21, 2024, a day earlier than analytical sampling. 2 - The total Table 3+ concentration (17 compounds) is rounded to two significant figures. Presented values of flow and mass discharge are limited to 1 and 2 decimal places, respectively. 3 - WC-2 is located approximately at the upgradient end of the long-term remedy alignment, and WC-1 is located approximately near the confluence with the Cape Fear River. ft3/sec - cubic foot per second A - delta or change ng/L - nanograms per liter mg/sec - milligrams per second TR0795C Page 1 of 1 June 2024 Geosyntec consultants Figures Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 TR0795C River Elevation During First Quarter (01/01/2024 through 03/31/2024) - Seep A 55 50 00 00 0 a z 45 a� v NTop of Wall a 40 Spillway O Top of GAC ca +, --------------------------------------- Discharge v Weir 35 Discharge 0 Invert r6 v w 30 25 1/1/2024 1/16/2024 1/31/2024 2/15/2024 3/1/2024 3/16/2024 3/31/2024 Legend River ...... GAC Changeout River Level During Reporting Period & FTC As -Built Elevations - Seep A Notes: Chemours Fayetteville Works As -built survey information for Seep A from Donaldson Garrett & Associates July 2021. Fayetteville, North Carolina River elevation from USGS Huske Lock and Dam site 02105500, converted to NAVD88. Figure FB1/FB2 = Filter Bed 1/Filter Bed 2 Geosyntec° co.­ea„rs of NC, PC NC WCense No C3500—C 295 GAC = Granular Activated Carbon consultants FTC = Flow -Through Cell 2-1A Raleigh, NC June 2024 55 50 00 00 0 a z 45 a� v a N a 40 O ca a� v 35 0 r6 v w 30 River Elevation During First Quarter (01/01/2024 through 03/31/2024) - Seep 6 Seep B - FB1 Top of Wall ----------------------------------------------------------------------------------.---------------------------------------------- Spillway Top of GAC Discharge Weir Discharge Invert 25 1 1/1/2024 Legend River ...... GAC Changeout 1/16/2024 1/31/2024 Notes: As -built survey information for Seep B from Donaldson Garrett & Associates July 2021. River elevation from USGS Huske Lock and Dam site 02105500, converted to NAVD88. FB1/FB2 = Filter Bed 1/Filter Bed 2 GAC = Granular Activated Carbon FTC = Flow -Through Cell 2/15/2024 3/1/2024 3/16/2024 3/31/2024 55 50 00 00 0 a z 45 a� v a N a 40 O ca a� v 35 O r6 N w 30 25 River Elevation During First Quarter (01/01/2024 through 03/31/2024) - Seep C Seep C - F131 Top of Wall -----•----------------------------------------------------------------------------------------------------------------------------------------------- Spillway Top of GAC ------------------------------------- Discharge Weir Discharge Invert 1/1/2024 Legend River ...... GAC Changeout 1/16/2024 1/31/2024 Notes: As -built survey information for Seep C from RMA Surveying October 2020. River elevation from USGS Huske Lock and Dam site 02105500, converted to NAVD88. FB1/FB2 = Filter Bed 1/Filter Bed 2 GAC = Granular Activated Carbon FTC = Flow -Through Cell 2/15/2024 3/1/2024 3/16/2024 3/31/2024 55 50 00 00 0 a z 45 a� v a N a 40 O ca a� 35 O r6 v w 30 25 1 1/1/2024 Legend River ...... GAC Changeout 1/16/2024 River Elevation During First Quarter (01/01/2024 through 03/31/2024) - Seep D . Seep D - FB2 1/31/2024 Notes: As -built survey information for Seep D from Donaldson Garrett & Associates July 2021. River elevation from USGS Huske Lock and Dam site 02105500, converted to NAVD88. FB1/FB2 = Filter Bed 1/Filter Bed 2 GAC = Granular Activated Carbon FTC = Flow -Through Cell 2/15/2024 3/1/2024 3/16/2024 Top of Wall Spillway Top of GAC Discharge Weir Discharge Invert 3/31/2024 i i 600 500 E 400 a) c� 0 `L 300 200 100 LAI 0 LN I I 1 11 1 It �t �t t �t �t N N N N N N N N r N N N N N N N N N N N N N -i LLn (n M N .\-I Lf Q\1 N W O 0000 N W c\-I LL l O\1 M n -i L 1 M N N N \ \ -I c-I -i N N \ \ \ -i c-I N N N \ \ \ \ \ N N \ \ \ \ \ M M M \ \ \ \ \ N N N N N M M M M M Legend Measured Discharge Flowrate 0 Pumping Flowrate 0 FTC off, no flow 0 Cape Fear River Above Discharge Weir Elevation FTC Discharge Flowrate Notes: (Jan - Mar 2024) - Seep A gpm - gallons per minute Chemours Fayetteville Works Batch mode (in which the FTC is closed to flow due to dry conditions) is designated with orange shading. Fayetteville, North Carolina This figure depicts two types of processing: (1) Passive flow through the system is calculated using the Effluent Stilling Basin transducer data (solid green). (2) Periodically during batch mode, the impoundment was pumped into the filter beds through a flowmeter skid; the approximate flow rate during intermittent pumping is shown with blue diamond symbols. GeosynCeCC GeoVntecConsultantsofNC,P.C. Figure From Jan. 10 to 18 and March 29 to 31, 2024, the Cape Fear River rose above the elevation of the discharge weir (W3), and head differentials throughout the flow -through cell were reduced and consultants NC License No.: C 3500 and C 295 flow through the system was hindered (pink shading). See section 2.3.5 for more details. 2-2A FTC - Flow -Through Cell Raleigh, NC June 2024 600 500 E 400 a) c� 0 `L 300 200 100 LAI 0 LN I I 1 11 1 It �t �t t �t �t N N N N N N N N r N N N N N N N N N N N N N -i LLn (n M N .\-I Lf Q\1 N W O 0000 N W c\-I LL l O\1 M n -i L 1 M N N N \ \ -I c-I -i N N \ \ \ -i c-I N N N \ \ \ \ \ N N \ \ \ \ \ M M M \ \ \ \ \ N N N N N M M M M M Legend Measured Discharge Flowrate 0 Pumping Flowrate 0 FTC off, no flow 0 Cape Fear River Above Discharge Weir Elevation FTC Discharge Flowrate Notes: (Jan - Mar 2024) - Seep A gpm - gallons per minute Chemours Fayetteville Works Batch mode (in which the FTC is closed to flow due to dry conditions) is designated with orange shading. Fayetteville, North Carolina This figure depicts two types of processing: (1) Passive flow through the system is calculated using the Effluent Stilling Basin transducer data (solid green). (2) Periodically during batch mode, the impoundment was pumped into the filter beds through a flowmeter skid; the approximate flow rate during intermittent pumping is shown with blue diamond symbols. GeosynCeCC GeoVntecConsultantsofNC,P.C. Figure From Jan. 10 to 18 and March 29 to 31, 2024, the Cape Fear River rose above the elevation of the discharge weir (W3), and head differentials throughout the flow -through cell were reduced and consultants NC License No.: C 3500 and C 295 flow through the system was hindered (pink shading). See section 2.3.5 for more details. 2-2A FTC - Flow -Through Cell Raleigh, NC June 2024 600 - 500 400 v c� L _0 `_ 300 TIM 200 100 I 0 N N N N N (14 N N N N N N N N N N N N N N N N N a 1 U) Q\1 M -i Lr a) N lOO O 1;t 0000 N Q0 -i Lr)r) Q\1 M � 1 Lr a) \ \ \ -i -i N N N \ \ . 1 rA rA N N \ \ N N \ \ \ \ \ M M \ rA M \ -i N N N \ \ \ \ c-I r-I r-I r-I r-I N N N N N M M M M M Legend Measured Discharge Flowrate p FTC off, no flow p Cape Fear River Above Discharge Weir Elevation Notes: FTC Discharge Flowrate gpm - gallons per minute (Jan - Mar 2024) - Seep B Batch mode (in which the FTC is closed to flow due to dry conditions) is designated with orange shading. Chemours Fayetteville works This figure depicts the measured discharge flowrate (solid green) of water processed through the filter beds calculated using the Effluent Stilling Basin transducer data. Fayetteville, North Carolina From Jan. 10 to 17 and March 29 to 31, 2024, the Cape Fear River rose above the elevation of the discharge weir (W3), and head differentials throughout the flow -through cell were reduced and Figure flow through the system was hindered (pink shading). See section 2.3.5 for more details. Geosyntec° Geusym[ecCunsul[zntsufNC,PC. NC License No.: C 3500 and C 295 FTC - Flow -Through Cell consultants 2-2B Raleigh, NC June 2024 500 450 400 350 I Q 300 a� Ica � 0 250 — I — 200 — 150 100 — — 50 0 0 - N N N N N N N N N N N N N N N N N N N N N N N c\-I LLn m M .\-I LLn a N L\D O 00 N �.O\-I LLn a) M �\-I LLn 01 N N N \ \ c-I rl r-i N N \ \ \ \ \ \ \ \ N N \ \ \ \ \ M M M c 1 \ c-I N N N \ \ \ \ rl ci ci c-I c-I N N N N N M M M M M Legend Measured Discharge Flowrate Pumping Flowrate p FTC off, no flow 0 Cape Fear River Above Discharge Weir Notes: FTC Discharge Flowrate gpm - gallons per minute (Jan - Mar 2024) - Seep C Batch mode (in which the FTC is closed to flow due to dry conditions) is designated with orange shading. Chemours Fayetteville works This figure depicts two types of processing: (1) Passive flow through the system is calculated using the Effluent Stilling Basin transducer data (solid green). (2) Periodically during batch mode, the Fayetteville, North Carolina impoundment was pumped into the filter beds through a flowmeter skid; the approximate flow rate during intermittent pumping is shown with blue diamond symbols. Geosynt onsultants of NC, P.C. Figure CNo.:C3500andC295 From Jan. 10 to 17 and March 30 to 31, 2024, the Cape Fear River rose above the elevation of the discharge weir (W3), and head differentials throughout the flow -through cell were reduced NCL nsetec and flow through the system was hindered (pink shading). See section 2.3.5 for more details. consultants nts 2-2C FTC - Flow -Through Cell Raleigh, NC June 2024 200 180 - 160 - 140 a 120 — a- cv L 0 100 LL N 80 PI 60 40 20 — — 0 N rV fV N N N N N N N N N N N N N N N N N N N N \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ rl Ln Ol M r" ri Ln a) rV l0 O 00 N l0 r-I Ln Ol M Ln 61 \ \ \ r I c I N N (V \ \ c I c I r N N \ \ \ r-I —I N N N N N \ \ \ \ \ M M M \ \ \ \ \ r-I r-I ri r-I r-I N N N N N M M M M M Legend Measured Discharge Flowrate p FTC off, no flow p Cape Fear River Above Discharge Weir Elevation Notes: FTC Discharge Flowrate gpm - gallons per minute (Jan - Mar 2024) - Seep D Batch mode (in which the FTC is closed to flow due to dry conditions) is designated with orange shading. Chemours Fayetteville works This figure depicts the measured discharge flowrate (solid green) of water processed through the filter beds calculated using the Effluent Stilling Basin transducer data. Fayetteville, North Carolina From Jan. 10 to 18 and March 29 to 31, 2024 the Cape Fear River rose above the elevation of the discharge weir (W3), and head differentials throughout the flow -through cell were reduced and flow through the system was hindered (pink shading). See section 2.3.5 for more details. GeOonsuIt nts NCLimseNo, C[3500 �dC25 Figure FTC - Flow -Through Cell consultants 2-2D Raleigh, NC June 2024 25 1 9 20 0 0 N N N N N N O O O O O O N N N N N N � -0 -0 -0 -0 9 E E Q 4-U O > U Q O a) O Z Ln N N N N N N N N N N N N O O O O O O N N N N N N L Z3 L :3 U L a f0 C LL Legend Monthly Total Volume Treated by the Flow -Through Cells (FTCs) N N N N N N N N N N N N O O O O O O N N N rq N N -0 -0 -0 -0 tto E 9 E E Q U a > U O O O Z 0 Ln USGS Precipitation (monthly totals) M M M M M M N N N N N N O O O O O O N N N N N N a LL Notes: The FTCs at Seeps A, B, C, and D became operational by late June 2021. This figure represents the monthly total volume treated by the FTCs beginning July 2021. Precipitation data obtained from USGS gauge #02105500 at the William O. Huske Lock and Dam. The barrier wall test panel was installed December 2022, and the remainder of the wall was installed from February through June 2023. M M M M M M N N N N N N O O O O O O N N N N N N -0 -0 -0 tto 9 E E Q U 4- O > U Q O (1) O Z 0 V) ,:I- It q:T N N N O O O N N N L L io fB L LL IV 7 V 5 � ti 2 W 47 46 - 45 - - — 00 44 - - z 43 - - +e C: 42 0 > 41 - a) LJ1 ` . . .... . .......n . . ........ . ............. . . ..... ..... . . . ... ............ ...... . . ..... ... ................... . . . . ........ ........ .. . ............. . ............ .. ... . 40 - 39 38 v v v v v v v v N N N N N N N N N N N N N N N N N N N N N N N r\-I Ln M M l" a\ -I Ln M N � O 00 N l\D .\-1 Ln M M r" a\ -I M Ql \ \ \ 1-1 \ \ \ \ \ N N \ \ \ \ \ M M M \ -1 N N N \ \ \ \ N N N N N M M M M M 2 v 1.5 — — — c 0 a 1 'v v 0.5 n � 0 - Legend Influent Chamber/Impoundment Water Elevation 0 USGS Precipitation (daily totals) Impoundment Water Elevation Above Bypass Spillway 0 FTC Off, no flow Bypass Spillway Elevation 0 Cape Fear River Above Spillway FTC Influent Water Elevation Notes: (Jan - Mar 2024) - Seep A Batch mode (in which the FTC is closed to flow due to dry conditions) is designated with orange shading. Chemours Fayetteville works This figure depicts the influent transducer data that was collected during the reporting period (blue line). Instances of impoundment bypass flow are shown as an orange line. Fayetteville, North Carolina Between Jan. 11 and Jan. 16, 2024, the Cape Fear River rose above the elevation of Bypass Spillway, causing the influent and effluent water elevations to be equal, and consequently ceasing any flow through the system (pink shading). See section 2.3.5 for more details regarding impacts of river flooding. GeOSynteCD GeosyntecConsultantsofNC,P.C. Figure Precipitation data obtained from USGS gauge #02105500 at the William O. Huske Lock and Dam. consultants NC license No.: C 3500 and C 295 FTC - Flow -Through Cell 2-4A Raleigh, NC June 2024 47 46 45 00 00 0 Q 44 z 43 c 0 42 w 41 40 39 .. .............. I _ .. ....................................................... I .................................................. ................... ................... . ............. v It v ItT ' 'T Kt 'T �t Kt Kt �t �t Kt �t v v qzt IZT N N N N N N N N N N N N N N N N N N N N N N N \-I Lr) O\1 M N -1 Y) Ql N l\O O 0000 N kD —i Ln O\1 M N c\-I u\i Ol N N N \ \ i--I c-I ­1 N N \ \ \ ­1 ­1 N N N \ \ \ \ \ N N \ \ \ \ \ m m M \ \ \ \ \ c-I c-I c-I c-I rl N N N N N M M M M M 2 1.5 o_ }' 1 .Q 0.5 a 0 Legend Influent Chamber/Impoundment Water Elevation USGS Precipitation (daily totals) Impoundment Water Elevation Above Bypass Spillway p FTC Off, no flow ••• Bypass Spillway Elevation 0 Cape Fear River Above Spillway Notes: Batch mode (in which the FTC is closed to flow due to dry conditions) is designated with orange shading. This figure shows the influent transducer data that was collected during the reporting period (blue line). Instances of impoundment bypass flow are shown as an orange line. Between Jan. 11 and Jan. 16, 2024, the Cape Fear River rose above the elevation of the Bypass Spillway, causing the influent water elevations to be equal, and consequently ceasing any flow through the system (pink shading). See section 2.3.5 for more details regarding impacts of river flooding. Precipitation data obtained from USGS gauge #02105500 at the William O. Huske Lock and Dam. FTC - Flow -Through Cell M 49 47 00 45 a z 43 c O +1 ca a, 41 w 39 37 N N N N N N N N N N N N N N N N N N N N N N N -1 Ln Ql M r, c\-I Ln M N l\D O 00 N l\D ­1 Ln Ql M -1 Ln Ol N N N \ \ r-I r-I r-I N N \ \ \ i i -I N N N N N \ \ \ \ \ M M f"n \ \ \ \ \ r-I r-I r-I r-I r-I N N N N N M M M M M Legend Influent Chamber/Impoundment Water Elevation p USGS Precipitation (daily totals) Impoundment Water Elevation Above Bypass Spillway p FTC Off, no flow ••• Bypass Spillway Elevation p Cape Fear River Above Spillway Notes: Batch mode (in which the FTC is closed to flow due to dry conditions) is designated with orange shading. This figure shows the influent transducer data that was collected during the reporting period (blue line). Instances of impoundment bypass flow are shown as an orange line. Between Jan. 11 and Jan. 16, 2024, the Cape Fear River rose above the elevation of the Bypass Spillway, causing the influent and effluent water elevations to be equal, consequently ceasing any flows through the system (pink shading). See Section 2.3.5 for more details regarding impacts of river flooding. Precipitation data obtained from USGS gauge# 02105500 at the William O. Huske Lock and Dam. FTC - Flow -Through Cell 46 45 44 e0 00 0 43 Q z ,} 42 c O 41 a� w 40 39 38 . . . . . . . . . . . . . . . . . . . . . . . . . . . . V* ............ ........ *- .............. 1 ..................... ......... TT 1�11 Itt v IZT I:t 1:t v �t 't �t 1:T �t IZT Zt Ict 1:t N N N N N N N [V N N N N N N N N N N N N N N N c\i u'1 M M n .\-I Ln 01 N l\o O 00 N to M M M .\-I Ln O1 \ \ \ I I N N N \ \ I cI I N N \ \ \ I I N N N I I I I I N N N N N M M M M M Legend Influent Chamber/Impoundment Water Elevation USGS Precipitation (daily totals) Impoundment Water Elevation Above Bypass Spillway p FTC Off, no flow ••• Bypass Spillway Elevation 0 Cape Fear River Above Spillway Notes: Batch mode (in which the FTC is closed to flow due to dry conditions) is designated with orange shading. This figure shows the influent transducer data that was collected during the reporting period (blue line). Instances of impoundment bypass flow are shown as an orange line. Between Jan. 11 and Jan. 16, 2024, the Cape Fear River rose above the elevation of the Bypass Spillway, causing the influent and effluent water elevations to be equal, and consequently, ceasing any flow through the system (pink shading). See Section 2.3.5 for more details regarding impacts of river flooding. Precipitation data obtained from USGS gauge# 02105500 at the William O. Huske Lock and Dam. FTC - Flow -Through Cell 43 42 00 41 00 Q Z 40 0 39 a� w 38 37 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ....... ] ..................... ..... .... 1. ---------------------- ----- t --------------- P ----- I ----- T ------- fV N N N N N N N N N N N N N N N rV N N N N N N \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ rl Ln O1 M r" c-I Ln Ol N l0 O 00 N LO rl Ln Q1 M Ln Ql N N N \ \ -I -I r-I N N \ \ \ r-I r-I N N N \ \ \ \ \ N N \ \ \ \ \ M M M \ \ \ \ \ ci ci ci c-I r-I N N N N N M M M M M 2 1.5 0 Q v o.s n n IIII 0 Legend Staff Gauge Water Elevation 0 USGS Precipitation (daily totals) Inlet Weir Elevation p FTC Off, no flow ••• Bypass Spillway Elevation 0 Staff Gauge Inundated Notes: Batch mode (in which the FTC is closed to flow due to dry conditions) is designated with orange shading. This figure shows the daily staff gauge water elevation that was collected during the reporting period (green line). The staff gauge was inundated during elevated water levels in January and March (pink shading). Precipitation data obtained from USGS gauge #02105500 at the William O. Huske Lock and Dam. FTC - Flow -Through Cell 43 42 00 41 Q z e 40 C 0 +1 > 39 aJ w 38 A"*"** ... ­1 **"****l***************.*********** .... F, ... ""*'***'I***"*""'* -*I"**"** ... * ... .... 1.1 1 37 . 1 .. N N N N fV N N N N N N N N N N N N N N N N N N c\i Ln Ql M c\-I Ln M N l0 O 00 N c\-I Ln 01 M c\-I L! Q1 \ \ \ .-I rI N N N \ \ rI I rI N N \ \ \ rI . I N N N \ \ \ \ \ N N \ \ \ \ \ M M M \ \ \ \ \ c-I ci ri -1 -1 N N N N N M M M M M 2 1.5 c 0 }' ca 1 .Q U 0.5 a 0 Legend Staff Gauge Water Elevation p USGS Precipitation (daily totals) Inlet Weir Elevation = FTC Off, no flow ••• Bypass Spillway Elevation 0 Staff Gauge Inundated Notes: Batch mode (in which the FTC is closed to flow due to dry conditions) is designated with orange shading. This figure shows the daily staff gauge water elevation data that was collected during the reporting period (green line). The staff gauge was inundated during elevated water levels in January (pink shading), and water elevations could not be collected. Precipitation data obtained from USGS gauge #02105500 at the William O. Huske Lock and Dam. FTC - Flow -Through Cell 43 42 00 ...... .... .. ........... ............................. ........... ...... ... .......... ..... ..... ... ... ........... ........... ....... ........ .. .. . . . . . . . .. .. .. . . . . . . .. . . . . 00 41 a \z 40 — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — r — — — — — — — — — — — — — — 0 w 39 38 - — 37 N N N N N N N N N N N N N N N N N N N N N N N \-I Ln a) M r, c\-I Ln al N l\O O 00 N l\D c 1 Ln a) M I� c\-I Ln Ol N N \ \ r-I r-I r-I N N \ \ \ i i -I N N N N N \ \ \ \ \ M M f"n \ \ \ \ \ r-I r-I r-I r-I r-I N N N N N M M M M M 2 C 1.5 — — -- c 0 }' 1 — — — CU .Q 0.5 — -- a n Legend Staff Gauge Water Elevation p USGS Precipitation (daily totals) Inlet Weir Elevation p FTC Off, no flow ••• Bypass Spillway Elevation 0 Staff Gauge Inundated Notes: Batch mode (in which the FTC is closed to flow due to dry conditions) is designated with orange shading. This figure shows the daily staff gauge water elevation data that was collected during the reporting period (green line). The staff gauge was inundated during elevated water levels in January and March (pink shading), and water elevations could not be collected. Precipitation data obtained from USGS gauge# 02105500 at the William 0. Huske Lock and Dam. FTC - Flow -Through Cell 43 42 41 00 \o z 40 0 39 c� a� w 38 37 I . • •1 • • • • • • • • • • • • • I 1 • • • • • • • • • • • P •1, • .1 . • • • • • • • • • • • • • • • • • • • • • • • • • • • • . . . . . . . . . . . . . . M • • • • • • • • • • • • .1 • • • • • • • • • • • • • • • • • • • • • • • • • • •1• • • • • • • • • • • • • • • • • • • • • 4 • • • • • • • • • • • • • • • • • • •1• • • • • • • • • • • • • 4 • • • • •1 ICT It It It 1;T 1:T 171- 'T 'T It �t It It t K �t It It It It N N N fV fV N N N N N N /V (V N [V N N N N N N N N LLn Ol M N .\-I Ln a) N l\O O 0000 N l.D .\I Lf M M N c\-I LLn Ol \ \ \ cI I N N N \ \ I I cI N N \ \ \ -1 I N N N \ \ \ \ \ N N \ \ \ \ \ M M M \ \ \ \ \ N N N N N M M M M M Legend Staff Gauge Water Elevation -- Inlet Weir Elevation ••• Bypass Spillway Elevation USGS Precipitation (daily totals) p FTC Off, no flow p Staff Gauge Inundated Notes: Batch mode (in which the FTC is closed to flow due to dry conditions) is designated with orange shading. This figure shows the daily staff gauge water elevation data that was collected during the reporting period (green line). The staff gauge was inundated during elevated water levels in January (pink shading), and water elevations could not be collected. Precipitation data obtained from USGS gauge# 02105500 at the William 0. Huske Lock and Dam. FTC - Flow -Through Cell 500,000 450,000 - 400,000 - 350,000 J dA 300,000 — 0 250,000 U C 0 U a 200,000Va.. ' � a +� ` J V (D 150,000 100,000 50,000 0 O . -I N N r-I r-I r-I r-1 r 1 N N N N N N N N N N N N N N N M M M N N N N N M N M M R N N N N N f O 0 0 Q 1..L Q 0 1..L Q Legend Seep A Influent Seep B Influent Seep C Influent _ Seep D Influent -•• Monthly Average of Seep A, B, C, and D Influent Notes: FTC Influent PFAS Concentrations The FTCs at Seeps A, B, C, and D all became operational by late June 2021. This figure represents the monthly influent concentration of Total Table 3+ PFAS (17+ compounds). The barrier wall test panel was installed December 2022, and the remainder of the wall was installed from February through June 2023. Chemours Fayetteville works FTC - flow through cell Fayetteville, North Carolina GeosyntecO Geosynt ..ad,ann,d. , z Figure COr1Sl11t3TItS NCLicense Nn:C 3500 and 295 2-6 Raleigh, NC June 2024 .11 500 400 a) O E v °C 300 V) Q a a) �a 200 E Z) U 100 M c-I i -I r -I r -I r -I �I N N N N N N N N N N N N M M M M M M M M M M M M d' Itt Itt N N cV fV N N N N N cV N N N N N N N N N N N (N N N N N N (N N N cV fV N O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O N fV N N N N N N N N N N N N N N N N N N N N N N fV N N N N N N N N N Q aJ v +� 0- a1 0 L a v > o L v v U v >, L M >, L f6 a, L U L _ L Q a >, ca W C >- +.+ V) D Q L a) -0 +J L a) -0 o 0 L aJ Q v > o L a) � v U a >, L l6 C >, L CO v Il U L L Q a >, CO Qj C >- a 1 V) Q L aJ -0 v +� L 0) -0 1a) 0 L a) -0 > L aJ � W U >, L CO C L U CO L ca v `� (3)LOO z �n z v; z Legend Cumulative PFAS Removed (Ibs) Notes: The FTCs at Seeps A, B, C, and D became operational by late June 2021. This figure presents the cumulative pounds (Ibs) of PFAS removed by the FTCs beginning July 2021. Total Ibs of PFAS removed is calculated for Total Table 3+ (17 Compounds). The barrier wall test panel was installed December 2022, and the remainder of the wall was installed from February through June 2023. NO rol Legend $ Surficial Aquifer Floodplain Deposits Black Creek Aquifer Black Creek Aquifer Extraction Well Surficial Aquifer Extraction Well Surficial and Black Creek Aquifer Extraction Well 0 Willis Creek Stilling Well OW-31 OW-32 OW-38 , A�4 OW-39 0-51 OW-29 OW-37 \` O O.Ws26 OW-4R 1 OW-49 OW-50 OW-25 OW-40 OW-9R ow-28 �r OW-33 00 Hydraulic Head Observation (Existing Well) Hydraulic Head O Observation (New Observation Well - Black Creek Aquifer) Hydraulic Head Observation (New Observation Well - Surficial Aquifer) Site Boundary Forcemain Barrier Wall; approximate surface elevation at 72 ft NAVD88 ®Groundwater Treatment Pad Ground Surface Elevation Contour (ft NAVD88) - 10 feet interval — — — Seep Nearby Tributary Nearby Tributary to River Cape Fear River MEN OF WAIL OW-53 ■.� 1 ;■ pl OW-46 ` OW-20 pIW-5SR OW-22 OW-52 PW-10RR �; OW-47 � V Notes: ft NAVD88 - feet North American Vertical Datum 1988. 1. Some wells have been offset for visibility. Therefore, the placement of wells on this map do not reflect their true geographic coordinates. 2. Ground surface elevation contours are based on 20-foot DEM grid cells generated from LiDAR. Data from NC OneMap (https://assets.nconemap.gov/pages/hub/ncom-contours-dd.htm). 3. The outline of Cape Fear River is approximate and is based on open data from ArcGIS Online and North Carolina Department of Environmental Quality Online GIS (MajorHydro shapefile). 4. Basemap source: Esri, Maxar, Earthstar Geographics, and the GIS User Community M&M 1,000 OW-42 OW-56 OW-12 OW-55 500 0 o b O 1,000 Feet Hydraulic Head Evaluation Network for Groundwater Remedy Chemours Fayetteville Works, North Carolina Ge o syn to c l�-' Geosyntec Consultants of NC, P.C. consultants Figure NC License No.: C-3500 and C-295 6-1 Raleigh, NC June 2024 I—P 1 Transect la Transect 1b 44 44 61 56 42 42 51 • 46 40 OW-39 PW-11 40 OW-39 { OW-40 38 0 100 200 300 f 1/31/2024 --6-2/27/2024 400 --0-3/27/2024 38 L 500 0 1a f+ �iL• PW-11 .r Legend Black Creek Aquifer Well Forcemain Completed Barrier Wall (as of June 11, 2023) Site Boundary Seep Nearby Tributary to River Hydraulic Gradient Transect ® Groundwater Treatment Pad Cape Fear River 1b 100 200 300 400 500 1/31/2024 2/27/2024 3/27/2024 OW-38 OW-39 0 W-30 Transect 2 PIW-10DR OW-30 OW-33 36 L 0 100 200 300 400 500 600 600 Baseline Dry Baseline Wet --0--1/31/2024 t2/27/2024 --*--3/27/2024 Charts Legend 48 i" 46 Q Z w 44 v 0 42 w 40 !% 38 v 3 36 0 34 z P 0 100 200 300 400 500 OW-26 Distance from Remedy Gauging Event Date Notes: OW=50. 1. Elevation data from the gauging events of August 17, 2022 and January 30, 2023 are represented in the charts as Baseline Dry and Baseline Wet, respectively. Only for PIW-10DR, elevation data from gauging event of August 4, 2022 is considered as Baseline Dry. 2. Baseline data are not available for OW-39 and OW-40 due to the installation of the barrier wall, and in PW-11 due to pumping as ppart of the interim groundwater remedy. The nearest available baseline data m EWs 63-65 as well as PIW-10DR to the east indicate the baseline elevation in this vicinity ranged from -59-64 feet NAVD88. 3. Some observation wells have been offset for visibility. Therefore, the placement of these wells on this map do not reflect their true geographic coordinates. 4. The outline of Cape Fear River is approximate and is based on open data from ArcGIS Online and North Carolina Department of Environmental Quality Online GIS (MajorHydro shapefile). 5. Basemap sources: Esri, Maxar, Earthstar Geographics, and the GIS User _ OW 27 Community. 200 100 0 200 Feet i Southern Alignment - I Downgradient Groundwater Transects OW-28 Chemours Fayetteville Works, North Carolina Ge o synte c O Geosyntec Consultants of NC, P.C. consultants Figure NC License No.: C-3500 and C-295 Fear Riuer 6-2A Raleigh, NC June 2024 -- , • — Z Transect 3 Transect 4 Transect 5 46 46 46 44 44 44 i 42 42 42 07 40 40 40 OW-50 OW-27 ` OW-28 OW-49 OW-25 38 OW-48 OW-23 PIW-7D 38 38 LTW-05 36 36 36 0 100 200 300 400 500 0 100 200 300 400 500 0 100 200 300 400 500 Baseline Dry Baseline Wet --o-1/31/2024 t2/27/2024 t3/27/2024 Baseline Dry Baseline Wet —0-1/31/2024 —0-2/27/2024 t3/27/2024 Baseline Dry Baseline Wet t1/31/2024 --*--2/27/2024 --*--3/27/2024 1 i- I J Charts Legend OW-38 _ h 48 Y T � 46 ! J Q Z w 44 w Z 42 0 ■;k1 a�i 40 —� rw t i � 38 3 v 36 OW-29 h ' � - - OW-24 34 0 100 200 300 400 500 Y Distance from Remedy }� _ , `� - tGauging Event Date , OW-26 OW-48 PIW-10DR Notes: 1. Elevation data from the gauging events of August 17, 2022 and - OW-49 Nt pyy-23 January 30, 2023 are represented in the charts as Baseline Dry and OW-50 Baseline Wet, respectively. 2. Some observation wells have been offset for visibility. Therefore, the placement of these wells on this map do not reflect their true geographic OW-25 5 coordinates. 3. The outline of Cape Fear River is approximate and is based on open ' data from ArcGIS Online and North Carolina Department of Environmental Quality Online GIS (MajorHydro shapefile). 4. Basemap sources: Esri, Maxar, Earthstar Geographics, and the GIS OW-30 ❑ User Community. 3 4= - PIW-7D OW-27 200 100 0 200 Feet Legend Black Creek Aquifer Well Forcemain Southern Alignment - Completed Barrier Wall (as of June 11, 2023) LTW-05 Downgradient Groundwater Transects � Site Boundary Chemours Fayetteville Works, North Carolina Seep Hydraulic Gradient Transect OW-28 ® Groundwater Treatment Pad Geosyntec Cape Fear River _ ape Fear River consultants GeosyntecConsultantsofNC,P.C. NC License No.: C-3500 and C-295 Figure C - 6-2B Raleigh, NC I June 2024 Transect 6a 46 46 r 44 44 42 42 40 — 40 OW-47 OW-22 PZ-22 38 38 36 36 0 100 200 300 400 500 0 2 Baseline Dry Baseline Wet --*--1/31/2024 --0--2/27/2024 t3/27/2024 t OW-8 hh OW-7 Y* i OW-24 � OW-23 Legend Black Creek Aquifer Well Forcemain Completed Barrier Wall (as of June 11, 2023) Site Boundary Seep Hydraulic Gradient Transect ® Groundwater Treatment Pad Cape Fear River.4 100 1/31/2024 1 OW-21 OW-53 Transect 6b 200 300 400 --*-2/27/2024 --0-3/27/2024 — — r z Transect 7 48 46 44 42 OW-46 OW-20 40 �♦ 38 36 500 0 100 200 300 400 500 Baseline Dry Baseline Wet --0--1/31/2024 --0-2/27/2024 --0-3/27/2024 Charts Legend �v 9 48 46 Q Z w 44 v 0 42 w 40 38 3 v 3 36 0 34 I AF 0 100 200 300 400 500 Distance from Remedy OW-46 --*--Gauging Event Date Notes: 1. Elevation data from the gauging events of August 17, 2022 and t January 30, 2023 are represented in the charts as Baseline Dry and F Baseline Wet, respectively. 2. Some observation wells have been offset for visibility. Therefore, the placement of these wells on this map do not reflect their true geographic coordinates. 0 3. The outline of Cape Fear River is approximate and is based on open data from ArcGIS Online and North Carolina Department of Environmental Quality Online GIS (MajorHydro shapefile). 4. Basemap sources: Esri, Maxar, Earthstar Geographics, and the GIS P , User Community. t 200 100 0 200 Feet Southern Alignment - Downgradient Groundwater Transects Chemours Fayetteville Works, North Carolina - G e o syn to c l�- Geosyntec Consultants of NC, P.C. Figure consultants F In u re NC License No.: C-3500 and C-295 y 6-2C Raleigh, NC June 2024 Transect 8 48 46 44 42 40 OW-45 PI W-4D LTW-02 38 36 0 100 200 300 400 500 Baseline Dry Baseline Wet t1/31/2024 t2/27/2024 --0-3/27/2024 OW-2 OW-3 OW-18 • * 19 PW-10RR--'OW-45` � OW-� , .OW-46 Legend Black Creek Aquifer Well Forcemain Completed Barrier Wall (as of June 11, 2023) Site Boundary Seep Hydraulic Gradient Transect Cape Fear River 1 11 1 — I . U.I* - w _,Mir Z f.Z { Transect 9 - �► 1 —� OW 44 OW-16 0 100 200 300 400 500 —Baseline Dry Baseline Wet --*--1/31/2024 --*--2/27/2024 t3/27/2024 PIW-2D O14-15,-.Wr T OW-16 i s i J # OL ' r ■ , a F 1 OW-43 OW-13 - . 1 Charts Legend 48 i" Q 46 Q Z w 44 v 0 42 w 40 38 4 3 3 36 0 34 0 100 200 300 400 500 Distance from Remedy t Gauging Event Date Notes: 1. Elevation data from the gauging events of August 17, 2022 and January 30, 2023 are represented in the charts as Baseline Dry and Baseline Wet, respectively. 2. Some observation wells have been offset for visibility. Therefore, the placement of these wells on this map do not reflect their true geographic coordinates. 3. The outline of Cape Fear River is approximate and is based on open data from ArcGIS Online and North Carolina Department of Environmental Quality Online GIS (MajorHydro shapefile). 4. Basemap sources: Esri, Maxar, Earthstar Geographics, and the GIS User Community. 200 100 0 200 Feet FM Southern Alignment - Downgradient Groundwater Transects Chemours Fayetteville Works, North Carolina Ge o syn to c l�-' Geosyntec Consultants of NC, P.C. consultants Figure NC License No.: C-3500 and C-295 6-2D Raleigh, NC June 2024 Transect 1 Transect 2 —OW-26 —OW-50 —OW-27 —OW-24 —OW-48 —OW-23 44 43 00 p 42 a Z 41 4 40 v 3 v 9 38 37 41 39 0 37 Z 35 c 33 0 > 31 v UJ 29 ti 27 i 1/1/2024 1/11/2024 1/21/2024 1/31/2024 2/10/2024 2/20/2024 3/1/2024 3/11/2024 3/21/2024 3/31/2024 L 25 1/1/2024 1/11/2024 1/21/2024 1/31/2024 2/10/2024 2/20/2024 3/1/2024 3/11/2024 3/21/2024 3/31/2024 46 46 44 p 42 Q 40 Z 38 36 34 > 32 N ai 30 28 44 o az Q 40 z 38 36 34 M N32'] *' 1111111111''. ''. ............. a 30 28 1/1/2024 1/11/2024 1/21/2024 1/31/2024 2/10/2024 2/20/2024 3/1/2024 3/11/2024 3/21/2024 3/31/2024 1/1/2024 1/11/2024 1/21/2024 1/31/2024 2/10/2024 2/20/2024 3/1/2024 3/11/2024 3/21/2024 3/31/2024 —Cape Fear River —Cape Fear River Legend Black Creek Aquifer Well Forcemain Completed Barrier Wall (as of June 11, 2023) Site Boundary — • Seep Nearby Tributary to River Dampening Analysis Transect ® Groundwater Treatment Pad Cape Fear River s. OW-7 Notes: _ 1. Gap in elevation data for OW-23 is due to malfunctioning of the installed transducer. OW-29 2. Groundwater elevation in observations wells downgradient of the OVV-24 barrier wall is susceptible to fluctuations in Cape Fear River elevation, thereby influencing the downgradient groundwater I n transects. 3. Some observation wells have been offset for visibility. Therefore, OW-26 the placement of these wells on this map do not reflect their true OW-48 geographic coordinates. - 2 4. The outline of Cape Fear River is approximate and is based on OW-49 open data from ArcGIS Online and North Carolina Department of 11111111111 } 4 r 0W-23 Environmental Quality Online GIS (MajorHydro shapefile). h W 50 - 5. Basesources: Esri, Maxar, Earthstar Geographics, and the OW-25 GIS Userr Community. JAW ` 1 all 250 125 0 250 Feet OW-30 PIW-7U oW-27 Southern Alignment - Dampening Analysis Transects - LTW-05 Chemours Fayetteville Works, North Carolina Ge o syn to cl�-' Geosyntec Consultants of NC, P.C. Figure consultants F i g u re NC License No.: C-3500 and C-295 6-3A Raleigh, NC I June 2024 Transect 3 Transect 4 —OW-7 —OW-47 —OW-22 — OW-46 —OW-20 41 39 00 00 0 Q 37 Z 35 O N 33 ai 31 29 r= 1/1/2024 1/11/2024 1/21/2024 1/31/2024 2/10/2024 2/20/2024 3/1/2024 3/11/2024 3/21/2024 3/31/2024 46 44 n - - 00 00 42 Q 4° Z 38 36 E O 34 _v 32 a 30 28 1/1/2024 1/11/2024 1/21/2024 1/31/2024 2/10/2024 2/20/2024 3/1/2024 3/11/2024 3/21/2024 3/31/2024 —Cape Fear River •ti it 91AV y 4 t OW-7 r • � � 5 , r .� 41 40.5 oo 40 00 0 Q 39.5 Z 39 O 38.5 v 38 37.5 - 37 1/1/2024 1/11/2024 1/21/2024 1/31/2024 2/10/2024 2/20/2024 3/1/2024 3/11/2024 3/21/2024 3/31/2024 46 44 00 42 - 0 Q 40 Z 38 36 O 34 ' 32 6 30 28 1/1/2024 1/11/2024 1/21/2024 1/31/2024 2/10/2024 2/20/2024 3/1/2024 3/11/2024 3/21/2024 3/31/2024 —Cape Fear River 00, CO) �t* OW-3 IF 0—W-21 OW-19 PW-10RR OW-8 1 - 3 ' OW-47 Ar OW-2, ih Ae 1-00 OW 46 y OW-20OP I � "I _ . Y'U. 7W Legend Black Creek Aquifer Well Forcemain Completed Barrier Wall (as of June 11, 2023) Site Boundary • Seep Dampening Analysis Transect ■ Cape Fear River Notes: 1. Groundwater elevation in observations wells downgradient of the barrier wall is susceptible to fluctuations in Cape Fear River elevation, thereby influencing the downgradient groundwater transects. 2. Some observation wells have been offset for visibility. Therefore, the placement of these wells on this map do not reflect their true geographic coordinates. 3. The outline of Cape Fear River is approximate and is based on open data from ArcGIS Online and North Carolina Department of Environmental Quality Online GIS (MajorHydro shapefile). 4. Basemap sources: Esri, Maxar, Earthstar Geographics, and the GIS User Community. 250 125 0 250 Feet Southern Alignment - Dampening Analysis Transects Chemours Fayetteville Works, North Carolina Ge o syn to c l> Geosyntec Consultants of NC, P.C. Figure nsultants NC License No.: C-3500 and C-295 o #FearRiver RCal,igh, NC June 2024 6-3B rn� Z Transect 5 —OW-45 —PIW-4D LTW-02 43 42 oo a Q 41 - . Z c 40 0 a� 39 38 - 37 1/1/2024 1/11/2024 1/21/2024 1/31/2024 2/10/2024 2/20/2024 3/1/2024 3/11/2024 3/21/2024 3/31/2024 44 42 00 0 40 Q 38 Z 36 c 34 v 32 v 30 28 1/1/2024 1/11/2024 1/21/2024 1/31/2024 2/10/2024 2/20/2024 3/1/2024 3/11/2024 3/21/2024 3/31/2024 —Cape Fear River Transect 6 —OW-44 —OW-16 38 37 00 0 36 Q a w 35 c O > 34 N I N 33 32 1/1/2024 1/11/2024 1/21/2024 1/31/2024 2/10/2024 2/20/2024 3/1/2024 3/11/2024 3/21/2024 3/31/2024 46 44 oo 42 0 Q 40 z 38 c 36 O Z 34 a 32 a 30 28 1/1/2024 1/11/2024 1/21/2024 1/31/2024 2/10/2024 2/20/2024 3/1/2024 3/11/2024 3/21/2024 3/31/2024 —Cape Fear River PIW-2D MW - 0 - OW-15 x - f' #. OW-17 jo OW-44 4 �+ OW-2 OW-3 hOW-18 - Y 6 hPW-10RR Y ar 4 Legend Black Creek Aquifer Well Forcemain Completed Barrier Wall (as of June 11, 2023) Site Boundary • Seep Dampening Analysis Transect Cape Fear River Notes: 1. Gap in elevation data for OW-45 is due to malfunctioning of the installed transducer. 2. Groundwater elevation in observations wells downgradient of the barrier wall is susceptible to fluctuations in Cape Fear River elevation, thereby influencing the downgradient groundwater transects. 3. Some observation wells have been offset for visibility. Therefore, the placement of these wells on this map do not reflect their true geographic coordinates. 4. The outline of Cape Fear River is approximate and is based on open data from ArcGIS Online and North Carolina Department of Environmental Quality Online GIS (MajorHydro shapefile). 5. Basemap sources: Esri, Maxar, Earthstar Geographics, and the GIS User Community. 250 125 0 250 Feet r Southern Alignment - Dampening Analysis Transects Chemours Fayetteville Works, North Carolina Ge o syn to c'% Geosyntec Consultants of NC, P.C. consultants Figure NC license No.: C-3500 and C-295 6-3C Raleigh, NC I June 2024 50 45 40 -- Willis Creek Flood 0 35 Q z s= 30 - 0 (10 > a� WON" w 25 - 20 Pumping Mode D_A -7oing Blade Flamm Total �gal) Flow Total (gal) Well la Pre -Flood past-=1aad Jan 3-9 Jan 10-16 55 Pumping lVlade pumping Mode --,t-%r Total (gal) Flow Total (gal) 50 45 00 00 0 a 40 z ° Willis Creek Flood a', 35 WAt "Poo 30 TFIVII AL AL IT1111"W)"ryll lll. lulh Il II J ,�IWII All ki 1,I�J 1016 n. 25 20 1/1/2024 1/6/2024 1/11/2024 1/16/2024 1/21/2024 1/26/2024 1/31/2024 Willis Creek Extraction Well Flood Response: EW-06 through EW-10 Notes: Chemours Fayetteville Works Willis Creek elevation data is from a transducer deployed in a locally installed stilling well, converted to NAVD88. Fayetteville, North Carolina Extraction Well (EW) level data is from transducer deployed in each well, converted to NAVD88. Figure Willis Creek and EW data both recorded at 15 minute frequency intervals. Geosyntec° �osY��e��o�.w;.��o��C.PC NC L;ce�se Na: C—.andC- consultants 6-4B Raleigh, NC June 2024 Well ID Pre -Flood post -Flood = Jan 3-9 Jan 10-16 EW-06 Continuous Continuous 7�,513 79.53� EW-07 Cycling i;�Q`j Cycling � 61`J 14.787 ��.9�� EVtif-OS Cycling i; 78`J Continuous 35,117 4�.015 Etiltif-09 Water Limited I;0`j Water Limited 1;1`� 39 179 Etiltif-10 Cycling (9`j Cycling l;�`� �,�39 13r7 55 Pumping Mode Pumping Mode FIo4f,+ Total (gal) Flow Total (gal) -Yrl; :;',j Legend Black Creek Aquifer Staff Gauge Stilling Well Extraction Well R lA OW-14 0.1 OW-41 \ OW-57 -2.54 -1.71 SW-5 1 1 N - PIW-11 1 1 0.49 - -2.17 \t 1 1 % \ 1 % \ 1 %` ` ` OW-56 \ 0.07 1 \ 0W-12 % % \ -o- SV\ 1 -4.16 % 1 SG-4 1 % 1 \ 1 J# EW-04 % 1 1 � � i � 1 ;'So 1 'SMW-12 � OW-55 1 1 , -4.74 -5.12 1 i OW-43 \ PIW-13 1 1.93 -6.19 \ EW-09 '-5.5 w ub/ • OW-13, -1.5 /EW-10 EW 11 PIW-14 \ - do {�} \ J# -3.45 1 OW-54 SW-3E SG 3 �0 EW 12 e� tvv-i4 j PIW-1D• 0.36 I __/ Ca, Notes: January 2024 Elevation —Site Boundary 1. Elevation difference = monthly elevation - January 2023 elevation Difference — 2. Elevation difference not calculated at locations where monthly — Seep elevation or baseline January 2023 not available Barrier Wall — Nearby Tributary 3. OW-54 dry in January 2024. Water assumed at bottom of screen in «� Z Forcemain elevation difference calculation Cape Fear River 4. Antecedent daily total rainfall (January 28-30): 0.02 inches 0 250 Feet A Northern Alignment January 2023 - January 2024 Elevation Difference Chemours Fayetteville Works, North Carolina Ge o sMte c l> Geosyntec Consultants of NC, P.C. Figure consultants NC License No.: C-3500 and C-295 6-5A Raleigh, NC I April 2024 A-1 a 1 / 0 n Legend P. Black Creek Aquifer Extraction Well Staff Gauge Stilling Well s a 2-ft January 2024 GW - - Elevation 10-ft January 2024 GW Elevation Barrier Wall 4 ' EW-02 ' bW-42 i ,gyp ppt EWR 40 SOW-12 ` 00, EW.0,1 OV1 5'� PIW-1 =0 3ti 3 A OW=43 EW-10 EW-08 1 PIW-13 EW=06 ' EW-0, PIW-14 PIW-21D �' ,' f OW-13/' OW-54 �' / Sw-03 �.. , SW-02 SG-03 EW-12 / SG-01 ' EW-13 { SW-01 I EW-141/%�, M�. PIW-15 �OW_14 2-ft January 2023 GW Elevation 10-ft January 2023 GW Elevation Forcemain 0 250 Feet z Site Boundary Notes: Seep Nearby Tributary 1. Antecedent daily total rainfall (January 28-30): 0.02 Inches Cape Fear River 2. Surficial elevations at staff gauges and stilling wells shown but not used for contouring of groundwater (GW) elevations Northern Alignment Potentiometric Map January 2023 - January 2024 Chemours Fayetteville Works, North Carolina GeosyntecGeosyntecConsultants ofNC.P.C. Figure consultants NC License No.: C-3500 and C-295 6-6A Raleigh, NC April 2024 LI t Legend P. Black Creek Aquifer Extraction Well Staff Gauge Stilling Well s a �E OW-. 1 a6 EV 021 11 OW-42 ; EW-03 -38- — — , — — -OW-5 OW-12 ' Ao- OW-55 3� SMW-12, ' PIW-12 08 11 PIW 1 W-EW-06 EW-05 PIW=14 EW-07 SW-03 33.28 V-54 s�-os -A:-4. 2-ft February 2024 GW - - Elevation 10-ft February 2024 GW Elevation Barrier Wall 2-ft January 2023 GW Elevation 10-ft January 2023 GW Elevation Forcemain 0 250 Feet z Site Boundary Notes: Seep Nearby Tributary 1. Antecedent daily total rainfall (February 24-26): 0.02 inches Cape Fear River 2. Surficial elevations at staff gauges and stilling wells shown but not used for contouring of groundwater (GW) elevations Northern Alignment Potentiometric Map January 2023 - February 2024 Chemours Fayetteville Works, North Carolina GeosyntecGeosyntecConsultants ofNC.P.C. Figure consultants NC License No.: C-3500 and C-295 6-6B Raleigh, NC April 2024 1. 1 40 / E J 0 / v 0 w` N Legend P. $ Black Creek Aquifer 4 Extraction Well Staff Gauge Stilling Well s a 4 1 O ' , ' EWE03 -38 34 _. •� O 2-ft March 2024 GW - - Elevation 10-ft March 2024 GW Elevation Barrier Wall V OW-12 PIW12, EW-0` / OW=43 ' PIW-13 / / / • EW=10/ EW-08 i > EW= 6 EW-09 �O/W--13 . — PIW=14 EWv.07 sw o3 - PIW-21D ' / / / / �/ EW-1,1 SW-02 33.35 SG-02 " OW-54 SG-03 / EW-12 // SG-01 SW-01 PIW-15 2-ft January 2023 GW Elevation 10-ft January 2023 GW Elevation Forcemain 0 250 Feet z Site Boundary Notes: Seep Nearby Tributary 1. Antecedent daily total rainfall (March 24-26): 0.00 inches 2. Surficial elevations at staff gauges and stilling wells Cape Fear River shown but not used for contouring of groundwater (GW) elevations Northern Alignment Potentiometric Map January 2023 - March 2024 Chemours Fayetteville Works, North Carolina GeosyntecGeosyntecConsultants ofNC.P.C. Figure consultants NC License No.: C-3500 and C-295 6-6C Raleigh, NC April 2024 EW-46 EW-45 EW-43 EW-42 EW-47 _ EW48 EW-44 EW-49 0 ° SPW-10RR EW-37 4P��80,300 PIW-5SR -39 154,000, z a� —EW-28 EW-26S 0 2,000 1,000 0 EW-19 EW-21 W -20 V. , EW 22` � r-• 223 4 i 20 � z kz 2,000 Feet EW-16 EW-171 �E-W=1'8 All I� Legend PFAS Sampling Location ❑ Surficial Aquifer ❑ Floodplain Deposits 0 Black Creek Aquifer ❑ Surface Water Total Table 3+ PFAS, 17 Compounds (ng/L) A ND A <10 10 - 100 0 100 - 1,000 0 1,000 - 10,000 Q 10,000 - 100,000 - 100,000 - 1,000,000 - > 1,000,000 Black Creek Aquifer Extraction Well Surficial Aquifer Extraction Well Site Boundary Forcemain Barrier Wall; approximate surface elevation at 72 feet NAVD88 — — — Seep Cape Fear River Notes: 1. This figure shows Total Table 3+ PFAS (17 Compounds) concentrations in near remedy and downgradient monitoring/observation wells (MWs/OWs), and Willis Creek (WC) stations. PFAS results for the collection of MWs/OWs are from the Q3 2023 and Q1 2024 sampling performed during July 13 to August 8, 2023 (in blue) and January 15 to February 6, 2024 (in black), respectively. WC PFAS results are from the Q1 2024 sampling (in black) performed on February 22, 2024. 2. The outline of Cape Fear River is approximate and is based on open data from ArcGIS Online and North Carolina Department of Environmental Quality Online GIS (MajorHydro shapefile). 3. Basemap source: Esri, Maxar, Earthstar Geographics, and the GIS User Community. 250 125 0 250 Feet PFAS Analytical Results Chemours Fayetteville Works, North Carolina Geosptec'% Geosyntec Consultants of NC, P.C. NC License No.: C 3500 and C 295 Figure consultants 6-7 B Raleigh, NC I June 2024 Z EW-10 EW PIW=1' EW1-11 t.. j� C EW �•2 PIUV-15 , 2 EW-16 SEW-17 EW-13 33,800 EW-19 EV1/-18EW=14 WC-1 EW�2,1 EW-15 1,420 �•EW-20 RIII W;i1S 44,200 �♦ 5,030 EW-7T vv MW-5 FEW -fa Legend PFAS Sampling Location ❑ Surficial Aquifer ❑ Floodplain Deposits 0 Black Creek Aquifer ❑ Surface Water Total Table 3+ PFAS, 17 Compounds (ng/L) A ND A <10 10 - 100 0 100 - 1,000 0 1,000 - 10,000 10,000 - 100,000 - 100,000 - 1,000,000 - > 1,000,000 Black Creek Aquifer Extraction Well Surficial Aquifer Extraction Well Site Boundary Forcemain Barrier Wall; approximate surface elevation at 72 feet NAVD88 — — — Seep Nearby Tributary to River Cape Fear River Notes: 1. This figure shows Total Table 3+ PFAS (17 Compounds) concentrations in near remedy and downgradient monitoring/observation wells (MWs/OWs), and Willis Creek (WC) stations. PFAS results for the collection of MWs/OWs are from the Q3 2023 and Q1 2024 sampling performed during July 13 to August 8, 2023 (in blue) and January 15 to February 6, 2024 (in black), respectively. WC PFAS results are from the Q1 2024 sampling (in black) performed on February 22, 2024. 2. The outline of Cape Fear River is approximate and is based on open data from ArcGIS Online and North Carolina Department of Environmental Quality Online GIS (MajorHydro shapefile). 3. Basemap source: Esri, Maxar, Earthstar Geographics, and the GIS User Community. 250 125 0 250 Feet PFAS Analytical Results Chemours Fayetteville Works, North Carolina Geosyntec'% Geosyntec Consultants of NC, P.C. consultants NC License No.: C-3500 and C-295 Figure 6-7C Raleigh, NC I June 2024 5,000 4,500 J 4,000 c 3,500 3,000 0 E 2,500 0 2,000 M 1,500 aU -0 1,000 9 —ru 500 12 0 00 00 Q z 0 a� w a� a� U Ln 7/1/2022 47 45 43 41 39 37 35 33 31 29 1 I I 1 I 1 1 I 1 1 1 I 1 I I 1 I I T- 9/19/2022 12/8/2022 2/26/2023 5/17/2023 8/5/2023 10/24/2023 1/12/2024 t WC-1 PFAS Sample Location WC-2 PFAS Sample Location f WC-3 PFAS Sample Location - - - Extraction Well Startup 7/1/2022 9/19/2022 12/8/2022 2/26/2023 5/17/2023 8/5/2023 10/24/2023 Cape Fear River Elevation Willis Creek Stilling Well 1 Notes: Stilling Wells were installed in Willis Creek (WC) in October 2023. For clarity, only WC-1 location is shown. Trends at WC-2 and WC-3 are similar. Prior to October 2023, Cape Fear River elevation are available from the USGS Huske Lock and Dam. 4/1/2024 1/12/2024 4/1/2024 30 25 0, 20 c c 0 15 c a� U 0 10 ME 5 ND 30 25 20 c c 0 15 c m U 0 10 5 ND Transect 1 - North of Willis Creek Flow: 9,630 cfs Gage Height: 5.37 ft West Sample Center Sample East Sample (T1-101) (T1-102) (T1-103) Transect 3 - Between W.O. Huske Dam and Outfall 002 Flow: 10,100 cfs Gage Height: 5.53 ft West Sample Center Sample East Sample (T3-301) (T3-302) (T3-303) Legend: ■ H FPO-DA Notes: cfs - cubic feet per second 11,000 • PFMOAA ft - feet ND - non -detect (see note 2) A PMPA ng/L - nanograms per liter 10,000 HFPO-DA - Hexafluoropropylene oxide dimer acid PFMOAA - Perfluoro-2-methoxyacetic acid V PMPA - Perfluoro-2-methoxypropionic acid 9,000 1. All samples along the river transacts were collected at the middle depth of the river. 0 2. The reporting detection limits are: HFPO-DA: 2 ng/L; PFMOAA: 2 ng/L; and PMPA: 10 ng/L. ILL 3. Gage height, total precipitation, and flow data are from the USGS gauging station #02105500 located at 8,000 the W.O. Huske Dam. 4. The gage height and flow posted on each graph corresponds to the sampling date and time that the center sample was collected. The total precipitation represents the total from the start date and time to the end date 7 000 30 25 20 c A 5 ND 30 25 20 c 5 ►1OM Transect 1 West Sample Center Sample East Sample (T2-201) (T2-202) (T2-203) Transect 4 - Downstream of Outfall 003 and Georgia Branch Creek Flow: 10,200 cfs Gage Height: 5.58 ft r-, u West Sample Center Sample East Sample (T4-401) (T4-402) (T4-403) Transect 4 Transect 2 �- Transect 3 and time of the sampling event. 3/12/2024 0:00 3/12/2024 6:00 3/12/2024 12:00 3/12/2024 18:00 3/13/2024 0:00 Date and Time Total Precipitation: 0 inchesl Outfall 003 Treatment System 400 Seep C FTC Seep B FTC Seep D FTC GWEC Fully Operational BW Completed \ Seep A FTC -,\\ � � Outfall 002 SWTS BW Construction Started / 350 U) c 300 .-. 0 J o -S 250 O f U c � o cu 200 O ❑ El + M o o 150 �O 000 O 0 �U 9 O ❑ OD O 50 C�-. � Ib'b'Trl❑ I 50 0 C E E 40 0 0 U L 30 + U co _(D l) 20 H 10 ME Q 0: O !Cop V o C) V.Mq kJ • O ❑ • O ❑ O • • :: O ❑ O :: 000 60S°0 C) 1 I� �® ❑�❑ 0 CD X 35,000 U) 30,000_ U) 25,000 0 20,000 >_ 15,000 U_ m 10,000 U 5,000 0 7 �Ti III a� I U i I I I I I I I F 5.E 3� 2 0 00' 00' Off' 00' 00' 00' 00' 00' 00' 00' Off' Off' 00' 00' 00' 00' 00' 00' 00' 00' 00' Off' 00' 00' 00' Off' 00' 00' 00' 00' 00' 00' 00' Off' 00' 00' 00' 00' 00' 00' Off' 00' Off' Off' Off' 00' 00' 00' 00' Total Daily Precipitation O Composite Sample Cape Fear River Flow ❑ Grab Sample Total Table 3+ (17 Compounds) Concen Notes: A concentration of 0 ng/L and mass discharge of 0 mg/s indicate that all the compounds were not detected above the reporting limit. Flow and precipitation data are from the USGS gauging station #02105500 located at the W.O. Huske Dam. PFAS concentrations calculated by summing over Attachment C compounds and Table 3+ (21 compounds) are provided in Appendix B. Abbrevations: BW - Barrier Wall mg/s - milligrams per second W/s - cubic feet per second ng/L - nanograms per liter FTC - Flow -through cell SWTS - Stormwater treatment system GWEC - Groundwater extraction and conveyance system Geosyntec consultants Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 Appendix A Laboratory Analytical Data Review Narratives (Full lab reports to be uploaded to OneDrlve and EQuZS) TR0795C ADQM Data Review Site: Chemours Fayetteville Protect: CAP 1 Q24 Sampling (selected lots) Project Reviewer: Bridget Gavaghan Sample Summary Field Sample ID Lab Sample ID Sample Matrix Filtered Sample Date Sample Time Sample Purpose CAP 1 Q24-P IW-7D-0 11524 320-108762-1 Groundwater N 01/15/2024 13:11 FS CAP1 Q24-B LADE N-1 DR-01 1524 320-108762-10 Groundwater N 01/15/2024 10:25 FS CAP1Q24-EQBLK-PP-011724 320-108762-11 Blank Water N 01/17/2024 13:00 EB CAP1Q24-PIW-7D-011524-D 320-108762-2 Groundwater N 01/15/2024 13:11 DUP CAP1Q24-PIW-7S-011524 320-108762-3 Groundwater N 01/15/2024 15:20 FS CAP1 Q24-SMW-1 2-011624 320-108762-4 Groundwater N 01/16/2024 15:06 FS CAP1Q24-LTW-04-011624 320-108762-5 Groundwater N 01/16/2024 13:05 FS CAP1Q24-PZ-22-011624 320-108762-6 Groundwater N 01/16/2024 15:20 FS CAP1Q24-PIW-1S-011624 320-108762-7 Groundwater N 01/16/2024 15:47 FS CAP1Q24-PW-06-011524 320-108762-8 Groundwater N 01/15/2024 14:35 FS CAP1Q24-LTW-05-011524 320-108762-9 Groundwater N 01/15/2024 12:05 FS CAP1 Q24-PIW-1 D-01 2224 320-109019-1 Groundwater N 01/22/2024 12:04 FS CAP1Q24-PIW-10DR-012224 320-109019-2 Groundwater N 01/22/2024 11:00 FS CAP1 Q24-PIW-4D-01 2224 320-109019-3 Groundwater N 01/22/2024 14:45 FS CAP1 Q24-PIW-8D-01 2224 320-109019-4 Groundwater N 01/22/2024 13:10 FS CAP1 Q24-EQBLK-DV-01 2224 320-109019-5 Blank Water N 01/22/2024 16:05 EB CAP1Q24-EQBLK-BAILER- 012224 320-109019-6 Blank Water N 01/22/2024 16:20 EB CAP1Q24-EQBLK-BAILER- 012224-Z 320-109019-7 Blank Water Y 01/22/2024 16:25 EB CAP1 Q24-LTW-01 -011724 320-109020-1 Groundwater N 01/17/2024 13:40 FS CAP1Q24-LTW-02-011724 320-109020-2 Groundwater N 01/17/2024 12:40 FS CAP1Q24-OW-37-011724 320-109020-3 Groundwater N 01/17/2024 10:15 FS CAP1 Q24-SMW-1 0-011724 320-109020-4 Groundwater N 01/17/2024 14:39 FS CAP1Q24-PW-04-011724 320-109020-5 Groundwater N 01/17/2024 15:55 FS CAP1Q24-PW-04-011724-Z 320-109020-6 Groundwater Y 01/17/2024 15:55 FS CAP1Q24-PIW-3D-011824 320-109020-7 Groundwater N 01/18/2024 13:21 FS CAP1Q24-SMW-11-011824 320-109020-8 Groundwater N 01/18/2024 15:25 FS CAP4Q23-OW-28-011824 320-109020-9 Groundwater N 01/18/2024 12:06 FS CAP1Q24-OW-32-012924 320-109381-1 Groundwater N 01/29/2024 14:45 FS CAP1Q24-OW-4R-012924 320-109381-2 Groundwater N 01/29/2024 11:00 FS CAP1Q24-OW30-013024 320-109381-3 Groundwater N 01/30/2024 15:15 FS CAP1Q24-OW-40-013024 320-109381-4 Groundwater N 01/30/2024 13:45 FS CAP1Q24-OW-33-013024 320-109381-5 Groundwater N 01/30/2024 12:14 FS CAP1Q24-PW-10RR-013124 320-109381-6 Groundwater N 01/31/2024 12:35 FS CAP1Q24-LTW-03-013124 320-109381-7 Groundwater N 01/31/2024 11:05 FS CAP1 Q24-PIW-6S-01 3124 320-109381-8 Groundwater N 01/31/2024 12:47 FS CAP1Q24-OW-51-013124 320-109381-9 Groundwater N 01/31/2024 12:32 FS CAP1Q24-OW-56-020124 320-109475-1 Groundwater N 02/01/2024 15:00 FS CAP1 Q24-PIW-1 1-020124 320-109475-2 Groundwater N 02/01/2024 11:45 FS CAP1Q24-EQBLK-BP-020224 320-109475-3 Blank Water N 02/02/2024 10:50 EB CAP1Q24-OW-55-020524 320-109475-4 Groundwater N 02/05/2024 12:30 FS CAP1 Q24-PIW-1 5-020524 320-109475-5 Groundwater N 02/05/2024 15:10 FS CAP1Q24-OW-54-020624 320-109475-6 Groundwater N 02/06/2024 11:50 FS CAP1Q24-OW-57-020624 320-109475-7 Groundwater N 02/06/2024 13:25 FS CAP1Q24-WC-1-24-022224 320-109943-1 Surface N 02/22/2024 09:06 FS Water CAP1Q24-WC-2-24-022224 320-109943-2 Surface N 02/22/2024 08:50 FS Water CAP1Q24-WC-3-24-022224 320-109943-3 Surface N 02/22/2024 08:27 FS Water CAP1Q24-WC-3-24-022224-D 320-109943-4 Surface N 02/22/2024 08:27 DUP Water CAP1Q24-EQBLK-IS-022224 320-109943-5 Blank Water N 02/22/2024 15:30 EB * FS=Field Sample DUP=Field Duplicate FB=Field Blank EB=Equipment Blank TB=Trip Blank Analytical Protocol Lab Name Lab Method Parameter Category Sampling Program Eurofins Environ Testing 537 Per- and Polyfluorinated Alkyl Substances CAP GW Sampling Northern Cali Modified PFAS 1Q24 Eurofins Environ Testing 537 Per- and Polyfluorinated Alkyl Substances CAP SW Sampling Northern Cali Modified PFAS 1 Q24 ADQM Data Review Checklist DVM Laboratory Exception Item Description Yes No* Narrative Report Report (ER) Report # Did samples meet laboratory acceptability A requirements upon receipt (i.e., intact, within X temperature, properly preserved, and no heads ace where applicable)? B Were samples received by the laboratory in X X agreement with the associated chain of custody? C Was the chain of custody properly completed by X the laboratory and/or field team? D Were samples prepped/analyzed by the laboratory X X X within method holding times? Were data review criteria met for method blanks, LCSs/LCSDs, MSs/MSDs, PDSs, SDs, replicates, E surrogates, sample results within calibration range, X X X total/dissolved samples, field duplicates, field/equipment/trip blanks? F Were all data usable and not R qualified? X ER# Description Other QA/QC Items to Note: See DVM Narrative Report, Laboratory Report, and/or ER # for further details as indicated. The electronic data submitted for this project were reviewed via the Data Verification Module (DVM) process. Overall, the data are acceptable for use without qualification, except as noted on the attached DVM Narrative Report. The lab reports due to a large page count are stored on a network shared drive and are available to be posted on external shared drives, or on a flash drive. Data Verification Module (DVM) The DVM is an internal review process used by the ADQM group to assist with the determination of data usability. The electronic data deliverables received from the laboratory are loaded into the Locus ElMTM database and processed through a series of data quality checks, which are a combination of software, Locus EIMTm database Data Verification Module (DVM), and manual reviewer evaluations. The data are evaluated against the following data usability checks: • Field and laboratory blank contamination • US EPA hold time criteria • Missing Quality Control (QC) samples • Matrix spike (MS)/matrix spike duplicate (MSD) recoveries and the relative percent differences (RPDs) between these spikes • Laboratory control sample (LCS)/laboratory control sample duplicate (LCSD) recoveries and the RPD between these spikes • Surrogate spike recoveries for organic analyses • Difference/RPD between field duplicate sample pairs • RPD between laboratory replicates for inorganic analyses • Difference/percent difference between total and dissolved sample pairs There are two qualifier fields in EIM: Laboratory Qualifier is the qualifier assigned by the laboratory and may not reflect the usability of the data. This qualifier may have many different meanings and can vary between labs and over time within the same lab. Please refer to the laboratory report for a description of the laboratory qualifiers. As they are laboratory descriptors they are not to be used when evaluating the data. Validation Qualifier is the 3rd party formal validation qualifier if this was performed. Otherwise this field contains the qualifier resulting from the ADQM DVM review process. This qualifier assesses the usability of the data and may not equal the laboratory qualifier. The DVM applies the following data evaluation qualifiers to analysis results, as warranted: Qualifier Definition B Not detected substantially above the level reported in the laboratory or field blanks. R Unusable result. Anal to may or may not be present in the sample. J An to resent. Reported value may not be accurate or precise. UJ Not detected. Reporting limit may not be accurate or precise. The Validation Status Code field is set to "DVM" if the ADQM DVM process has been performed. If the DVM has not been run, the field will be blank. If the DVM has been run (Validation Status Code equals "DVM"), use the Validation Qualifier. If the data have been validated by a third party, the field "Validated By" will be set to the validator (e.g., ESI for Environmental Standards, Inc.) DVM Narrative Report Site: Fayetteville Sampling Program: CAP GW Sampling 1Q24 Validation Options: LABSTATS Validation Reason Code: The preparation hold time for this sample was exceeded by a factor of 2. The reported result may be biased low. Date Validation Analytical Field Sample ID Sampled Lab Sample ID Analyte Result Units Type MDL PQL Qualifier Method CAP1Q24-EQBLK-BP- 02/02/2024 320-109475-3 Perfluorooctadecanoic 0.0020 ug/L PQL 0.0020 UJ 537 Modified 020224 Acid CAP1Q24-EQBLK-BP- 02/02/2024 320-109475-3 Perfluorooctadecanoic 0.0020 ug/L PQL 0.0020 UJ 537 Modified 020224 Acid CAP1Q24-EQBLK-BP- 02/02/2024 320-109475-3 PS Acid 0.0020 UG/L PQL 0.0020 UJ 537 Modified 020224 CAP1Q24-EQBLK-BP- 02/02/2024 320-109475-3 PS Acid 0.0020 UG/L PQL 0.0020 UJ 537 Modified 020224 CAP1Q24-EQBLK-BP- 02/02/2024 320-109475-3 EVE Acid 0.0020 UG/L PQL 0.0020 UJ 537 Modified 020224 CAP1Q24-EQBLK-BP- 02/02/2024 320-109475-3 EVE Acid 0.0020 UG/L PQL 0.0020 UJ 537 Modified 020224 CAP1Q24-EQBLK-IS- 02/22/2024 320-109943-5 Perfluorooctadecanoic 0.0020 ug/L PQL 0.0020 UJ 537 Modified 022224 Acid CAP 1Q24-LTW-03-013124 01/31/2024 320-109381-7 PS Acid 0.050 UG/L PQL 0.050 UJ 537 Modified CAP 1Q24-LTW-03-013124 01/31/2024 320-109381-7 EVE Acid 0.050 UG/L PQL 0.050 UJ 537 Modified CAP1Q24-OW-32-012924 01/29/2024 320-109381-1 PS Acid 0.050 UG/L PQL 0.050 UJ 537 Modified CAP1Q24-OW-32-012924 01/29/2024 320-109381-1 EVE Acid 0.050 UG/L PQL 0.050 UJ 537 Modified CAP1Q24-OW-33-013024 01/30/2024 320-109381-5 PS Acid 0.050 UG/L PQL 0.050 UJ 537 Modified CAP1Q24-OW-33-013024 01/30/2024 320-109381-5 EVE Acid 0.050 UG/L PQL 0.050 UJ 537 Modified CAP1Q24-OW-40-013024 01/30/2024 320-109381-4 PS Acid 0.050 UG/L PQL 0.050 UJ 537 Modified CAP1Q24-OW-40-013024 01/30/2024 320-109381-4 EVE Acid 0.050 UG/L PQL 0.050 UJ 537 Modified CAP1Q24-OW-4R-012924 01/29/2024 320-109381-2 PS Acid 0.050 UG/L PQL 0.050 UJ 537 Modified CAP1Q24-OW-4R-012924 01/29/2024 320-109381-2 EVE Acid 0.050 UG/L PQL 0.050 UJ 537 Modified CAP1Q24-OW-51-013124 01/31/2024 320-109381-9 PS Acid 0.050 UG/L PQL 0.050 UJ 537 Modified CAP1Q24-OW-51-013124 01/31/2024 320-109381-9 EVE Acid 0.050 UG/L PQL 0.050 UJ 537 Modified CAP1Q24-OW-54-020624 02/06/2024 320-109475-6 PS Acid 0.050 UG/L PQL 0.050 UJ 537 Modified CAP1Q24-OW-54-020624 02/06/2024 320-109475-6 EVE Acid 0.050 UG/L PQL 0.050 UJ 537 Modified CAP1Q24-OW-56-020124 02/01/2024 320-109475-1 PS Acid 0.050 UG/L PQL 0.050 UJ 537 Modified Pre -prep Prep 3535 3535 3535 3535 3535 3535 3535 3535 3535 3535 3535 3535 3535 3535 3535 3535 3535 3535 3535 3535 3535 3535 Page 1 of 16 Site: Fayetteville Validation Reason Code Sampling Program: CAP GW Sampling 1Q24 Validation Options: LABSTATS The preparation hold time for this sample was exceeded by a factor of 2. The reported result may be biased low. Date Validation Analytical Field Sample ID Sampled Lab Sample ID Analyte Result Units Type MDL PQL Qualifier Method CAP1Q24-OW-56-020124 02/01/2024 320-109475-1 EVE Acid 0.050 UG/L PQL 0.050 UJ 537 Modified CAP1Q24-OW-55-020524 02/05/2024 320-109475-4 PS Acid 0.050 UG/L PQL 0.050 UJ 537 Modified CAP1Q24-OW-55-020524 02/05/2024 320-109475-4 EVE Acid 0.050 UG/L PQL 0.050 UJ 537 Modified CAP1Q24-OW-57-020624 02/06/2024 320-109475-7 EVE Acid 0.050 UG/L PQL 0.050 UJ 537 Modified CAP1Q24-OW30-013024 01/30/2024 320-109381-3 PS Acid 0.050 UG/L PQL 0.050 UJ 537 Modified CAP1Q24-OW30-013024 01/30/2024 320-109381-3 EVE Acid 0.050 UG/L PQL 0.050 UJ 537 Modified CAP1 Q24-PIW-1 1-020124 02/01/2024 320-109475-2 PS Acid 0.050 UG/L PQL 0.050 UJ 537 Modified CAP1 Q24-PIW-1 1-020124 02/01/2024 320-109475-2 EVE Acid 0.050 UG/L PQL 0.050 UJ 537 Modified CAP1 Q24-PIW-1 5-020524 02/05/2024 320-109475-5 PS Acid 0.050 UG/L PQL 0.050 UJ 537 Modified CAP1 Q24-PIW-1 5-020524 02/05/2024 320-109475-5 EVE Acid 0.050 UG/L PQL 0.050 UJ 537 Modified CAP1Q24-PIW-6S-013124 01/31/2024 320-109381-8 PS Acid 0.050 UG/L PQL 0.050 UJ 537 Modified CAP1Q24-PIW-6S-013124 01/31/2024 320-109381-8 EVE Acid 0.050 UG/L PQL 0.050 UJ 537 Modified CAP1Q24-PW-11-013124 01/31/2024 320-109381-10 EVE Acid 0.050 UG/L PQL 0.050 UJ 537 Modified CAP1Q24-PW-10RR- 01/31/2024 320-109381-6 PS Acid 0.050 UG/L PQL 0.050 UJ 537 Modified 013124 CAP1Q24-PW-10RR- 01/31/2024 320-109381-6 EVE Acid 0.050 UG/L PQL 0.050 UJ 537 Modified 013124 Pre -prep Prep 3535 3535 3535 3535 3535 3535 3535 3535 3535 3535 3535 3535 3535 3535 3535 Page 2 of 16 Site: Fayetteville Sampling Program: CAP GW Sampling 1Q24 Validation Options: LABSTATS Validation Reason Code: Associated MS and/or MSD analysis had relative percent recovery (RPR) values less than the lower control limit but above the rejection limit. The reported result may be biased low. Date Validation Analytical Field Sample ID Sampled Lab Sample ID Analyte Result Units Type MDL PQL Qualifier Method Pre -prep Prep CAP1Q24-OW-56-020124 02/01/2024 320-109475-1 PS Acid 0.050 UG/L PQL 0.050 UJ 537 Modified 3535 CAP1Q24-OW-56-020124 02/01/2024 320-109475-1 EVE Acid 0.050 UG/L PQL 0.050 UJ 537 Modified 3535 Page 3 of 16 Site: Fayetteville Sampling Program: CAP GW Sampling 1Q24 Validation Options: LABSTATS Validation Reason Code: Associated LCS and/or LCSD analysis had relative percent recovery (RPR) values less than the lower control limit but above 10%. The actual detection limits may be higher than reported. Date Validation Analytical Field Sample ID Sampled Lab Sample ID Analyte Result Units Type MDL PQL Qualifier Method Pre -prep Prep CAP1Q24-EQBLK-BP- 02/02/2024 320-109475-3 Perfluorooctadecanoic 0.0020 ug/L PQL 0.0020 UJ 537 Modified 3535 020224 Acid CAP1Q24-EQBLK-BP- 02/02/2024 320-109475-3 PS Acid 0.0020 UG/L PQL 0.0020 UJ 537 Modified 3535 020224 CAP1Q24-EQBLK-BP- 02/02/2024 320-109475-3 EVE Acid 0.0020 UG/L PQL 0.0020 UJ 537 Modified 3535 020224 CAP1Q24-OW-54-020624 02/06/2024 320-109475-6 PS Acid 0.050 UG/L PQL 0.050 UJ 537 Modified 3535 CAP1Q24-OW-54-020624 02/06/2024 320-109475-6 EVE Acid 0.050 UG/L PQL 0.050 UJ 537 Modified 3535 CAP1Q24-OW-55-020524 02/05/2024 320-109475-4 PS Acid 0.050 UG/L PQL 0.050 UJ 537 Modified 3535 CAP1Q24-OW-55-020524 02/05/2024 320-109475-4 EVE Acid 0.050 UG/L PQL 0.050 UJ 537 Modified 3535 CAP1Q24-OW-57-020624 02/06/2024 320-109475-7 EVE Acid 0.050 UG/L PQL 0.050 UJ 537 Modified 3535 CAP1 Q24-PIW-1 1-020124 02/01/2024 320-109475-2 PS Acid 0.050 UG/L PQL 0.050 UJ 537 Modified 3535 CAP1 Q24-PIW-1 1-020124 02/01/2024 320-109475-2 EVE Acid 0.050 UG/L PQL 0.050 UJ 537 Modified 3535 CAP1 Q24-PIW-1 5-020524 02/05/2024 320-109475-5 PS Acid 0.050 UG/L PQL 0.050 UJ 537 Modified 3535 CAP1 Q24-PIW-1 5-020524 02/05/2024 320-109475-5 EVE Acid 0.050 UG/L PQL 0.050 UJ 537 Modified 3535 Page 4 of 16 Site: Fayetteville Validation Reason Code Sampling Program: CAP GW Sampling 1Q24 Validation Options: LABSTATS Associated MS and/or MSD analysis had relative percent recovery (RPR) values less than the lower control limit. The actual detection limits may be higher than reported. Date Field Sample ID Sampled Lab Sample ID CAP1Q24-OW-32-012924 01/29/2024 320-109381-1 Validation Analytical Analyte Result Units Type MDL PQL Qualifier Method Pre -prep Perfluorononanoic 0.034 UG/L PQL 0.034 UJ 537 Modified Acid Prep 3535 Page 5 of 16 Site: Fayetteville Sampling Program: CAP GW Sampling 1Q24 Validation Options Validation Reason Code: The preparation hold time for this sample was exceeded. The reporting limit may be biased low. Date Validation Analytical Field Sample ID Sampled Lab Sample ID Analyte Result Units Type MDL PQL Qualifier Method CAP1Q24-BLADEN-1DR- 01/15/2024 320-108762-10 PPF Acid 0.31 UG/L PQL 0.31 UJ 537 Modified 011524 CAP1Q24-BLADEN-1DR- 01/15/2024 320-108762-10 PPF Acid 0.31 UG/L PQL 0.31 UJ 537 Modified 011524 CAP1Q24-PZ-22-011624 01/16/2024 320-108762-6 6:2 Fluorotelomer 0.31 ug/L PQL 0.31 UJ 537 Modified sulfonate CAP1Q24-PIW-7D-011524- 01/15/2024 320-108762-2 6:2 Fluorotelomer 0.31 ug/L PQL 0.31 UJ 537 Modified D sulfonate CAP1Q24-PW-06-011524 01/15/2024 320-108762-8 6:2 Fluorotelomer 0.31 ug/L PQL 0.31 UJ 537 Modified sulfonate LABSTATS Pre -prep Prep 3535 3535 3535 3535 3535 Page 6 of 16 Site: Fayetteville Validation Reason Code Sampling Program: CAP SW Sampling 1Q24 Validation Options: LABSTATS High relative percent difference (RPD) observed between field duplicate and parent sample. The reported result may be imprecise. Date Validation Analytical Field Sample ID Sampled Lab Sample ID Analyte Result Units Type MDL PQL Qualifier Method CAP1Q24-WC-3-24- 02/22/2024 320-109943-3 PMPA 0.083 UG/L PQL 0.0034 J 537 Modified 022224 CAP1Q24-WC-3-24- 02/22/2024 320-109943-3 Hfpo Dimer Acid 0.050 UG/L PQL 0.015 J 537 Modified 022224 CAP1Q24-WC-3-24- 02/22/2024 320-109943-3 R-PSDA 0.0033 UG/L PQL 0.0028 J 537 Modified 022224 CAP1Q24-WC-3-24- 02/22/2024 320-109943-3 Perfluorobutane 0.0043 UG/L PQL 0.0020 J 537 Modified 022224 Sulfonic Acid CAP1Q24-WC-3-24- 02/22/2024 320-109943-3 PF02HxA 0.044 ug/L PQL 0.0055 J 537 Modified 022224 CAP1Q24-WC-3-24- 02/22/2024 320-109943-3 PFMOAA 0.022 ug/L PQL 0.0041 J 537 Modified 022224 CAP1Q24-WC-3-24- 02/22/2024 320-109943-4 PMPA 0.14 UG/L PQL 0.0020 J 537 Modified 022224-D CAP1Q24-WC-3-24- 02/22/2024 320-109943-4 Hfpo Dimer Acid 0.094 UG/L PQL 0.0040 J 537 Modified 022224-D CAP1Q24-WC-3-24- 02/22/2024 320-109943-4 R-PSDA 0.0092 UG/L PQL 0.0020 J 537 Modified 022224-D CAP1Q24-WC-3-24- 02/22/2024 320-109943-4 Perfluorobutane 0.0064 UG/L PQL 0.0020 J 537 Modified 022224-D Sulfonic Acid CAP1Q24-WC-3-24- 02/22/2024 320-109943-4 PF02HxA 0.086 ug/L PQL 0.0020 J 537 Modified 022224-D CAP1Q24-WC-3-24- 02/22/2024 320-109943-4 PFMOAA 0.038 ug/L PQL 0.0020 J 537 Modified 022224-D Pre -prep Prep 3535 3535 3535 3535 3535 3535 3535 3535 3535 3535 3535 3535 Page 7 of 16 Site: Fayetteville Validation Reason Code Sampling Program: CAP GW Sampling 1Q24 Validation Options: LABSTATS High relative percent difference (RPD) observed between LCS and LCSD samples. The reported result may be imprecise. Date Validation Analytical Field Sample ID Sampled Lab Sample ID Analyte Result Units Type MDL PQL Qualifier Method CAP1Q24-PIW-7D-011524- 01/15/2024 320-108762-2 PPF Acid 73 UG/L PQL 0.31 J 537 Modified D CAP1Q24-PZ-22-011624 01/16/2024 320-108762-6 PPF Acid 72 UG/L PQL 0.31 J 537 Modified CAP1Q24-PIW-7D-011524 01/15/2024 320-108762-1 PPF Acid 71 UG/L PQL 0.31 J 537 Modified Pre -prep Prep 3535 3535 3535 Page 8 of 16 Site: Fayetteville Sampling Program: CAP GW Sampling 1Q24 Validation Options: LABSTATS Validation Reason Code: Uncertainty around the analysis of R-PSDA, Hydrolyzed PSDA and R-EVE; J-qualifier added to all detects in the data set, even if there was no matrix spike analyzed for that particular sample. Date Validation Analytical Field Sample ID Sampled Lab Sample ID Analyte Result Units Type MDL PQL Qualifier Method Pre -prep Prep CAP1Q24-PW-11-013124 01/31/2024 320-109381-10 R-PSDA 0.30 UG/L PQL 0.035 J 537 Modified 3535 CAP1Q24-PW-11-013124 01/31/2024 320-109381-10 Hydrolyzed PSDA 0.85 UG/L PQL 0.034 J 537 Modified 3535 CAP1Q24-PW-11-013124 01/31/2024 320-109381-10 R-EVE 0.11 UG/L PQL 0.039 J 537 Modified 3535 CAP1Q24-SMW-11- 01/18/2024 320-109020-8 R-PSDA 0.12 UG/L PQL 0.035 J 537 Modified 3535 011824 CAP1Q24-SMW-11- 01/18/2024 320-109020-8 R-PSDA 0.12 UG/L PQL 0.035 J 537 Modified 3535 011824 CAP1Q24-SMW-11- 01/18/2024 320-109020-8 Hydrolyzed PSDA 0.088 UG/L PQL 0.034 J 537 Modified 3535 011824 CAP1Q24-SMW-11- 01/18/2024 320-109020-8 Hydrolyzed PSDA 0.088 UG/L PQL 0.034 J 537 Modified 3535 011824 CAP1Q24-SMW-11- 01/18/2024 320-109020-8 R-EVE 0.088 UG/L PQL 0.039 J 537 Modified 3535 011824 CAP1Q24-SMW-11- 01/18/2024 320-109020-8 R-EVE 0.088 UG/L PQL 0.039 J 537 Modified 3535 011824 CAP1Q24-WC-1-24- 02/22/2024 320-109943-1 R-PSDA 0.036 UG/L PQL 0.0020 J 537 Modified 3535 022224 CAP1Q24-WC-1-24- 02/22/2024 320-109943-1 Hydrolyzed PSDA 0.16 UG/L PQL 0.0020 J 537 Modified 3535 022224 CAP1Q24-WC-1-24- 02/22/2024 320-109943-1 R-EVE 0.018 UG/L PQL 0.0020 J 537 Modified 3535 022224 CAP1Q24-WC-2-24- 02/22/2024 320-109943-2 R-PSDA 0.012 UG/L PQL 0.0020 J 537 Modified 3535 022224 CAP1Q24-WC-2-24- 02/22/2024 320-109943-2 Hydrolyzed PSDA 0.014 UG/L PQL 0.0020 J 537 Modified 3535 022224 CAP1Q24-WC-2-24- 02/22/2024 320-109943-2 R-EVE 0.0077 UG/L PQL 0.0020 J 537 Modified 3535 022224 CAP1Q24-WC-3-24- 02/22/2024 320-109943-4 R-EVE 0.0046 UG/L PQL 0.0020 J 537 Modified 3535 022224-D CAP1Q24-PW-04-011724 01/17/2024 320-109020-5 R-PSDA 0.13 UG/L PQL 0.035 J 537 Modified 3535 CAP1Q24-PW-04-011724 01/17/2024 320-109020-5 R-PSDA 0.13 UG/L PQL 0.035 J 537 Modified 3535 CAP1Q24-PW-04-011724 01/17/2024 320-109020-5 R-EVE 0.066 UG/L PQL 0.039 J 537 Modified 3535 CAP1Q24-PW-04-011724 01/17/2024 320-109020-5 R-EVE 0.066 UG/L PQL 0.039 J 537 Modified 3535 CAP 1Q24-PW-04-011724- 01/17/2024 320-109020-6 R-PSDA 0.13 UG/L PQL 0.035 J 537 Modified 3535 Z CAP 1Q24-PW-04-011724- 01/17/2024 320-109020-6 R-PSDA 0.13 UG/L PQL 0.035 J 537 Modified 3535 Z CAP 1Q24-PW-04-011724- 01/17/2024 320-109020-6 R-EVE 0.065 UG/L PQL 0.039 J 537 Modified 3535 Z Page 9 of 16 Site: Fayetteville Sampling Program: CAP GW Sampling 1Q24 Validation Options: LABSTATS Validation Reason Code: Uncertainty around the analysis of R-PSDA, Hydrolyzed PSDA and R-EVE; J-qualifier added to all detects in the data set, even if there was no matrix spike analyzed for that particular sample. Date Validation Analytical Field Sample ID Sampled Lab Sample ID Analyte Result Units Type MDL PQL Qualifier Method Pre -prep Prep CAP 1Q24-PW-04-011724- 01/17/2024 320-109020-6 R-EVE 0.065 UG/L PQL 0.039 J 537 Modified 3535 Z CAP1Q24-PW-10RR- 01/31/2024 320-109381-6 R-PSDA 0.084 UG/L PQL 0.035 J 537 Modified 3535 013124 CAP1Q24-PW-10RR- 01/31/2024 320-109381-6 Hydrolyzed PSDA 0.084 UG/L PQL 0.034 J 537 Modified 3535 013124 CAP1Q24-PW-10RR- 01/31/2024 320-109381-6 R-EVE 0.12 UG/L PQL 0.039 J 537 Modified 3535 013124 CAP1Q24-PIW-3D-011824 01/18/2024 320-109020-7 R-PSDA 0.78 UG/L PQL 0.035 J 537 Modified 3535 CAP1Q24-PIW-3D-011824 01/18/2024 320-109020-7 R-PSDA 0.78 UG/L PQL 0.035 J 537 Modified 3535 CAP1Q24-PIW-3D-011824 01/18/2024 320-109020-7 Hydrolyzed PSDA 0.47 UG/L PQL 0.034 J 537 Modified 3535 CAP1Q24-PIW-3D-011824 01/18/2024 320-109020-7 Hydrolyzed PSDA 0.47 UG/L PQL 0.034 J 537 Modified 3535 CAP1Q24-PIW-3D-011824 01/18/2024 320-109020-7 R-EVE 0.39 UG/L PQL 0.039 J 537 Modified 3535 CAP1Q24-PIW-3D-011824 01/18/2024 320-109020-7 R-EVE 0.39 UG/L PQL 0.039 J 537 Modified 3535 CAP1Q24-PIW-6S-013124 01/31/2024 320-109381-8 R-PSDA 0.73 UG/L PQL 0.035 J 537 Modified 3535 CAP1Q24-PIW-6S-013124 01/31/2024 320-109381-8 Hydrolyzed PSDA 4.3 UG/L PQL 0.034 J 537 Modified 3535 CAP1Q24-PIW-6S-013124 01/31/2024 320-109381-8 R-EVE 0.36 UG/L PQL 0.039 J 537 Modified 3535 CAP1 Q24-PIW-1 5-020524 02/05/2024 320-109475-5 R-PSDA 0.19 UG/L PQL 0.035 J 537 Modified 3535 CAP1 Q24-PIW-1 5-020524 02/05/2024 320-109475-5 R-EVE 0.13 UG/L PQL 0.039 J 537 Modified 3535 CAP1 Q24-PIW-1 1-020124 02/01/2024 320-109475-2 R-PSDA 0.23 UG/L PQL 0.035 J 537 Modified 3535 CAP1 Q24-PIW-1 1-020124 02/01/2024 320-109475-2 Hydrolyzed PSDA 2.8 UG/L PQL 0.034 J 537 Modified 3535 CAP1 Q24-PIW-1 1-020124 02/01/2024 320-109475-2 R-EVE 0.077 UG/L PQL 0.039 J 537 Modified 3535 CAP1Q24-OW30-013024 01/30/2024 320-109381-3 R-PSDA 0.34 UG/L PQL 0.035 J 537 Modified 3535 CAP1Q24-OW30-013024 01/30/2024 320-109381-3 Hydrolyzed PSDA 0.52 UG/L PQL 0.034 J 537 Modified 3535 CAP1Q24-OW30-013024 01/30/2024 320-109381-3 R-EVE 0.27 UG/L PQL 0.039 J 537 Modified 3535 CAP1Q24-OW-56-020124 02/01/2024 320-109475-1 R-PSDA 0.14 UG/L PQL 0.035 J 537 Modified 3535 CAP1Q24-OW-56-020124 02/01/2024 320-109475-1 R-EVE 0.11 UG/L PQL 0.039 J 537 Modified 3535 Page 10 of 16 Site: Fayetteville Sampling Program: CAP GW Sampling 1Q24 Validation Options: LABSTATS Validation Reason Code: Uncertainty around the analysis of R-PSDA, Hydrolyzed PSDA and R-EVE; J-qualifier added to all detects in the data set, even if there was no matrix spike analyzed for that particular sample. Date Validation Analytical Field Sample ID Sampled Lab Sample ID Analyte Result Units Type MDL PQL Qualifier Method Pre -prep Prep CAP1Q24-OW-57-020624 02/06/2024 320-109475-7 R-PSDA 1.2 UG/L PQL 0.035 J 537 Modified 3535 CAP1Q24-OW-57-020624 02/06/2024 320-109475-7 Hydrolyzed PSDA 15 UG/L PQL 0.034 J 537 Modified 3535 CAP1Q24-OW-57-020624 02/06/2024 320-109475-7 R-EVE 0.21 UG/L PQL 0.039 J 537 Modified 3535 CAP1Q24-OW-55-020524 02/05/2024 320-109475-4 R-PSDA 0.10 UG/L PQL 0.035 J 537 Modified 3535 CAP1Q24-OW-55-020524 02/05/2024 320-109475-4 R-EVE 0.085 UG/L PQL 0.039 J 537 Modified 3535 CAP1Q24-OW-54-020624 02/06/2024 320-109475-6 R-PSDA 0.078 UG/L PQL 0.035 J 537 Modified 3535 CAP1Q24-OW-54-020624 02/06/2024 320-109475-6 R-EVE 0.042 UG/L PQL 0.039 J 537 Modified 3535 CAP1Q24-OW-51-013124 01/31/2024 320-109381-9 R-PSDA 0.65 UG/L PQL 0.035 J 537 Modified 3535 CAP1Q24-OW-51-013124 01/31/2024 320-109381-9 Hydrolyzed PSDA 1.4 UG/L PQL 0.034 J 537 Modified 3535 CAP1Q24-OW-51-013124 01/31/2024 320-109381-9 R-EVE 0.70 UG/L PQL 0.039 J 537 Modified 3535 CAP1Q24-OW-4R-012924 01/29/2024 320-109381-2 R-PSDA 0.57 UG/L PQL 0.035 J 537 Modified 3535 CAP1Q24-OW-4R-012924 01/29/2024 320-109381-2 Hydrolyzed PSDA 2.3 UG/L PQL 0.034 J 537 Modified 3535 CAP1Q24-OW-4R-012924 01/29/2024 320-109381-2 R-EVE 0.39 UG/L PQL 0.039 J 537 Modified 3535 CAP1Q24-OW-37-011724 01/17/2024 320-109020-3 R-PSDA 0.10 UG/L PQL 0.035 J 537 Modified 3535 CAP1Q24-OW-37-011724 01/17/2024 320-109020-3 R-PSDA 0.10 UG/L PQL 0.035 J 537 Modified 3535 CAP1Q24-OW-37-011724 01/17/2024 320-109020-3 Hydrolyzed PSDA 0.083 UG/L PQL 0.034 J 537 Modified 3535 CAP1Q24-OW-37-011724 01/17/2024 320-109020-3 Hydrolyzed PSDA 0.083 UG/L PQL 0.034 J 537 Modified 3535 CAP1Q24-OW-40-013024 01/30/2024 320-109381-4 R-PSDA 0.20 UG/L PQL 0.035 J 537 Modified 3535 CAP1Q24-OW-40-013024 01/30/2024 320-109381-4 Hydrolyzed PSDA 0.065 UG/L PQL 0.034 J 537 Modified 3535 CAP1Q24-OW-40-013024 01/30/2024 320-109381-4 R-EVE 0.10 UG/L PQL 0.039 J 537 Modified 3535 CAP1Q24-OW-33-013024 01/30/2024 320-109381-5 R-PSDA 0.21 UG/L PQL 0.035 J 537 Modified 3535 CAP1Q24-OW-33-013024 01/30/2024 320-109381-5 Hydrolyzed PSDA 0.038 UG/L PQL 0.034 J 537 Modified 3535 CAP1Q24-OW-33-013024 01/30/2024 320-109381-5 R-EVE 0.14 UG/L PQL 0.039 J 537 Modified 3535 Page 11 of 16 Site: Fayetteville Sampling Program: CAP GW Sampling 1Q24 Validation Options: LABSTATS Validation Reason Code: Uncertainty around the analysis of R-PSDA, Hydrolyzed PSDA and R-EVE; J-qualifier added to all detects in the data set, even if there was no matrix spike analyzed for that particular sample. Date Validation Analytical Field Sample ID Sampled Lab Sample ID Analyte Result Units Type MDL PQL Qualifier Method Pre -prep Prep CAP1Q24-PZ-22-011624 01/16/2024 320-108762-6 R-PSDA 0.44 UG/L PQL 0.035 J 537 Modified 3535 CAP1Q24-PZ-22-011624 01/16/2024 320-108762-6 Hydrolyzed PSDA 1.1 UG/L PQL 0.034 J 537 Modified 3535 CAP1Q24-PZ-22-011624 01/16/2024 320-108762-6 R-EVE 0.30 UG/L PQL 0.039 J 537 Modified 3535 CAP1Q24-OW-28-011824 01/18/2024 320-109020-9 R-PSDA 0.28 UG/L PQL 0.035 J 537 Modified 3535 CAP1Q24-OW-28-011824 01/18/2024 320-109020-9 R-PSDA 0.28 UG/L PQL 0.035 J 537 Modified 3535 CAP1Q24-OW-28-011824 01/18/2024 320-109020-9 R-EVE 0.12 UG/L PQL 0.039 J 537 Modified 3535 CAP1Q24-OW-28-011824 01/18/2024 320-109020-9 R-EVE 0.12 UG/L PQL 0.039 J 537 Modified 3535 CAP1Q24-OW-32-012924 01/29/2024 320-109381-1 R-PSDA 0.22 UG/L PQL 0.035 J 537 Modified 3535 CAP1Q24-OW-32-012924 01/29/2024 320-109381-1 Hydrolyzed PSDA 0.65 UG/L PQL 0.034 J 537 Modified 3535 CAP1Q24-OW-32-012924 01/29/2024 320-109381-1 R-EVE 0.14 UG/L PQL 0.039 J 537 Modified 3535 CAP 1Q24-LTW-03-013124 01/31/2024 320-109381-7 R-PSDA 0.77 UG/L PQL 0.035 J 537 Modified 3535 CAP 1Q24-LTW-03-013124 01/31/2024 320-109381-7 Hydrolyzed PSDA 5.3 UG/L PQL 0.034 J 537 Modified 3535 CAP 1Q24-LTW-03-013124 01/31/2024 320-109381-7 R-EVE 0.32 UG/L PQL 0.039 J 537 Modified 3535 CAP1Q24-PIW-7S-011524 01/15/2024 320-108762-3 R-PSDA 0.79 UG/L PQL 0.035 J 537 Modified 3535 CAP1Q24-PIW-7S-011524 01/15/2024 320-108762-3 Hydrolyzed PSDA 0.045 UG/L PQL 0.034 J 537 Modified 3535 CAP1Q24-PIW-7S-011524 01/15/2024 320-108762-3 R-EVE 0.88 UG/L PQL 0.039 J 537 Modified 3535 CAP1Q24-PW-06-011524 01/15/2024 320-108762-8 R-PSDA 0.042 UG/L PQL 0.035 J 537 Modified 3535 CAP1Q24-SMW-12- 01/16/2024 320-108762-4 R-PSDA 0.065 UG/L PQL 0.035 J 537 Modified 3535 011624 CAP1Q24-SMW-12- 01/16/2024 320-108762-4 R-EVE 0.045 UG/L PQL 0.039 J 537 Modified 3535 011624 CAP1Q24-PIW-10DR- 01/22/2024 320-109019-2 R-PSDA 0.61 UG/L PQL 0.035 J 537 Modified 3535 012224 CAP1Q24-PIW-10DR- 01/22/2024 320-109019-2 Hydrolyzed PSDA 2.3 UG/L PQL 0.034 J 537 Modified 3535 012224 CAP1Q24-PIW-10DR- 01/22/2024 320-109019-2 R-EVE 0.40 UG/L PQL 0.039 J 537 Modified 3535 012224 CAP1Q24-PIW-1D-012224 01/22/2024 320-109019-1 R-PSDA 0.38 UG/L PQL 0.035 J 537 Modified 3535 Page 12 of 16 Site: Fayetteville Sampling Program: CAP GW Sampling 1Q24 Validation Options: LABSTATS Validation Reason Code: Uncertainty around the analysis of R-PSDA, Hydrolyzed PSDA and R-EVE; J-qualifier added to all detects in the data set, even if there was no matrix spike analyzed for that particular sample. Date Validation Analytical Field Sample ID Sampled Lab Sample ID Analyte Result Units Type MDL PQL Qualifier Method Pre -prep Prep CAP1Q24-PIW-1D-012224 01/22/2024 320-109019-1 R-EVE 0.18 UG/L PQL 0.039 J 537 Modified 3535 CAP1Q24-PIW-4D-012224 01/22/2024 320-109019-3 R-PSDA 0.020 UG/L PQL 0.0020 J 537 Modified 3535 CAP1Q24-PIW-4D-012224 01/22/2024 320-109019-3 Hydrolyzed PSDA 0.080 UG/L PQL 0.0020 J 537 Modified 3535 CAP1Q24-PIW-4D-012224 01/22/2024 320-109019-3 R-EVE 0.012 UG/L PQL 0.0020 J 537 Modified 3535 CAP1Q24-PIW-8D-012224 01/22/2024 320-109019-4 R-PSDA 2.6 UG/L PQL 0.035 J 537 Modified 3535 CAP1Q24-PIW-8D-012224 01/22/2024 320-109019-4 Hydrolyzed PSDA 5.3 UG/L PQL 0.034 J 537 Modified 3535 CAP1Q24-PIW-8D-012224 01/22/2024 320-109019-4 R-EVE 2.3 UG/L PQL 0.039 J 537 Modified 3535 CAP1Q24-LTW-01-011724 01/17/2024 320-109020-1 R-PSDA 0.83 UG/L PQL 0.035 J 537 Modified 3535 CAP1Q24-LTW-01-011724 01/17/2024 320-109020-1 R-PSDA 0.83 UG/L PQL 0.035 J 537 Modified 3535 CAP1Q24-LTW-01-011724 01/17/2024 320-109020-1 Hydrolyzed PSDA 0.083 UG/L PQL 0.034 J 537 Modified 3535 CAP1Q24-LTW-01-011724 01/17/2024 320-109020-1 Hydrolyzed PSDA 0.083 UG/L PQL 0.034 J 537 Modified 3535 CAP1Q24-LTW-01-011724 01/17/2024 320-109020-1 R-EVE 0.31 UG/L PQL 0.039 J 537 Modified 3535 CAP1Q24-LTW-01-011724 01/17/2024 320-109020-1 R-EVE 0.31 UG/L PQL 0.039 J 537 Modified 3535 CAP 1Q24-LTW-02-011724 01/17/2024 320-109020-2 R-PSDA 0.78 UG/L PQL 0.035 J 537 Modified 3535 CAP 1Q24-LTW-02-011724 01/17/2024 320-109020-2 R-PSDA 0.78 UG/L PQL 0.035 J 537 Modified 3535 CAP 1Q24-LTW-02-011724 01/17/2024 320-109020-2 Hydrolyzed PSDA 1.8 UG/L PQL 0.034 J 537 Modified 3535 CAP 1Q24-LTW-02-011724 01/17/2024 320-109020-2 Hydrolyzed PSDA 1.8 UG/L PQL 0.034 J 537 Modified 3535 CAP 1Q24-LTW-02-011724 01/17/2024 320-109020-2 R-EVE 0.44 UG/L PQL 0.039 J 537 Modified 3535 CAP 1Q24-LTW-02-011724 01/17/2024 320-109020-2 R-EVE 0.44 UG/L PQL 0.039 J 537 Modified 3535 CAP 1Q24-LTW-04-011624 01/16/2024 320-108762-5 R-PSDA 1.4 UG/L PQL 0.035 J 537 Modified 3535 CAP 1Q24-LTW-04-011624 01/16/2024 320-108762-5 Hydrolyzed PSDA 2.8 UG/L PQL 0.034 J 537 Modified 3535 CAP 1Q24-LTW-04-011624 01/16/2024 320-108762-5 R-EVE 1.1 UG/L PQL 0.039 J 537 Modified 3535 CAP 1Q24-LTW-05-011524 01/15/2024 320-108762-9 R-PSDA 1.3 UG/L PQL 0.035 J 537 Modified 3535 Page 13 of 16 Site: Fayetteville Sampling Program: CAP GW Sampling 1Q24 Validation Options: LABSTATS Validation Reason Code: Uncertainty around the analysis of R-PSDA, Hydrolyzed PSDA and R-EVE; J-qualifier added to all detects in the data set, even if there was no matrix spike analyzed for that particular sample. Date Validation Analytical Field Sample ID Sampled Lab Sample ID Analyte Result Units Type MDL PQL Qualifier Method Pre -prep Prep CAP 1Q24-LTW-05-011524 01/15/2024 320-108762-9 Hydrolyzed PSDA 2.6 UG/L PQL 0.034 J 537 Modified 3535 CAP 1Q24-LTW-05-011524 01/15/2024 320-108762-9 R-EVE 1.5 UG/L PQL 0.039 J 537 Modified 3535 CAP1Q24-PIW-IS-011624 01/16/2024 320-108762-7 R-PSDA 0.11 UG/L PQL 0.035 J 537 Modified 3535 CAP1Q24-PIW-7D-011524 01/15/2024 320-108762-1 R-PSDA 0.57 UG/L PQL 0.035 J 537 Modified 3535 CAP1Q24-PIW-7D-011524 01/15/2024 320-108762-1 Hydrolyzed PSDA 1.1 UG/L PQL 0.034 J 537 Modified 3535 CAP1Q24-PIW-7D-011524 01/15/2024 320-108762-1 R-EVE 0.54 UG/L PQL 0.039 J 537 Modified 3535 CAP1Q24-PIW-7D-011524- 01/15/2024 320-108762-2 R-PSDA 0.56 UG/L PQL 0.035 J 537 Modified 3535 D CAP1Q24-PIW-7D-011524- 01/15/2024 320-108762-2 Hydrolyzed PSDA 1.1 UG/L PQL 0.034 J 537 Modified 3535 D CAP1Q24-PIW-7D-011524- 01/15/2024 320-108762-2 R-EVE 0.60 UG/L PQL 0.039 J 537 Modified 3535 D Page 14 of 16 Site: Fayetteville Validation Reason Code Sampling Program: CAP GW Sampling 1Q24 Validation Options: LABSTATS The preparation hold time for this sample was exceeded by a factor of 2. The reported result may be biased low. Date Validation Analytical Field Sample ID Sampled Lab Sample ID Analyte Result Units Type MDL PQL Qualifier Method CAP1Q24-PW-11-013124 01/31/2024 320-109381-10 Perfluoropentanoic 0.23 UG/L PQL 0.061 J 537 Modified Acid CAP1Q24-PW-11-013124 01/31/2024 320-109381-10 PS Acid 0.097 UG/L PQL 0.050 J 537 Modified CAP1Q24-PW-11-013124 01/31/2024 320-109381-10 Perfluoroheptanoic 0.11 UG/L PQL 0.031 J 537 Modified Acid CAP1Q24-PW-10RR- 01/31/2024 320-109381-6 Perfluoropentanoic 0.52 UG/L PQL 0.061 J 537 Modified 013124 Acid CAP1Q24-PIW-6S-013124 01/31/2024 320-109381-8 Perfluoropentanoic 0.76 UG/L PQL 0.061 J 537 Modified Acid CAP1Q24-OW30-013024 01/30/2024 320-109381-3 Perfluoropentanoic 0.46 UG/L PQL 0.061 J 537 Modified Acid CAP1Q24-OW-57-020624 02/06/2024 320-109475-7 PS Acid 0.33 UG/L PQL 0.050 J 537 Modified CAP1Q24-OW-51-013124 01/31/2024 320-109381-9 Perfluoroheptanoic 0.20 UG/L PQL 0.031 J 537 Modified Acid CAP1Q24-OW-51-013124 01/31/2024 320-109381-9 Perfluoropentanoic 1.4 UG/L PQL 0.061 J 537 Modified Acid CAP1Q24-OW-40-013024 01/30/2024 320-109381-4 Perfluoropentanoic 0.075 UG/L PQL 0.061 J 537 Modified Acid CAP1Q24-OW-33-013024 01/30/2024 320-109381-5 Perfluoropentanoic 0.12 UG/L PQL 0.061 J 537 Modified Acid CAP 1Q24-LTW-03-013124 01/31/2024 320-109381-7 Perfluoropentanoic 0.56 UG/L PQL 0.061 J 537 Modified Acid Pre -prep Prep 3535 3535 3535 3535 3535 3535 3535 3535 3535 3535 3535 3535 Page 15 of 16 Site: Fayetteville Sampling Program: CAP GW Sampling 1Q24 Validation Options Validation Reason Code: The preparation hold time for this sample was exceeded. The reported result may be biased low. Date Validation Analytical Field Sample ID Sampled Lab Sample ID Analyte Result Units Type MDL PQL Qualifier Method CAP1Q24-PW-06-011524 01/15/2024 320-108762-8 PPF Acid 0.95 UG/L PQL 0.31 J 537 Modified CAP1Q24-PW-06-011524 01/15/2024 320-108762-8 PPF Acid 0.59 UG/L PQL 0.31 J 537 Modified CAP1Q24-PW-06-011524 01/15/2024 320-108762-8 PFMOAA 0.13 ug/L PQL 0.051 J 537 Modified CAP1Q24-PIW-7S-011524 01/15/2024 320-108762-3 PPF Acid 17 UG/L PQL 0.31 J 537 Modified CAP1Q24-PIW-7S-011524 01/15/2024 320-108762-3 PPF Acid 11 UG/L PQL 0.31 J 537 Modified CAP1Q24-SMW-12- 01/16/2024 320-108762-4 PPF Acid 6.4 UG/L PQL 0.31 J 537 Modified 011624 CAP1Q24-SMW-12- 01/16/2024 320-108762-4 PPF Acid 4.0 UG/L PQL 0.31 J 537 Modified 011624 CAP 1Q24-LTW-04-011624 01/16/2024 320-108762-5 PPF Acid 43 UG/L PQL 0.31 J 537 Modified CAP 1Q24-LTW-04-011624 01/16/2024 320-108762-5 PPF Acid 28 UG/L PQL 0.31 J 537 Modified CAP1Q24-PIW-1S-011624 01/16/2024 320-108762-7 PPF Acid 1.3 UG/L PQL 0.31 J 537 Modified CAP1Q24-PIW-1S-011624 01/16/2024 320-108762-7 PPF Acid 0.79 UG/L PQL 0.31 J 537 Modified CAP1Q24-PIW-IS-011624 01/16/2024 320-108762-7 PFMOAA 0.39 ug/L PQL 0.051 J 537 Modified LABSTATS Pre -prep Prep 3535 3535 3535 3535 3535 3535 3535 3535 3535 3535 3535 3535 Page 16 of 16 ADQM Data Review Site: Chemours Fayetteville Protect: Seep Flow Through Sampling 1 Q24 (update 3) Project Reviewer: Bridget Gavaghan & Michael Aucoin Sample Summary Field Sample ID Lab Sample ID Sample Filtered Sample Sample Sample Purpose Matrix Date Time SEEP-A-INFLUENT-24- Surface 320-108586-1 N 01/06/2024 23:00 FS 010624 Water SEEP-C-INFLUENT-TSS- 320-108586-10 Surface N 01/08/2024 10:50 FS 010824 Water SEEP-C-EFFLUENT-TSS- Surface 010824 320-108586-11 Water N 01/08/2024 10:55 FS SEEP-A-INFLUENT-24- 320-108586-2 Surface N 01/06/2024 23:00 DUP 010624-D Water SEEP-A-EFFLUENT-24- Surface 010624 320-108586-3 Water N 01/06/2024 23:00 FS SEEP-C-INFLUENT-24- 320-108586-4 Surface N 01/06/2024 23:00 FS 010624 Water SEEP-C-EFFLUENT-24- 320-108586-5 Surface N 01/06/2024 23:00 FS 010624 Water SEEP-EB-010824 320-108586-6 Blank Water N 01/08/2024 09:50 EB SEEP-FB-010824 320-108586-7 Blank Water N 01/08/2024 09:55 FB SEEP-A-INFLUENT-TSS- Surface 320-108586-8 N 01/08/2024 11:35 FS 010824 Water SEEP-A-EFFLUENT-TSS- 320-108586-9 Surface N 01/08/2024 11:40 FS 010824 Water SEEP-A-INFLUENT-24- Surface 011024 320-108628-1 Water N 01/10/2024 12:00 FS SEEP-A-EFFLUENT-24- Surface 320-108628-2 N 01/10/2024 12:00 FS 011024 Water SEEP-B-INFLUENT-24- Surface 320-108628-3 N 01/10/2024 12:00 FS 011024 Water SEEP-B-EFFLUENT-24- 320-108628-4 Surface N 01/10/2024 12:00 FS 011024 Water SEEP-C-INFLUENT-24- Surface 320-108628-5 N 01/10/2024 12:00 FS 011024 Water SEEP-C-EFFLUENT-24- 320-108628-6 Surface N 01/10/2024 12:00 FS 011024 Water SEEP-D-INFLUENT-24- 320-108628-7 Surface N 01/10/2024 12:00 FS 011024 Water SEEP-D-EFFLUENT-24- Surface 320-108628-8 N 01/10/2024 12:00 FS 011024 Water SEEP-A-INFLUENT-TSS- Surface 011024 320-108630-1 Water N 01/10/2024 12:10 FS SEEP-A-EFFLUENT-TSS- Surface 320-108630-2 N 01/10/2024 12:15 FS 011024 Water SEEP-B-INFLUENT-TSS- 320-108630-3 Surface N 01/10/2024 12:40 FS 011024 Water SEEP-B-EFFLUENT-TSS- Surface 011024 320-108630-4 Water N 01/10/2024 12:45 FS SEEP-C-INFLUENT-TSS- 320-108630-5 Surface N 01/10/2024 13:20 FS 011024 Water SEEP-C-EFFLUENT-TSS- Surface 011024 320-108630-6 Water N 01/10/2024 13:25 FS SEEP-D-INFLUENT-TSS- 320-108630-7 Surface N 01/10/2024 13:40 FS 011024 Water SEEP-D-EFFLUENT-TSS- Surface 011024 320-108630-8 Water N 01/10/2024 13:45 FS SEEP-A-INFLUENT-24- 320-108999-1 Surface N 01/20/2024 23:00 FS 012024 Water SEEP-A-EFFLUENT-24- Surface 012024 320-108999-2 Water N 01/20/2024 23:00 FS SEEP-B-INFLUENT-24- 320-108999-3 Surface N 01/20/2024 23:00 FS 012024 Water SEEP-B-EFFLUENT-24- Surface 012024 320-108999-4 Water N 01/20/2024 23:00 FS Field Sample ID Lab Sample ID Sample Filtered Sample Sample Sample Purpose Matrix Date Time SEEP-C-INFLUENT-24- Surface 012024 320-108999-5 Water N 01/20/2024 23:00 FS SEEP-C-EFFLUENT-24- 320-108999-6 Surface N 01/20/2024 23:00 FS 012024 Water SEEP-D-INFLUENT-24- Surface 320-108999-7 N 01/20/2024 23:00 FS 012024 Water SEEP- D-EFFLU ENT-24- 320-108999-8 Surface N 01/20/2024 23:00 FS 012024 Water SEEP-A-INFLUENT-TSS- Surface 012324 320-109093-1 Water N 01/23/2024 09:20 FS SEEP-B-INFLUENT-TSS- 320-109093-2 Surface N 01/23/2024 09:40 FS 012324 Water SEEP-C-INFLUENT-TSS- Surface 320-109093-3 N 01/23/2024 10:05 FS 012324 Water SEEP-D-INFLUENT-TSS- 320-109093-4 Surface N 01/23/2024 10:25 FS 012324 Water SEEP-A-EFFLUENT-TSS- 320-109093-5 Surface N 01/23/2024 09:25 FS 012324 Water SEEP-B-EFFLUENT-TSS- 320-109093-6 Surface N 01/23/2024 09:45 FS 012324 Water SEEP-C-EFFLUENT-TSS- 320-109093-7 Surface N 01/23/2024 10:10 FS 012324 Water SEEP-D-EFFLUENT-TSS- Surface 320-109093-8 N 01/23/2024 10:20 FS 012324 Water SEEP-B-INFLUENT-24- Surface 012524 320-109165-1 Water N 01/25/2024 09:00 FS SEEP-B-EFFLUENT-24- Surface 012524 320-109165-2 Water N 01/25/2024 09:00 FS SEEP-D-INFLUENT-24- 320-109165-3 Surface N 01/25/2024 09:00 FS 012524 Water SEEP-D-EFFLUENT-24- Surface 320-109165-4 N 01/25/2024 09:00 FS 012524 Water SEEP-B-INFLUENT-TSS- 320-109165-5 Surface N 01/25/2024 11:10 FS 012524 Water SEEP-B-EFFLUENT-TSS- Surface 320-109165-6 N 01/25/2024 11:15 FS 012524 Water SEEP-D-INFLUENT-TSS- 320-109165-7 Surface N 01/25/2024 10:40 FS 012524 Water SEEP-D-EFFLUENT-TSS- Surface 012524 320-109165-8 Water N 01/25/2024 10:45 FS SEEP-A-INFLUENT-24- 320-109311-1 Surface N 01/31/2024 07:30 FS 013124 Water SEEP-A-EFFLUENT-24- Surface 013124 320-109311-2 Water N 01/31/2024 07:30 FS SEEP-B-INFLUENT-24- 320-109311-3 Surface N 01/31/2024 07:30 FS 013124 Water SEEP-B-EFFLUENT-24- 320-109311-4 Surface N 01/31/2024 07:30 FS 013124 Water SEEP-C-INFLUENT-24- 320-109311-5 Surface N 01/31/2024 07:30 FS 013124 Water SEEP-C-EFFLUENT-24- 320-109311-6 Surface N 01/31/2024 07:30 FS 013124 Water SEEP-D-INFLUENT-24- Surface 013124 320-109311-7 Water N 01/31/2024 07:30 FS SEEP-D-EFFLUENT-24- 320-109311-8 Surface N 01/31/2024 07:30 FS 013124 Water SEEP-A-INFLUENT-TSS- Surface 013124 320-109313-1 Water N 01/31/2024 08:40 FS SEEP-B-INFLUENT-TSS- 320-109313-2 Surface N 01/31/2024 11:50 FS 013124 Water SEEP-C-INFLUENT-TSS- Surface 013124 320-109313-3 Water N 01/31/2024 12:00 FS SEEP-D-INFLUENT-TSS- 320-109313-4 Surface N 01/31/2024 09:35 FS 013124 Water Field Sample ID Lab Sample ID Sample Filtered Sample Sample Sample Purpose Matrix Date Time SEEP-A-EFFLUENT-TSS- Surface 320-109313-5 N 01/31/2024 08:45 FS 013124 Water SEEP-B-EFFLUENT-TSS- 320-109313-6 Surface N 01/31/2024 11:55 FS 013124 Water SEEP-C-EFFLUENT-TSS- Surface 320-109313-7 N 01/31/2024 12:05 FS 013124 Water SEEP- D-EFFLUENT-TSS- 320-109313-8 Surface N 01/31/2024 09:40 FS 013124 Water SEEP-A-INFLUENT-24- Surface 320-109349-1 N 02/01/2024 07:38 FS 020124 Water SEEP-A-EFFLUENT-24- 320-109349-2 Surface N 02/01/2024 07:40 FS 020124 Water SEEP-B-INFLUENT-24- Surface 320-109349-3 N 02/01/2024 07:15 FS 020124 Water SEEP-B-EFFLUENT-24- 320-109349-4 Surface N 02/01/2024 07:12 FS 020124 Water SEEP-C-INFLUENT-24- 320-109349-5 Surface N 02/01/2024 06:58 FS 020124 Water SEEP-C-EFFLUENT-24- 320-109349-6 Surface N 02/01/2024 07:04 FS 020124 Water SEEP-D-INFLUENT-24- 320-109349-7 Surface N 02/01/2024 06:47 FS 020124 Water SEEP-D-EFFLUENT-24- 320-109349-8 Surface N 02/01/2024 06:46 FS 020124 Water SEEP-A-INFLUENT-TSS- 320-109661-1 Surface N 02/13/2024 09:50 FS 021324 Water SEEP-B-INFLUENT-TSS- Surface 320-109661-2 N 02/13/2024 10:30 FS 021324 Water SEEP-C-INFLUENT-TSS- 320-109661-3 Surface N 02/13/2024 10:40 FS 021324 Water SEEP-D-INFLUENT-TSS- Surface 021324 320-109661-4 Water N 02/13/2024 11:00 FS SEEP-A-EFFLUENT-TSS- 320-109661-5 Surface N 02/13/2024 09:55 FS 021324 Water SEEP-B-EFFLUENT-TSS- Surface 021324 320-109661-6 Water N 02/13/2024 10:35 FS SEEP-C-EFFLUENT-TSS- 320-109661-7 Surface N 02/13/2024 10:45 FS 021324 Water SEEP-D-EFFLUENT-TSS- Surface 021324 320-109661-8 Water N 02/13/2024 11:05 FS SEEP-A-INFLUENT-24- 320-109662-1 Surface N 02/13/2024 00:44 FS 021324 Water SEEP-FB-021324 320-109662-10 Blank Water N 02/13/2024 09:40 FB SEEP-EB-021324 320-109662-11 Blank Water N 02/13/2024 09:45 EB SEEP-A-EFFLUENT-24- 320-109662-2 Surface N 02/13/2024 01:07 FS 021324 Water SEEP-A-EFFLUENT-24- Surface 021324-D 320-109662-3 Water N 02/13/2024 01:07 DUP SEEP-B-INFLUENT-24- 320-109662-4 Water N 02/13/2024 00:26 FS 021324 SEEP-B-EFFLUENT-24- 021324 320-109662-5 Water N 02/13/2024 00:56 FS SEEP-C-INFLUENT-24- 320-109662-6 Surface N 02/13/2024 01:00 FS 021324 Water SEEP-C-EFFLUENT-24- Surface 021324 320-109662-7 Water N 02/13/2024 01:02 FS SEEP-D-INFLUENT-24- 320-109662-8 Water N 02/13/2024 01:17 FS 021324 SEEP-D-EFFLUENT-24- 021324 320-109662-9 Water N 02/13/2024 01:43 FS SEEP-A-INFLUENT-TSS- 320-109793-1 Surface N 02/15/2024 12:30 FS 021524 Water SEEP-B-INFLUENT-TSS- Surface 021524 320-109793-2 Water N 02/15/2024 12:50 FS Field Sample ID Lab Sample ID Sample Filtered Sample Sample Sample Purpose Matrix Date Time SEEP-C-INFLUENT-TSS- Surface 320-109793-3 N 02/15/2024 13:00 FS 021524 Water SEEP-D-INFLUENT-TSS- 320-109793-4 Surface N 02/15/2024 13:10 FS 021524 Water SEEP-A-EFFLUENT-TSS- Surface 320-109793-5 N 02/15/2024 12:35 FS 021524 Water SEEP-B-EFFLUENT-TSS- 320-109793-6 Surface N 02/15/2024 12:55 FS 021524 Water SEEP-C-EFFLUENT-TSS- Surface 320-109793-7 N 02/15/2024 13:05 FS 021524 Water SEEP-D-EFFLUENT-TSS- 320-109793-8 Surface N 02/15/2024 13:15 FS 021524 Water SEEP-A-INFLUENT-24- Surface 320-109798-1 N 02/14/2024 12:00 FS 021424 Water SEEP-A-EFFLUENT-24- 320-109798-2 Surface N 02/14/2024 12:00 FS 021424 Water SEEP-B-INFLUENT-24- 320-109798-3 Surface N 02/14/2024 12:00 FS 021424 Water SEEP-B-EFFLUENT-24- 320-109798-4 Surface N 02/14/2024 12:00 FS 021424 Water SEEP-C-INFLUENT-24- 320-109798-5 Surface N 02/14/2024 12:00 FS 021424 Water SEEP-C-EFFLUENT-24- 320-109798-6 Surface N 02/14/2024 12:00 FS 021424 Water SEEP-D-INFLUENT-24- 320-109798-7 Surface N 02/14/2024 12:00 FS 021424 Water SEEP-D-EFFLUENT-24- Surface 320-109798-8 N 02/14/2024 12:00 FS 021424 Water SEEP-C-INFLUENT-24- 320-110063-1 Surface N 02/24/2024 05:23 FS 022424 Water SEEP-C-EFFLUENT-24- Surface 022424 320-110063-2 Water N 02/24/2024 05:33 FS SEEP-A-INFLUENT-TSS- 320-110219-1 Surface N 03/04/2024 08:20 FS 030424 Water SEEP-B-INFLUENT-TSS- Surface 030424 320-110219-2 Water N 03/04/2024 08:55 FS SEEP-C-INFLUENT-TSS- 320-110219-3 Surface N 03/04/2024 09:25 FS 030424 Water SEEP-D-INFLUENT-TSS- Surface 030424 320-110219-4 Water N 03/04/2024 09:50 FS SEEP-A-EFFLUENT-TSS- 320-110219-5 Surface N 03/04/2024 08:25 FS 030424 Water SEEP-B-EFFLUENT-TSS- Surface 030424 320-110219-6 Water N 03/04/2024 09:00 FS SEEP-C-EFFLUENT-TSS- 320-110219-7 Surface N 03/04/2024 09:30 FS 030424 Water SEEP-D-EFFLUENT-TSS- 320-110219-8 Surface N 03/04/2024 09:55 FS 030424 Water SEEP-A-INFLUENT-24- 320-110221-1 Surface N 03/02/2024 18:03 FS 030224 Water SEEP-FB-030424 320-110221-10 Blank Water N 03/04/2024 08:20 FB SEEP-EB-030424 320-110221-11 Blank Water N 03/04/2024 08:25 EB SEEP-A-INFLUENT-24- 320-110221-2 Surface N 03/02/2024 18:03 DUP 030224-D Water SEEP-A-EFFLUENT-24- Surface 030224 320-110221-3 Water N 03/02/2024 18:45 FS SEEP-B-INFLUENT-24- 320-110221-4 Surface N 03/02/2024 16:20 FS 030224 Water SEEP-B-EFFLUENT-24- Surface 030224 320-110221-5 Water N 03/02/2024 18:10 FS SEEP-C-INFLUENT-24- 320-110221-6 Surface N 03/02/2024 18:00 FS 030224 Water SEEP-C-EFFLUENT-24- Surface 030224 320-110221-7 Water N 03/02/2024 18:06 FS Field Sample ID Lab Sample ID Sample Filtered Sample Sample Sample Purpose Matrix Date Time SEEP-D-INFLUENT-24- Surface 030224 320-110221-8 Water N 03/02/2024 18:03 FS SEEP-D-EFFLUENT-24- 320-110221-9 Surface N 03/02/2024 18:18 FS 030224 Water SEEP-A-INFLUENT-24- Surface 030724 320-110365-1 Water N 03/07/2024 09:50 FS SEEP-A-EFFLUENT-24- 320-110365-2 Surface N 03/07/2024 09:54 FS 030724 Water SEEP-B-INFLUENT-24- Surface 030724 320-110365-3 Water N 03/07/2024 09:42 FS SEEP-B-EFFLUENT-24- 320-110365-4 Surface N 03/07/2024 09:54 FS 030724 Water SEEP-C-INFLUENT-24- Surface 320-110365-5 N 03/07/2024 09:46 FS 030724 Water SEEP-C-EFFLUENT-24- 320-110365-6 Surface N 03/07/2024 09:45 FS 030724 Water SEEP-D-INFLUENT-24- 320-110365-7 Surface N 03/07/2024 09:55 FS 030724 Water SEEP-D-EFFLUENT-24- 320-110365-8 Surface N 03/07/2024 09:59 FS 030724 Water SEEP-A-INFLUENT-TSS- 320-110385-1 Surface N 03/07/2024 10:25 FS 030724 Water SEEP-B-INFLUENT-TSS- Surface 320-110385-2 N 03/07/2024 11:00 FS 030724 Water SEEP-C-INFLUENT-TSS- Surface 030724 320-110385-3 Water N 03/07/2024 11:10 FS SEEP-D-INFLUENT-TSS- Surface 030724 320-110385-4 Water N 03/07/2024 11:20 FS SEEP-A-EFFLUENT-TSS- 320-110385-5 Surface N 03/07/2024 10:30 FS 030724 Water SEEP-B-EFFLUENT-TSS- Surface 320-110385-6 N 03/07/2024 11:05 FS 030724 Water SEEP-C-EFFLUENT-TSS- 320-110385-7 Surface N 03/07/2024 11:15 FS 030724 Water SEEP-D-EFFLUENT-TSS- Surface 320-110385-8 N 03/07/2024 11:25 FS 030724 Water SEEP-A-INFLUENT-24- Surface 320-110423-1 N 03/11/2024 07:24 FS 031124 Water SEEP-A-EFFLUENT-24- Surface 031124 320-110423-2 Water N 03/11/2024 07:23 FS SEEP-B-INFLUENT-24- 320-110423-3 Surface N 03/11/2024 07:37 FS 031124 Water SEEP-B-EFFLUENT-24- Surface 031124 320-110423-4 Water N 03/11/2024 07:35 FS SEEP-C-INFLUENT-24- 320-110423-5 Surface N 03/11/2024 07:35 FS 031124 Water SEEP-C-EFFLUENT-24- 320-110423-6 Surface N 03/11/2024 07:41 FS 031124 Water SEEP-D-INFLUENT-24- 320-110423-7 Surface N 03/11/2024 07:44 FS 031124 Water SEEP-D-EFFLUENT-24- 320-110423-8 Surface N 03/11/2024 07:45 FS 031124 Water SEEP-A-INFLUENT-24- Surface 032324 320-110828-1 Water N 03/23/2024 23:00 FS SEEP-A-EFFLUENT-24- 320-110828-2 Surface N 03/23/2024 23:00 FS 032324 Water SEEP-B-INFLUENT-24- Surface 032324 320-110828-3 Water N 03/23/2024 23:00 FS SEEP-B-EFFLUENT-24- 320-110828-4 Surface N 03/23/2024 23:00 FS 032324 Water SEEP-C-INFLUENT-24- Surface 03, 320-110828-5 Water N 03/23/2024 23:00 FS SEEP-C-EFFLUENT-24- 320-110828-6 Surface N 03/23/2024 23:00 FS 032324 Water Field Sample ID Lab Sample ID Sample Filtered Sample Sample Sample Purpose Matrix Date Time SEEP-D-INFLUENT-24- Surface 032324 320-110828-7 Water N 03/23/2024 23:00 FS SEEP-D-EFFLUENT-24- 320-110828-8 Surface N 03/23/2024 23:00 FS 032324 Water SEEP-A-INFLUENT-TSS- Surface 320-110831-1 N 03/25/2024 09:30 FS 032524 Water SEEP- B-INFLU ENT-TSS- 320-110831-2 Surface N 03/25/2024 08:45 FS 032524 Water SEEP-C-INFLUENT-TSS- Surface 032524 320-110831-3 Water N 03/25/2024 08:25 FS SEEP-D-INFLUENT-TSS- 320-110831-4 Surface N 03/25/2024 08:00 FS 032524 Water SEEP-A-EFFLUENT-TSS- Surface 032524 320-110831-5 Water N 03/25/2024 09:35 FS SEEP-B-EFFLUENT-TSS- 320-110831-6 Surface N 03/25/2024 08:50 FS 032524 Water SEEP-C-EFFLUENT-TSS- 320-110831-7 Surface N 03/25/2024 08:30 FS 032524 Water SEEP- D-EFFLUENT-TSS- 320-110831-8 Surface N 03/25/2024 08:05 FS 032524 Water SEEP-A-INFLUENT-TSS- 320-111002-1 Surface N 03/28/2024 12:10 FS 032824 Water SEEP-B-INFLUENT-TSS- Surface 320-111002-2 N 03/28/2024 12:30 FS 032824 Water SEEP-C-INFLUENT-TSS- Surface 032824 320-111002-3 Water N 03/28/2024 12:45 FS SEEP-D-INFLUENT-TSS- Surface 032824 320-111002-4 Water N 03/28/2024 13:00 FS SEEP-A-EFFLUENT-TSS- 320-111002-5 Surface N 03/28/2024 12:15 FS 032824 Water SEEP-B-EFFLUENT-TSS- Surface 320-111002-6 N 03/28/2024 12:35 FS 032824 Water SEEP-C-EFFLUENT-TSS- 320-111002-7 Surface N 03/28/2024 12:50 FS 032824 Water SEEP-D-EFFLUENT-TSS- Surface 320-111002-8 N 03/28/2024 13:05 FS 032824 Water SEEP-A-INFLUENT-24- 320-111004-1 Surface N 03/28/2024 12:00 FS 032824 Water SEEP-A-EFFLUENT-24- Surface 032824 320-111004-2 Water N 03/28/2024 12:00 FS SEEP-B-INFLUENT-24- 320-111004-3 Surface N 03/28/2024 12:00 FS 032824 Water SEEP-B-EFFLUENT-24- Surface 032824 320-111004-4 Water N 03/28/2024 12:00 FS SEEP-C-INFLUENT-24- 320-111004-5 Surface N 03/28/2024 12:00 FS 032824 Water SEEP-C-EFFLUENT-24- 320-111004-6 Surface N 03/28/2024 12:00 FS 032824 Water SEEP-D-INFLUENT-24- 320-111004-7 Surface N 03/28/2024 12:00 FS 032824 Water SEEP-D-EFFLUENT-24- 320-111004-8 Surface N 03/28/2024 12:00 FS 032824 Water * FS=Field Sample DUP=Field Duplicate FB=Field Blank EB=Equipment Blank TB=Trip Blank Analytical Protocol Lab Name Lab Method Parameter Category Sampling Program Eurofins Environ CI. Spec. Table 3 Per- and Polyfluorinated Seep Flow Through Cell Sampling 2024 Testing Northern Cali Compound SOP Alkyl Substances PFAS Eurofins Environ Testing Northern Cali SM 2540 D-2015 Total Suspended Solids Seep Flow Through Cell Sampling 2024 ADQM Data Review Checklist DVM Laboratory Exception Item Description Yes No* Narrative Report Report (ER) Report # Did samples meet laboratory acceptability A requirements upon receipt (i.e., intact, within X temperature, properly preserved, and no heads ace where applicable)? B Were samples received by the laboratory in X agreement with the associated chain of custody? C Was the chain of custody properly completed by X the laboratory and/or field team? D Were samples prepped/analyzed by the laboratory X within method holding times? Were data review criteria met for method blanks, LCSs/LCSDs, MSs/MSDs, PDSs, SDs, replicates, E surrogates, sample results within calibration range, X X X total/dissolved samples, field duplicates, field/equipment/trip blanks? F Were all data usable and not R qualified? X ER# Description Other QA/QC Items to Note: See DVM Narrative Report, Laboratory Report, and/or ER # for further details as indicated. The electronic data submitted for this project were reviewed via the Data Verification Module (DVM) process. Overall, the data are acceptable for use without qualification, except as noted on the attached DVM Narrative Report. The lab reports due to a large page count are stored on a network shared drive and are available to be posted on external shared drives, or on a flash drive. Data Verification Module (DVM) The DVM is an internal review process used by the ADQM group to assist with the determination of data usability. The electronic data deliverables received from the laboratory are loaded into the Locus ElMTM database and processed through a series of data quality checks, which are a combination of software, Locus EIMTm database Data Verification Module (DVM), and manual reviewer evaluations. The data are evaluated against the following data usability checks: • Field and laboratory blank contamination • US EPA hold time criteria • Missing Quality Control (QC) samples • Matrix spike (MS)/matrix spike duplicate (MSD) recoveries and the relative percent differences (RPDs) between these spikes • Laboratory control sample (LCS)/laboratory control sample duplicate (LCSD) recoveries and the RPD between these spikes • Surrogate spike recoveries for organic analyses • Difference/RPD between field duplicate sample pairs • RPD between laboratory replicates for inorganic analyses • Difference/percent difference between total and dissolved sample pairs • Temperature upon laboratory receipt meets the range of not frozen to 6 deg. C with a target of 4 deg. C (manual check) There are two qualifier fields in EIM: Laboratory Qualifier is the qualifier assigned by the laboratory and may not reflect the usability of the data. This qualifier may have many different meanings and can vary between labs and over time within the same lab. Please refer to the laboratory report for a description of the laboratory qualifiers. As they are laboratory descriptors they are not to be used when evaluating the data. Validation Qualifier is the 3rd party formal validation qualifier if this was performed. Otherwise this field contains the qualifier resulting from the ADQM DVM review process. This qualifier assesses the usability of the data and may not equal the laboratory qualifier. The DVM applies the following data evaluation qualifiers to analysis results, as warranted: Qualifier Definition B Not detected substantially above the level reported in the laboratory or field blanks. R Unusable result. Anal to may or may not be present in the sample. J Anal to present. Reported value may not be accurate or precise. UJ Not detected. Reporting limit may not be accurate or precise. The Validation Status Code field is set to "DVM" if the ADQM DVM process has been performed. If the DVM has not been run, the field will be blank. If the DVM has been run (Validation Status Code equals "DVM"), use the Validation Qualifier. If the data have been validated by a third party, the field "Validated By" will be set to the validator (e.g., ESI for Environmental Standards, Inc.) DVM Narrative Report Site: Fayetteville Sampling Program: Seep Flow Through Cell Sampling 2024 Validation Options: LABSTATS Validation Reason Code: Associated MS and/or MSD analysis had relative percent recovery (RPR) values less than the lower control limit. The actual detection limits may be higher than reported. Date Validation Analytical Field Sample ID Sampled Lab Sample ID Analyte Result Units Type MDL PQL Qualifier Method Pre -prep Prep SEEP-A-INFLUENT-24- 02/14/2024 320-109798-1 PFECA B 0.027 UG/L PQL 0.027 UJ Cl. Spec. Table 3 PFAS_DI_Prep 021424 Compound SOP Page 1 of 12 Site: Fayetteville Validation Reason Code Sampling Program: Seep Flow Through Cell Sampling 2024 Validation Options: LABSTATS Associated MS and/or MSD analysis had relative percent recovery (RPR) values higher than the upper control limit. The reported result may be biased high. Date Validation Analytical Field Sample ID Sampled Lab Sample ID Analyte Result Units Type MDL PQL Qualifier Method Pre -prep Prep SEEP-A-INFLUENT-24- 03/28/2024 320-111004-1 PFMOAA 19 ug/L PQL 0.080 J Cl. Spec. Table 3 PFAS_DI_Prep 032824 Compound SOP Page 2 of 12 Site: Fayetteville Sampling Program: Seep Flow Through Cell Sampling 2024 Validation Options: LABSTATS Validation Reason Code: Quality review criteria exceeded between the REP (laboratory replicate) and parent sample. The reported result may be imprecise. Date Field Sample ID Sampled Lab Sample ID Analyte SEEP-C-INFLUENT-TSS- 01/08/2024 320-108586-10 Total Suspended 010824 Solids Result Units Type MDL 52 MG/L MDL 4.4 Validation PQL Qualifier 13 J Analytical Method SM 2540 D-2015 Pre -prep Prep Page 3 of 12 Site: Fayetteville Sampling Program: Seep Flow Through Cell Sampling 2024 Validation Options: LABSTATS Validation Reason Code: Uncertainty around the analysis of R-PSDA, Hydrolyzed PSDA and R-EVE; J-qualifier added to all detects in the data set, even if there was no matrix spike analyzed for that particular sample. Date Validation Analytical Field Sample ID Sampled Lab Sample ID Analyte Result Units Type MDL PQL Qualifier Method Pre -prep Prep SEEP-A-INFLUENT-24- 02/14/2024 320-109798-1 R-PSDA 0.81 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 021424 Compound SOP SEEP-A-INFLUENT-24- 02/14/2024 320-109798-1 Hydrolyzed PSDA 2.0 UG/L PQL 0.038 J Cl. Spec. Table 3 PFAS_DI_Prep 021424 Compound SOP SEEP-A-INFLUENT-24- 02/14/2024 320-109798-1 R-EVE 0.39 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 021424 Compound SOP SEEP-A-INFLUENT-24- 03/02/2024 320-110221-1 R-PSDA 0.83 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 030224 Compound SOP SEEP-A-INFLUENT-24- 03/02/2024 320-110221-1 Hydrolyzed PSDA 2.3 UG/L PQL 0.050 J Cl. Spec. Table 3 PFAS_DI_Prep 030224 Compound SOP SEEP-A-INFLUENT-24- 03/02/2024 320-110221-1 R-EVE 0.47 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 030224 Compound SOP SEEP-A-INFLUENT-24- 03/02/2024 320-110221-2 R-PSDA 0.86 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 030224-D Compound SOP SEEP-A-INFLUENT-24- 03/02/2024 320-110221-2 Hydrolyzed PSDA 2.3 UG/L PQL 0.050 J Cl. Spec. Table 3 PFAS_DI_Prep 030224-D Compound SOP SEEP-A-INFLUENT-24- 03/02/2024 320-110221-2 R-EVE 0.42 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 030224-D Compound SOP SEEP-A-INFLUENT-24- 03/07/2024 320-110365-1 R-PSDA 0.57 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 030724 Compound SOP SEEP-A-INFLUENT-24- 03/07/2024 320-110365-1 Hydrolyzed PSDA 1.2 UG/L PQL 0.050 J Cl. Spec. Table 3 PFAS_DI_Prep 030724 Compound SOP SEEP-A-INFLUENT-24- 03/07/2024 320-110365-1 R-EVE 0.28 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 030724 Compound SOP SEEP-A-INFLUENT-24- 03/11/2024 320-110423-1 R-PSDA 0.88 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 031124 Compound SOP SEEP-A-INFLUENT-24- 03/11/2024 320-110423-1 Hydrolyzed PSDA 1.3 UG/L PQL 0.050 J Cl. Spec. Table 3 PFAS_DI_Prep 031124 Compound SOP SEEP-A-INFLUENT-24- 03/11/2024 320-110423-1 R-EVE 0.37 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 031124 Compound SOP SEEP-A-INFLUENT-24- 03/23/2024 320-110828-1 R-PSDA 0.87 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 032324 Compound SOP SEEP-A-INFLUENT-24- 03/23/2024 320-110828-1 Hydrolyzed PSDA 1.7 UG/L PQL 0.050 J Cl. Spec. Table 3 PFAS_DI_Prep 032324 Compound SOP SEEP-A-INFLUENT-24- 03/23/2024 320-110828-1 R-EVE 0.40 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 032324 Compound SOP SEEP-A-INFLUENT-24- 03/28/2024 320-111004-1 R-PSDA 0.75 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 032824 Compound SOP SEEP-A-INFLUENT-24- 03/28/2024 320-111004-1 Hydrolyzed PSDA 1.6 UG/L PQL 0.050 J Cl. Spec. Table 3 PFAS_DI_Prep 032824 Compound SOP SEEP-A-INFLUENT-24- 03/28/2024 320-111004-1 R-EVE 0.38 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 032824 Compound SOP SEEP-B-EFFLUENT-24- 01/31/2024 320-109311-4 Hydrolyzed PSDA 0.0049 UG/L PQL 0.0020 J Cl. Spec. Table 3 PFAS_DI_Prep 013124 Compound SOP SEEP-B-EFFLUENT-24- 02/01/2024 320-109349-4 Hydrolyzed PSDA 0.0053 UG/L PQL 0.0020 J Cl. Spec. Table 3 PFAS_DI_Prep 020124 Compound SOP Page 4 of 12 Site: Fayetteville Sampling Program: Seep Flow Through Cell Sampling 2024 Validation Options: LABSTATS Validation Reason Code: Uncertainty around the analysis of R-PSDA, Hydrolyzed PSDA and R-EVE; J-qualifier added to all detects in the data set, even if there was no matrix spike analyzed for that particular sample. Date Validation Analytical Field Sample ID Sampled Lab Sample ID Analyte Result Units Type MDL PQL Qualifier Method Pre -prep Prep SEEP-B-EFFLUENT-24- 02/13/2024 320-109662-5 R-PSDA 0.0024 UG/L PQL 0.0020 J Cl. Spec. Table 3 PFAS_DI_Prep 021324 Compound SOP SEEP-B-EFFLUENT-24- 02/13/2024 320-109662-5 Hydrolyzed PSDA 0.0072 UG/L PQL 0.0020 J Cl. Spec. Table 3 PFAS_DI_Prep 021324 Compound SOP SEEP-B-EFFLUENT-24- 03/02/2024 320-110221-5 Hydrolyzed PSDA 0.0036 UG/L PQL 0.0020 J Cl. Spec. Table 3 PFAS_DI_Prep 030224 Compound SOP SEEP-B-EFFLUENT-24- 03/23/2024 320-110828-4 Hydrolyzed PSDA 0.0047 UG/L PQL 0.0020 J Cl. Spec. Table 3 PFAS_DI_Prep 032324 Compound SOP SEEP-B-EFFLUENT-24- 03/28/2024 320-111004-4 Hydrolyzed PSDA 0.0059 UG/L PQL 0.0020 J Cl. Spec. Table 3 PFAS_DI_Prep 032824 Compound SOP SEEP-D-INFLUENT-24- 01/10/2024 320-108628-7 R-PSDA 0.14 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 011024 Compound SOP SEEP-D-INFLUENT-24- 01/10/2024 320-108628-7 Hydrolyzed PSDA 0.19 UG/L PQL 0.038 J Cl. Spec. Table 3 PFAS_DI_Prep 011024 Compound SOP SEEP-D-INFLUENT-24- 01/10/2024 320-108628-7 R-EVE 0.13 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 011024 Compound SOP SEEP-D-INFLUENT-24- 01/20/2024 320-108999-7 R-PSDA 0.10 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 012024 Compound SOP SEEP-D-INFLUENT-24- 01/20/2024 320-108999-7 Hydrolyzed PSDA 0.062 UG/L PQL 0.038 J Cl. Spec. Table 3 PFAS_DI_Prep 012024 Compound SOP SEEP-D-INFLUENT-24- 01/20/2024 320-108999-7 R-EVE 0.073 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 012024 Compound SOP SEEP-D-INFLUENT-24- 01/25/2024 320-109165-3 R-PSDA 0.12 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 012524 Compound SOP SEEP-D-INFLUENT-24- 01/25/2024 320-109165-3 Hydrolyzed PSDA 0.069 UG/L PQL 0.038 J Cl. Spec. Table 3 PFAS_DI_Prep 012524 Compound SOP SEEP-D-INFLUENT-24- 01/25/2024 320-109165-3 R-EVE 0.086 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 012524 Compound SOP SEEP-D-INFLUENT-24- 01/31/2024 320-109311-7 R-PSDA 0.11 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 013124 Compound SOP SEEP-D-INFLUENT-24- 01/31/2024 320-109311-7 Hydrolyzed PSDA 0.088 UG/L PQL 0.038 J Cl. Spec. Table 3 PFAS_DI_Prep 013124 Compound SOP SEEP-D-INFLUENT-24- 01/31/2024 320-109311-7 R-EVE 0.077 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 013124 Compound SOP SEEP-D-INFLUENT-24- 02/01/2024 320-109349-7 R-PSDA 0.12 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 020124 Compound SOP SEEP-D-INFLUENT-24- 02/01/2024 320-109349-7 Hydrolyzed PSDA 0.090 UG/L PQL 0.038 J Cl. Spec. Table 3 PFAS_DI_Prep 020124 Compound SOP SEEP-D-INFLUENT-24- 02/13/2024 320-109662-8 R-PSDA 0.17 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 021324 Compound SOP SEEP-D-INFLUENT-24- 02/13/2024 320-109662-8 Hydrolyzed PSDA 0.12 UG/L PQL 0.038 J Cl. Spec. Table 3 PFAS_DI_Prep 021324 Compound SOP SEEP-D-INFLUENT-24- 02/13/2024 320-109662-8 R-EVE 0.10 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 021324 Compound SOP SEEP-D-INFLUENT-24- 02/14/2024 320-109798-7 R-PSDA 0.20 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 021424 Compound SOP Page 5 of 12 Site: Fayetteville Sampling Program: Seep Flow Through Cell Sampling 2024 Validation Options: LABSTATS Validation Reason Code: Uncertainty around the analysis of R-PSDA, Hydrolyzed PSDA and R-EVE; J-qualifier added to all detects in the data set, even if there was no matrix spike analyzed for that particular sample. Date Validation Analytical Field Sample ID Sampled Lab Sample ID Analyte Result Units Type MDL PQL Qualifier Method Pre -prep Prep SEEP-D-INFLUENT-24- 02/14/2024 320-109798-7 Hydrolyzed PSDA 0.16 UG/L PQL 0.038 J Cl. Spec. Table 3 PFAS_DI_Prep 021424 Compound SOP SEEP-D-INFLUENT-24- 02/14/2024 320-109798-7 R-EVE 0.13 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 021424 Compound SOP SEEP-D-INFLUENT-24- 03/02/2024 320-110221-8 R-PSDA 0.29 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 030224 Compound SOP SEEP-D-INFLUENT-24- 03/02/2024 320-110221-8 Hydrolyzed PSDA 0.26 UG/L PQL 0.050 J Cl. Spec. Table 3 PFAS_DI_Prep 030224 Compound SOP SEEP-D-INFLUENT-24- 03/02/2024 320-110221-8 R-EVE 0.19 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 030224 Compound SOP SEEP-D-INFLUENT-24- 03/07/2024 320-110365-7 R-PSDA 0.22 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 030724 Compound SOP SEEP-D-INFLUENT-24- 03/07/2024 320-110365-7 Hydrolyzed PSDA 0.22 UG/L PQL 0.050 J Cl. Spec. Table 3 PFAS_DI_Prep 030724 Compound SOP SEEP-D-INFLUENT-24- 03/07/2024 320-110365-7 R-EVE 0.16 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 030724 Compound SOP SEEP-D-INFLUENT-24- 03/11/2024 320-110423-7 R-PSDA 0.36 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 031124 Compound SOP SEEP-D-INFLUENT-24- 03/11/2024 320-110423-7 Hydrolyzed PSDA 0.33 UG/L PQL 0.050 J Cl. Spec. Table 3 PFAS_DI_Prep 031124 Compound SOP SEEP-D-INFLUENT-24- 03/11/2024 320-110423-7 R-EVE 0.27 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 031124 Compound SOP SEEP-D-INFLUENT-24- 03/23/2024 320-110828-7 R-PSDA 0.33 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 032324 Compound SOP SEEP-D-INFLUENT-24- 03/23/2024 320-110828-7 Hydrolyzed PSDA 0.30 UG/L PQL 0.050 J Cl. Spec. Table 3 PFAS_DI_Prep 032324 Compound SOP SEEP-D-INFLUENT-24- 03/23/2024 320-110828-7 R-EVE 0.22 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 032324 Compound SOP SEEP-D-INFLUENT-24- 03/28/2024 320-111004-7 R-PSDA 0.33 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 032824 Compound SOP SEEP-D-INFLUENT-24- 03/28/2024 320-111004-7 Hydrolyzed PSDA 0.29 UG/L PQL 0.050 J Cl. Spec. Table 3 PFAS_DI_Prep 032824 Compound SOP SEEP-D-INFLUENT-24- 03/28/2024 320-111004-7 R-EVE 0.23 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 032824 Compound SOP SEEP-B-INFLUENT-24- 01/10/2024 320-108628-3 R-PSDA 0.27 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 011024 Compound SOP SEEP-B-INFLUENT-24- 01/10/2024 320-108628-3 Hydrolyzed PSDA 0.91 UG/L PQL 0.038 J Cl. Spec. Table 3 PFAS_DI_Prep 011024 Compound SOP SEEP-B-INFLUENT-24- 01/10/2024 320-108628-3 R-EVE 0.21 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 011024 Compound SOP SEEP-B-INFLUENT-24- 01/20/2024 320-108999-3 R-PSDA 0.43 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 012024 Compound SOP SEEP-B-INFLUENT-24- 01/20/2024 320-108999-3 Hydrolyzed PSDA 0.94 UG/L PQL 0.038 J Cl. Spec. Table 3 PFAS_DI_Prep 012024 Compound SOP SEEP-B-INFLUENT-24- 01/20/2024 320-108999-3 R-EVE 0.28 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 012024 Compound SOP Page 6 of 12 Site: Fayetteville Sampling Program: Seep Flow Through Cell Sampling 2024 Validation Options: LABSTATS Validation Reason Code: Uncertainty around the analysis of R-PSDA, Hydrolyzed PSDA and R-EVE; J-qualifier added to all detects in the data set, even if there was no matrix spike analyzed for that particular sample. Date Validation Analytical Field Sample ID Sampled Lab Sample ID Analyte Result Units Type MDL PQL Qualifier Method Pre -prep Prep SEEP-B-INFLUENT-24- 01/25/2024 320-109165-1 R-PSDA 0.37 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 012524 Compound SOP SEEP-B-INFLUENT-24- 01/25/2024 320-109165-1 Hydrolyzed PSDA 0.94 UG/L PQL 0.038 J Cl. Spec. Table 3 PFAS_DI_Prep 012524 Compound SOP SEEP-B-INFLUENT-24- 01/25/2024 320-109165-1 R-EVE 0.26 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 012524 Compound SOP SEEP-B-INFLUENT-24- 01/31/2024 320-109311-3 R-PSDA 0.29 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 013124 Compound SOP SEEP-B-INFLUENT-24- 01/31/2024 320-109311-3 Hydrolyzed PSDA 1.1 UG/L PQL 0.038 J Cl. Spec. Table 3 PFAS_DI_Prep 013124 Compound SOP SEEP-B-INFLUENT-24- 01/31/2024 320-109311-3 R-EVE 0.21 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 013124 Compound SOP SEEP-B-INFLUENT-24- 02/01/2024 320-109349-3 R-PSDA 0.28 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 020124 Compound SOP SEEP-B-INFLUENT-24- 02/01/2024 320-109349-3 Hydrolyzed PSDA 1.1 UG/L PQL 0.038 J Cl. Spec. Table 3 PFAS_DI_Prep 020124 Compound SOP SEEP-B-INFLUENT-24- 02/01/2024 320-109349-3 R-EVE 0.21 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 020124 Compound SOP SEEP-B-INFLUENT-24- 02/13/2024 320-109662-4 R-PSDA 0.36 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 021324 Compound SOP SEEP-B-INFLUENT-24- 02/13/2024 320-109662-4 Hydrolyzed PSDA 1.4 UG/L PQL 0.038 J Cl. Spec. Table 3 PFAS_DI_Prep 021324 Compound SOP SEEP-B-INFLUENT-24- 02/13/2024 320-109662-4 R-EVE 0.24 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 021324 Compound SOP SEEP-B-INFLUENT-24- 02/14/2024 320-109798-3 R-PSDA 0.47 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 021424 Compound SOP SEEP-B-INFLUENT-24- 02/14/2024 320-109798-3 Hydrolyzed PSDA 0.94 UG/L PQL 0.038 J Cl. Spec. Table 3 PFAS_DI_Prep 021424 Compound SOP SEEP-B-INFLUENT-24- 02/14/2024 320-109798-3 R-EVE 0.28 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 021424 Compound SOP SEEP-B-INFLUENT-24- 03/02/2024 320-110221-4 R-PSDA 0.57 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 030224 Compound SOP SEEP-B-INFLUENT-24- 03/02/2024 320-110221-4 Hydrolyzed PSDA 1.7 UG/L PQL 0.050 J Cl. Spec. Table 3 PFAS_DI_Prep 030224 Compound SOP SEEP-B-INFLUENT-24- 03/02/2024 320-110221-4 R-EVE 0.37 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 030224 Compound SOP SEEP-B-INFLUENT-24- 03/07/2024 320-110365-3 R-PSDA 0.26 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 030724 Compound SOP SEEP-B-INFLUENT-24- 03/07/2024 320-110365-3 Hydrolyzed PSDA 0.44 UG/L PQL 0.050 J Cl. Spec. Table 3 PFAS_DI_Prep 030724 Compound SOP SEEP-B-INFLUENT-24- 03/07/2024 320-110365-3 R-EVE 0.19 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 030724 Compound SOP SEEP-B-INFLUENT-24- 03/11/2024 320-110423-3 R-PSDA 0.59 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 031124 Compound SOP SEEP-B-INFLUENT-24- 03/11/2024 320-110423-3 Hydrolyzed PSDA 0.76 UG/L PQL 0.050 J Cl. Spec. Table 3 PFAS_DI_Prep 031124 Compound SOP Page 7 of 12 Site: Fayetteville Sampling Program: Seep Flow Through Cell Sampling 2024 Validation Options: LABSTATS Validation Reason Code: Uncertainty around the analysis of R-PSDA, Hydrolyzed PSDA and R-EVE; J-qualifier added to all detects in the data set, even if there was no matrix spike analyzed for that particular sample. Date Validation Analytical Field Sample ID Sampled Lab Sample ID Analyte Result Units Type MDL PQL Qualifier Method Pre -prep Prep SEEP-B-INFLUENT-24- 03/11/2024 320-110423-3 R-EVE 0.35 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 031124 Compound SOP SEEP-B-INFLUENT-24- 03/23/2024 320-110828-3 R-PSDA 0.78 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 032324 Compound SOP SEEP-B-INFLUENT-24- 03/23/2024 320-110828-3 Hydrolyzed PSDA 1.9 UG/L PQL 0.050 J Cl. Spec. Table 3 PFAS_DI_Prep 032324 Compound SOP SEEP-B-INFLUENT-24- 03/23/2024 320-110828-3 R-EVE 0.54 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 032324 Compound SOP SEEP-B-INFLUENT-24- 03/28/2024 320-111004-3 R-PSDA 0.74 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 032824 Compound SOP SEEP-B-INFLUENT-24- 03/28/2024 320-111004-3 Hydrolyzed PSDA 1.6 UG/L PQL 0.050 J Cl. Spec. Table 3 PFAS_DI_Prep 032824 Compound SOP SEEP-B-INFLUENT-24- 03/28/2024 320-111004-3 R-EVE 0.54 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 032824 Compound SOP SEEP-C-EFFLUENT-24- 03/23/2024 320-110828-6 R-PSDA 0.0043 UG/L PQL 0.0020 J Cl. Spec. Table 3 PFAS_DI_Prep 032324 Compound SOP SEEP-C-EFFLUENT-24- 03/23/2024 320-110828-6 Hydrolyzed PSDA 0.0047 UG/L PQL 0.0020 J Cl. Spec. Table 3 PFAS_DI_Prep 032324 Compound SOP SEEP-C-INFLUENT-24- 01/06/2024 320-108586-4 R-PSDA 0.29 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 010624 Compound SOP SEEP-C-INFLUENT-24- 01/06/2024 320-108586-4 R-EVE 0.30 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 010624 Compound SOP SEEP-C-INFLUENT-24- 01/10/2024 320-108628-5 R-PSDA 0.18 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 011024 Compound SOP SEEP-C-INFLUENT-24- 01/10/2024 320-108628-5 R-EVE 0.15 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 011024 Compound SOP SEEP-C-INFLUENT-24- 01/20/2024 320-108999-5 R-PSDA 0.43 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 012024 Compound SOP SEEP-C-INFLUENT-24- 01/20/2024 320-108999-5 R-EVE 0.39 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 012024 Compound SOP SEEP-C-INFLUENT-24- 01/31/2024 320-109311-5 R-PSDA 0.24 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 013124 Compound SOP SEEP-C-INFLUENT-24- 01/31/2024 320-109311-5 R-EVE 0.22 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 013124 Compound SOP SEEP-C-INFLUENT-24- 02/01/2024 320-109349-5 R-PSDA 0.26 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 020124 Compound SOP SEEP-C-INFLUENT-24- 02/01/2024 320-109349-5 R-EVE 0.25 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 020124 Compound SOP SEEP-C-INFLUENT-24- 02/13/2024 320-109662-6 R-PSDA 0.25 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 021324 Compound SOP SEEP-C-INFLUENT-24- 02/13/2024 320-109662-6 R-EVE 0.23 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 021324 Compound SOP SEEP-C-INFLUENT-24- 02/14/2024 320-109798-5 R-PSDA 0.23 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 021424 Compound SOP SEEP-C-INFLUENT-24- 02/14/2024 320-109798-5 R-EVE 0.17 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 021424 Compound SOP Page 8 of 12 Site: Fayetteville Sampling Program: Seep Flow Through Cell Sampling 2024 Validation Options: LABSTATS Validation Reason Code: Uncertainty around the analysis of R-PSDA, Hydrolyzed PSDA and R-EVE; J-qualifier added to all detects in the data set, even if there was no matrix spike analyzed for that particular sample. Date Validation Analytical Field Sample ID Sampled Lab Sample ID Analyte Result Units Type MDL PQL Qualifier Method Pre -prep Prep SEEP-C-INFLUENT-24- 02/24/2024 320-110063-1 R-PSDA 0.30 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 022424 Compound SOP SEEP-C-INFLUENT-24- 02/24/2024 320-110063-1 Hydrolyzed PSDA 0.041 UG/L PQL 0.038 J Cl. Spec. Table 3 PFAS_DI_Prep 022424 Compound SOP SEEP-C-INFLUENT-24- 02/24/2024 320-110063-1 R-EVE 0.25 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 022424 Compound SOP SEEP-C-INFLUENT-24- 03/02/2024 320-110221-6 R-PSDA 0.35 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 030224 Compound SOP SEEP-C-INFLUENT-24- 03/02/2024 320-110221-6 R-EVE 0.29 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 030224 Compound SOP SEEP-C-INFLUENT-24- 03/07/2024 320-110365-5 R-PSDA 0.20 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 030724 Compound SOP SEEP-C-INFLUENT-24- 03/07/2024 320-110365-5 R-EVE 0.16 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 030724 Compound SOP SEEP-C-INFLUENT-24- 03/11/2024 320-110423-5 R-PSDA 0.48 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 031124 Compound SOP SEEP-C-INFLUENT-24- 03/11/2024 320-110423-5 R-EVE 0.39 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 031124 Compound SOP SEEP-C-INFLUENT-24- 03/23/2024 320-110828-5 R-PSDA 0.48 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 032324 Compound SOP SEEP-C-INFLUENT-24- 03/23/2024 320-110828-5 R-EVE 0.43 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 032324 Compound SOP SEEP-C-INFLUENT-24- 03/28/2024 320-111004-5 R-PSDA 0.44 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 032824 Compound SOP SEEP-C-INFLUENT-24- 03/28/2024 320-111004-5 R-EVE 0.36 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 032824 Compound SOP SEEP-A-INFLUENT-24- 01/06/2024 320-108586-1 R-PSDA 0.53 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 010624 Compound SOP SEEP-A-INFLUENT-24- 01/06/2024 320-108586-1 Hydrolyzed PSDA 1.8 UG/L PQL 0.038 J Cl. Spec. Table 3 PFAS_DI_Prep 010624 Compound SOP SEEP-A-INFLUENT-24- 01/06/2024 320-108586-1 R-EVE 0.29 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 010624 Compound SOP SEEP-A-INFLUENT-24- 01/06/2024 320-108586-2 R-PSDA 0.58 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 010624-D Compound SOP SEEP-A-INFLUENT-24- 01/06/2024 320-108586-2 Hydrolyzed PSDA 1.7 UG/L PQL 0.038 J Cl. Spec. Table 3 PFAS_DI_Prep 010624-D Compound SOP SEEP-A-INFLUENT-24- 01/06/2024 320-108586-2 R-EVE 0.26 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 010624-D Compound SOP SEEP-A-INFLUENT-24- 01/10/2024 320-108628-1 R-PSDA 0.46 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 011024 Compound SOP SEEP-A-INFLUENT-24- 01/10/2024 320-108628-1 Hydrolyzed PSDA 1.2 UG/L PQL 0.038 J Cl. Spec. Table 3 PFAS_DI_Prep 011024 Compound SOP SEEP-A-INFLUENT-24- 01/10/2024 320-108628-1 R-EVE 0.18 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 011024 Compound SOP SEEP-A-INFLUENT-24- 01/20/2024 320-108999-1 R-PSDA 0.64 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 012024 Compound SOP Page 9 of 12 Site: Fayetteville Sampling Program: Seep Flow Through Cell Sampling 2024 Validation Options: LABSTATS Validation Reason Code: Uncertainty around the analysis of R-PSDA, Hydrolyzed PSDA and R-EVE; J-qualifier added to all detects in the data set, even if there was no matrix spike analyzed for that particular sample. Date Validation Analytical Field Sample ID Sampled Lab Sample ID Analyte Result Units Type MDL PQL Qualifier Method Pre -prep Prep SEEP-A-INFLUENT-24- 01/20/2024 320-108999-1 Hydrolyzed PSDA 0.87 UG/L PQL 0.038 J Cl. Spec. Table 3 PFAS_DI_Prep 012024 Compound SOP SEEP-A-INFLUENT-24- 01/20/2024 320-108999-1 R-EVE 0.30 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 012024 Compound SOP SEEP-A-INFLUENT-24- 01/31/2024 320-109311-1 R-PSDA 0.57 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 013124 Compound SOP SEEP-A-INFLUENT-24- 01/31/2024 320-109311-1 Hydrolyzed PSDA 1.8 UG/L PQL 0.038 J Cl. Spec. Table 3 PFAS_DI_Prep 013124 Compound SOP SEEP-A-INFLUENT-24- 01/31/2024 320-109311-1 R-EVE 0.30 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 013124 Compound SOP SEEP-A-INFLUENT-24- 02/01/2024 320-109349-1 R-PSDA 0.60 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 020124 Compound SOP SEEP-A-INFLUENT-24- 02/01/2024 320-109349-1 Hydrolyzed PSDA 2.0 UG/L PQL 0.038 J Cl. Spec. Table 3 PFAS_DI_Prep 020124 Compound SOP SEEP-A-INFLUENT-24- 02/01/2024 320-109349-1 R-EVE 0.32 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 020124 Compound SOP SEEP-A-INFLUENT-24- 02/13/2024 320-109662-1 R-PSDA 0.62 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep 021324 Compound SOP SEEP-A-INFLUENT-24- 02/13/2024 320-109662-1 Hydrolyzed PSDA 1.9 UG/L PQL 0.038 J Cl. Spec. Table 3 PFAS_DI_Prep 021324 Compound SOP SEEP-A-INFLUENT-24- 02/13/2024 320-109662-1 R-EVE 0.32 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep 021324 Compound SOP Page 10 of 12 Site: Fayetteville Sampling Program: Seep Flow Through Cell Sampling 2024 Validation Options: LABSTATS Validation Reason Code: Associated MS and/or MSD analysis had relative percent recovery (RPR) values less than the lower control limit but above the rejection limit. The reported result may be biased low. Date Validation Analytical Field Sample ID Sampled Lab Sample ID Analyte Result Units Type MDL PQL Qualifier Method Pre -prep Prep SEEP-A-INFLUENT-24- 03/07/2024 320-110365-1 PFMOAA 12 ug/L PQL 0.080 J Cl. Spec. Table 3 PFAS_DI_Prep 030724 Compound SOP SEEP-A-EFFLUENT-24- 02/13/2024 320-109662-2 PFMOAA 0.023 ug/L PQL 0.0020 J Cl. Spec. Table 3 PFAS_DI_Prep 021324 Compound SOP Page 11 of 12 Site: Fayetteville Validation Reason Code Sampling Program: Seep Flow Through Cell Sampling 2024 Validation Options: LABSTATS The result is estimated since the concentration is between the method detection limit and practical quantitation limit. Date Validation Analytical Field Sample ID Sampled Lab Sample ID Analyte Result Units Type MDL PQL Qualifier Method SEEP-A-EFFLUENT-TSS- 02/13/2024 320-109661-5 Total Suspended 2.1 MG/L MDL 1.0 3.0 J SM 2540 D-2015 021324 Solids SEEP-A-EFFLUENT-TSS- 02/15/2024 320-109793-5 Total Suspended 1.0 MG/L MDL 1.0 3.0 J SM 2540 D-2015 021524 Solids SEEP-A-EFFLUENT-TSS- 03/04/2024 320-110219-5 Total Suspended 1.5 MG/L MDL 1.0 3.0 J SM 2540 D-2015 030424 Solids SEEP-A-EFFLUENT-TSS- 03/07/2024 320-110385-5 Total Suspended 2.0 MG/L MDL 1.0 3.0 J SM 2540 D-2015 030724 Solids SEEP-A-EFFLUENT-TSS- 03/25/2024 320-110831-5 Total Suspended 1.3 MG/L MDL 1.0 3.0 J SM 2540 D-2015 032524 Solids SEEP-A-EFFLUENT-TSS- 03/28/2024 320-111002-5 Total Suspended 2.6 MG/L MDL 1.0 3.0 J SM 2540 D-2015 032824 Solids SEEP-D-EFFLUENT-TSS- 01/10/2024 320-108630-8 Total Suspended 1.2 MG/L MDL 1.0 3.0 J SM 2540 D-2015 011024 Solids SEEP-D-EFFLUENT-TSS- 01/23/2024 320-109093-8 Total Suspended 1.5 MG/L MDL 1.0 3.0 J SM 2540 D-2015 012324 Solids SEEP-D-EFFLUENT-TSS- 01/31/2024 320-109313-8 Total Suspended 2.3 MG/L MDL 1.0 3.0 J SM 2540 D-2015 013124 Solids SEEP-D-EFFLUENT-TSS- 02/13/2024 320-109661-8 Total Suspended 1.9 MG/L MDL 1.0 3.0 J SM 2540 D-2015 021324 Solids SEEP-B-EFFLUENT-TSS- 02/13/2024 320-109661-6 Total Suspended 1.2 MG/L MDL 1.0 3.0 J SM 2540 D-2015 021324 Solids SEEP-B-EFFLUENT-TSS- 02/15/2024 320-109793-6 Total Suspended 1.2 MG/L MDL 1.0 3.0 J SM 2540 D-2015 021524 Solids SEEP-B-EFFLUENT-TSS- 03/04/2024 320-110219-6 Total Suspended 1.6 MG/L MDL 1.0 3.0 J SM 2540 D-2015 030424 Solids Pre -prep Prep Page 12 of 12 ADQM Data Review Site: Chemours Fayetteville Protect: 004 NPDES Sampling 01/24, 02/24, 03/24 Project Reviewer: Bridget Gavaghan Sample Summary Field Sample ID Lab Sample ID Sample Matrix Filtered Sample Date Sample Time Sample Purpose 004-INF-0124-2 320-108480-1 Other Liquid N 01/02/2024 08:00 FS 004-EFF-0124-2 320-108480-2 Other Liquid N 01/02/2024 08:00 FS 004-INF-0124- 2A 320-108578-1 Other Liquid N 01/08/2024 08:00 FS 004-EFF-0124- 2A 320-108578-2 Other Liquid N 01/08/2024 08:00 FS 004-INF-0124-3 320-108740-1 Other Liquid N 01/15/2024 07:30 FS 004-EFF-0124-3 320-108740-2 Other Liquid N 01/15/2024 07:30 FS 004-INF-0124-4 320-109025-1 Other Liquid N 01/22/2024 07:30 FS 004-EFF-0124-4 320-109025-2 Other Liquid N 01/22/2024 07:30 FS 004-FBLK-0124 320-109211-1 Blank Water N 01/29/2024 07:30 FB 004-INF-0124-5 320-109212-1 Other Liquid N 01/29/2024 07:30 FS 004-EFF-0124-5 320-109212-2 Other Liquid N 01/29/2024 07:30 FS 004-INF-0224 320-109451-1 Other Liquid N 02/05/2024 07:30 FS 004-EFF-0224 320-109451-2 Other Liquid N 02/05/2024 07:30 FS 004-INF-0224-2 320-109597-1 Other Liquid N 02/12/2024 07:45 FS 004-EFF-0224-2 320-109597-2 Other Liquid N 02/12/2024 07:45 FS 004-FBLK-0224 320-109597-3 Blank Water N 02/12/2024 07:45 FB 004-INF-0224-3 320-109834-1 Other Liquid N 02/19/2024 07:30 FS 004-EFF-0224-3 320-109834-2 Other Liquid N 02/19/2024 07:30 FS 004-INF-0224-4 320-110019-1 Other Liquid N 02/26/2024 07:30 FS 004-EFF-0224-4 320-110019-2 Other Liquid N 02/26/2024 07:30 FS 004-INF-0324 320-110235-1 Other Liquid N 03/04/2024 09:00 FS 004-EFF-0324 320-110235-2 Other Liquid N 03/04/2024 09:00 FS 004-INF-0324-2 320-110437-1 Other Liquid N 03/11/2024 08:30 FS 004-EFF-0324-2 320-110437-2 Other Liquid N 03/11/2024 08:30 FS 004-FBLK-0324 320-110437-3 Blank Water N 03/11/2024 08:30 FB 004-INF-0324-3 320-110619-1 Other Liquid N 03/18/2024 08:00 FS 004-EFF-0324-3 320-110619-2 Other Liquid N 03/18/2024 08:00 FS 004-INF-0324-4 320-110822-1 Other Liquid N 03/25/2024 07:30 FS 004-EFF-0324-4 320-110822-2 Other Liquid N 03/25/2024 07:30 FS * FS=Field Sample DUP=Field Duplicate FB=Field Blank EB=Equipment Blank TB=Trip Blank Analytical Protocol Lab Name Lab Method Parameter Category Sampling Program Eurofins Environ 537 Modified Per- and Polyfluorinated Alkyl 004 NPDES Sampling 2/24 Testing Northern Cali Substances PFAS Eurofins Environ Cl. Spec. Table 3 Per- and Polyfluorinated Alkyl 004 NPDES Sampling 1/24 Testing Northern Cali Compound SOP Substances PFAS Eurofins Environ Cl. Spec. Table 3 Per- and Polyfluorinated Alkyl 004 NPDES Sampling 2/24 Testing Northern Cali Compound SOP Substances PFAS) Eurofins Environ Cl. Spec. Table 3 Per- and Polyfluorinated Alkyl 004 NPDES Sampling 3/24 Testing Northern Cali Compound SOP Substances PFAS ADQM Data Review Checklist DVM Laboratory Exception Item Description Yes No* Narrative Report Report (ER) Report # Did samples meet laboratory acceptability A requirements upon receipt (i.e., intact, within X temperature, properly preserved, and no heads ace where applicable)? B Were samples received by the laboratory in X X agreement with the associated chain of custody? C Was the chain of custody properly completed by X the laboratory and/or field team? D Were samples prepped/analyzed by the laboratory X within method holding times? Were data review criteria met for method blanks, LCSs/LCSDs, MSs/MSDs, PDSs, SDs, replicates, E surrogates, sample results within calibration range, X X X total/dissolved samples, field duplicates, field/equipment/trip blanks? F Were all data usable and not R qualified? X ER# Description Other QA/QC Items to Note: See DVM Narrative Report, Laboratory Report, and/or ER # for further details as indicated. The electronic data submitted for this project were reviewed via the Data Verification Module (DVM) process. Overall, the data are acceptable for use without qualification, except as noted on the attached DVM Narrative Report. The lab reports due to a large page count are stored on a network shared drive and are available to be posted on external shared drives, or on a flash drive. Data Verification Module (DVM) The DVM is an internal review process used by the ADQM group to assist with the determination of data usability. The electronic data deliverables received from the laboratory are loaded into the Locus ElMTM database and processed through a series of data quality checks, which are a combination of software, Locus EIMTm database Data Verification Module (DVM), and manual reviewer evaluations. The data are evaluated against the following data usability checks: • Field and laboratory blank contamination • US EPA hold time criteria • Missing Quality Control (QC) samples • Matrix spike (MS)/matrix spike duplicate (MSD) recoveries and the relative percent differences (RPDs) between these spikes • Laboratory control sample (LCS)/laboratory control sample duplicate (LCSD) recoveries and the RPD between these spikes • Surrogate spike recoveries for organic analyses • Difference/RPD between field duplicate sample pairs • RPD between laboratory replicates for inorganic analyses • Difference/percent difference between total and dissolved sample pairs There are two qualifier fields in EIM: Laboratory Qualifier is the qualifier assigned by the laboratory and may not reflect the usability of the data. This qualifier may have many different meanings and can vary between labs and over time within the same lab. Please refer to the laboratory report for a description of the laboratory qualifiers. As they are laboratory descriptors they are not to be used when evaluating the data. Validation Qualifier is the 3rd party formal validation qualifier if this was performed. Otherwise this field contains the qualifier resulting from the ADQM DVM review process. This qualifier assesses the usability of the data and may not equal the laboratory qualifier. The DVM applies the following data evaluation qualifiers to analysis results, as warranted: Qualifier Definition B Not detected substantially above the level reported in the laboratory or field blanks. R Unusable result. Anal to may or may not be present in the sample. J An to resent. Reported value may not be accurate or precise. UJ Not detected. Reporting limit may not be accurate or precise. The Validation Status Code field is set to "DVM" if the ADQM DVM process has been performed. If the DVM has not been run, the field will be blank. If the DVM has been run (Validation Status Code equals "DVM"), use the Validation Qualifier. If the data have been validated by a third party, the field "Validated By" will be set to the validator (e.g., ESI for Environmental Standards, Inc.) DVM Narrative Report Site: Fayetteville Sampling Program: 004 NPDES Sampling 2/24 Validation Options: LABSTATS Validation Reason Code: Associated LCS and/or LCSD analysis had relative percent recovery (RPR) values less than the lower control limit but above 10%. The actual detection limits may be higher than reported. Date Validation Analytical Field Sample ID Sampled Lab Sample ID Analyte Result Units Type MDL PQL Qualifier Method Pre -prep 004-EFF-0224-2 02/12/2024 320-109597-2 Perfluorooctadecanoic 0.0020 ug/L PQL 0.0020 UJ 537 Modified Acid 004-FBLK-0224 02/12/2024 320-109597-3 Perfluorooctadecanoic 0.0020 ug/L PQL 0.0020 UJ 537 Modified Acid 004-INF-0224-2 02/12/2024 320-109597-1 Perfluorooctadecanoic 0.0020 ug/L PQL 0.0020 UJ 537 Modified Acid Prep 3535 3535 3535 Page 1 of 3 Site: Fayetteville Sampling Program: 004 NPDES Sampling 1/24 Validation Options: LABSTATS Validation Reason Code: Associated MS and/or MSD analysis had relative percent recovery (RPR) values less than the lower control limit. The actual detection limits may be higher than reported. Date Validation Analytical Field Sample ID Sampled Lab Sample ID Analyte Result Units Type MDL PQL Qualifier Method 004-EFF-0124-2 01/02/2024 320-108480-2 Hydrolyzed PSDA 0.0020 UG/L PQL 0.0020 UJ Cl. Spec. Table 3 Compound SOP 004-EFF-0124-2 01/02/2024 320-108480-2 PFMOAA 0.0020 ug/L PQL 0.0020 UJ Cl. Spec. Table 3 Compound SOP 004-EFF-0124-2 01/02/2024 320-108480-2 Hydro -PS Acid 0.0020 ug/L PQL 0.0020 UJ Cl. Spec. Table 3 Compound SOP 004-EFF-0124-2A 01/08/2024 320-108578-2 PFMOAA 0.0020 ug/L PQL 0.0020 UJ Cl. Spec. Table 3 Compound SOP 004-EFF-0224-3 02/19/2024 320-109834-2 PFMOAA 0.0020 ug/L PQL 0.0020 UJ Cl. Spec. Table 3 Compound SOP 004-EFF-0224-4 02/26/2024 320-110019-2 PMPA 0.010 UG/L PQL 0.010 UJ Cl. Spec. Table 3 Compound SOP 004-EFF-0224-4 02/26/2024 320-110019-2 PFMOAA 0.0020 ug/L PQL 0.0020 UJ Cl. Spec. Table 3 Compound SOP Pre -prep Prep PFAS_DI_Prep PFAS_DI_Prep PFAS_DI_Prep PFAS_DI_Prep PFAS_DI_Prep PFAS_DI_Prep PFAS_DI_Prep Page 2 of 3 Site: Fayetteville Sampling Program: 004 NPDES Sampling 2/24 Validation Options: LABSTATS Validation Reason Code: Uncertainty around the analysis of R-PSDA, Hydrolyzed PSDA and R-EVE; J-qualifier added to all detects in the data set, even if there was no matrix spike analyzed for that particular sample. Date Validation Analytical Field Sample ID Sampled Lab Sample ID Analyte Result Units Type MDL PQL Qualifier Method Pre -prep Prep 004-INF-0224-2 02/12/2024 320-109597-1 R-PSDA 1.8 UG/L PQL 0.035 J Cl. Spec. Table 3 PFAS_DI_Prep Compound SOP 004-INF-0224-2 02/12/2024 320-109597-1 Hydrolyzed PSDA 16 UG/L PQL 0.019 J Cl. Spec. Table 3 PFAS_DI_Prep Compound SOP 004-INF-0224-2 02/12/2024 320-109597-1 R-EVE 0.93 UG/L PQL 0.036 J Cl. Spec. Table 3 PFAS_DI_Prep Compound SOP 004-INF-0324-2 03/11/2024 320-110437-1 R-PSDA 1.3 UG/L PQL 0.035 J Cl. Spec. Table 3 PFAS_DI_Prep Compound SOP 004-INF-0324-2 03/11/2024 320-110437-1 Hydrolyzed PSDA 12 UG/L PQL 0.025 J Cl. Spec. Table 3 PFAS_DI_Prep Compound SOP 004-INF-0324-2 03/11/2024 320-110437-1 R-EVE 0.50 UG/L PQL 0.036 J Cl. Spec. Table 3 PFAS_DI_Prep Compound SOP 004-INF-0124-2 01/02/2024 320-108480-1 R-PSDA 0.94 UG/L PQL 0.071 J Cl. Spec. Table 3 PFAS_DI_Prep Compound SOP 004-INF-0124-2 01/02/2024 320-108480-1 Hydrolyzed PSDA 6.8 UG/L PQL 0.038 J Cl. Spec. Table 3 PFAS_DI_Prep Compound SOP 004-INF-0124-2 01/02/2024 320-108480-1 R-EVE 0.53 UG/L PQL 0.072 J Cl. Spec. Table 3 PFAS_DI_Prep Compound SOP Page 3 of 3 Geosyntec consultants Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 Appendix B FTC Transducer Data Reduction TR0795C 46 45 44 43 00 > 42 Q z 41 c O w 40 39 38 37 36 i I;t I:t IZT It It 't 't IZT �T It �t t It N N N N N N N N N N N N N N N N N \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ c-I L(1 0) M r" -i U) Q1 N lD O 00 N LA c-I Lr) \ \ \ cI I N N N \ \ . I I rI N N \ \ \ \ \ \ \ N N \ \ \ \ \ M M c-I N N N N N Legend Discharge Basin Elevation Weir 3 Elevation GAC Elevation Notes: GAC - granular activated carbon Figure B1-A shows the discharge basin transducer data that was collected during the reporting period. N N N N N N a) M r- c\I LI 0) M M M M M 45 43 41 00 000 39 r) Q z 37 0 35 c� aU w 33 31 29 N N N N N N N N N N N N N N N N N N N N N N N r\-I L 1 al M r\-I II a) N ED O qt 0000 N l\D .\I 11 M M r\ r\I I1 0\1 \ \ \ I I N N N \ \ r-I I r-I N N \ \ \ r -I -1 N N N \ \ \ \ \ N N \ \ \ \ \ M M M \ \ \ \ \ r-I r-I ri r-I r-I N N N N f V M M M M M Legend Discharge Basin Water Elevation River Stage Weir 3 Elevation 0 USGS Precipitation (daily totals) Notes: As water can flow through the flow -through cell both as a result of wet weather inflow and elevated river levels from flooding, Figure 132-A compares the available transducer data to precipitation and river stage elevation data available from the USGS Huske Lock and Dam. 46 45 0000 43 0 Q z 42 c 0 v LU 41 40 39 38 �t �t -t -t N N N N N N fV N N N N N N N N N N N N N c-I Ln Ql M r, -I L n M N l\O O 00 N l\O .\-I Lf a) M I� \ r-I r-I -I N N \ \ N N \ \ \ \ \ M M M \ \ ri ri ri -I -I N N N N N M M Legend — Influent Chamber/Impoundment Elevation Notes: Figure 133-A shows the influent transducer data that was collected during the reporting period. N fV N -i LI 01 \ \ \ M M M 45 43 41 00 0 > 39 Q Z 37 c 0 35 a� w 33 31 29 ......... .. ............. N N N N N N N N N N N N N N N N N N N N N N N r\-I if a) M n r\-I Lf Ol N koo O 00 N l\o c\-I U Ql M n r\-I L\n Ql N N N \ \ r-I -I c-I N N \ \ \ c-I r-I N N N \ \ \ \ \ N N \ \ \ \ \ M M M \ \ \ \ \ ri ri rl .--I r-I N N N N N M M M M M 2 C 1.5 c 0 m 1 .Q .0 v 0.5 a n Legend — Inlet Chamber Water Elevation USGS Precipitation (daily totals) — River Stage ••• Bypass Spillway Elevation Notes: As water can flow through the Bypass Spillway both as a result of wet weather inflow and elevated river levels from flooding, Figure 134-A compares the available transducer data to precipitation and river stage elevation data available from the USGS Huske Lock and Dam. 46 45 44 43 00 0 42 z c 0 > 41 v w 40 39 38 N N N N [V N N N N N N N cV N N (Iq N N [V N N N N c\I Ln 01 M r- \-I Ln C) N lDD O 0000 N l\D r\-I Ln Ol M r- \-I in m \ N \ \ I I r-I N N \ \ \ r-I c-I N N N \ \ \ \ N N \ \ \ \ \ M M M \ \ \ \ \ c-I rl r-I c-I c-I N N N N N M M M M M Legend Discharge Basin Elevation Weir 3 Elevation GAC Elevation Discharge Basin Water Elevation - Notes: Seep B GAC - granular activated carbon Chemours Fayetteville Works Figure BI-B shows the discharge basin transducer data that was collected during the reporting period. Fayetteville, North Carolina Geosyntecc Geosyntec ConsultantsoFNC, P.C. Figure consultants NC License No.: C3500 and C-295 B1-B Raleigh, NC June 2024 i i t i i 1 i I I i �1 40 44 42 40 00 38 Q Z 36 34 c0 v w 32 30 28 N N N N N N N N N N N N N N N N N N N N N N N r\-I L 1 al M r\i II a) N ED O qt 0000 N l\D .\I 11 M M r\ r\I I1 M \ \ \ I I N N N \ \ r-I I r-I N N \ \ \ r -I -1 N N N \ \ \ \ \ N N \ \ \ \ \ M M M \ \ \ \ \ r-I r-I ri r-I r-I N N N N f V M M M M M 2 C _— 1.5 C 0 � 1 Q U 2- 0.5 a 0 Legend Discharge Basin Water Elevation USGS Precipitation (daily totals) River Stage Weir 3 Elevation n Notes: As water can flow through the flow -through cell both as a result of wet weather inflow and elevated river levels from flooding, Figure 132-13 compares the available transducer data to precipitation and river stage elevation data available from the USGS Huske Lock and Dam. 46 45 IM11111111111 43 00 Q 42 0 41 +j a� w .M 39 38 ' N N N N fV N (V N N N N N N N N N N N N N N N N .\I L n 00) M r"\-I LO 01 N (,\D O 0000 N �.o c\-1 Ln 00) M r- .\-I if a) N N N \ \ c I I r-I N N \ \ \ c-I c- N N N rl r 1 rl N [V N cV N M M M M M Legend — Influent Chamber/Impoundment Elevation Notes: Figure 133-13 shows the influent transducer data that was collected during the reporting period. 45 43 41 00 39 Q Z 37 0 4� 35 c6 aU LU 33 31 29 .............. ..�...........I.......III .................................................................................................................................. I I N N N N N N N N N N N N N N N rq N N N N N N N rl Ln 61 c 7 N\-I L1 a) N l\O O qt 00 N lOO .\-I In M M N .\-I LI Q\l \ \ \ c I I N N N \ \ �1 I I N N \ \ \ I r-I N N N \ \ \ \ \ N N \ \ \ \ \ M M M \ \ \ \ \ N N N N N M M M M M Legend — Inlet Chamber Water Elevation 0 USGS Precipitation (daily totals) — River Stage ••• Bypass Spillway Elevation Notes: As water can flow through the Bypass Spillway both as a result of wet weather inflow and elevated river levels from flooding, Figure B4-B compares the available transducer data to precipitation and river stage elevation data available from the USGS Huske Lock and Dam. 46 45 44 43 00 42 0 Q z 41 0 "' 40 39 38 37 N N N N [V N N N N N N N cV N N (Iq N N [V N N N N c\I Ln 01 M r" \-I Ln C) N l\D O 0000 N l\O r\-I Ln Ol M r- \-I in m N \ \ -I -I r-I N N \ \ \ r-I c-I N N N \ \ \ \ \ N N \ \ \ \ \ M M M \ \ \ \ \ c-I rl r-I c-I c-I N N N N N M M M M M Legend Discharge Basin Elevation Weir 3 Elevation GAC Elevation Discharge Basin Water Elevation - Notes: Seep C GAC - granular activated carbon Chemours Fayetteville Works Figure B1-C shows the discharge basin transducer data that was collected during the reporting period. Fayetteville, North Carolina Geosyntecc Geosyntec ConsultantsoFNC, P.C. Figure consultants NC License No.: C3500 and C-295 B1-C Raleigh, NC June 2024 t ;i i s r 45 43 41 00 000 39 r) Q z 37 0 35 c� aU w 33 31 29 N N N N N N N N N N N N N N N N N N N N N N N r\-I L 1 al M r\-I II a) N ED O qt 0000 N l\D .\I 11 M M r\ r\I I1 0\1 \ \ \ I I N N N \ \ r-I I r-I N N \ \ \ r -I -1 N N N \ \ \ \ \ N N \ \ \ \ \ M M M \ \ \ \ \ r-I r-I ri r-I r-I N N N N f V M M M M M 2 1.5 O +_' 1 n a, 0.5 0 Legend Discharge Basin Water Elevation River Stage Weir 3 Elevation USGS Precipitation (daily totals) Notes: As water can flow through the flow -through cell both as a result of wet weather inflow and elevated river levels from flooding, Figure 132-C compares the available transducer data to precipitation and river stage elevation data available from the USGS Huske Lock and Dam. 46 45 44 43 00 Q z ! 42 -- — O > I w 41 - t i 40 39 N N N N N N N N N N N N N N N N N N N N N N N L! 0) M M\-I Lf a) N lDD O 1:* 0000 N l\D c\-I Ln a) M r- r\-I lI M \ \ \ cI cI N N N \ \ r-I I I N N \ \ \ ri -1 N N N \ \ \ \ \ N N \ \ \ \ \ M M M \ \ \ \ \ rl ci ri c-I r-I rV f V f V N N M M M M M Legend Influent Chamber/Impoundment Elevation GAC Changeout Inlet Chamber Water Elevation - Notes: Seep C Figure 133-C shows the influent transducer data that was collected during the reporting period. Chemours Fayetteville works Fayetteville, North Carolina Geosyntec" Figure consultants NC U—, N— C 3500 and C 295 B3-C Raleigh, NC June 2024 45 43 41 Z 00 39 Q z +; 37 35 _v w 33 31 29 N N N N N N N N N N N N N N N rq N N N N N N N rl Ln 61 c 7 N\-I L1 a) N l\O O qt 00 N lOO .\-I In M M N .\-I LI 0) \ \ \ c I I N N N \ \ �1 I I N N \ \ \ I r-I N N N \ \ \ \ \ N N \ \ \ \ \ M M M \ \ \ \ \ N N N N N M M M M M Legend — Inlet Chamber Water Elevation 0 USGS Precipitation (daily totals) — River Stage ••• Bypass Spillway Elevation Notes: As water can flow through the Bypass Spillway both as a result of wet weather inflow and elevated river levels from flooding, Figure B4-C compares the available transducer data to precipitation and river stage elevation data available from the USGS Huske Lock and Dam. 46 45 44 43 0000 42 0 Q z 41 c 40 � ca > v "' 40 39 38 37 N N N N [V N N N N N N N cV N N (Iq N N [V N N N N c\I Ln Ol M r- r\-I in C) N l\D O 0000 N l\D r\-I Ln dl M r- r\-I Ln m N \ \ -I -I r-I N N \ \ \ rH \ \ \ \ \ N N \ \ \ \ \ M M M \ \ \ \ \ c-I r-I c-I c-I c-I N N N N N M M M M M Legend Discharge Basin Elevation Weir 3 Elevation GAC Elevation Discharge Basin Water Elevation - Notes: Seep D GAC - granular activated carbon Chemours Fayetteville Works Figure BI-D shows the discharge basin transducer data that was collected during the reporting period. Fayetteville, North Carolina Geosyntecc Geosyntec ConsultantsoFNC, P.C. Figure consultants NC License No.: C3500 and C-295 B1-D Raleigh, NC June 2024 t s t s i i s 1 I 45 43 41 000 39 Q z 37 0 35 c� aU w 33 31 29 I;T 1:t It 1:t I:t Rt IZT It IZT I* IZT �t �t It qt �t �t �T qt It 1:t ::I- N N N N N N N N N N N N N N N N N N N N N N N r\-I L 1 al M r\-I II a) N ED O 0000 N l\D .\I 11 M M r\ r\I I1 M \ \ \ I I N N N \ \ r-I I -1 N N \ \ \ r -I -1 N N N \ \ \ \ \ N N \ \ \ \ \ M M M \ \ \ \ \ r-I r-I ri r-I r-I N N N N N M M ro M M 2 C _— 1.5 C O +_j � 1 .Q v 0.5 a 0 —sue= Legend Discharge Basin Water Elevation River Stage Weir 3 Elevation USGS Precipitation (daily totals) Notes: As water can flow through the flow -through cell both as a result of wet weather inflow and elevated river levels from flooding, Figure 132-D compares the available transducer data to precipitation and river stage elevation data available from the USGS Huske Lock and Dam. 46 45 44 43 00 Q 42 z 0 41 a� w 40 39 WOW 38 It It It IZI- It 11* It T* It It 'Z* R* �t �t �t Rt It It �t It IZI- lzt N N N N rV N (V N N N N N N N N N N N N N N N N LLn 00) M r" L 1 01 N l\D O �t 0000 N lD r-1 i- M M r- —i if Ql N N N \ \ c I I r-I N N \ \ \ c-I c- N N N \ \ \ \ \ N N \ \ \ \ \ M M M \ \ \ \ \ N N N N N M M M M M Legend Influent Chamber/Impoundment Elevation Inlet Chamber Water Elevation - Notes: Seep D Figure 133-1) shows the influent transducer data that was collected during the reporting period. Chemours Fayetteville works Fayetteville, North Carolina Geosyntec" Figure NC U—, N— C 3500 C 295 and consultants B3-D Raleigh, NC June 2024 i i — i 45 43 41 00 39 Q Z 37 0 4� 35 c6 aU LU 33 31 29 .....................r..... .......................... I ....... I ....... I ....... [....... [....... ...... ...... .............. ....... ;....... ; ....... I .....................I N N N N N N N N N N N N N N N rq N N N N N N N rl L n 61 c 7 N\-I Lr Q\l N l\O O qt 00 N lOO .-I-I In Ol M N .\-I L r Q\l \ \ \ c I I N N N \ \ �1 I I N N \ \ \ r -I \ \ \ \ \ N fV \ \ \ \ \ M M M \ \ \ \ \ N N N N N M M M M M Legend — Inlet Chamber Water Elevation USGS Precipitation (daily totals) — River Stage ••• Bypass Spillway Elevation Notes: As water can flow through the Bypass Spillway both as a result of wet weather inflow and elevated river levels from flooding, Figure B4-D compares the available transducer data to precipitation and river stage elevation data available from the USGS Huske Lock and Dam. Geosyntec consultants Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 Appendix C Corrected PFPrA Concentration for Previously Reported Results TR0795C Appendix C Corrected PFPrA Concentrations for Previously Reported Results July 2023 to November 2023 Chemours Fayetteville Works Fayetteville, North Carolina Sampling Program Location ID Sample ID Sample Date PFPrA Concentration (ng/L) Corrected Original CAP MW Sampling 3Q23 LTW-01 CAP3Q23-LTW-01-071323 7/13/2023 22,000 14,000 CAP GW Sampling 4Q23 LTW-01 CAP4Q23-LTW-0 1- 110323 11/3/2023 24,000 14,000 CAP MW Sampling 3Q23 LTW-02 CAP3Q23-LTW-02-071223 7/12/2023 16,000 11,000 CAP GW Sampling 4Q23 LTW-02 CAP4Q23-LTW-02-110323 11/3/2023 21,000 13,000 CAP MW Sampling 3Q23 LTW-03 CAP3Q23-LTW-03-071223 7/12/2023 62,000 J 37,000 CAP MW Sampling 4Q23 LTW-03 CAP4Q23-LTW-03-111323 11/13/2023 61,000 J 38,000 J CAP MW Sampling 3Q23 LTW-04 CAP3Q23-LTW-04-071123 7/11/2023 53,000 29,000 CAP GW Sampling 4Q23 LTW-04 CAP4Q23-LTW-04-110223 11/2/2023 48,000 30,000 CAP MW Sampling 3Q23 LTW-05 CAP3Q23-LTW-05-071123 7/11/2023 83,000 J 52,000 J CAP GW Sampling 4Q23 LTW-05 CAP4Q23-LTW-05-110223 11/2/2023 120,000 68,000 CAP MW Sampling 3Q23 OW-28 CAP3Q23-OW-28-071123 7/11/2023 5,200 3,500 CAP GW Sampling 4Q23 OW-28 CAP4Q23-OW-28-110223 11/2/2023 5,500 3,500 CAP MW Sampling 3Q23 OW-33 CAP3Q23-OW-33-071223 7/12/2023 9,900 5,400 CAP GW Sampling 4Q23 OW-33 CAP4Q23-OW-33-110223 11/2/2023 9,400 6,000 CAP MW Sampling 3Q23 PIW-11) CAP3Q23-PIW-1D-080223 8/2/2023 12,000 J 7,800 CAP GW Sampling 4Q23 PIW-11) CAP4Q23-PIW-ID-110723 11/7/2023 12,000 7,500 CAP MW Sampling 3Q23 PIW-31) CAP3Q23-PIW-3D-071323 7/13/2023 19,000 11,000 CAP GW Sampling 4Q23 PIW-31) CAP4Q23-PIW-3D-110323 11/3/2023 21,000 13,000 CAP MW Sampling 3Q23 PIW-71) CAP3Q23-PIW-7D-071123 7/11/2023 79,000 J 49,000 J CAP GW Sampling 4Q23 PIW-71) CAP4Q23-PIW-7D-110223 11/2/2023 86,000 52,000 CAP MW Sampling 3Q23 PIW-7S CAP3Q23-PIW-7S-071123 7/11/2023 14,000 9,700 CAP GW Sampling 4Q23 PIW-7S CAP4Q23-PIW-7S-110223 11/2/2023 18,000 12,000 CAP MW Sampling 3Q23 PW-04 CAP3Q23-PW-04-072823 7/28/2023 1,400 900 CAP MW Sampling 4Q23 PW-04 CAP4Q23-PW-04-110923 11/9/2023 1,500 960 CAP MW Sampling 3Q23 PZ-22 CAP3Q-PZ-22-071123 7/11/2023 76,000 48,000 CAP GW Sampling 4Q23 PZ-22 CAP4Q23-PZ-22-110223 11/2/2023 84,000 51,000 CAP MW Sampling 3Q23 SMW-12 CAP3Q23-SMW-12-071823 7/18/2023 5,900 3,900 CAP MW Sampling 4Q23 SMW-12 CAP4Q23-SMW-12-110823 11/8/2023 7,000 4,600 CAP MW Sampling 3Q23 OW-4R CAP3Q23-OW-4R-080423 8/4/2023 25,000 17,000 CAP MW Sampling 3Q23 OW-30 CAP3Q23-OW-30-071323 7/13/2023 19,000 12,000 CAP MW Sampling 3Q23 OW-32 CAP3Q23-OW-32-090823 9/8/2023 990 640 CAP MW Sampling 3Q23 OW-37 CAP3Q23-OW-37-081023 8/10/2023 8,200 J 5,200 J CAP MW Sampling 3Q23 OW-40 CAP3Q23-OW-40-071323 7/13/2023 5,700 3,700 CAP MW Sampling 3Q23 OW-51 CAP3Q23-OW-51-080323 8/3/2023 92,000 60,000 CAP GW Sampling 3Q23 OW-55 CAP3Q23-OW-55-072523 7/25/2023 2,900 11800 CAP MW Sampling 3Q23 OW-56 CAP3Q23-OW-56-073123 7/31/2023 2,200 1,400 CAP MW Sampling 3Q23 OW-57 CAP3Q23-OW-57-073123 7/31/2023 44,000 28,000 CAP MW Sampling 3Q23 PIW-41) CAP3Q23-PIW-4D-071323 7/13/2023 880 550 CAP MW Sampling 3Q23 PIW-5SR CAP3Q23-PIW-5SR-080423 8/4/2023 44,000 29,000 CAP MW Sampling 3Q23 PIW-6S CAP3Q23-PIW-6S-071223 7/12/2023 64,000 J 50,000 J TR0795C Page 1 of 2 June 2024 Appendix C Corrected PFPrA Concentrations for Previously Reported Results July 2023 to November 2023 Chemours Fayetteville Works Fayetteville, North Carolina Sampling Program Location ID Sample ID Sample Date PFPrA Concentration (ng/L) Corrected Original CAP MW Sampling 3Q23 PIW-81) CAP3Q23-PIW-8D-07l l23 7/11/2023 57,000 34,000 CAP MW Sampling 3Q23 PIW-IODR CAP3Q23-PIW-IODR-071423 7/14/2023 26,000 17,000 CAP MW Sampling 3Q23 PIW-lOS CAP3Q23-PIW-lOS-071323 7/13/2023 5,300 3,100 CAP MW Sampling 3Q23 PIW-I I CAP3Q23-PIW-11-073123 7/31/2023 3,400 2,000 CAP GW Sampling 3Q23 PIW-15 CAP3Q23-PIW-15-072523 7/25/2023 14,000 9,000 CAP MW Sampling 3Q23 PW-IORR CAP3Q23-PW-IORR-080323 8/3/2023 60,000 39,000 CAP MW Sampling 3Q23 PW-11 CAP3Q23-PW-11-070723 7/7/2023 25,000 17,000 CAP GW Sampling 3Q23 PIW-12 CAP3Q23-PIW-12-072423 7/24/2023 2,800 1,700 CAP GW Sampling 3Q23 PIW-13 CAP3Q23-PIW-13-072423 7/24/2023 4,600 2,800 CAP GW Sampling 3Q23 PIW-14 CAP3Q23-PIW-14-072423 7/24/2023 6,700 4,300 CAP SW Sampling 3Q23 WC-1 CAP3Q23-WC-1-24-072723 7/27/2023 770 500 CAP SW Sampling 4Q23 WC-1 CAP4Q23-WC-1-112323 11/23/2023 250 170 CAP SW Sampling 3Q23 WC-2 CAP3Q23-WC-2-24-072723 7/27/2023 570 360 CAP SW Sampling 4Q23 WC-2 CAP4Q23-WC-2-112323 11/23/2023 340 J 220 J CAP SW Sampling 3Q23 WC-3 CAP3Q23-WC-3-24-072723 7/27/2023 280 180 CAP SW Sampling 4Q23 WC-3 CAP4Q23-WC-3-112323 11/23/2023 150 96 Notes: 1 - PFPrA concentrations were revised following the discovery of a calculation error by the analytical laboratory. J - Analyte detected. Reported value may not be accurate or precise. ng/L - nanograms per liter PFPrA - perfluoropropanoic acid TR0795C Page 2 of 2 June 2024 Geosyntec consultants Geosyntec Consultants of NC, P.C. NC License No.: C-3500 and C-295 Appendix D Updated PFPrA Calculation Discussion and Table of Previously Reported Results Along with Revised, Corrected Results, Chemours Fayetteville Works, Fayetteville, NC TR0795C 9 Chemours- June 18, 2024 The Chemours Company Fayetteville Works 22828 NC Highway 87 W Fayetteville, NC 28306 Updated PFPrA Calculation Discussion and Table of Previously Reported Results Along with Revised, Corrected Results, Chemours Fayetteville Works, Fayetteville, NC Perfluoropropanoic acid (PFPrA) is a Table 3+ compound that was added to the Fayetteville Works commercial analytical suite in June 2023. It is considered an "early eluter" because it is a small compound (with a three -carbon backbone) that is not retained well on chromatographic columns and is subject to interferences from the sample matrix, which makes it difficult to analyze. Analytical improvements such as better sample cleanup using solid -phase extraction cartridges have made it possible for PFPrA to be analyzed by commercial analytical laboratories Method 537Mod Max. Certified PFPrA standards did not become available until July 2023. Prior to July 2023, commercial analytical laboratories were creating their own PFPrA standards from neat liquid PFPrA. It should be noted that when commercially prepared dilutions of PFPrA were first offered as certified solutions in July 2023, it was unclear if the solutions were correctly preserved to prevent esterification (short -chain fluorinated acids were believed to be prone to conversion to the methyl ester when prepared as methanolic solutions). One of Chemours' commercial analytical laboratories, Eurofins-Sacramento, conducted an internal comparative investigation in Q1 2024 to assess the validity of commercial standards. PFPrA standards were purchased from 3 vendors and compared to a standard correctly prepared at Eurofins- Sacramento. The comparative investigation indicated that the commercial standards were acceptable, and their use has now been implemented. On April 23, 2024, Eurofins-Sacramento, informed Chemours via email that a calculation error had been incorporated into the preparation of calibration standards for PFPrA under the laboratory's 537 Mod Max methodology. This error occurred when PFPrA standard solutions prepared at Eurofins-Sacramento did not correctly incorporate the density of neat liquid PFPrA when adding a known volume of neat liquid PFPrA to water, resulting in the incorrect calculation of the concentration of the standards. The density of PFPrA was assumed to be 1.0 grams per milliliter (g/ml), but the true density of liquid PFPrA is 1.56 g/ml. The neat liquid PFPrA was purchased from Sigma -Aldrich and was 97% pure (see Attachment 1 for Certificate of Analysis). This level of purity is acceptable under Eurofins-Sacramento's Standard Operating Procedure, and is slightly purer than the purity of 96% allowed when making standards under EPA Method 537, from which Eurofins-Sacramento derives its Method 537 Mod Max. For example, a standard solution created by adding 1.0 milliliters of PFPrA liquid to 1.0 liters of water was incorrectly determined to have a PFPrA concentration of 1.0 grams per liter (1.0 g/L), and the correct PFPrA concentration was 1.56 g/L. The error resulted in a 36% low bias (36% = 100*[1.56 — 1.0]/1.56) in PFPrA concentrations reported for approximately 550 Chemours samples collected at and in the vicinity of the Fayetteville Works Site and reported between June 2023 and April 2024. Eurofins-Sacramento is now using the newly available commercially available certified standards to prepare calibration curves for PFPrA. Consequently, this error will not be repeated in the future. Chemours informed the North Carolina Department of Environmental Quality (NCDEQ) of the PFPrA calculation error via telephone on May 15, 2024, and provided NCDEQ with Eurofins-Sacramento's memo describing their root cause analysis of the PFPrA calculation error on May 22, 2024 (Attachment 2). PFPrA results that were incorrectly calculated have been corrected by Eurofins-Sacramento and revised PFPrA results have been provided to Chemours (Table 1). Due to the requirement for fully defensible Level 4 data for PFPrA, the existing PFPrA results were not simply multiplied by 1.56 to correct for the low bias, but rather the laboratory generated the revised PFPrA data through their laboratory information management system (LIMS). Once reported, the original quantitative data becomes a permanent record in the LIMS, which necessitates regenerating the quantitative data in order to incorporate a fundamental change in the calculation basis, such as updated concentrations of calibration standards, and reporting of revised results. Re -generation of quantitative data includes re -integration of all analyte responses as well as generation of new calibration response factors and associated calculations of analyte concentrations. Note that this is a necessary process for many commercial analytical laboratories when regeneration of results from raw data is required. Re -integrating chromatographic peaks in both standards and samples may yield different integrated areas than were originally generated. The different integrated areas in turn yield different concentrations than expected. A change in concentration due to re -integration can occur with either automated or manual re -integration but is more likely to occur with manual re- integration because manual integrations are more subjective than automated integrations. In the current case, the revised PFPrA concentrations were expected to increase by a factor of 1.56, but this was not always observed (Table 1). When the PFPrA (or the associated isotope dilution analyte (IDA)) concentration is low or is impacted by chromatographic interferences, small changes in integrations may have a significant effect on the results, as described below: • Samples that contain very small amounts of PFPrA (i.e., the signal-to-noise ratio is large) - small changes in integration of the PFPrA results in changes to the revised PFPrA concentration that vary from the factor of 1.56; • Samples with low IDA response due to extract dilutions necessitated by high target analyte concentrations - small changes in integration of the IDA results in changes to the revised PFPrA concentration that vary from the factor of 1.56. Chemours maintains an inventory of dilutions required for specific sampling locations, so when these locations are sampled in the future the expected concentrations can be addressed without adverse impacts on the IDA response; and • Samples with significant effects from the matrix - the presence of chromatographic interferences means that the signal-to-noise ratio is large, whether or not the PFPrA or IDA 2 concentrations are small (although matrix effects tend to be more significant at lower PFPrA or IDA concentrations), which makes integration of the PFPrA and/or the IDA more variable. Consequently, each revised PFPrA concentration may not show an increase of exactly 1.56 over the original concentration (in a few cases, the revised PFPrA concentration is actually lower than the initial PFPrA concentration). However, the revised PFPrA concentrations increased by an average factor of 1.57 over the original concentrations, which is close to the expected increase of 1.56. The range in the factor was 0.81 to 2.56, with a standard deviation of 0.14. Ninety-two percent of the factors fall within one standard deviation of the average (i.e., 92 % of the factors are between 1.43 and 1.71). For upcoming Q1 2024 reports due on June 30, 2024, the PFPrA results will be corrected before they are submitted to NCDEQ. These reports will also include an appendix that provides corrected PFPrA results for samples collected between June 2023 to December 2023 that were previously submitted to NCDEQ. Revised lab reports for these 2023 samples will be uploaded to the shared OneDrive folder at the same time as the lab reports associated with the Q 12024 reports. Chemours is committed to producing good quality analytical data and will continue to work with its commercial analytical laboratories to monitor analytical data quality, implement improvements to analytical methods and communicate with NCDEQ regarding analytical issues. Enclosures Table 1 - Revised and Original PFPrA Concentrations Attachment 1 — Sigma Aldrich Certificate of Analysis for Pentafluoropropionic Acid Attachment 2 - RE: Investigation and Corrective Action for PFPrA Error TABLE 1 REVISED AND ORIGINAL PFPRA CONCENTRATIONS Chemours Fayetteville Works, North Carolina Sampling Program Sample ID Sample Date Sample Delivery Group Laboratory Sample ID PFPrA Concentration (ng/L) Factor (revised concentration / original concentration) Revised Concentration* Original Concentration 2023 Perched Zone Sampling FAY-D-EB-092023 20-Sep-23 320-105128-1 320-105128-1 <5 <5 2023 Perched Zone Sampling FAY-D-EB-122023 20-Dec-23 320-108308-1 320-108308-1 <5 <5 2023 Perched Zone Sampling FAY-D-MW-24-092023 20-Sep-23 320-105128-1 320-105128-5 300,000 200,000 1.50 2023 Perched Zone Sampling FAY-D-MW-24-122023 20-Dec-23 320-108308-1 320-108308-5 150,000 J 170,000 J 0.88 2023 Perched Zone Sampling FAY-D-NAF-03-092023 20-Sep-23 320-105128-1 320-105128-4 360,000 220,000 1.64 2023 Perched Zone Sampling FAY-D-NAF-03-122023 20-Dec-23 320-108308-1 320-108308-3 320,000J 370,000J 0.86 2023 Perched Zone Sampling FAY-D-NAF-03-122023-D 20-Dec-23 320-108308-1 320-108308-4 250,000J 220,000J 1.14 2023 Perched Zone Sampling FAY-D-NAF-12-092023 20-Sep-23 320-105128-1 320-105128-2 150,000 93,000 1.61 2023 Perched Zone Sampling FAY-D-NAF-12-092023-D 20-Sep-23 320-105128-1 320-105128-3 190,000 120,000 1.58 2023 Perched Zone Sampling FAY-D-NAF-12-122023 20-Dec-23 320-108308-1 320-108308-2 350,000J 430,000J 0.81 CAP GW Sampling 3 23 CAPS 23-BCA-04-072023 20-Jul-23 320-102901-1 320-102901-5 79 51 1.55 CAP GW Sampling 3 23 CAPS 23-MW-17D-072023 20-Jul-23 320-102901-1 320-102901-6 1,400 900 1.56 CAP GW Sampling 3 23 CAPS 23-NAF-01-072123 21-Jul-23 320-102898-1 320-102898-1 350,000 220,000 1.59 CAP GW Sampling 3 23 CAPS 23-NAF-02-072023 20-Jul-23 320-102901-1 320-102901-9 1,100,000 660,000 1.67 CAP GW Sampling 3 23 CAPS 23-NAF-03-072023 20-Jul-23 320-102901-1 320-102901-10 58,000 J 37,000 J 1.57 CAP GW Sampling 3 23 CAPS 23-NAF-09-072023 20-Jul-23 320-102901-1 320-102901-1 67,000 42,000 1.60 CAP GW Sampling 3 23 CAPS 23-NAF-10-072023 20-Jul-23 320-102901-1 1 320-102901-2 4,900 3,100 1.58 CAP GW Sampling 3 23 CAPS 23-OW-55-072523 25-Jul-23 320-102898-1 320-102898-7 2,900 1,800 1.61 CAP GW Sampling 3 23 CAPS 23-PIW-12-072423 24-Jul-23 320-102898-1 320-102898-5 2,800 1,700 1.65 CAP GW Sampling 3 23 CAPS 23-PIW-13-072423 24-Jul-23 320-102898-1 320-102898-6 4,600 2,800 1.64 CAP GW Sampling 3 23 CAPS 23-PIW-14-072423 24-Jul-23 320-102898-1 320-102898-4 6,700 4,300 1.56 CAP GW Sampfing 3 23 CAP3 23-PIW-15-072523 25-Jul-23 320-102898-1 320-102898-8 14,000 9,000 1.56 CAP GW Sampling 3 23 CAPS 23-PIW-2D-072023 20-Jul-23 320-102901-1 320-102901-7 18,000 12,000 1.50 CAP GW Sampling 3023 CAPS 23-PW-05-072023 20-Jul-23 320-102901-1 320-102901-4 1,100 790 1.39 CAP GW Sampling 3 23 CAPS 23-PZ-13-072023 20-Jul-23 320-102901-1 320-102901-3 51,000 33,000 1.55 CAP GW Sampling 3 23 CAPS 23-PZ-14-072123 21-Jul-23 320-102898-1 320-102898-2 13,000 7,900 1.65 CAP GW Sarnpling 3 23 CAPS 23-SMW-04B-072023 20-Jul-23 320-102901-1 320-102901-8 3,800 2,400 1.58 CAP GW Sarnpling 3 23 CAPS 23-SMW-05PR-072123 21-Jul-23 320-102898-1 320-102898-3 23,000 15,000 1.53 CAP GW Saxnpling 4 23 CAP4 23-BLADEN-IDR-010424 04-Jan-24 320-108551-1 320-108551-1 200 130 1.54 CAP GW Sampling 4 23 CAP4 23-E BLK-DV-110823 08-Nov-23 320-106887-1 320-106887-6 <5 <5 CAP GW Sampling 4023 CAP4 23-E BLK-DV-110823-Z 08-Nov-23 320-106887-1 320-106887-5 <5 <5 CAP GW Sampling 4 23 CAP4 23-E BLK-PP-010424 04-Jan-24 320-108551-1 320-108551-2 <5 <5 CAP GW Sampling 4 23 CAP4 23-E BLK-PP-110823 08-Nov-23 320-106887-1 320-106887-9 <5 <5 CAP GW Sampling 4 23 CAP4 23-E BLK-PP-110823-Z 08-Nov-23 320-106887-1 320-106887-8 <5 <5 CAP GW Sampling 4 23 CAP4 23-LTW-01-110323 03-Nov-23 320-106773-1 320-106773-1 24,000 14,000 1.71 CAP GW Sampling 4 23 CAP4 23-LTW-02-110323 03-Nov-23 320-106772-1 320-106772-7 21,000 13,000 1.62 CAP GW Sampling 4 23 CAP4 23-LTW-04-110223 02-Nov-23 320-106772-1 320-106772-5 48,000 30,000 1.60 CAP GW Sampling 4023 CAP4 23-LTW-05-110223 02-Nov-23 320-106772-1 320-106772-1 120,000 68,000 1.76 CAP GW Sampling 4 23 CAP4 23-OW-28-110223 02-Nov-23 320-106772-1 320-106772-6 5,500 3,500 1.57 CAP GW Sampling 4 23 CAP4 23-OW-33-110223 02-Nov-23 320-106773-1 320-106773-3 9,400 6,000 1.57 CAP GW Sampling 4 23 CAP4 23-OW-33-110223-D 02-Nov-23 320-106773-1 320-106773-4 9,000 5,900 1.53 CAP GW Sampling 4 23 CAP4 23-PIW-1D-110723 07-Nov-23 320-106887-1 320-106887-1 12,000 7,500 1.60 CAP GW Sampling 4 23 CAP4 23-PIW-1D-110723-Z 07-Nov-23 320-106887-1 320-106887-2 12,000 7,700 1.56 CAP GW Sampling 4 23 CAP4 23-PIW-3D-110323 03-Nov-23 320-106773-1 320-106773-2 21,000 13,000 1.62 CAP GW SamDling 4023 CAP4 23-PIW-7D-110223 02-Nov-23 320-106772-1 320-106772-3 86,000 52,000 1.65 CAP GW Sampling 4 23 CAP4 23-PIW-7S-110223 02-Nov-23 320-106772-1 320-106772-2 18,000 12,000 1.50 CAP GW Sampling 4 23 CAP4 23-PW-06-110623 06-Nov-23 320-106773-1 320-106773-5 840 520 1.62 CAP GW Sampling 4 23 CAP4 23-PW-09-110823 08-Nov-23 320-106887-1 320-106887-4 <5 UJ <5 UJ CAP GW Sampling 4 23 CAP4 23-PW-09-110823-Z 08-Nov-23 320-106887-1 320-106887-7 <5 UJ <5 UJ CAP GW Sampling 4 23 CAP4 23-PZ-22-110223 02-Nov-23 320-106772-1 320-106772-4 84,000 51,000 1.65 CAP GW Sampling 4 23 CAP4 23-SMW-11-110723 07-Nov-23 320-106887-1 320-106887-3 6,100 3,800 1.61 CAP MW Sampling 3 23 CAPS 23-BCA-01-070723 07-Jul-23 320-102399-1 320-102399-1 34,000 18,000 1.89 CAP MW Sampling 3 23 CAPS 23-BCA-02-070723 07-Jul-23 320-102399-1 1 320-102399-2 13,000 7,300 1.78 CAP MW Sampling 3 23 CAPS 23-BCA-03R-071123 I I-Jul-23 320-102509-1 320-102509-9 110,000 J 69,000 J 1.59 CAP MW Sampling 3 23 CAPS 23-BLADEN-IDR-071223 12-Jul-23 320-102527-1 320-102527-9 240 160 1.50 CAP MW Sampling 3 23 CAPS 23-BLADEN-2D-080223 02-Aug-23 320-103526-1 320-103526-3 <5 <5 CAP MW Sampling 3 23 CAPS 23-BLADEN-2S-080123 01-Aug-23 320-103526-1 320-103526-2 77 48 1.60 CAP MW Sampling 3 23 CAPS 23-BLADEN-3D-082323 23-Aug-23 320-104207-1 320-104207-1 <5 <5 CAP MW Sampling 3 23 CAPS 23-BLADEN-3S-082223 22-Aug-23 320-104225-1 320-104225-5 80 49 1.63 CAP MW Sampling 3 23 CAPS 23-BLADEN-4D-082323 23-Aug-23 320-104207-1 320-104207-2 <5 <5 CAP MW Sampling 3 23 CAPS 23-BLADEN-4S-082323 23-Aug-23 320-104225-1 320-104225-7 16 10 1.60 CAP MW Sampling 3 23 CAPS 23-BLADEN-4S-082323-Z 23-Aug-23 320-104225-1 320-104225-8 16 9.9 1.62 CAP MW Sampling 3 23 CAPS 23-CUMBERLAND-1D-072823 28-Jul-23 320-103202-1 320-103202-2 39 24 1.63 CAP MW Sampling 3 23 CAPS 23-CUMBERLAND-1S-072723 27-Jul-23 320-103202-1 320-103202-1 37 23 1.61 CAP MW Sampling 3 23 CAPS 23-CUMBERLAND-2D-072823 28-Jul-23 320-103202-1 320-1032024 5.7 B <5 CAP MW Sampling 3023 CAPS 23-CUMBERLAND-2S-072823 28-Jul-23 320-103202-1 320-103202-3 39 23 1.70 CAP MW Sampling 3 23 CAPS 23-CUMBERLAND-3D-082223 22-Aug-23 320-104207-1 320-104207-4 <5 <5 CAP MW Sampling 3 23 CAPS 23-CUMBERLAND-3S-082223 22-Aug-23 320-104207-1 320-104207-6 27 17 1.59 CAP MW Sampling 3 23 CAPS 23-CUMBERLAND-4D-082223 22-Aug-23 320-104225-1 320-104225-4 <5 <5 CAP MW Sampling 3 23 CAPS 23-CUMBERLAND-4S-082223 22-Aug-23 320-104225-1 320-104225-6 96 62 1.55 CAP MW Sampling 3 23 CAPS 23-CUMBERLAND-5DR-082423 24-Aug-23 320-104225-1 320-104225-3 <5 <5 CAP MW Sampling 3 23 CAPS 23-CUMBERLAND-5S-082423 24-Aug-23 320-104225-1 320-104225-10 22 13 1.69 CAP MW Sampling 3 23 CAP3 23-E BLK-BAILER-102423 24-Oct-23 320-106378-1 320-106378-1 <5 <5 CAP MW Sampling 3 23 CAPS 23-E BLK-BAILER-102423-Z 24-Oct-23 320-106378-1 320-106378-2 <5 <5 CAP MW Sampling 3 23 CAPS 23-E BLK-BP-071123 11-Jul-23 320-102509-1 320-102509-10 <5 <5 CAP MW Saxapling 3 23 CAPS 23-E BLK-DV-071223 12-Jul-23 320-102509-1 320-102509-11 <5 <5 CAP MW Sampling 3 23 CAPS 23-E BLK-DV-081623 16-Aug-23 320-104043-1 320-104043-6 <5 <5 CAP MW Sampling 3 23 CAP3 23-E BLK-FILTER-071423 14-Jul-23 320-102718-1 320-102718-11 <5 <5 Page 1 of 5 June 2024 TABLE 1 REVISED AND ORIGINAL PFPRA CONCENTRATIONS Chemours Fayetteville Works, North Carolina Sampling Program Sample ID Sample Date Sample Delivery Group Laboratory Sample ID PFPrA Concentration (ng/L) Factor (revised concentration / original concentration) Revised Concentration* Original Concentration CAP MW Sampling 3 23 CAPS 23-E BLK-PP-071223 12-Jul-23 320-102527-1 320-102527-10 <5 <5 CAP MW Sampling 3 23 CAPS 23-E BLK-PP-071723 17-Jul-23 320-102718-1 320-102718-10 <5 <5 CAP MW Sampling 3 23 CAPS 23-E BLK-PP-080423 04-Aug-23 320-104043-1 320-104043-4 <5 UJ <5 UJ CAP MW Sampling 3 23 CAPS 23-E BLK-PP-081823 18-Aug-23 320-104043-1 320-104043-5 <5 <5 CAP MW Sampling 3 23 CAPS 23-E BLK-PP-102423 24-Oct-23 320-106378-1 320-106378-3 <5 <5 CAP MW Sampling 3 23 CAPS 23-E BLK-PP-102423-Z 24-Oct-23 320-106378-1 320-106378-4 <5 <5 CAP MW Sampling 3 23 CAPS 23-FTA-01-071923 19-Jul-23 320-102791-1 320-102791-1 280 180 1.56 CAP MW Sampling 3 23 CAPS 23-FTA-02-071923 19-Jul-23 320-102791-1 320-102791-2 21,000 14,000 1.50 CAP MW Sampling 3 23 CAPS 23-FTA-02-071923-D 19-Jul-23 320-102791-1 320-102791-3 21,000 13,000 1.62 CAP MW Sampling 3 23 CAPS 23-FTA-03-071923 19-Jul-23 320-102791-1 320-102791-4 14,000 8,600 1.63 CAP MW Sarapling 3 23 CAPS 23-INSITU-01-071323 13-Jul-23 320-102712-1 320-102712-8 850 530 1.60 CAP MW Sarapling 3 23 CAPS 23-LTW-Ol-071323 13-Jul-23 320-102712-1 320-102712-2 22,000 14,000 1.57 CAP MW Sarapling 3 23 CAPS 23-LTW-02-071223 12-Jul-23 320-102527-1 320-102527-8 16,000 11,000 1.45 CAP MW Sarapling 3 23 CAPS 23-LTW-03-071223 12-Jul-23 320-102527-1 320-102527-5 62,000 J 37,000 1.68 CAP MW Sarapling 3 23 CAPS 23-LTW-04-071123 11-Jul-23 320-102527-1 320-102527-1 53,000 29,000 1.83 CAP MW Sanapling 3 23 CAPS 23-LTW-05-071123 11-Jul-23 320-102509-1 320-102509-6 83,000 J 52,000 J 1.60 CAP MW Sanapling 3023 CAPS 23-MW-24-071823 18-Jul-23 320-102688-1 320-102688-1 240,000 150,000 1.60 CAP MW Sanapling 3 23 CAPS 23-MW-13D-071023 10-Jul-23 320-102399-1 320-102399-9 61,000 J 39,000 J 1.56 CAP MW Sampling 3 23 CAPS 23-MW-14D-071323 13-Jul-23 320-102716-1 320-102716-2 130,000 83,000 1.57 CAP MW Sampling 3 23 CAPS 23-MW-15DRR-071123 11-Jul-23 320-102509-1 320-102509-1 8,800 5,300 1.66 CAP MW Sampling 3 23 CAPS 23-MW-16D-071223 12-Jul-23 320-102527-1 320-102527-7 1,000 630 1.59 CAP MW Sampling 3 23 CAPS 23-MW-18D-071723 17-Jul-23 320-102716-1 320-102716-6 680 430 1.58 CAP MW Sampling 3 23 CAP3 23-MW-19D-071023 10-Jul-23 320-102399-1 320-102399-10 960 640 1.50 CAP MW Sampling 3 23 CAPS 23-MW-12S-071823 18-Jul-23 320-102688-1 320-102688-2 6,600 4,300 1.53 CAP MW Sampling 3 23 CAPS 23-MW-20D-071123 11-Jul-23 320-102509-1 320-102509-7 4,900 3,300 1.48 CAP MW Sampling 3 23 CAPS 23-MW-20D-071123-D 11-Jul-23 320-102509-1 320-102509-8 5,300 3,300 1.61 CAP MW Sampling 3 23 CAPS 23-MW-21D-071423 14-Jul-23 320-102716-1 320-102716-4 800 500 1.60 CAP MW Sampling 3 23 CAPS 23-MW-22D-071223 12-Jul-23 320-102527-1 320-102527-4 970 580 1.67 CAP MW Sarapling 3 23 CAPS 23-MW-23-071723 17-Jul-23 320-102718-1 320-102718-2 2,500 1,400 1.79 CAP MW Sarapling 3 23 CAPS 23-MW-1S-071823 18-Jul-23 320-102688-1 320-102688-3 11,000 6,600 1.67 CAP MW Sampling 3 23 CAPS 23-MW-25-071823 18-Jul-23 320-102718-1 320-102718-7 10,000 6,700 1.49 CAP MW Sampling 3 23 CAPS 23-MW-27-071323 13-Jul-23 320-102712-1 320-102712-7 40,000 26,000 1.54 CAP MW Sampling 3 23 CAPS 23-MW-28-071323 13-Jul-23 320-102712-1 320-102712-4 730 460 1.59 CAP MW Sanapling 3 23 CAPS 23-MW-30-071823 18-Jul-23 320-102718-1 320-102718-5 7,000 4,700 1.49 CAP MW Sanapling 3 23 CAPS 23-MW-7S-071823 18-Jul-23 320-102718-1 320-102718-6 5,700 3,900 1.46 CAP MW Sampling 3 23 CAPS 23-MW-9S-071823 18-Jul-23 320-102718-1 320-102718-9 2,900 1,800 1.61 CAP MW Sampling 3 23 CAPS 23-NAF-04-081723 17-Aug-23 320-104207-1 320-104207-7 160,000 100,000 1.60 CAP MW Sampling 3 23 CAPS 23-NAF-05A-102423 24-Oct-23 320-106358-1 320-106358-1 240,000 150,000 1.60 CAP MW Sampling 3 23 CAPS 23-NAF-05A-102423-D 24-Oct-23 320-106358-1 320-106358-2 240,000 150,000 1.60 CAP MW Sampling 3 23 CAPS 23-NAF-05A-102423-D-Z 24-Oct-23 320-106358-1 320-106358-4 240,000 150,000 1.60 CAP MW Sampling 3 23 CAPS 23-NAF-05A-102423-Z 24-Oct-23 320-106358-1 320-106358-3 190,000 120,000 1.58 CAP MW Sampling 3 23 CAPS 23-NAF-06-071923 19-Jul-23 320-102796-1 320-102796-1 380,000 240,000 1.58 CAP MW Sampling 3 23 CAPS 23-NAF-06-071923-Z 19-Jul-23 320-102796-1 320-102796-2 410,000 250,000 1.64 CAP MW Sampling 3 23 CAPS 23-NAF-07-071923 19-Jul-23 320-102796-1 320-102796-3 3,600 2,100 1.71 CAP MW Sarapling 3 23 CAPS 23-NAF-08A-081723 17-Aug-23 320-104225-1 320-104225-2 41,000 26,000 1.58 CAP MW Sampling 3 23 CAPS 23-NAF-11A-071923 19-Jul-23 320-102796-1 320-102796-4 15,000 9,400 1.60 CAP MW Sampling 3 23 CAPS 23-NAF-12-081723 17-Aug-23 320-104225-1 320-104225-1 200,000 130,000 1.54 CAP MW Sampling 3 23 CAPS 23-NAF-13-102423 24-Oct-23 320-106358-1 320-106358-5 10,000 6,600 1.52 CAP MW Sampling 3 23 CAPS 23-NAF-13-102423-Z 24-Oct-23 320-106358-1 320-106358-6 10,000 6,600 1.52 CAP MW Sampling 3 23 CAP3 23-OW-28-071123 11-Jul-23 320-102509-1 320-102509-5 5,200 3,500 1.49 CAP MW Sarnpling 3 23 CAPS 23-OW-30-071323 13-Jul-23 320-102712-1 320-102712-10 19,000 12,000 1.58 CAP MW Sampling 3023 CAPS 23-OW-30-071323-Z 13-Jul-23 320-102712-1 320-102712-11 19,000 12,000 1.58 CAP MW Sampling 3 23 CAPS 23-OW-32-090823 08-Sep-23 320-104780-1 320-104780-1 990 640 1.55 CAP MW Sampling 3 23 CAPS 23-OW-32-090823-D 08-Sep-23 320-104780-1 320-104780-2 970 620 1.56 CAP MW Sampling 3 23 CAP3 23-OW-32-090823-D-Z 08-Sep-23 320-104780-1 320-104780-4 930 620 1.50 CAP MW Sampling 3 23 CAPS 23-OW-32-090823-Z 08-Sep-23 320-104780-1 320-104780-3 1,000 650 1.54 CAP MW Sampling 3 23 CAPS 23-OW-33-071223 12-Jul-23 320-102527-1 320-102527-3 9,900 5,400 1.83 CAP MW Sampling 3 23 CAP3 23-OW-37-081023 10-Aug-23 320-104266-1 320-104266-3 8,200 J 5,200 J 1.58 CAP MW Sampling 3 23 CAPS 23-OW-40-071323 13-Jul-23 320-102712-1 320-102712-9 5,700 3,700 1.54 CAP MW Sampling 3 23 CAPS 23-OW-4R-080423 04-Aug-23 320-103526-1 320-103526-7 25,000 17,000 1.47 CAP MW Sarapling 3 23 CAPS 23-OW-51-080323 03-Aug-23 320-103526-1 320-103526-6 92,000 60,000 1.53 CAP MW Sampling 3 23 CAPS 23-OW-56-073123 31-Jul-23 320-103202-1 320-103202-9 2,200 1,400 1.57 CAP MW Sampling 3 23 CAPS 23-OW-57-073123 31-Jul-23 320-103202-1 320-103202-10 44,000 28,000 1.57 CAP MW Sampling 3 23 CAPS 23-PIW-IODR-071423 14-Jul-23 320-102716-1 320-102716-5 26,000 17,000 1.53 CAP MW Sampling 3 23 CAPS 23-PIW-lOS-071323 13-Jul-23 320-102712-1 320-102712-5 5,300 3,100 1.71 CAP MW SarnDlina 3023 CAPS 23-PIW-11-073123 31-Jul-23 320-103202-1 320-103202-8 3,400 2,000 1.70 CAP MW Sampling 3 23 CAPS 23-PIW-16D-071423 14-Jul-23 320-102716-1 320-102716-3 <5 <5 CAP MW Sampling 3 23 CAPS 23-PIW-16S-071023 10-Jul-23 320-102399-1 320-102399-7 1,100 770 1.43 CAP MW Sampling 3 23 CAP3 23-PIW-1D-080223 02-Aug-23 320-103526-1 320-103526-4 12,000 J 7,800 1.54 CAP MW Sampling 3 23 CAPS 23-PIW-3D-071323 13-Jul-23 320-102712-1 320-102712-1 19,000 11,000 1.73 CAP MW Sampling 3 23 CAPS 23-PIW-4D-071323 13-Jul-23 320-102712-1 320-102712-3 880 550 1.60 CAP MW Sampling 3 23 CAPS 23-PIW-5SR-080423 04-Aug-23 320-103526-1 320-103526-8 44,000 29,000 1.52 CAP MW Sampling 3 23 CAP3 23-PIW-5SR-080423-Z 04-Aug-23 320-103526-1 320-103526-9 40,000 26,000 1.54 CAP MW Sampling 3 23 CAPS 23-PIW-6S-071223 12-Jul-23 320-102527-1 320-102527-6 64,000 J 50,000 J 1.28 CAP MW Sampling 3 23 CAPS 23-PIW-7D-071123 11-Jul-23 320-102509-1 320-102509-3 79,000 J 49,000 J 1.61 CAP MW Sampling 3 23 CAP3 23-PIW-7S-071123 11-Jul-23 320-102509-1 320-102509-2 14,000 9,700 1.44 CAP MW Sampling 3 23 CAPS 23-PIW-8D-071123 11-Jul-23 320-102509-1 320-102509-4 57,000 34,000 1.68 CAP MW Sampling 3 23 CAP3 23-PW-01-071723 17-Jul-23 320-102716-1 320-102716-10 48,000 33,000 1.45 Page 2 of 5 June 2024 TABLE 1 REVISED AND ORIGINAL PFPRA CONCENTRATIONS Chemours Fayetteville Works, North Carolina Sampling Program Sample ID Sample Date Sample Delivery Group Laboratory Sample ID PFPrA Concentration (ng/L) Factor (revised concentration / original concentration) Revised Concentration* Original Concentration CAP MW Sampling 3 23 CAPS 23-PW-02-071923 19-Jul-23 320-102796-1 320-102796-5 6,400 4,000 1.60 CAP MW Sampling 3 23 CAPS 23-PW-02-071923-Z 19-Jul-23 320-102796-1 320-102796-6 6,600 4,300 1.53 CAP MW Sampling 3 23 CAPS 23-PW-03-071923 19-Jul-23 320-102796-1 320-102796-7 76,000 47,000 1.62 CAP MW Sampling 3 23 CAPS 23-PW-04-072823 28-Jul-23 320-103202-1 320-103202-5 1,400 900 1.56 CAP MW Sampling 3 23 CAPS 23-PW-04-072823-Z 28-Jul-23 320-103202-1 320-103202-6 1,600 890 1.80 CAP MW Sampling 3 23 CAPS 23-PW-06-071023 10-Jul-23 320-102399-1 320-102399-11 920 620 1.48 CAP MW Sampling 3 23 CAPS 23-PW-09-081023 10-Aug-23 320-104266-1 320-104266-1 <5 UJ <5 UJ CAP MW Sampling 3 23 CAPS 23-PW-09-081023-Z 10-Aug-23 320-104266-1 320-104266-2 <5 UJ <5 UJ CAP MW Sampling 3 23 CAPS 23-PW-IORR-080323 03-Aug-23 320-103526-1 320-103526-5 60,000 39,000 1.54 CAP MW Sampling 3 23 CAPS 23-PW-11-070723 07-Jul-23 320-102399-1 320-102399-3 25,000 17,000 1.47 CAP MW Sarapling 3 23 CAPS 23-PW-12-071723 17-Jul-23 320-102716-1 320-102716-7 22 14 1.57 CAP MW Sarapling 3 23 CAPS 23-PW-13-071323 13-Jul-23 320-102716-1 320-102716-1 <5 <5 CAP MW Sarapling 3 23 CAPS 23-PW-14-070723 07-Jul-23 320-102399-1 320-102399-4 35,000 24,000 1.46 CAP MW Sarapling 3 23 CAPS 23-PW-14-070723-D 07-Jul-23 320-102399-1 320-102399-5 36,000 24,000 1.50 CAP MW Sarapling 3 23 CAPS 23-PW-15R-070723 07-Jul-23 320-102399-1 320-102399-6 91,000 J 58,000 J 1.57 CAP MW Sanapling 3 23 CAPS 23-PZ-11-071723 17-Jul-23 320-102716-1 320-102716-8 2,700 1,500 1.80 CAP MW Sanapling 3023 CAP3 23-PZ-15-071823 18-Jul-23 320-102718-1 320-102718-8 4,500 3,000 1.50 CAP MW Sanapling 3 23 CAP3 23-PZ-19R-081523 15-Aug-23 320-104207-1 320-104207-3 14,000 8,900 1.57 CAP MW Sampling 3 23 CAPS 23-PZ-20R-081523 15-Aug-23 320-104207-1 320-104207-5 13,000 8,200 1.59 CAP MW Sampling 3 23 CAPS 23-PZ-21R-081523 15-Aug-23 320-104225-1 320-104225-9 4,700 2,900 1.62 CAP MW Sampling 3 23 CAPS 23-PZ-24-071723 17-Jul-23 320-102718-1 320-102718-4 2,900 1,700 1.71 CAP MW Sampling 3 23 CAPS 23-PZ-26-071723 17-Jul-23 320-102718-1 320-102718-1 130 91 1.43 CAP MW Sampling 3 23 CAPS 23-PZ-27-071323 13-Jul-23 320-102712-1 320-102712-6 350 230 1.52 CAP MW Sampling 3 23 CAPS 23-PZ-28-071723 17-Jul-23 320-102718-1 320-102718-3 440 310 1.42 CAP MW Sampling 3 23 CAPS 23-PZ-35-082123 21-Aug-23 320-104266-1 320-104266-4 8,700 5,400 1.61 CAP MW Sampling 3 23 CAPS 23-PZ-35-082123-D 21-Aug-23 320-104266-1 320-104266-5 8,600 5,400 1.59 CAP MW Sarapling 3 23 CAPS 23-ROBESON-1D-072823 28-Jul-23 320-103202-1 320-103202-7 23 B 13 1.77 CAP MW Sarapling 3 23 CAPS 23-ROBESON-1S-080123 01-Aug-23 320-103526-1 320-103526-1 39 26 1.50 CAP MW Sampling 3 23 CAPS 23-SMW-Ol-071023 10-Jul-23 320-102399-1 320-102399-8 610 400 1.53 CAP MW Sampling 3 23 CAPS 23-SMW-03B-071923 19-Jul-23 320-102791-1 320-102791-5 150,000 95,000 1.58 CAP MW Sampling 3023 CAPS 23-SMW-06B-081623 16-Aug-23 320-104043-1 320-104043-1 260,000 170,000 1.53 CAP MW Sampling 3 23 CAPS 23-SMW-07-071823 18-Jul-23 320-102688-1 320-102688-4 1,000 500 2.00 CAP MW Sampling 3 23 CAPS 23-SMW-08B-081623 16-Aug-23 320-104043-1 320-104043-2 31,000 20,000 1.55 CAP MW Sampling 3 23 CAPS 23-SMW-08B-081623-D 16-Aug-23 320-104043-1 320-104043-3 31,000 20,000 1.55 CAP MW Sampling 3 23 CAPS 23-SMW-09-071923 19-Jul-23 320-102791-1 320-102791-6 4,800 3,100 1.55 CAP MW Sampling 3 23 CAPS 23-SMW-10-071723 17-Jul-23 320-102716-1 320-102716-9 210 130 1.62 CAP MW Sampling 3 23 CAPS 23-SMW-11-071723 17-Jul-23 320-102716-1 320-102716-11 4,500 3,000 1.50 CAP MW Sampling 3 23 CAPS 23-SMW-12-071823 18-Jul-23 320-102688-1 320-102688-5 5,900 3,900 1.51 CAP MW Sampling 3 23 CAPS-PZ-22-071123 II-Jul-23 320-102527-1 320-102527-2 76,000 48,000 1.58 CAP MW Sampling 4 23 CAP4 23-E BLK-BAILER-110923 09-Nov-23 320-107233-1 320-107233-6 <5 <5 CAP MW Sampling 4 23 CAP4 23-E BLK-BAILER-110923-Z 09-Nov-23 320-107233-1 320-107233-7 <5 <5 CAP MW Sampling 4 23 CAP4 23-LTW-03-111323 13-Nov-23 320-107233-1 320-107233-3 61,000 J 38,000 J 1.61 CAP MW Sampling 4 23 CAP4 23-PW-04-110923 09-Nov-23 320-107233-1 320-107233-1 1,500 960 1.56 CAP MW Sarapling 4 23 CAP4 23-PW-04-110923-Z 09-Nov-23 320-107233-1 320-107233-2 1,500 980 1.53 CAP MW Sampling 4023 CAP4 23-SMW-10-111623 16-Nov-23 320-107233-1 320-107233-5 230 160 1.44 CAP MW Sampling 4 23 CAP4 23-SMW-12-110823 08-Nov-23 320-107233-1 320-107233-4 7,000 4,600 1.52 CAP SW Sampling 3 23 CAPS 23-CFR-BLADEN-072623 26-Jul-23 320-103017-1 320-103017-5 44 26 1.69 CAP SW Sampling 3 23 CAPS 23-CFR-KINGS-080123 01-Aug-23 320-103199-1 320-103199-2 32 21 1.52 CAP SW Sampling 3 23 CAPS 23-CFR-RM-76-072623 26-Jul-23 320-103017-1 320-103017-1 27 17 1.59 CAP SW Sampling 3 23 CAPS 23-CFR-TARHEEL-072723 27-Jul-23 320-103017-1 320-103017-6 44 26 1.69 CAP SW Sampling 3 23 CAPS 23-CFR-TARHEEL-6-072723 27-Jul-23 320-103199-1 320-103199-1 32 20 1.60 CAP SW Sampling 3 23 CAP3 23-E BLK-IS-072723 27-Jul-23 320-103017-1 320-103017-7 <5 <5 CAP SW Sampling 3 23 CAPS 23-E BLK-PP-072723 27-Jul-23 320-103017-1 320-103017-8 <5 <5 CAP SW Sampling 3 23 CAPS 23-GBC-1-072623 26-Jul-23 320-103017-1 320-103017-2 540 330 1.64 CAP SW Sampling 3 23 CAPS 23-LOCK-DAM-NORTH-072623 26-Jul-23 320-103017-1 320-103017-4 5,500 3,300 1.67 CAP SW Sampling 3 23 CAPS 23-LOCK-DAM-SEEP-072623 26-Jul-23 320-103017-1 320-103017-3 22,000 13,000 1.69 CAP SW Sampling 3 23 CAPS 23-OLDOF-1-24-072723 27-Jul-23 320-103013-1 320-103013-6 1,400 920 1.52 CAP SW Sampling 3 23 CAPS 23-OUTFALL-002-24-072723 27-Jul-23 320-103016-1 320-103016-4 730 460 1.59 CAP SW Sampling 3023 CAPS 23-SEEP-A-EFF-24-072723 27-Jul-23 320-103013-2 320-103013-1 3,700 J 2,300 J 1.61 CAP SW Sampling 3 23 CAPS 23-SEEP-B-EFF-24-072723 27-Jul-23 320-103013-2 320-103013-2 1,700 J 1,100 J 1.55 CAP SW Sampling 3 23 CAPS 23-SEEP-C-EFF-24-072723 27-Jul-23 320-103013-2 320-103013-3 330 J 200 J 1.65 CAP SW Sampling 3 23 CAPS 23-SEEP-D-EFF-24-072723 27-Jul-23 320-103013-1 320-103013-4 370 240 1.54 CAP SW Sampling 3 23 CAPS 23-WC-1-24-072723 27-Jul-23 320-103016-1 320-103016-1 770 500 1.54 CAP SW Sampling 3 23 CAPS 23-WC-2-24-072723 27-Jul-23 320-103016-1 320-103016-2 570 360 1.58 CAP SW Sampling 3 23 CAPS 23-WC-3-24-072723 27-Jul-23 320-103016-1 320-103016-3 280 180 1.56 CAP SW Sampling 3023 OUTFALL-002-24-072723-D 27-Jul-23 320-103016-1 320-103016-5 730 480 1.52 CAP SW Sampling 3 23 RIVER-WATER-INTAKE2-072623 26-Jul-23 320-103013-1 320-103013-5 1 1,100 680 1.62 CAP SW Sampling 3 23 RNER-WATER-INTAKE2-24-072823 28-Jul-23 320-103199-1 320-103199-3 210 130 1.62 CAP SW Sampling 4 23 CAP4 23-CFR-BLADEN-120623 06-Dec-23 320-107896-1 320-107896-1 49 31 1.58 CAP SW Sampling 4 23 CAP4 23-CFR-KINGS-121423 14-Dec-23 320-108081-1 320-108081-1 44 J 28 J 1.57 CAP SW Sampling 4 23 CAP4 23-CFR-RM-76-112223 22-Nov-23 320-107648-1 320-107648-1 20 11 1.82 CAP SW Sampling 4 23 CAP4 23-CFR-TARHEEL-120623 06-Dec-23 320-107896-1 320-107896-2 50 32 1.56 CAP SW Sampling 4023 CAP4 23-GBC-1-112223 22-Nov-23 320-107648-1 320-107648-2 680 410 1.66 CAP SW Sampling 4 23 CAP4 23-LOCK-DAM-NORTH-112223 22-Nov-23 320-107648-1 320-107648-5 4,800 3,000 1.60 CAP SW Sampling 4 23 CAP4 23-LOCK-DAM-SEEP-112223 22-Nov-23 320-107648-1 320-107648-3 9,000 J 5,600 J 1.61 CAP SW Sampling 4 23 CAP4 23-LOCK-DAM-SEEP-112223-D 22-Nov-23 0-1077 0-107648-4 600 1,,000 J 0.86 CAP SW Sampling 4 23 2-Nov-2 0-10 320-9 1,600J 1000 1.60480-1 CAP SW Sampling 4 23 CAP4 23-OUTFALL-002-112323 23-Nov-23 320-107480-1 320-107480-6 230 150 1.53 Page 3 of 5 June 2024 TABLE 1 REVISED AND ORIGINAL PFPRA CONCENTRATIONS Chemours Fayetteville Works, North Carolina Sampling Program Sample ID Sample Date Sample Delivery Group Laboratory Sample ID PFPrA Concentration (ng/L) Factor (revised concentration / original concentration) Revised Concentration* Original Concentration CAP SW Sampling 4 23 CAP4 23-SEEP-C-112323 23-Nov-23 320-107480-1 320-107480-4 22 14 1.57 CAP SW Sampling 4 23 CAP4 23-TARHEEL-24-112423 24-Nov-23 320-107480-1 320-107480-8 37 25 1.48 CAP SW Sawlina 4023 CAP4 23-WC-1-112323 23-Nov-23 320-107480-1 320-107480-1 250 170 1.47 CAP SW Sampling 4 23 CAP4 23-WC-1-112323-D 23-Nov-23 320-107480-1 320-107480-7 330 210 1.57 CAP SW Sampling 4 23 CAP4 23-WC-2-112323 23-Nov-23 320-107480-1 320-107480-2 340 J 220 J 1.55 CAP SW Sampling 4 23 CAP4 23-WC-3-112323 23-Nov-23 320-107480-1 320-107480-3 150 96 1.56 CAP SW Sampling 4 23 RIVER-WATER-INTAKE2-24-112323 23-Nov-23 320-107480-1 320-107480-5 1,800 1,200 1.50 PI Dry Sampling 11/23 DITrailerOutlet-112823 28-Nov-23 320-107660-1 320-107660-3 <5 <5 PII Dry Sampling 11/23 STW-LOC-16-112823 28-Nov-23 320-107660-1 320-107660-4 150,000 95,000 1.58 P I I Dry Sam lin 11/23 STW-LOC-18-4-112823 28-Nov-23 320-107656-1 320-107656-2 43 J <25 UJ PII Dry Sampling 11/23 STW-LOC-19A-112823 28-Nov-23 320-107660-1 320-107660-1 46 29 1.59 PI Dry Sampling 11/23 STW-LOC-19B-112823 28-Nov-23 320-107660-1 320-107660-5 25 16 1.56 PI Dry Sampling 11/23 STW-LOC-22-4-112823 28-Nov-23 320-107656-1 320-107656-3 250 160 1.56 P11 Dry Sampling 11/23 STW-LOC-22-4-112823-D 28-Nov-23 320-107656-1 320-107656-4 270 170 1.59 P11 Dry Sampling 11/23 STW-LOC-23C-1-4-112823 28-Nov-23 320-107656-1 320-107656-5 170 120 1.42 PI Dry Sampling 11/23 STW-LOC-23C-2-4-112823 28-Nov-23 320-107656-1 320-107656-6 54 35 1.54 P I I Dry Sam lin 11/23 STW-LOC-23C-3-4-112823 28-Nov-23 320-107656-1 320-107656-7 20 13 1.54 PI Dry Sampling 11/23 STW-LOC-8-4-112823 28-Nov-23 320-107656-1 320-107656-1 870 570 1.53 PI Dry Sampling 11/23 STW-LOC-9A-112823 28-Nov-23 320-107660-1 320-107660-2 110 69 1.59 PI Dry Sampling 11/23 STW-LOC-EB-DR-112823 28-Nov-23 320-107660-1 320-107660-6 <5 <5 PII Dry Sampling 11/23 STW-LOC-EB-IS-112823 28-Nov-23 320-107660-1 320-107660-8 <5 <5 PI Dry Sampling 11/23 STW-LOC-FB-112823 28-Nov-23 320-107660-1 320-107660-7 <5 <5 P I I Dry Sampling 8/23 STW-LOC-l0A-4-080423 04-Aug-23 320-103457-1 320-103457-2 820 540 1.52 P I I Dry Sam lin 8/23 STW-LOC-11-3.66-080423 04-Aug-23 320-103457-1 320-103457-3 230 150 1.53 P I I Dry Sampling 8/23 STW-LOC-12-4-080423 04-Aug-23 320-103457-1 320-103457-4 150 95 1.58 P I I Dry Sampling 8/23 STW-LOC-13-4-080423 04-Aug-23 320-103457-1 320-103457-5 110 68 1.62 P I I Dry Sampling 8/23 STW-LOC-1-4-080423 04-Aug-23 320-103460-1 320-103460-1 150 94 1.60 P I I Dry Sampling 8/23 STW-LOC-14-4-080423 04-Aug-23 320-103457-1 320-103457-6 110 66 1.67 P I I Dry Sampling 8/23 STW-LOC-15-4-080423 04-Aug-23 320-103457-1 320-103457-7 930 610 1.52 P I I Dry Sampling 8/23 STW-LOC-16-080723 07-Aug-23 320-103451-1 320-103451-4 1,400,000 490,000 2.86 PH DrvSamD1inR 8/23 STW-LOC-18-4-080723 07-Aug-23 320-103461-1 320-103461-6 250 160 1.56 P I I Dry Sampling 8/23 STW-LOC-18-4-080723-D 07-Aug-23 320-103461-1 320-103461-7 250 160 1 1.56 P I I Dry Sampling 8/23 STW-LOC-19A-080723 07-Aug-23 320-103451-1 320-103451-1 99 64 1.55 PI Dry Sampling 8/23 STW-LOC-19B-080723 07-Aug-23 320-103451-1 320-103451-2 72 46 1.57 PI Dry Sampling 8/23 STW-LOC-20-4-080423 04-Aug-23 320-103457-1 320-103457-8 470 310 1.52 P I I Dry Sampling 8/23 STW-LOC-21A-080423 04-Aug-23 320-103457-1 320-103457-9 280 180 1.56 P I I Dry Sampling 8/23 STW-LOC-22-4-080723 07-Aug-23 320-103461-1 320-103461-1 140 J 911 1.54 P I I Dry Sam hn 8/23 STW-LOC-23C-1-4-080723 07-Aug-23 320-103461-1 320-103461-3 330 200 1.65 P I I Dry Sampling 8/23 STW-LOC-23C-2-2-080723 07-Aug-23 320-103461-1 320-103461-4 70 44 1.59 P I I Dry Sampling 8/23 STW-LOC-23C-3-4-080723 07-Aug-23 320-103461-1 320-103461-5 210 130 1.62 P I I Dry Sampling 8/23 STW-LOC-2-4-080423 04-Aug-23 320-103460-1 320-103460-2 120 80 1.50 P I I Dry Sampling 8/23 STW-LOC-3-4-080423 04-Aug-23 320-103460-1 320-103460-3 330 190 1.74 P I I Dry Sampling 8/23 STW-LOC-4-4-080423 04-Aug-23 320-103460-1 320-103460-4 130 78 1.67 P I I Dry Sampling 8/23 STW-LOC-5-3-080423 04-Aug-23 320-103460-1 320-103460-5 50 26 1.92 P I I Dry Sam lin 8/23 STW-LOC-7A-4-080423 04-Aug-23 320-103460-1 320-103460-6 140 91 1.54 P I I Dry Sampling 8/23 STW-LOC-7A-4-080423-D 04-Aug-23 320-103460-1 320-103460-7 150 95 1.58 P I I Dry Sampling 8/23 STW-LOC-7B-4-080423 04-Aug-23 320-103460-1 320-103460-8 170 110 1.55 P I I Dry Sampling 8/23 STW-LOC-7C-4-080423 04-Aug-23 320-103460-1 320-103460-9 180 120 1.50 P I I Dry Sampling 8/23 STW-LOC-8-3-080723 07-Aug-23 320-103461-1 320-103461-2 150 93 1.61 P I I Dry Sampling 8/23 STW-LOC-9-4-080423 04-Aug-23 320-103457-1 320-103457-1 750 490 1.53 PI Dry Sampling 8/23 STW-LOC-9A-080723 07-Aug-23 320-103451-1 320-103451-3 460 290 1.59 PI I Dry Sam lin 8/23 STW-LOC-DITrailerOutlet-080823 08-Aug-23 320-103451-1 320-103451-5 <5 <5 P I I Dry Sampling 8/23 STW-LOC-EB-DR-080723 07-Aug-23 320-103451-1 320-103451-9 <5 <5 P I I Dry Sampling 8/23 STW-LOC-EB-IS-080423 04-Aug-23 320-103451-1 320-103451-7 <5 <5 P I I Dry Sampling 8/23 STW-LOC-EB-IS-080723 07-Aug-23 320-103451-1 320-103451-8 <5 <5 P I I Dry Sampling 8/23 STW-LOC-FB-080423 04-Aug-23 320-103451-1 320-103451-6 <5 <5 P I I Dry Sampling 8/23 STW-LOC-FB-080723 07-Aug-23 320-103451-1 320-103451-10 <5 <5 PII Full Sampling 11/23 STW-LOC-1-4-112123 21-Nov-23 320-107670-1 320-107670-1 120 J 76 1.58 PI Full Sampling 11/23 STW-LOC-11-2.66-112223 22-Nov-23 320-107659-1 320-107659-1 220 140 1.57 PI Full Sampling 11/23 STW-LOC-12-4-112223 22-Nov-23 320-107659-1 320-107659-2 120 74 1.62 PI Full Sampling 11/23 STW-LOC-13-4-112223 22-Nov-23 320-107659-1 320-107659-3 170 110 1.55 PI Full Sampling 11/23 STW-LOC-l0A-4-112123 21-Nov-23 320-107670-1 320-107670-10 340 210 1.62 PI Full Sampling 11/23 STW-LOC-14-4-112123 21-Nov-23 320-107659-1 320-1076594 87 54 1.61 PI Full Sampling 11/23 STW-LOC-14-4-112123-D 21-Nov-23 320-107659-1 320-107659-5 88 55 1.60 PI Full Sampling 11/23 STW-LOC-15-4-112123 21-Nov-23 320-107659-1 320-107659-6 340 220 1.55 PI Full Sampling 11/23 STW-LOC-20-4-112123 21-Nov-23 320-107659-1 320-107659-7 240 150 1.60 PI Full Sampling 11/23 STW-LOC-21B-112223 22-Nov-23 320-107659-1 320-107659-8 120 72 1.67 PI I Full Sampling 11/23 STW-LOC-EB-IS-112223 22-Nov-23 320-107670-1 320-107670-11 <5 <5 PI I Full Sampling 11/23 STW-LOC-2-4-112223 22-Nov-23 320-107670-1 320-107670-2 96 63 1.52 PI Full Sampling 11/23 STW-LOC-3-3.66-112223 22-Nov-23 320-107670-1 320-107670-3 280 190 1.47 PI Full Sampling 11/23 STW-LOC-44-112223 22-Nov-23 320-107670-1 320-107670-4 73 48 1.52 PI Full Sampling 11/23 STW-LOC-5-4-112223 22-Nov-23 320-107670-1 320-107670-5 54 36 1.50 PI Full Sampling 11/23 STW-LOC-7A-4-112123 21-Nov-23 320-107670-1 320-107670-6 130J 82 1.59 PI Full Sampling 11/23 STW-LOC-7B-4-112123 21-Nov-23 320-107670-1 320-107670-7 1901 120 1.58 PI Full Sampling 11/23 STW-LOC-7C-4-112123 21-Nov-23 320-107670-1 320-107670-8 1801 110 1.64 PI Full Sampling 11/23 STW-LOC-9-4-112123 21-Nov-23 320-107670-1 320-107670-9 290 180 1.61 PI Full Sampling 11/23 STW-LOC-FB-112223 22-Nov-23 320-107659-1 320-107659-9 <5 <5 PI I Sampling 9/23 DITrailerOutlet-092523 26-Sep-23 320-105406-1 320-105406-10 75 75 Page 4 of 5 June 2024 TABLE 1 REVISED AND ORIGINAL PFPRA CONCENTRATIONS Chemours Fayetteville Works, North Carolina Sampling Program Sample ID Sample Date Sample Delivery Group Laboratory Sample ID PFPrA Concentration (ng/L) Factor (revised concentration / original concentration) Revised Concentration* Original Concentration P I I Sampling 9/23 STW-LOC-l0A-4-092223 22-Sep-23 320-105437-1 320-105437-2 900 640 1.41 PH Sampling 9/23 STW-LOC-12-092523 25-Sep-23 320-105437-1 320-105437-3 86 55 1.56 Pll Sampling 9/23 STW-LOC-13-4-092223 22-Sep-23 320-105437-1 320-105437-4 170 110 1.55 PH Sampling 9/23 STW-LOC-14-092623 26-Sep-23 320-105410-1 320-105410-1 110 69 1.59 Pll Sampling 9/23 STW-LOC-14-4-092223 22-Sep-23 320-105437-1 320-105437-5 78 49 1.59 PH Sampling 9/23 STW-LOC-16-092523 25-Sep-23 320-105406-1 320-105406-8 120,000 J 79,000 J 1.52 P I I Sampling 9/23 STW-LOC-18-4-092523 25-Sep-23 320-105406-1 320-105406-2 54 34 1.59 P I I Sampling 9/23 STW-LOC-19B-092523 25-Sep-23 320-105406-1 320-105406-9 46 29 1.59 PH Sampling 9/23 STW-LOC-20-4-092223 22-Sep-23 320-105437-1 320-105437-6 180 120 1.50 PH Sampling 9/23 STW-LOC-21B-092523 25-Sep-23 320-105437-1 320-105437-7 290 200 1.45 P I I Sampling 9/23 STW-LOC-22-4-092523 25-Sep-23 320-105406-1 320-105406-3 920J 560J 1.64 P I I Sampling 9/23 STW-LOC-23C-1-4-092523 25-Sep-23 320-105406-1 320-1054064 43 1 27 1.59 P I I Sampling 9/23 STW-LOC-23C-14-092523-D 25-Sep-23 320-105406-1 320-105406-5 40 25 1.60 PH Sampling 9/23 STW-LOC-23C-2-4-092523 25-Sep-23 320-105406-1 320-105406-6 48 31 1.55 PH Sampling 9/23 STW-LOC-2-4-092323 23-Sep-23 320-105410-1 320-105410-2 60 38 1.58 PH Sampling 9/23 STW-LOC-3-4-092323 23-Sep-23 320-105410-1 320-105410-3 150 95 1.58 P11 Sampling 9/23 STW-LOC-4-4-092323 23-Sep-23 320-105410-1 320-105410-4 78 50 1.56 PH Sampling 9/23 STW-LOC-5-4-092323 23-Sep-23 320-105410-1 320-105410-5 37 24 1.54 PH Sampling 9/23 STW-LOC-7A-080423 25-Sep-23 320-105410-1 320-105410-6 290 210 1.38 Pll Sampling 9/23 STW-LOC-7B-4-092223 22-Sep-23 320-105410-1 320-105410-7 310 200 1.55 Pll Sampling 9/23 STW-LOC-7114-092323-13 22-Sep-23 320-105410-1 320-105410-8 320 210 1.52 P I I Sampling 9/23 STW-LOC-7C-4-092223 22-Sep-23 320-105410-1 320-105410-9 340 230 1.48 P I I Sampling 9/23 STW-LOC-8-4-092523 25-Sep-23 320-105406-1 320-105406-1 1,600 970 1.65 PH Sampling 9/23 STW-LOC-9-4-092223 22-Sep-23 320-105437-1 1 320-105437-1 920 650 1.42 P I I Sampling 9/23 STW-LOC-9A-092523 25-Sep-23 320-105406-1 320-105406-7 510 330 1.55 P I I Sampling 9/23 STW-LOC-EB-DR-092523 25-Sep-23 320-105437-1 320-105437-12 <5 <5 PH Sampling 9/23 STW-LOC-EB-IS-092223 22-Sep-23 320-105437-1 320-105437-10 <5 <5 P I I Sampling 9/23 STW-LOC-EB-IS-092523 25-Sep-23 320-105437-1 320-105437-11 <5 <5 P I I Sampling 9/23 STW-LOC-FB-092223 22-Sep-23 320-105437-1 320-105437-8 <5 <5 PH Sampling 9/23 STW-LOC-FB-092523 25-Sep-23 320-105437-1 320-105437-9 <5 <5 Tarheel Sampling CFR-TARHEEL-121823 18-Dec-23 320-108237-1 320-108237-2 37 J 24 J 1.54 Tarheel Sampling CFR-TARHEEL-121923 19-Dec-23 320-108237-1 1 320-108237-3 <5 <5 Tarheel Sampling CFR-TARHEEL-24-100523 05-Oct-23 320-105969-1 320-105969-1 40 26 1.54 Tarheel Sampling CFR-TARHEEL-24-101023 10-Oct-23 320-105969-1 320-105969-2 40 26 1.54 Tarheel Sampling CFR-TARHEEL-24-101023-D 10-Oct-23 320-105969-1 320-105969-3 40 27 1.48 Tarheel Sampling CFR-TARHEEL-24-101223 12-Oct-23 320-106157-1 320-106157-1 38 25 1.52 Tarheel Sampling CFR-TARHEEL-24-101623 16-Oct-23 320-106157-1 320-106157-2 55 36 1.53 Tarheel Sampling CFR-TARHEEL-24-101923 19-Oct-23 320-106379-1 320-106379-1 42 26 1.62 Tarheel Sampling CFR-TARHEEL-24-102323 23-Oct-23 320-106379-1 320-106379-2 41 26 1.58 Tarheel Sampling CFR-TARHEEL-24-102623 26-Oct-23 320-106734-1 1 320-106734-1 26 17 1.53 Tarheel Sampling CFR-TARHEEL-24-103023 30-Oct-23 320-106734-1 320-106734-2 29J 191 1.53 Tarheel Sampling CFR-TARHEEL-24-110223 02-Nov-23 320-106957-1 320-106957-1 55 34 1.62 Tarheel Sampling CFR-TARHEEL-24-110623 06-Nov-23 320-106957-1 320-106957-2 35 23 1.52 Tarheel Sampling CFR-TARHEEL-24-110923 09-Nov-23 320-107164-1 320-107164-1 37 24 1.54 TarheelSampling CFR-TARHEEL-24-111323 13-Nov-23 320-107164-1 320-107164-2 40 27 1.48 Tarheel Sampling CFR-TARHEEL-24-111323-D 13-Nov-23 320-107164-1 320-107164-3 41 27 1.52 Tarheel Sampling CFR-TARHEEL-24-111623 16-Nov-23 320-107540-1 320-107540-1 45 30 1.50 Tarheel Sampling CFR-TARIIEEL-24-112023 20-Nov-23 320-107540-1 1 320-107540-2 65 44 1.48 Tarheel Sampling CFR-TARIIEEL-24-112123 21-Nov-23 320-107540-1 320-107540-3 47 31 1.52 Tarheel Sampling CFR-TARHEEL-24-112223 22-Nov-23 320-107540-1 320-107540-4 41 27 1.52 TarheelSampling CFR-TARHEEL-24-112723 27-Nov-23 320-107657-1 320-107657-1 52 J 33 J 1.58 Tarheel Sampling CFR-TARHEEL-24-113023 30-Nov-23 320-107657-1 320-107657-2 50 J 32 J 1.56 Tarheel Sampling CFR-TARHEEL-24-120423 04-Dec-23 320-107894-1 320-107894-1 50 31 1.61 Tarheel Sampling CFR-TARHEEL-24-120723 07-Dec-23 320-107894-1 320-107894-2 46 29 1.59 Tarheel Sampling CFR-TARHEEL-24-121123 II-Dec-23 320-108044-1 320-108044-1 41 26 1.58 Tarheel Sampling CFR-TARHEEL-24-121223 12-Dec-23 320-108044-1 1 320-108044-2 38 24 1.58 Tarheel Sampling CFR-TARHEEL-24-121223-D 12-Dec-23 320-108044-1 320-108044-3 47 30 1.57 Tarheel Sampling CFR-TARHEEL-24-121723 17-Dec-23 320-108237-1 320-108237-1 24J 15J 1.60 TazheelSam lin CFR-TARHEEL-24-122523 25-Dec-23 320-108425-1 320-108425-1 15 9.8 1.53 Tarheel Sam lin CFR-TARHEEL-24-122723 27-Dec-23 320-108425-1 320-108425-2 17 11 1.55 Notes: * - PFPrA concentrations were revised following the discovery of a calculation error by the analytical laboratory -- - revised and/or original concentration is non -detect; factor not calculated B - analyte detected in associated method blank J - analyte detected; reported value may not be accurate or precise ng/L - nanograms per liter PFPrA - perfluoropropanoic acid UJ - analyte not detected; reporting limit may not be accurate or precise < - analyte not detected above associated reporting limit Minimum factor = 0.81 Average factor = 1.57 Ma imam factor 2.86 Standard deviation = 0.14 Page 5 of 5 June 2024 IIII II IIII INIIIIII III III 3780325 ID: ProplonicAcd_00004 Eq).W1729 Prpd: Opn:0411824 PENTAFLUOROPROPIONIC ACID 3050 Spruce Street, Saint Louis, MO 63103, USA Website: www.sigmaaldrich.com Email USA: techserv@sial.com Outside USA: eurtechserv@sial.com Product Name: Certificate of Analysis Pentaffuoroprop(onic acid - 97% Product Number: 245917 Batch Number: MKCV1747 Brand: ALDRICH CAS Number: 422-64-0 MDL Number: MFCD00004170 Formula: C3 HF5O2 Formula Weight: 164.03 g/mol Quality Release Date: 06 OCT 2023 Test Appearance (Color) Appearance (Form) Infrared Spectrum Titration with NaOH GC (area %) Larry Coers, Director Quality Control Milwaukee, WI US 0 F3C OH F F Specification Result Colorless to Faint Yellow and Colorless Colorless to Faint Orange Liquid Liquid Conforms to Structure Conforms 96.5-103.5% 99.7% > 96.5 % 100.0 % Sigma -Aldrich warrants, that at the time of the quality release or subsequent retest date this product conformed to the information contained in this publication. The current Specification sheet may be available at Sigma-Aldrich.com. For further inquiries, please contact Technical Service. Purchaser must determine the suitability of the product for its particular use. See reverse side of invoice or packing slip for additional terms and conditions of sale. Version Number: 1 Page 1 of 1 tiff eurofins May 22, 2024 Environment Testing TestAmerica The Chemours Company 1007 Market Street Wilmington, DE 19801 Attn: Michael Aucoin, Corporate Remediation Group RE: Investigation and Corrective Action for PFPrA Error Dear Mr. Aucoin, It is the policy of Eurofins Sacramento to conduct its business with honesty and integrity, to produce accurate and useable environmental analytical test results and related services, and to provide the best possible service to our clients. As such, we routinely conduct internal data reviews to assess our adherence to method requirements and Quality Assurance protocols. If any issues are noted during these reviews that impact the quality of data, we will notify affected clients and correct the issue. Eurofins Sacramento recently identified a calculation error that was incorporated into the preparation of calibration standards for target analyte Perfluoropropanoic Acid (PFPrA) under the laboratory's 537M methodology. The calculation error yielded an assigned concentration for calibration standards that was 36% lower than the actual concentration of PFPrA. Use of these standards to quantitate PFPrA in client samples (including Chemours) has imparted a low bias of the same magnitude to results for this analyte reported between May, 2023 and April, 2024. Root Cause Analysis - The laboratory conducted a root cause investigation and determined that the incorrect concentration of PFPrA was assigned to calibration standards when the standards preparation chemist did not incorporate the density of the pure liquid PFPrA source material (1.56 g/ml) into the calculated concentration of the initial intermediate dilution prepared from this neat material. The incorrect assigned concentration for the initial dilution of the PFPrA source material was then propagated into all `daughter' solutions prepared from the initial dilution, including calibration solutions. The laboratory further concluded that the primary root cause of the lapse was insufficient training of the standards preparation chemist regarding correct preparation of calibration solutions from neat materials. Corrective Actions - The laboratory's standards preparation SOP has been updated to specifically emphasize density corrections when preparing intermediate solutions volumetrically from neat source materials, and all standards preparation chemists have been re-trained regarding the content of the updated SOP. Eurofins TestAmerica 880 Riverside Parkway T 1 916-373-5600 West Sacramento, CA 95605 www.TestAmericalne.com Additionally, the laboratory has secured commercially prepared/vendor-certified solutions of PFPrA for use in the preparation of calibration standards and fortification solutions. Use of the commercial solutions with certified concentrations of PFPrA will preclude the need to dilute neat liquid reference materials in the future, and associated corrections for density will no longer be required. Vendor -certified solutions of PFPrA are now available from several commercial suppliers, which will facilitate the use of these solutions to provide independent `second -source' verification of calibration standards. Eurofins Sacramento prides itself on supplying its clients with reliable quality data, and we have applied the utmost diligence to our root cause investigation and corrective actions. We are confident the corrective actions described above and summarized below will prevent recurrence of any similar error. In summary, these corrective actions include the following: 1) Updated standards preparation SOP emphasizing correct use of density in standards preparation. 2) Additional training of standards preparation chemists. 3) Use of vendor -certified solutions as the primary source for calibration standards in lieu of neat liquid PFPrA source materials. 4) Use of second -source vendor -certified solutions (alternate supplier) to verify primary standards. Please do not hesitate to contact us if you have additional questions. Sincerely, Eric Redman VP of Technical Services Eurofins Environment Testing Northern California Cc: Lam Leung (Chemours) Sathya Yalvigi (Chemours) Kevin Garon (Chemours)